Where the Poles come together

Abstract Proceedings
Open Science Conference
19 – 23 June 2018
Davos, Switzerland

A SCAR and IASC Event

These abstract proceedings were produced based on the program for the POLAR2018
SCAR/IASC Open Science Conference, updated until 25 May 2018. All changes after that
date (presenting authors, oral and poster contributions cancelled after that date, changes
from poster to oral presentation, additional co-authors) are not reflected in these
proceedings. The final version of the abstracts is available in the online program on
http://www.professionalabstracts.com/POLAR2018/iPlanner

ISBN 978-0-948277-54-2

WSL Institute for Snow and Avalanche Research SLF

Flüelastrasse 11 | CH – 7260 Davos Dorf
polar2018@slf.ch | www.polar2018.org

Photo credits: Destination Davos Klosters

© WSL/SLF 2014-2020

2
Where the Poles come together

Abstract Proceedings
Open Science Conference
19 – 23 June 2018
Davos, Switzerland

ISBN
978-0-948277-54-2

3
Table of contents

Oral Sessions Tuesday, 19 June 2018 5

Poster Session Tuesday, 19 June 2018 101

Oral Sessions Wednesday, 20 June 2018 569

Poster Session Wednesday, 20 June 2018 785

Oral Sessions Thursday, 21 June 2018 1152

Poster Session Thursday, 21 June 2018 1367

Oral Sessions Friday, 22 June 2018 1748

Poster Session Friday, 22 June 2018 1972

Oral Sessions Saturday, 23 June 2018 2319

Author Index 2506

4
AA-1a - Astrophysics and Astronomy in the Polar Regions
19.06.2018 09:00-10:30, A Studio

1272
A 76 Day Period G-M Eclipsing Binary Discovered from Dome C, Antarctica

Nicolas Crouzet1 (ncrouzet@iac.es), Djamel Mékarnia2, Daniel Bayliss3, Tristan Guillot2, Lyu Abe2, Abdelkrim
Agabi2, Yan Fanteï-Caujolle2, Michaël Gillon4, Laetitia Delrez5, George Zhou6, Jean-Pierre Rivet2, Eric Chapellier2,
François-Xavier Schmider2, Ivan Gonçalves2, Jean-Baptiste Daban7, Carole Gouvret2, Eric Aristidi2, Thomas
Fruth8, Anders Erikson8, Heike Rauer8, Erick Bondoux2, Zalpha Challita9, Cyprien Pouzenc10, Emmanuel Jehin4,
François Fressin6, Franck Valbousquet11, Alain Blazit2, Serge Bonhomme2, Jérôme Gerakis2, Guillaume Bouchez12
1
Instituto de Astrofísica de Canarias, La Laguna (Tenerife), Spain, 2Laboratoire Lagrange, Université de Nice
Sophia Antipolis, CNRS, Nice, France, 3University of Warwick, Warwick, United Kingdom, 4Université de Liège,
Liège, Belgium, 5University of Cambridge, Battcock Centre for Experimental Astrophysics, Cavendish Laboratory,
Cambridge, United Kingdom, 6Harvard University, Boston, United States, 7Observatoire Midi-Pyrénées,
Toulouse, France, 8Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany, 9Laboratoire
d'Astrophysique de Marseille, Université d'Aix-Marseille, CNRS, Marseille, France, 10n.a., Carpentras, France,
11
Optique et Vision, Juan-les-Pins, France, 12Université de Versailles Saint-Quentin-en-Yvelines, Groupe d'étude
de la matière condensée, Versailles, France

M dwarfs account for 75% of stars in the Milky Way. However, their properties are not well understood and
significant discrepancies exist between model predictions and observations. Low mass stars in detached
eclipsing binaries are the most valuable objects to study because their radius, mass, and temperature can be
measured. The vast majority of systems that have been characterized to date have short orbital periods (< 10
days), yielding a strong coupling between both stars. Sampling a larger parameter space is mandatory to
explore the observed discrepancies. The four month continuous night during the Antarctic winter combined
with excellent weather conditions is favourable to the detection of variable objects including with long periods.
We observed a field centred on the celestial South Pole during four winters with the ASTEP South instrument, a
10 cm refractor in a thermalised box installed at Dome C, Antarctica, and we detected a 76 day period G-M
eclipsing binary, among other objects. In this talk, we present this discovery, the follow-up observations of this
object, and we investigate the properties of the M dwarf. At such a long orbital period, both stars are largely
decoupled making this system a unique benchmark for the study of low mass stars. We also present some
results about the characterization of Dome C for photometry in the visible.

5
1376
Pulsations and Planetary Transit Events of Beta Pictoris as Observed by ASTEP

Djamel Mékarnia1 (mekarnia@oca.eu), Tristan Guillot1, Lyu Abe1, Karim Agabi1, Eric Chapellier1, François-Xavier
Schmider1, Konstanze Zwintz2, Anne-Marie Lagrange3, Lionel Bigot1, Nicolas Crouzet4, Jason Wang5, Kevin
Stevenson6, Paul Kalas5, Yuri De Pra7
1
Université Côte d'Azur, Nice, France, 2Universitat Innsbruck, Innsbruck, Austria, 3Université Grenoble Alpes,
Grenoble, France, 4Instituto de Astrofísica de Canarias, La Laguna, Spain, 5University of California, Berkeley,
United States, 6SETI Institute, Mountain View, United States, 7Unaffiliated, Roma, Italy

We present results of high-precision photometric observations of Beta Pictoris achieved during the 2017 and
2018 Antarctic polar campaigns, using the ASTEP-400 telescope installed at Dome C, in Antarctica. These
observations, only focused on Beta Pictoris, enabled us to characterize the delta scuti pulsations of the star, by
detecting 31 pulsation frequencies among which 28 are new, and to investigate the transit of the Hill sphere of
its planet Beta Pictoris b.
Furthermore, because of its location in Antarctica, ASTEP is ideally suited to monitor stars with declination
below -30°. In this talk, we will also present ASTEP+, the proposed ASTEP successor, designed to make the
instrument fully robotic and able to get higher accuracy photometry, by minimising any turbulence along the
optical path. ASTEP+, will be operational in 2019. It will observe stars with exoplanets detected in radial
velocimetry to check for possible planetary transits, confirmed transiting planetary systems to characterize
them, and generally any target of opportunity that is of high scientific interest. ASTEP+ will also follow up the
southern hemisphere planet candidates to be discovered by NASA/TESS space mission.

6
761
Exoplanets in the Antarctic Sky

Hui Zhang1 (huizhang@nju.edu.cn)

1
Nanjing University, Astronomy and Space Science, Nanjing, China

While the space based exoplanet survey projects (e.g. Kepler) have achieved great success, there is still
valuable exoplanetary science that can be done from the ground. This is especially important at some unique
sites. Dome A, the highest point of the Antarctic plateau, is one of these sites. In 2008, China established a
scientific site at Dome A. Now, in a significant collaboration with Australian astronomers, a large survey project
has been ongoing there for several years. This is the Antarctic Survey Telescope (AST3) project, consisting of
three 0.5m telescopes located at Dome A. The exoplanet searching program is one of the two major scientific
aims of AST3. I will briefly outline this project and introduce the progress of the exoplanet survey in details. It
will cover the exoplanet scientific goals, instruments, designs of survey strategy, data reduction pipeline and
exoplanet candidates we found within TESS's Southern Continuous Viewing Zone.

7
503
Optical Observations of LIGO Source GW 170817 by the ASTs at Dome A, Antarctica

Lei Hu1,2,3, Xuefeng Wu1,2,3, Igor Andreoni4,5, Michael C. B. Ashley6, Jeff Cooke4, Xiangqun Cui2,7, Fujia Du7, Zigao
Dai8, Bozhong Gu7, Yi Hu2,9, Haiping Lu7, Xiaoyan Li7, Zhengyang Li7, Ensi Liang8, Liangduan Liu8, Bin Ma9,
Zhaohui Shang2,9,10, Tianrui Sun1,2,11, Nicholas B. Suntzeff12, Charling Tao13,14, Syed A. Uddin1,2, Lifan Wang1,2,12,
Xiaofeng Wang14, Haikun Wen7, Di Xiao8, Jin Xu7, Shihai Yang7, Xiangyan Yuan7, Peng Jiang15
(jiangpeng@pric.org.cn), Hongyan Zhou15, Huigen Yang15, Hui Zhang8, Jilin Zhou8, Zonghong Zhu16,17
1
Purple Mountain Observatory, Nanjing, China, 2Chinese Center for Antarctic Astronomy, Nanjing, China,
3
University of Science and Technology of China, Hefei, China, 4Swinburne University of Technology, Hawthorn,
Australia, 5Australian Astronomical Observatory, North Ryde, Australia, 6University of New South Wales,
Sydney, Australia, 7Nanjing Institute of Astronomical Optics & Technology, National Astronomical
Observatories, CAS, Nanjing, China, 8Nanjing University, Nanjing, China, 9National Astronomical Observatories,
CAS, Beijing, China, 10Tianjin Normal University, Tianjin, China, 11Shanghai Normal University, Shanghai, China,
12
Texas A&M University, College Station, United States, 13Aix Marseille University, Marseille, France, 14Tsinghua
University, Beijing, China, 15Polar Research Institute of China, Shanghai, China, 16Beijing Normal University,
Beijing, China, 17Wuhan University, Wuhan, China

The LIGO detection of gravitational waves (GW) from merging black holes in 2015 marked the beginning of a
new era in observational astronomy. The detection of an electromagnetic signal from a GW source is the
critical next step to explore in detail the physics involved. The Antarctic Survey Telescopes (AST3), deployed at
the Chinese Antarctic Kunlun Station, is uniquely situated for rapid response time-domain astronomy with its
continuous night-time coverage during the winter. We report optical observations of the GW source (GW
170817) in the nearby galaxy NGC 4993 using AST3. The data show a rapidly fading transient at around 1 day
after the GW trigger, with the i-band magnitude declining from 17.23±0.13 magnitude to 17.72±0.09
magnitude in ∼1.8 hour. The brightness and time evolution of the optical transient associated with GW 170817
are broadly consistent with the predictions of models involving merging binary neutron stars. We infer from
our data that the merging process ejected about ∼10-2 solar mass of radioactive material at a speed of up to
30% the speed of light.

8
849
Measuring Atmospheric Turbulence at Dome A, Antarctica with AST3

Bin Ma1 (mabin22@gmail.com), Zhaohui Shang1,2, Yi Hu1, Michael Ashley3, Lifan Wang4,5
1
National Astronomical Observatories, CAS, Beijing, China, 2Tianjin Normal University, Tianjin, China, 3University
of New South Wales, Sydney, Australia, 4Purple Mountain Observatory, Nanjing, China, 5Texas A&M University,
College Station, United States

Dome A, Antarctica is expected to have excellent seeing, however, there has not been direct night seeing
measurement yet, because DIMM is hard to be operated at Dome A automatically. Alternatively, we have
attempted to measure seeing with the second Antarctic Survey Telescope (AST3-2). During CCD frame transfer,
a bright star generates a visible trail along the readout direction, whose random motions can be utilized to
derive seeing. When AST3-2 was tested in China, we compared this method with DIMM and found they agreed
moderately. However, this method is biased by telescope vibration. Our new method utilizes the differential
motion between a pair of stars. Benefiting from its wide field-of-view and adequately large aperture, AST3-2 is
able to capture multi stars even in a 10 ms exposure. Since the two light beams (i.e. air beams)from the two
stars to telescope have increasing distances with height, unlike DIMM, these image motions do not correspond
to seeing directly, but instead reflect Cn2 profile. In 2017, we have selected optimized fields with many bright
stars, and taken continuous short exposures from 5 ms to 100 ms. There are a dozen of stars with separations
from 0.1 deg to 2 deg. The rms of the differential motions has a typical values of ~ 0”.1 at the separation of 0.1
deg and it increases with separation linearly in most cases. We infer the turbulence properties from this and
show that Dome A is a superb site.

9
1939
Meteorological Data from KLAWS-2G for Site Testing at Dome A, Antarctica

Yi Hu1 (huyi.naoc@gmail.com), Zhaohui Shang1,2, Bin Ma1, Keliang Hu1, Michael Ashley3
1
National Astronomical Observatories, CAS, Beijing, China, 2Tianjin Normal University, Tianjin, China, 3University
of New South Wales, Sydney, Australia

We built the second generation Kunlun Automated Weather Station for monitoring astronomical site at Dome
A as well as for operation support of AST3 telescope. KLAWS-2G has 11 temperature sensors and 7
anemometers in different elevations, 1 humidity sensor and 1 barometer, which are mounted on a 15-meter-
tall mast. It was installed by the traverse team to Dome A in early 2015 during the 31st CHINARE. From then on,
it survived the extremely cold polar winter and continuously worked for more than one and half years. KLAWS-
2G has been maintained by the traverse team of the 33rd CHINARE, and now the sensors below 4m are still
working properly. By analyzing the data from KLAWS-2G, we find that a strong and lasting long time
temperature inversion and stable atmosphere existed at all heights for most of the time in 2015 and 2016,
confirming our finding for 2011 data from KL-AWS (Hu et al. 2014). The monthly wind speeds are 3-5 m/s.
Strong temperature inversion and moderate wind speed suggest that Dome A should have a very shallow
boundary layer above which we could obtain supreme free atmosphere seeing. All the data from KLAWS-2G
can be viewed in real-time on http://aag.bao.ac.cn/klaws/.

10
OS-6a - Polar Ocean Dynamics
19.06.2018 09:00-10:30, A Forum

986
Southern Ocean Air-sea Fluxes: An Overview and Contrasts with the Arctic

Simon Josey1 (simon.josey@noc.ac.uk)

1
National Oceanography Centre Southampton, Southampton, United Kingdom

The Southern Ocean is a key component of the global climate system: insulating the Antarctic polar region,
transferring climate signals and forming the southern component of the global overturning circulation.
However, the air-sea fluxes that drive these processes are severely under-observed due to the harsh and
remote location. This paucity of reference observations has resulted in large uncertainties in ship-based,
numerical weather prediction, satellite and derived flux products. Here, recent and ongoing analyses of
Southern Ocean observations from air-sea flux moorings, research ships, atmospheric reanalyses and high
resolution coupled climate models will be reviewed. The moorings provide the first accurate near-annual
quantifications of the cycle of net air-sea heat exchange and wind stress from Southern Ocean locations. They
reveal a strong degree of variability in the net heat flux and are key reference points for addressing the high
level of uncertainty that currently exists in Southern Ocean air-sea flux datasets. The reanalysis and coupled
model output enables these results to be put in a wider context and the dependence of the air-sea exchanges
on atmospheric modes of variability to be explored. Finally, Southern Ocean air-sea interaction will be
contrasted with the regime that prevails in the Arctic Ocean with a focus on differences between the dominant
terms in the surface heat budget and potential common causes for extreme heat loss events.

11
2524
PIPERS: Ocean Observations during an Anomalous Autumn-winter in the Ross Sea

Sharon Stammerjohn1 (sharon.stammerjohn@colorado.edu), Stephen Ackley2, Ted Maksym3, Peter Sedwick4,

Brice Loose5, Jean-Louis Tison6, Bruno Delille7, Guy Williams8, Madison Smith9, Sam Gartzman5, Sarah Searson10,
Mike Williams10, Lynne Talley11, Chris Zappa12
1
University of Colorado Boulder, Boulder, United States, 2University of Texas at San Antonio, San Antonio,
United States, 3Woods Hole Oceanographic Institution, Woods Hole, United States, 4Old Dominion University,
Norfolk, United States, 5University of Rhode Island, Kingston, United States, 6Universite Libre de Bruxelles,
Bruxelles, Belgium, 7Universite de Liege, Liege, Belgium, 8University of Tasmania / Institute for Marine and
Antarctic Studies, Hobart, Australia, 9University of Washington, Seattle, United States, 10National Institute of
Water and Atmospheric Research, Wellington, New Zealand, 11Scripps Institution of Oceanography, La Jolla,
United States, 12Lamont-Doherty Earth Observatory Columbia University, Palisades, United States

There are very few ocean observations during autumn-winter south of the Antarctic ice edge, particularly as far
south as the coastal polynyas. In the Ross Sea alone, we know of only three prior autumn-winter U.S.
oceanographic expeditions. In 2017 the PIPERS (Polynyas, Ice Production and seasonal Evolution in the Ross
Sea) project conducted an oceanographic expedition to the southwestern Ross Sea aboard the RVIB Palmer
during April-June. Its main objective was to assess the local/large-scale controls on sea ice production, water
mass transformation, and carbon/trace metal inventories during an autumn-winter transition. In contrast to
the strong positive sea ice trends observed over 1979-2015, the PIPERS ocean observations were acquired prior
to, and during, very anomalous air-sea-ice conditions in the Ross Sea. These hydrographic observations
extended from north of the ice edge, to the advancing ice edge, and along south/north transects to/from the
coastal polynyas under an anomalously thin ice cover. Extensive observations were collected in Terra Nova Bay
before/after several strong katabatic wind events, as well as in front of the Ross Ice Shelf under milder
katabatic conditions. These ocean observations (water mass types, mixed layer evolution, heat/salt inventories)
will be discussed within the context of the anomalous air-sea-ice conditions that occurred prior to and during
PIPERS, as well as to the few autumn-winter ocean observations available for the Ross Sea.

12
1433
Ocean Forcing of Pine Island Glacier Melt Rate on Weekly to Monthly Time Scales

Peter Davis1 (petvis@bas.ac.uk), Adrian Jenkins1, Keith Nicholls1, Paul Brennan2, Povl Abrahamsen1, Karen
Heywood3, Pierre Dutrieux4, Sang Hoon Lee5, Tae Wan Kim5
1
British Antarctic Survey, Cambridge, United Kingdom, 2University College London, London, United Kingdom,
3
University of East Anglia, Norwich, United Kingdom, 4Lamont-Doherty Earth Observatory Columbia University,
New York, United States, 5Korea Polar Research Institute, Incheon, Korea, Republic of

Ocean-driven basal melting of Amundsen Sea ice shelves has forced significant acceleration, thinning, and
grounding line retreat on many of West Antarctica's largest outlet glaciers. Here, we present a year-long (2014)
time series of basal melt rate at daily resolution from a single location on Pine Island Ice Shelf, and determine
the drivers behind the observed variability. Dynamical adjustment of the thermocline to local wind forcing is
proposed as the dominant control on basal melting at weekly to monthly time scales, and the temporal
variability in the basal melt rate appears to be representative of variability in the basal melt rate over a much
wider geographical area. In other years the impact of local wind forcing on thermocline height variability is
more limited, highlighting the various time scales of, and the intricate interplay between, the different
processes that ultimately set the basal melt rate beneath Pine Island Ice Shelf.

13
2246
Using Noble Gases to Show Upper Ocean Glacial Meltwater in the Amundsen Sea

Louise Biddle1,2 (louise.biddle@marine.gu.se), Brice Loose3, Karen Heywood2

1
University of Gothenburg, Department for Marine Science, Göteborg, Sweden, 2University of East Anglia,
Centre for Ocean and Atmospheric Sciences, Norwich, United Kingdom, 3University of Rhode Island, Graduate
School of Oceanography, Narragansett, United States

Pine Island Ice Shelf, in the Amundsen Sea, is a region of high ocean-driven basal melting. Tracing the glacial
meltwater it produces can help identify the regions most affected by the increased input of this freshwater.
Here, optimum multi-parameter analysis is used to deduce glacial meltwater content from independent water
mass tracers (hydrographic observations, noble gases and oxygen isotopes), collected during a ship-based
campaign in the eastern Amundsen Sea in February-March 2014. Noble gases (neon, argon, krypton and xenon)
are used to trace the glacial meltwater, and the results are compared to the standard hydrographic meltwater
signature. Differences between the water mass analyses of up to 4 per mil glacial meltwater content are
observed, and associated with the erosion of the hydrographic Winter Water properties by the meltwater. The
noble gases are used to improve the hydrographic method, by simulating a 'pure' Winter Water endpoint.
Remaining differences between analyses can be used to show upper ocean processes such as mixing and
biological activity. The corrected glacial meltwater content values show a persistent signature in the upper 400
m of the water column across all of the sample locations (up to 500 km from Pine Island Ice Shelf), with
increased concentration towards the west along the coastline.

14
1080
Convection in the Southern Ocean - What Controls it?

Erik Behrens1 (erik.behrens@niwa.co.nz), Graham Rickard1

1
National Institute for Water and Atmospheric Research, Wellington, New Zealand

Open ocean convection (“convection”) in the Southern Ocean is rare phenomena. Despite its re-occurrence in
the last years it was not present for roughly 40 years. However, coupled and forced simulations show an
occurrence of these events in the Southern Ocean on various time and spatial scales with drastic implications
for sea ice and heat content. We present results of an extensive sensitivity study of non-eddy resolving and
eddy permitting global forced simulations. The sensitivity studies consider changes in the surface freshwater
forcing, heat content management of Circumpolar Deep Water, vertical mixing and surface heat flux variations,
as well as the parameterisation of mesoscale eddies. Results show that freshwater forcing affects directly
surface stratification and thus the occurrence and intensity of convection. It will be demonstrated that brine
rejection as a consequence of sea ice growth and thus stratification during winter season is a potential critical
trigger for convection. Furthermore, we will show that increased vertical mixing leads to postponed onset of
deep convection but not to a reduction as other studies have suggested. Mesoscale eddies reduce convection,
since they tend increase the surface stratification.

15
386
Preconditioning of the Weddell Sea Polynya by the Ocean Mesoscale and Overflows

Carolina O. Dufour1 (carolina.dufour@mcgill.ca), Adele K. Morrison2, Stephen M. Griffies3, Ivy Frenger4, Hannah
Zanowski5, Michael Winton3
1
McGill University, Atmospheric and Oceanic Science, Montreal, Canada, 2Australian National University,
Research School for Earth Sciences, Canberra, Australia, 3NOAA/Geophysical Fluid Dynamics Laboratory,
Princeton, United States, 4GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, 5University of
Washington, Joint Institute for the Study of the Atmosphere and Ocean, Seattle, United States

The Weddell Sea polynya is a large opening in the open-ocean sea ice cover associated with intense deep
convection in the ocean. A necessary condition to form and maintain a polynya is the presence of a strong
subsurface heat reservoir. This study investigates the processes that control the stratification and hence the
buildup of the subsurface heat reservoir in the Weddell Sea. To do so, a climate model run for 200 years under
preindustrial forcing with two eddying resolutions in the ocean (0.25° CM2.5 and 0.10° CM2.6) is investigated.
Over the course of the simulation, CM2.6 develops two polynyas in the Weddell Sea, while CM2.5 exhibits
quasi-continuous deep convection but no polynyas, exemplifying that deep convection is not a sufficient
condition for a polynya to occur. CM2.5 features a weaker subsurface heat reservoir than CM2.6 owing to weak
stratification associated with episodes of gravitational instability and enhanced vertical mixing of heat,
resulting in an erosion of the reservoir. In contrast, in CM2.6, the water column is more stably stratified,
allowing the subsurface heat reservoir to build up. The enhanced stratification in CM2.6 arises from its refined
horizontal grid spacing and resolution of topography, which allows, in particular, a better representation of the
restratifying effect by transient mesoscale eddies and of the overflows of dense waters along the continental
slope.

16
BE-1a - From boots to bytes: ‘omics’ tools for microbial diversity and biogeography
19.06.2018 09:00-10:30, A Dischma

2140
Some Like it Hot: Metagenomics of an Isolated Antarctic Geothermal Refugium

Stephen Craig Cary1,2 (caryc@waikato.ac.nz), Craig Herbold1,3, Charles Lee1,3, Chelsea Vickers1, Ian McDonald1
1
University of Waikato, International Centre for Terrestrial Antarctic Research, Hamilton, New Zealand,
2
University of Delaware, College of Earth, Ocean, and Environment, Lewes, United States, 3University of Vienna,
Department of Microbiology and Ecosystem Science, Vienna, Austria

Geothermal systems in Antarctica support a diverse microbiota and may have served as essential refugia for
terrestrial organisms during periodic glacial maxima. As the most remote geothermal environments on the
planet, they provide a rare opportunity to address questions around microbial biogeography and the
interactions between globally distributed and endemic microbes. Despite their biological importance, these
extremely remote geothermal locations remain vastly understudied. Tramway Ridge, an Antarctic specially
protected geothermal area (ASPA 175 - elevation 3340 m), located near the summit of Mount Erebus, is home
to a unique and poorly understood community of micro-organisms. Here we provide the first metagenomic
characterization of high-temperature fumarolic sediments, and the first from terrestrial Antarctica. We
recovered 17 nearly complete genomes, representing 11 prokaryotic phyla/divisions to infer their role in the
environment. Our results demonstrate that the subsurface of Tramway Ridge on Mount Erebus is dominated
by novel, possibly endemic deep-branching members of several bacterial phyla, and a single deep branching
relative of the Thaumarchaeota. Based on its phylogenetic position and novel functional attributes we propose
Candidatus Austellarchaeum erebusii to help infer the defining characteristics of the earliest Thaumarchaeota.

17
2256
Dynamics of Microbial Community Succession in Polar Deglaciated Forefields

Asuncion de los Rios1 (arios@mncn.csic.es), Isaac Garrido-Benavent2, Carmen Ascaso2, Rüdiger Ortiz-Alvarez3,
Starri Heiðmarsson4, Francisco Navarro5, Ricardo Rodríguez5, Sergio Pérez-Ortega1,6
1
Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain, 2Museo Nacional de Ciencias Naturales, CSIC,
Biogeoquímica y Ecología Microbiana, Madrid, Spain, 3Centro de Estudios Avanzados de Blanes/ CSIC, Blanes,
Spain, 4Icelandic Institute of Natural History, Akureyri, Iceland, 5E.T.S. de Ingenieros de Telecomunicación/UPM,
Madrid, Spain, 6Real Jardin Botánico, Madrid, Spain

Melting glaciers in polar regions are indicators of global warming. A key consequence of the gradual ice retreat
is that new terrestrial habitats are created as recently exposed soils and rocks are susceptible to biological
colonization. Microorganisms are the first colonizers and subsequently vascular plants and cryptogams
establish. Thus, glacier forefields offer a type of natural experiment in which temporal colonization dynamics
can be explored.
In this study, chronosequences at Breiðamerkurjökull (Iceland) and Hurd (Livingston Island, Antarctica) glaciers
were used as a comparative framework to examine microbial forefield colonization dynamics in both polar
regions. By high-throughput amplicon sequencing of fungal and bacterial communities combined with scanning
electron microscopy, we identifed microbial colonizers at different successional stages and assessed the
specific colonization features of polar deglaciated areas.
Microbial community structure in recently uncovered soils and rocks (close to the glacier front) differed
considerably from the components found in later successional stages with cryptogam covers. Similar succession
patterns were detected for soil microbial communities along both glacier forefields. However, different
colonization strategies were shown by lithobiontic communities in each polar region, as the extent of
colonization was determined both by exposure time and by the textural features of the rocks.

18
2419
Cyanobacterial Diversity from Pole to Pole: Metagenome of Arctic and Antarctic

Nur Fadzliana Abdul Rahman1, Wan Maznah Wan Omar2 (wmaznah@usm.my), Peter Convey3
1
Universiti Sains Malaysia, Penang, Malaysia, 2Universiti Sains Malaysia, School of Biological Sciences, Penang,
Malaysia, 3British Antarctic Survey, Cambridge CB OET, Malaysia

Cyanobacteria are the most ancient and widespread group of photosynthetic prokaryotes, which had a major
role in the evolution of the plant kingdom and Earth's atmosphere. They are primary producers in a wide
variety of habitats, and are able to thrive in harsh environments. In this study, metagenomic approach was
used to determine the diversity of cyanobacteria in soil samples collected from selected areas of Antarctica
(Browning Peninsula, Dee Island, Greenwich Island and Reeve Hills) and Arctic (Spitsbergen, Kvartsitsletta and
Baranowski Polar Station). DNA was extracted using Mo-Bio Powersoil DNA kit and the genomic DNA was
sequenced using illumina, Miseq with targeted V3 and V4 regions. The reads were then processed using Qiime
with at least 97% similarity. East Antarctica (Browning Peninsular and Reeve Hills) recorded nine species of
cyanobacteria and west Antarctica (Dee Island and Greenwich Island) recorded seven species. The Arctic
recorded the least numbers of species; five in the east sampling localities (Kvartsittsletta and Polar Station
Baranowski). Nostoc sp., Leptolyngbya sp. and Pseudanabaena sp. were dominant in all Arctic and Antarctic
samples. The cyanobacterial diversity in Antarctica was higher than the Arctic. Thus, metagenomic is important
as a reliable tool to study the cyanobacteria diversity in soils.
Keywords: Cyanobacteria, Antarctic, Arctic, poles, sequencing, metagenomics.

19
1567
Biogeography of Cyanobacteria in Antarctic Mats and Implication for Conservation

Benoit Durieu1 (benoit.durieu@uliege.be), Yannick Lara1,2,3, Igor Stelmach Pessi1, Alexandre Lambion4, Elie
Verleyen5, Denis Baurain6, Annick Wilmotte1
1
University of Liège, InBioS-Centre for Protein Engineering, Department of Life Sciences, Liège, Belgium,
2
University of Liège, UR-Geology-Palaeo-Biogeology-Botany-Palynology, Liège, Belgium, 3Gembloux
AgroBioTech-University of Liège, Microbial Processes and Interactions, Liège, Belgium, 4University of Liège,
Genetics and Physiology of Microalgae, Department of Life Sciences, Liège, Belgium, 5Ghent University,
Protistology and Aquatic Ecology, Department of Biology, Ghent, Belgium, 6University of Liège, Eukaryotic
Phylogenomics, Department of Life Sciences, Liège, Belgium

On the Antarctic continent, cyanobacterial mats are widespread in the lacustrine biotopes and they often
dominate the phototrophic biomass. Their diversity and biogeography are poorly understood because most
studies cover a limited geographic area or are based only on morphotypes. Therefore, cyanobacteria are not
fully taken into account in the biological datasets used to delineate conservation biogeographic regions
(ACBRs). Recently, we have shown by 454 pyrosequencing of cyanobacteria-specific 16S rRNA amplicons that
their distribution across the lacustrine ecosystems could be explained by ecological parameters (e.g. salinity
and dissolved organic carbon). In order to further test this hypothesis, we significantly increased the spatial
coverage of our samples. Here, we describe the results of 16S rRNA amplicons Illumina sequencing of 98
cyanobacterial mat samples from 10 ACBRs. From the 16012393 raw reads, 713 OTUs were obtained by
bioinformatics analysis. Preliminary results show that both ecological parameters and latitude could explain the
patterns of cyanobacterial communities. Indeed, nonmetric multidimensional scaling shows that sub-Antarctic
samples (Macquarie and Marion Islands) group with North-East Antarctic Peninsula samples, whereas more
continental samples (e.g. East Antarctica, South Victoria Land) group together. These findings can form the
basis for a better understanding and a more adequate conservation of lacustrine ecosystems in Antarctica.

20
90
Did Antarctic Lichens Originate in, or Arrive to, Antarctica?

Isaac Garrido-Benavent1 (igbenavent@mncn.csic.es), Sergio Pérez-Ortega2, Asunción de los Ríos1

1
National Museum of Natural Sciences-CSIC, Biogeochemistry and Microbial Ecology, Madrid, Spain, 2Royal
Botanical Garden-CSIC, Mycology, Madrid, Spain

Lichens represent a paradigm of mutualism between two or more phylogenetically unrelated organisms
involving an heterotrophic fungus, also called the mycobiont, and a population of at least one photosynthetic
partner, either a green alga or cyanobacterium. About 500 lichens (ca. 2.5% of all known species worldwide)
occur in Antarctica and reach as far as 84º S. They constitute the most conspicuous component of terrestrial
macrobiota. Biogeographic evidence shows that about 38% of the current lichen diversity is shared with the
Arctic and Sub-Arctic regions (bipolar distribution). Long-distance dispersion has been commonly invoked to
explain this disjunct distribution pattern, but it is still unknown whether those species originated in or arrived
to Antarctica. Similarly, the proportion of endemic Antarctic lichens is considerable (ca. 33%); several authors
have suggested that these lichens have an ancient origin which pre-dates the last glaciations, implicating that
these species may have taken refuge in ice-free areas. So far however, no studies have formally tested
hypotheses modelling allele evolution in space and time in bipolar and endemic Antarctic species. Herein,
through phylogeography analyses (including genetic clustering, divergence time estimation and gene flow
inference), we provide evidence for the colonization of Antarctica in the Pleistocene by some bipolar species,
and point to endemics as long-term inhabitants of this continent.

21
1148
Microbial Biogeography in Arctic Soils

Lucie Malard1 (lucie.malard@northumbria.ac.uk), David Pearce1

1
Northumbria University, Faculty of Health and Life Sciences, Newcastle upon Tyne, United Kingdom

With a relatively low number of studies investigating microbial diversity in pristine Arctic soils and different
analytical approaches used in each, the identification of microbial biogeographical patterns across the region
remains difficult. Currently, differences in microbial communities are generally described on small scales,
however, whether these are true ecological difference or merely methodological variations remains to be
properly investigated. Furthermore, few studies have shown an absence of large-scale variation while other
studies suggest regional differences. Using a small scale, mid-scale and pan-Arctic soil sampling design, we
aimed to investigate the level of sampling required to understand terrestrial spatial patterns of microbial
diversity across the Arctic.
We analysed core physico-chemical properties of sampled soils, used amplicon-sequencing and geostatistics to
investigate biodiversity, diversity hotspots and to understand the potential drivers of microbial diversity in
Arctic terrestrial ecosystems.
We identified microbial biogeographical patterns on different scales, with distinct Arctic regions harbouring
different microbial communities. Alaska and Canada appear to support different communities than the
European Arctic and Siberia. Identifying biogeographical patterns is a step towards a better understanding of
microbial diversity and its drivers in the Arctic region.

22
OS-1 - The acoustic environment of the polar oceans: exploring polar soundscapes
19.06.2018 09:00-10:30, A Sertig

1311
The Soundscape of Western Fram Strait - A Key Habitat for Endemic Arctic Cetaceans

Heidi Ahonen1 (heidi.ahonen@npolar.no), Kathleen Stafford2, Laura de Steur1, Christian Lydersen1, Øystein
Wiig3, Kit Kovacs1
1
Norwegian Polar Institute, Fram Centre, Tromsø, Norway, 2University of Washington, Applied Physics
Laboratory, Seattle, United States, 3University of Oslo, Natural History Museum, Oslo, Norway

Global warming and concomitant reductions in sea ice will affect the underwater soundscape of the Arctic,
with the greatest changes expected to be linked to anthropogenic activities. Ocean noise is a growing
conservation concern, but management of underwater noise pollution is constrained by a lack of baseline data.
To address this concern, and to document area use by marine mammals, an acoustic recorder has been
deployed on an oceanographic mooring in western Fram Strait (78°49N, 4°59W) 2008-present. Analyses show
that the mean overall sound level of this area was low to moderate (< 60 dB). The level of anthropogenic
activity in the region was low, with few ships traversing the area. However, airgun signals were prevalent
throughout most of the year, in all years. During summer/autumn, signals from airgun surveys were detected >
12 h/day. Vocalisations by fin and bowhead whales were the main biotic sounds during autumn-spring. Nearly
constant singing by bowhead whales dominated the winter soundscape at frequencies between 100-1000 Hz.
Narwhal signals occurred year round, suggesting that this area is also important for this endemic Arctic
cetacean. Bearded seal vocalisations were detected March-July, whereas blue whale calls were recorded
mainly during summer/autumn. This study outlines the main contributors to the soundscape of western Fram
Strait, describes seasonal patterns of both noise and biota and thus provides baseline data from which
changing trends can be monitored.

23
2630
Sea Noise from Southern Australia to Eastern Antarctica

Robert McCauley1 (r.mccauley@curtin.edu.au), Curt Jenner2, Micheline Jenner2, Chritine Erbe1, Alexander
Gavrilov1
1
Curtin University, Perth, Australia, 2Centre for Whale Research, Fremantle, Australia

In conjunction with the Australian Antarctic Division sea noise data was collected from moorings at 44°S (2006-
2007), 54°S (2006-2009) and 65°S (2006-2007) using Curtin's underwater sound recorders. In January 2014,
during a cruise of RV Whale Song south from Hobart, to and along the ice edge (138°6'E to 115°42'E) and
returning to Fremantle, Western Australia, 140 sonobuoys were deployed at a ~4 hour interval. Mooring data
showed seasonal trends in calls from whales: Antarctic blue; Antarctic minke; fin; Australian pygmy blue (to
54°S only); and the unidentified species producing the so-called 'spot' call. Seal calling showed pronounced
seasonal patterns with a large variety of signal types. South of the Antarctic convergence sperm whale clicking
and seal calling rates increased towards Antarctica. Feeding humpbacks near the ice edge were largely silent
except on one occasion an animal approached a wide-band sonobuoy and produced a signal at ~20 kHz.
General, nondescript increases in high-frequency sea noise were detected in the presence of large krill
aggregations. Vessel noise was comparatively rare along the Antarctic coast. Seismic survey signals from a
vessel operating over the western edge of Bass Strait (~ 40°S) in 2006 were detected on the line of stationary
recorders to 65°S, although only when the vessel was operating over the shelf slope and at low levels. This
presentation will discuss major trends in sea noise south of Australia and down to the Antarctic coast.

24
946
Estimating the Distribution of Vocalizing Whales from Ambient Sound Spectra

Sebastian Menze1 (sebastian.menze@imr.no)

1
Institute of Marine Research, Bergen, Norway

Marine mammal vocalizations are transient sounds, but the combined sound energy of a population
continuously repeating a vocalization, adds up to a quasi-continuous chorus. These choruses are frequently
observed as peaks in ambient sound spectra throughout the worlds oceans. Here I present an approach to
estimate the distribution of vocalizing marine mammals from averaged ambient sound spectra.
This is an extremely under-determined inverse problem. The method is based on inverse theory and uses
simulated annealing to find the most likely distribution of sound sources (vocalizing animals) on a geodesic grid.
This includes calculating a transmission loss matrix connecting all grid nodes and recorders, using an arbitrary
sound propagation model. Two models were successfully implemented: geometrical spreading and the ray
trace model BELLHOP.
The inversion method was tested under different simulated scenarios for vocalizing fin whales in the North
Atlantic (ambient sound peak at 20 Hz). The accuracy of the inversion mainly depends on the number and
distribution of recorders. For the Norwegian Sea, simulations indicate that fin whale chorus inversion is
possible using as few as 12 recorders between Iceland and Svalbard.
Further development and application of the proposed method could admit automatic year-round monitoring of
marine mammal distribution on a basin-wide scale, using existing mooring and float platforms.

25
2516
Spatio-temporal Variation in Arctic Ambient Noise in the Canada Basin

Christopher Whitt1 (christopher.whitt@jasco.com), Bruce Martin1, Sean Pecknold2

1
JASCO Applied Sciences, Dartmouth, Canada, 2Defence Research and Development Canada, Atlantic Research
Centre, Dartmouth, Canada

The Canada Basin Acoustic Propagation Experiment (CANAPE) involved measuring underwater acoustic
propagation and ambient noise in the Arctic over the course of a year. As a part of this experiment, from
October 2016 to October 2017, four vertical hydrophone arrays were deployed north of Barrow, Alaska. The
arrays were moored in water depths between 100 and 300 m. Each array recorded at approximately 15% duty
cycle at sample rates between 4000 Hz and 64000 Hz, with a 24-bit dynamic range. The data from each
recorder were processed to produce 1-minute metrics over the entire duration. The 1-minute metrics were
then processed to look for correlations over time, frequency, space, and with environmental factors such as
weather and ice cover, including ice keel depth inferred from high-resolution Radarsat images. The recorders
were all equipped with Chip-Scale Atomic Clocks (CSAC), enabling each acoustic time series to be precisely
time-aligned with the others as well as with supporting oceanographic and remote sensing data. Therefore the
changes in soundscape can be compared at a wide range of temporal and spatial scales. We will compare the
soundscape temporal and spatial variability over spatial scales of 20-50 km and time scales of seconds up to
one year, in the area of the continental shelf break between the Chukchi Sea and the Canada Basin.

26
2547
Modelling the Effect of Air Gun Array Noise on Marine Mammal Communication

Benno Woelfing1 (benno.woelfing@tiho-hannover.de), Peter Stilz2, Alexander Gavrilov3, Matthias Fischer4,

Marianne Rasmussen1, Max Schuster4, Dietrich Wittekind4, Christine Erbe3, Ursula Siebert1
1
University of Veterinary Medicine, Hannover, Foundation, Institute for Terrestrial and Aquatic Wildlife
Research, Büsum, Germany, 2Freelance Biologist, Hechingen-Sickingen, Germany, 3Curtin University, Perth,
Australia, 4DW-ShipConsult GmbH, Schwentinental, Germany

Seismic airguns used in scientific surveys in the Southern Ocean produce high-intensity impulsive sounds with
most energy concentrated in the low frequency band. This frequency range overlaps with many marine
mammal vocalizations, especially the songs and calls of baleen whales. Even at large distances from the source,
airgun noise may therefore interfere with marine mammal communication.
In order to assess the masking effect of airgun noise we first studied the propagation of airgun signals in the
Southern Ocean. A parabolic equation approximation was used to model sound propagation. The propagation
models were verified based on recordings and metadata for two seismic surveys in the Southern Ocean.
Numerical predictions are consistent with the measurement results within a few dBs for the sound exposure
and energy spectral levels.
Subsequently we studied the ability of a listening animal to detect vocalisations of a conspecific in the absence
and presence of propagated airgun noise. The auditory detection process was modelled using a spectrogram
correlation.

27
2604
Marine Soundscape Planning: Seeking Acoustic Niches for Anthropogenic Sound

Ilse Van Opzeeland1,2, Olaf Boebel1 (olaf.boebel@awi.de)

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Ocean Acoustics, Bremerhaven,
Germany, 2Helmholtz Institute for Functional Marine Biodiversity (HIFMB) at University Oldenburg, Oldenburg,
Germany

Both marine mammals and hydroacoustic instruments use underwater sound to communicate, navigate or
infer information about the marine environment. Concurrent timing of acoustic activity or the use of similar
frequency regimes may result in (potentially mutual) masking of acoustic signals when both sources are within
reception range. In analogy to landscape planning, the concept of marine soundscape planning aims to
reconcile potentially competing uses of acoustic space by managing the anthropogenic sound sources. We here
present a conceptual framework exploring the potential of soundscape planning in reducing (mutual) acoustic
interference between hydroacoustic instrumentation and marine mammals. The basis of this framework is
formed by the various mechanisms by which acoustic niche formation occurs in species-rich communities that
acoustically coexist while maintaining high fidelity (hi-fi) soundscapes, i.e., by acoustically partitioning the
environment on the basis of time, space, frequency and signal structure. Hydroacoustic measurements often
exhibit certain flexibility in their timing, signal characteristics and even instrument positioning, offering the
opportunity to minimize the underwater acoustic imprint. We evaluate how the principle of acoustic niches
could contribute to reduce potential (mutual) acoustic interference based on actual acoustic data from three
recording locations in polar oceans.

28
GG-2a - Arctic and Antarctic past ice sheet dynamics and paleoclimate evolution
19.06.2018 09:00-10:30, A Schwarzhorn

812
West Antarctic Ice Sheet History: IODP Exp. 374 (Ross Sea) Initial Results

Robert McKay1, Laura De Santis2 (ldesantis@inogs.it), Denise K. Kulhanek3, Jeanine Ash4, François Beny5,
Imogen M. Browne6, Giuseppe Cortese7, Isabela M. Cordeiro de Sousa8, Justin P. Dodd9, Oliver M. Esper10,
Jenny A. Gales11, David M. Harwood12, Saki Ishino13, Benjamin A. Keisling14, Sookwan Kim15, Sunghan Kim16, Jan
Sverre Laberg17, R. Mark Leckie14, Juliane Müller18, Molly O. Patterson19, Brian W. Romans20, Oscar E. Romero21,
Francesca Sangiorgi22, Osamu Seki23, Amelia E. Shevenell6, Shiv M. Singh24, Saiko T. Sugisaki25, Tina van de
Flierdt26, Tim E. van Peer27, Wenshen Xiao28, Zhifang Xiong29
1
Victoria University of Wellington, Wellington, New Zealand, 2Instituto Nazionale di Oceanografia e di Geofisica
Sperimentale (OGS),, Trieste, Italy, 3International Ocean Discovery Program,Texas A&M University, College
Station, United States, 4Rice University, Department of Earth, Environmental, and Planetary Sciences, Houston,
United States, 5Université de Lille I, Laboratoire d'Océanologie et de Géosciences, Villeneuve d'Ascq, France,
6
University of South Florida, St. Petersburg, College of Marine Sciences, St. Petersburg, United States, 7GNS
Science, Department of Paleontology, Lower Hutt, New Zealand, 8Universidade de Brasília, Instituto de
Geociencias, Brasília, Brazil, 9Northern Illinois University, Department of Geology and Environmental
Geosciences, DeKalb, United States, 10Alfred Wegener Institute, Helmholz Centre for Polar and Marine Research,
Bremerhaven, Germany, 11Plymouth University, School of Biological and Marine Sciences, Plymouth, United
Kingdom, 12University of Nebraska, Lincoln, Department of Earth and Atmospheric Sciences, Lincoln, United
States, 13Nagoya University, Department of Earth and Planetary Sciences, Nagoya, Japan, 14University of
Massachusetts, Amherst, Department of Geosciences, Amherst, United States, 15Korean Polar Research
Institute, Division of Polar-Earth System Sciences, Incheon, Korea, Republic of, 16Korean Polar Research Institute,
Division of Polar Climate Change, Incheon, Korea, Republic of, 17University of Tromsø, Department of Geology,
Tromsø, Norway, 18Alfred Wegener Institute, Department of Marine Geology, Bremerhaven, Germany,
19
Binghamton University, State University of New York, Department of Geological Sciences and Environmental
Studies, Binghamton, United States, 20Virginia Tech, Department of Geosciences, Blacksburg, United States,
21
University of Bremen, MARUM, Bremen, Germany, 22University of Utrecht, Department of Earth Sciences,
Utrecht, Netherlands, 23Hokkaido University, Institute of Low Temperature Science, Sapporo, Japan, 24National
Centre for Antarctic and Ocean Research, Polar Biology Lab, Vasco-da-Gama, India, 25Geological Survey of
Japan, Marine Geology Research Group, Tsukuba, Japan, 26Imperial College London, Department of Earth
Science and Engineering, London, United Kingdom, 27Southampton University, National Oceanography Centre,
Southampton, United Kingdom, 28Tongji University, State Key Laboratory of Marine Geology, Shanghai, China,
29
State Oceanic Administration, First Institute of Oceanography, Qingdao, China

International Ocean Discovery Program (IODP) Expedition 374 was scheduled to collect a latitudinal and depth
transect of six drill sites in the eastern Ross Sea in January to March 2018. The expedition will resolve the
relationship between climatic/oceanic change and West Antarctic Ice Sheet (WAIS) evolution over the past 20
million years. This location was selected because numerical ice sheet models indicate that it is highly sensitive
to changes in ocean heat flux and sea level. The drilling was designed for optimal data-model integration, which
will enable an improved understanding of the sensitivity of WAIS mass balance during warmer-than-present
climates (e.g., Pliocene and middle Miocene). The objectives were to 1) Evaluate the contribution of WAIS to
far-field ice volume and sea level estimates; 2) Reconstruct ice-proximal atmospheric and oceanic
temperatures to identify past polar amplification and assess its forcings/feedbacks; 3) Assess the role of
oceanic forcing on WAIS stability/instability; 4) Identify the sensitivity of the WAIS to Earth's orbital
configuration under a variety of climate boundary conditions; 5) Reconstruct eastern Ross Sea bathymetry to
examine relationships between seafloor geometry, and ice sheet stability/instability. We will present the initial
scientific results that resulted from this expedition, with a focus on the paleoenvironmental reconstructions
that were obtained from the sedimentolgical, geochemical and paleontological datasets.

29
1950
Initial Seismic Stratigraphic Results from IODP Exp. 374 in the Ross Sea

Laura De Santis1 (ldesantis@inogs.it), Rob M. McKay2, Denise K. Kulhanek3, Jeanine Ash4, François Beny5,
Imogen M. Browne6, Giuseppe Cortese7, Isabela M. Cordeiro de Sousa8, Justin P. Dodd9, Oliver M. Esper10,
Jenny A. Gales11, David M. Harwood12, Saki Ishino13, Benjamin A. Keisling14, Sookwan Kim15, Sunghan Kim16, Jan
Sverre Laberg17, Mark R. Leckie14, Juliane Müller18, Oscar E. Romero19, Molly O. Patterson20, Brian W. Romans21,
Francesca Sangiorgi22, Osamu Seki23, Amelia E. Shevenell24, Shiv M. Singh25, Saiko T. Sugisaki26, Tina van de
Flierdt27, Tim E. van Peer28, Wenshen Xiao29, Zhifang Xiong30
1
Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Trieste, Italy, 2Victoria University of
Wellington, Antarctic Research Centre, Wellington, New Zealand, 3International Ocean Discovery
Program,Texas A&M University, College Station, United States, 4Rice University, Earth, Environmental, and
Planetary Sciences, Houston, United States, 5Université de Lille I, Laboratoire d'Océanologie et de Géosciences,
Villeneuve d'Ascq, France, 6University of South Florida, College of Marine Sciences, St. Petersburg, United States,
7
GNS Science, Department of Paleontology, Lower Hutt, New Zealand, 8Universidade de Brasília, Instituto de
Geociencias, Brasília, Brazil, 9Northern Illinois University, Geology and Environmental Geosciences, DeKalb,
United States, 10Alfred Wegener Institute, Helmholz Centre for Polar and Marine Research, Bremerhaven,
Germany, 11Plymouth University, School of Biological and Marine Sciences, Plymouth, United Kingdom,
12
University of Nebraska, Lincoln, Lincoln; Department of Earth and Atmospheric Sciences, Lincoln, United
States, 13Nagoya University, Earth and Planetary Sciences, Nagoya, Japan, 14University of Massachusetts Lowell,
Department of Geosciences, Amherst, United States, 15Korean Polar Research Institute, Division of Polar-Earth
System Sciences, Incheon, Korea, Republic of, 16Korean Polar Research Institute, Division of Polar Climate
Change, Incheon, Korea, Republic of, 17University of Tromsø, Geology, Tromsø, Norway, 18Alfred Wegener
Institute, Marine Geology, Bremerhaven, Germany, 19University of Bremen, MARUM, Bremen, Germany,
20
Binghamton University, State University of New York, Geological Sciences and Environmental Studies,
Binghamton, NY, United States, 21Virginia Tech, Department of Geosciences, Blacksburg, VA, United States,
22
University of Utrecht, Earth Sciences, Utrecht, Netherlands, 23Hokkaido University, Institute of Low
Temperature Science, Sapporo, Japan, 24University of South Florida, St. Petersburg, College of Marine Sciences,
St. Petersburg, FL, United States, 25National Centre for Antarctic and Ocean Research, Polar Biology Lab, Vasco-
da-Gama, Goa, India, 26Geological Survey of Japan, Marine Geology Research Group, Tsukuba, Japan, 27Imperial
College London, Earth Science and Engineering, London, United Kingdom, 28Southampton University, National
Oceanography Centre Southampton, Southampton, United Kingdom, 29Tongji University, State Key Laboratory
of Marine Geology, Shanghai, China, 30State Oceanic Administration, First Institute of Oceanography, Qingdao,
China

International Ocean Discovery Program Expedition 374 will core several sites in the Ross Sea in January-March
2018. The geological records will recover the distal component of a Neogene latitudinal and depth transect
across the continental shelf and rise, with previous ANDRILL and DSDP Leg 28 sites comprising the ice-proximal
component. This transect approach will allow for assessment of oceanic drivers of marine ice sheet instabilities.
The existing reflection seismic data suggests that intervals with limited ice cover occurred among episodes of
grounded ice that extended to the shelf margin during the Neogene. Following initial shipboard
characterization of the cores during the Exp. 374, the correlation between synthetic logs at the new drill sites
and the crossing seismic sections will provide crucial information about the age and the environmental
conditions during the deposition of glacial and marine strata. Changes in the bathymetry of the continental
shelf are important for understanding the dominant West Antarctic Ice Sheet mass balance controls. The
stratigraphic information from the Exp. 374 will allow us to date the paleobathymetric maps of the main
seismic unconformities and therefore provide a measure of the geomorphological changes under the action of
the ice sheet and ocean circulation. The results will be fundamental for numerical ice sheet models aimed to
infer the past Antarctic volume fluctuation contribution to Neogene sea-level changes.

30
303
Modeling Antarctic Climate and Ice-sheet Variability in the Mid-Miocene

Anna Ruth Halberstadt1 (ahalberstadt@umass.edu), Rob DeConto1, Edward Gasson2, Douglas Kowalewski3,
Richard Levy4, Timothy Naish5, Hannah Chorley5
1
University of Massachusetts-Amherst, Department of Geosciences, Amherst, United States, 2University of
Sheffield, Department of Geography, Sheffield, United Kingdom, 3Worcester State University, Department of
Earth Environment and Physics, Worcester, United States, 4GNS Science, Department of Paleontology, Lower
Hutt, New Zealand, 5Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand

The mid-Miocene Climatic Optimum (~17-15 Ma) serves as a possible analog for future Antarctic conditions,
because atmospheric CO2 concentrations were similar to those projected for the next few decades. During the
mid-Miocene Climatic Transition, the Antarctic Ice Sheet evolved into a continental ice sheet roughly
resembling its modern geometry.
Near-shore marine records from the Ross Sea (ANDRILL-2A; Levy et al., 2016) imply highly dynamic AIS
behavior in the mid-Miocene. Reconstructed environmental conditions during this time period range from a
fully glaciated Ross Sea region to a smaller 'interglacial' ice sheet during warmer conditions with higher CO2 and
orbital forcing sensitivity. These records are seemingly inconsistent with sedimentary and geomorphic studies
in the McMurdo Dry Valleys (MDVs) that suggest the East Antarctic Ice Sheet was mostly invariable since the
mid-Miocene (Sugden & Denton, 2004).
Here, we use a Regional Climate Model with a range of greenhouse gas concentrations, orbital configurations,
ice sheet and shelf geometries, and sea surface conditions to reconcile the apparent dichotomy between
marine and terrestrial records during the mid-Miocene. Model results are compared with emerging terrestrial
data from the Friis Hills in the MDVs to test the hypothesis that climate in the marginal, continental setting of
the MDVs remained relatively cold and insensitive to a highly variable West Antarctic Ice Sheet and marine
conditions in the proximal Ross Sea.

31
175
Ice Sheet, Ocean Basal Melting and Bathymetry Interactions: A Sensitivity Study

Florence Colleoni1 (flocolleoni@gmail.com), Laura De Santis2, Andrea Bergamasco3, Enea Montoli1, Elisabetta
Olivo2
1
Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici, Bologna, Italy, 2Istituto Nazionale di
Oceanografia e Geofisica Sperimentale, Trieste, Italy, 3CNR-ISMAR, Venezia, Italy

Marine sediment records from circum Antarctica show that the ice sheet volume and extent fluctuated
substantially through time. The understanding of past Antarctic ice sheet (AIS) dynamics highly depends on the
reconstruction of the bedrock and seabed morphologies evolution in time. Paleo-bathymetries based on
reflection seismic interpretation combined with sediment cores analysis show that the marine basins of
Antarctic continental shelf over-deepened through time. A first step of inner continental deepening below sea
level, resulted from the fluctuations of a dynamical and temperate AIS, increasing in volume in response to
global cooling prior to mid-Miocene (~15 Ma). A second step occurred between ~15 and 3 Ma, when the AIS,
gradually more stable and cold-based (as recorded by decreasing sedimentation rates), fluctuated over the
continental margins, thus causing an over-deepening with a pronounced landward slope due to the erosion and
sediment transport from the inner shelf to the outer shelf and slope. We investigate the impact of over-
deepening on the AIS by means of an ice-sheet model forced by Mid-Miocene and Last glacial cycle warm and
cold climates. Idealised bathymetries based on BEDMAP2 are used to test the importance of ice fluxes, ocean
water masses and bathymetry in the advances and retreats of the AIS. Results show the increasing influence of
ocean on the AIS while the circum Antarctic continental margins gradually over-deepened through time.

32
281
Pre-glacial to Glacial Amundsen Sea Shelf from Seismic and Seabed Drill Records

Karsten Gohl1 (karsten.gohl@awi.de), Gabriele Uenzelmann-Neben1, Robert Larter2, Johann Klages1, Claus-
Dieter Hillenbrand2, Torsten Bickert3, Steve Bohaty4, Ulrich Salzmann5, Thomas Frederichs3, Catalina Gebhardt1,
Katharina Hochmuth1
1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Dept. of Geosciences,
Bremerhaven, Germany, 2British Antarctic Survey, Cambridge, United Kingdom, 3MARUM at University of
Bremen, Bremen, Germany, 4University of Southampton, Ocean and Earth Science, Southampton, United
Kingdom, 5University of Northumbria, Dept. of Geography and Environmental Sciences, Newcastle, United
Kingdom

The sedimentary sequences of the Amundsen Sea Embayment (ASE) shelf contain records that have the
potential to reveal the environmental and ice sheet evolution from pre-glacial to glacial times for a very
dynamic sector of the West Antarctic Ice Sheet (WAIS). The currently observed massive loss of continental ice
in this region may be a precursor to a partial or full collapse of the WAIS. Deciphering paleoclimate and paleo-
ice sheet records from the shelf sediments is therefore a major scientific objective for studying processes of
past warm times that can be considered as analogues to the present and future WAIS behavior. In previous
work, the seismic stratigraphic model of the shelf was based solely on long-distance jump correlation with
seismic records from the Ross Sea shelf. New MeBo70 seabed drill cores collected in early 2017 from the ASE
shelf contain unconsolidated to highly consolidated sediments spanning time periods from the Holocene to
Cretaceous. We are now able to correlate the mapped seismic horizons and units with the physical property
and age information from the drill cores to obtain new insight into the sedimentary and paleoenvironmental
development of the entire shelf. The drill records and seismo-stratigraphic units of the ASE provide new
constraints on the timing of the transition from the pre-glacial terrestrial environment of the Cretaceous-
Paleocene to marine transgression thereafter, and the first advances of grounded ice across the shelf.

33
1740
Surface Paleoceanography of the Oligocene and Miocene Southern Ocean

Peter K. Bijl1 (p.k.bijl@uu.nl), Anja Bruls1, Francesca Sangiorgi1, Julian D. Hartman1, Francien Peterse1, Ariadna
Salabarnada2, Carlota Escutia2
1
Utrecht University, Earth Sciences, Utrecht, Netherlands, 2Instituto Andaluz de Ciencias de la Tierra, Granada,
Spain

Of notable interest, but poorly understood, is the magnitude and sensitivity of Oligocene and Miocene (35-5
Ma) Antarctic ice sheet change, and the role of warm ice-proximal oceans in past ice sheet behaviour.
Oligocene and Miocene sediments were recovered from the Wilkes Land continental Margin. These allowed us
to investigate Oligo-Miocene Southern Ocean oceanographic regime and variability therein also in older
sedimentary archives. We will present quantitative paleoceanographic reconstructions based on dinoflagellate
cyst and biomarker studies on Site U1356 and Site 269. These sites are conveniently situated below the
present-day Antarctic divergence, and are today dominated by sea-ice affiliated dinoflagellates. The obliquity-
paced glacial-interglacial variability detected in the lithologies allows us to separate our results between glacial
and interglacial extremes. In the Oligo-Miocene we document the dominance of dinocysts which now thrive at
the subtropical front. Moreover, we note considerable variation in oceanographic regime at the overlying site
over glacial/interglacial extremes, arguing for profound oceanographic and SST changes over g-i cycles. Our
results argue for a fundamental different and variable oceanographic regime during the Oligo-Miocene
compared to today. We argue that much of the Oligo-Miocene benthic foraminiferal d18O variability may be
explained by Southern Ocean surface ocean change, rather than ice volume change.

34
BE-3a - Polar perspectives on microbial evolution, adaptation, and ecological function
19.06.2018 09:00-10:30, A Seehorn

442
Stunning Stress Adaptation of a Black Fungus and Implications for Astrobiology

Claudia Pacelli1 (pacelli@unitus.it), Laura Selbmann1, Laura Zucconi1, Silvano Onofri1

1
University of Tuscia, Department of Ecological and Biological Sciences (DEB), Viterbo, Italy

The McMurdo Dry Valleys in Antarctica are the coldest hyper-arid desert on Earth characterized by several
environmental stressors including low temperatures, freeze-thaw cycles, low water availability, high solar and
UV irradiation; they are the best terrestrial analogue for Mars. Suitable niches for microbial colonization exist
inside the rocks where some microorganisms can find a refuge. The cryptoendolithic endemic black fungus
Cryomyces antarcticus demonstrated huge ability to withstand stresses beyond the conditions, already
prohibitive, of its natural environment.
Here, we review the ability of C. antarcticus, to resist temperature cycles (-20°C/+20°C), high temperature
(+90°C), high saline concentration (up to 25% NaCl), high UV exposure (up to 5x105 kJ/m2), ionizing radiation
(Co60, up to 55.81 kGy) and α particles (He2+, up to 1000 Gy). The fungus survived and recovered the metabolic
activity even after 1.5 years of real space exposure (10-4Pa vacuum, -20°C/+47°C, 439 MJ/m2 UV irradiation)
and simulated Martian conditions (-25°C,Mars-like CO2 atmosphere, 980Pa).For this remarkable resistance, this
fungus is nowadays considered the best eukaryotic model for astrobiological researches.
The outcomes of these studies outstretched the concept of limits for microbial life and are giving clues for
defining the boundaries for habitable environments on Earth, discovering life in environments previously
considered sterile, and assessing the habitability of Mars or other planets.

35
1589
New Finding of Marinilactobacillus sp in the Subglacial Antarctic Lake Vostok

Sergey Bulat1 (bulat@omrb.pnpi.spb.ru), Maxim Doronin1, Elizabeth Rudaya1, Dominique Marie2

1
Petersburg Nuclear Physics Institute of NRC 'Kurchatov Institute, St Petersburg, Russian Federation, 2Station
Biologique de Roscoff, Roscoff Cedex, France

The objective was to search for microbial life in the subglacial Antarctic Lake Vostok by analyzing the
uppermost water layer entered the borehole and got frozen within following three lake unsealing (05.02.2012;
25.01.2015; 03.02.2015). The borehole-frozen water samples proved to be generally contaminated with the
drill fluid. The cell concentrations varied from 167 (drillbit frozen water) until 5.5-38 cells per ml (clearer
borehole-frozen samples). The sequencing of 16S rRNA genes came up with total 62 bacterial phylotypes. Of
them only 3 phylotypes successfully passed all contamination criteria. Two phylotypes both detected after the
1st lake unsealing were reported before (Bulat, 2016) - hitherto-unknown and phylogenetically unclassified
phylotype w123-10 showing less than 86% similarity with known taxa and likely belonging to Parcubacteria
Candidatus Adlerbacteria featured by unusual biology and 3429v3-4 showing 93.5% similarity with
Herminiimonas glaciei of Oxalobacteraceae (Beta-Proteobacteria) - water-inhabited ultramicrobacterium
isolated from deep Greenland ice core. The new finding just came from the samples after the 3rd lake unsealing.
The phylotype discovered (3698v46-27) showed the conspecificity with several species of Marinilactobacillus of
Carnobacteriaceae (Firmicutes) featured by very similar 16S rRNA genes (e.g. M. piezotolerans from Nankai
Trough). Thus, 3 discovered bacterial phylotypes may represent ingenious life forms from the subglacial Lake
Vostok.

36
1745
Arctic Phytoplankton Can Compensate for the Effects of Multiple Stressors

Clara Jule Marie Hoppe1 (clara.hoppe@awi.de), Klara Wolf1, Nina Schuback2, Philippe D. Tortell3, Björn Rost1
1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2Curtin
University, Perth, Australia, 3University of British Columbia, Vancouver, Canada

Arctic phytoplankton are exposed to particularly fast rates of environmental change caused by anthropogenic
CO2 emissions. In experiments with natural phytoplankton assemblages from different regions of the Arctic, we
found primary production and species composition to be largely insensitive to ocean acidification, warming and
changes in irradiances. These results are in contrast to those of similar studies from the Southern Ocean. Our
Arctic results imply a high capacity to compensate for environmental change, which can be understood in light
of the environmental history of organisms thriving in highly variable environmental conditions. Based on
subsequent laboratory experiments and field observations, we could identify the underlying compensatory
mechanisms such as physiological plasticity of organisms, intraspecific diversity of populations and functional
redundancy of species.

37
2098
Arctic Bacterioplankton One-carbon and Methylated Compounds Metabolisms

Julie Dinasquet1,2 (jdinasquet@ucsd.edu), Laetitia Dadaglio2, Marti Galí3, Ingrid Obernosterer2, Fabien Joux2
1
Scripps Institution of Oceanography, University of California, San Diego, Marine Biology Research Division, La
Jolla, United States, 2Observatoire Océanologique de Banyuls sur Mer, Université Pierre et Marie Curie,
Laboratoire d'Océanographie Microbienne, Banyuls sur Mer, France, 3Laval University, Takuvik, Quebec, Canada

More widespread phytoplankton blooms predicted as the Arctic warms will impact the amount of algal
metabolites released in the system which may in turn be a good source of energy, C, N and S to marine
bacteria. Here, we assessed the metabolic potential of surface bacterial communities to use one-carbon and
methylated algae metabolites in the Baffin Bay during the GreenEdge cruise in summer 2016. The bacterial
response to a pulse of metabolites was also determined during 9-d enrichment experiments at sea-ice and
open water stations. Bacterial community composition and activity show that despite the capacity to use these
compounds in situ, bacteria did not appear to respond to the specific enrichments, suggesting that the summer
Arctic bacterioplankton is dominated by generalist taxa adapted to an already rich environment. These results,
complemented by quantification of functional genes of interest and single cell activity, will help understand
whether the Arctic bacterioplankton is well adapted to use and cleave some of the algae metabolites (such as
methanol, methylamines and DMSP) which may influence the fluxes of trace gases to the atmosphere. This is of
particular importance as the sea-ice coverage declines increasing the area of potential sea to air exchange and
the effect of biological emissions on atmospheric chemistry and radiative budget.

38
2214
Antarctic Subglacial Environments and the Extremophiles That They Host

Jill Mikucki1 (jmikucki@utk.edu), Richard Campen1, Bruce Boles1, Ellen Taylor1, Aaron Perry1, Samantha
Vancleave1, Peter Lee2
1
University of Tennessee, Knoxville, United States, 2College of Charleston, Hollings Marine Laboratory,
Charleston, United States

We now know that groundwater, saturated sediments and hundreds of subglacial lakes exist below the
Antarctic Ice Sheet. While few have been sampled, subglacial environments are proving to be diverse microbial
habitats. Because the overlying glacial ice can be 100s-1000s of meters thick, direct access is logistically
challenging and sample acquisition is rare. Two recent drilling expeditions have enabled detailed study of the
subglacial biomes below the Whillans Ice Stream (WIS) along the Siple Coast and the Taylor Glacier in the
McMurdo Dry Valleys. Below the WIS, Subglacial Lake Whillans, a shallow fresh water lake, drains along the ice
sheet base and into the Ross Sea at its grounding zone. Below Taylor Glacier an iron-rich brine episodically
emerges at Blood Falls. These ecosystems exhibit measureable microbial metabolic activity and appear to
persist independent of photosynthetically derived carbon inputs. Molecular data and biogeochemical
measurements indicate these systems are chemically and phylogenetically distinct, however both are
chemosynthetic with energy derived in part by cycling inorganic iron and sulfur compounds. Physiological and
genomic characterization of microbial isolates obtained show adaptation to their local environment includes
genes for growth at low temperatures and high salt concentrations. Collectively these data suggest that despite
extended isolation in icy darkness, microbial life persists and possibly thrives below the Antarctic Ice Sheet.

39
1548
C. psychrerythraea 34H: Glycoconjugates Structures and Cold Adaptation

Angela Casillo1, Annarita Ricciardelli1, Ermenegilda Parrilli1, Rosa Lanzetta1, Maria Luisa Tutino1, Maria Michela
Corsaro1 (corsaro@unina.it)
1
Università degli Studi di Napoli Federico II, Naples, Italy

Cold adapted microorganisms have evolved a large repertoire of adaptation strategies: the biosynthesis of
lipids and enzymes with a sufficient physical flexibility to contrast cellular membrane rigidity, and the
production of anti-freeze proteins and carbohydrate-based extracellular polymeric substances (EPS), which
serve as cryo- and osmo-protectants.1Colwellia psychrerythraea 34H is an obligate psychrophilic γ-
proteobacterium, isolated both from subzero Arctic sediments and Antarctic sea ice. It is considered a model to
study adaptive strategies to subzero lifestyle.2 In the last years, our team has been involved in an in-depth
study of the structure of carbohydrate molecules from this model organism and of its role in sea-ice lifestyle.
C.psychrerythraea 34H grown at 4°C produces a rough-LPS.3 In addition, three different exopolysaccharides, a
capsule4 and two totally released polysaccharides,5 displaying IRI activity, have been found. In this
communication, the structural characterization of glycoconjugates molecules produced by Colwellia grown at -
2°C, 8°C, and 15°C, is described. This study allowed us to establish how the carbohydrates polymers are
involved in Colwellia cold-adaptation.
1
Krembs, C. et al. Proc Natl Acad Sci USA 2011, 3653-3658.
2
Methé, B.A. et al. Proc Natl Acad Sci U.S.A. 2005, 10913.
3
Carillo S. et al. Eur J Org Chem 2013, 3771-3779.
4
Casillo A. et al. J Am Chem Soc 2015, 137,179-189.
5
Casillo A. et al. Carbohydr Polym 2017, 156,364-371.

40
TE-3a - Remote sensing of polar regions
19.06.2018 09:00-10:30, A Wisshorn

17
Improved subarctic and Arctic SWE Retrieval using Passive Microwave over Canada

Alain Royer1 (alain.royer@usherbrooke.ca), Fanny Larue1, Céline Vargel1, Alexandre Roy1, Alexandre Langlois1,
Vincent Vionnet2,3, Ghislain Picard4, Emmanuel Cosme4
1
University of Sherbrooke, CARTEL, Sherbrooke, Canada, 2University of Saskatchewan, Saskatoon, Canada,
3
Environment and Climate Change Canada, Meteorological Research Division, Dorval, Canada, 4Université
Grenoble-Alpes, IGE, Grenoble, France

Over northern snow-dominated basins, the snow water equivalent (SWE) is of primary interest for monitoring
the global warming impacts. SWE retrievals from satellite microwave (MW) observations, the only type of data
sensible to snow volume, are still not well resolved. On the other hand, the use of snowpack models is
challenging due to the large uncertainties in meteorological input forcings and the snow model
parameterization. This presentation shows improvements for SWE prediction by assimilating satellite
brightness temperatures (TB) in a detailed multilayer snowpack model (SURFEX/Crocus) without any ground-
based observations and driven by forcing data generated by the 10 km - Canadian GEM model. While the
results appear in agreement with continuous in-situ SWE observations for subarctic snow covers over North-
Eastern Canada, with 16 to 30% bias accuracy, the simulations are poor for arctic snow (in-situ database at the
Cambridge Bay, Nu). We discuss the sources of the main uncertainties, including a bad stratification of the
arctic snowpack density and microstructure simulated by the snow model. The presence of ice crusts within the
snowpack also generates significant variations in TB that have to be corrected. The snow radiative transfer
model SMRT, used in this study, need to be scaled in order to reduce the RMSE between simulated and
observed TB. Preliminary results of these improvements, specific for this type of arctic snow, are presented.

41
222
A New Dual-frequency Ku-band Radar Mission Concept for Cryosphere Applications

Chris Derksen1 (chris.derksen@canada.ca), Joshua King1, Camille Garnaud2, Stephane Belair2, Melanie
Lapointe3, Yves Crevier3, Ralph Girard3, Juha Lemmetyinen4, Geoff Burbidge5, Jose Marquez5, Duncan Bourne5
1
Environment and Climate Change Canada, Toronto, Canada, 2Environment and Climate Change Canada,
Montreal, Canada, 3Canadian Space Agency, Longueuil, Canada, 4Finnish Meteorological Institute, Helsinki,
Finland, 5Airbus, Portsmouth, United Kingdom

Moderate resolution (~1 km) terrestrial snow water equivalent (SWE) measured across the Northern
Hemisphere at a revisit of 1 to 5 days is a priority observational gap which limits operational environmental
monitoring, services, and prediction. To address this need, Environment and Climate Change Canada, the
Canadian Space Agency, industrial partners at Airbus, and international scientific collaborators are developing a
new dual frequency (Ku-band: 13.5 and 17.2 GHz) radar mission concept. Following technical trade-off studies,
a concept capable of providing 250m spatial resolution measurements across a 500 km swath was identified.
Orbital analysis defined a dawn/dusk orbit flying at a fixed offset of 3.5 hours ahead of Met-Op Second
Generation (Sat. B). This orbit will provide synergistic active and passive measurements through complete
swath overlap with the multi-frequency Microwave Imager (MWI). This presentation will provide an overview
of the technical mission concept, and how it addresses measurement requirements for the primary mission
objective of terrestrial snow, and secondary objectives related to sea ice, land ice, and ocean vector winds.
Modeling activities to
(1) identify the current state of backscatter modeling capabilities for layered snowpacks at Ku-band,
(2) develop and validate SWE retrieval algorithms, and
(3) determine the potential impact of radar backscatter measurements on radiance-based land surface data
assimilation will also be presented.

42
2324
Automated Monitoring of the Sea Ice in the Kara Sea for Practical Applications

Vladimir Volkov1, Natalia Zakhvatkina1,2 (natalia.piotrovskaya@niersc.spb.ru), Aleksandra Mushta1,3, Anna

Vesman1,2, Eduard Kazakov1, Dmitriy Shakhin4
1
Nansen International Environmental and Remote Sensing Centre, Saint-Petersburg, Russian Federation, 2Arctic
and Antarctic Research Institute, Saint-Petersburg, Russian Federation, 3Saint Petersburg State University, Saint-
Petersburg, Russian Federation, 4FRECOM, Moscow, Russian Federation

Monitoring of sea ice processes, i.e. ice edge variations and motion, is important for practical tasks such as ice
navigation and for scientific studies. High-resolution data from C-band SAR have been used as the main data
source for analysis of the sea ice regime in the Kara Sea to study details of ice distribution as well as changing of
the ice conditions and sea ice types. The aims of our study is to develop recommendations for the planning of
ship routes around the habitats, migration of the endangered species of fauna objects, taking into account
long-term trends, seasonal and interannual variations of the ice conditions in the Kara Sea. To accomplish this
goal, an automated classification algorithm based on the support vector machine (SVM) approach for Sentinel-
1 Extra Wide (EW) swath dual-polarization mode data (HH + HV), was applied. Several technical issues for
Sentinel-1 Extra Wide (EW) data were solved in the pre-processing stage including thermal noise reduction in
HV-polarization and correction of angular backscatter dependency in HH-polarization. Texture features were
explored and used in addition to supervised image classification. Algorithm was trained to classify types of
underlying surface in the Kara Sea region: first-year ice thin, first-year ice medium, young ice, water and nilas.
The automated classification is included in the ice conditions monitoring system developed at NIERSC for
solving practical problems.

43
2428
Spatial and Temporal Variability at the Toolik Lake Vegetation Grid (Alaska)

Birgit Heim1 (birgit.heim@awi.de), Alison Beamish1, D. A. Walker2, Howard E. Epstein3, Ulrike Herzschuh1,
Torsten Sachs4, Sabine Chabrillat4, Maximilian Brell4, Sebastian Roessler5, Marcel Buchhorn6
1
Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research AWI, Polar Terrestrial Ecosystems,
Potsdam, Germany, 2University of Alaska Fairbanks, International Arctic Research Center, Institute of Arctic
Biology, Fairbanks, United States, 3University of Virginia, Charlottesville, United States, 4Deutsches
GeoForschungsZentrum GFZ, Potsdam, Germany, 5FIELAX, Bremerhaven, Germany, 6VITO, Flemish Institute for
Technological Research, Mol, Belgium

Ground data for the validation of satellite-derived terrestrial Essential Climate Variables (ECVs) at high latitudes
are sparse. Also for regional model evaluation of terrestrial variables we lack accurate ranges of terrestrial
ground data and face the problem of a large mismatch in scale. Within the German research programs Regional
Climate Change (REKLIM) and the Environmental Mapping and Analysis Program (EnMAP), we conducted a
study on ground data representativeness for vegetation-related variables within a monitoring grid at the Toolik
Lake LTE Research station in Alaska. The grid covers an area of ~ 1 km2 containing Eight five grid points spaced
100 meters apart. Moist acidic tussock tundra is the most dominant vegetation type. Permanent 1 m2 plots
were also established to be representative of the individual gridpoints. During summer 2016, we conducted
field spectrometry at selected plots during early, peak and late summer. We experimentally investigate more
spatially extensive Elementary Sampling Units (ESUs) for the spatial representativeness of the permanent 1 m2
plots and to map ESUs for various tundra types. We will present the first data analyses and maps of
biophysically-focused ESUs for evaluation of the use of remote sensing data to estimate these ecosystem
properties.

44
2552
Hybrid Sentinel-1 / Radarsat Backscatter Time Series of Arctic Canada

David Small1 (david.small@geo.uzh.ch), Christoph Rohner1, Marius Vögtli1, Nuno Miranda2, Stephen Howell3,
Yves Crevier4
1
University of Zurich, Dept. of Geography, Zurich, Switzerland, 2European Space Agency ESRIN, Frascati, Italy,
3
Environment & Climate Change Canada, Toronto, Canada, 4Canadian Space Agency, St. Hubert, Canada

The Sentinel-1 satellites (S-1A/S-1B) currently provide approximately 1-2 day close-to-seamless revisit over
Ellesmere Island in the Canadian Arctic. The impressive temporal resolution achieved using these two satellites
can be further improved by integrating observations from other C-band satellites such as Radarsat-2 and, in the
near future, data from the Radarsat Constellation Mission.
We employ radiometric terrain flattening and local resolution weighting to generate normalised gamma nought
backscatter over wide regions, not restricted to a single sensor or track's swath width limitations. Ascending
and descending passes are integrated into composite backscatter maps. These can be used to generate
terrestrial snow/ice-melt and sea-ice-melt products with sufficient temporal resolution to delimit short-lived
melting periods.
We illustrate the temporal resolution of wide-area composites time-series achieved by using the Sentinel-1 or
Radarsat-2 in isolation. We then compare those results with what can be achieved with hybrid backscatter
maps that accept observations from both missions. These tests have been undertaken within the framework of
the World Meteorological Organisation's Polar Space Task Group (PSTG) and SAR Coordination Working Group
(SARCWG). We describe coordinating actions that can and have been taken by the space agencies to help
ensure generation of properly calibrated “hybrid” backscatter composite values that derive from multiple
sensors.

45
2638
Retrieval of Ice Thickness on Large Northern Lakes from Jason-2 Data

Claude Duguay1 (crduguay@uwaterloo.ca), Elena Zakharova2, Alexei Kouraev2, Homa Kheyrollah Pour1, Marie
Hoekstra1
1
University of Waterloo, Waterloo, Canada, 2Université de Toulouse, LEGOS, Toulouse, France

Lake ice grows steadily between the end of the freeze-up and onset of the break-up periods as a result of the
thermodynamics of freezing water as well as dynamic ice motion on the surface. The value of passive
microwave and radar altimeter data from satellite altimetry missions has been shown for the determination of
ice dates (freeze-up and break-up) and only very recently been evaluated for the estimation of ice thickness.
Data acquired from current satellite missions (e.g. Jason-2/3, Sentinel-3) provide an opportunity for
investigation of the development of lake ice thickness retrieval algorithms.
The objective of this study is to investigate the potential of radar altimeter and passive microwave radiometer
data from the Jason-2 satellite mission for the estimation of ice thickness on large northern lakes. Backscatter
and brightness temperature (Tb) measurements from its nadir-pointing radar altimeter (13.575/5.3 GHz) and
passive microwave radiometer (18.7 and 34 GHz) are compared against ice thickness estimates obtained with a
thermodynamic lake ice model and in situ measurements collected on three lakes in northern Canada over the
course of eight ice seasons (2008-2009 to 2015-2016). The temporal evolution of backscatter and Tb is then
explored to estimate ice thickness. Results show that both passive microwave and radar altimeter data
acquired in the 5-19 GHz frequency range allow for the retrieval of ice thickness on the lakes investigated with
a 10-20 cm accuracy.

46
OC-1_OC-2a - Innovation, partnership and impact in polar science communication & Polar
Research and Citizen Science: Exploring New Platforms and Opportunities
19.06.2018 09:00-10:30, B Pischa

141
A Framework to Increase the Value and Impact of Polar Education and Outreach

Heidi Roop1,2 (hroop@uw.edu), Rhian Salmon2

1
University of Washington, Climate Impacts Group, Seattle, United States, 2Victoria University of Wellington,
Science in Society Group, Wellington, New Zealand

Since the International Polar Year 2007-2008, polar education, outreach and communication (EOC) has
matured significantly. This is illustrated by a shift from 'pop outreach' aimed at the general public, to 'informing
decision-making' targeted at key stakeholders. However, a significant number of scientist communicators still
lack the support, training and professional recognition required for effective and thoughtfully designed EOC
activities.
Using a mixed-methods approach, including data from interviews and four different surveys, we explore the
field of polar EOC over the past ten years. We draw on four polar outreach case studies — an expedition, a
documentary, a festival, and an education event — that the authors have been associated with. We
supplement this with data from a survey of 170 scientist communicators from 22 countries, which shows that
while 90% of respondents engage in EOC activities, only 38% have training in science communication and only
10% incorporate formal or external evaluation.
Building on these data, we highlight the current barriers and opportunities associated with the evaluation and
reporting of EOC activities. We also present a new framework for engagement design that encourages reflexive
practice and mechanisms for development, delivery and evaluation of EOC activities based on explicit and
articulated objectives. Through more thoughtful approach to science communication, we hope to increase the
value, impact and reach of such activities.

47
2019
Engaging Students in Stem Education through Arctic Research

Halldor Johannsson1 (halldor@arcticportal.org), Agata Goździk2, Jan Borm3, Lis Mortensen4, Paul Aspholm5,
Tomasz Juńczyk6
1
Arctic Portal, Akureyri, Iceland, 2Institute of Geophysics Polish Academy of Sciences, Warsaw, Poland,
3
Université de Versailles Saint-Quentin-en-Yvelines, Relations Internationales, Versailles, France, 4Faroese
Geological Survey, Thorshavn, Faroe Islands, 5Norwegian Institute of Bioeconomy Research ( NIBIO), Kirkines,
Norway, 6American Systems, Poznan, Poland

The Arctic is changing rapidly with new business opportunities and environmental threats, calling for enhanced
knowledge, efficient education and innovative educational support programmes not least in the fields of STEM.
EU H2020 EDU-ARCTIC is a multilingual Pan-European science communication and educational support
initiative available for all secondary schools, using Arctic research as a vehicle to encourage pupils aged 13 to
20 to pursue education in science, technology, engineering and mathematics.
Objectives:
- Encourage interest in science, technology, engineering and mathematics (STEM) education to secondary
school students
- Provide an innovative and supportive educational program, accessible to schools, educators and students
across Europe and beyond
- Establish strong links between the research and education communities by connecting schools to scientists at
Arctic research stations and research institutes throughout Europe.
The project uses a mix of different innovative tools and methodologies for science communication supporting
STEM education, including virtual lessons with scientists dealing with polar research, environmental monitoring
program, teacher trainings and workshops, online Polarpedia, interactive portal explaining scientific
terminology through text, images, maps, videos and multimedia tools.
Edu-Arctic has a strong webportal at edu-arctic.eu and uses actively and innovatively Social media outreach
and communication tools to reach the widest audience.

48
2136
Major Lessons from Teaching Young Children Complex, Abstract Polar Concepts

Alexander Thornton1 (alexander.e.thornton@gmail.com), Gary Wesche2

1
University of Alaska Fairbanks, Fairbanks, United States, 2Polar Educators International, Kansas City, United
States

If researchers want to shift public perceptions about complex, abstract concepts—such as impacts of climate
change on polar ecosystems—we need to educate young children. Many kids form negative opinions about
Science, Technology, Engineering, & Mathematics (STEM) fields by the time they are seven-years-old; after this
age, educators must combat previously ingrained attitudes towards STEM to teach new ideas. However, young
children are not developmentally mature enough to understand complex, abstract concepts until reaching
adolescence after 10-years-old. This mismatch in educational development may seem unfortunate, but is not
insurmountable using the right engagement techniques to facilitate a child's exploration of the polar world.
Promoting development of cognitive and emotional intelligence at an early age combats poor polar literacy and
mistrust of scientists, opening the door for informed, public conversation on highly-politicized issues like
climate change. This presentation highlights experiences teaching complex, abstract polar concepts to
elementary school children in Fairbanks, Alaska, USA. We reflect upon methodology and major lessons learned
to provide suggestions for scientists interested in communicating broader impacts of their research with
children. We will also introduce plans to develop a working group for educators and researchers to collaborate
on a resource bank for polar curriculum meeting educational standards in multiple countries.

49
2448
Teenager and School Teacher Program for the Polar Education and Outreach

Ji Young Lee1 (jylee@kopri.re.kr), Hana Cho1, Mingu Kang1, Hye Lim Jun1, Hyoung Chul Shin1
1
Korea Polar Research Institute, Incheon, Korea, Republic of

A teenager program of Korea Polar Research Institute (KOPRI) has been running for over 10 years, allowing
selected individuals sent to visit the polar research infrastructure, usually our Arctic summer research station,
and to join the efforts of field scientists. A nation-wide call is made before essay writings and interviews that
help us to admit the best prepared and most willing students. Alumni are later invited to remain connected in
order to make the most use of collective experiences gained. In some years, this program opted to take some
variations to engage school teachers and artists. KOPRI also delivers customized education program,
particularly to high school science teachers as a community service, namely the Polar Academy. This also led to
our efforts to develop learning materials for students. Utmost challenge is to continue to engage these
participants and have them connected and networked. Furthermore, KOPRI makes efforts to actively
communicate via new social media; KOPRI vividly portrays activities like this program and others, for example,
conducted by field researchers through its coverage of the scientific achievements from the research stations.
For example, it creates and distributes contents such as interesting and informative news posts and events to
many followers. KOPRI also organizes various events such as 'feel the polar world yourself' exhibitions or photo
exhibitions in subway stations, to provide the urban audience with polar experiences.

50
2156
A Decade of USA-Mexico Virtual K-12 Participation in Antarctic Expeditions

Ana Lucia Weissling1 (ana.lucia.weissling@gmail.com), Julissa Jimenez2, Stephen Ackley3, Blake Weissling3
1
University of Texas at San Antonio, Bilingual and Bicultural Studies, San Antonio, United States, 2Grupo Escolar
Simon Bolivar, Briones Campus, Xalapa, Mexico, 3University of Texas at San Antonio, Geological Sciences, San
Antonio, United States

This session presents an innovative outreach initiative for the education and motivation of young learners on
themes related to polar regions and science. Two binational groups of elementary students worked alongside
polar scientists in an ongoing collaboration as virtual researchers. A decade of polar research in three Antarctic
expeditions, and a teacher-scientist partnership, served as a basis for an interdisciplinary primary and
secondary academic model. The project began with a 2nd/3rd grade bilingual class in Texas, transforming the
classroom into a virtual icebreaker during the 2007 SIMBA expedition, and afterwards in an Antarctic thematic-
unit to develop science knowledge and literacy skills. Many of the same children followed the 2010 Oden and
2017 PIPERS expeditions through digital technology, in classrooms in Texas and Mexico. With guidance by their
teachers and support from the scientists, the students have served as ambassadors of polar knowledge and
research creating research exhibits, presentations, science fairs, and conferences in their schools and
communities, including presenting at the 2012 TABE (Texas Association for Bilingual Education) Conference
where students demonstrated their acquired scientific polar knowledge in two languages. Through this session
we hope to inform and illuminate an amazing 10 year outreach effort in polar science and education across two
languages and cultures, and to promote this model in other schools and programs.

51
CR-1a - Permafrost: connecting measurements, monitoring, and modelling
19.06.2018 09:00-10:30, B Parsenn

2678
A Global Snapshot on the Thermal State of Permafrost and Active Layer Thickness

Boris Biskaborn1 (boris.biskaborn@awi.de), Vladimir E. Romanovsky2, Sharon S. Smith3, Dmitry Streletskiy4,

Jeannette Noetzli5, Goncalo Vieira6, Philippe Schoeneich7, Jean-Pierre F. Lanckman8, Hugues Lantuit1
1
AWI, Potsdam, Germany, 2Geophysical Institute, University of Alaska, Fairbanks, United States, 3Geological
Survey of Canada, Ottawa, Canada, 4George Washington University, Washington, United States, 5WSL Institute
for Snow and and Avalanche Research SLF, Davos, Switzerland, 6CEG/IGOT - Universidade de Lisboa, Lisboa,
Portugal, 7Institut de Géographie Alpine, Université de Grenoble Alpes, Grenoble, France, 8Arctic Portal,
Akureyri, Iceland

The Global Terrestrial Network for Permafrost (GTN-P) is part of GTOS of the Global Climate Observing System,
a joint undertaking of the WMO, IOC, UNESCO, UNEP and ICSU. GTN-P was established in 1999 by the
International Permafrost Association with the goal of systematic and long-term documentation of the
distribution, variability and trends of permafrost based on a global network of field measurements.
GTN-P developed a Data Management System (gtnpdatabase.org) for the collection, processing (incl.
standardization) and dissemination of permafrost data and metadata. Recent data of ground temperature and
active layer thickness are being compiled for a new global snapshot of the current permafrost state. Results
indicate that permafrost temperature is generally following the trends in air temperature and increasing,
especially in the Arctic areas where permafrost is relatively cold. In the Sub-Arctic, where permafrost
temperatures are relatively high, the warming trend is less pronounced and at many locations current
permafrost temperature is similar to that of the IPY snapshot. In alpine permafrost areas, most measurement
sites significant warming. Active layer thickness exhibits large interannual variability, mainly due to variations in
snow-cover, but has generally increased since the IPY, especially in the European Arctic sector. In several sites
at northwest Antarctic Peninsula, active layer thickness has been stable or even decreased.

52
1880
Strategies and Data of Long-term Permafrost Monitoring in the Swiss Alps

Jeannette Noetzli1 (jeannette.noetzli@slf.ch), Benno Staub2

1
WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland, 2University of Fribourg,
Department of Geosciences, Geography, Fribourg, Switzerland

The Swiss permafrost monitoring network PERMOS documents the state and changes of permafrost in the
Swiss Alps based on ground temperatures measured in boreholes and near the surface, changes in ice content,
and rock glacier creep velocities. The core task of long-term monitoring, and at the same time the biggest
challenge, is to deliver reliable, robust and comparable measurements from key sites over decades. This
requires coherent strategies that are repeatedly evaluated and adapted to new findings from research.
The PERMOS Scientific Committee re-evaluated the PERMOS observation strategy in 2017 and we present the
main outcomes. They mainly concern further improvement and definition of standard procedures for site
maintenance as well as data processing and documentation because PERMOS evolved from individual research
activities. The site maintenance in rough conditions is demanding and problems such as shearing of the
boreholes and blocked chains can threaten the continuation of the time series. Renovation or re-drilling, for
example, require careful planning to achieve overlap of the different systems and to consider experiences and
standards. A second major task is a robust data management system with standardized processing and quality
control of new and existing data as well as easy access. Finally, the results and assessments should be reported
timely and in an understandable and useful way to researchers, authorities and the public.

53
1486
Circumpolar Active Layer Monitoring Program: Results and Future Directions

Nikolay Shiklomanov1 (shiklom@gwu.edu), Dmitriy Streletskiy1, Frederick Nelson2, Anna Klene3

1
George Washington University, Geography, Washington, United States, 2Northern Michigan University,
Geography, Marquette, United States, 3University of Montana, Geography, Missoula, United States

The Circumpolar Active Layer Monitoring (CALM) program, established in the early 1990s, is designed to
observe temporal and spatial variability of the active layer, near-surface permafrost parameters, and their
response to changes and variations in climatic conditions. CALM is an integral part of the Global Terrestrial
Network for Permafrost (GTN-P). The CALM network incorporates sites distributed throughout the Arctic. The
majority of the sites are in Arctic and Subarctic lowlands. At approximately 90 sites, direct active-layer
measurements are conducted on standard rectangular grids ranging from 10 x 10 m to 1 x 1 km. The locations
of grids were selected to represent generalized surface and subsurface conditions characteristic of broad
regions. Vast majority of CALM sites have continuous active-layer records longer than five years and more than
40 have twenty-year records or longer. Auxiliary information includes air temperature, soil moisture, soil
temperature at different depth, snow cover, soil composition, and landscape characterization. Several sites
have records of frost heave and thaw subsidence. CALM is the world's primary source of information about the
active layer. The data is assimilated and distributed though CALM (www.gwu.edu/~calm) and GTN-P
(gtnpdatabase.org) online databases. This presentation summarizes results and accomplishments of the CALM
program and project future directions.

54
752
The Thermal State and Distribution of Rock Wall Permafrost in Norway

Florence Magnin1, Bernd Etzelmuller1, Paula Hilger2, Seabastian Westermann1, Cristian Lussana3, Ketil Isaksen3
(ketil.isaksen@met.no), Reginald Hermanns2
1
University of Oslo, Department of Geosciences, Oslo, Norway, 2Geological Survey of Norway, Geohazard and
Earth Observation Group, Trondheim, Norway, 3Norwegian Meteorological Institute, Oslo, Norway

Climatically driven permafrost degradation may be a serious threat to human activities and lives in Norway in
areas where steep rock slopes are located above houses, infrastructures and large water bodies. The CryoWALL
project (2015-2019) aims at studying rock wall permafrost in some of the most hazardous rockslide areas in
Norway. In 2015 and 2016, 20 Rock Surface Temperature (RST) loggers were installed at 10 cm depth in 7
selected sites along a latitudinal transect from 60°50'N to 69°46'N. Twelve of these loggers are located north of
the polar circle. In 2016 and 2017, 20 more loggers were installed at the surface of the coastal cliffs, canyons
and alpine rock walls in the Ny-Ålesund area (78°55´N) in Svalbard.
The RST time series are used for (a) characterizing the thermal state and distribution of rock wall permafrost
(RWP) across Norway and in Svalbard, (b) running steady-state and transient numerical models of RWP at
selected sites, and to (c) calibrate a general linear regression model that will be used to (d) predict the spatial
distribution of RWP at the national scale. The preliminary analysis shows that the mean RST differs by 3°C
between N and S faces in Southern Norway. In Northern Norway the midnight sun and polar night effects,
induce similar RST in both aspects during December, January, May and June and with a difference in RST of
1.5°C on annual scale. This first data set is shown to be of high relevance for predictive modelling.

55
2257
Decadal Landscape Change in the McMurdo Dry Valleys, Antarctica

Andrew Fountain1 (andrew@pdx.edu), Joseph Levy2, Maciej Obryk3, Michael Gooseff4, Rickard Pettersson5,
David Van Horn6
1
Portland State University, Geology, Portland, United States, 2Colgate University, Department of Geology,
Hamilton, United States, 3US Geological Survey, Cascade Volcano Observatory, Vancouver, United States,
4
University of Colorado, INSTAAR, Boulder, United States, 5Uppsala University, Geography, Uppsala, Sweden,
6
University of New Mexico, Biology, Albuquerque, United States

Recent observations of soil surfaces, streams, and glaciers in the McMurdo Dry Valleys of Antarctica (MDV)
show extensive evidence of subsidence, channel migration, and surface roughing. To evaluate the spatial
distribution and magnitude of change we compared elevations from two airborne LiDAR campaigns, one
collected in the summer of 2001-02 and 2014-15. During this period the intensity of solar radiation increased
significantly, indicated by long-term meteorological measurements and supported by long-term ecological
responses. Results show subsidence is strongly associated with the presence of massive ground ice and with
proximity to surface or shallow subsurface (active layer) water. Subsidence occurs across soil types and
landforms in both low-lying, low-slope terrain with impeded drainage and high on steep valley walls. These
observations, supported by modeling of heat transfer in the soils, highlights the importance of insolation-driven
thermokarst warming and thawing in the MDV. The regional melt pattern shows a transfer of water storage
from the local cryosphere (glaciers, permafrost) to the hydrosphere (closed basin lakes and ponds). We
interpret this pattern as reflective of a transition process to Arctic and alpine-style, hydrologically mediated
ground- and surface-ice loss. Although this may be only an episode within current climate variability, it is
suggestive of the processes to be expected when the region warms as predicted by climate models.

56
2627
Estimating Shrub Height as Indicator for Snow Height and Permafrost Modelling

Annett Bartsch1 (annett.bartsch@zamg.ac.at), Barbara Widhalm1, Marina Leibman2, Ksenia Ermokhina2, Yuri
Dvornikov2, Artem Khomutov2, Timo Kumpula3
1
Zentralanstalt für Meteorologie und Geodynamik ZAMG, Vienna, Austria, 2Earth Cryosphere Institute, Russian
Academy of Sciences, Tyumen, Russian Federation, 3University of Eastern Finland, Joensuu, Finland

Land cover has strong implications for the small-scale distribution of snow cover. Specifically shrub height is
required in order to identify areas with trapping of snow and subsequent impact on ground thermal conditions.
Current global and circumpolar maps lack thematic detail and/or spatial resolution to appropriately represent
shrubs, their types and height.
The recently launched Sentinel-2 satellite optical data suitable for land cover monitoring with 10 m spatial
resolution. We have selected a transect spanning from the northern tip of the Yamal peninsula (continuous
permafrost) to the south into the tundra-taiga transition zone (with discontinuous permafrost) in order to test
these data for shrub height retrieval. The region represents not only a gradient in vegetation zones but also
sites with high heterogeneity of shrubs. Especially central Yamal is characterized by shrubs of up to 1.5 m
height within continuous permafrost. Several studies over a CALM site and additional transects have
exemplified the role of the shrubs for active layer thickness in relation to snow using in situ measurements as
well as Synthetic Aperture Radar data from satellites in this region.
Shrub height measurements have been collected between 2014 and 2017. All available cloud-free images of
summer 2016 and 2017 have been combined and seven indices derived. An R² of 0.72 could be obtained. The
index can be potentially applied over the entire Arctic to derive maps of shrub height.

57
AC-5a - Tropical-Polar Teleconnections and their Climate impacts
19.06.2018 09:00-10:30, B Jakobshorn

2068
Links between Strong ENSO Events and Late Fall Barents-Kara Climate

Stefan Sobolowski1,2 (stefan.sobolowski@uni.no), Camille Li2,3, Martin King1,2

1
Uni Research Climate, Bergen, Norway, 2The Bjerknes Centre for Climate Research, Bergen, Norway, 3University
of Bergen, Geophysical Institute, Bergen, Norway

A late fall ENSO teleconnection with the midlatitudes involving the so-called tropical Northern Hemisphere
pattern has previously been reported. Recently this teleconnection pathway has been hypothesized to extend
eastward to the European sector with impacts on late fall continental temperature and precipitation. Given the
likely mechanisms of such a teleconnection it is reasonable to propose that there are effects that extend into
higher latitudes and the Barents-Kara region, in particular. This study investigates potential links between
strong ENSO events and conditions in the Barents-Kara region. Lagged composites show that robust late fall
ENSO - European teleconnections extend northward to include tropospheric atmospheric circulation, moisture
transport and surface turbulent fluxes over this important and rapidly changing region. Responses linked to El-
Niño and La-Niña are generally of opposite sense but are asymmetric suggesting nonlinear relationships.
Analyses examining Rossby wave source, eddy heat fluxes, sea ice, and the role of internal variability are also
presented, providing further support for a strong link between tropical variability and Arctic climate from early
- late fall. Given that fall conditions in the Barents-Kara region are often assigned a driving role in proposed
Arctic-midlatitude teleconnection pathways it is important to investigate the degree to which tropical, and
other sources of, variability can modulate said pathways.

58
1790
Sensitivity of High Latitude ENSO Teleconnection to Global Warming

Clio Michel1,2 (clio.michel@uib.no), Camille Li1,2, Ingo Bethke2,3

1
University of Bergen, Geophysical Institute, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen,
Norway, 3Uni Research Climate, Bergen, Norway

The El Niño Southern Oscillation teleconnection (ENSO) to the northern extratropics includes a robust response
in the Pacific-North America sector, and less robust responses in the Arctic and Euro-Atlantic sector. Recently,
Deser et al. (2017) showed that uncertainty in the response arises mainly from atmospheric internal variability
rather than from the diversity of El Niño/La Niña events. This presents a challenge in assessing how
teleconnections to high latitudes will change under global warming.
We investigate the high latitude atmospheric response to two El Niño and two La Niña events in multi-model
large ensembles (at least 100 members per model) for the present climate and in a 2ºC warmer world (relative
to pre-industrial climate). The sea surface temperatures (SSTs) are prescribed such that the events themselves
are identical in the two periods, but they occur within different background flows.
The multi-model ensemble mean response is stronger in the 2ºC world than for the present climate. This
response can be linked to changes in the mean wave-guide for the high latitude teleconnection patterns. We
also examine the spread in the responses and the changes in surface impacts associated with end members of
the ensemble. The model uncertainty is assessed by looking at model biases in the wave-guide and in poleward
propagating Rossby waves excited by tropical sources.

59
961
Spring Dust Weather in North China Linked to Sea Ice in the Barents Sea

Ke Fan1 (fanke@mail.iap.ac.cn)
1
Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China

The link between winter sea ice cover in the Barents Sea (SICBS) and the frequency of spring dust weather over
North China (DWFNC) is investigated. It is found that year-to-year variability of SICBS and DWFNC are strongly
correlated for the period 1996-2014, whereas the correlation between SICBS and DWFNC is not statistically
significant for the periods 1980-1995. During 1996-2014, low winter SICBS is associated with decreased snow
cover over western Siberia (SCWS) in both winter and spring, which is also supported by a strengthening
relationship between winter SICBS and spring SCWS since the mid-1990s. This leads to changes in atmospheric
circulation and climate conditions that are favorable for increased frequency of dust weather events over
North China. Our further analysis suggests that the interannual variability of the standard deviation of SICBS
has intensified and the center of actions has moved eastward to the north Barents Sea and Kara Sea since the
mid-1990s. Such change may easily induce stronger and southward stationary Rossby wave, influencing the
dust-related atmospheric circulation (strengthened East Asian subtropical jet, increased cyclogenesis, and
larger atmospheric thermal instability). Thus interannual variation of winter SICBS plays an increasingly
important role in dust-related climate conditions over North China, which might serve as a new precursor for
the prediction of spring dust activity in North China.

60
614
A Physical Mechanism for Indian Summer Monsoon Influence on Arctic Sea Ice

Suchithra Sundaram1 (suchithra.sundaram@nyu.edu), David M Holland1,2

1
New York University, Center for Global Sea Level Change, Abu Dhabi, United Arab Emirates, 2New York
University, Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York, United
States

Polar sea ice is a dominant component of the climate system and its the variability can cause great impact on
global climate. In the recent past, Arctic witnessed many years of rapid sea ice loss. The reason for such a
decrease has been attributed to both natural and anthropogenic drivers, though uncertainty remains. The aim
of the present study is to understand whether there exists any relation between Indian Summer (June-
September(JJAS)) Monsoon (ISM) and September Arctic sea ice retreat. The motivation behind the study is the
findings from the analysis of 48 years of Hadley Centre sea ice and APHRODITE precipitation data, which
indicated that during most of the strong (weak) ISM years, the Arctic sea ice increased (decreased) particularly
over the Chukchi and Beaufort Sea during September. Further analysis with atmospheric parameters (height
anomalies and wind divergence) from NCEP/NCAR reanalysis data showed that strong (weak) ISM is
accompanied by positive (negative) phase of Summer North Atlantic Oscillation (SNAO) due to the contribution
from strong/weak ISM, causing strong convergence/divergence over the upper/lower levels of the
Mediterranean-Sahara region through monsoon-desert mechanism. This has great impact on the summer
Azores high and SNAO which affects the Arctic circulation and sea ice. The link is supported by correlation with
ISM index and sea level pressure. Thus, a tropical-polar teleconnection mechanism between ISM and Arctic sea
ice is proposed.

61
661
Elucidating the Effects of Arctic Sea Ice Loss on Northern Hemisphere Climate

James Screen1 (j.screen@exeter.ac.uk), Clara Deser2, Doug Smith3, Xiangdong Zhang4, Russell Blackport1, Paul
Kushner5, Thomas Oudar5, Kelly McCusker6, Lantao Sun7
1
University of Exeter, Exeter, United Kingdom, 2National Center for Atmospheric Research (NCAR), Boulder,
United States, 3Met Office, Exeter, United Kingdom, 4University of Alaska Fairbanks, Fairbanks, United States,
5
University of Toronto, Toronto, Canada, 6University of Washington, Seattle, United States, 7Cooperative
Institute for Research in Environmental Sciences, Boulder, United States

The decline of Arctic sea ice is an integral part of anthropogenic climate change. Sea ice loss is already having a
significant impact on Arctic communities and ecosystems. Meanwhile, there is also intensive scientific interest
in considering its role as a cause of climate changes outside the Arctic. Evidence is mounting that Arctic sea ice
loss can affect weather and climate throughout the Northern Hemisphere.
To fully capture the remote impacts of Arctic sea ice loss, models that simulate interactions among the ocean,
sea ice, land and atmosphere are required. A synthesis of six such experiments with different models shows
consistent hemispheric-wide atmospheric warming, strongest in the mid-to-high latitude lower troposphere
and tropical upper troposphere; an intensification of the wintertime Aleutian Low and Siberian High; and a
weakening and southward shift of the midlatitude westerly winds in winter. Fuller diagnosis of the tropical
upper tropospheric warming response to Arctic sea ice loss suggests a critical role for ocean heat transport
changes. Freshening of the subpolar Arctic due to sea ice melt reduces the strength of the Atlantic Meridional
Overturning Circulation (AMOC) and associated northward ocean heat transport, causing a build-up of heat in
the tropical oceans. The resulting increase in tropical sea surface temperature enhances atmospheric deep
convection and associated latent heat release, leading to tropical upper tropospheric warming.

62
942
Changes in Climate Trends in the Antarctic Peninsula Region

Gennadi Milinevsky1,2 (genmilinevsky@gmail.com), Oleksandr Evtushevsky1, Volodymyr Kravchenko1, Asen

Grytsai1
1
Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, 2Jilin University, International Center for Future
Science, Changchun, China

The largest climate warming in the Southern Hemisphere since the middle of the last century is observed in the
Antarctic Peninsula in the winter months. Decadal variability of the winter temperature on the regional scale
has been analyzed by SCAR READER datasets from the four stations in the Antarctic Peninsula region. Wavelet
transform and Fourier analysis reveal both interannual (3-8 years) and decadal (10-20 years) temperature
oscillations. Running correlation shows decadal variability in the Antarctic Peninsula winter temperature
coupling with the central tropical Pacific. This variability is associated with intensity and persistency of the
meridional wavetrain of stationary planetary waves, along which tropical disturbances propagate poleward
reaching the Antarctic Peninsula. The period of the most significant tropical effects is 1980s-1990s, when the
most rapid winter warming at Faraday/Vernadsky station was observed. One of the components of the winter
temperature change on the Antarctic Peninsula is a 16-year periodicity with the amplitude of about 1°С, which
also contributes to regional climate change. Absence of 21st century warming on Antarctic Peninsula discussed
in the recent works can be partly caused by minimum in this periodicity.

63
AC-1a - Polar and high altitude atmosphere: clouds, aerosols, climate and interactions
19.06.2018 09:00-10:30, C Sanada I

360
Effect of Arctic Sea Ice on Aerosols in Eastern Lapland, Finland

Ella-Maria Duplissy1 (ella-maria.duplissy@helsinki.fi), Simo Hakala1, Victoria Sinclair1, Riikka Väänänen1, Veli-
Matti Kerminen1, Tuukka Petäjä1, Markku Kulmala1
1
University of Helsinki, Helsinki, Finland

Changes in sea ice are likely to affect the aerosols in the continental Arctic. We calculated linear regressions to
median aerosol concentrations and mode peak diameters at SMEAR I in eastern Lapland, Finland, as a function
of time over sea ice (TOSI), time over open sea (TOOS) and time over land (TOL). We divided the data into
summer (Jun-Sep) and winter (Oct-May) as well as NAO and AO positive and negative phases.
During summer, the total aerosol number, Aitken mode and accumulation mode concentrations were
decreasing with increasing time the air mass spent over the sea ice by -8.9, -5.3 and -1.6 cm-3h-1, respectively.
The Aitken mode diameter was decreasing -0.3 nm/h and the accumulation mode diameter -0.5 nm/h.
Accumulation mode concentration and diameter increased by +0.8 cm-3h-1 and +0.3 nm/h, respectively, as a
function of TOOS. During winter there was a decrease in total, nucleation mode and Aitken mode
concentrations (-1.3, -0.3, -0.6 cm3/h, respectively) as a function of TOSI. Accumulation mode concentration
and diameter were decreasing by -0.4 cm-3h-1 and -0.2 nm/h as a function of TOOS.
We conclude, that Arctic sea ice has strong impact on the aerosol concentrations in eastern Lapland, and the
changes in the sea ice extent and time that the air parcel spends over sea ice can have an influence on the
aerosol-cloud interactions in the continental Arctic. The concentrations of potential CCN have contrasting
trends with decreasing sea ice during summer and winter.

64
822
Enabling Atmospheric Process Research at MOSAiC

Matthew Shupe1,2 (matthew.shupe@noaa.gov), Markus Rex3

1
University of Colorado Boulder, CIRES, Boulder, United States, 2NOAA Earth System Research Laboratory,
Boulder, United States, 3Alfred Wegener Institute, Potsdam, Germany

The Arctic is undergoing substantial change, embodied by diminished sea-ice cover, which is opening the region
to enhanced human activities requiring an improved ability to model the system on many temporal and spatial
scales. Atmospheric processes pose some of the greatest challenges to modelling the Arctic due to a dearth of
detailed observations and the overall complexity of atmospheric processes and their interactions. Specific
challenges involve clouds, aerosols, precipitation processes, the boundary layer, and the roles these play in the
surface energy budget. The Multi-disciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) will
provide a unique opportunity to examine atmospheric processes and their role in the coupled Arctic system in
great detail over a full year. Atmospheric measurements will target science themes including: (1) Sea-ice
surface energy budget; (2) cloud and precipitation properties; (3) aerosol concentration and composition; and
(4) the stable and unstable atmospheric boundary layer. These measurements will enable a process-level
understanding of the Arctic system and specifically coupled processes involving the atmosphere. They will also
provide the basis for evaluating and improving process models and process representations in larger-scale
models. This presentation will introduce the MOSAiC atmosphere measurements and explore specific scientific
process-based analyses that they will enable.

On behalf of the MOSAiC Atmosphere Team International Consortium

65
1009
Aerosol Variability Linked to Clouds and Precipitation in the Sor Rondane Area

Alexander Mangold1 (alexander.mangold@meteo.be), Quentin Laffineur1, Andy Delcloo1, Christian Hermans2,

Francois Hendrick2, Alexandra Gossart3, Niels Souverijns3, Paul Herenz4, Heike Wex4, Hugo De Backer1, Nicole
Van Lipzig3
1
Royal Meteorrological Institute of Belgium, Brussels, Belgium, 2Royal Belgian Institute for Space Aeronomy,
Brussels, Belgium, 3Katholieke Universiteit Leuven, Heverlee-Leuven, Belgium, 4Leibniz Insititute for Tropospheric
Research, Leipzig, Germany

Since 2010, continuous measurements of the aerosol number size distribution and total number, and of the
aerosol absorption and total scattering coefficient within the boundary-layer have been realised at the Belgian
research station Princess Elisabeth, in the Sør Rondane Mountains, East Antarctica (72° S, 23° E, 1390 m asl). In
addition, an automatic weather station, a ceilometer (cloud base height and type) and a micro-rain radar
(precipitation observation) have been installed for continuous operation. In December 2015, a MAX-DOAS
instrument has been installed for the retrieval of the vertical profile of the aerosol extinction coefficient.
Backtrajectory calculations for air mass origin complemented the dataset.
The aerosol total number concentration Ntotal showed a clear seasonal cycle with some hundreds of
particles/cm3 during summer and some tens of particles/cm3 during winter. Frequently, Ntotal increased
distinctly during short periods (hours to one/two days; up to some thousands of particles/cm3), with particles
smaller than 90 nm responsible for the increase. Three types of such events could statistically be distinguished
and each of it with distinct meteorological, cloud and precipitation conditions. Clear changes of the spectral
dependency of the absorption coefficient could also be linked to distinct meteorological conditions. The
atmospheric stability parameter, MAX-DOAS and radio sounding observations help to link boundary-layer
observations and higher levels.

66
1475
The Effect of Cloud Microphysics on the Surface Energy Balance of Larsen C

Ella Gilbert1,2 (ellgil82@bas.ac.uk), Andrew Orr1, Tom Lachlan-Cope1, John C King1, Ian A Renfrew2
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of East Anglia, Norwich, United Kingdom

Clouds are a poorly constrained component of the Antarctic climate system, yet their importance is huge.
Antarctic clouds have a significant impact on the surface energy balance (SEB) of ice shelves, with consequent
effects on melt rates. Cloud microphysics greatly influence cloud radiative properties and therefore the SEB,
but there is a paucity of data due to the difficulty of making microphysical measurements in Antarctica.
However, ice shelves around the peninsula are undergoing considerable change: the most recent example of
this is the Larsen C ice shelf. Larsen C's stability may be diminishing following prolonged melting and surface
lowering, as well as the loss of ~12% of its volume in a single calving event in July 2017. Understanding the
drivers of change hinges on the development of atmospheric models that skilfully represent key (micro)physical
processes, and which more accurately predict surface melting and ice shelf collapse for future climate change
scenarios. In this work, we examine aircraft-based microphysical observations from campaigns over the
Antarctic Peninsula. Specific case studies are identified and compared with model simulations using the Met
Office Unified Model at 1.5 km grid spacing. We present preliminary findings and initial analysis, as well as
directions for future work. Our process-based approach could contribute to an improved understanding of
Antarctic clouds and reduced uncertainty in estimates of polar change.

67
1561
Impact of Meteorology on Aerosols and Clouds in the Antarctic Peninsula

Eija Asmi1,2 (eija.asmi@fmi.fi), Kimmo Neitola1,3, Edith Rodriguez1, Aki Virkkula1, Kimmo Teinilä1, Ewan
O'Connor1, Maria Elena Barlasina2, Gustavo Copes2, Germán Pérez Fogwill2, Miguel Mei2, Ricardo Sánchez2
1
Finnish Meteorological Institute, Helsinki, Finland, 2Servicio Meteorológico Nacional, Buenos Aires, Argentina,
3
The Cyprus Institute, Nicosia, Cyprus

Atmospheric aerosol particles are an integral part of the climate, having effects on water-, carbon-, and
nutrient cycles, the amount of solar radiation entering the surface and changing the amount of cloudiness and
rain, as well as the properties of clouds. To understand the inter-annual characteristics of the aerosols in
Antarctic Peninsula and their interaction with the Antarctic clouds and climate, we have studied aerosol
particle physical and chemical properties in the Peninsula continuously since year 2013. Furthermore, we have
studied the low-level clouds and fog, along with the aerosol profiles using a Vaisala ceilometer, operating since
year 2016. These measurements are run in Argentinean station Marambio.
Our long-term analysis of aerosol optical properties and chemistry have shown clear patterns with 1) more
chemically rich aerosol in summer with the origin in the Southern Ocean, 2) higher average aerosol scattering
during winter as a result of stronger storms, resulting in dispersion of marine and soil particles in wind-driven
processes, and 3) importance of primary aerosol sources, especially in winter. Currently, we are analyzing the
presence of fog and low-level clouds using the ceilometer data. Our observations indicate several fog episodes
during the Antarctic summer season. During these episodes, the scattering parameters present variability,
suggesting an impact of aerosol cloud processing. How systematic these changes are, and is yet to be
confirmed.

68
2598
Aerosol and CCN Properties and Sources in East Antarctica during Austral Summer

Paul Herenz1, Heike Wex1, Alexander Mangold2, Quentin Laffineur2, Irina V. Gorodestkaya3,4, Zoë L. Fleming5,
Marios Panagi5, Frank Stratmann1 (frank.stratmann@tropos.de)
1
Leibniz Insititute for Tropospheric Research, Leipzig, Germany, 2Royal Meteorological Institute of Belgium,
Brussels, Belgium, 3University of Aveiro Campus Universitário de Santiago, Centre for Environmental and Marine
Sciences Department of Physics, Aveiro, Portugal, 4KU Leuven, Department of Earth and Environmental Sciences,
Leuven, Belgium, 5University of Leicester, National Centre for Atmospheric Science, Department of Chemistry,
Leicester, United Kingdom

Aerosol measurements were carried out in the framework of the BACCHUS-project (project number: 603445)
at the Princess Elisabeth Antarctica Research Station during three Antarctic summers (Dec. 2013 - Feb. 2016).
The total particle number concentration (NCN) and the Cloud Condensation Nuclei number concentration (NCCN,
@ supersaturations (SS) between 0.1 and 0.7%) were determined using a Condensation Particle Counter and a
CCN counter, respectively. Particle number size distributions were measured between 90nm and 7µm using an
Optical Particle Counter. By applying the κ-Köhler-Theory (Petters and Kreidenweis, 2007) we determined a
median hygroscopicity parameter κ of 1 (@ SS=0.1%). To investigate the influence of the air mass origin on NCN
and NCCN we applied the dispersion model NAME and the Potential Source Contribution Function. In both
methods we looked at the air mass history of the past 10 days. The NAME dispersion footprints were analysed
for the proportional temporal stay in the surface layer (0-100m) over different categorized areas (continental,
ocean and a reactive zone, including chlorophyll, penguin and sea ice zones). We found an Antarctic
background of 200 to 400 #/cm³ for NCN. Only the occurrence of none continental air masses lead to an
enhanced NCN. In terms of NCCN this correlation in less clear, which might be attributable to sinks due to cloud
processes. NCCN covers a range between less than 10 at SS=0.1% and several hundreds #/cm³ for larger SS.

69
BE-4a - Climate change and ecosystems: physiology, biodiversity and ecological functions
19.06.2018 09:00-10:30, C Sanada II

2699
Impacts of Climate Change on Antarctic and Southern Ocean Species and Ecosystems

Dana Bergstrom1, S.A. Robinson2 (sharonr@uow.edu.au)

1
Australian Antarctic Division, Kingston, Australia, 2University of Wollongong, School of Biological Sciences,
University of Wollongong, Australia

Climate change resulting from greenhouse gases and/ or ozone depletion is presenting in a myriad of ways in
Antarctica, the subantarctic and the Southern Ocean. Effects including localised warming, cooling, altered
precipitation patterns, increased wind speeds, shifts in location of low pressure systems and extreme events
are being documented. Associated changes in species and ecosystems are now emerging including localised
species and ecosystem collapse, colonisation of new ground, shift in ranges, and species responses with various
lag phases. In this talk we will examine the variety of species and ecosystem changes recorded, and
demonstrate our development of species and ecosystem impact qualitative models.

70
965
Recent Species and Functional Diversity Dynamics across the Tundra Biome

Anne Bjorkman1 (annebj@gmail.com), Signe Normand1

1
Aarhus University, Ecoinformatics and Biodiversity, Bioscience, Aarhus, Denmark

Widespread changes in temperature and precipitation have the potential to drive substantial shifts in tundra
biodiversity, with important implications for the functioning of these ecosystems. We combine three decades
of tundra plant community surveys at nearly 200 Arctic and alpine locations with 75,000 tundra plant trait
observations to explore changes in both species and functional diversity in response to recent climate change.
We find little evidence of consistent changes in species richness, but substantial community turnover over time
in both species and functional composition. Our results suggest that the strongest impacts of near-term climate
warming on tundra biodiversity-ecosystem function relationships will occur through changes in composition
rather than diversity per se.

71
793
Tara Oceans: A Pan-arctic View on Plankton Diversity and Community Structure

Lee Karp-Boss1 (lee.karp-boss@maine.edu), Tara Oceans Consortium1

1
University of Maine, School of Marine Sciences, Orono, United States

The Tara Oceans expedition, a global-scale study on the diversity and structure of planktonic ecosystems,
conducted its circumpolar field campaign in the Arctic Ocean during the summer of 2013 (May-October).
Sampling was conducted on board the research schooner 'Tara', covering diverse environmental conditions on
Arctic shelves. The result is a rich data set that includes DNA and RNA sequences of viruses, prokaryotes and
eukaryotes for metabarcode, metagenome and metatranscriptome analyses, particle composition from
imaging (phytoplankton, zooplankton and detritus) and 25,000 km of high-resolution inline measurements of
physical, chemical and optical properties of surface waters (temperature, salinity, pCO2, pH, Mercury,
absorption and scattering), as well as other water column parameters (nutrients, light, DOM, HPLC pigments).
We will provide an overview of the sampling program and data sets that are available, and highlight on-going
research foci and major results. Particularly, we will show the pan-Arctic distributions and diversity of plankton
(unstructured (generalist) vs. localized geographic distributions) as well as cross-comparison of Arctic plankton
diversity with results already reported for the global ocean in the special issue of Science dedicated to the Tara
Oceans project (22 May 2015). Such direct comparisons are possible thanks to the use of common sampling
protocols and analytical pipelines at global scale.

72
333
The Way to the Top: The Drivers of Cold-climate Range Shifts in Plants

Jonas Lembrechts1 (jonas.lembrechts@uantwerpen.be), Jonathan Lenoir2, Aníbal Pauchard3, Martin Nuñez4,

Ann Milbau5, Ivan Nijs1
1
University of Antwerp, Biology, Wilrijk, Belgium, 2Université de Picardie Jules Verne, Amiens, France,
3
Universidad de Concepción, Concepción, Chile, 4Universidad Nacional del Comahue, Bariloche, Argentina,
5
Instituut voor Natuur- en Bosonderzoek, Brussels, Belgium

Until now, non-native plant species were rarely found at high elevations and latitudes. However, partly due to
climate warming and increased human presence in these cold environments, both non-native species and
upward moving natives are now on the rise. These rapid shifts in distributions in what is often seen as a slow-
reacting ecosystem make it timely to undertake a thorough assessment of what drives them, in order to
accurately predict their future in a changing world. Here, we show the results from a series of observations and
experiments in the subantarctic Andes and subarctic Scandinavian mountains. We assessed the role of human
interventions (i.e., disturbance, nutrient increase and propagule input) and climatic factors on shifts in plant
species distributions, with our integrative approach allowing us to tease apart the mechanisms. By
acknowledging the interactions of the plants with small-scale abiotic
(e.g. microclimate, soil properties) and biotic (e.g. mutualism, competition) factors, we found that disturbance
plays a defining role along all elevation gradients, a.o. through its effects on soils, biotic interactions,
microclimate and seed influx. Undisturbed vegetation, on the other hand, was surprisingly hard to colonise by
new-comers. These results -consistent within both our observational and experimental studies - suggest that
sub(ant)arctic ecosystems are still relatively resistant to change, unless disrupted by anthropogenic
disturbances.

73
AA-1b - Astrophysics and Astronomy in the Polar Regions
19.06.2018 11:00-12:30, A Studio

2637
Status and Future of Cosmic Microwave Background Measurements from Antarctica

John Carlstrom1 (jc@kicp.uchicago.edu)

1
The University of Chicago, Department of Astronomy and Astrophysics, Chicago, United States

Measurements of the CMB have driven our understanding of the universe and the physics that govern its
evolution from quantum fluctuations to its present state. They provide the foundation for the remarkable 6-
parameter cosmological model, ΛCDM. Far from being the last word in cosmology, the model raises deep
questions: Is Inflation correct? What is its energy scale? What is the dark matter? What is the nature of dark
energy? Are there light sterile neutrinos, or other light relics? There remains a great deal more to learn from
the CMB, especially from its polarization. South Pole experiments have have helped pioneer polarization
studies, starting with the DASI detection of E-mode polarization, to the SPT detection of lensing B-mode, to
BICEP/KECK's best limits on the level of B-mode polarization generated by inflationary gravitational waves. This
talk will briefly review the current state of the art and then outline the plan for the next generation ground
based CMB experiment, CMB-S4, stressing the critical role planned for measurements from the Antarctic.

74
2476
Spectral Distortions of the Cosmic Microwave Background from Dome-C

Silvia Masi1,2 (silvia.masi@roma1.infn.it)

1
Sapienza Università di Roma, Physics, Roma, Italy, 2INFN, Sezione di Roma, Roma, Italy

COSMO (COSmological Monopole Observer) is a spectrometer aimed at detecting spectral distortions in the
Cosmic Microwave Background (CMB). The spectrum of the CMB is a precise blackbody (within 100 ppm of the
maximum brightness, as measured by the FIRAS experiment on the COBE satellite). According to theory,
however, small spectral distortions must be present. Their measurement represents one of the very few ways
to investigate the early or very early universe. The main challenge in this measurement is the presence of
instrumental, atmospheric and astrophysical foregrounds, which must be minimized or carefully evaluated to
estimate the spectral brightness of the CMB with the required accuracy. COSMO is a differential Fourier-
transform spectrometer (DFTS) comparing the brightness of the sky above Dome-C to the brightness of a grey-
body which, in the spectral range of interest mimics the brightness of the atmosphere. The DFTS is cooled at 4K
to reduce its emission, and feeds two arrays of Kinetic Inductance Detectors covering the 1.3mm and 2.0mm
atmospheric windows with a spectral resolution of 2 GHz. Accurate atmospheric modelling and template fitting
allow to separate CMB spectral distortions from the other brightnesses. In a few months of integration, during
the Antarctic winter, we expect to be able to detect a comptonization-like distortion with y at the level of a few
ppm. See http://planck.roma1.infn.it/cosmo for info and a full list of collaborators.

75
2450
SWIPE-LSPE: Cosmic Microwave Background Polarimetry in the Polar Night

Paolo de Bernardis1,2 (paolo.debernardis@roma1.infn.it)

1
Sapienza Università di Roma, Physics, Roma, Italy, 2INFN, Sezione di Roma, Roma, Italy

The Large-Scale Polarization Explorer is a coordinated ground-based and balloon-borne effort to measure
Cosmic Microwave Background (CMB) polarization at the largest angular scales, where cosmic inflation left its
imprint in the form of a curly pattern (B-modes) of linear polarization. In this scenario the measurement of B-
modes represents a way to study physical phenomena happening a split-second within the big bang, at
energies which are not reacheable on Earth. The Short Wavelength Instrument on the Polarization Explorer
(SWIPE) is in an advanced phase of preparation, to be launched from Svalbard in a long-duration stratospheric
flight in the polar-night. The instrument features an array of 330 multi-mode TES bolometers, cooled at 0.3K,
and collecting a total of 8800 modes of the CMB. The frequency bands of the detectors have been selected to
optimize the sensitivity to CMB signals (with a 33% wide band at 140 GHz) while removing efficiently the
polarized dust foregorund (with two 5% bands at 220 GHz and 240 GHz). The detectors are fed by a 50 cm
refractive telescope; polarization modulation is achieved through a magnetically levitating spinning HWP, the
first element in the optical chain. In a two-weeks-long flight flown from Longyearbyen in the polar winter
SWIPE aims at a sensitivity to the tensor to scalar ratio r=0.01, roughly 10 times better than current upper
limits. See http://planck.roma1.infn.it/lspe for info and for the full list of LSPE collaborators.

76
1476
Latest Results from IceCube

Jenni Adams1 (jenni.adams@canterbury.ac.nz)

1
University of Canterbury, Christchurch, New Zealand

The clear ice below the South Pole has proven to be an excellent medium for neutrino detection. In December
2010 the IceCube collaboration completed the deployment of over 5000 optical sensors at depths between
1450m and 2450m below the South Pole surface. The sensors detect the light which is produced when
neutrinos interact in the ice or surrounding bedrock. Soon after completion, the IceCube telescope provided a
breakthrough for the astroparticle community, with the first detection of astrophysical neutrinos reported in
2013. In the ensuing years IceCube has provided many more results over its wide physics portfolio. The success
of IceCube has motivated plans for the extension of the current instrumentation. In this talk I will provide an
overview of the latest results from the IceCube collaboration and the plans for a near-term upgrade to IceCube,
and for a next-generation IceCube-Gen2 detector.

77
2481
The Askaryan Radio Array - Neutrino Astronomy at the South Pole

Albrecht Karle1 (albrecht.karle@icecube.wisc.edu)

1
University of Wisconsin-Madison, Wisconsin IceCube Particle Astrophysics Center, Madison, United States

The glacial ice at the South Pole offers ideal conditions for the detection of high energy neutrinos. The Askaryan
Radio Array seeks to discover extremely high energetic cosmic neutrinos. The goal is to understand the origin of
highest energy cosmic rays and there cosmic accelerators. I will report about new developments, new
instruments deployed in the 2017/18 field season, current results and the vision for a very large array.

78
481
Measurements of Radio Emission of Cosmogenic Neutrinos in the Antarctic Ice

Anna Nelles1 (anna.nelles@gmail.com), The Arianna Collaboration1

1
University of California Irvine, Irvine, United States

The most-energetic atomic particles known today, ultra-high energy cosmic rays, are created in yet unknown
astrophysical objects. A key ingredient to finding their origin will be the measurement of neutrinos of energies
higher than reachable with current detectors. The only feasible way forward is to detect the faint radio
emission that is associated with a neutrino interaction. To obtain the necessary sensitivity several tens of cubic
kilometers of material will have to act as detector. A detector of this size is also likely to be extremely sensitive
to neutrinos from explosive events such as recently observed in gravitational waves. An optimal place for such
a detector is the polar ice, which is transparent for the radio emission in the MHz regime. Several pilot-stage
experiments run in Antarctica to test the necessary hardware and different detector concepts. Following a
number of unexpected observations, also detailed measurements are being performed that aim to study the
propagation of radio waves in the ice, including the possibility of horizontal propagation of signals. We will
report on the current efforts, focusing on the ARIANNA HRA that has been deployed in Moore´s Bay on the
Ross Ice-shelf and the perspectives of radio detection of neutrinos.

79
OS-6b - Polar Ocean Dynamics
19.06.2018 11:00-12:30, A Forum

2241
Why Is Antarctic Bottom Water Disappearing?

Stephen Rintoul1,2,3 (steve.rintoul@csiro.au)

1
CSIRO Oceans & Atmosphere, Hobart, Australia, 2Antarctic Climate & Ecosystems Cooperative Research Centre,
University of Tasmania, Hobart, Australia, 3Centre for Southern Hemisphere Ocean Research, Hobart, Australia

Antarctic Bottom Water (AABW) has warmed, freshened and reduced in volume in recent decades. Changes
are largest near Antarctica but have spread through much of the abyssal ocean. The magnitude of the changes
are sufficient to make a substantial contribution to sea level rise and global energy budgets. However, the
causes of the widespread warming and freshening of AABW remain poorly understood because observations
are sparse near sources of AABW. The natural experiment resulting from calving of the Mertz Glacier Tongue in
2010 provides insight into polynya dynamics and bottom water change. Changes in the regional icescape after
calving reduced the size and activity of the polynya, leading to a sharp reduction in the salinity of dense shelf
water formed in winter. This signal propagated to the deep ocean, where a twenty year time series of abyssal
water properties confirmed a sharp reduction in the density of AABW. Freshening of the dense shelf water
caused warming of the AABW, a result explained by mixing of less dense overflows with ambient waters
offshore. Oxygen levels in the AABW remained high, suggesting that the new lighter variety of AABW was still
sufficiently dense to reach the sea floor and continued to ventilate the abyssal ocean. The results highlight the
sensitivity of AABW formation and ventilation to changes in surface forcing. Early results from a pilot array of
deep Argo floats deployed to track change in AABW properties will be presented.

80
1167
Sources of Southern Ocean Freshening Inferred from Oxygen Isotope Data

F. Alexander Haumann1,2,3 (alexander.haumann@gmail.com), Michael Meredith1, Jorge Sarmiento2, Nicolas

Gruber3, Katherine Leonard4,5
1
British Antarctic Survey, Cambridge, United Kingdom, 2Princeton University, Princeton, United States, 3ETH
Zurich, Zurich, Switzerland, 4University of Colorado Boulder, Boulder, United States, 5EPFL, Lausanne,
Switzerland

Long-term hydrographic observations of Southern Ocean waters reveal a substantial freshening signal in
Antarctic surface, intermediate, mode and bottom waters over recent decades. These changes have been
associated with a redistribution of freshwater by sea ice, an increased glacial meltwater flux from Antarctica,
and a potential increase in precipitation or ocean circulation changes. However, large uncertainties in the
magnitude and spatial pattern of the surface fluxes confound a quantification of their relative contribution to
the observed salinity changes. The stable isotopic composition of the seawater provides an alternative measure
of the contribution from these different freshwater sources, since it carries the characteristic imprint of the
surfaces processes in the source region. We analyze a newly-compiled dataset of salinity and oxygen isotope
samples from the Southern Ocean from the 1970s to the present. In particular, we investigate the hypothesis
that sea-ice freshwater fluxes strongly imprint on water masses formed in the seasonal sea-ice zone, and that
larger signals of meteoric freshwater can be found in water masses formed over the continental shelf and
north of the Subantarctic Front. We discuss decadal changes in these respective contributions, which provide
new insights into the driving processes of recent changes in the Southern Ocean properties and structure.
These changes critically influence its ability to take up anthropogenic heat and carbon.

81
148
Sea Ice Variability and Predictability in the Nansen Basin

Lars Smedsrud1,2 (larsh@gfi.uib.no), Ingrid Onarheim1, Tor Eldevik1, Michael Steel3

1
University of Bergen & Bjerknes Centre, Geophysical Institute, Bergen, Norway, 2University Centre in Svalbard,
Geophysics, Longyearbyen, Norway, 3University of Washington, Polar Science Center / Applied Physics
Laboratory, Seattle, United States

Rapid loss of Arctic sea ice is a clear indicator of climate change. Predicting future change based on mechanistic
understanding of air-ice-sea processes would be desirable in many regards, and this study investigates how
warm Atlantic water directly influences the Arctic sea ice cover. We particularly assesses observed winter sea
ice area variability and predictability in the Nansen Basin where the Atlantic water encounters the Arctic sea
ice. Observations from the Norwegian Young Sea Ice Cruise in winter and spring 2015 show a well-mixed low
salinity surface layer, with its freshwater predominately from sea ice melt moving in tandem with the Atlantic
water below. Rooted in observations, we present a conceptual model to assess the sea ice variability and water
mass transformation in the Nansen Basin. We find that Atlantic water melts approaching sea ice and thereby
transforms into a low salinity surface layer locally. An imbalance between Atlantic heat, heat loss to the
atmosphere, and heat needed for sea ice melt causes variations in the sea ice cover. Based on the proposed
framework, we show that the variability of winter sea-ice area in the Nansen Basin may be skillfully predicted
1-3 years in advance from observed Atlantic water hydrography upstream. The framework generally captures
the observed sea ice variability since the1970s, and we predict that the winter sea-ice cover in the Nansen
Basin will be close to its climatological mean in 2018 and 2019.

82
1526
Connection of the Sea Ice Drift in the Arctic Ocean with the Synoptic Processes

Aleksandra Mushta1 (chipichava@yandex.ru), Vladimir A. Volkov1, Denis M. Demchev1

1
Nansen International Environmental and Remote Sensing Center, Applied Meteorological and Oceanographic
Research for Industrial Activity, St. Petersburg, Russian Federation

The condition of ice formation and the temporal structure of ice cover variability are not homogeneous in the
Arctic ocean and depends on the dynamic processes. Transpolar drift and Beaufort gyre have time cycles with a
predominance of different frequencies in the Eurasian and Amerasian parts of the Arctic Basin. The intensity
and the position of the Transpolar drift and the center of the Beaufort gyre is changing from year to year,
creating the conditions for various ice distribution and ice removal.
Different types of sea ice circulation is formed under the influence of atmospheric pressure and wind fields
over the Arctic Ocean. The survey of predominant synoptic types in each year led us to allocation of the types,
that can create the conditions for ice accumulation (at an agreeable temperature range), for ice removal and
for the sea ice opposition formation.
The authors dissected the long-term changes in the atmospheric circulation and ice drift fields, basing of the
satellite data, the ice drift fields calculation (1979-2016) and synoptic types catalogue, and launched the
estimation of the relationships between ice drift fields changing and variability of the ice cover fluctuations in
the last decades.

83
576
Large Eddy Simulations of the Ice Shelf-ocean Boundary Layer

Madelaine G. Rosevear1 (mmr0@utas.edu.au), Bishakhdatta Gayen2, Benjamin K. Galton-Fenzi3,4

1
University of Tasmania/Institute for Marine and Antarctic Studies, Battery Point, Australia, 2Australian National
University, Research School of Earth Sciences, Canberra, Australia, 3Australian Antarctic Division, Hobart,
Australia, 4Antarctic Climate & Ecosystems Cooperative Research Centre, Hobart, Australia

The rate of melting at the base of an ice shelf is primarily controlled by oceanic processes that occur on very
small scales, namely the diffusive and turbulent fluxes of heat and salt through the viscous and turbulent
regions of the ice-ocean boundary layer. These processes are too small in scale to be resolved in the present
regional ocean models. Instead, heat and mass transport to the ice-ocean interface is parameterised using bulk
transfer coefficients, which determine the interface conditions based on the properties of the ocean interior.
Here we investigate the complex, dynamic processes inside the ice-ocean planetary boundary layer beneath an
Antarctic ice shelf and estimate basal melt rates using resolved Large Eddy Simulations. Fluxes through the
boundary layer are adequately captured, negating the need for parameterisations in the treatment of melting.
We force the simulation with oceanic conditions observed in mooring data from beneath the Amery Ice Shelf.
The resultant melt rate is consistent with the melt rate measured in situ at the same site. These results can be
used to improve the ice-ocean parameterisations in regional ocean models.

84
823
Ice Shelf Meltwater Pump Contribution to Vertical Exchange around Antarctica

Michael Dinniman1 (msd@ccpo.odu.edu), Pierre St-Laurent1, Kevin Arrigo2, Eileen Hofmann1, John Klinck1,
Robert Sherrell3, Sharon Stammerjohn4, Patricia Yager5
1
Old Dominion University, CCPO, Norfolk, United States, 2Stanford University, Palo Alto, United States, 3Rutgers
University, New Brunswick, United States, 4Univ of Colorado, Boulder, United States, 5University of Georgia,
Athens, United States

Satellite estimates of chlorophyll in Antarctic coastal polynyas are strongly correlated with the basal melt rate
of adjacent ice shelves. This has led to speculation that the high productivity of coastal polynyas may be related
to the release of the limiting micronutrient iron from melting ice shelves.
Strong basal melting of ice shelves can drive a vigorous overturning circulation within an ice shelf cavity
("meltwater pump"). We use a high resolution (1.5 km) ocean/sea-ice/ice shelf model of the Amundsen Sea to
examine the effects of this mechanism over the broader Antarctic continental shelf. Four plausible sources of
dissolved iron are simulated with independent tracers, assumptions about the end member concentrations,
and an idealized summer biological uptake. While direct injection of iron from melting ice shelves is an
important contributor to the total dissolved iron supply in the adjacent polynya surface waters, there is an
even larger contribution from "deep" sources of iron on the shelf (sediments and Circumpolar Deep Water).
The Amundsen Sea is not a strong dense water formation region and sensitivity experiments show that the
meltwater pump is far more effective than winter vertical mixing in bringing dissolved iron into the upper
water column. The effect of the meltwater pump on vertical mixing is expected to be heterogeneous around
Antarctica and experiments examining this were performed with a coarser resolution (5 km), circum-Antarctic
model.

85
BE-1b - From boots to bytes: ‘omics’ tools for microbial diversity and biogeography
19.06.2018 11:00-12:30, A Dischma

470
A Computational Pipeline for Taxon, Gene and Allelic Analysis of Microbial Omics

Gilda Varliero1 (gv16363@bristol.ac.uk), Maisie Nash1, Joshua Blacker2, Alex Anesio1, Liane G Benning2,3,4, Gary
Barker1
1
University of Bristol, Bristol, United Kingdom, 2University of Leeds, Leeds, United Kingdom, 3Helmholtz Centre
Potsdam - GFZ German Research Centre for Geosciences, Potsdam, Germany, 4Free University of Berlin, Berlin,
Germany

For environmental studies using high-throughput sequencing technologies, data analysis is now the limiting
step in furthering our understanding of structure and function of microbial communities. There are several
tools that facilitate the visualisation and analysis of such complex data, such as MEGAN and MG-RAST, but
these focus on the taxonomic and high-level (gene ontology) functional annotation of individual shotgun
sequences.
We have developed a pipeline to efficiently annotate assembled metagenome contigs using DIAMOND blast, to
map raw reads back to their identified gene models and to identify significant differential gene abundance
using a flexible General Linear Model. The approach relies on assembling all samples to create a common
reference (metagenome or metatranscriptome) on which all DNA/RNA sequences can be mapped and
quantified. Users can perform taxon and gene-wise statistical analyses of microbial communities and examine
taxon * gene interactions. Differential abundance of functional Single Nucleotide Polymorphisms (SNPs)
between sample factor levels is also included: a hitherto unexplored source of variation.
To demonstrate the utility of this approach and how it can be used to analyse complex data, such as microbial
communities with geochemical data from different biogeographic regions, we present an analysis of microbial
diversity and gene variation in samples from glacial forefield chronosequences collected from Greenland,
Svalbard and Sweden.

86
2065
Keystone Arctic Microbial Genomes Linked to the Dynamics of Phytoplankton Blooms

Marta Royo-Llonch1 (royo@icm.csic.es), Pablo Sánchez1, Carlos Pedrós-Alió2, Tara Oceans Consortium1, Silvia G
Acinas1
1
Institut de Ciències del Mar ICM-CSIC, Marine Biology and Oceanography, Barcelona, Spain, 2Centro Nacional
de Biotecnología CNB-CSIC, Madrid, Spain

Microbial community composition in the north polar waters varies greatly throughout the year. Spring melting
of the ice and increase in light disposal spur the bloom of phytoplankton, taking over the functional and
phylogenetically diverse bacterioplankton communities of dark and cold winter waters. Mainly heterotrophic
and photoheterotrophic bacterial populations feed on the nutrients derived from the phytoplankton bloom
during summer. With fall´s shorter light hours and colder seawater temperatures, the bacterial community
shifts to those chemolithoautotrophic that will prevail during winter. TaraOceans navigated around the north
polar waters extensively sampling the microbial plankton communities during spring, summer and the
beginning of fall (May to October 2013). We have generated around 900 microbial metagenomic assembled
genomes (or MAGs) from the combination of the 41 sequenced metagenomes, which cover the whole polar
circle from spring to the beginning of fall. Together with the physical and chemical information of all stations
we are capable of detecting the distribution of the different keystone prokaryotic taxa around the pole and
through the seasons at maximum resolution possible, at genome level, with a particular focus on the genomics
and metabolic potential of those following the phenology of phytoplankton blooms.

87
694
Biodiversity of Endolithic Communities in Battleship Promontory, Antarctica

Claudia Coleine1 (coleine@unitus.it), Laura Zucconi1, Jason E. Stajich2, Silvano Onofri1, Laura Selbmann1
1
University of Tuscia, Department of Ecological and Biological Sciences (DEB), Viterbo, Italy, 2University of
California, Department of Microbiology and Plant Pathology and Institute of Integrative Genome Biology,
Riverside, United States

The McMurdo Dry Valleys (Southern Victoria Land) constitute the most extensive ice-free area in Antarctica,
represent the coldest, driest and windiest desert on Earth; they are considered the closest Martian analogous
habitat on Earth, exhibiting extraordinary aridity, low temperatures, wide thermal fluctuations, low nutrient
availability, seasonal increased UV radiation, and geographical isolation. In this study, we investigated both
bacterial and fungal components of lichen-dominated communities in Battleship Promontory, McMurdo Dry
Valleys. Nine rock samples were analyzed with a meta-barcoding approach on Illumina platform coupled,
targeting the V4 of 16S and Internal Transcribed Sequence 1 (ITS1) regions for bacteria and fungi respectively.
Taxonomic results, alpha-diversity and statistical analysis were performed to investigate microbial diversity and
community structure to optimize sampling amplitude for a proper and exhaustive biodiversity description.
Preliminary results show a large predominance of phylotypes belonging to the phylum Actinobacteria in
bacterial compartment, while Ascomycota, with the classes Lecanoromycetes and Dothideomycetes prevail
among fungi. Bacterial was higher than fungal richness (517 OTUs and 189 OTUs, respectively); both these
microbial components showed a 'core' of recurrent species (OTUs present in at least 75% of samples) among all
samples.

88
1132
Ice Microbiome: From Antarctic Glaciers to Alpine Ice Caves

Cristina Purcarea1 (cristina.purcarea@ibiol.ro), Corina Itcus2, Constantin Marin3, Soon Gyu Hong4, Victoria I.
Paun1, Aurel Persoiu1, Paris Lavin5, Traian Brad6, Alexandra Hillebrand-Voiculescu3, Denisa Pascu1, Cristian
Coman7, Iris Tusa2, Manuela Sidoroff2
1
Institute of Biology, Romanian Academy, Bucharest, Romania, 2National Institute of Research and
Development for Biological Sciences, Bucharest, Romania, 3Emil Racovita Institute of Speleology, Bucharest,
Romania, 4Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 5University of Antofagasta,
Antofagasta, Chile, 6Emil Racovita Institute of Speleology, Cluj Napoca, Romania, 7Institute of Biological
Research, Cluj Napoca, Romania

Environmental changes due to recent glacier retreat phenomenon are expected to challenge the structural and
functional variability of ice microbiomes, with different impact on specific glacial habitats.
Our comparative study of Antarctic glaciers and Alpine ice cave investigated the bacterial and fungal diversity
from glacier transects and subglacial water flows of Barton and Weaver peninsulas from King George Island,
and a 13,000-years old ice chronosequence of Scarisoara ice cave. Illumina sequencing of 16S rRNA and ITS2
genes indicated major differences in microbial composition correlated with the habitat type, spatial
distribution, geochemistry and age of ice.
Glacier ice showed lower diversity relative to subglacial water and cave ice. Proteobacteria clearly dominated
all Antarctic samples, while the major phylum of cave ice block alternated between Proteobacteria,
Bacteroidetes, Actinobacteria, Firmicutes and Cyanobacteria based on the age, organic content and light
exposure of ice layers. Different Beta/ Gamma-Proteobacteria ratios were specific for Antarctic ice/water and
cave ice of different age. Acinetobacter and Polaromonas prevailed in all Antarctic samples with a relative
abundance depending on sample type and location. Fungal community analyses based on ITS2 sequencing,
currently under way, will complete the comparative microbiomes overview of these icy habitats, and their
response to environmental variables.
Funding: H2020 ELAC2014/ DCC0178 and PN16190105

89
1128
Metabolic and Community Changes Underpinning life Phase Transition of Snow Algae

Matthew Davey1 (mpd39@cam.ac.uk), Lloyd Peck2, Peter Convey2, James Blake2,3, Peter Fretwell2, Alison
Smith3
1
University of Cambridge, Cambridge, United Kingdom, 2British Antarctic Survey, Cambridge, United Kingdom,
3
University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom

Snow algae communities consist mainly of green algal species of the genera Chlamydomonas and Chloromonas.
They have a bi-phasic life cycle consisting of an active reproductive motile stage, seen as green patches in the
snow, and a dormant encystment phase during which the cells accumulate the red keto-carotenoid
astaxanthin, giving rise to red snow patches. We measured the metabolic composition of snow algae in both
green and red phases, from samples taken in the field at various locations in Antarctica during the 2014/15 and
2017/18 austral summer seasons. We also determined the community composition of the blooms using 16S
and 18S metagenomic sequencing. Our data showed that the metabolic composition of the cells was the same
from four geologically distinct but spatially close locations in the vicinity of Ryder Bay (Adelaide Island, 68°S).
However, our data also show a high degree of patchiness in the snow melt between the locations where snow
algae communities occurred, from mean values of 0.5 g dry algae per L of snow melt at Lagoon Island to 3.25 g
dry algae per L of snow melt at Léonie Island. Our metabolite data showed that the snow algae were rich in
unsaturated fatty acids and that metabolomic assays could detect detailed changes in lipid, carbohydrate and
protein chemistry in the cells during encystment. These Antarctic data are compared to similar community
studies carried out in Arctic ecosystems.

90
SH-1 - Environmental Protection, Resource Rights and Evolving Geopolitics in Antarctica
19.06.2018 11:00-12:30, A Sertig

59
The Legal Grounds of Territorial Claims in Antarctica: A Sober Assessment

Alejandra Mancilla1 (alejandra.mancilla@ifikk.uio.no)

1
University of Oslo, Philosophy, Oslo, Norway

By virtue of the Antarctic Treaty, the territorial claims made by seven countries over the continent in the
previous decades were “frozen”. Putting the question of sovereignty on hold, the Treaty and its related legal
instruments came to be considered over the years as a diplomatic success, allowing peaceful cooperation in the
continent, built around science and with the protection of the environment at its core. Notwithstanding, the
original claimant countries have never surrendered their territorial aspirations, and they have been actively
engaged in antarctic matters, signaling their ongoing interest through the establishment of bases, the
organization of scientific expeditions, active participation in the ATMs, and so on and so forth. In this
presentation, I examine the legal instruments and doctrines upon which these countries grounded their claims,
and assess them from a normative perspective. I inquire, that is, into their reasonableness and legitimacy both
then and today. Old international treaties, unilateral declarations and later transfers based on them, as well as
international law doctrines tailor-made for imperialist powers—like contiguity and continuity—played a key
role founding these countries' aspirations. But do they withhold scrutiny? I suggest that they do not, and that a
sober evaluation of them would dramatically reduce their scope. I conclude with some thoughts on how this
should lead us to rethink the territorial status of most of the White Continent.

91
366
Property Rights: A Solution to the Tragedy of the Commons in Antarctica?

Yelena Yermakova1 (yy646@cornell.edu)

1
University of Oslo, Oslo, Norway

Antarctica brings to many minds an image of a peaceful no man's land: pristine environment and scientific
cooperation. However, the reality is that Antarctica is one of the least environmentally protected regions on
the planet: only 1.5% of the ice-free habitats on the continent are designated as specially protected areas.
Unresolved territorial claims in Antarctica create a jurisdictional vacuum that leads to one of the worst cases of
the tragedy of the commons. Climate change and improvements in technology foreshadow future exploration
and exploitation of Antarctic resources. To avoid potential conflict there is a need for a normative guidance for
management of natural resources on the seventh continent. This paper builds upon Dr. Margaret Moore's work
on the theory of territory in unoccupied areas. Dr. Moore suggests that the question of “unclaimed” territory in
Antarctica should not be seen as a territorial dispute, but rather a property one. She argues that resources in
unoccupied territories have instrumental value and should be regarded as property. This paper discusses some
practical implications of applying this property conception to the management of natural resources in
Antarctica and whether doing so would strengthen environmental protections. The paper investigates potential
roles that stakeholders other than nations, such as the private sector and international organizations, would
play in the governance of natural resources in the property-rights scenario.

92
651
Protection of Antarctic Historic Sites and Monuments by Domestic Law

Gustavo Ramirez Buchheister1,2 (gusramirezb@gmail.com)

1
Universidad de Magallanes, Departamento de Ciencias Jurídicas, Punta Arenas, Chile, 2Philipps-Universität
Marburg, Fachbereich Rechtswissenschaften, Marburg, Germany

In February of 2014 a 'historic first' in Antarctic Environmental Protection occurred: two visitors to Antarctica
were tried and condemned to pay a fine of ten thousand Euros each, due to the damage caused to an object of
protection by the Madrid Protocol: A Historic Site or Monument. This outcome, however, is not product of a
direct enforcement of a provision of the Protocol -a non-self-executing agreement-, but rather the
implementation of an Antarctic Treaty-Party's domestic law. Article 13 of the Protocol requires Parties to take
appropriate measures within their competence to comply with it, including laws and regulations. On the other
hand, Annex V regulates Antarctic Specially Protected and Managed Areas, which include Historic Sites and
Monuments.
Would the outcome have been similar if the case had been tried by another Party? Is the protection of Historic
Sites and Monuments effectively implemented by domestic law? Is there room for improvement? Could ATCM
measures or recommendations broaden the protection of these sites?

93
2429
Environment Protocol Challenges and Achievements: 20 Years in force

Luis Valentin Ferrada1 (lvferrada@derecho.uchile.cl)

1
Universidad de Chile, Facultad de Derecho, Departamento de Derecho Internacional, Santiago, Chile

The Protocol on Environmental Protection to the Antarctic Treaty was signed in 1991 and entered into force in
1998. Its adoption was a reaction to the environmental damage risks of the mineral activities regulated by the
Convention on the Regulation of Antarctic Mineral Resource Activities (signed in 1988, not yet in force). But it is
also a result of the Antarctic Treaty System long-time evolution. The Protocol is a milestone in this international
regime putting the environmental protection as a central aim of it.
Since 1991 and more clearly since 1998, important advances in this task have been achieved: the establishment
of a group of environmental principles (article 3), the prohibition of mineral resource activities (article 7), the
prior assessment of the environmental impacts of major activities (article 8), the establishment of the
Committee for Environmental Protection (articles 11 y 12), or the environmental inspections (article 14).
However, there are still several challenges. Some of them are results of the Protocol structure like the activities
that are not covered by it or its geographical scope or the number of States for whom it is compulsory. Others
come from the new and changing environmental problems that it is necessary to confront. Finally, some come
from the implementation of the Protocol itself and how the national domestic law applies its regulations and
control its fulfillment.
All this challenges and achievements will be discussed.

94
2606
How Should We Justify Ecologically Sustainable Resource Rights in Antarctica?

Øyvind Stokke1 (oyvind.stokke@uit.no)

1
UiT The Arctic University of Norway, Department of Philosophy, Tromsø, Norway

How should we justify resource rights within a cryosphere that is being transformed as a result of
anthropogenic climate change? In light of the increasing environmental pressure on Antarctica in terms of ice-
melt, illegal, illegal, unreported and unregulated fishing, as well as tourism, we need to rethink our way of
theorising both territory and the legal regimes that govern it. This paper argues that territorial claims in
Antarctica have to fulfil certain conditions of environmental responsibility and distributive justice. More
specifically we need to
1) question the connection between political self-determination and the claims to huge territories in the Polar
regions, and
2) rethink the justification of resource rights under conditions of extreme environmental vulnerability.
The Earth's natural resources and ecosystems are an environmental commons, and hence access to this
commons and its services should be shared. However, several of the claimants in Antarctica are taking more
than their fair share of these commons, especially in terms of carbon emissions. Consequently, any principle of
ecological justice in Antarctica has to include some sort of benefit-sharing mechanism to ensure that any given
claimant state realises its desired capabilities with the lowest impact on ecosystems. I end by scrutinising to
what extent the justifications in the Antarctic Treaty could ground ecologically sustainable resource rights.

95
GG-2b - Arctic and Antarctic past ice sheet dynamics and paleoclimate evolution
19.06.2018 11:00-12:30, A Schwarzhorn

2588
Multiple Evidence for Early Deglacial Ice Mass Loss in East and West Antarctica

Michael E. Weber1 (mike.weber@uni-bonn.de), Christopher J. Fogwill2, Matthew Decesare3, Nicholas R.

Golledge4, Natalya Gomez5, Peter U. Clark6
1
University of Bonn, Bonn, Germany, 2Keele University, Staffordshire, United Kingdom, 3Louisiana State
University, Baton Rouge, United States, 4Victoria University of Wellington, Wellington, New Zealand, 5McGill
University, Montreal, Canada, 6Oregon State University, Corvallis, United States

Based on recent studies conducted on well-dated deep-ocean, near-shelf- and ice-core records from both West
and East Antarctica, we show clear evidence for a very dynamic deglacial behavior o the Antarctic Ice Sheet
(AIS) with multiple retreat events in sync with global meltwater and climate events, contrary to scenarios
developed earlier (e.g., Bentley et al., 2014).
Highly resolved deep-ocean records from Iceberg Alley indicate major AIS discharge events (AID) bracketing
Meltwater Pulse 1A (AID6) and 1B (AID2), between ~14.7 - 11.3 ka (Weber et al., 2014). Also, a blue-ice field in
the Patriot Hills area indicates marked AIS draw down (in excess of 650 m) and ice mass loss across the Weddell
Sea Embayment during the Antarctic Cold Reversal (ACR, 14.7 - 12.7 ka) (Fogwill et al., 2017). Foraminiferal
radiocarbon ages from shallow-marine sediment archives in the eastern Ross Sea (DeCesare et al., submitted)
directly constrain discrete intervals of WAIS grounding line retreat of 30 km at 14.7 ka (AID6) and 200 km at
11.5 ka (AID2).
The data evidence combined with thermodynamic ice-sheet modeling (Golledge et al., 2014, 2017), confirm
that the AIS was highly-dynamic and sensitive to ocean warming and/or sea level forcing that allowed rapid
retreat of ice margins into the interior of the ice sheet. Our findings are important in light of current discussions
on potential AIS collapse in the near future and its impact on sea-level rise for the coming decades to centuries.

96
2664
Northern Hemisphere Influence on Antarctic Ice Dynamics during Last Deglaciation

Natalya Gomez1 (natalya.gomez@mcgill.ca), Gabriel Tseng1, Michael Weber2, Peter U. Clark3

1
McGill University, Earth and Planetary Sciences, Montreal, Canada, 2University of Cologne, Institute of Geology
and Mineralogy, Cologne, Germany, 3Oregon State University, College of Earth, Ocean, and Atmospheric
Sciences, Corvallis, United States

Recent work suggests that the Antarctic Ice Sheet was highly dynamic during the Last Deglaciation. Weber et al.
(2014)'s analysis of iceberg-rafted debris in ocean sediment cores from Iceberg Alley shows that Antarctic
deglaciation was punctuated by a series of rapid ice discharge events (AIDs). An ocean thermal forcing has been
proposed, but triggers for these events and their connection to global ice and climate changes are still being
explored. There was up to ~130 m global mean sea level equivalent of additional grounded ice cover globally at
the Last Glacial Maximum. The majority of this ice was in the Northern Hemisphere (NH), but there remains
significant uncertainty in the timing and distribution of global ice cover during the Deglaciation. Rapid pulses of
ice loss occurring in the NH that are not fully resolved in the geological record could have raised sea level in
Antarctica significantly. We adopt the coupled dynamic ice sheet - global sea level model described in Gomez et
al. (2013) to investigate the possibility that the AID events observed in Antarctica could have been triggered or
enhanced by pulses of sea-level rise associated with NH ice loss. We present results of simulations of Antarctic
ice sheet evolution through the Deglaciation driving by climate changes and a suite of punctuated NH ice
histories, and highlight the possibility of inter-hemispheric teleconnection through a sea level feedback on
marine ice dynamics.

97
1889
Weddell Sea Embayment Deglaciations Traced by Provenance of Ice-rafted Debris

Trevor Williams1 (williams@iodp.tamu.edu), Sidney R. Hemming2, Kathy Licht3, Liana Agrios3, Tina van de
Flierdt4, Claus-Dieter Hillenbrand5, Werner Ehrmann6, Yue Cai2, Alison Corley2, Gerhard Kuhn7
1
Texas A&M University, International Ocean Discovery Program, College Station, United States, 2Lamont-
Doherty Earth Observatory of Columbia University, Palisades, United States, 3IUPUI, Earth Sciences,
Indianapolis, United States, 4Imperial College, London, United Kingdom, 5British Antarctic Survey, Cambridge,
United Kingdom, 6Inst fuer Geophysik & Geologie, Leipzig, Germany, 7Alfred Wegener Institute, Bremerhaven,
Germany

Here we present iceberg-rafted debris (IRD) provenance records from sediment core PS1571-1 in the NW
Weddell Sea, and interpret these records in terms of the geographic sequence of ice sheet retreat in the
Weddell Sea embayment during the last three deglaciations. We first characterize the geochemical and
geochronological fingerprint of eroded debris from the source areas using: 1. Till in modern moraines at the
edges of the Foundation Ice Stream, the Academy Glacier, and the Recovery Glacier; and 2. Subglacial till from
cores along the front of the Filchner and Ronne Ice Shelves. Provenance tracers include 40Ar/39Ar hornblende
and biotite thermochronology, U-Pb zircon geochronology, Nd isotopes, and clay mineralogy. Results so far
indicate that samples along the front of the ice shelves record the fingerprint that would be expected from
tracing ice flow lines back to the upstream bedrock terranes, and that the Ronne (west), Hughes (central), and
Filchner (east) sectors have distinguishable provenance source fingerprints. In core PS1571-1, changes in IRD
provenance reflect output of debris-laden icebergs during ice sheet retreats from the different sectors of the
embayment through each deglaciation. Preliminary indications are that different sectors of the embayment
tend to export glacially-eroded debris sequentially, rather than all at the same time, and that MIS-5 has more
of a West Antarctic fingerprint than the other deglaciations.

98
826
Ross Sea Deglaciation - Environmental Reconstruction from the RICE Ice Core

Nancy A.N. Bertler1,2 (nancy.bertler@vuw.ac.nz), Howard Conway3, Dorthe Dahl-Jensen4, Giovanni Baccolo5, W.
Troy Baisden2, Thomas Blunier4, Edward Brook6, Christo Buizert3, Lionel Carter1, Ruzica Dadic1, Babara
Delmonte5, Ross Edwards7, Lukas Eling1,2, T. J. Fudge3, Nicholas Golledge1,2, Richard C. A. Hindmarsh8, Katelyn
Johnson1,2, Elizabeth Keller2, Jonathan Kingslake9, Sepp Kipfstuhl10, Helle A. Kjær4, Elena Korokikth11, Andrei
Kurbatov11, James E. Lee12, Dan Lowry1, Paul A. Mayewski11, Robert McKay1, Laurie Menviel13, Timothy Naish1,
Peter Neff14, Rebecca E. Pyne2, Reed P. Scherer15, Jeffrey P Severinghaus16, Marius Simonsen4, Eric J. Steig3,
Abhijith Ulayottil Venugopal1,2, Paul T. Vallelonga4, Edwin D. Waddington17, Mai Winstrup4, Cunde Xiao18,
Dongqi Zhang19,20
1
Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand, 2GNS Science, Lower
Hutt, New Zealand, 3University of Washington, Seattle, United States, 4Niels Bohr Institute - University of
Copenhagen, Copenhagen, Denmark, 5University of Milano-Bicocca, Department of Earth and Environmental
Sciences, Milano, Italy, 6Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Covallis,
United States, 7University of Curtin, Perth, Australia, 8NERC British Antarctic Survey, Cambridge, United
Kingdom, 9Columbia University, Department of Earth and Environmental Sciences, New York, United States,
10
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 11Climate
Change Institute, University of Maine, Orono, United States, 12Oregon State University, College of Earth, Ocean
and Atmospheric Sciences, Corvallis, United States, 13n.a., Sydney, Australia, 14University of Rochester,
Rochester, United States, 15Northern Illinois University, Dekalb, United States, 16Scripps Institution of
Oceanography, University of California, San Diego, United States, 17University of Washington, Seattle, New
Zealand, 18State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing, China, 19State Key
Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Beijing, China,
20
Chinese Academy of Sciences, Lanzhou, China

The Roosevelt Island Climate Evolution (RICE) project recovered a 763.6 m deep ice core to bedrock during
2011-2013 from Roosevelt Island (RI), at the northern edge of the Ross Ice Shelf. The ice at RI is grounded 210
m below sea level and accumulates in situ, with the Ross Ice Shelf flowing around the rise. High resolution
radar surveys show well-developed Raymond Arches of isochrones suggesting a stable ice divide.
Here, we show isotope and geochemical data spanning the past 30 ka and discuss reconstructions of sea
surface and air temperature, sea ice extent, atmospheric circulation patterns, and ice shelf grounding line
retreat. An ensemble of sensitivity modelling experiments is used to determine thresholds for the removal of RI
ice and correlated grounding line and ice volume changes of the Ross Ice Shelf and the West Antarctic Ice
Sheet.
Our data suggest that the onset of the Ross Ice Shelf grounding line retreat during the deglaciation was driven
at least in part by the early deglaciation in West Antarctica as recorded in the WAIS Divide ice core, perhaps
through a freshwater feedback. The Ross Ice Shelf grounding line started to retreat rapidly with the initiation of
an ice shelf cavity. Atmospheric circulation changes precede the onset of the Antarctic Cold Reversal (ACR) by
about 200 years. Maximum ACR sea ice extent is reached at the termination of the ACR and is maintained into
the early Holocene, a time period of rapid atmospheric warming and circulation changes.

99
626
Totten Glacier History in Continental Slope Sediments, East Antarctica

Phil O'Brien1, Leanne Armand2 (leanne.armand@anu.edu.au), Amy Leventer3, Bradley Opdyke2, Alix Post4,
Andrea Caburlotto5
1
Macquarie University, Dept of Environmental Sciences, North Ryde, Australia, 2Australian National University,
Research School of Earth Sciences, Acton, Australia, 3Colgate University, Dept of Geology, Colgate, United
States, 4Geoscience Australia, Canberra, Australia, 5Istituto Nazionale di Oceanografia e di Geofisica
Sperimentale, Trieste, Italy

Developing an understanding of how the Antarctic Ice Sheet responds to climate change will require data from
the continent's major drainage basins, records that cover multiple glacial cycles and data on how the ocean and
ice sheet interact. To achieve this coverage, sediment cores from the Antarctic continental slope will be
needed. The Totten Glacier is a large outlet glacier in East Antarctica which is potentially vulnerable to
accelerated melting. The glacier occupies a trough that extends deep into the East Antarctic interior and has
displayed rapid thinning, which could draw down of some of the thickest ice in Antarctica. The 2017 Sabrina
Seafloor Survey aimed to collect palaeoclimate records from the continental slope seaward of the Totten
Glacier to study the interactions of this part of the ice sheet and the Southern Ocean over multiple glacial
cycles. Multibeam bathymetry surveying identified large sediment ridges separating submarine canyons. Ridge
morphology and seismic stratigraphy suggest that they are composed of canyon overbank deposits. Six long
piston cores and 11 Kasten cores were collected. Five of the six piston cores contain cyclic sedimentary facies
indicating records going back to Marine Isotope Stage 10 (~350ka.). A single core was aimed at a condensed
section and may have sampled Pliocene to Early Pleistocene sediments. Preliminary analysis of the cores
suggests that each glacial-cycle sampled has unique features.

On behalf of the Sabrina Seafloor Shipboard Party, Australian National University, Acton, Australia

100
Tue_280_GG-2_1479
Holocene Climate Evolution off Northern Victoria Land, East Antarctica

Olivia Truax1,2 (olivia.truax1@gmail.com), Christina Riesselman1,2, Gary Wilson2, Rebecca Parker3, Kyu-Cheul
Yoo4, Jae Il Lee4, Richard Levy5, Robert McKay6
1
University of Otago, Geology Department, Dunedin, New Zealand, 2University of Otago, Marine Science,
Dunedin, New Zealand, 3University of Exeter, Exeter, United Kingdom, 4Korea Polar Research Institute (KOPRI),
Incheon, Korea, Republic of, 5GNS Science, Wellington, New Zealand, 6Victoria University of Wellington,
Wellington, New Zealand

Regionally representative records of how the Antarctic climate system evolved through the Holocene are an
essential component of understanding the processes that drive the Antarctic climate. We present a high-
resolution multi-proxy record of Antarctic paleoclimate evolution during the last 7,200 yr from a sediment core
retrieved by the RV/IB Araon from Robertson Bay, a previously unstudied sector of the Victoria Land Margin.
Using diatom assemblages, bulk sediment geochemistry, and the magnetic properties of RS15-GC57, we
reconstruct Holocene climate variability at the interface between the East Antarctic Ice Sheet and the Southern
Ocean.
A rapid transition at ~3,500 cal yr BP, constrained using novel ramped pyrolysis 14C dating, is evident in all
environmental proxies and is coincident with the Hypsithermal-Neoglacial transition recorded in sediment
cores from Adélie Land, the Ross Sea, and the Antarctic Peninsula. A sea ice-associated diatom assemblage
characterizes a discrete interval from 700 cal yr BP to modern, suggesting an environmental response to the
Little Ice Age at the northern margin of the EAIS. High frequency (80-350yr) environmental variations,
attributed to solar variability in previous marine Antarctic studies, are superimposed onto these millennial scale
regional trends. Preliminary analysis suggests that changes in westerly wind stress and the upwelling of
Circumpolar Deep Water were a primary driver of late Holocene climate dynamics in the Antarctic.

101
BE-3b - Polar perspectives on microbial evolution, adaptation, and ecological function
19.06.2018 11:00-12:30, A Seehorn

633
Temperature-driven Structure and Activity of the Global Ocean Microbiome

Guillem Salazar1 (guillems@ethz.ch), Tara Oceans Consortium1, Shinichi Sunagawa1

1
ETH Zurich, Department of Biology, Zurich, Switzerland

Marine microbes cope with a variety of environmental gradients that may impact their global distribution and
their metabolic state. Previous studies have shown that the distribution and structure of microbial
communities in low and mid latitudes are largely governed by temperature. Temperature is thus one of the
major environmental factors that marine microbes will need to respond to. Given that the rate of seawater
temperature change is particularly high in polar regions, a better understanding of microbial responses to
temperature change is crucial. Here we analyze a dataset composed of 367 epipelagic and mesopelagic
metagenomes and metatranscriptomes from the Tara Oceans Expedition (2009-2013). Sample collection sites
are distributed across all main oceanic regions, covering a 143° latitudinal range, and includes a focused
sampling effort from a circumnavigation of the Arctic Ocean. We describe a universal relationship between
seawater temperature and the structure of microbial communities, which is consistent across the entire
temperature gradient (-1.6 to 30.6º C). We define cold-adapted taxa and explore metabolic capacities that are
enriched in cold waters using metagenomic data. We combine these data with metatranscriptomic information
to analyze how metabolic potential and activities vary across the global ocean. The results are expected to help
us predict how microbial communities will respond to the impact of climate change.

102
2151
Functional Responses of Microbial Mat Communities in Glacial Meltwater Streams

Angela Zoumplis1 (azoumplis@gmail.com), Andrew Allen1,2

1
Scripps Institution of Oceanography, La Jolla, United States, 2J. Craig Venter Institute, La Jolla, United States

The McMurdo Dry Valleys are considered a Martian analog environment due to extremes in aridity, high-speed
winds and low temperatures. Life in this environment survives an absence of water for around 9 out of 12
months and is primarily comprised of cyanobacteria mats that harbor bacteria, eukaryotic algae, and micro-
invertebrates. During the austral summer, rising temperatures cause glacial melting and streams of freshwater
begin to flow downward through the valleys carrying alluvium and rehydrating cyanobacteria mats.
Temperature fluctuations of the meltwater streams reach anywhere from 0.1 °C to a maximum of 15 °C with
daily shifts between 6°C-9°C. Von Guerard is one of the longest streams (4.9km) in the Taylor Valley, Antarctica
and has a record of high interannual stream flow variability. Microbial mat samples from Von Guerard were
collected early summer before flow started and continued on a weekly basis until the stop of flow in late
summer. This study shows the transcriptional responses of the Von Guerard microbial mat communities
compared through the start and end of the season with the inclusion of stream discharge, water/air
temperature and conductivity data. Transcriptional profiles under low temperatures and frozen conditions
display an upregulation of known stress response genes. This investigation is the first to determine in situ
function of Dry Valley transient stream microbial communities through a whole melt season.

103
2188
Sulphur Cycling and Microbial Dynamics along a Glacial-oceanic Transect

Daniel Aagren Nielsen1 (danielaagrennielsen@gmail.com), Jean-Baptiste Raina1, Mark Vincent Brown2, Justin
Seymour1, Katherina Petrou1
1
University of Technology Sydney, Broadway, Australia, 2University of New South Wales, Randwick, Australia

Antarctica has been identified as a hot spot of organic sulphur cycling and ocean-atmospheric sulphur fluxes.
Organic sulphur compounds, such as dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) produced
by Antarctic phytoplankton affect marine food-web interactions, which are key to marine sulphur cycling and
flux dynamics. This study examined Antarctic phytoplankton-bacteria associations and their influence on
marine sulphur cycling along a coastal transect from an inner fjord of the Sørsdal glacier to the open ocean.
Phytoplankton abundance increased with distance from the glacier, while community composition remained
fairly constant. There was a corresponding increase in DMSP concentrations toward the open ocean, likely
attributed to the increased biomass. Through combining nutrient dynamics, 16S next generation sequencing
and qPCR, we aim to understand the way in which these observed patterns link to bacterial community
composition and specific sulphur-metabolising genes and how environmental gradients produced from glacial
runoff influences marine microbial communities and sulphur cycling.

104
2283
The Colonisation and Selection Processes Shaping Frost Flower Communities

Rose Emma Layton1 (r.layton@enoveo.com), Timothy Vogel1, James France2, Catherine Larose1
1
École Centrale de Lyon, Laboratoire Ampère, Lyon, France, 2University of East Anglia, Environmental Sciences,
Norwich, United Kingdom

The temporal and spatial coverage of frost flowers on sea ice is expected to increase in the Arctic in line with
the predicted impact of climate change, and yet, their ecological, biogeochemical and climatic roles are poorly
understood. Frost flowers have been shown to host distinct microbial communities relative to the underlying
sea ice, sea water and brine as a result of selective colonisation processes. To explore the mechanisms
influencing frost flower community structure and the potential of atmospheric deposition as a colonisation
route, sea ice and frost flowers were cultivated from sea water in the Roland von Glasow sea ice chamber at
the UEA, UK. Samples were subsequently subjected to 16S rRNA gene and metagenomic sequencing. The
community structure and the extent of the mobile gene pool were analysed. The formation of multiple niches
within the ocean-sea ice-atmosphere profile is probably responsible for shaping the community structure.
Metagenomic sequencing revealed an enrichment in mobile genetic elements that are suspected to contribute
to the rapid adaptation of microorganisms to alien microhabitats. These results provide novel insights into
poorly characterised ecosystems with increasing global significance in terms of their role in biogeochemical
cycling. In addition, the mechanisms involved in the colonisation of microorganisms throughout sea ice
formation can be deciphered with the metagenomic data.

105
2376
Antarctic Cyanobacteria and Toxins in Captain Scott's Discovery Microbial Mats

Anne D. Jungblut1 (a.jungblut@nhm.ac.uk), Ian Hawes2, Geoffrey A. Codd3,4, James S. Metcalf3,5, Jo Wilbraham1
1
Natural History Museum London, London, United Kingdom, 2University of Waikato, Tauranga, New Zealand,
3
University of Dundee, Dundee, United Kingdom, 4University of Stirling, Sterling, United Kingdom, 5Institute for
Ethnomedicine, Jackson, United States

Climate models predict that Antarctica will warm more rapidly than many other parts of the globe, and more
widespread warming of continental Antarctica is expected to accelerate. Much of the productivity and
biodiversity is linked to benthic cyanobacteria-based microbial mat communities. However, to identify and
forecast biological responses to environmental change, baseline data is essential to understand the level, and
time scales over which environmental change affects community assemblages and functioning such as
cyanotoxin production. We carried out cyanobacteria-specific 16S rRNA gene high throughput sequencing and
cyanotoxin analysis of freshwater cyanobacterial mats collected in 1902-03 during Captain Scott's Discovery
expedition in Antarctica. We found that historic cyanobacteria assemblages showed some variation in
community structure to modern cyanobacterial mats, but were dominated by the same genotypes. It suggests
slow cyanobacterial genotype turnover and considerable community stability. Ultra-performance liquid
chromatography-photodiode array detection and tandem mass spectrometry identified microcystins at
concentrations from 0.5 to 16.1 µg g-1 dry weight. BMAA (β-N-methylamino-L-alanine) and its isomers were
found for the first time in Antarctic cyanobacteria. The results demonstrate the value and potential of historic
cyanobacteria collections in temporal investigations of cyanobacteria, freshwater ecosystems and clima in
Antarctica.

106
2488
Metagenomics and Viromics of the Mackay Glacier Ecotone

Marc Van Goethem1 (mwvangoethem@gmail.com), Surendra Vikram2, Evelien Adriaenssens3, Rolf Kramer2,
Don Cowan2, Thulani Makhalanyane1
1
University of Pretoria, Centre for Microbial Ecology and Genomics, Department of Genetics, Pretoria, South
Africa, 2University of Pretoria, Genetics, Pretoria, South Africa, 3University of Pretoria, Pretoria, South Africa

Climatic variations will have profound effects across the cryosphere. Ecotones are susceptible regions, and are
defined as boundaries between adjacent ecosystems. Macro-organisms within ecotones are sensitive to
variations in climate - which have potentially long-lasting impacts. Here we show, for the first time, that
microbial and viral communities within ecotones can be analysed to monitor biological changes resulting from
warming. Collectively, we show that the Mackay Glacier ecotone, Eastern Antarctica represents a distinct
ecosystem compared to the McMurdo Dry Valleys. We found soil respiration to be an order of magnitude
lower in the ecotone than surrounding bioregions, likely the result of extremely low soil nutrient contents and
soil stoichiometric imbalance. Isotope data indicate that soil carbon is transformed via the Calvin cycle, while
soil nitrogen is recurrently assimilated in situ. These trends were supported by in silico gene analyses of 18
assembled metagenomes, which showed a prevalence of these carbon and nitrogen cycling pathways. These
mechanisms are driven by dominant chemosynthetic heterotrophic bacteria of the Bacteroidetes and
Acidobacteria. Site altitude was the strongest predictor of microbial community structure, which was also
shown to drive viral populations within the ecotone. Finally, we show that viral population constitute the
lowest trophic tier of Antarctic soil communities, and interact with their hosts to maintain diversity and
function.

107
TE-3b - Remote sensing of polar regions
19.06.2018 11:00-12:30, A Wisshorn

134
Comparing L- and C-band Synthetic Aperture Radar Estimates of Sea Ice Motion

Stephen Howell1 (stephen.howell@canada.ca), Alexander Komarov2, Mohammed Dabboor3, Benoit Montpetit2,

Michael Brady1, Randy Scharien4, Mallik Mahmud5, Vishnu Nandan5, Torsten Geldsetzer5, John Yackel5
1
Environment and Climate Change Canada, Toronto, Canada, 2Environment and Climate Change Canada,
Ottawa, Canada, 3Environment and Climate Change Canada, Montreal, Canada, 4University of Victoria, Victoria,
Canada, 5University of Calgary, Calgary, Canada

Estimating sea ice motion from synthetic aperture radar (SAR) imagery at C-band is the most reliable approach
because of its high spatial resolution and ever increasing temporal resolution given the multiple current and
upcoming SAR platforms. However, there is still uncertainty in SAR derived sea ice motion depending on the ice
type and its thermodynamic state. There have been suggestions (mostly theoretical) that use of L-band SAR
and its inherent longer wavelength (15-30 cm) and subsequent increased penetration capability could be
beneficial for estimating sea ice motion, especially during the melt season. Here, we estimate and analyze sea
ice motion for 9 pairs of C- and L-band SAR imagery from RADARSAT-2, PALSAR-1 and PALSAR-2 located in the
Canadian Arctic over a variety of sea ice types at different thermodynamic states. Results show that the
increased signal penetration of L-band SAR into multi-year ice (MYI) during the melt season facilitates the
detection of more motion vectors with stronger cross-correlation coefficients compared to C-band SAR. Over
newly formed ice and dry first-year ice, the reduced sensitivity to surface scattering and richer texture from L-
band SAR imagery facilitates the detection of more motion vectors with stronger cross-correlation coefficients
compared to C-band SAR. Over dry MYI, L-band provided stronger cross-correlation coefficients but C-band
detected more motion vectors with a more representative spatial distribution.

108
1196
ZY-3 Multi-view Satellite and Its Applications in Antarctica Remote Sensing

Shijie Liu1,2 (liusjtj@tongji.edu.cn), Chenxi Wu1,2, Haifeng Xiao1,2, Xiaohua Tong1,2, Rongxing Li1,2
1
Center for Spatial Information Science and Sustainable Development Applications,Tongji University, Shanghai,
China, 2College of Surveying and Geo-Informatics, Tongji University, Shanghai, China

ZY-3 is the first civilian high-resolution stereo mapping satellite of China, launched in January, 2012. It is
equipped with a three-line-scanning camera system to build along track and quasi-real-time (~30 seconds)
stereo pairs by a combination of forward, nadir and backward looking images. The along track stereo mapping
technique has the advantages of quasi-real-time capturing of the 3D ground movement . The satellite was first
time programmed in February 2014 to adjust its sensor parameters to fit the Antarctic setting and collected a
collection of Antarctic stereo images for a number of selected sites. Two typical applications in Antarctica
remote sensing by using ZY-3 images are investigated. First one is the detection and speed estimation of large
scale blowing snow, for which we proposed a stereo photogrammetric technique. Blowing snow is referred as
the phenomenon of uplift and horizontal transport of snow by wind. It occurs frequently in Antarctica and is
important in many aspects including surface mass balance and surface morphology. The second application is
3D modelling of ice shelf rifts, which are a precursor to iceberg calving. The 3D models of a newly detected
large rift in Filchner Ice Shelf from ZY-3 stereo images revealed important topographic information (rift length,
width, depth, wall and mélange) that can be used to improve the reliability of ice shelf modeling and support
enhanced analyses of ice shelf stability.

109
1465
Snow Deposition Characteristics at Union Glacier by SAR and Geospatial Analysis

Christian Gobel1,2 (cfgobel@gmail.com), Jorge Arigony-Neto1,2, Ricardo Jaña3

1
Federal University of Rio Grande, Oceanographic Institute, Rio Grande, Brazil, 2Instituto Nacional de Ciencia e
Tecnologia da Criosfera, Porto Alegre, Brazil, 3Instituto Antárctico Chileno, Punta Arenas, Chile

Surface mass balance is a key component to assess the net contribution of the ice sheet to the ocean. A precise
quantification of the accumulation processes as snow precipitation and wind transport and deposition of snow
is required. Union Glacier (UG) is an outlet glacier at the Ellsworth Mountain Range and drains into the Ronne-
Filchner Ice Shelf. Previous studies agree that mean surface mass balance for this glacier range from 0.18 to
0.33m a-1. Although it seems a good estimation, they do not represent spatial variability in snow deposition
due to: (i)topographic relief; (ii)wind driven accumulation; and (iii)sublimation rate. Our aim is to identify and
delimitate different deposition zones on the glacial drainage basin of UG. Thus, we generate qualitative maps
of snow density and grain-size, as derived from backscattering values of five Cosmo-SkyMed X-band images.
We interpret these maps together with 7 snow pits dug in different sites through the glacier basin. Results
confirmed a distinct pattern of snow deposition and densification along the glacier, strongly driven by wind.
Wind exposed areas have larger snow crystals (i.e., 1-4mm against 0.5-1mm in wind protected areas), faceted
forms due to higher temperature gradient, more deposition layers and layers with higher hardness. In order to
delimitate different depositional zones, we run a cluster analysis with the snow density and grain-size maps,
together with slope, aspect and wind effect data derived from TanDEM-X.

110
1833
Mitigating Effects of Penetration in the CS2-Swath Rates of Elevation Change

Flora Weissgerber1 (flora.weissgerber@ed.ac.uk), Noel Gourmelen1

1
The University of Edinburgh, Edinburgh, United Kingdom

One of the aim of the ESA Altimetry mission CryoSat-2 (CS2) is to identify changes in ice thickness to quantify
the contribution of the cryosphere to sea level change. CS2 revolutionary design features SAR and
interferometric capacities, that allow to increase spatial resolution while resolving the angular origin of off-
nadir echoes occurring over sloping terrain, making it particularly adapted to monitor ice-sheet margins. On top
of measuring more precisely the elevation of Point Of Closest Approach (POCA), the standard level-2 product,
CS2 SARIn mode allows also the so-called CS2 Swath SARIn (CSSARIn) approach: elevations beyond the POCA
are produced, leading to between 1 and 2 orders of magnitude more measurements than level-2 product.
Among other products, the ESA project CryoTop Evolution aims to deliver to the community maps of rates of
surface elevation change over the Greenland and Antarctic Ice Sheets. To produce accurate rate of elevation
changes from the CS2 elevations, changes in the penetration properties of the snow or ice has to be taken into
account. If retrackers have been developed to limit the effect of penetration in the POCA retrieval, CSSARIn
samples far from the POCA can be heavily subject to penetration changes. Here we will present first attempts
to separate changes in penetration from the rate of elevation change by including proxies for penetration in
the model linking elevations to elevation changes.

111
2103
An Integrated Approach to Map Ice-free Areas of the Antarctic Peninsula Region

Thomas Schmid1 (thomas.schmid@ciemat.es), Stéphane Guillaso2,3, Jerónimo López-Martínez4, Ana Nieto4,

Sandra Mink4,5, Magaly Koch6, Enrique Serrano7
1
Centro de Investigaciones Energéticas Medio Ambientales y Tecnológicas -CIEMAT, Environment, Madrid,
Spain, 2Computer Vision and Remote Sensing Group, Technische Universität Berlin, Berlin, Germany, 3CNRS
GIPSA-lab, Saint Martin d'Hères, France, 4Universidad Autónoma de Madrid, Dpt. Geología y Geoquímica,
Madrid, Spain, 5Instituto Geológico y Minero de España, Madrid, Spain, 6Boston University, Center for Remote
Sensing, Boston, United States, 7Universidad de Valladolid, Dpt. Geografía, Valladolid, Spain

Ice-free areas within the studied Antarctic region are considered highly dynamic and show a complex mosaic of
surface covers due to periglacial, glacial and fluvial processes. The objective of this work is to develop an
integrated remote sensing approach to map periglacial, glacial and geological structures in ice-free areas of
King George, Livingston and Deception islands. This includes using remotely sensed satellite-borne Synthetic-
Aperture Radar (SAR) RADARSAT-2 and Sentinel-1 data, and optical Landsat-8 and Sentinel-2 data. A
georeferenced data base is compiled containing site specific data that include field measurements,
observations and laboratory soil analysis, geomorphological and geological maps that are used as reference
and validation data to obtain a distribution of the different landforms. The supervised classification results
show the identification of complex and relatively small scale geomorphological features such as periglacial
landforms. In this case, characterizing and monitoring the distribution of some of these landforms is often an
indicator of the presence of permafrost and related to hydrological changing processes. The integrated
approach shows that the synergetic use of SAR backscattering characteristics and optical reflectance properties
improves extracting and identifying different surface covers. Furthermore, it has been possible to extrapolate
the results to ice-free areas over a larger region where access is limited.

112
2227
Optical Fractional Snow Cover Retrievals under Development at Three Continents

Igor Appel1 (iappel@earthlink.net)

1
TAG, Washington, United States

A large scale international snow products intercomparison and validation project initiated by the European
Space Agency was recently completed in the Environmental Earth Observation company at Innsbruck, Austria.
The project provides an independent comparison of various approaches to map snow, including subpixel snow
fraction, using detailed stratified comparison with almost 500 Landsat reference data sets. The validation of
snow fraction demonstrates that the algorithm initially developed by the author of the presentation jointly
with Dr. Salomonson, NASA has advantages in comparison with other products both on open land and in
forested areas.
The algorithm takes into account that the reflectances of snow and non-snow are characterized by a significant
local variability and also by changes from one scene to another. The local snow and non-snow endmembers are
approximated by the Normalized Difference Snow Index. The magnitudes of snow and non-snow Normalized
Difference Snow Indexes are scene-specific and calculated on the fly to retrieve snow fraction. The
development of scene-specific algorithms is an optimal way to fractional snow retrieval from moderate
resolution satellite observations.
European Space Agency and Japan Aerospace Exploration Agency recently decided to derive snow fraction
using visible observations from Sentinel-3 and GCOM-C respectively. It is assumed that the collaboration
between several parties tackling the same problem can be very promising.

113
OC-1_OC-2b - Innovation, partnership and impact in polar science communication & Polar
Research and Citizen Science: Exploring New Platforms and Opportunities
19.06.2018 11:00-12:30, B Pischa

584
School of Ice: Professional Development Program for College Geoscience Faculty

Louise Huffman1 (louise.t.huffman@dartmouth.edu), Hilarie Davis2

1
Dartmouth College, Rotonda West, United States, 2Technology for Learning, Inc., Jensen Beach, United States

The School of Ice (SOI) from the US Ice Drilling Program Office (IDPO) is designed for college faculty to increase
background knowledge about ice core science and climate change and provide experiences with activities and
labs for transferring information to students.
This presentation will identify valuable key ideas from our model: pairing researchers and educators as
presenters; building a science community willing to participate in education/outreach; increasing participants'
background knowledge and confidence; and encouraging teacher buy-in to ensure replication and
dissemination. IDPO's drilling technologies also make it an ideal platform for intertwining engineering practices
with science research to meet new science standards.
Results of the institute evaluations will be shared including the impact on the educators and a longitudinal
analysis of data from interviews with past participants concerning continued impacts on their teaching, their
courses and their students. Faculty who have attended this institute in the last three years have reported
increases in their understanding of the content and how to teach it, as well as increased confidence in their
ability to teach ice core science and climate change concepts.
Elements of SOI can inform the development of college professional development and student courses, as well
as the creation of successful education and outreach programs for science research teams wanting greater
impact of their research results.

114
625
A new South African National Antarctic Programme Portal Designed by ALSA

Anche Louw1 (anchelouw072@gmail.com)

1
University of Stellenbosch, Botany and Zoology, Stellenbosch, South Africa

The Antarctic Legacy of South Africa (ALSA) fulfil various aims within the South African National Antarctic
Programme (SANAP), one aim being to promote the human involvement in the South African sector of the
Antarctic region. This aim is achieved mainly through attracting post graduate students to the different
research disciplines that form part of SANAP through the World Wide Web, social media and awareness
activities e.g. museum exhibitions.
The success that the ALSA website has within the reach of South Africa did not go unnoticed by partners in the
SANAP environment. This resulted into a collaboration effort with South Africa's Department of Environmental
Affairs (DEA), Branch: Oceans and Coasts. DEA is responsible for the logistics and environmental management
of our involvement in the Antarctic region. The collaboration effort entail the design of a new and improved
SANAP- portal, in the form of a new website. This portal will present information on the logistics and research
efforts of South Africa in the Antarctic region. The research efforts will cover the four themes as stipulated by
SANAP, namely Earth Systems, Living Systems, Human Enterprise and Innovation: technology and engineering.
Therefore, the portal will serve as a contact point within the broader SANAP community, including funding
agencies and the public.
This presentation will thus focus on ALSA's role in promoting South Africa's involvement in the Antarctic
community through the new SANAP portal.

115
1793
Science Outreach & STEM Education in Antarctica: Virtual Reality and Robotics

Nuno Pereira1 (nuno.pereira@ipbeja.pt), Ludmila Filipova2,3, João Rocha4

1
Polytechnic Institute of Beja, Mathematics and Physical Sciences, Beja, Portugal, 2Sofia University, St. Kliment
Ohridski, Sofia, Bulgaria, 3Bulgarian Antarctic Institute, Sofia, Bulgaria, 4Independent Scholar, Évora, Portugal

The Antarctic Research & Education Program (AREP) is going to be implemented on the “St. Kliment Ohridski"
Antarctic Bulgarian Base during the 2017-18 campaign, as a collaboration between the Physics and
Instrumentation Laboratory of the Polytechnic Institute of Beja, Portugal, the Bulgarian Antarctic Institute, and
the Sofia University St. Kliment Ohridski. Two schools in each country, with students with ages from 6 to 15
years old, are involved as case studies and proof of concept of the program. This edition of AREP contemplates
two projects: ViRAL - Virtual Reality Antarctic Laboratory, and Antarctuino - Physical Computing with Arduino in
Antarctica. The first initiative is a Virtual Reality based science outreach project, with the objective of bringing
Antarctica closer to the public. Antarctuino aims the development of coding skills with an open source
hardware platform, the Arduino, and robot programming with a scratch based language, engaging educators
and students in project based learning in the framework of STEM education. The output of these projects will
be used in several initiatives to increase public awareness on Antarctica related issues, such as global warming,
and the importance of research, and monitoring in this region of the Planet. This communication will report the
results of the first edition of AREP in terms of science outreach sessions, STEM education activities, lessons
learned, and the future steps for the next campaign.

116
2180
Using Podcasts to Extend your Audience and Expand Content Communication Options

Nicholas O'Flaherty1 (nicholaso@camino.co.nz)

1
The Antarctic Report, Auckland, New Zealand

The Antarctic Report is an online portal dedicated to all things on Antarctica and the Southern Ocean,
published by Camino, a digital content and publishing company based in Auckland, New Zealand. The site
showcases the hard science which underlines the importance of Antarctica as a bellwether of global climate
change. It also highlights the continent´s unique political status, as well as the exceptional demands its
environment places on people and equipment, and the romantic allure for travelers and explorers as the least
discovered continent on the planet.
The weekly podcasts were introduced on the portal in June 2017 as a way to extend content options. The
format of the podcasts is an interview with one expert, usually 30 minutes in duration. This long-form interview
allows for greater focus on subject matters. It also creates transcript opportunities to extend the channels. The
podcast are cost-effective with editing done in-house.
This presentation will outline why The Antarctic Report chose the podcast format, as well as present the
practical step-by-step process in getting the podcast launched, and the lessons that were learnt on the way.

117
2389
A Special Role for Feature Films in Science Communication

Peter Barrett1 (peter.barrett@vuw.ac.nz)

1
Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand

Through the 19th and 20th centuries scientists communicated within and beyond the community itself through
peer-reviewed journal articles and books, advancing knowledge through a self-correcting process for the
betterment of many. In the 21st century the pace of technology-driven change and media-driven competition
for attention is making it increasing difficult to inform community thinking with evidence-based knowledge on
solutions to the pressing problems of our time.
Though technology has made huge advances over its hundred year history, I'll suggest that film continues to
appeal as an essentially communal viewing experience for such issues. With a viewing time of typically 1-2
hours a film has time to appeal both intellectually and emotionally on any one of a range of big issues. Arnold
Schwarzenegger said recently the challenge is to be “simple and clear and make it a human story.” These days
the film maker also needs to ensure self-evident authenticity.
Arguably the most effective in the “pressing problems of our time” genre is Al Gore's “An Inconvenient Truth”
(2006), driven by good timing, sound science and a personal story. Since then there have been half a dozen
science-based stories with a similar mission and a TV series “Years of Living Dangerously” (2014, 2016 - a total
of 17 1-hour stories) that address both problem and solution. I'll discuss their different qualities and varying
degrees of success. We can learn from these stories and need more of them.

118
1244
Taking Antarctica to the World. ICE101x, an Antarctic Massive Open Online Course

Cliff Atkins1 (cliff.atkins@vuw.ac.nz), Rebecca Priestley1, Jacqueline Dohaney1, Rhian Salmon1

1
Victoria University of Wellington, Wellington, New Zealand

In 2017 Victoria University of Wellington, supported by Antarctica New Zealand, launched ICE101x Antarctica:
From Geology to Human History, a Massive Open Online Course (MOOC) via the edX platform. The fully online,
interactive, interdisciplinary course attracted over 5700 students from 128 countries. Students had a wide
range of backgrounds: from school and university students to retired people, science lecturers to Antarctic
base staff.
ICE101x featured innovative, field-based video lectures filmed in Antarctica and at the 2014 and 2016 SCAR
Conferences, supported by open access online resources and a discussion board. It was led by Antarctic experts
from VUW and featured guest lectures or interviews with artists and scientists, offering a truly interdisciplinary
teaching programme. Given the severely limited opportunities to take students to Antarctica, this MOOC gave
students an authentic, yet remote, experience and insight into this unique environment.
Analysis of students' interactions with the course, and response to an end of course survey, revealed that
students were highly engaged and satisfied with the course and emerged from the course with new
understandings of issues such as climate change and the process of scientific research. A new version of the
course ICE102X (2019) will include a new module on Antarctic biology.
We will present an overview of the course, including our insights, findings, and opportunities for future
collaboration.

119
CR-1b - Permafrost: connecting measurements, monitoring, and modelling
19.06.2018 11:00-12:30, B Parsenn

302
Impacts of Forest Fires on Discontinuous Permafrost in the Northwest Territories

Jean Holloway1 (jean.holloway77@gmail.com), Antoni Lewkowicz1

1
University of Ottawa, Geography, Environment and Geomatics, Ottawa, Canada

Forest fire is rarely taken into account in predictive modelling of permafrost change even though severe fires
have been shown to accelerate degradation. Moreover, the frequency and magnitude of fires is increasing as
the climate warms. We are examining permafrost change following the 2014 fires in the Northwest Territories,
Canada in order to improve predictive modelling of the fate of permafrost in the region. A total of 18 burned
and unburned sites representing a range of conditions were established in 2015 and 2016. At each site, air and
near-surface ground temperature are being monitored continuously. Direct current electrical resistivity
tomography (ERT) surveys and frost table measurements are being been conducted annually. Burned sites
were warmer than unburned ones: surface offsets averaged 0.5°C greater and the thermal offsets 0.1°C
smaller. Average frost table depths at burned sites were 17 cm greater than at unburned sites, and were
generally greater in 2017 compared to 2015. This reflects impacts of the burn as mean summer air
temperatures differed by only 0.3°C. Results from ERT surveys show the possible loss of permafrost within
some sites. The most-affected sites are underlain by coarser-grained substrates with thin organic layers,
whereas peatland sites are less impacted. These results indicate the heterogeneity of permafrost reaction to
fire at the landscape scale and suggest that permafrost may persist in peatlands while degrading elsewhere in
the region.

120
274
Modelling Convective Heat Transfer in Permafrost Using Long-term Monitoring Data

Jonas Wicky1 (jonas.wicky@unifr.ch), Christian Hauck1

1
University of Fribourg, Department of Geosciences, Alpine Cryosphere and Geomorphology Group, Fribourg,
Switzerland

Thermal modelling is important for a better understanding of the ground thermal regime in Alpine permafrost.
We present a modelling approach that makes use of common concepts in engineering sciences (FE-modelling)
to represent and quantify convective heat transfer in air in coarse permafrost substrate. The effect of
convective heat transfer in air has been addressed in many observation-based studies. Modelling approaches
are still rare and often limited to one dimension which neglects lateral heat transfer. Previous results from a 2-
D model showed that convective heat transfer may have a significant influence on the ground thermal regime
in a talus slope. This modelling approach is now extended to explore the effects of convective heat transfer in
other landforms (e.g. rock glaciers) and to more site-specific calibration allowing the validation of the used
model approach. Studying different sites and landforms in the Swiss Alps is possible thanks to the availability of
long-term monitoring data of different field sites which are systematically processed and stored within the
PERMOS (PERmafrost MOnitoring Switzerland) network. Modelling results show that convective heat transfer
in air cannot be neglected in Alpine permafrost and it has, at least for some landforms, important effects on
ground temperatures. The study also shows that easily available long-term and high-quality monitoring data is
of great benefit for model forcing and validation.

121
1129
Thermal Evolution of a Holocene Arctic Environment in Western Greenland

Juha Hartikainen1 (juha.hartikainen@tut.fi), Lillemor Claesson Liljedahl2, Pauli Kolisoja1, Anne Kontula3, Reijo
Kouhia1, Jens-Ove Näslund2, Dirk van As4, Thomas Zwinger5
1
Tampere University of Technology, Tampere, Finland, 2Swedish Nuclear Fuel and Waste Management Co,
Stockholm, Sweden, 3Posiva Oy, Eurajoki, Finland, 4Geological Survey of Denmark and Greenland, Copenhagen,
Denmark, 5CSC - IT Center for Science Ltd., Espoo, Finland

We present a Holocene temperature reconstruction at the arctic Greenland Analogue Project (GAP) study area
near Kangerlussuaq in western Greenland. The air temperature history is obtained by combining
meteorological data from (i) the GAP tundra site, (ii) Kangerlussuaq and coastal sites in South-West Greenland,
and (iii) selected Greenland Ice Sheet sites, together with temperature proxy ice-core records. For the glacial
stage in the early Holocene, a one-dimensional steady-state ice-sheet model is developed to reproduce the ice
thickness and basal thermal conditions of the ice-sheet, and the associated isostatic adjustment. The model
uses the geologically-determined ice-margin position and modelled Holocene elevation change of the ice
divide. Using the temperature reconstruction and information on present-day vegetation and water bodies, a
numerical model, calculating e.g. heat transfer, groundwater flow and salt transport, is used to simulate the
thermal evolution of the subsurface including soil and bedrock temperatures, geothermal heat flow and the
depth and distribution of permafrost and perennially frozen ground. Seasonal variations in surface processes
such as the freezing and thawing of the active layer are taken into account. Comparison with measured soil
temperatures and bedrock temperatures measurements down to 570 metres reveals several important factors
and processes for the development of permafrost and perennially frozen ground in Greenland.

122
2036
A High-resolution Coupled Permafrost - Ice Sheet Model

Thomas Zwinger1 (zwinger@csc.fi), Juha Hartikainen2, Denis Cohen3

1
CSC -- IT Center for Science Ltd., Espoo, Finland, 2Tampere University of Technology, Tampere, Finland, 3New
Mexico Institute of Mining and Technology Socorro, Socorro, United States

We present the development of a high-resolution coupled permafrost - ice sheet model based on continuum
thermodynamics. The model includes heat-transfer within ice, water and soil, including phase change,
saturated groundwater flow, salinity transport as well as deformation and stress-distributions of ice, soil and
bedrock. It further takes into account important couplings, such as effects of permafrost on glacier sliding and
hydraulic conductivity of soil and bedrock, effects of solutes on the development of permafrost, and effects of
ice flow and groundwater flow on heat transfer. Implemented in the Finite Element code Elmer, this package
provides the possibility to couple a permafrost to a high-resolution glacier or ice-sheet model (Elmer/Ice) that
accounts for all stress components (full-Stokes) and thereby - in contrast to usually deployed lower order
approximations - has no limitations in spatial resolution. This makes it possible to study detailed processes at
places that need high resolutions, such as ice-sheet margins where permafrost may play an important role in
controlling the basal ice temperature, or geologically strongly varying bedrocks where permeability changes as
a result of permafrost formation or degradation can significantly alter groundwater flow paths. The model is
tested on problems of approaching and retreating ice margins using synthetic settings, and real geometries,
where measurements for comparison and model constraints are available.

123
1522
Snow Observation and Modeling for Polygonal Tundra Permafrost Thermal Assessment

Isabelle Gouttevin1 (isabelle.gouttevin@gmail.com), Moritz Langer2,3, Henning Löwe4, Julia Boike2,3, Martin
Proksch4, Martin Schneebeli4
1
IRSTEA, Grenoble, France, 2Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI),
Potsdam, Germany, 3Humboldt-Universität, Geography, Berlin, Germany, 4WSL Institute for Snow and
Avalanche Research SLF, Davos, Switzerland

Lacking knowledge on snow properties in high latitude regions poses a major limit to the modelling of the
ground thermal regime for permafrost and climate science. To this end a dedicated snow campaign took place
in 2013 at the Samoylov permafrost observatory in Siberia. We present estimations of snow thermal
conductivity Keff-z based on X-ray microtomography from Samoylov samples, and investigate the links
between snow properties and the polygonal tundra micro-topography. We analyse the consistency of
estimated Keff-z with respect to measured soil temperatures. For that purpose, the snow model SNOWPACK is
phenomenologically adapted to Arctic conditions to ensure a bare agreement with snow observations.
Our observations describe a relatively conductive snowpack at Samoylov (0.21 ± 0.01 W m-1 K-1 across grass-
covered polygons) where the thermal resistance of the snowpack is mostly controlled by variations in snow
height induced by the polygonal micro-topography. The modified SNOWPACK simulates reasonable density and
Keff-z profiles, which strongly improves the simulation of the ground thermal regime. Finally, we use chained
SNOWPACK and permafrost modelling to assess the thermal impact of snow spatial variability in both depth
and structure: the sensitivity of soil temperatures to snow cover variability is high and most pronounced during
the early and dark winter. This highlights the demand for improved snow characterization and snow
parameterization in these periods.

124
2485
Efficient Data Assimilation in a Quasi-distributed Permafrost Modeling Framework

Joel Fiddes1 (joelfiddes@gmail.com), Kristoffer Aalstad1, Sebastian Westermann1

1
University of Oslo, Oslo, Norway

The mountain cryosphere is undergoing significant changes globally, yet these changes are in many cases
poorly constrained, particularly in remote regions where data is sparse. Previously developed methods for
downscaling driving meteorology (Fiddes and Gruber 2014) and a subgrid scheme (Fiddes and Gruber 2012)
have proven to be promising approaches to large area transient simulations of permafrost in remote areas due
to order of magnitude efficiency gains. However, major sources of uncertainty still remain in the
meteorological forcing, particularly precipitation which features high spatiotemporal variability and is heavily
modulated by local topographic effects. Additional complexity arises due to the inherent uncertainty in
precipitation observations, especially in the solid phase. Solid precipitation is an important target variable to
accurately quantify as it is a key control on the ground thermal regime. To address these issues we employ an
ensemble data assimilation scheme, based on the particle batch smoother, that assimilates MODIS fractional
snow cover observations into the modelling framework. Efficiency gains in the underlying framework, due to
the downscaling and subgrid scheme, make this approach particularly suited for the treatment of uncertainty
through ensemble simulations and data assimilation.
We present results from validation in the European Alps and test applications in the Himalaya together with
new results from the latest ECWMF reanalysis ERA5.

125
AC-5b - Tropical-Polar Teleconnections and their Climate impacts
19.06.2018 11:00-12:30, B Jakobshorn

465
A 20th Century Perspective on Summer Antarctic Pressure Change and Variability

Ryan Fogt1 (fogtr@ohio.edu), Chad Goergens1, Julie Jones2, David Schneider3, Julien Nicolas4, David Bromwich4
1
Ohio University, Geography, Athens, United States, 2University of Sheffield, Sheffield, United Kingdom,
3
National Center for Atmospheric Research (NCAR), Boulder, United States, 4Ohio State University, Byrd Polar
and Climate Research Center, Columbus, United States

During the late 20th Century, the Antarctic atmospheric circulation has changed and significantly influenced the
overall Antarctic climate, through processes including a poleward shift of the circumpolar westerlies. However,
little is known about the full spatial pattern of atmospheric pressure over the Antarctic continent prior to 1979.
Here we investigate surface pressure changes across the entire Antarctic continent back to 1905 by developing
a new summer pressure reconstruction poleward of 60°S. We find that only across East Antarctica are the
recent pressures significantly lower than pressures in the early 20th century; we also discern periods of
significant positive pressure trends in the early 20th century across the coastal South Atlantic sector of
Antarctica. Climate model simulations reveal that both tropical sea surface temperature variability and other
radiative forcing mechanisms, in addition to ozone depletion, have played an important role in forcing the
recent observed negative trends.

126
2194
Amazon and Antarctic Stable Isotope Ratios in the Southern Brazilian Rainfall

Francisco Aquino1,2 (francisco.aquino@ufrgs.br), Ronaldo Bernardo1, Jefferson Simões1, José Celso Griebler
Junior1, Venisse Schossler1, Pedro Reis1
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Geography, Porto Alegre, Brazil, 2Centro Polar e
Climatico, Geography, Porto Alegre, Brazil

This study examines interactions between the Antarctic air masses and those from tropical South America (SA)
responsible for severe and regular precipitations events in Southern Brazil (SB) during 2016. This year also
stands out as the warmest in the world since 1921, and the second in SA, but with regional monthly contrast
(including negative anomalies in the La Plata Basin and the SB). A Palmex Rain Sampler RS1 collected rain in the
city of Porto Alegre; the oxygen isotope ratios were determined by the Cavity Ring-Down Spectroscopy method
(Picarro system). To analyze the geopotential height fields, wind vectors, zonal wind, precipitable water and
temperature at 925, 750, 500 and 200 hPA, monthly and seasonally, using ERA-Interim Reanalysis data. The
presence of polar fronts, coupled with the low and high atmospheric circulations, strengthened convection by
developing severe storms in the SB. In addition, we have three moisture sources of intense rainfall in southern
Brazil: the Amazon Forest, South Atlantic Ocean and Antarctica. So, it is suggested that temperature contrast
observed between advection and circulation of tropical and polar air masses enhance convection and could be
one of the reasons for stronger storms in the SB and other parts of the southern SA in 2016. The δ18O values
found in the precipitation present high variability, from -2.93 ‰ to -9.80 ‰ and show the different sources of
air masses responsible for precipitation in Porto Alegre.

127
1436
Simulating the Southern Hemisphere Storm Track Shift

Jonathan Wille1 (jonathan.wille@univ-grenoble-alpes.fr), Vincent Favier1, Francis Codron2, Gerhard Krinner1,

Hubert Gallée1, Julien Beaumet1, Nicolas Jourdain1
1
IGE, Université Grenoble Alpes, CNRS, IRD, Grenoble, France, 2LOCEAN - Sorbonne Universités -
UPMC/CNRS/IRD/MNHN, Paris, France

In accordance with the Clausius Clapeyron equation, a warmer atmosphere will lead to an increase in
atmospheric moisture content which theoretically will provide a positive trend in the Antarctic surface mass
balance. An increasing surface mass balance over Antarctica would have negative implications on future sea
level rise. This is why it is essential to accurately simulate changes to the Antarctic upper-level circulation to
determine how circulation changes will impact these potential increases in Antarctic snow accumulation.
During the past century, the Southern Annular Mode (SAM) has been increasingly positive which has shifted
the storm track southward. This has resulted in significant warming along the Antarctic Peninsula and increased
snow accumulation in West Antarctica and along the western side of the Peninsula. This shift in SAM is poorly
represented in climate models along with its potential impact on future surface mass balance changes on the
Antarctic continent. To properly simulate the potential Antarctic storm track changes requires a better
simulation of the tropical and mid-latitude teleconnections that influence the Antarctic climate. Here we
propose to improve the modeling of the storm track location using the stretched grid global model LMDZ6 and
analyze the impact on the surface mass balance of Antarctica using the regional circulation model MAR.

128
2091
The Antartic Atmospheric Circulation and Cyclogenesis Anomalies in Spring 2016

Venisse Schossler1 (venisse.schossler@ufrgs.br), Francisco Eliseu Aquino1, Pedro Amaral dos Reis1, Jefferson
Cardia Simões1
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Centro Polar e Climático, Porto Alegre, Brazil

This work examines teleconnections between the cyclogenesis in Southern Hemisphere (SH) and its
relationship to the Southern Annular Mode (SAM) and to the zonal wave three (ZW3) pattern at the end of
October 2016. From 26th to 28th of that month, a strong extratropical cyclone developed on the southern
coast of Brazil (SB). Then, from the 29th to the 31st, the southern coast of Australia (AU), including Tasmania
(TA), was hit by an extratropical cyclone coming from the Indian Ocean. Both events caused numerous social
and environmental damages. That year also stands out as the warmest in the instrumental record, both
globally and in the SH, and recorded the smallest Antarctic sea ice extent (SIE) since 1979. This sea ice cover
reduction has been attributed to positive sea surface temperature anomalies, the ZW3 and a SAM negative
phase. Considering these observations, we reconstructed the geopotential height fields, wind vectors, zonal
wind and temperature at 925, 750, 500 and 200 hPA, monthly, seasonally and annually, using ERA-Interim
Reanalysis data. The analyzed SAM index and the wave, tidal and wind records show that the two observed
anomalous events resulted from a combination of a negative SAM phase and of the ZW3. This association
favored intense cyclogenesis, with a baroclinic intensification, as a response to the tropic-pole temperature
contrast, and an exceptional atmospheric circulation observed between subtropical and polar latitudes in 2016.

129
207
Sensitivity of SH Westerly Winds to Boundary Conditions for the LGM

Seong-Joong Kim1 (seongjkim@kopri.re.kr), Sang-Yoon Jun1, Baek-Min Kim1

1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

The southern hemisphere (SH) westerly wind change in the LGM is critical in understanding the glacial-
interglacial carbon cycle since its strength and position influence the upwelling of the carbon rich deep water to
the surface. To examine the change in SH westerly wind in the LGM, we adopted CAM5 atmosphere general
circulation model (GCM) and performed LGM simulation with sensitivity experiments by specifying the LGM sea
ice in the Southern Ocean (SO), ice sheet over Antarctica, and tropical pacific sea surface temperature. The SH
westerly response to LGM boundary conditions in the CAM5 was compared with those from CMIP5 LGM
simulations. In the CAM5 LGM simulation, the SH westerly wind substantially increases between 40S and 65S,
while the zonal-mean zonal wind decreases at latitudes higher than 65°S. The position of the SH maximum
westerly wind moves poleward by about 8 degree in the LGM simulation. Sensitivity experiments suggest that
the increase in SH westerly winds is mainly due to the increase in sea ice in the SO that accounts for 60% of
total wind change. In the CMIP5-PMIP3 LGM experiments, most of the models show the slight increase and
poleward shift of the SH westerly wind as in the CAM5 experiment. The increased and poleward shifted
westerly wind in the LGM obtained in the current model result is consistent with previous model results and
some lines of proxy evidence, though opposite model responses and proxy evidence exist for the SH westerly
wind change.

130
2288
Evolution of Pacific to Southern Hemisphere Teleconnection in the Last Ice Age

William Roberts1 (william.roberts@bristol.ac.uk), Paul Valdes1, Tyler Jones2, Eric Steig3

1
University of Bristol, School of Geographical Sciences, Bristol, United Kingdom, 2University of Colorado at
Boulder, Boulder, United States, 3University of Washington, Seatlle, United States

Jones et al (Nature, 2017) recently showed that the amplitude of the interannual variability in West Antarctica
was substantially larger during the last ice age than it is today. They showed that the reduction in the
amplitude of the variability can be linked to the height of the Laurentide Ice Sheet. In this presentation we shall
show in detail how changes in the tropical Pacific climate altered the interannual variability seen in West
Antarctica. Analysing the Rossby Wave source terms in a series of climate model simulations we can show that
a shift in the mean convection in the West Pacific makes a more efficient teleconnection from the tropical
Pacific to the high southern latitudes, particularly the Amundsen Sea region. By analysing the effect of the
different glacial boundary conditions (the presence of ice sheets, lowered greenhouse gases, altered orbital
forcing), we can show that the largest single cause of the change is the size of the Laurentide Ice Sheet. The ice
sheet alters the position of the mean convection in the West Pacific, which makes a stronger Rossby Wave
source. The shifted convection is supported by other paleoclimate proxy evidence. We shall show that although
glacial boundary conditions cause changes in the zonal mean westerly winds, which might alter the
teleconnection from the tropical Pacific to higher southern latitudes, these changes can not explain the climate
variability seen in the water-isotope record of the WAIS divide ice core.

131
AC-1b - Polar and high altitude atmosphere: clouds, aerosols, climate and interactions
19.06.2018 11:00-12:30, C Sanada I

66
Warming by Moist Air Intrusion and Cloud Radiation in the Arctic and Antarctic

Takashi Yamanouchi1 (yamanou@nipr.ac.jp)

1
National Institute of Polar Research, Tachikawa-shi, Japan

At Ny-Ålesund, Arctic, two distinct states are seen in downward longwave radiation (LD) during winter 2015/16.
After the cold state with the temperature around -10 to -20 C, a warm state with plus temperature appears and
LD increases from about 170 to 320-330 W/m2. This abrupt and large increase of LD might be due to the change
of cloud condition, from clear to overcast, which was examined from the cloud radar data taken during GRENE
Arctic Research Project. However, only the cloud change could not explain this large change of LD. During the
warm state, the atmospheric circulation patterns changes, distortion of tropospheric polar vortex appears with
a high pressure ridge (blocking high), and strong low and intrusion of warm and moist air from the Atlantic
Ocean together with longwave radiation from clouds influences the warming at Svalbard. This intrusion of
warm-moist air from the lower latitude is one of the major processes contributing to the Arctic amplification,
just as proposed using GCM by Yoshimori et al. (2017).
In the Antarctic, similar intrusion of warm-moist air brings abrupt temperature increases and high
precipitations. These intrusions are called “Atmospheric River”, and attributed to the strong low and/or
blocking high. Although the suppression of warming in East Antarctica has been explained by the strengthening
of polar vortex in the strat. and trop. due to ozone hole, the role of intrusion and clouds is still an issue of
discussion compared to the Arctic.

132
298
Climate Modeling of Ice Supersaturation and Haze at Dome C, Antarctica

Jean-Baptiste Madeleine1 (jean-baptiste.madeleine@upmc.fr), Hubert Gallée2, Richard Forbes3, Dana Veron4,

Christophe Genthon2, Frédéric Hourdin5, Florentin Lemonnier5, Luc Piard2
1
UPMC/LMD, Paris, France, 2IGE, Grenoble, France, 3ECMWF, Reading, United Kingdom, 4University of
Delaware, Newark, United States, 5CNRS/LMD, Paris, France

Ice supersaturation is usually found at high altitudes where cirrus clouds form. At such altitudes, continuous
and detailed measurement of the different steps leading to cloud formation and their comparison to climate
models is difficult. The Concordia station on the Antarctic plateau offers an opportunity to document
supersaturation and cloud formation in similar thermodynamical conditions and over the long term. The 40-m
meteorological mast at Dome C was therefore instrumented with two special hygrometers, one at the top and
one at the bottom, and haze formation was detected via visibility measurements. Ice supersaturation is found
in all seasons and a RHi of up to 200% is measured. During summer, in the evening, the RHi often reaches 120%
and sometimes precedes the formation of haze and a drop in visibility (for more detail, see Genthon et al., this
conference). This timing of events is examined in four atmospheric models: the ECMWF IFS, the MAR limited
area model, PolarWRF and the IPSL Climate Model, for which the parameterization of supersaturation is being
developed. The models predict realistic supersaturations but the detailed diurnal cycle and statistical
distributions differ from the observations. Haze is predicted and compared in detail with the observations. The
use of the mast also gives access to the vertical gradients of humidity. The strengths and weaknesses of the
models are compared, and pave the way to improvements in the different parameterizations.

133
460
Clouds, Aerosols and Radiation Measurements during the Polarstern Cruise PS106

Andreas Macke1 (macke@tropos.de)

1
Leibniz Insititute for Tropospheric Research, Leipzig, Germany

As a central experiment of the German Collaborative Centre "Arctic Amplification: Climate Relevant
Atmospheric and Surface Processes, and Feedback Mechanisms (AC)3" the Arctic expedition PASCAL (Physical
feedbacks of Arctic PBL, Seaice, Cloud And Aerosol, PS106.1) of the German research ice breaker Polarstern has
been performed with a focus on clouds, aerosol and radiation measurements from May 24 to June 21 2017,
followed by Arctic underway atmospheric measurements at the expedition PS106.2 until July 20, 2017. A 36
GHz cloud radar, a microwave radiometer, a Raman aerosol lidar, a network of pyranometer as well as a
tethered balloon with in-situ aerosol, turbulence and radiation observations up to a height of 1500m were
deployed on an ice floe at 82°N, 10°E for two weeks. Furthermore, detailed surface near-in-situ aerosol physical
and chemical characterizations have been carried out. The presentation provides an overview of vertical
aerosol and cloud profiling and discusses the relation to the observed surface fluxes.

134
493
Measured Radiation Budget Profiles of Arctic Clouds using a Tethered Balloon

Matthias Gottschalk1 (matthias.gottschalk@uni-leipzig.de), Ulrike Egerer2, Felix Lauermann1, Holger Siebert2,

André Ehrlich1, Manfred Wendisch1
1
University of Leipzig, Leipzig Institute for Meteorology, Leipzig, Germany, 2Leibniz Insititute for Tropospheric
Research, Leipzig, Germany

Arctic low-level clouds modify the surface energy budget as well as the vertical energy fluxes from the surface
to the free troposphere. Thus, understanding the cloud radiative effects and their dynamics is a key factor to
identify and quantify the processes leading to Arctic Amplification. However, observations of boundary layer
energy flux profiles that determine the interaction of clouds and surface are challenging and limited in the
central Arctic.
The Arctic Balloon profiling EXperiment (ABEX) took place north of Svalbard in June 2017 as part of an intense
observational campaign coordinated by the Transregional Collaborative Research Centre TR 172 “Arctic
Amplification” (AC)³, which combined the research vessel Polarstern and the Polar 5 and Polar 6 aircraft. During
a two-week ice floe camp, radiative and turbulent energy flux profiles were investigated under different cloud
conditions using a tethered balloon. Broadband solar and terrestrial irradiance profiles were measured.
Furthermore, the cloud top cooling rates driving the cloud dynamics were derived while high-resolution probes
measured the turbulent energy fluxes. The radiative energy flux profiles were affected by the cloud water
content, the cloud base altitude and the temperature profile of the boundary layer, resulting in changes of
cloud surface radiative forcing.
First results of radiative energy flux profiles determined during ABEX will be presented.
This work was supported by DFG Grant TR 172/1 A02.

135
502
Cloud Response to Moisture Intrusions into the Arctic

Abhay Devasthale1 (abhay.devasthale@smhi.se), Michael Tjernström2, Erik Johansson1, Karl-Göran Karlsson1

1
Swedish Meteorological and Hydrological Institute, Research and Development, Norrköping, Sweden,
2
Meteorological Institute, Stockholm University (MISU), Stockholm, Sweden

Moisture transport into the Arctic influences surface energy budget in the time scales ranging from few days to
few months. Moisture intrusions, i.e. the episodic extreme moisture transport events, are especially said to
have a large impact on air-sea interaction processes, by inducing rapid changes in the thermodynamical
structure of the lower troposphere. Persistent intrusions can have lasting impact on the seasonal sea-ice
evolution, both during the recovery and melt phases. Apart from their direct radiative impact on the lower
troposphere, moisture intrusions potentially modulate cloud frequency and physical properties, which in turn
have feedback on the longwave surface forcing. Here we assess this cloud response to moisture intrusions and
its seasonal character in detail. We use 10-years of A-Train data (CloudSat, CALIPSO and MODIS) as well as
multidecadal climate data record of cloud properties, CLARA-A2, from EUMETSAT's Satellite Application Facility
for Climate Monitoring (CM-SAF) for the period from 1982-2016. We investigate cloud response using two
approaches, namely the “large-scale approach” and the “local approach”. In the former, the moisture intrusion
events are defined based on the large-scale moisture variability, while in the latter, the local moisture
variability is taken into account. We discuss relative merits and significance of these approaches.

136
1796
Stratocumulus Breakup in Cold Air Outbreaks over the North Atlantic

Gary Lloyd1 (gary.lloyd@manchester.ac.uk), Thomas Choularton1, Keith Bower1, Martin Gallagher1, Jonathan
Croser1, Sebastian O'Shea1, Steven Abel2, Stuart Fox2, Ian Boutle2, Richard Cotton2, Phil Brown2
1
University of Manchester, Manchester, United Kingdom, 2Met Office, Exeter, United Kingdom

In this paper we show from in-situ field observations that this break-up in cold air outbreaks over the eastern
Atlantic is controlled by the development of precipitation in the cloud system while the boundary layer
becomes decoupled, with both supercooled liquid and solid precipitation playing a role. Flights were conducted
using the UK FAAM aircraft in the North Atlantic region around the U.K. featuring 4 case studies, making
detailed microphysical, dynamical and thermodynamic measurements in the cloudy boundary layer during the
cold air outbreaks. It is found that as the cloud moves over progressively warmer waters it initially deepens,
with increasing drop size and the formation of liquid precipitation. Small numbers of ice particles are observed.
In 3 of the cases the aerosol number in the boundary layer and the cloud droplet number, decreased with
distance south as the aerosol was scavenged by precipitation, leading to increased precipitation and a
reduction in the liquid water path and the eventual break-up of the cloud. It is concluded that it is the
precipitation process that dominates the timing of the cloud break-up although both weakening of the capping
inversion and boundary layer decoupling also occurred which may play a critical role in determining the timing
of precipitation onset.

137
BE-4b - Climate change and ecosystems: physiology, biodiversity and ecological functions
19.06.2018 11:00-12:30, C Sanada II

56
The Greater than Expected Affect of Temperature on Antarctic Marine Species

Lloyd Samuel Peck1 (l.peck@bas.ac.uk)

1
British Antarctic Survey, Biodiversity, Evolution and Adaptation, Cambridge, United Kingdom

Antarctic marine species have evolved over millions of years in cold, thermally stable, but also seasonally
intense conditions. In response to this many unique adaptations have been produced including antifreeze in
fish, an absence of haemoglobin in Channichthyd fish and the absence of a heat shock response in some
species. Recently (Peck 2016) it has been shown that the vast majority of biological processes are slowed in
Antarctic marine species compared to those from warmer water sites. For respiration, aerobic capacity and
activity the slowing in Antarctic species compared to temperate and tropical species is in line with the expected
effect of temperature on biological functions as first described by Arrhenius over 100 years ago. For other
processes, such as growth, embryonic development and the duration of elevated metabolic rates after feeding,
the slowing is much greater than the expected effect of temperature. This contribution presents these data and
then shows why the impact of low temperature on protein synthesis is the likely reason for these differing
results.
Peck L.S. (2016). A cold limit to Adaptation in the Sea. TREE. 31 (1), 13-26.

138
2612
Polygenic Adaptation Drives Genomic Divergence between Spawning Modes in Capelin

Kim Præbel1 (kim.praebel@uit.no), Shripathi Bhat1

1
UiT The Arctic University of Norway, Norwegian College of Fishery Science, Tromsø, Norway

Capelin (Mallotus villosus) is a small salmonid fish that display two alternative life histories within its
circumpolar distributional area: a long distance migrating ecotype that spawns offshore and are strictly
semelparous or a more resident ecotype that spawns intertidally and can be considered as facultative
iteroparous. Intraspecific divergence in life history may be regarded as a process of incipient speciation and
when this process occurs in sympatry, the theory of speciation predicts that adaptive genomic differences will
accumulate as a result of divergent natural selection acting against unbeneficial traits. In other words, adaptive
genomic differences are expected to be the main driver of divergence between the two ecotypes and spawning
modes. Here we addressed this prediction on two replicated systems of capelin spawning offshore vs
intertidally from Norwegian waters. We compared divergence from a genome-wide panel of single nucleotide
polymorphisms obtained by massively parallel sequencing of Restriction Site Associated DNA libraries
(RADseq). Via machine learning approaches we firstly revealed that the ecotypes and spawning modes diverge
at the genomic level, and secondly, we revealed that polygenic adaptive genomic differences have accumulated
within the two alternative life histories. We discuss these results in light of how a changing Arctic environment
may influence the apparent ongoing process of incipient speciation.

139
75
Quantifying the Role of Allochrony in Sympatric Seabird Niche Partitioning

Harriet Clewlow1,2 (halow73@bas.ac.uk), Akinori Takahashi3, Stephen Votier4, Rod Downie5, Norman Ratcliffe1
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Exeter, Centre for Ecology and
Conservation, Penryn, United Kingdom, 3National Institute of Polar Research, Tokyo, Japan, 4University of
Exeter, Environment and Sustainability Institute, Penryn, United Kingdom, 5World Wide Fund for Nature - UK,
Polar Program, Woking, United Kingdom

Competition within and between species shapes community structure and species distribution. Levels of
competition are particularly high when closely related species share limited resources, meaning they must
differentiate along multidimensional niche axes in order to co-exist. The degree of competitive dominance may
also be affected by climate change. Sympatric central-place foraging seabirds with similar resource
requirements experience high levels of competition during the breeding season and often display allochrony
(differences in timing of breeding) to reduce this. We used sympatrically breeding Adélie (Pygoscelis adeliae)
and Chinstrap penguins (P. antarctica) on Signy Island, South Orkneys, as a model system to quantify the role of
allochrony in niche partitioning for the first time.
Foraging location (GPS tag) and dive depth (TDR tag) data were collected during 4 breeding seasons. We
determined that the two species display 3D niche partitioning, utilising different core foraging areas during
different breeding phases and diving to significantly different maximum dive depths within areas of high spatial
overlap. Allochrony reduced horizontal overlap between species by 70%.
Both species breed later in colder years and recent cooler springs have seen both delay breeding by 10 days
over the last 20 years. Penology changes have occurred in parallel over this time, maintaining allochrony, but if
allochrony offset is reduced by a single day competition will increase by 2.6%.

140
2102
Climate Change and the Threat of Novel Marine Predators in Antarctica

K.E. Smith1, J. McClintock2 (mcclinto@uab.edu), B.V. Steffel3, S. Thatje4, M.O. Amsler2, O. Moksnes5, J.N.
Havenhand5, R.B. Aronson3
1
University of Exeter, College of Life and Environmental Sciences, Exeter, United Kingdom, 2University of
Alabama at Birmingham, Department of Biology, Birmingham, United States, 3Florida Institute of Technology,
Department of Biology, Melbourne, United States, 4University of Southampton, Ocean and Earth Science,
Southampton, United Kingdom, 5University of Gothenburg, Department of Marine Sciences, Gothenburg,
Sweden

Historically low temperatures have limited skeleton-breaking predation on the Antarctic shelf, facilitating the
evolution of a fauna poorly defended against durophagy. Now, rapid warming is restructuring Antarctic marine
ecosystems as conditions become favorable for range expansions. The lithodid crab Paralomis birsteini
currently inhabits some areas of the continental slope off Antarctica. They could potentially expand along the
slope and upward to the shelf, where temperatures are no longer prohibitively low. We identified two sites
inhabited by different densities of lithodids in the slope environment of the Antarctic Peninsula. Gut contents
of crabs on the slope revealed them to be opportunistic invertivores. The abundances of three eurybathic
prey—ophiuroids, echinoids, and gastropods—were negatively associated with P. birsteini off Marguerite Bay,
where lithodid densities averaged 4280 ind·km-2 at depths of 1100-1499 m (range 3440-5010 ind·km-2), but not
off Anvers Island, where lithodid densities were lower, averaging 2060 ind·km-2 at these depths (range 660-
3270 ind·km-2.) Higher abundances of lithodids appear to exert a negative effect on invertebrate distribution on
the slope. Lateral or vertical range expansions of P. birsteini at sufficient densities could substantially reduce
populations of their benthic prey off Antarctica, potentially exacerbating the direct impacts of rising
temperatures on the distribution and diversity of the contemporary shelf benthos.

141
290
Biodiversity, Distribution and Ecology of Cephalopods in Polar Marine Ecosystems

Jose Xavier1,2 (jccx@cantab.net), Yves Cherel3, Louise Allcock4, Rui Rosa5, Rushan Sabirov6, Martin Blicher7,
Alexey Golikov6
1
University of Coimbra, Life Sciences, Coimbra, Portugal, 2British Antarctic Survey, Cambridge, United Kingdom,
3
Centre d'Etudes Biologiques de Chizé (CEBC), Villiers-en-Bois, France, 4Ryan Institute and School of Natural
Sciences, National University of Ireland Galway, Galway, Ireland, 5MARE - Marine and Environmental Sciences
Centre Laboratório Marítimo da Guia - Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal,
6
Kazan Federal University, Department of Zoology, Kazan, Russian Federation, 7Greenland Climate Research
Center, Greenland Institute of Natural Resources, Nuuk, Greenland

Cephalopods are known to play an important role, both as prey and predators, in polar marine ecosystems. In
this review, we compared the biodiversity, distribution and ecological role of cephalopods in the Arctic and in
the Antarctic. Sixty-one species have been reported from the Arctic (including the Pacific Subarctic) while 54
species are known from the Antarctic. The only confirmed species known to occur in both poles is the giant
squid Architeuthis dux. No cuttlefish species occur in either polar region. The cephalopod fauna of the Arctic
and Antarctic are different and have different origins: the Arctic fauna colonized the Arctic relatively recently (<
12 000 years ago), whereas some of the Antarctic fauna has evolved in situ over the past 33 Ma (e.g., most
octopods). Polar cephalopods prey on crustaceans, fish, and other cephalopods (including cannibalism),
whereas predators include fish, other cephalopods, seabirds, seals and whales. Cephalopods from these
regions are likely to be influenced by climate change: Arctic fauna is more subjected to increasing temperatures
per se, with these changes increasing species ranges and probably their abundance. Antarctic species are likely
to be influenced by changes in mesoscale oceanography, changes of position of oceanic fronts, changes of sea
ice and increase of ocean acidification. Polar cephalopods may have the capacity to adapt to environmental
change but more studies are needed on taxonomy, distribution and ecology.

142
AA-1c - Astrophysics and Astronomy in the Polar Regions
19.06.2018 14:00-15:30, A Studio

2204
Results from the High Elevation Antarctic Terahertz (HEAT) Telescope on Ridge A

Craig Kulesa1 (ckulesa@email.arizona.edu), Michael C. B. Ashley2, Michael G. Burton3, David Lesser1,

Christopher K. Walker1, Mark Wolfire4, Abram Young1
1
University of Arizona, Steward Observatory, Tucson, United States, 2University of New South Wales, School of
Physics, Sydney, Australia, 3Armagh Observatory and Planetarium, Armagh, United Kingdom, 4University of
Maryland, College Park, United States

Deployed to Ridge A in 2012, the HEAT telescope forges entirely new capabilities for ground based infrared and
submillimeter astronomy which otherwise would be unachievable except via expensive airborne or space-
based platforms. HEAT and PLATO-R represent a new generation of polar instrumentation that permits the
excellent conditions available from remote sites like Ridge A to be harnessed without the costs and hazards
associated with manned operations. The unparalleled stability, exceptional dryness, low wind and extreme cold
make Ridge A a site without equal for astronomy at infrared and submillimeter wavelengths. HEAT operates in
the far-IR atmospheric windows in which the most crucial astrophysical spectral diagnostics of the formation of
galaxies, stars, planets, and life are found. Through large-scale Galactic surveys, the measurement and impact
of the Galactic environment on the life cycles of interstellar clouds and their relation to star formation are
gradually being realized. HEAT´s key project is to map, with great sensitivity and precision, portions of the
Southern Galactic Plane in the spectral light of the dominant coolants of the interstellar medium from 200-600
microns wavelength. HEAT´s mixer, local oscillator, low-noise amplifier, cryogenic, and DSP technologies will
play essential roles in future Terahertz observatories. This pioneering mission paves the way for future
astronomical investigations from the high plateau and beyond.

143
2619
Galaxy Cluster Science from the North Pole: The OLIMPO Experiment

Alessandro Paiella1 (alessandro.paiella@roma1.infn.it)

1
Sapienza Università di Roma, Physics, Roma, Italy

Polar regions represent the best sites on Earth to observe the distant Universe. High atmospheric transparency,
low temperature, seasonal presence/absence of the Sun, and circumpolar currents make the polar
stratosphere optimal for balloon-borne IR and mm-wave astronomy measurements.
The OLIMPO experiment will be launched from Svalbard islands during the arctic summer, and will float at 40
km of altitude in the arctic circumpolar current. OLIMPO is a mm-wave observatory, to be pointed in the
direction of many galaxy clusters, to detect the Sunyaev-Zel'dovich (SZ) effect of the Cosmic Microwave
Background (CMB) photons crossing clusters. Measurements of the SZ effect provide important morphological
and dynamical information on galaxy clusters.
OLIMPO is equipped with a large-aperture telescope (2.6 m), feeding multi-band cryogenic focal planes
populated with arrays of kinetic inductance detectors sensitive at 150, 200, 350 and 480 GHz. In addition to
photometric measurements, OLIMPO provides spectroscopic measurements taking advantage of a plug-in
differential Fourier transform spectrometer (DFTS), enabling the characterization of all the components of the
SZ effect and its foregrounds with unprecedented precision and accuracy.
In addition to the scientific target, OLIMPO has a technological target: it will demonstrate that the KIDs and the
DFTS can reach the expected performance in a space-like environment, representing the pathfinder of future
space missions like Millimetron.

144
1403
The Kunlun Infrared Sky Survey

Jeremy Mould1 (jmould@swin.edu.au), Michael Burton2, Lifan Wang3, Michael Ashley4, John Lawrence5, Anna
Moore6
1
Swinburne University of Technology, CAS, Hawthorn, Australia, 2Armagh Observatory, Belfast, United Kingdom,
3
Purple Mountain Observatory, Nanjing, China, 4University of New South Wales, Physics, Sydney, Australia,
5
Australian Astronomical Observatory, N Ryde, Australia, 6ANU, RSAA, Weston Creek, Australia

The high Antarctic plateau provides exceptional conditions for infrared observations on account of the cold, dry
and stable atmosphere above the ice surface. We describe the scientific goals behind the first program to
examine the time-varying universe in the infrared from Antarctica - the Kunlun Infrared Sky Survey (KISS). This
will employ a 50cm telescope to monitor the southern skies in the 2.4µmK dark window from China´s Kunlun
station at Dome A, on the summit of the Antarctic plateau, through the uninterrupted 4-month period of
winter darkness. An earlier paper discussed optimisation of the K dark filter for sensitivity (Li et al. 2016). Here
we examine the scientific program for KISS. We calculate the sensitivity of the camera for the extrema of
observing conditions that will be encountered. We present the parameters for sample surveys that could then
be carried out for a range of cadences and sensitivities. We then discuss several science programs that could be
conducted with these capabilities, involving star formation, brown dwarfs and hot Jupiters, exoplanets around
M dwarfs, the terminal phases of stellar evolution, fast transients, embedded supernova searches,
reverberation mapping of AGN, gamma ray bursts and the detection of the cosmic infrared background.

145
528
The BLAST-TNG Experiment

Federico Nati1 (fnati@physics.upenn.edu)

1
University of Pennsylvania, Physics and Astronomy, Philadelphia, United States

BLAST-TNG is a long-duration, high altitude, balloon-borne telescope scheduled to fly in the 2018-2019 season
from Antarctica. The data from the 28 day flight will provide new insight into the properties of dust and the
role of magnetic fields in the interstellar medium through a wide range of densities, producing several degree-
scale polarimetric maps at sub-arcminute resolution. It will perform simultaneous measurements in its 3 broad
bands centered at 250, 350, and 500 µm. BLAST-TNG is the rebuilt and upgraded Balloon-borne Large Aperture
Sub-millimeter Telescope for Polarimetry (BLASTPol), and with a 16-fold increase in mapping speed it will make
larger and deeper maps. Major improvements include a 2.5 m carbon fiber mirror (40% larger diameter than
the BLASTPol mirror), and ~3000 polarization sensitive detectors. The telescope will also serve as a pathfinder
project for microwave kinetic inductance detector (MKID) technology, applied to feed-horn coupled sub-
millimeter detector arrays. The arrays are cooled to 270 mK by a closed-cycle 3He refrigerator, all enclosed in a
liquid helium cooled cryostat with long hold time (28 days expected). This will enable us to map more targets at
a much higher level of detail than any sub-millimeter polarimeter to date. BLAST-TNG will also be the first
balloon-borne telescope to offer shared risk observing time to the community.

146
2414
Cosmic Ray and Air Shower Studies with IceCube

Javier Gonzalez1 (javierg@udel.edu)

1
University of Delaware, Newark, United States

The IceCube Neutrino Observatory at the South Pole has been in stable operation since it was completed in
2010. The observatory consists of an array of more than 5000 optical modules deployed between 1450m and
2450m deep in the Antarctic ice, and IceTop, an array of detectors on the surface of the ice. These two arrays
provide a complementary view of cosmic ray induced air showers, giving us a unique vantage point to study
cosmic rays and the air showers they produce. We will review the insights we have gained on the composition
of the cosmic ray flux and on high-energy interactions by using this hybrid approach. We will also discuss how
the combination of a surface detector with a deep detector can be used to further the search for the sources of
astrophysical neutrinos.

147
511
Advances in the LAGO Antarctic Node Implementation Design

Adriana Maria Gulisano1 (adrianagulisano@gmail.com), Sergio Dasso2, Omar Areso3, Maximiliano Ramelli3,
Matias Pereira3, Ubaldo Hereñú3, Hernán Asorey4, Viviana Elisa López5, Héctor Ochoa6
1
IAA/DNA, IAFE (UBA-CONICET), Depto de Física FCEyN UBAA, Atmospheric Sciences Department, Vicente Lopez,
BsAs, Argentina, 2IAFE (UBA-CONICET), DCAO FCEyN UBA, Depto de Física, Ciudad autónoma de Buenos Aires,
Argentina, 3IAFE (UBA-CONICET), Ciudad Autónoma de Buenos Aires, Argentina, 4Laboratorio Detección de
Partículas y Radiación, Instituto Balseiro y Centro Atómico Bariloche, Bariloche, Argentina, 5Servicio
Meteorológico Nacional, Ciudad Autónoma de Buenos Aires, Argentina, 6IAA/DNA, Ciudad Autónoma de Buenos
Aires, Argentina

The LAGO (Latin American Giant Observatory) project is a collaborative network of Cherenkov detectors in
water (WCDs) over ten Latin American countries (Argentina, Bolivia, Colombia, Chile, Ecuador, Guatemala,
Mexico, Peru, Venezuela, and Brazil). The Scientific Objectives include the study of the energy spectrum and
the integrated flux of the secondary particles generated by the primaries at the atmosphere. The collaboration
network has nodes at sites with different rigidity cut-offs and different altitudes and asseses the monitoring of
the Space Weather conditions through the modulation of the cosmic ray flux . This node will also permit to
analyze energetic particles from solar origin, the so-called Ground Level Enhancements (GLEs), We present the
update of the testing results for the implementation of the LAGO node in Antarctica. These were obtained at
the precampaign of 2017, where the in situ data telemetry testing was performed for the meteorological
station designed for the Marambio node, including the testing of the thermic control for the system. The
improvements in the new design of the Cherenkov detector in water and first results are also presented.

On behalf of the The Latin American Giant Observatory (LAGO) Collaboration, Ciudad Autónoma de Buenos
Aires, Argentina. See List of Members at www.lagoproject.org, lago-pi@lagoproject.org

148
OS-6c - Polar Ocean Dynamics
19.06.2018 14:00-15:30, A Forum

1002
Dynamic Barriers Preventing Flow of Warm Ocean Currents into Ice Shelf Cavities

Anna Wåhlin1 (anna@gu.se), Nadine Steiger2, Celiné Héuzé1, Elin Darelius2, Mirjam Glessmer3, Laura Herraiz-
Borruguero4, Ho Kyung Ha5, Adrian Jenkins6, Tae Wan Kim7, Jean Baptiste Sallee8, Joel Sommeria9, Samuel
Viboud9
1
University of Gothenburg, Department of Marine Sciences, Gothenburg, Sweden, 2University of Bergen, bergen,
Norway, 3Kiel University, Kiel, Germany, 4University of Southampton, Southampton, United Kingdom, 5Inha
University, Seoul, Korea, Republic of, 6British Antarctic Survey, Cambridge, United Kingdom, 7KOPRI, Incheon,
Korea, Republic of, 8LOCEAN, Paris, France, 9LEGI, Grenoble, France

The observed thinning of many of the ice-shelves surrounding the Antarctic Ice Sheet is linked to oceanic heat
fluxes, but the dynamics governing the flow of ocean currents towards and into the ice shelf cavities are poorly
known. Dynamical constraints cause large scale, geostrophically balanced flows to follow depth contours. The
warm salty ocean currents hence move towards the ice shelf cavities mainly in the deep troughs connecting the
shelf break to the inner shelf. The water must then pass the ice shelf front - a vertical ice wall with a draft of
several hundreds of meter, representing a major discontinuity in the water column thickness. Conservation of
potential vorticity is expected to restrict barotropic flow across the front and into the ice-shelf cavity. It is not
clear to what extent currents are blocked by the ice shelf front, and whether there is a difference between
baroclinic and barotropic flows in entering the cavity.
We present the results of a set of experiments conducted on the Coriolis rotating platform. By inserting an
idealized ice shelf on top of a deep trough representing an Antarctic continental shelf and ice shelf cavity,
dynamical constraints of this system were explored. Barotropic and baroclinic currents were created by
pumping water of different density in the trough and the flow was documented using in situ probes and various
image techniques.

149
1183
Atlantic Water Supply toward the 79N Glacier in Northeast Greenland

Torsten Kanzow1,2 (torsten.kanzow@awi.de), Janin Schaffer1, Claudia Wekerle1, Wilken-Jon von Appen1, Sandra
Tippenhauer1, Christoph Mayer3, Paul Dodd4, Andreas Münchow5
1
Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2Bremen
University, Physics and Electrical Engineering, Bremen, Germany, 3Bayerische Akademie der Wissenschaften,
München, Germany, 4Norwegian Polar Institute, Tromsø, Norway, 5University of Delaware, Newark, United
States

The ocean plays an important role in modulating the mass of the Greenland Ice Sheet by delivering heat to the
marine outlet glaciers. The largest of the glaciers draining the Northeast Greenland Ice Stream is the 79 North
Glacier. It is in contact with subsurface, warm Atlantic Water (AW). In order to understand how the AW
supplies heat towards the glacier, we analyse mooring-based, shipboard and AUV-based observations obtained
between 2014 and 2017 on the shelf of Northeast Greenland, complemented by an eddy-resolving ocean-sea
ice model, which realistically represents the AW circulation in Fram Strait.
A sizeable amount of the AW carried northward from the Subtropics toward the Nordic Seas recirculates in
Fram Strait, contributing to both the subduction below cold and fresh Polar Water and the formation of the
East Greenland Current. A trough system on the shelf allows for the penetration of the subsurface AW across
the 300 km wide shelf toward the inner shelf as a narrow boundary current.
Our moored measurements reveal a year-round, subsurface flow of AW towards the glacier, feeding into a
hydraulically controlled density plume in the vicinity of the calving front, causing a rapid inflow of AW warmer
than 1°C into the subglacial cavity. Historical observations further suggest a coherent decadal increase in AW
temperatures both in Fram Strait and on the shelf. A warming-induced increase of basal melt may explain the
observed thinning of the glacier over the past 15 years.

150
1604
Heat Loss in the Atlantic Water Boundary Current North of Svalbard

Angelika Renner1 (angelika.renner@imr.no), Arild Sundfjord2, Markus Janout3, Randi Ingvaldsen4, Agnieszka
Beszczynska-Möller5
1
Institute of Marine Research, Tromsø, Norway, 2Norwegian Polar Institute, Tromsø, Norway, 3Alfred Wegener
Institute for Polar and Marine Research, Bremerhaven, Germany, 4Institute of Marine Research, Bergen,
Norway, 5Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland

A mooring array has been deployed since 2012 north of Svalbard, tracking the Atlantic Water (AW) inflow into
the Arctic Ocean as it follows the upper continental slope. This topographically steered boundary current is the
largest oceanic heat source for the Arctic Ocean. Heat content in the upper ocean varies significantly
throughout the year with largest heat transport and highest heat loss in autumn and winter. Between 22 and
31 deg E, the longitudes of the moorings, the annual mean heat loss along the slope north of Svalbard is 16 W
m^-2 in the upper 200 m. A large part of the AW heat is thus lost to the atmosphere. In autumn and early
winter, sea ice is advected into the region on several occastions. This coincides with episodic events of heat
fluxes > 100 W m^-2 which last over several days. These high ocean-to-ice heat fluxes contribute to ice melt
and help to keep the slope area ice free well into winter. A persistent ice cover is then established in March
2013, modulating air-sea fluxes and leading to the formation of a cold and fresh mixed layer above the AW
core. Local vertical processes such as wind- and tide-driven mixing and shedding of mesoscale eddies
contribute to the spatial and temporal variability in the heat content. This study underlines the complexity of
the oceanic heat budget in the Arctic Ocean inflow region north of Svalbard and highlights the ocean's role in
modulating the sea ice cover.

151
2676
Hotspots of Internal Solitary Waves and Mixing in the Ice-free Arctic Ocean

Igor Kozlov1,2,3 (igor.eko@gmail.com), Evgenia Zubkova1, Tomas Rippeth4, Mattias Green4, Benjamin Lincoln4,
Arild Sundfjord5, Vladimir Kudryavtsev1, Andrey Proshutinsky3
1
Russian State Hydrometeorological University, Satellite Oceanography Laboratory, St. Petersburg, Russian
Federation, 2Marine Hydrophysical Institure of RAS, Remote Sensing Department, Sevastopol, Russian
Federation, 3Woods Hole Oceanographic Institute, Physical Oceanography Department, Woods Hole, United
States, 4Bangor University, School of Ocean Sciences, Bangor, United Kingdom, 5Norvegian Polar Institute,
Tromsø, Norway

In this work we present the results of Arctic-wide observations of internal solitary waves (ISWs) derived from
high-resolution spaceborne synthetic aperture radar (SAR) measurements acquired over the seasonally ice-free
Arctic Ocean. Analysis of the data reveals key regions of ISW distribution that are primarily found over the
shelf/slope regions poleward the M2 critical latitude. Most of the ISWs are observed in regions where enhanced
tide-induced vertical mixing and heat fluxes have been previously reported. We further show that satellite-
derived probability of ISWs attributes well to model-predicted sites of high barotropic-to-baroclinic tidal energy
conversion. Positive correlation is also obtained between ISW probability and the rate of TKE dissipation
derived from microstructure observations over the continental slope, suggesting that internal solitary waves
may promote enhanced vertical mixing in these regions. This work is supported by RFBR grant 16-29-02106
mol_a_dk, RSF grant No. 17-77-30019, and FASO Russia project No. 0827-2014-0011. ENVISAT ASAR data used
in this study were provided by the European Space Agency (ESA) through Cat-1 Project C1F-29721.

152
499
Opening the Window to the Southern Ocean: Abrupt Change in Ventilation

Andreas Klocker1 (andreas.klocker@utas.edu.au)

1
University of Tasmania/Institute for Marine and Antarctic Studies, Hobart, Australia

The surface waters of the Southern Ocean act as a control valve through which climatically important tracers
such as heat, freshwater, and CO2 are transferred between the atmosphere and the ocean. The process that
transports these tracers through the surface mixed layer into the ocean interior is known as ocean ventilation.
Changes in ocean ventilation are thought to be important for both rapid transitions of the ocean´s global
overturning circulation during the last deglaciation, and the uptake and storage of excess heat and CO2 as a
consequence of anthropogenic climate change. Here I show how the interaction between Southern Ocean jets,
topographic features, and ocean stratification can lead to an abrupt change in Southern Ocean ventilation. For
increasing winds, this interaction leads from a state in which tracers are confined to the surface mixed layer, to
a state in which tracers fill the ocean interior. This abrupt onset of Southern Ocean ventilation with increasing
winds directly impacts the uptake of heat and CO2 into the global ocean. For the Kerguelen Plateau, in the
Indian sector of the Southern Ocean, this abrupt change in ventilation occurs for wind forcing predicted by
climate models for the 21st century. These results imply a prominent role for jet dynamics in understanding
rapid transitions of the global climate system.

153
1157
Subsurface Response of the Southern Ocean to Changing Westerly Winds

Edward Doddridge1 (ewd@mit.edu), John Marshall1

1
Massachusetts Institute of Technology, Earth, Atmospheric, and Planetary Sciences, Cambridge, United States

Anthropogenic influences have produced a strengthening and poleward shift of the westerly winds over the
Southern Ocean. We use observations and a hierarchy of models to explore the subsurface response of the
Southern Ocean to a step-change in the westerly wind. The initial response is robust across models and
observations, and consists of Ekman driven cooling at the surface and warming below the seasonal ice zone, as
well as warming in the seasonal thermocline due to increased vertical diffusion. However, the long-term
response is largely inaccessible from the observations and varies across models. The spread between the
models can be explained by variations in the response of the residual overturning circulation. Our results
highlight the importance of accurately representing the eddy contribution to the residual overturning
circulation, and may provide a mechanism to explain the discrepancy between model predicted warming of
Southern Ocean sea surface temperatures and the observed cooling.

154
OS-8 - Unifying perspectives: conceptualizing pan-Arctic and pan-Antarctic ecosystems
19.06.2018 14:00-15:30, A Dischma

203
New Concepts for the Role of Sea Ice in Structuring Southern Ocean Ecosystems

Klaus M Meiners1,2 (klaus.meiners@aad.gov.au)

1
Australian Antarctic Division, Department of the Environment and Energy, Kingston, Australia, 2Antarctic
Climate & Ecosystems CRC, University of Tasmania, Hobart, Australia

Studies in different sectors of the Southern Ocean have shown that sea ice structures Antarctic marine
ecosystems in multiple and complex ways. Sea ice acts as a biogeochemically active barrier for atmosphere—
ocean gas exchange, controls light availability for phytoplankton, serves as habitat for microalgae and provides
a refuge for pelagic herbivores. Antarctic sea ice is also changing with different sectors exhibiting opposite
trends in both sea ice extent and ice cover duration. Models predict a significant decline in Antarctic ice extent
and ice volume by the end of the century, and these changes are expected to have significant ramifications for
Southern Ocean ecosystems. In this presentation I will provide an overview of new and emerging concepts for
the role of sea ice in different sectors of the Southern Ocean, discuss the applicability of recently developed
Arctic concepts of ice algal and phytoplankton phenology on Antarctic marine ecosystems, and highlight new
research questioning the paradigm of the Antarctic sea ice - ice algae - krill relationship. Using recent findings
on the physical drivers of Antarctic ice algal temporal and spatial variability, I will highlight the need to better
understand sea ice quality rather than quantity to understand its role in structuring marine ecosystems.
Furthermore I will discuss problems associated with extrapolating cause - effect relationships, identified in one
Antarctic sector, to the entire Southern Ocean.

155
1119
An Integrative Conceptual Model of the Arctic Ocean's Freshwater System

Eddy Carmack1 (eddy.carmack@dfo-mpo.gc.ca), Kristina Brown1, Johnna Holding2, Motoyo Itoh3, Terry
Prowse4, William J. Williams1, Paul Wassmann5
1
Institute of Ocean Sciences, Department of Fisheries and Oceans Canada, Sidney, Canada, 2Aarhus University,
Arctic Research Centre ARC, Århus, Denmark, 3JAMSTEC, Institute of Arctic Climate and Environment Research,
Yokosuka, Japan, 4University of Victoria, Water & Climate Impacts Research Centre, Victoria, Canada, 5UiT The
Arctic University of Norway, Institute of Arctic and Marine Biology, Tromsø, Norway

Two facts stand out from recent research: first, many key processes within and external to the Arctic Ocean are
linked to its freshwater system, and second, the state and structure of the Arctic Ocean is undergoing rapid and
uncertain change. To address these two facts we here propose a revised and integrative conceptual model of
the Arctic Ocean freshwater system - its internal dynamics and external drivers - that links physics to
geochemistry and biology, and land and atmosphere to the ocean. In so doing we follow a scaled hierarchical
approach that recognizes regionality, seasonality, pattern and scale. The proposed model extends the Arctic
Ocean's freshwater budget far beyond its classical 'gateway' boundaries fully to the Tropics and mid-latitudes,
and draws attention to smaller scale sources and distributions within the Arctic Ocean.

156
1345
Arctic Marine Ecosystem Conceptual Model: Interactions Matrix Revealed (Part A)

Kristina Brown1 (kristina.brown@dfo-mpo.gc.ca), Johnna Holding2, Henry Huntington3, Uma Bhatt4, Susana
Agusti5, Carlos Duarte5, Eddy Carmack1, Paul Wassmann6
1
Institute of Ocean Sciences, Department of Fisheries and Oceans Canada, Sidney, BC, Canada, 2Aarhus
University, Arctic Research Centre ARC, Aarhus, Denmark, 3The Pew Charitable Trusts, Eagle River, United
States, 4University of Alaska - Fairbanks, Geophysical Institute, Fairbanks, United States, 5King Abdullah
University of Science and Technology, Red Sea Research Center, Thuwal, Saudi Arabia, 6University of Tromsø,
Faculty of Biosciences, Fisheries, and Economics, Tromsø, Norway

In November 2016, the US Bureau of Ocean Energy Management, Office of Naval Research, and National
Science Foundation supported a workshop to create a unifying pan-Arctic conceptual model of the current
state and future changes of the Arctic Marine Ecosystem (AME). One component of this conceptual model is a
matrix of interactions that determine the functioning of the AME. This matrix was developed using a
parsimonious list of Key Elements, distributed between five categories: Atmosphere, Land-Ocean/Shelf-
Interior Connections, Physical Environment, Biology, and Human Impacts. To determine the strength and
direction of connections between Key Elements, direct interactions were characterized in a matrix array by
evaluating directionality, relative magnitude, and scientific (un)certainty. Indirect interactions were removed,
because these should be captured by chains of direct interactions. We found a relative paucity of two-way
interactions between Key Elements as well as few very strong connections. Further work is needed to explore
indirect causal pathways and the existence of multi-element feedback loops. We present the results of this
work in two parts. In Part A we describe the iterative process followed creating the interactions matrix,
including the challenges of choosing and characterizing direct interactions. Discussion generated during this
presentation will be used to refine the matrix.

157
1352
Models and Methods to Support Marine Ecosystem Assessments for Polar Oceans

Rowan Trebilco1 (rowan.trebilco@utas.edu.au), Jess Melbourne-Thomas2, Michael Sumner2, Stuart Corney1,

Andrew Constable2
1
Antarctic Climate & Ecosystems CRC, University of Tasmania, Hobart, Australia, 2Australian Antarctic Division
and ACE CRC, Kingston, Australia

A fundamental challenge for marine ecosystem ecology and management is that the properties that determine
how ecosystems function are extremely hard to observe and measure - a challenge that is made even more
difficult by the remote and challenging environment of the Southern Ocean. Furthermore, because of the scale
and complexity of Southern Ocean ecosystems, it is hard to know how to robustly measure and summarize
their overall status, and track how status is changing (i.e. to measure trends). In response to these challenges,
there is growing international coordination to develop complementary suites of observation and models to
enable quantification of ecosystem status and trends at circumpolar scales. At the recent Marine Ecosystem
Assessment for the Southern Ocean (MEASO) conference in Hobart in April 2018, we sought to identify and
synthesise current capabilities and to identify key future priorities for models and methods to support
ecosystem assessment in the Southern Ocean. In this presentation, we summarise the outcomes of these
discussions. We also consider similarities and differences between Antarctic and Arctic ecosystems that may
help develop synergies in approaches to undertaking polar marine ecosystem assessments generally.

158
2100
Arctic Continental Slopes

Bodil Bluhm1 (bodil.bluhm@uit.no), Melanie Bergmann2, Antje Boetius2, Eddy Carmack3, Seth Danielson4, Maria
Gavrilo5, Jackie Grebmeier6, Ingrid Ellingsen7, Katrin Iken4, Markus Janout2, Russell Hopcroft4, Ksenia
Kosobokova8, Igor Polyakov4, Alexandra Ravelo9, Mikael Sejr10, Andrey Vedenin8
1
UiT The Arctic University of Norway, Arctic and Marine Biology, Tromso, Norway, 2Alfred Wegener Institute for
Polar and Marine Research, Bremerhaven, Germany, 3Institute of Ocean Sciences, Fisheries and Oceans Canada,
Victoria, Canada, 4University of Alaska - Fairbanks, Fairbanks, United States, 5National Park Russian Arctic,
Moscow, Russian Federation, 6University of Maryland Center for Environmental Science, Solomons, United
States, 7SINTEF, Trondheim, Norway, 8P.P. Shirshov Institute of Oceanology, Moscow, Russian Federation, 9Sitka
Sound Science Center, Sitka, United States, 10University of Aarhus, Aarhus, Denmark

Arctic continental slopes form a contiguous domain encircling the Arctic Basins and are currently experiencing
dramatic climate change. Here we present an integrative conceptual model that connects physical processes to
ecological conditions in both the water column and at the seafloor. Vertical gradients in water mass properties
above Arctic slopes are relatively large, while horizontal gradients along specific isobaths are weak, thus
resulting in lateral belts - intersected by numerous canyons - of similar physico-chemical conditions and
biological communities. The upper slope (approx. 200-800 m) is characterized by its contact with boundary
currents, while the lower slope (approx. 800-2500 m) is a more quiescent environment. Owing to its contact
with inflows from the sub-Arctic Atlantic and Pacific the upper slope domain is more productive, biomass rich
and distinct in community structure across trophic levels (from phytoplankton to seabirds). The upper slope
also shows evidence of a response to climate change including warming, sea ice loss, increased wind mixing,
and shelf-basin exchange. The lower slope, in contrast, is cooler, less dynamic, lower in pelagic and benthic
biomass and carbon input, and has not displayed evidence of climate change.

159
413
State of the Arctic Marine Biodiversity Report: Plankton across Sectors

Connie Lovejoy1,2 (connie.lovejoy@bio.ulaval.ca), Cecilie von Quillfeldt3, Russell Hopcroft4, Michel Poulin5, Mary
Thaler2, Kristin Arendt6, Hogni Debes7, Astthor Gislason8, Ksenia Kosobokova9
1
Université Laval, Biologie, Quebec, Canada, 2Institute de Biologie Intégrative et des Systémes, Quebec, Canada,
3
Norwegian Polar Institute, Tromso, Norway, 4University of Alaska Fairbanks, Fairbanks, United States,
5
Canadian Museum of Nature, Ottawa, Canada, 6Greenland Insitute of Natural Resources, Nuuk, Greenland,
7
University of the Faroe Islands, Tórshavn,, Faroe Islands, 8Marine and Freshwater Research Insitute, Reykjavík,
Iceland, 9P.P. Shirshov Institute of Oceanology, Moscow, Russian Federation

Microbial plankton and zooplankton are the base of the pelagic Arctic marine food web, feeding large-sized
zooplankton, fishes, seabirds and marine mammals. Changes in these species can have cascading effects
throughout the ecosystem and can represent the first sign of overall ecosystem perturbation. Despite their
importance, their biogeography and taxonomic diversity are underappreciated and inadequately known. The
Circumpolar Biodiversity Monitoring Program (CBMP) which is the cornerstone program of the Arctic Council´s
Conservation of Arctic Flora and Fauna (CAFF) Working Group has recently, published a review of status and
trends of Focal Ecosystem Components (FECs) across the Arctic. The CBMP Plankton Expert Network
aggregated and reviewed data on Bacteria, Archaea, phytoplankton, heterotrophic protists and zooplankton as
FECs across eight Arctic Marine Areas as well as documenting the state of current monitoring efforts for these
species. Plankton are strongly affected by climate and differ between open water and ice-cover conditions,
oceanic current patterns and salinity. Increased open water and less saline surface water could lead to range
shifts and establishment of non-Arctic species, with unknown consequences for the Arctic marine food web.
The approach and lessons learned from this exercise by scientists from all of the marine Circum-Arctic nations
could be applied to a pan-national initiative to monitor plankton across international claims in the Antarctic.

160
SH-2 - Indigenous Governance and Knowledge: Intersection of people, policy & priorities
19.06.2018 14:00-15:30, A Sertig

484
Towards Data Sovereignty for Indigenous Arctic Communities

Colleen Strawhacker1 (colleen.strawhacker@colorado.edu), Peter Pulsifer1, Noor Johnson1

1
National Snow and Ice Data Center, Boulder, United States

The Exchange for Local Observations and Knowledge of the Arctic (ELOKA, eloka-arctic.org) fosters
collaboration between resident Arctic experts and visiting researchers to facilitate the collection, preservation,
exchange, and use of local observations and Indigenous knowledge of the Arctic. ELOKA provides data
management and user support to Indigenous communities to ensure their data and knowledge are managed,
visualized, and shared in an ethical manner in order to work toward information and data sovereignty for Arctic
residents. In existence for over a decade, ELOKA's mission has evolved primarily from a data management
project, creating archival and preservation tools for Indigenous Knowledge and information, towards enabling
data and information sovereignty for our Indigenous partners. By data sovereignty, we mean that any data
collected by, for, and about Indigenous peoples should be held under the control of those Indigenous groups,
challenging many of the assertions made under the 'open data' movement. This paper will outline new efforts
and future directions of the ELOKA project to ensure sovereignty of Indigenous peoples over their data and
information, including full ownership and control over that information, with the development of a new
research coordination network to further ensure data sovereignty for Arctic Indigenous peoples.

161
2174
Community-based Monitoring and Resource Governance in the Arctic

Noor Johnson1,2 (noor.johnson@colorado.edu), Peter Pulsifer1, Colleen Strawhacker1

1
University of Colorado Boulder, National Snow and Ice Data Center, Boulder, United States, 2Tufts University,
Fletcher School of Law and Diplomacy, Medford, United States

Over the past decades, different actors have approached the Arctic with diverse agendas and visions, from
laboratory to resource frontier to wilderness in need of conservation action. For Arctic Indigenous residents,
these non-local visions impede a broad recognition of the Arctic as a homeland and adoption of governance
models rooted in recognition of Indigenous rights.
Alongside these developments, community-based monitoring (CBM) has been proposed as a mechanism for
supporting local involvement in resource governance, including oversight of extractive industry and
participation in wildlife management. The scientific community has also embraced CBM based on its potential
to contribute observations to broader scientific observing networks.
This paper examines possibilities and limitations of CBM as a mechanism to advance Indigenous peoples' rights
and research priorities. We consider examples of the role that CBM has played in co-management approaches
to resource governance as well as in community-initiated efforts for knowledge and information sovereignty.
We also examine the role of data infrastructure, including current barriers to access for Arctic communities, in
facilitating the use of CBM in different governance. We base our discussion on observations from participation
in several CBM network building initiatives as well as interviews with CBM practitioners and members of the
broader Arctic observing community.

162
1981
Mobilizing Inuit Research Methodologies: A Pond Inlet Case Study

Katherine Wilson1 (kjw314@mun.ca), Shelly Elverum2, Trevor Bell1, Andrew Arreak3

1
Memorial University, Geography, St. John's, Canada, 2Ikaarvik, Pond Inlet, Canada, 3SmartICE, Pond Inlet,
Canada

Inuit are heavily reliant on sea- ice travel for harvesting activities to maintain their nutritional and cultural
needs (ICC-Canada, 2008; 2014). In response to unprecedented changes in sea-ice due to climate warming, and
to augment Inuit decision-making in sustaining safe sea-ice travel, a community-driven sea-ice information
service called SmartICE was established in Pond Inlet, Nunavut, Canada (www.smartice.org). A community-
based participatory research (CBPR) approach (Castleden et al., 2015) is being followed to ensure SmartICE
meets community needs, builds capacity, reclaims leadership and decision-making roles for Inuit, and utilizes
Inuit Qaujimajatuqangit (IQ, Inuit Knowledge) on its own scientific merit. While Indigenous scholars find CBPR a
decolonizing ally (Kovach, 2009; Smith, 2012), it does not capture the relational accountability inherent in IQ,
(Price, 2007; McGrath, 2011; Healey, 2014). Thus, SmartICE has partnered with Ikaarvik, a community-based
organization in Pond Inlet that engages and empowers Inuit youth in community research
(www.vanaqua.org/act/direct-action/ikaarvik). Guided by IQ Societal Values (Government of Nunavut, 2013),
Ikaarvik youth are developing an Inuit specific relational accountability model called “scIQ” that bridges the
strengths of two ways of knowing between scientific enquiry and IQ. This presentation will highlight key
aspects of the developing scIQ-CBPR methodology to guide Inuit and non-Inuit in co-producing Arctic research.

163
773
Indigenous Rights and the Sámi in Sweden - An Analysis of the Girjas Trial

Charlotte Wenner1 (charlotte.wenner@gmail.com)

1
Eberhard-Karls Universität Tübingen, Tübingen, Germany

In 2009 a Sámi village went to court against the Swedish state to figure out who holds the right to permit
fishing and hunting in the village's reindeer herding land, owned by the State. The Girjas trial was the major
trial in recent years and gained international interest, especially since the district court granted the village an
exclusive right to permit fishing and hunting in the specific area. Hence, the trial is used to reflect the current
legislative and juridical situation of the Sámi in Sweden. Amongst others, inappropriate utterances by the state
attorney and the handling of the Sámi's status as an Indigenous People need to be taken into account, too. On
these grounds, the Girjas trial can also serve as a mirror for the social and sociological development and
situation of, inter alia, the relationship Sámi- Swedish state.
Sweden has been criticized repeatedly for not including the Sámi in decision making processes and for not
living up to the aims set by the UNDRIP. Therefore, this interdisciplinary study on one hand analyses the Girjas
trial by various factors - the legislative and juridical one and the social one- and on the other hand develops a
solution-oriented outlook. Since the Sámi are Europe's only Indigenous People, Sweden should work forward to
protect and promote their rights and their cultural heritage.

164
1893
Opportunities & Limitations in Co-managing Water Resources in Yukon, Canada

Sujata Manandhar1,2 (smanandhar@yukoncollege.yk.ca), Douglas A. Clark2

1
Yukon College, Northern Climate Exchange- Yukon Research Centre, Whitehorse, Canada, 2University of
Saskatchewan, School of Environment and Sustainability, Saskatoon, Canada

Yukon Energy Corporation (YEC) opened the Aishihik Hydroelectric Facility within Champagne and Aishihik First
Nations' (CAFN) Traditional Territory in the Yukon, in 1975. Since then, CAFN has repeatedly expressed social
and environmental concerns associated with the facility´s operation. As a solution to this persistent issue, YEC
and CAFN are currently undertaking to co-manage the water resources for the Aishihik Water License renewal
in 2019. One of their objectives is to fully integrate traditional knowledge into understanding the context and
issues, as well as making management decisions. However, water resource co-management is a new field of
governance, so opportunities and limitations are only just beginning to be identified. Our study assesses
opportunities and limitations of the ongoing co-management approach through a conceptual adaptive co-
management framework based on collaborative governance models. Data are collected using multiple methods
such as semi-structured interviews, and participants observation. We identify some of the complexities and
opportunities for improving water resources co-management in the Yukon, across Canada, and elsewhere.

165
2368
Changing Requirements for Indigenous Lands Documents: What Affect Do These Have?

Viktoriia Filippova1 (filippovav@mail.ru), Antonina Savvinova2, Gail Fondahl3

1
Institute for Humanities Research and Indigenous Studies of the North, Yakutsk, Russian Federation, 2M.K.
Ammosov North-Eastern Federal University, Yakutsk, Russian Federation, 3University of Northern British
Columbia, Prince George, Canada

This paper analyzes the extent to which the adoption of various laws on indigenous peoples has affected the
dynamics of the number of Clan Communes (korennye rodovye obshchiny or KROs), as well as the preparation
of concomitant documents (such as certificates and licenses), and cadastral maps. In the 1990s, to establish a
KRO required relatively informal documentation. More recently (year here) legally formalized documents are
required for the establishment and continued functioning of such indigenous organizations. We look at the
experiences of the Union of Clan Communes of South Yakutia, and its experiences with the increased
requirement for formalized paperwork. To what extent are those KROs without formalized documents
protected in today's legal environment? To what extent are they seeking the greater protection offered by
more extensive documentation? The Law on the Far East Hectare has accelerated the requirement for
documentation, a process that had already been initiated by the Government of Yakutia.

166
GG-2c - Arctic and Antarctic past ice sheet dynamics and paleoclimate evolution
19.06.2018 14:00-15:30, A Schwarzhorn

885
Greenland Ice Cores Tell Tales on past Sea Level Changes

Dorthe Dahl-Jensen1 (ddj@nbi.ku.dk)

1
University of Copenhagen, Niels Bohr Institute, Copehagen, Denmark

All the deep ice cores drilled to the base of the Greenland ice sheet contain ice from the previous warm climate
period, the Eemian 130-115 thousand years before present. This demonstrates the resilience of the Greenland
ice sheet to a warming of 5 oC. Studies of basal material further reveal the presence of boreal forest over
Greenland before ice covered Greenland. Conditions for Boreal forest implies temperatures at this time has
been more than 10 oC warmer than the present.
To compare the paleo-behavior of the Greenland ice sheet to the present in relation to sea level rise knowledge
gabs include the reaction of ice streams to climate changes. To address this the international EGRIP-project is
drilling an ice core in the center of the North East Greenland Ice Stream (NEGIS). The first results will be
presented.

167
1973
Variability of Terrigenous Supply in the Northern Bering Sea over the Past 23 ka

Yanguang Liu1 (yanguangliu@fio.org.cn), Xuefa Shi1, Tengfei Song1

1
First Institute of Oceanography, Department of Marine Geology, Qingdao, China

We use gravity core B11 recovered in the northern Bering Slope to reconstruct millennial-scale changes of
paleoproductivity and terrigenous matter supply since 23 ka BP. Based on the geochemical and high-resolution
XRF core logging data, our results demonstrate closely interactions between the paleoproductivity and the
terrigenous matter supply. Overall, the paleoproductivity is low during the LGM, Heinrich Stadial 1 (HS 1) and
Younger Dryas cold phases (YD), and high during Bølling/Allerød (B/A) and Holocene. There are calcium
carbonate peaks during B/A which suggest the high calcareous productivity whereas the siliceous productivity
increasing rapidly since B/A. The paleoproductivity turns sustained high after YD. Ice rafting debris(IRD) are one
of the major terrigenous matter of the Bering Slope, it plays significance role during the cold phases like LGM,
especially early HS 1 period. Sea ice extended southward to the Bering Slope carrying masses of shelf sediment
by glacier over deepening, the excavation transported vast of clay and terrigenous organic matter into the
Bering Slope which responses for the high clay and Total Organic Carbon (TOC) contents during HS 1. The high
Fe/S value reveals that the Bering Sea shallower than 1500m was well ventilated under the sea ice cover
condition during HS 1. Since B/A, the terrigenous matter source turns to be the submerged shelf which is
eroded by the current, tide and the river as the sea level raised.

168
1200
Late Cenozoic Sedimentary Processes Shaping the Lomonosov Ridge, Arctic Ocean

Lara F. Pérez1 (lfp@geus.dk), Tove Nielsen1, Thomas Funck1, Finn Mørk1, Katrine J. Andresen2, Martin
Jakobsson3
1
Geological Survey of Denmark and Greenland, Department of Geophysics, Copenhagen, Denmark, 2Aarhus
University, Department of Geoscience, Aarhus, Denmark, 3Stockholm University, Department of Geological
Sciences, Stockholm, Sweden

With local water depths (wd) shallower than 1000 m, the Lomonosov Ridge is the most prominent feature of
the Arctic Ocean. Several tectonic events have shaped the ridge during its Cenozoic history. Moreover, other
sedimentary processes have also contributed to the ridge shaping during the recent past. These processes are
poorly known, mainly due to the sparse coverage of data in the Arctic Ocean. However, substantial quantities
of geophysical data have been collected during the past years in the framework of international research
projects or the national UNCLOS programs of the circum-Arctic countries. Detailed analysis of the sub-bottom
profiles across the entire Lomonosov Ridge has revealed the regional distribution of sedimentary features in
the most recent sedimentary record, suggesting a variety of cryospheric and oceanographic processes involved
in their formation. Truncated reflectors are identified in the highs of the Siberian side of the Lomonosov Ridge,
above 1000 m wd. They have been linked to grounding ice sheet and iceberg ploughing. Sediment waves are
identified between 1000 and 1500 m wd particularly along the ridge flank towards Amundsen Basin, slightly
deepening in the surroundings of the North Pole. These sediment waves are linked to the Siberia-Greenland
flow of intermediate water masses in the Arctic Ocean constrained by the morphology of the Lomonosov Ridge
and following the Arctic cyclonic circulation.

169
2167
Last Interglacial Meltwater Signal from Far-field Sea-level and Proxy-climate

Ian Goodwin1 (ian.goodwin@mq.edu.au), Mick O'Leary2, Jerry Mitrovica3

1
Macquarie University, Sydney, Australia, 2Curtin University, Perth, Australia, 3Harvard University, Boston,
United States

Most of the geological record of Antarctic Ice Sheet extent during warmer interglacials has been lost due to
glacial expansion and retreat cycles, and the ice-core record is geographically sparse. We take the novel
approach of using the Southern Hemisphere (SH) coastal and specifically the Australian region imprint of sea-
level history to identify ice sheet instability during the last interglacial (MIS5). The unique sea level signal
archived in the coastal sediments and morphology contains evidence for a pulse of meltwater input during the
mid-late MIS5e of ~2-3 m of sea-level equivalent. The spatial pattern of the differential sea-level rise during
MIS5e, after correction for Glacio-Isostasy is matched to the gravitational meltwater fingerprint for each of the
three polar ice sheets to determine the origin of the excess meltwater and hence, the source of ice sheet
instability.
We also report our progress in reconstructing the MIS5e SH atmospheric pressure and wind field evolution. We
apply a coastal and climate proxy-data -model assimilation by using a Last Interglacial simulation together with
a regionally distributed multivariate proxy dataset, to produce atmospheric reanalysis for 129 ka BP, 125 ka BP
and 120 ka BP (after Goodwin et al., Clim. Dyn., 2013). Ultimately, we compare the atmospheric circulation
patterns together with the meltwater fingerprint pattern to the MIS5e ice core record and the Antarctic shelf-
sedimentary record of meltwater discharge.

170
2014
Environmental Conditions in East Antarctica - Evidence from Mumiyo Deposits

Sonja Berg1 (sberg0@uni-koeln.de), Martin Melles1, Wolf-Dieter Hermichen2, Janet Rethemeyer1, Gerhard
Kuhn3
1
University of Cologne/Institute of Geology and Mineralogy, Cologne, Germany, 2Alfred Wegener Institute -
Helmholtz Center for Polar and Marine Research, Potsdam, Germany, 3Alfred Wegener Institute - Helmholtz
Center for Polar and Marine Research, Bremerhaven, Germany

Antarctic snow petrels (Pagodroma nivea) produce stomach oil, which is ejected against predators to defend
their nests. In some locations stomach oil accumulates and fossilizes and forms centimetre to decimetre thick
deposits of so-called Antarctic mumiyo.
We studied mumiyo deposits from different sites in central Dronning Maud Land to explore their potential as a
paleoclimate archive. Comprehensive 14C-analysis shows that the finely-laminated deposits provide consistent
age depth profiles. Besides from organic compounds, which are derived from stomach oil (mainly wax-ethers),
the deposits contain inorganic minerogenic particles sourced from bedrock and from guano. High-resolution
XRF elemental scans indicate that changes in inorganic composition are consistent within one deposit and likely
reflect local environmental conditions. Mumyio profiles from one region can be correlated based on their age
and chemical composition, which suggests that the deposits provide a regional signal.
Our data confirm the existence of un-glaciated areas during the Last Glacial Maximum (LGM) and extend the
archive far into Marine Isotope Stage (MIS) 3, which is poorly understood in coastal Antarctica

171
1656
New Constraints on post-LGM Ice Sheet Dynamics in the Southern Weddell Sea

Jan Erik Arndt1 (jan.erik.arndt@awi.de), Claus-Dieter Hillenbrand2, Hannes Grobe1, Gerhard Kuhn1, Lukas
Wacker3, Robert D. Larter2, Boris Dorschel1, Simon Sørli4, Matthias Forwick4
1
Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, 2British Antarctic Survey,
Cambridge, United Kingdom, 3ETH Zurich, Zürich, Switzerland, 4UiT The Arctic University of Norway in Tromsø,
Tromsø, Norway

Past ice sheet conditions in the southern Weddell Sea remain poorly known. Previous studies have led to
contradicting scenarios of maximum ice extent during the Last Glacial Maximum (LGM). Scenario A is mainly
based on terrestrial data indicating limited ice sheet thickening in the hinterland and suggests a LGM
grounding-line position on the inner shelf. Scenario B is based on marine geological/-physical data and
concludes that the grounding line was located on the outer shelf (~650 km further offshore than in scenario A).
In addition, studies suggest a complex history of ice retreat and drainage pattern since the LGM that needs
further constraint. We investigated hydroacoustic data acquired during 17 expeditions. A key finding is a
previously unknown stacked grounding zone wedge (GZW) located in Filchner Trough on the outer shelf
showing that a palaeo-ice stream stabilized at this position at least twice. Radiocarbon dates from sediment
cores indicate that (i) the GZW was formed in the early Holocene and (ii) grounded ice did not extend seaward
at the LGM. Hence, the grounding line in Filchner Trough experienced dynamic changes in the Holocene and ice
sheet retreat after the LGM was not linear. Ice-flow switches in the hinterland possibly explain this behaviour.
Further interesting findings are made in Brunt Basin suggesting the existence of cold-based ice or impacts of
large icebergs. In addition, new data will be acquired in the area with RV Polarstern in Jan-Mar 2018.

172
OC-4 - Art meets Science: That Which Cannot Be Transmitted
19.06.2018 14:00-15:30, A Seehorn

2330
That Which Cannot Be Transmitted

Sandra Kuehne1 (info@sandrakuehne.ch), Tamsin Relly2, Daniel Kukla3

1
Visual Artist, Zürich, Switzerland, 2Visual Artist, London, United Kingdom, 3Visual Artist, New York, United
States

In 2014 a group of visual artists sailed in a tall ship up the west coast of Svalbard. They all witnessed the same
landscape, yet, as they filtered the experience through their individual thematic and aesthetic concerns, a
series of translations occurred, across a range of media including photography, video and drawing. In response,
seven of the artists developed That Which Cannot Be Transmitted, a project which considers how the process
of translation can shape contemporary discourse about the Arctic. Exploring overlapping themes of temporality
and the Anthropocene, three of these artists will each present their work.
Tamsin Relly works with the fluid and unpredictable qualities of printmaking and photography to disrupt the
translation of landscape into image, and offer impressions of environments in states of uncertainty or
impermanence.
Paper, lines and cutting are central to Sandra Kuehne´s practice. Printed materials such as polar maps are
frequently used as media. Kuehne employs the variations of the line, its formal lyricism, but also challenges the
absolute assertion of any printed map by making references to topography that is in continual flux.
Daniel Kukla´s work is informed by the intersection of his art practice and formal training in the biological and
anthropological sciences. He is interested in the shifting tensions towards the natural world as our society
expands with an insatiable appetite for resources.

173
1726
Invisible Dust: Making the Invisible Visible

Victoria Burns1 (victoria@invisibledust.com)

1
Invisible Dust, London, United Kingdom

Invisible Dust's mission is to encourage awareness of, and meaningful responses to, climate change and
environmental issues. We facilitate dialogue between leading visual artists, creative technologists and
scientists.
We aim to connect with people on a personal level through making the invisible visible.
Visibility plays a key role in creating understanding around the need to live sustainably and dramatically reduce
climate change. Artists have many ways of making things visible and, particularly since the Land Art movement
in the 60s and 70s (such as the ephemeral works of Richard Long and Robert Smithson) have responded to
changes in the natural environment in a variety of forms.
How can people understand their own effect on the environment when the resulting gases disappear into the
sky? Since the industrial revolution there have been huge gains to society but the creation of many of the gases
are now poisoning the earth. Invisible Dust creates partnerships to illuminate these consequences and bring a
sense of something human and fantastical to often very invisible problems.
Our lecture will case study Kasia Molga's Human Sensor which premiered in the streets of Manchester in 2016 -
Molga created striking wearables which change colour in response to air pollution; and our 2017 exhibition
Offshore - Artist Explore the Sea which included 23 artists works and 10 new commissions which were created
in consultation with Ocean Scientists.

174
2220
There Is Always Something More Important

Mariele Neudecker1 (mail@marieleneudecker.co.uk)

1
Bath School or Art and Design - Bath Spa University, Fine Art, Bath, United Kingdom

Both scientific scrutiny and intuitive artistic exploration can give insights to the blurred zones between
subjectivity and objectivity and alter our perception of the world.
I am a visual artist and often use technology's virtual capabilities in order to reproduce a heightened
experience, often of Northern or Arctic landscapes. I am interested in notions of a contemporary sublime and
have worked with scientists and engineers and their methods and research with the on-going quest to make
the immeasurable measurable, the invisible visible.
I find it inspiring to look at places and situations that are overtly international, with a communal goal of seeking
new knowledge, often situated on the fringes of civilization. In these “borderless” places, we find academic
research centres that prioritize humanity to a social and political unit, where egos, politics and nationalities
have become secondary.
I have travelled in Arctic Scandinavia and Greenland. With works that followed these journeys, I have been
exploring the interphases and overlaps of imaginary and factual realities, the two and three-dimensional, as
well as the analogue and digital.
In this talk I will present my projects that connect to the Poles or the Arctic in some way. I work with a variety
of media, including sound, sculptural installations and scale.
I am interested in how knowledge: past, present and future, can come to life and what it means to be human in
age of the Anthropcene.

175
2591
Resonant Evidence: Music and Soundscapes from the Ice

Douglas Quin1 (dhquin@syr.edu), Jay Needham2

1
Syracuse University, Television, Radio & Film, Syracuse, United States, 2Southern Illinois University Carbondale,
Carbondale, United States

This 15-minute panel focuses on the work of Jay Needham and Douglas Quin, two sound artists with extensive
polar experience.
Needham utilizes multiple creative platforms and his works often have a focus on recorded sound, archives and
the interpretation of artifacts. His field recordings from Antarctica have become the basis for his composition
Chronography: Animal, that premiered at the Internationale Ferienkurse für Neue Musik Darmstadt in 2012.
An interest in soundscape and where art and science intersect are threaded throughout Quin's practice: from
direct collaboration with scientists in field-based bioacoustics research into Weddell seal vocalization to
drawing inspiration from and using ice-core data to inform compositional strategies and outcomes. Quin was
the first composer and sound artist to be selected by the US National Science Foundation's Antarctic Artists and
Writers Program in 1996. Over the past 20 years, his varied polar projects include site-specific and interactive
sound installations, soundscape recording, composition, performance, live satellite broadcasts, and film.
The panel will include discussion and listening to samples of their compositions.

176
1690
Modern Hyperboreans

Evgenia Arbugaeva1 (arbugaeva@gmail.com)

1
Freelance Visual Artist, Yakutsk, Russian Federation

I am a documentary photographer, most of my life has been spent traveling in the North and pursuing personal
stories and editorial assignments: I have been visiting hard-to-reach scientific stations; migrated with Nenets
reindeer herders; explored the rush for natural resources across the Arctic; and lived on New Siberian islands
with “pirates” who excavate mammoth tusks from melting permafrost.
In my journeys, I'm attracted to the visual simplicity of the Arctic landscape, and to the emotional complexity of
the humans who inhabit it. I am curious about the motives that bring people to remote Arctic locations — a
land that, quite honestly, is not made for living. But its remoteness offers refuge to those souls that seek
isolation.
In this presentation, I would like to share the story of Slava - chief of the meteorological station Khodovarikha
located on the narrow peninsula in the Barents Sea in Russia. Slava has been living at the station for 13 years.
He is the kind of rare character that you meet only in the Arctic - Polyarnik, a specialist in the polar north, a
hermit who chooses to live away from the rest of the world. Looking at him, I had a strange feeling that he is
not only measuring the weather, but that he also lights up the sky with the Aurora Borealis, exchanges news
with the wind, and converses with the sea. I tried to capture this impression in my photographs of a weather
magician living in extreme solitude.

177
TE-3c - Remote sensing of polar regions
19.06.2018 14:00-15:30, A Wisshorn

32
Geospatial Tracking of Antarctic Iceberg Calving via Indian Space-borne Missions

Shridhar Jawak1 (shridhar.jawak@gmail.com), Alvarinho Luis1

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Ministry of Earth Sciences, Vasco da Gama,
India

This study focuses on the tracking of iceberg calving events in the vicinity of Larsemann hills and environ, Ingrid
Christensen coast, east Antarctica using multispectral images from Linear Imaging Self Scanning Sensor (LISS-IV)
aboard IRS-P6 satellite. The two images captured specifically 384 days apart from LISS-IV, enabled a detailed
understanding of the changes that have occurred during this short epoch. A careful and expert-guided
onscreen manual digitization was used for tracing icebergs present in both the images. A total of 369 common
icebergs present in both images were identified on the basis of their shape, size and texture for analyzing the
changes in their dimensions because of melting or disintegration. Also, several among these were found to
have deformed and diminished during the period from December 31, 2013 and January 19, 2015. Our analysis
estimates that the number of icebergs is decreased by 70 from 2013 to 2015, suggesting the complete
disintegration of these icebergs over the ≈1 year period. In case of 369 common icebergs, the total surface area
has been decreased by 12.51%, suggesting the melting of icebergs in the given time period. The average
deviation of the newly disintegrated icebergs from the coastline is found to be 51.59 m for 384 days. This study
demonstrates the quantitative analysis of iceberg calving, changes in iceberg numbers, rate of iceberg
disintegration, and rate of iceberg drift in the Prydz bay of the Larsemann hills area.

178
316
Snowmelt in Antarctica as Derived from SMOS Observations

Marion Leduc-Leballeur1 (m.leduc@ifac.cnr.it), Ghislain Picard2, Giovanni Macelloni1, Arnaud Mialon3, Marco
Brogioni1, Yann H Kerr3
1
IFAC-CNR, Sesto Fiorentino, Italy, 2IGE, UGA-CNRS, Grenoble, France, 3CESBIO, CNES, CNRS, IRD, UPS, Toulouse,
France

In the polar regions, the state of the surface is essential to understanding and predicting the surface energy
and mass budgets, which are two key nivo-meteorological variables for the study of the climate and the
contribution to the sea level rise of ice-sheets. The inter-annual variations of melt duration and extent are
valuable indicators of the summer climate in coastal regions of the ice-sheets, especially on ice-shelves where
melt water contributes to their fate.
Liquid water have a significant impact on the microwave emissivity of the surface and several studies exploited
the 19 and 37 GHz long time series to detect snowmelt events. The European Space Agency (ESA)'s SMOS
satellite carried on board a microwave radiometer operating at 1.4 GHz. At this low frequency, the signal is
sensitive to a large thickness of snow when it is dry contrary to higher microwave frequencies, which are
sensitive up to the first meters of the snowpack. Thanks this large penetration depth, SMOS observations could
detect if melt water persists at depth and impacts on snowpack stability. In this study, we developed
algorithms based on previous studies in order to detect melt from the SMOS brightness temperature at
horizontal polarization. Snowmelt product is obtained from July 2010 and June 2015 with SMOS observations.
Here, we explore the potential of combined low and high frequencies to provide a synergetic description of
surface melting events in Antarctica and investigate their variations.

179
1761
Long-term Antarctic Elevation Change from Multi-mission Satellite Altimetry

Ludwig Schröder1 (ludwig.schroeder@tu-dresden.de), Martin Horwath1, Reinhard Dietrich1, Veit Helm2

1
Technische Universität Dresden, Institut für Planetare Geodäsie, Dresden, Germany, 2Alfred Wegener Institute -
Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

The contribution of the Antarctic Ice Sheet to present-day sea level change still contains large uncertainties. In
several regions of West Antarctica, changing ice flow leads to rapid dynamic thinning while in East Antarctica
the rates are relatively small. The time period of a single satellite altimetry mission is not long enough to
distinguish between long-term elevation changes and interannual variations. Therefore, we apply a multi-
mission approach to combine the observations of different missions and thus are able to create a joint long-
term elevation time series. We show that a consistent reprocessing of ice sheet altimetry from different
missions is not only a prerequisite for the combination, but also improves the accuracy and precision of
conventional pulse limited radar altimetry by about 30%. We will discuss which special aspects have to be
considered when combining conventional radar altimetry with the high resolution SARIn-mode data of CryoSat-
2 and the high precision ICESat laser altimeter measurements. Therefore we will present a novel approach to
create a joint time series. Our results provide an unprecedented insight into the variations of the interior of
East Antarctica and help to separate the long-term trends from interannual variations.

180
1861
Surface Water Ocean Topography Mission Retrievals in the Ice-covered Ocean

Thomas Armitage1 (tom.w.armitage@jpl.nasa.gov), Ron Kwok1

1
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States

Satellite radar altimetry has proven to be a valuable tool for remote sensing of the polar oceans, with
techniques for estimating sea ice thickness and sea surface height in the ice-covered ocean advancing to the
point of becoming routine, if not operational, products. Scheduled for launch in 2021, the Surface Water Ocean
Topography mission (SWOT) payload, the Ka-band Radar Interferometer (KaRIn), will employ radar
interferometry to estimate an ~120km across-track swath of surface elevation. In the polar oceans, SWOT will
provide high resolution two-dimensional maps of sea level and sea ice elevation, offering the potential to
derive instantaneous 2-D ocean currents and a detailed picture of the sea ice thickness distribution. Here, we
present results from preliminary investigations into the KaRIn retrieval performance in the ice-covered oceans.
First, we utilise the available near-incidence Ka-band airborne and satellite data to study the range of possible
radar backscatter profiles. Second, the range of possible radar backscatter profiles will be applied in the SWOT
mission simulator to produce synthetic data and evaluate the expected measurement capability.

181
2051
Recent Achievements in Deriving Sea Ice Thickness from Radar Altimetry

Robert Ricker1 (robert.ricker@awi.de), Stefan Hendricks1, Stephan Paul1, Lars Kaleschke2, Xiangshan Tian-
Kunze2
1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2University
of Hamburg, Hamburg, Germany

The retrieval of Arctic sea ice thickness is one of the major objectives of the European CryoSat-2 radar altimeter
mission and the 7-year long period of operation has produced an unprecedented record of monthly sea ice
thickness information. We present CryoSat-2 results that show changes and variability of Arctic sea ice for the
period 2010 to 2018. CryoSat-2, however, was designed to observe thick perennial sea ice, while retrieving thin
seasonal sea ice accurately is more challenging. We have therefore developed a method of completing and
improving Arctic sea ice thickness information by merging complementary satellite retrievals. The European
SMOS satellite can detect thin sea ice, whereas its companion CryoSat-2 lacks sensitivity. Using these satellite
missions together overcomes several issues of single-mission retrievals and provides a more accurate and
comprehensive view on the state of Arctic sea-ice thickness at higher temporal resolution. Nevertheless, stand-
alone CryoSat-2 observations can be used as reference data for the exploitation of older radar altimetry data
sets over sea ice. In order to observe trends in sea ice thickness, it is required to minimize biases between
subsequent satellite missions. We show a climate data record of sea ice thickness derived from satellite radar
altimetry that has been developed for both hemispheres, based on the 15-year (2002-2017) monthly retrievals
from Envisat and CryoSat-2 and calibrated in the 2010-2012 overlap period.

182
2360
The Last Antarctic Frontier: Airborne Survey of the Satellite South Pole Datagap

Rene Forsberg1 (rf@space.dtu.dk), Arne V Olesen1, Tom Jordan2, Fausto Ferracioli2, Hugh F J Corr2, Kenichi
Matsuoka3
1
Technical University of Denmark, DTU Space - National Space Institute, Kongens Lyngby, Denmark, 2British
Antarctic Survey/NERC, Cambridge, United Kingdom, 3Norwegian Polar Institute, Tromsø, Norway

Satellite remote sensing cover Antarctica to varying degrees, leaving polar data acquisition gaps, depending on
satellite orbit inclination. While GRACE provided mass change data for all of Antarctica, radar and laser satellite
altimetry missions such as CryoSat, IceSat and EnviSat covered only regions in the range from 88-83°S from the
South Pole; recent geophysical missions such as GOCE (gravity field) and SWARM (magnetic field) covered only
regions north of 83°S and 87°S, respectively. To improve the coverage of the polar gap region, especially for the
GOCE mission, the European Space Agency funded a major airborne remote sensing campaign - PolarGap
2015/16 - to provide a first systematic fill-in of the southern polar gap data. The PolarGap campaign were
carried out by a British Antarctic Survey Twin-Otter operating from two deep interior field camps and
Amundsen-Scott South Pole station, collecting a variety of lidar, radar, gravity and magnetic data. In the
presentation the results of the PolarGap campaign are presented, along with comparisons to satellite data in
the overlap zones, and some of the major discoveries summarized. The comparisons confirm large errors in
existing data compilations such as BEDMAP2, ADMAP and ANTGRAV, and also provide new understanding of
CryoSat Ku-band radar firm penetration on the Antarctic Plateau, confirming the sub-meter accuracy in ice
sheet radar elevation mapping.

183
OC-1_OC-2c - Innovation, partnership and impact in polar science communication & Polar
Research and Citizen Science: Exploring New Platforms and Opportunities
19.06.2018 14:00-15:30, B Pischa

1848
Using Digital Resources to Stimulate International Public Engagement

Jean Holloway1 (jean.holloway77@gmail.com), Alexander Thornton2, Jilda Caccavo3, Gabriela Roldan4, Hanne
Nielsen5, Gerlis Fugmann6
1
University of Ottawa, Geography, Environment and Geomatics, Ottawa, Canada, 2University of Alaska -
Fairbanks, Fairbanks, United States, 3University of Padova, Padua, Italy, 4University of Canterbury, Christchurch,
New Zealand, 5University of Tasmania, Hobart, Australia, 6Association of Polar Early Career Scientists, Alfred-
Wegener Institute, Helmholtz Center for Polar and Marine Research, Potsdam, Germany

The Association of Polar Early Career Scientists (APECS) is a multidisciplinary, international organization
dedicated to maintaining a network of early career researchers to share ideas, develop collaborative research
directions, provide career development opportunities, and promote education and outreach related to polar
research. APECS has stimulated polar literacy through innovative science communication, well-integrated
public outreach and engagement, and partnerships with Arctic and Antarctic organizations. Examples of one-
and two-way engagement between APECS' members and the general public are illustrated in our involvement
with digital events and social media initiatives. Successful events include Antarctica Day, webinars, and APECS'
annual online conference. One of our popular social media initiatives is the biannual Polar Week celebration.
This includes Twitter campaigns, Reddit “Ask Me Anything” discussions, and photo and video contests. Benefits
to using modern technologies and techniques for stimulating public engagement about polar research include
easier dissemination of ideas across geographical distances as well as to remote areas with minimal cost and a
low carbon footprint. While this presentation focuses on APECS' experiences, we will highlight how innovative
communication promotes international discussion and cooperation across disciplines, then offer suggestions
on how to incorporate similar elements into other outreach programs.

184
380
The Power of the Tourism Fleet to Contribute to Science and Create Ambassadors

Annette Bombosch1,2 (annette.polarcollective@gmail.com), Robert W. Gilmore1, Lauren Farmer2, Alex Cowan2,

Ted Cheeseman3, Susan Adie2, Brandon Harvey1
1
Polar Latitudes, White River Junction, United States, 2G Adventures, Toronto, Canada, 3Southern Cross
University, Lismore, Australia

Polar Regions are the focus of scientific research due to accelerated effects of climate change. Yet data
collection in these areas is often limited by its remoteness and financial constraints. At the same time these
areas experience increased traffic due to a heightened interest amongst travellers and a growing tourism fleet.
Often visitors are well-educated and eager to gain a deeper understanding of the places they visit. Citizen
science has developed into a recognised and indispensable means for robust data collection and guest
education.
Expedition ships operate entire seasons in Polar Regions, providing cost-effective platforms for data collection
over longer time periods than research cruises. Benefits of citizen science projects aboard encompass valuable
data for the scientific community as well as turning guests into active polar ambassadors by increasing
awareness and concern for the conservation of the Polar Regions.
Here we present how to successfully undertake citizen science programs aboard, using examples from tour
operators Polar Latitudes and G Adventures, as well as how to coordinate data collection amongst the tourism
fleet. Possibilities for guest engagement cover activities aboard, during Zodiac and land excursions. Challenges
addressed include selecting suitable projects ensuring both data quality and feedback from scientists. Also an
ambitious platform for coordinating and faciliating industry-wide citizen science efforts is introduced.

185
866
Antarctic Ambassadors Explore Meltwater Influence on Phytoplankton within Fjords

Allison Lee1 (allisonlee9@gmail.com), Maria Vernet1

1
Scripps Institution of Oceanography, UC San Diego, Biological Oceanography, La Jolla, United States

The Antarctic Peninsula has experienced rapid warming for decades, leading to an increase in glacial meltwater
input within the coastal fjords. This freshwater released at the glacier front creates changes that may
drastically impact various levels of the food web, particularly with phytoplankton. Small environmental
variations may favor different compositions of phytoplankton and shift the timing of blooms during the season.
These seasonal and interannual variations regarding phytoplankton phenology and community composition are
not available within the fjords and detailed monitoring can provide insights into changes that may occur. A
great opportunity exists for scientists to collect this vital data by engaging the Antarctic tourism community.
The International Association of Antarctic Tour Operators (IAATO) brings visitors throughout the year,
occupying coastal fjords during the austral growth period. This established community can collect scientific
data thereby improving the knowledge gap of phytoplankton composition and phenology. This citizen science
partnership with the IAATO operators, in which tourists can participate, will supplement our current scientific
datasets gaining a more comprehensive view of phytoplankton community structure and bloom dynamics in
the Antarctic fjords. This new knowledge will not only provide a better understanding of glacial meltwater
impacts on biodiversity and ecology, but also increase public engagement and understanding of science.

186
396
How Citizen Science Evolved a Whole New Platform for Coastal Polar Research

Ben Wallis1 (ben@ocean-expeditions.com)

1
Ocean Expeditions, Sydney, Australia

Harnessed correctly, citizen science can be a huge asset to Antarctic science. During the 2017/18 season, the
IAATO fleet alone is expecting more than 46,000 tourists to visit Antarctica. In recent years, such visitors have
begun observing and cataloguing animals including humpback whales, orcas and leopard seals. There is a huge
potential to further utilise this resource to create crowd-sourced observation data.
In 2011, when I created a fellowship program to host Antarctic scientists, I Initially hoped to add value to my
passengers' Antarctic experience through their engagement with (and assistance to) guest scientists. In doing
so, I picked up valuable lessons in the planning, permitting, organising and onboard management of small
vessels support of both 'citizen' and government science.
During the 2017/18 season alone, I will be supporting seven different science projects, ranging from visual
observations by tourists, to dedicated research voyages for national Antarctic programs. To date, these voyages
have resulted in 28 published papers, 175 citations, the support of nine national Antarctic programs and 40
institutions, the transport of 90 scientists and 915 tourists. On voyages with both passengers and scientists, the
interaction between the two has not only assisted scientists in their data gathering, but resulted in passengers
returning north as true Antarctic ambassadors.

187
2494
Operational Ice Service Perspectives on Collaborations with Polar Tourism

Penelope Wagner1 (penelopew@met.no), Nick Hughes1, Keld Qvistgaard2

1
Norwegian Meteorological Institute, Norwegian Ice Service, Tromsø, Norway, 2Danish Meteorological Institute,
Copenhagen, Denmark

With the increase of polar tourism, the Norwegian and Danish Ice Services have been collaborating with polar
tourism to better understand data needs of ship operators when making tactical decisions travelling through or
along icy waters. A main challenge that has been identified from an operational perspective is providing ship
operators with sufficient and reliable daily ice information, including high quality sea ice and iceberg detection
in the marginal ice zone, along the ice edge, and in harbours, and inshore. The operational ice services are
developing better methods to provide better outlooks and forecasts which may require customized products,
particularly for large ships that have less flexibility to change their planned trajectory. Near-real time data
transmission continues to be unreliable in specific areas. It is essential that ice services supporting maritime
safety in navigation consolidate efforts to work with the polar tourism industry and develop strategies to
improve the coordination between data providers and users. Additionally, increasing citizen science
endeavours on ships is ideal for ice services to exchange routine ship observations and satellite information. It
also allows passengers to fully engage with operational and science activities. Using case studies of ice services
providing support to Arctic and Antarctic cruise ships and participating in citizen science activities, we
demonstrate how we can improve collaboration between the two groups.

188
1917
Encouraging Citizen Science with Community-based Science Month Events

Regina Brinker1,2 (brinker.science@gmail.com)

1
Livermore Valley School District, Science, Livermore, United States, 2Polar Educators International, Livermore,
United States

Science and Engineering Month (SEM) is celebrated during February in Livermore, California. Over 40 programs
encourage the community to learn about science and engineering, get outdoors and observe the natural world
around them, and contribute to citizen science projects. Many events, including lectures, bio-blitz surveys,
water quality testing, and nature walks, relate to environmental and climate awareness.
A range of public agencies, including government, K - 12 and college education, libraries, park and recreation
centers, and businesses participate in SEM. Programs are publicized through the internet, local newspapers,
and social media.
Goals of SEM are to engage the community in science, make citizens more knowledgeable of and connected to
local ecosystems, and increase awareness of local impacts of climate change.
This presentation will discuss SEM's concepts, planning, and implementation. As the program coordinator, I will
share best practices and lessons learned for creating a successful community-wide program. SEM may be
modeled in other communities to fit the needs and interests of that area, including engaging citizens in
community science project related to polar science.

189
CR-3a - Cryosphere-Hydrosphere interactions: The water cycle at the three Poles
19.06.2018 14:00-15:30, B Parsenn

157
Variable Connectivity between Glacial Melt and Streamflow, McMurdo Dry Valleys

Anna Bergstrom1 (anna.bergstrom@colorado.edu), Michael Gooseff1

1
University of Colorado, Boulder, United States

The Dry Valleys of Antarctica are a system closely tied to the energy balance. In the summer months with air
temperatures around 0 degrees C, slight shifts in incoming radiation, temperature, or albedo can have drastic
effects on both the magnitude and partitioning of glacial ablation for sublimation and melt water generated for
streamflow. Snowmelt is a very minor contributor to streamflow. The McMurdo Long Term Ecological Research
site has been collecting records of glacial ablation, streamflow, and meteorological data for over 23 years. In
the 2001-2002 season, unusually high persistent temperatures and solar flux caused unprecedented glacial
melt and stream flow orders of magnitude higher than average. After this season, relationships between glacial
melt and stream flow have shifted. There is better correlation between streamflow and ablation for all studied
streams after the warm season. It is hypothesized that the melt event reorganized and concentrated sediment
at or near the surface of the glaciers, lowering the albedo. This research utilizes the long-term records of
streamflow, glacier ablation, and meteorological data to assess how the melt event may have resulted in
lasting changes in the energy balance dynamics and degree of melt water generation from the Dry Valley
glaciers. This work will help us better understand the controls on glacial melt as well as the connection
between glaciers and the downstream ecosystems.

190
1347
Investigating Large Active Subglacial Lake Drainages in East Antarctica

Matthew Siegfried1 (siegfried@stanford.edu), Susheel Adusumilli2, Helen Fricker2, Ted Scambos3,4, Dustin
Schroeder1, Benjamin Smith5
1
Stanford University, Department of Geophysics, Stanford, United States, 2Scripps Institution of Oceanography,
UC San Diego, Institute of Geophysics and Planetary Physics, La Jolla, United States, 3National Snow and Ice
Data Center, Boulder, United States, 4University of Colorado Boulder, Boulder, United States, 5University of
Washington, Seattle, United States

Spatially coherent surface-height anomalies have been mapped in regions of fast ice-flow across Antarctica.
These features have been interpreted as the surface manifestation of a dynamic subglacial water system, with
up to cubic kilometers of water moving into and out of active subglacial lakes on timescales of months to
decades. By impounding and episodically releasing water, these subglacial lakes have been hypothesized to
drive regional hydrological variability and modify the flow of the overlying ice. However, no datasets have been
available with high enough time resolution to simultaneously observe surface-height motion, map velocity
changes, and image the ice-bed interface through a hypothesized subglacial lake drainage event, leaving the
relationship between surface-height anomalies, the basal environment, and ice dynamics unclear. Using
satellite and airborne altimetry from the CryoSat-2 mission and Operation IceBridge, Landsat 8 feature tracking,
MODIS image differencing, and repeat airborne radar sounding, we investigate two large (> 10 m) surface-
height anomalies on Slessor and Recovery glaciers, East Antarctica. By mapping regional basal reflectivity and
velocity changes before, during, and after surface-height changes, we explore the cause of these enigmatic,
widespread features and their ultimate impact on ice flow in Antarctica.

191
2152
A Regional System of Briny Aquifers in the McMurdo Dry Valleys, Antarctica

Slawek Tulaczyk1, Esben Auken2, Hilary Dugan3, Peter Doran4, Jill Mikucki5, Ross Virginia6, Krista Myers4
(kmyer19@lsu.edu)
1
University of California, Santa Cruz, Earth and Planetary Sciences, Santa Cruz, United States, 2Aarhus
University, Geosciences, Aarhus, Denmark, 3University of Wisconsin, Center for Limnology, Madison, United
States, 4Louisiana State University, Geology and Geophysics, Baton Rouge, United States, 5University of
Tennessee, Microbiology, Knoxville, United States, 6Dartmouth College, Environmental Studies, Hanover, United
States

Liquid water is relatively scarce in high-latitude polar environments but plays an outsized role by influencing,
and integrating, biological, biogeochemical, glaciological, and geological processes. Whereas surface hydrology
and its role in ecosystem processes has been thoroughly studied over the last several decades, it has been
difficult to map out and characterize subsurface water reservoirs and to understand their interactions with
regional lakes, glaciers, and coastal waters. As part of the NSF-funded AntAEM project, we are using ground-
based and airborne Time-domain ElectroMagnetics sensors to provide the first integrative system-scale
overview of subsurface water distribution and hydrological connectivity in a partly ice-free coastal region of
Antarctica, the McMurdo Dry Valleys. Our previous survey documented existence of a briny aquifer in Taylor
Valley (Mikucki et al., 2015) and new data indicate similar subsurface features in neighboring valleys. In
particular, we see that Don Juan Pond, the second saltiest waterbody on Earth, is likely connected to a
subsurface aquifer, as is the largest lake in the Wright Valley, Lake Vanda. Airborne data collection in 2018 will
further elucidate these relationships between surface and subsurface water systems. It will also focus on
clarifying the connectivity between these inland groundwaters and the coastal zone. The briny groundwater
systems found by us in the Dry Valley region may be common in coastal Antarctica.

192
1111
Using GPR to Investigate the Subglacial Hydrology of an Alpine Glacier

Pascal Emanuel Egli1 (pascal.egli@unil.ch), Stuart Nicholas Lane1, James Irving2, Martino Sala1
1
University of Lausanne / Institute of Earth Surface Dynamics, Lausanne, Switzerland, 2University of Lausanne /
Institute of Earth Sciences, Lausanne, Switzerland

Hydrological inference suggests that subglacial drainage networks under temperate valley glaciers are
dendritic, meaning that their subglacial conduits have both streams and stream junctions. These networks, at
their most developed, comprise subglacial conduits. They are typically associated with the combined effect of
opening by hydraulic-pressure-driven ice melt and closure by ice overburden pressure. Inference from dye
breakthrough curves has supported theoretical arguments that:
(1) these channels open up progressively during the summer; and
(2) close during the winter to leave a more inefficient drainage network at the start of spring.
This model has dominated modern glaciology for over 50 years, but geomorphological reasoning questions this
domination. Temperate valley glaciers, when they retreat, commonly reveal beds of soft sediments. Borehole
imagery as well as speological investigations have confirmed that the channels have potentially erodible beds.
As such, they might better be viewed as rivers under ice rather than channels eroded into ice.
Here, we present the results of ground-penetrating radar (GPR) surveying on the Glacier d'Otemma in the
south-western Swiss Alps. By looking at spatially dense grids of GPR measurements with a line spacing of 2 m,
we aim to determine the locations and geometry of sub-glacial conduits below the glacier tongue, for ice
thicknesses between 30 m and 80 m.

193
2041
Conceptual Model of Englacial Water Fluctuations of Hansbreen, Svalbard

Léo Decaux1 (leodecaux@gmail.com), Kenneth Mankoff2, Mariusz Grabiec1, Jacek Jania1

1
Faculty of Earth Sciences, University of Silesia, Centre for Polar Studies, Sosnowiec, Poland, 2The Geological
Survey of Denmark and Greenland (GEUS), Department of Glaciology and Climate, Copenhagen, Denmark

Drainage of meltwater and rainwater plays an important role in glacier dynamics. Behavior of drained water
within the drainage system is poorly known and understood. During the years 2016 and 2017, our study
focuses on the well-explored perennial conduit, known as Crystal Cave, present inside the tidewater glacier
Hansbreen located in the southern part of the Svalbard archipelago. The polythermal regime of this glacier
allows the development of a well-channelized internal drainage system.
Innovative ice cave monitoring techniques have been created in order to instrument the central part of an
englacial conduit, preventing it to move because of water circulation and to freeze into the walls. Results are
the first temperature and water pressure fluctuations recorded at 30 min frequency during the whole
hydrological year inside an englacial system.
During the winter period, when the internal drainage system is inefficient, water levels rise up in the englacial
conduits in response to positive air temperature and precipitation events with a few days of delay. On the
contrary, during the summer period, when the internal drainage system is efficient, water level rises up in the
englacial conduits synchronously with higher air temperature and precipitation events. In addition, during the
winter period we observed reverse flow-water coming from the lower part of the internal system toward the
upper part. Finally, presence of liquid water storage during the winter season was monitored.

194
371
Measuring Glacier Dry Calving with SAR Interferometry

Brian Moorman1 (moorman@ucalgary.ca), Ken Whitehead2, Allison Gunther3

1
University of Calgary, Geography, Calgary, Canada, 2SAIT, Calgary, Canada, 3Solas Energy Consulting, Calgary,
Canada

The glaciers of the Canadian Arctic Archipelago are currently undergoing rapid retreat. There is considerable
interest in the mechanisms leading to ice loss in this region, as these glaciers have been identified as being a
significant contributor to rising sea levels. Unlike surface melting or direct calving into the ocean, little is known
about the contribution of meltwater from dry calving. This is where ice breaks off steep glacier edges and melts
in place at a greatly increased rate. This results in accelerated water contributions to the ocean for which there
are no reliable estimates available. A measure of the location and discharge rate of dry calving is required to
better model glacial contributions to sea level rise.
For this project we developed a methodology for estimating calving potential, using estimates of glacier
velocity at the main calving faces, derived from SAR interferometry. This study uses Fountain Glacier on Bylot
Island as a case study because of the extensive baseline data in the region. Specifically, the SAR data enabled
the identification of calving faces and their activity level, the speed and direction of glacier motion and along
with ancillary data discharge estimates of the glacier from the calving front. It is believed that this is a practical
approach, which will allow for the estimation of mass loss through dry calving for specific glaciers and the
identification of calving potential at a regional level.

195
BE-10 - Polar fish: physiological adaptations and their responses to climate change
19.06.2018 14:00-15:30, B Jakobshorn

384
Acclimation Potential of Polar Cod from the Rapidly Warming Arctic Ocean

Helen Drost1 (helen.drost@dfo-mpo.gc.ca), Mandy Lo2, Eddy Carmack1, Tony Farrell2, Nadja Steiner1
1
Department of Fisheries and Oceans Canada, Sidney, Canada, 2University of British Columbia, Vancouver,
Canada

The physics and biogeochemistry of the Arctic Ocean have changed significantly in the past century and are
predicted to continue changing as rapidly. Missing, however, is a general knowledge on the thermal tolerance
ranges for Arctic ectotherms and their acclimation potential, which are minimum knowledge requirements to
accurately forecast the distributional patterns of marine species and their chances of survival in a changing
environment. Thus, it is imperative to understand thermal optima, tolerance and acclimation potential of Arctic
fishes to predict food web consequences with continued warming of the Arctic Ocean.
Polar cod (Boreogadus saida) are able to acclimate to different temperatures over time. We quantified
acclimation potential using 3 methods including: the critical thermal maximum of 3 acclimation groups (0.5,
3.5, 6.5°C); the aerobic scope (AS) of similarly acclimated B. saida; and the heart rate of long term acclimated
fish. A variety of compensatory responses to thermal acclimation were observed that would benefit B. saida in
a warmer environment. These compensations include an increase in Tcmax, a > 2°C increase in the Topt window
for AS, and a significant down regulation of heart rate.
Climate models that predict species distribution and survival rarely include plasticity of thermal tolerance. We
are developing a comprehensive physiological limits and acclimation potential database of key Arctic marine
species to help improve model predictions.

196
2613
Parallel Adaptive Divergence in Fjord vs. Shelf Populations of Arctic Gadids?

Kim Præbel1 (kim.praebel@uit.no), Shripathi Bhat1, Chi-Hing Christina Cheng2

1
UiT The Arctic University of Norway, Norwegian College of Fishery Science, Tromsø, Norway, 2University of
Illinois, Urbana-Champaign, Dept. of Animal Biology, Urbana-Champaign, United States

The cryopelagic Arctic gadids, Boreogadus saida and Arctogadus glacialis, occurs in North Eastern Greenland
fjords and shelf areas, where they occupy the same habitats and have partly overlapping feeding niches. We
have previously shown that populations of B. saida occupying fjords vs. shelf areas can be genetically
discriminated at microsatellite loci suggesting that ecological, environmental, and/or spatial factors fuels the
divergence. However, nothing is known about the population genetic structure of A. glacialis from this area.
Here we tested whether replicated fjord vs. shelf population-pairs of B. saida and A. glacialis, respectively,
show genome-wide differentiation. We compared divergence at a genome-wide panel of single nucleotide
polymorphisms obtained by massively parallel sequencing of Restriction Site Associated DNA libraries
(RADseq). Via machine learning approaches we firstly explored the genomic divergence within and between
species, and secondly, we explored whether the footprint of the environment, ecology and life history, and
spatial separation have resulted in parallel divergence in polygenic adaptive genomic traits. We discuss the
results in light of how climate change may influence intra and interspecific divergence in these Arctic key-
species.

197
1746
Historical DNA Metabarcoding of Trematomid Fishes using Museum Samples

Franz Maximilian Heindler1 (franzmaximilian.heindler@kuleuven.be), Bart Hellemans1, Henrik Christiansen1,

Agnès Dettai2, Anton P. Van de Putte3, Gregory E. Maes4, Filip A. M. Volckaert1
1
KU Leuven, Laboratory of Biodiversity and Evolutionary Genomics, Leuven, Belgium, 2Muséum National
d'Histoire Naturelle, Paris, France, 3Royal Belgian Institute of Natural Sciences, Brussels, Belgium, 4KU Leuven,
Laboratory of Cytogenetics and Genome Research, Leuven, Belgium

The Southern Ocean hosts delicate and unique ecosystems. Despite its distance to densely populated areas,
human influence includes direct impacts such as commercial fishing, tourism and research, as well as indirect
impacts such as global warming and pollution. With the exception of fishing, the largest increase of these
impacts occurred within the past 100 years. Unfortunately, the knowledge on biodiversity in support of
management remains small. This study focuses on prey item and microbiome composition of members of the
circumantarctic genus Trematomus, which are amongst the most abundant members of the Antarctic icefish
community. We collected tissue, stomachs and guts from 400 specimens curated at the Natural History
Museum London. Specimens were had been collected between 20 and 120 years ago, were fixed in formalin
and later transferred to ethanol. A 450 bp fragment of the cytochrome c oxidase subunit I (COI) was amplified
and sequenced for prey item identification in the stomach and a 313 bp region of the 16S gene to investigate
microbiome composition in the gut system. We evaluated various protocols for the suitability to infer DNA
information from historically formalin-fixed samples. Based on the best protocol, we identified interspecific
prey and microbiome variation. Unlocking information from museum stored samples holds great potential for
microevolutionary insights that will benefit efforts to prioritize conservation units in the Southern Ocean.

198
390
Characterization of Protein Turnover and Proteome Stability in Antarctic Fish

Sean Place1 (places@sonoma.edu)

1
Sonoma State University, Biology, Rohnert Park, United States

How susceptible are endemic fauna to the rapid changes in environmental parameters? Are stenothermal
animals more at risk of global climate change impacts as a consequence of their evolutionary history? These
are critical questions limited by a lack of basic understanding with regards to the drivers of divergence in the
cellular stress response that has occurred in many endemic species of the Southern Ocean. The focus of this
study is to understand how changes in seawater temperature impact protein homeostasis in Antarctic fishes.
Previous studies have reported a permanent activation of the heat shock response and have suggested this
change in regulation is related to an imbalance in protein folding efficiency at sub-zero temperatures in these
fishes. Thus, these endemic fish may, at some level, benefit by the increase in sea surface temperatures
expected to accompany global climate change. However, if protein folding efficiency does not increase with
warming seawater then that would suggest the disruption is genetically hardwired. In this study we utilize
fluorescent non-canonical amino acid tagging to assess the impact of increased seawater temperature on
protein turnover in the proteome of Antarctic notothenioid fish acclimated to +4 °C for up to a month. We
further link the changes in rates of protein synthesis and degradation to tissue specific changes in energy
budgets in order to gain insight into the energetic cost of maintaining a stable proteome in a warming ocean.

199
2601
Metabolic Capacity to Acclimate to Multiple Stressors in an Antarctic Fish

Anne Todgham1 (todgham@ucdavis.edu), Brittany Davis2

1
University of California Davis, Animal Science, Davis, United States, 2University of California Davis, Davis,
United States

Although the Southern Ocean is experiencing some of the fastest rates of ocean change, few studies have
explored how Antarctic fishes may be affected by co-occurring warming and acidification, and even fewer have
examined early life stages. To date, no studies have characterized potential trade-offs in physiology and
behavior in response to projected multiple climate change stressors on Antarctic fishes. Juvenile Trematomus
bernacchii were exposed to three PCO2 treatments at two temperatures After 2, 7, 14, and 28 days, metrics of
physiological performance including cardiorespiratory function, metabolic rate, and cellular enzyme activity
were measured. Behavioural responses, including scototaxis, activity, and escape response were assessed after
7 and 14 days. Elevated PCO2 independently had little impact on either physiology or behaviour in rockcod,
whereas warming resulted in significant changes across acclimation time. Increased physiological costs were
accompanied by behavioural alterations including increased dark zone preference, reduced activity and
reduced escape time. After 28 days, fish demonstrated a degree of temperature compensation; however,
temperature compensation was only evident in the absence of elevated PCO2. Our results provide evidence of
stressor-induced energetic trade-offs in physiology and behaviour that may be an important mechanism
leading to vulnerability of Antarctic fishes to future ocean change.

200
1451
Reproduction in Parachaenichthys charcoti (Bathydraconidae) in West Antarctica

Manuel Novillo1,2 (jmanuelnovillo@gmail.com), Eugenia Moreira3, Gustavo Macchi4,5, Esteban Barrera Oro1,2,6
1
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina, 2Museo
Argentino de Ciencias Naturales 'Bernardino Rivadavia', Ictiologia, Buenos Aires, Argentina, 3Instituto Antártico
Argentino, Biologia, Buenos Aires, Argentina, 4Consejo Nacional de Investigaciones Científicas y Técnicas
(CONICET), Mar del Plata, Argentina, 5INIDEP, Ecologia Reproductiva, Mar del Plata, Argentina, 6Instituto
Antártico Argentino, Biología, Buenos Aires, Argentina

The reproductive biology of dragon fishes is poorly understood and particularly in P. charcoti (PCH). A
histological analysis of PCH ovaries together with reproductive effort data using fish caught at Potter Cove,
South Shetland Islands (SSI), are compared with data reported for the South Georgia's congener P. georgianus
(PGE). In gravid females of PCH, GSI of 16-31%, mature oocytes of 1.8-3.9 mm and total fecundity (TF) of 9790-
18937 oocytes/individual (mean 13216) were recorded. The histology of the ovaries confirmed the common
characteristics of the suborder Notothenioidei observed macroscopically, i.e., two distinct batches of oocytes,
one in previtellogenic stage, and the other in vitellogenesis and likely to be released in the current season. A
longer incubation period of PCH compared to PGE is associated to colder waters at the SSI. Our sampling and
reproductive effort data and the known nesting behavior of PCH, everything recorded at Potter Cove, suggest
that this species spawns nearshore in summer, from late Dec to Feb. Spawning periods of both congeners differ
from those reported for other notothenioids in the Seasonal Pack-ice Zone, suggesting divergence in some
aspects of the life strategies in the genus Parachaenichthys. Likewise, although there are no substantial
differences between PCH and other notothenioids regarding gonadal development, this genus shows distinct
features in its reproductive strategies (e.g. higher TF) in comparison with other bathydraconids.

201
AC-1c - Polar and high altitude atmosphere: clouds, aerosols, climate and interactions
19.06.2018 14:00-15:30, C Sanada I

7
Sources of Ice Crystals and Cloud Droplet in Orographic Mixed-Phase Clouds

Ulrike Lohmann1 (ulrike.lohmann@env.ethz.ch), Alexander Beck1, Olga Henneberg1, Jan Henneberger1, Larissa
Lacher1
1
ETH Zurich, Zürich, Switzerland

Knowledge about the phase and longevity of mixed-phase clouds (MPCs) is important for the radiative balance
and the hydrological cycle. The co-existence of cloud droplets and ice crystals in MPCs is thermodynamically
unstable due to the lower saturation vapor pressure over ice than over liquid water. Thus, MPCs are expected
to quickly glaciate, as ice crystals grow at the expense of cloud droplets. In-situ measurements have, however,
shown that MPCs can be persistent. As will be shown in the talk, this was confirmed by km-scale model
simulations pointing to the dominant role of updraft velocities as a source of cloud droplets.
In addition, the ice crystal number concentration (ICNC) in MPCs regularly exceeds the ice nucleating particles
(INP) concentration by several orders of magnitude. Therefore, additional sources of ice crystals, e.g. secondary
ice production and ice outside the cloud, have to contribute significantly to ICNCs in MPCs. Here, we will
present results estimating the various ice crystal sources. Measurements of cloud droplets and ice crystals,
obtained with our digital holographic imager HOLIMO, and INP measurements taken with our continuous flow
diffusion chamber, were performed at 3580 m asl at the Jungfraujoch (JFJ) in the Swiss Alps. To estimate the
importance of blowing snow, in-situ observations of cloud particles were taken at different heights above
ground taken at the Sonnblick observatory in Austria.

202
425
Recent Observations of Arctic INP and their Variation over the past 500 Years

Markus Hartmann1 (markus.hartmann@tropos.de), Sandra Brügger2, Xianda Gong1, Hartmut Herrmann3,

Manuela van Pinxteren3, Julia Schmale4, Margit Schwikowski5, Alexander Vogel5, André Welti1, Heike Wex1,
Sebastian Zeppenfeld3, Frank Stratmann1
1
Leibniz-Institute for Tropospheric Research, Experimental Aerosol and Cloud Microphysics, Leipzig, Germany,
2
University of Bern, Institute of Plant Sciences, Bern, Switzerland, 3Leibniz-Institute for Tropospheric Research,
Atmospheric Chemistry, Leipzig, Germany, 4Paul Scherrer Institute, Laboratory of Atmospheric Chemistry,
Villingen, Switzerland, 5Paul Scherrer Institute, Laboratory of Environmental Chemistry, Villingen, Switzerland

Measurements of ice nucleating particle (INP) concentrations in the Arctic are scarce, and historical records did
not exist until now. Here, present-day observations onboard the RV Polarstern (PASCAL cruise from May to July
2017 in the area around Svalbard up to 83.7°N) and ice core-derived concentrations for the past 500 years are
presented.
During PASCAL, the INP concentrations were measured online with the Spectrometer for Ice Nuclei (SPIN;
DMT), and determined from filter samples by application of freezing array techniques. By combining these
methods, the whole temperature regime relevant for mixed phase clouds is covered. The ice cores originate
from Summit (Greenland) and Lomonosovfonna (Svalbard), and cover a time range from 1457 to 1989 AD and
1480 to 2001 AD, respectively. The ice core samples were analyzed by the freezing array techniques only.
The contribution of local sources to present-day INP is assessed by comparing the INP populations,
(a) from different sources such as the sea surface micro layer, deeper sea water, snow and fog,
(b) the correlation to meteorological parameters, and
(c) the use of back trajectory modelling. The sensitivity of the historical INP concentrations to other ice core-
derived parameters is investigated to identify potential INP sources..
These datasets can be used in climate models to study the role of INP in the observed Arctic Amplification.
The works were carried out in the framework of the DFG-funded TR 172 (Arctic Amplification).

203
433
Variations in Ice Nucleating Particle Concentrations at Four Arctic Locations

Heike Wex1 (wex@tropos.de), Lin Huang2, Hayley Hung3, Rita Traversi4, Rebecca Sheesley5, Claire Moffett5, Tate
Barrett5, Rossana Bossi6, Markus Hartmann1, Frank Stratmann1
1
Leibniz Institute for Tropospheric Research, Experimental Aerosol and Cloud Microphysics, Leipzig, Germany,
2
Environment & Climate Change Canada, Climate Research Division, Toronto, Canada, 3University of Toronto
Scarborough, Department of Physical and Environmental Sciences, Toronto, Canada, 4University of Florence,
Department of Chemistry 'Ugo Schiff', Florence, Italy, 5Baylor University, Department of Environmental Science,
Waco, United States, 6Aarhus University, Department of Bioscience - Arctic Research Centre, Roskilde, Denmark

Filter samples collected at four Arctic measurement stations, Alert, Barrow, Ny-Ålesund and Villum were
analyzed with respect to number concentrations of ice nucleating particles (NINP). Measurements were done
following the method proposed by Conen et al. (2012), examining immersion freezing. The obtained
temperature dependent freezing curves were used to derive NINP.
For Ny Alesund, samples from spring and summer months were examined, while a yearly coverage existed for
the other stations. Differing values of NINP were observed during the year, and in general during summer and
fall, particles were more ice active than during winter and early spring, indicating that different sources of ice
nucleating particles contributed to the pan-arctic area, their influence varying with season and site. The highest
values determined for the Arctic samples were comparable to NINP determined from precipitation samples
collected in North America and Europe (Petters & Wright 2015), but the lowest values were more than two
orders of magnitude lower. Ice nucleating particles have an influence on Arctic cloud glaciation and hence
influence Arctic warming. This study reveals open questions and suggests future pathways concerning the
examination of Arctic ice nucleating particles.
Literature:
Conen et al., 2012, Atmos. Meas. Tech., doi: 10: .5194/amt-5-321-2012.
Peters & Wright, 2015, Geophys. Res. Lett., doi: 10.1002/2015gl065733.

204
1222
Arctic Mixed-phase Cloud Sensitivity to Surface Forcing and Aerosol Perturbation

Gesa Eirund1 (gesa.eirund@env.ethz.ch), Anna Possner2, Ulrike Lohmann1

1
ETH / IAC, Zurich, Switzerland, 2Carnegie Institution for Science, Stanford, United States

Arctic clouds play a key role in the radiative balance of the Arctic region. In summer, the reflection of the
incoming radiation dominates, while during the rest of the year the absorption and emission of longwave
radiation prevails, causing a warming effect at the surface. The radiative properties of these clouds are strongly
linked to the relative abundance of both phases (liquid and ice), which in turn is governed by a multitude of
processes operating in conjunction across a wide range of spatial scales. The large-scale dynamical forcing,
surface processes as well as the ambient aerosol concentration all impact mixed-phase cloud (MPC) amount
and phase partitioning. Up to now, the persistence as well as the formation of Arctic MPCs remain largely
unclear and their representation in models of all complexities poses a considerable challenge.
In this study we focus on the relative importance of different aerosol conditions on MPC formation and
persistence in the Arctic. To address this issue, we perform COSMO-LES simulations (Possner et al., 2017) and
designed a case study for the ACCACIA campaign in March 2013 in the European Arctic (Young et al., 2016). In
our setup we successfully simulate a MPC with properties close to observations. In several sensitivity studies
we explore the mechanisms in MPCs across different temperature ranges and aerosol loadings. Moreover, we
contrast these effects in MPCs over ocean and sea ice.

205
1288
How Important Are Local Marine Sources for Arctic Mixed-phase Clouds?

Luisa Ickes1,2, Corinna Hoose2, Annica M. L. Ekman1 (annica@misu.su.se)

1
Stockholm University, Department of Meteorology, Stockholm, Sweden, 2Karlsruhe Institute of Technology,
Institute of Meteorology and Climate Research, Karlsruhe, Germany

Arctic low-level clouds are highly sensitive to microphysical processes, which can either sustain or break down
the unstable mixed-phase state and thereby determine the longevity of the clouds and their radiative impact.
They are influenced by the availability of aerosol particles, which can act as ice nuclei (IN) or cloud
condensation nuclei (CCN). Potential sources of aerosols in the pristine Arctic include local marine aerosol
emissions and long-range transport, but it is not very well known what governs the Arctic background aerosol
concentration and its variability. Therefore, it is important to quantify Arctic aerosol concentrations and the
associated impact on cloud microphysics.
We derive characteristic vertical profiles of CCN and IN for two different situations in the Arctic and investigate
the influence on the cloud microphysics and the evolution of a mixed-phase Arctic cloud. We compare a
situation where the aerosol concentrations are predominantly governed by local sources (emitted at the
surface) with one dominated by long-range transport (introduced above the boundary layer inversion). To
compile the vertical profiles for different aerosol scenarios we use field measurements in combination with
regional modeling using the regional model COSMO-ART (Vogel et al., 2009). The influence of the different
vertical aerosol profiles on the cloud microphysics is investigated using the LES model MIMICA (Savre et al.,
2014).

206
1473
Understanding the Sources of Arctic Biological Ice Nucleating Particles

Jessie Creamean1,2 (jessie.creamean@noaa.gov), Amy Solomon1,2, Regina Hanlon3, David Schmale3, Rachel
Kirpes4, Kerri Pratt4, Nicholas Spada5, Jessica Cross6, Robert Pickart7, Vaughan Phillips8
1
University of Colorado Boulder, Boulder, United States, 2National Oceanic and Atmospheric Administration,
Boulder, United States, 3Virginia Tech, Blacksburg, United States, 4University of Michigan, Ann Arbor, United
States, 5University of California, Davis, United States, 6National oceanic and Atmospheric Administration,
Seattle, United States, 7Woods Hole Oceanographic Institution, Woods Hole, United States, 8Lund University,
Lund, Sweden

The Arctic is warming at an alarming rate, yet the wide range of processes that contribute to the surface energy
balance are not well constrained. The effects of clouds and aerosols on the extent of sea ice is particularly not
well represented in models. Specifically, relatively little knowledge exists regarding aerosols that serve as ice
nucleating particles (INPs) and their subsequent impact on Arctic cloud ice formation. In general, biological
aerosols such as bacteria, algae, and phytoplankton have been hypothesized to serve as some of the most
efficient INPs in the Arctic region. The Arctic Ocean is a large vessel for biological productivity, but such
productivity is highly variable depending on time of year and location. Here, we present results from ice
nucleation studies in a relatively polluted coastal location in Prudhoe Bay during the spring and from a
shipborne expedition through the Bering Strait and Chukchi Sea during the following summer of 2017. Prudhoe
Bay is largely influenced by local oil extraction activities, while the marine measurements were conducted in a
cleaner oceanic environment. INP concentrations and onset freezing temperatures were found to widely vary,
but were highest in both locations when air masses originated from exposed ocean water from fresh sea ice
melt and near phytoplankton blooms and coastal upwelling. Overall, these results demonstrate the crucial role
the ocean plays as a source of cloud nuclei in disparate Arctic locations.

207
BE-4c - Climate change and ecosystems: physiology, biodiversity and ecological functions
19.06.2018 14:00-15:30, C Sanada II

1490
The Changing form of Antarctic Biodiversity

Steven L Chown1, ACE Expedition Members1 (steven.chown@monash.edu)

1
Monash University, Melbourne, Australia

Antarctic biodiversity was once thought to be poor, recent and isolated. Over the last two decades, this
perception has been wholly altered. Both in marine and terrestrial systems, diversity is greater, with more
structure and regular connections, both among sites and to areas beyond the polar front or Southern Ocean,
than previously thought. Molecular approaches have been instrumental in revealing the substantial structure
and dynamics of Antarctic biodiversity. But so has interdisciplinary work, combining new surveys, modern and
palaeoclimatic information, data from marine and terrestrial sediment cores, and novel forms of analyses. In
this talk, an overview is provided of these developments, how they are changing fundamental understanding of
the biodiversity of the region and its evolution, and what they imply for conservation. Particular emphasis is
given to work demonstrating links across the entire Antarctic and Southern Ocean regions, including the
Southern Ocean islands.

208
60
Global Change Effects on Arctic and Antarctic Ecosystems

Rien Aerts1 (m.a.p.a.aerts@vu.nl)

1
VU University Amsterdam, Dept of Ecological Science, Amsterdam, Netherlands

Both Arctic and Antarctic ecosystems are affected by global change drivers, such as elevated temperatures and
changing precipitation regimes. These effects can be investigated by experiments and research along gradients.
In this presentation the results of our long-term warming experiments in sub-arctic Sweden (since 2000) and
the Antarctic Peninsula (since 2004) will be presented and a bi-polar comparison will be made of the warming
effects on the diversity and functioning of the various components of the food web, including soil micro-
organisms, soil arthropods, cryptogams and vascular plants. Moreover, we will also compare the results of our
geographical gradient studies with those of the experiments in order to investigate if geographical temperature
gradient studies can be used as an analogue for experimental studies.

209
924
Can Antarctic Lichens Acclimatise to Changes in Temperature?

Claudia Colesie1 (claudia.colesie@slu.se), Burkhard Büdel2, Vaughan Hurry3, Allan Green4,5

1
Swedish University of Agricultural Sciences (SLU), Forest Genetics and Plant Physiology, Umeå, Sweden,
2
University of Kaiserslautern, Plant Ecology and Systematics, Kaiserslautern, Germany, 3Swedish University of
Agricultural Sciences (SLU), Forest Genetics and Plant Physiology, Umea, Sweden, 4Universidad Complutense,
Departamento de Biologia Vegetal II, Farmacia Facultad, Madrid, Spain, 5University of Waikato, Department of
Biological Sciences, Hamilton, New Zealand

The Antarctic Peninsula, a tundra biome dominated by lichens and bryophytes, is an ecozone undergoing
temperature shifts. Such changes may demand a high physiological plasticity of the local species in order for
them to maintain their role as key drivers in this habitat. We investigated how increasing temperatures vary
the physiological responses of lichen species with different ecological response amplitudes. The main goal was
to find out whether thermal acclimation occurs as biological feedback which would ameliorate the effects of
temperature changes. All species tested at 5, 15 and 22°C were negatively affected, with 15°C representing the
upper thermal limit for two endemic species. A widespread lichen species was able to recover its homoeostasis
by a consistent increase in net photosynthesis. As a result, we postulate that any acclimation processes in
lichen are species specific. This, together with the high degree of response variability and sensitivity to
temperature in different species that co-occur spatially close, complicates predictions regarding future species
composition. Our results suggest that species with a broad ecological amplitude may be favoured with ongoing
changes. Such community shifts could lead to regional-scale biotic homogenization, which could alter
ecosystem functioning and productivity in Antarctic ice-free habitats. The consequences for the conceptual
view of physiological acclimation are highlighted and future research perspectives discussed

210
2189
Drivers of Soil Bacterial Community Structure in Antarctic Water Tracks

Kelli Feeser1 (kfeeser@unm.edu), David Van Horn1, Jordan Okie2, Becky Ball2, Andrew Fountain3, Michael
Gooseff4, Joseph Levy5, Maciej Obryk3
1
University of New Mexico, Biology, Albuquerque, United States, 2Arizona State University, Tempe, United
States, 3Portland State University, Portland, United States, 4University of Colorado at Boulder, Boulder, United
States, 5Colgate University, Hamilton, United States

Water availability is a key limitation of ecosystem function in the McMurdo Dry Valleys, Antarctica. Climate
change in this region is projected to alter precipitation and promote melting of ground ice, resulting in the
creation and expansion of water tracks that transport water, solutes, and heat downslope. We utilized surveys
and perturbation experiments to understand the microbial communities associated with two water tracks. In
the first track, diversity (Chao1; means of 4438/2593, P < 0.005) and abundance (16S copy number; means of
20055/10266, P = 0.076) were higher inside the track, corresponding to decreased salinity (EC; means of
59/307 µS, P < 0.001). Salinity did not vary significantly across the second track, although in the middle reach,
diversity and abundance decreased inside where salinities were elevated (Chao1; means of 1638/4223, P <
0.001; 16S copy number; means of 1462/8522, P = 0.017). Overall, salinity was negatively correlated to
diversity (r = -0.43, P < 0.001) and abundance (r = -0.32, P = 0.003). Experiments designed to simulate changes
in water and solutes associated with the expansion of water track systems into dry soils suggested that
lowering moisture and raising salt content increase the abundance of Acidobacteria and decrease
Proteobacteria. These results highlight the sensitivity of endemic dry soil communities to future climate change
and potentially provide insights into the limits of life with applications to astrobiology.

211
1432
Physiological and Genomic Responses of Chlorella to UVR across a Global Gradient

Chiew-Yen Wong1,2 (wongchiewyen@imu.edu.my), Aniqah Zulfa Abdul Latif3, Wan-Loy Chu4, Jeannette W.S.
Lai5,6, Sze-Wan Poong5, Phaik-Eem Lim5, Siew-Moi Phang5,6, Peter Convey7
1
International Medical University, School of Health Sciences, Kuala Lumpur, Malaysia, 2University of Malaya,
National Antarctic Research Center, Kuala Lumpur, Malaysia, 3International Medical University, School of
Postgraduate Studies, Kuala Lumpur, Malaysia, 4International Medical University, Institute for Research,
Development and Innovation (IRDI), Kuala Lumpur, Malaysia, 5University of Malaya, Institute of Ocean & Earth
Sciences, Kuala Lumpur, Malaysia, 6University of Malaya, Institute of Biological Sciences, Kuala Lumpur,
Malaysia, 7British Antarctic Survey, High Cross, Madingley Road, United Kingdom

Changes in the global environment, which resulted in increased UVR fluxes can have far-reaching impacts on
microalgae, affecting their physiological processes and productivity. The present study investigated the
physiological response of Chlorella strains isolated from the Antarctic, Arctic, temperate and tropical regions to
UVR stress. Transcriptomic approach was used to investigate genetic responses of Chlorella to UVR stress.
Chlorella originating from different latitudes exhibited different growth trends and photosynthetic
performance. UVB inhibited the growth of the both polar Chlorella, but enhanced the growth of temperate and
tropical Chlorella, compared to those exposed to PAR alone. Chlorella from polar regions appeared to be more
responsive towards the damaging effects of UVB while tropical Chlorella tended to have higher tolerance
towards UVB stress. However, the cellular contents of carotenoids and chl-a increased under UVB stress in both
polar Chlorella while the pigment contents decreased in the tropical and temperate strains. Differentially
expressed genes, relating to the fatty acid degradation, amino acid metabolism, starch metabolism and
peroxisome pathways, suggest that conservation and remobilisation of energy resources, maintenance of
newly synthesised protein and inhibition of protein degradation, ensuring membrane lipid homeostasis and
regulating antioxidative mechanisms, are important in the acclimation strategies expressed in response to UVR
stress.

212
Poster
19.06.2018 16:00-17:30, Foyer

Tue_1_AA-1_74
PAIX: Opening a New Window into the Universe

Merieme Chadid1 (chadid@unice.fr)

1
Universdité Nice Sophia Antipolis, Nice, France

PAIX, the first robotic multi-color photometer Antarctica project, has been successfully launched during the
polar night 2007. This ongoing program gives a new insight to cope with unresolved stellar enigmas and stellar
oscillation challenges with a great opportunity to benefit from an access to the best astronomical site on Earth,
Dome C. PAIX achieves astrophysical measurement time-series of stellar fields, challenging photometry from
Space. A continuous and an uninterrupted series of multi-color photometric observations has been collected
each polar night - 150 days - without regular interruption, Earth's rotation effect.
PAIX shows the first multiband photometric light curves from Antarctica and the first steep for the Astronomy
in Antarctica giving new insides in remote polar observing runs and robotic instruments towards a new
technology.

213
Tue_2_AA-1_398
Developing a Spectrograph for Observing the Atmospheric Emission in K-dark Band

Kohji Tsumura1 (tsumura@astr.tohoku.ac.jp), Takashi Ichikawa2, Yoshifusa Ita2

1
Tohoku University, Frontier Research Institute for Interdisciplinary Science, Sendai, Japan, 2Tohoku University,
Astronomical Institute, Sendai, Japan

We are developing a spectrograph for observing the spectrum of the atmospheric emission in the K-dark band
(~2.4 µm) from the Antarctica.
Low atmospheric foreground environment can be obtained at the K-dark band at the Antarctica because there
is a “window” of the dense forest of OH emission lines and the low temperature of the atmosphere (~200 K).
Although the absolute brightness of the atmospheric emission at the K-dark band from the Antarctica is several
tens of times brighter than the zodiacal light (Phillips et al. 1999), it is still beneficial for observations of diffuse
radiations such as the zodiacal light and the extragalactic background light (EBL). Spatial structures with
arcminute to degree scale of the atmospheric emission and its time variations are critical for subtracting the
atmospheric foreground for the study of EBL.
To validate the atmospheric foreground environment for the EBL study, we are planning to observe the
spectrum, spatial structure, and time variance of the atmospheric emission in the K-dark band from the
Antarctica. We have developed an Antarctica-proof near-infrared camera in Tohoku University, and it will be a
5-cm aperture telescope with 2-degree FoV by putting a small lens on the camera. To obtain a simple
spectrograph, we are developing a linear-variable filter (LVF) covering 2.2-2.55 µm with Δλ~0.02 µm, which will
be installed in a filter wheel in the camera. We want to bring the camera with the LVF to the Antarctica by
2020.

214
Tue_3_AA-1_403
Opening the Dynamic Infrared Sky from Antarctica

Anna Moore1 (anna.moore@anu.edu.au)

1
Australian National University, Research School of Astronomy and Astrophysics, Canberra, Australia

While optical and radio transient surveys have enjoyed a renaissance over the past decade, the dynamic
infrared sky remains virtually unexplored. The infrared is a powerful tool for probing transient events in dusty
regions that have high optical extinction, and for detecting the coolest of stars that are bright only at these
wavelengths. The fundamental roadblocks in studying the infrared time-domain have been the overwhelmingly
bright sky background (250 times brighter than optical) and the narrow field-of-view of infrared cameras
(largest is VISTA at 0.6 sq deg). To address this challenge, we propose a low risk, economical and agile
instrument located in the high polar regions to take advantage of the low thermal sky emission in the 2.5
micron region in particular. Such an instrument has the ability to observe the entire hemisphere sky to a depth
of the VISTA VHS survey every 4 hours.

215
Tue_4_AA-1_679
Study of Cloud Cover and Aurora Contamination by KLCAM at Dome A in 2017

Zhaohui Shang1,2 (zshang@gmail.com), Xu Yang1, Keliang Hu1, Yi Hu1, Bin Ma1, Wei Wang1
1
National Astronomical Observatories, CAS, Beijing, China, 2Tianjin Normal University, Tianjin, China

An all-sky camera KunLun Cloud and Aurora Monitor (KLCAM) was installed at Dome A, Antarctica in January
2017 and has been working automatically through the austral winter. The unattended KLCAM aims for long-
term monitoring for site testing and has collected tens of thousands of images used to evaluate usable
observing time and optical sky background at Dome A. We have analyzed the data and developed methods to
automatically classify the cloud cover and aurora contamination to the night sky. We present the results on the
site characteristics in 2017.

216
Tue_5_AA-1_981
Introduction of Chinese Antarctic Optical Telescopes

Zhengyang Li1 (zyli@niaot.ac.cn), Xiangyan Yuan1, Xuefei Gong1

1
Nanjing Institute of Astronomical Optics & Technology, National Astronomical Observatories, CAS, Nangjing,
China

The Antarctica plateau is widely considered to be an excellent astronomical site for the superb seeing
conditions. The preliminary site testing performed since the beginning of 2008 shows that Antarctic Dome A is
an excellent astronomical site for observing wavelengths ranging from visible to infrared and sub-millimetre. In
polar nights, the in-situ Antarctic telescopes manage to continuous observe for three months, which is quite
suitable for the transits detection and time domain astronomy. Several Chinese wide field Antarctic telescopes
have been built. The first generation is Chinese Small Telescope Array known as CSTAR, which is composed of
four identical telescopes with 145mm entrance pupil, 20 square degrees FOV. CSTAR was fixed to point at the
South Pole, and mainly used for variable stars detection and atmosphere extinction measurement, and
deployed on Antarctica in 2008 and its automatic operation continued for four consecutive winters. The second
generation is three Antarctic Survey Telescopes (AST3), with 500mm entrance pupil, 8.5 square degrees FOV
can precisely pointing and tracing. AST3-1 and AST3-2 were respectively mounted on Antarctic plateau in 2012
and 2015, fully remotely controlled for supernovae survey, exoplanets search and GW counterpart
photometry.

217
Tue_6_AA-1_1059
Modeling Ice Birefringence from SPICEcore for ARA Stations

Jennifer Cooper1 (jrc323@cornell.edu), ARA Collaboration1

1
University of Kansas, Lawrence, United States

The Askaryan Radio Array (ARA) is an in-progress ultra-high energy (>1017 eV) cosmic neutrino detector
composed of 37 radio receiver stations located ~200 meters below the surface in the ice at the South Pole.
Interactions of neutrinos with the ice generate radio pulses that can be detected and observed in the 150 - 850
MHz range through the Askaryan Effect. The structure of the ice plays an important role in signal propagation
between production and measurement point. The nearby South Pole Ice Core (SPICEcore) has been used to
study changes in the Earth's climate from an ice core drilled to a depth of 1751 meters. This core has ice grain
orientation data, which can be related to the birefringence properties of ice in the vicinity of ARA. Here we
model an incoming signal propagating through a 3-axis ice crystal bulk orientation from SPICEcore data for a
range of depths relevant to ARA stations, and compare with ARA data.

218
Tue_7_AA-1_1084
Cosmic Microwave Background Observations in Antarctica

Chao-Lin Kuo1 (clkuo@stanford.edu)

1
Stanford University, Physics, Stanford, United States

The exceptionally dry and cold Antarctic climate is ideal for CMB observation. I will discuss lessons learned over
the past 20 years and prospects for future searches for primordial gravitational waves in CMB polarization.

219
Tue_8_AA-1_1088
The Antarctic Advantage for Optical Transient Follow-up Observations

Michael Ashley1 (m.ashley@unsw.edu.au)

1
University of New South Wales, Sydney, Australia

The rapid follow-up of transient sources will become an increasingly important aspect of astronomy over the
next decade. This is primarily driven by new facilities coming on-line, such as LSST, more sensitive gravitational
wave detectors, and precursors to SKA. Positioning a telescope in Antarctica has the obvious advantage that,
during mid-winter at least, the sun has no effect on whether a source can be observed. Cloud permitting,
observations can commence rapidly and continue uninterrupted for weeks, producing a higher quality and
more uniform dataset than a network of telescopes from a lower latitude. There are a host of other advantages
such as low-scintillation noise, low-airmass variations, low aerosols, and low & stable water vapor. There are
also some more subtle advantages such as lower variations in CO2 content. On the negative side, aurora need
to be taken into account. On the whole, Antarctica offers significant improvements for precision photometry
and spectroscopy, making it an excellent location for following up transient sources.

220
Tue_9_AA-1_1295
Photometric Monitoring of Proxima Centauri at the Chinese Zhongshan Station

Peng Jiang1 (jiangpeng@pric.org.cn), Huigen Liu2, Fujia Du3, Jian Wang4, Zhengyang Li3, Xiaoyan Li3, Haiping Lu3,
Minghao Jia4, Awiphan Supachai5
1
Polar Research Institute of China, Shanghai, China, 2Nanjing University, Nanjing, China, 3Nanjing Institute of
Astronomical Optics & Technology, National Astronomical Observatories, CAS, Nanjing, China, 4University of
Science and Technology of China, Hefei, China, 5National Astronomical Research Institute of Thailand, Chiang
Mai, Thailand

Proxima Centauri is known as the closest star from the Sun. Recently, radial velocity observations revealed the
existence of an Earth-mass planet around it, with an orbital period of 11 days. If the planet transits, it would be
interesting to probe its radius, internal compositions and atmospheric properties. We took a photometric
monitoring campaign of Proxima Centauri using the Bright Star Survey Telescope at the Zhongshan Station in
Antarctica. A candidate transit event occurring on September 8th, 2016, is identi

221
ed tentatively. Its transit epoch, 2,457,640.1990±0.0017 HJD, is consistent with the predicted ephemeris based
on RV orbit in a 1σ con

222
fidence interval. Time-correlated noise is pronounced in the light curve of Proxima Centauri, affecting detection
of transits. The candidate transit event reported in this work, has a con

223
fidence level of 2.5σ. Kipping et al. (2017) reported two candidate transit events of Proxima Centauri b,
observed by the Microvariability and Oscillation of Stars space Telescope in 2014 and 2015, respectively. The
midtransit time of our detection is 138 minutes later than that predicted by their transit ephemeris. If all the
transit events are real, the misalignment of the epochs plausibly suggests transit timing variations of Proxima
Centauri b induced by an outer planet in this system. We plan to perform follow-up observation of Proxima
Centauri in next Polar night at the Chinese Kunlun Station in Antarctica.

224
Tue_10_AA-1_1322
Key Areas on Polar Astronomy and Related Sciences in Thailand

Boonrucksar Soonthornthum1 (boonrucksar@narit.or.th)

1
National Astronomical Research Institute of Thailand, Research, Chiang Mai, Thailand

Thailand has established a Polar Sciences Committee, under the Information Technology Foundation under the
Initiative of Her Royal Highness Princess Maha Chakri Sirindhorn and has become an associate member of SCAR
since August 2016. Due to the long and continuous 6 months dark clear winter sky and the stable atmospheric
condition with excellent sky seeing, Polar region (Arctic/Antarctic Plateau) is a perfect place for astronomical
observations. Some Astronomy and related sciences research proposals initiated by NARIT have been planned
to be performed in Polar region with some collaborative institutes.
NARIT signed the MoU with the Yunnan Observatories (YNO) since February 2007 and the Polar Research
Institute of China (PRIC) since April 2016. The study on the evolution of close binary systems was closely
collaborated with YNO. Several deep contact binary systems were observed and analyzed using observational
data from optical telescopes at Dome A in Antarctica. Result from the collaborative meeting, NARIT and PRIC
agree to cooperate on several fields of astronomical research, for example, on the search for exoplanets,
astroseimology of oEA and other pulsating stars, the study of the growth of supermassive black holes and co-
evolution of host galaxies etc. Other related sciences such as Jupiter's and Earth's aurora activities, latitude
survey project etc. will also be discussed.

225
Tue_11_AA-1_1377
Solar Energetic Particle Spectra using Neutron Detectors at South Pole

Waraporn Nuntiyakul1 (w.nuntiyakul@gmail.com), John Bieber2, John Clem2, Paul Evenson2, Tom Gaisser2, Allan
Hallgren3, James Madsen4, Pierre-Simon Mangeard2, Roger Pyle5, David Ruffolo6, Alejandro Sáiz6, Surujhdeo
Seunarine4, Serap Tilav2
1
Chiang Mai University, Department of Physics and Materials Science, Chiangmai, Thailand, 2University of
Delaware, Department of Physics and Astronomy, Bartol Research Institute, Newark, United States, 3Uppsala
University, Department of Physics and Astronomy, Box 516, Uppsala, Sweden, 4University of Wisconsin-River
Falls, Physics Department, River Falls, United States, 5Pyle Consulting Group, Inc., St. Charles, United States,
6
Mahidol University, Department of Physics, Faculty of Science, Ratchathewi, Thailand

Neutron monitors are ground-level detectors of cosmic ray induced atmospheric secondary particles (mostly
neutrons) that are employed worldwide to study variations in the flux of galactic cosmic rays and solar
energetic particles (SEPs) in the GeV regime. The neutron monitor standard design (NM64) minimizes detector
response to neutrons below ∼10 MeV produced by cosmic ray interactions in the ambient medium. Bare
detectors or simply “bares”, which lack the lead and polyethylene of NM64 detect such neutrons and therefore
respond on average to cosmic rays of lower energy. The array of NM64 and bares at the South Pole has been
used for many years to measure SEP spectra relying primarily on relative response functions derived from a
single latitude survey in 1976. We have recently completed analysis of a second survey from Nov, 1995 to Feb,
1996 from three bares operated together with a 3NM64. The solar modulation conditions in 1995 and 1976
were remarkably similar but the results from the 1995-6 survey differ significantly from the interpretation of
the 1976 survey most commonly used for the determination of SEP spectra. We present results from a third
survey from Nov, 2009 to Apr, 2010 with two bares that are now installed at the South Pole. A significant
correction to the 2009-10 data due to highly different modulation conditions, and implications for
interpretation of SEP spectra will be discussed.
Supported in part by Thailand Research Fund grants MRG6080086 and RTA5980003.

226
Tue_12_AA-1_1564
ITM (International Telescope Maffei) Improvements: A New Robotic Interface

Jean Marc Christille1 (jeanmarc.christille@gmail.com), Yuri De Pra2, Daniele Tavagnacco3, Stefano Sartor3,
Maurizio M. Busso4, Albino Carbognani1, Marco Bagaglia5, Giuliano Nucciarelli4
1
Fondazione Clément Fillietroz - ONLUS, Nus, Italy, 2CNR, Perugia, Italy, 3Astronomical Observatory of Trieste,
Trieste, Italy, 4University of Perugia, Physics and Geology, Perugia, Italy, 5Univeristy of Perugia, Physics and
Geology, Perugia, Italy

IRAIT-ITM is a s a f/21.16 Cassegrain-like reflector with two Nasmyth foci and a 0.8m parabolic primary mirror
and a wobbling secondary mirror suitable for the specific techniques for mid and near IR but is also suitable for
observations in the visible spectrum. During these first ten years of activity several modification has been done
in order to provide a more robust control system in terms of hardware and software, using new technologies
and materials. We present the status of the project ITM (International Telescope Maffei) formerly Irait
(International Robotic Antarctic Infrared Telescope), that is located at Dome C in the Italo-French Concordia
station and hosted by PNRA (Programma Nazionale di Ricerche in Antartide) and CNR (Consiglio Nazionale delle
Ricerche). Managing a robotized telescope in Antarctica is not a trivial job. A thermal excursion about more
than 70°C during the year with minimal peak around -84°C and a mean pressure of 630 hPa are not the best
conditions to deal with for a telescope which goal is to perform continuous observations. In this presentation
we want to present all the hardware/software features provided during this period of activity in order to
achieve a remote continuous complete monitoring and control. The management system, basing on rts2 open
software, has been fully customized for our altazimuthal mount. The first rt2 webapp has been released for a
remote VPN management of all devices connected to the telescope.

227
Tue_13_AA-1_1782
Bipolar Disorder: The Uncertain Future of Spaceship Earth

Paul Evenson1 (evenson@udel.edu)

1
University of Delaware, Physics and Astronomy, Newark DE, United States

Neutron monitors are ground-level detectors of cosmic ray-induced atmospheric secondary particles (mostly
neutrons employed world-wide to study variations in the flux of galactic cosmic rays and solar energetic
particles in the GeV regime. Proper geographic distribution of the monitors is critical due to two characteristics
of a particular location resulting from the geomagnetic field. One is the geomagnetic cutoff, or minimum
primary particle energy that can reach the location, and the other is asymptotic direction - a rather specific
direction outside the magnetosphere from which the primary particles must come to reach the location.
Locations near the auroral zones are particularly important for observation of low energy but highly anisotropic
solar energetic particles. In the late 1990's an informal collaboration of station operators known as Spaceship
Earth was formed to coordinate observations from this critical region. Primarily due to retirement of several
key people it is necessary to restructure this collaboration; some preliminary steps have been taken. The South
Pole NM64 and Bares are now being operated by the University of Wisconsin, River Falls. Move of the
McMurdo monitor to the South Korean station at Jang Bogo should be complete in 2018. A partial move and
common data taking in 2016 provide for continuity of data. We are continuing to search for opportunities to
keep the other Spaceship Earth monitors running, but a complete path forward has not yet emerged.

228
Tue_14_AA-1_2086
Optical Modules for the Next-generation Neutrino Telescope at the South Pole

Lew Classen1 (classenl@wwu.de)

1
Westfälische Wilhelms-Universität Münster, Institut für Kernphysik, Münster, Germany

Following the first observation of an astrophysical high-energy neutrino flux with the IceCube observatory in
2013, planning for a next-generation neutrino telescope at the South Pole - IceCube-Gen2 - is under way.
Instrumenting 5 - 10 km³ of the deep clear ice with up to 15,000 sensors, the envisioned detector will
significantly expand the sensitivity both towards high and low neutrino energies.
The sensors, so-called digital optical modules (DOMs), record the Cherenkov light emitted by charged
secondaries created in the interaction of neutrinos in the ice, allowing the reconstruction of the energy and
direction of the original particle. Apart from the larger volume, a significant increase in sensitivity and
reconstruction precision is anticipated to be achieved by advanced optical module technology. The devices
currently under development, include the modernization of the conventional IceCube DOM as well as new
concepts featuring increased sensitive areas, homogeneous angular acceptance, UV sensitivity, directional
information as well as reduced sensor self-noise.
This contribution, presented on behalf of the IceCube-Gen2 collaboration, will introduce the new module
concepts and introduce the planned detector infrastructure and readout scheme.

229
Tue_15_AA-1_2209
Bringing Access to Space Down to Earth: The GUSTO Balloon-borne Observatory

Craig Kulesa1 (ckulesa@email.arizona.edu), Christopher K. Walker1, Pietro Bernasconi2, Paul Goldsmith3,

Christopher E. Groppi4, David Hollenbach5, Gary Melnick6, David Neufeld7, Mark Wolfire8
1
University of Arizona, Steward Observatory, Tucson, United States, 2Johns Hopkins University / Applied Physics
Laboratory, Laurel, United States, 3Jet Propulsion Laboratory, California Institute of Technology, Pasadena,
United States, 4Arizona State University, SESE, Tempe, United States, 5SETI Institute, Mountain View, United
States, 6Harvard-Smithsonian Astrophysical Observatory, Cambridge, United States, 7Johns Hopkins University,
Baltimore, United States, 8University of Maryland, College Park, United States

Recently funded by NASA´s Explorer Program, the Galactic ULDB Spectroscopic THz Observatory (GUSTO) will
dramatically improve our understanding of the Universe by probing the topology and ecology of interstellar gas
throughout the Milky Way and Large Magellanic Cloud (LMC). GUSTO is a cryogenic balloon-borne, 0.9m
Cassegrain telescope designed to stay aloft on a long duration balloon for 100 days or more. During this time
GUSTO will survey 124 square degrees of the Milky Way and all of the LMC in three important interstellar lines:
[CII], [OI], and [NII] at 158, 63, and 205 um, respectively. From these data the global structure, dynamics,
energy balance, pressure, and evolution of the interstellar medium within these objects will be discerned for
the first time. The mission will be one of the first to utilize the 100+ day flight potential of the Super Pressure
Balloon, also known as the Ultra Long Duration Balloon (ULDB), provided by NASA's Balloon Program Office.
GUSTO features a proven measurement approach, a high-heritage payload, and a simple, repeatable observing
strategy that, combined with the ultra-long duration capability of the SPB, enables these important new
galactic and extragalactic observations at a fraction of the cost of a comparable orbital mission. GUSTO is slated
to fly in 2021 from the LDB payload integration facility near McMurdo Station, Antarctica.

230
Tue_16_AA-1_2218
ALMA Band 11 Science without ALMA: A Terahertz Interferometer for Ridge A

Craig Kulesa1 (ckulesa@email.arizona.edu), Michael C. B. Ashley2, David Lesser1, Abram Young1

1
University of Arizona, Steward Observatory, Tucson, United States, 2University of New South Wales, School of
Physics, Sydney, Australia

The exceptional atmospheric transparency and stability above the high Antarctic plateau at Terahertz
frequencies (50-500 microns wavelength) lends itself to two important applications for astronomy: wide-field
(spectroscopic) imaging, and interferometry. With the advent of the ALMA interferometer in Chile, the power
of submm-wave interferometry is having a dramatic impact on astronomy. However, at the highest frequency
ALMA bands near and beyond 1 THz, the number of days with suitable observing conditions is scant. Coupled
with the high costs of outfitting dozens of stations with advanced receivers, it is unlikely that the Band 11
capability will ever become a reality. To this end, the Ridge A site that hosted the pathfinding HEAT telescope
and PLATO-R observatory can play an enabling role. Recent, cross-cutting advances in low-cost telescope
construction, sensitive receivers at temperatures above 4K, low-power cryocoolers, and low-cost hybrid
correlators make the case compelling: a capable THz interferometer can tackle the critical Band 11 science
questions at a small fraction (5%) of the cost of outfitting ALMA. Here, we explore the science questions,
capabilities and requirements that can be advanced by a Twin-Otter-deployable THz interferometer at the most
remote, space-like site on Earth. We also highlight the technological prototyping efforts that demonstrate its
feasibility. Terahertz phase closure at Ridge A could happen as early as 2021.

231
Tue_17_AA-1_2221
GCR and Radioactivity in the Colombian Expeditions to the Antarctic

Edwin Alexander Casallas Moreno1 (edwin.casallas@fac.mil.co), Fernando Quiñonez2, Luis Alberto Núñez2,
Carlos Alberto Rios Reyes3, Giovanna Estefania Ramírez Ruíz1, María Betsabé Rubiano Esmeral1, Jesús Peña-
Rodríguez2,4, Jesús Bonilla-Neira4, Andrés Felipe Morales Guerrero3, Christian Julián Delgado Mateus3
1
Fuerza Aérea Colombiana, Dirección de Ciencia Tecnologı́a e Innovación, Bogota, Colombia, 2Universidad
Industrial de Santander, Escuela de Física, Bucaramanga, Colombia, 3Universidad Industrial de Santander,
Escuela de Geología, Bucaramanga, Colombia, 4Universidad Industrial de Santander, Escuela de Ingeniería
Eléctrica, Electrónica y Telecomunicaciones, Bucaramanga, Colombia

We have calculated the absorbed effective radiation doses on a human phantom flying on route SKBO-SKCL-
SCEL-SCCI-SCRM-SAWB with software CARI-7A from the Federal Aviation Agency FAA using the model ISO
TS15390:2004-MSU-NYMMIK of Galactic Cosmic Rays GCR. Additionally we have calculated the same on a
human phantom modelled as a sphere with radius equals to 30 cm, composed of water, flying in the same
routes by using a simulation chain involving CORSIKA and GATE/GEANT4. Equivalent radiation doses are going
to be measured with four particle detectors SAFECAST bGeigie Nano inside the aircrafts that will be used in the
fourth Colombian scientific expedition to the Antarctic flying on the route mentioned above. We also are going
to measure the equivalent dose around the scientific base of Marambio in the Antarctic. With the
characterization of major, minor elements and trace done on the geological material collected in the fourth and
second Colombian scientific expeditions to the Antarctic, we build new simulated materials according to their
element mass fraction on each geological material compound sample and incorporate them into the GATE
materials database and calculate the absorbed effective radiation dose by the spherical phantom due to the
presence of radioactive elements in the samples. With the information obtained in the simulations and
measured data, we establish a criterion for cellular repair and estimate the risks caused by exposure to
radiation.

232
Tue_18_AA-1_2263
Current Status of Optical/Infrared Telescopes at Chinese Kunlun Station

Xuefei Gong1 (xfgong@niaot.ac.cn), Yongtian Zhu1, Lifan Wang2, Xiangyan Yuan1

1
Nanjing Institute of Astronomical Optics & Technology, National Astronomical Observatories, CAS, Nanjing,
China, 2Texas A&M University, College Station, United States

The first Chinese Small Telescope ARray (CSTAR, with entrance pupil of 145mm) was successfully mounted on
Dome A at 2008. The first inland station of Chinese, called Kunlun, has been erected in 2009, and then two
Antarctic Survey Telescopes (AST3) with entrance pupil of 500mm has been installed. Now Chinese
astronomers have proposed a plan to build a 2.5-meter optical/infrared telescope at Dome A. Kunlun Dark
Universe Survey Telescope, one of two major facility of Antarctic Observatory at Chinese Kunlun Station, is a
2.5-meter optic/infrared telescope. It is intended to take advantage of the exceptional seeing conditions, as
well as the low temperature reducing background for infrared observations. KDUST will adopt an innovative
optical system, which can deliver very good image quality over a 2 square degree flat field of view. KDUST will
be perched on a 14.5-meter-high tower to lift it above the turbulence layer.

233
Tue_19_AA-1_2319
Neutrino Point Source Searches in IceCube Using a Multi-messenger Approach

Imen Al Samarai1 (imen.alsamarai@unige.ch)

1
Université de Genève, DPNC, Genève 2, Switzerland

The IceCube high energy neutrino detector is deployed in Antarctica, with highly sensitive photodetectors
buried deep within the ice sheet at the South Pole. Its construction started in 2005 and was completed in 2010.
It is the first experiment to report the detection of high energy neutrinos of astrophysical origin. Given the low
astrophysical neutrino fluxes expected, and the high atmospheric background, multi-wavelength observations
are used to further enhance the sensitivity to potential neutrino sources. By requiring space and/or time
correlation between neutrinos and gamma-rays, or high-energy cosmic rays, the background associated to a
neutrino detection is reduced as uncorrelated backgrounds from different observatories are considered. This
contribution will present the various aspects of multi-messenger searches for cosmic sources in IceCube. The
latest results of targeted source searches and all-sky source searches will be presented.

234
Tue_20_AA-1_2511
Radio Frequency and Optical Measurements of the Glacial Ice at the South Pole

Michael DuVernois1 (duvernois@icecube.wisc.edu)

1
University of Wisconsin - Madison, Wisconsin IceCube Particle Astrophysics Center, Madison, United States

A unique opportunity to investigate the radio glaciological properties of the glacial ice has become available
through the SPICE core hole. A program and is in preparation to perform measurements of RF transmitters
deployed in the SPICE core hole to a depth of more than 1500 m. Optical measurements are also planned.
The signals will then be recorded with multiple radio detector stations of the Askaryan Radio Array and possibly
other instruments for the RF signals. First results will be presented from a field campaign in 2017/18. The
measurements are especially interesting the radio neutrino detector community that uses the almost 3 km
thick glacial ice with experiments such as IceCube and ARA and future extensions of these programs.

235
Tue_21_AA-1_2655
A Brief Review of the Science Potential of Antarctic Astronomy

Hans Zinnecker1 (hzinnecker50@gmail.com)

1
University of Stuttgart, Deutsches SOFIA Institut, Stuttgart, Germany

In 2007, I chaired a conference on "The Astrophysical Science Cases at Dome C" in Antarctica, the results of
which are published in Vol. 33 of EAS/EDP Sciences (Zinnecker, Epchtein, and Rauer 2008, eds.) Being cold,
high, dry, stable, and completely dark for 3 long winter months, Antarctic astronomy offers exceptional ground-
based atmospheric conditions to achieve unique astronomical observations and wide-field surveys (from the
near- and mid-IR part of the spectrum to the far-IR/submm domain). Antarctic astronomical sites may also
provide an outstanding platform for far-IR interferometry (perhaps at Ridge A) and for follow-up of future
space missions of the 21st century.
In my presentation, I will briefly recall and review some of these science cases, including the potential for day-
time and twilight astronomy as well as long time-seriesmonitoring (particularly in the Magellanic Clouds). In the
far-IR (30-300 micron or 1-10 THz), future Antarctic THz astronomy (high-resolution spectroscopy, particularly
of the interstellar medium) from the Chinese Kunlun station at Dome A with a 5m or larger aperture dish might
compete with the airborne infrared observatory SOFIA (a 2.5m telescope in B747SP flying in the stratosphere,
funded by NASA/DLR). Finally, I discuss the potential of balloon-borne far-IR astronomy from the Antarctic
continent (e.g. GUSTO), compared to SOFIA and the ground-based facilities ALMA/APEX or TAO/CCAT´.

236
Tue_22_AA-1_2669
Inflationary Cosmology and South Pole´s Leading Measurements of CMB Polarization

John Kovac1 (jmkovac@cfa.harvard.edu)

1
Harvard University, Astronomy, Cambridge, United States

The BICEP Array and 10m South Pole Telescope are a suite of small and large microwave telescopes at the
South Pole working together to detect polarization patterns in the cosmic microwave background (CMB) arising
from primordial gravitational waves. Cosmologists believe that the entire observable Universe may have been
spawned in a fraction of a second by the rapid “inflation” of a sub-atomic volume. Inflation provides a testable
prediction: the same quantum process that plants the seeds of structure also produces a gravitational-wave
background that may be detectable now via faint "B-mode" patterns imprinted in the polarization of the CMB.
Detecting this faint pattern requires making maps of unprecedented sensitivity, while separating the faint
polarization signals intrinsic to the CMB from other signals including polarized emission from dust and electrons
in our own galaxy and patterns caused by weak gravitational lensing of large scale structure. The small-
aperture BICEP/Keck Array telescopes have produced the deepest-ever maps of CMB polarization in four
frequency bands. They are exploiting the unique Polar atmosphere to push these maps to high (up to 270 GHz)
and low frequencies (down to 30 GHz) to separate galactic emission from CMB signals. The 10m SPT has
deployed a new receiver with 17000 detectors and resolution sufficient to reconstruct the weak lensing
patterns. Together they are producing the most sensitive constraints yet on primordial gravitational waves.

237
Tue_23_AC-1_71
Arctic Mixed Phase Clouds Observed from Tethered Balloon Platform

Monika Sikand1 (monika.sikand@bcc.cuny.edu), Levente Krizsan2, Milos Szitpanov2, Nan Chen2, Wei Li2, Knut
Stamnes2
1
Bronx Community College, City University of New York, Department of Engineering, Physics & Technology,
Bronx NY, United States, 2Stevens Institute of Technology, Department of Physics, Hoboken, United States

Mixed phase clouds, consisting of ice particles and super cooled liquid droplets, are frequently found in the
Arctic. The impact of these clouds on sea ice, cloud radiation feedbacks, and the Earth's surface radiative
energy balance, critical to climate is poorly represented in various climate models. This research addresses the
need for improved modeling capabilities in describing the role of Arctic clouds in climate models. This study
hypothesizes that mixed phase Arctic clouds affect the surface energy budget due to unique cloud optical
properties and positive cloud surface feedback in the near infrared wavelength channels. Therefore, it is
important to estimate inherent cloud optical properties in wavelength channels including near infrared
channels to provide an understanding about the cloud radiative forcing that affects the radiative transfer (RT)
and energy budgets. A unique tethered balloon campaign carrying 4π radiometer, a cloud particle imager, and
a meteorological package on board was conducted in 2008 in Ny-Alesund, Spitzbergen. Sikand et al. (2010,
2013) concluded that it would be valuable to build a next-generation radiometer that would include near-
infrared channels. This research performs a feasibility study based on RT simulations using measurements from
a test flight carrying an improved 4π radiometer including near-infrared wavelength channels that will be useful
in the planned May 2018 Tethered Balloon Campaign to be conducted in Ny-Alesund, Spitzbergen.

238
Tue_24_AC-1_72
Black Carbon in the Russian Arctic Atmosphere:Anthropogenic and Wildfire Sources

Anna Vinogradova1 (anvinograd@yandex.ru)

1
A.M.Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russian Federation

Black carbon (BC) emissions from Russian territory (2000-2014) were analyzed basing on official RF datasets
and satellite data GFED. Some corrections for BC emissions from Russian intensive flaring zones of gas/oil
mining industry are discussed. Total anthropogenic emission from Northern Eurasia (to the North of 52ºN) is
estimated as 315 kt BC annually (with about 2/3 from Russia). The best estimate of air BC concentration from
RF wildfires (with 25% deviation for every point of the Russian Arctic) is the mean value calculated from Russian
and GFED emission data.
Spatial divergences of air BC concentrations along the Arctic coast are up to 100 times and more.
Anthropogenic air BC concentrations prevail annually, but in summer wildfire's BC concentrations may in some
years at some points be higher than anthropogenic ones. Also, there are high variations in BC pollution from
year to year due to variations in atmospheric circulation processes. Great inter-annual and seasonal variations
in BC air concentration through Russian Arctic territory do not allow to use the measured BC air concentrations
(obtained at one point during one season or even one year) for long term conclusions/forecasts concerning the
Arctic region and climate in general.
The work is supported by RFBR (grant No. 17-05-00245).
Vinogradova A.A., Vasileva A.V.. Black Carbon in Air Over Northern Regions of Russia: Sources and
Spatiotemporal Variations // Atmos. Ocean. Opt. 2017. V. 30. No. 6. P. 533-541.

239
Tue_25_AC-1_241
Long Term Aerosol Optical Measurements in Polar Regions from the GAW-PFR Network

Stelios Kazadzis1,2 (skazan@auth.gr), Natalia Kouremeti1, Georg H. Hansen3, Kerstin Stebel4, Aaltonen Veijo5,
Edith Rodríguez5, Stephan Nyeki1
1
Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos, Switzerland, 2IERSD,
National observatory of Athens, Athens, Greece, 3NILU - Norwegian Institute for Air Research, Tromsø, Norway,
4
NILU Norwegian Institute for Air Research, Tromsø, Norway, 5Finnish Meteorological Institute, Helsinki, Finland

Long term ground-based sun-photometer measurements conducted at 2 Arctic (Ny-Ålesund 50 m asl, 8.91 N,
11.88 E, Summit 3238 m asl 72.58 N, 38.46 W) and 2 Antarctic sites (Marambio 205 m asl, 64.24 S, 56.62 W,
Troll 1309 m asl, 72.01 S, 2.54 E) were examined to investigate aerosol optical depth (AOD) seasonal and year
to year changes. Together with the AOD's at 368, 412, 500 and 865 nm, Ångström´s exponents have been
calculated for spring to autumn in the Arctic and for austral summer in Antarctica. Sun-photometers used are
part of the GAW-PFR network, where instrument calibration and data processing is performed by PMOD/WRC.
Higher AODs have been measured in Ny-Ålesund (0.5 for 500nm) with a pronounced decreasing trend from
spring to autumn and Summit (0.4 for 500nm) showing also a less pronounced change. This has been
commonly attributed to the position of the Arctic polar front. During the winter, the front is situated at ~50°N,
hence allowing long-range transport from major industrial regions in Europe, Russia and N. America into the
Arctic. The circulation pattern is different in summer when the front is situated further to the north (about
70°N), hence preventing polluted air masses from effectively reaching the Arctic. Lower AODs (from 0.2 to 0.4
for 500 nm) have been found for the Antarctic sites.

240
Tue_26_AC-1_242
Development and AOD Measurements with a Lunar Photometer at Ny-Ålesund

Natalia Kouremeti1 (natalia.kouremeti@pmodwrc.ch), Stelios Kazadzis1,2, Mauro Mazzola3, Georg H. Hansen4,

Kerstin Stebel4, Julian Groebner1
1
Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos, Switzerland, 2IERSD,
National observatory of Athens, Athens, Greece, 3National Research Council of Italy, Bologna, Italy, 4NILU
Norwegian Institute for Air Research, Tromsø, Norway

Atmospheric aerosols are known to impact the climate, but they still represent one of the largest uncertainties
in climate change studies. Night-time AOD measurements could provide valuable information on the
climatology of aerosols at high latitude stations, where direct sun measurements are not possible throughout
the year. For example, in the northern hemisphere they can be used to monitor the arctic haze during polar
winter. In passive remote sensing techniques, the moon or the stars are used as the light source.
The growing interest in night-time observations of aerosol optical depth (AOD) has led to the development of a
lunar Precision Filter Radiometer (PFR) at PMOD/WRC. In addition to the retrieval of nocturnal AOD, the
radiometric calibration of the lunar PFR aims to provide absolute lunar irradiance measurements with an
expanded uncertainty of less than 5% (k = 2).
A lunar PFR was installed at Ny-Ålesund, Norway in October 2014 and it provides measurements from October
to February.

241
Tue_27_AC-1_244
Cloud Condensation Nuclei and Ice Nucleating Particles in the Southern Ocean

Silvia Henning1 (henning@tropos.de), Welti André1, Markus Hartmann1, Mareike Löffler1, Andrea Baccarini2,
Heini Wernli3, Frank Stratmann1, Julia Schmale2, ACE-SPACE Team1,2,3
1
Leibniz Institute for Tropospheric Research, Leipzig, Germany, 2Paul Scherrer Institute, Villigen, Switzerland,
3
ETH Zurich, Dep. of Environmental Systems Science, Zurich, Switzerland

The Southern Ocean (SO) region is the most pristine aerosol environment on Earth, however almost the entire
region is considered as heavily under-sampled. As partner of the “Study of Preindustrial-like-Aerosol Climate
Effects” (SPACE) project, we participated in the unprecedented Antarctic Circumnavigation Expedition (ACE,
December 2016 - March 2017), which gave us the unique opportunity to conduct high quality aerosol
measurements in this remote region. ACE-SPACE in general aims at a detailed characterization of the pristine
aerosol which is unaffected by anthropogenic pollution and therefore represents an aerosol comparable to that
in a pre-industrial atmosphere. Our, i.e., TROPOS' special focus in context of ACE-SPACE is on aerosol particles
involved in aerosol cloud interactions, specifically on particles able to act as cloud condensation (CCN), as well
as particles able to nucleate ice (INP). We will present results concerning the spatial distribution of CCN and INP
concentrations around the Antarctic continent, CCN hygroscopicity and INPs' freezing characteristics, and
possible CCN and INP sources based on the analysis of back trajectories. Please notice two further
contributions on ACE-SPACE at this conference giving (a) an ACE-SPACE overview and (b) results on new
particle formation events.

242
Tue_28_AC-1_249
Tethered Balloon-borne Turbulent Energy Fluxes in the Cloudy Central Arctic

Ulrike Egerer1 (egerer@tropos.de), Holger Siebert1, Matthias Gottschalk2, Manfred Wendisch2

1
Leibniz Insititute for Tropospheric Research, Leipzig, Germany, 2Leipzig University, Leipzig, Germany

Climate change is most pronounced in the Arctic, which is generally known as Arctic Amplification.
The Transregional Collaborative Research Centre TR 172 "Arctic Amplification" (AC)3 aims to improve the
understanding of climate relevant atmospheric and surface processes and feedback mechanisms by different
modeling and observational projects.
Quantifying vertical energy fluxes in the Arctic Atmospheric Boundary Layer (ABL) is most important for
understanding the exchange of energy between the surface and higher altitudes, and therefore is a key factor
to understand the changing atmosphere in a warming Arctic. However, observations of vertical profiles of
energy fluxes in the central Arctic are still rare due to the challenging conditions in that region.
One major field campaign of (AC)3 is PASCAL: a cruise of R/V Polarstern into the Arctic sea ice north of Svalbard
in June 2017. From an ice floe camp, we measured vertical profiles of turbulent energy fluxes with a tethered
balloon under different stratification and cloud conditions. Turbulence parameters were measured with a hot-
wire anemometer and an ultrasonic anemometer, which enables us to determine turbulent fluxes of heat and
momentum. Additional radiation packages, developed by the University of Leipzig, complete the observations.
Within the conference, we will present first results of balloon-borne turbulence and radiation measurements
performed during PASCAL.
This work was supported by DFG Grant TR 172/1 A02.

243
Tue_29_AC-1_348
Assessing Aerosol-cloud-rainfall Associations at a High Altitude Himalayan Site

Sachchida Tripathi1 (snt@iitk.ac.in), Alok Gautam2, Vijay Kanawade3

1
Indian Institute of Technology Kanpur, Department of Civil Engineering, Kanpur, India, 2Hemwati Nandan
Bahuguna Garhwal University, Department of Physics, School of Science, Srinagar - Pauri Garhwal, India,
3
University of Hyderabad, Centre for Earth and Space Sciences (UCESS), Hyderabad, India

The lack of an accurate understanding of the interplay between aerosol, cloud, and rainfall is one of the major
scientific questions for global climate studies. Aerosols can affect cloud formation processes via activation of
cloud condensation nuclei (CCN) and thereby modifying the cloud as well as rainfall patterns. The aerosol-
mediated changes in cloud is termed as aerosol-indirect effect (AIE), and is a major source of uncertainty in
assessing climate change, largely due to the regional variability in aerosol, clouds, and the complexity in
aerosol-induced microphysical and/or dynamical feedbacks at different spatio-temporal scales. In an
anthropogenically warming Earth, the accurate understanding of aerosol-cloud-rainfall interactions is
essentially required to better project the future changes in the rainfall patterns and climate. In this context, we
are in the process to setup a High Altitude Aerosol-Cloud Physics Laboratory (HAACPL) at Swami Rama Tirtha
(SRT) campus of Hemvati Nandan Bahuguna Garhwal University (30.08oN, 78.61oE, 1706 amsl) to conduct
continuous and long-term measurements of various aerosol and cloud properties together with weather
observations in Himalayan ecosystem. The HAACPL research station is designed to address current
shortcomings in aerosol-cloud-rainfall interactions. In this presentation, we will present a conceptual
framework for studying aerosol-related impacts on climate from a high altitude site in Himalaya and
preliminary data.

244
Tue_30_AC-1_377
Evaluation of Satellite Derived Cloud Top Properties on the Antarctic Peninsula

Marta Caballero1 (marta.caballero@fau.de), Matthias Braun1, Thomas Mölg1

1
Friedrich Alexander-Universität Erlangen-Nürnberg, Institut für Geographie, Erlangen, Germany

Clouds play a key role in the energy balance of the atmosphere due to their radiative effects, and have a critical
influence on the ice sheet's radiation budget. Changes in the glacier system on the Antarctic Peninsula (AP)
have been observed: disintegration of ice shelves, acceleration and thinning of glaciers, variations in the limits
between glacier faces and retreat of glacier fronts. However, rising surface air and ocean temperatures, as well
as substantially increased snow fall in some regions, are also known, with tendencies linked to changes in
atmospheric circulation. Hence, a better understanding of the processes and mechanisms leading to such
changes is required, and the role of clouds over AP has not been yet studied well in this context. The
measurement of cloud properties through satellite sensors is still a challenge, since discrepancies between data
from passive and active sensors exist. Here, retrievals of satellite-derived cloud top properties from MODIS and
CALIPSO are compared with cloud top properties derived from radiosonde measurements in Rothera and will
be presented. This has the goal to identify undetected clouds in these sensors over the AP. The data is being
analyzed in the special light of improving parameterizations in the Polar Weather Research and Forecasting
model. This aims to ultimately enhance our understanding of how variations in the cloud cover and properties
impact the energy balance on the Antarctic Peninsula at regional scales.

245
Tue_31_AC-1_405
Mineral Dust Radiative Forcing in the Arctic

Arve Kylling1 (arve.kylling@nilu.no), Christine Groot Zwaaftink1, Andreas Stohl1

1
NILU-Norwegian Institute for Air Research, Kjeller, Norway

The polar regions experience relatively large temperature changes due to feedback processes leading to Arctic
amplification of global climate change. It has been suggested that mineral dust contributes to Arctic
amplification. We use recent dust load estimates from Groot Zwaaftink et al. (2016), to quantify the direct
mineral dust radiative forcing (RF) in the Arctic. The annual direct mineral dust RF in the Arctic is estimated to
be 0.43 W/m2 and 0.21 W/m2 at the top (TOA) and bottom (BOA) of the atmosphere, respectively. The largest
individual source contributions to the TOA mineral dust RF come from dust transported from Asia south of
60oN (~35 %) and Africa (~24 %), while all high-latitude dust sources contribute ~37 % to the TOA RF. The
albedo reduction due to deposited mineral dust accounts for half of the TOA RF when there is snow on the
ground. In terms of Arctic RF efficiency, i.e. TOA RF in the Arctic per emitted kilogram of mineral dust, high-
latitude (>60oN) dust sources are about one to two orders of magnitude more efficient than lower latitude dust
sources. Mineral dust deposited on snow accounts for nearly all of the BOA RF of 0.21 W/m2. More than half of
the BOA RF is caused by dust from high-latitude sources, indicating substantial regional climate impacts not
accounted for in current climate models.

246
Tue_32_AC-1_561
Shipborne Measurement of Particle Hygroscopicity and Volatility in Arctic Summer

Teresa Vogl1 (teresa.vogl@tropos.de), Simonas Kecorius1, Andreas Held2, Alfred Wiedensohler1

1
Leibniz Insititute for Tropospheric Research, Leipzig, Germany, 2Universität Bayreuth, Bayreuth, Germany

Continuous measurements of aerosol particle hygroscopicity and volatility have been performed on board the
German research ice-breaker Polarstern in the high Arctic during June and July 2017, using a volatility
hygroscopicity tandem differential mobility analyzer (VH-TDMA).
Here we present first results obtained by the VH-TDMA, combined with particle number size distributions
(PNSDs) measured by a mobility particle size spectrometer (MPSS).
While being run in H-TDMA mode, the instrument measures the hygroscopicity of particles of a certain mobility
diameter, which was chosen according to the maxima of the measured PNSD. When run in VH-TDMA mode,
the measured signal is a result of the volatility of particles of the selected size and the hygroscopicity of their
cores, i.e. the part of the particle that is left after volatilization at 300°C. In combination, these measurements
give an indirect information about the chemical composition and mixing state of the atmospheric aerosol in a
higher temporal resolution than e.g. filter or impactor samples.
We will present preliminary results of particle hygroscopicity and the refractory fraction encountered for
discrete mobility diameters of the atmospheric aerosol in the high Arctic. These findings will be used to discuss
the contribution of different compounds to the composition of the Arctic aerosol and thus its origins.

247
Tue_33_AC-1_579
A Significant Methane Source over the Chukchi Sea Shelf and its Sources

Yuhong Li1 (liyuhong@tio.org.cn), Liyang Zhan1, Jiexia Zhang1

1
Third Institute of Oceanography, State Oceanic Administration, Xiamen, China

Dissolved methane (CH4) was measured at various depths in the western Arctic Ocean. The CH4 concentrations
at the surface show an increasing trend northward toward stations at the shelf break and a decreasing trend
toward stations in the Canada Basin. The mean sea-to-air flux is estimated to be 10.08 µmol/m2/d, indicates
that the Chukchi Sea shelf (CSS) is an active site of CH4. Methane concentrations at the shelf stations increase
from the surface to the bottom, and the maximum nutrient concentrations occur in the bottom layer. Strong
correlations exist between CH4 and PO43-, SiO42-, or NO2-, suggesting that the production of CH4 is likely related
to the degradation of organic matter in the sediment, supporting a biogenic source. At the slope and basin
stations, the maximum values were observed in the subsurface of the upper halocline layer (UHL), and the
concentrations decrease with increasing depth. The CH4 concentrations are elevated by ~7.9 nmol/L in the UHL
compared with the homogeneous CH4 concentrations observed in the deep water. The elevated values in the
UHL result primarily from northward spreading of CH4-rich water from the shelf. The mass balance model
shows that effluxes of CH4 from the sediment-water interface and the in situ production of CH4 represent the
major sources of CH4 over the CSS (95%). The main outputs for CH4 in the CSS are the sea-to-air flux and
oxidation of CH4 in the water column, which account for 95% of the CH4 exports.

248
Tue_34_AC-1_621
Comparing Three Kinds of Satellite Retrieval Cloud Data in Tibet Plateau

Jian Liu1 (liujian@cma.gov.cn)

1
National Satellite Meteorological Center, Beijing, China

The Tibet Plateau is called the third polar in the earth. It plays a key role in weather and climate in the Asia,
even the North Hemisphere. Cloud is an important parameter in either climate monitoring or weather analysis
in Tibetan. Tibet Plateau has complex surface types, but there are less ground observation stations that are
mainly located in the eastern part of Plateau. Satellite observation is a good supplement for ground based
observations because of its advantage in wide observation rage and higher temporal resolution. Since the first
meteorological satellite was launched in 1960, the operational meteorological satellite data have been
accumulated more than 40 years. There are several long term cloud data sets that can be used to research
cloud properties. CLARA-A2, Patmos-x and MODIS-ST cloud data records are used in this research. Firstly three
kinds of cloud fraction are evaluated by comparing with synoptic observation data from 2003 to 2015. The
compared results show that except different retrieval algorithm and observation ability, temporal and spatial
properties may be a reason to cause different results. Based on different time scale, MODIS and Patmos-x
cloud fraction data were analyzed. The data record of Patmos-x and CLARA-A2 are used to do cloud fraction
tendency analysis. Associated with precipitation, cloud properties such as the different phase cloud fraction,
cloud top temperature, cloud optical thickness, water path are discussed in Tibet Plateau.

249
Tue_35_AC-1_719
Single Particle Mass Spectrometry of Arctic Ambient Aerosol and Cloud Residuals

Oliver Eppers1,2 (o.eppers@mpic.de), Franziska Köllner2, Hans-Christian Clemen2, Heiko Bozem1, Stephan
Mertes3, Emma Järvinen4, Martin Schnaiter4, Regis Dupuy5, Marco Zanatta6, Andreas Herber6, Johannes
Schneider2, Peter Hoor1, Stephan Borrmann1,2
1
Johannes Gutenberg University Mainz, Institute for Atmospheric Physics, Mainz, Germany, 2Max Planck
Institute for Chemistry, Particle Chemistry, Mainz, Germany, 3Leibniz Insititute for Tropospheric Research,
Leipzig, Germany, 4Karlsruhe Institute of Technology, Karlsruhe, Germany, 5Laboratoire de Météorologie
Physique, Clermont-Ferrand, France, 6Alfred Wegener Institute, Bremerhaven, Germany

The composition and origin of cloud forming particles in the Arctic is currently not fully understood. We show
first results of aircraft-based particle measurements that were conducted during the ACLOUD campaign in
May/June 2017 in the Svalbard region. An aerosol inlet was used for air sampling outside clouds, while a
Counterflow Virtual Impactor (CVI) inlet allowed sampling of clouds residuals and ambient aerosol. Using the
single particle aerosol mass spectrometer "ALABAMA", particle size in the range of 0.2 - 0.9 µm and chemical
composition of single particles were investigated. Simultaneous measurements of gaseous air mass tracer such
as CO, CO2 and O3 were used to identify different air masses.
The results show a significant difference between boundary layer and free troposphere particle chemical
composition. The boundary layer composition was largely characterised by particles from marine origin like sea
spray aerosol and organic particulate matter, such as trimethylamine (TMA). In contrast, pollution plumes with
high fractions of elemental carbon (EC) and levoglucosan were measured above the boundary layer up to 4 km.
More than 50 % of the analysed spectra from cloud residuals show signatures of amines. The molecular
structure of these amines differ significantly from particulate TMA sampled in ambient air. Furthermore, the
large abundance of amines in cloud residuals shows the importance of amines in cloud processes in the Arctic.

250
Tue_36_AC-1_738
Characterizing Tropospheric Clouds and Precipitation Using LIDAR in Antarctica

Claudio Duran-Alarcon1 (claudio.duran-alarcon@univ-grenoble-alpes.fr), Alexis Berne2, Brice Boudevillain1,

Valentin Simeonov2, Dana Veron3, Audrey Teisseire4, Julien Jumelet4, Christophe Genthon1
1
Université Grenoble Alpes, Institut des Géosciences de l'Environnement (IGE), CNRS - UMR 5001, Saint Martin
d'Hères, France, 2École Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Télédétection
Environnementale (LTE), Lausanne, Switzerland, 3University of Delaware, Department of Geography, Newark,
United States, 4Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), CNRS - UMR 8190,
Stratosphère, Haute Troposphère et Interfaces, Paris, France

Studying Antarctic atmospheric composition and processes with in-situ observations is challenging due to
operational difficulties, implying a limited understanding of their interactions with climate and weather.
Despite this complex scenario, significant efforts have been carried out using LIDAR techniques to monitor
clouds, mainly to analyze cloud effects on the radiation budget, aerosols and ozone distribution both in
troposphere and stratosphere. Recently a single-wavelength depolarization LIDAR has been deployed at
Dumont d'Urville station on the coast of East Antarctica in February 2017 to characterize tropospheric clouds
and precipitation in the framework of the Antarctic Precipitation Remote Sensing from Surface and Space
project (APRES3). The observations are complemented with measurements from an automatic weather station,
a Micro Rain Radar, a precipitation weighing gauge and daily radiosoundings. Profiles of backscattering
coefficient and particle linear depolarization ratio (Dp) are used to analyze the vertical distribution of
supercooled liquid water (SLW) and mixed-phase (MP) clouds, as well as the extent and occurrence of blowing
snow (BS). Dp is retrieved using elastic assumptions of the backscattering and attenuation coefficients.
Preliminary results show the predominance of low-level clouds, with high frequency of low depolarization ratio
between 1-3 km height, suggesting the presence of SLW and MP clouds. BS has been mainly observed during
the winter.

251
Tue_37_AC-1_767
Free Troposphere Wintertime Gas-phase Composition using CI-APi-TOF

Ugo Molteni1 (ugo.molteni@gmail.com), Federico Bianchi2, Joachim Curtius3, Josef Dommen1, Heikki Junninen2,
Markku Kulmala2, Andreas Kuerten3, Linda Rondo3, Yulia Sosedova1, Douglas R. Worsnop2,4,5, Urs
Baltensperger1
1
Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, Villigen, Switzerland, 2University of Helsinki,
Department of Physics, Helsinki, Finland, 3Goethe University Frankfurt, Institute for Atmospheric and
Environmental Sciences, Frankfurt, Germany, 4Aerodyne Research Inc., Billerica, United States, 5University of
Eastern Finland, Kuopio, Finland

Atmospheric aerosols influence radiative forcing through direct interaction with radiation and by acting as
cloud condensation nuclei (CCN).
Up to 45% of CCN are formed via new particle formation (NPF), with a large fraction formed in the free
troposphere (FT).
While in the planetary boundary layer (PBL) new particle formation events have been frequently observed,
measurements at high altitude because of intrinsic technical difficulties are scarce.
The high-altitude research station Jungfraujoch (JFJ), Switzerland (3580 m above sea level) is a research site in
the Swiss Alps and is in the FT for a substantial fraction of the time (especially in winter).
NPF events often occur at JFJ (Tröstl et al., 2016) and it has been shown that they involve either sulphuric acid-
ammonia or highly oxygenated molecules (HOMs) (Bianchi et al., 2016).
Nitrate chemical ionization atmospheric pressure interface time of flight mass spectrometry (CI-APi-TOF) has
been shown to be selective in detecting gas phase sulfuric acid and HOMs at extremely low concentration (ppq)
(Ehn et al., 2014).
Here we present the results of two winter periods during intensive campaigns involving CI-APi-TOF
measurements. We describe the chemistry linked to NPF. A special focus is given to HOMs and their temporal
variability, which provides various scenarios, in which HOMs from biogenic and anthropogenic precursors were
identified to participate in NPF.

252
Tue_38_AC-1_784
Changes in OLR over Arctic as Depicted by AIRS, CERES, and MERRA-2

Jae N. Lee1 (jae.n.lee@nasa.gov)

1
University of Maryland, Baltimore County, Joint Center for Earth Systems Technology, Greenbelt, United States

In this presentation, we compare the temporal and spatial characteristics of monthly mean level-3 anomaly
time series of OLR contained in the AIRS Version-6 with those in the CERES Edition 4 and MERRA-2 data sets
over the 14 year period September 2002 through August 2016. Fourteen year global mean OLR average rates of
change (ARCs) of AIRS and CERES data sets show slightly positive trends. The increase of OLR and clear sky OLR
over Barents and Kara Sea region is noteworthy. The clear sky OLR changes more rapidly with surface warming,
since it is more sensitive to surface skin temperature than the OLR. AIRS and CERES OLR time series agree
extremely well in this aspect. This agreement validates the results of both data sets. Agreement of AIRS OLR
with CERES also validates to some degree the AIRS retrieved geophysical parameters, which are used to
calculate the AIRS OLR.
Analogous results are shown with regard to the MERRA-2 OLR data set. Some aspects of the MERRA-2 OLR data
set perform reasonably well. MERRA-2 OLR has a serious short-coming however: The MERRA-2 OLR data set
has a discontinuity, which results in a large spurious global mean OLR trend over the last 14 years.

253
Tue_39_AC-1_887
Poleward Transport of Saharan Dust Initiated by a Saharan Cyclone

Diana Francis1 (diana.francis@nyu.edu), Jean-Pierre Chaboureau2, Juan Cuesta3, Clare Eayrs1, Cyrille Flamant4,
David Holland5
1
New York University, CSLC, Abu Dhabi, United Arab Emirates, 2Laboratoire d'Aérologie, Université de Toulouse,
CNRS, Toulouse,, France, 3Laboratoire Interuniversitaire des Systèmes Atmosphériques, CNRS and Université
Paris-Est Créteil, Val de Marne, France, 4Sorbonne Universités, UPMC Université Paris 6, LATMOS, CNRS, Paris,
France, 5New York University, New York, United States

To enhance the understanding of the role of Saharan mineral dust in the Arctic climate system, this study
focuses on the mechanisms by which Saharan dust emitted over North Africa reaches the Arctic. The poleward
transport of dust was associated with an intense Saharan cyclone that occurred over North Africa in early April
2011. Satellites observations are used in this study in order to characterize qualitatively and quantitatively the
dust activity over North Africa associated with the Saharan cyclone as well as the transport of dust toward the
Arctic and its deposition over Greenland. Beside the observations, a simulation at high resolution is performed
using the MesoNH model in order to estimation the dust load transported northward and to evaluate the dust
deposition north to 60◦N. In this study, we identify a new mechanism for the transport of dust over long
distances toward the northern pole: the poleward migration of the Saharan cyclone, in which the dust is
transported toward the Arctic, was favorite by a negative-Arctic-Oscillation like situation associated with a
slowed polar vortex and polar jet stream, which caused the intrusion of a lobe of low pressure further south
with which the Saharan cyclone has merged and moved northward. A total dust load of about 38.35 Tg was
carried by this cyclone to north of 40 N and dust deposition was estimated to be 1.3 Tg to the north of 60N.

254
Tue_40_AC-1_971
Possible Feedbacks of Arctic Cirrus Clouds on the Composition of the UTLS

Florian Haenel1 (florian.haenel@kit.edu), Wolfgang Woiwode1, Michael Höpfner1, Roland Ruhnke1, Farahnaz
Khosrawi1, Oliver Kirner2, Felix Friedl-Vallon1, Anne Kleinert1, Björn-Martin Sinnhuber1
1
Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Karlsruhe, Germany,
2
Karlsruhe Institute of Technology, Steinbuch Centre for Computing, Karlsruhe, Germany

Cirrus clouds in the UTLS can affect the vertical distributions of the important greenhouse gas H2O via the
direct processes of condensation and sedimentation of ice particles. They are further capable of trapping and
redistributing nitric acid. The modification of the chemical budget of these gases may affect the distributions of
ozone and methane. The role of high latitude and particularly arctic cirrus clouds is hardly understood. The aim
of the project ICECREAM is to use measurements by the airborne infrared limb sounder GLORIA (Gimballed
Limb Observer for Radiance Imaging of the Atmosphere) during the POLSTRACC (Polar Stratosphere in a
Changing Climate) campaign for the detection of cirrus clouds and to analyze the vertical distribution of the
critical trace gases H2O, HNO3, O3 and CH4 during an entire arctic winter. The data will be compared with
model simulations by the high-resolution forecast model ICON-ART (ICOsahedral Nonhydrostatic - Aerosols and
Reactive Trace gases) and the climate-chemistry model EMAC (ECHAM/MESSy Atmospheric Chemistry)
including and omitting cirrus cloud particle sedimentation and HNO3 trapping. The aims are to gain insight,
how well cirrus cloud feedbacks on the vertical distributions of H2O, HNO3, O3 and CH4 at high latitudes can be
simulated in the models, and to estimate the significance of the vertical redistribution of H2O and HNO3 in the
UTLS at high latitudes for the distributions of the greenhouse gases H2O, O3 and CH4 in the UTLS.

255
Tue_42_AC-1_1039
Human Impacts on the Local Sources of Aerosols at King George Island

Sérgio J. Gonçalves Jr.1 (sjrgoncalves@gmail.com), Ricardo H. M. Godoi1, Heitor Evangelista2, Johannes Weis3,4,
Tristan H. Harder3,4, Swarup China5, Simon Müller3,4, Ana Flávia L. Godoi1, Mary K. Gilles3,4, Alexander Laskin5
1
Federal University of Paraná, Environmental Engineering, Curitiba, Brazil, 2LARAMG, Rio de Janeiro State
University, Rio de Janeiro, Brazil, 3Lawrence Berkeley National Laboratory, Berkeley, Chemical Sciences Division,
Berkeley, United States, 4University of California, Department of Chemistry, Berkeley, United States, 5William R.
Wiley Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland,
United States

Black carbon (BC) is important for the Earth´s climate because it absorbs sunlight efficiently, heats the
atmosphere. BC particles originates from the incomplete combustion of fossil fuel or biomass burning. In
pristine regions, local emission and their influence on the regional climate are typically neglected.The
Antarctica exploration mode can be questionable, as the sustainability of occupation and daily activities have
not been considered.The sampling site of this study was the King George Island, close to the flight´s arrival
point. The aerosols were assessed using a multi-wavelength Aethalometer-AE33 and Scanning Transmission X-
ray Microscopy with near edge X-ray absorption fine structure spectroscopy (STMX/NEXAFS). BC data indicate
that fossil fuel combustion is the mainly source of carbonaceous aerosols, with the total average of 41.8 ng.m-
3
,much higher than the average of related studies. STXM/NEXAFS was used for the carbon-specific
characterization, demonstrating that almost all particles on site have a considerable portion of carbon content.
Considering growing Antarctica tourism and scientific activities during austral summer among the last years,
the main sources of BC particles can be related to the presence of ships and flights.The above conclusions
reaffirm the urgency of a new discussion on sustainability issues in the exploration of Antarctica, highlighting
the duty of all government authorities to take into account the impact of these actions in Antarctica.

256
Tue_43_AC-1_1052
Aerosol Integrated Analysis in Central West Antarctica:Brazilian Standalone Unit

Ricardo H. M. Godoi1 (rhmgodoi@gmail.com), Sérgio J. Gonçalves Jr.1, Heitor Evangelista2, Johannes Weis3,4,
Tristan H. Harder3,4, Swarup China5, Simon Müller3,4, Marcelo Sampaio6, Ana Flávia L. Godoi1, Alexander Laskin5,
Mary K. Gilles3,4
1
Federal University of Paraná, Environmental Engineering, Curitiba, Brazil, 2LARAMG, Rio de Janeiro State
University, Rio de Janeiro, Brazil, 3Lawrence Berkeley National Laboratory, Berkeley, Chemical Sciences Division,
Berkeley, United States, 4University of California, Department of Chemistry, Berkeley, United States, 5William R.
Wiley Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland,
United States, 6Brazilian National Space Institute, INPE, São José dos Campos, Brazil

Changes in Antarctica ice sheets and ice shelves are of primary concern to the regional and global climate. We
hypothesize that the West Antarctic warming can be related to the aerosols transported and/or formed in this
region. Rather than being inert, snow is highly active, with snowpack impurities being photolysed to release
reactive trace gasses such as OH, NO/NO2 and O3 into the troposphere. The impact of solar radiation, enhanced
by O3 depletion, creates the optimal conditions for heterogeneous gas-to-particle reaction, modifying the
chemical and physical properties of aerosols substantially. This study shows evidence of atmospheric
processing, via microscopic and molecular speciation of individual aerosol by Scanning Transmission X-ray
microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Specifically, STXM
reveals an accurate fraction of internally mixed particles with NaCl cores and nitrate coatings. The scattering
efficiency of sea salt particles may decrease as a consequence of the external nitrate covering since the
hygroscopicity of a mixed nitrate-salt particle is weak. The unique signal of ClO-type-molecules could be
possibly associated with OH radical oxidation products of NaCl particles. Considering the perchlorate has a
supercooling property, it is possible to assume that perchlorate could produce a small melting effect especially
at ablation zones of Antarctic glacier experiencing severe mass loss due to warming.

257
Tue_44_AC-1_1122
Sea-air Transfer Measurements of Marine Carbohydrates in the Arctic

Sebastian Zeppenfeld1 (zeppenfeld@tropos.de), Markus Hartmann1, Manuela van Pinxteren1, Frank

Stratmann1, Hartmut Herrmann1
1
Leibniz Insititute for Tropospheric Research, Leipzig, Germany

Marine polysaccharides in sea spray aerosol are being discussed as an important source of ice nucleating
particles in the Arctic. They may enter the planetary boundary layer by sea-air phase transfer processes such as
bubble bursting and breaking waves. In this connection, the sea surface microlayer (SML) may play a key role as
the direct interface between the ocean and the atmosphere. To date, there are only very few concerted
measurements for carbohydrates in all these compartments in the Arctic available.
During the field campaign PS 106 aboard the German research vessel Polarstern during summer 2017
concerted sampling of aerosol particles, SML and underlying water was performed. The monosaccharide
composition of these samples was determined via HPAEC-PAD, a very sensitive method for sugar analysis,
before and after acidic hydrolysis. For avoiding analytical problems due to the high sea salt content in sea
water samples a newly developed desalination step via electrodialysis has been applied.
The concentrations of neutral sugars, aminosugars and uronic acids in arctic sea water were determined in the
low to middle µgL-1 range. Depending on the kind of monosaccharide enrichment in SML samples could be
determined up to a factor of 2.0. Via enrichment factors in aerosol samples, sea spray aerosol will be discussed
as an important local source of organic matter in arctic aerosol particles.
This work was supported by the DFG-funded TR 172 (Arctic Amplification).

258
Tue_45_AC-1_1139
Particle Chemical Composition in the Arctic Summer - Local vs. Remote Sources

Franziska Köllner1 (f.koellner@mpic.de), Johannes Schneider1, Megan D. Willis2, Thomas Klimach1, Frank
Helleis1, Heiko Bozem3, Daniel Kunkel3, Peter Hoor3, Julia Burkart2, W. Richard Leaitch4, Amir A. Aliabadi4,
Jonathan P.D. Abbatt2, Andreas B. Herber5, Stephan Borrmann1
1
Max Planck Institute for Chemistry, Mainz, Germany, 2University of Toronto, Department of Chemistry,
Toronto, Canada, 3Johannes Gutenberg University Mainz, Institute for Atmospheric Physics, Mainz, Germany,
4
Environment and Climate Change Canada, Toronto, Canada, 5Alfred Wegener Institute for Polar and Marine
Research, Bremerhaven, Germany

We present size-resolved and vertical profile (up to 3 km) measurements of single particle chemical
composition conducted during the aircraft-based measurement campaign NETCARE 2014 in July 2014 in the
Canadian high Arctic (Resolute Bay, Nunavut). The single particle laser ablation aerosol mass spectrometer
ALABAMA (0.2 - 1 µm vacuum aerodynamic diameter (Brands et al., 2011)) was deployed to identify different
particle types and their mixing states.
We found that a significant fraction (approximately 60 %) of particles within the Arctic boundary layer
contained trimethylamine (TMA). Several pieces of evidence suggest that this particulate TMA results from
secondary conversion of precursor gases released by the ocean (Köllner et al., 2017). In contrast,
a large fraction of particles above the local boundary layer contained levoglucosan (approximately 20 %). Mass
spectra of levoglucosan-containing particles indicate the internal mixing with organic acids
(e.g., dicarboxylic acids) (Sullivan and Prather, 2007; Zauscher et al., 2013), sulfate, potassium etc. Air mass
history predicted by FLEXPART shows that those particles partly originated from remote biomass burning
sources.
Brands et al., Aerosol Science and Technology, 45 (2011): 46-64.
Köllner et al., Atmos. Chem. Phys., accepted (2017).
Sullivan and Prather, Environ. Sci. Technol., 41 (2007): 8062-8069.
Zauscher et al. Environ. Sci. Technol., 47 (2013): 7633−7643.

259
Tue_46_AC-1_1156
High-latitude Cloud-aerosol-Climate Interactions in GFDL Climate Model CM4

Yi Ming1 (yi.ming@noaa.gov), Ming Zhao1

1
NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, United States

GFDL´s CMIP6 model CM4 contains a prognostic treatment of cloud-aerosol interactions. The analysis of a suite
of simulations (e.g., with variable or fixed droplet number concentrations) yields a number of interesting
findings related to the strength of negative cloud feedback and climate sensitivity. Besides this comprehensive
model, an effort is made to use an idealized model for understanding those findings at the process level. The
potential utility of satellite observations for constraining (or falsifying) model physics is also explored.

260
Tue_47_AC-1_1169
Polynya-driven Heat and Moisture Fluxes and the Associated Cloud Response

Emily Monroe1 (emily.e.monroe@nasa.gov), Patrick Taylor2

1
Science Systems and Applications, Inc., Hampton, United States, 2NASA Langley Research Center, Hampton,
United States

The opening of a polynya in the North Water (NOW) region of the Arctic introduces positive fluxes of heat and
moisture to the overlying atmosphere. This perturbation in surface radiative energy fluxes can impact cloud
formation over the open water and cloud evolution over the nearby icepack as the rising plume of moisture
and heat is advected downstream. With polar regions experiencing warming at a rate much greater than the
global average, the effects of polynyas on the surface energy budget will become increasingly important. As
such, it is imperative that models accurately capture resultant changes in the overlying atmospheric column to
reduce intermodel spread, better quantify surface-atmosphere feedbacks, and improve precision in climate
projections. This research uses the CALIPSO-Cloudsat-CERES-MODIS merged product (C3M) to study surface
cover and associated cloud fraction, liquid water path, and ice water path profiles over and adjacent to
wintertime polynyas in the NOW region between 2006 and 2010. Moisture and sensible heat fluxes, derived
from NASA's EOS are combined with C3M-derived cloud and radiative heating rate profiles to quantify
relationships between polynya-induced surface turbulent fluxes and lower tropospheric (0-3 km) clouds,
testing the hypothesized link. It is expected that the opening and extent of a polynya strongly correlates with
increases in heat and moisture to the atmosphere forcing a cloud response that supports longer polynya
events.

261
Tue_48_AC-1_1182
Processes Governing Arctic Cloud Formation in CMIP5 Models

Robyn Boeke1,2 (robyn.c.boeke@nasa.gov), Patrick Taylor1

1
NASA Langley Research Center, Hampton, United States, 2Science Systems and Applications, Inc., Hampton,
United States

CMIP5 models simulate rapid Arctic climate change by 2100 and large intermodel spread in cloud amount (CA).
Many processes govern Arctic cloud formation, namely 1) surface-atmosphere interactions (clouds affect
surface temperature and sea ice, and indirectly surface turbulent fluxes and BL stability), 2) microphysical
processes (e.g. cloud ice formation), 3) temperature/humidity advection that provides a moisture source for
cloud formation, and 4) the vertical structure of temperature/humidity. We use a multilinear regression
methodology to determine CA using these variables as predictors: upper and lower tropospheric stability (UTS;
LTS), 500-hPa vertical velocity (ω500), temperature (Tsurf; Tair), sensible and latent heat fluxes, and sea ice
concentration (SIC). These variables were chosen because their effects on CA can be attributed to unique
climate processes: UTS and LTS are thermodynamic indicators of the relationship between CA and stability, SIC
and Tsurf determine surface-cloud interaction, Tair governs cloud microphysical processes, and ω500 is a metric
for dynamical change. Vertical profile data are obtained from the CMIP5 historical simulation, and statistical
significance tests are used to confirm the regression equation and test the models for their ability to capture
observed CA and behavior. Lastly, the intermodel spread in Arctic CA will be attributed to individual processes
to shed light on emergent constraints in the Arctic climate change.

262
Tue_49_AC-1_272
Modelling Sulfate Aerosols over the Southern Ocean

Laura Revell1 (laura@bodekerscientific.com), Stefanie Kremser1, Vidya Varma2, Jonny Williams2, Mike Harvey2,
Olaf Morgenstern2
1
Bodeker Scientific, Alexandra, New Zealand, 2NIWA, Wellington, New Zealand

Dimethyl sulfide (DMS) is estimated to be the largest source of natural atmospheric sulfur over the Southern
Ocean. It is released into the atmosphere via biogenic activity of marine phytoplankton, and subsequently
undergoes several oxidation reactions ultimately leading to sulfate aerosol formation. Atmospheric aerosols
affect Earth's radiative balance, and can act as cloud condensation nuclei, thereby altering cloud properties.
Uncertainties in simulating aerosols in global climate models cascade to uncertainties in cloud formation,
absorption of shortwave radiation by the ocean, and atmospheric circulation, thus reducing confidence in
climate change projections for the Southern Ocean and surrounding countries. This presentation outlines an
investigation into the representation of DMS in the HadGEM3(GA7)+chem coupled chemistry-climate model.
We show the effects of different sea-air transfer velocities on atmospheric DMS concentrations, the role that
modelled sea ice plays in blocking oceanic emissions of DMS, and results from a sensitivity study on increasing
the complexity of simulated DMS oxidation chemistry. Finally, we present the sensitivity of Southern Ocean
clouds to atmospheric DMS concentrations.

263
Tue_50_AC-1_1218
Attributing Convection in Arctic Mixed-phase Clouds to Large-scale Subsidence

G. Young1,2 (giyoung@bas.ac.uk), P. J. Connolly1, C. Dearden1, T. W. Choularton1

1
University of Manchester, Centre for Atmospheric Science, Manchester, United Kingdom, 2British Antarctic
Survey, Cambridge, United Kingdom

Models on various scales are notoriously poor at reproducing the persistent mixed-phase stratocumulus (MPS)
clouds commonly observed in the Arctic. The role of microphysics-dynamics interactions in sustaining these
unstable clouds is poorly understood; therefore, it is imperative to assess such feedbacks to gain a holistic view
of their role in the Arctic system. Large-scale subsidence, associated with high pressure systems, is often
imposed in cloud-resolving models to maintain the height of these boundary layer (BL) clouds; however, the
interaction between subsidence and mixed-phase cloud microphysics has not been previously studied.
Using the UK Met Office Large Eddy Model (LEM), we find strong cloud microphysical sensitivities to large-scale
subsidence: by enforcing BL inversion strength and reducing entrainment from above, widespread subsidence
dynamically stimulates Arctic marine MPS, promoting a greater cloud liquid-water path and efficient
precipitation formation. Convection development is driven by longwave radiative cooling at cloud top, and rain
evaporative cooling and latent heating from snow growth below cloud base. Our results indicate that high
pressure systems in the ocean-exposed Arctic regions have the potential to affect resident BL MPS by
enhancing their liquid fraction, thus helping to sustain them for longer against cloud glaciation.

264
Tue_51_AC-1_1220
Systematic Investigation of Shortterm Variability in Antarctic Aethalometer Data

Anna E. Jones1 (aejo@bas.ac.uk), Neil Brough1, Stephen Edmundson1, Zoë L. Fleming2, Tom Lachlan-Cope1,
Steve R. Colwell1
1
British Antarctic Survey/NERC, Cambridge, United Kingdom, 2University of Leicester/NCAS, Leicester, United
Kingdom

Combustion processes at lower latitudes are primary sources of black carbon (BC) to the polar regions.
Deposited BC can alter albedo of snow/ice surfaces, so reliably recording variability and trends in atmospheric
BC is critical. Within ice cores, soot records changes in combustion activities over historic time periods, but data
interpretation requires understanding of present-day mechanisms delivering BC to the poles.
Various instruments, including Aethalometers, measure BC via filter-based absorption methods. Being robust
and easy to operate, Aethalometers have been widely used in the polar regions to determine, e.g. BC
seasonality and long-term trends. Concerns exist, however, over possible artefacts in data from filter-based
instruments. While these have been partially addressed through laboratory studies, they have not been
adequately tested under field conditions.
Here we present a systematic investigation of short-term variability in Aethalometer data, measured over 1
year in coastal Antarctica. We find no direct correlation with wind speed (a concern raised in the literature) but
episodes of high sea salt aerosol loading clearly influence observed BC values. Equally, 10-day air mass
footprints link episodes of high BC in coastal Antarctica to biomass burning activities, primarily in South
America, but occasionally in Africa. We thus demonstrate that filtering of Aethalometer data can render useful
datasets to study BC variability over long- and short-timescales.

265
Tue_52_AC-1_1221
Modelling Aerosol-cloud Interactions over the Weddell Sea, Antarctica

G. Young1 (giyoung@bas.ac.uk), T. Lachlan-Cope1, C. Listowski2, S. O'Shea3, K. N. Bower3, T. W. Choularton3

1
British Antarctic Survey, Cambridge, United Kingdom, 2LATMOS, Guyancourt, France, 3University of
Manchester, Centre for Atmospheric Science, Manchester, United Kingdom

Clouds play a key role in the Antarctic radiative budget, yet numerical models cannot accurately reproduce
them due to our poor understanding of aerosol-cloud interactions in the region. Current models typically
underestimate cloud fractions leading to strong radiative biases, particularly at the coastal regions.
Coastal Antarctic clouds in the summertime are often mixed-phase; however, the ice phase is sporadically
distributed throughout the clouds, hindering modelling efforts of primary ice nucleation based solely on cloud
temperature. The patchy nature of the ice phase suggests that local aerosol sources - from the sea ice, ocean,
or snow-covered continent - may be influencing these clouds, and such sources are not commonly represented
in regional models which only consider meteorology.
To better comprehend the importance of spatially-dependent aerosol-cloud interactions in Antarctica, we need
to increase the complexity of the models we use in the region. Using the Weather Research and Forecasting
model coupled with Chemistry (WRF-Chem), we investigate the effect of local aerosol sources on cloud
microphysics through comparisons with in-situ observations made during the Microphysics of Antarctic Clouds
(MAC) campaign. During MAC, measurements of aerosol particle and cloud properties were taken in the
vicinity of the Weddell Sea, Antarctica in the austral summer of 2015, providing an invaluable dataset for model
validation, investigation, and development.

266
Tue_53_AC-1_1313
Observation of Polar Stratospheric Clouds at McMurdo and Dome C (Antarctica)

Marcel Snels1 (m.snels@isac.cnr.it), Francesco Cairo1, Federico Fierli1, Andrea Scoccione1, Luca di Liberto1,
Michael Pitts2, Francesco Colao3
1
Institute of Atmospheric Sciences and Climate - CNR, Roma, Italy, 2NASA Langley Research Center, Hampton,
United States, 3ENEA, Frascati, Italy

From 1991 up to 2010 a lidar observatory has been active at the Antarctic station McMurdo. Since 2014 the
same lidar has been operated succesfully at Dome C on the Antarctic plateau. The lidar performs optical
measurements of the stratospheric and tropospheric aerosols from about 6 km asl up to 40 km at wavelengths
of 532 and 1064 nm. The scattered signal at 532 nm is detected at two different polarizations. The observations
have been analyzed in terms of occurrences of different classes of aerosols present in the polar stratospheric
clouds. A statistical comparison of polar stratospheric clouds (PSCs) occurrence from 2006 to 2010 at McMurdo
and from 2014-2017 at Dome C, both included as a primary station in the NDACC (Network for Detection of
Atmospheric Composition Change) with the satellite borne CALIOP lidar measuring over the stations, in order
to assess possible biases arising from different classification methods deriving from the specific geometry and
sampling. Point-to-point comparison between ground based and satellite based lidar measurements is
practically impossible due to the intrinsic differences in the observation geometries and the imperfect overlap
of the observed areas. Therefore a statistical approach has been used to compare ground based and satellite
based observations. Recent results will be presented.

267
Tue_54_AC-1_1448
Free Tropospheric New Particle Formation Observed above the Andes

Federico Bianchi1 (federico.bianchi@helsinki.fi), Claudia Mohr2

1
University of Helsinki, Helsinki, Finland, 2Stockholm University, Stockholm, Sweden

A significant fraction of atmospheric cloud condensation nuclei arises from new particle formation (NPF) where
35% are directly formed in the free troposphere. While NPF has been observed in many places around the
world, the mechanisms governing this process are still poorly understood, especially at high altitude. So far,
only few studies have shown that NPF can frequently take place at high altitudes. However, none of these have
identified the chemical composition of the growing clusters.
In the last few years, we have focused our studies on further characterizing NPF processes at high altitudes
taking advanced instrumentation at specific locations, in order to have a better understanding of the chemical
cluster composition and therefore the nucleation precursors. The equipment includes Atmospheric Pressure
interface Time-Of-Flight mass spectrometers, Particle Size Magnifier and Neutral clusters and Air Ion
Spectrometer. Measurements were performed at the Chacaltaya station (Andes, Bolivia), the highest in the
world (5240m a.s.l.) for in situ aerosol observations.
In this study, we will present observations of NPF events that have been measured at this particular station, for
the time period December 2017 - May 2018.

268
Tue_55_AC-1_1461
Relative Roles of Different Types of PSCs to Polar Ozone Depletion

Ole Kirner1 (ole.kirner@kit.edu), Rolf Müller2, Farah Khosrawi3, Roland Ruhnke3

1
Karlsruhe Institute of Technology, Steinbuch Centre for Computing, Karlsruhe, Germany, 2Research Centre
Jülich, Institute of Energy and Climate Research - Stratosphere (IEK-7), Jülich, Germany, 3Karlsruhe Institute of
Technology, Institute of Meteorology and Climate Research, Karlsruhe, Germany

Heterogeneous reactions on the surfaces of PSC particles and denitrification of the stratosphere are the cause
for Antarctic and Arctic ozone depletion in polar spring. We investigate the impact of the different types of
PSCs on this polar ozone depletion with the help of the chemistry-climate model ECHAM5/MESSy Atmospheric
chemistry (EMAC).
One standard and four sensitivity EMAC simulations (nudged with ERA-Interim) have been performed from
2005 to 2016 to evaluate the contribution of liquid, NAT and ice particles to ozone depletion in different polar
winters due to chlorine activation by heterogeneous chemistry on their surfaces and due to denitrification of
the stratosphere.
In the first three sensitivity simulations, we changed the heterogeneous chemistry on PSC particles by switching
on and off the chemistry on liquid, NAT and ice particles. One further sensitivity simulation without NAT
formation (only liquid and ice particles) was performed to evaluate the contribution of NAT due to
denitrification of the stratosphere.
With the help of these different EMAC simulations, we will show the significance of liquid, NAT and ice particles
to polar ozone depletion caused by chlorine activation and denitrification.

269
Tue_56_AC-1_1467
Is New Particle Formation an Aerosol Source over the Southern Ocean?

Andrea Baccarini1 (andrea.baccarini@psi.ch), Silvia Henning2, Katrianne Lehtipalo3, Markus Hartmann2, Fiona
Tummon4, Andrea Welti2, Aemisegger Franziska4, Conor Bolas5, Ken Carslaw6, Harris Neil7, Leighton Regayre6,
Frank Stratmann2, Iris Thurnherr4, Heini Wernli4, Martin Gysel1, Urs Baltensperger1, Josef Dommen1, Julia
Schmale1
1
Paul Scherrer Institute, Villigen PSI, Switzerland, 2Leibniz Insititute for Tropospheric Research, Leipzig, Germany,
3
University of Helsinki, Helsinki, Finland, 4ETH Zurich, Institute for Atmospheric and Climate Science, Zurich,
Switzerland, 5University of Cambridge, Cambridge, United Kingdom, 6University of Leeds, Leeds, United
Kingdom, 7University of Cranfield, Cranfield, United Kingdom

Models estimate that about 43% of the cloud condensation nuclei (CCN) in the atmosphere are formed from
condensable vapors [1] but field and laboratory experiments are required to confirm the validity of these
predictions and improve their accuracy. With this contribution we will present the first comprehensive
investigation of new particle formation (NPF) in the Southern Ocean.
Concentration of gaseous precursors (in particular sulfuric acid and iodic acid), chemical composition of small
nucleating clusters and size distribution of ions and neutral particles at the nanometer scale were measured
during the Antarctic Circumnavigation Expedition (ACE) as part of the 'Study of Preindustrial-like-Aerosol
Climate Effects' (SPACE) project (a general overview of the campaign will be presented in another
contribution).
Here we will show that, despite of the generally low temperatures and small condensational sink, NPF in the
Southern Ocean rarely happen due to the small amount of condensable vapors. Our observations suggest that
the few NPF events observed are sulfuric acid driven and the recently discovered iodic acid nucleation
mechanism [2] is not relevant over the Southern Ocean. Finally, we will discuss the relevance of NPF in the
Southern Ocean as a source of CCN (specific CCN and ice nucleating particles observations during ACE will be
presented in another contribution).
[1] Dunne M. et al., 2016, Science
[2] Sipilä M. et al., 2016, Nature

270
Tue_57_AC-1_1492
Inter-annual Cycle of Bacteria in Atmosphere/Snow of King George Is. / Antarctica

Daniela Kozlowsky1 (dani.ksky@gmail.com), Heitor Evangelista1, Ricardo Godoi2, Leandro Stival2

1
University of State of Rio de Janeiro, Rio de Janeiro, Brazil, 2Federal University of Paraná, Curitiba, Brazil

In this work we analyse bacteria reaching Antarctic Peninsula/king George Is. by atmospheric transport and
their deposition on surface. Air was collected using a BioSampler® flask attached to a pumping system during
the summer season and fresh snow was analysed from the winter season between February 2010 and February
2011. The samples were inoculated by amid R2A and were incubated at different temperatures (2° C, 12° C and
28° C). Aliquots of the samples were analyzed by flow cytometry for visualization and size quantification of
living and dead organisms using the fluorochromes propidium iodide (PI) and SYTO 13, respectively. Replicas of
samples were filtered on Isopore membranes and the retained material was analyzed by X-ray fluorescence
(XRF) and SEM + EDS to determine the elemental composition of metals of terrigenous and marine origin of
inorganic aerosols attached to the bacterias. For each monthly bacteria number concentration we conducted
the HYSPLIT/NOAA atmospheric dispersion model to set the trajectories of air parcels reaching Antarctica.
Results indicated mostly positive cocci gram and catalase. The quantitative variability of bacteria showed
strong influence of precipitation and the inter-annual melting process being the bacteria content associated
with the terrigenous elements and soil temperatures. Analysis of cell viability in fresh snow seems to correlate
with UV, in Antarctica, when apoptotic cells in flow cytometry were analysed.

271
Tue_58_AC-1_1493
Shipborne and Ground-based Observations of Clouds in the Southern Ocean

Peter Kuma1 (peter.kuma@pg.canterbury.ac.nz), Adrian McDonald1, Olaf Morgenstern2, Simon Parsons1

1
University of Canterbury, School of Physical and Chemical Sciences, Christchurch, New Zealand, 2NIWA,
Wellington, New Zealand

The Southern Ocean is characterised by sparse ground-based and in-situ atmospheric measurements. While
satellite measurements provide continuous spatial and temporal coverage, they are generally not capable of
observing low-level clouds and the cloud base, which are critical for accurately modelling radiative transfer.
Results from general circulation models show significant biases in outgoing shortwave radiation in this region,
believed to be related to deficiencies in representation of clouds, aerosols or their interaction. As part of the
Cloud and Aerosol project of the New Zealand Deep South Challenge (DSC) we collected and analysed cloud
measurements from multiple shipborne and ground-based deployments of several meteorological instruments:
ceilometer, lidar, micro rain radar, radio soundings, aerosol sensors, sky cameras and UAV-borne sensors.
With this combination of instruments we hope to advance understanding of cloud processes in this region,
quantify model error compared to observations and contribute to the modelling effort of the DSC. Currently we
have collected observations from a ground-based deployment on Macquarie Island and multiple voyages:
Aurora Australis, R/V Tangaroa, HMNZS Wellington and R/V Nathaniel B. Palmer. By incorporating data from
these and planned future deployments we intend to produce a Southern Ocean dataset of atmospheric
measurements available for general use. This presentation will provide an overview of our progress and results.

272
Tue_59_AC-1_1546
Arctic Mixed-phase Clouds Properties from in Situ Measurements

Guillaume Mioche1 (g.mioche@opgc.fr), Olivier Jourdan2, Julien Delanoe3, Christophe Gourbeyre2, Guy Fèbvre2,
Régis Dupuy2, Marie Monier2, Szczap Frédéric2, Schwarzenboeck Alfons2
1
LaMP, Aubiere, France, 2LaMP, AUBIERE, France, 3LATMOS, Paris, France

This study aims to characterize the microphysical and optical properties of low-level Arctic mixed-phase clouds
(MPCs) in order to improve the knowledge of these particular polar clouds. Cloud in situ measurements from
four airborne campaigns (18 flights, 71 vertical profiles in MPCs) in the vicinity of the Svalbard region are
combined and analyzed.
Cloud phase discrimination and representative vertical profiles of the number, size, mass and shape of ice
crystals and liquid droplets are established. The results highlight that the liquid phase dominates the upper part
of the MPCs. The ice phase dominates the cloud properties in the lower part and below the cloud in the
precipitation region. The analysis of the ice crystal morphology highlights that riming and diffusional growth
processes, including the Wegener-Bergeron-Findeisen (WBF) mechanism, are the main growth mechanisms
involved in the observed MPCs.
The impact of larger-scale meteorological conditions (temperature regimes, air mass origin) on the MPC
properties is also investigated. The results highlight that clean situations with low temperatures exhibit larger
values of ice crystal size and IWC, whereas the situations more polluted with air mass origins from the south
exhibit larger values of LWC and number of smaller droplets associated with very low values of ice crystal size
and IWC.
Finally, these data lead to the determination of several parameterizations relevant for remote sensing or
modeling studies.

273
Tue_60_AC-1_1635
Intraseasonal Variability of Near Surface Weather Parameters Observed Antarctica

Sakthivel Samy1 (vssamy@ncaor.gov.in), Ravichandran M2, Jeni Victor N3, Sathish Kumar S3
1
National Centre for Antarctic & Ocean Research (ESSO-NCAOR), ICTD & National Polar Data Center, Vasco da
Gama, India, 2National Centre for Antarctic & Ocean Research (ESSO-NCAOR), Vasco da Gama, India, 3Indian
Institute of Geomagnetism, Tirunvelveli, India

High temporal resolution (1 Hz) records of temperature, wind speed and air pressure recorded at Antarctic
research station Maitri (70° S, 11° E) during 2012-2016 are analysed to identify oscillations from daily to
intraseasonal/extralong period timescales. The diurnal cycle dominates the hourly time series of temperature
during the Antarctic summer and is almost non-existent during winter. In comparison, the hourly time series of
wind speed and air pressure show a weak diurnal cycle. The dominant pattern of the intraseasonal variability of
these quantities, which captures the out-of-phase of temperature and wind speed with air pressure, shows
enhanced variability at timescales of, ~16 days respectively. The second pattern of intraseasonal variability,
which captures in-phase variations of temperature, wind and air pressure, shows enhanced variability at
timescales of ~8 days, ~16 days, ~32 days and ~40 days.

274
Tue_61_AC-1_1639
Surface Radiation Budget at Thule, Greenland: Role of Clouds and Surface Albedo

Daniela Meloni1 (daniela.meloni@enea.it), Tatiana Di Iorio1, Alcide di Sarra1, Giandomenico Pace1, Giovanni
Muscari2, Gabriele Mevi2,3, Marco Cacciani4
1
ENEA, Laboratory for Observations and Analyses of Earth and Climate, Rome, Italy, 2Istituto Nazionale di
Geofisica e Vulcanologia, Rome, Italy, 3Roma Tre University, Mathematics and Physics Department, Rome, Italy,
4
University of Rome 'La Sapienza', Physics Department, Rome, Italy

The surface radiation budget (SRB) has peculiar characteristics in the polar regions, due to the predominance of
the infrared radiation and to the absence of solar radiation during part of the year, as well as to the
meteorological conditions related to low temperature and humidity values, and to the presence of highly
reflecting surfaces.
Measurements of downward shortwave (SW) and longwave (LW) irradiance were available at Thule High Arctic
Atmospheric Observatory (THAAO, 76.5° N, 68.8° W, http://www.thuleatmos-it.it/) since 2009. In July 2016,
additional instruments were installed during the summer campaign of the Study of the water VApour in the
polar AtmosPhere (SVAAP) project: among them, downward-looking SW and LW radiometers, a RPG HATPRO
microwave radiometer, an infrared pyrometer, a meteorological station, a sky imager.
Measurements of SRB and of the derived cloud radiative forcing are presented and discussed as a function of
simultaneous data of integrated water vapour, cloud parameters like liquid water path, cloud optical thickness
and particles' effective radius (only during summertime), and under different regimes of surface albedo, typical
of snow-free (from June to September) and of snow covered terrain. In summer the SRB is positive and its
variability is dominated by the SW irradiance. The LW component offsets about 20% of the SW at noon in clear
sky, and contributes up to 50% of the total SRB in thick cloud conditions.

275
Tue_62_AC-1_1679
Role of Katabatic Wind in Altering the Fair-weather Electric Field at Antarctica

N Jeni Victor1 (jenivictor@gmail.com), Sakthivel Samy2, M Ravichandran3, C Paneerselvam1, Elango

Paramasivan1
1
Indian Institute of Geomagnetism, Tirunvelveli, India, 2National Centre for Antarctic & Ocean Research (ESSO-
NCAOR), ICTD & National Polar Data Center, Vasco da Gama, India, 3National Centre for Antarctic and Ocean
Research (ESSO-NCAOR), Vasco da Gama, India

Automatic Weather Station (AWS) and Electric Field Mill (EFM) measurements at Maitri (70° S, 11° E),
Antarctica from 2013-2016 are presented in this analysis. Time series of fair weather electric field shows the
signature of katabatic wind is highly dominant in the summer than winter. There are ~ 80 such events
categorized, which results from the criterion like the constancy of fair weather field range/gradient pre-and
post event periods. It also applies to the wind speed & direction pattern where the event is taken only when
they stable for more than one hour. From the statistics analysis, the average wind speed varied nearly 10 m/s
during the event periods and the average response time of electric field is 50-65 min for the wind speed change
of 30-45 min with the wind direction changes less than 30 mini. The effect of katabatic wind on electric field
has seasonal and Local Time (LT) dependency. We suggest that the electric field response varied at season may
be due to 1. Summer has relatively more number of fair weather days than winter, hence the only dominant
factor is aerosol carrying wind, Katabatic, that modulates the conductivity of near surface region, 2. The added
effect of winter, snowfall and blizzard and enhanced pattern of Katabatic wind together influence the fair
weather field. Local time dependence is validated with other AWS observations (IMD, Dozer point).

276
Tue_63_AC-1_1703
Study of Ice Core and Present Day Mineral Dust in Antarctica by PIXE Analysis

Silvia Nava1 (nava@fi.infn.it), Giulia Calzolai1, Franco Lucarelli2, Rita Traversi3, Silvia Becagli3, Mery Malandrino4,
Ornella Abollino4, Marco Grotti5, Francisco Ardini5, Beatrice Moroni6, Chiara Petroselli6, David Cappelletti6
1
Istituto Nazionale di Fisica Nucleare (INFN), Sesto Fiorentino, Italy, 2University of Florence and INFN-Firenze,
Sesto Fiorentino, Italy, 3University of Florence, Sesto Fiorentino, Italy, 4University of Torino, Torino, Italy,
5
University of Genoa, Genoa, Italy, 6University of Perugia, Perugia, Italy

Atmospheric mineral dust deflated from continental surfaces is an important player in Earth climate. As it
reaches inner Antarctica after long-range transport from other continents, the study of both current-days and
ice-core-archived Antarctic mineral dust is very useful in recognizing its main source areas and therefore the
present day and past atmospheric dust pathways. While glacial conditions, when dust concentrations are
higher, have been well investigated assessing a dominant dust origin from Southern South America, a poorer
knowledge is available for the Holocene and interglacials.
At the LABEC-INFN accelerator, a PIXE-PIGE setup has been optimized for high efficiency particulate matter
analysis. These techniques, which are high sensitive to mineral dust elements, have been used for the analysis
of dust in EPICA ice core samples (Marino et al., GRL 2009) and for preliminary measurements on present day
mineral dust collected at Dome C.
This research activity will be carried forward and enlarged by the recently started PNRA SIDDARTA project,
whose aim is studying present-day sources and transport processes supplying mineral dust to the Antarctic
plateau (by the analysis of atmospheric aerosol, surface snow and snow-pit samples collected at Dome C, as
well as soil samples collected in Southern South America and Australia).
Motivation, design and first results of SIDDARTA will be described together with results obtained by previous
PIXE analysis of Antarctic mineral dust.

277
Tue_64_AC-1_1704
Source Apportionment of Arctic Aerosol: Results of the Ny Ålesund 2015 Campaign

Giulia Calzolai1 (calzolai@fi.infn.it), Silvia Nava1, Massimo Chiari1, Franco Lucarelli2, Silvia Becagli3, Laura
Caiazzo3, Fabio Giardi3, Mirko Severi3, Mauro Mazzola4, Rita Traversi3
1
National Institute for Nuclear Physics, Florence Division, Sesto Fiorentino, Italy, 2University of Florence and
INFN-Firenze, Department of Physics and Astronomy, Sesto Fiorentino, Italy, 3University of Florence,
Department of Chemistry, Sesto Fiorentino, Italy, 4CNR-ISAC, Bologna, Italy

Ny Ålesund is located on a western fjord of Svalbard Islands, in the northernmost point influenced by the warm
West Spitsbergen Current, and thus it is an ideal site for the study of the interaction between the climate
change and the atmosphere, ocean and land variations. At the Gruvebadet laboratory, samplings are ongoing
since 2010 in the period March to September; in particular, in this work we will focus on the results gained by
the analysis of daily PM10 samples collected during the 2015 campaign.
Daily PM10 samples were analyzed for the ionic composition by Ion Chromatography (IC) and for metals and
rare earth elements (REEs) by Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP-AES). Further,
for the first time, daily samples were analysed for the elemental composition by Particle Induced X-ray
Emission (PIXE) analysis. PIXE is an almost unrivalled technique for the characterization of mineral dust, as it is
sensitive to all the crustal elements (except O), included Si, which is usually not accurately quantifiable with
other common chemical techniques.
Data on PM10 concentrations and speciation will be shown. Further, the Positive Matrix Factorization (PMF)
model was applied for source apportionment and allowed the identification and the quantification of the
contributions to the aerosol burden of several sources such as mineral dust, nitrate, ammonium sulfate, sea
salt, biogenic emissions, anthropic emissions.

278
Tue_65_AC-1_1731
Black Carbon Snow Surface Processes Connected to Atmospheric Variables

Michele Bertò1 (michele.berto@psi.ch), Andrea Spolaor2, Cristiano Varin3, David Cappelletti4,5, Elena Barbaro3,
Mauro Mazzola4, Krzysztof Markowicz6, Jean-Charles Gallet7, Carlo Barbante2,3
1
Paul Scherrer Institute, Energy and Environment Research Division, Villigen, Italy, 2CNR-IDPA, Venice, Italy, 3Ca
Foscari University of Venice, DAIS, Venice, Italy, 4CNR-ISAC, Bologna, Italy, 5Università degli Studi di Perugia,
Dipartimento di Chimica, Biologia e Biotecnologie, Perugia, Italy, 6University of Warsaw, Institute of Geophysics,
Warsaw, Poland, 7Norvegian Polar Institute, Tromsø, Norway

This work is the results of two experiments performed in Ny-Alesund (Svalbard) during the 2014 and 2016
spring. Two different experiments were performed to evaluate the relation between the atmospheric load of
black carbon (BC) and its concentration in surface snow. One experiment focused on the daily BC concentration
changes in the first 10 cm of the snow layer for a total of 80 days, the second with hourly temporal frequency
for 3 consecutive days and 3 cm of snow for study the possible fluctuation of BC in surface snow due to the day
and night cycle.
The atmospheric equivalent BC mass was measured by an Aethalometer, a PSAP and a mini- Aethalometer.
Refractory BC concentrations in snow samples were measured with a SP2 (DMT) and the insoluble particles
numbers with an Abakus system (Klotz).
Statistical modelling was considered to evaluate the relationships between the parameters and the variability
of rBC variability in the snow. In both experiments a statistically significant relation was found between the
dust content and rBC concentration in snow, indicating common atmospheric and depositional patterns. In the
“80 days” experiment a negative relation was found between the atmospheric and the snow BC, whereas a
positive relation between snow rBC content and snow conductivity. The high resolution sampling of the “3
days” experiment allowed detecting a diurnal cycle of the rBC in snow, inversely proportional to solar radiation
and snow temperature.

279
Tue_66_AC-1_1752
Climatological Analysis of Aerosol Properties Including Moon Photometric Results

Edith Rodríguez1 (edith.rodriguez@fmi.fi), Aaltonen Veijo1, Rigel Kivi2, Antti Arola3, Gerrit de Leeuw1
1
Finnish Meteorological Institute, Climate Change Unit, Helsinki, Finland, 2Finnish Meteorological Institute,
Arctic Research Unit, Helsinki, Finland, 3Finnish Meteorological Institute, Atmospheric Research Centre of
Eastern Finland, Helsinki, Finland

Over the past decades, the Arctic has warmed more than any other region on Earth. However, the causes of
this so-called Arctic amplification are not yet fully understood. Although model estimation of Black Carbon (BC)
has been improved in the past years there is still an under or overestimation of BC in the prediction of a factor
of two, which could be due to the mismatch of long-range transport due to the limited horizontal resolution. To
provide better information to models, Finnish Meteorological Institute (FMI) has extended the Arctic
observations to improve the capability to monitor the vertical atmospheric column in the dark period. In this
work we present a new method to retrieve aerosols properties using a novel instrument that measures in dark
conditions, using the moon as a source of radiation. The Lunar Photometer is an extension to the traditional
Cimel sun-photometer with some significant technical modifications to optimize its performance to allow the
retrieval of reduced incoming energy. Fifteen years of AOD and AE measured by collocated PFR and Cimel
photometer measurements have been analyzed together with the first year of the lunar photometer
measurements installed at Sodankylä station. The physical aerosol properties such as aerosol size distribution,
refractive index, and the single scattering albedo analyses are also included, starting in 2013.

280
Tue_67_AC-1_1781
Aerosol as a Player in Arctic Climate Change - An Aerosol-climate Model Study

Jacob Schacht1 (schacht@tropos.de), Bernd Heinold1, Ina Tegen1

1
Leibniz Institute for Tropospheric Research (TROPOS), Modelling Department, Leipzig, Germany

The Arctic is warming twice as fast as any other part of the world. The rapid climate change is associated with
various feedback mechanisms which relative importance is still debated. The German project “Arctic
Amplification (AC)3” aims to better quantify relevant processes and enhance the understanding of mechanisms
involved with a range of field measurements and modeling.
Aerosol particles affect the Arctic energy balance by direct and indirect radiative effects. This study contributes
to (AC)3 by investigating sources and transport pathways of natural and anthropogenic aerosol and its radiative
impact by global and Arctic-focused transport modeling. Particular focus is on black carbon (BC) which is highly
absorbing at solar wavelengths and tends to warm the atmosphere. When deposited on snow/ice it lowers the
surface albedo and accelerates sea ice melting.
Here, we present an evaluation study with the aerosol-climate model ECHAM6.3-HAM2.3. Using different
state-of-the-art emission inventories, simulations have been performed in nudged mode with 1.8° grid spacing
for the years 2006-15. The evaluation's emphasis is on the vertical layering and seasonality of Arctic aerosol
using ground and airborne field data. The evaluation will reveal emission and transport-related uncertainties in
aerosol radiative properties and forcing. Finally, the model results will provide an up-to-date estimate of the
budget and direct radiative forcing of aerosol in the Arctic region.

281
Tue_68_AC-1_1789
Black Carbon Deposition to the Greenland Ice Sheet from Forest Fires in Canada

Jennie L. Thomas1 (jennie.thomas@latmos.ipsl.fr), Christopher M. Polashenski2,3, Amber Soja4, Louis Marelle5,

Kimberly A Casey2, Hyun Deok Choi4, Jean-Christophe Raut6, Christine Wiedinmyer7, Louisa K. Emmons7, Jerome
Fast8, Jacques Pelon1, Mark Flanner9, Jack E. Dibb10
1
LATMOS/CNRS, Paris, France, 2Dartmouth College, Thayer School of Engineering, Hanover, United States, 3Cold
Regions Research and Engineering Laboratory, Fairbanks, United States, 4National Institute of Aerospace,
Resident at NASA Langley Research Center, Hampton, United States, 5Center for International Climate and
Environmental Research, Oslo, Norway, 6LATMOS, Paris, France, 7National Center for Atmospheric Research
(NCAR), Boulder, United States, 8Pacific Northwest National Laboratory, Richland, United States, 9University of
Michigan, Department of Climate and Space Sciences and Engineering, Ann Arbor,, United States, 10University of
New Hampshire, Earth Systems Research Center, EOS, Durham, United States

Black carbon (BC) concentrations has been observed in 22 snowpits sampled in the northwest sector of the
Greenland ice sheet in April 2014. The pits contain a strong and widespread BC aerosol deposition event, which
accumulated in the pits during two snow storms between 27 July and 2 August 2013. This event comprises a
significant portion (57% on average across all pits) of total BC deposition measured in the snowpits (~10 month
record). We link this deposition event to forest fires burning in Canada during summer 2013 using modeling
and remote sensing tools. Specifically, we use high-resolution regional chemical transport modeling (WRF-
Chem) combined with high-resolution fire emissions (FINNv1.5) to study aerosol emissions, transport, and
deposition to Greenland snow during this event. The model captures the timing of the BC deposition event and
shows that fires in Canada were the main source of deposited BC. The potential implications for understanding
the influence of BC originating from fires on the optical properties of snow is discussed.

282
Tue_69_AC-1_1820
10 Years of Polar Lows Using AMSU-B, MHS, ASR and Radiative Transfer Simulations

Ana Radovan1 (aradovan@uni-koeln.de), Susanne Crewell2, Mario Mech2, Erlend Moster Knudsen2, Annette
Rinke3
1
Institute for Geophysics and Meteorology, Cologne, Integrated Remote Sensing, Cologne, Germany, 2Institute
for Geophysics and Meteorology, Cologne, Germany, 3Alfred Wegener Institute - Helmholtz Center for Polar and
Marine Research, Potsdam, Germany

Polar lows (PLs) are intense, high-latitude maritime cyclones that bring heavy precipitation and winds above
gale force. Their small horizontal scale and short life time makes them hard to predict. Therefore, improved
understanding and prediction is of high importance. Satellite observations in the microwave range that have a
good coverage of the Arctic region offer high potential due to theirs sensitivity to snow. Two such satellite
instruments, namely Advanced Microwave Sounding Unit -B (AMSU-B) and Microwave Humidity Sounder
(MHS) have been used. The investigation of PLs is done for January, 2003 to December, 2012 over which 134
cases were reported. Arctic System Reanalysis version 1 (ASRv1) is used for the analysis of atmospheric genesis
conditions of PLs and compared with satellite observations. For the latter, radiative transfer simulator called
PAMTRA (Passive and Active Microwave Radiative Transfer Model) has been employed. We found that AMSU-B
and MHS are performing well in representing the PLs, where channels around strong water vapour line, namely
183.31 GHz, are showing strong depression in PL convective cores that At times depression can be over 40 K.
Generally, simulations show good agreement with satellite observations, though not all cores of multi-low PL
are resolved. Furthermore, we investigate PL cases originating in different geographical area and the amount of
snowfall they bring.

283
Tue_70_AC-1_1895
Tropical Palynomorphs Detected at Central-Western Antarctic

Kamila da Matta Agostini1 (kamila_matta@hotmail.com), Heitor Evangelista1, Claudia Barbieri Ferreira

Mendonça2, Franco Nadal Junqueira Villela3, Marcelo de Araujo Carvalho2, Vania Gonçalves Esteves2, Alerson
Rodrigues Bezerra1
1
Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil, 2Universidade Federal do Rio de Janeiro, Rio de
Janeiro, Brazil, 3Instituto Nacional de Meteorologia, São Paulo, Brazil

The regime of transport and deposition of pollen grains and spores to Antarctica may help understanding the
atmospheric capability of transporting biological material intercontinentally. Snow samples were collected in
Central-Western Antarctica (84ºS-079ºW), Criosfera 1 laboratory, in the years of 2013 and 2015 to investigate
occurrences of palinomorphs. The collected snow was filtered in polyester blanket with 6 µm lumen and later,
the palinological slides were assembled. Simultaneously, atmospheric modeling (HYSPLIT/NOAA), surface wind
diagrams and data obtained in situ (wind direction, snow accumulation, air temperature and relative humidity)
were used to corroborate the sources of the palynomorphs. Eleven pollen / spore grains represented the taxa:
Thelypteris sp., Waltheria sp., Pinus sp., Smilax sp., Morus alba L, Anadenanthera colubrina Brenan and
Campanulaceae were observed in the year of 2015 and only one grain of Poaceae in 2013. We have attributed
the difference in pollen concentration to an extratropical cyclone in the coastal South Atlantic characterized as
explosive that occurred near Uruguay and North / Northeast of Argentina in November 2015. Polen source
region was corroborated by radiogenic Sr/Na in concomitant dust. This event, due to its high energy, was
responsible for the suspension of palynomorphs, followed by transportation to the high latitudes. In the
Weddell Sea, a polar cyclone assisted the entry of palynomorphs into the Antarctic continent.

284
Tue_71_AC-1_1913
An Experiment at Lat 84S to Study the Link between Cosmic Ray and Cloud Cover

André Massafferri1 (massafferri@cbpf.br), Heitor Evangelista2, Leonardo Guedes1, Ulisses Carneiro1, Marcos
Koebcke1, Heber Passos3
1
Centro Brasileiro de Pesquisas Físicas, COHEP, Rio de Janeiro, Brazil, 2Universidade Estadual do Rio de Janeiro,
Rio de Janeiro, Brazil, 3Instituto Nacional de Pesquisas Espaciais, São Jose dos Campos, Brazil

Since Charles Wilson invented the cloud chamber in 19´s it is known that ionizing particles are capable to
trigger cloud droplets. Only in 1997 the first evidence of a response of the cloud formation with respect to
cosmic rays in real atmosphere has been reported, motivating many other studies, given to it potential
implications to the global climate changes.
Recently the CLOUD Collaboration designed a special chamber dedicated to study the ion-aerosol mechanisms,
the microphysical process to form clouds. They found that ions from galactic cosmic rays could strongly
enhance the production rate of pure biogenic particles as well as oxidised biogenic vapours dominate particle
growth in unpolluted environments.
In order to study the role of the cosmic ray in climate, the Criosfera 1, a remote Brazilian self-energy sustained
laboratory, installed at 840 S, setup an experiment, named CREAT (Cosmic Ray Experiment at AnTartic),
dedicated to monitor low energy muon flux efficiently, by means of plastic scintillators, multianode photo-
multiplier and FPGA technologies. The location is benefited by the high cosmic flux, absence of background
radiation, human pollution and rainfall. We will present the preliminary results obtained from 2014 to 2017,
analyzed using advanced statistical method to quantify their correlation with cloud of different altitudes using
NASA and ERA datasets. We will also discuss the long term perspective for the CREAT project and its upgrade.

285
Tue_72_AC-1_1920
US Dept. of Energy Atmospheric Radiation Measurement Facilities in the Arctic

Mark Ivey1 (mdivey@sandia.gov), Joe Hardesty1

1
Sandia National Laboratories, Albuquerque, United States

The U.S. Department of Energy (DOE) operates scientific user facilities at locations around the world, including
polar regions. The Atmospheric Radiation Measurement (ARM) facility is a scientific user facility that provides
researchers with strategically located atmospheric observatories. The resulting data are used to improve the
understanding of how the Earth's atmosphere works and the way those processes are represented in regional
and global models. Data from these facilities are provided to the international research community through an
archive that is easily accessed via the web.
The ARM program currently operates two fixed ground-based facilities in Alaska and has a third inland location
that can be used for field campaigns. These facilities include:
> Barrow: to measure ocean-land-atmosphere interface conditions,
> Atqasuk: to measure land-atmosphere interface for comparison of Barrow measurements for differences
between land and shore conditions,
>Oliktok (AMF-3): to measure ocean-land-atmosphere interface; use of R-2204 and W-220 for aerial
atmospheric measurements.
In addition to providing full time ground-based observations, the ARM facility at Oliktok is used for operations
of instrument unmanned aerial systems and tethered balloon systems. Several activities related to the Year of
Polar Predication (YPP) at North Slope ARM facilities have been proposed and are under review.

286
Tue_73_AC-1_2020
Study on the Cloud Condensation Nuclei Concentration and Aerosol Optical Depth

Chang Hoon Jung1 (jch@kiwu.ac.kr), S.H. Ahn2, Young Jun Yoon2, H.J. Kang2, Y.T. Gim2, B.Y. Lee2
1
Kyungin Women's University, Incheon, Korea, Republic of, 2Korea Polar Research Institute, Incheon, Korea,
Republic of

The aerosol optical measurement to estimate CCN concentrations is challenging because of various aerosol
characteristics. Thus, it is important to investigate the CCN-AOD relation using remote AOD data according to
the regional and seasonal aerosol characteristics.
In this study, CCN-AOD relation at 500 nm is given in the Arctic region based on CCN measurement data
collected during the period 2007-2013 at the Zeppelin observatory (78.91° N, 11.89° E, 474 masl). For remote
sensing data, the AERONET network and MODIS AOD as well as MERRA-2 reanalysis data are analyzed. The
seasonal characteristics as well as long term trends are also considered.
As a results, CCN concentration remains high during spring because of aerosol transportation from the mid-
latitudes, known as Arctic Haze. Lowest CCN number densities were observed during autumn and early winter
when aerosol long-range transport into the Arctic is not effective and new particle formation ceases. The
results also show that the relation between AOD and CCN has a seasonally different tendency. This seasonal
different CCN-AOD relation can be interpreted as many physico-chemical aerosol properties including aerosol
size distribution and composition. Subsequently, CCN-AOD relation can be interpreted as many physico-
chemical aerosol properties including aerosol size distribution and composition.

287
Tue_74_AC-1_2048
POLARUBI Field Campaign: Individual Particle Analysis of Atmospheric Aerosols

Sandra Mogo1,2,3 (sipmogo@gmail.com), V. Cachorro2, D. Mateos2, E. Conceição1, A. Barroso1, R. Monteiro1, R.

Zocca1, A. M. de Frutos2
1
Universidade da Beira Interior, Covilhã, Portugal, 2Universidad de Valladolid, Valladolid, Spain, 3Instituto Dom
Luíz, Lisbon, Portugal

This work presents in situ data from aerosol measurements that took place at the Arctic Lidar Observatory for
Middle Atmosphere Research, located in the Andøya island, ~300 km north of the Arctic Circle. The main goal
of the measurements is the characterization of individual aerosol particles to know their morphology, size
distribution, mass and chemical composition. The technique used is the collection of aerosol particles on filters
for posterior analysis in the laboratory. The system is composed by an inlet, an in-line filter holder, a vacuum
pump and a flow meter. The filters are weighed before and after collection for determination of the amount of
particulate matter. After weighed, the filters are prepared for observation on a scanning electron microscope
(SEM) or on a transmission electron microscope (TEM). Both electron microscopes allow to see the size and
morphology of the individual particles. A RONTEC energy dispersive x-ray system allows to obtain the
information about elemental composition of the particles.This work is supported by Fundação para a Ciência e
Tecnologia (FCT) through the Portuguese Polar Program (ProPolar), Project POLARUBI.

288
Tue_75_AC-1_2054
Columnar Aerosol Observations by Sun-sky-Lunar Photometry in Ny-Ålesund (79ºN)

D. Mateos1 (mateos@goa.uva.es), C. Velasco-Merino1, V. E. Cachorro1, C. Ritter2, S. Mogo1,3, C. Toledano1, R.

Neuber2, R. González1, M. Herreras1, A. Calle1, A. M. de Frutos1
1
Universidad de Valladolid, Valladolid, Spain, 2Alfred Wegener Institute - Helmholtz Center for Polar and Marine
Research, Postdam, Germany, 3Universidade da Beira Interior, Covilhã, Portugal

The Atmospheric Optics Group of the University of Valladolid and the Alfred Wegener Institute (AWI) have
started a joint research project which included the installation of a new generation Cimel sun-sky-lunar
radiometer (CE318-T) in the Ny-Ålesund Arctic base (Svalbard, 78.9ºN). This kind of instrument, in the
framework of the worldwide AERosol ROBotic NETwork (AERONET), can provide aerosol properties during
summer (sun) and winter (moon) time. This instrument follows all the standardized AERONET daylight
observations and gives a large set of aerosol properties that can be combined with lidar and other collocated
instruments using novel algorithms such as GRASP (Generalized Retrieval of Atmosphere and Surface
Properties) open source code.
We present here the preliminary results of aerosol optical and microphysical observations in the French and
German joint facility AWIPEV in Ny-Ålesund after several months of operation. The aerosol optical depth time
series (since 1991) from a Schulz sun photometer at the AWIPEV site is compared with the first months of
CIMEL database and the results highlight the necessity of re-calibration of the 1020 nm channel.
This work was supported by: project POLARMOON (CTM2015-66742-R) and IJCI-2014-19477 and PTA2014-
09522-I grants of Spanish Government (MINECO), EU-H2020 under Grant Agreement Nr. 654109 [ACTRIS 2];
and RIS-ID 10745 project. Thanks to AWIPEV station crew.

289
Tue_76_AC-1_2119
Single Particle Characteristics of Biomass Burning Aerosol Transported in Arctic

Beatrice Moroni1, Kris Markowicz2, Justyna Lisok2, Christoph Ritter3, Mauro Mazzola4, Silvia Becagli5, Rita Rita5,
Roberto Udisti5, David Cappelletti1 (david.cappelletti@unipg.it)
1
University of Perugia, Department of Chemistry, Biology and Biotechnology, Perugia, Italy, 2University of
Warsaw, Institute of Geophysics, Warsaw, Poland, 3AWI - Alfred Wegener Institute for Polar and Marine
Research, Potsdam, Germany, 4CNR - ISAC - National Research Council, Italy, Bologna, Italy, 5University of
Florence, Department of Chemistry, Florence, Italy

This paper reports an exceptional biomass burning (BB) advection event from Alaska registered at Ny-Ålesund
from 10 to 17 July 2015 with special interest on the evolution of the particle characteristics and mixing state
over time in relation to the optical properties of the aerosol. To this purpose we considered two DEKATI 12-
stage aerosol samples spanning over the entire advection and analyzed them by scanning electron microscopy
(SEM) techniques. Daily chemical data and hourly optical measurements were also evaluated in order to
correlate individual particle characteristics with bulk aerosol properties at ground level. Results depict a
complex advection event characterized by a first phase (P1) of massive input of BB organic particles (OPs), and
by a second phase (P2) dominated by inorganic salts (ISs). The mixing state conditions also varied greatly,
ranging from prevailing internal mixing of IS on OPs in P1 to prevailing external mixing of IS and MD particles
with pre-existent OPs in P2. Optical measurements at ground level of Jul 10 are in good accordance with the
particle features, but rapidly evolved likely due to a strong increase of the grain size by hygroscopic growth
upon humidification. The observations reveal the influence of aging effects due to the long-range transport and
to the stationing of the BB particles in the boundary layer.
References:
JGR., 121 (2016) 14487-14512.
Amos. Environ., 156 (2017) 135-145

290
Tue_77_AC-1_2134
Pico Mountain Observatory, a Free Tropospheric Remote Site in the North Atlantic

Andrea Baccarini1 (andrea.baccarini@psi.ch), Paulo Fialho2, Swarup China3, Simeon Schum4, Lynn R. Mazzoleni4,
Claudio Mazzoleni4
1
Paul Scherrer Institute, Villigen PSI, Switzerland, 2Universidade dos Açores, Ponta Delgada, Portugal, 3Pacific
Northwest National Laboratory, Richland, United States, 4Michigan Technological University, Houghton, United
States

Pico Mountain Observatory (PIC) is a mountaintop research station located in the summit caldera of the Pico
Volcano (2225 m.a.s.l.) in the Azores. During summer, this site typically, lays in the free troposphere, sampling
air decoupled from the boundary layer, which is different from other mountaintop observatories. PIC and the
Izaña station are the only places in the North Atlantic where free tropospheric air masses can be studied over
extended periods of time. Therefore, PIC, due also to its central location in the Atlantic, is an ideal place to
investigate atmospheric background conditions and long-range transport effects.
We will present results of the aerosol measurements conducted at PIC since 2012. This dataset includes aerosol
scattering and backscattering (by a 3-wavelength integrating nephelometer), aerosol absorption, black carbon
and iron containing particles mass concentration (by a 7- wavelength aethalometer) and particle
concentrations for particles bigger than 300 nm (with a 2-channel optical particle counter). In addition, several
filters were collected for chemical characterization (using ion chromatography and ultrahigh resolution mass
spectrometry), for microscopy and elemental analysis, and for ice nuclei analysis. During two summer seasons,
we used an instrumented backpack to measure the vertical distribution (from 1225 to 2351 m.a.s.l.) of particle
concentrations, in-situ optical properties, aerosol optical depth, and meteorological parameters.

291
Tue_78_AC-1_2250
Long-term Variability of Cloudiness over the Russian and Norwegian Arctic

Alexander Chernokulsky1 (a.chernokulsky@ifaran.ru), Igor Esau2, Olga Bulygina3, Igor Mokhov1,4

1
A.M.Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russian Federation,
2
Nansen Environmental and Remote Sensing Center, Bergen, Norway, 3All-Russian Research Institute of
Hydrometeorological Information - World Data Center, Obninsk, Russian Federation, 4Lomonosov Moscow State
University, Moscow, Russian Federation

The study presents a long-term climatology of cloudiness over the Norwegian and Russian parts of the Arctic
Ocean. The analysis is based on routine visual surface observations that conducted at island and coastal
Russian and Norwegian stations from 1930s. Total and low cloud cover and fraction of different morphological
cloud types are assessed. The climatology and inter-annual variability is evaluated separately for different seas
(from the Norwegian to Chukchi seas) and for open-water and solid-ice regions. In general, total cloud cover
(TCC) has higher intra- and inter-annual variability over SI than over OW. A decrease of TCC in the middle of the
20th century and an increase in the last few decades is revealed at individual stations and for the Atlantic
sector. Long-term positive trend of convective and negative trend of stratiform cloud forms are found.
Statistically significant relationship between cloudiness and sea-ice concentration is shown.

292
Tue_79_AC-1_2292
A Study of the Interaction between Precipitation and Blowing Snow in Adélie Land

Hubert Gallée1 (hubert.gallee@univ-grenoble-alpes.fr)

1
Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, UMR 5001, Grenoble, France

A recent study (Grazioli et al., 2017) has shown that a significant part of precipitation in Adélie Land sublimates
in the upper part of the katabatic flow. On the other hand airborne snow particles eroded from the surface also
sublimate in the lower part of the katabatic layer. The question raised here is to which extent both processes
influence each other, as they may influence the surface mass balance of the antarctic ice sheet margin.
A new version of MAR (Modèle Atmosphérique Régional - Gallée, 2017, in preparation) has been developed,
including a new blowing snow module. The code has been rewritten and parallelized using domain
decomposition and the MPI (Message Passing Interface) software.
Validation show a good agreement between the model and observations made in Adélie Land. Sensitivity tests
have been performed by switching on and off the blowing snow module, in order to better understand the
interaction between snow precipitation and erosion by the wind. Here we show how the interaction develops
along the slopes of Adélie Land.

293
Tue_81_AC-1_2374
Aerosol Optical Properties over the Arctic in the Light of Absorbing Particles

Justyna Lisok1 (jlisok@igf.fuw.edu.pl), K.M. Markowicz1, Ch. Ritter2, P. Makuch3, D. Cappelletti4, M. Mazzola5, R.
Udisti6
1
IGF, University of Warsaw, Warsaw, Poland, 2AWI, Potsdam, Germany, 3IOPAS, Sopot, Poland, 4DCBB,
University of Perugia, Perugia, Italy, 5CNR-ISAC, Bologna, Italy, 6Dept. of Chemistry, University of Florence,
Florence, Italy

The aim of this research is to investigate aerosol optical and microphysical properties during spring and
summer conditions in the European Arctic. In the first part of the study, we performed a model-based
investigation on spring and summer AOD trends in the last 15 years with the emphasis put on the changes in
the occurrence of Arctic Haze and biomass burning transport events. We confirmed the negative trend of Arctic
Haze AOD and a positive one of the latter. Secondly, we estimated mean spring conditions of the aerosol
optical and microphysical properties (such as scattering and absorption coefficients, single scattering albedo,
Angstrom exponent, AOD, etc.) during background conditions and high concentration events of respective
aerosol species. These results utilised in-situ measurements from spring campaigns conducted in 2014-2017 at
Ny-Alesund, Spitsbergen under iAREA (Impact of Absorbing Aerosols in the European Arctic) project. Finally, an
investigation of HYSPLIT back-trajectories during high load events was performed indicating possible source
regions of particular aerosol species.

294
Tue_82_AC-1_2527
Sensitivity Study of Energy Budget to Optically Thin Ice Clouds in the Arctic

Housseyni Sankare1 (sankare.housseyni@gmail.com), Jean-Pierre Blanchet1, René Laprise1, Oumarou Nikiema2

1
Universite du Quebec a Montreal, Earth and Atmospheric Sciences, Montreal, Canada, 2Centre pour Étude et la
Simulation du Climat à l'Échelle Régionale (ESCER), Montreal, Canada

In situ and satellite-based observations reveal the existence of two types of optically thin ice cloud (TICs) in the
Arctic during the polar night. The first type, TIC-1, consists of small none precipitating ice crystals and invisible
to the CloudSat radar. The second type, TIC-2, is detected by CloudSat radar and CALIPSO lidar and is
characterized by a low concentration of large ice crystals of sufficient size to precipitate. Energy budget
diagnostics appears to be one of the most efficient ways to improve functioning physical mechanisms in
atmosphere. In this study, the energy cycle equations as formulated by Nikiéma and Laprise (2013) will be used
to analyse the energy budget of the atmospheric circulation in the Arctic during the polar night. To address this
question, satellite-based observations (CloudSat and CALIPSO) are used to characterize the ice clouds and
analyze the atmospheric conditions conducive to their formation. A reanalysis driven application of the
Canadian Regional Climate Model version 5 (CRCM5) is used to perform two simulations, one with the TIC-1
conditions and the other with TIC-2 conditions. A comparative analysis will be carried out to determine the role
of the thin ice cloud according to their type in the response of the energy balance. Overall, this study
contributes to evaluate the relative importance of polar clouds on the atmospheric energy balance.

295
Tue_83_AC-1_2541
Arctic Urban Air Pollution: Knowledge Gaps, Challenges & Future Directions

Steve Arnold1 (s.arnold@leeds.ac.uk), Julia Schmale2, Kathy Law3, Kerri Pratt4, William Simpson5, Jingqiu Mao5
1
University of Leeds, School of Earth & Environment, Leeds, United Kingdom, 2Paul Scherrer Institute (PSI),
Villigen, Switzerland, 3Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), CNRS - UMR 8190,
Paris, France, 4University of Michigan, Ann Arbor, United States, 5University of Alaska - Fairbanks, Fairbanks,
United States

Urban areas in many high latitude regions have been shown to suffer from regular air quality standard
violations, particularly during winter. Locally produced air pollution, in combination with cold, stagnant
weather conditions and strong inversion layers, can lead to significant localized pollutant concentrations.
Despite these effects, there are important knowledge gaps in our understanding of chemical and physical
processes occurring under polluted conditions with limited sunlight and very low temperatures. Studies suggest
wintertime aerosol in high latitude urban areas often comprises large mass concentrations of fine particulate
organic carbon resulting from domestic wood burning, as well as substantial sulfate mass fractions. However,
our knowledge about formation mechanisms, based on lower latitude studies, cannot explain these aerosol
abundances under conditions of limited photochemistry.
We will present an overview of current knowledge regarding sources, processing and fate of wintertime air
pollution in high latitude urban environments, and discuss challenges related to reconciling understanding of
pollution formation and loss processes with limited observations available. A roadmap for recommended
action to address knowledge gaps, being developed under the IGAC/IASC PACES (air Pollution in the Arctic:
Climate, Environment and Societies) initiative will be presented, including plans for an international field
experiment and new model evaluation activities.

296
Tue_84_AC-1_2650
Cloud, Aerosol, and Radiation Observations at Multiple Polar Sites

James Mather1 (jim.mather@pnnl.gov), Kim Nitschke2, Heath Powers2, Maciej Ryczek2, Jennifer Comstock1
1
Pacific Northwest National Laboratory, Richland, United States, 2Los Alamos National Laboratory, Los Alamos,
United States

The Atmospheric Radiation Measurement (ARM) facility is operated by the United States Department of Energy
and provides extensive suites of atmospheric instrumentation for studying the interactions among clouds,
aerosols, precipitation, and the surface energy budget at multiple ground-based observatories around the
world (www.arm.gov). Two of these observatories are deployed for about a year at a time through a
competitive proposal process. One of these deployable observatories has recently undertaken two separate
missions to Antarctica and the surrounding Southern Ocean (which will have just recently been completed at
the time of the Polar 2018 conference) and will soon be deployed on a third polar mission to the central Arctic
Ocean as part of the Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAIC) initiative.
ARM also operates two observatories along the North Slope of Alaska, in Barrow and Oliktok, which will be the
subject of a separate presentation. The goal of this presentation is to provide an overview of the capabilities of
these ARM Mobile Facilities, highlight some observations obtained from these unique deployments, and
describe how scientists interested in polar measurements can engage with the ARM facility, either through
analysis of previously archived data (which are available to anyone) or by proposing future field campaigns.

297
Tue_85_AC-1_2671
Radiative Impact, Long-term Trends and Source Attributions of Arctic Aerosols

Hailong Wang1 (hailong.wang@pnnl.gov), Rudong Zhang1,2, Yang Yang1, Steven Smith3, Philip Rasch1
1
Pacific Northwest National Laboratory, Atmospheric Sciences and Global Change, Richland, United States,
2
Nanjing University, Institute for Climate and Global Change Research, School of Atmospheric Sciences, Nanjing,
China, 3Joint Global Change Research Institute, College Park, United States

Aerosols affect the Arctic radiative budget directly by interfering radiation and indirectly by modifying clouds.
Black carbon (BC) in snow/ice can reduce the surface albedo. The direct radiative impact of aerosols on the
Arctic climate can be either warming or cooling, depending on their composition and location. Anthropogenic
emissions, especially, BC and SO2, have changed drastically in low/mid-latitude source regions in the past few
decades. Arctic observations show that BC and sulfate aerosols had a decreasing trend in the recent decades.
We use the Community Earth System Model (CESM) equipped with a BC and sulfur source-tagging technique to
quantify the source-receptor relationships and decadal trends of Arctic sulfate and BC during 1979-2014 and to
identify variations in their transport pathways from lower latitudes. Emissions came from the CMIP6 datasets,
which show strong regional trends in BC and SO2 emissions during the simulation time period. Results show
that emissions from East Asia and South Asia together have the largest contributions to Arctic sulfate/BC and
their increasing trend in the upper troposphere, while the strong decrease in emissions from Europe, Russia
and North America contributed significantly to the overall decreasing trend, especially, in the lower
troposphere. The long-term changes in the spatial distributions of aerosols, their radiative impacts and source
attributions, along with implications for the Arctic warming trend, will be discussed.

298
Tue_87_AC-5_176
Antarctic Surface Mass Balance Evolution through the Plio-Pleistocene Transition

Florence Colleoni1 (flocolleoni@gmail.com), Annalisa Cherchi1, Laura De Santis2, Fabio Florindo3, Nicholas
Golledge4,5, Simona Masina1,6, Robert McKay7, Enea Montoli1, Francesca Sangiorgi8
1
Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici, Bologna, Italy, 2Istituto Nazionale di
Oceanografia e Geofisica Sperimentale, Trieste, Italy, 3Istituto Nazionale di Geofisica e Vulcanologia, Roma,
Italy, 4Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand, 5GNS Science,
Avalon, New Zealand, 6Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy, 7Antarctic Research Centre,
Victoria University of Wellington, Wellington, Italy, 8Utrecht University, Utrecht, Netherlands

Changes in global Sea Surface Temperature (SST) gradients modulate the strength of the Southern atmospheric
teleconnections, but the implications for Antarctic ice sheet (AIS) surface mass balance (SMB) are seldom
investigated. Considering the Plio/Pleistocene transition as a good past analogue to future SST changes over
the 21st century, idealized numerical Pliocene atmospheric and SMB simulations show that strong SST
gradients induce dynamical changes that enhance or dampen the sensitivity of the AIS to teleconnections. A
strong meridional SST gradient increases the influence of the Southern Annular Mode over the AIS Pacific
sector. A strong zonal equatorial SST gradient strengthens the stationary Rossby wave pattern between East
Australia and the Amundsen Sea, modifying the moisture fluxes pathway, which brings more precipitation over
the main drainage basins of the East AIS. Similar dynamical mechanisms are simulated for projected RCP2.6 and
RCP4.5 Antarctic SMB changes but compensations occur between the effect of teleconnections and the mean
climate states of the simulations. Under warm climates, the SMB sensitivity to teleconnections increases, even
though the atmosphere dynamics weakens and vice-versa under cold climate conditions. Although the mean
climate state is a good indicator for future AIS changes, local SMB, modulated by teleconnections, might
influence the retreat of key marine-based sectors.

299
Tue_88_AC-5_797
SSW Signatures of Semidiurnal Tides and 2 Day Waves in Low Latitude MLT Region

Koushik N1 (koushiknk@gmail.com), Karanam Kishore Kumar1, Geetha Ramkumar1, Kandula V Subrahmanyam1

1
Space Physics Laboratory, Vikram Sarabhai Space Centre, Indian Space Research Organisation,
Thiruvananthapuram, India

Sudden Stratospheric Warming (SSW) events are found to be capable of significantly affecting the low latitude
middle atmosphere. In the present study, we examine the signatures of SSW events in semidiurnal tides and
quasi 2-day waves in the Mesosphere- Lower Thermosphere (MLT) region over low and equatorial latitudes
using meteor wind radar observations from two stations Thumba (8.5oN, 76.5oE) and Kototabang (0.2oS. 100oE).
After developing the climatology of the above parameters, behavior of equatorial and low latitude MLT region
during typical polar stratospheric conditions, namely Quiet winter, Major SSW winter and Minor SSW winter, is
investigated. The analysis clearly shows the amplification of semidiurnal tides during major SSW events, albeit
the magnitude of enhancement varies from event to event. Interestingly, the semidiurnal tidal amplitudes are
found to enhance selectively in zonal and meridional components, respectively over the low latitude and
equatorial stations. Quasi 2-day wave amplitudes over both the observational sites increased in association
with SSW events, with anomalously large amplitudes as high as 95 m/s during the minor SSW of January 2012.
Unlike many case studies, the present study distinctively demarcates the characteristic response of semidiurnal
tides and quasi 2-day waves simultaneously over low latitude and equatorial MLT region to typical polar
stratospheric conditions.

300
Tue_92_AC-5_256
Influence of ENSO, PDO and Climate Change on Tropical Andean Glaciers

Bijeesh Veettil1 (bijeeshnair1982@gmail.com), Jefferson Simões2

1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, 970, Brazil, 2Universidade Federal do Rio
Grande do Sul / INCT da Criosfera, Porto Alegre, Brazil

Since the late 1970s, tropical Andes witnessed rapid glacier shrinkage in parallel with a warming trend
observed in this region. Variation in the maximum snowline during the dry season (austral winter), which can
be taken as nearly equivalent to the equilibrium line in the tropical Andes, was estimated using satellite data
for selected glaciers along the tropical Andes since the early 1980s. Meteorological datasets were also analysed
to observe changes in precipitation, temperature, and humidity. Inner tropical glaciers, particularly those
situated near the January Intertropical Convergence Zone (ITCZ), are more vulnerable to increases in
temperature and these glaciers are less sensitive to variations in precipitation. In contrast, outer tropical
glaciers respond to variations in precipitation very rapidly that to temperature changes, particularly when
moving towards the subtropics. Glaciers in the northern tropics and dry outer tropics showed relatively slower
retreat, possibly due to the occurrence of cold phases of El Niño-Southern Oscillation (ENSO) and Pacific
Decadal Oscillation (PDO) together in some years. The observed anomalies in the meteorological variables
slightly follow PDO patterns and annual snowline variations follow El Niño events, particularly when in phase
with warm PDO.

301
Tue_93_AC-5_532
Influence of SST in the Tropical Oceans on the Arctic Climate

Genrikh Alekseev1 (alexgv@aari.ru), Svetlana Kuzmina2, Natalia Glok1

1
Arctic and Antarctic Research Institute, St. Petersburg, Russian Federation, 2Nancen Center, St. Petersburg,
Russian Federation

The first objective is to assess the role of meridional atmospheric heat and moisture transport (MAHT) in the
temperature variations in the Arctic. MAHT across 70N into 70-90N area was calculated using ERA/Interim
reanalysis data for 1979-2016. It is found that main inflow in winter comes across 0-80E within layer between
the surface and 750 hPa and explains more than 50 % of variability of surface air temperature in the 70-90N
area. The second objective was to assess the influence of SST anomalies in the low latitudes of Atlantic, Indian
and Pacific oceans on change in the winter MAHT to the Arctic. The area and month with maximal correlation
between SST and winter MAHT (up to 0.75) as well as respective lags (27-30 months) in each ocean were
found. The third objective is an assessment of the influence of SST anomalies on sea ice cover in the Arctic.
Series of water temperature at the section in the Barents Sea, sea ice extent and surface air temperature in the
Arctic were used additionally. It is found intimate link between change of Atlantic SST in low latitudes and sea
ice extent in the Arctic with correlation coefficients up to 0.90 and delays up to 3 years. A mechanism of the
influence of SST anomalies in low latitudes on winter MAHT, sea ice and air temperature is proposed. It
includes the interactions of atmospheric (Hadley and Ferrel circulations, NAO) and oceanic (Gulf Stream, the
North Atlantic and the Norwegian currents) circulation patterns..

302
Tue_94_AC-5_672
Interdecadal Pacific Oscillation Influences Timing of an Ice-free Arctic Ocean

James Screen1 (j.screen@exeter.ac.uk)

1
University of Exeter, Exeter, United Kingdom

One of the most visible and iconic aspects of recent climate change is the dramatic loss of Arctic sea-ice.
Without efforts to slow manmade global warming, an ice-free Arctic would likely occur in summer by the
middle of this century. The precise timing of an ice-free Arctic will depend however, on both the magnitude of
future human-induced global warming and upon the magnitude and phasing of internal climate variability. This
talk will present results from a large initial condition ensemble of global climate model simulations. Each
ensemble member has a different realization of internal variability superimposed on the underlying externally
forced response. Ensemble members that transition more quickly from present-day to ice-free conditions tend
to be those that over the same time period are transitioning from negative to neutral/positive conditions of the
Inter-decadal Pacific Oscillation (IPO). The phase of the IPO can shift the projected timing of first ice-free
conditions by 5-10 years. Ensemble members that depict the IPO- phase in the 10-year period ending 2016
tend to transition toward IPO+ in the following decades, which accelerates the loss of ice and leads to an earlier
projection of ice-free conditions. If the real world IPO continues to transition towards it's positive phase, away
from IPO- in the recent past, this may hasten the emergence of ice-free summers in the Arctic.

303
Tue_95_AC-5_841
Understanding the Interactions between Polar, Midlatitude and Tropical Regions

Irina Rudeva1,2 (irina.rudeva@unimelb.edu.au), Ian Simmonds1

1
University of Melbourne, Melbourne, Australia, 2P.P. Shirshov Institute of Oceanology, Moscow, Russian
Federation

Many studies document Southern Hemisphere tropical and midlatitude influences on the Antarctic sea ice, and,
vice versa, Antarctic sea ice influence on the midlatitudes and tropics. Analogous types of associations have
been documented for NH polar and midlatitude/tropical regions. In this study potential teleconnection
patterns are identified using a range of techniques, including ray tracing (e.g. Karoly 1983, Shaman et al. 2012)
and wave activity flux (WAF, Takaya and Nakamura 2001). These approaches allow one to diagnose a path of
wave packets that propagate from a specific region, that can be interpreted in terms of 'waveguides'. A suit of
low-frequency and stationary ray tracing experiments will be conducted with an ensemble of rays starting
within Arctic/Antarctic sea ice regions and, then, midlatitude/tropics to identify 'hot spots' within them.
Particular attention will focus on the refraction of rays and to what extent the stationary and low-frequency
waves can 'escape' the sea ice zone regions, hence, be able to influence climate in lower latitudes.

304
Tue_96_AC-5_1149
Black Carbon Deposition to Antarctica: Low Latitude Hydroclimate Teleconnections

Monica Arienzo1 (marienzo@dri.edu), Joe McConnell1, Nathan Chellman1, Kelly Gleason1, Sepp Kipfstuhl2
1
Desert Research Institute, Reno, United States, 2Alfred Wegener Institute Helmholtz Center for Polar and
Marine Research, Meeresforschung, Bremerhaven, Germany

Black carbon (BC) and other biomass-burning emissions increasingly are recognized as major components of
climate forcing. BC aerosols impact climate directly by changing Earth's radiation budget and indirectly by
reducing albedo when deposited on bright surfaces such as snow and ice. Yet quantification and predictive
climate modeling have been hampered by limited understanding of the drivers of regional-scale biomass
burning and few long-term burning records.
In this work, we will compare the Antarctic BC results from an array of eastern Antarctic ice cores to low-
latitude paleoclimate proxies to investigate a potential link between low latitude climate, biomass burning, and
BC emissions. We will present high-resolution records of BC concentration and BC particle mass distributions (a
proxy for BC particle sizes) from these ice cores focusing on the last 2,000 years of BC deposition. For BC
concentration and particle mass determinations, ice cores were analyzed using the Desert Research Institute
continuous flow analysis method, allowing for seasonal resolution of BC measurements. Results will be
compared between ice cores, to previously published BC modeling results, and to low latitude hydroclimate
records from the BC source areas to determine potential teleconnections between the low and high latitudes.

305
Tue_97_AC-5_2495
Forty-year Negative Accumulation Trend in the Ellsworth Mountains

Francisco Fernandoy1 (francisco.fernandoy@unab.cl), Shelley MacDonell2, Arno Hammann2, Sarah Feron3

1
Universidad Nacional Andres Bello (UNAB), Vina del Mar, Chile, 2Centro de Estudios Avanzados en Zonas Aridas
(CEAZA), La Serena, Chile, 3Universidad de Santiago de Chile (USACH), Santiago, Chile

The Ellsworth Mountains are located at the intersection between the western border of the West Antarctic Ice
Sheet and the Ronne Ice Shelf (RFIS), at the base of the Antarctic Peninsula (AP).
Several firn cores retrieved from this region in 2014 and 2015, were analyzed for stable water isotopes and
glacio-chemical content. The dating of the cores shows that the accumulation in this region is relatively high for
Inland regions but low for coastal areas, with annual accumulation ranging between 200 and 400 kg m2 y-1.
A clear decrease of the accumulation is observed from the ice shelf border inland, with a clear orographic
effect of the mountains. This indicates that moisture masses approached the region from the Weddell Sea (and
not from the Bellingshausen-Amundsen Sea). Annual accumulation values show a strong decrease from the
1970´s to present, with the annual mean falling by a.50%. This is the opposite of observations made on the
west coast of the AP, where accumulation has doubled during the last century.
In this work we will integrate circulation model and re-analysis datasets to explain the strong decrease of
accumulation during recent decades and its link to changing oceanic conditions, with special focus on sea ice
variability and the environmental forcing of the accumulation variability. Finally, we will compare our results to
CMIP5 to better calibrate our observations and to generate future predictions, which are important to
determine the stability of the RFIS.

306
Tue_98_AC-5_2611
Transient Atmospheric Response to Reduced Sea Ice Cover in the Barents-Kara Seas

Anne Seidenglanz1,2 (anne.seidenglanz@unive.it)

1
Ca Foscari University of Venice, Venice, Italy, 2Centro Euro-Mediterraneo sui Cambiamenti Climatici CMCC,
Bologna, Italy

Sea ice is an important player in the global climate system owing to its properties:
1) It acts as an insulator between ocean and atmosphere,
2) it is an efficient reflector of incoming shortwave radiation and
3) phase changes related to freezing and melting processes alter the vertical stability characteristics of the
water column and therefore ocean circulation.
Of the Arctic Ocean, the Barents-Kara Seas have experienced the largest loss in sea ice cover since the start of
the observational period in 1979. For the atmospheric flow, areas of sea ice loss/reduction mean a change in
the lower boundary condition. Areas of sea ice loss are characterized by increased latent and sensible heat
fluxes from the ocean to the atmosphere, elevated near-surface air temperature and reduced vertical stability.
Re-analysis data have revealed November sea ice anomalies to have a significant impact on later winter sea
level pressure, surface air temperature, and precipitation anomalies over the Euro-Atlantic sector (Garcìa-
Serano et al. 2015). The proposed coupled response with the stratospheric polar vortex could explain the
delayed late-winter tropospheric response in the North Atlantic Oscillation seen in observational and modeling
data. This study aims at investigating this aspect further by initializing a seasonal prediction system with
reduced sea ice cover in the B/K Seas in autumn to study the timing and character of the atmospheric response
in the following winter season.

307
Tue_99_AC-5_306
Arctic Warming and the Amazon Rainforest Precipitation

Enoil de Souza Junior1,2 (souzajunior777@yahoo.com.br), Eder Bayer Mayer3, Jefferson Cardia Simões2
1
University of Manitoba, Winnipeg, Canada, 2Universidade Federal do Rio Grande do Sul / INCT da Criosfera,
Porto Alegre, Brazil, 3Universidade Federal do Rio Grande, Rio Grande, Brazil

The current atmospheric warming of the Arctic may weaken the Azores high pressure centre and,
consequently, weaken the northeast trade winds, may reduce precipitation in part of the Amazon region. From
this hypothesis, we explore possible teleconnections between the variability in the extent of Arctic sea ice and
the volume of precipitation in low latitudes. Using NCEP reanalysis data for precipitation in the Amazon and
NSIDC data for the extent of sea ice over the period 1979-2015, a linear regression analysis shows a positive
correlation around r = 0.4. When we selected a point in the Amazon region called P1 (r = 0.45), where we
extracted a time series for the volume of precipitation to compare with the Arctic sea ice variability, a linear
scatter plot shows r-square = 0.2. The work also shows the behaviour of the pressure fields that highlight the
teleconnections described here.

308
Tue_100_AC-5_474
South Pacific Climate Recorded in an Ice Core from the Pine Island Glacier

José Mauro Dalla Rosa1 (jmaurodallarosa@gmail.com), Jefferson Cardia Simões1, Francisco Eliseu Aquino1,
Isaías Ullmann Thoen1, Ronaldo Torma Bernardo1
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Centro Polar e Climático, Porto Alegre, Brazil

This work examines the South Pacific Ocean climate variability as recorded by two proxies (MSA and δ18O) from
an ice core collected in the Pine Island Glacier at the Mount Johns site (79°55´S, 94°23´W; 2100 m a.s.l.). The
two proxies show a positive trend in the period 1979-2008 [MSA (+0.210 µg L-1 a-1), and δ18O (+0.054‰ a-1)]. At
the same time, the Southern Hemisphere annular mode index (SAM) showed a positive trend in summer
(+0.078 a-1) and in autumn (+0.050 a-1), indicating a more intense cyclogenesis in the Southern Ocean,
displacement of the storm tracks towards the south, the deepening of the Amundsen Sea Low and the
decrease in the sea ice extent, contributing to a greater advection of oceanic air masses into the interior of the
Western Antarctica ice sheet, these are the probable causes for the positive trends of the two proxies. In
winter and spring, the SAM does not show the same tendency (-0.004 a-1) and (+0.004 a-1), favouring the
displacement of the polar jet stream and the storm tracks to the north, increasing the south flow from the
Antarctic Plateau to the Mount Johns region. We also discuss the influence of the ENSO phenomenon on the
environmental variability of the Mount Johns region.

309
Tue_101_AC-5_534
Influence of Tropical SST on Antarctic Sea Ice in the Global Warming

Genrikh Alekseev1, Nanalia Glok1 (glok.natasha@mail.ru), Anastasia Vyazilova1, Nikolai Ivanov1, Alexander
Smirnov1
1
Arctic and Antarctic Research Institute, St. Petersburg, Russian Federation

The sea ice cover in the Antarctic did not show a downward trend for the observed global warming while global
climate models show a decrease. The aim of our study is to explain this climatic phenomenon on base of the
idea of joint dynamics of ocean structures in the Southern Ocean - the Antarctic circumpolar current (ACC), the
Antarctic polar front (APF) and the edge of the maximumal extent of sea ice while the locations of these
structures are changed under the influence of SST anomalies in low latitudes. We used ERA/Interim, HadISST
data and sea ice data base for 1979-2016. The dependence between SST anomalies in the low latitudes of the
Northern Hemisphere and the position of the Antarctic polar front, maximum sea ice extent is found. The
obtained results reflect the opposite trends in the change of sea ice extent in the Arctic and in the Antarctic
under the influence of SST anomalies in common region of the North Atlantic. This influence is spread by
means of the shift of atmospheric circulation modes (intertropical convection zone (ITCZ), the Hadley
circulation (HC)) to the north with a positive SST anomaly and vice versa for negative anomaly with the
corresponding displacements of the zonal modes in the atmospheric circulation in the Southern hemisphere
(AAO, SAM) and zonal ocean modes (ACC, APF) in the Southern Ocean, followed by the boundary of sea ice
extent.

310
Tue_102_AC-5_1712
An Exceptional “Warm Arctic/cold Eurasia” Event in Autumn 2016

Konrad Schlichtholz1, Pawel Schlichtholz2 (schlicht@iopan.gda.pl)

1
University of Gdansk, Faculty of Mathematics, Physic and Informatics, Gdansk, Poland, 2Institute of Oceanology
of the Polish Academy of Sciences, Sopot, Poland

During the last two decades, when surface air temperature (SAT) in the Arctic increased faster than globally,
several abnormally severe winters occurred in northern continents. The "warm Arctic/cold continents" pattern
of SAT anomalies in these winters has often been attributed to the Arctic sea ice loss. Here, using monthly
mean fields from the ERA-Interim reanalysis, we investigate a spectacular event of this type observed in
autumn 2016. Anomaly fields for each month in 2016 were constructed by removing local, 1979-2016 means
from the raw data. In October 2016, negative SAT anomalies reached about 6°C over Eurasia (mainly in the
Asian sector). They were accompanied by a weaker “cold spot” in North America and positive SAT anomalies
exceeding 8°C in the Arctic. This SAT anomaly pattern was driven dynamically by an abnormal atmospheric
circulation, as indicated by a wavenumber-2 pattern of sea level pressure anomalies with major centres of
action over Scandinavia and North Pacific. In October 2016, temperature advection by northerly wind
anomalies over Asia exceeded by far (4 times) the corresponding standard deviation in the 1979-2016 period.
The distribution, magnitude and timing of the anomalies of sea ice concentration, sea surface temperature and
surface heat flux from September to December indicate that the atmospheric circulation anomaly in autumn
2016 was rather triggered by anomalous air-sea interactions in the North Pacific than by Arctic sea ice
anomalies.

311
Tue_103_AC-5_2129
Antarctic Surface Temperature Variability and its Relation to ENSO

Gabriel Retamales-Muñoz1, Claudio Duran-Alarcon2, Cristian Mattar1 (cmattar@uchile.cl)

1
Universidad de Chile, Laboratory for Analysis of the Biosphere (LAB), Santiago, Chile, 2Université Grenoble
Alpes, Institut des Géosciences de l'Environnement (IGE), Grenoble, France

The variability of Antarctic tropospheric circulation is dominated by the Antarctic Oscillation (AO) and
influenced by El Niño-Southern Oscillation (ENSO), due to the low-high latitude atmospheric teleconnections.
Previous works have evidenced the impact of the warming/cooling phases of ENSO (El Niño/La Niña) on the
distribution of precipitations, sea ice and near-surface temperature mainly in west Antarctica. Under a climate
change scenario, the frequency of extreme El Niño episodes is expected to increase in response to a projected
eastern equatorial Pacific warming. Therefore, the aim of this work is to assess the role of ENSO on the
Antarctica Land Surface Temperature (LST) during the last century until the present in the framework of a
project of the Chilean Antarctic Institute (INACH). LST is retrieved using data from MODerate resolution
Imaging Spectroradiometer (MODIS), ERA-Interim and ERA 20th Century reanalysis and in-situ weather stations.
Non-parametric test were used to estimate the trend of LST and the correlation in different spatiotemporal
scales to the Oceanic Niño Index (ONI). Preliminary results showed a cooling trend (-0.324 K/decade; p>0.05)
over the Peninsula and the eastern part of the Antarctic zone in the period of years 2001-2016. We also explore
the seasonal variation of these trends and the relationship to ONI. The cooling and warming evidence
contributes to better understand the surface temperature of antarctic climate system.

312
Tue_104_AC-5_2179
ENSO and SAM Influence in Southern Brazil Precipitation Anomalies

Pedro Valente1,2, Francisco Aquino1,2, Pedro Reis1,2, Jefferson Simões1,2 (jefferson.simoes@ufrgs.br)

1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Geography, Porto Alegre, Brazil, 2Centro Polar e
Climatico, Instituto de Geociências, Porto Alegre, Brazil

We used precipitation data from the University of Delaware reanalyzes, zonal and meridional wind,
geopotential height (925, 500 and 200 hPa), OLR anomalies (ERA-Interim), Niño (CPC/NOAA) and SAM
(Marshall) index to examine the influence of the El Niño-Southern Oscillation (ENSO), the Southern Annular
Module (SAM) and atmospheric circulation in the Southern Brazil (SB) spring and summer precipitation
anomalies (1970-2000 period). Previous studies indicated positive (negative) precipitation anomalies during El
Niños (La Niñas), but these anomalies vary with the ENSO intensity and its interaction with the SAM, by altering
the atmospheric circulation pattern between Tropics and Antarctica. In summer, positive precipitation
anomalies in El Niño exceed 150 mm, with weak (strong) SAM (Niño), negative anomalies below 50 mm with
neutral (moderate) SAM (Niño). To La Niña, positive anomalies above 90 mm with negative SAM and Niño.
Negative anomalies below 100 mm occur with neutral (strong) SAM (Niño). In spring, in El Niño years, positive
(negative) anomalies of geopotential height are observed in the SB and negative (positive) anomalies in the
subtropical jet. In La Niña years, the subtropical jet is strengthened (weakening of the subpolar jet) and there is
a negative (positive) geopotential anomaly in the SB region and in Bellingshausen Sea (Weddell). We identified
that the positive precipitation anomalies are more frequent during La Niñas, despite the highest occurrence in
El Niños.

313
Tue_105_AC-5_2432
The High Frequency Variability of Antarctic Sea Ice and Transient Systems

Camila Carpenedo1 (camila.carpenedo@ufu.br), Nathalie Boiaski2, Tércio Ambrizzi3

1
UFU, Geography, Uberlândia, Brazil, 2UFSM, Physics, Santa Maria, Brazil, 3USP, Atmospheric Science, São
Paulo, Brazil

There is a great potential for Antarctic sea ice to affect atmospheric circulation, because its extent located in a
very sensitive region, to the south of the Southern Hemisphere baroclinic zone of the. Thus, the objective of
this study is to evaluate the propagation of transient systems over South America (SA) associated with the high
frequency of Antarctic sea ice variability. We employed the NSIDC Antarctic sea ice dataset for the
Bellingshausen-Amundsen Seas (BAS) and Weddell Sea (WS) sectors and the ECMWF ERA-Interim global
atmospheric reanalysis. The anomalies without linear tendency were filtered for the 2-10 day period,
generating a daily high frequency anomaly dataset. The quartile analysis defined the extreme high frequency
sea ice anomalies. In the austral winter (JJA), extreme sea ice retraction (expansion) events for the BAS sector
were associated with the extratropical (tropical-extratropical) high frequency wave train. Consequently, there
are air temperature anomalies at 2 meters over the SA extratropical (tropical-extratropical) latitudes, with the
warming/cooling associated with low / high anomalous surface air pressure. On the other hand, the high
frequency wave train associated with extreme sea ice retraction (expansion) events in the WS sector does not
affect SA, but suggest heating/cooling event modulation over Australia.

314
Tue_106_BE-1_93
Influence of Glacial Melt Water on Bacterioplankton Community of Kongsfjorden

Rupesh Kumar Sinha1 (kineto.magnetic@gmail.com), K.P. Krishnan1

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Cryobiology, Vasco-da-Gama, India

The Kongsfjorden, an Arctic fjord is experiencing warming due to increased input of Atlantic water masses.
High-throughput sequencing was performed to examine bacterial diversity from the outer and inner zone of
the fjord in summer and fall. A total of 11,999 operational taxonomic units (OTUs) were assigned into 19 known
phyla and 5 genera incertae sedis. Significant variation (p = 0.001, n = 4) was observed between the bacterial
community structure of outer and inner fjord while variation between summer and fall was minimum.
Proteobacteria was the most abundant phylum (55.9-61.0%) in summer and fall. The most dominant
alphaproteobacterial member of this phylum (OTU 263 Pelagibacteriaceae) contributed maximum to the
observed dissimilarity between the outer and inner fjord community. Characterised by relatively fresher and
warmer water, glacial meltwater input could be a major source of predominance of Flavobacteriaceae,
Psychrobacter, Sphingomonadales and Loktanella in the inner fjord in summer. Thus, the significant variation in
the bacterioplankton community composition of outer and inner fjord indicates strong and localized influence
of glacial melt water in shaping the community structure.

315
Tue_107_BE-1_122
The Diversity of Ice Algal Communities on the Greenland Ice Sheet

Stefanie Lutz1 (stlutz@gfz-potsdam.de), Jenine McCutcheon2, James B. McQuaid2, Liane G. Benning1,2,3

1
GFZ German Research Centre for Geosciences, Potsdam, Germany, 2School of Earth & Environment, University
of Leeds, Leeds, United Kingdom, 3Free University of Berlin, Department of Earth Sciences, Berlin, Germany

The Greenland Ice Sheet (GrIS) is an important component of Earth's cryosphere. Due to the extensive area
over which surface melting occurs, which can be up to 100% during extreme melt events, it can be regarded as
the largest supraglacial ecosystem on Earth. Ice algae are the dominant primary producers on bare ice surfaces
throughout the course of a melt season. Ice-algal-derived pigments cause a darkening of the ice surface, which
in turn decreases albedo and increases melt rates. Their role and importance in changing melt rates has only
recently been recognized, yet we know little about their community compositions and functions.
Here we present the first high-throughput sequencing analysis of ice algal communities along a 100 km transect
across the 'dark zone' of the GrIS combined with subsequent oligotyping of the most abundant taxa. Our data
reveal an extremely low algal diversity with Ancylonema nordenskiöldii and a Mesotaenium species being by
far the dominant taxa in all sites. We show that an OTU-based approach is not sufficient for the evaluation of
the low ice algal diversity on the GrIS. Oligotyping revealed hidden diversity that could not be detected by
conventional clustering of OTUs. Oligotypes of the dominant taxa exhibit a site-specific distribution, which may
be linked to different stages in the melt season. Our results document for the first time the unknown
distribution patterns of ice algal communities that play a crucial role in the GrIS ecosystem.

316
Tue_110_BE-1_664
Particle-associated and Free-living Bacterial Communities in Kongsfjorden

Anand Jain1 (microanand2003@gmai.com), Femi Anna Thomas1, Rupesh Kumar Sinha1, Archana Singh1,
Kottekkatu Padinchati Krishnan1
1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Cryobiology, Vasco da Gama, India

Particle-associated bacteria are likely to play an increasing role in coastal biogeochemistry and carbon fluxes as
a result of increased particle transport to coastal Arctic waters. However, few studies have characterized
particle associated (PA) and free-living (FL) bacterial communities in coastal Arctic ecosystem. In the present
study V3-16S rRNA amplicon sequencing was used for analyzing difference between free-living (FL, < 1.2 to 0.2
mm) and particle-associated (PA, >1.2 mm) bacterial community, and their spatial variation between inner
fjord (IF) and outer fjord (OF) of Kongsfjorden. A total of 4,454,142 high quality V3-16S rRNA sequences
obtained clustered into 32,058 OTUs which are distributed among 24 known bacterial phyla. There was a clear
spatial variation among FL bacterial community, while PA community remained similar at both sampling
locations. In addition, FL bacterial community differs from that of PA community and had relatively higher
abundance (>4 fold) of Alteromonas and Pseudoalteromonas, while PA community was relatively more
enriched with Balneatrix, Ulvibacter, Formosa, Candidatus Planktomarina, Sulfitobacter, Loktanella, members
of SAR116 and Acidimicrobiales. However, certain bacterial taxa Polaribacter and SAR11 co-occurred in both FL
and PA fractions with varied proportions in IF and OF. Our results suggest co-occurrence of both PA and FL
specialist as well as generalist bacterial groups in Kongsfjorden.

317
Tue_111_BE-1_695
Bacterial Diversity in Rocks over 14 Localities of Victoria Land, Antarctica

Claudia Coleine1 (coleine@unitus.it), Fabiana Canini1, Laura Selbmann1, Jason E. Stajich2, Silvano Onofri1, Laura
Zucconi1
1
University of Tuscia, Department of Ecological and Biological Sciences, Viterbo, Italy, 2University of California,
Department of Microbiology and Plant Pathology and Institute of Integrative Genome Biology, Riverside, United
States

The endolithic microbial communities represent a borderline adaptation to extreme environmental stressors
and are the predominant life form in the ice-free regions of Victoria Land, Antarctica. In the last decades, many
studies focused on prokaryotic component in soils, while our understanding and knowledge on distribution and
structure of bacteria in endolithic communities are still limited. In this study, we investigated the diversity of
bacteria in cryptoendolithic communities growing within sandstone in Victoria Land, Antarctica. Rock samples
were collected from 14 different sites, ranging from 1000 to 3300 m a.s.l of altitude and over a latitude of
about 3°. V4 region of 16S rDNA was sequenced through meta-barcoding approach on Illumina platform. Our
results showed that Actinobacteria and Alphaproteobacteria are predominant among all samples as 'core'
group component of the bacterial taxa characterizing these communities. The general belief that such extreme
environments harbor a relatively low species diversity was confirmed by the diversity indices values. In
addition, the detection of a higher number of unclassified bacterial phylotypes respect to many other
environments (about 20% of relative abundance) suggests that Antarctic rocks host a pool of novel taxa.

318
Tue_112_BE-1_949
Chronosequence of Active Bacterial Community from an Alpine Ice Cave

Victoria Ioana Paun1 (ioana.paun@ibiol.ro), Corina Itcus1, Constantin Marin2, Aurel Persoiu1, Paris Lavin3,
Alexandra Hillebrand-Voiculescu2, Antonio Mondini1, Carmen Badaluta1, Cristina Dorador3, Cristina Purcarea1
1
Institute of Biology, Romanian Academy, Microbiology, Bucharest, Romania, 2Emil Racovita Institute of
Speleology, Bucharest, Romania, 3University of Antofagasta, Antofagasta, Chile

Investigation of glacial habitats became a priority due to the impact of climate changes on the dynamics of
Polar and alpine glaciers. Our study focused on cave ice microbiome unraveled the diversity of total and active
bacterial communities from the 13,000 years old ice chronosequence of Scarisoara Ice Cave, Romania.
Vertical ice coring of the perennial ice block was carried out, reaching a record depth of 25.3 m. Radiocarbon
dating of the ice core indicated a linear chronosequence up to 13,000 years B.P.
16 melted ice samples from every 1,000 years interval were filtered and used for total DNA and RNA extraction
and geochemical analyses. Chemical parameters revealed large variations for the last 5 centuries followed by a
stable period, and significant changes in the 5000 years B.P. ice layer. Bacterial diversity based on 16S rRNA
gene MiSeq Illumina sequencing of both gDNA and cDNA is currently underway. Correlation with the chemistry
of the ice substrate will unravel the microbial resilience, highlighting the active community composition in this
habitat for the last 13,000 years. Total and viable microbial content of each sample was quantified by qPCR and
LIVE/DEAD staining, indicating a correlation with age and organic content of the ice.
This report of the oldest cave ice chronosequence could contribute to identifying biomarkers of climate and
environmental changes.
Acknowledgments: This work was supported by the UEFISCDI H2020 ERANET-LAC ELAC2014/DCC0178 joint
project.

319
Tue_113_BE-1_1038
Paprica: A Pipeline for Estimating Microbial Metabolisms in Antarctic and Beyond

Jeff Bowman1 (jsbowman@ucsd.edu), Natalia Erazo1

1
Scripps Institution of Oceanography, UC San Diego, La Jolla, United States

Microbial communities are often described by the diversity of 16S and 18S rRNA gene amplicons. The cost of
amplicon sequencing has dropped considerably in recent years, making analyses of hundreds or thousands of
samples a reality for even single investigator projects. Although this approach continues to provide enormous
insight into microbial ecology, it can be difficult to interpret the metabolic processes underlying diversity
without a priori knowledge of the observed taxa. To more easily connect 16S and 18S rRNA gene data with
likely microbial metabolisms we developed paprica, an open source pipeline for metabolic inference. Rather
than cluster reads into operational taxonomic units (OTUs), paprica assigns reads to their best location on a
phylogenetic reference tree constructed from all completed genomes in Genbank. This allows for an easy
analysis of samples through phylogenetic structure, and by associating environmental reads to the metabolism
found at that location on the tree, metabolic structure. Paprica was initially developed for the analysis of
marine samples from the western Antarctic Peninsula, but we have applied it to Antarctic marine and lake
samples. Here we will provide an update on the paprica methodology, and highlight both the strengths and
limitations of our approach.

320
Tue_114_BE-1_1366
Prokaryotic Communities in Sediments along the Pasvik River (Arctic Norway)

Maria Papale1 (mpapale@unime.it), Marco Graziano1, Antonella Conte1, Gabriella Caruso2, Alessandro Ciro
Rappazzo2, Angelina Lo Giudice2, Giovanna Maimone2, Anu Mikkonen3, Carmen Rizzo1, Serena Savoca1, Emilio
De Domenico1, Rosabruna La Ferla2, Maurizio Azaro2
1
University of Messina, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences,
Messina, Italy, 2IAMC-CNR Messina, Messina, Italy, 3University of Jyvaskyla, Jyvaskyla, Finland

The Pasvik river is one of the largest river in the Northern Fennoscandia. Its water conditions are representative
of Eastern European rivers. The river collects snowmelt, and it is typically a freshwater environment at its inner
zone and brackish at its outer zone. Sediment samples were collected from 9 stations during two seasonal
surveys (May and July 2014). Physical-chemical parameters were monitored at sampling time. Samples were
analyzed for viable heterotrophic bacteria, total prokaryotic abundance, microbial enzymatic activity rates, and
phylogenetic composition of bacterial community. Microbial enzymatic activities generally increased in July,
but showed spatial and temporal variability. In May, leucin aminopeptidase showed the highest values at outer
stations (9.37 mmol/g/h). The bacterial community resulted highly variable among the sampling stations with
the predominance of the Proteobacteria, followed by the Actinobacteria and CF group of Bacteroidetes. In July,
an increased abundance of the Acidobacteria was observed at St.1 (from 4.7 to 22.1%). This study highlights
both seasonal (May and July) and spatial differences within the microbial community that inhabit sediments
along the Pasvik river. This finding is probably strictly dependent on freeze-thaw cycles of the water body, with
consequent organic inputs to sediments in July. The microbial community appears to be adapted to fluctuating
conditions modulated by seasonality.

321
Tue_115_BE-1_1368
Are they Really Poles Apart? Aerial Connection between High Latitude Ecosystems

David Velazquez1 (david.velazquez@uam.es), Pablo Almela1, Sergi Gonzalez2, Francisco Vasallo3, Eugenio Rico4,
Ana Justel5, Antonio Quesada1
1
Universidad Autonoma de Madrid, Biology, Madrid, Spain, 2Agencia Española de Meteorologia, Barcelona,
Spain, 3Agencia Española de Meteorologia, Rota, Spain, 4Universidad Autonoma de Madrid, Ecology, Madrid,
Spain, 5Universidad Autonoma de Madrid, Mathematics, Madrid, Spain

Extreme cold is a defining feature of High Arctic, Antarctic and Alpine sites which are separated by large
distances and climatic barriers. Microbial environments are major features across those cryoenvironments.
However, little is known about the biogeography and communalities of cold-dwelling microbes along the
Cryosphere.
Recently attention has been focused on the rapid changes observed in polar regions. Summer warming in the
Arctic has been observed to accelerate, peaking in the snow-free season and soil evapotranspiration. This
alteration would potentially strength airborne microbial transportation at a planetary scale. In this context,
Antarctica would become an ideal site for examining global scale microbial dispersal given that it is isolated
from neighbour lands over 20 million years and it hosts habitats that are selective for the settlement and
thriving of certain communities.
Generation times of bacteria in cloud-water mirror those in Arctic freshwater ecosystems and point out to
atmosphere as a tributary site that may potentially act as bridge among the whole Cryosphere. Here, we test
geographical isolation as an effective barrier to microbial transport by computing long distance trajectories
from both Polar Regions and across different atmospheric layers. We study the 16S rRNA gene of different
freshwater communities to evaluate the global affinities of low-temperature ecotypes throughout the
Cryosphere.

322
Tue_116_BE-1_1633
Phylogenetic Relationships and Evolution of the Antarctic Bangiales (Rhodophyta)

Sun-Mi Kim1, Tae-Kun Seo1, Ji Hee Kim1, Hosung Chung1, Han-Gu Choi1 (hchoi82@kopri.re.kr)
1
Korea Polar Research Institute (KOPRI), Division of Polar Life Sciences, Incheon, Korea, Republic of

Members of the Bangiales (Rhodophyta) are distributed worldwide from tropic to Antarctic and Arctic waters.
Three species of the Bangiales; Bangia sp. (as B. atropurpurea), Pyropia endiviifolia (as Porphyra endiviifolium)
and Wildemania plocamiestris (as Porphyra plocamiestris), have been reported in the Antarctic. Morphological
and molecular data were investigated for the Bangiales from the Antarctic and its adjacent waters. Molecular
data from over 150 taxa of the Bangiales worldwide including previously published sequences, indicated that
the genera Bangia, Dione, Porphyra, Pyropia, Wildemania and other related genera be recognized in the
Bangiales as in the previous molecular study. The Bangia sp. from the Antarctic was strongly allied to B. sp.
from Atlantic Canada, interestingly. Pyropia endiviifolia is olive green in color and it allied to a clade with at
least three Pyropia species from Falkland Islands, Navarino Island, Rio Seco and Punta Arenas, Chile.
Wildemania plocamiestris growing on other macroalgae in sub-tidal zone grouped into the genus Wildemania
with the species having one or two cell layers in molecular data. The diversity, taxonomic issues, phylogenetic
relationships, distribution and the divergence times of the Antarctic members of the Bangiales will be
discussed.

323
Tue_117_BE-1_1948
Biogeography of Arctic Microbial Communities across the Svalbard Shelf

Catarina Magalhaes1 (cmagalhaes@ciimar.up.pt), António Sousa2, Maria Paola Tomasino2, João Santos1, Pedro
Duarte3, Luís Torgo4, Philipp Assmy3
1
CIIMAR- Interdisciplinary Centre of Marine and Environmental Research, 
University of Porto, Matosinhos,
Portugal, 2CIIMAR- Interdisciplinary Centre of Marine and Environmental Research, 
University of Porto, Porto,
Portugal, 3Norwegian Polar Institute, Fram Centre, Tromso, Norway, 4LIAAD - Laboratory of Artificial
Intelligence and Decision Support, INESC 
Technology and Science, Porto, Portugal, Porto, Portugal

Global warming and climate change have been manifested in the decrease of Arctic sea ice extent and
thickness. The thinner sea-ice regime has significant implications for Arctic primary productivity and
biogeochemistry. It is therefore necessary to improve our understanding of microbial dynamics that ultimately
drive productivity and the strength of the biological carbon pump in order to better predict future trends in
Arctic biogeochemistry. In this study we present a comprehensive analysis of the biogeographic patterns of
Arctic prokaryote and eukaryotic protist diversity and distribution along two oceanographic transects in late
July 2016 crossing fjord, shelf and oceanic domains along the western (Kongsfjorden) and northern
(Rijpfjorden) coast of Svalbard. A total of 11 stations were sampled at three depths (surface, chlorophyll
maximum and above the seafloor) and amplification of 16S rRNA and 18S rRNA genes was performed and
sequenced in Illumina MiSeq with a sequence depth of about 100 thousand read-pairs. The prokaryotic and
eukaryotic protist data set comprises highly complex and diverse microbial communities with a marked
biogeographic pattern. Strong links were identified between bacterioplankton and
phytoplankton/picophytoplankton distribution driven by environmental and biogeochemical factors that will
help to unravel the role of microbial pathways in supporting Arctic Ocean primary productivity and system
integrity.

324
Tue_118_BE-1_1999
Highest Cyanobacteria Diversity on Granite Substrates in Sør Rondane Mountains

Valentina Savaglia1 (valentina.savaglia@uliege.be), Zorigto Namsarev1,2, Marie-José Mano1, Annick Wilmotte1

1
University of Liège, InBioS-Centre for Protein Engineering, Liège, Belgium, 2NRC “Kurchatov Institute”, Moscow,
Russian Federation

In the Sør Rondane Mountains (Dronning Maud Land, East Antarctica), cyanobacteria are mainly present in
sheltered spots in rocky areas, supporting the importance of micro-topographic and -climatic conditions.
Biofilms, crusts and gravels on granite and gneiss substrates were sampled in 2009-2010 near the Belgian
Princess Elisabeth Station and their morphological (126 samples) and molecular diversity (26 samples) was
assessed. Furthermore, strains were isolated. A DNA extraction protocol was designed for the taxa with large
polysaccharidic sheaths. Based on microscopy, crusts were the richest samples followed by gravels. The most
diverse communities were found on the granites. Based on DGGE of 16S rRNA gene, 28 OTUs shared at least
97.5% of 16S rRNA similarity. OTUs' richness varied between 1 and 5 per sample. A comparison of
morphological and DGGE analyses showed that for most samples, the number of morphotypes was higher than
the number of OTUs. However, both methods were congruent in defining the richest sites. The most frequently
observed OTU was affiliated to Phormidium/Microcoleus sp. No OTU was common to all the 10 sites. The
higher diversity on granite substrates (mainly big boulders) could be explained by higher stability of the
underlaying rock and its ability to keep water on the surface, thus creating favorable conditions for
development of organisms. Further insights will be given by the analysis of more samples with High-
Throughput amplicon sequencing.

325
Tue_120_BE-1_2362
Seasonal Ecology and Biogeochemistry of Snow during Summer in Svalbard

Archana Dayal1,2 (adayal1@sheffield.ac.uk), Andrew J. Hodson1,2, Arwyn Edwards3

1
University of Sheffield, Geography, Sheffield, United Kingdom, 2University Centre in Svalbard (UNIS), Arctic
Geology, Longyearbyen, Svalbard and Jan Mayen, 3Aberystwyth University, Institute of Biological, Rural and
Environmental Sciences, Aberystwyth, United Kingdom

Snow covers >90% of glacial surfaces at the start of the summer and is a biologically active and dynamic habitat
for microorganisms (Hodson et al., 2008) rather than merely a repository of deposited material. With a
warming cryosphere, snow packs are getting wetter and less persistent globally but we are yet to understand
the distribution of microbes and nutrients within different layers of a snowpack and how this supports the
concept of the snowpack as an ecosystem. We therefore hypothesized that with the thermal evolution of a
snow pack, greater heterogeneity will be expected in terms of microbial cell numbers, viability, species richness
and nutrients within different layers. To test our hypothesis, we sampled seven different sites over four months
from spring to summer on the Svalbard ice cap, Foxfonna. Snowpack communities were studied for microbial
abundance, pigment inventories and nutrient chemistry. Our results demonstrate snow ecology is driven not
only by meltwater evolution but by geochemical and physical changes within the snowpack as the melt season
progresses. We also present microbial community analyses showing how the structure of microbial populations
within snow and ice change during the transition from spring to summer. Our results highlight the importance
of integrating snowpack physical and geochemical conditions to appreciate the dynamic response of resident
microbes to seasonal melting in the High Arctic.

326
Tue_121_BE-3_573
Compare and Contrast the Arctic and Antarctic Atmospheric CH4-oxidizing Bacteria

Maggie Lau1 (maglau@princeton.edu), Collin R. Edwards1, Calvin Rusley1, Tullis C. Onstott1

1
Princeton University, Department of Geosciences, Princeton, United States

Annually thawed near-surface cryosols that occur in the Arctic and Antarctic exhibit atmospheric CH4 (atmCH4)
consumption. AtmCH4 is believed to be utilized by aerobic CH4-oxidizing bacteria (MOB) that have high affinity
for atmCH4 (atmMOB). By deep sequencing of soil metagenomes and binning, we constructed 90%-complete
genomes of Upland Soil Cluster (USC) alpha from Axel Heiberg Island, Nunavut, Canadian high Arctic, and
USCgamma from Taylor Dry Valley, Victoria Land, Antarctica. This study aims to compare and contrast the
genomes and metabolic potential of these two genotypes that occur in the acidic Arctic and alkaline Antarctic
cryosols. USCalpha and USCgamma both possess the high-affinity form of methane monooxygenase, and
enzymes for complete CH4 oxidation. The atmMOB genomes do not code for soluble methane monooxygenase.
No genes for nitrogen fixation were detected but nitrate reductase. The ribulose monophosphate (RUMP)
pathway for assimilation of formaldehyde typically found in gamma-proteobacterial methanotrophs is not
detected in the USCgamma genome. Notably, both atmMOB genomes indicate the potential to use acetate,
and store and consume glycogen, suggesting that they may be facultative methanotrophs. This genetic
information provides insight into their adaption to the changing climate and their respective roles in the carbon
cycle of the polar terrestrial ecosystems.

327
Tue_122_BE-3_616
Distribution of Picoeukaryotes in Summer and Autumn of the Southern Chukchi Sea

Fang Zhang1 (zhangfang@pric.org.cn), Jianfeng He1, Shunan Cao1

1
Polar Research Institute of China, Shanghai, China

Picoeukaryotes dominate the photosynthetic biomass and will thrive with increasing temperature in the polar
marine ecosystems. The study of picoeukaryotes in the Chukchi Sea are rare. This work relates the community
distribution and composition of the picoeukaryotes to different water masses and physicochemical parameters
in the southern Chukchi Sea in both the middle summer (July) and early autumn (September) of 2012.
Chrysophyceae, Mamiellophyceae and Dinophyceae were the main microbial classes in July, with relative
abundance > 0.5%. Mamiellophyceae, Chrysophyceae, Trebouxiophyceae, Mediophyceae and Dinophyceae
were the main microbial classes in September. Nannochloris and Bathycoccus were indicators to the Alaskan
Coastal Water. Cryptococcus, Prasinoderma and Bolidomonas were indicators to the Bering Sea Water. The
prevalence of Poterioochromonas malhamensis, a nano-Chrysophyceae and a bloom disordered the
distribution of the picoeukaryotes in July. The abundance, biodiversity and structure of the picoeukaryotes
community low related to the physicochemical parameters. Micromonas predominated in September, when all
the community parameters of the picoeukaryotes high correlated to the physicochemical parameters. An
upwelling were detected (67.7ºN, 168.9 ºW) and greatly influenced the distribution of picoeukaryotes and
supplied nutrients to the regrowth or the P. malhamensis and diatoms.

328
Tue_123_BE-3_620
Bacterial Community Structure across East Antarctica Glacial Foreland

Hongmei Ma1 (mahongmei@pric.org.cn), Wenkai Yan2, Yu Zhang2

1
Polar Research Institute of China, Shanghai, China, 2Shanghai Jiao Tong University, Shanghai, China

Glacial forefields are extremely sensitive to temperature changes and considered ideal places to explore how
microbial communities will response to climate-driven environmental changes. Our knowledge of how the
bacterial community activities and structure was influenced by changing environment due to glacier retreat is
still very limited. Here A series of soil samples with ice and without ice coverage along the glacial retreat path
were sampled in the forehead of Larsemann Hill of East Antarctica ice sheet. By employing the Miseq
sequencing methods, and combining geochemical data analysis, the bacterial diversity including the abundant
and rare group were studied and compared among samples. Our results show that abundant bacterial
communities were more sensitive to changing conditions in the early stages of deglaciat ion than rare
community members. Moreover, among the environmental parameters tested, which included total organic
carbon, pH, and moisture of the soils, ice thickness was the most influential factor affecting the community
structure of abundant bacteria. These results show the different effects of abundant and rare bacteria on
community shifts and highlight ice thickness as the primary factor affecting the bacterial community in the
early stages of deglaciation. The response of microbial community to climate change can be predicted with
more certainty in this polar region.

329
Tue_124_BE-3_956
Cold Adaptation Strategy of the Antarctic Cyanobacterium P. priestleyi ULC007

Benoit Durieu1 (benoit.durieu@uliege.be), Denis Baurain2, Annick Wilmotte1, Yannick Lara1,3,4

1
University of Liège, InBioS-Centre for Protein Engineering, Department of Life Sciences, Liège, Belgium,
2
University of Liège, Eukaryotic Phylogenomics, Department of Life Sciences, Liège, Belgium, 3University of Liège,
UR-Geology-Palaeo-Biogeology-Botany-Palynology, Liège, Belgium, 4Gembloux AgroBioTech-University of Liège,
Microbial Processes and Interactions, Liège, Belgium

In Antarctica, Cyanobacteria are key primary producers and play a major role in the colonization of deglaciated
habitats. Cyanobacterial mats are widespread in aquatic biotopes and often dominate the total phototrophic
biomass. In order to gain further insights on the mechanisms underlying the ecological success of Antarctic
cyanobacteria, we studied the gene repertoire of Phormidesmis priestleyi ULC007, a filamentous
cyanobacterium isolated from shallow freshwater lake microbial mats in the Larsemann Hills. Here, we
investigate the occurrence of genes involved in the cold stress response as a proxy to the adaptation to
environmental conditions in Antarctica. We compare a selection of 42 PEGs (protein encoding genes) linked to
cold adaptation in 72 cyanobacterial genomes. Polar strains have the highest number of copies of genes coding
for fructose aldolase, chaperone Hsp, and universal stress protein and a high number of fatty acid desaturase
and genes involved in exopolysaccharide (EPS) biosynthesis. To provide a better overview of the genetic
mechanisms of adaptation to cold, we investigated the gene functional categories based on the RAST
subsystems technology. Polar strains have the most occurrences for subsystems “Choline and Betain
Biosynthesis”, “DNA repair”, “EPS biosynthesis” and “Heat shock DnaK gene cluster”. Our results underline the
importance of these functions in the adaptation mechanisms of cyanobacteria to the polar environment.

330
Tue_125_BE-3_1019
Dispersant Impacts on Arctic Microbial Community Dynamics and Oil Biodegradation

Saskia Rughöft1 (saskia.rughoeft@uni-tuebingen.de), Christian Hallmann2,3, Andreas Kappler1, Sara Kleindienst1

1
Eberhard-Karls-University Tübingen, Centre for Applied Geoscience (ZAG), Tübingen, Germany, 2Max-Planck-
Institute for Biogeochemistry, Jena, Germany, 3University of Bremen, MARUM, Bremen, Germany

As a response strategy to oil spills in the marine environment, chemical dispersants are frequently applied to
reduce oil slicks and oil delivery to shorelines. However, the impact of chemical dispersants on native microbial
communities and, more specifically, oil degrading bacteria remains unclear. Particularly pristine, more extreme
environments like the Arctic Ocean are largely unexplored in this regard, even though pollution risks are
increasing with rising interests in Arctic oil exploration and transportation routes. Here, we assessed the impact
of the chemical dispersant Corexit 9500A on Arctic microbial seawater communities and their oil
biodegradation potential. For this, oil spill conditions were simulated in laboratory microcosms at 1.5 °C and 15
°C with Arctic seawater from 150 m depth, amended with oil only (± nutrients), oil-dispersant mixtures, or only
dispersant. Dissolved organic carbon (DOC) concentrations, bacterial productivity data, and cell counts
suggested active oil and dispersant degraders. Marine oil snow formation and DOC degradation was enhanced
in oil microcosms compared to oil-dispersant setups. Additionally, 14C-naphthalene oxidation rates suggested
that the native microbial community might not be equipped for rapid biodegradation of aromatic
hydrocarbons. Analyses of microbial community composition and hydrocarbon quantifications will help to
further elucidate the impacts of oil and dispersants in Arctic pelagic ecosystems.

331
Tue_126_BE-3_1092
Nitrifiers Still Alive in Antarctic Soils under Moss Vegetation

Kentaro Hayashi1 (kentaroh@affrc.go.jp), Yukiko Tanabe2,3, Nobuhide Fujitake4, Morimaru Kida4, Masahito
Hayatsu1, Sakae Kudoh2,3
1
Institute for Agro-Environmental Sciences, NARO, Division of Biogeochemical Cycles, Tsukuba, Japan, 2National
Institute of Polar Research, Tachikawa, Japan, 3SOKENDAI (The Graduate University of Advanced Studies),
Tachikawa, Japan, 4Kobe University, Kobe, Japan

Nitrogen (N) as a macronutrient is cycled also in Antarctic terrestrial ecosystems, in which microbes are a main
driver. In the N cycle, nitrification is the only source of nitrate other than atmospheric deposition of perhaps
very small contribution in Antarctica. Nitrification is a two-step process, ammonia oxidation and subsequent
nitrite oxidation. We measured ammonia oxidation potentials (AOP) of soils collected at two sites (69°14.5′S,
39°44.7′E, 52 m ASL and 69°14.4′S, 39°45.1′E, 114 m ASL) in Yukidori-zawa, Langhovde, East Dronning Maud
Land, and at one site (66°46.3′S, 50°35.3′E, 121 m ASL) near Mt. Riiser-Larsen, West Enderby Land, East
Antarctica. Soils were collected for each layer, i.e., moss layer, mineral surface soil with accumulated organic
matter (A layer), and subsoil (B layer(s)). Fresh soils were used to determine their AOP values at around 10 °C
by means of aerobic static incubation adding a substrate solution. Responses of AOP to a combination of
incubation temperatures (10 and 20 °C) and substrate concentrations (8 steps from 0.1 to 4 mM ammonium)
were also measured for the soil with the highest AOP (A layer of the site 2 in Yukidori-zawa). In all the sites, the
A layers had relatively high AOP values. A unique response to the substrate concentrations was also found, it
will be shown at the conference in combination with the relationships of AOP to key soil properties and
characteristics of nitrifiers, i.e., ammonia oxidizing bacteria and archaea.

332
Tue_127_BE-3_1101
Horizontal Gene Transfer of dmdA Gene among Distantly Related Marine Bacteria

Yin-Xin Zeng1 (yxzeng@yahoo.com)

1
Polar Research Institute of China, Shanghai, China

Dimethylsulfoniopropionate (DMSP) is mainly produced by marine phytoplankton serving as an osmolyte,

antioxidant, predator deterrent, and cryoprotectant. It is also a carbon and sulfur source for marine bacteria.
Bacteria may metabolize DMSP via the demethylation pathway involving DMSP demethylase (dmdA) gene and
the cleavage pathway involving several different DMSP lyase genes. Most of DMSP released into seawater is
degraded by bacteria via demethylation. A total of thirty bacterial strains were isolated from Arctic
Kongsfjorden seawater using low-nutrient medium containing 1mM DMSP. Analysis of 16S rRNA gene
sequences showed that, except for strains BSw22131 and BSw22132 respectively belonging to the genera
Pseudomonas and Glaciecola, all bacteria fell into the genus Pseudoalteromonas. dmdA genes were detected in
three Arctic strains Pseudoalteromonas sp. BSw22112, Pseudomonas sp. BSw22131 and Glaciecola sp.
BSw22132 within the Gammaproteobacteria, as well as one Antarctic marine alphaproteobacterial
Roseicitreum antarcticum ZS2-28. Their dmdA genes showed significant similarities (97.7-98.3%) to that of
Ruegeria pomeroyi DSS-3, a well-known roseobacterium possessing both pathways for metabolism of DMSP.
Among the four tested strains, only Pseudomonas sp. BSw22131 was able to grow in M9 medium
supplemented with DMSP as sole carbon source. Results in this study support a hypothesis of lateral gene
transfer for dmdA among taxonomically heterogenous bacterioplankton.

333
Tue_128_BE-3_1138
Mycobryosphere: Fungi Associated with Bipolar Mosses Present in Antarctica

Camila Rodrigues1, Mariana Ferreira1, Vívian Gonçalves1, Micheline Carvalho-Silva2, Paulo Câmara3, Carlos
Rosa1, Luiz Rosa1 (lhrosa@icb.ufmg.br)
1
Federal University of Minas Gerais, Microbiology, Belo Horizonte, Brazil, 2Federal University of the Vales of
Jequitinhonha and Mucuri, Unaí, Brazil, 3University of Brasília, Botany, Brasília, Brazil

Mosses are a major component of the vegetation in ice-free regions of Antarctica. The aim of the study was to
examine the diversity of epiphytic and endophytic fungi, as well as those present in the rhizoids of
Polytrichastrum alpinum and Polytrichum juniperinum collected in Antarctica. Five gametophytes were
collected at King George Island, which were subjected to surface sterilization and inoculated onto Sabouraud
agar (SBA) for isolation of fungi. After the different isolation process, 217 fungi isolates were recovered and 19
taxa were identified by molecular biology methods. Thelebolus sp., Pseudogymnoascus sp., and Tumularia sp.
were the most abundant taxa recovered. Pseudogymnoascus sp., Glarea sp., Chalara pseudoaffinis,
Gyoerffyella entomobryoides, Helotiales sp., Leotiomycetidae sp., Microdochium phragmitis, Phaeosphaeria sp.,
and Pochonia sp. were isolated only from P. alpinum. Cladosporium sp., Exophiala sp., Fusicladium sp.,
Leptosphaeria sp. and Oleoguttula sp. were isolated only from P. juniperinum. Our results suggest that bipolar
mosses shelter rich and diverse fungal communities, including taxa phylogenetically near to symbionts,
decomposer, and phytopathogenic fungi.

334
Tue_129_BE-3_1107
Surface Water Masses Constrain Microbial Communities across the Southern Ocean

Swan Li San Sow1,2 (swanlisan.sow@csiro.au), Levente Bodrossy1, Thomas W. Trull1,3, Phillip W. Boyd2,3, Bruce E.
Deagle4, Laurence J. Clarke3,4, Jodie van de Kamp1, Eric J. Raes5, Mark V. Brown6, Andrew Bissett1
1
Commonwealth Scientific and Industrial Research Organisation (CSIRO), Oceans and Atmosphere Flagship,
Hobart, Australia, 2University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia,
3
Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Australia,
4
Australian Antarctic Division, Kingston, Australia, 5Alfred Wegener Institute Helmholtz Center for Polar and
Marine Research, Bremerhaven, Germany, 6University of New South Wales, School of Biotechnology and
Biomedical Sciences, Sydney, Australia

The Southern Ocean (SO) is a major site for sequestration of anthropogenic carbon dioxide (CO2). The
epipelagic regions are where key processes of photosynthetic CO2 fixation are performed by both pro- and
micro-eukaryotes. The effects of climate change on physical oceanography of the SO may have a globally
significant impact on the efficiency of the biogeochemical cycling, but the extent of this is unclear, because the
basic biogeography of these organisms are still quite limited to select locations of the SO. We sampled
epipelagic seawater at multiple transects along the Indian, Australian and Pacific regions of the SO (71°E-
170°W) and mapped both pro- and eukaryotic community composition using high resolution 16S and 18S rRNA
tag sequencing. This is aligned with corresponding physical/biogeochemical observations to investigate
potential triggers of observed community shifts. Across all transects, samples are dominated by the
Pelagibacteraceae (SAR11) family with shifts in different Pelagibacteraceae oligotypes observed from low to
high latitude samples. Spatial/longitudinal distance were not observed to drive community differences
between samples at similar latitudes or surface water zones. Statistical analysis show temperature to be the
major driving force for community selection. These findings contribute to filling critical knowledge gaps on how
changes in SO physical oceanography under forcasted global change scenarios might alter CO2 uptake and the
biological pump.

335
Tue_130_BE-3_1130
Polar Ecology - A Guide for Planetary Research

Jean-Pierre de Vera1 (jean-pierre.devera@dlr.de), Mickael Baqué1, Andreas Lorek1

1
German Aerospace Center (DLR), Institute of Planetary Research, Berlin, Germany
We highlight the findings of several years of research in Astrobiology and Planetary Sciences using concepts
and methods of polar eco-physiological research, combining field research with planetary simulations in the lab
and in space. The studies were carried out to gain insights into the interactions between extremophilic
microorganisms (archaea, bacteria and eukarya) and changing environment which are achieving conditions as
they were observed on another terrestrial planet such as Mars. Furthermore, the experiments which will be
presented were performed to check the responses of the organisms to new simulated planetary and space
conditions. They are the basis for classifying a planet from an experimentally point of view as to be habitable or
not to be able to support any kind of life forms. The second eco-physiologically relevant investigation
enterprise in the presented work focuses on key-molecules which play a specific active or protective role in
physiological processes such as e.g. chlorophyll, carotene and methane besides others. These molecules are
characterized by Raman spectroscopy and wavelength modulation spectroscopy and checked if they can be
detected as specific bio-traces or biosignatures in a polar and Mars-like environment, what might support
future exploration missions to other planets with the final goal to search for life.

336
Tue_131_BE-3_1141
Diversity and Antifreeze Activity of Fungi in Snow of Antarctic Peninsula

Graciéle de Menezes1, Bárbara Porto1, Jefferson Simões2, Carlos Rosa1, Luiz Rosa1 (lhrosa@icb.ufmg.br)
1
Federal University of Minas Gerais, Microbiology, Belo Horizonte, Brazil, 2Federal University of Rio Grande do
Sul, Polar and Climate Center, Porto Alegre, Brazil

The present study focused the characterization of the fungal community present in the seasonal snow of
Antarctic Peninsula. Approximately 10 kg of snow from the uppermost 1.5 m layer was collected in the
Deception, King George, Snow and Robert islands as well as in two sites of Peninsular region (Hope Bay and
Arctowiski Peninsula) and melted at 20 °C over a period of about 12 h. This process resulted in 10 L of water
and a total of 1.5 L of melted snow was filtered through of 0.45 µm membrane with 47 mm diameter in
duplicate. The membranes were placed on the media Sabouraud agar, minimum medium and incubated at 10
°C for 60 d. Two hundred thirty-four fungi isolates were obtained and identified by molecular biology methods
in taxa belonging to 24 genera of the Ascomycota, Zygomycota and Basidiomycota phyla. The genus
Penicillium, Phenoliferia and Leucosporodium were the most abundant. A new, blue and endemic species,
Antarctomyces pellizariae, was described. Fungal diversity of snow was high represented by cosmopolitan cold-
adapted and endemic species. In addition, all fungi were submitted to deep freeze conditions and 82 isolates
were able to survive at -74 °C after 30 days. The detection of the antifreeze capabilities of these fungi suggests
that they have adaptive strategies to survive in the snow and can represent sources of compounds to
biotechnological applications.

337
Tue_132_BE-3_1145
Mycosphere of Antarctic Plants Deschampsia antarctica and Colobanthus quitensis

Lívia Costa1, Camila Rodrigues1, Carlos Rosa1, Luiz Rosa1 (lhrosa@icb.ufmg.br)

1
Federal University of Minas Gerais, Microbiology, Belo Horizonte, Brazil

The aims of our study were to characterize the endophytic and epiphytic fungi, as well as those present in the
rhizome of the two Antarctic angiosperms Colobanthus quitensis and Deschampsia antarctica. Plants were
collected in the King George, Penguin, Elephant, Halfmoon Islands, as well as the Continental Peninsula. After
the different isolation processes, 309 fungal isolates were recovery from D. antarctica and 89 from C. quitensis
as endophytic and epiphytic of their leaves and roots. All fungi obtained were identified by molecular biology
methods in 23 taxa from the 12 different orders. Penicillium was the most abundant genera associated with D.
antarctica and Vishniacozyma with C. quitensis. Antarctomyces, Pseudogymnoascus, Vishniacozyma,
Microdochium, and Penicillium occurred in both plants. Our results indicate that the Antarctic angiosperms
shelter rich fungal communities in/on their tissues and represent a hotspot microhabitat of fungal diversity in
different regions of Antarctic Peninsula.

338
Tue_133_BE-3_1197
Winter Survival of Freshwater Diatoms in the High Arctic

Eva Hejduková1 (hejdukova.eve@gmail.com), Linda Nedbalová1,2, Josef Elster2,3

1
Charles University, Faculty of Science, Prague, Czech Republic, 2Academy of Sciences of the Czech Republic,
Institute of Botany, Třeboň, Czech Republic, 3University of South Bohemia in České Budějovice, Faculty of
Science, Centre for Polar Ecology, České Budějovice, Czech Republic

Natural conditions in Polar Regions are characterized by many extremes and could seem unfavourable for life.
Despite this fact, diatoms (Bacillariophyceae) apparently adapted well and belong to very important primary
producers in a wide range of habitats in both Arctic and Antarctic environments. However, it remains unknown,
which strategy enables them to survive long polar winters. For microorganisms, dormancy is a strategy to
overcome unfriendly conditions, but morphologically distinct resting stages are rarely observed in diatoms. The
aim of this project is the study of annual cycle of polar freshwater diatoms to reveal their overwintering
strategy. We hypothesize that only a small amount of cells survive winter season and that diatoms do not form
any morphologically different stages for survival. Morphology and viability of diatom cells is studied in natural
samples collected during one year. For the multiple sampling four study sites (streams, shallow wetland, and
seepage with high abundance of diatoms) were established during summer season 2017 in the Arctic (Central
Spitsbergen, close to Longyearbyen). The viability of cells is evaluated five times following key events for
survival (summer vegetative season, autumn freezing, winter, spring melting, summer season) using a
multiparameter fluorescent staining (SYTOX Green, CTC and DAPI combination) combined with light
microscopy.

339
Tue_134_BE-3_1284
Phenotypic Traits of Prokaryotic Cells Variability in the Southern Ocean

Rosabruna La Ferla1 (rosabruna.laferla@iamc.cnr.it), Giovanna Maimone1, Monique Mancuso1, Giuseppe

Arena2, Filippo Azzaro1, Maurizio Azzaro1
1
National Research Council, Institute for Coastal Marine Environment, Messina, Italy, 2University of Messina,
Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, Messina, Italy

The Terra Nova Bay (Ross Sea, Antarctica) is a microbiological laboratory owing to its high environmental
variability that affects plankton dynamics. Previous studies on plankton communities mainly focused on
phytoplankton biomass and production processes. Studies of the succession the heterotrophic populations
have relatively been neglected also if a sudden variability of the micro- nano- and picoplankton size fractions
biomass with the ice melting has been highlighed. In this context the prokaryotic cell morphometry and
morphology assume a key role to quantify the carbon budget.
In the frame of CEFA “Coastal Ecosystem Functioning in a changing Antarctic ocean” project (31st PNRA
expedition), in a fixed station of Terra Nova Bay (Michaud Pier - MP, repeatedly sampled) and along the
roundtrips from New Zealand to the bay (NZ-TNB) seawater samples were collected.
The prokaryotic cell abundances, phenotypic variability (cell morphometry and morphology) and biomass were
determined by image analysis. Moreover, the nutrient concentrations (NO3+NO2, NH4 and PO4) were detected.
The aim of the study is to assess the relationships among the phenotypic variability and the nutrient pools.
ANOVA showed a significant variability of cell morphometry among MP and NZ-TNB (P< 0,05). Different
significative correlations between the prokaryotic abundance, cell volumes, biomass and cell morphotypes vs.
nutrient concentrations were computed in MP and NZ-TNB.

340
Tue_136_BE-3_1442
Bacteria in the Atlantic Southern Ocean

Jodi Pieterse1, Ethel Phiri2, James Lloyd2, Susanne Fietz3 (sfietz@sun.ac.za)

1
Stellenbosch University, Conservation Ecology, Stellenbosch, South Africa, 2Stellenbosch University, Institute of
Plant Biotechnology, Stellenbosch, South Africa, 3Stellenbosch University, Earth Sciences, Stellenbosch, South
Africa

Bacteria play a key role in the Southern Ocean ecosystem functioning, including in the carbon, nitrate and iron
cycles. We present a study aimed at identifying and cultivate bacteria from the subtropical, subantarctic and
antarctic zones of the Atlantic Southern Ocean. We further interrogated the roles the observed bacteria play in
the marine polar ecosystem. Metagenomic samples were collected from surface waters across the three zones
in summer 2015, and summer and winter 2017. Microbial plates for cultivation and experiments were added in
2017. Results are discussed with regards to the functional characteristics of the observed and/or cultivated
bacteria. For example, five genera were identified and cultivated in austral summer 2017: Halomonas,
Pseudoalteromonas and Salinibacterium from the sub-tropics, Citricoccus and Pseudoalteromonas from the
subantarctic, and Pseudoalteromonas, Salinibacterium and Vibrio from the Antarctic zone. Their functional
roles in the ecosystem differ; for example, Citricoccus is a potential producer of siderophores, essential in the
iron availability for phytoplankton, whereas Halomonas might play a role in the nitrogen cycle, but might also
be involved in the degradation of hydrocarbons. In addition to the in-situ, transect biodiversity data we will
present the impact of iron enrichment on shifts in the prokaryotic communities in the three zones.

341
Tue_137_BE-3_1551
LPS Structure from the Cold-adapted Shewanella sp. HM13 Grown at 4°C and 18°C

Angela Casillo1 (angela.casillo@unina.it), Chen Chen2, Jun Kawamoto2, Kohei Kamasaka2, Tatsuo Kurihara2,
Maria Michela Corsaro1
1
Università degli Studi di Napoli Federico II, Naples, Italy, 2Kyoto University, Institute for Chemical Research,
kyoto, Japan

Lipopolysaccharides (LPS) are the main component of the outer membrane of Gram-negative bacteria. Due to
their external location, it is reasonable to think that LPS are involved into the life adaptation at low
temperature. The LPS is composed of three different domains: an O-specific polysaccharide and a core
oligosaccharide, which in turn is covalently linked to the third domain, the lipid A.1 It has been reported that
unsaturated fatty acids belonging to both phospholipids and lipid A moiety are responsible of the membrane
fluidity enhancement when bacteria thrive at low temperature.2 Up to now, only few LPS structures from cold-
adapted bacteria have been characterized, and an interesting common feature is the production of rough-LPS.3-
5
The characterization of other LPS structures from cold-adapted bacteria can shed light about the interaction
between the cell and the environment.
In this communication, the molecular characterization of LPSs from the fish intestinal bacterium Shewanella sp.
HM13 is reported. In particular, the LPS structures obtained from Shewanella sp. HM13 grown at 4°C and 18°C
are analyzed and compared.
1
Caroff M, et al. Carbohyd Res 2003 338:2431-2447
2
De Maayer et al., EMBO reports 2014 15(5): 508-517.
3
Corsaro M.M. et al., Eur. J. Biochem. 2001 268: 5092-5097.
4
Carillo S. et al., Eur J Org Chem 2013 18: 3771-3779.
5
Casillo A. et al., Mar. Drugs 2015 13: 4539-4555.

342
Tue_138_BE-3_1694
Microbial Respiration in the Ross Sea, Antarctica (ROSSMIZE and P-ROSE Projects)

Rosabruna La Ferla1 (rosabruna.laferla@iamc.cnr.it), Giovanna Maimone1, Filippo Azzaro1, Ermanno Crisafi1,

Alessandro C. Rappazzo1, Olga Mangoni2, Maurizio Azzaro1
1
CNR, National Research Council, IAMC Institute of Marine and Coastal Environment, Messina, Italy, 2University
of Naples Federico II, Department of Biology, Naples, Italy

The Ross Sea continental shelf is a unique region of the Antarctic, both with regard to its physics and its ecology
and it is considered a “natural laboratory” for investigating the potential effects of climate change. It is
noteworthy that sea ice distributions has significantly changed with years in the Ross Sea, inducing unpredicted
cascade effects on trophic dynamics and carbon and nutrient drawdown.
With the aims to identify signs and patterns of microbial responses to current climate change, the variability of
the microbial respiration rates in the Ross Sea was assessed by comparing the data of two cruises carried out in
late-spring and early summer (ROSSMIZE 1994-95 and P-ROSE 2016-17) twenty-two years later.
In particular, estimates of microbial community respiration and carbon dioxide production rates by ETS assay
were performed.
A high variability of respiratory rates was detected on both time and space scales in the Ross Sea. The
distribution of plankton respiration and organic matter degradation was put in relation with the different ice
cover of the investigated areas. Comparing the two expeditions could help to better understand the carbon flux
transfer efficiency and carbon export variability on a large time scale.

343
Tue_139_BE-3_1708
Total and Free Enzymes in the Ross Sea during the Austral Summer 2017

Renata Zaccone1 (renata.zaccone@iamc.cnr.it), Filippo Azzaro1, Maurizio Azzaro1, Francesco Bolinesi2,

Giannetta Fusco3, Olga Mangoni2, Ermanno Crisafi1, Rosabruna La Ferla1
1
CNR, National Research Council, IAMC Institute of Marine and Coastal Environment, Messina, Italy, 2University
of Naples Federico II, Department of Biology, Naples, Italy, 3University of Naples Parthenope, Department of
Science and Technology, Naples, Italy

The Ross Sea, one of the most productive seas of the South Ocean, includes polynyas, marginal ice zones,
coastal areas and open sea that contribute differently to biological processes. To identifying responses of
plankton compartment to climate change, an oceanographic PNRA campaign (P-ROSE Project) was here carried
out in January-February 2017. Two polynyas occurred, a small near the Terra Nova Bay (TNB) and a larger one
between the Ross Ice Shelf and Cape Adare. The variability of extracellular enzymatic activity (a proxy of
organic matter degradation) in relation to environmental conditions (temperature, salinity and total
phytoplankton biomass) was studied along longitudinal and latitudinal transects. Hydrolysis rates of
aminopeptidase (LAP), beta-glucosidase (GLU) and alkaline phosphatase (AP) and -for the first time in this area-
the corrispective free enzymes (dissolved in waters) were determined. Results showed decreasing trends in the
TNB from coastal to off-shore stations and from surface to depth for LAP, that were related positively to
temperature (T) and negatively to salinity (S) and depth (p< 0.01%). High values in the N-S transect of offshore
stations were observed, probably due to fresh organic matter. LAP were positively correlated with T and
negatively with S and depth (p< 0.01%). GLU was positively correlated with AP and LAP (p< 0.05%). Free
enzymes ranging from 17 to 99% on total showed variability among stations and high percentages for free-GLU
at DCM.

344
Tue_140_BE-3_2003
Genomic Comparative Analysis of Bacteria Associated to Antarctic Sponges

Mario Moreno1 (mario.moreno@mayor.cl), Mariela Guajardo1, Nicole Trefault2

1
Universidad Mayor, Doctoral Program in Integrative Genomics, Santiago, Chile, 2Universidad Mayor, Center for
Genomics and Bioinformatics, Faculty of Sciences, Santiago, Chile

Sponge microbiome is composed of a wide range of microbial communities which display a key role in different
aspects of the sponge biology and in biogeochemical cycling of key elements for ecosystem functioning. Here,
we studied the metabolic potential of seven bacterial strains isolated from two Antarctic sponges, with
emphasis on nutrient cycling and symbiotic lifestyle, using whole-genome Illumina sequencing and genomic
comparative analysis using the RAST server. Bacteria isolated were assigned to the genera Pseudoalteromonas
(E16.1, E19.1, 19.4), Nesterenkonia (E16.7, E16.10), Sporosarcina (E16.8), and Cellullophaga (E16.2). Genomic
completeness was estimated as higher as 98% for all genomes. Bacterial strains isolated display metabolic
potential to perform: nitrite reduction (Nitrite reductase, nir; Pseudoalteromonas and Nesterenkonia genera)
and phosphorous cycle (i.e. Polyphosphate kinase, ppk gene; all genera). Interestingly, Cellulophaga has
genomic elements associated with CRISPR systems. Genomic comparative of sponge-associated Nesterenkonia
and Cellulophaga against free-lifestyle strains showed that associated bacterias have higher genome size and
uniques functions related to virulence, phages. Overall, genomic features in bacterial isolated from Antarctic
sponges shown a metabolic potential related to nutrient cycling and display signatures related to symbiotic
lifestyle, extending previous results from tropic and temperate environments to polar systems.

345
Tue_142_BE-3_2165
Limits to the Three Domains of Life: Lessons from an Antarctic Salinity Gradient

Xiaoben Jiang1 (pet@utk.edu), David Van Horn2, Jordan Okie3, Egbert Schwartz4, Daniel Colman5, Kelli Hughes2,
Cristina Takacs-Vesbach2
1
University of Tennessee, Knoxville, Earth and Planetary Sciences, Knoxville, United States, 2University of New
Mexico, Biology, Albuquerque, United States, 3Arizona State University, School or Earth and Space Exploration,
Tempe, United States, 4Northern Arizona University, Biological Sciences, Flagstaff, United States, 5Montana
State University, Microbiology and Immunology, Bozeman, United States

Extremophiles are found in all three domains of life, however, extremophiles from different domains utilize
varying mechanisms for dealing with harsh environmental conditions. We used next-generation sequencing to
investigate differences in inter-domain responses to extreme conditions along a high elevation salinity gradient
in the McMurdo Dry Valleys, Antarctica. The soil salinity for the 25 samples collected along the gradient ranged
from 50 to 8355 µS cm-1. Richness varied widely between domains along the transect with a total of 354
bacterial, 2 archaeal, 56 fungal, and 69 non-fungal eukaryotic OTUs. Richness for all domains declined
significantly (P ≤ 0.01) with increasing conductivity, however, the strength of the relationship varied (R2 of 0.83
for bacterial to 0.25 for fungal OTUs). Ordination (PCoA) revealed significant (ANOSIM R = 0.97) groupings of
low/high conductivity bacterial OTUs, while OTUs from other domains were not significantly clustered. Beta-
diversity analyses found significant patterns for bacteria only, including evidence of a nested structure
indicating species loss as opposed to replacement. A PICRUSt analysis, which predicts metagenome functional
content, indicated the high conductivity bacterial OTU cluster had an over representation of genes responsible
for coping with osmotic stress. These results suggest that while increased salinity acts as a stressor for
organisms across all three domains, within-domain responses also vary considerably.

346
Tue_143_BE-3_2271
ACBC - Antarctic Circumnavigation Bacterial Collection: Highway to Knowledge

Marion Fourquez1 (marion.fourquez@gmail.com), Amandine Laffite1, Christel Hassler1

1
University of Geneva, F.-A. Forel for Environmental and Aquatic Sciences Marine and Lake Biogeochemistry,
Genève, Switzerland

A freely accessible culture collection of polar bacteria will be available shortly (2019). We collected natural
bacterial communities during the Antarctic Circumnavigation Expedition (ACE) from Dec. 2016 to Mar. 2017 for
isolation and identification purposes. The expedition has travelled for 33,565 km all around Antarctica, allowing
us to bring back unprecedented live samples from the Southern Ocean. Water samples were collected at 15
different sites at the surface, 15, 100 and 1000m depth. Two additional samples were collected: one in the Ross
Sea at 3800m to get the signature of the Antarctic Bottom Water, and another one at 700m at on seabed
underneath the Mertz glacier. Bacteria colonies were first grown in nutrient rich (Marine Agar) and poor (R2A)
media at 4°C directly on board the R/V Akademik Treshnikov. Each colonies were subsequently isolated a first
time at sea, followed by additional isolation steps in our home lab (Geneva, Switzerland) until we get pure
cultures. A total of 314 isolates were recovered, documented and archived at -80°C. Using 16S rRNA Sanger
sequencing, we have so far characterized the bacterial diversity of 186 of these isolates. One of the project's
overarching goals was to identify the key microbial players across the Southern Ocean and to stimulate
research on bacteria inhabiting this extremely harsh region of our world. The outcome of this project resonates
with a better understanding of the functioning and diversity of the Southern Ocean.

347
Tue_144_BE-3_2272
Metabolic Response of Sea-ice Diatoms to Shifting Temperature and Salinity

Hannah M. Dawson1 (hmdawson@uw.edu), Angela K. Boysen1, Katherine R. Heal1, Laura T. Carlson1, Anitra E.
Ingalls1, Jodi N. Young1
1
University of Washington, Oceanography, Seattle, United States

In polar oceans, sea-ice algae are important primary producers during the spring and winter months. However,
we have a limited understanding of how they are physiologically adapted to the large variations in temperature
and salinity associated with seasonal cycling of sea ice. Here, we use a mass spectrometry-based targeted
metabolomics approach to evaluate the response of sea-ice algae to changing temperature and salinity. Axenic
cultures of the Antarctic sea-ice diatom, Nitzschia lecointei were grown at salinities of 32 and 41 and at -1 and
+4˚C. Under the culture conditions tested, growth, cell size and photosynthetic efficiency were unaffected
despite large differences in intracellular metabolites among treatments. Temperature had a greater affect than
salinity on metabolite composition, influencing cryo- and osmoprotectants, antioxidants as well as other
metabolites. Compatibles solutes, including N-rich glycine betaine and proline, along with S-rich
dimethylsulfoniopropionate (DMSP) were among the most abundant metabolites detected. Surprisingly, these
compounds displayed different responses to temperature and salinity. We will compare laboratory results to
environmental samples of first-year sea ice with a dominant Nitzschia community that we collected from
Utqiaġvik, AK. Changes in metabolite composition in response to environmental change could have implications
for biogeochemical cycling and ecosystem dynamics in sea ice over the season.

348
Tue_145_BE-3_2289
Growth Performance of Psychrotolerant Cyanobacteria from Svalbard Archipelago

Zoya Khan1, Azmir Hamidi1, Wan Maznah Wan Omar1 (wmaznah@usm.my), Peter Convey2, Faradiana Merican1
1
Universiti Sains Malaysia, School of Biological Sciences, Penang, Malaysia, 2British Antarctic Survey,
Cambridge, United Kingdom

A filamentous benthic cyanobacteria, strain USMAC16, was isolated from High Arctic Svalbard archipelago,
Norway, and was identified to species level using polyphasic approach that combine morphological and
molecular characterization (16S rRNA gene sequence). Cell dimensions, and apical cell shape are consistent
with the Pseudanabaena genus description. The molecular characterization of USMAC16 gave 100% similarity
with Pseudanabaena catenata SAG 1464-1, originally reported from Germany. Strain USMAC16 was cultured
under a range of temperature (4±2˚C, 15±2˚C and 25±2˚C), and photoperiod (24 hours light, 16 hours light, 12
hours light and 24 hours dark) conditions in liquid media, and harvested at exponential phase to examine
growth and biochemical composition. The highest growth rate (0.538day-1) and chlorophyll a (306.7 mg/L)
concentration was recorded at 15±2˚C under 24L:0D and 16L:08D light durations, respectively. Highest
carbohydrate (216.6 µg/L) and protein (2.67 µg/L) was observed at 25˚C in the absence of light. This analysis
provides baseline data documenting the variations in biochemical compositions of P. catenata in response to
changing temperature regimes and this indicates that the strain was psychrotolerant as it is an organism from a
cold environment that can adapt to culture temperatures of > 15˚C.

349
Tue_146_BE-3_2310
The Resistance of Antarctic Stichococcus bacillaris to Cycloheximide

Nur Hidayu Syuhada Adnan1 (nurhidayusyuhada@gmail.com), Faradina Merican1, Paul Broady2, Peter Convey3
1
Universiti Sains Malaysia, School of Biological Sciences, Penang, Malaysia, 2University of Canterbury, School of
Biological Sciences, Canterbury, New Zealand, 3British Antarctic Survey, Cambridge, United Kingdom

The microalga Stichococcus bacillaris isolated from Signy Island soil was found to be resistant to cycloheximide
(CHX), a eukaryotic protein synthesis inhibitor produced by Streptomyces griseus. The strain was first obtained
from a mixed assemblage of several green algae species. When introduced to media containing 100µg/ml CHX,
only S. bacillaris survived and continued to grow after three weeks of incubation. An initial lag of growth in the
first two weeks of incubation indicates that S. bacillaris attained the tolerance by adaptation. Morphological
comparison between cell cultures grown with and without CHX indicated no measurable change in their
phenotypic characteristics. Species identification was confirmed by sequencing 18S rDNA. Subsequently, a
series of experiments conducted using different CHX concentrations confirmed the ability of S. bacillaris to
tolerate up to 400µg/ml CHX concentration. Ongoing research is addressing the mechanism by which
S.bacillaris achieves resistance, and whether this phenomenon is widespread in the species or specific to this
Antarctic strain.

350
Tue_147_BE-3_2461
The Secret Life of Bacteria: Ecological Function in Cryoconite Hole Environments

Ewa A Poniecka1 (ponieckaea@cardiff.ac.uk), Elizabeth A Bagshaw1, Henrik Sass1, Christopher J Williamson2,

Alexandre M Anesio2, Martyn Tranter2
1
Cardiff University, School of Earth and Ocean Sciences, Cardiff, United Kingdom, 2University of Bristol, Bristol
Glaciology Centre, Bristol, United Kingdom

Polar regions serve as a natural laboratory to study simplified microbial and biogeochemical processes in
habitable niches. An example of such niches are cryoconite holes, regarded as hotspots of microbial processes
on glacier surfaces. Data on how microorganisms, especially anaerobic ones, function in cryoconite holes are,
however, scarce.
We applied a range of microbiological tests to understand the physiological capabilities of the most abundant
cultivable microorganisms from cryoconite holes worldwide (Greenland, Svalbard, Antarctica). Oxic and anoxic
conditions were applied to mimic microniches within the habitat. The growth of bacteria was assessed under a
range of treatments: freeze-thaw cycles, temperature gradients, and varying organic carbon substrates.
Our study demonstrates that heterotrophs of cryoconite holes are adapted to fast - changing environmental
conditions by ability to survive multiple freeze-thaw cycles and changing oxygen conditions, and scavenging a
wide range of organic substrates. The elevated growth of anaerobic part of the community in the lowest
temperatures indicates they might be key players in winter conditions or in early melt season, when the oxygen
is potentially depleted and accumulated dead cells provide a source of organic matter for scavenging.
Consequently, anaerobic heterotrophs are likely crucial for the reactivation of the community after the polar
night.

351
Tue_148_BE-3_2513
The Nutrient Limitation of Soil Microbial Community in High Arctic Forefield

Petra Lulakova1 (petrica@centrum.cz), Petra Vinsova2, Petr Capek3, Jacob Yde4, Marek Stibal2, Hana
Santruckova1
1
University of South Bohemia, Faculty of Science, Ceske Budejovice, Czech Republic, 2Charles University in
Prague, Faculty of Science, Department of Ecology, Prague, Czech Republic, 3Pacific Northwest National
Laboratory, Environmental Molecular Sciences Laboratory, Richland, United States, 4Western Norway University
of Applied Sciences, Faculty of Engineering and Science, Sogndal, Norway

Although the soil succession has been studied intensively in the forefields of retreating glaciers, little is known
about the physicochemical constraints of microbial functioning which determines the rate of initial soil
development. Knowing these constraints may improve our understanding of factors limiting microbial growth
during the soil succession. Commonly meaured soil characteristics such as moisture and pH have been shown
to change along the soil age and to shape microbial community structure and activity during the succession.
However, the extent of microbial nutrient limitation, which is more difficult to estimate, remains unclear. It has
been suggested that nutrient limitation has even stronger effect on the rate of microbial succession than
climate, especially at very harsh conditions.
We assume that nutrient limitation of soil microbial community is especially pronounced on the bare forefields
of the High Arctic regions, where the plant cover establish much longer. In order to estimate nutrient limitation
of the microbial activity on the bare forefields in Svalbard, we set up an incubation experiment where we
added organic carbon (C), inorganic nitrogen (N) and phosphorus (P) separately or in different combinations
and measured the changes in microbial respiration rate and microbial biomass. The effect of nutrient addition
on the microbial activity and growth is discussed in respect to microbial community structure and available
nutrients at in-situ conditions.

352
Tue_149_BE-3_2647
Psychrophilic Adaptation of Cyanobacteria in Polar Regions

Saloomeh Ebrahimi1 (salomeh.ebrahimi@estudiante.uam.es)

1
Universidad Autonoma de Madrid, Biology Department, Madrid, Spain

Life on Earth appeared with UV resistant anaerobic organisms. Then, cyanobacterial prokaryotes have
flourished oxygenic life on earth. In spite of global change biology, they are still the most successful organisms.
Adaptive evolution create contemporary cyanobacteria, very tolerant to extreme circumstances. Foremost, UV
radiation as the most lethal factor increase mutation rate. Also, prime necessities of life such as liquid water
supply would play a key role on habitability on survivability of resistant life forms. A molecular dynamics
approach can be used in order to obtain insights water/ice interface over continued cycles of freezing and
thawing. Adventures in protein world revealed many positive biosignatures of antifreeze, ice-binding and ice
structure proteins at Polar Regions. Although, working mechanisms has a long way to go, this study review
these themes and psychrophilic adaptation process. It will make possible to understand the thermal hysteresis
structures and function to potential biologic niches in more detail.

353
Tue_150_BE-3_2653
Global Metagenomic Analysis of Cold Desert Bacteria

David M Robinson1 (thedavidrobinson@gmail.com), Byron Adams2, Zachary Aanderud1

1
Brigham Young University, Plant and Wildlife Sciences, Provo, United States, 2Brigham Young University,
Biology, Provo, United States

Bacterial taxa when stimulated by water additions will break dormancy, grow, and become dominant members
of the community, contributing significant pulses of CO2. Pulses are associated with high levels of bacterial
productivity in soils. (Aanderud et al. 2011) I have examined the bacteria taxa that resuscitate and become
metabolically active following two forms of water stress (soil drying-rewetting and freeze-thaw cycles) and I
have captured and measured the CO2 emanating from those soils. Specifically, I used target metagenomics,
which uses a specific gene pool within bacteria that is associated with a function of an ecological process, in
this case active (16S mRNA communities) bacteria and all bacteria (16S rRNA communities) during drying-
rewetting and freeze-thaw cycles. I have measured an array of community dynamics as dry soils were rewetted
and as frozen soils thaw multiple times in three cold desert soils. I am searching for continuity or predictability
in the bacteria rapidly responding in ecosystems to understand if there are coherent or universal patterns of
the bacteria within these stresses in cold desert ecosystems. I have examined three cold deserts which include
the Great Basin Desert, UT, The Junggar Desert, China, and the McMurdo Dry Valleys, Antarctica. Overall I am
looking to; Identify whether bacterial response to water stress is universal or only localized and if bacterial
adaptations are the same within similar but geographically isolated systems.

354
Tue_151_BE-3_1888
Detection of Lipase Gene from Sphingobacterium sp. Isolated from Polar Region

Rashidah Abdul Rahim1 (rashidahrahim@gmail.com)

1
Universiti Sains Malaysia, School of Biological Sciences, Penang, Malaysia

In past few decades, microbial enzymes have been favorable demands among industrial fields due to their high
specificity and stability of being active under mild conditions. Known as a versatile enzyme beneficial to many
biotechnological approaches, lipases have received massive interest worldwide. A psychrophilic microorganism
isolated from polar soil sample tested positive as a lipase producer was studied. DNA extraction was conducted
by modified CTAB method and 16S rRNA sequencing result revealed its identity to be in close resemblance with
Sphingobacterium sp. (97% identity). The bacterium was found to be psychrotolerant with the growth
temperature ranging from 4oC to 25oC ±2oC. Halo zone formation in qualitative (primary) screening using
sensitive and specific plate assay detected the presence of lipase produced by the bacterium. To date, not
many studies on lipases from Sphingobacterium sp was done, and lipase structure from this bacterium has not
been solved yet for better understand of its enzymatic activity. In the study on detection of lipase gene by PCR
method using specific designed primers, two different lipase sequences from Sphingobacterium sp. which are
SGNH subfamily hydrolase (lisophospholipase) (553bp) and alpha/beta hydrolase (esterase/lipase) (845bp)
were detected. The lipase genes will be cloned, expressed and purified for further structure-function study of
the enzyme.

355
Tue_152_BE-4_46
Isotopic-related Warming Effects on the Northern Antarctic Peninsula Ecosystem

Elisa Seyboth1,2 (elisaseyboth@gmail.com), Silvina Botta3, Carlos Rafael Borges Mendes4, Javier Negrete5,
Luciano Dalla Rosa3, Eduardo Resende Secchi3
1
Universidade Federal do Rio Grande, Instituto de Oceanografia, Laboratório de Ecologia e Conservação da
Megafauna Marinha, Rio Grande, Brazil, 2Universidade Federal do Rio Grande, Programa de Pós-Graduação em
Oceanografia Biológica, Rio Grande, Brazil, 3Universidade de Federal do Rio Grande, Instituto de Oceanografia,
Laboratório de Ecologia e Conservação da Megafauna Marinha, Rio Grande, Brazil, 4Universidade de Federal do
Rio Grande, Instituto de Oceanografia, Laboratório de Fitoplâncton e Microorganismos Marinhos, Rio Grande,
Brazil, 5Instituto Antártico Argentino, Departamento de Biología de Predadores Tope, Buenos Aires, Argentina

An isotopic approach was used to investigate whether the temporal and spatial patterns of energy transfer
along the food web is similar in areas under different effects of warming around the Northern Antarctic
Peninsula (NAP). Samples were obtained from 2013 to 2016 in Bransfield and Gerlache Straits and in Powell
Basin. Mean values of δ13C and δ15N were, respectively, ‐26.3‰ (± 2.9) and 0.9‰ (± 1.7) for POM - particulate
organic matter (n=65), ‐25.6‰ (± 0.9) and 5.3‰ (± 1.1) for krill (n=29), ‐24.1‰
(± 2) and 8.9‰ (± 1.5) for humpback whales - Megaptera novaenglieae (n=67), ‐24.6‰ (± 1.2) and 8.2‰ (± 0.7)
for fin whales - Balaenoptera physalus (n=23) and ‐24.4‰ (± 1.6) and 8.7‰ (± 1) for Antarctic minke whales -
Balaenoptera bonaerensis (n=16). The isoscapes generated for baseline at the NAP ecosystem provided
knowledge on how the δ13C and δ15N values of POM varied spatially and temporally in the region. POM samples
in which diatoms and cryptophytes were predominant significantly differed in the δ13C values and the
contribution of these groups to the total phytoplankton biomass was positively and negatively correlated with
the POM δ13C values, respectively. The differences observed are considered representative of contrasting
environmental conditions. The present study provides new insights for the stable isotope values in the
Antarctic ecosystem and may help to foresee the consequences of physico-chemical changes in water
properties to the biota due to global warming.

356
Tue_153_BE-4_145
In Situ Antarctic Seabed Warming Drives Species and Assemblage Level Responses

Lloyd Samuel Peck1 (l.peck@bas.ac.uk), Gail V Ashton2, David KA Barnes3, Simon A Morley3, Melody S Clark3
1
British Antarctic Survey, Biodiversity, Evolution and Adaptation, Cambridge, United Kingdom, 2Smithsonian
Environmental Research Center, Tiburon, United States, 3British Antarctic Survey, Cambridge, United Kingdom

Forecasting assemblage-level responses to climate change is a great challenges for global ecology. Marine data
limited because they largely come from experiments using small numbers of species, mesocosms whose
interior conditions are unnatural, and long-term correlation studies based on historical collections. We describe
the first experiment to warm benthic assemblages to ecologically relevant levels in situ. Heated settlement
panels were deployed near Rothera Station on Adelaide Island, Antarctica,with three test conditions: ambient
and 1°C and 2°C above ambient (predicted sea temperature increases in the next 50 and 100 years,
respectively).There were massive impacts on the marine assemblage, with near doubling of growth rates.
Growth increases far exceeded those expected from biological temperature relationships established more
than 100 years ago by Arrhenius, and demonstrated to accurately describe temperatue effects on biological
systems since then. The growth increases resulted in a single “r-strategist” pioneer species (the bryozoan
Fenestrulina rugula) dominating seabed spatial cover and drove a reduction in overall diversity and evenness.
In contrast, a 2°C rise produced divergent responses across species, resulting in higher assemblage variability.
This divergence in response at 2°C warming probably indicates some, but not all, species were warmed to
temperatures near their long-term physiological limits and their capacities to resist warming were
compromised.

357
Tue_154_BE-4_149
Ecological Consequences of a Species Introduced to the Antarctic

Jesamine Bartlett1 (jcb553@bham.ac.uk), Peter Convey2, Scott Hayward3

1
University of Birmingham, School of Biosciences, Birmingham, United Kingdom, 2British Antarctic Survey,
Cambridge, United Kingdom, 3University of Birmingham, Birmingham, United Kingdom

Rising human activity in Antarctica, combined with the recent changes to the polar climate mean that
establishing the risk of non-native terrestrial species to vulnerable, biodiversity and nutrient-poor ecosystems is
urgent. Yet the impact on Antarctic ecosystem function from existing introduced species remains unclear. Of
the five known non-native invertebrate species in terrestrial Antarctica, the flightless midge Eretmoptera
murphyi may currently present the highest risk to local indigenous communities and is an excellent case study
to establish these impacts, as the only higher invertebrate in the terrestrial ecosystem of Signy Island.
Introduced to Signy in the 1960s from sub-Antarctic South Georgia, E. murphyi has established successfully,
with an estimated mean biomass 2-5 times greater than the entire native arthropod communities in the areas
it has colonised. As a detritivore and with no competitors or predators, E. murphyi may have a major impact on
nutrient cycling which will, in turn, affect peat decomposition and soil structure, thereby having wider impacts
on all levels of biodiversity. This study seeks to identify whether and how much the midge is impacting the local
ecosystem through in situ measurements of key nutrient levels, invertebrate community assemblage, substrate
microbial loads and vegetation diversity, and will be combined with a revision of the species' current
distribution range and abundance on Signy to establish the scope of its impact.

358
Tue_155_BE-4_180
Vertical Profiles and Feeding Strategies of Copepods in Prydz Bay, Antarctica

Guang Yang1 (yangguang@qdio.ac.cn), Chaolun Li1, Yanqing Wang1

1
Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China

The vertical profiles of zooplankton community structures and feeding strategies and trophic niches of
dominant copepod species were investigated using fatty acids and stable isotopic biomarkers based on samples
collected from various water strata of Prydz Bay, Antarctica during austral summer of 2013. Four zooplankton
communities belonging to distinct water strata were identified. The four groups differed more in animal
abundance than in species composition. A few species (Metridia gerlachei, Rhincalanus gigas, Alacia spp.)
showed significant diel vertical migration based on quadratic regression analysis. Sampling depth was the
strongest differentiating factor between samples. These results suggest that depth-related differences in the
environmental characteristics of water masses, such as temperature and salinity, may have the greatest effect
upon community structure. Copepods showed species-specific and depth-related differences in fatty acid
biomarkers and stable isotopic values. Intra-population variability and higher δ15N values in M. gerlachei and
Paraeuchaeta antarctica dwelled in the mesopelagic and bathypelagic zone indicated the flexible feeding
strategies of these copepods responding to the changing food availability. The species-specific and depth-
related feeding strategies of copepods based on biomarkers in this study could enable them to utilize different
ecological niches and minimize inter- and intra-specific completion in the Prydz Bay ecosystem.

359
Tue_156_BE-4_269
Exploring an Undocumented Diversification of Parasitic Gastropods in Antarctica

Kara K.S. Layton1,2 (kara.layton@research.uwa.edu.au), Nerida G. Wilson1,2

1
University of Western Australia, School of Biological Sciences, Crawley, Australia, 2Western Australian Museum,
Aquatic Zoology & Molecular Systematics Unit, Welshpool, Australia

Benthic marine invertebrates are diverse in Antarctica, but little is known about their parasitic counterparts.
Asterophila, a genus of eulimid gastropod, is endoparasitic in asteroid sea stars. There are four known
members in this genus, one of which has been described from the Antarctica Peninsula and forms part of a
putative radiation of species in this region. In order to further explore this radiation, 61 Asterophila specimens
were collected from 38 hosts in Antarctica. Five genes were used for phylogenetic reconstruction and species
delimitation and a test of host-parasite co-evolution was conducted by employing global congruence and
event-based reconciliation analyses. The resulting Asterophila phylogeny shows high support for nine species-
level entities in Antarctica, suggesting undocumented diversity in this group. These nine putative species show
varying degrees of host specificity and species with more extensive sampling show higher host diversity.
Significant global congruence between host and parasite phylogenies was detected, suggesting these groups
are co-evolving, but the majority of links were explained by host switching rather than strict co-speciation.
Investigating co-phylogenetic patterns provides insight into whether host and parasite lineages are evolving in
synchrony, which may have important implications for biodiversity conservation. In all, these results advance
our understanding of diversity and the processes driving this diversity in Antarctica.

360
Tue_157_BE-4_334
The Effect of Low Temperature on Photosynthetic Processes in an Antarctic Lichen

Michaela Marečková1 (mareckova.mm@gmail.com), Miloš Barták1

1
Masaryk University, Faculty of Science, Department of Experimental Biology, Brno, Czech Republic

Physiological responses of autotrophic constituents of Antarctic vegetation oasis have met a great importance
in respect to recent climate variability in the region of Antarctic Peninsula. In our study, we investigated the
effects of low temperature and short-term photoinhibition at high and low thallus temperature, respectively,
on the fast chlorophyll fluorescence transient (OJIP) and OJIP-derived photosynthetic parameters in foliose
lichen Dermatocarpon polyphyllizum. The lichen thalli were collected at James Ross Island, Antarctica. In a
laboratory, the samples were expossed to a gradually decreasing temperature (22, 18, 14, 12, 10, 7, 4, 0 and -
5°C). The initial phase of the transient (O-J) caused by the reduction of the primary quinone acceptor (QA) was
found temperature-dependent. The K-step was apparent for the samples measured at the temperature above
12°C, but not below 10°C in light-adapted lichen thalli. In photoinhibited samples, we used OJIPs, OJIP-derived
parameters, and evaluated the effect of photoinhibition on samples with scraped and intact upper cortex of a
lichen at 18°C (measured temperature optimum of D. polyphyllizum) and 4°C. In conclusion, OJIP is an useful
tool to investigate temperature-dependent changes in photosystem II as well as the effect of photoinhibition
and consequent recovery of photosynthesis in chlorolichen photobionts. The method thus might be used in
thermal resistence studies. We thank to CzechPolar2 and ECOPOLARIS for funding.

361
Tue_158_BE-4_389
Winter Physiological Suppression in Antarctic Krill is Not Observed Everywhere

Kim Bernard1 (kbernard@coas.oregonstate.edu), Anthony Cossio2, Jennifer Walsh2, Christian Reiss2

1
Oregon State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, United States, 2National
Oceanic and Atmospheric Administration, Antarctic Ecosystem Research Division, La Jolla, United States

With a combined biomass greater than almost any other animal on Earth, Antarctic krill (Euphausia superba)
supports vast numbers of top predators, contributes to biogeochemical cycling, and is the subject of a growing
fishery. Overwinter survival is one of the key factors contributing to the success of the Antarctic krill population
but it is one of the least understood aspects of the species' life cycle. Physiological suppression is an important
strategy used by krill to survive in regions where winter food resources are low, such as the Lazarev Sea.
However, it has been shown that in other regions, such as the Bransfield Strait in the northern Antarctic
Peninsula (AP), krill continue to feed during the winter, suggesting minimal physiological suppression. We
measured winter respiration rates of krill in the northern AP, an important, but rapidly warming, overwintering
region for these organisms. Our measured respiration rates were higher than those reported for other regions.
Our results highlight the importance of the northern AP for overwintering krill. Elevated respiration rates,
however, correspond to greater minimum energy demands and we will discuss potential food resources
available to krill overwintering in this region. Finally, we suggest that the elevated winter respiration rates in
the northern AP are indicative of life history plasticity with important implications for the timing of
reproductive development.

362
Tue_159_BE-4_430
The Belgica120 Expedition: A Proof of Concept for Antarctic Ecology

Bruno Danis1 (bdanis@ulb.ac.be), Anton P. Van de Putte2, Ben Wallis3, Antonio Agüera Garcia4, Charlène
Guillaumot4, Francesca Pasotti5, Franz Heindler6, Henri Robert2, Henrik Christiansen6, Thomas Saucède7
1
Université Libre de Bruxelles, Marine Biology Lab, Brussels, Belgium, 2Royal Belgian Institute of Natural
Sciences, Brussels, Belgium, 3Ocean Expeditions, Bondi, Australia, 4Université Libre de Bruxelles, Brussels,
Belgium, 5Ghent University, Ghent, Belgium, 6Katholieke Universiteit Leuven, Leuven, Belgium, 7Université de
Bourgogne Franche Comté, Dijon, France

There is a dearth of knowledge about biodiversity levels found in shallow environment in the Southern Ocean,
a situation opposite to that found in other oceans. These habitats are however exposed to fast-paced changes
in key environmental parameters. Shallow marine fauna has been facing past climatic events, but at time
frames of different orders of magnitudes. Its response to current change is (re-)shaping the function and
structure of ecosystems. On top of understanding these aspects, the ongoing RECTO/vERSO projects have
identified plasticities (trophic, dispersive) and connectivities as key research areas to characterize the response
of Southern Ocean ecosystems to Global Change.
The Belgica120 expedition is an attempt to delineate the impact of contrasted glacial regimes on the structure
of shallow benthic communities by

• mapping marine habitats and quantifying the physiological sensitivity of selected taxa
• assessing the levels of biodiversity in an underexplored area of the West Antarctic Peninsula (WAP)
• using genomics to unravel past and present connectivity of key species
• modelling trophic networks in fast-changing environmental conditions
• testing the concept of using an agile platform for Antarctic marine biology work

In this presentation, we will give an overview of the Belgica120 experience, present initial results as well as
discuss new perspectives for future research on Southern Ocean biodiversity.

363
Tue_160_BE-4_443
Microbial Diversity by NGS along a Vegetation Transect in West Greenland

Fabiana Canini1 (canini.fabiana@unitus.it), Claudia Pacelli1, Claudia Coleine1, Laura Selbmann1, Silvano Onofri1,
Laura Zucconi1
1
University of Tuscia, Department of Ecological and Biological Sciences (DEB), Viterbo, Italy

Greenland is one of the Arctic regions that might be severely affected by climate change. The trend towards a
rise in temperature could cause changes in soil microbial diversity. Despite the high ecological interest in Polar
Regions, little is known about the structure and diversity of the terrestrial microbial communities in ice-free
areas in West Greenland, compared to other Arctic regions. In the frame of the International Network for
Terrestrial Research and Monitoring in the Arctic (INTERACT), the Effects of Climate change On Microbial
Community of Soil in Greenland (COMICS-G) project aimed
i) to characterize and compare the soil prokaryotic and eukaryotic diversity along a vegetation transect (NERO
line transect, established in July 2007 for monitoring future changes of boundaries between vegetation zones
and in the species composition of the plant communities, including heat, bedrock, snow patch and nude soil) in
the Kobbefjord field Station, West Greenland and
ii) to clarify how the biodiversity of these communities would respond to climate change. To this scope, meta-
barcoding approach, targeting the ITS region and V4 region of 16S for fungi and bacteria respectively, is being
performed on Illumina Miseq. The results will give important clues to figure out the potential effects of
environmental changes predicted for the Arctic regions.

364
Tue_161_BE-4_446
Call to Complete the Circumarctic Juniper Network - An Environmental Proxy

Jiří Lehejček1 (jirilehejcek@gmail.com), Allan Buras2,3, Rohan Shetti3, Martin Wilmking3

1
Tomas Bata University, Department of Environmental Security, Zlin, Czech Republic, 2Technische Universität
München, Professorship of Ecoclimatology, Freising, Germany, 3University of Greifswald, Institute of Botany and
Landscape Ecology, Greifswald, Germany

Due to spatial scarcity and lack of long instrumental climatic records as well as missing written sources from the
Arctic, studies focusing on proxy archives and environmental reconstructions are important evidence of eco-
climatic variations in (sub)-polar regions. We introduce here one such highly valuable proxy archive, the long-
lived, circumpolar, and relatively abundant tundra shrub Juniperus communis. Although it has shown good
potential for environmental reconstructions (e.g. summer temperature, or ice-sheet melt) it is still a chronically
understudied species, not only in terms of its ecology but also with respect to its wide geographical
distribution. As environmental reconstructions are becoming integral parts of climate and environmental
change research the demand for reliable and complex proxy data rises. Therefore, we are currently building the
circumpolar wood anatomy juniper network to satisfy this need. So far, seven locations - mainly along the
Northern Atlantic coast - have been sampled. Nonetheless, field campaigns covering Asia and N. America are
still missing. Here, we invite the polar scientific community to contribute to our juniper network with the
benefits of co-authorship and network access for each data contributor. We have developed a sampling
procedure to guarantee the comparability of the obtained collections. Sampling per site takes approx. two
person days, only basic equipment is needed and samples are easy to transport.

365
Tue_162_BE-4_453
Primary Photosynthesis in Antarctic Lichen at Subzero Temperature: A Lab Study

Josef Hájek1 (jhajek@sci.muni.cz), Miloš Barták1, Jana Morkusová1, Marie Forbelská2

1
Masaryk University, Faculty of Science, Laboratory of Photosynthetic Processes, Section of Plant Physiology and
Anatomy, Institute of Experimental Biology, Brno, Czech Republic, 2Masaryk University, Faculty of Science,
Department of Mathematics and Statistics, Brno, Czech Republic

Antarctic lichens in wet state may witness freezing and thawing cycles during austral summer. It is well
established that the lichens are capable to perform photosynthesis at subzero temperature. In our study, we
focused on the decline of photosynthesis due to gradual freezing. To evaluate the temperature dependence of
primary photochemical processes of photosynthesis, we exposed hydrated thalli of Usnea antarctica (collected
at James Ross Island) to linear cooling from +20 to -50°C at a constant rate of 2°C/min. Simultaneously, two
chlorophyll fluorescence parameters (FV/FM: potential yield of photosynthetic processes in photosystem II, ϕPSII:
effective quantum yield of PSII) were measured by a modulated fluorometer. The two parameters showed a S-
curve decline with temperature decrease. The decline started at -5 (FV/FM) and +5°C (ϕPSII), respectively. U.
antarctica exhibited the first sign of FV/FM decline at -12°C. The critical temperature (CT) related to full
inhibition of the photosynthetic processes in PSII (FV/FM), was found at -20°C. For individual samples, CT for
FV/FM was typically lower than for ϕPSII. Analysis of S-curves was done in order to find a parameter evaluating
lichen resistance to subzero temperature. The method of linear cooling combined with simultaneous
measurements of chlorophyll fluorescence parameters proved to be an efficient tool in the estimation of lichen
sensitivity/resistance to freezing. Acknowledgements: CzechPolar infrastructure, ECOPOLARIS.

366
Tue_163_BE-4_457
Genetic Patterns at Fine Spatial Scales: Complex Findings in a Complex Landscape

Daniela Monsanto1 (dmonsanto119@gmail.com), Arsalan Emami-Khoyi1, Peter Teske1, Ian Meiklejohn2, Bettine
van Vuuren1
1
University of Johannesburg, Department of Zoology, Johannesburg, South Africa, 2Rhodes University,
Department of Geography, Grahamstown, South Africa

Landscape genetics describes spatial genetic patterns, and overlays these onto a habitat matrix. Observed
patterns can then be interpreted from the viewpoint of the individual organism, and how different organisms
move and interact within their habitat. Using Cryptopygus antarcticus travei from sub-Antarctic Marion Island
as a model organism, we explored spatial genetic structure across a 350 m transect, and interpreted our results
in light of the factors driving small-scale evolution within the group. Our results for 390 individuals from 22
sampling sites revealed the presence of two genetic lineages whose, contact zone broadly coincides with a
ridge in the landscape. The contact zone does not manifest as a clean break, but rather a complex pattern of
clustering, with sampling sites on either side of the ridge showing alternating lineage membership. Individuals
within each site were not admixed but, uniformly belonged to the same lineage, and the level of inbreeding
was consistent with what is expected for sexually reproducing organisms. High genetic diversity reflects a large
effective population size, consistent with the high census population size reported for the species. Taken
together, our results argue against asexual reproduction as an explanation for the complex spatial pattern. A
more plausible explanation might involve the occurrence of divergent micro-habitat preferences and/or a
fitness vacuum driven by local adaptations.

367
Tue_164_BE-4_466
Lipid Carbon Turnover Reveals Stage-specific Differences in Antarctic Copepods

Wilhelm Hagen1 (whagen@uni-bremen.de), Martin Graeve2, Lauris Boissonot2, Barbara Niehoff2

1
University of Bremen/BreMarE, Marine Zoology, Bremen, Germany, 2Alfred Wegener Institute Helmholtz
Center for Polar and Marine Research, Bremerhaven, Germany

Lipid turnover dynamics of two herbivorous Antarctic copepod species with different types of lipid depots (wax
esters, triacylglycerols) were investigated by compound-specific isotope analysis to elucidate biochemical
pathways and energetic adaptations. The dominant Calanoides acutus and Calanus propinquus were collected
in the Antarctic Weddell Sea in late December and fed with 13C labeled diatoms for 9 days. 13C incorporation
was monitored by isotope ratio mass spectrometry. Total lipid (TL) mass and fatty acid/alcohol compositions
did not change significantly during the experiment. However, lipid carbon turnover was intense especially in
the copepodid V (CV) specimens of C. acutus, which exchanged 80% TL, whereas lipid turnover rates of female
C. propinquus and C. acutus were lower. Structural fatty acids (FA) were exchanged with similar rates in all
copepod groups and twice as high for 16:0 and 20:5(n-3) as for 18:0 and 22:6(n-3). Long-chain
monounsaturated FAs (MUFA) are largely stored as energy reserves. 20:1(n-9) and 22:1(n-11) showed highest
turnover rates in C. acutus CVs, only 20:1(n-9) was exchanged in C. acutus females and there was no MUFA
turnover in C. propinquus females. Fatty alcohols also exhibited much higher exchange rates in C. acutus CVs
than in the females. These differences emphasize the more intense biochemical activities in growing CV stages,
whereas in females metabolic processes are less pronounced and probably more related to egg production.

368
Tue_165_BE-4_513
Ecosystem Research at the Canadian High Arctic Research Station (CHARS)

Ian Hogg1 (ian.hogg@polar.gc.ca), Ioan (Johann) Wagner1, Donald McLennan1, Jean-François Lamarre1,
Stephanie Coulombe1
1
Polar Knowledge Canada, Canadian High Arctic Research Station, Cambridge Bay, Canada

Polar Knowledge Canada (POLAR) was established to provide a world-class research station in the Canadian
Arctic anchoring a strong research presence that serves Canada and the world. A strong component of this is to
advance knowledge of the Arctic and to improve the quality of life for people living in the north. The Canadian
High Arctic Research Station (CHARS) at Cambridge Bay in the central Canadian Arctic is now nearing
completion and will provide a range of laboratory and office facilities in the 7,500 m2 Main Research Building.
From a regional biodiversity perspective, the station is located near four major bioclimatic zones and provides
access to a range of freshwater, terrestrial and marine habitats. Available data suggest an abundance of
previously unknown and/or cryptic species in the Arctic. This, combined with the area around CHARS being
relatively little studied, make the CHARS location a highly interesting region for ecological and cryosphere
studies. A nearby “Experimental and Reference Area” (ERA), will be the focus of intensive research efforts over
the next two years in an effort to provide an accurate assessment of ecosystems within the ERA. This would
benefit strongly from international collaborators. POLAR is strongly committed to developing productive
research partnerships with national and international scientists and opportunities exist for international
researchers to visit and use the facilities.

369
Tue_166_BE-4_581
Impact of Sea Ice on Phytoplankton Dynamics in the Northern Antarctic Peninsula

Carlos Rafael Mendes1 (crbmendes@gmail.com), Virginia Maria Tavano1, Rodrigo Kerr1, Tiago Segabinazzi
Dotto2, Tiago Maximiano1, Eduardo Secchi1
1
Federal University of Rio Grande, Rio Grande, Brazil, 2National Oceanography Centre, Southampton, United
Kingdom

The seasonal advance and retreat of sea ice around the northern Antarctic Peninsula can have a significant
impact on phytoplankton, mainly due to alterations in the availability of ice-free areas, micro-nutrient inputs by
meltwater and variations in water column structure. The aim of this work was to evaluate the effect of sea ice
conditions on phytoplankton biomass and community composition in an area off the northern Antarctic
Peninsula. Two contrasting conditions were studied: a strong environmental gradient around the sea ice edge,
with a marked meltwater signal (summer 2013) and the same area with little indication of meltwater and no
detectable sea ice conditions (summer 2014). There was a clear distinction between the phytoplankton
communities under sea ice influence, where mainly cryptophytes were associated with shallow mixed layers
and high water column stability in 2013 and an important presence of diatoms in 2014, associated with deeper
mixed layers, lower silicic acid concentrations and higher magnitudes of both salinity and temperature, under
very little sea ice influence. Gymnodinioid dinoflagellates were an important component in both years,
apparently occupying sites/conditions less favourable to cryptophytes. These results support previous
suggestions that climate factors leading to shortening of the sea ice season in the region do have an important
impact particularly in shaping the dominance of the main phytoplankton functional groups in the region.

370
Tue_167_BE-4_662
Combining SDM and DEB Theory - An Integrative Approach to Ecological Niche Models

Salomé Fabri-Ruiz1 (salome.fabri-ruiz@u-bourgogne.fr), Antonio Agüera2, Rose Stainthorp3, Bruno Danis4,

Thomas Saucède1
1
Laboratoire Biogéosciences UMR CNRS 6282, Dijon, France, 2Marine Biology Lab, Dijon, France, 3National
Oceanography Centre Southampton, Southampton, United Kingdom, 4Marine Biology Lab, Brussels, Belgium

Ecological niche models are now commonly used to characterize the relationship between species occurrences
and environmental conditions. Amongst these models, the correlative approach (species distribution models,
SDMs) has been widely applied to modeling the distribution of various organisms at different spatial scales.
However, this approach has received some criticisms because it assumes that species distribution is at the
equilibrium with the environment. This constitutes a serious limitation to modeling dynamic predictions such as
future range shifts due to climate change. SDM are unable to integrate the full range of processes involved in
physiological responses of species to environmental changes. In order to consider these biological processes in
modeling procedures, we generated mechanistic models based on the Dynamic Energy Budget (DEB) theory,
capturing metabolic processes of an organism during its entire life cycle using temperature and food
availability. This approach allows getting an enhanced assessment of fitness components such as survival,
development, growth and reproduction.
We modeled the distribution of the echinoid Sterechinus neumayeri, a common species in benthic communities
from Antarctic shallow areas. We used an integrative approach based on both correlative and mechanistic
models to predict species range shift with predicted environmental changes, a crucial issue for biodiversity
conservation and management.

371
Tue_168_BE-4_675
Estimating Adaptive Capacities of Salpa thompsoni Facing Southern Ocean Warming

Wiebke Wessels1 (wiebke.wessels1@uni-oldenburg.de), Katharina Michael1, Gabriele Sales2, Chiara Romualdi2,

Bettina Meyer1,3
1
Carl-von-Ossietzky University of Oldenburg, Institute for Chemistry and Biology of the Marine Environment,
Oldenburg, Germany, 2University of Padova, Department of Biology, Padova, Italy, 3Alfred Wegener Institute,
Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

The polar regions and the western Atlantic sector of the Southern Ocean in particular are among the fastest
warming areas on the planet. Long-term data sets indicating a decline in krill abundance in the northern part of
the Western Antarctic Peninsula (WAP) and an increase of salp populations as well as a shift in food quality and
quantity, highlight the unique characteristic of the WAP region to observe the ecosystem response to climate
change. Krill and salps are among the most important grazers, playing a crucial role in the WAP ecosystem.
Thermal limits on physiological processes in krill and salp life cycles on different levels of the organism are yet
unknown, limiting the accuracy of predictions on how these two species might respond to climate change. To
assess the natural plasticity of Antarctic salp, Salpa thompsoni, between seasons, winter and summer samples
were subjected to high throughput sequencing as well as additional cellular analyses. The de novo generated
transcriptomes of S. thompsoni and its Mediterranean relative, S. fusiformis, were compared to detect regional
adaptive strategies. First results on metabolic and reproductive activity in S. thompsoni in response to seasonal
differences will be presented. The unique life cycle, changing between solitary and aggregate stage and
therefore facilitating fast reproduction under favourable conditions, might be the baseline for potential
adaptive capacity of S. thompsoni.

372
Tue_169_BE-4_712
A First Approach to the Leaf Hydraulic Properties of Deschampsia antarctica

Patricia L. Sáez1 (patrisaezd@gmail.com), Lohengrin Cavieres2, Constanza Ramírez2, Betsy Rivera2, Valentina
Vallejos2, Yessenia Aguayo2, Domingo Sancho-Knapik3, José Peguero-Pina3, Eustaquio Gil-Pelegrin4, Jeroni
Galmes5, Leon A. Bravo6
1
Universidad de Concepción, Silvicultura, Concepcion, Chile, 2Universidad de Concepción, Concepcion, Chile,
3
Universidad de Concepción, Zaragoza, Spain, 4CITA, Aragon, Zaragoza, Spain, 5Universidad de Islas Baleares,
Palma de Mallorca, Spain, 6Universidad de la Frontera, Temuco, Chile

Increase temperature produces changes in photosynthetic limitations of Deschampsia antarctica, promoting

higher rates of net photosynthesis. This photosynthetic response is related to change in leaf traits, specifically
associated to the CO2 mesophyll conductance (gm). Considering that the CO2 and water vapor share, partially,
diffusion pathways in the leaf mesophyll, we ask if change in gm under warmer condition are accompanied by
changes in the leaf hydraulic properties of D. antarctica. Given that currently there are no studies about the
hydraulic characteristics of Antarctic vascular species, both under field or laboratory conditions, our first goal
was tune-up methodologies to measure the leaf hydraulic conductance (Kleaf) and the whole hydraulic
conductance (gplants). The increase in net photosynthesis triggered at higher growth temperatures were
accompanied by increases in both Kleaf and gplant. These changes were also associated to adjustment in the leaf
traits as leaf density and leaf mass area production, and also with changes at vascular leaf level. Despite these
adjustments could be positive for the growth of D. antarctica under warmer growth conditions, plants could be
more susceptible to damage during sudden freezing events, which could increase, as a result of regional
climate change.
Acknowledgments: INACH RT 13_16.

373
Tue_170_BE-4_723
Under Ice Flagellates Bloom in Coastal Area of the Ross Sea (Antarctica)

Maria Saggiomo1 (m.saggio@szn.it), Francesco Bolinesi2, Laura Escalera3, Francesca Margiotta3, Vincenzo
Saggiomo3, Olga Mangoni4
1
Stazione Zoologica 'Anton Dohrn', RIMAR (MEDA), Naples, Italy, 2Stazione Zoologica 'Anton Dohrn' and
Università degli Studi di Napoli Federico II, Naples, Italy, 3Stazione Zoologica 'Anton Dohrn', Naples, Italy,
4
Università degli Studi di Napoli Federico II, Biologia, Naples, Italy

In early spring 2016 water samples, under annual fast ice from 0-100 m, were collected in a coastal area in
Terra Nova Bay (Ross Sea) from December to January (2015-2016). We investigated temporal distribution of
temperature, chlorophyll a, particulate organic carbon and phytoplankton composition. Several new and
unusual events were observed in the under-ice phytoplankton community of the Ross Sea. A massive under ice
bloom dominated by flagellates, < 10 µm of length, was recorded. This group was numerically similar and/or
dominant compared to diatoms in this study. Flagellates blooms showed a high temporal variability in species
composition: i) the chrysophyte Ochromonas spp., generally found in Antarctic lakes, was observed for the first
time in the sea; ii) the parmales Pentalamina corona, known for the Antarctic pelagic environments, was found
for the first time under the ice with unusually high concentrations and iii) the haptophyte Phaeocystis
antarctica, was reported for the first time in the under ice system in high concentrations.These events could be
related to a peculiar seasonal progression in the ice melting process in the 2015-2016 period or may indicate an
environmental change. The ecological role of this flagellates under the pack ice should be studied in detailed.

374
Tue_171_BE-4_836
Morphological Differentiation Reflect Ecological and Genetic Background in Usnea

Shunan Cao1 (caoshunan@pric.org.cn), Fang Zhang1, Hongyuan Zheng1, Chuanpeng Liu2, Fang Peng3, Qiming
Zhou2
1
Polar Research Institute of China, Shanghai, China, 2Harbin Institute of Technology, School of Life Science and
Technology, Harbin, China, 3Wuhan University, College of Life Science, Wuhan, China

King George Island is the second largest ice-free area of the South Shetland Islands, and the fruticose lichen
Usnea aurantiaco-atra is the most dominant and widespread flora around King George Island. It had been
observed that the individuals of U. aurantiaco-atra with different phenotypes could grow on various substance.
A comprehensive analysis combining morphological and phylogenetic traits reveals that the phenotypic
differentiation of U. aurantiaco-atra (erect growth on stones or with prostrate growth with mosses) provides
an effective approach to adapt to different micro-environments, and those individuals with complicated
morphological traits grow on different substances (eg. Stone, wood, even other lichen such as Umbilicaria
antarctica) could share the same genotypes (they have the same ITS rDNA sequences of both mycobiont and
photobiont). Moreover, haploid disequilibrium testing indicates that there is no significant genetic difference
for the two growth forms (erect and prostrate) when fungal and algal ITS rDNA were treated as two alleles of
one lichen individual. The two growth forms of U. aurantiaco-atra appear to reflect different stages of lichen-
moss community succession, and a mode is proposed for demonstrating the occurrence of this succession.
Also, the current study implies that lichen is a mini-ecosystem more than a dual symbiotic association of fungus
and alga.

375
Tue_172_BE-4_905
Introduction of the Journal Advances in Polar Science and Call for Papers

Jing Huang1 (huangjing@pric.org.cn), Xiaoliang Ling1, Beichen Zhang1

1
Polar Research Institute of China, Shanghai, China

Advances in Polar Science (APS) has been published since 1990 as a peer-reviewed English-language journal
dedicated to the presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and
research (until 2011 it was known as the Chinese Journal of Polar Science [English Edition]). In 2015, we made
APS more truly international, with two new Co-Editors-in Chief, Dr. Huigen Yang and Prof. Ian Allison, and a
new expert team of disciplinary Editors from China and many other nations involved in polar research
(http://www.aps-polar.org/home/editorialboard). Our broad goals for the journal in the near future are to
improve the quality of contributions and to attract more involvement and contributions from outside China.
Specific objectives will include using APS as a platform to raise international awareness of Chinese polar
research and to facilitate collaboration between China and other nations in polar science, and to build both
inter-disciplinary and bi-polar links within our research community. APS is a true open-access, quarterly
scientific journal. Articles published in APS are free of charge with generous funding from PRIC. For more
details, please see the attached introduction file or visit the APS's websites: www.aps-polar.org

376
Tue_174_BE-4_950
The Results of Camera and Satellite Transmitter Deployment in Vernadsky Area

Gennadi Milinevsky1,2 (genmilinevsky@gmail.com), Dmytro Lutsenko3,4, Oleksandr Savitsky4,5, Andrii Simon1,

Ihor Dykyy6, Marta Telipska6, Valery Lytvynov4, Leonid Pshenichnov7, Svitlana Kovalonok8, Ivan Parnikoza9
1
Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, 2Jilin University, International Center for Future
Science, Changchun, China, 3Institute for Problems of Cryobiology and Cryomedicine of NAS of Ukraine, Kharkiv,
Ukraine, 4National Antarctic Scientific Center of Ukraine, Kyiv, Ukraine, 5Institute of Hydlobiology NAS of
Ukraine, Kyiv, Ukraine, 6Ivan Franko National University of Lviv, Lviv, Ukraine, 7Institute for Fisheries and Marine
Ecology, Berdyansk, Ukraine, 8JSC Kyivstar, Kyiv, Ukraine, 9Institute of Molecular Biology and Genetics NAS of
Ukraine, Kyiv, Ukraine

We report the results of the work on establishing of camera network and penguin tags deployment in penguin
colonies in the area around Vernadsky Sation as a part of the CCAMLR/CEMP Projects. The projects have been
initiated by scientists from USA, Argentina and Poland, and supported by the CEMP Fund. The data of the
project will allow analysing the climate changes and krill fishery influence on the Antarctic Peninsula
ecosystem. Ukraine is responsible for support and providing the cameras and satellite transmitter deployment
in gentoo and Adelie penguin colonies at the Galindez, Petermann, and Yalour Islands. The pictures of gentoo
colonies at the Galindez and Petermann Islands, and Adelie colonies at Yalour Island have been processed
according protocol and methods provided and coordinated by US scientists. Information on copulation, egg lay,
maximum number of eggs, hatch, maximum number of chicks, date of cheche, and the maximum number of
adults have been obtained and analysed during breeding season 2016/2017 from the photos of the all nine
cameras. The results of visual observations coinsided with camera photos are discussed. ARGOS satellite tags
have been installed successfully at fifteen adult gentoo penguins in Galindez Island colony and some of tags are
still transmitting in the end of October 2017.
The work is supported by CEMP Fund of the CCAMLR, by National Antarctic Scientific Center of Ukraine and
Taras Shevchenko National University of Kyiv, project 16BF051-02.

377
Tue_175_BE-4_999
Faraway, So Close: Midtrophic Feeding at the Poles, an Ecomorphological Study

Erica Carlig1 (erica.carlig@ge.ismar.cnr.it), Davide Di Blasi1, Laura Ghigliotti1, Eva Pisano1, Jorgen S.
Christiansen2, Marino Vacchi1
1
National Research Council of Italy, Institute of Marine Sciences (ISMAR), Genoa, Italy, 2University of Tromsoe,
Department of Arctic and Marine Biology (AMB), Tromsoe, Norway

The polar cod (Boreogadus saida) and the Antarctic silverfish (Pleuragramma antarctica) are pelagic fish
endemic of the Arctic and Antarctica, respectively. Shaped for life in icy waters, both the polar cod and the
Antarctic silverfish are nowadays abundant in the pertaining polar marine ecosystem, playing a central role as
link between top predators and lower trophic levels. Although phylogenetically distant, during their
independent evolutionary histories in polar regions, these two polar fish has been subjected to similar
ecological drivers, eventually leading to a comparable suite of, biological and ecological adaptations.
Both species are zooplanktivorous, known to primarily feed on copepods, euphausiids and amphipods.
Intraspecific regional differences in diet, reflecting prey availability, have been recorded for both the cod and
the silverfish, supporting the hypothesis of them being opportunistic feeders. In the light of the ongoing
climate change how each of the species might cope with changes in the prey availability is of particular
relevance with strong implications for the polar food web.
Here we apply an ecomorphological approach to characterize the feeding modes of the polar fishes, aiming at
better understand their feeding adaptation, and their potential trophic flexibility. The morphofunctional bases
of the feeding mechanisms are assessed through morphometric analysis of mouth structures, jaws, buccal
cavity, muscles of the head and gill rakers.

378
Tue_176_BE-4_1121
Five Millennia of Environmental Dynamics from an Ice Core in the Mongolian Altai

Sandra Brügger1 (sandra.bruegger@ips.unibe.ch), Erika Gobet2, Michael Sigl3, Dimitri Osmont3, Tatjana Papina4,
Natalia Rudaya5, Margit Schwikowski3, Willy Tinner2
1
University of Bern, Physics Institute & Oeschger Centre for Climate Change Research, Bern, Switzerland,
2
University of Bern / Institute of Plant Sciences and Oeschger Center for Climate Change Research, Bern,
Switzerland, 3Paul Scherrer Institute, Villigen, Switzerland, 4Institute of Water and Environmental Problems,
Russian Academy of Sciences, Barnaul, Russian Federation, 5Institute of Archaeology and Ethnography, SB RAS,
Novosibirsk, Russian Federation

The Central Asian forest-steppe ecotones are highly vulnerable to environmental shifts such as drought and
overgrazing. Knowledge about past vegetation and fire responses to environmental change may contribute to a
better understanding of future ecosystem dynamics. However, paleo records are scarce in the region.
Our novel high-alpine ice record from Tsambagarav glacier (4130m asl) in the Mongolian Altai provides unique
paleoenvironmental information at the landscape scale with an exceptional temporal resolution and a sound
chronology covering the past 5500 years. We use pollen as proxies for vegetation composition and structure,
microscopic charcoal as a proxy for fire activity, and spheroidal carbonaceous particles (SCPs) to infer fossil fuel
combustion.
We present the first microcharcoal-inferred fire history record from Mongolia which can be directly linked to
past vegetation dynamics. Reconstructed mid to late Holocene forests collapsed and fire increased, likely in
response to climate change. Our results underscore the vulnerability of relict forest ecosystems in the
Mongolian Altai and imply that in these steppic areas, moisture is more important than temperature for tree
growth. We conclude that Central Asian forest ecosystems including the Russian Altai are highly vulnerable and
may collapse rapidly in the future, if global warming will be associated to moisture declines as anticipated by
regional climate models.

379
Tue_177_BE-4_1146
Diversity Structure of Rotifer Communities in Deglaciation Areas of Svalbard

Tomotake Wada1 (wada.tomotake@nipr.ac.jp), Nataliia Iakovenko2,3,4, Miloslav Devetter5,6,7, Karel Janko7,8,9,

Sakae Kudoh1,10, Masaki Uchida1,10
1
SOKENDAI, Tokyo, Japan, 2Schmalhausen Institute of Zoology NAS of Ukraine, Invertebrate Fauna and
Systematics, Kyiv, Ukraine, 3University of Ostrava, Biology and Ecology, Ostrava, Czech Republic, 4Institute of
Animal Physiology and Genetics, Laboratory of Fish Genetics, Liběchov, Czech Republic, 5Institute of Soil Biology
AS CR, České Budějovice, Czech Republic, 6Biological Centre AS CR, České Budějovice, Czech Republic, 7Centre for
Polar Ecology, České Budějovice, Czech Republic, 8Institute of Animal Physiology and Genetics, Liběchov, Czech
Republic, 9University of Ostrava, Ostrava, Czech Republic, 10National Institute for Polar Research, Tokyo, Japan

Glacial retreat occurs worldwide due to global climate change. Svalbard glaciers are ones of the most retreating
in the world (Norwak & Hondson 2014). Their exposed forelands create new niches for terrestrial microbial
organisms, in particular for microscopic invertebrates that influence further changes of the rock substrates.
This study aims at understanding the diversity patterns, in particular, gradients of diversity and abundance in
deglaciation areas, of a key group of soil microfauna, rotifers (Rotifera).
Soil and moss were collected in Adolfsbukta (Nordenskiöldbreen, NB), and the vicinity of Ny-Ålesund (Austre
Brøggerbreen, ABB), both at a single point and along the transects, 0 to circa 500 m from the glaciers. Rotifers
were extracted using the method of Freckman & Virginia (1993), counted and identified to species.
Eighteen rotifer species were found in NB and 12 in ABB, respectively, with Adineta gracilis, Ceratotrocha
cornigera, C. velata, Habrotrocha cf aspera, Macrotrachela cf concinna, M. insolita being the most common and
abundant species. Abundance varied from 0 ind/g (near the glacier) to 50-75 ind/g of soil (more than 200 m
from the glacier), however no strict diversity and abundance gradients were observed, with a higher number of
species and individuals occurring under moss patches.
Therefore, deglaciation areas in Svalbard provide new niches for microinvertebrate communities that might
cause further changes in structure and composition of the exposed soils.

380
Tue_178_BE-4_1158
Relationships between Soils and Plant Communities in Maritime Antarctica

Flávia Ramos Ferrari1 (flaviarferrari@gmail.com), André Thomazini2, Antonio Batista Pereira3, Carlos Ernesto
Gonçalves Reynauld Schaefer4
1
Universidade Federal de Viçosa / INCT da Criosfera, Departamento de Biologia Vegetal - Núcleo TERRANTAR,
Viçosa, Brazil, 2Universidade Federal de São João del Rei, Departamento de Ciências Agrárias - Núcleo
TERRANTAR, Sete Lagoas, Brazil, 3Universidade Federal do Pampa, NEVA - Núcleo de Estudos da Vegetação
Antártica, São Gabriel, Brazil, 4Universidade Federal de Viçosa / INCT da Criosfera, Departamento de Solos -
Núcleo TERRANTAR, Viçosa, Brazil

Soil characteristics allow the understanding of the factors that drive vegetation development and dynamics in
Maritime Antarctica, being extremely sensitive to between environmental changes. We investigated the
relation between soil attributes with landscape features and plant community. We analyzed soil attributes in
ten different plant communities following a toposequence, near Henryk Arctowski Polish Station, Admiralty
Bay, Antarctica Maritime. Results indicate that coastal phanerogamic communities presented greater
phosphorus and organic matter contents due to ornithogenic influence. In these areas, soil shows low levels of
sodium and low pH at the bottom of the toposequence. Fruticose lichen communities were observed at high
altitudes, characterized by higher exchangeable sodium and calcium contents, as well as lower amounts of
phosphorus and organic matter. Mosses carpets are mainly found on wet soils, with low diversity of species,
coupled with little soil organic matter accumulation. Bare soil as reference, presented very low organic matter
content, high pH and sodium saturation. We observed that organic matter only accumulates at the bottom of
the topossequence, under phanerogamic community. Lichens communities are found at higher positions of the
landscape under very of higher diversity shallow and skeletic soils, indicating a strong dependence of
vegetation establishment to physical conditions, especially moisture.

381
Tue_180_BE-4_1207
Similarity of Trends of Scrubs Expansion in Arctic and High Mountains in Russia

Elena Belonovskaya1, Arkadiy Tishkov1 (tishkov@biodat.ru)

1
Institute of Geography, RAS, Biogeography, Moscow, Russian Federation

In the beginning of the XXI century in tundra and high mountains growth of plant productivity and vegetative
index (NDVI) was revealed (Walker et. al. 2012; Bhatt et. al. 2013; Belonovskaya et al., 2016; Tishkov et al.,
2016; Shiyatov 2009; Vinogradova et al., 2015). The main cause of this process is synergism of climatic and
anthropogenic impact changes. Growing season's increasing, active temperature sum's raising and soil melting
depth's deepening result scrub vegetation of Betula, Salix, Dusсhekia, Pinus, Juniperus, Rhododendron, etc.
genera's spreading in Russian tundra (Kola Peninsula, lower Pechora-river, Yakutia) and in the high mountains
(Khibini, Urals, Eastern Sibiria, Caucasus). Similar process is noticed for Alaska and Canadian Arctic (Dusсhekia,
Salix and Betula) (Tape et al., 2006). The trend of scrub vegetation invasion was recognized in global scale for
various treeless biomes. In high mountain regions scrub area's enlargement is caused by climatic changes as
well by abandoning of alpine pastures. In Arctic and high mountains widening of scrub vegetation initiates
development of landscape diversity, increasing of snow accumulation and therefore development of
continuous scrub cover, organic matter accumulation and changes of soil thermal regime. Thus this process
may have the cyclic character because according the “cascading effect” it induces “inverse relationships”:
reaction of all landscape components and as a result scrub degradation in the future.

382
Tue_181_BE-4_1234
Ecophysiology of the Sub-Antarctic Intertidal Midge Halirytus magellanicus

Felipe Lorenz Simões1,2 (felsim@bas.ac.uk), Tamara A. Contador Mejías3,4, Javier A. Rendoll Cárcamo3, Scott A.
L. Hayward5, Peter Convey2
1
University of Cambridge, Zoology, Cambridge, United Kingdom, 2British Antarctic Survey, Cambridge, United
Kingdom, 3Universidad de Magallanes, Puerto Williams, Chile, 4Instituto Antárctico Chileno, Punta Arenas, Chile,
5
University of Birmingham, Birmingham, United Kingdom

First described around 100 years ago, Halirytus magellanicus is a non-biting midge native and probably
endemic to southern South America. The species has received no specific research attention since its discovery,
and little is known about its habitat, life cycle and other biological characteristics. Recently, it has been
relocated in Navarino Island, southern Chile, providing the opportunity to document the species' biology, and
compare with other, better studied, Antarctic and sub-Antarctic relatives. We completed a spatial point-
pattern analysis to characterise its habitat at several bays on Navarino Island, and ecophysiological experiments
addressing its adaptive features in terms of tolerance to desiccation, salinity, temperature variation and
salinity+temperature interaction. The species is active for most of the year and has a multivoltine life cycle, in
contrast with its assumed closest relatives, the Antarctic/sub-Antarctic endemics Belgica antarctica and
Eretmoptera murphyi. Primary habitat requirements for the larvae include filamentous algae and thin sand,
which appear to be necessary to secure larvae and pupae from being washed away during the tidal cycle. While
the larvae can withstand wide variation in salinity and temperature, as may be expected during intertidal
exposure, they are vulnerable to desiccation stress, especially at higher temperatures. These features permit
the species to inhabit a wide range of intertidal microhabitats.

383
Tue_182_BE-4_1265
Biodiversity of Canadian Arctic Plants and Lichens: Field Work and Floristics

Jeffery M. Saarela1 (jsaarela@mus-nature.ca), Lynn J. Gillespie1, R. Troy McMullin1, Paul C. Sokoloff1, Roger D.
Bull1
1
Canadian Museum of Nature, Centre for Arctic Knowledge & Exploration, Ottawa, Canada

Exploration of the flora of the Canadian Arctic has been ongoing for almost two hundred years, yet substantial
gaps remain in our floristic understanding of this large, rapidly changing and difficult-to-access region. Detailed
information on the diversity and distribution of Arctic plants and lichens at local, regional and global levels is
urgently needed to understand the potential impacts of climate change on Arctic flora. Since 2008 we have
been conducting floristic surveys in botanically-understudied regions of the Canadian Arctic; lichen exploration
began in 2016. The comprehensive baseline data of our >8000 new collections, all housed permanently in the
National Herbarium of Canada at the Canadian Museum of Nature, and other herbaria in Canada and
internationally, adds important baseline knowledge to our understanding of Arctic plant and lichen
biodiversity. Our collections include first records for specific areas (e.g., territories, parks, islands), major and
minor range extensions, second or third collections of poorly-known species at the northern or southern edges
of their ranges, new discoveries of rare species, and they fill in gaps in the known distributions of Arctic species.
We are working on a new Arctic Flora of Canada and Alaska, which aims to bring together all available
information on the diversity and distribution of vascular plants in this region, including keys, descriptions,
nomenclature, distribution maps, images and more.

384
Tue_183_BE-4_1364
A Spatially Explicit Food Web Model to Evaluate Change on the Kerguelen Plateau

Roshni Subramaniam1,2,3 (roshni.subramaniam@utas.edu.au), Jessica Melbourne-Thomas2,3, Stuart Corney2,

Kerrie Swadling1, Patrice Pruvost4, Matt Pinkerton5
1
Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia, 2Antarctic Climate &
Ecosystems Cooperative Research Centre, Hobart, Australia, 3Australian Antarctic Division, Hobart, Australia,
4
Muséum National d'Histoire Naturelle, Département Milieux et Peuplements Aquatiques, Paris, France,
5
National Institute for Water and Atmospheric Research, Wellington, New Zealand

The Kerguelen Plateau is a highly productive area. Seabirds and seals breed on the islands, parts of the plateau
support nurseries and larval development for fish species, and iron enrichment from the shelf produces
phytoplankton blooms that attract a wide range of species to forage in the area. The plateau also supports
valuable fisheries for Patagonian toothfish and icefish. The area is changing, with increasing temperatures, and
movement of oceanographic frontal systems that interact with the plateau. Climate model projections suggest
that these changes are likely to lead to increases in primary productivity. We have developed the first balanced
Ecopath with Ecosim model for the Kerguelen Plateau using published information on species biomass and diet.
We present this model with an added spatial component (Ecospace) that allows us to examine spatial variation
of the food web across the plateau. We present results from a set of spatially explicit scenarios to examine the
combined effects of changes in primary productivity and fisheries for the Kerguelen Plateau and evaluate the
impacts of these changes throughout the food web.

385
Tue_184_BE-4_1367
Abundances and Activities of Prokaryotic Community in Water of an Arctic River

Marco Graziano1 (margraziano@unime.it), Maria Papale1, Antonella Conte1, Gabriella Caruso2, Alessandro Ciro
Rappazzo2, Angelina Lo Giudice2, Stefano Amalfitano3, Giovanna Maimone2, Carmen Rizzo1, Serena Savoca1,
Emilio De Domenico1, Rosabruna La Ferla2, Maurizio Azzaro2
1
University of Messina, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences,
Messina, Italy, 2IAMC-CNR Messina, Messina, Italy, 3Water Research Institute (IRSA), National Research Council,
Roma, Italy

The spatial and temporal distribution of microbial biomass and metabolic rates were investigated in water
samples collected along the Pasvik River (Arctic Norway) from 9 stations during two sampling campaigns (May
and July 2014). Water samples were analyzed for physico-chemical parameters, viable bacterial abundance
(VCs), prokaryotic abundance (PA), microbial enzymatic and respiratory activity. All data were statistically
analyzed. VCs were generally homogeneous in May and July. PA showing enhanced abundance in July and
higher values in the outer than in inner stations. Microbial respiration was higher in July than in May. Pearson's
correlation coefficients showed that physical and chemical parameters affected both the PA and functionality.
Respiration was significantly related to Temperature, suggesting its stimulation on the oxidation process.
ANOSIM analysis showed seasonal significant differences (R=0.231, p=0.002), with temperature accounting for
11.4% of total variability. Psychrophilic microorganisms of the Pasvik river appear to be quite plastic to
acclimate to seasonal changes of the cold habitat in which they live, modifying their abundance and
metabolism, although further research is needed for a deepen knowledge of this Arctic ecosystem.

386
Tue_185_BE-4_1369
Dwarf Brooder versus Giant Broadcaster: Unrecognized Species in a Brittle Star

Quentin Jossart1,2 (qjossart@gmail.com), Chester Sands2, Mary A. Sewell1

1
University of Auckland, Auckland, New Zealand, 2British Antarctic Survey, Cambridge, United Kingdom

Characterizing a species reproductive mode (brooder, broadcaster) is key to understand the evolution and
resilience of SO organisms as reproductive mode affects connectivity and demographic patterns. Distinct
reproductive modes might sometimes suggest unrecognized speciation that can be confirmed through genetic
or morphological investigations. This is the case for the brittle star Astrotoma agassizii where divergent genetic
clades were associated with a brooding (Patagonia) and a broadcasting reproductive mode (Ross Sea). Here we
investigated the genetic diversity and reproductive mode of A. agassizii from individuals collected in South
Georgia (SG) and around Antarctica (208 samples). Two CO1 clades were found, one restricted to SG (clade 1)
and another shared between SG and Antarctica (clade 2). Size investigations revealed a dimorphism at SG: only
small individuals (disc diameter < 2.5cm) were found in clade 1 while all the largest specimens (up to 6cm) were
found in clade 2. Moreover, five specimens of clade 1 were brooding, whereas clade 2 included seven Antarctic
specimens exhibiting broadcasting. These results suggest that there are different species in SG: a large
broadcaster (shared with Antarctica) and a smaller brooder (specific to SG). This SG clade is also separate from
the two Patagonian clades described in other studies. Species integrity and distribution will be tested by exome
capture analysis (hundreds of nuclear loci) and by the addition of more locations.

387
Tue_186_BE-4_1419
Corals as a Model to Measure Change in Polar Oceans

Narissa Bax1 (baxn@utas.edu.au), Laura Robinson2, David Barnes3, Chester Sands3, Rachel Downey4, Christoph
Held5, Camille Moreau6, Bernabe Moreno7, Maria Paulsen8
1
University of Tasmania, Hobart, Australia, 2University of Bristol, Bristol, United Kingdom, 3British Antarctic
Survey, Cambridge, United Kingdom, 4Australian National University, Canberra, Australia, 5Alfred Wegener
Institute, Bremerhaven, Germany, 6Universite Libre de Bruxelles, Brussels, Belgium, 7Universidad Científica del
Sur, Lima, Peru, 8University of Bergen, Bergen, Norway

Initial research by the Antarctic Seabed Carbon Capture Change (ASCCC: www.asccc.co.uk) project indicates
that Arctic and Antarctic seabeds are absorbing and storing more carbon as the climate warms. Understanding
the oceanic carbonate system across space and time is a key objective of the ASCCC multidisciplinary team. This
study uses stylasterid corals, which are key global habitat constructors, as a model taxa to conduct a systematic
study of how, where and why the changing chemistry of the ocean has the potential to affect calcification (the
ability to grow skeletons). Stylasterid corals may have the capacity to calcify and survive the predicated
acidification of the Polar regions (where pH change linked to anthropogenic CO2 is strongest). Unlike other
coral groups, stylasterids can either be composed of aragonite (more soluble), calcite (less soluble), and in
some species both. If stylasterids are able to manipulate their skeletal composition in response to oceanic
change, then they may acclimate to anthropogenic activities, such as predicted ocean warming and
acidification, which would be a significant advance in our understanding of ocean life adaptation to current and
predicted environmental change.

388
Tue_187_BE-4_1457
A New Centric Diatom Species from the Maritime Antarctic Region

Anna Oaquim1 (oaquim.bia@gmail.com), Heitor Evangelista2, Gleyci Moser3

1
Federal Fluminense University, Chemistry, Niterói, Brazil, 2State University of Rio de Janeiro, Biology, Rio de
Janeiro, Brazil, 3State University of Rio de Janeiro, Oceanography, Rio de Janeiro, Brazil

The freshwater genus Aulacoseira(Thwaites 1848: 167) was established in 1848 (Round et al.1990).In the
Antarctic Region, only one specie was recorded so far (A. principissa Van de Vijver (2012: 35)), widespread on
all sub-Antarctic islands such as Iles Crozet, South Georgia or Heard Island (Van de Vijver 2012). Doing a
qualitativy analysis in a corer with 50cm sampled at the Glubokoe Deepe Lake, Fildes Peninsula, King George
Island,west coast of the Antarctic Peninsula, 34 taxa were found and identified, of which only 19 were
considered as frequent. Among these 19 taxa the most abundant species along all layers was the centric
diatom Aulacoseira glubokoyensis, a new species discovered throughout this study. This data was relationed
with environmental variables, and showed a decrease in relative abundance and cell size in the period of higher
ozone variation. According with VICENT & SOY, 1993,
UV-B radiation can lead to harmful effects in all organisms living in aquatic environments, and some
physiological adaptation to this new condition may take generations to occur, which could explain the decline
in the relative abundance of Aulacoseira glubokoyensis during some phases and consecutive increase, showing
a possible adaptation. As it is a new species further studies about the ecology and correlation with
environmental factors are still underway.

389
Tue_188_BE-4_1501
Trophic Ecology of Antarctic Deep-sea Echinoderms of the Weddell Sea

Sergio Rossi1,2 (sergio.rossi@unisalento.it), Francyne Elias-Piera2,3

1
Università del Salento, DiSTeBA, Lecce, Italy, 2Universitat Autònoma de Barcelona, ICTA, Cerdanyola del Vallés,
Spain, 3Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

In the Southern Ocean, the trophic ecology of deep-sea communities is probably one of the most neglected. In
the present study, the food sources and energy mobilization of three different deep-sea echinoderms living in
the Weddell Sea (around 1500 m depth) were investigated with indirect tools (i.e. stable isotopes, biochemical
balance and free fatty acids contents). The stalked crinoid Dumetocrinus antarcticus, the holothurian
Rhipidothuria racovitzai, and the ophiuroid Ophiura carinifera were sampled in spring during a Polarstern
cruise. We found that stable isotopes were in line of previous results of other species (δ13C ranging from -
24.3‰ to -26.5‰; δ15N ranging from 6.8‰ to 7.9‰), showing similarities in the food sources used by the
three echinoderms. The capability to store energy by these three organisms is conspicuous and different [e.g.
from 18 to 45% of the organic matter (OM) are lipids]. The capability to mobilize energy in the form of
carbohydrates and free fatty acids among species was also very different (e.g. biomolecules ranging from 9 to
22 µg Carbohydrates mgOM-1 and from 4 to 39 µg free fatty acids mgOM-1). The fatty acid markers and the
Saturated, Mono Unsaturated and Poly Unsaturated Fatty Acid proportion were also very different depending
on the species. It is suggested that even if the food sources are similar for the three echinoderms, the
strategies to manage the energy inputs in these deep-sea organisms in polar environments may be quite
different.

390
Tue_189_BE-4_1558
Sea Ice Duration and Ice Scour Influence Macroalgae at Potter Cove, Antarctica

Dolores Deregibus1 (dderegibus@dna.gov.ar), María Liliana Quartino2,3, Katharina Zacher4, Gabriela Laura
Campana2,5, David K. A. Barnes6
1
Instituto Antartico Argentino, Coastal Biology, San Martin, Argentina, 2Instituto Antartico Argentino, Coastal
Biology, Buenos Aires, Argentina, 3Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Buenos Aires,
Argentina, 4Alfred Wegener Institute, Bremerhaven, Germany, 5Universidad Nacional de Luján, Departamento
de Ciencias Básicas, Buenos Aires, Argentina, 6British Antarctic Survey/NERC, Cambridge, United Kingdom

Isla 25 de Mayo/King George Island is one of the best studied areas, particularly Potter Cove. At Carlini station
we recorded the (1) duration of sea ice cover, (2) iceberg scouring (using experimental markers on the seabed
at 5 and 10m) and (3) biological responses, in terms of macroalgal % cover, since 2014. Although links between
sea ice duration, ice scour and benthos structure have been established, only one other locality (Rothera,
Adelaide Island) makes similar measures. We found much variability in sea ice duration, just 46, 64 and 20 days
respectively in 2014, 2016 and 2017 compared with 118 days in 2015. Correspondingly more markers were hit
(i.e. higher ice scour frequency) in 2014 and 2016 (53%±14 and 75%±10, respectively) than in 2015 (41±9). The
macroalgal % cover was significantly lower (34%±8) in 2016 compared to 2014 and 2015 (78% ±4 and 57% ±14,
respectively). These preliminary results suggest that a lower macroalgal % cover could be related with higher
ice scouring due to reduced sea ice duration among abiotic and biotic factors controlling macroalgal cover.
Maintaining these studies long term should tease out natural short term variability in time and space from
benthic ecosystem responses to regional climate-forced physical changes. Collaboration between UK,
Argentina and Germany has established matched protocols, enabling us to quantify how life on Antarctica's
seabed is responding to profound sea ice losses.

391
Tue_190_BE-4_1559
Wind & Tide Affect Antarctic Krill Aggregations in a Biological Hotspot

Kim Bernard1 (kbernard@coas.oregonstate.edu), Megan Cimino2, William Fraser3, Joshua Kohut4, Matthew
Oliver5, Donna Patterson-Fraser3, Oscar Schofield4, Hank Statscewich6, Deborah Steinberg7, Peter Winsor6
1
Oregon State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, United States, 2Scripps
Institution of Oceanography, University of California, San Diego, La Jolla, United States, 3Polar Oceans Research
Group, Sheridan, United States, 4Rutgers University, New Brunswick, United States, 5University of Delaware,
Newark, United States, 6University of Alaska - Fairbanks, Fairbanks, United States, 7Virginia Institute of Marine
Science, Gloucester Point, United States

Antarctic krill, Euphausia superba, is an abundant and ecologically important zooplankton species in the
Southern Ocean. Biological hotspots, with elevated krill biomass, exist around Antarctica, often as a result of
the concentrating effect of bathymetry and ocean currents. Such areas are key foraging grounds for numerous
top predators. A hotspot of krill biomass exists off southern Anvers Island, Western Antarctic Peninsula, and
supports a population of Adélie penguins that feed almost exclusively on it. We investigated the variability in
krill aggregations in the nearshore waters of this hotspot over four consecutive summers, identifying
environmental factors that were responsible. We identified three distinct krill aggregation types (Large-Dense,
Small-Close & Small-Sparse aggregations) and found that the relative proportion of each type varied
significantly between survey days. Large-Dense aggregations were more frequent when westerly winds
dominated and when the local mixed tide was in the diurnal regime. Small-Close aggregations were also more
frequent during diurnal tides. Conversely, Small-Sparse aggregations were more prevalent when the mixed tide
was in the semi-diurnal phase. We suggest that, under certain conditions, the biological hotspot in the
nearshore waters off southern Anvers Island, functions as a zone of accumulation, concentrating krill biomass.
Our findings provide important information on the dynamics of Antarctic krill at the local scale.

392
Tue_191_BE-4_1581
Permafrost Peatlands and Climate Change: Response on Hydrological Variations

Olga Ogneva1 (ogonlogin@gmail.com), George Matyshak1, Matvey Tarkhov1

1
Lomonosov Moscow State University, Soil Science, Moscow, Russian Federation

Nowdays permafrost peatlands (PP) of the forest-tundra transition zone are subjected to annual temperature
increase which leads to permafrost thawing and evolution of PP landscapes. In present study two predictable
scenarios of PP landscapes evolution were tested: i) flooding of PP and ii) drying with following forest invasion
in case of good drainage. The aim of the study was to estimate how organic carbon (OC) of PP will respond to
these scenarios. Peat samples were collected in northwest Siberia in the zone of discontinuous permafrost
(N65°19', E72°53'). To simulate flooding peat samples were incubated under laboratory conditions (25°C)
during 1 week at a range of WHC - from 15 to 100% and then basal respiration was measured. To simulate
drying peat samples were dried completely (25°C) and later rewetted to 60% of WHC, CO2 effluxe was
measured after the rewetting and during 30 days, to reveal fast response of OC to changed moisture
conditions.
PP show resilience to flooding and the water content changes as a whole. CO2 efflux from peat ranged from 6.0
to 6.8 mkg C-CO2 g-1 h-1 with max for 35 and min for 55% of WHC. For the dried samples CO2 effluxes increased
up to 2.5 times in the first four days after rewetting and reached values of 16.3 C-CO2 g-1 h-1, whereas declined
afterwards and reached the 5.5 C-CO2 g-1 h-1 at the end of experiment.
Thus, drying promotes rapid decomposition of OC, whereas flooding wouldn´t have the determinative effect on
peat mineralization.

393
Tue_192_BE-4_1611
Squid Prey of Antarctic fur Seals as an Environmental Change Indicator

José Abreu1 (abreu.jose@ua.pt), Iain Staniland2, José Pedro Queirós1, Jorge Miguel Pereira1, José Carlos
Xavier1,2
1
Marine and Environmental Sciences Centre - University of Coimbra, Departamento Ciencias da Vida, Coimbra,
Portugal, 2British Antarctic Survey, Cambridge, United Kingdom

Understanding how changes in environmental conditions affect prey and their predators is fundamental for
interpreting variability in natural marine ecosystems. We used the Antarctic fur seals (Arctocephalus gazella), a
top predator of cephalopods, to evaluate their potential as an indicator of change in prey availability and
local/regional environmental conditions. We used Antarctic fur seal scats (i.e. faeces) to assess the cephalopod
component of their diet from 2009 to 2013 and relate the stable isotopic signature of lower beaks (δ13C and
δ15N) to oceanographic conditions around South Georgia. Our results showed that Antarctic fur seals are
capable of feeding on a wide variety of ecologically different squid species, with S. circumantarctica being the
most frequent and with the highest number of lower beaks in the scats collected. Isotopic data revealed that S.
circumantartica is an Antarctic water species, predominantly inhabiting an offshore/oceanic habitat, with low
trophic level in relation to other species of Antarctic squids. From an ecological view, we demonstrated that in
years of abnormal environmental conditions associated with low Antarctic krill Euphausia superba density, S.
circumantarctica exhibited a higher trophic level as well a clear predominance for more offshore areas and,
occurred more frequently in the diet of Antarctic fur seals.

394
Tue_193_BE-4_1613
Unrevealing the Life of the Giant Antarctic Octopus Megaleledone setebos

José Pedro Queirós1, Darren Stevens2, José Abreu1 (abreu.jose@ua.pt), José Carlos Xavier1,3
1
Marine and Environmental Sciences Centre - University of Coimbra, Departamento Ciencias da Vida, Coimbra,
Portugal, 2National Institute of Water and Atmospheric Research (NIWA), Auckland, New Zealand, 3British
Antarctic Survey, Cambridge, United Kingdom

Gigantism among Southern Ocean organisms is a very common feature, due to the cold and oxygen-rich water.
The Giant Antarctic Octopus (Megaleledone Setebos), is known to inhabit the Southern Ocean, reaching sizes
up to 90cm and 14500g. In our study, we report the largest specimen ever found with 115cm and 18300g,
caught in January of 2017 at Dumont D'Urville Sea. This species have an important role in the food web being
present in the diet of the valuable Antarctic toothfish (Dissostichus mawsoni) and other charismatic top
predators. Yet, nothing is known about its ecology. To answer some questions, we used beaks found in the diet
of D. mawsoni and measured the content of δ13C and δ15N along the beak to reveal habitat and trophic shifts
along the life. Our results show that the values of δ13C are relative stable along the life, suggesting that this
species doesn't migrate, however the small increase of 13C content may suggest a little movement towards
offshore. In terms of δ15N values, an increase of values along the beak suggest an increase of the trophic
position along the life. Also, a correlation between δ13C and δ15N values suggest that the movement towards
offshore and the increase in the trophic chain are related. Being a benthic species, the results might suggest
that the octopus tend to descend the slope along the life, going to deeper waters and changing the type of diet
along the life, being also available in bigger sizes to the deep-sea predators.

395
Tue_194_BE-4_1652
Diversity of Photoautotrophic Mats in Lakes on James Ross Island

Linda Nedbalová1,2 (lindane@natur.cuni.cz), Jiří Komárek2, Josef Elster2,3

1
Faculty of Science, Charles University, Ecology, Prague, Czech Republic, 2Institute of Botany, Academy of
Sciences of the Czech Republic, Třeboň, Czech Republic, 3Faculty of Science, University of South Bohemia, Centre
for Polar Ecology, České Budějovice, Czech Republic

In connection to the threats connected with current climate changes, there is a growing interest in unravelling
species diversity patterns across a range of Antarctic terrestrial and freshwater habitats. There is growing
evidence that polar lakes represent valuable centres of biodiversity as well as sensitive indicators of
environmental changes. A recent limnological survey described six lake types on the Ulu Peninsula (James Ross
Island) that were classified according to their geomorphological position, stability, physico-chemical
characteristics and biota. The lakes form a valuable set of ecosystems in the transitional zone between the
maritime and continental Antarctica and therefore play an important role in the comparison with other
freshwater sites. The aim of our study was to characterize the taxonomic composition of benthic autotrophic
assemblages in the lakes and to assess the key factors that influence their composition. The sampling revealed
high diversity of microbial assemblages that was primarily determined by lake type and associated differences
in water chemistry. Massive autotrophic mats were observed mainly in the littoral zone of relatively old stable
shallow lakes, whereas the mats were absent from the young lakes. However, a large variability was also
observed within lakes belonging to one type suggesting the possible importance of priority effect in
determination of community structure in environments with minor differences in environmental conditions.

396
Tue_195_BE-4_1688
Shrubs in a Changing Arctic: Benefit or Vulnerability?

Maitane Iturrate-Garcia1 (maitane.iturrate@ieu.uzh.ch), Monique M.P.D. Heijmans2, Fritz H. Schweingruber3,

Trofim C. Maximov4,5, Pascal A. Niklaus1, Gabriela Schaepman-Strub1
1
University of Zurich, Evolutionary Biology and Environmental Studies, Zurich, Switzerland, 2Wageningen
University & Research, Plant Ecology Group and Nature Conservation, Wageningen, Netherlands, 3WSL Swiss
Federal institute for Forest Snow and Landscape Research, Birmensdorf, Switzerland, 4Institute for Biological
Problems of the Cryolithozone Siberian Branch, Yakutsk, Russian Federation, 5Institute for Natural Sciences of
North Eastern Federal University, Yakutsk, Russian Federation

Air temperature is increasing and will keep rising, more rapidly in the Arctic than in other regions. As a
consequence, soil warming is expected, which will accelerate permafrost thawing and soil organic matter
mineralization. This acceleration will enhance in turn the nutrient availability for plants. The projected changes
might affect plant diversity, traits and strategies, altering ecosystem functioning and vegetation-climate
interactions.
Here, we explore experimentally the effects of increased permafrost thawing depth and shallow nutrient
availability on plant traits, resource acquisition and growth strategy of tundra shrubs. We measured seventeen
plant traits related to resource acquisition, light interception and growth in four shrub species in a thawing and
fertilization experiment in a Siberian tundra ecosystem.
Shallow nutrient addition caused shrubs to shift from resource conservation to more rapid resource acquisition
and faster growth. These strategy responses might enhance shrub vulnerability to pests and climate extremes,
which are projected to become more frequent.
Our findings suggest that plant traits of tundra shrubs respond in a coordinated way to environmental changes.
Taking this coordinated response into account will contribute to more realistic dynamic global vegetation
models and robust predictions of shifts in vegetation, ecosystem functioning and vegetation-climate feedbacks.

397
Tue_196_BE-4_1737
Effect of Detached Algae and Predation on Soft-bottom Communities in Both Poles

María José Díaz Aguirre1 (maguirre@awi.de), Markus Molis1, Christian Buschbaum2

1
Alfred-Wegener Institute Helmholtz Institute for Polar and Marine Research, Section Functional Ecology - Rocky
Shore Ecology, Bremerhaven, Germany, 2Alfred-Wegener Institute Helmholtz Institute for Polar and Marine
Research, Wadden Sea Station Sylt, List / Sylt, Germany

The polar areas are being affected hard by the climate change. By altering the characteristics of the marine
ecosystem in both poles. In case of the sedimentary communities, which have been very little studied mostly in
relation to the importance of the biological factors (i.e. consumption, competition and bioturbation) on the
dynamic, structure and diversity of the communities.
The increase in climate change has led to an get increased in the storms, and therefore a greater action of
waves on sessile organisms such as seaweeds. Which are detached, and afterwards stranding in the intertidal
or staying at the bottom. These deposits of algae could attract predators, provide protection, perhaps to be a
nursery, or this maybe physically disturbed the organisms that live in the soft sediment. This could trigger a
change in the structure and dynamics of the community.
During 2017 work was done in the Arctic. There, samples were taken from soft bottom communities
(intermareal and subtidal) characterizing the community through species richness, individual number, Shannon
index and Evenness, as well as biomass. At the same time, field experiments are carried out to determine the
effect of detached algae and the exclusion of predators on population dynamics. These activities will be
repeated in Antarctica during the 2018 campaign.
Experiments and sampling will determine the degree of incidence of detached algae and the presence of
predators in these communities.

398
Tue_197_BE-4_1932
Thermal Stress Response in Arctic and Antarctic Pseudogymnoascus spp. Soil fungi

Nuradilla Mohamad-Fauzi1,2, Mohammed Rizman-Idid2, Siti Alias2,3 (siti.alias@gmail.com)

1
University of Malaya, Institute of Biological Sciences, Kuala Lumpur, Malaysia, 2University of Malaya, Institute
of Ocean and Earth Sciences, Kuala Lumpur, Malaysia, 3University of Malaya, National Antarctic Research
Centre, Kuala Lumpur, Malaysia

Pseudogymnoascus fungi, commonly isolated from polar soils, have been shown to secrete high levels of
extracellular hydrolase enzymes (EHE), suggesting a role as important decomposers. Pseudogymnoascus has
been shown to yield varying levels of enzymatic activity across different temperatures, but not much is known
about their initial response to heat stress and how this modulates EHE production. We sought to measure the
expression of known molecular markers of stress response following heat challenge. Three possible orthologs
of Saccharomyces cerevisiae HSP70 genes (SSA1, SSA2, SSA3 and SSA4) and one possible ortholog of HSP90
(HSP82 and HSC82) were identified among available Pseudogymnoascus spp. protein predictions. Primers for
quantitative real-time PCR were designed to amplify these identified orthologs (named HSP70A, HSP70B,
HSP70C, HSP90) as well as nine putative reference genes. Two Arctic and two Antarctic strains were cultured at
15°C (ideal temperature) for 5 days then transferred to 25°C (heat challenge temperature) for 2 hours. Similar
degrees of gene expression changes were observed in all four polar isolates. Expression of HSP70A, HSP70B and
HSP90 was induced following heat challenge, suggesting thermal stress response was elicited. HSP70B and
HSP90 showed greater upregulation and thus may be good candidates to serve as molecular markers for heat
stress in Pseudogymnoascus. This study will be expanded to include temperate strains and time-course
experiments.

399
Tue_198_BE-4_1996
Photosynthetic Activity of Marine Phytoplankton in the Antarctic Peninsula

Sazlina Salleh1 (sazlina@usm.my), Hilal Zainudin2, Firdaus Abdul Mutalib2, Mahadi Mohammad2,3, Wee Cheah4,
Nur Aqilah Muhamad Darif1,2
1
Universiti Sains Malaysia, Center for Policy Research and International Studies (CenPRIS), Penang, Malaysia,
2
Universiti Sains Malaysia, Center for Marine and Coastal Studies (CEMACS), Minden, Malaysia, 3Universiti Sains
Malaysia, School of Biological Sciences, Minden, Malaysia, 4University of Malaya, Institute of Ocean and Earth
Sciences, Kuala Lumpur, Malaysia

The photosynthetic activities of coastal marine microalgal community in the Antarctic Peninsula were
investigated during the Malaysia Antarctic Scientific Expedition 2016 conducted from 13th January to 14th
February 2016. A total of 7 stations were investigated along a southbound transect from King George Island
(62°S 58°W) to Darboux Island, Graham Coast (65°S 64°W). Sea water temperature varied from 10.5°C to -1.2°C
during the sampling. Microalgae communities were dominated by diatoms within the genus of Odentella,
Proboscia, Eucampia, Chaetoceros, Coscinodiscus and Thalassiosira during the study. The ratio of variable to
maximum fluorescence, a measure of maximum quantum yield of photosystem II (Fv/Fm) was recorded at
Darboux Island with a value of 0.291, whereas the minimum Fv/Fm of 0.053 was measured at Trinity Island.
Statistical analysis shows that although temperature, pH and light intensity, and nutrients (ammonia,
orthophosphate, nitrite and nitrate) were significantly different (p< 0.05) among the sampling stations,
photosynthetic activities of coastal marine microalgae in the Antarctic Peninsula were mainly driven by
nutrients (mainly phosphate and nitrogen).

400
Tue_199_BE-4_2008
Predicting Diatom Diversity in the McMurdo Dry Valleys with Metacommunity Models

Eric R. Sokol1 (sokole@gmail.com), Tyler Kohler2, Diane McKnight3, Mark Salvatore4

1
Battelle Ecology, Inc., National Ecological Observatory Network (NEON), Boulder, United States, 2Charles
University in Prague, Department of Ecology, Prague, Czech Republic, 3University of Colorado Boulder, INSTAAR,
Boulder, United States, 4Northern Arizona University, Department of Physics & Astronomy, Flagstaff, United
States

Diatoms represent a diverse group of primary producers that reside in microbial mats in aquatic habitats in the
McMurdo Dry Valleys. Recent work has shown that different factors control diatom biodiversity in stream and
pond ecosystems. Glacier-fed streams provide intermittent habitats where flow permanence can vary widely
depending on the geomorphology of the catchment and factors controlling glacier melt. Alternatively, ponds
provide insulated and persistent habitats for microbial mats and their resident diatoms. As such, diatom
community composition is predicted by flow permanence in streams, whereas variation in diatom biodiversity
among ponds appears to be better explained by dispersal dynamics and colonization history. Numerical models
provide a tool to test alternative hypotheses about the underlying processes that shape observed biodiversity
patterns, and make informed predictions about biodiversity in future climate scenarios. Here we present
advances in a metacommunity simulation package for R (MCSim) and demonstrate how it can be used to test
alternative community assembly hypotheses to explain freshwater diatom biodiversity data that was collected
by the McMurdo Dry Valleys Long Term Ecological Research (MCM-LTER) program. Further, we demonstrate
how parameterized simulations can be used to predict biodiversity metrics, such as beta-diversity (among-pond
or among-stream variation in community composition), in altered climate scenarios.

401
Tue_200_BE-4_2075
Down-fjord Changes in Macrobenthos in Glacially Influenced Andvord Bay, WAP

McKenna Lewis1 (mslewis@hawaii.edu), Craig Smith1, Iris Altimira1, Maria Vernet2, Andrew Sweetman3, Clifton
Nunnally1
1
University of Hawai`i at Manoa, Oceanography, Honolulu, United States, 2Scripps Institution of Oceanography,
La Jolla, United States, 3Herot-Watt University, Edinburgh, United Kingdom

Glaciomarine fjords exhibit substantially different ecosystem forcing than adjacent continental shelves and can
be highly sensitive to climate warming. Extensive research indicates that subpolar Arctic fjords are heavily
influenced by glacial meltwater/sediment inputs, resulting in high turbidity and seafloor burial rates, yielding
macrofaunal communities with low abundance and diversity. In contrast, poorly-studied sub-polar fjords along
the Western Antarctic Peninsula (WAP) sustain weak meltwater influences, resulting in low turbidity and
seafloor burial rates. Thus, benthic communities in WAP fjords may not currently be limited by turbidity and
burial disturbance, and have the potential to harbor abundant and diverse macrobenthic communities. Here
we characterize the benthic macrofaunal community of Andvord Bay, a subpolar fjord along the warming WAP.
We compare down-fjord changes in macrobenthic abundance, diversity and functional-group structure to a
variety of potential ecological drivers including sediment burial rate, sediment Chl-a concentration (an indicator
of labile detritus availability), and sediment-community respiration (an indicator of seafloor detrital carbon
flux). Benthic abundance is high in mid-fjord, and is most strongly correlated with carbon flux and food
availability, while burial disturbance may occur only within 1-kilometer of actively flowing tidewater glaciers.
These patterns are likely to change as warming increases meltwater/sediment inputs.

402
Tue_201_BE-4_2097
Plant-endophyte Association: Tolerance Mechanism to Drought Stress in Antarctic

Rasme Hereme-Ruedlinger1 (rasme.hereme@gmail.com), Marco Molina-Montenegro1, Simon Ruiz-Lara1

1
Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile

One of plants mechanisms for stress tolerance is the functional symbiosis such as endophytism, which is
defined as the mutual association of a plant with a microorganism, which lives inside the tissues of the plant
without causing any symptom of disease. On the other hand, Antarctica is known as one of the most stressful
environment, due to its extreme aridity and subzero temperature, however, despite the adverse conditions it is
possible to find two vascular plant species: Deschampsia antarctica and Colobanthus quitensis. The presence of
C. quitensis in Antarctica stands out above D. antartica, due to the fact that it has not been possible to establish
a charasteristic to survive such extreme conditions. In this investigation, we compared the production of total
soluble sugars, proline and oxidative stress in individuals of C. quitensis with endophytic fungi (E+) and without
endophytic fungi (E-) under optimal irrigation (H+) and drought stress conditions (H-), concluding that the
presence of endophytes plays an important role in the mechanism of tolerance to stress, since in individuals E+,
there is a higher production of sugars and less damage by oxidative stress. Besides, this pattern was observed
in three sampling sites along a latitudinal gradient from -53° to -67° latitude (South of SouthAmérica, Polish
Base Arctowski and Lagotellerie in Antarctica), being individuals from more stressful sites more dependent on
the presence of endophytes to tolerate drought stress.

403
Tue_204_BE-4_2348
Transcriptome of the Branchinecta gaini: Unraveling the Thermal Stress Response

Marcelo Gonzalez1 (mgonzalez@inach.cl), Alejandro Font1, Cesar Cardenas1, Magdalena Osorio1, Jean-Yves
Toullec2, Erwan Corre2
1
Instituto Antartico Chileno, Punta Arenas, Chile, 2Station Biologique de Roscoff, Roscoff, France

The Antarctic fairy shrimps crustacean Branchinecta gaini (Branchiopoda, Anostraca) inhabits freshwater lakes
and pools in Antarctica, one of the most hostile environments on earth. In Maritime Antarctica occurs in
several fresh water lakes in Fildes Peninsula (King George Island, South Shetland Islands). This crustacean
showed a great physiological flexibility to support highly fluctuating environments. Despite their adaptations
for cope a high environmental variability, transcriptome studies have not yet been performed on this
crustacean. RNA samples were extracted from a pool of adults individuals and the sequencing was performed
using the Illumina platform HiSeq2500. Over 48 million total reads were assembled into 43,847 contigs. 16,503
annotated genes were obtained and they represent 36,68 % of total transcriptome. A total of 57 GO terms in
three ontologies was obtained. B.gaini expressed several heat shock proteins like as Hsp90, Grp94, Hsp70,
Hsp40 and proteins related to ubiquitin mediated proteolysis. These data sets are the first transcriptome
resource for this Antarctic Brachiopoda and constitute the first step toward further studies linked to stress
response, phylogenetics or molecular mechanics to stress response.

404
Tue_205_BE-4_2404
GHG Emissions Potentials in Maritime Antarctica

Flávia Ramos Ferrari1 (flaviarferrari@gmail.com), André Thomazini2, Antonio Batista Pereira3, Kurt Spokas4,
Carlos Ernesto Gonçalves Reynauld Schaefer5
1
Universidade Federal de Viçosa / INCT da Criosfera, Departamento de Biologia Vegetal - Núcleo TERRANTAR,
Viçosa, Brazil, 2Universidade Federal de São João del Rei, Departamento de Ciências Agrárias - Núcleo
TERRANTAR, Sete Lagoas, Brazil, 3Universidade Federal do Pampa, NEVA - Núcleo de Estudos da Vegetação
Antártica, São Gabriel, Brazil, 4University of Minnesota, Soil and Water Management Unit, Saint Paul, United
States, 5Universidade Federal de Viçosa / INCT da Criosfera, Departamento de Solos - Núcleo TERRANTAR,
Viçosa, Brazil

Soil development and nutrient cycling are the main drivers of greenhouse gas production in terrestrial
ecosystems of Antarctica. Vegetation cover, biological influence, temperature and soil moisture strongly affect
this dynamic. Thus, the objective of this work was to evaluate the potential of greenhouse gases production in
lab of the main terrestrial ecosystems in a toposequence in King George Island, Maritime Antarctica, under
different temperatures (-2, 4, 6 and 22ºC). Greater N2O emissions were observed in Deschampsia - Prasiola
communities, under ornithogenic influence, reaching 22.58 ngN/gsoil/day at 6ºC. Higher CH4 emissions were
observed in Moss Carpets and Fanerogamic Communities, showing greater variations at 6ºC (2.67
ngC/g_soil/day). Lichen community presented low potential of emission in elevated positions of the landscape,
with similar behavior of bare soil. We observed elevated CO2 emissions in Fruticosus Lichens community at
22ºC (22.08 ugC/g_soil/day), followed by Fanerogamic Communities. Biological activity and increasing
temperatures enhances the potential of greenhouse gases emissions, especially in communities with
ornithogenic influence and vegetation coverage.

405
Tue_206_BE-4_2463
Increase Temperature Favors the CO2 Assimilation of Antarctic Vascular Species

Patricia L. Sáez1 (patrisaezd@gmail.com), Lohengrin Cavieres1, Constanza Ramírez1, Jeroni Galmes2, Leon A.
Bravo3
1
Universidad de Concepción, Concepcion, Chile, 2Universidad de Islas Baleares, Palma de Mallorca, Spain,
3
Universidad Andres Bello, Temuco, Chile

Under in situ warming experiment we have detected that the increase temperature favors the carbon gain of
only one Antarctic vascular species, Colobanthus quitensis; whilst Deschampsia antarctica seems to be less
responsive.Our in situ warming experiments increasing daytime temperature by about 3 ºC. However, climate
change predictions indicate that event of supra-optimal temperatures become more prevalent. This raises the
question of whether the differential response between Antarctic species depending on the magnitude of the
increase temperature. In other words, would D. antarctica be able to show a similar response facing higher
temperature increases? With this aim,Antarctic species were cultivated in room chambers at 5, 10 and 16 °C.
Increase temperature favored the net photosynthesis (AN) of both Antarctic species. However,D. antarctica
requires higher increase temperature to respond. In both species, higher AN were triggered by a reduction in
mesophyll conductance, accompanied by changes in leaf anatomy. Therefore, in the long term, it is possible to
assume that both species could be affected by regional climate change and their ability to respond will depend
not only on functional but also structural adjustments that allow them to grow under the new conditions.
Acknowledgments: FONDECYT 11130332, PIA ART-1102, INACH RT 13_16 and H. Arctowski Polish Antarctic
Station.

406
Tue_207_BE-4_2493
Transcriptome of Antarctic-endemic Sponge Reveals Heat Shock Proteins Expression

Magdalena Osorio1,2 (magdalena.osorio.a@gmail.com), Marcelo Gonzalez1, Alejandro Font1, Nathan Kenny3,

Ana Riesgo3, Cesar Cardenas1
1
Instituto Antártico Chileno, Punta Arenas, Chile, 2Universidad de Chile, Departamento de Bioquimica y Biologia
Molecular, Santiago, Chile, 3Natural History Museum London, London, United Kingdom

At the molecular level, the production of heat shock proteins (HSPs) has been commonly used as an indicator
of environmental stress. HSPs are highly conserved proteins that act as chaperones to stabilize and refold
denatured proteins, preventing the formation of cytotoxic aggregates. The production of HSPs is a potential
ecophysiological mechanism whereby Antarctic sponges can adapt to thermal stress; however, there is mixed
evidence that HSPs are an important regulating mechanism in Antarctic organisms. In some Antarctic marine
invertebrates the expression of HSP is absent. Although, previous studies on sponges from tropical waters have
reported that thermal stress produces rapid molecular shutdown of sponge's molecular systems and increased
expression of HSPs, the effect of heat stress on Antarctic sponges remains largely unexplored. In order to
identify the heat stress protein in the Antarctic sponges, we obtained a reference transcriptome of Antarctic-
endemic sponge Isodictya sp. resulted in 125,873 transcripts with an average size of 812 bp. In depth analysis
of the data revealed an extensive catalogue of the cellular chaperone systems. Full length sequences were
characterized for the chaperones HSP70 and several isoforms were identified during the thermal stress at 3°C
and 5°C. Further studies of qPCR analysis will be used to validate changes in the transcript abundance of HSP70
during the heat shock.

407
Tue_208_BE-4_2515
Long-term Effects of Climate Change on High Arctic Plant Species

Esther R. Frei1,2 (esther.frei@wsl.ch), Greg Henry2

1
WSL Swiss Federal Institute for Forest Snow and Landscape Research, Birmensdorf, Switzerland, 2University of
British Columbia, Vancouver, Canada

Rapid climate change leads to changes in the structure and composition of Arctic tundra plant communities
with unknown consequences for ecosystem functioning. Plant traits act as key mechanisms explaining
feedbacks between climate change and vegetation. We investigated how elevated temperatures and altered
snowmelt regimes affect common tundra plant species in a High Arctic evergreen shrub heath community at
the International Tundra Experiment (ITEX) site at Alexandra Fiord on Ellesmere Island, Nunavut, Canada. A
factorial experiment combining passive warming, snow removal, snow addition and control treatments was
established in 1995. We examined phenological, growth and leaf functional trait responses of six common
tundra species to two decades of experimental warming and altered snowmelt regimes. Snowmelt timing
primarily controlled early season phenology, but had less influence on later phenological stages, on growth and
leaf functional traits. Experimental warming generally advanced flowering and seed ripening. Warming effects
persisted over the course of the growing season increasing plant growth, but had little effects on leaf functional
traits. Our results underline the importance of understanding how interactions of temperature and snowmelt
timing drive plant species responses to climate change in the Arctic.

408
Tue_209_BE-4_2528
The Distribution of Aerotechnogenic Pollutants on Islands of Arctic

Olga Gommershtadt1 (gommershtadt_olga@mail.ru)

1
Moscow State University, Environmental Management, Moscow, Russian Federation

In this study, the results of a year research in the field of Arctic ecology will be considered. This research took
place in different islandic territories of Arctic, such as Franz-Joseph Land, Novaya Zemlya, Svalbard, Iceland,
Faroe islands. All of these islands are located in the western sector of Eurasian Arctic. In summer 2017 I took
moss samples on several islands: Franz-Joseph Land (Heiss, Alger, Hooker islands), Novaya Zemlya (cape
Zhelaniya on Northern island), Faroe islands (Sandoy, Mykines, Vágar, Streymoy). Also I have samples that were
taken in Svalbard (with help of glaciology students in July, 2017) and Iceland's samples data (taken earlier by
MSU research group).
The main goal of this investigation is deep analysis of spatial distribution of aerotechnogenic pollutants in Arctic
and mapping it. Knowing the pollution values can help to investigate what affects the ecosphere of these
islandic territories.
The main moss samples are mostly represented by following species: Tomentyphnum nitens, Sphagnum,
Flavocetraria, Calliergon, etc. All of them have gone through the process of atomic absorption spectrometry
analysis which is a procedure for the quantitative determination of chemical elements using the absorption of
optical radiation by free atoms in the gaseous state. This type of analysis is considered as one of the most-used
type of bioindication.
The results of this research will be represented in Moscow State University in may, 2018.

409
Tue_211_BE-4_2621
Meroplankton and Potential for Benthic Colonization in High-Arctic Ecosystems

Katarzyna Walczyńska1 (katarzyna.walczynska@phdstud.ug.edu.pl), Agata Weydmann1, Marta Ronowicz2,

Janne Søreide3, Tove Gabrielsen3
1
University of Gdansk, Institute of Oceanography, Department of Marine Plankton Research, Gdynia, Poland,
2
Polish Academy of Sciences/Institute of Oceanology, Sopot, Poland, 3The Univeristy Centre in Svalbard,
Longyearbyen, Norway

Barnacles (Crustacea: Cirripedia) are an important group of organisms in marine ecosystems, but they are also
meaningful from the human perspective. They have big potential for biofouling, which is a significant vector for
transferring invasive species. Furthermore, spreading over large distances and colonization of new territories is
possible due to possessing planktonic larvae. Still, knowledge about larval development is scarce and because
of their small sizes, differentiation of species by morphological methods is almost impossible.
We studied the timing, growth and duration of Cirripedia larvae year-round in a high Arctic fjord Adventfjorden
(Spitsbergen). Zooplankton community analyses revealed that cirripedia occasionally was found in February-
March, but first busted in abundance in late April at the onset of the spring bloom. DNA barcoding revealed the
presence of two species: Balanus balanus and Semibalanus balanoides, of which the first one totally dominated
the zooplankton community in April-May during the peak spring bloom. Image analyses based on photographs
taken prior to molecular identification allowed to estimate the duration of each larval stage, including nauplii
and cypris, and their growth over 300µm.
Long pelagic presence, large potential for biofouling on ships and larger plastic debris, combined with the
disappearance of landfast sea ice and thus less ice scouring opens new opportunities for barnacles to colonize
high-Arctic littoral zone.

410
Tue_212_BE-4_2632
Why the Arctic Calanus glacialis and Boreal C. finmarchicus Cannot Hybridize?

Agata Weydmann1 (agataw@ug.edu.pl), Aleksandra Przyłucka2, Marek Lubośny2, Katarzyna Walczyńska1, Ester
Serrao3, Gareth Pearson3, Artur Burzyński2
1
University of Gdansk, Department of Marine Plankton Research, Gdynia, Poland, 2Institute of Oceanology of
Polish Academy of Sciences, Sopot, Poland, 3University of Algarve, CCMAR, Faro, Portugal

Due to the recently observed climatic changes copepods are shifting their spatial distribution northwards, and
increasing numbers of boreal species co-occur with the Arctic ones, what may potentially lead to interbreeding
between sibling species. We determined the nearly complete mitochondrial genomes of the Arctic Calanus
glacialis and its North Atlantic sibling Calanus finmarchicus, which are key zooplankton components in marine
ecosystems. The sequenced part of C. glacialis mitogenome is 27,342 bp long and consists of two contigs, while
for C. finmarchicus it is 29,462 bp and six contigs, what makes them the longest reported copepod
mitogenomes. The typical set of metazoan mitochondrial genes is present in these mitogenomes, although the
non-coding regions (NCRs) are unusually long and complex. The mitogenomes of the closest species C. glacialis
and C. finmarchicus, followed by the North Pacific C. sinicus, are structurally similar and differ from the much
more typical of deep-water, Arctic C. hyperboreus. This evolutionary trend for the expansion of NCRs within the
Calanus mitogenomes increases mitochondrial DNA density, what resulted in its similar density to the nuclear
genome. Large differences in the length and structure of the sibling C. glacialis and C. finmarchicus
mitochondrial genomes indicate that the species are genetically distinct and have evolved independently for
quite a long time. Thus, it seems unlikely that C. glacialis and C. finmarchicus can hybridize.

411
Tue_213_BE-4_2672
Effects of Sea Ice on Arctic Biota

Marc Macias-Fauria1 (marc.maciasfauria@ouce.ox.ac.uk), Eric Post2

1
University of Oxford, School of Geography and the Environment, Oxford, United Kingdom, 2University of
California, Davis, Department of Wildlife, Fish and Conservation Biology, Davis, United States

The rapid decline in Arctic sea ice (ASI) area and volume during recent decades poses urgent questions
regarding its effects on Arctic biota. These trends are occurring before we can understand many of the
mechanisms through which ASI is coupled with biological processes both at sea and on land. This, in turn,
hampers our ability to predict and manage the consequences of this enormous environmental change, making
this a crisis discipline. Here, we propose a framework to study these effects, defining direct effects as those
acting on life history events of Arctic biota, and indirect effects, where ASI acts upon biological systems through
chains of events, normally involving weather/climate and/or biotic interactions. Examples of these processes,
and of the array of methodologies used to study them, are presented. Given the breadth and complexity of
ASI's effects on Arctic biota, Arctic research requires a truly multidisciplinary mindset to address this issue. In
the absence of effective global efforts to tackle anthropogenic global warming, ASI will likely continue to
decrease, the conservation of many ASI-related taxonomic groups and ecosystems becoming severely
compromised, with mitigation actions limited to other processes that interact with the biological effects of ASI,
such as industrial human activities.

412
Tue_214_BE-4_2680
Phylogeography of Halicarcinus planatus: First Marine Alien Reaching Antarctica

Karin Gerard1 (karin.gerard@umag.cl), Zambra Lopez2, Constanza Ceroni1, Claudio Gonzalez1,3, Elie Poulin3
1
Universidad de Magallanes, Facultad de Ciencias, Punta Arenas, Chile, 2Universidad de Chile, Santiago, Chile,
3
Instituto de Ecologia y Biodiversidad, Santiago, Chile

Climate change directly impacts and shapes the biodiversity. Biological invasions are a crucial component of
global change, but also a threat to native biodiversity. Antarctica remains the most pristine and isolated
continent surrounded by oceanographic, bathymetric, climatic and geographic barriers. Shallow marine benthic
communities around Antarctica exhibit high levels of endemism, gigantism, slow growth, longevity and late
maturity. The decapods are highly abundant and diverse in the Subantarctic but almost completely absent from
the shallow Antarctic benthos. The West Antarctic Peninsula (WAP) is one of the areas most affected by global
warming thus enhancing the probabilities of introduction of alien species. In 2010, a mature female
Halicarcinus planatus was reported in Deception Island (WAP; Aronson et al., 2015). This species has a circum-
subantarctic distribution, a low bathymetric range, an extended planktonic larval duration. In the Subantarctic,
the genetic diversity of H. planatus is high and the phylogenetic relationships (mitochondrial and nuclear locus)
between the Magellanic Region, Falklands/Malvinas Islands and Kerguelen Islands indicates a recent
connectivity. However, some genetic differentiation is observed between close locations. An appraisal of the
presence of H. planatus along the West Antarctic Peninsula at the end of our two first Antarctic expeditions is
detailed.

413
Tue_215_BE-4_2685
DREB/CBF Analysis in Colobanthus quitensis (Kunth) Bartl., under Abiotic Stress

Carolina Galleguillos1 (carogalleguillos@gmail.com), Marco Molina2

1
Universidad de Talca, Instituto de Ciencias Biológicas, Talca, Chile, 2Universidad de Talca, Talca, Chile

Colobanthus quitensis is one of the two vascular plants native to Antarctica. Antarctic enviromental conditions
are highly stressful for terrestrial vegetation, for example; low temperatures, low water availability and high
winds are combined to make this continent a hostile habitat. Transcription factors DREB / CBF type, regulators
of the response to abiotic stress, are activated by low water availability, low temperatures and salinity. The
knowledge of this type of transcription factors in C. quitensis until now is limited. From the transcriptome
sequenced antarctic Colobanthus quitensis fifteen putative sequences with a high percentage of similarity from
DREB / CBF family were obtained. From these fifteen sequences, eight of them present a high percentage of
identity for homologous genes and also present the APETALA2 (AP2) domain, characteristic for the family of
this type of transcription factors. An analysis of the sequences, alignment and phylogenetic analysis were
performer. Primers were design for eight sequences with greater identity. Results from quantitative real time
PCR, showed significantly high levels of relative expression of putative DREB/CBF Colobanthus quitensis genes
in response to abiotic-stress treatments.

414
Tue_216_BE-4_2690
Spiders in Warmer, Wetter Climates Experience Higher Rates of Egg Sac Parasitism

Amanda Koltz1 (amanda.koltz@gmail.com)

1
Washington University in St Louis, Biology, St. Louis, United States

Host-parasite relationships can be important drivers of population dynamics with community-level

consequences. Although these relationships are often studied by monitoring populations through time, spatial
variation also plays a role in shaping dynamics of host and parasite populations. In the Arctic, frequent turnover
in arthropod community composition between habitats suggests that host-parasite dynamics also vary across
the landscape. Moreover, differences in species-specific responses to rapid climatic changes are expected to
result in altered host-parasite dynamics, although it is unclear what the primary drivers of these dynamics may
be. Here I show that while rates of parasitism in wolf spider egg sacs by parasitoid wasps differ along a
latitudinal gradient of tundra in Alaska (0-18%), they are not related to wolf spider population sizes, abundance
of egg sac prey, or to abundances of potential parasitoid wasps. Rather, higher rates of parasitoid attacks on
wolf spider egg sacs occur in areas that have warmer and wetter climates. Climate projections for N. Alaska
include warmer temperatures and increased precipitation, suggesting that wolf spiders may experience higher
rates of parasitism in the future with potential consequences for their population dynamics. As wolf spiders are
one of the most abundant predators across much of the Arctic, increasing parasitism rates could also have
cascading effects on lower trophic levels and on ecosystem functioning.

415
Tue_217_BE-4_2692
Integrative Biogeography in Southern Ocean Mollusks

Claudio Gonzalez-Wevar1,2 (claudio.gonzalez@umag.cl), Karin GERARD1, Sebastian Rosenfeld1,2, Thomas

Saucède3, Elie Poulin2
1
Universidad de Magallanes, Facultad de Ciencias, Punta Arenas, Chile, 2Instituto de Ecologia y Biodiversidad,
Santiago, Chile, 3Université de Bourgogne Franche-Comté, Dijon, France

The biogeography of the Southern Ocean marine benthic biota and its current bioregionalization are the
consequence of major tectonic, oceanographic and climate changes during the last 50 Ma. Here, we present
new biogeographical analyses based on nuclear and mitochondrial markers in different groups of near-shore
benthic mollusks with contrasting developmental modes that are currently distributed in different provinces of
the Southern Ocean; direct developers (Margarella, Laevilitorina, and Siphonaria) and broadcast-spawners
(Nacella, and Yoldia). In general, all groups exhibited major levels of genetic divergence between Antarctic and
Subantarctic provinces suggesting that the Antarctic Polar Front is an effective biogeographic barrier.
Phylogeographic analyses recorded low levels of genetic diversity in Southern Ocean mollusks as a
consequence of Quaternary glacial processes that affected population sizes. Surprisingly, direct developers
(Margarella, Siphonaria) exhibited high levels of genetic identity, thus supporting that rafting as an important
biogeographic mechanism in the Southern Ocean. In contrast, broadcast-spawners (Nacella, Yoldia) showed
marked genetic distinction among distant Subantarctic provinces. In this case, life-history traits constrains
prevent long-dispersal through larvae in these groups. Finally, current biogeographical patterns in Southern
Ocean mollusks are not related to particular groups but to historical and contemporary processes.

416
Tue_218_BE-10_67
Functionality of the Aryl Hydrocarbon Receptor 2 in Antarctic Notothenioid Fish

Anneli Strobel1 (anneli.strobel@unibas.ch), Roger Lille-Langøy2, Patricia Burkhardt-Holm1, Helmut Segner3,

Anders Goksøyr2, Odd André Karlsen2
1
University of Basel, Environmental Sciences, MGU, Basel, Switzerland, 2University of Bergen, Bergen, Norway,
3
University of Bern, Bern, Switzerland

The Aryl hydrocarbon receptor (Ahr) pathway is a common entry point for the biological activity of dioxin-like
compounds. Currently, no information exists on the presence and functionality of the Ahr in Antarctic
notothenioid fishes.
Several proteins have been lost in in Antarctic fish. We aimed to investigate if Antarctic notothenioids have
conserved a functional Ahr. Specifically, we identified and cloned the Ahr2 sequence and tested its sensitivity
to Ahr model-agonists in vitro using a luciferase reporter gene assay in which COS7-cells were transfected to
express the Ahr2 ligand binding domain of the red-blooded Trematomus loennbergii and the white-blooded
Chionodraco hamatus, originating from the Weddell Sea.
We firstly demonstrated that Antarctic fish express Ahr2 in liver and found that the Ahr2 of both species was
activated by Ahr agonists (e.g. Benzo(a)pyrene & dioxine-like PCBs) in the ligand binding assay. The activation
was similar or only 50% in the Antarctic fish compared to the response of the Atlantic cod (G. morhua) ligand-
binding domain, which served as reference.
Our study revealed that Ahr2 in (the investigated) Antarctic fish have retained the ability of being ligand-
activated, and could potentially induce the Ahr2-mediated toxicant metabolism. We thus conclude that
Antarctic fish might have the capability to handle anthropogenic pollutants, yet differences in the induction
capability and thus xenobiotics metabolism rate may exist to temperate zone fish.

417
Tue_219_BE-10_392
Regulation of a Lost Inducible Heat Shock Response in Antarctic Fishes

Samuel Bogan1 (bogans@sonoma.edu), Sean Place2

1
Sonoma State University, Biology, Rohnert Park, United States, 2Sonoma State University, Rohnert Park, United
States

The perciform suborder Notothenioidei is comprised of Antarctic and sub-Antarctic fishes, several of which
have lost their ability to rapidly upregulate major heat shock proteins (HSPs) in response to stress. Rather,
inducible HSPs such as the hsp70 and hsp90 families are constitutively expressed under normal environmental
conditions and do not upregulate following oxidative damage to the cell. While it was initially suggested that
the constitutive expression of HSPs resulted from constant cold-denaturation of the proteome, inducible HSPs
are not downregulated by these species following reduced protein damage. It is plausible that this trait is
attributed to functional alterations in regulatory elements of the inducible heat shock response (HSR). In order
to identify genomic divergence within Notothenioidei that may confer the loss of an inducible HSR, we
sequenced the full coding region of the transcription factor HSF1 as well as genome-wide, cis-acting heat shock
element (HSE) motifs in two members of the Nototheniidae family: Trematomus bernacchii, which has lost
induction of the HSR, and Notothenia angustata, a temperate notothen exhibiting a classical HSR. We have
compared the degree of conservation between HSF1 orthologs in both species in addition to their homology
and spacing of HSE repeats. These results provide insight into how the regulation of inducible proteins can be
modified to confer constitutive expression or activation as a process of adaptation.

418
Tue_220_BE-10_1776
Evolutionary Adaptation Potential and Population Structure of Notothenia spp

Henrik Christiansen1 (henrik.christiansen@kuleuven.be), Franz M. Heindler1, Bart Hellemans1, Esteban Barrera-

Oro2, Anton P. Van de Putte1,3, Filip A. M. Volckaert1
1
KU Leuven, Laboratory of Biodiversity and Evolutionary Genomics, Leuven, Belgium, 2Instituto Antártico
Argentino and CONICET, Buenos Aires, Argentina, 3Royal Belgian Institute of Natural Sciences, OD Nature,
Brussels, Belgium

Global change is fundamentally altering marine ecosystems of Antarctica, albeit with at times opposite effects
in different areas, e.g., decreasing or increasing sea ice cover. Marine organisms are expected to cope variably
with these changes; some may benefit, while others face extinction. Adaptation to changing environmental
conditions is one option to avert demise. Standing genetic variation is key for this as it can facilitate adaptation
at much faster rates than adaptation from new mutations. In this context, knowledge of genetic diversity in
time and space is important to investigate evolutionary adaptation potential of Antarctic species. We use
reduced representation sequencing to genotype thousands of genetic markers in the Antarctic fish Notothenia
coriiceps and Notothenia rossii. We assess genetic variation and differentiation, particularly in the Western
Antarctic Peninsula region. Furthermore, we employ a series of genome scan methods to detect loci that are
putatively under selection, i.e., showing signs of recent evolutionary action. Combining patterns of neutral and
adaptive genetic variation can give clues as to how species have evolved in the past and how they may react to
rapid changes in the future.

419
Tue_221_BE-10_2087
Identifying Thresholds for Cellular Stress Responses to Heat in Antarctic Fishes

Bradley Buckley1 (bbuckley@pdx.edu)

1
Portland State University, Biology, Portland, United States

The fishes of the Southern Ocean display profoundly cold-adapted physiologies due to their long evolutionary
history in the extreme cold. As oceans warm, these fishes are poised to act as bellwethers for the likely impacts
of small incremental rises in water temperature. While the fact that these fish possess some of the lowest
upper thermal tolerance limits of any vertebrate species has been established, the impact of sub-lethal heat
stress is not as well characterized. Here, we measured the effects of increases in temperature on thermal
tolerance and cellular stress responses in the common Antarctic rockcod genus, Trematomus. Interspecific
differences in thermal tolerance and heat shock protein expression were characterized among co-occurring
Trematomus spp. from McMurdo Sound. Flow cytometry revealed perhaps the lowest upper thermal threshold
for the onset of programmed cell death in any vertebrate species, with significant increases in the number of
hepatocytes entering apoptosis occurring at only 2°C. A key cell cycle arrest regulator was also induced by heat
in these fish. Together these findings provide evidence at the cellular level that even seemingly minor
elevations in temperature produce deleterious impacts on species from extremely cold environments.

420
Tue_222_BE-10_2128
Correlation between Degree of Herbivory and Gut Morphology in 8 Notothenioids

Eugenia Moreira1 (eugeniamoreira@yahoo.com.ar), Manuel Novillo2,3, Joseph T. Eastman4, Esteban Barrera-

Oro1,2,3
1
Instituto Antártico Argentino, División Ictiología, Buenos Aires, Argentina, 2CONICET, Caba, Argentina, 3Museo
Argentino de Ciencias Naturales 'Bernardino Rivadavia', Caba, Argentina, 4Ohio University, Department of
Biomedical Sciences, Athens, United States

Although many notothenioid fishes are primarily carnivorous, some species consistently feed on macroalgae
and are therefore omnivorous. The degree of herbivory is reflected in the morphology of the digestive tract
especially intestine length. We examined a large number of juvenile and adult specimens of eight sympatric
notothenioid species collected at Potter Cove during eight consecutive seasons. We compare, in most cases for
first time for an ontogenetic series, the distinct proportions of algae and animal prey in their diets (W %), and
provide their relative intestine lengths [RIL= (IL/SL)*100]. Based on this correlation a “ranking” or degree of
herbivory is established for the fish species analysed, and this was found to be related to their distinct feeding
types and strategies. The benthos feeders Gobionotothen gibberifrons, Notothenia coriiceps, N. rossii and
Trematomus bernacchii were the most herbivorous with higher RILs (> 70%). Conversely, Lepidonotothen
nudifrons, T. newnesi and Harpagifer antarcticus were predominantly carnivorous, with lower and intermediate
RILs values (< 43-52%). Our results are discussed in context of gut morphology, trophic ecology and buoyancy
as aspects of their divergence into to the trophic web of the Antarctic ecosystem.

421
Tue_223_BE-10_2331
Notothenioids in the Ichthyoplankton at Potter Cove, South Shetland Islands

Esteban Barrera-Oro1,2,3 (ebarreraoro@dna.gov.ar), Gabriela Piacentino2, Eugenia Moreira1

1
Instituto Antártico Argentino, Biology, San Martín, Argentina, 2Museo Argentino de Ciencias Naturales
'Bernardino Rivadavia', Ictiología, Buenos Aires, Argentina, 3CONICET, Buenos Aires, Argentina

At Potter Cove, King George Island/Isla 25 de Mayo, significant ichthyological research has been conducted in
the last three decades, mainly on general ecology of notothenioid species in demersal stages from young
juveniles to adults. Nevertheless, the knowledge of the ichthyoplankton composition in the cove, necessary for
the overall comprehension of the species life-cycles, remained unexplored. Herein we report the first record of
early stages of Antarctic notothenioids collected in pelagic hauls at Potter Cove in summers of 2014 and 2016
at depths of 6-9 m from the surface, where total bottom depth ranged 30-190 m. The ichthyoplankton
consisted of a), 37 larval stages (preflexion and postflexion) of the species Harpagifer antarcticus (the most
abundant), Psilodraco breviceps, Lepidonotothen squamifrons, Pleuragramma antarcticum and Trematomus
scotti; b), 15 eggs of Notothenia coriiceps, of which two larvae hatched in aquarium. Part of this material is
illustrated with photographs. The presence of early life stages of fish in the cove is linked to the major influx
from the Bransfield Strait and also depends on local environmental conditions (i.e. hydrologic, water
circulation). In addition to the spawning behavior of Parachaenichthys charcoti already reported in the
literature, nearshore localities of the South Shetland Islands such as Potter Cove appear to be spawning sites
also for N. coriiceps and H. antarcticus.

422
Tue_224_BE-10_2373
Lipid Dynamics and Trophic Patterns of Antarctic Silverfish in the Weddell Sea

Jilda Alicia Caccavo1 (jildaalicia.caccavo@studenti.unipd.it), Marc Boutoute2, Doreen Kohlbach3,4, Hauke

Flores3,4, Patrick Mayzaud2
1
Università degli Studi di Padova, Dipartimento di Biologia, Padova, Italy, 2Laboratoire d'Océanographie de
Villefranche, UMR7093 du CNRS-UPMC Université Paris 06, BP 28, Villefranche-sur-Mer, France, 3Alfred
Wegener Institute Helmholtz Center for Polar and Marine Research, Polar Biological Oceanography,
Bremerhaven, Germany, 4Centre for Natural History (CeNak), Zoological Museum, University of Hamburg,
Hamburg, Germany

Antarctic silverfish (Pleuragramma antarctica) are a keystone species in the Southern Ocean, providing an
essential link between trophic levels. Pelagic throughout all of their life history, with an energy-efficient
foraging strategy, P. antarctica population structure is heavily impacted by hydrography and bathymetry.
Considering the role of water mass dynamics in the distribution and availability of P. antarctica prey species,
prey consumption might vary depending on the local hydrographic environment. High abundances of silverfish
have been found associated with trough systems in the Weddell Sea. While much is known about the trophic
plasticity and habits of adult P. antarctica, these data largely come from outside of the Weddell Sea, or from
stomach content analysis which tends to represent only a snapshot of an organism's diet in time and space. In
this context, we sought to provide a more comprehensive outlook on silverfish diet in the Weddell Sea by
employing a lipids-based analysis illustrative of feeding over periods of weeks to months by analyzing fatty acid
composition in adult P. antarctica and potential prey species. The question of diet variation within the Weddell
Sea was framed in a hydrographic context by comparing diet in fish located along a trough inflow in the
Filchner Trough, with those collected along the continental shelf near Halley Bay. Our results are a first step
towards uncovering how physical-biological interactions impact silverfish diet.

423
Tue_225_BE-10_2416
Climate Change and Mitochondrial Metabolism in High-Antarctic Notothenioids

Felix Christopher Mark1 (fmark@awi.de), Hanna Scheuffele1, Nils Koschnick1

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Integrative Ecophysiology,
Bremerhaven, Germany

Climate change affects the ocean systems world-wide by unprecedented rates of warming, acidification and
deoxygenation. Marine fish possess physiological mechanisms of coping with these drivers, yet to a different
extent in different species. While species from habitats with large diurnal or seasonal fluctuations in
temperature, PO2 and PCO2 are naturally better adapted to cope with changing habitat conditions, especially
Antarctic fish have been proposed to display very little metabolic plasticity to cope with a warming and
acidifying ocean.
To shed more light on the fate of cold-adapted fish in a changing ocean, we investigated the metabolic
capacities to cope with ocean warming and acidification in several high-Antarctic notothenioids, including red-
and white-blooded species, during the RV Polarstern cruise ANT XXXI-2 to the southern Weddell Sea.
Much of the recent climate change research on fish has looked into effects at the whole animal level, while
knowledge of the acclimation and adaptation potential of lower levels of organisation, e.g. metabolic
pathways, is scarce. We thus focussed on the basis of sustainable aerobic energy metabolism, mitochondrial
ATP formation, and investigated the acute effects of warming, rising intracellular PCO2 and [HCO3-] on the
performance and efficiency of the involved biochemical pathways in isolated mitochondria and permeabilised
muscle fibers.

424
Tue_226_BE-10_2469
Antarctic Silverfish Pleuragramma antarctica - Condition and the Role of Lipids

Katja Mintenbeck1 (katja.mintenbeck@awi.de), Christian Bock1

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

The Antarctic silverfish, Pleuragramma antarctica, is a key species in the high Antarctic food web and
threatened by direct as well as indirect effects of climate change. The lack of a swimbladder is compensated in
this pelagic fish by high amounts of lipids which make up to 60% of dry weight, and the functional role of these
lipids is discussed since decades. The lipids are not stored in common adipose cells but in intermuscular and
subcutaneous lipid sacs, indicating that the lipids might be decoupled from metabolism, i.e. the lipids' role is
limited to buoyancy. If the stored lipids are not available as energy reserve, Pleuragramma's capability to cope
with indirect effects of climate change such as (temporal) changes in prey availability and food shortage would
be extremely low.
To gain deeper insight, data from several regions with different primary production were compared using a
combination of classical ecological methods and Magnetic Resonance Imaging (MRI). Fish condition was found
to vary strongly between different regions and these variations were reflected in total amount of lipids and in
the size of the lipid sacs.
The data clearly show that the functional role of lipids in Pleuragramma is not exclusively limited to buoyancy
but lipids may be used as energy reserve for periods with limited food supply.

425
Tue_228_BE-10_2695
Evaluation of the Dispersal Capacity of Sub-Antarctic Crab Halicarcinus planatus

Zambra Lopez1,2 (zambralopez@gmail.com), Karin Gerard3, Elie Poulin1

1
University of Chile, Santiago, Chile, 2University Austral of Chile, Research Center Dynamics of High Latitude
Marine Ecosystems, Valdivia, Chile, 3University of Magellan, Punta Arenas, Chile

Atmospheric temperature in the West Antarctic Peninsula has increased between 5 and 6°C in the last 50 years.
In the mean time, human activity (scientific and tourism) has dramatically increased in Antarctic, and so did the
number of exotic species that reached the Antarctic. Until recently, there were no report of marine exotic
species established in the shallow Antarctic ecosystem. However, in 2010, an ovigerous female of Halicarcinus
planatus was reported in the shallow waters of Deception Island (Aronson et al; 2015). Halicarcinus planatus, is
a small brachyuran crab distributed in southern South-America and Subantarctic islands, with a planktonic
larval phase of 45 to 60 days. Moreover, H. planatus has the ability to down-regulate hemolymph's Magnesium
ion concentration below sea water concentration, that would help to survive in Antarctic cold waters. Through
population genetics analysis using SNPs, the population structure and connectivity of H. planatus will be
evaluated at three different geographical scales: across the Southern Ocean (between Patagonia and
Kerguelen), between Patagonia and Falkland Islands, and at regional scale among three locations in Patagonia
(Punta Arenas, Beagle Channel and Tortel Cove). The potential of dispersal and capacity to broadcast to the
West Antarctic Peninsula will then be discussed. Financial support: Fondecyt 1161358 and INACH DG_14_17.

426
Tue_229_CR-1_138
A Comparison of the Frost Environment of Three Disparate Climatic Locations

Christel Hansen1 (christeldhansen@gmail.com)

1
Rhodes University, Geography, Grahamstown, South Africa

Frost processes occur across climatic zones and warming temperatures affect regions where climatic thresholds
are narrow. This paper explores the annual, seasonal and diurnal frost environments of three locations:
western Dronning Maud Land (WDML) of Antarctica, sub-Antarctic Marion Island, and the High Drakensberg of
the Eastern Cape of South Africa. WDML is characterised by annual frost with a paucity of diurnal thaw where
permafrost is common and active layers shallow. Permafrost is absent for both sub-Antarctic Marion Island and
mainland South Africa. Marion Island is characterised by a dynamic diurnal frost environment, with shallow and
high-frequency cycles in evidence. The High Drakensberg of the Eastern Cape of South Africa exhibit seasonal
freezing at higher altitudes with frozen ground occurring for up two months at a time at ~ 3 000 m.a.s.l. Global
warming scenarios (1°C, 2°C and 5°C increases) and how these affect freezing cycles are explored, as are
environmental and locational forcings on freezing cycles observed. Furthermore, results of WDML contribute
towards ANTPAS scientific output and research. Higher altitudes show an increase in frost cycles; vegetation
cover dampens such cycles. Furthermore, snow cover reduces diurnal frost in WDML, whereas it increases
freezing depth on Marion Island. Finally, diurnal frost cycles are highly sensitive to temperature changes and
associated thresholds and that such cycles can be used as indicators for warming conditions.

427
Tue_230_CR-1_139
The Active Layer and Permafrost Environment of Flårjuven (Antarctica): 2008 - 2017

Christel Hansen1 (christeldhansen@gmail.com), Ian Meiklejohn1

1
Rhodes University, Geography, Grahamstown, South Africa

This paper provides a 10-year synopsis of the ground thermal and moisture regime of Flårjuven (western
Dronning Maud Land, Antarctica) and contributes to ANTPAS scientific research and output. Flårjuven is
associated with sediment of low organic content (TOC < 0.3%) and a coarse texture (fine gravel; fine earth
fraction < 40%). The site is characterised by annual frost with a ground freezing index approaching 6 000. This is
associated with a negligible thawing index approaching zero for summer, compared to a high freezing index of
~500 for winter. Annual degree days reflect the insulating effect of snow cover on ground thermal regimes and
permafrost is present (average temperature of -19°C), with a shallow active layer (~15 cm). Temperature
variability is highest for the active layer and lowest for permafrost. Diurnal thaw is rare, although
approximately 15% of all diurnal cycles oscillate above and below 0°C. These potential thaw events occur
exclusively during spring and summer months and thaw generally occurs from mid-morning to late afternoon
(10:00-17:00), with most thaw events representing single diurnal cycles. An analysis of potential thaw events
coupled with ground moisture data recorded show that less than half (~ 45%) of all potential thaw events
translate into freeze-thaw events. The greatest active layer depth is reached in December and January, as are
the longest ground thaw duration and most freeze-thaw cycles observed.

428
Tue_231_CR-1_202
Geomorphology and Antarctic Ecosystems in Dronning Maud Land

Ian Meiklejohn1 (i.meiklejohn@ru.ac.za)

1
Rhodes University, Geography, Grahamstown, South Africa

Active-layer and ground thermal dynamics, together with periglacial landforms have been researched in the
Ahlmannryggen and Jutulsessen areas of Droning Maud Land since 2007. Nine shallow boreholes were used to
measure ground temperatures and moisture. All boreholes show distinctive ground thermal regimes from a
combination of diurnal and synoptic-scale controls. Additionally, thermal conditions in autumn and spring
suggest continent-wide controls.
The Nunataks in the Ahlmannryggen originate from ice-heaved pre-jointed and weathered bedrock that have
formed blockfields. A spatial inventory has been developed with records of such landforms together with rock
glaciers, unsorted and sorted patterned ground, weathering forms, solifluction terraces, lake ice blisters, and
pro-nival ramparts. Many of these landforms are the first examples documented in region. Their presence is
controlled by lithology, moisture supply and the substrate. Several of the landforms identified, such as the rock
glaciers and pro-nival ramparts are unique and their formation and morphology challenge accepted
characterisations.
The Geomorphology of Western Dronning Maud Land has resulted in a landscape that is crucial for the
provision of a habitat for the region's biodiversity at a variety of scales. Changes in the landscape, and the
associated links between the active layer and biodiversity in a changing climate, provide ideal positions to
answer questions created by the SCAR Horizon Scan.

429
Tue_232_CR-1_284
Current State of Active Layer Research on James Ross Island

Filip Hrbacek1 (hrbacekfilip@gmail.com), Daniel Nyvlt2, Michaela Knazkova2, Kamil Laska2, Zbynek Engel3,
Tomas Uxa3,4, Jana Smolikova3, Barbora Kampova2
1
Masaryk University, Faculty of Science, Brno, Czech Republic, 2Masaryk University, Faculty of Science,
Department of Geography, Brno, Czech Republic, 3Charles University in Prague, Faculty of Science, Department
of Physical Geography and Geoecology, Prague, Czech Republic, 4Institute of Geophysics, Academy of Sciences
of the Czech Republic, Department of Geothermics, Prague, Czech Republic

Ulu Peninsula, the northern part of James Ross Island, is the largest ice free area in Antarctic Peninsula region.
More than 300 km2 of ice-free land offer unique opportunity to study active layer, permafrost and related
periglacial processes from different perspectives and in variable environmental conditions within the area.
Currently, three main topics are under study by the Czech research team:
1) Analysis of driving factors affecting active layer thermal regime and thickness,
2) Modelling of active layer thickness, permafrost temperature and ground thermal parameters,
3) Spatial monitoring of active layer thickness using geophysical methods.
To reach the goals, the network of about 15 sites for ground temperature monitoring (using Pt100 resistance
thermometers) in profiles of depth from 2 to 30-200 cm has been gradually established since 2006 and
significantly extended after 2014. Every site also provides data on air temperature. Furthermore, at the key
sites of the network incoming radiation, albedo, snow thickness and wind speed and direction are measured as
well. Additionally, we installed TDR CS616 sensors (Campbell) for soil moisture measurement and HFP01 plates
(Hukseflux) for near-surface ground heat flux measurement at the key sites. The geophysical surveying of active
layer thickness has been carried out using GPR Ramac CU-II with 500 MHz antenna (Mala Geoscience) and
multidepth electromagnetic conductivity meter CMD-MiniExplorer (GF Instruments).

430
Tue_233_CR-1_452
Sulphur Dynamics in Permafrost Thaw Lakes

João Canário1 (joao.canario@tecnico.ulisboa.pt), Margarida C. Santos1, Teresa Duarte1, Vânia André1, Martin
Pilote2, Gonçalo Vieira3, Warwick F. Vincent4
1
Centro de Química Estrutural - Instituto Superior Técnico - Universidade de Lisboa, Lisboa, Portugal,
2
Environment and Climate Change Canada, Montreal, Canada, 3IGOT, Centro de Estudos Geográficos,
Universidade de Lisboa, Lisboa, Portugal, 4Centre for Northern Studies (CEN) & Département de Biologie, Laval
University, Quebec City, Canada

Little attention has been given to sulphur (S) in thaw lakes, but its chemistry is of special environmental
importance, since it plays a key role in natural organic matter (NOM) degradation. To understand sulphur
dynamics in thaw lakes, we undertook studies in the Canadian subarctic in summer and winter. Water samples
and sediment cores were collected from three thaw lakes. Results show that the amount of S is dependent on
lake origin: in lakes derived from organic-rich palsa soils, S content is much higher than in mineral lithalsa lakes.
NOM is the main source of S in the thaw lakes and its degradation in the water column and/or in the topmost
sediment layers dominates S-mineralization. This process was more efficient in winter when the lake surface
was frozen, decreasing oxygen availability, thus increasing the activity of sulphate reducing bacteria. Upon
removal of lake ice, a rapid increase of sulphate occurred in the near-surface waters (5 cm) followed by its
reduction within minutes, indicating the rapid system kinetics for both S reduction and oxidation. In deeper
waters, dissolved sulphides promote the precipitation of metal sulphides, resulting in a sediment surficial layer
that is enriched in amorphous trace element sulphides. These results show the importance of sulphur
biogeochemistry and its strong linkage to lake origin, thus signalling the need for a regional assessment of
sulphur related processes, based on broad, in-depth surveys of thaw lake origin.

431
Tue_234_CR-1_600
A High Resolution Permafrost Thermal Stability Map in the Third Pole

Youhua Ran1,2 (ranyh@lzb.ac.cn), Xin Li1,2

1
Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,
Lanzhou, China, 2University of Chinese Academy of Sciences, Beijing, China

The Qinghai-Tibet plateau (QTP), which is also called Earth's third pole, is the highest and most extensive
plateau in the world. The degradation of “warm” and sensitive permafrost on the QTP has resulted in an
increase in environmental fragility and the related hazards. Existing permafrost maps that cover the QTP
typically rely on sparse air temperature data and employ continuity-based classification systems. In general, the
continuity criteria are scale-dependent, inconsistent, not comparable, and are difficult to use in engineering
applications. This study presents a new permafrost map based on the thermal stability classification system.
The map was developed using a geographically weighted regression (GWR) model to integrate MODIS
(Moderate Resolution Imaging Spectroradiometer) land surface temperatures (LSTs) with leaf area index (LAI)
values from the Global Land Surface Satellite (GLASS), soil properties from SoilGrids250, highly accurate soil
moisture and precipitation data, and in situ mean annual ground temperature (MAGT) measurements made at
142 boreholes distributed throughout the QTP and acquired in about 2010. Cross validation of the permafrost
extent shows that the consistency with the latest permafrost distribution map covering the QTP and borehole
measurements at 142 sites exceeds 94%. The new map is of fundamental importance for engineering planning
and design to reduce permafrost-related hazards on the QTP in the future.

432
Tue_235_CR-1_715
OTC-induced Effects on Ground Thermal Regime and Moss Cover in James Ross Island

Miloš Barták1 (mbartak@sci.muni.cz), Peter Váczi1, Kamil Láska2, Filip Hrbáček2, Josef Hájek1, Gokhan Halici3,
Martin Bačkor4
1
Masaryk University, Faculty of Science, Department of Experimental Biology, CzechPolar2/ECOPOLARIS Project
Group, Brno, Czech Republic, 2Masaryk University, Faculty of Science, Department of Geography,
CzechPolar2/ECOPOLARIS Project Group, Brno, Czech Republic, 3Erciyes University, Faculty of Science,
Department of Biology, Kayseri, Turkey, 4Pavol Jozef Safarik University in Košice, Faculty of Science, Institute of
Biology and Ecology, Košice, Slovakia

Since 2007, a long-term research focused on the effects of climate variability along the eastern coast of the
Antarctic Peninsula on the ground temperature (GT) has been carried out. On James Ross Island, GT was
measured in the profile at depths of 5, 10, and 15 cm at control plots as well as those with open top chambers
(OTCs). The OTCs were installed in a seashore ecosystem dominated by moss carpet (Bryum pseudotriquetrum)
supplemented with a patchy distribution of more than 20 lichen species. GT regime in the particular depths
was continuously monitored and related to presence/absence of OTCs and annual reference meteorological
data from a nearby weather station (close to Mendel Base, Czech Rep.). For majority of OTC installations, the
GT increase caused by OTC was apparent in the period of September-March. Detailed analysis of chamber
effect on the increases in air and surface temperature, GT, and vegetation cover changes was done for austral
summer seasons (Dec-2014 to Feb-2015, and Dec-2015 to Feb-2016). OTCs induced an increase in surface
temperature, GT, and moss cover area. The increase in temperature was highest in warm radiation days with
low wind speed (WS). On stormy overcast days with high WS, the temperature increase was smaller.
Consequences of a long-term manipulation of Antarctic terrestrial ecosystems by OTCs for seasonal dynamics
of GT are also discussed. Acknowledgements: The study was supported by CzechPolar infrastructure and
Ecopolaris project.

433
Tue_236_CR-1_858
The Spatial Distribution of Critical Soil Properties in the McMurdo Dry Valleys

Pierre Roudier1,2 (roudierp@landcareresearch.co.nz), Fraser Morgan3, Tommy Robertson3, Ben Jolly1

1
Manaaki Whenua Landcare Research, Palmerston North, New Zealand, 2Te Punaha Matatini, Auckland, New
Zealand, 3Manaaki Whenua Landcare Research, Auckland, New Zealand

Despite extreme conditions, a wide range of life forms occurs throughout Antarctic soils, and represent a major
part of the Antarctic biodiversity. The spatial distribution of these microbiological communities has been shown
to be strongly influenced by soil attributes such as water content, salinity, organic carbon, and pH. But while
pedological maps have been published for various ice-free regions across the continent, the spatial distribution
of the soil properties (as opposed to genetic classification) is largely unknown.
In this study, we collated different soil surveys in the McMurdo Dry Valleys in order to investigate the spatial
distribution of soil properties that are critical for understanding the distribution of life in Antarctic soils: pH,
electrical conductivity (EC), organic carbon, and nitrogen. To do so, we used geostatistical analysis to study the
spatial structures of these soil properties. Two different sampling depths were considered: the desert
pavement (0-2 cm), and the next layer down (2-10 cm), where most of the life forms has been observed. Semi-
variograms of the soil properties selected were computed and analysed, and the results can be interpreted in
relation to the sampling density that is necessary to capture a given amount of variability in each soil property.
Finally, once the spatial structure of these variables has been modelled, maps estimating those soil properties
across the region can be produced at the two sampling depths considered.

434
Tue_237_CR-1_1256
Effect of Mosses on Ground Thermal Regime in Three Different Areas of Antarctica

Filip Hrbacek1 (hrbacekfilip@gmail.com), Mauro Guglielmin2, Nicoletta Cannone3

1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic, 2University of
Insubria, Department of Theoretical and Applied Sciences, Varese, Italy, 3University of Insubria, Department of
Science and High Techonology, Como, Italy

The role of vegetation as an insulating factor on ground thermal regime is well-known from Arctic region.
However, the knowledge on the interactions between vegetation and ground thermal regime in Antarctica are
limited to few studies only from Maritime Antarctica and Continental Antarctica. In this study we evaluate the
role of moss carpets on ground thermal regime across latitudinal and climate transect which consists of the
sites on Signy Island (60°S, maritime climate), James Ross Island (64°S, maritime to continental climate),
Victoria Land (75°S, continental climate) during thawing season 2015/16. The study sites have similar
characteristics in terms of altitude, distance from sea and topography. On all sites, ground temperature was
measured in profiles under moss carpets and under bare surfaces in depths 2 and 30 cm. The most pronounced
effect of moss carpet was observed as smoothing the daily maximums under moss compared to bare ground,
which could be lowered by more than 15 °C at 2 cm depth, while about 10 °C difference in maximum was found
at 30 cm. This first comparative study of these areas suggest important role of mosses as a very effective
insulator of ground temperature in these study areas.

435
Tue_238_CR-1_1562
Retrogressive Thaw Slumps: Indicators of Holocene Climate Changes

Roxanne Frappier1 (roxanne.frappier@outlook.com), Denis Lacelle1, André Viau1

1
University of Ottawa, Department of Geography, Environment and Geomatics, Ottawa, Canada

The ongoing climate warming is expected to increase thermokarst activity and their impacts by inducing
permafrost degradation and active layer deepening. A retrogressive thaw slump, which represents the most
dynamic thermokarst landform, was investigated in the Peel Plateau region of the Northwest Territories,
Canada. The exposed material at the thaw slump represents an opportunity to characterize the
cryostratigraphy of the uppermost 5 m of permafrost and to make detailed observations of a thaw layer, a
relict thaw layer, and four massive ground ice units. Analyses of the stratigraphy, sedimentology, isotope
geochemistry and radiocarbon dating are presented. The main conclusions are that
1) the physical and chemical parameters of the massive ground ice exposed at the thaw slump are
characteristic of buried glacier ice that experienced water infiltration and partial refreezing,
2) the relict thaw layer represents the period of maximum active layer deepening which occurred during the
Holocene thermal maximum,
3) association of the region's thaw slump activity with paleoclimatic parameters indicate that stream-incised,
ice-rich permafrost in formerly glaciated areas, coupled with major rainfall events, represent a set of conditions
that is favourable to thaw slump activity.
The conclusions contribute to the understanding of the genesis of thaw slumps and how they fit in the climate
history and terrain conditions of the region.

436
Tue_239_CR-1_1732
Stability of Relic Hydrates in Permafrost of Northern Eurasia and North America

Maxim Arzhanov1, Igor Mokhov1 (mokhov@ifaran.ru)

1
A.M.Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russian Federation

Global warming contributes to the permafrost degradation with destabilization of methane hydrates and the
corresponding methane emissions to the atmosphere. Model estimates of the methane hydrates instability in
regions of Northern Eurasia and North America with the risk of gas emission into the atmosphere during the
Holocene Climate Optimum (HCO), under current climate changes and for future projections are obtained. The
risk of craters and gas emissions into the atmosphere can be characterized by the probability that the strength
of the soil upper layer with permafrost would be less than the pressure in the methane hydrate deposits.
According to model simulations the regional excess of the annual mean temperature in 2008-2017 relative to
the HCO could reach 1.5-2°C at a depth of 10 m in high latitudes of Northern Eurasia and North America. This
trend contributes to a higher methane pressure during the dissociation of methane hydrates and a lower
strength of the overlying layer of soil. In a number of regions of Northern Eurasia and North America the
probability of craters and gas emissions into the atmosphere due to the relic hydrates dissociation is estimated
from model simulations to be higher than during the HCO.
The results of model simulations indicate that the formation of craters of the type identified on the Yamal
Peninsula in 2014 is associated with a high surface temperature in the regions of Northern Eurasia during last
years.

437
Tue_240_CR-1_1840
Permafrost Thaw Related Surface Displacement in Qaanaaq Village, NW Greenland

Eva Mätzler1 (eva@asiaq.gl), Mikkel Høegh Bojesen1, Rafael Caduff2, Jens Gottlieb1, Alexander Helland1,
Thomas Ingeman-Nielsen3, Kirsty Langley1, Mikkel Mikkelsen1, Tazio Strozzi2
1
Asiaq Greenland Survey, Nuuk, Greenland, 2Gamma Remote Sensing Research and Consulting AG, Gümligen,
Switzerland, 3DTU Civil Engineering, Department of Civil Engineering, Kgs. Lyngby, Denmark

The infrastructure of the village Qaanaaq in NW Greenland suffers from surface displacement due to
permafrost thawing. The typical gabble-roofed single-family wooden houses in Qaanaaq are constructed on
shallow wooden foundations, which suffer from active layer slope movement and differential settlements from
seasonal freeze-thaw cycles.
The aim of this investigation is to assess surface displacements in the Qaanaaq area of NW Greenland from a
combination of remote sensing data and in situ measurements.
We have used a number of different techniques and data sources to assess ground movement around the
settlement and neighbouring region. This allows a range of temporal and spatial scales to be addressed in the
study as well as providing some means of cross-validation of results.
The study uses Sentinel-1 differential radar interferometry, DEM-differencing, long term GNSS survey, ground
observations and base maps of the town to determine and validate surface displacements.
Assessment is challenging due to the lack of stable benchmarks in a region where it is likely that surface
displacement is occurring non-linearly over a wider area. However, first results indicate that surface
displacements occur in order of 3 - 15 cm/yr in the region.

438
Tue_241_CR-1_1904
The Permafrost Physics Performance of the Coupled CLASS-CTEM Model

Joe Melton1 (joe.melton@canada.ca)

1
Environment & Climate Change Canada, Victoria, Canada

The Canadian Land Surface Scheme (CLASS) and the Canadian Terrestrial Ecosystem Model (CTEM) form the
land surface component of the Canadian Earth System Model (CanESM). I present results derived from offline
simulations of CLASS-CTEM forced with historical observed meteorology at the same model spatial resolution
as CanESM. Model results are evaluated against observations from the Global Terrestrial Network for
Permafrost for borehole temperatures (18 sites) and active layer depth measurements (51 sites). Several
alternative parameterizations of snow and soil physics are investigated to determine their impact on simulated
permafrost on a pan-Arctic scale. CLASS-CTEM, particularly after deepening and increasing the number of soil
layers, does a good job of simulating the areal extents of permafrost zones and active layer depths of most
sites. Borehole temperatures are more challenging to simulate with some sites well captured but other sites
showing large differences between the model and observations. Overall, the model physics appear well suited
to simulate the soil environment adequately for permafrost regions.

439
Tue_242_CR-1_1969
2-D Subsurface Permafrost Structure in the Canadian Beaufort Sea

Jong Kuk Hong1 (jkhong@kopri.re.kr), Seung-Goo Kang1, Young Keun Jin1, Sookwan Kim1, Scott Dallimore2,
Michael Riedel3, Changsoo Shin4
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Geological Survey of Canada, Sidney,
Canada, 3GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, 4Seoul National University, Seoul,
Korea, Republic of

Subsurface permafrost formed in the continental shelf of the Canadian Beaufort Sea has been degraded since
the last glaciation. Many studies to reveal distribution of permafrost were done using reflection, refraction and
well logging method. However, cross section of permafrost distribution was not provided yet. In 2014, Korea
Polar Research Institute conducted multichannel seismic survey with the cooperation of GSC of Canada. We
applied the full waveform inversion(FWI) to the multichannel seismic data to get inverted 2-D velocity profile.
FWI is a data fitting procedure based on wave field modeling and numerical analysis to extract quantitative
geophysical parameters such as P-, S-wave velocities and density from seismic data. Because P-wave velocity in
the permafrost varies depend on the concentration of ice, we deduced permafrost distribution from the
inverted velocity model. Relatively high P-wave velocity cell is regarded as ice bearing sediment, and higher
than 3.2 km/sec is regarded as fully ice saturated sediment. Inverted velocity models show permafrost bodies
distributed irregularly and their size range from hundreds to thousands meters. The content of ice is higher in
the core of permafrost body and lower in the outer body. Permafrost exists down to 600~700 meters and
highest ice concentration exists at the depth of about 400 meters which coincide with previous well logging
results.

440
Tue_243_CR-1_1995
Periglacial Landforms from Semi-arid Seymour Island, Weddell Sea, Antarctica

Caroline Delpupo Souza1,2 (carolinedelpupo@gmail.com), Mariane Batalha Roque3, André Luiz Lopes de Faria4,
Davi Gjorup2, Carlos Ernesto Schaefer2
1
Federal Institute of Minas Gerais, Conselheiro Lafaiete Campus, Conselheiro Lafaiete, Brazil, 2Federal University
of Viçosa/Núcleo Terrantar, Soil Department, Viçosa, Brazil, 3Federal University of Viçosa, Rural Economy
Department, Viçosa, Brazil, 4Federal University of Viçosa, Geography Department, Viçosa, Brazil

Periglacial processes and landforms together with the presence of permafrost are among the most relevant
geomorphological elements in the northern Antarctic Peninsula region. This study aimed to identify, analyze
and map the landform and processes at Seymour Island, Weddell Sea, Antarctic Peninsula. For this, different
thematic maps such as lithology, slope and shaded relief were manually overlain. The slope map was an
effective tool to determine the occurrence of landforms and their limits, which together with the interpretation
of the satellite image and lithology, allowed to identify and quantify the periglacial features of Seymour Island.
Twelve landform units were identified, as follows: summit structural surface, little dissected structural surface,
highly dissected structural surface, steep slopes, gentle slopes associated with solifluction processes, fluvio-
marine plain, tidal flat, fluvioglacial plain, beaches, marine terraces and cliffs, talus deposit, patterned grounds,
and lakes. The periglacial environment from Seymour Island is less intense than that of South Shetland and
primarily conditioned by the regional semi-arid climatic conditions and strong geological and geotectonic
control; most landforms and geomorphological processes are related to wind action, hydrogeology, lithological
influence and presence of permafrost, in which altitude plays an important role. We acknowledge Fapemig for
granting financial support.

441
Tue_244_CR-1_2539
Air & Soil Temperatures, Vegetation, & ALT (1995-2017), Toolik Lake, Alaska, USA

Brianna Rick1 (brianna.rick@umontana.edu), Anna E. Klene1

1
University of Montana, Geography, Missoula, United States

The Circumpolar Active Layer Monitoring (CALM) Project has been monitoring 1 ha and 1 km2 plots at Toolik
Lake on the Alaskan North Slope. These sites are located in the Arctic foothills physiographic province. The 1 ha
plot is composed of moist acidic tundra and a water-track complex. Air temperature and soil-surface
temperature are measured in-situ daily at the 1 ha plot, and active layer thickness (ALT) is measured annually
during maximum thaw (August) at both. This study describes changes over time (1995-2017), reporting an
overall slight increase in mean summer (July-August) air temperatures and a slight decrease in mean soil-
surface temperatures, resulting in an increase in the difference between these two measurements. Trends in
ALT are less clear. Such an increase in the difference between air and soil-surface temperatures may be related
to changing vegetation properties. Color-infrared aerial photograph pairs from peak greenness in 1995 and
2017 were analyzed using modern photogrammetric techniques to quantify vegetation change. This research
complements coarser remote sensing efforts as well as plot-level biomass measurements showing Arctic
greening in this region.

442
Tue_245_GG-2_124
Variations in Ice Sheet Dynamics along the West Antarctic Ice Sheet Margin

Gabriele Uenzelmann-Neben1 (gabriele.uenzelmann-neben@awi.de)

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Geophysics, Bremerhaven,
Germany

Modern global warming and their possible contribution to sea level rise and flooding of low lying coastal areas
has moved both Antarctic and Greenland ice sheets into the focus of public and scientific interest. Research has
concentrated on reconstructing the dynamics of the ice sheets in order to understand their vulnerability to a
changing climate by combining data collection and numerical simulations. Synchronous changes in ice sheet
extent along its margin are often assumed. Here, the regional and chronological appearance, distribution, and
modification of sedimentary features and structures identified at the slope and rise off the West Antarctic Ice
Sheet margin are analysed to test this assumption.
A synchronous West Antarctic Ice Sheet dynamic is not supported but rather a West-East trend with an early
Miocene ice advance in the Amundsen Sea, while a glacial advance in the Bellingshausen Sea occurs only post-
15 Ma. For the Bellingshausen Sea a stronger variability in depositional energy is observed indicating stronger
variability in ice extent. The dominance of down-/along-slope sediment transport is on opposing trends
between the two seas, which also reflects the advance/retreat of the local ice sheet and thus an
increase/decrease in sediment input from the continent and a modification in intensity and relocation of the
bottom currents' pathways. A possible reason for this may be the local geology, basal geomorphology, and the
geometry of the local ice sheets.

443
Tue_246_GG-2_187
Large Impact of the Agulhas Return Current on Late Glacial Indian Southern Ocean

Minoru Ikehara1 (ikehara@kochi-u.ac.jp), Xavier Crosta2, Katsunori Kimoto3, M.C. Manoj4

1
Kochi University, Nankoku, Japan, 2Université Bordeaux 1, Bordeaux, France, 3JAMSTEC, Yokosuka, Japan,
4
Birbal Sahni Institute of Palaeosciences, Lucknow, India

The Agulhas Current is a major actor of the Atlantic Meridional Overturning Circulation and thereof of global
climate. Models and paleoceanographic data suggest that the volume of warm and saline Agulhas water
leaking into the South Atlantic stimulates regional buoyancy anomalies that ultimately impact convective
activity in the northern North Atlantic. Spillage of Agulhas Current into the South Atlantic was shown to
strongly vary on glacial-interglacial timescales, possibly in relation to meridional shifts of the mobile Subtropical
and Subantarctic fronts and the monsoon system. Conversely, the impact of the Agulhas Current on the
Southern Ocean (SO), via its return branch, is much less documented.
Through the analysis of ice-rafted debris, diatom census counts and planktic foraminifera δ18O and Mg/Ca we
here reconstruct cool and icy conditions during the early Marine Isotope Stage 2 (MIS2, 30-23 ka) but warm,
ice-free conditions during the full glacial late MIS2 (23-15 ka) in core DCR-1PC from Del Caño Rise (46°S, 44°E,
2632m), Indian sector of the SO. We propose that these unexpected warm conditions result from increased
transport of warm waters from low latitudes to the SO via the Agulhas Return Current in time of reduced
Agulhas Current leakage due to a northward shift of the Westerlies and SO hydrographic fronts. As such, a
general cooling in the SO may conduct, via negative feedbacks, to warm surface conditions in regions of strong
western boundary current.

444
Tue_247_GG-2_200
The Newly Discovered Odyssea Drift (Ross Sea): Preliminary Results

Michele Rebesco1 (mrebesco@ogs.trieste.it), Yanguang Liu2, Jenny Gales3,4, Renata Giulia Lucchi1, Andrea
Caburlotto1, Ester Colizza5, Fabrizio Zgur1, Laura De Santis1, Andrea Bergamasco6, Vedrana Kovacevic1, Cristian
Florindo-Lopez4, Laura De Steur7, Sookwan Kim8,9, Daniela Accettella1, Elisabetta Olivo1, Florence Colleoni10,
Riccardo Codiglia1, Manuel Bensi1, Laura Ursella1, Dino Viezzoli1, Leonardo Rui1
1
OGS, Sgonico (TS), Italy, 2First Institute of Oceanography, Qingdao, China, 3Plymouth University, School of
Biological & Marine Sciences, Plymouth, United Kingdom, 4NOC, National Oceanography Centre, Southampton,
United Kingdom, 5University of Trieste, Matematica e Geoscienze, Trieste, Italy, 6ISMAR, CNR, Venezia, Italy,
7
Norwegian Polar Institute, Tromsø, Norway, 8KOPRI, Incheon, Korea, Republic of, 9UST-Korea, Daejeon, Korea,
Republic of, 10CMCC, Bologna, Italy

The Hillary Canyon is one of the main conduits for dense shelf water forming in the Ross Sea, over-flowing the
shelf edge and transforming into the Antarctic Bottom Water (AABW). The main changes in past ocean
circulation are recorded in the adjacent sediment drift. A wealth of data were acquired on the drift west of the
Hillary Canyon during the 2017 OGS Explora expedition, which included the PNRA ODYSSEA and EUROFLEETS
ANTSSS projects. Data were obtained by various technics: single channel seismics, sub-bottom profiling,
multibeam bathymetry surveying, gravity and box coring, XBT launching, water sampling, CTD, L-ADCP, ADCP-
VM, turbidity and florescence profiling. This drift (that we name Odyssea Drift) is elongated in the NNE
direction with dimensions of several tens of km. Prominent landslide scars and a giant landslide deposit, over
70 ms thick and spanning 200 km2, are visible on the drift. The cores evidence a well-developed cross bedding
suggesting vigorous past bottom currents. The oceanographic data show a well defined bottom layer with
temperature < 0°C, presumably a newly-formed AABW, with downward increased turbidity and current
velocity.
The overall aim of this work is to develop, together with the results of the forthcoming IODP drilling expedition
374, a conceptual model of sediment deposition relating to marine-based ice sheet and oceanic processes
along the Ross Sea continental margin occurring through the Neogene and Quaternary.

445
Tue_248_GG-2_206
Paleo-Current Activity in the Eastern Arctic Ocean - Evidence from Seismic

Estella Weigelt1 (estella.weigelt@awi.de), Wilfried Jokat1

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany

Four stages of deposition regime have been detected on high-resolution seismic reflection profiles. First, in
strata of Paleocene-Eocene age small vertical faults indicate differential compaction of probably anoxic
sediments deposited in the still isolated Eurasian Basin.
Than, a high-amplitude-reflector sequence indicates a time of widespread changes in deposition realm
associated with the gradual opening of the Fram Strait and ongoing subsidence of the Lomonosov Ridge (LR) in
Eocene and Oligocene. Episodical incursions of water masses from the North Atlantic were the consequences
and led to the deposition of sediments of strongly different lithology.
The third stage marks widespread and pelagic sedimentation since earliest Miocene. Sediment waves are
evidence for paleo-bottom current activity and the onset of an ocean circulation system. The slope of the LR is
structured into terraces, indicating fault-controlled sediment drifts arisen due to the onset and intensification
of current circulation. Advanced deepening of the Fram Strait likely enabled an effective exchange of water
masses between the North Atlantic and Arctic Ocean. Continuous sagging of the LR, reactivation of former
faults and bottom currents passing along the ridge may shape the steep sediment free flanks of the terraces in
addition.
At least, a continuous regional drape of reflectors marks the transition to glaciation of the northern hemisphere
in early Pliocene.

446
Tue_249_GG-2_328
Late Holocene Sedimentary Record from Two Infilled Lakes, Southwestern Greenland

Matej Roman1,2, Barbora Chattová3, Jiří Lehejček4, Václav Tejnecký4, Petra Luláková5, Karel Němeček4, Jakub
Houska4, Ondrej Drabek4, Daniel Nyvlt2 (daniel.nyvlt@seznam.cz)
1
Charles University in Prague, Faculty of Science, Department of Physical Geography and Geoecology, Praha,
Czech Republic, 2Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic,
3
Masaryk University, Faculty of Science, Department of Botany and Zoology, Brno, Czech Republic, 4Czech
University of Life Sciences, Praha, Czech Republic, 5University of South Bohemia, Ceske Budejovice, Czech
Republic

The Greenland Ice Sheet has sensitively responded to past and current climatic fluctuations. In order to
reconstruct the past regional environmental and climatic variability, sedimentary cores from two infilled lake
basins in the Kobbefjord area, SW Greenland, were retrieved and subjected to multi-proxy investigation. The
absolute chronostratigraphic framework was established by 14C and short-lived radioisotopes (210Pb, 137Cs)
dating. We further performed analyses of magnetic susceptibility, grain size distribution, element composition
by means of XRF and ICP-AES (for C, N, S and BSi content), and diatom biostratigraphy. The presented
palaeoenvironmental reconstruction records ~800 years of lake ontogeny that was modulated by catchment
processes and regional climate, manifested as alternating periods of enhanced biological productivity and
increased influx of clastic material. Our reconstruction agrees with other proxy-based lacustrine, marine and
glacier records as well as instrumental measurements. Main cooling events occurred at ~850-650 and ~100-30
years BP. The former coincides with the demise of the nearby Norse Western Settlement. The latter event
corresponds to culmination of the Little Ice Age and maximum glacier advances. Warmer periods predominated
~550-150 years BP and in the 20th century, and coincided with mostly negative phases of North Atlantic
Oscillation. Current warming is, however, obliterated by transition of the lakes into oligotrophic peat bogs.

447
Tue_250_GG-2_363
Holocene Oceanographic Change: Sabrina Coast, East Antarctica Diatom Assemblages

Isabel Dove1 (idove@colgate.edu), Natalie Kozlowski1, Meghan Duffy1, Amy Leventer1, Leanne Armand2, Philip
O'Brien3
1
Colgate University, Dept. of Geology, Hamilton, United States, 2Australian National University, Research School
of Earth Sciences, Acton, Australia, 3Macquarie University, Dept. of Environmental Sciences, North Ryde,
Australia

The Sabrina Coast, East Antarctica, is an area of interest because

(1) satellite and airborne geophysical studies indicate substantial loss of glacial ice over the past decade, and
(2) the region is underlain by a deep subglacial basin, a configuration that is susceptible to “runaway” ice loss.
Quantitative diatom abundance and assemblage data preserved in marine sediments in four kasten cores
retrieved from the continental slope during the RV Investigator mission IN2017_V01, record Holocene
oceanographic conditions as well as the transition from a glacial to interglacial period. During the last glacial
period, diatom abundance was low, possibly due to increased sea-ice cover, resulting in light limitation of
primary production. In addition, a greater proportion of reworked, extinct species are present, due to the input
of older, glacially-scoured sediments sourced from the continental shelf. The environment transitioned steadily
from a glacial to interglacial setting, marked by an increase in diatom abundance by up to three orders of
magnitude. The mid-Holocene is characterized by the highest productivity, but no significant change in diatom
assemblage accompanies the productivity peak. The assemblage is dominated by a single diatom species,
Fragilariopsis kerguelensis, the signature species of the Antarctic Circumpolar Current, however, greater overall
sea-ice cover in the western half of the field area is reflected by increased relative abundance of Fragilariopsis
curta.

On behalf of the Sabrina Seafloor Shipboard Party, Australian National University, Acton, Australia

448
Tue_251_GG-2_364
Diatom Proxy Record of Quaternary Glacial Cycles, Sabrina Coast, East Antarctica

Meghan Duffy1 (mduffy@colgate.edu), Amy Leventer1, Leanne Armand2, Philip O'Brien3

1
Colgate University, Dept of Geology, Hamilton, United States, 2Australian National University, Research School
of Earth Sciences, Acton, Australia, 3Macquarie University, Dept of Environmental Sciences, North Ryde,
Australia

Observed melting rates of the Totten Glacier, Sabrina Coast are among the fastest of the East Antarctic ice
sheet yet this area remains notably understudied. Piston core C012_PC05, collected from the Sabrina Coast
continental slope during the RV Investigator mission IN2017_V01, contains a 16m sediment record of the past
nine marine isotopic stages, as estimated using magnetic susceptibility data, sediment lithology, and absolute
diatom abundance, and constrained using the diatom biostratigraphic markers Rouxia leventerae, Rouxia
constricta and Hemidiscus karstenii. Interglacial periods are characterized by biosiliceous clay-rich silts with low
magnetic susceptibility. Glacial sediments are diatom-poor silts and fine sands with relatively high magnetic
susceptibility. Quantitative diatom counts document diatom abundances more than one order of magnitude
lower during glacials as compared to interglacials, a consequence of greater sea-ice cover and dilution. Glacial
periods also show much higher proportions of extinct species, indicating reworking of sediments. Notable
variation in abundance is observed among interglacials; early MIS 5 and mid-MIS 1 contain distinct peaks in
productivity while MIS 3 has comparatively low overall primary productivity. Fragilariopsis kerguelensis is the
dominant species (60-90%) throughout, with Thalassiosira lentiginosa subdominant; both open ocean zone
indicators. Common sea ice associated species are present, but in low relative abundances.

On behalf of the Sabrina Seafloor Shipboard Party, Australian National University, Acton, Australia

449
Tue_252_GG-2_370
Crevasse Casts Preserved in the Whales Deep Basin Middle Continental Shelf

Philip Bart1 (pbart@lsu.edu), Slawek Tulaczyk2

1
Louisiana State University, Geology and Geophysics, Baton Rouge, United States, 2University of California Santa
Cruz, Earth and Planetary Science, Santa Cruz, United States

The Whales Deep Basin (WDB) is a paleo-glacial trough that was occupied by the Bindschadler Ice Stream when
grounded ice advanced to the outer continental shelf during the last glacial maximum (LGM). A bathymetric
saddle that separates the WDB outer and middle continental shelf corresponds to a compound grounding zone
wedge (CGZW) formed during post-LGM retreat. The north face of the bathymetric saddle corresponds to the
marine foreset of the CGZW. The low slope on the southern side of the WDB saddle corresponds to the
subglacial topography that existed prior to a major retreat of the grounded ice towards Roosevelt Island. This
GZW topset is mantled by a series of relatively small-scale sinuous ridges. The ridges have amplitudes ranging
from 2 to 11 m above grade and have an overall northeast-southwest orientation over an area of at least 500
km2 in water depths ranging from ~500 to ~550 m. The ridges have spacing that mostly range between 1 and 2
km. The longest ridges are observed to be 40 km. In our ongoing investigation of these interesting features, we
hypothesize that the ridges formed below a rapidly flowing ice stream as it thinned. The rapid ice-stream flow
caused the development of large crevasses that reached the seafloor. Subglacial till was injected upward as the
crevasses formed. Chronologic data indicates that these crevasse casts formed during rapid sea-level rise at
11.5 kyr BP, i.e., during MWP1B, which partly explains their amazing preservation.

450
Tue_254_GG-2_669
The Impact of the Totten Glacier on the Depositional Processes off Sabrina Coast

Federica Donda1 (fdonda@inogs.it), Roberto Romeo1, Riccardo Geletti1, Andrea Caburlotto1, Leanne Armand2,
Philip O'Brien3, Raffella Tolotti4, Laura De Santis1
1
OGS, Borgo Grotta Gigante, Italy, 2The Australian National University, Acton ACT, Australia, 3Macquarie
University, Sydney, Australia, 4University of Genova, Genova, Italy

The National Institute of Oceanography and Applied Geophysics (OGS) acquired about 320 km of multichannel
seismic profiles offshore the Sabrina Coast (East Antarctica), in the frame of the PNRA Tytan Project, during the
CSIRO survey IN2017-V01 on board the RV Investigator (Jan-March 2017).
The project aims at reconstructing the depositional environment of the continental margin off the Totten
Glacier, starting from the Miocene, when temperatures and CO2 levels were more similar to those predicted
for the next century. The PNRA Tytan project consists in two main research units: Unit 1 is focused on the
integrated analysis of the new geophysical dataset and data available through the Seismic Data Library System
(SLDS), aimed at identify key acoustic features indicative of advances and retreats of the ice sheet and of
variations in the glacial regime. The comprehensive analysis of the seismic dataset will also be crucial to
prioritize areas of interest for IODP deep drilling by identifying expanded and well-preserved sedimentary
successions. Within Unit 2, sediment core analysis collected during the IN2017-V01 cruise are performed and
are focused on Diatom biomarkers and assemblages.
The IN2017-V01 geophysical dataset has been undergoing several processing steps, which greatly improved the
data quality. A preliminary analysis allowed recognizing key seismic reflectors indicative of major evolution
steps of the continental margin.

451
Tue_255_GG-2_705
Late Cretaceous Model Paleogeography for Antarctica

Graeme Eagles1 (graeme.eagles@awi.de), Jamieson Stewart2, Lucía Pérez Díaz3

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Geophysics, Bremerhaven,
Germany, 2Durham University, Durham, United Kingdom, 3Royal Holloway University of London, Egham, United
Kingdom

We present the newest interim versions of ANTScape's Late Cretaceous model paleogeography. Recent plate
kinematic reconstruction parameters have been used to reconstruct a late Cretaceous austral landmass with
Antarctica at its core, and continental connections to Australia and South America at its margins. The depths of
the oceans and continent-ocean transitions surrounding this landmass have been modelled from an
understanding of the variety of processes that can be expected to have led them to attain their current depth.
In contrast, we model continental paleotopography by applying process-based adjustments to present-day
measurements. In view of ongoing controversy regarding the history and development of the Transantarctic
Mountains, we present two candidates. In one, the mountains do not figure because they developed as a
marginal uplift to the Cenozoic West Antarctic Rift System. In the other, the mountains form just part of a much
larger West Antarctic altiplano, supported by thickened crust that formed by long-lasting plate convergence at
Gondwana's active margin. The candidate paleogeographies will be of interest as boundary conditions for
paleo-ice sheet modelling and regional circulation and climate modelling.

452
Tue_256_GG-2_743
Simple Model of Melange and Its Influence in an Antarctic Ice Sheet Model

David Pollard1 (pollard@essc.psu.edu), Robert DeConto2

1
Pennsylvania State University, Earth & Environmental Systems Institute, University Park, United States,
2
University of Massachusetts-Amherst, Department of Geosciences, Amherst, United States

Rapid grounding-line retreat and marine ice loss from West Antarctica,
and possibly from major East Antarctic basins, may be triggered by
climate warming. These rapid retreats are associated with geologic evidence
of past high sea-level stands, and pose a threat of drastic sea-level rise
in the future.
Rapid calving of ice from deep grounding lines generates substantial
downstream melange (floating ice debris). It is unknown whether this melange
has a significant effect on ice dynamics during major Antarctic retreats,
through clogging of seaways and back pressure at the grounding line.
Observations in Greenland fjords suggest that melange can have a significant
buttressing effect, but the lateral scales of Antarctic basins are an order
of magnitude larger (100´s km compared to 10´s km), with presumably much
less influence of confining margins.
Here we attempt to include melange as a prognostic variable in a 3-D
ice sheet-shelf model. Continuum mechanics is used as a heuristic
representation of discrete particle physics. Melange is created by ice calving
and cliff failure. The melange model is first tested with idealized
geometries, and calibrated very basically to observed melange properties
in Jakobshavn fjord, West Greenland. The influence of the new melange
component is then examined in simulations of rapid Antarctic retreat
in response to warm mid-Pliocene climate.

453
Tue_257_GG-2_747
Long-term Landscape Evolution of the Pensacola-Pole Basin, East Antarctica

Guy Paxman1 (guy.j.paxman@durham.ac.uk), Stewart Jamieson1, Fausto Ferraccioli2, Mike Bentley1, Neil Ross3,
Tom Jordan2, Rene Forsberg4, Arne Olesen4, Kenichi Matsuoka5, Tania Casal6
1
Durham University, Durham, United Kingdom, 2British Antarctic Survey, Cambridge, United Kingdom,
3
Newcastle University, Newcastle upon Tyne, United Kingdom, 4DTU Space - National Space Institute, Lyngby,
Denmark, 5Norwegian Polar Institute, Tromsø, Norway, 6European Space Agency, ESTEC, Noordwijk,
Netherlands

The evolution of Antarctic bedrock topography is a key control on ice sheet behaviour. Evolution of the
subglacial landscape over geological timescales is controlled by tectonics, erosion, and deposition, as well as
the solid Earth response to these processes. Here we aim to quantify these processes to better constrain the
palaeotopographic evolution of the Pensacola-Pole Basin in East Antarctica, a previously unexplored sector of
the ice sheet with bedrock situated over 1 km below sea level. The effective elastic thickness of the lithosphere
in this region is determined by modelling recently acquired bedrock topography and airborne gravity data. We
then use flexural isostatic modelling to quantify the response of the solid Earth to changes in surface loading
associated with glacial and fluvial erosion and tectonic activity. Geological constraints on the amount of erosion
and uplift include peneplanation surfaces exposed in the Pensacola Mountains and offshore sediment records.
We also use 2D forward gravity modelling to determine the upper crustal structure of the basin and examine
the role of the inherited tectonic structure in the topographic evolution of the region. By quantifying the
landscape evolution of the Pensacola-Pole Basin since ice sheet inception at ca. 34 Ma, we can provide an
improved boundary condition for modelling ice sheet behaviour close to the boundary between East and West
Antarctica since the Early Oligocene.

454
Tue_258_GG-2_751
A Pliocene δ18Odiatom Record of East Antarctic Glacial Discharge

Freya Mitchison1 (mitchisonf@cardiff.ac.uk), George Swann2, Jennifer Pike3, Melanie Leng4

1
Cardiff University, Earth & Ocean Sciences, Cardiff, United Kingdom, 2University of Nottingham, Nottingham,
United Kingdom, 3Cardiff University, Cardiff, United Kingdom, 4British Geological Survey, Keyworth, United
Kingdom

The East Antarctic Ice Sheet (EAIS) is traditionally thought to have remained largely stable since the middle
Miocene. However, some evidence suggests the EAIS retreated substantially during intervening warm periods,
e.g. the Pliocene. Given the major societal implications of a more dynamic EAIS, resolving the issue and
determining what forces retreat, e.g. a warmer ocean, is essential. However, direct evidence for substantial
retreat, and a thorough understanding of ice/ocean interactions during past warm periods, remain elusive.
Here we take advantage of the particularly negative δ18O signature of glacial ice (δ18O< −20‰) to generate the
first Pliocene diatom oxygen isotope (δ18Odiatom) record of East Antarctic glacial discharge. The Pliocene can be
considered an analogue for future climate, as the last time pCO2 was >400 ppm and sea levels were ~20 m
higher than today. Using material from the well-characterised continental rise IODP Site 1165B, our target
interval (3.75-3.45 Ma) includes a period of proposed substantial retreat of both the local Amery ice shelf and
more distal Aurora subglacial basin, as well as an episode of dramatic circum-Antarctic warming when sea
surface temperatures (SSTs) increased to ~6ºC above present. Considered alongside existing diatom
assemblage, SST, sea ice and ice-rafted debris records from the same cores, we investigate the role of ocean
forcing on ice dynamics and constrain suborbital-scale glacial discharge/retreat during the Pliocene.

455
Tue_259_GG-2_765
Deep-water Evolution in the Southwest Atlantic from New Seismic Profiles

Robert Larter1 (rdla@bas.ac.uk), Steven Bohaty2, Jude Castelino1, Claus-Dieter Hillenbrand1, Paul Wilson2, Kelly
Hogan1, Gabriele Uenzelmann-Neben3, Thomas Westerhold4
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Southampton, Southampton, United
Kingdom, 3Alfred Wegener Institute, Bremerhaven, Germany, 4University of Bremen, MARUM, Bremen,
Germany

Antarctic Bottom Water (AABW) flowing northwards into the South Atlantic Ocean has to pass around Maurice
Ewing Bank (MEB), which lies at the eastern end of the Falkland Plateau. Above the AABW, the Antarctic
Circumpolar Current (ACC), the largest ocean current on Earth with a mean transport of >100 Sverdrups, flows
eastwards across MEB and the Georgia Basin. The two main fronts of the ACC, the Polar Front and the Southern
ACC Front, traverse the region and interact with major topographic features. AABW is a key component of the
global thermohaline overturning circulation, whereas the ACC is the main agent of water exchange between
the world's large ocean basins and is important in blocking ocean heat transport towards Antarctica. Both
currents initiated and strengthened during the Cenozoic era as bottom water production increased and the
Southern Hemisphere westerly winds strengthened due to the intensification of Antarctic glaciation. Over the
same period plate tectonic movements resulted in opening of deep gateways in the Southern Ocean, allowing
circum-Antarctic circulation. These major currents control patterns of sediment deposition, and thus changes in
sediment accumulation patterns through time record the history of the currents. However, seismic profile
coverage of the region remains sparse. We plan to collect new multichannel seismic data over the MEB and
Georgia Basin on RRS Discovery cruise DY087 in January-February 2018, and will present initial results.

456
Tue_260_GG-2_769
Unravelling a High-altitude Antarctic Blue Ice Field Meteorite Trap

Harry Zekollari1,2,3 (zharry@ethz.ch), Steven Goderis3, Matthias van Ginneken3,4, Jerome Gattacceca5, Akira
Yamaguchi6, Philippe Huybrechts3, Vinciane Debaille4, Philippe Claeys3
1
ETH Zurich, Zürich, Switzerland, 2WSL Swiss Federal Institute for Forest Snow and Landscape Research,
Birmensdorf, Switzerland, 3Vrije Universiteit Brussel (VUB), Brussel, Belgium, 4Université Libre de Bruxelles,
Brussel, Belgium, 5CEREGE, Aix en Provence, France, 6National Institute for Polar Research, Tokyo, Japan

Antarctic blue ice zones are the most successful locations for meteorite retrieval missions on Earth. These
zones are furthermore of large interest, as they can potentially contain old ice, which is easily accessible and
available in large quantities. Despite this, meteorite traps remain generally not very well understood. Here, we
use an interdisciplinary approach to improve our understanding of an ice trap in Dronning Maud Land (East
Antarctica) on the Nansen blue ice field (2600-3100 m a.s.l.).
From the collected surface blue ice samples, one of the largest observed spatial patterns in the δ18O to date is
found. Relying on 14C and 36Cl terrestrial age dated meteorites, this surface ice is interpreted to be from the
previous interglacial up to the present-day. Based on satellite derived surface velocities, we estimate less than
0.4 new meteorites per year are supplied to the ice field through ice flow. This suggests that the hundreds of
new meteorites found after revisiting the ice field after 25 years are mostly meteorites that were previously
not found, rather than newly supplied meteorites. By comparing the isotopic signal of the surface blue ice to
the one from deep drilling projects, we derive information about the past glaciological and climatic conditions
that occurred over this region.

457
Tue_261_GG-2_783
Enhanced Coal Fragment Input in the Chukchi Borderland during Last Deglaciation

Taoliang Zhang1 (ztl1989@hotmail.com), Rujian Wang1, Wenshen Xiao1, Leonid Polyak2, Jens Bischof3, Xiaoxuan
Huang1
1
Tongji University, State Key Lab of Marine Geology, Shanghai, China, 2Ohio State University, Byrd Polar and
Climate Research Center, Columbus, United States, 3Old Dominion University, Department of Ocean, Earth, and
Atmospheric Sciences, Norfolk, United States

Frequent ice discharge events were identified as Ice Rafted Debris (IRD) peaks in the Chukchi Borderland,
western Arctic Ocean sediments between the Brown Layers 1 (B1, Holocene) and 2 (B2, mid MIS3), but the
timing and sources of these events are still poorly constrained. In this study, IRD (>250 um) grains from this
interval in 10 sediment cores recovered from the Chukchi Borderland were examined under the microscope.
Coal fragments and detrital carbonates were identified and the peak layers were dated at ~14 ka, making it a
proper stratigraphic marker at the Chukchi Borderland during the last deglaciation. The abundances of coal
fragments show clear northward and westward decreasing trend in the study area, suggesting a eastern source
most probably the northern Alaska. During the deglaciation, the melting water from ice cap on the Brooks
Range allowed the entrainment of coal fragments from the coal bearing the North Alaskan Slope terrain to the
Chukchi Margin and spread by the Beaufort Gyre north- and westwards.

458
Tue_262_GG-2_833
Characterizing Holocene Climate Variability from Adélie Basin Sediment Core

Katelyn M. Johnson1,2 (katelyn.johnson@vuw.ac.nz), Rob McKay1, Francisco J. Jiménez-Espejo3, Nancy A.

Bertler1,2, Anya Albot1
1
Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand, 2GNS Science - Institute
of Geological and Nuclear Sciences Ltd., National Ice Core Research Laboratory, Lower Hutt, New Zealand,
3
Japan Agency for Marine-Earth Science and Technology, Department of Biogeochemistry, Yokosuka, Japan

In 2010, a 180 m laminated sediment core was collected offshore East Antarctica in the Adélie Basin during
International Ocean Discovery Program Exp. 318. Radiocarbon ages date the core to ~12,000 years B.P., and
high sedimentation rates at the site suggest a high-resolution record capable of capturing both large and small
scale climate variabilities. Initial findings of greyscale analysis on line scan photographs indicate cyclical
frequencies of high productivity phytoplanktic bloom events, but these data were noisy due to gas expansion
during core extraction and color issues associated with differential oxidation after core extraction. X-Ray
Computed Tomography (CT) scans were undertaken to circumvent these issues and improve the frequency and
facies characterizations of the phytoplanktic bloom events. Here we present the conclusions of our frequency
and greyscale analyses, and how these analyses relate to the core X-Ray Fluorescence (XRF) data. We will also
discuss these results in relation to a larger project aimed at linking the Roosevelt Island Climate Evolution (RICE)
ice core and the U1357 sediment core. The U1357 site lies downstream from RICE and is influenced by Ross
and Amundsen Sea waters, in addition to local variations. The relationship between these highly resolved
records will better constrain the seasonal and long-term variations and (dis)connections between polynya
activity and ice-ocean interactions in these regions during the Holocene.

459
Tue_263_GG-2_848
Ice Dynamics during the past 37 ka on Ross Sea Continental Shelf, Antarctica

Rujian Wang1 (rjwang@tongji.edu.cn), Wenshen Xiao1, Mengxue Huang1

1
Tongji University, State Key Lab of Marine Geology, Shanghai, China

The Ross Sea Dense Shelf Water (DSW) comprises about 25% of the Antarctica Bottom Water today. The
formation of this DSW is closely linked to the interactions with the Ross Ice Shelf (RIS). Thus the retreating
processes of the RIS since the Last Glacial are of great importance understanding past changes of global ocean
circulation and climate. Core ANT31-JB06 retrieved from the Joides Trough on the northwest Ross Sea
continental shelf during the 31th Chinese Antarctic Expedition was investigated to reconstruct the RIS
deglaciation history since the late Marine Isotope Stage (MIS) 3. The analysis includes AMS 14C dating, ice rafted
debris (IRD) abundances and grain size. The dating results suggest an fossil carbon contamination of ~3045
years in the organic carbon. The continuous 14C sequence also indicates a lack of sediment disturbance, and the
grounding line persistently south of the core site. 27-21 ka marks the coldest period during the Last Glacial,
possibly with maximum extension of the RIS at ca. 24 ka. The initial RIS retreat from the Joides Trough started
at about 21 ka. Major retreats and disintegration of the RIS occurred at the Antarctic Isotope Maximum (AIM) 1
warm interval (~17 ka - 14 ka) and the early Holocene, while the retreat was slowed down or ceased during the
Antarctica Cold Reversal (ACR, ~14 ka - 12 ka). The RIS may have stabilized after about 5 ka, reaching its current
location.

460
Tue_264_GG-2_889
Late Quaternary Lambert Glacier System Dynamics on Prydz Bay East Antarctica

Li Wu1 (wuli@tongji.edu.cn), Rujian Wang1, Wenshen Xiao1, Wout Krijgsman2, Qianyu Li1, Shulan Ge3
1
Tongji University, State Key Laboratory of Marine Geology, Shanghai, China, 2Utrecht University, Department
of Earth Sciences, Utrecht, Netherlands, 3State Oceanic Administration, First Institute of Oceanography,
Qingdao, China

The Antarctica Ice Sheet (AIS) plays an important role in modulating global system. Our understanding on its
dynamics, however, is still largely insufficient. In this study, the clay mineral composition and ice-rafted debris
(IRD) data from two sediment cores retrieved off Prydz Bay extending back to 523 ka are reported to explore
the late Quaternary forcing mechanisms of the Lambert Glacier Amery Ice Shelf system (LGAISS) on orbital time
scales. The clay mineral assemblage is composed of illite, smectite, kaolinite and minor chlorite. Illite was likely
produced by physical erosion of rocks rich in biotite. Kaolinite and smectite were mostly reworked from the
older successions beneath the LGAISS and/or the Kerguelen Plateau. The kaolinite/illite ratio reveals the
oscillation history of the LGAISS. It presents a power spectral structure similar with that of the global ice
volume record, reflecting the dominant role of the northern hemispheric climate cycles in affecting the austral
ice dynamics during late Quaternary. A more pronounced obliquity periodicity on the kaolinite/illite ratio may
reflect the austral summer energy to exert a significant role in modulating the LGAISS dynamics. The IRD MAR
record, however, only responded to the eccentricity forcing, likely indicating the EAIS became increasingly
stable in response to the long-term climate cooling and development of the sea-ice field which prevents it from
contacting with low-latitude warmer sea water.

461
Tue_265_GG-2_909
Thinning History and Modelling of a Paleo Ice Stream: David Glacier, Antarctica

Jamey Stutz1 (jamey.stutz@vuw.ac.nz), Andrew Mackintosh1, Kevin Norton1, Ross Whitmore1, Stewart
Jamieson2, Richard Selwyn Jones2
1
Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand, 2Durham University,
Department of Geography, Durham, United Kingdom

Ice-shelf collapse and grounding-line migration may result in rapid ice sheet retreat, representing a significant
uncertainty in predicting future sea level rise. Marine ice-sheet processes, strongly influenced by ocean heat,
have been monitored for less than 50 years. Geological evidence can extend this record over centuries to
millennia, providing insights into the processes and rates of change that drive marine-ice retreat. Associated
modelling, evaluated against geological data can aid understanding of these processes and lead to more
realistic prediction of sea level changes. In this study, we aim to understand the pattern of thinning and retreat
of David Glacier, the largest outlet glacier in northern Victoria Land, Antarctica.
We present the initial results from the 2017 field season, where we sampled ice-transported erratic clasts and
bedrock from nunataks adjacent to David Glacier. In situ cosmogenic nuclide exposure dating of glacial erratics,
sampled along vertical transects from the modern ice surface to several hundred metres above, constrains the
ice-elevation history of David Glacier. We link ice surface lowering rates onshore to the offshore retreat
chronology in the Drygalski Trough where at the LGM the David Glacier formed an ice stream, extending
hundreds of kilometers into the western Ross Sea. We test the sensitivity of the glacier to ocean warming and
ice shelf debuttressing using a flowline model with robust marine grounding line parameterisation.

462
Tue_266_GG-2_988
XRD-XRF Analysis Insight on Post-LGM Sediments from the NW Barents Sea (Arctic)

Maria Elena Musco1,2 (mmusco@inogs.it), Renata Giulia Lucchi2, Francesco Princivalle3, Giovanna Giorgetti1,
Chiara Caricchi4, Leonardo Sagnotti4, Patrizia Macrì4
1
University of Siena, Siena, Italy, 2OGS, Trieste, Italy, 3University of Trieste, Trieste, Italy, 4INGV, Rome, Italy

This study focuses on the sedimentation history along the North-western Barents Sea continental margin after
the Last Glacial Maximum (LGM). The sedimentary record contained in the Trough Mouth Fans (TMFs) of the
Kveithola and Storfjorden glacial troughs and in the contouritic drift facing the Bellsund Fjord provides several
proxies that can be useful for reconstructing the ice-streams dynamics during glacial periods, the onset of
deglaciation and the climatic variability during interglacials. This area of the North-western Barents Sea
continental margin has been investigated during several international oceanographic cruises: SVAIS onboard
R/V BIO Hespérides; EGLACOM, onboard R/V OGS Explora; PNRA Project CORIBAR, onboard R/V Maria S.
Marien; Eurofleets-2 PREPARED, onboard RV-G.O. Sars.
For this study five cores collected during these international cruises have been investigated through XRD
analyses on clay minerals and XRF analyses through Avaatech core scan on the whole length of the cores. In
polar areas clay mineral analysis can be used for reconstructing sedimentary processes, associated with glacial
and interglacial conditions. XRF data provide useful proxies for environmental changes, provenance studies and
core correlation.
Here we aim to describe the clay mineral distribution in response to the climatic variations that followed the
LGM, the changes in ice-stream dynamics and related oceanographic/environmental changes along the margin.

463
Tue_267_GG-2_1005
Past Climate Records from the Ross Sea: Initial XRF Results from IODP Exp. 374

Denise K. Kulhanek1 (kulhanek@iodp.tamu.edu), Rob M. McKay2, Laura De Santis3, Jeanine Ash4, François
Beny5, Imogen M. Browne6, Giuseppe Cortese7, Isabela M. Cordeiro de Sousa8, Justin P. Dodd9, Oliver M.
Esper10, Jenny A. Gales11, David M. Harwood12, Saki Ishino13, Benjamin A. Keisling14, Sookwan Kim15, Sunghan
Kim16, Jan Sverre Laberg17, R. Mark Leckie14, Juliane Müller18, Molly O. Patterson19, Brian W. Romans20, Oscar E.
Romero21, Francesca Sangiorgi22, Osamu Seki23, Amelia E. Shevenell6, Shiv M. Singh24, Saiko T. Sugisaki25, Tina
van de Flierdt26, Tim E. van Peer27, Wenshen Xiao28, Zhifang Xiong29
1
Texas A&M University, International Ocean Discovery Program, College Station, United States, 2Victoria
University of Wellington, Antarctic Research Centre, Wellington, New Zealand, 3Instituto Nazionale di
Oceanografia e di Geofisica Sperimentale (OGS), Trieste, Italy, 4Rice University, Department of Earth,
Environmental, and Planetary Sciences, Houston, United States, 5Université de Lille I, Laboratoire d'Océanologie
et de Géosciences, Villeneuve d'Ascq, France, 6University of South Florida, College of Marine Sciences, St.
Petersburg, United States, 7GNS Science, Department of Paleontology, Lower Hutt, New Zealand, 8Universidade
de Brasília, Paleontology, Brasília, Brazil, 9Northern Illinois University, Department of Geology and
Environmental Geosciences, DeKalb, United States, 10Alfred Wegener Institute, Helmholz Centre for Polar and
Marine Research, Bremerhaven, Germany, 11Plymouth University, School of Biological and Marine Sciences,
Plymouth, United Kingdom, 12University of Nebraska, Lincoln, Department of Earth and Atmospheric Sciences,
Lincoln, United States, 13Nagoya University, Department of Earth and Planetary Sciences, Nagoya, Japan,
14
University of Massachusetts, Amherst, Department of Geosciences, Amherst, United States, 15Korean Polar
Research Institute, Division of Polar-Earth System Sciences, Incheon, Korea, Republic of, 16Korean Polar Research
Institute, Division of Polar Climate Change, Incheon, Korea, Republic of, 17University of Tromsø, Department of
Geology, Tromsø, Norway, 18Alfred Wegener Institute, Department of Marine Geology, Bremerhaven, Germany,
19
Binghamton University, State University of New York, Department of Geological Sciences and Environmental
Studies, Binghamton, United States, 20Virginia Tech, Department of Geosciences, Blacksburg, United States,
21
University of Bremen, MARUM, Bremen, Germany, 22University of Utrecht, Department of Earth Sciences,
Utrecht, Netherlands, 23Hokkaido University, Institute of Low Temperature Science, Sapporo, Japan, 24National
Centre for Antarctic and Ocean Research, Polar Biology Lab, Vasco da Gama, India, 25Geological Survey of
Japan, Marine Geology Research Group, Tsukuba, Japan, 26Imperial College London, Department of Earth
Science and Engineering, London, United Kingdom, 27Southampton University, National Oceanography Centre
Southampton, Southampton, United Kingdom, 28Tongji University, State Key Laboratory of Marine Geology,
Shanghai, China, 29State Oceanic Administration, First Institute of Oceanography, Qingdao, China

International Ocean Discovery Program (IODP) Expedition 374 will core several sites on the Ross Sea outer
continental shelf and slope/rise in January-March 2018 with the primary objective to examine the evolution of
the West Antarctic Ice Sheet (WAIS) during the Neogene. Numerical models indicate that the Ross Sea sector of
the WAIS is sensitive to changes in ocean heat content, making this an ideal location to examine past changes
to improve predictions for future warming. Following initial shipboard characterization of the cores during the
expedition, the cores will be shipped to the IODP Gulf Coast Repository in College Station, TX, USA. X-ray
fluorescence (XRF) scanning of Ross Sea sediment cores will commence in May 2018 using an Avaatech XRF
core scanner at the IODP Gulf Coast Repository. Final scanning details will be determined after the cores are
collected, but we initially plan to scan at 9 kV, 30 kV, and 50 kV energies (2 cm resolution) to collect counts of
Al, Si, K, Ti, Mn, Fe, Br, Rb, Sr, Zr, and Ba. This non-destructive technique will be used to distinguish lithologies
and to make environmental interpretations based on elemental ratios at high resolution. These data will also
be used to confirm stratigraphic splices for the continental slope/rise sites (where double or triple coring is
planned). Coupled with other postcruise research results, these data sets should provide significant insights
into changing conditions in the Ross Sea during the Neogene.

464
Tue_268_GG-2_1022
Geothermal Heat Flux Measured in the Amundsen Sea Embayment

Ricarda Dziadek1 (ricarda.dziadek@awi.de), Karsten Gohl1, Norbert Kaul2

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2University
of Bremen, Bremen, Germany

Due to a complex tectonic and magmatic history of West Antarctica, the region is suspected to exhibit strong
heterogeneous geothermal heat flux variations. Although the maximum ice extent has retreated from the shelf
since the last glacial maximum, the trends of offshore GHF patterns and the overall order of magnitude are
hypothetically related to those areas onshore where the West Antarctic Ice Sheet (WAIS) rests on geologically
related structures. High-resolution GHF will aid the understanding of the paleo-retreat of the ice sheet in the
Amundsen Sea Sector. This presentation builds on our previous studies in which we discussed geothermal heat
flux based on 26 in-situ temperature measurements that were conducted in 2010 in the Amundsen Sea
Embayment (ASE) in West Antarctica. We found, that the shallow (3 m) in-situ temperature measurements
were likely influenced by inter-annual bottom-water temperature variability, leading to GHF estimates biased
towards lower values (mean = 33 mWm-²). During RV Polarstern expedition PS104 in early 2017 we collected
additional 28 in-situ temperature measurements in marine sediments (11 m) for deriving geothermal heat flux
in the ASE, which will overall improve the spatial coverage of this region. Furthermore, we monitored the
vertical temperature profile of the water column at these stations, which allows to map Circumpolar Deep
Water (CDW) distributions across the inner Pine Island Shelf with greater detail.

465
Tue_269_GG-2_1086
The Eocene Evolution of Bathymetry in the Australian-Antarctic Basin

Isabel Sauermilch1 (isabel.sauermilch@utas.edu.au), Jo Whittaker1, Anya Reading2, Katharina Hochmuth3

1
University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia, 2University of Tasmania /
Mathematics and Physics, Hobart, Australia, 3Alfred Wegener Institute, Helmholtz Center for Polar and Marine
Research, Bremerhaven, Germany

Sediments on the conjugate Australian-Antarctic margins have been deposited through the interplay between
continental sediment supply, tectonic motions, and ocean currents. During the transition from Greenhouse to
Icehouse conditions, most of these components underwent drastic regional and global changes. Here,
constraints from both conjugate margins are correlated using a comprehensive network of seismic reflection
profiles and drill sites. The formation of two major hiatuses (33.6 - 47.9 Ma, 51.06 - 51.9 Ma) recently
recovered by the IODP site U1356A offshore Wilkes Land, are the centre of this study. We propose a drastic
sediment starvation along both margins during the pre-glacial Eocene period causing those gaps in
sedimentation. During the warm and humid Late Cretaceous period (~83 - 65 Ma), fluvial sediments were
deposited along both margins. Prominent sediment drift deposits of younger Early Paleogene age (~65 - 48
Ma), can be observed along both continental rises, indicating onset of clockwise bottom currents. With the
following progressive global cooling (< 48 Ma) and increasing current strength, a large-scale sediment
starvation occurred, which is geologically constrained along Southern Australia and most likely also affected the
Antarctic margin till the onset of glaciation (~33.6 Ma). Using this interpretation, we create paleobathymetric
reconstructions at ∼83, ∼65 and ∼48 Ma which provide essential information for paleoceanographic and -
climatic investigations.

466
Tue_270_GG-2_1097
Eruptions and Lava-ice Interactions Elucidate past Ice Sheet Characteristics

Adam Martin1 (a.martin@gns.cri.nz), John Smellie2, Dougal Townsend3

1
GNS Science, Dunedin, New Zealand, 2University of Leicester, Department of Geology, Leicester, United
Kingdom, 3GNS Science, Wellington, New Zealand

Some of the most important and unknown aspects of past ice sheet conditions, such as ice thickness and
thermal regime (ice sheet stability), are best enlightened by looking at lava—ice interactions
(glaciovolcanology). Lava—ice interactions were recently mapped at Mason Spur, a Miocene to recent eruptive
centre approximately 100 km southwest of Ross Island, McMurdo Sound, Antarctica. A newly identified
Miocene eruption was interpreted from the voluminous mapped caldera in-fill at this location. The eruption
records environmental conditions at the time and may have been significant enough to have affected all of
Antarctica's atmosphere. It occurred immediately after the mid Miocene Climatic Optimum during the descent
into a deeper icehouse world, a time that is crucial to understanding how modern global warming and sea-level
changes will affect the planet. Lava—ice interactions were also mapped in younger volcanic rocks (< 6 Ma) from
which the thickness of the past Antarctic ice sheet can be calculated and wet- versus dry-based glaciation
determined. Glaciovolcanology remains critical for understanding ice sheet behaviour; predicting variations in
Antarctic ice sheets is a fundamental step in quantifying future global climate and sea level change.

467
Tue_271_GG-2_1124
OSL Dates of Moraines from Ny-Alesund Indicating Late Quarternary Climate Change

Prakash Kumar Shrivastava1 (pks.shri@gmail.com), Sandip Kumar Roy2, Abhishek Verma2, Deepak Y Gajbhiye2
1
Geological Survey of India, Gangtok, India, 2Geological Survey of India, Faridabad, India

Luminescence dating is micro-dosimeteric technique used on quartz / feldspar to estimate the time elapsed
since the last day light exposure of the sediments, specially on Late Quaternary sediments. Sediment samples
from the terminal moraines of Vestre and Austre Broggerbreen glaciers of NY-Alesund area, Svalbard, Arctic
region were dated by OSL techniques. In order to remove the unstable luminescence signals an optimum
heating temperature was found out which yielded best dose recovery. Many Arctic samples were not found
suitable for OSL dating because their dose recovery was not optimal. In most of the Arctic samples
recuperation is observed because of their dull nature. The correction was of recuperation was made by adding
an additional step of Illumination at 2800 C at the end of every run of SAR protocol. The OSL data suggests the
advancement of widespread glaciations in this area during Last Glacial Maxima (LGM). The dates of 32±3 ka and
19±2 ka obtained from the terminal moraines highlights deglaciations before and after LGM period. The date
32±3 ka marks the major recession of glacier system of Ny-Alesund region just before Last Glacial Maxima.
After this, during LGM time, the glacier system has advanced to a much greater extent. After LGM time, the
area has again witnessed the major recession at around 19± 2 Ka coinciding with the Late Weichselian ice sheet
retreat as the climate became warmer. The results represent time span of Last deglaciations in Ny-Ålesund
area.

468
Tue_272_GG-2_1160
The Climatic Significance of Laminated Sediments on the NW Barents Sea (Arctic)

Renata Giulia Lucchi1 (rglucchi@inogs.it), Jan Sverre Laberg2, Caterina Morigi3,4, Katrine Husum5, Maria Elena
Musco1,6, Mauro Caffau1, Chiara Caricchi7, Leonardo Sagnotti7, Patrizia Macrì7, Michele Rebesco1, Francesco
Princivalle8, Giovanna Giorgetti6
1
Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Geophysics, Sgonico, Italy, 2UiT The Arctic
University of Norway in Tromsø, Tromsø, Norway, 3Università di Pisa, Department of Earth Sciences, Pisa, Italy,
4
Geological Survey of Denmark and Greenland, Department of Stratigraphy, Copenhagen, Denmark,
5
Norwegian Polar Institute, Tromsø, Norway, 6Università di Siena, Dipartimento di Scienze Fisiche della Terra e
dell'Ambiente, Siena, Italy, 7Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy, 8Università di Trieste,
Dipartimento di Matematica e Geoscienze, Trieste, Italy

The recent depositional architecture of the north-western Barents Sea continental margin derives from past
climate changes with alternating deposition of highly consolidated glacigenic diamicton (continental shelf) and
debris flows (continental slope) associated to shelf-edge glaciations, and low-density, normally consolidated
biogenic-rich sediments deposited during interglacial conditions. In addition, sub-bottom records outline the
presence of acoustically laminated deposits locally having thickness of more than 10 m, which lithofacies
characteristics indicate deposition from turbid meltwaters (plumites) during short-living, phases of glacial
retreat (meltwater pulses, MWP). One of the youngest stratigraphic intervals recognized along the NW Barents
Sea margin was related to the MWP-1a that was responsible for the deposition of about 1.1 x 1011 tonnes of
sediments on the upper slope of the Storfjorden-Kveithola TMFs (south of Svalbard) (Lucchi et al., 2015). New
compositional analyses of such plumites revealed a distinct signature that allow us to distinguish deposition
from glacial melting form that related to the ice-sheet sub-glacial erosion and transport to the edge of margins.
Sediment facies and compositional analyses lead to a new climate-related interpretation of the laminated
deposits recognized during Marine Isotopic Stages 3 and 2 on the NW margin of the Barents Sea, including
Heinrich Event H2.
References: Lucchi et al., αrktos DOI 10.1007/s41063-015-0008-6

469
Tue_274_GG-2_1202
Major Climatic Transitions Linked to the Tasman-Drake Tectonic Evolution

Johan Etourneau1 (johan.etourneau@iact.ugr-csic.es), Ari Salabarnada1, Dimitrios Evangelinos1, Adrian López-

Quirós1, Marie-Alexandrine Sicre2, Peter Bijl3, Philippe Martinez4, Vincent Klein2, Wilrieke Boterblom3, Karine
Charlier4, Carlota Escutia1
1
Instituto Andaluz de Ciencias de la Tierra, Armilla, Spain, 2Laboratoire d'Oceanographie et du Climat, Paris,
France, 3University of Utrecht, Utrecht, Netherlands, 4Universite de Bordeaux, Talence, France

The tectonic evolution of the Drake and Tasman passages during the Eocene-Oligocene and Oligocene-Miocene
transitions have led to the modern-like Antarctic Circumpolar Current (ACC) accompanied by drastic changes in
both terrestrial and oceanic conditions. However, the timing, the oceanic and climatic responses of these
tectonic changes on the isolation of Antarctica and their role in the onset of major Antarctic glaciations remain
largely debated. This is particularly true for the Drake passage history, for which several ages of opening have
been proposed between 40 and 17 Ma. In this study, we aim at focusing on specific period of times by
investigating sedimentary archives from the Ocean Drilling, Deep Sea Drilling and Integrated Ocean Drilling
programs (ODP, IODP and DSDP, respectively) Sites 696 (~33.35 Ma), U1356 (~30.5-24.5Ma) and 269 (~25-14
Ma). Here we combined a suite of molecular proxies (d13C/dD of the n-alkanes, CPI and ACL indexes) with bulk
organic matter parameters (d13C/d15N, TOC) in order to i) characterize the organic matter origin, ii) the related
changes in vegetation type (C3 vs C4 plants) and iii) the hydrological variations (eg. precipitation) associated
with the two gateways. Preliminary data reveal sufficient amounts of biomaterial for further isotopic analyses
and refinement of interpretation. These new results will be presented during the POLAR2018 conference.

470
Tue_275_GG-2_1300
Clues to Glacial Regime and Bottom-current Changes in the Northwestern Ross Sea

Sookwan Kim1,2 (skwan@kopri.re.kr), Laura De Santis3, Jong Kuk Hong1,2, Diego Cottlerle3, Lorenzo Petronio3,
Ester Colizza4, Young-Gyun Kim5, Seung-Goo Kang1, Hyoung Jun Kim1, Suhwan Kim1, Nigel Wardell3, Riccardo
Geletti3, Andrea Bergamasco6, Robert McKay7, Young Keun Jin1, Sung-Ho Kang1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2University of Science and Technology-
Korea, Polar Science, Daejeon, Korea, Republic of, 3Istituto Nazionale di Oceanografia e di Geofisica
Sperimentale-OGS, Trieste, Italy, 4University of Trieste, Trieste, Italy, 5Research Institute of Oceanography, Seoul
National University, Seoul, Korea, Republic of, 6Institute of Marine Sciences-National Research Council (ISMAR-
CNR), Venice, Italy, 7Victoria University of Wellington, Wellington, New Zealand

The sedimentary record in polar continental margins provides useful insights into the glacial regime and
bottom-current changes during the past glacial and interglacial periods. Many of the previous seismic
stratigraphic studies have been conducted over the Ross Sea embayment to reveal the Cenozoic Antarctic
glacial history. Due to lack of data, however, there have been much less studies that could provide a more
continuous record of ice-sheet dynamics and bottom-current activity on the Ross Sea slope and rise. Here, we
present a seismic stratigraphic analysis of sediments in the Joides Basin mouth and Central Basin, northwestern
Ross Sea using the new and existing seismic and adjacent drill site data. The seismic profiles and sequence
maps indicate that gravity sedimentation processes dominated the Central Basin infill, and then downslope
sediment supply to the lower slope and rise was gradually reduced through the late Neogene and Quaternary.
The bottom-current-controlled sedimentary features that may initiated on the surrounding banks and slopes
since the mid-Miocene were overlain by glacigenic debris flows near the Joides Basin mouth after the late
Pliocene. These results would indicate that the Antarctic glacial regime was evolved toward a cooler, less
erosive through the late Neogene and Quaternary and bottom-current activity was diminished near the paleo-
shelf edge after the late Pliocene in the northwestern Ross Sea margin.

471
Tue_276_GG-2_1354
Diatom Reworking in the Ross Sea: Evidence for Quaternary Bottom Currents?

Michael Bollen1,2 (bolmi518@student.otago.ac.nz), Christian Ohneiser1, Christina Riesselman1,2, Min Kyung

Lee3, Kyu-Cheul Yoo3, Olga Albot4, Robert McKay4, Sunghan Kim3, Jae Il Lee3, Richard Levy5
1
University of Otago, Department of Geology, Dunedin, New Zealand, 2University of Otago, Department of
Marine Science, Dunedin, New Zealand, 3Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of,
4
Victoria University of Wellington, Wellington, New Zealand, 5GNS Science - Institute of Geological and Nuclear
Sciences Ltd., Wellington, New Zealand

Temporally accurate paleo-reconstructions of past ocean circulation can help us to understand climate
change's influence on the Southern Ocean and the Antarctic in the past and into the future. Here, we present
new chronostratigraphic constraints on an 11.75 m marine sediment core, RS15-LC42, recovered by the RV/IB
Araon during the Korea Polar Research Institute cruise ANA05B. Collected from the continental slope in the
Ross Sea at 2084 m water depth, this core is composed of alternating laminated muds and IRD bearing sand
lithologies.
Our age model is based around a single paleomagnetic reversal at 8.26 meters below sea floor (mbsf), which
we interpret to be the Bruhnes/Matuyama boundary (0.781 Ma). This interpretation is supported by the first
occurrence (FO) of the diatom Thalassiosira antarctica (0.50 Ma) at 5.40 mbsf. While the presence of
Fragilariopsis kerguelensis (FO 2.49 Ma) at 11.65 mbsf provides a maximum possible age for the base of the
core, our preferred interpretation assigns the entire reverse polarity interval below 8.26 mbsf to chron C1r.1r
(upper Matuyama), which provides a maximum basal age of 0.98 Ma. Diatom reworking is prevalent below
3.25 mbsf, so last occurrence biostratigraphic datums cannot be used to further constrain the age of the core.
The transition from extensive reworking to primary accumulation at ~0.25 Ma suggests a change in circulation,
which we now aim to evaluate using magnetic fabric as a paleocurrent indicator.

472
Tue_277_GG-2_1373
Unlocking Atmospheric Temperatures from Antarctica's past

Jacob Anderson1 (jacob.anderson@otago.ac.nz), Gary Wilson1, Craig Cary2, David Fink3, Toshiyuki Fujioka3,
Christina Riesselman1
1
University of Otago, Dunedin, New Zealand, 2University of Waikato, Hamilton, New Zealand, 3Australian
Nuclear Science and Technology Organisation, Sydney, Australia

Computer model reconstructions of Antarctic ice sheet configurations during Earth's past warm intervals
underestimate the contribution from East Antarctica - i.e. measured sea levels are higher than calculated melt
amounts. These climate models employ ocean driven melt as the primary control of ice mass loss rather than
atmospheric warming. To date, atmospheric temperatures have not been considered as a mechanism to melt
Antarctic ice sheets. Instead, past Antarctic ice sheet configurations have been derived from geomorphic
deposits in the Dry Valleys, and sea floor moraines. Such deposits do not reveal temperatures for inclusion in
climate models. Deriving a paleothermometer for Antarctica that predates ice core records is required to test
the role of atmospheric temperature in ice sheet melt. Recent discoveries of bacteria in Antarctic permafrost
samples provide a potential solution. New molecular genetic tools allow microbial diversity and concentrations
to be calculated for ancient permafrost horizons. We are developing a terrestrial paleoecological transfer
function for paleotemperature from the microbial diversity and concentrations preserved in these permafrost
horizons.

473
Tue_278_GG-2_1455
Buried Landscapes in Antarctica are Records of Ancient Local-scale Ice

Stewart Jamieson1 (stewart.jamieson@durham.ac.uk), Michael Bentley1, Neil Ross2, Chris Stokes1, Jane Francis3
1
Durham University, Dept. of Geography, Durham, United Kingdom, 2Newcastle University, Dept. of Geography,
Politics and Sociology, Newcastle, United Kingdom, 3British Antarctic Survey, Cambridge, United Kingdom

The degree to which The Antarctic Ice Sheet retreated during the Pliocene, mid-Miocene, or between the
Eocene-Oligocene Transition (EOT) and the mid-Miocene is not well constrained. This limits our understanding
of the potential response of the modern ice sheet to changing climate. A barrier to quantifying past ice
distribution in Antarctica is the lack of direct record inland of the coast. However, the geomorphology of buried
landscapes may reflect former ice configurations, but is relatively unexploited. We map the distribution of
ancient small-scale ice caps and valley glaciers in the highlands of the Weddell Sea region of Antarctica. We
exploit patterns visible at the ice surface in MODIS MOA and Radarsat AMM-1 data and map small-scale glacial
landscape features including subglacial valleys, ridges and buried cirques. The geomorphology is consistent
with glacial erosion under alpine glaciation such that localised ice caps or icefields existed separately from a
smaller than present ice sheet. There are no direct dates for these landscapes, but there are 4 possibilities: 1)
they document past retreat during the Pliocene; 2) they record ice configuration prior to the establishment of
polar conditions during the mid-Miocene; 3) they date from the onset of glacial conditions in Antarctica at the
EOT; or 4) they have survived since small-scale Neogene glaciation, for which there is some evidence in the
Antarctic Peninsula.

474
Tue_279_GG-2_1478
Eastern Ross Sea Shelf and Slope Marine and Glacial Processes

Elisabetta Olivo1 (eolivo@inogs.it), Laura De Santis2, Edy Forlin2, Phil Bart3, John Anderson4, Nigel Wardell2,
Andrea Bergamasco5, Vedrana Kovacevic2, Florence Colleoni6, Michele Rebesco2, Jenny Gales7, Manuel Bensi2,
Christian Lopez8, Sookwan Kim9, Yanguang Liu10, Daniela Accettella2, Emiliano Gordini2, Isabella Tomini2,
Riccardo Codiglia2, Fabrizio Zgur2, Gianpaolo Visnovic2, Paolo Mansutti2, Paolo Sterzai2, Marco Cuffaro11, Laura
Ursella2, Dino Viezzoli2
1
OGS, University of Siena, Trieste, Italy, 2OGS, Trieste, Italy, 3LSU, Baton Rouge, United States, 4Rice University,
Houston, United States, 5ISMAR, CNR, Venezia, Italy, 6CMCC, Bologna, Italy, 7Plymouth University, Plymouth,
United Kingdom, 8NOC, National Oceanography Centre, Southampton, United Kingdom, 9KOPRI, Incheon, Korea,
Republic of, 10Qingdao National Laboratory for Marine Science and Technology, Shandong, China, 11IGAG CNR,
Roma, Italy

The advance and retreat of the West Antarctic Ice Sheet (WAIS) from the outer shelf and oceanic circulation are
the main causes of depositional processes on the Eastern Ross Sea (ERS) continental slope. During the Last
Glacial Maximum, the WAIS advanced to outer shelf and then retreated ~1000 km to the inner shelf. Currently
Antarctic Bottom Water formation is linked to mixing of the relatively warm Circumpolar Deep Water (that
encroaches the continental shelf) with the colder Ross Sea Bottom Water (RSBW).
The objective of our ongoing investigation is to understand interactions between glacial and oceanographic
processes that occurred in the past and are currently active on the shelf and the slope of the ERS. Here we use
geophysical, bathymetric and oceanographic datasets acquired during two recent campaigns (NBP1502B and
PNRA16).
The data reveals several seabed structures:

• incised gullies, canyons and an elongated SSW-NNE ridge on the SE side of Hayes Bank;
• wedges and two large canyons in the Whales Deep Basin;
• ridges and incisions on the western side of Houtz Bank.

Here we discuss if 1) the origin of the structures found on the slope and shelf depends on processes related to
bottom currents or sea level changes or 2) shelf structures are most related to grounding-zone repositioning
whereas slope structures are caused by erosional processes that are linked to either meltwater discharge
and/or RSBW overflow and down-slope flow.

475
Tue_281_GG-2_1533
Collapse of the British-Irish Ice Sheet: The Role of Climate and Sea Level Rise

Niall Gandy1 (eeng@leeds.ac.uk), Lauren Gregoire1, Jeremy Ely2, David Hodgson1, Christopher Clark2, Dayton
Dove3
1
University of Leeds, School of Earth and Environment, Leeds, United Kingdom, 2University of Sheffield,
Geography, Sheffield, United Kingdom, 3British Geological Survey, Edinburgh, United Kingdom

The pattern and timing of retreat of the last British Irish Ice Sheet has been constrained in more detail than any
other palaeo ice sheet. The Minch Palaeo Ice Stream flowed NW from the Scottish Highlands to the continental
shelf edge, and retreated from 30-16ka BP. The ice stream is thought to have been laterally topographically
constrained, and on a reverse slope. Using the palaeo record it is possible to study timescales far greater than
observations of the contemporary record allow. We test if topographic influence and Marine Ice Sheet
Instability were influential during the retreat of the Minch Palaeo Ice Stream. We use BISICLES, an ice sheet
model capable of accurately simulating marine ice sheets, to simulate the retreat of the Minch Palaeo Ice
Stream. We ran a series of model simulations to isolate the influence of topography on the retreat of the ice
stream. Experiments with a step-change climate perturbation reveal a non-linear volume and area response,
caused by instabilities from basal topography and surface mass balance change. We found that the retreat
pattern of the Minch was influenced by instabilities once retreat was established, and mapped a retreat margin
beyond which the simulated ice stream did not recover to LGM extent given LGM forcing. A similar model set
up has also been used for other domains of the British-Irish Ice Sheet, working to reveal the mechanisms of
LGM Irish Glaciation, and North Sea common ice configurations.

476
Tue_282_GG-2_1557
The Glaciogenic Records in the Grove Mountains, East Antarctica

Aimin Fang1 (fam@mail.iggcas.ac.cn), Xiaohan Liu2

1
Institute of Geology and Geophysics, Chinese Academy of Science, Beijing, China, 2Institute of Tibet Plateau
Research, Chinese Academy of Sciences, Beijing, China

The glacial sediments in Grove Mountains include:

(1) different kinds of moraine dikes distributes along or perpendicular to the ice moving directions above blue
ice or surrounding the nunatakss.
(2) glaciogenic deposits occurred as ice debris of solitude tillite or loosen tills in different sizes. They are formed
in the ice-sheet frontal area by the activities of local glaciers or the East Antarctic Ice-sheet.
(3) large glacial erratic boulders perched in the outcrops of the basement rocks.
Glacial erosion landforms is ubiquitous in the outcrops of the basement rocks this area, such as horns, cirques,
U-shaped valleys, hanging valleys, roches moutonnées and so on. Furthermore, striations on rocks in the Gale
Escarpment, and other 3 nunataks are observed and their directions are measured, which show an ice flow
direction of 325-345 degree.
All the glaciogenic deposits and erosion marks found in Grove Mountains are closely related to the climatic
changes in Antarctica that resulted in the major glacial movements. They involve at least three ice-sheet
evolutionary events in east Antarctica. (1) The activities of the East Antarctic Ice-sheet at the period of the Last
Glacial Maximum. (2) A warm event, and most probably the Pliocene warmth. (3) The products of the local
Mountain glaciers developed before the formation of the Antarctic Ice-sheet. All these records are of great
significances in understanding the ice-sheet evolutionary history in east Antarctica.

477
Tue_283_GG-2_1640
Analysis of the Climate during MIS3 Using the Climate Model EC-Earth

Ida Margrethe Ringgaard1,2 (iri@dmi.dk), Shuting Yang2, Peter Lang Langen2, Jens Hesselbjerg Christensen1, Eigil
Kaas1
1
University of Copenhagen, Copenhagen, Denmark, 2Danish Meteorological Institute, Copenhagen, Denmark

As observations of the past climate are spatially sparse, climate models can be used to “fill in the gaps” and
provide a qualitative estimate of the climatic state of the past, consistent with the proxy data. In this study we
aim at investigating the state of the climate during the Marine Isotope Stage 3 (MIS3) as simulated by the
climate model EC-Earth. Comparisons of the atmospheric and oceanic circulation patterns as simulated by EC-
Earth and another Earth System Model, NorESM, are also carried out to understand the possible climate
responses to the MIS3 conditions. Additionally, the sensitivity of the simulated circulation to changes in sea ice
will also be addressed by nudging EC-Earth towards different sea ice extents as suggested by proxy data.

478
Tue_284_GG-2_1643
Plio-Pleistocene Nunatak Exposure Histories from Western Dronning Maud Land

Jennifer Newall1,2,3 (jennifer.newall@natgeo.su.se), Derek Fabel4, Marc Caffee5, Fin Stuart4, Nathaniel Lifton2,5,
Ola Fredin6,7, Neil Glasser8, Jon Harbor1,2,3, Jorge Bernales9, Irina Rogozhina9,10, Sarah Sams2, Arjen Stroeven1,3
1
Stockholm University, Department of Physical Geography, Stockholm, Sweden, 2Purdue University, Department
of Earth, Atmospheric, and Planetary Sciences, West Lafayette, United States, 3Stockholm University, Bolin
Centre for Climate Research, Stockholm, Sweden, 4Scottish Universities Environmental Research Centre,
Glasgow, United Kingdom, 5Purdue University, Department of Physics and Astronomy, and Purdue Rare Isotope
Measurement Laboratory (PRIME Lab), West Lafayette, United States, 6Geological Survey of Norway,
Trondheim, Norway, 7Norwegian University of Science and Technology, Department of Geography, Trondheim,
Norway, 8Aberystwyth University, Centre for Glaciology, Department of Geography and Earth Sciences,
Aberystwyth, United Kingdom, 9GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam,
Potsdam, Germany, 10Bremen University, Centre for Marine Environmental Sciences (MARUM), Bremen,
Germany

Confidence in the ability of numerical ice sheet models to retrodict and predict ice sheet geometries requires
model outputs to broadly agree with empirical data. For significant parts of the East Antarctic Ice Sheet
empirical data on paleo ice sheet thickness and extent is patchy. MAGIC-DML, a Swedish-US-Norwegian-
German-UK collaboration, is working in western Dronning Maud Land to determine the timing and pattern of
ice surface changes. A combination of geomorphological mapping using remote sensing data, field
investigations, cosmogenic nuclide analyses, and numerical ice sheet modelling are being used iteratively to
reconstruct the glacial history. Glacially modified bedrock and erratic boulders were sampled from nunataks at
different elevations above the modern ice surface. Measured concentrations of 10Be, 26Al, and 21Ne in these
samples reveal a complex exposure history of the nunataks implying fluctuations in ice sheet thickness since at
least the last 3.7 million years.

479
Tue_285_GG-2_1669
Pliocene Diatom Biomarkers in Sabrina Coast. EAIS Continental Marginal Dynamics

Raffaella Tolotti1,2 (raffaella.tolotti@virgilio.it), Federica Donda3, Roberto Romeo2, Leanne Armand4, Meghan
Duffy5, Andrea Caburlotto2, Amy Leventer5, Phil O'Brien6, Maria Cristina Bonci1, Nicola Corradi1, Laura De
Santis2
1
Università di Genova, DISTAV, Genova, Italy, 2Istituto Nazionale di Oceanografia e di Geofisica Sperimentale -
OGS, Trieste, Italy, 3Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Trieste, India,
4
Australian National University, Acton, Australia, 5Colgate University, Hamilton, United States, 6Macquarie
University, Department of Environment and Geography, Sydney, Australia

PNRA Tytan project, supported by the National Institute of Oceanography and Applied Geophysics (OGS),
focused on the advances and retreats dynamics of the ice sheet and on variations in the glacial regime. Unit 2
focused on Diatom biomarkers and assemblages analysis on sediments of core PC03, collected during the
IN2017-V01 cruise on the eastern flank of the Minang-a (or Whale) submarine Canyon. The project aims at
reconstructing the depositional environment of the continental margin off the Totten Glacier and diatom data
remained a key tools to constrain past ice-sheet dynamics and to forecasting future behaviour in a warming
world. Preliminary dataset from diatom biostratigraphic tools allows to refer the base of the core to Pliocene
while the upper part of the core records more modern EAIS dynamics, indicative of minor sedimentary
evolution steps of the continental margin.
Diatom assemblage analyses highlight Eocene-Oligocene reworked material and freshwater diatom inputs in
Pliocene sequence, strengthening the debate about ice-sheet and paleoceanographic models, WAIS cyclic
collapse and suspected Pliocene EAIS retreat into major subglacial Antarctic basins.

480
Tue_286_GG-2_1730
Ice Sheet Retreat in the Northern Baffin Bay Reconstructed from Bathymetric Data

Boris Dorschel1 (boris.dorschel@awi.de), Patricia Slabon1

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

The retreat histories of the Greenland, Laurentide and Innuitian Ice Sheets that bordered the northern Baffin
Bay during the last glacial are only poorly understood. Glacial landforms visible in high-resolution multibeam
data can help to reconstruct the post-glacial retreat of these ice sheets. During two expeditions in 2015 and
2017, extensive surveys with multibeam and sediment echosounders were conducted in the Melville Bay, the
Lancaster Sound trough mouth and on the north Baffin Island area to collect bathymetric data and data on
shallow sediment architectures. In the recorded data, a variety of ice-sheet marginal and sub-glacial landforms
including moraines, crag-and-tails, glacial lineations and grounding-zone wedges can be identified.
The distribution of these landforms in the northern Baffin Bay shows that in cross-shelf troughs, grounded ice
sheets reached to the shelf edge during past glacials. Grounding-zone wedges in the cross-shelf troughs
indicate that the retreat of the ice-sheet margins from their Last Glacial Maximum extents to their recent
positions was not continuous but interrupted by repeated phases of stabilisations in mid-shelf positions.
Furthermore, the distribution of glacial landforms on the continental shelves indicates an asynchronous retreat
of the ice sheets in the northern Baffin Bay. Glacial landforms on the inter-trough banks furthermore point
towards localised ice caps on the continental shelf.

481
Tue_287_GG-2_1734
Invigorated Southern Ocean Circulation Preceding Oligocene Antarctic Glaciation

Alexander Houben1, Peter K. Bijl2 (p.k.bijl@uu.nl), Appy Sluijs2, Stefan Schouten3, Henk Brinkhuis2,3
1
TNO, Utrecht, Netherlands, 2Utrecht University, Earth Sciences, Utrecht, Netherlands, 3NIOZ Royal Netherlands
Institute for Sea Research & Utrecht University, Texel, Netherlands

During the Eocene - Oligocene Transition (EOT, 34-33.5 Ma), Antarctic ice-sheets rapidly expanded leading to
the first Cenozoic continent-scale glaciation. Quasi-coeval opening of Southern Ocean gateways and resulting
changes in ocean circulation are probably not the primary driver of Antarctic glaciation, but the exact role of
tectonic changes across the EOT remain unknown. Here we use organic dinoflagellate cysts (dinocysts) to
stratigraphically date and correlate critical EOT Southern Ocean sedimentary successions. The results imply that
typical, winnowed glauconite-rich lithological units were deposited ubiquitously all around Antarctica starting
at ~35.7 Myrs ago, and continued across the EOT. In addition, quantitative biomarker- and dinocyst-based
temperature reconstructions show progressive cooling during the Late Eocene. In contrast, the southwest
Pacific experienced late Eocene warming, related to troughflow of low-latitude surface currents. Organic
microfossil assemblages document a shift towards more productive, vertically mixed surface waters in areas
influenced by polar wind-driven currents. The results imply (I) accelerated deepening of the Tasman Gateway,
(II) invigorated surface and bottom water circulation at sites affected by polar westward currents (III)
progressive southward migration of ocean frontal systems (IV) cooling of the circum-Antarctic surface waters.
These positive feedbacks have preconditioned the Antarctic continent for glaciation.

482
Tue_288_GG-2_1894
Modelling Long Term Climate and Ice Sheet Changes to Understand Future Warming

Zahra Rahimian1 (zrahimia@ucalgary.ca), Shawn Marshall1

1
University of Calgary, Geography, Calgary, Canada

This study explores Greenland Ice Sheet reconstructions during the last interglacial period (~125,000 years ago)
using the U.S. National Center for Atmospheric Research (NCAR) global climate model. Stable water isotopes
(δ18O) of precipitation on the Greenland Ice Sheet are traced through the ice sheet and climate system, using
precipitation isotopes that are simulated in the NCAR hydrological cycle. Isotope-tracing capabilities in the ice
sheet model allow a prediction of 3D δ18O fields, which can be compared with modern observed fields (e.g., in
ice cores) to better understand and constrain the past. Of particular interest is how the Greenland Ice Sheet
changed in response to a warmer climate at this time, and whether some portion of the isotopic signals from
the last interglacial period are associated with melt effects on the ice sheet. I will be examining the question of
what threshold temperature, if any, causes the decline of the Greenland Ice Sheet, and how isotopes can be
used to constrain ice sheet volume and associated sea level rise during this last major warm interval.

483
Tue_289_GG-2_1937
The Response of the Totten Glacier to Past Climate Warming Using Marine Sediment

Sian Tooze1 (sian.tooze@utas.edu.au), Taryn Noble1, Jacqueline Halpin1, Zanna Chase1

1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia

The Totten Glacier is responsible for an average ice-loss of 7 ± 2 Gt/yr from East Antarctica (Li et al. 2016) and
upon absolute melting, would contribute to a considerable 3.5m rise in global sea-level (Greenbaum et al.
2015). Marine sediment can be used to expand our understanding of ice dynamics and ocean circulation, which
will ultimately facilitate the development of current ice sheet climate models. This study focuses on three
marine sediment cores recovered aboard the RV Investigator from the continental slope of the Sabrina Coast.
Multiple laboratory techniques have been employed to unravel the response of the ocean and the ice sheet to
climate variability over the past glacial cycle. A transition from glacial to warmer conditions of the Holocene is
characterised by a prominent peak in biological productivity - implying an ice-free, nutrient-rich photic zone.
This transition is supported by trends in the XRF data which illustrate a change from clay-rich glaciogenic
sediment (higher K/Ti values) to diatom-rich sandy surface sediments (lower K/Ti values) - and by an increase in
the abundance of biogenic barium (Ba/Al) - a proxy of productivity export. Ongoing work will quantify the
iceberg-rafted debris flux and measure temporal variations in primary productivity and ocean circulation. The
provenance and age of heavy minerals will also be determined to help define the subglacial geology of the
Aurora Subglacial Basin.

484
Tue_290_GG-2_1959
Late Eocene Marine Transgression Indicated by Glaucony Facies (Drake Passage)

Adrián López-Quirós1 (alquiros@iact.ugr-csic.es), Carlota Escutia1, Antonio Sánchez-Navas2, Fernando Nieto2,

Agustín Martín-Algarra3, Dimitris Evangelinos1, Ariadna Salabarnada1
1
Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Marine Geosciences, Armilla (Granada), Spain,
2
Universidad de Granada, Departamento de Mineralogía y Petrología, Granada, Spain, 3Universidad de
Granada, Departamento de Estratigrafía y Paleontología, Granada, Spain

The rapid onset of continent-wide Antarctic glaciation during the Eocene-Oligocene transition was the most
dramatic climatic perturbation of the Cenozoic. The Late Palaeocene separation of the Tasman Rise and South
America from Antarctica led to the establishment of the Tasmanian and Drake Passages and to the
development of the Antarctic Circumpolar Current. The Powell Basin formed as the South Orkney
Microcontinent (SOM) was rifted from Antarctica in the Late Eocene. Sediments bearing Late Eocene green clay
(glaucony) facies are a significant feature in the sediment cores recovered by the Ocean Drilling Program at Site
696 in the southeastern margin of the SOM. The mode of occurrence, mineralogy and chemistry of glaucony
facies are important sedimentological proxies for paleoenvironmental reconstructions, as syn- to post-
depositional controls determine the texture and composition of authigenic minerals that evolve from iron-rich
smectite precursors to glauconite. The morphological, mineralogical and geochemical features of Late Eocene
glauconitized fecal pellets/mica flakes denote an autochthonous origin of the evolved (mature) glaucony grains,
indicating a period of low sedimentation rate probably associated with rising sea levels related to plate
reorganization and opening of Drake Passage. In this scenario, the Powell Basin may have provided pathways
for a proto-circumpolar current, favouring upwelling, stratigraphic condensation and glauconitization in the
SOM margin.

485
Tue_291_GG-2_1963
The 'Ona Paleovalley' (Drake Passage): A Submarine Slope Failure System

Adrián López-Quirós1 (alquiros@iact.ugr-csic.es), Francisco J. Lobo1, Carlota Escutia1, Fernando Bohoyo2, F.

Javier Hernández-Molina3, Lara F. Pérez4, Marga García1, Dimitris Evangelinos1, Ariadna Salabarnada1
1
Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Marine Geosciences, Armilla (Granada), Spain, 2Instituto
Geológico y Minero de España, Madrid, Spain, 3Royal Holloway University of London, Department of Earth
Sciences, Egham, United Kingdom, 4Geological Survey of Denmark and Greenland, Geophysical Department,
Copenhagen K, Denmark

The southern Scotia Sea hosts small oceanic basins developed through continental break-up and oceanic
spreading during the Cenozoic. Ona Basin is the southwestern most basin of the Scotia Sea. It is bounded by
several structural highs: the Shackleton Fracture Zone to the west, Terror Bank to the east, and the South
Scotia Ridge to the south. The southern part of the basin is further divided in two sub-basins (the western and
eastern Ona basins) separated by the submarine relief called Ona High. The Ona Basin is mainly affected by two
major water masses the deeper branch of the Antarctic Circumpolar Current flowing eastwards and a westward
flowing branch of the Weddell Sea Deep Water (WSDW). Interaction between mass movement and contouritic
processes are likely to occur as a consequence of the complex geologic, physiographic and oceanographic
setting. A combined approach including geomorphological, stratigraphic and seismic analyses allows us to
document, for the first time, the record of repeated large-scale submarine landslides in the western Ona Basin.
A major morphological feature named as 'Ona Paleovalley' is genetically related to large-scale recent
gravity/mass transport processes. The valley infill records channelized depositional periods alternated with
erosive events when sediments were evacuated basinwards. This morpho-sedimentary pattern is attributed to
the interplay between tectonic events leading to gravitational processes and the channelized flow of the
WSDW.

486
Tue_292_GG-2_1968
Eocene-miocene Paleoceanographic Changes in Drake Passage (Antarctica)

Adrián López-Quirós1 (alquiros@iact.ugr-csic.es), Carlota Escutia1, Johan Etourneau1, Francisco J. Rodríguez-

Tovar2, Peter K. Bijl3, Francisco J. Lobo1, Fernando Bohoyo4, Dimitris Evangelinos1, Ariadna Salabarnada1
1
Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Marine Geosciences, Armilla (Granada), Spain,
2
Universidad de Granada, Departamento de Estratigrafía y Paleontología, Granada, Spain, 3Utrecht University,
Department of Earth Sciences, Utrecht, Netherlands, 4Instituto Geológico y Minero de España, Madrid, Spain

The timing and impact of the opening of the Drake Passage during the Eocene-Oligocene and Oligocene-
Miocene transitions on global climate remain controversial. In this study, we aim to better understand the
regional reorganization of the ocean circulation in the southeastern margin of the South Orkney
Microcontinent (SOM) that remained isolated from Antarctica during these transitions. We combined a multi-
proxy study: sediment facies analysis, diagenesis, ichnology, X-ray diffraction and fluorescence, and
geochemical analyses using marine sediment samples from the Ocean Drilling Program (ODP) Site 696. The late
Eocene, during which the SOM was still attached to the Antarctic Peninsula, was characterized by a thick,
terrigenous sequence deposited at shallow-water (neritic) depths under reduced-oxygen conditions. However,
the latest Eocene is marked by syn-depositional glauconitization under slow sedimentation and a relative sea-
level rise/subsidence. The continuous sea-level rise led to the establishment of bathyal depths during the early
Oligocene. At that time, the water column was stratified and local/temporal anoxic bottom water conditions
developed, likely associated with a restricted ocean circulation in the Powell Basin due to the clockwise drift of
the SOM from Antarctic Peninsula. The end of the transgressive pulse is detected at the end of the mid
Miocene, recorded by a siliceous-biogenic ooze associated with oxic conditions as a result of the modern SOM
geography.

487
Tue_293_GG-2_2130
Reconstruction of Antarctic Ice Sheet Variability during the Last Interglacial

Osamu Seki1 (seki@pop.lowtem.hokudai.ac.jp), Keiji Horikawa2, Kenta Suzuki1, Masanobu Yamamoto1, Minoru
Ikehara3, Saiko Sugisaki4, Takuya Itaki4, Yusuke Suganuma5
1
Hokkaido University, Sapporo, Japan, 2Toyama University, Toyama, Japan, 3Kochi University, Kochi, Japan,
4
National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan, 5National Institute of Polar
Research, Tachikawa, Japan

Recent observation revealed that the fastest melting rate of polar ice sheets ever observed is ongoing due to
the global warming and there is growing concern of greatly rise of sea level in the future. Knowledge of sea
level fluctuations in the past warm period provides useful information to better understand future sea level
changes. Geological records have suggested that sudden and abrupt rises in sea level (~6 m) were happened
during the last interglacial when global mean sea surface temperature was slightly higher than the preindustrial
level. If this were really happening, there is a critical ice sheet stability threshold resulting in the catastrophic
collapse of polar ice sheets and substantial rapid sea-level rise in the interglacial climate condition. Since the
Greenland ice core record showed a 2 m eustatic component from the Greenland ice sheet during the last
interglacial, the Antarctic ice sheet greatly contributed to eustatic rise of sea level at that time. However,
variability of the Antarctic ice sheets during the period has not been investigated. In this study, we measured
paleoclimate proxies in sediment cores collected from different parts of the Antarctic margins in order to
reconstruct variability of Antarctic ice sheets during the last interglacial. In this presentation, we will show you
preliminary results of our sediment core data.

488
Tue_294_GG-2_2035
Ocean Circulation across the Tasman Gateway during Mid-Oligocene to Mid-Miocene

Dimitris Evangelinos1 (dimevangelinos@correo.ugr.es), Carlota Escutia1, Tina van de Flierdt2, Katharina

Kreissig2, Luis Valero3, José-Abel Flores4, Johan Etourneau1, Adrián López-Quirós1, Ariadna Salabarnada1, C.
Hans Nelson1, Francisco Lobo1, Marga García1
1
Instituto Andaluz de Ciencias de la Tierra, CSIC-Univ. de Granada, Armilla (Granada), Spain, 2Department of
Earth Science and Engineering, Imperial College London, London, United Kingdom, 3Universitat Autònoma de
Barcelona, Facultat de Ciències, Laboratory of Paleomagnetism CCiTUB and CSIC-Institut de Ciències de la Terra
Jaume Almera, Barcelona, Spain, 4University of Salamanca, Department of Geology, Salamanca, Spain

Establishment of deep ocean circulation between Australia and Antarctica through the Tasman Gateway has
been suggested to start 30 million years ago (Ma), mostly attributed to the onset and strengthening of the
Antarctic Circumpolar Current (ACC). However, uncertainty remains regarding the timing and intensity of such
paleoceanographic reorganization because of the lack of data. Here, we present sedimentological records
spanning the mid-Oligocene to mid-Miocene at two strategic Deep Sea Drilling Project (DSDP) Sites (a) 278 and
(b) 269A from the Pacific and Indian sectors of the Southern Ocean, respectively. Paleomagnetic and
biostratigraphic analyses have been conducted to obtain a new age model. In addition, visual core descriptions,
conventional sedimentological analyses and geochemical X-ray Fluorescence (XRF) data were performed in
order to define the main lithofacies and facies associations. Neodymium isotope ratios (εNd) were obtained
from fossil fish teeth to reconstruct regional water masses and ocean circulation. At Site 269A, we find
Oligocene/Miocene εNd values of -8.2 to -8.8, indistinguishable from modern deep circumpolar εNd values.
More radiogenic εNd values (-6.2 to -6.9) are recorded at Site 278, similar to other records from the region. We
conclude that from around 30 Ma, the signature of the ACC records mixing processes between Indian-Atlantic
waters with Pacific and possibly Ross Sea deep waters after crossing the gateway.

489
Tue_295_GG-2_2040
Sedimentary Evidence for a Pre-Pleistocene Marine Environment in West Antarctica

Rosemary Vieira1 (rosemaryvieira@id.uff.br), Vanessa Costa2, Jefferson Cardia Simões3

1
Universidade Federal Fluminense, Geography, Niterói, Brazil, 2Universidade Federal Fluminense, Niterói, Brazil,
3
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Porto Alegre, Brazil

Elephant Head (79°49.298´S / 83°20.426´15 W), Ellsworth Mountains, is a deglaciated valley in which sediment
samples were collected in the moraines. Particle size, morphometric, and chemical and mineralogical
composition analyses were performed on the sediments. The predominance of calcium carbonate was
observed in most samples; ripple marks suggested the existence of a shallow marine environment. A marine
sedimentation possibly filled a shallow inland sea, associated with local tectonic uplift, posterior glacial
covering and erosion. Calcareous and clastic sedimentation dominates the valley, reflecting the nature and
composition of the main source of the sediments. Conglomerates also reflect the nearby source area. Further
glacial conditions have not modified the sediment conditions substantially due to the dry climatic conditions. It
is suggested that Elephant Head Valley preserves geomorphologic and sedimentological evidence for a marine
sedimentary environment, potentially of pre-Pleistocene glacial cycles, supporting recent inferences from
terrestrial deposits, which suggest the continuous presence of the WAIS in the southern sector of Ellsworth
Mountains and the preservation of landforms and sediments at the scale of 3.5 Ma. The main unknowns now
concern the timing of the events.

490
Tue_296_GG-2_2044
Eocene-Oligocene Tectonic-driven Paleoceanographic Changes, off the Cape Adare

Dimitris Evangelinos1 (dimevangelinos@correo.ugr.es), Carlota Escutia1, Luis Valero2, Johan Etourneau1, Adrián
López-Quirós1, Ariadna Salabarnada1, C. Hans Nelson1, Francisco Lobo1, Marga García1
1
Instituto Andaluz de Ciencias de la Tierra, CSIC-Univ. de Granada, Armilla (Granada), Spain, 2Laboratory of
Paleomagnetism CCiTUB and CSIC. Institut de Ciències de la Terra Jaume Almera, Barcelona, Spain

The opening of the Tasman Gateway drastically affected Antarctic ice sheet and global climate through its
impact on atmospheric and ocean circulations. The relationships between the tectonics, circulation changes
and Antarctic glaciation are still debated. We studied late Eocene to early Oligocene age sediments from DSDP
Site 274 to provide insights into the relationship between the opening of the Tasman Gateway, the beginning
of Antarctic glaciation and the onset of the “proto”- Antarctic Circumpolar Current (ACC). For this, we
conducted paleomagnetic and biostratigraphic analyses to obtain a new age model. Sedimentary facies were
defined based on visual core descriptions, scanning electron microscope (SEM) images, conventional
sedimentological analyses, geochemical (XRF) and mineralogical (XRD) data. During the late Eocene, Site 274
sedimentation was dominated by high terrigenous inputs (silty clays). Towards the latest Eocene, silty clays are
interbedded with cherts. From the early Oligocene onwards, sedimentation is dominated by siliceous oozes
with sporadic ice rafted debris. We infer that the shift from terrigenous sedimentation to cherts reflects the
onset of a prolonged period of high primary productivity. Fossil fish teeth will be analysed for Nd isotopes to
identify intermediate/deep water masses across the observed shift in sedimentation and its relation with the
establishment of the proto-ACC.

491
Tue_297_GG-2_2197
Late Pliocene Contraction of the Pacific Polar Front: A Warming Climate Analog?

Christina Riesselman1,2 (christina.riesselman@otago.ac.nz), Briar Taylor-Silva3

1
University of Otago, Department of Geology, Dunedin, New Zealand, 2University of Otago, Department of
Marine Science, Dunedin, New Zealand, 3University of Otago, Geology, Dunedin, New Zealand

The Late Pliocene is the most recent interval in Earth's history to sustain global temperatures within the range
of warming predicted for the 21st century. Global reconstructions and climate models find an average +2° C
summer SST anomaly relative to modern during the ~3.3-3.0 Ma PRISM interval, when atmospheric CO2
concentrations last reached 400 ppm. Here, we present a new diatom-based reconstruction of Pliocene (3.8-
2.8 Ma) interglacial sea surface conditions from IODP Site U1361, on the East Antarctic continental rise. A
prominent feature of this record is the transient southward shift of the Antarctic polar frontal zone during a
single interglacial, marine isotope stage KM3 (3.17-3.15 Ma), bathing U1361 in warmer subantarctic waters.
Building on this result, we revisited earlier reconstructions to explore the response of the Southern Ocean to
peak late Pliocene warmth. By applying a modern chronostratigraphic framework to those lower-resolution
records, we identify the same frontal migration in 4 other cores in the Pacific sector of the Southern Ocean,
documenting a major migration of the polar front during a key interval of warm climate. These new results
suggest that increased summer insolation during KM3, combined with atmospheric CO2 similar to modern
concentrations, provided sufficient forcing to overcome bathymetric constraints on polar frontal position,
pushing warm subantarctic waters into proximity with vulnerable portions of Antarctica's marine ice sheets.

492
Tue_298_GG-2_2261
Paleoceanographic Changes during the Past One Million Years in the Ross Sea

Min Kyung Lee1 (mklee@kopri.re.kr), Kyu-Cheul Yoo1, Jae Il Lee1, Christian Ohneiser2, Sunghan Kim1, Robert
McKay3, Olya Albot3, Christina Riesselman2, Michael Bollen2, Ho Il Yoon1, Richard Levy4
1
Korea Polar Resarch Institute, Incheon, Korea, Republic of, 2University of Otago, Dunedin, New Zealand,
3
Victoria University of Wellington, Wellington, New Zealand, 4GNS Science, Wellington, New Zealand

A 11.75 m-long core RS15-LC42 was collected from the Central basin in the Ross Sea (71°49´ S, 178°35.´E,
2084m deep) in 2015, by the Korean RVIB Araon. The chronology is inferred by paleomatnetism and diatom
biostratigraphy, and the core covers about one million years. Magnetic susceptibility, grain size, oxygen and
nitrogen isotopes, and concentrations of total organic carbon (TOC), opal, and CaCO3 were measured. Foram
oxygen isotopic compositions were analyzed, and elemental compositions were scanned by ITRAX system. The
core is composed of two alternating facies:
1) well-laminated greenish gray diatomaceous mud, and
2) massive light gray sandy mud.
Well-laminated facies tend to include higher TOC, opal and carbonate compared to the other, so it is likely that
they were deposited during interglacial period, but the possibility of remobilizing of sediments from the outer
shelf to continental slope during glacial period cannot be excluded. Around 280 cm (about 0.25 Ma) from the
core top, the massive facies is dominant in the upper part, whereas the laminated facies is dominant in the
lower part. This indicates that there iwas a major shift in the depositional condition in the Central Basin at this
time and which could be related with the extensive glaciation during Marine Isotope Stage (MIS) 8 in the
McMurdo Sound (Christ and Marchant, 2017). Further work like clay mineral assemblage is necessary in order
to ascertain whether the laminated sediments are primary or reworked.

493
Tue_299_GG-2_2327
Widespread Fine-grained Sedimentation in Melville Bay: A Huge Meltwater Event?

Jens Weiser1 (jweiser@marum.de), Dierk Hebbeln1

1
MARUM - Centre for Marine Environmental Sciences at University of Bremen, Bremen, Germany

Reconstructing the past dynamics of the Greenland Ice Sheet (GrIS) offers invaluable insight into its dynamics
under a modern day changing climate. Two sediment cores (GeoB19946-4 and GeoB19948-3) from Melville Bay
(NE Baffin Bay), into which 27% of the GrIS drain, were used to investigate the melting history and sedimentary
dynamics in the area. The near-by cores were retrieved from two different major shelf troughs that are
separated by a shallow sill. These are fed by individual glacier sources which allows for a clear differentiation of
two major modes of glacier-derived sediment transport: in a surface plume potentially affecting both core sites
vs. near-bed transport affecting only one site. Regarding grain size distribution, sediment elemental
composition and microfossil content, both records reveal a very similar alteration of characteristic core
sections, where large portions of the cores can be classified as glaciomarine-hemipelagic sediments. However,
in both cores these layers are intersected by several meter thick, homogenous and very fine-grained sediment
packages, barren of microfossils and showing little to no variation in their elemental composition. Combined,
this synchronous, strong and sudden change in sediment characteristics indicates the occurrence of at least
one huge, surge-like meltwater event that was not confined to a single trough. This interpretation is supported
by initial radiocarbon dates that place the more recent surge at around 7.5 ka BP.

494
Tue_300_GG-2_2339
Deglaciation of the Eastern Antarctic Ice Sheet in Queen Maud Land

Naki Akçar1,2 (akcar@geo.unibe.ch), Serdar Yeşilyurt1,2, Marcus Christl3, Christof Vockenhbuer3

1
Istanbul Technical University, Polar Research Center, Istanbul, Turkey, 2University of Bern, Institute of
Geological Sciences, Bern, Switzerland, 3ETH Zurich, Laboratory of Ion Beam Physics, Zurich, Switzerland

The assessment of the stability of Antarctic ice sheets and of their contribution to the global sea level change as
a response to climate change requires the reconstruction of their past volume variations. For instance,
dramatic surface lowering of East Antarctic Ice Sheet (EAIS) during the last million years have been recently
reported in several publications. However, the spatial distribution of this unloading and subsequent isostatic
rebound remain unexplored. In this study, we will decipher the pace of deglaciation and quantify subglacial
erosion of the EAIS in the Sør Rondane Mountains in the Queen Maud Land. To do this, we will focus on the
Nunatacks around Mount Wideroe, Mount Nils Larsen and Perlabandet in the western Sør Rondane Mountains.
We will use in-situ produced cosmogenic 10Be, 14C, 26Al and 36Cl to reveal the deglaciation history and
amount of subglacial erosion. In the field, we will locate and map the paleo-positions of the ice margin during
the retreat in the Nunataks. Measured cosmogenic nuclide concentrations will be then converted to both
exposure ages and amount of glacially eroded bedrock. This study will produce scientific knowledge on
(1) deglaciation of the Queen Maud Land,
(2) amplitude, timing and frequency of the deglaciation, and
(3) subglacial erosional processes. The first results will be presented.

495
Tue_301_GG-2_2440
Landscape Evolution of the Ellsworth Mountains: Implications for Subglacial Lakes

Michael Bentley1 (m.j.bentley@durham.ac.uk), Guy Paxman1, Stewart Jamieson1, Andres Rivera2, Neil Ross3,
David Sugden4, Andy Smith5, Martin Siegert6
1
Durham University, Geography, Durham, United Kingdom, 2Centro de Estudios Cientificos, Valdivia, Chile,
3
Newcastle University, School of Geography, Politics and Sociology, Geography, Newcastle upon Tyne, United
Kingdom, 4University of Edinburgh, Geosciences, Edinburgh, United Kingdom, 5British Antarctic Survey,
Cambridge, United Kingdom, 6Imperial College London, London, United Kingdom

Antarctic subglacial lakes contain sediment records of past environmental change and ice sheet history. To
interpret sediment records in context it is important to understand the nature, origin and history of such lakes.
Here, we determine the long-term landscape evolution of the Ellsworth Mountains region, where at least two
subglacial lakes have been suggested as targets for exploration, Subglacial Lake Ellsworth, and Subglacial Lake
CECS. New geomorphological observations of exposed areas show that the Ellsworths contain preserved
remnants of a pre-glacial landscape, incised by alpine glaciation and subsequent ice sheet glaciation, and with
multiple trimlines recording former ice levels. Based on geochronologic techniques we suggest the likely timing
of each of these stages of development. Beneath the ice we present a new bedrock topography based on a
combination of new and existing radar survey data. Using this coupled to mapping of supraglacial ice
topography we identify key features in the landscape including prominent glacial troughs cutting through the
Ellsworth-Whitmore Block. Using this new subglacial topography we explore the contemporary subglacial
hydrology of the region, and the hydrologic connectivity of the lakes through time. We will explore the
implications for subglacial exploration, especially the likely nature of the sediment record preserved in the
lakes, and which can provide insight into long-term ice sheet behaviour.

496
Tue_302_GG-2_2480
Modelling a Kilometre-thick Arctic Ice Shelf during MIS6

Edward Gasson1 (egw.gasson@gmail.com), Rob DeConto2, David Pollard3, Chris Clark1

1
University of Sheffield, Department of Geography, Sheffield, United Kingdom, 2University of Massachusetts,
Amherst, Geoscience, Amherst, United Kingdom, 3Pennsylvania State University, Earth and Environmental
Systems Institute, State College, United States

<ol style="list-style-type: none;">

Sets of parallel erosional features have recently been identified on the Lomonosov Ridge in the central Arctic
Ocean, indicative of ice grounding in modern water depths of up to 1,280 m. These features have been
interpreted as being formed by an ice shelf, either restricted to the Amerasian basin (the 'minimum model'), or
from an ice shelf covering the entire Arctic basin. We use a numerical ice sheet-shelf model of the Arctic and
surrounding grounded ice sheets to explore how such a thick Arctic ice shelf could form and determine which
ice sheet/shelf configurations are most consistent with the ice-flow features observed in the Arctic Basin. We
suggest that such an Arctic ice shelf could only form with complete ice cover in the Arctic Basin, which places a
minimum estimate on its volume. We explore how buttressing provided by an Arctic ice shelf would have
affected the dynamics of the surrounding terrestrial ice sheets and examine how grounding on the Lomonosov
Ridge affects the stability of the ice shelf. Our results also have significance for a hypothesized East Siberian ice
sheet. <ol style="list-style-type: none;">

497
Tue_303_GG-2_2505
Exploring the Range of Parameters Favouring Antarctic Glaciation

Jonas Van Breedam1 (jonas.van.breedam@vub.be), Philippe Huybrechts1, Michel Crucifix2

1
Vrije Universiteit Brussel (VUB), Earth System Science and Departement Geografie, Brussels, Belgium,
2
Université Catholique de Louvain (UCL), Georges Lemaître Centre for Earth and Climate Research (TECLIM),
Earth and Life Institute, Louvain-la-Neuve, Belgium

It is generally believed that a large ice sheet started to grow on the Antarctic continent around 34 million years
ago. The development of the Antarctic ice sheet occurred at a time when ocean gateways surrounding
Antarctica opened and atmospheric CO2 concentrations declined from values likely above 1000 ppm to below
600 ppm. Recent work suggests that the elevation and configuration of the Antarctic continent was rather
different from today when accounting for the effects of erosion and tectonic uplift, which impacts have not yet
been studied in much detail.
Previous work considering off-line ice sheet simulations or asynchronous coupling with climate models show
that CO2 might have been the decisive factor in cooling the Antarctic climate and initiating ice sheet growth.
Here we present transient simulations around the Eocene-Oligocene transition using HadSM3, a climate model
that performs particularly well above the Antarctic continent, coupled with the Antarctic ice sheet model VUB-
AISM. The latest insights in paleogeography and bedrock topography are used for the reconstruction of the
boundary conditions. We make use of an emulator to predict temperature and precipitation above the
Antarctic continent for a large range in CO2, orbital parameters and ice sheet volumes to determine where ice
sheet initiation is favoured.

498
Tue_304_GG-2_2572
Neogene Seismic Stratigraphy, McMurdo Sound: Tectonic and Climate Controls

Tricia Hall1, Terry Wilson1 (wilson.43@osu.edu)

1
Ohio State University, SES/BPCRC, Columbus, United States

The interplay of tectonics and climate is recorded in the sedimentary strata within the Victoria Land Basin,
McMurdo Sound, Antarctica, where patterns of sedimentation documented from interpretation of seismic
reflection profiles are calibrated by drillhole data. Mapping of reflectors marking unconformities identified
from the AND-2A core indicates that grounded ice did not extend from the south throughout McMurdo Sound
until ~14.4 Ma. Prior to that point, erosion was limited to the western shelf as ice extended eastward from
TAM outlet glaciers. Seismic facies patterns suggest that the shelf-slope-basin geometry within McMurdo
Sound did not shift laterally through the Miocene, and was very similar to the present morphology. Mass
accumulation rates calculated in this study are variable, but the broad trends are dictated by a combination of
available accommodation space in the depocenter and ice sheet thermal regime. Sediment volumes and mass
accumulation rates calculated for critical climatic intervals show that from ~22 Ma to ~13 Ma the overall trend
of mass accumulation rates declined, with a particularly noticeable decline following the onset of cold-based
glaciation following the Mid Miocene Climate Optimum ~15 Ma.

499
Tue_305_GG-2_2602
Sedimentary Processes at the Northern Svalbard Continental Margin

Andrea Catalina Gebhardt1 (catalina.gebhardt@awi.de), Dilip Adhikari2, Jens Matthiessen3, Felix Gross4, Judith
Elger5, Sebastian Krastel4, Wolfram H. Geissler6
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Geophysics, Bremerhaven,
Germany, 2HafenCity University Hamburg, Hamburg, Germany, 3Alfred Wegener Institute Helmholtz Center for
Polar and Marine Research, Marine Geology, Bremerhaven, Germany, 4Christian-Albrechts-Universität zu Kiel,
Kiel, Germany, 5GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, 6Alfred Wegener Institute
Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

Hydroacoustic and high-resolution seismic data reveal that glacial processes and slope instability extensively
shape the sedimentary drape on the shelf north of Svalbard and the southern Yermak Plateau (YP). A complex
association of overlapping submarine landforms is linked to the Middle to Upper Pleistocene glaciation history
in the Arctic Ocean:
(i) Mega-scale glacial lineations (MSGL) formed either by an ice shelf advance from Svalbard or a coherent mass
of large-scale icebergs exiting the Arctic Ocean across the YP,
(ii) Quasi-linear, huge ploughmarks, younger than the MSGL, formed by keels of a mega-iceberg or several
icebergs trapped together in multi-year sea ice.
(iii) Freshly-looking large iceberg ploughmarks, and
(iv) irregular smaller-scale ploughmarks formed by keels of small icebergs.
A grounding-zone wedge located close to NW Spitsbergen potentially represents the maximum extent of the
youngest advance of the Svalbard-Barents ice sheet. The shelf and slope off Nordaustlandet was subject to the
giant Hinlopen/Yermak Megaslide (HYM) some 30 ka ago. Internal deformation of the sedimentary structures
reveals secondary, partly incomplete sliding processes of different age. Gas seeping, paleo pockmarks and a
former gas-pipe structure are likely linked to the mass failure. Large parts of the Nordaustlandet shelf and slope
are currently preconditioned to fail completely in future.

500
Tue_307_OC-1_294
Challenges in Polar Education: Lessons Learnt Since International Polar Year?

Jose Xavier1,2 (jccx@cantab.net), Patricia Azinhaga3, Sarah Bartholow4, Betty Trummel5, Matteo Cattadori6, Julia
Dooley7, Gerlis Fugmann8, Louise Huffman9, Rhian Salmon10, Gary Wesche11
1
MARE, University of Coimbra, Life Sciences, Coimbra, Portugal, 2British Antarctic Survey, Cambridge, United
Kingdom, 3Polar Educators International, Lisbon, Portugal, 4Polar Educators International, Alaska, United States,
5
Science Roadshow, Massachusetts, United States, 6Liceo Fabio Filzi, Rovereto, Italy, 7Polar Educators
International, Newark, United States, 8Association of Polar Early Career Scientists, Alfred-Wegener Institute,
Helmholtz Center for Polar and Marine Research, Potsdam, Germany, 9Ice Drilling Program Office, Dartmouth
College, New Hampshire, United States, 10Victoria University of Wellington, Science in Society Group,
Wellington, New Zealand, 11Polar Educators International, Kansas, United States

Education is a major legacy of the International Polar Year (IPY) carried out in 2007-08. This presentation aims
to discuss how certain aspects of polar education have grown. For example, Regular international science
education workshops and meetings, POLAR WEEKS (mainly coordinated by the Association of Polar Early Career
Scientists (APECS) (with Polar Educators international (PEI) in some countries) are still a huge success while
education and outreach is a growing theme within the Antarctic Treaty Consultative Meetings. However,
challenges on polar education still stands, such as: a thorough evaluation of long-term educational activity
success, and an activity implementation plan for other countries (and in other languages). To meet these
challenges, there is increasing need of using the most recent technologies, placing polar subject into national
curricula. In POLAR 2018, we will also aim to compare both Arctic and Antarctic education goals and discuss
how further international and collaborative initiatives can be developed and implemented, under a polar
framework for education.

501
Tue_308_OC-1_346
A Worldwide Glacier Information System to Go

Michael Zemp1 (mzemp@geo.uzh.ch), Samuel U. Nussbaumer1, Nico Mölg1, Jacqueline Huber1, Isabelle
Gärtner-Roer1
1
University of Zurich, World Glacier Monitoring Service, Zurich, Switzerland

In the forefront of the Paris Climate Conference in December 2015, the WGMS and UNESCO jointly launched a
glacier application for mobile devices. The wgms Glacier App aims at bringing scientifically sound facts & figures
on worldwide glacier changes to the interested public and teachers. With the launch of the app at high-level
events, we target the awareness of decision makers at governmental and intergovernmental levels for climate
change. The app provides a map interface based on satellite images that display all the observed glaciers in the
user's proximity. Graphs with observation data illustrate the glacier's development, along with information on
latest principal investigators and their sponsoring agencies as well as detailed explanations of the
measurement types. A text search allows the user to filter the glaciers by name, country, region, measurement
type, special events (e.g. floods or avalanches) and the current “health” status, i.e. if the glacier has gained or
lost ice over the past decade. A compass shows the closest observed glaciers in all directions from the user's
current position. The app further allows the user to submit own glacier photographs and to send feedback.
Finally, the card game allows the user to compete against the computer on the best-monitored glaciers in the
world. In this presentation, we provide a visual entrance point to the app and discuss our experiences with this
new way of sharing scientific observations with a wider audience.

502
Tue_310_OC-1_494
Preparing and Conducting a Live Online Class to Popularize Antarctic Science

Silvia Dotta1,2,3 (silviadotta@gmail.com), Diego Marques1, Claudineia Lizieri4,5, Francyne Elias-Piera6, Nubia
Caramello7, Patricia Fialho Azinhaga8
1
Federal University of ABC, Center of Mathematics, Computation and Cognition, Santo André, Brazil, 2Polar
Educators International, Santo André, Brazil, 3APECS - Brazil, Santo André, Brazil, 4Centro Universitário de Belo
Horizonte-UniBH/, Belo Horizonte, Brazil, 5APECS - Brazil, Belo Horizonte, Brazil, 6Korea Polar Research Institute
(KOPRI), Yeonsu-gu, Korea, Republic of, 7Universidad Autonoma de Barcelona, Grupo de Recerca Agua,
Territtorio y Sostenibilidad, Barcelona, Spain, 8Polar Educators International, Lisbon, Portugal

This paper reports the process of preparation and delivery of an inaugural class of the distance course for
teachers Antarctic or Antarctica?
In order to contribute to the formation of a scientific culture, the preparation started from a dialogical learning
approach, in which the teacher must abandon the role of information issuer and assume the place of learning
mediator and, together with the student, to produce meanings. It was also considered to insert the polar
sciences in contexts of popularization, reducing the abyss and the distance between specialists and laymen.
The class was conducted by a multidisciplinary team with the objective of promoting the connection between
participants in Portugal and 14 Brazilian states.
The broadcast of the class was performed live on YouTube by free and open source Open Broadcaster Studio
(OBS). In total, 257 participants had access to the class and interacted with six tutors through multiple
platforms: YouTube, Facebook and Whatsapp chat.
The use of collective teacher conception together with accessible tools was fundamental for the development
of the class by promoting the interaction of people from different locations and the breaking of the barriers
imposed for access to scientific knowledge. Synchronous mediation contributed to the consolidation of
knowledge about Antarctica and promoted a greater involvement of the participants in the proposed course,
enhancing such knowledge.

503
Tue_311_OC-1_577
Significant Learning on Antarctica in a Distance Learning Course for Teachers

Silvia Dotta1,2,3 (silviadotta@gmail.com), Edson Pimentel4, Juliana Braga4

1
Federal University of ABC, Center of Mathematics, Computation and Cognition, Santo André, Brazil, 2Polar
Educators International, Santo André, Brazil, 3APECS - Brazil, Santo André, Brazil, 4Federal University of ABC,
Santo André, Brazil

This article aims to present partial results of a research conducted in the learning process of the participants of
a distance teacher training course: Antarctic or Antarctica: How to introduce the polar sciences in the primary
school curriculum?
Our theoretical foundation is based on the socio-interactionist approaches, dialogic learning, and collaborative
learning.
Antarctic or Antarctica? Is a fourty-hour distance learning course, structured in four modules (Ice, Convergence,
Environment, and Life). There is a face to face class, and all others classes happen online and should be finished
in ten weeks.
The course is composed of texts, video lessons, puzzles, etc. All the teaching material was prepared in an
accessible language to different audiences and can be used by teachers to teach their classes.
Course participants had to answer a quiz before and after the course. Before the beginning of the course, there
were a lot of misconceptions about Antarctica.
After attending the course, a few misconceptions persisted. However, most of the participants were able to
learn crucial information about the continent.
The course helped participants to understand the importance of teaching about the continent in primary
schools. There was significant learning about basic knowledge of Antarctica. Participants were able to
contextualize that knowledge in their classes. Producing Portuguese teaching material is crucial to introduce
Antarctica into the curriculum.

504
Tue_312_OC-1_925
Exposing Students to Polar Scientific Field Work: Partnership, Rocks & ECW

Jamey Stutz1 (jamey.stutz@vuw.ac.nz), Anne Grunow2, Jen Horn3, Janessa Jaggi4

1
Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand, 2Polar Rock Repository,
Byrd Polar and Climate Research Centre, Ohio State University, Columbus, United States, 3Catawba Springs
Elementary, Denver, United States, 4Gros Cap Elementary, St. Ignace, United States

Over the past 10+ years, through a partnership with elementary school teachers, the United States Polar Rock
Repository (PRR) and Antarctic researchers, we have engaged with elementary classrooms highlighting the
nature of Antarctic scientific field work. A typical classroom visit involves the use of google earth to orient the
students, sharing field videos & photos, an opportunity to dress up in extreme cold weather (ECW) gear and a
chance to inspect geologic samples from the PRR collection. In 2017, we expanded on our typical classroom
visit to include a school-year-long project whereby a field team engages with the class over the entire life cycle
of a field season, including blog updates from the field. After the initial class visit, we introduce the project and
challenge the class to submit specific questions to the field team and teachers that may form the basis for a
student designed project aimed at planning a field season to Antarctica. Near the end of the school year, the
students present to a team of scientists to highlight their plans. For this session, we will present the results of
this experiment, share lessons learned and seek input for further refinement.

505
Tue_313_OC-1_1282
Climate Change: A Semester Course Elective at the High School Level

Sarah Bouckoms1 (sbouckoms@gmail.com)

1
Miss Porters School, Science, Farmington, United States

In its 4th year, Climate Change is a semester elective open from 10th to 12thgrade students at a private boarding
school in Connecticut, USA. This course focuses on Earth systems, key environmental issues, political actions,
social and cultural impacts as well as developing science literacy skills. Ideas are presented from both sides of
the spectrum and students are able to arrive at their own opinions as they evaluate science sources. There are
great discussions but also hands on labs, field trips and group projects. Students read through the
Intergovernmental Panel on Climate Change report learning how to read various graphs and charts. Students
observe the long term studies which enforces the difference between weather and climate. The variation in
potential outcomes shows the difficulties of modeling and the meaning of uncertainty. Beyond reading
technical papers, students also follow scientists, expeditions and latest news through various social media
platforms. A final project is to have students craft a local project on campus that will last longer than their
enrollment in the class. This is necessary to leave the students empowered as often when they become savvy
to these dire issues there is an overwhelming sense of urgency and powerlessness. For the youth, having a real
but hopeful take away message is imperative. This course has been highly successful, encouraging students to
take further environmental courses or pursue higher studies in this field during college.

506
Tue_314_OC-1_1337
The Tiny Silverfish. A Journey of Discovery through the Southern Ocean

Eva Pisano1,2 (eva.pisano@ge.ismar.cnr.it), Laura Ghigliotti2, Marino Vacchi2, Clive Evans3

1
University of Genoa, Department of Educational Sciences, Genoa, Italy, 2National Research Council of Italy,
Institute of Marine Sciences (ISMAR-GE), Genoa, Italy, 3University of Auckland, School of Biological Sciences,
Auckland, New Zealand

Ross and Sesi are two tiny fish, waiting to come to life in the midst of the Antarctic sea ice. After hatching from
small eggs they travel across the Southern Ocean, growing up in a fantastic environment inhabited by
wonderful creatures and dangerous predators. Children are involved in this adventure, following Ross and Sesi
as their life journeys unravel, and participating in the experience of discovering Antarctic marine life. This
children's book, published in Italian in 2013, is now translated and available in English, ready to reach a wide
audience of young readers and primary school teachers. In the book, the life cycle of a key fish species of the
Antarctic Ocean, the Antarctic silverfish, and its unique relationship with sea ice, are translated into appealing
graphics to illustrate the basic structure of the Antarctic ecosystem and the implications of ongoing climate
change. The book is a result of the project "Communicate polar science: Antarctic fish", supported by the Italian
Programme for Antarctic Research (PNRA). Both the graphics and the text are set with rigorous attention to the
educational message in polar scientific issues, and to gender equality. The book is dedicated to John
Macdonald, a much appreciated Antarctic researcher from the University of Auckland who, together with the
authors, participated in the discovery of the Antarctic silverfish nursery in the northern Ross Sea region.

507
Tue_315_OC-1_1571
Training Scientists in Effective Science Communication via Lightning Talks

Jessica Rohde1 (jrohde@arcus.org), Emily Osborne2

1
Interagency Arctic Research Policy Committee, Washington, United States, 2National Oceanic and Atmospheric
Administration, Washington, United States

Scientists are regularly expected to communicate their research and results with non-scientists although they
often don't receive training in how to do so effectively. Further, with a growing emphasis on interdisciplinary
research, scientists must also become adept at communicating with scientists outside of their discipline who
may not be familiar with the discipline's base-level knowledge and jargon. The Interagency Arctic Research
Policy Committee (IARPC) in the United States provides a unique platform to expedite communication between
the research community and US agencies which fund Arctic research. The IARPC has created a virtual
opportunity via the IARPC Collaborations website (iarpccollaborations.org) for early career scientists to receive
training on communicating science to communities outside their discipline, non-scientists and policy makers.
IARPC Collaborations hosted a workshop to train early career researchers in conducting a “lightning talk,” or a
short format presentation that emphasizes streamlined communication. The training focused on developing
communication skills such as considering audience, avoiding jargon, and utilizing narrative structure. Following
the workshop, participants presented their lightning talks to an audience of interdisciplinary Arctic scientists
and Federal program managers. IARPC plans to repeat this workshop to promote interdisciplinary networking
through IARPC Collaborations and continue to provide communication training.

508
Tue_316_OC-1_1574
Permafrost Young Researchers Network: The Next Generation of Permafrost ECRs

Alevtina Evgrafova1,2 (alevtina.evgrafova@gmail.com), Caroline Coch3, Denis Frolov4, Florence Magnin5, Justine
Ramage3, Simon Dumais6
1
University of Bern, Bern, Switzerland, 2University of Koblenz-Landau, Koblenz, Germany, 3Alfred Wegener
Institute Helmholtz Center for Polar and Marine Research, Potsdam, Germany, 4Moscow State University,
Moscow, Russian Federation, 5University of Oslo, Oslo, Norway, 6Laval University and CNRS, Quebec, Canada

The Permafrost Young Researchers Network (PYRN) is a platform created to engage future generations of
permafrost early career researchers (ECRs) to promote multidisciplinary research collaboration, establish
exchange on scientific news and activities around the world and make career development opportunities
available by supporting activities, improving communication among permafrost ECRs and engineers,
accumulating and sharing technical and non-technical information on permafrost such as upcoming events,
travel grant and scholarship opportunities, and job postings. PYRN has been actively using the social media
such as Facebook (https://www.facebook.com/PYRNofficial), Twitter (https://twitter.com/PYRN_official) and
Instagram (https://www.instagram.com/pyrn_official) in order to reach as many ECRs as possible.
PYRN also works in close collaboration with the International Permafrost Association (IPA) and other partners
in order to assist with the organization of the ECRs' activities during the regional and international permafrost
events such as the coordination of travel grant programs and student presentation awards as well as
organization of international PYRN workshops (e.g. EUCOP, ICOP), which represent a key contribution of the
PYRN to the permafrost research community. In addition, PYRN has been continuously developing and the
PYRN North America was established in order to increase the collaboration among ECRs based in Canada and in
the USA in December 2017.

509
Tue_317_OC-1_1681
Use of Facebook for the Polar Sciences Popularization

Sílvia Dotta1,2,3 (silviadotta@gmail.com), Diego Marques4, Paulo Lopes4, Emmanuel Duarte4, José Norberto
Sousa Lopes4, Lucas Almeida4
1
Federal University of ABC, Mathematics, Computation and Cognicion Centre, São Paulo, Brazil, 2Polar
Educators International, Santo André, Brazil, 3APECS - Brazil, Santo André, Brazil, 4Federal University of ABC,
Mathematics, Computation and Cognicion Centre, Santo André, Brazil

Social media are spaces for collaboration, information sharing and collective construction of knowledge.
Facebook (FB) has in Brazil a penetration in 45% of the population, therefore approximately, 90 million of the
users connected to the internet. This is the main reason the social platform was chosen to host an activity on
the distance learning course to teachers Antártica or Antártida?
Sharing information, news and curiosities about Antarctica, on the Portuguese language, was the main
objective along eight weeks when the students had to post on their FB profiles at least one weekly article about
Antarctica, followed by the hashtag #CursoAntartica.
114 students published at about 912 posts on different subjects covering Antartica. Beyond sharing news and
curiosities, it was realized that the students were engaged in the dissemination of what they have learned and
researched, reaching the largest number of people among their connections on Facebook
Those posts had a potential reach of 1317 users, with 10 potential influential subjects that amplified the
discussions about Antarctica. The sum of those users' Share of Voice reached a score of 99.491, therefore
proving the potential of Facebook to popularize science.
The creation of a connected people network was fundamental to popularize science. Social networks are part
of the students' lives and allow the educators new pedagogic possibilities, enabling flexible contexts, individual
and collective approaches etc.

510
Tue_318_OC-1_1718
Digging for Gold: How New Metrics & Big Data Inform the Future of Polar Research

Igor Osipov1 (igor@uberresearch.com), Euan Adie2, Lars Kullerud3

1
Digital Science / UArctic Research Analytics Institute, Moscow, Russian Federation, 2Altmetric, London, United
Kingdom, 3University of the Arctic, Arendal, Norway

The Arctic and Polar North have seen a dramatic increase in global attention from policy-makers and industry
due to several important topics, including climate change and resource competition. International Arctic
research collaboration has existed since the 19th century and, irrespective of political conditions, has grown
visibly over the last decades through initiatives such as “International Polar Year” and annual activities and
meetings of the Arctic Council.
As a result of these developments and the growing scale of research data there is an increasing need to
regularly analyze research cooperation, activities and outcomes, identify centers of excellence, and to foster
further international collaboration between disciplines and across geographies.
It is apparent that there are a lot of new insights that the Polar research community and decision makers can
gain through the lenses of various research metrics. Questions that this session will address include:

• How big-data analytics tools and methods can be used to identify and evidence challenges and gaps in
knowledge, and what solutions they might offer.

• A review of how policy makers and global audiences have engaged with the research - and what that
might mean for its future.

• A discussion of we can identify centers of excellence and surface new opportunities for collaboration.

The session is open to anyone with an interest in the development of research programs, collaborations,
evaluation and connected data.

511
Tue_320_OC-1_1898
Homeward Bound: Leadership, Science, Strategy and Gender in Antarctica

Justine Shaw1,2 (j.shaw6@uq.edu.au), Mary-Anne Lea2,3

1
The University of Queensland, Centre for Biodiversity Conservation Science, Brisbane, Australia, 2Homeward
Bound, Melbourne, Australia, 3University of Tasmania / Institute for Marine and Antarctic Studies, Hobart,
Australia

The world's first leadership, strategy and science program for women in science, set sail for Antarctic in
December 2016. It was the first voyage of a 10 year outreach initiative to build a 1,000 strong global
collaboration of women in science, who have had shared experience and learning in Antarctica, with a
curriculum focusing on leadership, strategy and science. Antarctica was the backdrop for this initiative and we
report on how why Antarctica was pivotal to Homeward Bound's success.
The 2016 program selected 76 female scientists from around the world. They worked on a range of projects
focusing on global change and sustainability throughout the year. They met for the first time as they embarked
on a 20-day trip to Antarctica. Together and individually, they learnt to elevate their leadership capabilities,
refining their ability to design and execute strategy, and devise plans for future collaborations as science
leaders working towards a sustainable future. While undertaken this transformational journey, an immersive
science program on Antarctic conservation, marine and terrestrial ecosystems, was delivered by experts. A
participant led science symposium was held at sea, off the Antarctic Peninsula. There were 76 science
presentations, the scientists then explored opportunities for collaborations, with new initiatives emerging from
the voyage. The program is rolling out again in Feb 2018 with a new cohort of scientists, and a third voyage is
fully subscribed for 2019.

512
Tue_321_OC-1_1915
Games and Art as Tools to Teach Astrobiology and Polar Science

Lucy Coleman1,2 (lucyecoleman@gmail.com), Megan Dillon3

1
Twelve Bridges Middle School, Science, Lincoln, United States, 2Montana State University, Science Education,
Bozeman, United States, 3University of California, Davis, Department of Earth and Planetary Sciences, Davis,
United States

Earth's polar regions contain extreme environments that are the best analogs to those on other planetary
bodies, like Mars and Europa. Furthermore, they can serve as analogs to early Earth, allowing us to explore
questions about how life starts and thrives. Polar environments also serve as testing grounds for prototypes
bound for other solar system locales.
A compelling combination of science, art, and gaming can inspire curiosity in young people about extreme
environments of our polar regions, astrobiology, and frontiers in science and engineering. Teens love gaming,
making them the perfect audience for this lesson series. Art and games can make abstract science concepts
more accessible and help youth envision themselves as polar scientists.
The series begins as youth play a game about extremophiles, matching their environments with extraterrestrial
environments within our solar system. Next, students compare and contrast environments of Antarctica and
Europa, which are then highlighted in student-created, annotated artwork. After that, they play Microbe
Madness, a game of evolution in which the microbe with the best genes survives changes over time. As a
culmination of the lesson series, youth create their own game about being an polar astrobiologist, modeled
after a “choose your own adventure” style of board game.Templates of the activities are offered for easy
modification for other outreach purposes and goals across science disciplines.

513
Tue_322_OC-1_2025
The UK Polar Network: An Interactive Journey through UKPN Outreach and Workshops

Kyle Mayers1,2 (kyle.mayers@soton.ac.uk), Chelsey Baker1,2, Archana Dayal2,3, Tun Jan Young2,4, Malu Avila2,
Samantha Buzzard2,5
1
University of Southampton, Southampton, United Kingdom, 2UK Polar Network, Cambridge, United Kingdom,
3
University of Sheffield, Sheffield, United Kingdom, 4Scott Polar Research Institute, University of Cambridge,
Cambridge, United Kingdom, 5University College London, London, United Kingdom

The UK Polar Network is the UK branch of APECS, one of our main aims is running education and outreach
activities to excite and inspire young people about the Polar Regions. Another main aim is to run workshops
and provide networking opportunities for early career researcher's interested in Polar Science. In 2017 the
UKPN ran two ECR workshops, which included a session where participants thought up innovative outreach
ideas and were awarded funding to the best idea from each workshop. One idea was a soundscape called
'Sounds of Change: Greenland Ice Sheet Melt' to be used in classrooms and outreach activities. A clip of the
soundscape will be debuted and discussed during our talk. The UKPN also works with collaborators, such as the
International Polar Foundation, using Arctic and Antarctic map continental jigsaw puzzles at science festivals to
engage children and the general public. The UKPN also leads the APECS Antarctic flag project in which
schoolchildren design a flag for Antarctica, which is then taken to Antarctica by scientists and photographed for
the students to see. During this interactive presentation showcase the innovative outreach tools used by the
UKPN at a variety of recent events. We will share our experiences on what we believe are effective outreach
tools for polar science. We hope to provide others with ideas, as well as begin discussions on the best way to
deliver polar science outreach now, and into the future.

514
Tue_323_OC-1_2117
Going vVrtual: 3D Opportunities for Antarctic Museums in the Internet Era

Stefano Schiaparelli1,2 (stefano.schiaparelli@unige.it), Maria Chiara Alvaro2, Matteo Cecchetto1,2, Claudio

Ghiglione2, Alice Guzzi1,2, Paola Piazza2, Claudio Mazzoli3
1
Università degli Studi di Genova, DISTAV, Genova, Italy, 2Museo Nazionale dell'Antartide 'Felice Ippolito' (Sez.
di Genova), Genova, Italy, 3Università degli Studi di Padova, Dipartimento di Geoscienze, Padova, Italy

In recent years, several worldwide museums, especially those focusing on archaeology, have launched virtual
galleries of artefacts in order to enable a detailed observation of these items through 3D technology. Precious
objects can now be observed at home, at the computer, virtually turned around and zoomed without any risk
or damage for the museum item. In the biological field, such 'virtual galleries' of museum vouchers are not that
common and, usually, are limited to type materials and new species. In the last year the Italian National
Antarctic Museum (MNA) has launched the first 'virtual gallery' of 3D models of Antarctic organisms with the
aim of providing the widest accessibility to the MNA collections and of producing materials useful for
educational purposes. In this way, researchers from all around the world can have a 'direct' access to these
museum materials and find hints and information for outreach activities. This initial set of biological 3D models
will soon be increased by the addition of 3D models of historical artefacts related to the history of exploration
of Antarctica, equipment, rocks, meteorites, etc. The 3D biological models of the MNA virtual gallery produced
so far are based on micro-computed tomography for smaller specimens and on photogrammetry for larger
ones. Either way, these 3D models are suitable to be printed. The MNA 3D virtual gallery is now visible on
Sketchfab at: https://sketchfab.com/MNA.

515
Tue_324_OC-1_2247
Methods for Training Early Career Researchers in Polar Prediction

Fiona Tummon1 (fiona.tummon@apecs.is), Gerlis Fugmann2, Alice Bradley3, Kirstin Werner4, Jonathan Day5
1
University of Tromsoe, Tromso, Norway, 2APECS Directorate/Alfred Wegner Institute, Potsdam, Germany,
3
Dartmouth College, Hanover, United States, 4Alfred Wegener Institute, Bremerhaven, Germany, 5University of
Reading, Reading, United Kingdom

Rapidly changing weather and climate is profoundly affecting the Arctic region, opening up new opportunities
but also exposing new challenges such as environmental hazards. A growing user community thus requires
enhanced predictive capacity at multiple spatial and temporal scales. The Horizon 2020 APPLICATE (Advance
predictions in the Polar regions and beyond) project is bringing together a wide range of stakeholders to
improve our predictive capacity for the Arctic and beyond. Knowledge transfer is a key aspect of APPLICATE
and as part of it a training school is being organised in collaboration with the Association of Early Polar Career
Scientists (APECS) and the Year of Polar Prediction (YOPP).
The second Polar Prediction School will take place in Abisko, northern Sweden, from 17-27 April 2018. The
school will provide in-depth training on all aspects of making polar weather and climate predictions. This
includes hands-on field measurements, exercises using computer models, and lectures covering topics ranging
from chaotic systems to high latitude ocean processes. Each component of the course forms a crucial pillar of
the prediction problem; combining these will provide participants with a complete overview of what is required
to predict polar weather and climate. This presentation will describe the curriculum and learning tools
developed to train early career researchers in polar prediction, focusing on active and skills-based learning
through small projects and exercises.

516
Tue_325_OC-1_2393
Education and Capacity Building about Polar Regions through Science

Meric Karahalil1 (merickrhll@gmail.com), Ozgun Oktar1, Sinan Yirmibesoglu1, Burcu Ozsoy1

1
Istanbul Technical University, Polar Research Center, Istanbul, Turkey

Today's students are eager to understand climate change, global warming and greenhouse gases. Therefore the
evaluation of the following question plays an important role “Are teaching programs adequately planned for
students to understand what is happening in Polar Regions?”. Providing students with the perspective and skills
to address these challenges often requires instructional approaches from a variety of disciplines.
Today's early career scientists have more opportunities to develop their science communication skills with the
range of tools and resources. For instance, visual tools such series of photographic, cinematographic images,
clips and methodology currently being utilized to educate and inspire people around the world, in regard to
Polar Regions issues. In this study, we share experiences, resources and lessons learned while teaching about
climate change, also describe how students in all contexts arrive at understandings or problem-solve in
response to the challenges. We aim to share new ideas and technologies that enhance Polar Regions
education, advance learning and literacy.

517
Tue_326_OC-1_2402
Educational Role of Polar Researches

Deniz Vural1 (vrl.dnz@gmail.com), Sinan Yirmibesoglu1, Dogac B. Isiler1, Ozgun Oktar1, Burcu Ozsoy1
1
Istanbul Technical University, Polar Research Center, Istanbul, Turkey

Climate is studied with parameters as temperature, sea, wind and humidity. Temperature differs from season
to season depending on the location. Likewise; Seas warm up slowly than the land and keep the temperature
longer to balance the warm and cold water currents. Wind, plays an important role for the climate, allows to
flow from one place to another depending on the variant in the temperature in the world. Another catalyst in
the system is the moisture which is created by the water evaporating from sea and lakes. Moisture, is
proportional to the temperature of the air, is able to carry the evaporated water and air currents in the seas to
the interior of the land due to its continuous motion. We can refer those components as mechanism that works
harmoniously with each other.
Sustainability of Earth´s current mechanism including Polar Regions have faced with extended difficulties
because of the over-growth in population and accompanying role of industrialization. As of APECS Turkey, we
teach climate mechanism including Global Climate Change by visiting primary-secondary-high school students
with specifially established curriculum for twenty weeks. The general aim here is to spread social awareness
starting from individuals. This has been an ongoing effort since APECS Turkey was established and we have
created awareness by sharing dedicated disciplines of climate and polar regions to students. Therefore, this
study will share APECS Turkey experiences and activities.

518
Tue_327_OC-1_2445
Experience about Scientific Committee on Antarctic Research (SCAR) Photo Exhibit

Sinan Yirmibesoglu1 (sinanybo@gmail.com), Deniz Vural1, Ozgun Oktar1, Dogac B. Isiler1, Burcu Ozsoy1
1
Istanbul Technical University, Polar Research Center, Istanbul, Turkey

This study provides the information about the exhibition; “Our Antarctica - Images from the Great White
South” which exhibited several places in Turkey which aimed to raise awareness and inform people about
scientific activities in Polar Regions. Ministry of Foreign Affairs hosted the photo exhibition, jointly with the
Council of Managers of National Antarctic Programs (COMNAP), the Scientific Committee on Antarctic Research
(SCAR) and Istanbul Technical University (ITU) Polar Research Center (PolReC). The exhibition included boards
by PolReC illustrating Turkey's scientific activities in Antarctica. The opening reception was held on 14 October
2016 at the Ministry's art gallery in Ankara. National and foreign diplomats, including ambassadors, officials
from Turkish government departments and academics attended the opening ceremony. Furthermore, ITU
PolReC hosted the images in Istanbul. Significant number of people, from national maritime community,
government departments, non-governmental maritime organizations, academicians, ITU maritime students
and graduates, visited the exhibition. ITU PolReC and APECS Turkey arranged the photo exhibition to travel to
several middle and high level schools in Istanbul. Exhibition took a lot of attention of young generation. This
study will visualize the SCAR photo exhibition experience in Turkey. We do believe that SCAR photo exhibition
reached more than a thousand citizens about of the importance of scientific activities in Antarctica.

519
Tue_328_OC-1_2498
Outreach Activities During and after Antarctic Expedition

Ozgun Oktar1 (ozgunoktar@gmail.com), Sinan Yirmibesoglu1, Burcu Ozsoy1

1
Istanbul Technical University, Polar Research Center, Istanbul, Turkey

Turkish Antarctic Expedition - I (TAE - I) was carried out by participation of nine scientists between February-
April 2017 onboard the Research Vessel Australis. Authors, APECS Turkey members, were participant in the
expedition used the iridium satellite system to communicate with middle school and high school students via
writing on blogs for interactive education from Antarctica. After the expedition, more interactive arrangements
were made about polar science to raise awaraness and knowledge about Southern Ocean. Additionally, many
seminars had been given to students from primary schools to universities about conducting science in Polar
Regions.
Those nine scientists took nearly twenty five thousand photographs during the Antarctic expedition. After
some detailed evaluation, best thirty of them were choosen. These photographs were displayed to raise
knowledge about Antarctica in the public areas and museums as TAE - I Photo Exhibition. The first exhibit for
the TAE - I Photo Exhibition was held during Polar Science Workshop, conducted at Istanbul Technical
University in April 2017. Finally the exhibit moved with great effort to the many public and private schools,
aimed as outreach activities about polar science by Turkish Student's Polar Research Team (PolSTeam) and
APECS Turkey.

520
Tue_329_OC-1_2599
Elementary Polar Educational Material: Please Don't Forget the Younger Students

Julia Dooley1,2 (julia.dooley@gmail.com), José Xavier3,4, Heidi Roop5, Lona Ani6

1
Polar Educators International, Oxford, United States, 2Christina School District, Newark, United States,
3
University of Coimbra, Marine and Environmental Sciences Centre (MARE-UC), Coimbra, Portugal, 4British
Antarctic Survey, Cambridge, United Kingdom, 5University of Washington, College of the Environment, Climate
Impacts Group, Seattle, United States, 6Edmonton Schools, Edmonton, Canada

If a six-year old knows all about a Tyrannosaurus Rex they can certainly make sense of Cryospheric Processes.
Although, just as with the misconceptions regarding the T-Rex, science content needs to be presented
appropriately with collaboration from science research experts and experienced primary educators. The issues
are not localized; this need is recognized internationally. A greater quality educational opportunities are
available for middle and secondary education, leaving primary educators with the task of adapting material for
use with younger students, as best they can. This can result in an oversimplification, or misconception of the
science. This presentation is both a call for assistance from scientists and a sharing of some effective strategies
and activities that are both engaging and appropriate. Collaborations help to get it right.

521
Tue_330_OC-2_461
A Symbiotic Relationship: Sailboat and Scientist - Citizen Science Partnerships

Laura K.O. Smith1 (laura.ko.smith@gmail.com)

1
Quixote Expeditions, Oakland, United States

There is a need for more research in the polar regions and an increased public understanding of science.
Scientific funding is stretched and the public rarely has opportunities to engage with scientists. Quixote
Expeditions' Guest Scientist Program supports scientific efforts and provides passengers (non-scientists) with
the opportunity to engage and participate in research.
The program provides free room and board to one scientist per trip for research. The scientist is encouraged to
involve the guests and give presentations. For most of the Guest Scientists this is their only way to access
Antarctica, as projects not associated with national research programs are often left without necessary
logistical support. Highlights for scientists are the flexibility of a small vessel, and the enthusiasm of passengers.
The guests interact daily with the scientists, asking questions throughout the day and helping with small tasks:
from holding an instrument to making an observation. Most guests return home as ambassadors for Antarctic
and its science, often giving talks to friends and family.
The presentation will discuss the Guest Scientist Program and its impact, as well as its life cycle from the
application process to onboard experiences of scientists.
The data collected as a part of this program has been presented in a wide range of outlets, including PhD
theses and academic manuscripts, as well as aiding public policy decisions.

522
Tue_332_OC-2_2162
Ghost Particle Catchers: The First IceCube Citizen Science Project

Silvia Bravo Gallart1 (silvia.bravo@icecube.wisc.edu), James Madsen2

1
University of Wisconsin - Madison, Wisconsin Icecube Particle Astrophysics Center, Madison, United States,
2
University of Wisconsin - River Falls, River Falls, United States

The IceCube Neutrino Observatory launched the citizen science project Ghost Particle Catchers in winter 2018
to engage learners of all ages in the analysis of neutrino data taken at the South Pole. This project is built on
Zooniverse, the largest platform for online citizen science projects in the world, and has been developed with
four high school internship cohorts with a total of 15 students (7 girls and 8 boys) from four Madison (WI) area
schools.
Volunteers examine data to help improve existing IceCube analyses, such as searches for astrophysical
neutrinos or for new physics in the neutrino sector. Volunteers are trained to categorize data, e.g., determine
the direction and whether more than one particle path is seen. Interns studied small samples of data with both
the 2D displays implemented on Zooniverse and the more complex interactive 4D displays that IceCube
scientists use. The results show that their classifications have an accuracy similar to computer algorithms when
they use 2D displays but can be improved after practice with interactive 4D displays.
A main goal of this project is to inform enhancements to current algorithms and search for unexpected
neutrino signatures. We will present the analysis of the first data from volunteers for Ghost Particle Catchers,
which will inform a future IceCube in 4D citizen science project.

523
Tue_335_OC-4_1351
The Tale of Anna Schwartz

Judit Hersko1 (jhersko@csusm.edu)

1
California State University San Marcos, Art, Media and Design, San Marcos, United States

This performance lecture is based on speculative eco-feminist autobiographical/ historiographical fiction and
draws on my multimedia artwork including, photo-collage, sculpture, and projections. It builds on my
collaboration with scientists and my experience in Antarctica as a recipient of the NSF Antarctic Artists and
Writers Grant.
It examines Polar exploration and science from the perspective of a fictitious, unknown, female explorer, Anna
Schwartz, who travels to Antarctica with the 1939 Byrd Antarctic expedition. Schwartz is a photographer and a
naturalist obsessed with the microscopic and transparent planktonic snail the Limacina helicina and its
predator the Clione antarctica. While the character of Schwarz is fictitious, I insert her into real events, and
thus, her “archives” contain factual materials from the past and present. They also include objects and images
created by me in the name of my protagonist. Hence my art making process is intricately linked to the narrative
that explores bi-Polar research on climate change as well as the contrasting histories of exploration at the two
Poles (with the presence of native populations in the north and their absence in the south). The archives also
incorporate materials pertaining to Schwartz's daughter, who follows in her mother's foot-steps and finds that
her mother's beloved planktonic snail, the Limacina helicina, functions as the canary in the coalmine when it
comes to ocean acidification.

524
Tue_336_OC-4_1768
Artistic Snow Crystal Casting during the Antarctic Circumnavigation Expedition

Yvonne Weber1 (yvonne.weber@epfl.ch), Irina Gorodetskaya2, Maria Tsukernik3, Michael Lehning1, Katherine
C. Leonard1
1
EPFL, ENAC CRYOS, Lausanne, Switzerland, 2University of Aveiro, Centre for Environmental and Marine Studies,
CESAM - Centre for Environmental and Marine Sciences Department of Physics, Aveiro, Portugal, 3Brown
University, Department of Earth, Environmental and Planetary Sciences, Rhode Island, United States

This project is a collaboration between an artist and scientists exploring commonalities such as applied
methods and instruments, and visualizing the process of modeling in natural science. The goal is showing in an
intuitive, tangible way how contemporary science is made to a wider public. Scientists are not only creating the
most powerful actual pictures of our contemporary world, they are also shaping our awareness of the world.
The starting point for this collaboration is the first Swiss Antarctic Circumnavigation Expedition ACE. By
investigating snowflakes, the science project “quantifying precipitation and its contribution to surface
freshening in the Southern Ocean” seeks to understand the fundamental question of how much snow falls over
the Southern Ocean. Better information on precipitation is critical to the improvement of atmospheric models
for the Antarctic. The ACE scientists collected Formvar replicates of falling snow on microscopic slides for
quantification of precipitation characteristics and amounts. They collected similar samples for the artist on
plates 24 time the size of the microscopic slides, applying the Formvar solution with an artistic tool, a paint
brush. In the context of an art exhibition, the artwork questioned the non-scientific audience regarding
whether the scientists were involved in the act of creating in the same way an artist would be? When collecting
the flakes on larger sheets of glass, did the scientists actually compose a picture?

525
Tue_337_OC-4_1919
The soniDOME Project

Timothy Weaver1, Jody Deming2 (jdeming@uw.edu), Jennifer Biddle3, Jonathan Berger4

1
University of Denver, Emergent Digital Practices, Denver, United States, 2University of Washington, School of
Oceanography, Seattle, United States, 3University of Delaware, College of Earth, Ocean & Environment, Lewes,
United States, 4Stanford University, Center for Computer Research in Music & Acoustics, Stanford, United States

The soniDOME project (Sonification of Deep Ocean Microbial Ecology) innovates a sensorial path of inquiry for
artist-scientist collaborations related to polar and deep ocean microbial ecologies. This unique collaboration
spans data development and analysis through display, interaction, open-source software toolkit distribution
and public engagement. We are expanding the sensoria of existing methods of complex data interpretations
from visual forms to interactive soundscapes to explore and interpret structures, interactions and dynamics of
remote microbial communities. Investigative outcomes include: creation and documentation of artist-scientist
collaboration from data development through translation to sonic and listening-space outcomes; development
of a 'lexicon' for enlightened data modeling/simulation, display, interactions and ecoinformational narratives in
a shared spatiotemporal context; fostering of collaboration among scientists, artists and students in
microbiology, marine ecology, digital media and sound arts; 'reduction-to-practice' of methods and vehicles for
expressing sonic representations of “master ecological narratives”, specifically datasets of polar origin; and
'case studies' for workshop production, software toolkit distributions, exhibitions, concert performances and
journal articles to further consciousness to polar oceans and the deep ocean biosphere. The soniDOME project
is sponsored by the National Academies Keck Futures Initiative (NAKFI).

526
Tue_338_OC-4_2135
Art for the [Ant]Arctic's Sake: A Call for Greater Artist Involvement in APECS

Alexander Eliot Thornton1 (alexander.e.thornton@gmail.com), Jean Holloway2, Hanne Nielsen3, Alice Bradley4,
Gerlis Fugmann5
1
University of Alaska Fairbanks, College of Fisheries & Ocean Sciences, Fairbanks, United States, 2University of
Ottawa, Ottawa, Canada, 3University of Tasmania, Hobart, Australia, 4Dartmouth College, Hanover, United
States, 5Association of Polar Early Career Scientists, Alfred-Wegener Institute, Helmholtz Center for Polar and
Marine Research, Bremerhaven, Germany

The Association of Polar Early Career Scientists (APECS) prides itself on being at the forefront of developing
innovative science communication techniques, and to continue doing so means we need to advocate for
greater involvement of artists in our work. By including professionals from these creative fields, STEM
education becomes STEAM (Science, Technology, Engineering, Art, & Mathematics), an acronym more
reflective of the interdisciplinary nature of modern polar research. APECS recognizes that including art in
educational outreach increases public engagement and makes academic research more accessible to those
without extensive STEM backgrounds. With nearly 3,000 members in over 67 countries, APECS' network
represents a diverse group of professionals interested in Earth's polar regions and wider cryosphere. We aim to
utilize uniting features of art to bridge barriers to, for example, language or geographic proximity to increase
engagement from traditionally underrepresented places and cooperation amongst future polar experts. As
well, we hope to improve understanding and inclusion of Indigenous peoples through artist partnerships. We
will discuss how APECS has included art in past outreach efforts—such as biannual Polar Week celebrations—
and call for greater artist involvement in the future. We believe that both our members and artists can benefit
from collaborations, and that we can more effectively influence positive attitudes towards polar research by
working together.

527
Tue_339_OC-4_2139
Art-science in the Development of IceCube Volumetric LED Displays

Mark-David Hosale1, James Madsen2 (james.madsen@uwrf.edu)

1
York University, Toronto, Canada, 2University of Wisconsin - River Falls, Physics, River Falls, United States

Artist Mark-David Hosale (York University, Toronto, Canada), and physicist James Madsen (University of
Wisconsin, River-Falls, USA) have been working regularly with each other since 2012. This presentation will
describe several projects they have jointly developed that explore the visualization and sonification of data sets
collected at the cubic kilometer South Pole IceCube Neutrino Observatory, The primary approach is in the
construction of scale models of the observatory. The 3-D models have a one-to-one mapping to the actual
ICECUBE array, where each light sensor in the array is represented by a full-color LED in the model. We have
developed two versions of the display, one two meters in each dimension and the other one meter. The
addition of spatial sonification (sound mapping) of the data enhances the representation of events on the
models, allowing observers to audio-locate events as well as see them. Through these projects we create a high
quality experience of the information being presented, with the goal of knowledge dissemination and the
development of an intuitive understanding of the operation of the detector.The creation of novel interfaces of
this kind represent an epistemological nexus between art and science. It has the potential to facilitate an
empirical approach to sub-atomic astrophysics by using art methodologies to find optimal means for the
expression of data in the domain of the human sensorium.

528
Tue_340_OC-4_2523
The Language of Ice

Tamsin Edwards1 (tamsin.edwards@kcl.ac.uk)

1
King's College London, Department of Geography, London, United Kingdom

What do you think of when you hear the word ice? Frozen - not only cold, but unchanging and brittle. Silent,
white, lifeless. But ice is far richer than this. If we listen to the language of ice, we hear whispers of its secrets.
And imagining polar landscapes can give voice to inner worlds and unheard stories.
Drawing on work using images and metaphors with art therapists, themes of polar exploration with 8-11 year
old artists, and other collaborations, I will use images and myths to show beauty, contradictions and surprises
of ice in the natural world, and how we - as scientists, artists, and storytellers - respond to them.

529
Tue_341_OC-4_2574
Emotional Response to CryoZenGarden: Installation on Ice Melt and Sea Level Rise

Julia Dooley1 (julia.dooley@gmail.com)

1
Polar Educators International, Oxford, United States

For some, an abstraction of scientific objectivity resonates more clearly. CryoZen Garden installation operates
as visual metaphor, modeling cryospheric processes and exploring the resulting effects of a warmer global
climate on sea levels. For this installation, the tranquility of a traditional Zen garden is disturbed. In this altered
garden, blocks of ice melt continually over the course of the exhibition. The melt water drips and pours into the
neatly raked lines in the sand, creating jarring interruptions. The sound of dripping water is discordant with the
expected static tranquility. As ice continues to melt, ocean levels rise. Flooding is a result.
Over the course of several months, viewers of this work responded with varying comments, but few expressed
indifference. Rather, questions were raised and dialogue ensued. It is through this dialogue that engagement
with science concepts occurs. A favored response was, “your CryoZen Garden is freaking me out!” And that was
the point.
http://www.streetroad.org/julia-dooley-images-from-the-bottom-of-the-world-and-cryozen-garden.html

530
Tue_342_OC-4_2620
Flights of Fact and Fancy: Birds as Messengers in Antarctic Writing

Elizabeth Lewis Williams1 (elw0168@gmail.com)

1
University of East Anglia, Literature, Drama and Creative Writing, Norwich, United Kingdom

In The Ancient Mariner, a poem partly inspired by narratives of polar travel, the shooting of an albatross
triggers a series of events which leads to the mariner's eventual transformation. He pays a heavy penance for
his crime against Nature, freed from his suffering only when he learns to appreciate the beauty of the creatures
in the world around him.
Birds are a consistent presence in writing about the Antarctic: they are trapped, shot, admired, preserved,
dissected, and eaten. Cook's published journals record careful observations, of their appearance, their habits
and their numbers, as well as a sense of their watching consciousness. Birds are a focus of scientific interest
and of personal affection. The base record for Port Lockroy in 1954 describes the behaviour of cold and hungry
sheathbills becoming “cocky” and bossing one another about after being given food; a later entry notes that a
seagull with a broken leg “failed to appear for scraps”.
Physical creatures of the air, birds are a natural symbol, intermediaries between the spiritual and human
worlds. A study of the ways in which they are represented in Antarctic writing reveals birds, real and imagined,
as messengers; more than repositories of information, they are embodiments of a particular quality of the
continent as a place where the actual collides with the metaphorical, the scientific with high art, and the
material with the spiritual; in fiction and in fact, birds have something to tell us.

531
Tue_343_OS-1_896
Delimitation of the Arctic Shelf: Harmonizing UNCLOS, Customary International Law

Alexander Vylegzhanin1 (danilalvy@mail.ru), Inna Dudykina1

1
MGIMO, Moscow, Russian Federation

Among the Arctic Coastal States Canada, Denmark, Norway and Russia are parties to UNCLOS, while the USA is
not. According to prevailing teachings, most rules of UNCLOS reflect customary International Law, but neither
Part XI (about the Area - a “common heritage of mankind”) nor article 76 of UNCLOS (about delineation of the
continental shelf from the Area; in contrast to article 83 of UNCLOS - which definitely reflects customary rules of
International Law on delimitation of the continental shelf. The paper provides what is an indisputable title of all
five Arctic Coastal States relating to their respective parts of the Arctic continental shelf - independently of the
fact whether a specific State is a Party to UNCLOS or not. In such a complicated legal environment, the paper
provides critical analysis of the contemporary “Shelf rivalry” created by submissions of Russia, Norway and
Denmark according to art. 76 of UNCLOS - in contrast to more conservative Arctic legal policy of Canada and US
aimed at securing their established rights on the Arctic Shelf as existing ipso facto and ab initio. Taking into
account specific factual and legal peculiarities of the Arctic Ocean it is argued that only international customary
law is applicable for delimitation of the Arctic Shelf in the High North.

532
Tue_344_OS-1_1219
The Soundscape of a Calving Glacier: Blomstrandbreen, Western Svalbard

Elias Strandell Erstorp1 (eliasse@kth.se), Peter Sigray2, Nina Kirchner3

1
KTH Royal Institute of Technology, Stockholm, Sweden, 2Swedish Defence Research Agency, Stockholm,
Sweden, 3Stockholm University, Department of Physical Geography, Stockholm, Sweden

In the rapidly changing Arctic, investigation of its marine sectors, and especially the underwater domain, has
become increasingly important and is of interest to benefit areas ranging from environmental monitoring to
safeguarding society. A robust characterization of the soundscape of the polar marine domains is essential if
autonomous underwater vehicles shall be used in these regions. A first step is to characterize the ambient
sound near to a glacier and to relate sound levels to specific
dynamical events. Ambient sound will not only contain information on the glacial activity but will also pose
challenges for communication between autonomous underwater vehicles and underwater sensor nodes. Here,
we report on first results describing the soundscape in front of the calving glacier Blomstrandbreen,
Kongsfjorden, western Svalbard, based on acoustic data collected during September 8-10, 2017. This project is
carried out within SMaRC, the Swedish Maritime Robotics Centre.

533
Tue_345_OS-1_1429
Acoustic Observations of Melting of Glaciers in the Arctic

Latha Ganesan1 (latha@niot.res.in), Ashokan Muthuraj1

1
National Institute of Ocean Technology, Ocean Acoustics, Chennai, India

Underwater acoustic observations in the ocean provide the ambient noise prevailing in the location and they
are useful for variety of applications. An ocean Ambient Noise Measurement System(ANMS) consisting of a
hydrophone, a data acquisition system and power pack, has been developed to withstand the environmental
conditions in the polar region and incorporated with the IndArc mooring in the Kongsfjorden region, Arctic sea.
which was jointly deployed by NIOT and NCAOR, India. The ANMS has been placed at 30 m depth in the
mooring where the ocean depth is 192m. ANMS was first deployed with IndArc in July 2015 and continuous
data for a period of 280 days were obtained. The sampling rate was 50kHz, for a duration of 60 seconds, in
every 3 hours. Later, in July 2016, hourly samplings were made, at the rate 25 kHz for a duration 180 seconds
and 240 days of time series data obtained. It is observed from the analysis that the noise in Kongsfjorden ice
bay in summer is strongly associated with different types of ice melting mechanisms such as calving, bobbing
and blooping. Comparison of noise spectra in the summer 2015 and 2016 reveals that the melting events are
more in 2016. Detailed analysis reveals that the maximum noise is produced below 2 kHz. In winter, the peak
noise is due to marine animals. The main aim is to understand the arctic acoustic environment from the
continuous measurements of noise and its usefulness in climate change studies.

534
Tue_346_OS-1_1621
The Chukchi Plateau: A True “Arctic” Soundscape?

Kathleen Mary Stafford1 (kate2@uw.edu), Catherine Berchok2, Humfrey Melling3, Sue Moore4
1
University of Washington, Applied Physics Laboratory, Seattle, United States, 2Alaska Fisheries Science Center,
Marine Mammal Laboratory, Seattle, United States, 3Institute of Ocean Sciences, Department of Fisheries and
Oceans Canada, Victoria, Canada, 4National Oceanic and Atmospheric Administration, Science and Technology,
Seattle, United States

Climate change is altering the underwater acoustic environment of the Pacific Arctic as loss of sea ice results
higher levels of environmental, biological, and anthropogenic noise. Since 2008, a long-term recorder has been
moored at the Arctic Ice Monitoring site (75.1 N, 168 W) on the Chukchi Plateau. The recorder was deployed in
October annually (except for 2012-13 when ice conditions impeded mooring servicing); recording duration
varied by year due to battery life. This is a location that, although within the region of rapid sea ice loss and
ocean warming, is still sea ice-covered for most of the year. Indeed, other instruments at the AIM site provide
detailed information on sea ice, including surface cover, movement, thickness and topographic features (floes,
leads and ridges). Overall, sound sources include wind and waves during the open water and shoulder season
(August through early November), Arctic marine mammals from May into September or October, some ships
and airguns August through October, primarily from seabed mapping efforts, and ice failure, and ridge building,
and blowing snow during the months with heavy ice cover (usually late October through early August) . Overall,
sound levels at this high Arctic location are low relative to sites further south in the Pacific Arctic and compared
to data from further north in the Atlantic Arctic.

535
Tue_347_OS-1_1717
Fin Whale Vocal Activity on the SWIR: Temporal Patterns and Potential Drivers

Virginia Sciacca1,2 (virginia.sciacca@iamc.cnr.it), Olaf Boebel3, Emilio De Domenico2, Vera Schlindwein4,

Salvatore Viola5, Daniel P. Zitterbart3,6
1
Istituto per l'Ambiente Marino Costiero - Consiglio Nazionale delle Ricerche (IAMC-CNR), Sede secondaria di
Messina, Messina, Italy, 2Università degli Studi di Messina, Dip. Scienze Chimiche, Biologiche, Farmaceutiche ed
Ambientali, Messina, Italy, 3Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI),
Climate Sciences - Physical Oceanography of the Polar Seas, Bremerhaven, Germany, 4Alfred Wegener Institute,
Helmholtz Center for Polar and Marine Research (AWI), Geosciences - Geophysics, Bremerhaven, Germany,
5
Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), Catania, Italy, 6Woods Hole
Oceanographic Institution, Department of Applied Ocean Physics and Engineering, Woods Hole, MA, United
States

The main objective of this study was to reveal the presence and to explore the temporal patterns of fin whale
vocal activity in an offshore area on South-West Indian Ridge (SWIR). Data were obtained from a 10-element
ocean bottom seismometer network deployed near 13°E and 52°S, at an average depth of 3500m. Recorders
digitized seismic and acoustic signals at a rate of 100Hz, continuously for about 1 year, from December 2012 to
November 2013. Data were analyzed by using a custom MATLAB code for the automatic detection of 20-Hz
calls. About 60.300 hours of acoustic data from 8 recorders were analyzed and calls were detected in about the
75% of the recording time. The spectral features of detected 20-Hz calls were consistent with other
observations reported for southern fin whale populations (1-50 Hz frequency band). Results show that the
animals were present and acoustically active in the study area from February 2013 to November 2013, when
they stopped singing or left the area. Moreover, a periodicity was observed in call detection rates, with
greatest peaks between August and October 2013. A positive correlation was also found between peaks in call
detection and Sea Surface Height values obtained from satellite data. This possibly indicates that the
meandering ACC (Antarctic Circumpolar Current) fronts may influence the location and possibly formation of
prey aggregations and hence act as a driver for presence and acoustic activity of fin whales in the area.

536
Tue_348_OS-1_1918
Sonification of Deep Ocean Microbial Ecology (soniDOME)

Timothy Weaver1, Jonathan Berger2, Jennifer Biddle3, R. Eric Collins4, Zachary Cooper5, Jody Deming5
(jdeming@uw.edu)
1
University of Denver, Emergent Digital Practices, Denver, United States, 2Stanford University, Center for
Computer Research in Music & Acoustics, Stanford, United States, 3University of Delaware, College of Earth,
Ocean & Environment, Lewes, United States, 4University of Alaska Fairbanks, College of Fisheries and Ocean
Sciences, Fairbanks, United States, 5University of Washington, School of Oceanography, Seattle, United States

The soniDOME Project is a National Academies Keck Futures Initiative (NAKFI)

sponsored art-science investigation into novel means to model and experience deep ocean microbial
ecosystems, and expand the perceptive foundations of research, all through sound. Parallel to the critical
understanding, perception and interpretation of the natural ocean soundscape, we are investigating the sonic
display of ecoinformatic data forms to expand current versions of deep ocean information beyond
visualizations to explore ecological paradigms and representations of deep ocean microbiology, beginning with
deepwater formation in polar regions. Our work investigates exemplary datasets as sources and structures for
sonic transcoding. As an experimental 'reduction to practice' for our methods, a ´master ecological narrative'
library of software processes and sound representations is being developed for polar and deep ocean, deep
biosphere and pelagic microbial ecosystem data sets. This presentation will review our application of
transcoding and sonification processes to the hima meta-database of Low Temperature Genomes and
Metagenomes as an exemplary dataset for sonic interpretation, one that links sequences and phenotypic data
of cold-active microorganisms from all three domains of life. Specifically, we will review our investigation into
the use of sonic sensoria for the interpretation of Colwellia spp. from sea ice microbial communities, the Arctic
cryosphere and the deep ocean.

537
Tue_349_OS-1_1940
Measurements of Under-ice Noise North of Svalbard Using Deep-sea Recorders

Dag Tollefsen1 (dag.tollefsen@ffi.no), Helge Buen1, Vidar Forsmo1

1
Norwegian Defence Research Est. (FFI), Maritime Systems, Horten, Norway

This paper describes long-term passive acoustic recordings in the seasonally ice-covered ocean north of the
Svalbard archipelago (eastern Arctic Ocean) from July 2016 to September 2017. Data from two mooring
deployments has been analyzed for ambient noise spectra and noise statistics at frequencies from 10 Hz to 8
kHz. We present seasonal spectra and compare these with historic data from the Arctic Ocean. We discuss
characteristics of the spectra and noise levels in relation to environmental forcing factors including ice cover,
wind and sea state, and oceanographic conditions. Identification of components of the soundscape including
transients due to marine mammals and anthropogenic noise will also be presented. The measurements were
performed with AMAR Ultra Deep acoustic recorder instruments fitted to bottom-moored rigs. Technical
details of the mooring design, deployment and retrieval will be discussed.

538
Tue_350_OS-1_1978
The Marine Soundscape off Elephant Island: A Southern Ocean Coastal Habitat

Elke Burkhardt1 (elke.burkhardt@awi.de), Olaf Boebel1, Boris Cisewski2, Ramona Mattmueller1, Marlene
Meister1, Elena Schall1, Stefanie Spiesecke1, Karolin Thomisch1, Ilse Van Opzeeland1
1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Physical Oceanography of the
Polar Seas, Bremerhaven, Germany, 2Thünen-Institut für Seefischerei / Thünen Institute of Sea Fisheries,
Bremerhaven, Germany

Here we present a comprehensive description of the acoustic environment approximately 31 km west-

northwest of Minstrel Point, Elephant Island, Antarctica at 210 m water depth based on three years (Jan 2013 -
Feb 2016) of subsampled (5 min per hour) passive acoustic recordings. Long-term spectrograms reveal a
notable recurrence of acoustic environments between years. Fin and Antarctic blue whale calls dominate the
low (< 100 Hz) part of the biophonic spectrum energetically from end of January to late July/early August.
November through early January are dominated by leopard seal vocalizations at around 300 Hz. Concurrently,
the geophonic spectrum exhibits strong fluctuations between days, both due to storm and tidal influences,
causing flow and shackle noise from the instrumentation itself. Manual analysis of every second day of the
subsampled data by visual and aural screening (employing short term spectrograms) was used to examine the
data in greater detail for additional acoustic contributions and to assign the various acoustic signatures to their
sources. Six cetacean and two pinniped species were identified based on their acoustic signatures and analysed
for seasonal and diel patterns in occurrence. Anthrophonic signatures were attributed to air guns on 3 % of the
analysed days. Vessel noise was noted between 10 and 12% of days on annual averages, occurring mainly in
austral summer and fall with sporadic events throughout the remainder of the year.

539
Tue_351_OS-1_2032
Arctic and Antarctic Soundscapes: Contributors and Acoustic Levels

Delphine Mathias1 (mathias.somme@orange.fr), Aurelie Jolivet1,2, Erwan Amice3, Frédéric Olivier4, Mikael Sejr5,
Øivind Strand6, Julien Thébault3, Sylvain Chauvaud2, Christine David-Beausire3, Laurent Chauvaud3
1
SOMME, Plouzané, France, 2TBM Environnement, Auray, France, 3Laboratoire des Sciences de l'Environnement
Marin, UMR 6539, Plouzane, France, 4Muséum National d'Histoire Naturelle, UMR BOREA 7208, CNRS/MNHN/
UPMC/IRD, Concarneau, France, 5Arctic Research Centre, Aarhus University, Aarhus, Denmark, 6Institute of
Marine Research, Bergen, Norway

Polar ecosystems are undergoing major changes driven by sea ice decrease, air temperature warming and
increasing anthropogenic activities. The ocean acoustic environment, called the “marine soundscape,” consists
of biological, abiotic and anthropogenic sounds. In polar seas, biological sound sources include marine
mammals, fishes, and benthic organisms. Abiotic sound sources correspond to physical processes such as ice
dynamics and meteorological events. Contributors to anthropogenic noise are classically commercial shipping
and military activities.
In order to monitor how anthropogenic changes is impacting polar ecosystems, the first step is to identify,
describe and quantify the features of soundscape contributors. Since 2013, underwater acoustic recorders
have been deployed up to several months in several locations of the Arctic (Spitzbergen, Greenland) and the
Antarctic.
In the Arctic, results show a strong variation of ambient noise levels between sites and seasons. Noise levels
measured in Spitzbergen in October 2013 are up to 15 dB re1µPa higher than those measured in Mai 2013, due
to an increase in wave and water flow noises. The Daneborg acoustic recordings display extreme differences in
noise levels between August 2015 and August 2016 with a very quiet environment in 2015 and many ice
sounds in 2016.
Antarctica soundscape is dominated by biological sound sources: benthic sounds and marine mammals
vocalizations (including weddel seals, orcas and blue whales).

540
Tue_352_OS-1_2249
Overview of the Deep Water Soundscape off East Antarctica

Brian S. Miller1, Jason Gedamke2, Susannah Buchan3, Ken Findlay4, Danielle Harris5, Flore Samaran6, Ana
Širović7, Kathleen Stafford8 (stafford@apl.washington.edu), Ilse Van Opzeeland9, Elanor Miller10, Michael
Double1
1
Australian Antarctic Division, Australian Marine Mammal Centre, Kingston, Australia, 2National Oceanographic
and Atmospheric Administration, Office of Science and Technology- Ocean Acoustics Program, Washington DC,
United States, 3COPAS Sur-Austral, Department of Oceanography, Concepcion, Chile, 4Cape Peninsula University
of Technology, Cape Town, South Africa, 5University of St Andrews, Centre for Research into Ecological and
Environmental Modelling, St Andrews, United Kingdom, 6Ensta Bretagne, LabSTICC CNRS UMR 6285, Brest,
France, 7University of California San Diego, Scripps Institution of Oceanography, San Diego, United States,
8
University of Washington, Applied Physics Lab and School of Oceanopgraphy, Seattle, United States, 9Alfred-
Wegener Institute Helmholtz Institute for Polar and Marine Research, Ocean Acoustics Lab, Bremerhaven,
Germany, 10EJM Consulting, Hobart, Australia

Since 2004 the Australian Antarctic Division has collected over 100,000 hours of underwater sound recordings
in Southern Ocean off East Antarctica. The bulk of these recordings were made by mooring autonomous
acoustic recorders in deep water. Continuous year-long recordings were made at sites along shipping routes
during the annual resupply of Australia's three stations in East Antarctica, and many sites have now yielded
several years of data. Initial work focused on blue and fin whales, but the number of species recorded has
increased over the years in step with improvements in instrumentation. Since 2013, recordings have been able
to provide information on the presence and behaviour of many top predators including some toothed whales,
most pinnipeds, and all Antarctic baleen whales. Here we present an overview of this rich acoustic dataset to
highlight advantages and challenges of remote acoustic monitoring in the Southern Ocean. We begin with
investigation of wind and ice driven ambient noise. Then we present the highly seasonal contributions of blue,
fin, and minke whales and leopard seals to the soundscape. Lastly we present systematic observations of sperm
whales and preliminary observations of crabeater seals and humpback whales. Continued acoustic data
collection and analysis are planned by the Southern Ocean Hydrophone Network (SOHN), a joint long-term
project of the IWC's Southern Ocean Research Partnership (IWC-SORP) and the Southern Ocean Observing
System (SOOS).

541
Tue_353_OS-1_2600
Spatio-temporal Patterns in Antarctic Marine Mammal Community Composition

Ilse Van Opzeeland1,2 (ilse.van.opzeeland@awi.de), Helmut Hillebrand2,3

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Ocean Acoustics, Bremerhaven,
Germany, 2Helmholtz Institute for Functional Marine Biodiversity (HIFMB) at University Oldenburg, Oldenburg,
Germany, 3Institute for Chemistry and Biology of Marine Environments [ICBM], Oldenburg, Germany

Passive acoustic monitoring tools have the potential to provide insights into community structure as devices
can autonomously collect data on the acoustic presence of species. Data can provide information on local
species diversity, residency times and patterns in species co-occurrence. Here, we apply multiple biodiversity
measures to explore how marine mammal community composition develops over time using information
derived from multi-year passive acoustic data from 6 sites throughout the Atlantic sector of the Southern
Ocean, the Weddell Sea. Overall species richness showed relatively little variation over time, showing that a
substantial number of species remains in Antarctic waters throughout austral winter, but community
composition showed almost complete seasonal overturn, recognizing that species replace each other
throughout the year. For all 6 sites, community dissimilarity increased with increasing temporal distance
reflecting temporal trends in community composition beyond seasonality. Species co-occurrence analyses
showed that a number of species exhibited either consistently positive or negative relations, while at the
recording site off the Western Antarctic Peninsula, some relations were inversed compared to the oceanic
sites. Patterns in co-occurrence are suggestive of predator-prey relationships between species, inter-specific
interference with respect to prey species as well as acoustic interference between co-occurring marine
mammal species.

542
Tue_354_OS-8_638
Sea Ice-ocean Modeling Study Collaborated with the Western Arctic Sediment Trap

Eiji Watanabe1 (ejnabe@jamstec.go.jp)

1
Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan

Seasonal and interannual variability in biogenic particle sinking was captured by the multi-year bottom-
tethered sediment trap moorings in the Northwind Abyssal Plain (Station NAP: 75°N, 162°W, 1975 m water
depth) of the Arctic Chukchi Borderland. The analysis of trap samples revealed summer and early-winter flux
peaks of the biogenic particle including fresh organic materials and lithogenic minerals [Watanabe et al., 2014;
Onodera et al., 2015; Watanabe et al., 2015]. In this study, background mechanisms of the observed variability
on a couple of timescales were investigated using a numerical modeling approach. A pan-Arctic sea ice-ocean
general circulation model COCO is coupled with a lower-trophic marine ecosystem model Arctic NEMURO,
which represents both sea ice algae and pelagic plankton species (e.g., diatom, flagellate, and copepod). The
horizontal resolution is about 5 km so that mesoscale eddies and narrow boundary currents are resolved
[Watanabe et al., 2017]. An interannual experiment from 2001 to 2014 demonstrated that the higher sinking
flux of Particulate Organic Nitrogen (PON) was located along the pathways of mesoscale shelf break eddies
originating in the Barrow Canyon. Ongoing works with additional trap data newly obtained north of the Barrow
Canyon (Station NBC), north of the Hanna Canyon (Station NHC), and in the Chukchi Abyssal Plain (Station CAP)
will also be reported.

543
Tue_355_OS-8_795
Pan-Arctic Phylogeography and Connectivity of Pseudocalanus (Copepoda)

Jennifer M. Questel1, Ole N.S. Aarbakke2, Leocadio Blanco-Bercial3, Russell R. Hopcroft4, Fredrika Norrbin2,
Claudia Halsband5, Agata Weydmann6, Elizavert A. Ershova2, Ksenia N. Kosobokova7, Ann Bucklin1
(ann.bucklin@uconn.edu)
1
University of Connecticut, Marine Sciences, Groton, United States, 2University of Tromsoe, Arctic and Marine
Biology, Tromsoe, Norway, 3Bermuda Institute of Ocean Sciences, St. George's, Bermuda, 4University of Alaska -
Fairbanks, Institute of Marine Science, Fairbanks, United States, 5Akvaplan-niva AS, Tromsoe, Norway, 6Polish
Academy of Sciences and University of Gdańsk, Institute of Oceanology, Sopot and Gdynia, Poland, 7P.P.
Shirshov Institute of Oceanology, Moscow, Russian Federation

Phylogeographic analysis of marine zooplankton species can reveal patterns of population connectivity. Three
species of the copepod genus Pseudocalanus exhibit widespread distributions over polar and sub-polar
latitudes of the northern hemisphere. These species are frequently highly abundant, and are ecologically
important as trophic links in pelagic food webs. We report findings based on phylogeographic analysis of the
mitochondrial cytochrome oxidase I (COI) gene for Pseudocalanus acuspes, P. minutus and P. newmani from
Atlantic and Pacific sectors of the Arctic Ocean. Population connectivity was evaluated using Migrate-N to
estimate the magnitude of directional, asymmetrical, non-equilibrium migration rates and evaluate
hypothesized migration models based on Bayesian statistics. Pan-Arctic dispersal patterns and pathways were
shown to differ among the three species of Pseudocalanus: the N. Atlantic Current and Pacific currents are
most important for P. acuspes; P. minutus shows Pan-Arctic connectivity; and P. newmani shows panmixia
among the sampled locations. Pan-Arctic phylogeographic analysis of widely-distributed and ecologically-
important species can provide new insights into how a warming Arctic with diminishing sea-ice cover may
reduce barriers to gene flow and alter patterns of population connectivity for Arctic and sub-Arctic copepods
and other marine zooplankton species.

544
Tue_356_OS-8_810
Uncertainties in Light Supply to Phytoplankton in Arctic Waters

Martin Vancoppenolle1 (martin.vancoppenolle@locean-ipsl.upmc.fr), Julienne Stroeve2, Marcel Babin3, Marion

Lebrun1
1
Sorbonne Universités (Université Pierre et Marie Curie Paris 6), LOCEAN-IPSL, CNRS/IRD/MNHN, Paris, France,
2
University College London, CPOM Centre for Polar Observation and Modelling, London, United Kingdom, 3Laval
University and CNRS, Takuvik Joint International Laboratory, Québec, Canada

Light exerts a primary control on photosynthesis. In the Arctic Ocean, this control differs from the classical
open water situations because of the complex match between the very specific solar input and the seasonal
variations in the the icescape, including contributions of open water, bare ice, snow and melt ponds, all
exhibiting large spatial and temporal variations.
Here, we question how well satellite or modelling products could be used to derive under-ice light, in a relevant
manner for ecosystem studies at pan-Arctic scales. To address this problem, we combine various satellite and
modelling products to describe the seasonal evolution of the icescape characteristics. Using a simple radiative
transfer formulation, we retrieve daily maps of under-ice light fields, from which various estimates of the
photoperiod can be retrieved. We perform a sensitivity analysis to see which sea-ice phenology transitions are
the most critical in terms of photo-period.

545
Tue_357_OS-8_840
Making and Breaking Stratification in the Kitikmeot Sea

William Williams1 (bill.williams@dfo-mpo.gc.ca), Bodil A Bluhm2, Kristina Brown1, Eddy Carmack1, Seth
Danielson3, C.J. Mundy4, Lina M. Rotermund5, Adrian Schimnowski6
1
Fisheries and Ocean Canada, Institute of Ocean Sciences, Sidney, Canada, 2UiT The Arctic University of Norway,
Institute for Arctic and Marine Biology, Tromso, Norway, 3University of Alaska - Fairbanks, Institute of Marine
Science, Fairbanks, United States, 4University of Manitoba, Winnipeg, Canada, 5University of Victoria, Victoria,
Canada, 6Arctic Research Foundation, Winnipeg, Canada

The Kitikmeot Sea Science Study was initiated in 2014 to provide the Canadian High Arctic Research Station a
scientific basis for long-term ecological monitoring and research in the southern central Canadian Arctic
Archipelago. The region is unique in the Arctic due to massive freshwater input relative to its area and its
shallow bounding sills. Thus, 3 foci guide the study: the Pacific-origin estuarine inflow, which sets the
oceanographic structure; the origin and pathways of freshwater, which influence the nutrient balances and
stratification; and tidally influenced biological communities in narrow passages. To investigate these, we apply
a suite of tools deployed from the R/V Martin Bergmann.
Our results show that the Kitikmeot Sea is characterised by two-layer estuarine flow, with surface outflows and
sub-surface inflows across the bounding sills. River inputs along the southern boundary deliver freshwater,
terrestrial nutrients, and carbon to the riverine-coastal domain, which then spreads throughout the system .
Strong tidal currents in narrow passages enhance vertical heat and nutrient flux to maintain ice free conditions
in winter and tight benthic pelagic coupling in summer. These sites have hard bottom substrate inhabited by
suspension feeders, while elsewhere are soft sediments with deposit feeders. Our analysis reveals a dynamic
ecosystem characterised by pelagic benthic coupling forced by the physical flow field and external inputs of
nutrients and freshwater.

546
Tue_358_OS-8_940
Arctic Marine Ecosystem Conceptual Model: Interactions Matrix Revealed (Part B)

Johnna Holding1 (johnna@bios.au.dk), Kristina Brown2, Henry Huntington3, Uma Bhatt4, Susana Agusti5, Carlos
Duarte1,5, Eddy Carmack2, Paul Wassmann6
1
Aarhus University, Arctic Reseach Centre, Aarhus C, Denmark, 2Institute of Ocean Sciences, Department of
Fisheries and Oceans, Sidney, Canada, 3The Pew Charitable Trusts, Eagle River, United States, 4University of
Alaska - Fairbanks, Geophysical Institute, Fairbanks, United States, 5King Abdullah University of Science and
Technology, Red Sea Research Centre, Thuwal, Saudi Arabia, 6University of Tromsø, Faculty of Biosciences,
Fisheries and Economics, Tromsø, Norway

In November 2016, the US Bureau of Ocean Energy Management, Office of Naval Research, and National
Science Foundation supported a workshop to create a unifying pan-Arctic conceptual model of the current
state and future changes of the Arctic Marine Ecosystem (AME). One component of this conceptual model is a
matrix of interactions that determine the functioning of the AME. This matrix was developed using a
parsimonious list of Key Elements, distributed between five categories: Atmosphere, Land-Ocean/Shelf-
Interior Connections, Physical Environment, Biology, and Human Impacts. To determine the strength and
direction of connections between Key Elements, direct interactions were characterized in a matrix array by
evaluating directionality, relative magnitude, and scientific (un)certainty. Indirect interactions were removed,
because these should be captured by chains of direct interactions. As described in Part A, further work is
needed to explore indirect causal pathways and the existence of multi-element feedback loops. In Part B
participants can explore connections between Key Elements through an interactive platform. With this
participatory presentation we hope to elicit feedback, comments, and criticisms of the interactions presented,
including their magnitude and the direction of their effects now and into the future. Discussion generated
during this presentation will be used to refine the matrix.

547
Tue_360_OS-8_1960
Arctic in Rapid Transition: Pan-Arctic Interdisciplinary & International Network

Alexey Pavlov1 (pavlov.alexey.k@gmail.com), Helen Findlay2, Allison Fong3, Michael Fritz4, Christopher Horvat5,
Jinyoung Jung6, Kathrin Keil7, Sanna Majaneva8, Nathalie Morata9,10, Allyson Tessin11
1
Norwegian Polar Institute, Fram Centre, Tromsø, Norway, 2Plymouth Marine Laboratory, Plymouth, United
Kingdom, 3Alfred-Wegener-Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany,
4
Alfred-Wegener-Institute Helmholtz Center for Polar and Marine Research, Potsdam, Germany, 5Brown
University, Providence, United States, 6Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of,
7
Institute for Advanced Sustainability Studies (IASS), Potsdam, Germany, 8UiT The Arctic University of Norway,
Tromsø, Norway, 9Laboratoire des Sciences de l'Environnement Marin (LEMAR), Brest, France, 10Akvaplan-niva
AS, Fram Centre, Tromsø, Norway, 11University of Leeds, Leeds, United Kingdom

The Arctic is changing at an unprecedented pace. Sea ice plays a central role in the Arctic system, and its
decline and thinning has a multitude of implications ranging from physics and biology to geopolitics and
economics. To enable robust future projections, a holistic pan-Arctic approach spanning across multiple
disciplines is required. Arctic in Rapid Transition (ART; www.arcticinrapidtransition.com) is an international and
interdisciplinary pan-Arctic scientific network, developed and steered by early-career scientists, aimed at
implementing such an approach to address present and future changes of Arctic systems. The main goals of
ART are bridging time-scales by incorporating paleo-studies with modern observations and modelling, and
applying various science disciplines to better understand the past and present response of the Arctic marine
ecosystems to changes in sea-ice cover, thus improving our capability of predicting their future state. Initiated
in 2008, ART became an official IASC network in 2013. Past ART activities included the organization of science
workshops, the coordination of a special issue in Polar Research, and the publication of topical priority fact
sheets for the future of Arctic research, which contributed to the ICARP III process. Focusing on active data
collection, ART led the TRANSSIZ expedition onboard RV Polarstern in 2015. Along with these activities, the
new 5-year Strategic Plan of ART will be presented.

548
Tue_361_OS-8_2287
Ocean, Sea Ice, and Ecosystem Concepts for the Siberian Shelves and Slopes

Markus Janout1 (markus.janout@awi.de), Jens Hölemann1, Dorothea Bauch2, Georgi Laukert2, Dieter
Piepenburg1, Anya Waite1, Andrey Novikhin3, Fedor Martinov3, Vasily Povashny3, Qiang Wang1, Claudia
Wekerle1, Bennet Juhls1,4
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2GEOMAR
Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, 3Arctic and Antarctic Research Institute, St.
Petersburg, Russian Federation, 4Freie Universitaet Berlin, Berlin, Germany

The Kara, Laptev and East Siberian Seas are wide and shallow interior Arctic shelves, with ecosystems
dominated by the interplay between large rivers, seasonal ice cover, complex bathymetry and strong oceanic
fronts. The seasonal sea ice system features mobile pack ice and a landfast ice cover that extends hundreds of
kilometers across the shelf. Polynyas frequently open along the fast ice edge in winter and spring and
contribute to the region's strong sea ice formation and export to the Transpolar Drift. Hydrography and
ecosystem processes are dominated by freshwater runoff from the Lena, Ob and Yenisey, some of the largest
rivers on earth. The distribution of the river plumes is variable and depends on the atmospheric circulation in
summer. The river water controls water column stratification and therefore vertical mixing processes as well as
biogeochemical conditions on the shelf. Summer expeditions in 2013 and 2014 provided comprehensive
information from two years with contrasting winds and are now used to highlight the physical and
biogeochemical linkages based on shipboard sampling and year-round oceanographic moorings. These recent
observations combined with earlier campaigns to this under-explored part of the Arctic Ocean provide the base
for the conceptual understanding of the Laptev Sea, representative of the interior Siberian shelves. In this
presentation we link the important components of the ocean, sea ice and ecosystem, and discuss them in a
pan-Arctic context.

549
Tue_362_OS-8_2543
Epibenthic Feeding of Chrysaora melanster Jellyfish in the Arctic

Maciej Mańko1 (mmanko@ug.edu.pl), Jennifer Purcell2, Andrew Juhl3, Craig Aumack4

1
Insititut of Oceanography, Department of Marine Plankton Research, Gdynia, Poland, 2Western Washington
University, Biology Department, Bellingham, United States, 3Lamont-Doherty Earth Observatory Columbia
University, Palisades, United States, 4Georgia Southern University, Statesboro, United States

Ecological and economic impacts of gelatinous zooplankton are increasingly apparent in the pelagic realm, but
few studies have explored the idea that jellyfish can be of similar importance for benthic communities. Jellyfish
exert a strong predatory pressure on invertebrates in the water column, controlling the population size of
zooplankton, including pelagic larvae of zoobenthos. Unfortunately, no research so far has directly examined
the idea that jellyfish may prey upon benthic fauna.
Video recordings made from 2011 to 2014 beneath land-fast sea ice in the Chukchi Sea near Utqiaġvik (Barrow,
Alaska) demonstrate that large overwintering Chrysaora melanaster medusae often drag tentacles along the
seabed, apparently feeding on zoobenthos as implied by the observation of an isopod entangled in the
tentacles. We also review the existing, circumstantial evidence on benthic feeding by jellyfish and, with our
own observations we propose that epibenthic feeding may be a common, but periodic trait of gelatinous
predators, even in areas as remote as the Arctic.

550
Tue_363_OS-8_2616
Marine Planktonic Larvae -Vectors of Dispersal of Benthic Species in the Arctic

Elizaveta Ershova1,2 (elizaveta.ershova@uit.no), Raphaelle Descoteaux1, Bodil Bluhm1, Katrin Iken3, Jackie
Grebmeier4, Russ Hopcroft3, Caitlin Smoot3, Ksenia Kosobokova2
1
Universitetet i Tromsø - The Arctic University of Norway, Tromsø, Norway, 2Shirsov Institute of Oceanology,
Russian Academy of Sciences, Moscow, Russian Federation, 3University of Alaska Fairbanks, Fairbanks, United
States, 4University of Maryland Center for Environmental Science, Cambridge, United States

Pelagic larval stages of benthic animals (meroplankton) can play a seasonally significant role in planktonic
communities, as well as influence the abundance and distribution of benthic species, yet are frequently
overlooked by both plankton and benthic studies. Within the Arctic, the role of meroplanktonic larvae may be
particularly important in regions of inflow from the Atlantic and Pacific Oceans, where they can serve as vectors
of advection of sub-Arctic species into the Arctic. In this study, we describe the links between the distribution
of meroplankton on two important inflow shelves: the Bering/Chukchi Seas and the Barents Sea, using
molecular tools to resolve larval taxonomic diversity, and the benthic macrofaunal and epifaunal communities
in the region, based on original and published data from the past decade. We observed limited correlation
between observed larval and adult benthos at similar locations, particularly for infaunal organisms, suggesting
that most larvae are advected from other areas rather than produced locally. Seasonality and distribution of
water masses were the most important parameters shaping meroplankton communities. We discuss
differences between the two sectors and the implications of changing oceanographic and climatic conditions
on the potential of range extensions by temperate species into the Arctic Ocean.

551
Tue_364_OS-8_535
New Views on the Conceptual Model of Advective Contiguous Domains

Paul Wassmann1 (paul.wassmann@uit.no)

1
UiT The Arctic University of Norway, Institute of Arctic and Marine Biology, Tromsø, Norway

A conceptual model is a representation of a system, made of the composition of concepts which are used to
help people know, understand or simulate a subject the model represents. Here and before switching to
Antarctica, I focus upon the central Arctic Ocean which is not isolated, but advection of water, nutrients and
biomass: it is tightly connect to the hitherto ice-covered, lest known World Ocean and a gateway to/from the
northern Pacific and Atlantic Oceans. The Arctic Ocean is thus an integral part of the oceans of the Northern
Hemisphere and cannot be understood in isolation. The concept of the advective contiguous domain illustrates
to which degree and how the integration of the Arctic Ocean is effectuated. Four advective contiguous domain
are distinguished: The Atlantic, the Pacific, the Barents Sea and the Transpolar Drift domain. These lengthy
contiguous domains connect subarctic with the arctic biota, supporting both primary production and higher
trophic level consumers. In turn, the Arctic influences the physical, chemical and biological oceanography of
adjacent subarctic waters through southward fluxes. In contrast to the central Arctic Ocean characterized by
mainly perpendicular advective contiguous domains, strongly circular and isolating contiguous domains
characterize Antarctica and the high latitude Southern Ocean.

552
Tue_365_SH-1_132
How to Establish a Legitimate Claim to Territory in the Antarctic

Cara Nine1 (cara.nine@gmail.com)

1
University College Cork, Philosophy, Cork, Ireland

Despite the fact that the Antarctic Treaty has 'frozen' claims to territory, countries continue to perform actions
intended to establish future claims in Antarctica. They hope to build the basis for a claim to territory, when
such claims become politically feasible.
This paper aims to outline the moral basis for a claim to territory. That is, this is a moral strategy for legitimacy,
not a legal or political strategy. The moral strategy is commonsensical and rooted in the values at the
foundation of contemporary international law. As such, it should carry significant weight in the thinking of
international actors.
This paper draws on recent work done in political philosophy that characterizes morally legitimate claims to
territory. Legitimate claims:
- are established by a verified political authority (i.e., not rogue governments or military dictators);
- contribute measurable value to the region and resources;
- do not take more than their fair share (defined broadly) of the Earth's natural resources; and
- make a claim to an area to which the group has a thick historical 'attachment'.
The paper argues that the final, attachment, condition is the least applicable in the context of Antarctica,
especially given that the continent has never been home to a permanent population. It may be possible,
though, to build the basis for future territorial claims through political, juridical, scientific and economic
institutional investment that adds measurable value to the region.

553
Tue_367_SH-1_251
Critical View of Annex VI of the Antarctic Environment Protocol, on liability

Luis Valentin Ferrada1 (lvferrada@derecho.uchile.cl)

1
Universidad de Chile, Facultad de Derecho, Departamento de Derecho Internacional, Santiago, Chile

The Annex VI to the Protocol on Environmental Protection to the Antarctic Treaty “on Liability Arising from
Environmental Emergencies” was adopted by the Antarctic Treaty Consultative Meeting (ATCM) in 2005 after
14 years of negotiations. It will enter into force once has been approved by the 28 Consultative Parties that had
rights to participate in that meeting. Up to now (October 2017), only 15 Consultative Parties have approved it.
The reasons why the approval process has been so slow are of course multiples, including the diverse domestic
rules to approve an international agreement. But there are also some legal and political factors that were
discussed in the negotiation and that are present in the text approved which can explain why States haven't
shown a more enthusiastic attitude. The adopted text was unsatisfactory to several Parties. As well it has some
elements that will do very complex its implementation if the Annex finally entry into force. It isn't clear that can
be possible to reach an effective and better environmental protection with the Annex VI as we know it today.
The presentation will review negotiation process of Annex VI, the finally adopted text, its approbation process
and its domestic implementation by some States that have approved it. Some conclusions are presented and
different alternatives to advance to a more effective regime of liability for Antarctic environment damage are
discussed.

554
Tue_368_SH-1_722
A Regional International Society? The Exception of Antarctica

Daniela Portella Sampaio1 (d.portellasampaio@leeds.ac.uk)

1
University of Leeds, Sustainability Research Institute, Leeds, United Kingdom

The expansion of international society brought to Antarctica its primary institutions, although they have not
been incorporated in similar terms. Sovereignty primary institution was suspended by the Antarctic Treaty in
1959, establishing a particular governance framework to the region. As a regional international society is
formed when a region's institutions are absent at the global level, or when this region presents different
interpretations for global level institutions, this work aims to understand Antarctica as a regional international
society. Antarctic practices have been normalised despite the lack of a definition of its sovereignty and
challenges have always emerged when the remaining international primary institutions (territoriality,
diplomacy, balance of power, equality of peoples, nationalism and trade) demand addressment, producing
different normative arrangements. Therefore, this work examines how resource management and
environmental protection issues created particular norm localisation for primary institutions in the region.
Resource management resulted in side agreements such as the 1964 Agreed Measures for the Conservation of
Antarctic Fauna and Flora, the CCAS, the CCAMLR and the attempted CRAMRA. Likewise, the establishment of
the Environment Protocol resulted from the environmental stewardship primary institution's growth,
consolidating environmental preservation (along with peace maintenance and scientific cooperation) as
Antarctica's own institutions.

555
Tue_369_SH-1_867
The Politics of Antarctic Marine Conservation: The Role of Argentina and Chile

Cristian Lorenzo1,2 (clorenzo@conicet.gov.ar)

1
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Centro Austral de Investigaciones
Científicas (CADIC), Ushuaia, Argentina, 2Universidad Nacional de Tierra del Fuego (UNTDF) - Instituto de
Ciencias Polares, Ambiente y Recursos Naturales (ICPA), Ushuaia, Argentina

The establishment of Marine Protected Areas is one of the key issues discussed at the annual meetings of the
Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). CCAMLR members decided
by consensus to establish a Marine Protected Area (MPA) on the South Orkney Islands (2009) and the other in
the Ross Sea (2016). Other MPA proposals still remain under discussions, such as a MPA around the Western
Antarctic Peninsula proposed by Argentina and Chile. In this context, this conference paper examines the
politics of MPAs at CCAMLR and the role of Argentina and Chile within this context.
This conference paper analyzes the transformations in the politics of Antarctica and discussions around MPAs
at CCAMLR. It also addresses Argentina and Chile as original signatories of the Antarctic Treaty by analyzing the
main guidelines of their Antarctic diplomacy and domestic policy on MPAs as well.
The research results suggest that the politics of MPAs in antarctic waters at CCAMLR happens in a context of
antarctic environmental changes, a rising demand for natural resources and asymmetrical relations between
states members of the ATS. In order to understand the role of Argentina and Chile within this framework, it is
necessary to consider the importance of historical territorial claims in Antarctica, the role of science as a tool
for diplomacy and also MPAs policies in the domestic domain.

556
Tue_370_SH-1_1409
Antarctica and the Environmental Account of Territory

Alfonso Donoso1 (aldonoso@uc.cl)

1
Catholic University of Chile, Institute of Political Science, Santiago, Chile

The Protocol on Environmental Protection to the Antarctic Treaty (PEPAT) sets forth the environmental
principles governing activities in Antarctic. It expresses the conviction of the signatories regarding the
protection of the Antarctic, designating the white continent as a natural reserve, devoted to peace and science
(Art.2). More strikingly, PEPAT expresses the commitment to protect “the intrinsic value of Antarctica, including
its wilderness and aesthetic values” (Art.3). These resolutions are to work as key elements in the planning and
conduct of all activities in the Antarctic Treaty area (Art.3). Interestingly, there is no mention in PEPAT of one of
the most remarkable elements of the Antarctic Treaty, namely, the freezing of State sovereignty on the
Antarctic territory (AT Art.4). In a post-Westphalian world, this omission is problematic: comprehensive
protection of the environment and its value requires reflecting on the question of state sovereignty claims over
a territory. Although issues about the environment and its value are not central elements in most theories of
territory, in this presentation I sketch an account of territory that both takes seriously PEPAT's idea on the
intrinsic value of the Antarctic and incorporates environmental sustainability considerations as key aspects of
legitimate territorial claims. The proposal, I argue, is a normative account of territory that is more adequate to
face the environmental challenges in Antarctica motivating PEPAT.

557
Tue_371_SH-1_2131
Collaborative Governance in the Southern Oceans: The Ross Sea MPA

Seth Sykora-Bodie1 (seth.sykora.bodie@duke.edu)

1
Duke University, Marine Science & Conservation, Beaufort, United States

As global extinction rates have accelerated, international regimes, such as the Convention for the Conservation
of Antarctic Marine Living Resources (CCAMLR), have proposed a variety of responses, including establishing
networks of marine protected areas (MPAs). To address threats posed to Antarctic marine ecosystems by
fisheries and climate change, CCAMLR endorsed efforts to establish a representative network of MPAs. In 2012,
the United States and New Zealand proposed the Ross Sea Region MPA (RSRMPA) and following several years
of negotiations it was agreed to by CCAMLR signatories in 2016. This research effort applied the collaborative
governance framework, which stresses engaging state and non-state actors in building consensus to manage
public resources, to identify the influential factors that contributed to this agreement and understand how it
might be replicated in the future. More than forty interviews, ranging from twenty-five to ninety minutes, were
conducted during and following CCAMLR's 36th meeting with delegation heads, chief scientists, committee
chairs, Secretariat leadership, and observer delegates to provide a representative sample of key actors.
Thematic coding of interviews using QSR Nvivo revealed the key drivers of consensus, which will be presented
along with recommendations on how to incorporate the lessons learned from the RSRMPA negotiations into
ongoing efforts to develop a network of Southern Ocean MPAs.

558
Tue_372_SH-1_2532
Enlightening Antarctica Deep Seabed's Unsettled Issues

Nicolas Kempf1 (nicolaskempf@yahoo.fr)

1
Université de Montréal, Faculté de Droit, Montréal, Canada

Even though the current and increasing natural resources dwindling might put pressure on the ATS, it seems
that the core principles enshrined in it, such as Article IV of the Antarctic Treaty establishing the agreement to
disagree on sovereignty, as well as Article II of the Madrid Protocol, designating Antarctica “as a natural
reserve, devoted to peace and science”, are strongly rooted enough to prevent any future litigation's arousal
on land.
At sea though, and especially under the sea, the legal regime remains highly uncertain, and the expected fore
coming pressure calls for its acute determination.
Indeed, with the recent evolution of the law of the sea and the fast development of new maritime areas,
stagnant legal issues call for further certainties on austral seabed's legal regime.
Are Southern Ocean seabed's resources to be exploited in the future? Shall it be protected? Which State(s) or
international entity should be in charge of doing so?
This communication proposes to focus on the issue of Antarctica seabed's legal regime, especially emphasizing
on the articulation between two distinct regimes: seafloor's global legal regime, set up in the UNCLOS, as well
as the specific one supposed to govern the seabed in the southern area according to the ATS.
A particular attention will first be brought on the general adequacy of those regimes, before moving to its
apparent contradictions.
Finally, different proposals to avoid those contradictions will be evoked.

559
Tue_373_SH-1_2605
Multi-level Protection of Antarctic Region Against to Non-native Species

Onur Sabri Durak1,2,3 (duraks@itu.edu.tr)

1
Istanbul Technical University, Maritime Faculty, Istanbul, Turkey, 2Istanbul Technical University, Polar Research
Institute, Istanbul, Turkey, 3Ankara University, Ankara University Law of the Sea and Maritime Law Research
Center, Ankara, Turkey

The Region of Antarctica is biologically distinct from other regions. And, the increasing introduction of non-
native species to the Antarctic Region is presenting a serious risk to biodiversity and environment of the
Antarctica. Introduction of non-native species may arise from two different ways; native Antarctic species are
moved by human activities between biogeographic regions, or non-native species established in one Antarctic
biogeographic region and then are distributed to other regions by human or natural mechanisms.
At the 39th Antarctic Treaty Consultative Meeting (ATCM) Resolution 4 (2016) was introduced. The Annex of the
Resolution introduces the “Non-native Species Manual”. The Manual aims to establish key guiding principles
for minimising the risks associated with the introduction of non-native species. International Maritime
Organization's (IMO) newly entered into force “International Convention for the Control and Management of
Ships' Ballast Water and Sediments, 2004” deals with non-native species as well. Taking into other international
law instruments, it is to say that, there is a multi-level protection of Antarctica against to non-native species.
This paper aims to analyse the multi-level protection of Antarctic Region from a critical viewpoint, tries to
extract gaps and overlaps among different international legal documents. Accordingly, the paper aims to
provide recommendations for better coordinated and synchronized legal regime for the Antarctic.

560
Tue_374_SH-2_204
Establishing Indigenous TTP in Evenkia, Russia

Nikita Kaplin1 (kaplinik@bk.ru)

1
Union of Indigenous Communities of the Evenkia Municipal District, Krasnoyask, Russian Federation

According to the Federal Law No. 49, Government of the Krasnoyarsk region had recently adopted the order on
establishment of the traditional land use areas (TTP) of the indigenous peoples of the North. The Agency for
Northern Development and Support of the Indigenous Minorities is designated an authorized executive for this
action. The formation of such territories is to be carried out by decision of the regional government on the
recommendation of the relevant Commission which is to consider the appeals of indigenous persons,
communities or their authorized representatives. For the TTP decision process, it is necessary to take into
account the prospects for socio-economic and investment development of the region, including possible
negative effects from the imposed environmental protection and other restrictions on the use of aboriginal
lands. The TTP establishment should not compromise or violate the rights and freedoms of other ethnic
communities inhabiting these lands. This is a very important step in protecting the ancestral habitat of the
indigenous minorities of the North in Evenkia district. Regional government took into account the proposals of
neighboring provinces where TTP have already been formed: Irkutsk, Khakassia, Sakha (Yakutia), Khanty-Mansi
(Yugra). But at the same time many legal obstacles on the way for protecting traditional land use areas are still
existent and the perspectives for their operational management are to be revealed and analyzed.

561
Tue_375_SH-2_322
State Intervention in Whaling: A Case of Whaling in the Faroe Islands and Taiji

Nazuna Nakao1 (nnazuna@outlook.com)

1
Doshisha, Global Studies, Kyoto, Japan

Disputes about whaling have been polarized into for or against, and ignored to form a platform for diversified
agenda such as politics, international relationships, environment, and animal welfare. In particular, subjects
concerning indigenous knowledge of whaling and ethics based on rules shared among local people were less
focused. I wish to discuss coastal whaling not from for or against point of view. My research fields are the Faroe
Islands and Taiji town of Japan. In the past decades, traditional whaling in the two regions have been affected
by anti-whaling movements and the controversies have changed them. In Taiji, they inevitably have made
changes such as their method and regulations of killing, and reinforce security control. The Japanese
government have taken some measures for protecting whaling in Taiji, however, its aim is in another issue, to
protect the vested rights of government sponsored whaling. Another changes could be observed is local
people's awareness of whaling. As the town exposed worldwide criticism some people have started
questioning by themselves reasons of continuing whaling. In contrast, people in the Faroe Islands have not
been tossed about by the changes compared to Taiji. From examining these findings, I have concluded that the
state intervention greatly changes whaling and it may also affect people's way of thinking. I wish to show the
difference of the changes in the regions and hope I could make a few contributions toward this subject.

562
Tue_376_SH-2_926
Sharing Knowledge as a Tool to overcome Socio-economical Issues

Pia Bailleul1 (pia.rennes@gmail.com)

1
Paris Nanterre - LESC, Anthropology, Nanterre, France

Since october 2013, Greenlandic politicians have their own legislation regulating the exploitation of their soil´s
natural ressources. Following this parlementarian vote, several companies and private industrials have shown
their interest for the mineral ressources of Greenland, leading to the construction of the first greenlandic
uranium and rare earths mine in Kvanefjeld (South Greenland).
In response, an anti-uranium movement began to actively criticize the Environmental and Social Impact
Assessement procedure, thus being at odds with Greenlandic politics and private companies. Hence, the mine
of Kvanefjeld has become a social debate articulated at different levels between farmers, anti-uranium
activists, the governement of Greenland, and with the international private sector.
Through a multi-located ethnography - political spheres, anti-uranium movement, farming communities
adjoining the mine - and understanding the criticisms towards the Assessement procedure, this contribution
aims to articulate the farmers´ knowledge of the land and their will to be part of the implementation plan with
the socio-economic necessities that motivate each stakeholder.
The study of this case is a tool to deepen the discussion about the place and role of Indigenous Knowledge and
include them meaningfully by taking the socio-economical perspectives into account; In order to produce
Indigenous Governance Model locally constructed connecting Indigenous People and Foreigners.

563
Tue_377_SH-2_2570
Future Challenges for Arctic Indigenous Peoples

Anna Deteva1 (anna.deteva@gmail.com)

1
Arctic Council IPS, Tromsø, Norway

Multiple drivers of environmental and social change can be identified across the Arctic and more change is
expected. Infrastructure development is currently the most
significant driver of change in land use. Climate change is an increasing threat to traditional livelihoods. Impacts
on indigenous peoples are exacerbated by their lack of voice
in the development of adaptation tools and strategies for future planning and development.
Arctic Indigenous Peoples cooperate in the Arctic Council in Unique way through the Indigenous Peoples
Secretariat in Arctic Council for more than 20 years. Building competence locally is important to be able to
adapt to these changes.

564
Tue_379_SH-2_2652
The Current State of Mapping Indigenous Land Rights in the Sakha Republic Russia

Antonina Savvinova1 (sava_73@mail.ru), Viktoriia Filippova2, Gail Fondahl3

1
North-Eastern Federal University, Ecology and Geography, Yakutsk, Russian Federation, 2The Institute for
Humanities Research and Indigenous Studies of the North, Siberian Branch of the Russian Academy of Sciences,
Yakutsk, Russian Federation, 3University of Northern British Columbia, Prince George, Canada

Clan communes (KROs) offer a mechanism by which families and groups of indigenous persons can request an
allocation land on which to pursue their traditional activities (e.g. reindeer herding, hunting). KROs have been
formed since the early 1990s. A federal law governing their creation passed in 2000. Local laws in various
regions of the Russian North often preceded this: for instance, in the Sakha Republic (Yakutia), a law on KROs
passed in 1992. Over the past 25 years, a variety of legislative revisions have affected KROs. KROs are best
protected when situated inside a “Territories of Traditional Nature Management” (territoriya traditsionnogo
prirodopol'zovaniya or TTP). TTPs, governed by a 2001 law, provide protection of lands for traditional use,
including some capacity to exclude industrial activities that might negatively affect traditional activities.
Our paper will present the application of a cartographic-geoinformation method for studying the TTPs in the
Republic of Sakha (Yakutia) under the situation of intensive industrial development. This method allows the
identification of changes in the organization of TTPs as they are related to changes in the boundaries of the
KRO, and thus the withdrawal of land from economic circulation, in areas of potentail conflict between
industrial and 'traditional' users Completed maps can be used as an documents to protect and defend the TTPs,
and thus the KROs situated within them, in case where legislation is changed.

565
Tue_COMNAP_2718
Nautical Assets' Fostering Scientific Research in the Antarctic Treaty Area

Andrea Colombo1 (sec@comnap.aq), Michelle Rogan-Finnemore1

1
COMNAP Secretariat, Christchurch, New Zealand

Vessels play a pivotal role in science and science support for the national Antarctic programs operating in the
Antarctic Treaty Area. In fact, vessels not only deliver people and supplies to coastal infrastructures but also,
while sailing, conduct an array of multi-disciplinary scientific projects thanks to their on-board facilities and
personnel. The Council of Manager of National Antarctic Programs (COMNAP) developed two tools to display
and share vessels position data for national Antarctic program vessels operating in waters below 60°S (as per
ATCM XXXVI Resolution 4 (2013)). These tools help to foster international scientific projects through, and with,
the support of national Antarctic programs and are also useful in times of emergency. The poster showcases
examples of successful international collaborations on board of vessels operated by COMNAP Members, and
hopes to create new opportunities for future multi-disciplinary and “big science” international projects. The
sharing of capabilities on vessels amongst the international scientific community is another good example of
international co-operation in Antarctica.

566
Tue_COMNAP_2719
Information Exchange: How COMNAP Productises Data for Members & the Community

Andrea Colombo1 (sec@comnap.aq), Brad Herried2, Michelle Rogan-Finnemore1

1
COMNAP Secretariat, Christchurch, New Zealand, 2Polar Geospatial Center, Minnesota, United States

The Council of Managers of National Antarctic Programs (COMNAP) often requests information from its
Member national Antarctic programs. Once collected, the information is housed in the COMNAP database and
is used and exchanged in a range of COMNAP products. Those products support the work of COMNAP Member
national Antarctic programs in regards to international co‐operation in science, science support, operations,
logistics, and in Search and Rescue (SAR) situations to name only a few examples. COMNAP has produced
procedures for such information exchange and there are also information exchange requirements which are an
obligation on Antarctic Treaty Parties in Articles III and VII (5) of the Antarctic Treaty, in several articles of the
Protocol on Environmental Protection to the Antarctic Treaty and in a number of Recommendations, Measures,
and Resolutions as adopted by the Parties. This poster gives an overview of the projects and products served by
the COMNAP database and how these can inform and advance exchange of information with Members, the
wider Polar community and the general public. The COMNAP database was developed as a source of
information primarily for use by Member national Antarctic programs and the COMNAP Secretariat. However,
advances in technology coupled with good planning in development mean that information exchange into
duplicate fields in separate databases is now possible.

567
Tue_COMNAP_2720
Antarctic Facilities: Hubs for Science and Environmental Protection

Andrea Colombo1 (sec@comnap.aq), Michelle Rogan-Finnemore1

1
COMNAP Secretariat, Christchurch, New Zealand

This poster showcases a portion of the facilities-related data in the Council of Managers of National Antarctic
Programs (COMNAP) database. Ninety-seven facilities (stations, camps, laboratories, refuges, depots, and
airfield camps) are run and personned by the COMNAP Members in the Antarctic Treaty Area (2017-18 season
data). A great array of facilities-related data, from main scientific disciplines supported, to hydroponics
facilities, through medical capabilities and climate-related data, are available for the Members through the
COMNAP database. The non-sensitive data, are also available to the Antarctic Treaty System organisations and
to the general public.
In light of the COMNAP Antarctic Roadmap Challenges (ARC) project outcomes, sharing information on facilities
and capabilities are seen as a tool which can directly support the key goal of improving international co-
operation in Antarctica. The poster introduces some of the facilities-related data in the COMNAP database
showcasing scientific activities, measures in place to reduce direct impact on the environment and waste
management practices. The final aim is to stimulate the exchange of knowledge, scientific personnel and best
practices furthering international co-operation.

568
Morning Plenary I
20.06.2018 07:50-09:00, A Davos

Keynote Lecture I
China’s potential contributions to SOOS and MOSAiC

Dake Chen (dchen@ldeo.columbia.edu)

Second Institute of Oceanography, State Oceanic Administration, China

The Southern Ocean Observing System (SOOS), and the Multidisciplinary drifting Observatory for the Study of
Arctic Climate (MOSAiC), are two of the major ongoing international initiatives for polar research. SOOS was
officially launched at the end of 2011, and since then it has built a network of stakeholders and contributors, all
working together to achieve its well-defined mission and objectives. Currently SOOS is implemented based on
its regional working groups and there is a clear need for a broad-scale circumpolar design. On the other hand,
MOSAiC is a more focused, short-term experiment presently at its final planning stage. It will have a three-
tiered observational strategy, including a central observatory, a distributed network and a large-scale
connection, as well as a comprehensive modeling hierarchy. This calls for a strong international collaboration to
provide scientific, technic and logistic supports.
Here we first briefly review the scientific goals of SOOS and MOSAiC from a global perspective, and then discuss
the potential roles of China in these two international initiatives, in accordance with our national polar
research programs supported by various agencies. In particular, starting with a description of our existing
capabilities in both Antarctic and Arctic research; we outline our plans for future enhancement in technology
and infrastructure, as well as our suggestions on the implementation of SOOS and MOSAiC. The take-home
messages include:
(1) China is now in the process of largely enhancing its polar research activities, which certainly will lead to
significant contributions to SOOS and MOSAiC;
(2) For SOOS, we propose a multi-platform, multi-disciplinary circumpolar “Big Ring” design to serve as its
sustained “backbone”;
(3) For MOSAiC, we will participate in all three tiers of its field observations as well as modeling efforts, aside
from providing logistic support.

569
Morning Plenary I
20.06.2018 07:50-09:00, A Davos

Keynote Lecture II
Frozen in time - Unlocking the Earth’s climate history using ice cores

Elizabeth Thomas (lith@bas.ac.uk)

British Antarctic Survey, UK

Ice cores have proved to be a powerful tool for reconstructing past climate. These “two-mile time machines”
have driven our understanding of global climate variability, tracing the transitions from glacial to interglacial
over the past 800,000 years. And yet the secrets in the ice are still being unlocked. In this presentation I will
outline recent advances in ice core research, touching on the development of exciting new climate proxies and
demonstrating the power of international collaboration in producing continental reconstructions with
unprecedented spatial coverage. I will focus on climate variability over human timescales, decades to centuries,
in Antarctica; a continent experiencing dramatic climate change in recent decades but one with the shortest
historical observations and arguably the largest potential to drive future climate through its contribution to
global sea levels. I will summarise findings from two recent community based reconstructions, of past surface
temperature and snow accumulation, capturing the drivers of Antarctic climate variability and its influence on
global sea levels during the 20th century.

570
OS-6d - Polar Ocean Dynamics
20.06.2018 09:00-10:30, C Aspen

1112
AW Boundary Current Characteristics and Eddy Formation North of Svalbard

Laura Crews1 (laura.crews@npolar.no), Arild Sundfjord1, Tore Hattermann2, Jon Albretsen3

1
Norwegian Polar Institute, Fram Centre, Tromsø, Norway, 2Akvaplan-niva AS, Tromsø, Norway, 3Institute of
Marine Research, Flødevigen, Norway

Despite the importance of Atlantic Water (AW) to Arctic halocline formation and sea ice distribution, the
dynamics and seasonality of the AW inflow and redistribution north of Svalbard are not well documented. Here
we use a high resolution (800 x 800 meter) eddy-resolving sea ice and ocean model to characterize the
boundary current, with particular focus on eddy formation. The flow regime in the Yermak Plateau (YP) region
is variable, with flow over the YP alternating between a faster, narrower northern current and a slower, more
diffuse current. Downstream of the Yermak Plateau, the current follows the shelf break. Directly north of
Svalbard the current is most unstable between October-March, similar to previous findings from Fram Strait.
Further East, the current is most unstable several months later. The boundary current sheds AW eddies along
most of the length of continental slope considered, from the western YP to 40°E, though eddies forming east of
20°E are likely more important for slope-to-basin transport. Eddy formation seasonality reflects current
instability in the eastern portion of the study domain, but on and immediately east of the YP eddy formation is
out of phase with current instability, with formation rates highest during summer. Most of the AW eddies are
anticyclonic, with radii close to the local deformation radius, and are centered in the halocline. They transport
roughly 0.1 Sv of AW and, due to their warm cores, nearly 1.0 TW away from the AW current.

571
1341
Circumpolar Deep Water Variability in High Resolution Coupled Climate Models

Hannah Zanowski1 (zanowski@uw.edu), Frazer Christie2, Kyle Armour1, Cecilia Bitz1, Eric Steig1
1
University of Washington, Seattle, United States, 2University of Edinburgh, Edinburgh, United Kingdom

Observations have shown that West Antarctic ice shelf basal melt is strongly related to warm Circumpolar Deep
Water (CDW) impinging on the continental shelf in this region. This critical discovery has led to multiple, high-
resolution regional modelling studies aimed at identifying the underlying mechanisms that lead to CDW
intrusions on the West Antarctic continental shelf and their subsequent circulation in ice shelf cavities.
However, many of these models do not include a coupled atmosphere, potentially missing relevant ice-ocean-
atmosphere interactions that impact CDW variability in the West Antarctic.
Here we characterize West Antarctic CDW variability in two coupled climate models with 0.1˚ oceans and
identify the mechanisms that control this variability on interannual to decadal timescales. Consistent with
observations, we find that temperature variability on the West Antarctic continental shelf is related to wind
stress curl along the shelf break in the models. In addition to wind stress curl, we explore a range of local and
large-scale atmospheric and oceanic processes, such as ENSO, that could contribute to CDW variability, and
quantify the relative importance of each in controlling shelf water temperature variability.

572
2125
Circum-Antarctic Eddy/Tidal Overturning and Shoreward Heat Transport

Andrew Stewart1 (astewart@atmos.ucla.edu), Andreas Klocker2,3,4, Dimitris Menemenlis5

1
University of California Los Angeles, Atmospheric and Oceanic Sciences, Los Angeles, United States, 2University
of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 3University of Tasmania, Australian
Research Council Centre of Excellence for Climate System Science, Hobart, Australia, 4University of Tasmania,
Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, Australia, 5Jet Propulsion Laboratory,
California Institute of Technology, Science Division, Pasadena, United States

The passage of warm Circumpolar Deep Water onto the Antarctic continental shelf is dynamically obstructed by
the continental slope to varying degrees around the Antarctic margins. Previous studies indicate that high-
frequency processes, such as tides and mesoscale eddies, are required to overcome this dynamical barrier and
supply heat to the Antarctic coast. In this study we use a very high-resolution (1/48 degree) ocean/sea ice
simulation to quantify the relative roles of mean flows, eddies and tides in transporting heat across the entire
Antarctic continental slope and shelf. We find that eddies transfer heat across the continental slope, but tides
make the largest contribution to the shoreward heat flux across the shelf break. However, the tidal heat flux is
almost entirely compensated by an opposing offshore heat transport by mean flows. Consequently, the
shoreward eddy heat fluxes coincides closely with the net shoreward heat transport across the shelf break.
Approximate overturning circulations for the mean, eddy and tidal components of the cross-slope transport
also show strong compensation between mean flows and tides at the shelf break, with negligible eddy-driven
overturning. Taken together, these results suggest that eddy stirring of heat anomalies along isopycnals or
along the ocean bed is the primary mechanism of heat transfer across most of the Antarctic continental
shelf/slope.

573
2199
Eddies, Sub-mesoscale Structures, and Water Mass Variability In the Beaufort Sea

Luc Rainville1 (rainville@apl.uw.edu), Craig Lee1, Jim Thomson1

1
University of Washington, Applied Physics Laboratory, Seattle, WA, United States

Observations in the Arctic are often sparse in space and time. Mesoscale and sub-mesoscale processes are
poorly captured by typical hydrographic sampling from large icebreakers, which is often the only way to
provide access to the challenging ice-covered regions. In 2014 and 2015, the US Office of Naval Research
funded a pair of programs designed to capture important processes in the changing Arctic Ocean and promote
the use of autonomous technology and intense ship sampling. In particular, Seagliders surveys conducted as
part of the Marginal Ice Zone Program in 2014, and ship-based underway CTD sampling in the SeaState
Program in 2015 provide repeated sampling of important regions in the Beaufort Sea high spatial and temporal
resolutions, capturing several eddies and upper ocean fronts. Eddies appear particularly important near the ice
edge and near the shelf breaks. In this presentation, we synthesize observations from these intensive programs
and describe the dynamics of mesoscale and sub-mesoscale processes in the Arctic, as well as the
characteristics of dominant water masses (Pacific and Atlantic Waters) over the basin.

574
1568
Frontal Processes and Extreme High Chlorophyll a Values Investigated with an AUV

Sandra Tippenhauer1 (stippenh@awi.de), Thorben Wulff2, Wilken-Jon von Appen1

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Physical Oceanography of the Polar
Seas, Bremerhaven, Germany, 2Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Deep
Sea Ecology and Technology, Bremerhaven, Germany

Small-scale processes and their effects get more and more attention when it comes to understanding processes
and changes in the (Arctic) ocean. Here we present a study on physical processes and ecological responses at a
submesoscale front in Fram Strait at the interface between the Arctic Ocean and waters of lower latitude origin
investigated using an autonomous underwater vehicle (AUV). The AUV is equipped with several physical and
biogeochemical sensors.
High-resolution observations from the upper 50m of the water column, show extremely large physical and
biogeochemical gradients associated with the frontal system. Extraordinarily high chlorophyll a values between
20m and 40m water depth were observed to be associated with polar surface water, which may recently have
been raised above the compensation depth resulting in the subsurface bloom. A mooring in the vicinity showed
that the chlorophyll a patch was present for a few days. Additional observations conducted from a Zodiac in
parallel to the AUV survey show that the observed patch had an along-front extent of more than 400m. This
indicates, that the observed feature was a dynamically active front, possibly experiencing wind-driven
frontogenesis or the growth of mixed layer eddies.
The study was conducted in Fram Strait but the results are most likely transferable to other, dynamically
comparable frontal systems in the marginal ice zone that experience large horizontal density gradients, e.g. in
the Southern Ocean.

575
1292
Dynamical Controls on the Export of Antarctic Bottom Water from the Weddell Gyre

Alberto Naveira Garabato1 (acng@soton.ac.uk), Carl Spingys2, Eleanor Frajka-Williams2, Kurt Polzin3, Christian
Buckingham4, Povl Abrahamsen4, Sonya Legg5, Stephen Griffies5, Keith Nicholls4, Michael Meredith4
1
University of Southampton, Ocean and Earth Science, Southampton, United Kingdom, 2University of
Southampton, Southampton, United Kingdom, 3Woods Hole Oceanographic Institution, Woods Hole, United
States, 4British Antarctic Survey, Cambridge, United Kingdom, 5Geophysical Fluid Dynamics Laboratory,
Princeton, United Kingdom

During the last three decades, AABW has exhibited a striking warming and contraction in volume over much of
the global ocean abyss, particularly in the South Atlantic. The causes of these changes are unknown. In the
Atlantic sector, observations suggest that climatic variations in the basin-scale properties of AABW downstream
of its sources in the Weddell Sea are primarily controlled by wind-forced changes in export, via a mechanism
involving the modulation of small-scale turbulent mixing in the Orkney Passage. To test this hypothesis, the
U.K. DynOPO (Dynamics of the Orkney Passage Outflow) programme set out to measure the circulation of
AABW in the Passage, and to assess the dynamical controls underpinning the water mass´ transformation in the
region. With this goal in mind, a finescale-resolving mooring array was recently deployed in the Passage for 2
years (2015 - 2017), and a research cruise was conducted to measure the turbulent properties of the AABW
outflow with fine- and microstructure instrumentation and the autonomous underwater vehicle Autosub Long
Range. Here, we will present results from the project. These indicate that: (1) the AABW outflow experiences
concurrent broadening, deceleration, and intense mixing as it navigates the Passage; (2) these changes are
underpinned by a distinct mechanism involving downslope Ekman flows and submesoscale dynamical
instabilities. The implications of these findings for our starting hypothesis will be discussed.

576
OC-1_OC-2d - Innovation, partnership and impact in polar science communication & Polar
Research and Citizen Science: Exploring New Platforms and Opportunities
20.06.2018 09:00-10:30, A Studio

1474
Not Just Penguins: Increasing Public Understanding of Antarctic Ecosystems

Claire Christian1 (claire.christian@asoc.org), Amanda Lynnes2, Lisa Kelley2

1
Antarctic and Southern Ocean Coalition, Washington, DC, United States, 2International Association of
Antarctica Tour Operators, Newport, United States

People love pictures of cute penguins and seals, but often know little else about Antarctic marine ecosystems.
Most Antarctic organizations and programs recognize these gaps but have limited resources to do large public
education campaigns. Partnerships between organizations are therefore a logical choice to enhance capacity
and reach a wider audience. In this presentation, we will analyse the outcomes of a successful joint social
media campaign between the Antarctic and Southern Ocean Coalition (ASOC), an environmental organization,
and the International Association of Antarctica Tour Operators (IAATO) to promote knowledge of lesser-known
species. We developed a series of tweets and Facebook posts containing facts about Antarctic invertebrates,
with accompanying videos, photos and graphics.
We will share our analysis of the campaign's success as measured by audience engagement with posts and
tweets, as well as lessons learned. A key conclusion is that a multi-day, fact-based series of posts and images
seems to be more popular on Twitter than on Facebook. The overall increased engagement demonstrates that
social media campaigns are therefore an effective way to reach out to followers who are already interested in
Antarctica (as well as gain new ones) and can be used to increase public understanding about Antarctic issues.
Partnership was also effective as it expanded the content available to both organizations, and helped distribute
the workload.

577
355
Building a Scientific Culture on Antarctica through a Discussion Forum

Silvia Dotta1,2,3 (silviadotta@gmail.com), Eduardo Rodrigues da Silva1

1
Federal University of ABC, Mathematics, Computation and Cognicion Centre, Santo André, Brazil, 2Polar
Educators International, Santo André, Brazil, 3ApECS - Brazil, Santo André, Brazil

This paper aims to analyze the contribution of a discussion forum for the process of building a scientific culture
on Antarctica.
The concept of scientific culture is broader than that of scientific literacy since it incorporates a social
component of analysis and interpretation into the appropriation of the knowledge process. Communication
and pedagogical strategies that seek scientific literacy, more focused on appreciation, lead to the incorporation
of scientific knowledge as much to the social imaginary of the individual as to the surrounding society.
Recognizing science as "interesting, stimulating and entertaining" is more realistic than equating the knowledge
of non-specialists with that of scientists.
A discussion forum was conducted at a distance-learning training course for primary school teachers to whom
were asked to discuss conceptual errors about Antarctica. It proposed the debate on where the lung of the
world is: The Amazon or Antarctica. Participants were encouraged to defend predetermined ideas, based on
scientifically consolidated arguments. 114 students and 6 tutors attended. Over three weeks, 577 messages
were exchanged. Most of participants (76%) returned to interact with colleagues and tutors.
A forum is a tool that can contribute to incite interest in the research and dialectical construction of
knowledge. Dialogue around the ways of problem solution has helped to encourage the popularization of
socio-constructed scientific knowledge about Antarctica.

578
791
Using Media to Drive Conservation in the Ross Sea: Protecting the Last Ocean

John Weller1 (johnwellerphotography@gmail.com), Cassandra Brooks2

1
Pew Marine Fellow & Safina Center Fellow, Boulder, United States, 2University of Colorado Boulder,
Environmental Studies, Boulder, United States

During this session, John B. Weller, an internationally acclaimed photographer, filmmaker and author, invites
you to journey above and below the ice in Antarctica. In 2004, Weller and Antarctic ecologist David Ainley
founded The Last Ocean Project - the first dedicated campaign for a marine protected area of the Ross Sea,
Antarctica. They later co-founded The Last Ocean Charitable Trust with New Zealand filmmaker Peter Young
and also brought on Antarctic scientist Cassandra Brooks. Weller's photographs of the Ross Sea became the
face of Antarctic conservation efforts worldwide. He will explain how his efforts to protect the Ross Sea,
Antarctica inspired a global coalition of organizations, scientists, diplomats and more than a million people, and
helped entrain world leaders from the White House to the Kremlin. Twelve years of work came to fruition in
October 2016 in a stone fortress in the center of Hobart, Tasmania, where diplomats from 24 countries and the
EU adopted the Ross Sea Marine Protected Area - one of the most profound international environmental
agreements of our times. It is the first large-scale international marine protected area and the largest MPA in
the world. Focusing on lessons learned and the creative applications of media to emerging conservation
opportunities, this session will examine ways in which media can help drive marine conservation.

579
1668
Social Media Outreach Coordinated across a Multinational Polar Research Project

Jennifer Newall1,2,3 (jennifer.newall@natgeo.su.se), Jan-Ola Olofsson4, Ida Kinner4, Julia Spinolo1, Maddie
McGrath5, Gryphen Goss1, Logan Judy1, Sarah Sams1, Cody Wilson5, Malin Stenberg de Serves2,3, Jorge
Bernales6, Derek Fabel7, Ola Fredin8,9, Neil Glasser10, Jon Harbor1,2,3, Nathaniel Lifton1, Irina Rogozhina6,11, Arjen
Stroeven2,3
1
Purdue University, Department of Earth, Atmospheric, and Planetary Sciences, West Lafayette, United States,
2
Stockholm University, Department of Physical Geography, Stockholm, Sweden, 3Stockholm University, Bolin
Centre for Climate Research, Stockholm, Sweden, 4Swedish Polar Research Secretariat, Stockholm, Sweden,
5
Purdue University, Lamb School of Communications, West Lafayette, United States, 6GFZ German Research
Centre for Geosciences, Helmholtz Centre Potsdam, Potsdam, Germany, 7Scottish Universities Environmental
Research Centre, Glasgow, United Kingdom, 8Geological Survey of Norway, Trondheim, Norway, 9Norwegian
University of Science and Technology, Department of Geography, Trondheim, Norway, 10Aberystwyth University,
Centre for Glaciology, Department of Geography and Earth Sciences, Aberystwyth, United Kingdom, 11Bremen
University, Centre for Marine Environmental Sciences (MARUM), Bremen, Germany

MAGIC-DML is an ongoing Swedish-US-Norwegian-German-UK collaboration focused on improving ice sheet

models by filling critical data gaps in our knowledge of the timing and pattern of ice surface changes in
Dronning Maud Land (DML), Antarctica. Outreach and science communication through social media is a priority
in this international collaboration, and involves students, scientists, and communication staff at the partner
universities and the Swedish Polar Research Secretariat (SPRS). One main focus of our outreach has been an
online presence with an SPRS component focused in particular on research expeditions, and coordinated with
the project website, blog, and social media elements (Facebook, Twitter, Instagram). Scientists and staff at the
partner universities and SPRS coordinate with the overall social media, and repost/tweet to enhance impact.
We will share both the challenges and achievements of coordinating social media across multiple organizations
and countries with different levels of communications expertise and resources, and with target audiences that
include the general public, teachers/students, and colleagues/peers. Quantitative and qualitative analyses of
the social media component of our outreach program will also be presented, including special events
(competitions), types of material posted, timing of posts, coordinated 'shares', and interactive elements.

580
2158
An IceCube Interactive and Immersive Exhibit for Learners of All Ages

Silvia Bravo Gallart1, Andrew Chase2, Phil Dougherty3, David Gagnon3, James Madsen4
(james.madsen@uwrf.edu), Kevin Ponto2, Melanie Rush2, Ross Tredinnick2
1
University of Wisconsin - Madison, Wisconsin Icecube Particle Astrophysics Center, Madison, United States,
2
University of Wisconsin - Madison, Winsconsin Institute for Discovery, Madison, United States, 3University of
Wisconsin - Madison, Madison, United States, 4University of Wisconsin - River Falls, River Falls, United States

Research shows that virtual and interactive environments can boost learning outcomes for learners of all ages.
These technologies can also increase engagement of underrepresented communities, since these environments
are not usually associated with performance stereotypes and academic language proficiency.
The IceCube Neutrino Observatory in Antarctica has partnered with technology and education researchers to
develop a virtual reality exhibit that connects users to the polar observatory, which is leading a new field in
astronomy. IceCube detects small particles called neutrinos that can help us explore the universe in ways that
cannot be done with light.
This novel exhibit combines a multitouch table and commercially available virtual reality (VR) head-mounted
displays to facilitate learning of polar research. The exhibit, launched in November 2017, is studying how
immersive VR can enhance informal STEM learning.
We will discuss the challenges and opportunities of working with an interdisciplinary team as well as
assessment results. They seek to evaluate how technology can improve engagement of all learners, and to
determine which technologies are better suited to enhance STEM learning. Contributing to the understanding
of these questions is the goal of this NSF-funded project, which in the future plans to port this exhibit to more
affordable platforms-such as tablets and google cardboards-, as well as integrate Antarctic research from other
disciplines.

581
1506
The @OceanseaiceNPI Initiative: Polar Science Communication using Social Media

Amelie Meyer1, Alexey Pavlov1, Anja Rösel1 (anja.rosel@npolar.no), Polona Itkin1, Jean Negrel1, Lana Cohen1,
Jennifer King1, Sebastian Gerland1, Stephen Hudson1, Laura de Steur1, Paul A. Dodd1, Nick Cobbing2, Mats A.
Granskog1
1
Norwegian Polar Institute, Tromsø, Norway, 2National Geographic Magazine, Washington, United States

Successful science communication is essential but also challenging with time constrains, limited financial
resources and a lack of incentives in the academic environment. Many social media platforms have recently
emerged, providing free and simple science communication tools to reach the general public, journalists, fellow
scientists, and younger generations in particular. While individual researchers and large institutions are present
on social media, smaller research groups are under-represented.
@oceanseaicenpi is a science communication initiative led by a small group of polar oceanographers, sea ice,
and atmospheric scientists at the Norwegian Polar Institute in Norway. Here we present our experience
establishing, developing, and maintaining this successful Arctic science communication initiative on Instagram,
Twitter, and Facebook. The initiative is run entirely by the team of 25 researchers with limited time and
financial resources. Over 4 years, it has built a broad audience of more than 7000 followers.
The initiative has boosted the alternative metric scores of our publications and helped researchers in the group
to become better writers and communicators. We hope to inspire other research groups by sharing our
experience on how to develop and conduct effective science communication using social media!

582
TE-1a - Observing with autonomous vehicles in polar regions
20.06.2018 09:00-10:30, A Forum

2559
Marginal Ice Zone Processes Observed from Unmanned Aircraft Systems

Christopher J Zappa1 (zappa@ldeo.columbia.edu), Scott Brown1, Tejandra Dhakal2, Carson Witte1, Ajit
Subramaniam3
1
Lamont-Doherty Earth Observatory of Columbia University, Ocean and Climate Physics, Palisades, United
States, 2Lamont-Doherty Earth Observatory of Columbia University, Marine Geology and Geophysics, Palisades,
United States, 3Lamont-Doherty Earth Observatory of Columbia University, Marine Biology, Palisades, United
States

Unmanned Aircraft Systems (UAS) are ideal to study sub-pixel satellite variability as well as providing “eyeballs
over the horizon” information for both ship- and land-based field studies. For the past 5 years, we have
developed and flown a number of payloads to study under-observed sea ice regions aboard long-range (5- to
20-hour endurance) UAS including most recently fixed-wing UAS with vertical take-off and landing capability.
We have demonstrated the capability from both land and ships during a number of experiments in Alaska
(Beaufort and Chukchi Seas) and Svalbard, Norway. We have developed and deployed payloads that include:
1) Down-looking hyperspectral visible imaging spectrometer to determine ocean color and biogeochemical
mapping;
2) Upward- and downward-looking pyranometers (solar) and pyrgeometers (longwave) to measure full
hemispheric irradiance to quantify the surface energy budget and map sea ice, ice floe, and ocean solar albedo;
3) High-resolution visible and infrared imaging is used to discern sea ice extent and coverage, whitecapping and
other upper ocean processes as well as SST skin and ice temperature;
4) air-sea-ice turbulent fluxes as well as wave height, ice freeboard, and surface roughness with a LIDAR; and
5) drone-deployed micro-drifters (DDµD) deployed from the UAS that telemeter both atmosphere and upper
ocean data. Measurements from UAS offer a unique opportunity to observe physical processes at sea-ice
margins and will be explored here.

583
255
GLOBAL ARCHER The GLOBAL ARCtic High-altitude Environmental Research Initiative

Janet Intrieri1 (janet.intrieri@noaa.gov)

1
NOAA Earth System Research Laboratory, Physical Sciences Division, Boulder, United States

Additional activity in Arctic waters requires reliable environmental & domain awareness information critical for
ecosystem, resource, community & emergency management & economic sectors including transportation,
fisheries, tourism, & energy & mineral industries. Ice hazards that originate in the Arctic threaten maritime
shipping in mid-latitudes further expanding the domain of Arctic impact on safe maritime operations. To
address these issues, an international study team identified observational needs & developed mission
objectives using UAS. The range, altitude (~20 km), & endurance (~26 hr) of High Altitude Long Endurance
(HALE) UASs like the Global Hawk. This capability can fill critical gaps for Arctic Domain Awareness observations
required for sea ice forecasting, transportation safety, oil spill detection & response, & extreme weather
watches & warnings. Demonstrating HALE technology & communication innovations in the Arctic are needed
for the growing number of requirements & stakeholders operating at high latitudes. The study team prioritized
& developed flights that demonstrate Global Hawk's observational capability for providing: a) enhanced
environmental knowledge; b) maritime awareness & responsiveness; &, c) insight into weather extremes in the
Arctic. We present the concept of a month-long campaign, GLOBAL ARCHER (ARCtic High altitude
Environmental Research), to demonstrate how Global Hawk can advance our capabilities & responses in a
rapidly evolving Arctic.

584
1113
Internal Polar Boundary Layer Affected by Open Water in Antarctic Sea Ice

Barbara Altstädter1 (b.altstaedter@tu-braunschweig.de), Andreas Scholtz1, Astrid Lampert1, Falk Pätzold1,

Christof Lüpkes2
1
Technische Universität Braunschweig, Institute of Flight Guidance, Braunschweig, Germany, 2Alfred Wegener
Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany

As part of the Polarstern cruise ANT-XXIX, the Meteorological Mini Aerial Vehicle (M²AV) was operated in the
Antarctic Weddell-Sea during winter 2013. It was the first time that unmanned aerial system (UAS) were used
on board Polarstern and the authors have gained high expertise in performance of UAS influenced by harsh
polar environment (cold temperature, high wind speeds, potential of icing) since then. The aircraft's nose is
equipped with fast meteorological sensors in order to investigate turbulence in the lowermost 1000 m. The
main aim of the study was to analyse the effect of open water in sea ice that causes an internal boundary layer
due to the high temperature difference of around 30 K between see ice surface and open water in the small
horizontal extent of several metres. Taken from studies in modelling, the small-scale effect influences the
Earth's climate. However, the knowledge of the extent is poor and leads to a high uncertainty in weather and
climate predictions. Therefore, horizontal flights were operated with M²AV perpendicular to open sea ice with
a flight distance of at least 4 km in low heights of 15-150 m. Fluctuations of 3D-wind vector and potential
temperature were significantly affected by one crack of around 500 m wide and showed updraft up to the
height of 100 m, however downdraft above and near the inversion layer. The crack led to pronounced fluxes of
sensible heat and turbulent kinetic energy, in contrast to measurements above closed sea ice.

585
670
RPAS Based Observations on the Arctic ABL over Sea Ice in the Baltic Sea

Stephan Kral1, Joachim Reuder1, Line Båserud1, Gabin Urbancic2, Marius Jonassen3, Alexander Rautenberg4
(alexander.rautenberg@uni-tuebingen.de), Jens Bange4, Marie Hundhausen4, Philipp Hilsheimer4, Burkhard
Wrenger5, Carsten Langohr5, Hendrik Voss5, Martin Müller6, Christian Lindenberg6, Timo Vihma7, Irene Suomi7,
Ewan O'Connor7, Rostislav Kouznetsov7
1
University of Bergen & Bjerknes Centre, Geophysical Institute, Bergen, Norway, 2University of Bergen,
Geophysical Institute, Bergen, Norway, 3University Centre in Svalbard, Longyearbyen, Norway, 4University of
Tuebingen, Tuebingen, Germany, 5Ostwestfalen-Lippe University of Applied Sciences, Hoexter, Germany,
6
Lindenberg und Mueller GmbH & Co. KG, Hohenhameln, Germany, 7Finnish Meteorological Institute, Helsinki,
Finland

The purpose of the research project ISOBAR (Innovative Strategies for Observations in the Arctic Atmospheric
Boundary Layer) is to increase our understanding of the Atmospheric Boundary Layer (ABL) in the Arctic. In
February 2017 we carried out a measurement campaign on the Finnish island Hailuoto in the northern Baltic
Sea. During the three-week long field period, we studied processes within the ABL over the sea-ice of the
Bothnian Bay, based on observations from several different Remotely-Piloted Aircraft Systems (RPAS) as well as
ground based flux and automatic weather stations and remote sensing systems (Doppler Lidar and Sodar).
Turbulence measurements from different altitudes were obtained by two different fixed-wing aircraft systems
(MASC and miniTalon). A small fixed-wing system (SUMO) was used for atmospheric profiles from about 30 to
1800 m. In addition, different multicopter systems were applied to take profiles from the ground to an altitude
of up to 400 m. In total more than 150 scientific flights were conducted during the three weeks with five
intensive observational periods. Together with the ground based and remote sensing data this results in an
extensive high-resolution data set of observations on the stable ABL which will be used for detailed
investigations of the processes within the stable ABL. We further aim to take these processes into account in
new ABL parametrization schemes for numerical models.

586
1586
U.S. DOE ARM Tethered Balloon System at AMF3 in Oliktok Point, Alaska

Darielle Dexheimer1 (ddexhei@sandia.gov), Erika Roesler1, Fan Mei2, Jasper Hardesty1, Mark Ivey1, Benjamin
Hillman1
1
Sandia National Laboratories, Albuquerque, United States, 2Pacific Northwest National Laboratory, Richland,
United States

Sandia National Laboratories (SNL) has operated a tethered balloon system (TBS) at the Advanced Mobile
Facility 3 (AMF3) in Oliktok Point, Alaska, since 2015 on behalf of the U.S. Department of Energy's (DOE)
Atmospheric Radiation Measurement (ARM) Climate Research Facility. The TBS was flown as part of ICARUS
(Inaugural Campaigns for ARM Research using Unmanned Systems) and AALCO (Aerial Assessment of Liquid in
Clouds at Oliktok).
The TBS offers advantages for Arctic observations. Our TBS has operated for over nine continuous hours, within
clouds, and at altitudes up to 1.45 km above ground (AGL). Varied instruments have been deployed
simultaneously on the TBS, including Distributed Temperature Sensing (DTS) systems, printed optical particle
spectrometers, a condensation particle counter, and supercooled liquid water content sensors (SLWCs).
Measurements from these sensors, and their comparison with sUAS, radiosonde, and ground-based
measurements are discussed. Additionally, technical aspects of DTS measurements, including the use of a fiber
optic rotary joint, and comparisons of results from two DTS systems, are shown. Varied deployments of the TBS
and DTS are touched on, including recent efforts to measure ocean temperature profiles as conducted on a
research vessel deployed offshore of Oliktok Point, and DTS measurements collected by an sUAS.

587
2491
Manned Aircraft vs. UAS Surveys for Arctic Cetacean Density and Distribution

Megan Ferguson1 (megan.ferguson@noaa.gov), Robyn Angliss1

1
NOAA Alaska Fisheries Science Center, Marine Mammal Laboratory, Seattle, United States

Manned aerial surveys are routinely used to assess cetacean distribution and density, often over large
geographic areas. Unmanned aircraft systems (UAS) have been identified as a technology that could augment
or replace manned aerial surveys for cetaceans. To understand what research questions involving cetacean
distribution and density can be addressed using manned and UAS technology in the Arctic, we conducted a
three-way comparison near Utqiaġvik, Alaska, among visual observations made by marine mammal observers
aboard an aircraft; imagery autonomously collected by a Nikon D810 camera system mounted to a belly port
on the manned aircraft; and imagery collected by a similar camera system on a remotely-controlled ScanEagle
UAS. Each survey platform conducted five flights within a 16,800 km2 study area. The manned aircraft collected
23,580 images in 17.9 flight hours, during which marine mammal observers simultaneously collected sighting
data. The UAS collected 20,568 images in 21.8 flight hours. Various technologies and operational procedures
contributed to the ability to conduct routine, successful and safe beyond line-of-sight UAS flights. Comparisons
of density estimates, associated estimates of uncertainty, data processing time, and cost can be the basis for
design of future large-scale UAS projects.

588
CR-7a - Snow and firn: an open measurement and modelling challenge
20.06.2018 09:00-10:30, A Dischma

198
Assessing past Snow Cover Changes in the Kola Peninsula, Arctic Russia

Rebecca Vignols1,2 (regnos32@bas.ac.uk), Yulia Zaika3, Ilona Blinova4, Gareth Marshall1, Gareth Rees2
1
British Antarctic Survey, Cambridge, United Kingdom, 2Cambridge University, Cambridge, United Kingdom,
3
Moscow State University, Moscow, Russian Federation, 4Polar Alpine Botanical Garden-Institute, Apatity,
Russian Federation

The very high albedo of snow means that changes in its coverage have a significant impact on the Earth´s global
energy budget. Thus, Northern Hemisphere snow cover, which comprises approximately 98% of the global total
area of seasonal snow, is responsible for the largest annual and interannual differences in land surface albedo.
Here we examine recent changes in snow cover in the Khibiny Mountains on the Kola Peninsula in Arctic Russia,
a region that has undergone significant climate change in recent decades. Future changes in snow cover have
the potential to have a major socio-economic impact in this region, which is primarily dependent on mining and
skiing for its economy. We used a combination of remote sensing data, meteorological observations and field
data in our analysis. Field measurements of snow parameters were employed to validate the MODIS (Moderate
Resolution Imaging Spectroradiometer) fractional snow cover and albedo products. First and last days of snow
cover were derived for each year and compared to snow depth observations from three field stations in the
Khibiny Mountains and three additional meteorological stations in the region to look for systematic biases in
the satellite data. These 'locally calibrated' MODIS data were then used to determine the trends and variability
in the duration of the snow season across the Khibiny Mountains from 2000 to 2016.

589
771
Are Accumulation Regimes of Central Asian Glaciers Changing?

Marlene Kronenberg1 (marlene.kronenberg@unifr.ch), Horst Machguth1,2, Silas Walter1, Margit Schwikowski3,4,

Martin Hoelzle1
1
University of Fribourg, Department of Geosciences, Fribourg, Switzerland, 2University of Zurich, Department of
Geography, Zurich, Switzerland, 3Paul Scherrer Institute, Villigen, Switzerland, 4University of Bern, Department
for Chemistry and Biochemistry, Bern, Switzerland

Various studies have shown that glacier mass loss in certain areas of Central Asia is low compared to the global
average. The reasons for glaciers in these regions being relatively close to equilibrium, however, remain
unresolved. A possible explanation is increased accumulation due to changes in atmospheric circulation. For
the regions concerned, however, precipitation data are sparse. This lack of data could be mitigated by using in-
situ measurements of glacier accumulation rates.
Here, we focus on the firn cover of Abramov glacier located in the Pamir Alay, southern Kyrgyzstan. Abramov
glacier is the only glacier with a very rich set of historical scientific data located close to the areas of near-
equilibrium mass balance. We use snow pits, firn cores and GPR measurements to derive present-day
accumulation characteristics including annual accumulation rates and snow distribution. Furthermore, we
compile past accumulation rates from the exceptionally detailed glacier mass balance measurements from the
1960s to the 1990s as well as from ice cores reaching down to the early 1920s. The accumulation rates and
snow distribution patterns from the different periods are used to quantify temporal changes of the firn cover of
Abramov glacier. First results suggest that annual accumulation rates may have increased during the last years.

590
901
Using Weather Radar Data to Estimate the Winter Mass Balance on Swiss Glaciers

Rebecca Gugerli1 (rebecca.gugerli@unifr.ch), Matthias Huss1,2, Nadine Salzmann1

1
University of Fribourg, Fribourg, Switzerland, 2ETH Zurich/VAW, Zuerich, Switzerland

Precipitation estimates in high-mountain regions are essential for environmental studies in many research
fields (glaciology, meteorology, hydrology, etc.). Although precipitation data exist for the Swiss Alps, accuracy is
limited by data sparsity and measurement challenges in high-mountain regions. In glaciology, we propose a
novel approach to estimate the snow water equivalent (SWE) on glaciers and to spatially integrate these
measurements by combining continuous observations of SWE, conventional glaciological surveys and
operational measurements of solid precipitation.
We investigate the application of weather radar data compiled by MeteoSwiss to estimate the amount and the
spatial distribution of solid precipitation on glaciers in winter. To validate the time evolution of snowfall, we
use a cosmic ray sensor (CRS) which directly measures the SWE of the snowpack. The CRS has shown a
satisfying agreement with manual measurements (snow pits) taken over two winter seasons on the Glacier de
la Plaine Morte in Switzerland. To expand the validation over several Swiss glaciers, we use end-of-winter
glaciological surveys (snow pits, snow probings) provided by the Swiss monitoring network (GLAMOS). The
advantage of the weather radar data is its spatial footprint with which we gain further insights on the snow
distribution on glaciers, especially at high altitudes. Hence, we can show the usefulness of readily available
weather radar data for the application in cryospheric studies.

591
1449
Quantifying Sublimation and Melt from Snow in the Semi-arid Andes

Shelley MacDonell1 (shelley.macdonell@ceaza.cl), Marion Réveillet1, Simon Gascoin2, Christophe Kinnard3,

Nicole Schaffer1, Arno Hammann1
1
Centro de Estudios Avanzados en Zonas Aridas (CEAZA), La Serena, Chile, 2Centre d'Etudes Spatiales de la
Biosphère (CESBIO), Université de Toulouse, Toulouse, France, 3Université du Québec à Trois-Rivières, Trois-
Rivières, Canada

Water is a critical resource in semiarid Chile, as the area supports more than 55% of the country's population,
and the regional economy depends on agricultural production and mining, which are two industries that rely
heavily on a consistent water supply. Despite the importance of snow cover for water resources in this region,
there is currently a limited understanding of snow depth distribution and mass balance. Analysing relative
ablation rates are critical for understanding snow depth sensitivity to variations in climate and simulating the
evolution of the snow pack over a larger area and over time. This study aims to quantify melt and sublimation
rates over a catchment during two contrasting years to determine the impact of El Niño and La Niña climatic
modes on snow distribution and ablation. In this study, we model the snow cover evolution using a distributed
snowpack model (SnowModel) in the instrumented watershed of La Laguna (3150-5630 m above sea level,
30°S), during 2014 and 2015. The model is calibrated and forced with meteorological data from seven
Automatic Weather Stations (AWS) located in the watershed, and modeled WRF results. Temporal evolution of
the simulated snow depth is validated using the snow depth measured at each AWS. The snow duration and
snow cover extent are compared to MODIS and selected Sentinel-2 images. Results highlight the importance of
accurately accounting for the precipitation forcing and the sensitivity to the chosen roughness length.

592
1318
Monitoring the Evolution of the Surface Snow on the East Antarctic Plateau

Ghislain Picard1 (ghislain.picard@univ-grenoble-alpes.fr), Laurent Arnaud1, Eric Lefebvre1, Quentin Libois2

1
Institut des Géosciences de l'Environnement, Saint Martin d'Hères, France, 2Centre National de Recherches
Météorologiques, Toulouse, France

The Antarctic Ice Sheet has a highly dynamical surface playing an active role in the exchanges of energy and
mass between the atmosphere and the firn. The evolution of the surface geometry and snow properties are
mainly driven by the local atmospheric conditions which in turn impacts the radiative and turbulent exchanges.
This coupling results in feedback loops that can amplify or weaken the Antarctic response to global changes.
Understanding the surface evolution is a major issue to address the prominent questions of the fate of
Antarctic climate and ice sheet, the continental warming and the contribution to sea-level rise.
For nearly 10 years, we have been studying the surface and the upper snowpack at Dome C and on the East
Antarctic Plateau. To this end, we have deployed automatic instruments, conducted intensive measurements
during summer campaigns, organized long-term data collection in winter and participated to scientific
traverses. The accumulated information concerns snow properties (SSA, density, temperature), surface
properties (pictures, roughness) and snow accumulation. We found that the evolution of some variables (SSA
or snow temperature) conforms to state-of-the-art model simulations while others (surface roughness or
density) remain hard to explain using existing tools. This presentation will give an overview of the available
observations, show the successful modeling simulations and discuss future developments needed to model
Antarctic specificities.

593
1988
Modelling the Impact of Drifting Snow on the Surface Mass Balance of Adelie Land

Christoph Kittel1 (ckittel@ulg.ac.be), Charles Amory1, Cécile Agosta1,2, Hubert Gallée3, Xavier Fettweis1
1
Laboratoire de Climatologie, ULiège, Liège, Belgium, 2LSCE (UMR 8212 CEA-CNRS-UVSQ/IPSL), Université Paris
Saclay, Paris, France, 3Université Grenoble-Alpes, Institute of Geosciences and Environment, Grenoble, France

The transport of snow by the wind is an important component of the Antarctic surface mass balance (SMB) as
drifting snow counts up for a large amount of snow ablation over the ice sheet. However, this process is
frequently neglected in atmospheric models. Two simulations (one with drifting snow and one without) were
performed at a resolution of 8 km with the regional climate model MAR forced by ERA-Interim, in order to
assess the impact of drifting snow on the SMB of Adelie Land (East Antarctica) during the period 2002 - 2016.
We evaluated results against field observations (including meteorological and snow skate measurements).
Besides to better represent climate surface as airborne snow particles can sublimate and interact with the
lowest atmospheric levels, the drifting snow simulation improves the modelled spatial distribution of the SMB
and reduces the overestimation of the accumulation in comparison with MAR results without drifting snow.

594
SH-5a - Current and future change, sustainability and resilience in the Polar Regions
20.06.2018 09:00-10:30, A Sertig

5
Navigating the New Arctic: Trajectories of Change

Amanda Lynch1 (amanda_lynch@brown.edu), Michael Goldstein2

1
Brown University, Institute at Brown for Environment and Society, Providence, United States, 2Babson College,
Finance Division, Babson Park, United States

Because of Arctic amplification, the Arctic has been labeled the 'canary in the coal mine' or 'the frontline' of
climate change. Rapid changes in temperature, ice and snow cover, and ecosystem distributions are leading to
serious impacts on Arctic peoples. At the same time, these changes are inciting a "race for the North", with a
range of industries showing increased interest the region. Low global oil prices, along with technological,
geopolitical and security challenges, may render Arctic fossil fuel and mineral reserves economically nonviable
for the foreseeable future, but industries such as freight, tourism and commercial fishing may benefit.
Because of the high variability and concomitant low predictability of many components of the Arctic system in
the near term, economic benefits have not accrued at the expected rate. Development trajectories remain
highly contested. Safety and reliability concerns are ongoing. This confluence of opportunity and risk raises
critical questions as to how well we understand the changing Arctic system on policy-relevant time scales.
These questions will be explored through the lens of Arctic navigability.

595
199
Politics of Postcoloniality and Sustainability in the Arctic

Ulrik Pram Gad1 (gad@cgs.aau.dk), Marc Jacobsen2

1
Aalborg University, Aalborg, Denmark, 2University of Copenhagen, Political Science, Copenhagen K., Denmark

In the Arctic as elsewhere, there is no overall agreement on what exactly ´sustainability´ or ´sustainable
development´ refer to. However, received discourses of the Arctic as a special place, characterized by a nature
at once hostile and fragile, has empowered a distinct constellation of actors in the Arctic. For NGOs, indigenous
peoples´ organizations, states, and companies ´sustainability´ implies different sets of opportunities and
precautions. The paper reports the findings of a collaborative research project mapping sustainability
narratives in the Arctic and analyzing the political consequences of sustainability becoming pivotal for politics in
the region. Analysing sustainability as a concept that re-orders the relationship between society (identity),
development (time), and nature (space) we find that: First, presenting one´s venture as contributing to
sustainability has indeed become a precondition for participation in the negotiation of Arctic development and
governance. Second, when sustainability meets the Arctic it changes meaning from a universal concern with a
global ecosphere to a particular concern with a series of more limited environments (natural, cultural, societal,
economic). Third, in practical governance and pragmatic discourse, cultural and societal sustainabilities often
crowd out environmental sustainabilities. Fourth, sustainability is undergoing a transformation of meaning
from being a concept that limits development to one that allows development to take place in the Arctic. Fifth,
the variety of postcolonial configurations is central for understanding both the overall dynamics of the politics
of sustainability and the variation across the Arctic.
Keywords: Sustainability, Postcoloniality, Political Theory, Arctic

596
545
Ground-scale Socioecological Interactions and Arctic Environmental Governance

Nadia French1 (nadinfrench@gmail.com)

1
University of Birmingham, Geography, Earth and Environmental Sciences, Birmingham, United Kingdom

The changing landscape and economic relevance of the Arctic present a unique opportunity to monitor the
change in interactions between people and the arctic nature as well as to shed light onto the funnelling of the
existing at different scales environmental governance regimes to the local level and vice versa.
The work done within this framework attempted to understand and map ground-scale interactions between
human and non-human actants (individual and community-based behaviour that can impact the environment
especially if multiplied) in a case study conducted in Mys Kamenny, Yamal district, Russia, in 2017. Yamal is a
region of rapid socioeconomic development undergoing noticeable climatic and geomorphological shifts.
Individual and community level relationship with the environment especially of non-indigenous descent is often
overlooked in assessments of environmental integrity, yet, it holds clues to the feedback loops between
climate change, development and society.
The study found that using multiple tools to measure landscape change (e.g. GIS, interviews, fieldwork) relative
to social and economic dynamics, individual behaviour and environmental regulation and enforcement can
help better understand not only local but also generic ecological issues of the present day Arctic and draw
insights from a close-up view to the environmental governance on a larger scale.

597
538
Resilience of the Antarctic Treaty System Beyond 2048

Akiho Shibata1 (akihos@kobe-u.ac.jp)

1
Kobe University, Polar Cooperation Research Centre (PCRC), Kobe, Japan

In my presentation, I argue that it is the resilience of the Antarctic Treaty legal system nurtured and
strengthened by the very members of its system over the past six decades that would effectively control within
its manageable confines any future “manifestation of territorial pressures”, “international power plays”, and
the potential reviews after 2048 of the operation of the Madrid Protocol, which prohibits mineral resource
activities in the Antarctica.
After recapitulating the systemic resilience of the Antarctic Treaty System, which consists of an intricate
balance between a few fundamental principles of unchanging nature and its flexibilities in adapting to the
changing political and environmental landscape surrounding the Antarctic (Shibata 2015), I will re-examine the
legal, political and environmental contexts within which the 1988 Convention on the Regulation of Antarctic
Mineral Resource Activities (CRAMRA) was negotiated, agreed, and, because of the two claimant states'
sudden change of policies, buried in oblivion. The external and internal accommodation the consultative
parties at the time (1980s) endeavoured to achieve (and failed?) can serve as an interesting reference case
when we consider the potential challenges the Antarctic Treaty System may face into the mid-21st century
arising out of Antarctic resources.
Shibata, A. (2015): Japan and 100 Years of Antarctic Legal Order. 7 Yearbook of Polar Law, 1-51.

598
2275
Human Activity in the Ross Sea Region: A Temporal and Spatial Analysis

Fraser Morgan1 (morganf@landcareresearch.co.nz), Thomas Robertson1, Pierre Roudier2, Daniela Liggett3, Neil
Gilbert4
1
Landcare Research, Auckland, New Zealand, 2Landcare Research, Palmerston North, New Zealand, 3University
of Canterbury, Gateway Antarctica, Christchurch, New Zealand, 4Constantia Consulting Ltd, Christchurch, New
Zealand

With increasing human activity in Antarctica and the associated environmental pressures (such as non-native
species incursions or protected area planning), there is a need to understand the scale of historic and current
human activity on the continent.
Collating and harmonising data from various sources, we have developed a database of human activity within
the Ross Sea region for the last 15 years. Data sources used to create the database account for tourism,
science, and national operator activities within the region. This paper will utilise spatial analysis to explore how
scientists, tourists, and base staff in Antarctica interact with the landscape. The paper will also highlight the
various sources and methods used to access human activity data in the region.
We expect the database to enable the visualisation of the current and historic scale of human activity across
the ice-free areas of the Ross Sea region and to assist in the management of the associated environmental
pressures.

599
636
In the Footsteps of Visitors to the Ross Sea: Tracing Antarctic Tourism Patterns

Daniela Liggett1 (daniela.liggett@canterbury.ac.nz), Neil Gilbert2, Fraser Morgan3

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand, 2Constantia Consulting Ltd,
Christchurch, New Zealand, 3Landcare Research, Auckland, New Zealand

The last two decades have seen a rapid increase in Antarctic tourism numbers and a proliferation of Antarctic
tourism research. Most of the growth in visitor numbers has occurred in the Antarctic Peninsula, which
receives over 95% of all Antarctic tourists, and consequently much of the scholarly literature on Antarctic
tourism focuses its attention to the particularities of tourism in this region. It is less well known that the Ross
Sea region has been visited semi-regularly by commercial tour operators since the mid-1960s and annually
since 1990. Tourism in the Ross Sea is concentrated on a dozen sites, out of just over 50 different visitor sites,
and generally involves expedition cruising. While anecdotal accounts of tourism operations in the Ross Sea
have shed some light on tourist experiences in this part of the world, no systematic analysis has been
undertaken of tourism patterns in the Ross Sea over time.
In this paper, we present the results of a comprehensive study of tourism activities in the Ross Sea region and,
using GIS-based analysis, discuss the changing footprint of Antarctic tourism in the Ross Sea over the last 50
years. This study forms one component of two larger integrated research programmes that aim at
understanding the interconnected natural processes and human impacts that (re-)shape ecosystems in the
Ross Sea in order to inform environmental management.

600
GG-2d - Arctic and Antarctic past ice sheet dynamics and paleoclimate evolution
20.06.2018 09:00-10:30, A Schwarzhorn

1958
East Antarctic Ice Sheet Dynamics Inland of Shackleton and West Ice Shelves

Duanne White1 (duanne.white@canberra.edu.au), Marcello Blaxell1, Steven Phipps2, Tobias Staal2, Alexandru
Codilean3, David Fink4, Matt Jeromson1, David Small5, Pippa Whitehouse5, Mike Bentley5, Matt King6
1
University of Canberra, Institute for Applied Ecology, Canberra, Australia, 2University of Tasmania / Institute for
Marine and Antarctic Studies, Hobart, Australia, 3University of Wollongong, Wollongong, Australia, 4Australian
Nuclear Science and Technology Organisation, Sydney, Australia, 5Durham University, Durham, United Kingdom,
6
University of Tasmania, Hobart, Australia

Geological constraints of former ice extent are very limited in the interior of East Antarctica, particularly in
areas near deep subglacial basins. Not surprisingly, the absence of empirical constraints mean these areas also
contain some of the most divergent models of both modern Glacio-Isostatic Adjustment (GIA), and projections
of future ice loss from the continent. To improve this situation, we have collected records of past ice sheet
geometries along flowlines from inland to coast in the poorly explored regions inland of the Shackleton and
West Ice Shelves. Here, isolated nunataks in the middle of subglacial basins, and mountain ranges flanking
outlet glaciers draining deep basins provide a rare opportunity to improve our understanding of the influence
of subglacial basins on past ice dynamics.
In this presentation we will detail results from field observations collected since 2015/16 and an initial tranche
of 10Be exposure ages from inland outcrops in this area. Preliminary results suggest limited change in elevation
during the LGM along the upper Denman Glacier, along with a substantive recent (potentially late Holocene)
retreat close to the modern grounding line. We will discuss the significance of former ice sheet surface
elevations in the context of existing models of GIA, present day ice loss, and the role of sub-glacial topography
ice dynamics from a significant outlet of the Aurora Subglacial basin.

601
881
New Records of Holocene Glacial Fluctuations from Victoria Land, Antarctica

Ross Whitmore1 (ross.whitmore@vuw.ac.nz), Andrew Mackintosh1, Kevin Norton1, Cliff Atkins1, Jamey Stutz1,
Richard Jones2
1
Victoria University of Wellington, Wellington, New Zealand, 2Durham University, Durham, United Kingdom

Antarctic ice sheets represent the largest reservoir of melt water in a warming climate. Yet the most important
and dynamic portions of these large systems have only been observed for ~50 years, since the beginning of the
satellite era. Using geological dating techniques and focusing on outlet glaciers, the observational record can be
extended 100-fold, from decades to millennia. By extending the observational range we can illuminate past
changes in coupled ice-climate systems and infer their future response and related sea level change in a
warming climate.
To more fully understand the nature of these important coupled ice-climate systems, surface-exposure dating
of rocks adjacent to outlet glaciers can provide insight to the style and rate of change for outlet glacier surface-
elevation through time. Sampling campaigns in Victoria Land have produced robust, high-resolution age-
elevation transects for two glaciers draining East Antarctica along the Transantarctic Mountains.
We present 33 new 10Be ages from Mawson and Tucker Glaciers. These new ice surface elevation chronologies
directly constrain the style, rate, and magnitude of change for two outlet glaciers; and provide critical insight to
Holocene ice-load history in Victoria Land. Both age-elevation profiles show rapid significant thinning of outlet
glaciers during the Holocene. These data are critical analogues for modelling the response of present and
future ice-climate systems in a warming world.

602
1374
Deglacial History of the Western Ross Sea since the Last Glacial Maximum

Jacob Anderson1 (jacob.anderson@otago.ac.nz), Gary Wilson1, David Fink2, Richard Jones3,4, Toshiyuki Fujioka2
1
University of Otago, Dunedin, New Zealand, 2Australian Nuclear Science and Technology Organisation, Sydney,
Australia, 3Victoria University of Wellington, Wellington, New Zealand, 4Durham University, Durham, United
Kingdom

Retreat of grounded ice in the Ross Sea since the LGM provides valuable insight into marine ice sheet stability
and response to environmental change. Here, we present 10Be exposure ages from glacially transported
erratics from South Victoria Land to gauge past extent and timing of retreat. Ages from Skelton Névé indicate
the ice surface was between 50 and 106 m higher than present during the LGM. The ice surface elevation
remained close to its maximum extent prior to 19.1 ka and lowered by at least 50 m since ~15.0 ka. These
results suggest that ice sheet thinning in the Skelton Névé coincided with meltwater pulse 1A (MWP-1A).
However, the thinning did not make a significant contribution at this time. Thinning continued after 9.7 ka at
Skelton Glacier and data from southern McMurdo Sound reveals a late-glacial and Holocene deglaciation
chronology. This is consistent with studies suggesting that EAIS outlet glaciers that drained into the western
Ross Sea experienced most mass loss during the early to middle Holocene. This chronology coupled with
sediment provenance define a two-stage ice flow scenario for McMurdo Sound. The thinning and pattern of
retreat is likely to be in response to retreat of the grounded ice in the Ross Embayment causing a reduction in
buffering of the Skelton Glacier and gravitational draw down into the Ross Sea.

603
1710
Variability in Sediments Deposited at a Retreating ice Stream Grounding Line

Zoe Roseby1,2 (z.roseby@noc.soton.ac.uk), James Smith2, Matthieu Cartigny3, Claus-Dieter Hillenbrand2, Kelly
Hogan2, Robert Larter2, Peter Talling3, Claire Allen2, Brad Rosenheim4, Werner Ehrmann5, Gerhard Kuhn6
1
University of Southampton, Southampton, United Kingdom, 2British Antarctic Survey, Cambridge, United
Kingdom, 3Durham University, Durham, United Kingdom, 4University of South Florida, St. Petersburg, St.
Petersburg, United States, 5Leipzig University, Leipzig, Germany, 6Alfred Wegener Institute, Bremerhaven,
Germany

Understanding the future response of ice streams and glaciers to climate change is of high importance but
remains uncertain, due to the limited timescales over which we have recorded observational and satellite data.
Sedimentary sequences, deposited on polar continental shelves during past episodes of ice sheet advance and
retreat, can be used to improve our understanding of long term changes. Past studies on marine sediment
cores have typically identified three sediment facies assemblages; sub-glacial, transitional and open marine.
Transitional sediment facies, deposited proximal to the ice stream grounding line, have the potential to capture
the ice-proximal environment and processes taking place during deglaciation; thus providing an insight into the
cause and style of ice stream retreat. Despite the development of depositional models to help explain the
processes occurring at grounding lines, there is still uncertainty about the variability in sediments deposited in
this environment. Here we use a multi-proxy approach on marine sediment cores recovered from the Anvers-
Hugo Palaeo-Ice Stream Trough, western Antarctic Peninsula shelf, to identify the variability in transitional
sediment facies deposited along and across the trough. Our data reveal systematic variability in the types and
volume of transitional sediments, resulting from changes in retreat rate, bathymetry, thermal regime,
grounding line oscillations and the evolving nature of the ice margin over deglaciation.

604
973
Retreats of Ice Sheet/Ice Shelf Driven by Warm Water Incursions in the Ross Sea

Zhihua Chen1,2,3 (chenzia@fio.org.cn), Mengshan Ju1, Shulan Ge1, Zheng Tang1, Yuanhui Huang1, Renjie Zhao1,
Ralf Tiedemann3, Lester Lembke-Jene3
1
Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, State
Oceanic Administration, Qingdao, China, 2Laboratory for Marine Geology, Qingdao National Laboratory for
Marine Science and Technology, Qingdao, China, 3Alfred-Wegener-Institut für Polar- und Meeresforschung,
Bremerhaven, Germany

The stratigraphic data provide direct evidences and opportunities to address questions concerning retreat
history of the Ross Ice Sheet and Ice Shelf, but there are significant uncertainties in the chronologies and
interpretation. Here, we present and compare stratigraphic records of several sediment cores dredged from
the continental shelf and slope of the Ross Sea. The sedimentological and geochemical records reveal the
Circumpolar Deep Water (CDW) upwelled, mixed with more surface waters and contained higher oxygen since
the Last Glacial Maximum (LGM), while sedimentary facies and paleoenironmental proxies indicate
synchronous and rapid retreats of (ice sheet) grounding-line and (ice shelf front) calving line occurred on the
continental shelf especially during Holocene. The stability of marine-based margins of the Antarctic Ice Sheet
was evidently controlled by postglacial warm deep-water incursions onto the shelf in the past. Thus, it can be
inferred that the ice sheet and ice shelf in the Ross Embayment will melt and retreat faster, or even
disastrously collapse and disappear in the future with more incursions of much warmer water in a continuously
warming world.
Keywords: Ross Sea, continental shelf and slope, paleo-records, retreats of ice sheet and ice shelf, warm water
incursions, since the Last Glacial Maximum

605
1056
Ice Sheet Instability in the Western Ross Sea during the Last Glacial Maximum

Jae Il Lee1 (leeji@kopri.re.kr), Cristina Subt2, Brad Rosenheim2, Eugene Domack2, Min Kyung Lee1, Kyu-Cheul
Yoo1, Heung Soo Moon1, Young-Suk Bak3
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2University of South Florida, St. Petersburg,
United States, 3Chonbuk National University, Jeonju, Korea, Republic of

Last Glacial Maximum (LGM) deposit in the western Ross Sea is represented by glacial diamicton facies, and
with an absence of sediment facies other than diamicton, it has been assumed that thick ice sheet was
extended to the outer shelf and was grounded to the sea floor during the LGM. However, we cannot preclude
the possibility that the ice sheet did not remain stable in the western Ross Sea, considering the unstable nature
of a marine-based ice sheet, presence of deep Drygalski Trough that makes warm water-intrusion easier, and
sporadic warm climate events such as AIM2 during the LGM.
Here we show that diatomaceous mud layers underlie diamicton in cores collected from the Southern Drygalski
Trough (SDT), indicating there was an open marine environment prior to the latest glacial event in the western
Ross Sea. Ramped PyrOx (RP) 14C dating on the diatomaceous mud revealed that ice sheet on the western Ross
Sea retreated at ~26.6 ky BP (all ages here are uncorrected 14C), and the SDT remained ungrounded until the
latest ice sheet advanced at ~20.8 ky BP. The latest ice sheet retreated from the SDT at ~8.7 ky BP. This
chronology is remarkably consistent with previous RP 14C ages on glacial and deglacial successions from
condensed sections on the open Ross Sea. Combined with a result from the eastern Ross Sea implying an
earlier retreat of ice sheet prior to the LGM, it is possible that large areas of the Ross Embayment remained
ungrounded during the global LGM period.

606
TE-3d - Remote sensing of polar regions
20.06.2018 09:00-10:30, A Seehorn

13
Regional Geology Mapping Using Satellite-Based Remote Sensing Data in Antarctica

Amin Beiranvand Pour1 (amin.beiranvand@kopri.re.kr), Yongcheol Park1, Jong Kuk Hong1, Jusun Woo2, Tae-
Yoon Park1
1
Korea Polar Research Institute (KOPRI), INCHEON, Korea, Republic of, 2Korea Polar Research Institute (KOPRI),
Incheon, Korea, Republic of

Satellite remote sensing imagery is especially useful for geological investigations in Antarctica because of its
remoteness and extreme environmental conditions that constrain direct geological survey. The highest
percentage of exposed rocks and soils in Antarctica occurs in Northern Victoria Land (NVL). Exposed Rocks in
NVL were part of the paleo-Pacific margin of East Gondwana during the Paleozoic time. This investigation
provides a satellite-based remote sensing approach for regional geological mapping in the NVL, Antarctica,
focusing on the Bowers terrane with high potential for hosting orogenic gold mineralization. The Landsat-8 and
the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) datasets were used to extract
lithological-structural and mineralogical information. Several new spectral-band ratio indices were developed
using Landsat-8 and ASTER bands and proposed for Antarctic environments to map spectral signatures of
snow/ice, iron oxide/hydroxide minerals, Al-OH-bearing and Fe, Mg-O-H and CO3 mineral zones, and quartz-
rich felsic and mafic-to-ultramafic lithological units. The new spectral-band ratio indices were tested and
implemented to Level 1 terrain-corrected (L1T) products of Landsat-8 and ASTER datasets covering the NVL.
The new spectral-band ratio indices are especially useful for geological investigations in inaccessible locations
and poorly exposed lithological units in Antarctica environments.

607
1153
Application of Navigation System for the Vessels Sailing in the Sea Ice Area

Jian Liu1 (liujian@pric.org.cn)

1
Polar Research Institute of China, Shanghai, China

Sea ice is an important factor affecting vessels navigation in the polar ocean. The University of Bremen, NSIDC
and other agencies released the sea ice concentration and thickness of products etc.. In addition, such as visible
light, SAR remote sensing data can provide data support for vessel navigation. So, how to apply these data in
the best way to provide navigation guidance for vessels in the sea ice area? We use the combination of GIS,
remote sensing and big data technology to realize the application of sea ice data in the vessel terminal. At the
same time, the path planning of vessel sailing is realized by using visible light, SAR and other data. China Snow
Dragon vessel equipped with a satellite receiver system, it can receive real-time data, such as MODIS and HY-
2A remote sensing data. These data can be used to provide remote sensing monitoring products and wind
products for the vessel, so as to ensure the navigation safety of vessel in the sea ice area.

608
1271
Late Winter Snow Thickness Estimation from Early Summer Melt Pond Fraction

Saroat Ramjan1 (saroat.ramjan@ucalgary.ca), Torsten Geldsetzer1, Randall Scharien2, John Yackel1

1
University of Calgary, Geography, Calgary, Canada, 2University of Victoria, Geography, Victoria, Canada

It is of great interest to understand the snow thickness variability in the Arctic to understand the geophysical
properties at the ocean-seaice-atmosphere interface. The radiative and thermal properties of snow
significantly affect the sea ice growth and decay. Moreover, presence of snow cover on sea ice plays a crucial
role in satellite-based sea ice thickness retrievals. Prior research reported that, during summer melt, thin snow
cover leads to dominant surface flooding (larger pond fraction), whereas thick snow cover leads to a greater
fraction of snow patches (smaller pond fraction). Thus, summer measurements of melt pond fraction can be
utilized as a proxy to estimate relative winter snow thickness. In order to quantify regional-scale melt pond
fraction, aerial photography surveys were conducted in 2012, near Cornwallis Island, Nunavut. Polarimetric
parameters and polarimetric texture parameters of winter RADARSAT-2 SAR fine quad-pol images were
analyzed at different incidence angles, to estimate the relationship between the winter backscatter from snow
cover on first year sea ice and early summer melt pond fraction, to predict late winter snow thickness. Our
results indicate that the regression models derived from the most significant polarimetric and texture
parameters provide better prediction to estimate the winter snow thickness variability and snow topography.

609
1741
Comprehensive Monitoring of Polar Land Ice by Sentinel-1

Jan Wuite1 (jan.wuite@enveo.at), Thomas Nagler1, Markus Hetzenecker1, Stefan Scheiblauer1, Helmut Rott1
1
ENVEO IT GmbH, Innsbruck, Austria

The Sentinel-1 acquisition planning for polar regions provides nearly uninterrupted observations of the
Greenland Ice Sheet margin, key regions in Antarctica and other polar ice masses. The dual satellite
constellation has thereby changed the landscape for satellite earth observation entirely, providing excellent
opportunities for operational monitoring of key climate variables like ice velocity (IV) and glacier discharge.
Continuous coverage is now extended to include most of the Antarctic margin, allowing retrieval of dense time
series of ice flow for major outlet glaciers hitherto only sparsely observed.
We developed a system for IV retrieval and discharge monitoring, applying advanced iterative offset tracking,
utilizing repeat pass Sentinel-1 SAR. Generated IV maps compare well with those derived from other high-
resolution sensors and provide detailed coverage even in regions with high accumulation and fast flow.
Combined with ice thickness from RES, the maps form the basis for studying glacier dynamics, ice discharge and
mass balance.
Including the latest observational data, we present IV maps of Greenland, Antarctica and smaller ice caps
highlighting time series of IV fluctuations of major outlet glaciers. We demonstrate how IV and discharge varies
over time scales ranging from days to years and between adjacent basins. Continuous monitoring of the polar
regions, exploiting both satellites, is ongoing to detect changes of ice flow as indicators of climate change.

610
1774
PIPERS: Preliminary Analysis of Satellite Radar Imagery from Terra Nova Bay

Thomas Hollands1 (thomas.hollands@awi.de), Wolfgang Dierking1, Kathrin Höppner2, Paul Wachter2

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Climate Sciences, Bremerhaven,
Germany, 2German Aerospace Center (DLR), Earth Observation Center, Wessling, Germany

Satellite images provide the opportunity to differentiate different ice units in and around the Terra Nova Bay
Polynya (TNBP) in the Ross Sea (Antarctica) on different spatial scales. However, at a first stage, the separation
of units is usually be carried out in terms of radar signature variations, i. e. the result are “radar units” with
statistically significant signature differences. In a second step, the radar units have to be linked to observations
in the field in order to enable a geophysical interpretation of the stage of polynya development and the sea ice
conditions around the polynya. In this specific analysis we focus on the first step. The radar imagery acquired
over the TNBP comprises data from TerraSAR-X strip-map dual-polarization (HH, VV) mode, TerraSAR-X
ScanSAR mode (HH-polarization), Sentinel-1 extra wide-swath mode (HH and HV polarization), and Sentinel-1
interferometric wide-swath mode (HH-polarization). Dependent on the temporal gap between image
acquisitions it is possible in some cases to produce layer stacks including different imaging modes. We use
different segmentation methods (such as e. g. Support Vector Machine) to arrive at a map of different radar
units with only small overlaps of their radar signatures (i. e. significant discernibility). The goal is to generate a
temporal sequence of radar unit maps, which in the second step in collaboration with the PIPERS team can be
related to ground data gathered in the field.

611
1926
High-resolution Mapping of Streams and Moulins on the Greenland Ice Sheet

Vena Chu1 (venachu@ucsb.edu), Kang Yang2

1
University of California Santa Barbara, Geography, Santa Barbara, United States, 2Nanjing University, Nanjing,
China

Increasing surface melting on the Greenland ice sheet and rising sea level have heightened the need for
understanding the complex pathways transporting meltwater from the ice sheet surface to the ice edge and
the ocean. Supraglacial streams abundantly cover the western ablation zone throughout the melt season,
transporting large volumes of meltwater into moulins and to englacial and subglacial networks before entering
the ocean. However, current regional and global model projections of meltwater runoff from the GrIS do not
incorporate this hydrological process. This knowledge gap is due to the lack of observations of meltwater
transport off the surface of the ice sheet and into the ocean. Furthermore, current ice sheet watershed models
lack the ability to determine actual flow paths on the ice because terrain-modeled networks cannot account for
the presence of moulins without observations from satellite imagery. In this study, we map supraglacial stream
networks and moulin termination points using high-resolution WorldView-1/2/3 satellite imagery from 2012
and 2015. These image-extracted features are also combined with a high-resolution digital elevation model
(ArcticDEM) to model ice sheet watersheds.

612
OS-2a - Interdisciplinary research on sea-ice biogeochemistry and associated ecosystems
20.06.2018 09:00-10:30, A Wisshorn

497
Carbon Flux in Ice Algae-fuelled Food Webs of the Arctic and the Antarctic Ocean

Hauke Flores1,2 (hauke.flores@awi.de), Carmen David1,2, Doreen Kohlbach1,2, Fokje Schaafsma3, Benjamin
Lange1,2,4, Julia Ehrlich1,3, Kristin Hardge5, Martin Graeve6, Ilka Peeken7, Benoit Lebreton8, Barbara Niehoff7,
Thomas Krumpen9, Benjamin Rabe10, Jan Andries van Franeker3, Katja Metfies5, Angelika Brandt2,11
1
AWI, Young Investigators Group Iceflux, Bremerhaven, Germany, 2University of Hamburg, CeNak, Hamburg,
Germany, 3Wageningen Marine Research, Den Helder, Netherlands, 4Department of Fisheries and Oceans
Canada, Winnipeg, Canada, 5AWI, Young Investigators Group PLANKTOSENS, Bremerhaven, Germany, 6AWI,
Ecological Chemistry, Bremerhaven, Germany, 7AWI, Polar Biological Oceanography, Bremerhaven, Germany,
8
Institut du Littoral et de l'Environnement, La Rochelle, France, 9AWI, Sea Ice Physics, Bremerhaven, Germany,
10
AWI, Physical Oceanography, Bremerhaven, Germany, 11Senckenberg Gesellschaft für Naturforschung,
Frankfurt a.M., Germany

Climate-driven changes of sea ice habitats are impacting large parts of the Southern Ocean and virtually the
entire Arctic Ocean. At the same time, we have only just begun understanding the importance of sea ice for the
functioning of Polar ecosystems. Within the Iceflux project, we analysed the structure of ice-associated and
planktonic communities in Arctic and Antarctic ecosystems in relation to habitat properties. Using isotopic and
biochemical trophic marker analysis, the dependency of sea-ice fauna and zooplankton on ice algae-produced
carbon was estimated. Our results show that sea ice properties were a key driver of community structure in
both Polar Oceans. Certain abundant metazoan species were highly dependent on ice algae-produced carbon.
Based on the consumption rates of these species, differences in the proportional trophic carbon flux from see
ice into the pelagic food web were investigated between the Arctic Ocean and the Southern Ocean. Effects of
declining sea-ice habitats on the food web structure in both Polar Oceans will vary seasonally and regionally,
with winners who can adapt to new carbon sources and losers facing increasing difficulties to obtain resources
and complete their life cycles. Due to the close linkage of central carbon transmitters with sea ice (polar cod in
the Arctic and Antarctic krill in the Southern Ocean), sea ice decline may lead to disruptions of ecosystems until
a new equilibrium is found.

613
1722
The Role of Mixotrophic Algae in Sea Ice Ecosystems

Tobias Vonnahme1 (tobias.vonnahme@uit.no), Ulrike Dietrich2, Brandon Hassett2, Rolf Gradinger2

1
UiT The Arctic University of Norway, Arctic Marine System Ecology, Tromsø, Norway, 2UiT The Arctic University
of Norway in Tromsø, Tromsø, Norway

The finding of heterotrophic carbon uptake in diatoms has challenged the representation of algae as pure
autotrophs in current ecosystem models. Mixotrophy as adaptation to nutrient or light limitations, both typical
conditions in sea ice ecosystems, have been described. Thus, it is not surprising to find living algae in the polar
night, but the survival strategies remain speculative. For describing the importance of mixotrophy in sea ice
algae, a variety of methods are applied. Multiple omics approaches are used for a molecular understanding of
the metabolic processes involved. Metagenomics and Metatranscriptomics data are integrated and the
potential for organic matter degradation in diatoms explored. Stable isotope probing experiments are used to
estimate fluxes of dissolved organic matter uptake in algae under varying light conditions. The potential for
phagotrophy is explored via fluorescent in situ hybridisations and feeding experiments with fluorescently
labelled sea ice bacteria. All data will be integrated into a dynamic phytoplankton growth and photoacclimation
model and the implications for bacteria-algae interactions and higher trophic levels discussed.

614
1309
Windows in Arctic Pack Ice: The Role of Leads for Algal Blooms

Hanna M. Kauko1 (hanna.kauko@npolar.no), Mats. A Granskog1, Alexey K. Pavlov1, Lasse M. Olsen1, Mar
Fernández-Méndez1, Pedro Duarte1, Torbjørn Taskjelle2, C. J. Mundy3, Stephen R. Hudson1, Penelope M.
Wagner4, Amelie Meyer1, Ilka Peeken5, Geir Johnsen6, Ashley Elliott3, Feiyue Wang3, Philipp Assmy1
1
Norwegian Polar Institute, Tromso, Norway, 2University of Bergen, Bergen, Norway, 3University of Manitoba,
Winnipeg, Canada, 4Norwegian Meteorological Institute, Tromsø, Norway, 5Alfred Wegener Institute Helmholtz
Center for Polar and Marine Research, Bremerhaven, Germany, 6Norwegian University of Science and
Technology, Trondheim, Norway

Changes in the Arctic icescape include higher light availability for primary producers due to declining and
thinning ice pack. In addition, the increasing dynamics of the thinner ice pack may result in higher ice
deformation rates and more open water areas (leads) covered by new thin ice with higher light transmittance.
Both the detailed light climate and the algal response to it require further studies. During the Norwegian young
sea ICE expedition (N-ICE2015) in spring 2015 we studied the implications of thinner ice in leads, which enabled
development of a phytoplankton bloom beneath the otherwise opaque ice cover - transmittance through the
snow-covered thick ice was < 0.3 %, whereas up to 40 % of incoming light penetrated through the studied
refrozen lead. Yet, ice algal biomass in the lead ice did not exceed that of the surrounding thicker and older ice
over the lifetime (1 month) of the lead, suggesting that ice algal growth was not only a function of increased
light availability. We discuss potential controlling factors, including high-light acclimation indicated by high
concentrations of ultraviolet-protecting mycosporine-like amino acids (MAAs), and time needed for
recruitment. The ice algal community shifted from dominance of flagellates towards dominance of pennate,
ice-adapted diatom species. In summary, our results suggest that high-light environments like young ice benefit
under-ice phytoplankton blooms but might not boost ice algal production per unit area.

615
2060
Phaeocystis versus Diatoms Blooms in the Ice Covered European Arctic

Ilka Peeken1 (ilka.peeken@awi.de), Mathieu Ardyna,2, Philipp Assmy,3, Flavienne Bruyant,4, Hauke Flores1,
Pierre-Luc Grondin4, Yannick Huot5, Markus Janout1, Christian Katlein1, Hanna M Kauko3, Zoe Koenig6, Piotr
Kowalczuk7, , Benjamin Lange8, Philippe Massicotte4, Katja Metfies1, Amelie Meyer3, Christine Michel8, Anna
Nikolopoulos9, Eva Maria Nöthig1, Lasse Mork Olson3, Jean-Éric Tremblay4, Marcel Babin4
1
Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI), Bremerhaven, Germany,
2
Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire d'Océanographie de Villefranche (LOV),
Villefranche, France, 3Norwegian Polar Institute, Tromsø, Norway, 4Takuvik (CNRS & U Laval) and Québec-
Océan, Université Laval, Québec, Canada, 5Université de Sherbrooke, Faculté des lettres et Sciences Humaines,
Québec, Canada, 6Laboratoire LOCEAN-IPSL, Sorbonne Universites (UPMC, Univ. Paris 6)-CNRS-IRD-MNHN,
Paris, France, 7IOPAS - Institute of Oceanology Polish Academy of Sciences, Sopot, Poland, 8Department of
Fisheries and Oceans Canada, Manitoba, Canada, 9AquaBiota Water Research, Stockholm, Sweden

The Arctic Ocean is one of the key regions where the effects of climate change are most pronounced. Massive
reductions in sea ice thickness and extent are anticipated to cause large changes in the Arctic ecosystem. Two
comprehensive expeditions in 2015, the Norwegian young sea ICE expedition (N-ICE2015) from January-June
and the Transitions in the Arctic Seasonal Sea Ice Zone (TRANSSIZ) cruise from May-June carried out ecological
and biogeochemical process studies during ice floe drift experiments and shelf-to-basin sampling across the
European Arctic margin and on the Yermak Plateau. As previously reported, a Phaeocystis under-ice bloom was
observed over the south-eastern Yermak Plateau, while the north-western Yermark Plateau was characterized
by deep mixed layers associated with low standing phytoplankton stocks and weak productivity. In contrast, a
large diatom bloom dominated by various Thalassiosira and Chaetoceros species, was observed over the
continental slope further east. The diatom bloom was found above the core of the Atlantic water boundary
current, concurrent with enhanced dissipation and large diapycnal heat fluxes into the mixed layer. Highlights
from these contrasting bloom scenarios will help to improve our understanding of ecosystem functioning and
predictions of the potential annual primary production in a rapidly changing Arctic Ocean.

616
1164
Impact of Ice Algae and under-ice Phytoplankton on the Marine Carbonate System

Brent Else1 (belse@ucalgary.ca), Jeremy Whitehead1, Virginie Galindo2, C.J. Mundy2, Soren Rysgaard2, Joannie
Ferland3, Marcel Babin3
1
University of Calgary, Geography, Calgary, Canada, 2University of Manitoba, CEOS, Winnipeg, Canada, 3Laval
University and CNRS, Takuvik, Quebec, Canada

Past research has suggested that ice algae play a role in reducing surface water dissolved inorganic carbon (DIC)
during spring, pre-conditioning surface waters to low dissolved CO2 (pCO2sw) and uptake of atmospheric CO2
during the ice free season. The potential role of under-ice phytoplankton blooms in this seasonal cycle has
generally not been considered. The objective of this study was to look at trends in the inorganic carbon system
in the upper water column under sea ice from early spring to ice melt onset near Qikiqtarjuaq, NU. Sample
collection started midway through an ice algae bloom, and continued until the early stages of an under-ice
phytoplankton bloom. During most of the ice algae bloom period we observed a slight increase in DIC and
pCO2sw in the top 5m of the water column, as opposed to the expected reduction in those parameters.
Although it is possible that substantial pCO2sw/DIC drawdown was missed at the initiation of the ice algae
bloom, biomass calculations show that previous studies may have overestimated the role of ice algae, and that
this null result may be widely applicable. Following the formation of melt ponds, we observed a rapid
phytoplankton bloom in the upper 25 m of the water column that did dramatically reduce DIC and pCO2sw. We
conclude that under-ice phytoplankton blooms may be the most important biological mechanism predisposing
the Arctic surface mixed layer to act as a CO2 sink in the open water season.

617
2066
The Dependence of Sea Ice Algal Production on Conditions of Sample Melt

Karley Campbell1 (umcampb2@myumanitoba.ca), C.J. Mundy1, Andrew Juhl2, Laura Dalman1, Christine
Michel1,3, R Galley1, B E Else4, Nicolas-Xavier Gelfius1, Soren Rysgaard1,5,6
1
University of Manitoba, Centre for Earth Observation Science, Winnipeg, Canada, 2Colombia University,
Lamont Doherty Earth Observatory, New York, United States, 3Fisheries and Oceans Canada, Freshwater
Institute, Winnipeg, Canada, 4University of Calgary, Department of Geography, Calgary, Canada, 5University of
Aarhus, Biosciences, Aarhus, Denmark, 6Greenland Institute of Natural Resources, Nuuk, Greenland

The influence of algae on sea ice biogeochemical conditions is a significant aspect of sea ice flux and ecosystem
modeling. Accurate estimates of sea ice algal productivity and responses to environmental change are
particularly important in light of shifting Arctic sea ice conditions. The foundation of production estimates in
such studies historically, and at present, often relies on the melt of ice samples prior to incubation. The specific
procedure varies between studies, particularly the duration of melt and whether samples are buffered for
changes in salinity. In this study we combine field and laboratory measurements to comprehensively
investigate the impact of melt procedure on the gross production and photophysiology of sea ice algae, and
demonstrate the potential for scientific protocols to contribute to variability of estimates reported across the
Arctic. We found that estimates of productivity are likely artificially enhanced or reduced in individual studies
depending on melt conditions, including: duration of melt, volume of filtered seawater added, and
temperature. Recommendations for best practices in melting ice samples for biogeochemical studies is
provided.

618
CR-3b - Cryosphere-Hydrosphere interactions: The water cycle at the three Poles
20.06.2018 09:00-10:30, B Parsenn

223
Variability and Trends in Arctic Snow Cover

Chris Derksen1 (chris.derksen@canada.ca), Lawrence Mudryk1, Ross Brown2

1
Environment and Climate Change Canada, Toronto, Canada, 2Environment and Climate Change Canada,
Montreal, Canada

Determining robust trends in Arctic snow cover with quantitative uncertainty estimates is required to better
constrain impacts on the climate system, the freshwater budget of the Arctic, and impacts of changing snow
cover on vegetation, biogeochemical activity, exchanges of carbon dioxide and trace gases, and ecosystem
services. In this study, we determine the spread in Arctic seasonal snow cover extent (SCE) and snow water
equivalent (SWE) trends from multiple sources. The NOAA snow chart Climate Data Record (NOAA-CDR), dating
back to 1967, shows dramatic reductions in Arctic spring SCE, particularly since 2005, and a positive trend in fall
SCE. Trends derived from five other sources of snow information, including surface observations, passive
microwave satellite data and land surface models (with snow schemes of varying complexity) driven by modern
era reanalyses (from various reanalysis centres) identify weaker reductions in spring SCE compared to NOAA-
CDR, along with a loss of fall snow cover. SCE trend sensitivity to surface temperature forcing is anomalous for
the NOAA-CDR compared to other data sets for the months of October, November, May, and June, and so
should be interpreted with caution in these months. Trends in maximum pre-melt SWE over the 1981 - 2016
period are negative when the Arctic is considered as a whole, but considerable regional and inter-dataset
variability in the spatial patterns of change limit the confidence in these trends.

619
952
Arctic Snowfall from CloudSat Observations and Reanalyses

Léo Edel1 (leo.edel@lmd.polytechnique.fr), Chantal Claud1, Christophe Genthon2

1
Laboratoire de Météorologie Dynamique, Ecole Polytechnique, Palaiseau, France, 2Institut des Géosciences de
l'Environnement, Grenoble, France

While snowfall likely has a major contribution to the Arctic amplification, available state-of-the-art
climatologies still significantly disagree. We will present a satellite-based characterization of snowfall in the
Arctic using CloudSat data, and compare with and between various other climatologies. First, we examine the
frequency, phase and rate of snowfall from CloudSat over 2007-2010. Then we compare with ECMWF
(European Center for Medium Range Weather Forecast) Interim reanalysis (ERA-I), Arctic System Reanalysis
(ASR) and Global Precipitation Climatology Center Monitoring Product (GPCC MP). Similar general patterns are
observed in all datasets. Yet, significant mean snowfall rates differences are found over continents between
58° and 82°N between ERA-I (155 mm/an), ASR (197), GPCC MP (156) and CloudSat (210). These differences are
larger between CloudSat (317 mm/an) and GPCC MP (181 mm/an), and larger overall over Greenland. In spite
of its limitations, CloudSat clearly contributes to a better characterization of snowfall in the Arctic.

620
959
From the Clouds to the Ground - Snow Precipitation Patterns in Complex Terrain

Franziska Gerber1,2 (gerberf@slf.ch), Nikola Besic1,3, Varun Sharma1, Megan Daniels4, Rebecca Mott2,5, Marco
Gabella3, Urs Germann3, Alexis Berne1, Michael Lehning1,2
1
School of Architecture and Civil Engineering, École Polytechnique Fédérale de Lausanne (ENAC-EPFL), Lausanne,
Switzerland, 2WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland, 3MeteoSwiss,
Locarno-Monti, Switzerland, 4n.a., Sydney, Australia, 5Institute of Meteorology and Climate Research,
Atmospheric Environmental Research (KIT/IMK-IFU), KIT-Campus Alpin, Garmisch-Partenkirchen, Germany

Snow accumulation patterns are determined by many different processes from ice crystal nucleation in clouds
to snow redistribution by wind and avalanches. In between, snow precipitation undergoes different dynamical
and microphysical processes, such as ice crystal growth, aggregation and riming, which determine the growth
of particles and thereby influence the intensity and structure of the snowfall event. In alpine terrain the
interaction of different processes and the topography may lead to orographic enhancement and preferential
deposition of precipitation.
To better understand the relative importance of different pre-depositional processes on snow precipitation we
analyze three snowfall events between January and March 2016 in Davos (CH). Snow precipitation patterns
from MeteoSwiss operational weather radar measurements on Weissfluhgipfel and very high resolution
Weather Research and Forecasting (WRF) model simulations show reasonable agreement with measurements
from automatic weather stations. Overall, radar precipitation patterns show higher small scale variability
compared to WRF simulations. Two-dimensional autocorrelation maps and variograms of precipitation patterns
reveal a strong dependence of radar and WRF precipitation on topography and the prevailing wind direction,
which emphasizes the importance of large-scale orographic enhancement on regional scales and small-scale
topography-wind interactions on a mountain ridge scale.

621
1865
The Required Model Resolution for Resolving the SMB of the Greenland Ice Sheet

Willem Jan van de Berg1 (w.j.vandeberg@uu.nl), Erik van Meijgaard2, Bert van Ulft2
1
Utrecht University, Faculty of Science, Department of Physics, Institute for Marine and Atmospheric Research
(IMAU), Utrecht, Netherlands, 2KNMI, De Bilt, Netherlands

For reliable estimates of past, current and projected mass changes of the Greenland Ice Sheet and its
peripheral glaciers and ice caps, the surface mass balance (SMB) must be determined with sufficient spatial
detail, which could be carried out with a global or regional climate model or statistical downscaling. This raises
a number of questions: Which resolution is sufficient? Which method is appropriate for the SMB refinement at
this resolution? Can we assess which method is most accurate?
In order to answer these questions, the regional climate model RACMO2.3 is run at 4 different resolutions
ranging from 2.2 to 60 km for South Greenland. The results of these runs are statistically downscaled. Analysis
of the downscaled products from various model resolutions shows that statistical downscaling improves the
estimates of runoff and hence of SMB compared to interpolation, but has no beneficial effect on the other SMB
components. From the comparison with observations it can be concluded that 20 km resolution is sufficient to
represent the ice sheet accumulation zone. In the ablation zone, RCMs outperform statistical downscaling
although the performance gain per grid refinement factor decreases for finer resolutions. Furthermore, we
show that for RCMs run at resolutions finer than 20 km, snow pack initialization, snow model tuning and cloud
physics are of equal importance for the quality of model results as resolution.

622
2506
Model-observed Runoff along the West Greenland Ice Sheet

Samiah Moustafa1 (samiah_moustafa@brown.edu), Asa Rennermalm2, Dirk van As3, Irina Overeem4, Marco
Tedesco5, Thomas Mote6, Lora Koenig7, Laurence Smith8, Birgit Hagedorn9, Ronald Sletten10, Andreas
Mikkelsen11, Bent Hasholt11, Xavier Fettweis12, Lincoln Pitcher8, Alun Hubbard13
1
Brown University, Providence, United States, 2Rutgers University, New Brunswick, United States, 3Geological
Survey of Denmark and Greenland, København, Denmark, 4University of Colorado Boulder, Boulder, United
States, 5Columbia University, Palisades, United States, 6University of Georgia, Athens, United States, 7National
Snow and Ice Data Center, Boulder, United States, 8University of California Los Angeles, Los Angeles, United
States, 9University of Alaska - Fairbanks, Fairbanks, United States, 10University of Washington, Seattle, United
States, 11University of Copenhagen, Copenhagen, Denmark, 12University of Liège, Liege, Belgium, 13Aberystwyth
University, Aberystwyth, United Kingdom

Despite the increasing importance of ice sheet surface ablation in Greenland's sea-level contribution, a
quantitative inter-comparison between modeled and measured meltwater discharge across multiple drainage
basins is conspicuously lacking. Here we investigate the accuracy of model discharge estimates from the
Modèle Atmosphérique Régionale (MAR) regional climate model by comparison with in situ proglacial river
discharge measurements at three West Greenland drainage basins - North River (Thule), Watson River
(Kangerlussuaq), and Naujat Kuat River (Nuuk). At each basin, we:
1) determine optimal drainage basin delineations;
2) evaluate MAR at daily, 5-, 10- and 20-day time scales; and
3) identify potential sources for model-observation discrepancies by analyzing model bias relative to data from
automatic weather stations.
Our results reveal that daily discharge is best captured by MAR across the Watson basin, whilst there is lower
correspondence between modeled and observed discharge at the Thule and Nuuk basins. Model agreement
with observed is reduced during periods of peak discharge, but is improved at the Thule and Nuuk basins over
longer time scales. Our study highlights the importance of reducing MAR overestimation of surface albedo and
warm bias in near surface air temperature, underestimation of cloud cover representation, and adding more
realistic runoff delay functions to reduce model error and to improve prediction of Greenland's contribution to
sea level rise.

623
2510
From Slope-scale Snow Processes to Hydrologic Response: A Validation of Alpine3D

Tristan Brauchli1 (tristan.brauchli@epfl.ch), Ernesto Trujillo1, Hendrik Huwald1, Michael Lehning1,2

1
Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering,
Lausanne, Switzerland, 2WSL Institute for Snow and Avalanche Research, SLF, Davos, Switzerland

Snow modeling in mountainous areas remains a challenge because of the numerous processes affecting the
mass and energy balance. In this study, we examine the influence of snowmelt on the hydrological response of
the Dischma river basin, a high-alpine catchment of 43.2 km2 in Switzerland. Based on recent developments in
Alpine3D, we study the influence of snow distribution and liquid water transport within the snowpack on runoff
dynamics. We show the added value of a more realistic snow distribution by comparing our results with multi-
scale observations (snow lysimeter, distributed snow depths and streamflow). At the plot scale, snowpack
runoff is well simulated when the initial (peak of snow season) mass balance errors are small, which is achieved
with a precipitation scaling approach. At the sub-basin scale, a more realistic snowpack leads to a faster runoff
pulse originated in the shallower areas while the melting period is extended by a month with snowmelt coming
from deeper areas. The hydrological response at the basin scale is also enhanced by the more realistic
snowpack, even though calibration processes smoothen the differences. The added value of a more complex
liquid water transport scheme is obvious at the site scale but decreases at larger scales. Our results highlight
not only the importance but also the difficulty of getting a realistic snowpack distribution even in a well-
instrumented area and present a model validation from multi-scale observations.

624
BE-6a - Ongoing change in terrestrial and freshwater ecosystems of Polar Regions
20.06.2018 09:00-10:30, B Jakobshorn

1326
Arctic Freshwater Plankton Response to Environmental Stressors

Heather Mariash1 (h.l.mariash@uu.nl), Ann Kristin Schartau2, Kirsten Christoffersen3

1
Utrecht University, Utrecht, Netherlands, 2Norwegian Institute for Nature Research, Oslo, Norway, 3University
of Copenhagen, Copenhagen, Denmark

Arctic freshwaters are facing a number of environmental pressures, including rapid climate change that affects
both the formation and loss surface waters, along with changing biogeochemistry of these waters. Freshwater
plankton assemblages are expected to reflect the impacts of these stressors through shifts in productivity and
species composition. This paper examines spatial and contemporary trends in phytoplankton and zooplankton
biodiversity throughout the circumpolar Arctic. We have analyzed contemporary (1950-present) data of abiotic
variables and plankton diversity collected from more than 400 Arctic and subarctic lakes in USA, Canada,
Greenland, Iceland, Faroe Islands, Norway, Sweden, Finland and Russia using various univariate and
multivariate analysis techniques. Based on our findings we will establish contemporary baselines for future
comparisons of plankton communities in the Arctic region. We will evaluate patterns in biodiversity and
environmental stressors to allow discussion of current and future responses to environmental pressures on
Arctic plankton communities. We will also discuss the implications our findings have for the future monitoring.

625
352
Exploring Patterns of Diatom Assemblages from Circumpolar Arctic Lakes & Streams

Maria Kahlert1 (maria.kahlert@slu.se), Isabelle Lavoie2, Kathleen M. Rühland3, Francois Keck1, Jennifer Lento4,
Daniel Bogan5, Robert Brua6, Stephane Campeau7, Joseph Culp8, Kirsten Christoffersen9, Árni Einarsson10, Satu-
Maaria Karjalainen11, Emilie Saulnier-Talbot12, Susanne Schneider13, Rebecca Shaftel5, John P. Smol3
1
Swedish University of Agricultural Sciences, Aquatic Sciences and Assessment, Uppsala, Sweden, 2Institut
National de la Recherche Scientifique, Quebec, Canada, 3Paleoecological Environmental Assessment and
Research Laboratory (PEARL), Queen's University, Biology, Kingston, Canada, 4University of New Brunswick,
Canadian Rivers Institute, New Brunswick, Canada, 5Alaska Center for Conservation Science, University of Alaska
Anchorage, Anchorage, United States, 6Environment and Climate Change Canada, Canada, Canada, 7Université
du Québec à Trois-Rivières, Environmental Sciences, Trois-Rivières, Canada, 8Environment and Climate Change
Canada, Ottawa, Canada, 9University of Copenhagen, Copenhagen, Denmark, 10University of Iceland, Reykjavík,
Iceland, 11Finnish Environment Institute (SYKE), Oulo, Finland, 12Laboratoire de Paléoécologie Aquatique, Centre
d'Études Nordiques (CEN), Université Laval, Quebec, Canada, 13Norwegian Institute for Water Research, Oslo,
Norway

The assessment of spatial and temporal trends in Arctic freshwater biota and their physical and biogeochemical
habitat in response to a warming climate requires a large-scale harmonized monitoring program. The
presented work, performed by the freshwater group of the Circumpolar Biodiversity Monitoring Plan (Arctic
Council: Conservation of Arctic Flora and Fauna), is one of the first steps towards such a harmonized
monitoring program. Using circum-Arctic diatom assemblage data, specific goals of this study include:
1) establishing current and pre-industrial environmental conditions as reference points to guide future
environmental monitoring programs, and
2) understanding the historical context of diatom distributions.
Large-scale assessments of diatom distributions in Arctic regions are currently scarce, and detailed taxonomic
studies tracking species compositional changes in both lakes and streams have yet to be undertaken. We used
contemporary stream and lake data from ongoing monitoring programs, spot data from research projects, as
well as surface sediment (modern) diatoms from paleolimnological studies to provide a spatial assessment of
species distributions of the circum-Arctic region. Additionally, we analysed a large set of dated and “top-
bottom” paleolimnological records to better describe historical background conditions on a circum-Arctic scale.

626
1854
Landscape Filters as Drivers of Arctic Benthic Macroinvertebrate Biodiversity

Joseph Culp1,2 (joseph.culp@canada.ca), Jen Lento3, Willem Goedkoop4, Jukka Aroviita5, Maria Baturina6, Daniel
Bogan7, John Brittain8, Krista Chin9, Catherine Docherty10, Arni Einarsson11, Nikolai Friberg12, Jani Heino13, Þóra
Katrín Hrafnsdottir14, Dean Jacobsen15, Danny C.P. Lau16, Olga Loskutova6, Alexander Milner17, Heikki Mykrä18,
Anna Novichkova19, Jón Ólafsson20, Anna Kristin Schartau21, Rebecca Shaftel7
1
Environment & Climate Change Canada, Waterloo, Canada, 2Wilfrid Laurier University, Waterloo, Canada,
3
University of New Brunswick, Fredericton, Canada, 4Swedish University of Agricultural Sciences, Uppsala,
Sweden, 5Finnish Environment Institute, Helsinki, Finland, 6Institute of Biology, Komi Scientific Centre of the Ural
Branch of the RAS, Syktyvkar, Komi Republic, Russian Federation, 7Alaska Center for Conservation Science,
University of Alaska Anchorage, Anchorage, Alaska, United States, 8Norwegian Water Resources and Energy
Directorate, Norway, Oslo, Norway, 9Government of Northwest Territories, Canada, Yellowknife, Canada,
10
University of Birmingham, UK, Birmingham, United Kingdom, 11University of Iceland, Reykjavík, Iceland,
12
Aarhus University, Copenhagen, Denmark, 13Ministry of the Environment, Finland, Helsinki, Finland, 14Natural
History Museum of Kópavogur, Reykjavík, Iceland, 15University of Copenhagen, Copenhagen, Denmark, 16Umeå
University, Umeå, Sweden, 17University of Birunimingham, Birmingham, United Kingdom, 18University of Oulu,
Oulu, Finland, 19Lomonosov Moscow State University, Moscow, Russian Federation, 20Marine and Freshwater
Research Institute, Reykjavik, Iceland, 21The Norwegian Institute for Nature Research, Trondheim, Norway

The concept of landscape filters allows us to test hypotheses about environmental driver-biological response
relationships by examining the relative importance of drivers at different spatial scales. Across the Arctic,
differences in warming rates, human development, and biogeography may be expected to contribute to
differences in the relative importance of variables at different spatial scales. For example, in regions where
large-scale variables, such as climate, have already had an effect on community structure: Are regional patterns
of benthic assemblages more strongly associated with small-scale structuring variables such as water chemistry
and substrate? This paper explores driver-response relationships across different spatial scales (i.e., both
latitudinal and longitudinal) to determine whether similar patterns are evident among the sub-, low-, and high-
Arctic across the circumpolar region. Specifically, the response of benthic macroinvertebrate assemblages to
landscape filters across latitudinal gradients is used as a proxy for predicting shifts in biological pattern as a
result of climate change. Moreover, longitudinal contrasts with respect to the importance of climate-related
variables on biological pattern has implications for the importance of warming history across the circumpolar
region, particularly when projecting risk for those areas that have experienced less warming.

627
1435
Trends in Biodiversity and Environmental Etressors in Fennoscandian Arctic Lakes

Willem Goedkoop1 (willem.goedkoop@slu.se), Danny Lau2, Jennifer Lento3

1
Swedish University of Agricultural Sciences (SLU), Aquatic Sciences and Assessment, Uppsala, Sweden, 2Umeå
University, Umeå, Sweden, 3University of New Brunswick, Fredericton, Canada

Arctic lakes in Fennoscandia are experiencing rapid environmental changes resulting from human activities,
large-scale oligotrophication, and climate change. These stressors are expected to alter both abiotic variables
and biodiversity, i.e. communities of benthic invertebrates, algae, zooplankton, water plants, and fish. We
compiled a data set for 74 selected Arctic/alpine lakes in Norway, Sweden and Finland and analyzed their
spatiotemporal trends using both univariate and multivariate analyses. Multiple indicators will be used to
assess biodiversity trends that are hypothesized to associate with spatial and temporal abiotic changes, and to
identify regional biodiversity hotspots. Findings from this study will provide the basis for regional impact
assessments for Fennoscandian Arctic lakes and establish contemporary abiotic and biotic baselines for future
comparisons. The work is done in the framework of the Circumpolar Biodiversity Monitoring Group under the
Convention of Arctic Flora and Fauna (CAFF).

628
2633
Aquatic Ecosystem Change in High Arctic Catchments due to Permafrost Change

Scott Lamoureux1 (scott.lamoureux@queensu.ca), Kaitlyn Roberts1, Amanda Schevers1, Melissa Lafreniere1,

Derek Muir2, Anna Pienkowski3,4
1
Queen's University, Geography and Planning, Kingston, Canada, 2Environment and Climate Change Canada,
Aquatic Contaminants Research Division, Burlington, Canada, 3MacEwan University, Physical Sciences,
Edmonton, Canada, 4Bangor University, School of Ocean and Natural Sciences, Anglesey, United Kingdom

Understanding how climate-induced permafrost changes will alter riverine and lacustrine environments is
critical to develop accurate predictions of how aquatic ecosystems will respond. We assess the impact of recent
climate and permafrost perturbation on the hydrochemistry, nutrient transport and downstream aquatic
ecosystem in paired catchments at the Cape Bounty Arctic Watershed Observatory ((75°N, 109°W; CBAWO) in
the Canadian High Arctic between 2003-2017.
There has been a sharp increase in solutes in the lakes at CBAWO, and sulfate has notably increased 380-500%.
River fluxes have similarly increased, exemplified by dissolved inorganic nitrogen fluxes. These hydrochemical
and nutrient fluxes are interpreted to be associated with deep thaw and mobilization from the upper
permafrost. Fish condition factor has improved steadily during the observation period and otolith analysis
indicates that fish show abrupt geochemical changes associated with solute loading. Diatoms show a shift to
small planktonic species in the past decade, suggesting primary productivity has responded to climate
amelioration, ice cover, and river fluxes.
Our results from CBAWO indicate that climate-induced permafrost changes can impart rapid changes on High
Arctic aquatic systems, and indicate that an integrated approach to predicting aquatic responses to
environmental forcings will be necessary to predict future changes.

629
2294
Effects of Environmental Change on Signy Island Terrestrial Algae Diversity

Faradina Merican1 (faradina@usm.my), Peter Convey2, Paul Broady3, Japareng Lalung4, Wan Maznah Wan
Omar1
1
Universiti Sains Malaysia, School of Biological Sciences, Penang, Malaysia, 2British Antarctic Survey,
Cambridge, United Kingdom, 3University of Canterbrury, School of Biological Sciences, Christchurch, New
Zealand, 4Universiti Sains Malaysia, School of Industrial Technology, Penang, Malaysia

The terrestrial algal microflora of Signy Island (lat. 60o 43'S) has been sporadically studied since the 1960s. The
first extensive report is that of Broady, investigating the microalgae diversity in the late 1970s from 122
samples including two Signy Island Reference Sites. The island has changed markedly since then under the
influence of trends of rapid regional climate change. In 2016 we re-visited and re-examined in detail the
diversity of the terrestrial microalgae at locations on Signy Island previously studied by Broady. Polyphasic
assessments conducted to date indicate changes in the microflora community over the four decades between
surveys. Morphological features observed in the new material suggest either the presence of species/strains
not previously recorded at specific sites, or the expression of phenotypic plasticity in response to the
environmental changes experienced. We also found morphospecies that were absent from previous records to
be present in a number of sites, in some cases with high abundance. Increased understanding of past and
present diversity and distribution of microalgae on Signy Island will support conservation of the indigenous
biota and aid future research on ecological processes, including consequences of environmental change.

630
AC-1d - Polar and high altitude atmosphere: clouds, aerosols, climate and interactions
20.06.2018 09:00-10:30, C Sanada I

1199
A Critical Evaluation of NorESM1 to Understand Aerosol Effects on Arctic Climate

Tanja N. Dallafior1, Srinath Krishnan2, Anna Lewinschal2, Ilona Riipinen1, Hans-Christen Hansson1, Annica M. L.
Ekman2 (annica@misu.su.se)
1
Stockholm University, Department of Environmental Sciences and Analytical Chemistry, Stockholm, Sweden,
2
Stockholm University, Department of Meteorology and Bolin Centre for Climate Research, Stockholm, Sweden

Previous studies using the earth system model NorESM1 show that changing SO2 emissions in various regions in
the northern hemisphere mid-latitudes result in significant temperature responses in the Arctic. Evidence so far
suggests that in NorESM1, amplified Arctic surface temperature response is obtained despite a weak sea-ice
albedo feedback and without significant aerosol-induced changes in cloud properties in the Arctic.
This work aims at gaining a process understanding of the Arctic temperature response to mid-latitude emission
changes both in the real world and in the model. To this end, we evaluate aerosol size distributions, cloud
properties, and other entities in NorESM1 against remote and in-situ observations at high latitudes.
Furthermore, results are compared to a newer version of NorESM1 including improvements of the sea ice
model, convective transport and nucleation of aerosols to identify critical processes affecting Arctic climate.
A preliminary comparison between the NorESM1 output and in-situ measurements of aerosol size-distributions
show that the model underestimates particle sizes, which is of direct importance to cloud droplet activation.
Furthermore, a comparison with aerosol optical depths obtained from the CALIOP satellite suggests that the
model overestimates aerosol transported to the Arctic through the free troposphere which implies that the
modeled aerosol impacts on high-latitude low-level clouds are underestimated in NorESM1.

631
401
Characteristics of Biogenically-derived Aerosols in the Amundsen Sea, Antarctica

Jinyoung Jung1 (jinyoungjung@kopri.re.kr), Sang-Bum Hong1, Meilian Chen2, Jin Hur2, Liping Jiao3, SangHoon
Lee4
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Sejong University, Department of
Environment & Energy, Seoul, Korea, Republic of, 3Third Institute of Oceanography, SOA,, Xiamen, China, 4Korea
Polar Research Institute (KOPRI), Incheon, China

Atmospheric concentrations of ionic species, water-soluble organic carbon (WSOC), total organic carbon (TOC),
and total carbon (TC) were measured over the Southern Ocean and the Amundsen Sea, Antarctica between
43°S and 75°S during the ANA06B cruise conducted in the austral summer of 2016 on board the Korean
icebreaker IBR/V Araon, in order to investigate abundance of biogenically-derived aerosol species and source of
organic carbon. During the cruise, mean concentrations of non-sea-salt sulfate (nss-SO42−) and methanesulfonic
acid (MSA) in bulk aerosols were 0.61 ± 0.17 µg m−3 and 0.22 ± 0.13 µg m−3, respectively. In the Amundsen Sea
Polynya, MSA concentration increased from 0.35 µg m−3 up to 0.57 µg m−3, and it showed a positive relationship
with dimethyl sulfide (DMS) in sea surface water, showing significant influences of marine biological activities.
Estimate using the MSA/nss-SO42− ratio measured in Antarctica revealed that mean contribution of biogenic
nss-SO42− accounted for 69 ± 34% of total nss-SO42−. Atmospheric TOC concentration varied from 0.16-0.65 µg
m−3, of which 16−47% was WSOC, showing that water-insoluble OC was dominant organic carbon species.
Excitation emission matrix (EEM) analysis revealed that protein-like WSOC was dominant WSOC type (46−98%).
This result suggests that most WSOC was derived from marine biological processes, and that biogenic WSOC as
well as sulfur species could be a important source of cloud condensations nuclei in the Amundsen Sea.

632
1134
Sea-salt Aerosol from Blowing Snow on Sea Ice: A New CCN Source in Polar Regions

Xin Yang1 (xinyang55@bas.ac.uk), Markus Frey1, Rachael Rhodes2, Sara Norris3, Ian Brooks3, Philip Anderson4,
Kouichi Nishimura5, Anna Jones1, Eric Wolff2
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Cambridge, Department of Earth Sciences,
Cambridge, United Kingdom, 3University of Leeds, School of Earth and Environment, Leeds, United Kingdom,
4
Scottish Association for Marine Science, Oban, United Kingdom, 5Nagoya University, Graduate School of
Environmental Studies, Nagoya, Japan

Using winter cruise data collected within in the Weddell Sea during June-August 2013, for the first time, we are
able to carry out a systematic examination to the parameterization of sea salt aerosol (SSA) production from
blowing snow as proposed by Yang et al. [2008].
Aerosol elevation events have been frequently observed within the sea ice zone, which, however, could not be
solely explained by the sea spray. When the SSA production scheme from blowing snow is implemented in to
the model, further constrained by the campaign data, the model could reproduce well many of the elevation
events. In addition, modelled SSA size spectrum generally matches the observations at size range of ~0.4-10 µm
strongly indicating that the SSA production scheme implemented is working and the micro-physical process
involved in the parameterization could be reasonable.
Moreover, the widely observed winter peaks of SSA in mass in polar regions can be reproduced by the model.
Model also predicts that the total number density of SSA (down to size of 0.2 µm) over the sea ice zone can be
larger than that in the marine boundary layer by about one order of magnitude, indicating blowing snow is
favorable of producing sub-micron sized SSA compared to sea spray. These small SSA are not limited within the
sea ice zone and can be long distance transported. Therefore they could potentially act as a source of CCN in
high latitudes.

633
1846
Arctic Sea Ice Melt Leads to Atmospheric New Particle Formation

Manuel Dall´Osto1 (dallosto@icm.csic.es), R Simo1, Roy Harrison2, D Beddows2, R Lange3, H Skow3, A Massning3,
S Becagli4, R Udisti4, R Krejci5, J Strom5, P Tunved5, YJ Yoon6
1
ICM CSIC, Barcelona, Spain, 2University of Birmingham, Birmingham, United Kingdom, 3ENVS, Copenhagen,
Denmark, 4University of Florence, Florence, Italy, 5ACES, Stockholm, Sweden, 6KOPRI, Inchan, Korea, Democratic
People`s Republic of

Atmospheric new particle formation and growth significantly influences climate by supplying new seeds for
cloud condensation and brightness. Currently, there is a lack of understanding of whether and how marine
biota emissions affect aerosol-cloud-climate interactions in the Arctic. Here, the aerosol population was
categorised via cluster analysis of aerosol size distributions taken at Mt Zeppelin (Svalbard) during a 11 year
record (2000-2010) and at Station Nord (Greenland) during a 7 year period (2010-2016). Air mass trajectory
analysis and atmospheric nitrogen and sulphur tracers link these frequent nucleation events to biogenic
precursors released by open water and melting sea ice regions. The occurrence of such events across both
temporal periods (2000-2010 and 2010-2016) are anti-correlated with sea ice extent.

634
2274
Details of Secondary Aerosol Formation in the Polar Atmosphere

Lisa Beck1 (lisa.beck@helsinki.fi), Clémence Rose1, Ella-Maria Duplissy1, Matthieu Riva1, Federico Bianchi1,
Heikki Junninen1,2, Olga Garmash1, Yee Jun Tham1, Clara Hoppe3, Alexander Schulz4, Angelo Viola5, Vito Vitale6,
Mauro Mazzola6, David Cappelletti6,7, Markku Kulmala1, Veli-Matti Kerminen1, Mikko Sipilä1
1
University of Helsinki, Helsinki, Finland, 2University of Tartu, Tartu, Estonia, 3Alfred Wegener Institute -
Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 4Alfred Wegener Institute, Potsdam,
Germany, 5Institute of Atmospheric Sciences and Climate - CNR, Rome, Italy, 6Institute of Atmospheric Sciences
and Climate - CNR, Bologna, Italy, 7University of Perugia, Perugia, Italy

Secondary aerosol formation is globally contributing about 50% of cloud condensation nuclei. With increasing
temperature, the emission of gases from the different spheres is changing, and therefore, the molecular
composition of the atmosphere is changing as well.
For understanding to which extent the temperature rise and sea ice loss might contribute to future cloud
formation and the radiation feedback, the mechanisms of secondary aerosol formation must be known.
Therefore, we conducted a field campaign from March to August 2017 in Ny Ålesund, Svalbard. The key
instrumentation included mass spectrometers for solving the molecular mechanism of particle formation. The
known contributing gases to secondary aerosol formation in polar regions are sulphuric acid and iodic acid -
detailed mechanisms are still only vaguely known. Changes in the phytoplankton dynamics, and sea ice extent
will have an important effect on aerosol formation in those regions. To understand the effect of temperature
change on secondary aerosol formation, all different spheres have to be taken into account. This study tries to
combine all the components related to gas-to-particle conversion necessary for predicting the future behaviour
of arctic clouds and climate.

635
2398
Vertical Dimethylsulfide Flux and its Relations to Sea Ice in Arctic Ocean

Bo Qu1 (qubo@ntu.edu.cn), Albert Gabric2

1
Nantong University, School of Science, Mathematics Department, Nantong, China, 2Griffith University,
Environmental Faculty, Brisbane, Australia

Global warming of climate is connected to ecosystem change, especially in the Arctic ocean. Biogenic emissions
of dimethylsulfide (DMS) are the main biogenic source of sulfate aerosols to the marine atmosphere and may
make a rapid change in the Arctic due to the massive melting ice. Here we simulate DMS distributions and sea-
to-air fluxes in the Barents Sea (30°W-40°E and 70°N-80°N) and Greenland Sea (20°W-10°E and 70°N-80°N) for
the period 2003-2005. A genetic algorithm (GA) is used to calibrate the key parameters in the DMS model for
both regions. Due to limitation of DMS observations in the Arctic Ocean, multiple data sources were used.
Parameter sensitivity analysis were studied using a limit method. CMIP5 global model is used for obtaining the
forcings for 4 CO2 conditions. DMS flux under quadrupled CO2 increases much more compared to late 20thC
levels (1 CO2). The reason for the increase in DMS flux under 4 CO2 conditions is due to changes in sea surface
temperature (SST), the sea ice melting and shoaling of the mixed layer depth (MLD). The double or tripling of
DMS fluxes indicates that warming in the Arctic could be slowed through the controlling of greenhouse gases
and changing of radiative budget associated with DMS derived aerosols.

636
BE-4d - Climate change and ecosystems: physiology, biodiversity and ecological functions
20.06.2018 09:00-10:30, C Sanada II

196
Hide, Survive and Hitch a Ride, a New View on the Krill-sea Ice Relationship

Bettina Meyer1 (bettina.meyer@awi.de)

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Biosciences, Bremerhaven,
Germany

A dominant Antarctic ecological paradigm suggests that winter sea ice is the feeding ground for larval Antarctic
krill. Results from a late winter study in the northern Weddell Sea in combination with previous findings
contradict this view and present the first evidence that although there's abundant food in winter sea ice, it is
not accessible for larval krill compared to food supply in neighbouring open water regions. Despite high
biomass in winter sea ice the growth rates of larval krill are constant low in winter pack ice regions. We found
that complex under ice habitats are vital for larval krill, providing shelter from currents. During daytime the
larvae feed on the sparse ice-associated food but after sunset, they migrate down into the water below the ice.
This behaviour increases food uptake in a patchy food environment and ensures transport of larvae to spring
feeding grounds in the Scotia Sea. Our study shows the first mechanistic linkage between larval krill and winter
sea ice.

637
2562
Long Dark Winters Thwart the Borealization of High Arctic Plankton Communities

Janne E. Søreide1 (janne.soreide@unis.no), Tove M. Gabrielsen1, Anna Vader1, Ragnheid Skogseth2, Malin
Daase3, Jørgen Berge3, Kjetil Lygre4, Kasia Dmoch5, Katarzyna Blachowiak-Samolyk5, Ksenia Kosobokova6, Elena
Druzhkova7, Igor Berchenko7, Pavel Makarevich7, Denis Moiseev7
1
The University Centre in Svalbard, Department of Arctic Biology, Longyearbyen, Norway, 2The University Centre
in Svalbard, Department of Arctic Geophysics, Longyearbyen, Norway, 3UiT The Arctic University of Norway,
Tromsø, Norway, 4Nansen Environmental and Remote Sensing Center, Bergen, Norway, 5Institute of Oceanology
Polish Academy of Sciences, Sopot, Poland, 6Shirshov Institute of Oceanology, Moscow, Russian Federation,
7
Murmansk Marine Biological Institute, Murmansk, Russian Federation

Isfjorden Marine Observatory Svalbard (IMOS) is a long-term plankton time series from the largest fjord system
in Svalbard, with data dating partly 20 years back. Hydrography, protist - and mesozooplankton are regularly
sampled along a climate gradient from the ice-free outer fjord with Atlantic water influence to the seasonal ice
covered inner fjord where local cold water of Arctic characteristics prevails. The high seasonal resolution of this
time series makes it possible to disentangle natural variability in the plankton community from persistent
changes caused by climate warming.
Microbial eukaryotes (0.45-10 µm size) display strong seasonality in community composition with rapid shifts
during spring and summer, when also inter-annual differences are most apparent. In contrast, highly similar
and stable communities are found during winter, suggesting a high degree of resilience in the system.The
mesozooplankton community consists of a mix of boreal and Arctic species with a growing share of boreal ones
towards the outer part of the fjord.The seasonal variability in community structure is higher than the inter-
annual variability. While boreal species may be prominent during summer and autumn, the zooplankton
community resets to a more Arctic community each winter. The long dark winter likely represent a bottleneck
for survival of more temperate species. This may potentially thwart the Atlantification of the plankton
community in the European Arctic.

638
682
Sensitivity and Adaptability of Antarctic Krill to a Warming Southern Ocean

Katharina Michael1 (katharina.michael@uol.de), Wiebke Wessels1, Rob King2, So Kawaguchi2, Bettina Meyer1,3
1
Carl-von-Ossietzky University of Oldenburg, Institute for Chemistry and Biology of the Marine Environment,
Oldenburg, Germany, 2Australian Antarctic Division, Kingston, Tasmania, Australia, 3Alfred Wegener Institute,
Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany

Antarctic krill (Euphausia superba) is a key species in the marine Antarctic ecosystem due to its central position
in the food web. As the krill's life cycle is characterized by a strong interplay between endogenous physiological
processes and seasonal environmental factors, it is crucial to understand how increasing water temperatures
affect these processes. However, physiological studies providing insights on the performance of Antarctic krill
under climate-induced environmental changes are scarce. By combining physiological performance indicators
with transcriptomic approaches, we aimed to identify effective mechanisms determining sensitivity as well as
adaptability of this species to a warming Southern Ocean. The seasonal transcriptome of E. superba was
compared to a de novo seasonal transcriptome of the closely related Northern krill (Meganyctiphanes
norvegica). Furthermore, long-term acclimation of E. superba at different temperature scenarios during austral
summer provided insights into the effects of elevated ambient temperatures on Antarctic krill physiology,
enabling a first estimate of putative effects on whole animal energy status when facing upcoming winter
season. Therefore, our data do not only provide a more detailed insight into krill thermal physiology but also
determine the capacity of E. superba to cope with Southern Ocean warming.

639
906
Energetic Value of Zooplankton and Nekton of the Southern Ocean: A Review

Fokje L. Schaafsma1, Yves Cherel2, Hauke Flores3, Jan A. van Franeker1, Mary-Anne Lea4, Ben Raymond4,5,
Rowan Treblico6, Andrea Walters4, Anton P. Van de Putte7 (anton.vandeputte@kuleuven.be)
1
Wageningen Marine Research, Den Helder, Netherlands, 2Centre d'Etudes Biologiques de Chizé, Villiers-en-Bois,
France, 3Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany,
4
Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia, 5Australian Antarctic
Division, Kingston, Australia, 6Antarctic Climate and Ecosystems Cooperative Research Centre, University of
Tasmania, Hobart, Australia, 7Royal Belgian Institute for Natural Sciences, Brussels, Belgium

The energy content of different prey items is an important factor in structuring food webs and relationships
between species. Information on the energetic value of prey can be a key predictor of the behaviour and
population dynamics of predators, trophic interactions between species and of energy flow through trophic
levels. The Southern Ocean (SO) represents approximately 10% of the earth's surface and is home to a variety
of top predators such as birds, seals and whales, which forage on zooplankton and nekton species. The strong
seasonality occurring in the SO, in combination with regional differences in environmental properties caused by
latitude, currents and/or fronts, cause variations in the energetic density within a single species or between
ecologically equivalent species. Here we present the results of a review on available energetic data that
contributed to the Southern Ocean Diet and Energetics Database. This database is a product of the Expert
Group on Antarctic Biodiversity Informatics (EG-ABI). Data that contributed to the review include summary
data as published in scientific literature as well as individual measurements kindly provided by the authors on
request. The data on individual measurements can help to better assess possible ontogenetic, spatial and
temporal patterns. Furthermore, we provide an overview of knowledge gaps, possible uses of the data in larger
ecosystem studies and consider implications for models.

640
716
Genomic Basis of Adaptation of the Southern Ocean Salp, Salpa thompsoni

Ann Bucklin1 (ann.bucklin@uconn.edu), Kate Divito2, Paola Batta-Lona3, Peter H. Wiebe4, Jennifer M. Questel5,
Rachel J. O'Neill6
1
University of Connecticut, Marine Sciences, Groton, United States, 2University of Conneticut, Molecular and Cell
Biology, Institute for Systems Genomics, Storrs, United States, 3CISESE, Biotecnologia Marina, Ensenada,
Mexico, 4Woods Hole Oceanographic Institution, Biology, Woods Hole, United States, 5University of Conneticut,
Marine Sciences, Groton CT, United States, 6University of Connecticut, Molecular and Cell Biology, Institute for
Systems Genomics, Storrs, United States

The Antarctic salp, Salpa thompsoni, is an increasingly important player in the vulnerable Southern Ocean
pelagic ecosystem. Field studies have documented rapid population growth resulting in dense blooms of salps
that can displace other species, including the keystone Antarctic krill (Euphausia superba), and significantly
perturb the pelagic ecosystem. We are developing new genomic resources, including a comprehensive
reference genome, for the Antarctic salp to enable identification of genes and gene networks underlying
physiological responses, including bloom formation. Our comparative genomic analysis is focused on novel
aspects of genomic evolution found only in the invertebrate Class Tunicata and detailed characterization of
genome evolution of S. thompsoni. We are examining evidence that rapid evolution of S. thompsoni orthologs
(genes of the same function that share a common ancestor) is driven by positive selection, and that these
genes and associated gene networks provide the basis for adaptation of the Antarctic salp to environmental
conditions. Our results build upon our previously-published genomic resources and comparative transcriptomic
data for this species, including de novo genome assembly, de novo transcriptome assembly, and small RNA
analyses. Our results are yielding new understanding of the genomic basis of adaptation to environmental
variation associated with climate change for the Antarctic salp.

641
OS-6e - Polar Ocean Dynamics
20.06.2018 11:00-12:30, C Aspen

486
Origin of CDW Intruding onto the Amundsen and Bellingshausen Sea Shelves

Yoshihiro Nakayama1 (yoshihiro.nakayama@jpl.nasa.gov), Dimitris Menemenlis1, Michael Schodlok1,2, Eric

Rignot1,3
1
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States, 2University of California
Los Angeles, Los Angeles, United States, 3University of California Irvine, Irvine, United States

The ice shelves and glaciers of the West Antarctic Ice Sheet are thinning rapidly, which is mainly caused by
Circumpolar Deep Water (CDW) intruding onto the Amundsen and Bellingshausen Seas (ABS) continental
shelves. Despite existing works on cross-shelf and on-shelf CDW transports, CDW pathways onto the ABS
originating from further offshore have never been investigated. Here, we show that simulated CDW from the
World Ocean Circulation Experiment (WOCE) S04P section (67ºS) circulates along the Antarctic Circumpolar
Current (ACC) and Ross Gyre and travels into the ABS after 3-5 years. Simulated CDW warming off the ABS
continental shelves in 2009-2014, consistent with limited observations available, is associated with different
CDW pathways due to the strengthened Ross Gyre circulation and warmer temperature at the northern model
boundary. Although wind over shelf and shelf-break areas has been commonly considered to control CDW
intrusion, we conclude that the far field ocean properties and circulation control more than half of the off-shelf
CDW warming in our model simulations, demonstrating a dominant link between large-scale atmospheric
forcing and off-shelf CDW properties. Given the trend towards positive Southern Annular Mode causing a
southern shift of the westerlies, the proposed mechanism may exert a dominant control on the on-shelf CDW
intrusion and thus accelerate the retreat of West Antarctic glaciers and its impact on global sea level rise.

642
697
Impact of Glacial Meltwater on Ocean Warming and Antarctic Bottom Water

Alessandro Silvano1 (alessandro.silvano@utas.edu.au), Steve Rintoul2, Beatriz Pena-Molino3, Will Hobbs3,

Esmee Van Wijk2, Guy Williams1, Shigeru Aoki4, Takeshi Tamura5
1
University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia, 2CSIRO Oceans &
Atmosphere, Hobart, Australia, 3ACE CRC, Hobart, Australia, 4Hokkaido University, Sapporo, Australia, 5National
Institute of Polar Research, Tachikawa, Japan

Strong heat loss and brine release during sea-ice formation in coastal polynyas act to cool and salinify waters
on the Antarctic continental shelf. Polynya activity thus both limits the ocean heat flux to the Antarctic Ice
Sheet and promotes formation of Dense Shelf Water (DSW), the precursor to Antarctic Bottom Water.
However, despite the presence of strong polynyas, DSW is not formed on the Sabrina Coast in East Antarctica
and in the Amundsen Sea in West Antarctica. Using a simple ocean model driven by observed forcing, we show
that freshwater input from basal melt of ice shelves partially offsets the salt flux by sea-ice formation in
polynyas found in both regions, preventing full-depth convection and formation of DSW. In the absence of
deep convection, warm waters from the Southern Ocean can spread across the continental shelf at depth and
reach the ice-shelf cavities to drive the rapid basal melt observed at the Totten Ice Shelf on the Sabrina Coast
and at the Dotson and Getz ice shelves in the Amundsen Sea. Our results suggest that increased glacial-
meltwater input in a warming climate will both reduce Antarctic Bottom Water formation and trigger increased
mass loss from the Antarctic Ice Sheet, with consequences for the global overturning circulation and sea-level
rise.

643
1006
Observing Southern Subpolar Gyres: Thermodynamics and Dynamics Contraints

Jean Baptiste Sallee1 (jbsallee@gmail.com), Christopher Chapman2

1
LOCEAN - Sorbonne Universités - UPMC/CNRS/IRD/MNHN, Paris Cedex, France, 2CSIRO Oceans & Atmosphere,
Hobart, Australia

Large gyre systems are prominent features of the polar Southern Ocean. They form elongated cyclonic features
south of the eastward-flowing Antarctic Circumpolar Current, and provide pathways between the World ocean
basins and the main global production sites of abyssal water. The subpolar gyre intensity therefore plays a key
role in climate as a “dam” that ultimately controls the rate of Antarctic Bottom Water entering the world's
ocean overturning circulation. Despite their potential key control on the Southern Ocean circulation, on water-
mass pathway, and on the global overturning circulation, very little is known about Southern Ocean subpolar
gyre. Here we use a novel observation database to investigate extent and seasonal variability of subpolar gyres
in the Southern Ocean. We investigate the dynamics that sets their extent and variability using a combination
of observation, as well as realistic and idealised models. Interestingly, the presence of sea-ice plays both a
dynamical role in shaping the subpolar gyre structure, and thermodynamical role in driving seasonal variability
of its strength. Variability and long-term change of sea-ice associated with a shift in wind regime might change
strength, vertical structure, and extent of Southern Ocean subpolar gyres, with important consequences for the
large-scale water-mass circulation.

644
1136
Circulation Beneath Filchner-Ronne Ice Shelf and Exchange with Open Ocean

Tore Hattermann1,2 (tore.hattermann@awi.de), Peter Davis3, Keith W. Nicholls3, Svein Østerhus4, Elin Darelius5,
Hartmut Hellmer6
1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2Akvaplan-
niva AS, Tromsø, Norway, 3British Antarctic Survey, Cambridge, United Kingdom, 4Uni Research, Bergen,
Norway, 5University of Bergen, Bergen, Norway, 6Alfred Wegener Institute Helmholtz Center for Polar and
Marine Research, Bremerhaven, Germany

During the austral summer 2015/16 and 2016/17, seven oceanographic moorings were deployed through hot-
water-drill holes located over the Filchner Trough east of Berkner Island. The aim was to investigate and
monitor the processes determining the access of ocean heat to the ice base. The vertical structure beneath the
southern part of the ice shelf is dominated by tidal mixing, and the water mass properties are related to the
densest High Salinity Shelf Water (HSSW), which is known to be produced in front of the Ronne Ice Shelf. This
water mass is observed to exit the cavity along the western flank of the Filchner Trough during parts of the
year. In contrast, the northeastern part of the cavity is filled with HSSW and its Ice Shelf Water derivatives that
have a local origin, in front of Filchner Ice Shelf. The preliminary time series shows that this less dense HSSW
enters the cavity on the eastern side of the Filchner Trough during parts of the year, but seems to be trapped in
the deep trough where it interacts laterally with derivatives of the Ronne-sourced HSSW; there is no evidence
that it can penetrate to the deep southern grounding lines. The link of these two circulation regimes to
different regions of dense water formation on the continental shelf needs to be taken into account, when
investigating whether an inflow of warmer water in front of the Filchner Ice Shelf is important for basal melting
today, and how that might change in a future climate.

645
1334
Flow Paths of the Arctic Halocline and Atlantic Layer Derived from Tracer Data

Angelica Pasqualini1 (ap@ldeo.columbia.edu), Peter Schlosser1,2,3, Robert Newton3, Tobias N. Koffman3, Ronny
Friedrich4
1
Columbia University, Department of Earth and Environmental Engineering, New York, United States, 2Columbia
University, The Earth Institute of Columbia University, New York, United States, 3Columbia University, Lamont
Doherty Earth Observatory, Palisades, United States, 4Curt-Engelhorn-Centre Archaeometry gGmbH, Mannheim,
Germany

We present 3H/3He age and hydrographic data from 21 expeditions spanning 25 years of Arctic Ocean section
work (1987 and 2013) to independently estimate spreading velocities, flow paths, and stability of upper and
lower halocline waters (UHW and LHW), as well as the Atlantic Water branches on a pan-Arctic scale. Our
results corroborate and add a time dimension to previously established circulation schemes. Tracer data
confirm the presence of a well-organized boundary current that cyclonically flows along the continental slope
and add insights into the other, typically topographically steered, circulation branches for the LHW and Atlantic
layers. The circulation scheme for the UHW still shows similarities to those of the Atlantic layer but differs
significantly in certain regions of the Arctic Ocean. Tracer data show that within the limits of our method the
current system has been stable over the 25 years of observation. The results are discussed in the context of the
temporal stability of the circulation in the Arctic Ocean, as well as regional variability of spreading velocities
along individual branches of the circulation pattern due to topographic and dynamic forcing.

646
1171
Polar Ocean State Estimation around the Greenland Ice Sheet

Ian Fenty1 (ian.fenty@jpl.nasa.gov)

1
NASA Jet Propulsion Laboratory, Pasadena, United States

Four-dimensional (space and time) ocean and ice data assimilation allows for the synthesis of diverse and
temporally and spatially heterogeneous observational data with a numerical model to create a coherent
representation of the coupled ocean, sea ice, and ice sheet system. This coherent representation of the time-
evolving system, referred to a state estimate, is a dynamically-consistent reconstruction that is constrained to
observations and their uncertainties in a least squares sense. In this talk I will describe recent progress,
outstanding challenges, and future prospects of using four-dimensional data assimilation to reconstruct
decadal changes in ocean circulation, temperature and salinity around the Greenland Ice Sheet with the goal of
understanding the causes of increasing submarine melting of its tidewater glaciers. This effort supported by
NASA's Estimating the Circulation and Climate of the Oceans (ECCO) project and its Oceans Melting Greenland
(OMG) mission.

647
AC-4a - The Polar Atmosphere and Geospace
20.06.2018 11:00-12:30, A Studio

509
Perturbations on the Stratosphere Due to Intense Geomagnetic Storms: Study Cases

Viviana Elisa López1, Adriana Maria Gulisano2 (adrianagulisano@gmail.com), Sergio Dasso3

1
Servicio Meteorológico Nacional, Ciudad Autónoma de Buenos Aires, Argentina, 2IAA/DNA, IAFE (UBA-
CONICET), Depto de Física FCEyN UBA, Atmospheric Sciences Department, Vicente Lopez, BsAs, Argentina, 3IAFE
(UBA-CONICET), DCAO FCEyN UBA, Depto de Física, Ciudad Autónoma de Buenos Aires, Argentina

We analyzed balloon sounding data gathered at the Argentinean Marambio Antarctic station from 1998 to
2016 (inclusive) by the National Meteorological Service of Argentina, in order to study the atmospheric profiles
with height of temperature and pressure variables. During the study, and taking into account seasonality, we
have found the associated climatology at Marambio station in order to compare the same profiles during 5
cases of intense geomagnetic storms (GS) where the balloon measurements where available. We compute the
temperature anomalies for the day of the GS, and 14 days after the event at different height levels. The
knowledge of the deviation of the seasonal profile during a geomagnetic storm will help to assess the possible
deviation from the expected cosmic ray flux at the station during these GS events. The atmospheric profile with
height is necessary to perform the Monte Carlo simulations of secondary cosmic rays showers, so this kind of
study will help to improve them.

On behalf of the The Latin American Giant Observatory (LAGO) Collaboration, Ciudad Autónoma de Buenos
Aires, Argentina. See List of Members at www.lagoproject.org, lago-pi@lagoproject.org

648
2228
Temperature Variations of Polar Ionosphere during Stratospheric Sudden Warming

Yasunobu Ogawa1 (yogawa@nipr.ac.jp), Satonori Nozawa2, Masaki Tsutsumi1, Chris Hall3, Ingemar Haggstrom4
1
National Institute of Polar Research / SOKENDAI, Tokyo, Japan, 2ISEE, Nagoya University, Nagoya, Japan, 3UiT
The Arctic University of Norway, Tromso, Norway, 4EISCAT Scientific Association, Kiruna, Sweden

We analyzed ion temperature and velocity observed by the European Incoherent Scatter (EISCAT) UHF radar at
Tromsoe (69.6°N, 19.2°E) during a stratospheric sudden warming (SSW) that occurred in January-February
2017. The zonal ion velocities at 85-100 km height reversed approximately 8 days earlier than the zonal wind
reversal in the upper stratosphere and the ion temperature at 85-95 km decreased simultaneously with the
zonal ion velocity reversal at the same altitude. We found that the time variations of ion temperature in the
daytime are close to those of ambipolar diffusion coefficients derived from the the Nippon/Norway Tromsoe
Meteor Radar (NTMR) data at the same altitude even when geomagnetic activity is moderate. This suggests
that the D- and lower E-region ion temperature in the daytime is a good proxy for neutral temperature at the
same altitude. We will explain the reliable ion temperature derivation in the D-region and its limitation, and
also discuss relationship between ion temperature and vertical ion velocity variations at 85-95 km measured
with the EISCAT UHF radar.

649
1676
Ionospheric Scintillation Climatology at Ny-Ålesund across Solar Cycle 23 and 24

Lucilla Alfonsi1 (lucilla.alfonsi@ingv.it), Luca Spogli2,3, Claudio Cesaroni2, Vincenzo Romano2,4, Ingrid Hunstad2,
Giorgiana De Franceschi2
1
Istituto Nazionale di Geofisica e Vulcanologia, Environment, Rome, Italy, 2Istituto Nazionale di Geofisica e
Vulcanologia, Rome, Italy, 3Space Physics LaboratoryEarth Technology, Rome, Italy, 4SpacEarth Technology,
Rome, Italy

INGV operates a network of GNSS receivers acquiring data at 50 Hz incorporating a firmware especially
modified to provide several parameters useful to monitor the perturbations of the high latitudes upper
atmosphere. In particular, the first GPS receiver was installed in 2003 at Ny-Ålesund (Svalbard Island, 78°55'N
11°55'E). Currently, three receivers are operating at Ny-Ålesund, recording GPS, GLONASS, Galileo signals. The
analysis exploits the scintillation parameters (S4 and sf), TEC and its rate of change (ROT) measured by INGV
receivers to study the behaviour of the high latitudes ionosphere during the different phase of a solar cycle.
The analysis is supported by the climatological reconstruction of the probability of the scintillation occurrence
sorted also according different conditions of the geospace and of the geomagnetic field. This would enable to
infer the relationship between the physical processes ruling the morphology of the high latitudes ionosphere
and the amplitude and phase scintillations on GNSS signals. The knowledge of such relationship is necessary in
view of a long term forecasting of the disruptive effects of the ionosphere on the L-band signals affecting the
applications based on GNSS such as precise positioning and navigation. Moreover, a climatology of the
scintillation over Galileo signals is here provided for the first time in the high latitude European sector.

650
1873
Chemical Impacts of Energetic Particle Precipitation in the Middle Atmosphere

Yvan Orsolini1,2 (yor@nilu.no), Christine Smith-Johnsen3, Dan Marsh4, Frode Stordal3

1
Norwegian Institute for Air Research, Kjeller, Norway, 2Birkeland Centre for Space Science, Bergen, Norway,
3
University of Oslo, Oslo, Norway, 4NCAR, Boulder, United States

Energetic particle precipitation generates perturbations in the abundance of various neutral and ionic species
in the polar mesosphere-lower thermosphere, partly through a complex ion cluster chemistry. In particular,
mesospheric polar nitric acid enhancements have been attributed to energetic electron precipitation (EEP). We
investigate such nitric acid enhancements following a series of EEP events during April and May 2010 with
WACCM-D, a recently developed variant of the Whole Atmosphere Community Climate Model (WACCM) that
includes a sophisticated ion chemistry of the D-layer of the ionosphere (50-90 km). Whereas the standard
WACCM includes only 5 positive ions, WACCM-D comprises 21 negative ions and 20 positive ions. Using the
specified-dynamics mode, we perform a one-year long simulation and contrast WACCM-D with the standard
WACCM. Both simulations are performed with and without a forcing by medium-to-high energy electrons. We
demonstrate the effects of the EEP events on nitric acid and on key ion cluster species, as well as other key
species of the nitrogen family. The one-year long simulation allows placing the event-related changes in key
neutral and ionic species in the context of their annual cycle. We especially highlight the important role played
by medium-to-high energy electrons in triggering ion cluster chemistry in the mesosphere and lower
thermosphere, leading to the production of nitric acid through the ion-ion recombinations.

651
1728
Surveys of 557.7/630.0-nm Dayside Auroral Emissions in Arctic and Antarctica

Zejun Hu1 (huzejun@pric.org.cn), Huigen Yang1, Hongqiao Hu1, Beichen Zhang1

1
Polar Research Institute of China, SOA Key Laboratory for Polar Science, Shanghai, China

The synoptic distributions of dayside aurora in the Northern and Southern Hemispheres, acquired from all-sky
imagers at Yellow River Station in Arctic and South Pole Station in Antarctica, respectively, present the same
two-peak structure, namely, the prenoon 09:00 MLT and postnoon 14:00-15:00 MLT peaks. The auroral
intensity presents a hemispheric asymmetry, i.e., the postnoon intensity is less than the prenoon intensity in
the Southern Hemisphere but more in the Northern Hemisphere. The hemispheric asymmetry is not changed
with the change of IMF's polarity. We suggested that 1) the two-peak structure in the dayside oval are
predominantly related with the prenoon/postnoon antiparallel reconnection in high-latitude magnetopause
produced to the prenoon and postnoon peaks; 2) the IMF By should modulate the dayside aurora through the
inter-hemispheric current, which is produced by a north-south oriented electric field, and changing the
distribution of midday R0-R1 current; 3) the opposite prenoon-postnoon asymmetries of dayside auroral
distributions in the two hemispheres are the combined effect of the prenoon-postnoon variations of the
magnetosheath density and the variation of the local ionospheric conductivity in the two ground-based
observatories.

652
1650
Unusual Amplitude Scintillation on GNSS Signals Recorded in Antarctica

Giulia D'Angelo1 (giu.dangelo8@gmail.com), Mirko Piersanti2,3, Lucilla Alfonsi4, Luca Spogli4,5, Claudio Cesaroni4,
Lasse Boy Novock Clausen6, Ingrid Hunstad4, Vincenzo Romano4,5, Pierre Cilliers7
1
Roma Tre University, Mathematics and Physics Department, ROMA, Italy, 2Università di L'Aquila, Dipartimento
di Scienze Fisiche e Chimiche, L'Aquila, Italy, 3Università di L'Aquila, Consorzio Area di Ricerca in Astrogeofisica,
L'Aquila, Italy, 4Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy, 5SpacEarth Technology, Roma, Italy,
6
University of Oslo, Department of Physics, Oslo, Norway, 7South African National Space Agency, Hermanus,
South Africa

The storm onset on September 7, 2017 triggered several electron density fluctuations in the ionosphere
causing severe phase scintillations at polar latitudes in both hemispheres. Concurrently, unusual amplitude
scintillations were also recorded in Antarctica. At high latitudes, indeed, scintillations on the GNSS signal phase
are expected to be more frequent than those on the amplitude. This is due to the higher reaction of the GNSS
signal phase to the complex plasma dynamics caused by the coupling between the Interplanetary Magnetic
Field (IMF) and the Earth's magnetic field, which directly exposes the high latitude ionosphere to the solar wind
variability. This work investigates the physical mechanisms triggering the observed amplitude scintillations. In
particular, leveraging on observations provided by receivers located at Concordia (75.10°S, 123.35°E), Mario
Zucchelli (74.41°S, 164.10°E) and SANAE (71.68°S, 2.83°O) stations, supported by ancillary data, we reconstruct
the scenario in which irregularities form, move and trigger both amplitude and phase scintillation. Our study
includes scintillations derived from GPS, GLONASS and Galileo data.

653
TE-1b - Observing with autonomous vehicles in polar regions
20.06.2018 11:00-12:30, A Forum

116
Environmentally Adaptive Acoustic Navigation and Communication in the New Arctic

Henrik Schmidt1 (henrik@mit.edu)

1
Massachusetts Institute of Technology, Mechanical Engineering, Cambridge, United States

The climate change induced enhancement of the “Beaufort Lens”, a warm water layer penetrating from the
Bering Strait, has severe implications for under-ice acoustic sensing, communication and navigation. As part of
the ICEX16 US Navy Exercise, an AUV with a towed hydrophone array was used for assessing the associated
changes to the undersea ambient noise environment. The AUV operation depended on navigation updates
from the submarine tracking range being communicated to the vehicle for fusion with the onboard inertial
navigation. However, the tracking performance was severely deteriorated compared earlier deployments, to
the presence of the warm layer, which creates a double duct environment with severe shadow zones for
shallow sources and receivers. In addition, the dominant ice mechanical sources for the ambient noise has
dramatically changed due to the reduced average thickness and the associated ice mechanics. As a combined
effect of these environmental changes, the spatial and temporal signal/noise budget is fundamentally changed,
characterized by robust environmental features that may be exploited by unmanned underwater vehicles. This
paper describes the environmental effects observed and discusses how robust acoustic connectivity in requires
manned or unmanned under-ice platforms to be capable of using their mobility to adapt to the environment
for reliable sensing, communication and navigation [Work supported by ONR and DARPA].

654
2238
A Decade of Under-ice Operations by Long-endurance Seagliders

Craig M. Lee1 (craig@apl.washington.edu), Jason Gobat1, Luc Rainville1

1
University of Washington, Applied Physics Laboratory, Seattle, United States

Over the past decade, the long-endurance, buoyancy-driven autonomous underwater vehicle Seaglider has
successfully completed a range of Arctic and Antarctic science missions that have included extended, multi-
month operation beneath ice. Early developments began in 2004, targeting year-round operation in the
seasonally ice-covered Davis Strait, a critical gateway connecting the Arctic with the Subpolar North Atlantic.
Seaglider capabilities were augmented with enhanced autonomy, ice detection and avoidance, and real-time
acoustic navigation. First-generation ice-capable Seagliders geolocated by multi-lateration from an array of
780-Hz RAFOS acoustic sources. Seaglider's first extended (hundreds of kilometers) under-ice transits occurred
in 2008, followed by year-round occupation of Davis Strait and a multi-day transit, without acoustic navigation,
under the ice bridge separating the Ross ice self from the Ross Sea Polynya in 2010. Continued development
has included enhanced autonomy and navigation, and integration of a broadband acoustic source capable of
encoding information onto the navigation signal. These advances opened new operational possibilities,
including a 2014 experiment that employed four Seagliders to sample the marginal ice zone of the Beaufort
Sea. This presentation will review the history of Seaglider missions under ice and the technological
developments undertaken to enable them, and discuss ongoing missions and future plans for ice-capable
Seagliders.

655
530
The Polar-ARV Unmanned Underwater Vehicle and Investigation of Sea Ice in Arctic

Shuo Li1 (shuoli@sia.cn), Junbao Zeng1, Yuangui Tang1, Yiping Li1

1
Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China

Pole-ARV is a UUV used for observation under sea ice in Arctic, it has both the characteristics of AUV and ROV
with onboard power and optical fiber technology, its scientific payloads include radiometer, CTD, altimeter,
cameras and pressure sensor. Pole-ARV has been deployed in the Chinese Arctic expedition for three times
since it was developed in 2008. The vehicle's maiden sub-ice voyage occurred during the summer of 2008 and
the control system and sub-ice navigation system was tested. In 2010 the Polar-ARV was launched and
recovered from an ice hole in the ice station, and collected a lot of scientific data, include ice thickness, spectral
irradiance, video, photo, conductivity, temperature, pressure etc. Its volume and weight of the vehicle was
reduced for field application after this deployment. In 2014, Polar-ARV was deployed in the 6th Chinese Arctic
expedition. It surveyed under designated ice area for three times and got a detail ice draft based on the ice
thickness and 3D spatial distribution of spectral irradiance. Recently we are just upgrading the Polar-ARV, and
are now preparing for a 2018 deployment in Arctic to test the acoustic system and perform sub-ice
investigation mission. The acoustic system includes a long range homing system, short range localization
system and acoustic propagation system. In future, we plan to expand the operating range of Polar-ARV, and
equip more sensors on it, such as multi-beam sonar.

656
2001
The West Spitsbergen Current in summer 2017

Marie-Noelle Houssais1 (mnh@locean-ipsl.upmc.fr), Agnieszka Beszczynska-Möller2, Christophe Herbaut1,

Pierre Testor1, Laurent Mortier1, Jean-Luc Fuda3, Jeanne Melkonian3, Hassane Benabdelmoumene3, Pierrette
Duformentelle4
1
UPMC/LOCEAN, Paris, France, 2Polish Academy of Sciences/Institute of Oceanology, Sopot, Poland,
3
CNRS/Division Technique INSU, La Seyne sur Mer, France, 4IFREMER/Centre Méditerranée, La Seyne sur Mer,
France

The flow of Atlantic Water through Fram Strait is the main provider of heat to the Arctic Ocean. The poleward
transport in the strait is achieved mostly by the West Spitsbergen Current, which flows as a slope current over
the Svalbard shelf and slope. Repeat glider sections were carried out in July-September 2017 across the eastern
Fram Strait as part of the EU-H2020 INTAROS project. These measurements aimed at monitoring the cross-
slope structure of the West Spitsbergen Current and identifying possible mesoscale features and recirculation.
Combining the glider data with results from a high-resolution sea ice-ocean model allows us to characterize the
time-space structure of the eddies and to estimate their contribution to the flow of Atlantic Water which is
diverted westward and possibly recirculates southward in the strait. The variability of the recirculated transport
will be analyzed in relation to the interannual variability of the volume and heat transports, which eventually
enters the Arctic Ocean through Fram Strait.

657
2212
Ocean Boundary Layer Variability in Drake Passage from Gliders: Hours to Seasons

Andrew Thompson1 (andrewt@caltech.edu), Zachary Erickson1, Mar Flexas1, Xiaozhou Ruan1, Giuliana
Viglione1, Janet Sprintall2, Sebastiaan Swart3
1
California Institute of Technology, Geological and Planetary Sciences, Pasadena, United States, 2Scripps
Institution of Oceanography, La Jolla, United States, 3University of Gothenberg, Gothenberg, Sweden

The Southern Ocean's surface boundary layer plays a key role in the exchange of heat and carbon between the
atmosphere and the ocean interior. Submesoscale motions strongly impact mixed layer depths and vertical
velocities, but observations that resolve these scales in the Antarctic Circumpolar Current (ACC) are extremely
limited. We present observations from multiple glider deployments in Drake Passage for both summer
(December 2014 - March 2015) and winter (May - August 2016) periods. The gliders provided persistent
measurements of the ACC's frontal structure over the shelf and slope in southern Drake Passage, and
completed multiple crossing of the Polar Front during the 2016 deployment. These observations provide a
comprehensive view of surface and bottom boundary layer variability in this region. This presentation will
summarize the major results of the project, which include:
(i) observations of strong eddy-induced subduction of shelf properties across the continental shelf break that
sustains an off-shore subsurface chlorophyll maximum;
(ii) abrupt spatial transitions, modulated by topography, in how submesoscale motions influence mixed layer
depths;
(iii) strong turbulent mixing and water mass modification arising from submesoscale symmetric instability in
bottom boundary layers over the continental slope;
(iv) seasonal variations in submesoscale eddy mixing lengths and subduction properties at the Southern ACC
Front (SACCF) and Polar Front.

658
1687
Revealing Physical and Ecological Dynamics at the Ice Edge - A Robotic Approach

Thorben Wulff1 (thorben.wulff@awi.de), Sascha Lehmenhecker1, Jonas Hagemann1, Michael Busack1, Sandra
Tippenhauer2, Michael Strohmeier3
1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, HGF-MPG Joint Research Group for
Deep Sea Ecology and Technology, Bremerhaven, Germany, 2Alfred Wegener Institute, Helmholtz Centre for
Polar and Marine Research, Physical Oceanography of Polar Seas, Bremerhaven, Germany, 3University of
Wuerzburg, Wuerzburg, Germany

Marginal ice zones (MIZs) are characterized by the complex and dynamic interaction between the atmosphere,
the ice, and the ocean. These high dynamics put MIZs among the - biologically - most productive regions of the
world ocean and make them an ideal place to investigate the coupling between physics and ecology. Fostered
by the last decades´ technological progress in robotics and sensor technology, marine sciences are increasingly
able to investigate these processes, which occur on very small scales - both temporal and spatial.
The Alfred Wegener Institute (AWI) has regularly operated its Autonomous Underwater Vehicle (AUV) “PAUL”
in the Arctic and especially in the MIZ of the Fram Strait since 2009. Starting in 2011 / 2012 AWI has also used
Unmanned Aerial Vehicles (UAVs) to support AUV operations and gather a holistic picture of the investigated
area. In our talk we will give an overview on the equipment and infrastructure used to support our AUV dives
including an UAV for operations at high latitudes. We will present technical details of our vehicle´s scientific
payload which is specifically designed to study the physical dynamics of the marginal ice zone and its ecological
response.

659
CR-7b - Snow and firn: an open measurement and modelling challenge
20.06.2018 11:00-12:30, A Dischma

995
Effects of Snow Grain Shape on Climate Simulations with NorESM

Petri Räisänen1 (petri.raisanen@fmi.fi), Risto Makkonen2, Alf Kirkevåg3, Jens B. Debernard3

1
Finnish Meteorological Institute, Helsinki, Finland, 2University of Helsinki, Dept. of Physics, Helsinki, Finland,
3
Norwegian Meteorological Institute, Oslo, Norway

Snow consists of non-spherical grains of various shapes and sizes. Still, in climate model snow albedo
calculations and many other radiative transfer applications, snow grains are often treated as spherical. We
evaluate the effects of snow grain shape on climate simulated by the Norwegian Earth System Model (NorESM)
in a slab ocean configuration of the model. An experiment with spherical snow grains (SPH) is compared with
another (NONSPH) in which the snow shortwave single-scattering properties are based on a combination of
three non-spherical snow grain shapes, optimized using measurements of angular scattering by blowing snow.
The key difference between these treatments is that the asymmetry parameter is smaller in the non-spherical
case (0.77-0.78 in the visible region) than in the spherical case (0.89). Therefore, for a given snow grain size, the
use of non-spherical snow grains leads to a higher snow broadband albedo, typically by 0.02-0.03. Considering
the spherical case as the baseline, this results in an instantaneous negative change in net shortwave radiation,
with a global-mean top-of-the-model value of -0.22 Wm-2. The effects on climate simulated by NorESM are,
however, larger than what one would expect based on the global-mean radiative effect. The global annual-
mean 2-m air temperature in NONSPH is 1.17 K lower than in SPH, with substantially larger differences at high
latitudes. The climatic response is amplified by strong snow and sea ice feedbacks.

660
807
Dual Frequency Radar Altimetry - Measuring Greenland Firn Properties from Space

Sebastian B. Simonsen1 (ssim@space.dtu.dk), Louise Sandberg Sørensen1, Lars Stenseng2, Rene Forsberg1
1
DTU Space - National Space Institute, Geodynamics, Kongens Lyngby, Denmark, 2DTU Space - National Space
Institute, Geodesy, Kongens Lyngby, Denmark

For the last seven years the ESA CryoSat-2 Ku-band radar altimeter has been measuring the elevation of the
Greenland Ice Sheet. Ku-band enables surface penetration at firn covered areas, which hampers the direct
interpretation of surface elevation change from Cryosat-2 and other Ku-band altimeters. However, mapping
the changes in penetration depth can provide information on firn stratigraphy. If the physical surface (snow/air
interface) of the ice sheet can be determined from an independent source, the differences in the two surfaces
may directly be linked to the penetration depth of Ku-band radar altimetry, and hence to the temperature and
density of the upper firn.
Here, we use independent estimates of the surface elevation changes from the Ka-band radar altimeter (AltiKa)
operated onboard the French/Indian satellite SARAL. The higher frequency of Ka-band reduces surface
penetration to a minimum and combining the records from both Ku- and Ka-band satellites is the key to
utilizing the full potential of CryoSat-2. Hence, providing both high spatial-resolution surface elevation change
and insights into changes in firn properties. The interpretation of dual-frequency altimetry is supported by firn
modeling. The model has previously been applied to gain mass balance from ICESat, and is now updated with a
conceptual model for Ku-band radar penetration.
Ultimately, a dual-band radar altimeter operating from space may provide ice sheet wide measurements of firn
densities.

661
1560
Snow-air Exchange and its Influence on Preservation of Climate Signals in Ice

Abigail Thayer1, Hans Christian Steen-Larsen2 (hans.christian.steen-larsen@uib.no), Maria Hörhold3, Sepp

Kipfstuhl3, Bruce Vaughn1, James White1
1
University of Colorado Boulder, Institute of Arctic and Alpine Research, Boulder, United States, 2University of
Copenhagen, Center for Ice and Climate, Copenhagen, Denmark, 3Alfred Wegener Institute, Bremerhaven,
Germany

Water isotopes in ice cores have been used for decades as a temperature proxy in Greenland and Antarctica to
provide information about past climate. However, there are still deficiencies in our knowledge about how post-
depositional processes influence the recorded water isotope signal. It is unclear why water isotopes reflect
continuous temperature changes when depositional snow events have a seasonal bias and can be separated by
weeks or months. Recent studies have shown that surface snow isotopes exhibit intra-day to inter-day
variations in parallel with near-surface atmospheric water vapor isotopes, suggesting that the snowpack is
more closely tracking atmospheric conditions such as near-surface temperatures.
A study at the EGRIP field camp (North-East Greenland) in July 2017 showed that over a 40-hour period, surface
snow experienced sublimation and interaction with near-surface atmospheric water vapor, changing the snow
isotopic composition. A series of lab experiments conducted in a controlled environment in Fall 2017 will better
quantify the acting processes, by filling a sealed chamber with homogeneous snow and an inflow of
isotopically- and humidity-controlled vapor. Continuous laser-based measurements of water vapor are used to
monitor changes in the air, and snow samples are measured over the duration of multiple-day periods. Effects
such as wind and thermal gradients in the snow can be simulated to better understand natural processes taking
place on the ice sheet.

662
1938
Measurement and Modelling of Tundra Snowpack Structure

Richard Essery1 (richard.essery@ed.ac.uk), Nick Rutter2

1
University of Edinburgh, School of GeoSciences, Edinburgh, United Kingdom, 2Northumbria University,
Newcastle, United Kingdom

Shallow tundra snowpacks subject to strong winds and strong vertical temperature gradients have distinctive
structures, with basal layers of large faceted grains overlain by hard fine-grained slabs. The physical properties
of these layers differ greatly in how they control, amongst other processes, conduction of heat and scattering
of microwave radiation; these are important for determining the amount of snow on the ground by remote
sensing and the influence of that snow on ground - atmosphere heat exchanges for numerical weather
prediction. Even the most sophisticated current snow physics models, which have largely been developed for
alpine applications, are known to perform poorly in reproducing tundra snowpack structures. A Year of Polar
Prediction / UK-Canada Arctic Partnership experiment will be conducted in the Canadian Northwest Territories
during March 2018 to combine ground measurements of vertical microstructure and horizontal topographic
variations in snow with airborne microwave measurements. Preliminary measurement and modelling results
will be presented.

663
1235
Evolution in Geometry of Firn in Ice Sheets Detected by Dielectric Anisotropy

Shuji Fujita1 (sfujita@nipr.ac.jp), Koaro Fukui2, Motohiro Hirabayashi3, Yoshinori Iizuka4, Sumito Matoba4,
Atsushi Miyamoto5, Hideaki Motoyama1, Takeshi Saito4, Toshitaka Suzuki6
1
National Institute for Polar Research / SOKENDAI, Tachikawa, Japan, 2Tateyama Caldera Sabo Museum,
Tateyama-machi, Japan, 3National Institute for Polar Research, Tachikawa, Japan, 4Institute of Low
Temperature Science, Hokkaido University, Sapporo, Japan, 5Institute for the Advancement of Higher Education,
Hokkaido University, Sapporo, Japan, 6Yamagata University, Yamagata, Japan

Ice in polar ice sheets once experience a state of firn at near-surface depths. Therefore, it is important to
understand physical processes of firn formation, metamorphism and deformation for ice core studies. We
investigated firn through measurement of tensorial values of the dielectric permittivity at microwave and
millimeter-wave frequencies. This method can detect presence and strength of anisotropic structure in the
geometry of pore spaces and ice matrix. We applied the method to many firn cores drilled at both ice sheets.
We find that firn that have shorter residence time at the near-surface depths does not form strong vertical
anisotropy that is caused by vertical movement of moistures. In contrast, firn that have longer residence time
at the near-surface depths tend to form vertical anisotropy. When density exceeds more than ~600 kg/m3, a
common feature of firn at many polar sites is that there are evolution of vertically elongated features of pore
spaces in firn despite growth of vertical compression. We hypothesize an explanation as follows. As firn
becomes denser, air within firn needs to "escape" to upward directions as compared to sinking firn. In firn,
porous structure tend to have vertically elongated structure because of this vertical escape movement of air.
The observed phenomena of the growth of the vertical dielectric anisotropy can be understood by this vertical
movement of the air within firn.

664
1306
The ETracer+ a Wireless Sensor Suite for Monitoring Firn Processes

Nanna Bjørnholt Karlsson1,2 (nbk@geus.dk), Elizabeth Bagshaw3, Ben Lishman4, Lai Bun Lok5, Stephen Burrow6,
Jemma Wadham6, Lindsay Clare6, Keith Nicholls7, Hugh Corr7, Paul Brennan5, Olaf Eisen2,8, Dorthe Dahl-Jensen9
1
Geological Survey of Denmark and Greenland, Copenhagen, Denmark, 2Alfred Wegener Institute Helmholtz
Center for Polar and Marine Research, Bremerhaven, Germany, 3Cardiff University, Cardiff, United Kingdom,
4
London South Bank University, London, United Kingdom, 5University College London, London, United Kingdom,
6
Bristol University, Bristol, United Kingdom, 7British Antarctic Survey, Cambridge, United Kingdom, 8University of
Bremen, Bremen, Germany, 9University of Copenhagen, Copenhagen, Denmark

Long-term monitoring of the subsurface processes taking place in snow and firn presents a significant
technological challenge. Many in situ observational studies cover only short time intervals, or rely on sensors
connected to surface dataloggers. Wired sensors connected to the surface may impact the physical processes
within the firn, resulting in altered percolation pathways and the potential formation of artificial ice pipes or ice
lenses. Here, we present results from a measurement campaign conducted with a suite of small (50 mm
diameter) wireless sensors (ETracer+) that continuously transmit information on temperature, pressure and
electrical conductivity (as a proxy for meltwater presence and solute content). The tested sensor platforms are
small, robust and low cost, and communicate data via a very high frequency (VHF) radio link to surface
receivers. The sensors can accurately log subsurface temperatures, and transmit the recorded data through up
to 150 m firn.
The sensors were deployed in the upper 15 cm snow layer at the East Greenland Ice Core Project campsite in
northeastern Greenland. Tests demonstrated that the sensors are capable of prolonged operation in low
temperature environments, accurate measurement of subsurface temperatures, and of detecting meltwater
pulses within otherwise dry firn. Our results show that wireless sensors have great potential for long term
monitoring of sub-surface processes in firn.

665
SH-5b - Current and future change, sustainability and resilience in the Polar Regions
20.06.2018 11:00-12:30, A Sertig

1388
New Arctic Straits and Islands and their Potential Influence on Human Activity

Wieslaw Ziaja1 (wieslaw.ziaja@uj.edu.pl), Krzysztof Ostafin1

1
Jagiellonian University, Institute of Geography and Spatial Management, Krakow, Poland

32 new islands (each above 0.5 km2) appeared due to recession of Arctic glaciers under climate warming since
the 1960s. Analysis of satellite images was a basic method of recognizing them. The islands' origin is a final
stage of a process which began in the 20th century. They appear in the coasts where bedrock elevations above
the sea are surrounded by depressions below its level, filled (at least from a land-side) with glaciers. Their
recession leads to flooding the depressions by sea water and thus origin of new straits separating them from a
mainland. Such new islands appear in Greenland and the European Arctic. Their ecosystems accommodate to
new environmental conditions. In the nearest future, this process will be: - intensified in a case of further
warming, - continued if climate will stabilize, - stopped after light cooling, - reversed after heavy cooling. All the
new straits will become new sea-ways. Most of them will be of a local significance for an off-shore coastal
traffic. However, a few new straits may become important for a state or international traffic, shortening
important Arctic sea-ways. Such a new potential strait across the today's southern Spitsbergen - which may
appear due to connection of the Hornsund and Hambergbukta fjords - would be of a great political-economic
and ecological importance. It would become a useful way for ships going from west to the Barents Sea (to the
eastern Spitsbergen coast, eastern Svalbard islands, Franz Josef Land, etc.).

666
1908
Engaging Youth to Envision and Advance Sustainability in Arctic Russia

Andrey Petrov1 (andrey.petrov@uni.edu), Tatiana Vlasova2, V Volkov2, Nikita Kaplin3, Varvara Korkina1, Diane
Hirshberg4, Joan Nymand Larsen5
1
University of Northern Iowa, Cedar Falls, United States, 2Russian Academy of Science, Moscow, Russian
Federation, 3ARUN- Evenki Municipal District, Tura, Russian Federation, 4University of Alaska Anchorage,
Anchorage, United States, 5Stefansson Arctic Institute, Akureyri, Iceland

In order to ensure that the perspectives of youth are included in the investigation of sustainability issues, it is
critical to involve youth directly in the research process. Involving youth as co-researchers ensures true
participation and a 'voice' in both identifying relevant issues and determining appropriate solutions. The ability
to manage and control social-ecological processes with active participation of young people is a key factor in
achieving social-ecological resilience and sustainability. This paper presents the results of a youth engagement
project to explore youth perspectives on these processes, using multiple methods including semi-structured
interviews, quantitative data on key sustainability indicators and scenario planning. The project includes young
people aged 15-29 from different regions of the Russian Arctic: Evenkia, Murmansk, Yakutia, and Chukotka.
These regions and communities differ in terms of status (capital/regional center, village) natural-climatic
conditions) and most importantly, access to transport and communication infrastructure, and thus provide
good examples for comparing the relations between perceived quality of life and regional Arctic specific. The
analysis helps to identify key indicators to monitor issues of the Arctic social-ecological sustainability facing
Arctic youth and important steps for their solution.

667
1907
How Does Change Actually Affect Arctic Communities?

Henry Huntington1 (hph@alaska.net)

1
Huntington Consulting, Eagle River, AK, United States

We know that Arctic communities are experiencing rapid and far-reaching social, cultural, economic,
environmental, and climatic changes. These changes in turn have had many effects on the communities and
their residents, and are predicted to have many more. The closer we look at cause-and-effect relationships,
however, the less clear the picture becomes. Using Arctic Alaska as one example, there is no evidence of
demographic effects from climate change or other notable shocks to the social-ecological system. To the
contrary, despite high reliance on traditional hunting and fishing, human outcomes appear de-coupled from
environmental influences. Among the possible explanations are robust innovation that creates new
opportunities, suffering that is not apparent in standard demographic metrics, and the use of reserves or
subsidies as a buffer against negative effects. Each explanation has distinct implications for policies and
practices aimed at achieving sustainability or resilience, a topic worthy of further study. We cannot rely on
innovation, but neither can we expect communities to respond to change in mechanical and inevitable ways.
Hidden suffering needs to be recognized to avoid undermining long-term sustainability. Buffers, too, need to be
understood for what they are, so that they are used effectively rather than exhausted before long-term
changes are made. This presentation will use examples from recent research to explore these ideas.

668
68
Socio-economic Changes in Mining Communities of Murmansk Region, Arctic Russia

Yulia Zaika1 (yzaika@inbox.ru)

1
Lomonosov Moscow State University, Faculty of Geography, Khibiny Research Station, Kirovsk, Russian
Federation

Murmansk region is the part of Arctic zone of Russian Federation; and is one of the most heavily industrialized.
Among other Arctic territories of Russia, region holds the first place by number of single-industry cities. At
present 1/3 of region's urban population live and work in single-industry cities and set up the greatest
industrial potential for socioeconomic development of this area. The most part of regions' single-industry cities
has a mining profile allocating several “industry big-player” companies. Along with its resource role Murmansk
region is also perceived by the government as the model territory for the current socio-economic and more
innovative way of development. Moreover it plays an international role as well by being the part of the Barents
Euro-Arctic region. Even though there are a lot of positive changes in the state regulatory system and
mechanisms such as development of regional and municipal territories with special financial regimes for
investment projects, there are also some uncertainties and factors which deepen the disparity of socio-
economic development within region. One of the ways to overcome this can be spatial development of
territory. The most dramatic trend of the past 10 years in Murmansk region is depopulation which leads to the
compression of socioeconomic and demographic space of the region. Nevertheless, such a compression can
force the consolidation of social and economic resources which will be discussed during the conference.

669
1952
An Arctic Village Facing New Socio-economic Transformations: Teriberka, Russia

Gleb Kraev1 (kraevg@gmail.com), Jessica Graybill2, Andrey Petrov3

1
Russian Academy of Sciences, Center of Forest Ecology and Productivity, Moscow, Russian Federation, 2Colgate
University, Hamilton, Hamilton, United States, 3University of Northern Iowa/IASSA, Cedar Falls, United States

This study documents and analyzes recent socio-economic and socio-ecological transformations of the coastal
village of Teriberka in the Barents region of Russia. Teriberka is undergoing rapid and potentially radical change
due to external pressures generated by various outside interests. Since the mid-20th century it experienced a
number of boom and bust cycles: the rise and fall of shipyards and the fishing industry, construction and
operation of hydropower facilities, and infrastructure development for the now-frozen Shtokman gas project.
Since 2014, after the award-winning film "Leviathan" was produced there, the village has become an
International tourist attraction, bringing thousands of visitors annually and building new hotels and
restaurants. In 2016 it was designated as a priority development settlement meaning the regional government
decides what investments are “appropriate” and how the settlement should look like. The local people are to
be displaced and resettled while the region benefits from touristic, and bioresources processing development.
Disappointed and clustered local commune quietly disavows the changes, but cannot make an offer of any
alternative. Is “Leviathan” script being literally reproduced this time? Our socio-ecological study, employing
interview, focus group, and environmental science methods, and community meeting allowed introduction of
changes to the new area development plan.

670
2663
Mining Settlements in Transition: Analyzing Svalbard's Post-coal Future

Eric Paglia1 (paglia@kth.se), Dag Avango2, Albina Pashkevich3

1
Swedish Defence University, Department of Security, Strategy and Leadership, Stockholm, Sweden, 2KTH Royal
Institute of Technology, Stockholm, Sweden, 3Dalarna University College, Falun, Sweden

Svalbard is at a historical crossroads, with five former coalmining settlements in states of transition
simultaneously. The Norwegian government's 2017-2018 budget proposition for Svalbard calls for the de facto
end of coalmining, which has been Norway's primary means of effective occupation for over 100 years.
Following a 2016 white paper, which signaled such a direction for Svalbard policy, the proposed budget entails
the abandonment of Sveagruva, major changes in the socio-economic foundation of Longyearbyen and
significant reorganization in Ny-Ålesund. Similarly, the Russian coalmining settlements at Svalbard are in
different stages of transition to post-mining. In future visions for Barentsburg and Pyramiden, scientific
research, tourism and cultural heritage are cornerstones. The process underway on Svalbard provides a point
of departure for exploring how areas based on resource extraction in the Arctic can transition to post-
extraction futures. To analyze this process, we draw upon research on the sustainable development of former
Arctic mining communities within the Mistra Arctic Sustainable Development program and the Nordic Centre of
Excellence REXSAC—Resource Extraction and Sustainable Arctic Communities. Research has included document
analysis, interviews and contemporary archeological fieldwork on Svalbard and other Arctic locations. The
paper provides an overarching analysis of Svalbard's post-coal future, built on five case studies of settlements
in transition.

671
GG-2e - Arctic and Antarctic past ice sheet dynamics and paleoclimate evolution
20.06.2018 11:00-12:30, A Schwarzhorn

2607
Plio/Pleistocene Preconditioning at Both Poles as Driver of Super Interglacials

Julie Brigham-Grette1 (juliebg@geo.umass.com), Rajarshi Roychowdhury1, Robert de Conto1

1
University of Massachusetts-Amherst, Geosciences, Amherst, United States

Paleoclimate records of climate change from northeast Arctic Russia (Lake El'gygytgyn) and Antarctica over the
past 3-4 Million years provide a new opportunity for understanding the sensitivity of the polar regions to
forcings involving natural green house gas variability, changing orbital configurations and associated feedbacks.
While geography and transient atmospheric CO2 in excess of preindustrial levels can explain most of the
Pliocene warming, the occurrence of Arctic super interglacials without clear pacing documented over the past
2.78 Myrs requires additional explanation. We hypothesize that super interglacials in the Arctic correspond
with extremes in insolation leading to the demise of the WAIS. During MIS 11c, 31, 49, 55, 77, 87, 91, and 93
Milankovitch forcing coinciding with extreme lows in eccentricity and high obliquity likely preconditioned the
Earth system to synchronize summer melt intensity and duration to produce bipolar warming. This warming
likely led to the demise of the WAIS in the Southern Hemisphere and super interglacials in the Arctic Northern
Hemisphere. Diatomite layers in the ANDRILL AND-1B record coincide reasonably well super interglacials
(Melles et al, 2012) but unconformities in the AND-1B cores prevent direct correlation. The challenge has been
to understand how these high latitude sites are linked with changes in ocean circulation and heat transport.

672
1826
A Transantarctic View of the Plio-Pleistocene East Antarctic Ice Sheet
Rachel Bertram1, Tina van de Flierdt2, Richard Levy3 (r.levy@gns.cri.nz), Rob McKay4
1
Imperial College London, London, United Kingdom, 2Imperial College London, Earth Science and Engineering,
London, United Kingdom, 3GNS Science, Wellington, New Zealand, 4Victoria University of Wellington,
Wellington, New Zealand

The East Antarctic Ice Sheet likely underwent some prominent changes as a result of global cooling from the
mid- to late-Pliocene, yet direct evidence from the Antarctic ice margin is sparse. We here present new
geochemical provenance analyses on Plio-Pleistocene marine sediment from the CIROS-2 drill site at the mouth
of the Ferrar Glacier in the Transantarctic Mountains. Stratigraphic and sedimentological analysis revealed
alternating sequences of diamictites and mudstones, interpreted as glacial and interglacial deposits
respectively. New radiogenic isotope analyses show distinct provenance variations between these units, which
can be directly compared to exposed bedrock samples from the vicinity of the Ferrar Glacier valley. Diamictites
are characterised by locally-sourced material throughout the core, while mudstones from the early- to mid-
Pliocene show an integrated provenance signature representative of additional lithologies located upstream
within the Ferrar Glacier valley. We observe a fundamental shift in the provenance of the interglacial
mudstones at ~3 Ma. A more local erosional source in younger sediments may indicate that the ice sheet
margin became increasingly stable in the late Pliocene. Comparison of this new CIROS-2 record with other sites
in the vicinity (e.g. ANDRILL, IODP Sites U1361 and 1165) will help to build a spatial understanding of the East
Antarctic ice sheet at this crucial climate transition.

673
1877
Meltwater Contributions to Mid to Late Pliocene (3.3-2.6Ma) Global Sea-level

Georgia Grant1, Tim Naish1 (tim.naish@vuw.ac.nz), Gavin Dunbar1, Paolo Stocchi2, Michelle Kominz3, Peter
Kamp4
1
Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand, 2Royal Netherlands
Institute for Sea Research, Amsterdam, Netherlands, 3Western Michigan University, Kalamazoo, United States,
4
Waikato University, Hamilton, New Zealand

The mid Pliocene (3.3 -3 Ma) has long been considered an analogue for future warming scenarios with climate
conditions of 400 ppm pCO2, temperatures 2-3 °C higher-than-present and a lack of large-scale ice sheets in the
Northern Hemisphere. We present a direct and continuous sea-level record, from a shallow marine margin,
Whanganui Basin, New Zealand, derived from a newly developed grainsize water-depth relationship. An
integrated age model, independent of the global benthic δ18O stack, was developed from
paleomagnetostratigraphy, tephrochronology and biostratigraphy. Following back-stripping to remove effects
of subsidence, our relative sea-level record characterises glacial-interglacial precession-paced fluctuations of
15±5m during the mid Pliocene, and obliquity-paced cycles of 23±5m for the Late Pliocene, not registered to
present-day sea-level. Four paleomagnetic reversals allow correlation to orbital time-series, demonstrating sea-
level in phase with 65°S summer insolation. We conclude an Antarctic dominated meltwater source eustatic
sea-level for the mid Pliocene. An Antarctic ice-rafted debris record also suggest the marine based margins of
the Antarctic ice sheets continue to be paced by local insolation (precession) through the Late Pliocene. The
emergence of obliquity in the record is driven by developing northern hemisphere ice sheets. Glacio-isostatic
adjustment modelling for the mid Pliocene suggests the Whanganui site approximates eustatic sea-level.

674
1430
A Framework for Understanding the Long-term Andscape Evolution of Antarctica

David Sugden1, Stewart Jamieson2 (stewart.jamieson@durham.ac.uk)

1
University of Edinburgh, School of GeoSciences, Edinburgh, United Kingdom, 2Durham University, Dept. of
Geography, Durham, United Kingdom

The subglacial landscape of Antarctica is less well known than that of the moon or Mars. Much of our
understanding of its evolution derives from land exposed at the coast, but the geomorphological record that
lies beneath the ice holds significant potential for understanding changes in the Antarctic. As knowledge of
modern bed topography increases yearly, we present a framework for using it to test hypotheses of
interactions between plate movement, tectonics, surface processes and glacial erosion. We suggest that the
landscape evolution of Greenhouse Antarctica before ca.34 Ma, has analogues with typical passive margin
evolution (e.g. Australia), displaying feedbacks between base-level change, fluvial erosion, scarp retreat and
marginal uplift. Intense weathering would occur under the warm conditions, and flat regions near the coast
would form via surface wash. In Icehouse Antarctica, we propose that expansion and contraction of ice
produced waves of warm-based erosion which were most effective where flow directions were maintained
regardless of ice sheet scale, and where pre-glacial topography steers ice. There may be thresholds of glacial
behaviour whereby topography controls significant jumps in ice volume between mountain icefields and ice
sheet glaciation. Glacial erosion occurs over long timescales so marine-based beds continually deepen and
become more reverse-sloped. We therefore suggest the modern ice sheet is more sensitive to climate changes
than in the past.

675
745
Long-term Landscape Evolution of the Wilkes Subglacial Basin, East Antarctica

Guy Paxman1 (guy.j.paxman@durham.ac.uk), Stewart Jamieson1, Fausto Ferraccioli2, Mike Bentley1, Neil Ross3,
Egidio Armadillo4, Tony Watts5, German Leitchenkov6
1
Durham University, Durham, United Kingdom, 2British Antarctic Survey, Cambridge, United Kingdom,
3
Newcastle University, Newcastle upon Tyne, United Kingdom, 4University of Genova, Genova, Italy, 5Oxford
University, Oxford, United Kingdom, 6St. Petersburg State University, St. Petersburg, Russian Federation

Reconstructions of the bedrock topography of Antarctica since the Eocene-Oligocene Boundary (ca. 34 Ma)
provide an important boundary condition for modelling past Antarctic ice sheets. This is particularly vital in
regions where the bedrock presently lies below sea level, since these sectors are thought to be most vulnerable
to future change. Here we use 3D flexural modelling to reconstruct the evolution of the topography of the
Wilkes Subglacial Basin and Transantarctic Mountains, which are situated beneath the East Antarctic Ice Sheet.
We estimate the spatial distribution of glacial erosion and restore this material to the topography, which is also
adjusted for the associated flexural isostatic responses. We constrain our erosion estimates and the pace of
landscape evolution since 34 Ma using offshore sediment stratigraphy. In our reconstructions, the 2 km-deep
troughs within the Wilkes Subglacial Basin were much shallower at the Eocene-Oligocene Boundary due to the
restoration of selectively eroded material. Our models provide a better-defined boundary condition for
modelling early ice sheets, and show that the majority of glacial erosion and landscape evolution occurred prior
to 14 Ma, which we interpret to reflect a more dynamic and erosive early East Antarctic Ice Sheet. Our flexural
modelling shows that the inherited (pre-34 Ma) topography is consistent with long-wavelength elastic plate
flexure and influenced by the inherited crustal structure.

676
1910
Glacial Geomorphic Features: West Antarctic Seafloor and Subsurface Barents Sea

Julia Wellner1 (jwellner@uh.edu), Janet Kong1, Yuribia Munoz1

1
University of Houston, Houston, United States

Analysis of subsurface geomorphic features, found beneath the modern-day seafloor, can illustrate past ice-
sheet characteristics from before the last glacial maximum. Such analysis is not possible in the Antarctic but
petroleum industry 3-D seismic data from Arctic Norway allow such subsurface mapping at a scale comparable
to low-resolution multibeam swath bathymetry grids. This study uses detailed interpretation from 3-D seismic
data from the Barents Sea to identify glacial features formed following the onset of glaciation across the
region, around 1 Ma. A series of parallel, evenly spaced glacial lineations ranging from 0.5-10 km long,
minimum length, and trending northwest-southeast, has been identified. The seafloor surface picked on 3-D
seismic shows evidence of iceberg scours carved by drifting icebergs that formed following ice-sheet retreat
after the LGM. In our data, iceberg scours have only been identified on the seafloor, and glacial lineations
found only in the subsurface. Comparison of glacial features from multiple layers in the subsurface allows
examination of the history of ice flow through multiple periods over the last several glacial cycles, with slight
reorganization of flow direction between each glacial readvance. We compare the subsurface Barents Sea
geomorphology to seafloor geomorphology from multibeam data collected in West Antarctica, where flow
direction reorganization is mapped throughout the deglacial period.

677
TE-3e - Remote sensing of polar regions
20.06.2018 11:00-12:30, A Seehorn

1602
New Enhanced-resolution Passive Microwave Climate Record for Historical Analysis

Mary J. Brodzik1 (brodzik@nsidc.org), David G. Long2, Molly A. Hardman1, Joan M. Ramage3, Richard L.
Armstrong1
1
NSIDC/CIRES/Univ of Colorado, Boulder, United States, 2Brigham Young University, Provo, United States,
3
Lehigh University, Bethlehem, United States

Since 1978, satellite sensors have observed Earth passive microwave emissions. Collected globally both day and
night and able to see through most clouds, passive microwave measurements are used to derive significant and
meaningful cryospheric climate records at high latitudes and high elevations, including sea ice concentrations,
snow water equivalent and snow and ice melt onset. Until now, spatial resolution of historical products has
been relatively coarse. Historical gridded passive microwave data sets did not meet many requirements of
climate data records, most notably in intersensor calibration and consistent processing methods. Original
gridding techniques for these data were relatively primitive, produced on 25 km grids using the original EASE-
Grid definition that is not easily accommodated in modern software packages. Funded by NASA MEaSUREs, we
have processed SMMR, SSM/I-SSMIS and AMSR-E (1978-2016) as gridded Earth System Data Records using
state-of-the-art image reconstruction methods. The improved spatial resolution, enhanced to 3 km for the
highest-frequency channels, is enabling new analysis of the sea ice concentration and SWE records, especially
in mountainous regions that had not previously been possible. We will summarize the methods used to
improve spatial resolution and include examples of melt onset detection and melt onset variability in the high-
relief Upper Indus Hunza basin (13,000 sq. km, at 36N, 74E).

678
1605
Thermodynamic Technique for Estimating Ice Thickness from a Moving Icebreaker

Ola Persson1 (ola.persson@colorado.edu), Byron Blomquist1, Blake Weissling2, Stephen Ackley2, Christopher
Fairall3
1
University of Colorado/CIRES/NOAA/ESRL/PSD, Boulder, United States, 2University of Texas at San Antonio, San
Antonio, United States, 3NOAA/Earth System Research Laboratory/PSD, Boulder, United States

Ice thickness is a crucial parameter for coupled modeling on many time scales, for understanding ice evolution,
and for the increasing polar operational maritime navigation. Correct ice thickness initialization has been
recently identified as having the greatest impact on seasonal sea-ice forecasting, and even on seasonal
terrestrial temperature anomalies. The proposed thermodynamic technique has previously been used with
satellite measurements, but its use from an icebreaker allows elimination of some key assumptions and derived
quantities to be directly measured. Measurements of the surface temperature over sea-ice in combination with
measurements of surface energy budget terms allows the retrieval of ice thickness through inversion of a
thermodynamic model. High temporal-resolution data, including the surface energy budget, from the Sea State
research cruise in autumn 2015 are used for the ice thickness retrieval and validation. This cruise provides
three other sources of independent measurements/estimates of ice thickness to be used as validation,
including 1 Hz data from an electromagnetic device. The resultant 1 Hz ice thickness data set provides a
resolution of approximately 3 m along the track of the ship. Ice statistics parameters, such as ice concentration,
derived from the thicknesses have a nominal resolution of 2 km. This provides a unique data set with numerous
scientific uses, a few of which will be illustrated.

679
1954
An New Algorithm to Detect Blowing Snow from Ceilometers in East Antarctica

Alexandra Gossart1 (alexandra.gossart@hotmail.com), Niels Souverijns1, Irina V. Gorodetskaya2, Stef

Lhermitte3, Jan T.M. Lenaerts4, Stephen P. Palm5, Nicole P.M. van Lipzig1
1
KU Leuven, Department of Earth and Environmental Sciences, Leuven, Belgium, 2University of Aveiro, Centre for
Environmental and Marine Studies, Aveiro, Portugal, 3TU Delft, Department of Geoscience and Remote Sensing,
Delft, Netherlands, 4University of Colorado Boulder, Department of Atmospheric and Oceanic Sciences, Boulder,
United States, 5Science Systems Applications Inc., Maryland, United States

Surface mass balance (SMB) strongly controls spatial and temporal variations in the Antarctic Ice Sheet (AIS)
and its contribution to sea level rise. The current scarcity of observational data and the challenges of climate
modelling over the ice sheet limit our understanding of the processes controlling AIS SMB. Particularly, the
impact of blowing snow (BS) on local SMB is not yet constrained and is subject to large uncertainties.
Tho assess the impact of BS on local SMB, we investigate the backscatter profiles from ceilometers at two East
Antarctic locations in Dronning Maud Land. In addition to the traditional cloud base height and vertical
structure retrievals, these instruments also provide information on the particles present in the boundary layer.
We developed a new algorithm to detect BS from the ceilometer attenuated backscatter.
BS detection is also possible by satellite imagery: the near-surface BS layers are apparent in CALYPSO lidar
backscatter profiles and enable BS events detection. However, the remote sensing detection of these events is
limited to minimal BS layers thicknesses of 20-30 m. In addition, thick clouds, mostly occurring during winter
storms, can impede BS detection from satellite products while the algorithm indicates that the majority of
these events occur together or shortly after a storm. We will compare both ceilometer and satellite detections
of BS, and present case studies focusing on the days when concurrent and divergent retrieval occur.

680
1957
Calibration and Validation of SARIn Radar Altimetry for Mass Balance Estimation

Richard Ashley Morris1 (richard.ashley.morris@npolar.no), Geir Moholdt1, Laurence Gray2, Thorben Dunse3,
Thomas Schuler3
1
Norwegian Polar Institute, Tromsø, Norway, 2University of Ottawa, Department of Geography, Environment
and Geomatics, Ottawa, Canada, 3University of Oslo, Department of Geosciences, Oslo, Norway

Cryospheric applications of radar altimetry are hampered by spatiotemporal variability of signal penetration
into snow, and uncertainties in the location of the Point of Closest Approach over sloping glaciers, ice caps, and
ice sheet margins. The SARIn mode of the SIRAL instrument onboard ESA's CryoSat-2 allows Doppler and
Interferometric processing, overcoming the latter limitation, and providing spatially extensive measurements
of ice elevation. However, strong backscatter from within the snowpack, as well as underlying firn and glacial
ice has the potential to lead to a 'radar elevation' which is below the physical surface. Airborne and field-based
calibration and validation campaigns are necessary to assess this bias, allowing more precise calculation of
elevation change and mass balance. Here, we present results from the 'Radar altimetry for ice mass balance -
impact of melting and refreezing in the snowpack' project, which aims to derive optimum techniques for
elevation change estimation over glaciers and ice caps in different climatic regimes, using Austfonna, Svalbard
as an analogue for melt-affected snowpacks in the Arctic, and ice rises on Fimbulisen, Antarctica, as an
analogue for dry snowpacks. In particular, we focus on bias estimation through the comparison of radar
elevations with co-located GPS and Airborne Laser Scanner elevations from Svalbard and Antarctica.
Additionally, we highlight glaciological results from Svalbard and Dronning Maud Land, Antarctica.

681
2409
A Decade of Changes of Glacier Facies Extents on Hansbreen (Svalbard)

Barbara Barzycka1 (bbarzycka@us.edu.pl), Mariusz Grabiec1, Małgorzata Błaszczyk1, Dariusz Ignatiuk1, Jacek
Jania1
1
University of Silesia, Department of Geomorphology, Sosnowiec, Poland

Extents of glaciers facies can facilitate estimations of glaciers mass balance and assessment of their drainage
systems. In addition, changes in facies spatial distribution in time are indicative of glaciers response to the
warming climate of the Arctic. Especially advantageous for distinguishing glaciers facies are Synthetic Aperture
Radar (SAR) satellite sensors, which are sensitive on surface characteristic and independent on sunlight.
However, due to complexity of SAR data, in situ measurements are recommended for their validation. For
verification of glaciers facies determination both Ground Penetrating Radar (GPR) and shallow ice cores are
very valuable source of information.
In our study, we analysed both SAR and in situ data in order to distinguish extends of facies of Hansbreen
during last 10 years. Analysis included both simple classification of single- and dual-polarisation SAR data
(thresholding, unsupervised classifications) and advanced analysis of fully-polarimetric images (H-α
segmentation). For validation purposes we visually interpreted GPR data and applied Internal Reflection Energy
(IRE) coefficient, sensitive on glacier's subsurface characteristic. Shallow ice cores provided additional
information on the thickness and character of the facies and helped to assess the GPR visual interpretation. As
a result, we present changes of Hansbreen's facies during last 10 years with a description of advantages and
limitations of SAR sensors and methods of analysis.

682
2681
UAV Multispectral Remote Sensing of Sub-arctic Ponds (Nunavik, Canada)

Pedro Freitas1, Goncalo Vieira2,3 (vieira@campus.ul.pt), Simone Girst1, Carla Mora2, João Canário4, Warwick F.
Vincent3
1
IGOT - Universidade de Lisboa, Lisboa, Portugal, 2CEG/IGOT - Universidade de Lisboa, Lisboa, Portugal, 3Centre
d'Etudes Nordiques, Universite Laval, Quebec, Canada, 4CQE, Instituto Superior Técnico, Universidade de Lisboa,
Lisboa, Portugal

Thaw ponds are frequent features in Arctic and Sub-Arctic wetlands associated with degrading ice-rich
permafrost. They show strong biogeochemical dynamics and are important players in the carbon cycle. Arctic
warming is accelerating thaw, affecting whole landscapes and influencing hydrology and soils, generating new
conditions for ecosystems and human activities. Significant changes have been affecting the tundra-forest
boundary, with a marked increase in both tree and shrub formations.
Identifying small ponds using remote sensing is an important challenge for quantifying the processes affecting
polar wetlands. The launch of Sentinel 2-A in 2015 and Sentinel 2-B in 2017 (S2 - 10 m resolution), that
followed Landsat 8 (L8 - 30 m resolution) in 2013, offering revisiting times of a few days, opened a new breadth
of possibilities for monitoring and advancing the understanding of remote Arctic and Sub-Arctic regions. Two
field surveying missions were conducted in the summers of 2015 and 2017 in the sporadic and discontinuous
permafrost zones (Kuujjuarapik and Umiujaq, Nunavik) using an Unmanned Aerial Vehicle (UAV) and a
multispectral camera. The high spatial resolution (ci 15 cm) and spectral quality of the imagery provides ground
truthing and allows assessing the quality of Landsat-8 and Sentinel-2 imagery and their accuracy for regional
assessments of landcover, including lake colour.

683
OS-2b - Interdisciplinary research on sea-ice biogeochemistry and associated ecosystems
20.06.2018 11:00-12:30, A Wisshorn

231
Sea-ice Phenology in a Warmer Arctic

Letizia Tedesco1 (letizia.tedesco@environment.fi), Marcello Vichi2, Enrico Scoccimarro3

1
Finnish Environment Institute, Marine Research Centre, Helsinki, Finland, 2University of Cape Town, Cape Town,
South Africa, 3Euro-Mediterranean Center on Climate Change, Bologna, Italy

Future projections of Arctic sea-ice changes are alarming, but the response of the ice-associated biological
community is still uncertain. Here we investigate future changes in timing and intensity of primary production
in Arctic first-year ice using a combination of climate and sea-ice biogeochemistry models. Overall, model
results suggest a general increase in sea-ice primary production at all latitudes during this century. However,
the projected phenological changes are not as quasi-monotonic as the changes in physical drivers. Three
latitudinal clusters are identified and distinctly explained by snow cover thinning at the lowest latitudes,
biological time windows narrowing in the mid latitudes, and ice seasons advancing towards more favourable
photoperiods at the highest latitudes. When considering the changes in ice extent, the increase in sea-ice
production at the highest latitudes is boosted due to significant first-year ice expansion at the expense of
multiyear ice. The projected changes in sea-ice primary production suggest potential far-reaching
consequences for the whole Arctic marine food web.

684
1777
Scales of Variability of Sea-ice Algae in Spring: Observations and Model Results

Giulia Castellani1 (giulia.castellani@awi.de), Ilka Peeken1, Benjamin A. Lange2, Hauke Flores1

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Biosciences - Polar Biological
Oceanography, Bremerhaven, Germany, 2Fisheries and Ocean Canada, Freshwater Institute, Winnipeg, Canada

Sea ice provides a stable environment for algae growth and survival. In the Arctic Ocean, ice associated algae
guarantee a food source for sympagic and pelagic biota. The rapid decline of Arctic sea ice and the changes in
its physical structure will lead to a new biological environment causing shifts in sea-ice algae dependent
ecosystems. The impact of these changes on ice algae distribution and production can be quantified on large
scales by sea ice numerical models. These models need data for calibration, comparison and parameterization
of processes. Due to the high variability of sea-ice physical, chemical and biological properties, field sampling
and representative model output of ice algae are challenging. In this work we present data from a 2-weeks ice
station in the Arctic Ocean in spring 2017. Sea-ice algal chl a has been sampled at different spatial scales to
asses its variability, and to determine any relationship of sea ice algae distribution with the variability of
physical and chemical sea ice properties in spring. In addition, this work focuses on the study of ridged and
deformed ice. We present a characterization of the biophysical environment of ridges in terms of temperature,
salinity, nutrients, biomass. The results are used to assess the importance of ridges for the total biomass. We
upscale the along-transect variability of sea-ice algae on a floe scale and on the average grid length of sea-ice-
ocean numerical models to compare with recent model results.

685
2195
Progress in Modelling Coupled Sympagic-pelagic Ecosystems in the Canadian Arctic

Eric Mortenson1 (ericthemort@gmail.com), Hakase Hayashida1, Adam Monahan1, Tessa Sou2, Nadja Steiner1,2
1
University of Victoria, Victoria, Canada, 2Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney,
Canada

We will summarize recent progress in coupling sympagic (ice-associated) and pelagic ecosystems using 1-D and
3-D model approaches. The 1-D model studies highlight processes relevant to adequately represent ice algal
growth, as well as carbon and sulfur fluxes. Important processes include ecosystem productivity, ice growth
(via brine transport) and melt, and air sea exchange. 3-D model studies highlight gaps and issues when
transferring parameterisations from 1-D to 3-D as well as preliminary results with respect to ice algal and
pelagic primary production and air-ice-sea sulfur and carbon exchanges.

686
2090
Winter to Summer CO2 Chemistry in Antarctic Sea Ice

Elizabeth Jones1,2,3 (elizabeth.jones@imr.no), Mairi Fenton4, Jacqueline Stefels2, Maria van Leeuwe2, Sharyn
Ossebaar3, Hein de Baar2,3
1
Institute of Marine Research, Tromsø, Norway, 2University of Groningen, Groningen, Netherlands, 3Royal
Netherlands Institute for Sea Research, Den Burg, Netherlands, 4British Antarctic Survey, Cambridge, United
Kingdom

The west Antarctic Peninsula is a highly productive ecosystem where sea ice plays an important role in
biological processes and the biogeochemical cycling of carbon and other elements. Carbon dioxide (CO2)
chemistry in sea ice and under-ice water was investigated to examine ice-ocean exchanges from austral winter
to summer in the Antarctic coastal zone. Algal production and CO2 uptake reduced winter concentrations of
inorganic carbon (CT) to less than 200 µmol/kg within the ice pack. Sea ice total alkalinity (AT) reached lowest
values (< 100 µmol/kg) during melting of the sea ice. Processes in the sea ice such as brine rejection and
carbonate (CaCO3) mineral precipitation also affected the carbon chemistry, increasing the AT-CT ratio in the ice
to >1.5 from winter to summer. Nitrate concentrations at the ice-water boundary were enriched compared to
bulk ice by late summer, likely resulting from re-supply from underlying ocean waters and sustaining ice-algal
CT uptake. Biological production and CaCO3 dissolution during sea ice melt increased the AT-CT ratio in the
under-ice water by late summer. Concomitant reduction in sea surface CO2 enhanced CO2 uptake upon retreat
of the ice pack. Wintertime remineralisation of organic matter contributed to enhanced inorganic carbon and
nitrogen in the snow-capped sea ice. This study reveals intense biogeochemical cycling in Antarctic sea ice to
help to further elucidate the role of sea ice and ice-ocean interactions in a changing climate.

687
699
Seasonal Evolution of Light Transmission through Central Arctic Sea Ice

Christian Katlein1, Stefanie Arndt1, H. Jakob Belter1, Marcel Nicolaus1 (marcel.nicolaus@awi.de)

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany

Light transmission through sea ice has been identified as a critical process for energy partitioning at the polar
atmosphere-ice-ocean boundary. Transmission of sunlight influences direct sea ice melting by absorption, heat
deposition in the upper ocean, and in particular primary productivity. The recent years have seen an increase in
spatially distributed light measurements underneath sea ice using remotely operated vehicles. These
measurements allow us to reconstruct the seasonal evolution of the spatial variability in light transmission.
Here we present measurements of sea ice light transmittance from 6 years of polar ROV operations. The
dataset covers the entire melt cycle of Central Arctic sea ice. This data from multiple years is combined into a
pseudo timeseries describing the seasonal evolution of the changing spatial variability of sea ice optical
properties. Snow melt in spring increases light transmission continuously, until a secondary mode originating
from translucent melt-ponds appears in the histograms of light transmittance. This secondary mode persists
long into autumn, before snow fall reduces overall light levels again. Comparison to several autonomous time
series measurements from single locations confirms the detected general patterns of the seasonal evolution of
light transmittance variability. These results will allow further insights on the validity of radiation transfer
parameterization used in ice-ocean models.

688
1778
Review on Status and Changes of the Barents Sea System

Sebastian Gerland1 (gerland@npolar.no), Tor Eldevik2, Marit Reigstad3

1
Norwegian Polar Institute, Tromsø, Norway, 2Geophysical Institute, University of Bergen, Bergen, Norway,
3
Institute of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway

As a part of the new Norwegian research project “Nansen Legacy”, involving eight Norwegian governmental
and two private research institutions (https://site.uit.no/nansenlegacy/), a scientific review about the status
and changes in the Barents Sea System is developed. We will present first results from this synthesis, focusing
on the physical, biological and biogeochemical systems. The review is based on recent peer-review publications
about the region, with additional use of publically available longterm monitoring data, such as satellite-based
sea ice extent. The Barents Sea represents both geographically and temporarily a gateway to a changing Arctic:
It is connected to the Arctic Basin in the central Arctic and ocean currents, sea ice drift and ship traffic illustrate
this connection. One question scientists work with is to what extent the Barents Sea can be seen as a sentinel
for current changes that in a similar way could happen in the future in other Arctic regions. The Barents Sea is
highly relevant as a part of the climate system, as a habitat, and within socio-economics. It is exposed to
natural forcing and direct or indirect human impacts, and it is is changing relatively fast, compared with other
Arctic regions. We will present examples of such changes and relevant processes, including results from
numerical modelling.

689
CR-3c - Cryosphere-Hydrosphere interactions: The water cycle at the three Poles
20.06.2018 11:00-12:30, B Parsenn

649
Global-scale Hydrological Response to Future Glacier Mass Loss

Matthias Huss1,2 (huss@vaw.baug.ethz.ch), Regine Hock3,4

1
ETH Zurich, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), Zurich, Switzerland, 2University of
Fribourg, Department of Geosciences, Fribourg, Switzerland, 3University of Alaska Fairbanks, Geophysical
Institute, Fairbanks, United States, 4Uppsala University, Department of Earth Sciences, Uppsala, Sweden

Worldwide glacier retreat and associated future runoff changes raise major concerns over the sustainability of
global water resources, but global-scale assessments of glacier decline and resulting hydrological consequences
are scarce. Here, we compute global glacier runoff changes until 2100 for three greenhouse gas emission
scenarios and analyze the glacial impact on streamflow for 56 large-scale glacierized drainage basins on Earth.
In roughly half of the investigated basins modelled annual glacier runoff continues to rise until a maximum
(´peak water´) is reached, beyond which runoff steadily declines, while in the remaining basins this tipping
point has already been passed. Peak water occurs later in basins with larger glaciers, higher ice-cover fractions,
and at higher latitudes. Most basins experience future glacier runoff increases in early summer but decreases in
late summer. Although most of the 56 basins have below 2% ice coverage, by 2100 one third of them might
experience runoff decreases greater than 10% in at least one melt season month due to glacier mass loss. The
reductions are largest in central Asia and the Andes, hence exacerbating future water stress in these regions.
We conclude that even in large-scale basins with minimal ice-cover fraction, the downstream hydrological
effects of continued glacier wastage can be substantial, but magnitudes vary greatly among basins and
throughout the melt season.

690
753
Pan-Third Pole Environment (Pan-TPE)

Tandong Yao1 (tdyao@itpcas.ac.cn)

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

Tibetan Plateau and its surrounding areas are known as the earth's Third Pole (TP). Major environmental
changes are taking place on the TP characterized by complex interactions of atmospheric, cryospheric,
hydrological, geological and environmental processes. We identified three modes of the modern westerlies-
monsoon interaction system based on variation patterns of precipitation stable isotopes on the TP: Indian
monsoon mode, westerlies mode and transition mode. The three modes directly affect environmental changes
on the TP. We found the largest retreat of glaciers in the monsoon mode on southern TP, moderate retreat in
the transition mode on central TP, and the least retreat, or even slight advance in the westerlies mode on
northwestern TP. Further study shows that the enhancing westerlies against the weakening summer monsoon
is the major driver of regional differences in environmental changes on the TP.
As TP research goes further, the Third Pole environment is not isolated, interacting with the changes in the
Northern hemisphere and even the Arctic and Antarctic. The new program, called Pan-TPE, works to
characterize the scenarios of monsoon-westerly interaction and its implications, the water-ecosystem
interaction and oasis sustainability, as well as human and disaster impact on environment and consequent
uncertainties, regarding earth system behavior in Pan-TP. It endeavors to map out a coordinated strategy for
regional sustainable development with scientific vision.

691
1503
Impact of a Global Temperature Rise of 1.5 °C on Asia's Glaciers

Philip D.A. Kraaijenbrink1 (p.d.a.kraaijenbrink@gmail.com), Marc F.P. Bierkens1,2, Arthur F. Lutz3, Walter W.
Immerzeel1,4
1
Utrecht University, Physical Geography, Utrecht, Netherlands, 2Deltares, Utrecht, Netherlands, 3FutureWater,
Wageningen, Netherlands, 4International Centre for Integrated Mountain Development, Kathmandu, Nepal

Glaciers in the high mountains of Asia (HMA) play a substantial role in regional water resources. In general,
these glaciers have been losing mass over the last decades, a trend that is most likely to persist in the future. In
2015, 195 nations signed the “Paris Agreement” and agreed on efforts to limit the global temperature rise to
1.5 °C. It is unknown, however, how much of Asia's ice will be lost under a 1.5 °C temperature increase, or
under more extreme temperature scenarios. To determine this, we modelled all individual glaciers in HMA
larger than 0.4 km2 transiently up to 2100 using the entire CMIP5 ensemble within a Monte Carlo framework to
account for parameter uncertainty. Only a handful of the climate models project a global temperature rise of
1.5 °C. Under such a scenario HMA warms stronger than the global average (2.1±0.1 °C). By the end of the 21st
century, the 1.5 °C scenario results in a 36±7% mass loss relative to the present-day ice mass. Mass losses
projected by RCP4.5, RCP6.0 and RCP8.5 ensembles are considerably higher with 49±7%, 51±6% and 65±6%,
respectively. Results also show large regional differences, which are primarily caused by differences in debris
cover, ice mass, observed mass balance, and glacier sensitivity to climate perturbations. We conclude that even
under the ambitious 1.5 °C scenario over one third of HMA's glacier mass will be lost by the end of century, and
that the difference with more likely scenarios is considerable.

692
903
Fate of Glaciers on the Tibetan Plateau by 2100

Keqin Duan1 (kqduan@snnu.edu.cn), Tangdong Yao2

1
Shaanxi Normal University, Xi'an, China, 2Institute of Tibetan Plateau Research, Chinese Academy of Sciences,
Beijing, China

As the third polar on the Earth, the Tibetan plateau holds more than 40,000 glaciers which have experienced a
rapid retreat in recent decades. Glacier loss has increased concern for water resources around the Tibetan
plateau. The variability of equilibrium line altitude (ELA) indicates expansion and wastage of glacier directly.
Here we simulated the ELA variability in the Tibetan Plateau based on a full surface energy and mass balance
model. The simulation results are agreement with the observations. The ELAs have risen at a rate of 2-8m/a
since 1970 throughout the Plateau, especially in the Qilian Mountain and the southeastern Plateau where the
ELAs have risen to or over the top altitude of glacier, indicating the glaciers are accelerating to melting over
there. Then the future ELA variability on the Tibetan plateau are forecasted in the scenarios of RCP2.6, RCP4.5
and RCP 8.5 given by IPCC. The results show the ELAs of most glaciers will arrive to its maximum in around 2040
in RCP2.6. While the ELAs will be over the top altitude of glaciers in the eastern Plateau in 2040-2050 in RCP4.5
and RCP8.5, suggesting most of the glaciers on the Tibetan Plateau will accelerate to melt until to disappear by
the end of 2100.

693
1365
Possible Impacts of Black Carbon on Water Cycle Pattern over the Third Pole

Baiqing Xu1 (baiqing@itpcas.ac.cn), Mo Wang1

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

Water cycle pattern over the Third Pole has been changed apparently since the early-1990s. Stabilization even
advance of glaciers and expansion of lakes accompanied with an increase of precipitation were found in the
northwest Third Pole dominated by westerlies, in contrast to an accelerated decline of glaciers and lakes led by
a decrease of precipitation in the south and east controlled by Indian monsoons. Despite its far-reaching
influence on regional water supply, the reason is unknown. Here, we propose black carbon (BC) may have a
dominating contribution to the different water cycle patterns in the Third Pole, demonstrated by 8 sequences
of BC concentration for the last 150 years documented in ice cores. We found BC concentration has decreased
by half since the early-1990s in westerly domain, while doubled in Indian monsoon region due to an increased
emission in South Asia. It indicates BC effect on glacier melt has been greatly reduced in westerly domain, but
increased in monsoon region, as well as its effect on rainfall suppression by interacting with clouds, especially
an effect called “cloud-top gathering BC” in our new finding. The opposite trends of BC content in both glacier
and atmosphere can explain the different water cycle patterns in the same background of global warming. We
suggest reducing BC emission in South Asia can effectively mitigate glacier melting and increase precipitation in
Indian monsoon region as happened in the westerly domain.

694
1970
The Role of Vegetation Dynamics in the Water Cycle over the Pan-Third Pole

Tao Wang1 (twang@itpcas.ac.cn)

1
The Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

Changes in terrestrial vegetation could modulate the water cycle, with direct impacts on changes in soil
moisture, evapotranspiration, streamflow and regional precipitation. The pan-Third pole vegetation has
witnessed significant variations over the past several decades. However, analyses of the impacts of vegetation
changes on the water cycle has so far been lacking over this region. Here we examined consequences of the
two contrasting scenarios of vegetation changes (vegetation restoration and degradation) on the water cycle.
The first case is to quantify the impact of large-scale ecological restoration program implemented in the
headstream region of Yangtze River since 2000. Our analyses showed that grassland restoration in the
headstream reduces the streamflow and increased evapotranspiration (ET), which improves local soil water
conditions but undercuts any gain in downstream water resources associated with precipitation increases. The
second case is to understand the role of deforestation in driving the long-lasting drying trend that is widely
observed in the South Asian monsoon region of the pan-Third pole. We indicate that deforestation is the
second primer driver of summer drying trend over the 20th century, while increasing aerosol emissions
primarily contribute to this drying trend. Our results from these two case studies highlighted the importance of
vegetation changes in understanding the past and future evolution of the water cycle over the pan-Third Pole.

695
BE-6b - Ongoing change in terrestrial and freshwater ecosystems of Polar Regions
20.06.2018 11:00-12:30, B Jakobshorn

2141
Causes of Multi-decadal Environmental Change near Toolik Lake, Arctic Alaska

George Kling1 (gwk@umich.edu), Gaius Shaver2, John Hobbie2, Anne Giblin2, Vladimir Romanovsky3, Edward
Rastetter2
1
University of Michigan, Ecology and Evolutionary Biology, Ann Arbor, United States, 2Marine Biological
Laboratory, Woods Hole, United States, 3University of Alaska - Fairbanks, Fairbanks, United States

Long-term data near the Arctic LTER site in arctic Alaska show 40 years of environmental change on land and in
surface waters. While some changes have been substantial (e.g., a doubling of alkalinity in Toolik Lake and an
increase in permafrost temperatures and NDVI), other changes are small or undetectable. In addition, changes
in the drivers of these trends, e.g., increases in air temperature or mean catchment thaw depth, have been
muted. Clearly these terrestrial and aquatic ecosystems are vulnerable to change, and the stressors causing the
changes are either undiscovered or hidden from our ability for detection. One hypothesis to explain the
variability in ecosystem response is that certain changes are integrating the effects of a climate signal on multi-
year to decadal time scales, acting as a medium-pass filter of climate that reduces the signal variability yet
allows the effects of long-term warming to emerge, as seen in the alkalinity, NDVI, and permafrost temperature
records. Other likely effects of climate change on the landscape are seen in dramatic land-surface disturbances
such as thermokarst failures and tundra fires, which have the potential to rapidly alter land and water
biogeochemistry and may result in larger transformations than will the steady trends of climate change. Similar
environmental changes may be occurring in unmonitored regions of the Arctic, even when the obvious drivers
of climate have changed little over time.

696
1543
Groundwater Exchanges on the Land Surface Control Stream Chemistry in Permafrost

Bethany Neilson1, M. Bayani Cardenas2 (cardenas@jsg.utexas.edu), Michael O'Connor2, Mitchell Rasmussen1,

Tyler King1, George Kling3
1
Utah State University, Civil and Environmental Engineering, Logan, United States, 2University of Texas at
Austin, Geological Sciences, Austin, United States, 3University of Michigan, Ecology and Evolutionary Biology,
Ann Arbor, United States

The mechanisms for export of dissolved carbon (C) and nitrogen (N) from land to rivers and lakes are poorly
understood in arctic landscapes. In watersheds with continuous permafrost, overland flow at high discharge is
thought to dominate export. We show here that surface microtopography drives overland flow into the
ground, where surface water exchanges with soil waters having higher C and N concentrations. These surface-
subsurface exchanges in the seasonal shallow aquifer control dissolved organic C and N export, regardless of
whether the landscape is saturated or inundated by overland flow. Combined with rapid leaching of organic
matter in shallow soils, these vertical exchanges explain the relatively constant dissolved C and N stream
concentrations observed across a wide range of stream discharge. The dominance of groundwater influence on
surface water C and N export, and the response of these transport and exchange mechanisms to ongoing
permafrost thaw, is key to the fate of organic C and N stored in arctic soils.

697
645
How Do CO2 and CH4 Effluxes from Toolik Lake Change with Climate Change?

Werner Eugster1 (werner.eugster@usys.ethz.ch), Tonya DelSontro2, Gaius R. Shaver3, George W. Kling4

1
ETH Zurich, Department of Environmental Systems Science, Zurich, Switzerland, 2Université du Québec à
Montréal, Département des Sciences Biologiques, Montréal, Canada, 3Marine Biological Laboratory, Ecosystems
Center, Woods Hole, United States, 4University of Michigan, Department of Ecology & Evolutionary Biology, Ann
Arbor, United States

Effluxes of CO2 and CH4 from Toolik lake, northern Alaska, during the ice-free season were measured from 2010
to 2015 using the eddy covariance technique. Measurements were made on a floating platform ca. 400 m from
the lake shore. Our measurements are thus representative of the open water where the lake is deep enough to
show a distinct thermal stratification throughout most of the ice-free season (typically end of June to mid-
September). We analyzed the relationship between daily aggregated CO2 and CH4 fluxes and lake level height,
hypothesizing that a low lake level would increase gas evasion from the lake and thus enhance the fluxes of
these two greenhouse gases. Our measurements however showed that (a) ebullition of gases from bottom
sediments was not detectable with a sonar device, thus indicating that diffusive fluxes are dominating total
efflux; that there is a significant increase of (b) daily CO2 effluxes with increasing lake level (p=0.029); and (c) of
CH4 fluxes with increasing lake level (p=0.005). Over the 28 years of continuous lake level measurements a
significantly decreasing trend of 1.0 ± 0.2 cm per year was observed (except for the annual maximum lake
level), which suggests that CO2 and CH4 effluxes should slightly decrease over time if this trend continues. This
actual trend is in contrast to predicted increases in precipitation by 2100, which should increase rather than
decrease the lake level, thereby increasing CO2 and CH4 effluxes.

698
307
Variability of Ecosystem Connectivity in the McMurdo Dry Valleys, Antarctica

Michael Gooseff1 (michael.gooseff@colorado.edu), Byron Adams2, Jeb Barrett3, Shawn Devlin4, Peter Doran5,
Adrian Howkins6, Diane McKnight1, Rachael Morgan-Kiss7, John Priscu8, Cristina Takacs-Vesbach9
1
University of Colorado, INSTAAR, Boulder, United States, 2Brigham Young University, Biology Department,
Provo, United States, 3Virginia Tech, Biological Sciences, Blacksburg, United States, 4University of Montana,
Flathead Lake Biological Station, Polson, United States, 5Louisiana State University, Geological Sciences, Baton
Rouge, United States, 6University of Bristol, Environmental History, Bristol, United Kingdom, 7University of
Miami, Department of Microbiology, Miami, United States, 8Montana State University, Land, Resources, and
Environmental Sciences Department, Bozeman, United States, 9University of New Mexico, Biology Department,
Albuquerque, United States

The McMurdo Dry Valleys are the largest ice-free area of Antarctica, made up of exposed soils, glaciers,
streams, and ice-covered closed-basin lakes. The connections among these landscape units facilitate the
movement of energy, mass, and biota - largely driven by physical processes of glacier melt water transport and
aeolian transport. Glacial melt occurs during a 6-10 week period in the austral summer, with significant
interannual variability. Aeolian transport, however, typically occurs during strong foehn events, which are most
common during the austral winter. Despite these two primary modes of transport being out of phase, their
impacts are most significant during the austral summer, when biological activity is the highest. Here we explore
the ecosystem impacts of these differential connections.

699
1684
The Ecology of Small Glacier Animals: A Case Study from the Arctic

Marie Sabacka1 (sabacka.marie@gmail.com), Tobias Vonnahme2, Karel Janko3, Krzysztof Zawierucha

Zawierucha3, Miloslav Devetter4, Josef Elster1
1
University of South Bohemia, Centre for Polar Ecology, Ceske Budejovice, Czech Republic, 2The Arctic University
of Norway, Department of Arctic and Marine Biology, Tromso, Norway, 3Institute of Animal Physiology and
Genetics, Libechov, Czech Republic, 4Institute of Soil Biology AS CR, Ceske Budejovice, Czech Republic

Unique freshwater environments, called cryoconite holes, occur globally on the surface of glaciers. They are
predominantly water filled and frozen throughout the winter and can cover up to 10% of the ablation zone of a
glacier. These microhabitats host diverse viral, prokaryotic and eukaryotic life forms and are among the most
productive ecosystems in the Polar Regions. The organisms living within the holes are able to cope with cold,
dryness, strong winds and low levels of nutrients, and include small grazing animals such as rotifers and
tardigrades. Whilst the autotrophic and bacterial communities have received considerable attention over the
past decade, the grazing predators and their role on the cryoconite community composition and productivity
remains an enigma.
These small animals occur in high numbers in cryoconite holes in Petuniabukta glaciers, Svalbard, and are likely
to play a key role in recycling of nutrients, which is extremely important in sustaining the physiological
functioning of the autotrophic and bacterial communities. The aim of this project is to understand the role of
small grazing predators (rotifers and tardigrades) on the ecology of the cryoconite holes by assessing their
effect on biogeochemical cycling and ecosystem production within the cryoconite communities.
Initial findings showed that nutrient levels related to recycling of limiting nutrients are the main factor driving
variation in the community structure of microalgae and grazers.

700
2145
Roles of Hydrologic Variability in Understanding Arctic River lTemperature

Bethany Neilson1 (bethany.neilson@usu.edu), Tyler King1, Douglas Kane2

1
Utah State University, Civil and Environmental Engineering, Logan, United States, 2University of Alaska -
Fairbanks, Civil and Environmental Engineering, Fairbanks, United States

Understanding the dynamics of heat transfer in arctic rivers is critical for forecasting the effects of climate
change on river temperatures. Building on the collection of five years of data throughout the Kuparuk River
basin in Alaska, USA, spanning dry to wet summer seasons, we have adapted a dynamic river temperature
model to quantify heat fluxes during varied hydrologic conditions in order to understand drivers of thermal
change in arctic systems. We have identified hydrologic conditions where the dominant heat fluxes shift from
lateral inflows, to solar radiation, to hyporheic exchange. We found that accounting for the mass contribution
of lateral inflows throughout the basin was critical during high flow periods. However, the lower order portion
of the basin is more sensitive to the temperatures assigned to these inflows. Under lower flow conditions,
temperatures in the lower order portion of the basin also shift from a high dependence on lateral inflows to
one relying primarily on air-water or surface heat exchanges. During the lowest flow conditions, the system is
still dependent on these surface heat fluxes, but the heat transfer with the bed sediments, primarily via
hyporheic exchange, rivals their influence and significantly buffers instream temperatures. Together the data
and modeling results provide insight into the potential influences of the changing climate and the associated
hydrologic shifts in areas of continuous permafrost.

701
AC-1e - Polar and high altitude atmosphere: clouds, aerosols, climate and interactions
20.06.2018 11:00-12:30, C Sanada I

246
Arctic Cloud Residual and Ambient Aerosol Properties Measured during ACLOUD

Stephan Mertes1 (mertes@tropos.de), Udo Kästner1, Oliver Eppers2,3, Marco Zanatta4, Johannes Schneider2,
Heiko Bozem3, Emma Järvinen5, Olivier Jourdan6, Andreas Herber4
1
Leibniz Institute for Tropospheric Research, Leipzig, Germany, 2Max Planck Institute for Chemistry, Mainz,
Germany, 3Insitute for Atmospheric Physics, University of Mainz, Germany, 4Alfred Wegner Institute,
Bremerhaven, Germany, 5Karlsruhe Institute of Technology, Karlsruhe, Germany, 6Laboratoire de Météorologie
Physique, Université Clermont Auvergne, Clermont Ferrand, France

Supercooled or mixed-phase clouds are suspected to contribute considerably to the amplified warming of the
Arctic. Thus, it is studied which arctic aerosol particles are involved in their formation during the aircraft-based
field campaign ACLOUD, part of the German arctic research project (AC)3. In May/June 2017 cloud particles of
low and mid-level clouds were sampled by means of a Counterflow Virtual Impactor inlet (CVI) aboard the Polar
6 aircraft in order to characterize their cloud particle residues (CPR), which are closely related to the original
cloud condensation and ice nuclei. Number density, size distribution, chemical composition and mixing state of
the CPR are determined to derive which aerosol particles form the arctic clouds. A case study reveals that all
particles larger 150 nm are activated and that the 50% activation diameter is around 115 nm.
Beside these in-cloud investigations, it is of great importance to infer the origin of the cloud forming particles
(natural vs anthropogenic, local vs long range transported) by measuring the vertical profiles of the same
aerosol parameters from below cloud inside the boundary layer across the inversion up to the free troposphere
operating the CVI as aerosol inlet. First results show particle number accumulation at the lower inversion,
depletion above the cloud layer and a strong increase in long-range transported pollution layers. Absolute
values of the BC mass concentration are found to be in the order of 50 ngm-3.

702
1041
ACE-SPACE: Overview of Southern Ocean Aerosol and Trace Gases Measurements

Julia Schmale1 (julia.schmale@psi.ch), Silvia Henning2, Andrea Baccarini3, Conor Bolas4, Katrianne Lehtipalo5,
Markus Hartmann2, Andre Welti2, Fiona Tummon6, Iris Thurnherr7, Franziska Aemisegger7, Heini Wernli7, Daniel
Rosenfeld8, Leighton Regayre9, Neil Harris10, Pascal Graf7, Irina Gorodetskaya11, Martin Schnaiter12, Frank
Stratmann2, Urs Baltensperger3, Josef Dommen3, Ken Carslaw9, Martin Gysel3
1
Paul Scherrer Institute, ENE, Villigen, Switzerland, 2Leibniz Insititute for Tropospheric Research, Leipzig,
Germany, 3Paul Scherrer Institute, Villigen, Switzerland, 4University of Cambridge, Cambridge, United Kingdom,
5
University of Helsinki, Helsinki, Finland, 6University of Tromsoe, Tromso, Norway, 7ETH Zurich, Institute for
Atmospheric and Climate Science, Zurich, Switzerland, 8Hebrew University of Jerusalem, Jerusalem, Israel,
9
University of Leeds, Leeds, United Kingdom, 10University of Cranfield, Cranfield, United Kingdom, 11University of
Aveiro, Centre for Environmental and Marine Studies, Aveiro, Portugal, 12Karlsruhe Institute of Technology,
Karlsruhe, Germany

The main purpose of the 'Study of Preindustrial-like-Aerosol Climate Effects' (SPACE) was to conduct a
comprehensive aerosol and trace gas characterization during the Antarctic Circumnavigation Expedition (ACE)
from December 2016 to March 2017 in partly unexplored areas of the Southern Ocean. The data are not only
of interest to understand atmospheric processes under pristine conditions, but also particularly to validate
satellite retrievals of aerosol properties and model simulations, which are both essentially unconstrained in
that region.
Here, we will present aerosol microphysical and chemical characteristics, discuss particle origin and trace gas
correlations. Important factors influencing aerosol properties were different meteorological conditions, the
thermodynamic structure of the boundary layer and ocean microbial regimes. For example, the leg between
South Africa and Australia experienced a series of low-pressure systems characterized by a large fraction of
Aitken mode particles, hinting at downward mixing of particles processed in the free troposphere. Near the
west Antarctic coast larger particles were found and associated with Antarctic air masses and potentially cloud
processing. They also contained methane-sulfonic acid. First results of a model-measurement intercomparison
will be shown as well.
Note, there will be two more ACE-SPACE contributions on cloud condensation nuclei and new particle
formation specifically.

703
1771
Aerosol and Surface Snow Chemical Composition at Dome C from 10-yr Long Records

Rita Traversi1 (rita.traversi@unifi.it), Silvia Becagli1, Laura Caiazzo1, Maurizio Busetto2, Francesco Calzolari2,
Paolo Cristofanelli2, Boyan Petkov2, Mirko Severi1
1
University of Florence, Chemistry Dept. 'Ugo Schiff', Sesto F.no, Italy, 2CNR-ISAC, Bologna, Italy

Chemical composition and the physical parameters of the atmospheric aerosol in the Antarctic plateau provide
basic information on the main natural inputs, tropospheric transformation and long-range transport processes
of the aerosol components. In addition, chemical and physical processes occurring at the atmosphere-snow
interface are yet not fully understood and work is needed to assess the impact of atmospheric chemistry on
snow composition and to better interpret ice core records there retrieved.
Thus, simultaneous aerosol and surface snow sampling was set up and run at Dome C station (75° 06' S; 123°
20' E, 3233 m a.s.l) all year-round over 2004-2013. Aerosol and snow samples were analyzed for main and trace
ion markers, in order to study the extent and timing of main aerosol sources as sea salt (open ocean/frost
flowers/blowing snow), biogenic production, crustal input, as well as transport
(e.g. free troposphere, stratosphere-troposphere exchange) and atmospheric reaction processes
(e.g. neutralization, chemical fractionation).
A comparison with ozone and solar irradiance measurements, carried out continuously over the same time
period, is also attempted to better constrain the atmospheric processes involving the atmosphere-snow
exchanges of N-cycle species.
Moreover, preliminary results achieved in the framework of a PNRA project (LTCPAA), started in 2016 and
continuing the previous 10-yr long sampling and direct measurement activity, are presented.

704
1924
Full System Characterization of a Summer to Winter Transition

Taneil Uttal1 (taneil.uttal@noaa.gov), Alexander Makshtas2, Andrey Grachev3, Tuomas Laurila4, Christopher
Cox3, Sara Morris3, Vasily Kustov2, Eija Asmi4, John Backman4
1
NOAA Earth System Research Laboratory, Physical Science Division, Boulder, United States, 2Arctic and
Antarctic Research Institute of Roshydromet (AARI), St Petersburg, Russian Federation, 3Cooperative Institute
for Research in Environmental Sciences, NOAA/ESRL/PSD, Boulder, United States, 4Finnish Meteorological
Institute, Helsinki, Finland

Measurements of turbulent and radiation fluxes, CO2, equivalent black carbon, aerosol sizes/concentrations,
meteorology and surface and near-surface temperatures are presented for a period during the fall freeze-up
period in 2013 at Tiksi, Russia. The measurements are assessed in the context of cloud forcing, the first snow
accumulations, and more winter-like, synoptic transport patterns and aerosol transports for expected and
unexpected correlations and dependencies. Four episodes of precipitation occurred, one synoptically driven
warming event, and 3 clear sky events which clearly impacted the timing of freeze up. The snow that
accumulated on the ground during the precipitation periods was important as it acted as an insulator and
essentially shut off communication between some atmosphere and surface for processes such as turbulent,
radiative and CO2 fluxes. For some components of the system the primary control was advection from either
local or remote source regions.One elevated equivalent black carbon (eBC) event was likely the result of long-
range transport while two shorter eBC events on were due to contamination from the town of Tiksi (north of
the observatory site). Ozone values were impacted by bromine sources from the open ocean - as the adjacent
bay froze, ozone levels began to rise to higher winter values. The forcers, responders and feedbacks in the
system are evaluated.

705
1967
Airborne Measurements in the Polar Boundary Layer over Sea Ice during ACLOUD

Christof Lüpkes1 (christof.luepkes@awi.de), Dmitry Chechin1, Andre Ehrlich2, Manfred Wendisch2

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Climate Sciences, Bremerhaven,
Germany, 2University Leipzig, Leipzig, Germany

In May/June 2017 the aircraft campaign ACLOUD (Arctic CLoud Observations Using airborne measurements
during polar Day) has been carried out in the framework of the project (AC)3 over the Fram Strait close to
Svalbard. Two polar aircraft of the German Alfred Wegener Institute (AWI) were used during this joint project
of the universities Leipzig, Köln, and Bremen, of the AWI, and of the Leibniz institute for tropospheric research
(TROPOS). The aircraft were equipped with a large suite of instruments measuring mean and turbulent
meteorological quantities as well as cloud particles and aerosol. We show first results of four flight missions
that were mainly focusing on the boundary layer over sea ice. We discuss especially the turbulence
measurements carried out with both aircraft which have been equipped with identical turbulence probes. It is
shown that in general the turbulent fluxes were small as usual during Arctic summer conditions, but that both
strongly stable conditions occurred with bulk Richardson numbers up to 0.26 and slightly unstable conditions
with upward fluxes. We discuss especially the strong variability (intermittent and wave-like character) of the
high resolution wind and temperature data during horizontal flight legs in strongly stable conditions. We
further show that vertical flux profiles were nonlinear in the weakly convective boundary layer as a
consequence of cloud cover.

706
2499
Surface Aerosols at Dome C and Comparison with Observations at the South Pole

Aki Virkkula1 (aki.virkkula@fmi.fi), Henrik Grythe2, John Backman1, Pasi Aalto3, Tuukka Petäjä3, Maurizio
Busetto4, Angelo Lupi4, Vito Vitale4, Roberto Udisti5, Silvia Becagli5, Patrick Sheridan6, John Ogren6, Markku
Kulmala3
1
Finnish Meteorological Institute, Helsinki, Finland, 2Norwegian Institute for Air Research, Kjeller, Norway,
3
University of Helsinki, Helsinki, Finland, 4CNR - ISAC - National Research Council, Italy, Bologna, Italy,
5
University of Florence, Dept. of Chemistry, Sesto Fiorentino, Italy, 6NOAA/Earth System Research
Laboratory/GMD, Boulder, United States

In situ aerosol measurements have been conducted at the Concordia station at Dome C (75˚S, 123˚E) on the
upper plateau at about 3200 m amsl since December 2007. Part of these measurements have been continuous
since then, part of them only for shorter periods. The size distributions in the size range 10 - 600 nm have been
measured with a differential mobility particle sizer (DMPS) and with a Grimm Model 1.108 optical particle
counter in the size range 0.3 - 15 µm. Air Ion Spectrometer (AIS), that measures charged particle size
distributions in the size range of about 0.8 - 40 nm, was operated for almost a year. Light absorption by
aerosols was measured with a 3-wavelength PSAP. There was no nephelometer so scattering was calculated
from the size distributions using a Mie code. In addition to calculating scattering coefficients from the DMPS
data it was calculated from PM1 and PM10 mass concentrations.
A comparison of the aerosol scattering at Dome C and at the South Pole Observatory (SPO) was conducted for 6
consecutive years. Despite being separated by approximately 1400 km some prominent features are visible at
both stations at the same time, lasting from some days to a week. FLEXPART simulations show that the BC
aerosols observed on the Antarctic upper plateau often have travelled more than 30 days from the sources in
the surrounding continents South America, Africa and Australia.

707
BE-4e - Climate change and ecosystems: physiology, biodiversity and ecological functions
20.06.2018 11:00-12:30, C Sanada II

1114
How will Arctic Algal Bloom Phenology Change in the Future?

Eva Leu1 (eva.leu@akvaplan.niva.no), Clara Jule Marie Hoppe2, Ane Cecilie Kvernvik3, Zofia Smola4,5, Klara
Wolf2, Jozef Wiktor4, Tove Gabrielsen3, Marit Reigstad6, Peygham Ghaffari1, Finlo Cottier7
1
Akvaplan-niva AS, Arctic R&D, Oslo, Norway, 2Alfred Wegener Institute Helmholtz Center for Polar and Marine
Research, Bremerhaven, Germany, 3UNIS The University Centre in Svalbard, Longyearbyen, Norway, 4Institute of
Oceanology, Polish Academy of Sciences, Sopot, Poland, 5Centre for Polar Studies, Sosnowiec, Poland, 6The
Arctic University of Norway, Tromsø, Norway, 7Scottish Association for Marine Science, Oban, United Kingdom

The phenology of Arctic algal blooms in sea ice and water is determined largely by their environment. The
Arctic has been changing rapidly during the past decades with a decreasing sea ice cover affecting light
availability and ocean stratification. Further, ocean acidification poses physiological challenges that may lead to
changes in species composition exacerbated by temperate species being transported towards the Arctic by
ocean currents. The FAABulous project (Future Arctic Algae Blooms - and their role in the context of climate
change) aims to improve our understanding of how these multiple stressors may affect the timing, species
composition and productivity of future algae blooms in the Arctic. It has utilized two model arctic fjord systems
with contrasting oceanic and ice characteristics. In a multidisciplinary approach we combined seasonal field
observations with high temporal resolution, with experiments and modelling.
First results show that the extent of Atlantic water advection determines the temperature regime and nutrient
supply in the two different systems, resulting in large differences in bloom scenarios. Furthermore,
experimental work shows a clear physiological response by dominating sea ice diatoms to future stress
scenarios that differs fundamentally from their pelagic counterparts. We therefore anticipate profound
changes in bloom phenology in the Arctic with cascading implications for higher trophic levels.

708
2260
Controls on Primary Productivity and Nitrogen Fixation in Arctic Waters

Allison Fong1 (allison.fong@awi.de), Eric Raes1, Anya Waite1

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Polar Biological Oceanography,
Bremerhaven, Germany

In recent years, new studies demonstrate that biological nitrogen fixation (BNF) is an unresolved process in
Arctic marine ecosystems. Low BNF rates have been measured in the shallow shelves of the Chukchi Sea and
areas of the Canadian basin, and nifH genes have been recovered from widespread areas across the Arctic
Ocean. However, there remains little to no evidence of BNF activity from offshore Arctic waters. Previous
studies suggest that diazotrophic assemblages are potentially dominated by heterotrophic bacteria in Arctic
marine waters, and not by photosynthetic cyanobacteria as is common in (sub)tropical oceans. This could imply
decoupling between primary productivity and BNF in the photic zone. In the summer of 2017, experiments
were conducted during an ice drift campaign in the Atlantic sector of the Arctic Ocean (~82N), north of
Svalbard, to test controls on primary productivity and BNF activity. Natural, whole seawater microbial
assemblages were amended with glucose and subjected to simple alterations in incoming irradiance to test
how these variables may induce or suppress Arctic BNF activity and alter primary productivity. Experimental
bottles were incubated in situ on an under-ice mooring line. Together, these experiments aim to elucidate
plankton assemblage responses to variations in light and measure stimulations of BNF rates in the Arctic
Ocean.

709
2302
Impacts of Light and Nutrients on Simulated Under-ice Phytoplankton Blooms

Aurélie Delaforge1 (delafora@myumanitoba.ca), Joannie Ferland2, Virginie Galindo1, Patrick Raimbaud3, Marcel
Babin2, Søren Rysgaard1,4,5, C.J. Mundy1
1
University of Manitoba, Centre for Earth Observation Science, Winnipeg, Canada, 2Laval University, Takuvik
Joint International Laboratory, Québec, Canada, 3Centre d'Océanologie de Marseille, Laboratoire
d'Océanographie et de Biogéochimie, Marseille, France, 4University of Aarhus, Arctic Research Centre, Aarhus,
Denmark, 5Greenland Institute of Natural Resources, Greenland Climate Research Centre, Nuuk, Greenland

The warming Arctic Ocean and increasing first-year ice cover (FYI) has helped fuel recent attention on under-ice
phytoplankton blooms. Here we focus on the response of under-ice phytoplankton growth and taxonomic
composition to varying light and nutrient conditions. This study will allow to better understand potential
responses of a developing bloom. Experiments were carried out during the 2016 Green Edge ice camp, near
Qikiqtarjuak (Baffin Island, Canada). The experiment included mimic of three light regimes (light availability
underneath FYI, open water, and open water with an UV-blocking filter) and two nutrient conditions (ambient
and doubled ambient concentrations). Experiments were ran from June 17 to July 06. For all ambient nutrient
conditions the peak of chl a was obtained on day 12, whereas for all doubled nutrients treatments the peak
occurred on day 14. However, chl a concentrations were significantly higher for conditions under lowlight
whereas highlight and highlight minus UV treatments had similar results. All experimental conditions resulted
in dominance of Phaeocystis pouchetii, but diatom species such as Thalassiossira spp., Attheya spp.,
Synedropsis hyperborea, Cylindrotheca closterium as well as Navicula spp. were also observed to be dominant
in different samples. These results highlight the sensitivity of under-ice phytoplankton to rapid light exposure,
shedding light on the potential response of a surface under-ice phytoplankton bloom during ice break-up.

710
1427
Photophysiology of Nitrate Limited Phytoplankton Communities in Kongsfjorden

Gemma Kulk1 (g.kulk@rug.nl), Willem Hendrik van de Poll1, Anita Buma1,2

1
University of Groningen, Ocean Ecosystems, Groningen, Netherlands, 2University of Groningen, Arctic Centre,
Groningen, Netherlands

In Arctic coastal regions, the phytoplankton bloom is initiated by meltwater induced stratification in spring,
while the subsequent depletion of nutrients from surface waters is believed to be a driving factor in
phytoplankton succession. A series of nutrient addition experiments showed that the phytoplankton
community in Kongsfjorden, Spitsbergen, became N limited from mid-June onwards and co-limitation with P
occurred later in summer. The onset of N limitation was followed by a pronounced change in taxonomic
composition with a shift in dominance from chrysophytes to haptophytes and a decrease in phytoplankton cell
size. Additional measurements of PSII photophysiology and electron transport rates by Fast Repetition Rate
Fluorometry (FRRf) showed that the community dominated by chrysophytes was characterized by high PSII
efficiency and electron transport rates that were efficiently used for growth. While the taxonomic composition
of the phytoplankton community changed, alternative electron requirements became more important and
energy was likely allocated to the uptake of nutrients rather than growth. It is suggested that the ongoing
changes in sea ice cover and melting of marine terminating glaciers could change the duration and intensity of
nutrient limitation in the Arctic with consequences for not only phytoplankton taxonomic composition, but also
photophysiology and primary production.

711
2340
Combined Effects of Light, CO2 and Iron on Antarctic Phytoplankton

Franziska Pausch1,2 (franziska.pausch@awi.de), Jasmin P. Heiden1,2, Florian Koch1,3, Christel S. Hassler4, Scarlett
Trimborn1,2
1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, EcoTrace, Biogeosciences, Bremen,
Germany, 2University of Bremen/BreMarE, Marine Botany, Bremen, Germany, 3University of Applied Science
Bremerhaven, Bremerhaven, Germany, 4University of Geneva, Institute F.A. Forel, Geneva, Switzerland

The Southern Ocean (SO) is an important sink for anthropogenic carbon dioxide (CO2). Climate change will
cause changes in various environmental parameters, which in turn can affect growth and productivity of SO
phytoplankton. Due to global warming, sea surface temperatures will increase and lead to a more stratified and
shallower mixed layer resulting potentially in higher light availability and enhanced primary production of iron-
limited phytoplankton. On the other hand, ocean acidification may reduce the bioavailability of iron to
phytoplankton. To examine the influence of iron availability in combination with current and future higher CO2
concentrations under low and high irradiance on SO phytoplankton physiology, bottle manipulation
experiments with a natural phytoplankton assemblage from the Drake Passage were conducted. Ocean
acidification led to lowered abundances of Pseudo-nitzschia species at both irradiances. While higher irradiance
stimulated daily particulate organic carbon production, this stimulating effect, however, was reduced under
high pCO2, but only under iron-limitation. Moreover, the ratio of biogenic silicate to particulate organic carbon
remained unchanged by high pCO2 for both iron treatments under high light, but declined under low light.
Gaining more insight on the complex interplay of multiple environmental factors is valuable to predict future
responses of SO phytoplankton to climate change.

712
2182
The Diatom Carbon Sink in a High CO2 World

Katherina Petrou1 (katherina.petrou@uts.edu.au), Kirralee Baker2, Daniel Aagren Nielsen1, Alyce Hancock3, Kai
Schulz4, Andrew Davidson5
1
University of Technology Sydney, Broadway, Australia, 2University of Essex, Colchester, United Kingdom,
3
University of Tasmania, Hobart, Australia, 4Southern Cross University, Lismore, Australia, 5Australian Antarctic
Division, Kingston, Australia

Coastal Antarctic waters are amongst the most vulnerable to ocean acidification, as a result of their cold, well-
mixed waters making a disproportionally large contribution to global anthropogenic CO2 uptake. Changes in
oceanic carbonate chemistry have been shown to differentially effect marine microbial communities, in some
cases resulting in strong shifts in primary productivity and community composition, both of which have
implications for carbon sequestration and biogeochemical cycling. Here we used 650 L tanks to incubate
natural Antarctic marine microbial communities at six levels of fCO2 (343 - 1641 uatm). Increasing fCO2 resulted
in a shift in the diatom community, with the larger diatoms (>20um) being negatively affected, while smaller
diatoms increased in abundance or showed no change. Similarly, photosynthetic capacity of large diatoms
declined, while smaller species were unaffected by the high fCO2. There was a strong decline in silicate
incorporation rates with increasing fCO2, and total diatom silicification dropped by >60% from the ambient (343
uatm) to the highest (1641 uatm) fCO2 incubation. The loss of larger diatoms and decline in silicification could
have broad implications for trophic interactions, primary productivity and biogeochemical cycling, altering
carbon sequestration capacity of Antarctic waters. Taken together, these data suggest that in a high CO2 world,
major changes to the future carbon sink can be expected for this region.

713
OS-6f - Polar Ocean Dynamics
20.06.2018 16:00-17:30, C Aspen

958
Circulation Patterns of the Atlantic Boundary Current along the Svalbard Shelf

Sebastian Menze1 (sebastian.menze@imr.no), Randi Ingvaldsen1

1
Institue of Marine Research, Bergen, Norway

Warm Atlantic water enters the Arctic as boundary current through Fram Strait (West Spitzbergen Current,
WSC) and is the major oceanic heat source to the Arctic Ocean. Along the North-Western Svalbard shelf, the
WSC splits into the shallow Svalbard Branch, the Yermak Branch that follows the slope of the Yermak Plateau
and possibly the Yermak Pass Branch that flows across the plateau.
The WSC has previously been studied using moorings, dedicated oceanographic transects and models. In this
study, we mapped the WSC using Vessel Mounted Acoustic Doppler Current Profiler data from multiple surveys
and vessels during 4 consecutive summers. Despite the “snapshot” nature of this compiled data set, persistent
circulations patterns could be discerned.
We observed a stable northward jet between 79 and 80 °N and the 1000 - 500 m isobath, before the WSC
divided into several branches, in all summers. Current profiles West of Svalbard and on the Yermak Plateau
showed higher variability than North of Svalbard, which is linked to eddies, recirculation, tides and internal
waves. Objective mapping showed a meandering boundary current West of Svalbard and a more homogeneous
current centered around the 1000 m isobath North of Svalbard. In our data set, the shallow Svalbard Branch
reunites with the Yermak Pass Branch between 10 and 15 °E. Transport estimates are given for several sections
and compare well with previous observations and models.

714
1659
Atlantic Water Properties and Circulation North of Svalbard in a Changing Arctic

Zoé Koenig1 (zoe.koenig@locean-ipsl.upmc.fr), Christine Provost1, Nathalie Sennéchael1, Amélie Meyer2, Gilles
Garric3, Jean-Claude Gascard1
1
LOCEAN - Sorbonne Universités - UPMC/CNRS/IRD/MNHN, Paris, France, 2Norwegian Polar Institute, Fram
Centre, Tromsoe, Norway, 3Mercator Ocean, Ramonville Saint Agne, France

The Atlantic Water (AW) inflow is crucial for the heat and salt budget of the Arctic. Its properties encountered
in the Arctic Basin depend on the processes that largely alter the AW layer North of Svalbard.
IAOOS (Ice Atmosphere Ocean Observing System) platforms were deployed during the N-ICE2015 expedition
gathering the first winter hydrographic data in the area. They document shallow warm water over the Svalbard
continental slope that melts sea ice with ice-ocean heat fluxes reaching up to 400W.m-2. Heat is brought from
the AW layer up to the surface through near-inertial waves generated by winter storms, barotropic tides and
geostrophic adjustments. Sea ice extent largely differs between winters 2015 and 2016 and can be explained by
convection-induced upward heat fluxes suggested by the analysis of 1/12° operational model outputs from
Mercator Ocean.
Model is used to examine AW inflow pathways north of Svalbard. It shows an AW winter pathway not much
documented before : the Yermak Pass Branch (YPB) across the Yermak Plateau. YPB properties are examined
using one-year (2007-2008) of moored ADCP data in the Yermak Pass. The flow is largely dominated by tides. In
winter, baroclinic eddies and pulses of AW carrying AW eastward in the Pass are found.
Finally, the model suggests an important mesoscale activity along the AW flow, also suggested by high
resolution glider observations performed in summer 2017 across the main AW branches and over the Yermak
Plateau.

715
1857
Satellite-derived Sea Level in the Ice-covered Polar Oceans

Thomas Armitage1 (tom.w.armitage@jpl.nasa.gov), Ron Kwok1, Andrew Thompson2, Sheldon Bacon3, Alek
Petty4,5
1
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States, 2California Institute of
Technology, Environmental Science and Engineering, Pasadena, United States, 3National Oceanography Centre,
Southampson, United Kingdom, 4NASA Goddard Space Flight Center, Cryospheric Sciences Laboratory,
Greenbelt, United States, 5University of Maryland, Earth System Science Interdisciplinary Center, Greenbelt,
United States

Sea surface height (SSH) is poorly observed in the polar oceans due to a lack of tide gauges, poor coverage by
conventional altimeters, and the seasonal or perennial ice-cover. Using recently developed techniques to
combine conventional altimetry with SSH retrievals from openings in the ice cover, time series of monthly SSH
composites have been produced at both poles. In the Arctic, seasonal freshwater fluxes lead to a large SSH
seasonal cycle, and SSH changes in the 2000's reflect Beaufort gyre (BG) freshwater accumulation. Meanwhile,
surface circulation intensified and the center of the BG shifted some 300km to the northwest. In the Southern
Ocean, the Antarctic Slope Current system is revealed to be a circumpolar feature which is strongest in autumn.
Monthly circulation variability in the Ross and Weddell gyres is modulated by the local wind stress curl, which
in turn is weakly correlated with the Southern Annular Mode (SAM). There are significant SSH responses to the
SAM and the Southern Oscillation; in particular, the 2015-16 El Niño drove sustained negative coastal SSH
anomalies, implying shoaling of isopycnals with the potential to deliver circumpolar deep water to the cavities
of West Antarctic ice shelves. These data sets provide first looks at seasonal and sub-seasonal SSH variability in
the polar oceans and their coupling to atmospheric forcing; extending this data set would provide invaluable
observations of how the polar oceans are adjusting under climate change.

716
2171
Deep-water Upwelling in the Southern Ocean: Spirals, Hotspots, Carbon, and Ice

Lynne Talley1 (ltalley@ucsd.edu), Matthew Mazloff1, Veronica Tamsitt1, Henri Drake2, Adele Morrison3, Alison
Gray4, Kenneth Johnson5, Ryan Abernathey6, Seth Bushinsky7, Carolina Dufour7, Stephen Griffies8, Stephen
Riser4, Isabella Rosso1, Joellen Russell9, Ariane Verdy1, Jinbo Wang10, Nancy Williams11, Jorge Sarmiento7
1
University of California San Diego, Scripps Institution of Oceanography, La Jolla, United States, 2Massachusetts
Institute of Technology, EAPS, Cambridge, United States, 3Australian National University, Canberra, Australia,
4
University of Washington, School of Oceanography, Seattle, United States, 5MBARI, Monterey, United States,
6
Columbia University, Lamont Doherty Earth Observatory, Palisades, United States, 7Princeton University,
Princeton, United States, 8NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, United States, 9University
of Arizona, Tucson, United States, 10NASA Jet Propulsion Laboratory, Pasadena, United States, 11Oregon State
University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, United States

Northern Deep Waters upwell in the Southern Ocean, carrying low oxygen, high nutrients/carbon from the
Indian/Pacific to the sea surface, as well as warm and relatively saline waters from all oceans and especially the
Atlantic. The 3-dimensional upwelling within the ACC is tracked using modelled particles and observations. The
global-scale southward spiraling of the fronts is guided by underlying topography, shifting them far
northeastwards in some regions, interleaving with regions of southward Sverdrup transport over abyssal plains.
The nearly isopycnal upwelling is greatly enhanced at eddy hotspots where the ACC crosses topography. A
circumpolar 'upwelling chimney' of carbon and nutrients results in large carbon outgassing to the atmosphere,
as shown from a new array of biogeochemical Argo ('SOCCOM') floats and the Southern Ocean State Estimate.
These fronts also guide the winter sea ice extent and its variability. Hydrographic observations show stronger
penetration of full-depth ACC water into the Amundsen/ Bellingshausen Seas in 2011 compared with 1992,
consistent with decreasing sea ice and increasing ice-shelf melt. In contrast, winter sea ice has increased where
the southern ACC is topographically locked into northeastward pathways. The standing eddy pattern of ACC
poleward heat flux, strengthening winds, and decadal winter sea ice changes are consistent with strengthening
circulation along the southern side of the ACC, likely driven by increasing westerly winds.

717
2518
Distinct Dynamics of Arctic Heat Transport under Climate Change and Variability

Kyle Armour1 (karmour@uw.edu)

1
University of Washington, Seattle, United States

Climate model simulations suggest that ocean heat transport (OHT) into the Arctic is connected to a strong
Atlantic Meridional Overturning Circulation (AMOC) under decadal variability (e.g., Zhang 2015). Meanwhile,
when driven by greenhouse gas (GHG) forcing, models predict a robust increase in OHT into the Arctic and a
high correlation with the degree of Arctic warming (Hwang et al. 2011; Nummelin et al. 2017). Yet, they also
simulate a weakening of AMOC under GHG forcing, suggesting that the dynamics linking AMOC and OHT
changes under GHG forcing are distinct from that seen under internal variability.
Here, we identify the dynamics governing OHT changes into the Arctic within GHG-forced and pre-industrial
simulations of NCAR's CCSM4. We quantify OHT anomalies in terms of 'active' circulation changes versus
'passive' changes (warming advected by climatological currents). Unforced decadal variability in OHT is
dominated by AMOC changes to the south of the subpolar gyre, while increased OHT into the Arctic is driven by
active and passive gyre circulations in the Nordic Seas.
Under GHG forcing, OHT at 45N decreases as AMOC weakens, while OHT into the Arctic increases due to a
combination of climatological overturning and changing gyre circulations in the Nordic Seas. These findings
suggest that distinct dynamics control forced and unforced OHT changes, and that links between AMOC and
OHT under decadal variability cannot be extrapolated to explain future forced changes.

718
2536
Metrics for the Evaluation of the Southern Ocean in Climate Models

Joellen Russell1 (jrussell@email.arizona.edu), Igor Kamenkovich2, Cecilia Bitz3, Raffaele Ferrari4, Sarah Gille5,
Paul Goodman1, Robert Hallberg6, Ken Johnson7, Karina Khazmutdinova8, Irina Marinov9, Matthew Mazloff5,
Stephen Riser10, Jorge Sarmiento11, Kevin Speer8, Lynne Talley5, Rik Wanninkhof12
1
University of Arizona, Department of Geosciences, Tucson, United States, 2University of Miami, Rosenstiel
School of Marine and Atmospheric Science, Miami, United States, 3University of Washington, Atmospheric
Sciences, Seattle, United States, 4Massachusetts Institute of Technology, Boston, United States, 5University of
San Diego, Scripps Institution of Oceanography, La Jolla, United States, 6Geophysical Fluid Dynamics Laboratory,
Princeton, United States, 7Monterey Bay Aquarium and Research Institute, Monterey, United States, 8Florida
State University, Tallahassee, United States, 9University of Pennsylvania, Philadelphia, United States,
10
University of Washington, Oceanography, Seattle, United States, 11Princeton University, Princeton, United
States, 12Atlantic Oceanographic and Meteorological Laboratory, Miami, United States

The Southern Ocean and its role in, and response to, the ongoing anthropogenic trend varies widely among
global coupled climate models and earth system models. Observationally-based metrics are critical for
discerning processes and mechanisms, and for validating and comparing climate and earth system models. New
observations and understanding, especially those gained from semi-autonomous, biogeochemically-sensored
floats (from SOCCOM), have allowed for progress in the creation of observationally-based data/model metrics
for the Southern Ocean. These metrics provide a means to assess multiple simulations relative to the best
available observations and observational products: climate models that perform better according to these
metrics also better simulate the uptake of heat and carbon by the Southern Ocean. Observationally-based
benchmarks are essential in order to reduce uncertainties in climate projections, and especially uncertainties
related to oceanic heat and carbon uptake.

719
AC-4b - The Polar Atmosphere and Geospace
20.06.2018 16:00-17:30, A Studio

1499
Developing Synthetic Observation System for Polar Atmospheric Research at PRIC

Wentao Huang1 (huangwentao@pric.org.cn), Rui Wang1, Huigen Yang1, Hongqiao Hu1, Zhiguang Han1, Zejun
Hu1, Dehong Huang1, Fang He1
1
Polar Research Institute of China, Shanghai, China

The polar regions are the entrances for the solar wind energy entering geospace. A conjugated system for
space physics observation has been established at the Antarctic Zhongshan Station and Arctic Yellow River
Station, which are both located in the unique polar cusp regions and approximately at the conjugated ends of
one magnetic field line. To fill the current blank of atmospheric observation, we are developing a synthetic
observation system for polar atmosphere, including a Na Doppler lidar currently and other lidars in the future.
The Na Doppler lidar under developement is to measure the diurnal temperature and winds in the Mesosphere
and lower Thermosphere, aiming to investigate the coupling between the activities of space weather and the
neutral upper atmosphere. A coherent Doppler wind lidar for measuring tropospheric winds, a Raman
temperature lidar and a Rayleigh temperature lidar for measuring tropospheric and mesospheric temperature
are in the plan to form a synthetic observation system capable of profiling the vertical structure of atmospheric
temperature and/or winds from surface up to lower thermosphere. This system will provide comprehensive
data to study the interactions of solar activities with the Earth's atmosphere, and the dynamical coupling
among the atmospheric layers in polar regions.

720
1003
Ground Based Water Vapor Retrieval over Antarctica

Monia Negusini1 (negusini@ira.inaf.it), Boyan H. Petkov2, Pierguido Sarti1, Claudio Tomasi2

1
National Institute of Astrophysics, IRA, Bologna, Italy, 2Consiglio Nazionale delle Ricerche, ISAC, Bologna, Italy

Atmospheric water vapor is an important indicator of the Earth's climate state and evolution. Although
representing a few percentages of the total content, Antarctic water vapor plays an important role in snowfall
accumulation and surface mass balance. Thus, accurate long time series of water vapor content are crucial to
understand the current climate and to assess the reliability of global climate models. Geodetic measurements
are being made at permanent research stations maintained by different institutions. IGS, POLENET and regional
networks now cover large sectors of Antarctica and provide long-term data sets that can be used for studying
Precipitable Water (PW) and its variability. Long and consistent time series of data are required, possibly
recorded by different and independent sensors to overcome systematic errors and obtain accurate results.
Thus, Radiosounding (RS) data performed at 7 coastal stations using Vaisala radiosondes were analysed, to fully
exploit the capability of GPS to provide reliable PW, even if RS observations are not available. A regional model
of the mean Temperature was computed for this purpose. Up to 20-year time series of GPS observations
acquired at all available geodetic stations were processed with the purpose of ensuring the utmost accuracy of
the results adopting homogeneous, consistent, and up-to-date processing strategies. Results are shown for the
available GPS sites, giving an up-to-date picture of the PW behavior over Antarctica.

721
1693
Latitudinal Ionospheric Scintillation Study in the American Sector

Emilia Correia1,2 (ecorreia@craam.mackenzie.br), Lucilla Alfonsi3, Luca Spogli3, Giorgiana De Franceschi3,

Vincenzo Romano3, Nicola Linty4, Ingrid Hunstad3, Olivier Terzo5, Fabio Dovis4, Gilmar Alves2, Roberto Camara6
1
National Institute for Space Research (INPE), DAS/CEA, Sao Paulo, Brazil, 2Universidade Presbiteriana
Mackenzie, CRAAM, Sao Paulo, Brazil, 3Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy, 4Politecnico
di Torino, Torino, Italy, 5Istituto Superiore Mario Boella, Torino, Italy, 6Universidade Federal de Roraima, Boa
Vista, Brazil

Demonstrator for Global Navigation Satellite System (GNSS) Research and Application for Polar Environment
(DemoGRAPE) is an international project leaded by the Istituto Nazionale di Geofisica e Vulcanologia (INGV), in
partnership with Politecnico di Torino, Istituto Superiore Mario Boella, and with South African National Space
Agency (SANSA) and the Brazilian National Institute of Space Physics (INPE), as collaborators. The aim of project
is to improve satellite navigation particularly in Antarctica, where the accuracy is of paramount importance for
the surface displacements, and it is strongly affected by atmospheric disturbances. The DemoGRAPE activities
started on November 2015 with the system installed at Brazilian Antarctic Station Comandante Ferraz (EACF,
62o 05´07"S, 58o23´29" W) located in the King George Island. To investigate the ionospheric disturbances from
high to low latitudes in the American sector we present the GNSS scintillations observed at EACF inside
DemoGRAPE activities, which are combined with GNSS observations done at Universidade Mackenzie in São
Paulo (23°32′56″S, 46°38′20″W, inside the South American Magnetic Anomaly - SAMA) and at Cauamê Campus
of Universidade Federal de Roraima (02°49´12"N, 60°40´23" W) during 2016. The goal is to characterize the
occurrence of scintillation at high latitudes in association with the fountain effect at low latitudes and inside
the SAMA region.

722
2184
Small and Medium Scale Gravity Waves Climatology over Ferraz Station

Jose Valentin Bageston1 (bageston@gmail.com), Gabriel Augusto Giongo1,2, Cristiano Max Wrasse3, Cosme
Alexandre O. B. Figueiredo3, David C. Fritts4, Diego Janches5, Yong-Ha Kim6, Hosik Kam7
1
National Institute for Space Research (INPE), Southern Regional Space Research Center (CRS), Santa Maria,
Brazil, 2Federal University of Santa Maria (UFSM), Physics, Santa Maria, Brazil, 3National Institute for Space
Research (INPE), Aeronomy, Sao Jose dos Campos, Brazil, 4Gats. Inc., Boulder, United States, 5NASA Goddard
Space Flight Center, Space Weather Laboratory, Greenbelt, United States, 6Korea Polar Research Institute
(KOPRI), Division of Polar Climate Change Research, Incheon, Korea, Republic of, 7Chungnam National
University, Dept. Astronomy, Space Science and Geology, Daejeon, Korea, Republic of

Gravity waves at distinct spectrum of wavelengths and periods play an important role in communicating,
through energy and momentum transportation, between the different atmospheric layers. The main aspects
associated to the gravity waves are the general circulations processes in the middle and upper atmosphere and
the temperature gradients. Regarding the high gravity wave activity and observations at the Brazilian Ferraz
Station (62.1°S, 58.4°W), we have been observed small and medium scale gravity waves from an all-sky airglow
imager in the last three years, besides a full winter campaign in 2007 and two consecutive winters in 2010-
2011. Even we suffered from a lack of observations in 2008-2009 and 2012-2014, during the observed years it
was possible to identify many gravity waves of very distinct morphology, i.e., bands, ripples and mesospheric
fronts, and a wide range of horizontal wavelength, period and propagation directions. In the present work we
will summarize the gravity waves observations at Ferraz Station since 2007 up to 2016, focus firstly in the
morphology of the small scale waves, its parameters and propagation directions. Latter on, it will be presented
the methodology used to extract the medium-scale gravity wave parameters and the observed and intrinsic
wave parameters. At last, will be presented the current status of the observations at Ferraz Station and future
plans to maintaining these observations and restore or expand other type of observations.

723
1786
On the Impact of High-latitude Ionosphere on Synthetic Aperture RADAR

Elvira Musicò1,2 (elvira.musico@ingv.it), Cesaroni Claudio1, Luca Spogli1,3, Marco Polcari1, Giorgiana De
Franceschi1, Roberto Seu2
1
Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy, 2Università Sapienza, Information
Engineering, Electronics and Telecommunications (DIET), Rome, Italy, 3SpacEarth Technology, Rome, Italy

The ionosphere can affect space-borne Synthetic Aperture Radar (SAR) measurements especially at lower
frequencies producing some artefacts in the SAR images. They are mainly addicted to the Total Electron
Content (TEC), i.e. the integral of the electron density along the path between the satellite and a given target.
TEC fluctuations along the azimuth direction result in the degradation of the quality of the SAR imaging, visible
as streaks in SAR images. Furthermore, TEC temporal variation between two SAR passes produces an error in
the SAR Interferometry (InSAR) technique known as phase advance. These errors are expected to exacerbate at
high latitudes, characterized by ionospheric irregularities and scintillation phenomena due to the direct
interaction of the ionospheric plasma with the geospatial environment. In this work, the effects of high latitude
ionosphere on selected SAR images are investigated in detail using TEC and scintillation measurements from
GNSS receiver networks located at ground. The outcomes of this investigation are shown and critically
discussed in relationship with the different roles of troposphere and ionosphere impacts on SAR data.

724
1944
Comparison between FPI and Meteor Radar Observations for MLT at KSS, Antarctica

Changsup Lee1 (cslee@kopri.re.kr), Geonhwa Jee1, Qian Wu2, Jeong-Han Kim1

1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2National Center for Atmospheric Research
(NCAR), Boulder, United States

Neutral winds and temperature in the mesosphere and lower thermosphere (MLT) have been simultaneously
observed by Fabry-Perot interferometer (FPI) and meteor radar (MR) at King Sejong Station (KSS), Antarctica
for a full year of 2017. The simultaneous optical and radar observations for the neutral atmosphere in the MLT
region provide us with an excellent opportunity of comparing the measurements from the two observation
techniques. Furthermore, since Antarctic peninsula has been well known for strong wave activities such as
orographic gravity waves, the observations from these two instruments can be used to reveal the
characteristics of neutral atmospheric responses to the waves in the MLT region. Using these observations, the
neutral winds are compared at two airglow layers of 87 km and 97 km. We found the well-defined semidiurnal
tidal structures such as downward phase progression and 90-degree phase difference between zonal and
meridional winds. Neutral temperatures estimated from two instruments are also compared to investigate the
geomagnetic effects on MLT temperature.

725
TE-1c - Observing with autonomous vehicles in polar regions
20.06.2018 16:00-17:30, A Forum

1619
Saildrone Measurements in the Arctic

Edward Cokelet1, Calvin Mordy1,2, Jessica Cross1 (jessica.cross@noaa.gov), Alex De Robertis3, Carey Kuhn3,
Richard Jenkins4, Noah Lawrence-Slavis1, Christian Meinig1, Heather Tabisola1,2, Phyllis Stabeno1
1
NOAA Pacific Marine Environmental Laboratory, Seattle, United States, 2University of Washington, JISAO,
Seattle, United States, 3NOAA Alaska Fisheries Science Center, Seattle, United States, 4Saildrone, Inc., Alameda,
United States

Saildrones are sail- and solar-powered USVs developed by Saildrone Inc., NOAA and UW to make remote,
season-long meteorological, oceanographic and fisheries measurements. They sail autonomously between
user-controlled waypoints and transmit data ashore via satellite. Saildrones conducted three missions in the
Bering Sea in summers 2015-2017 and into the Chukchi Sea and Arctic Ocean in 2017, each sailing over 6000
km per mission. They measure solar irradiance, wind, humidity, barometric pressure, air and water
temperature, sea-surface salinity, dissolved oxygen, chlorophyll a, CDOM, and optical backscatter. In 2016-
2017 the Bering vehicles made acoustic measurements of the abundance and distribution of walleye pollock,
conducted focal follows of satellite-tagged fur seals and recorded the presence of marine mammals. A pCO2
system was added in 2017 to measure CO2 exchange. Measurements were compared with ships and moorings.
Wind speeds exceeded 40 knots at times. Low salinity and high CDOM and pCO2 were found 200 km seaward of
the Yukon River mouth. Near Bering Strait, the saildrones observed high chlorophyll a and oxygen saturation
implying enhanced biological production. One saildrone reached 75˚N in the Arctic Ocean basin where it
measured a cold surface temperature of -0.23˚C and a low salinity of 26.5 (PSS-78) on 13 August 2017. The
Saildrone platform has proven to address key research questions and is continually being updated with new
sensors and data-sharing capacity.

726
2237
Under-ice Argo Floats in the Southern Ocean

Esmee van Wijk1,2 (esmee.vanwijk@csiro.au), Luke Wallace1,3, Stephen Rintoul1,4

1
CSIRO Oceans & Atmosphere, Hobart, Australia, 2Antarctic Climate & Ecosystems Cooperative Research Centre,
Hobart, Australia, 3RMIT University, Melbourne, Australia, 4Antarctic Climate and Ecosystems Cooperative
Research Centre, Hobart, Australia

The seasonal sea ice zone of the Southern Ocean is one of the largest remaining 'blind spots' in the global
ocean observing system. Key science questions relevant to climate and sea level rise require sustained, broad-
scale observations in the high latitudes. Historically, measurements from shipboard hydrography are sparse,
particularly during the winter months. Ice-capable Argo floats have provided year-round sampling of the
Southern Ocean since 1999, measuring approximately 50,000 profiles below 60°S. We review the status,
achievements and future of the Argo array in the Southern Ocean with a focus on under-ice floats (longevity,
reliability, dispersion and loss). Novel missions for under-ice Argo, including floats deployed on the Antarctic
continental shelf and in polynyas have provided new insights into sea-ice production, air-sea-ice-ocean
interactions, circulation, water mass formation and tides. Ice-capable floats parked on the sea-floor between
profiles can provide data for several years on the Antarctic continental shelf. A major issue for under-ice
profiles is the loss of position data when floats are unable to surface in winter. A new algorithm was developed
to improve the estimates of profile location and uncertainty of under-ice data. Deployments of ice-capable
floats have proven the feasibility of under-ice observing and provide guidance for the design of a sustained
under-ice observing system.

727
147
A Challenge towards Cost-effective and Autonomous Observations under the Sea-Ice

Michel Rixen1 (mrixen@wmo.int)

1
World Meteorological Organization (WMO), Geneva, Switzerland

The cryosphere is a major indicator of global climate change and plays a fundamental role in the Earth System.
Despite advances in numerical modelling, the reliability of weather forecasts and long-term climate predictions
in the Arctic and Antarctic is severely limited by the lack of systematic in situ observations of and beneath the
sea-ice. In situ ocean observations in polar regions are inherently expensive, risky and sparse, even more so
under the sea-ice. Those shortfalls can be addressed by recent progress in Autonomous Underwater Vehicle
(AUV) technology.
The World Climate Research Programme (WCRP) and the Prince Albert II of Monaco Foundation (FPA2) are
jointly promoting a Polar Challenge that will reward with a Prize of 500,000 Swiss Francs the first team to
complete a 2 000 km mission with an AUV under the Arctic or Antarctic sea-ice. Bonus awards will also be
delivered for regular measurements of sea-ice thickness or draft, and for successful transmission of under-ice
position and environmental data to operational networks in near real-time.
The overall vision of this challenge is to promote a cost-effective, sustainable and autonomous polar ocean
monitoring system to drive a new era for research, application and services. The ultimate goal is to achieve
with some analogy what ARGO (www.argo.ucsd.edu/) has accomplished for the open ocean with profiling
floats.
More details at www.wcrp-climate.org/polarchallenge

728
1008
Autonomous Marine and Aerial Vehicles for Marine Glacier Surveys in Arctic

Gabriele Bruzzone1 (gabriele.bruzzone@ge.issia.cnr.it), Roberta Ferretti1, Angelo Odetti1, Andrea Ranieri1,

Massimo Caccia1
1
CNR-ISSIA, Genova, Italy

Acquiring scientific data in Polar Regions is often problematic due to harsh weather and risky operating
conditions. In the last decade the use of robots for substituting human beings in performing difficult, dangerous
and burdensome tasks has become more and more frequent. According to this trend, in summer 2015 and
2017, a group of researchers of ISSIA-CNR carried out two scientific campaigns in the Kongsfjorden, an Arctic
glacial fjord located in the Svalbard Archipelago. The campaigns involved both marine and aerial autonomous
vehicles for collecting environmental parameters. In particular, the two USSVs (Unmanned Semi-Submersible
Vehicles) Shark and PROTEUS, and the UAV (Unmanned Aerial Vehicle) OTTO were used to acquire both marine
and atmospheric data in the proximity of the dangerous fronts of tidewater glaciers. Sampling in these areas is
important to understand the peculiar local phenomena occurring during ice calving but data are missing due to
the difficulties in accessing these extremely hazardous sites. The possibility of sudden falls of massive ice blocks
and the steep and friable slopes of the sides make it impossible for operators to get close to the front of
glaciers and the use of unmanned vehicle proved to be decisive. The success of the campaigns demonstrated
that unmanned vehicles technology is mature for collecting data in these areas and can be of great help to
scientists involved in the monitoring of processes occurring in the Arctic region.

729
289
Snow and Ice Thickness Retrieval from SIMBA Temperature Profiles in Antarctic

Jiechen Zhao1 (zhaojiechen@outlook.com), Qinghua Yang1, Bin Cheng2, Fengming Hui3, Hui Shen1, Lin Zhang1
1
National Marine Environmental Forecasting Center, Beijing, China, 2Finnish Meteorological Institute, Helsinki,
Finland, 3Beijing Normal university, Beijing, China

Antarctic snow and sea ice thickness is an important indicator for global climate change and the main
parameters for icebreaker sailing in the ice-covered region. A kind of SIMBA buoy with 240 sensors in every 2
cm interval was deployed in the fast ice near Antarctic Zhongshan Station during 2014 and 2015 to record snow
and ice temperature profiles and heating responses and study the method to retrieve snow and ice thickness.
The analysis showed that the adjacent temperature profiles changed largely in the air, about 2℃; Sea water
beneath ice showed stable temperature, -1.7~-1.9℃; Snow and ice had a large temperature gradient vertically.
The 60 s heating responses showed that, temperature increment was about 2.0~4.0℃ in the air, about
2.5~5.0℃ in the snow, about 0.8~1.0℃ in the ice and about 0.6~1.2℃ in the water. Depending on those results
above, two independent methods “automatic algorithm” and “manual detection” were used to analyze snow
and ice thickness. Compared to field observed ice thickness, RMSE of those two methods was 6.4 cm and 6.4
cm respectively in 2014, and 6.6 cm and 6.5 cm respectively in 2015. As to snow depth, RMSE was 10.8 cm and
8.5 cm respectively. The retrieved snow and ice thickness had acceptable bias of around 3 sensors for ice and
4~5 sensors for snow, considering the maximum ice thickness of around 150 cm. Therefore this kind of SIMBA
buoy and the two methods were suitable and flexible for Antarctic snow and fast ice thickness retrieval.

730
730
Observing Stratigraphy and Crevasses with Robot-towed Ground Penetrating Radar

Laura Ray1, Austin Lines1 (austin.p.lines.th@dartmouth.edu), Joshua Elliot1, Madeleine Jordan1,2, Benjamin
Walker1, Mary Albert1, Steven Arcone1, James Lever3, Lynn Kaluzienski4, Peter Koons4
1
Dartmouth College, Thayer School of Engineering, Hanover, United States, 2Helmut Schmidt University,
Hamburg, Germany, 3U.S. Army Cold Regions Research and Engineering Laboratory, Hanover, United States,
4
University of Maine, Orono, United States

We present results of using robot-towed ground penetrating radar for measurements of stratigraphy and
crevasse features. We describe the development of lightweight (< 80 kg), electric and solar-electric rovers that
navigate autonomously and tow scientific instruments secured to a sled. We report on use of the rovers for
1) imaging surface stratigraphy in a dry snow zone to estimate local variability in compaction;
2) imaging a 25 km2 area of a marginal shear zone from surface to marine ice to observe complex shear zone
dynamics from the characteristic surface and marine ice crevassing; and
3) autonomous detection and mapping of the length of individual crevasses within the shear zone.
From the first project, we demonstrate how local surveys relate to longer transects for establishing variation in
snow and firn compaction. From the latter projects, we demonstrate construction of a local velocity map within
the McMurdo Shear Zone (MSZ) derived from annual crevasse motion. The survey provides multiple crossings
of long (> 1 km) crevasses that appear in echelon on the western and eastern boundary of the shear zone as
well as two or more crossings of shorter crevasses in the chaotic zone. A local velocity field is estimated by
mapping these crevasses and crevasse segments in annual datasets and projecting movement of crevasses
annually. These projects demonstrate the use of autonomous robots to acquire data that would otherwise be
inaccessible from human-operated vehicles.

731
CR-2 - Permafrost landforms in the two Poles as possible Mars analogue.
20.06.2018 16:00-17:30, A Dischma

215
Biogeochemistry of Lake Untersee Oasis, Queen Maud Land, Antarctica

Benoit Faucher1 (bfaucher@uottawa.ca), Denis Lacelle2, Wayne Pollard3, David Fisher4, Davila Alfonso5, Mary
Beth Wilhelm6, Dale Andersen7
1
University of Ottawa, Geography, Environment and Geomatics, Gatineau, Canada, 2University of Ottawa,
Geography, Environment and Geomatics, Ottawa, Canada, 3McGill University, Geography, Montreal, Canada,
4
University of Ottawa, Earth and Environmental Sciences, Ottawa, Canada, 5NASA Ames, Exobiology Branch,
Mountain View, United States, 6NASA Ames, Planetary Science Branch, Mountain View, United States, 7SETI
Institut, Carl Sagan Center, Mountain View, United States

Regions of juxtaposed active and relict biogeochemical cycling are rare on Earth. Lake Untersee Oasis is one of
these environments: it contains two perennially ice-covered lakes (Untersee and Obersee) with benthic,
photosynthetic microbial mats, and an adjacent ice-free valley (Aurkjosen) that has evidence of a paleo-lake
basin, with relic dried microbial mats buried in permafrost soils. We will present preliminary results of a broad
research effort that aims at:
1) characterizing the present-day hydrological conditions of Lake Untersee;
2) characterizing the dynamics of microbial ecosystem in Lake Untersee;
3) reconstructing the past hydrological conditions in the Oasis; and
4) asessing the preservation state of molecular biomarkers in relic microbial mats of the Aurkjosen Valley
paleo-basin.
Hydrogeochemical analysis indicates that the lake's primary source of water is derived from glacial meltwater
with a small contribution of groundwater and that water loss is mainly through sublimation of its ice cover.
Modeling suggest that the lake's geochemistry is controlled by sublimation, which affects the amount of
freezing and associated D-18O and solute fractionation. d18O analysis of carbonates found in relict microbial
mats suggests a water d18O composition evolution to higher values over the Holocene. Upcoming
biogeochemical analysis of active and relict organics mats should provide further insights on the preservation
potential of organic compounds in this cold environment.

732
2094
Soils Influenced by Periglacial Processes in the South Shetland Islands

Thomas Schmid1 (thomas.schmid@ciemat.es), Jerónimo López-Martínez2, Tanya O'Neill3, Marta Pelayo1, Javier
Díaz-Puente1, María José Sierra1, Rocio Millán1, Megan Balks3
1
Centro de Investigaciones Energéticas Medio Ambientales y Tecnológicas -CIEMAT, Environment, Madrid,
Spain, 2Universidad Autónoma de Madrid, Dpt. Geología y Geoquímica, Madrid, Spain, 3Waikato University,
School of Science, Hamilton, New Zealand

Ice-free areas in the Northern Antarctic Peninsula region are influenced by periglacial, glacial, fluvial, and
coastal processes and landforms. Permafrost is present in these areas and influences the fragile ecosystems
containing cryosols. The objective of this work is to determine the interaction between periglacial processes
and landforms on a variety of soil characteristics within different ice-free areas of the South Shetland Islands.
Recent field work identified glacial deposits, patterned ground, pavements, and slope debris among the most
prevalent surfaces. Laboratory analyses showed that soil properties are clearly related to lithological and
geomorphological factors. In a number of cases, the soils have a sandy loam texture, which indicate a good
drainage. Some soils have increased clay content which results in poorly-drained soils. In this case, drainage of
the soil and surface processes defining the land cover are closely related to the permafrost environments.
Active layer depth with freeze-thaw cycles that take place during the summer influence soil properties such as
bulk density, texture and structure as well as the water holding capacity. Factors such as lithology, elevation,
slope and distance from the coast further influence the soil properties. Therefore, the active surface processes
during the limited Antarctic summer are dominant and soil material becomes displaced causing unstable soil
development.

733
2371
Endolithic and Hypolithic Systems as Protosoils: Evidence from the Two Poles

Nikita Mergelov1 (nikvox@yandex.ru)

1
Institute of Geography Russian Academy of Sciences, Moscow, Russian Federation

Endolithic and hypolithic bio-abiotic systems can be regarded as protosoils from the several aspects:
(1) as the closest modern analogues of soil progenitors that existed on Earth before vascular plants with root
systems established,
(2) as precursors of more advanced soil formations in contemporary landscapes and
(3) as steady state soil-like bodies in regions with climatic extremes (e.g. East Antarctica). We will discuss in the
presentation the structure, composition and weathering mechanisms in endolithic and hypolithic bio-abiotic
systems providing the evidence for soil-like processes that occur in these formations at the both Poles: East
Antarctica oases (Larsemann and Thala Hills, Schirmacher) and High Arctic archipelagos (Novaya Zemlya and
Franz Josef Land). The areas with extreme climatic conditions at the both poles give an opportunity to study
cyanobacteria and lichen driven endo- and hypolithic systems as protosoils with the minimum influence from
more advanced organisms common to other environments. The newly formed products of biota-to-mineral
interactions both in hypo- and endo- cryptic niches are redistributed by erosion processes and contribute
significantly to raising complexity of the polar landscapes that are limited in energy and nutrients sources.
Besides that endolithic colonization increases weathering rates, induces exfoliation and, thus, reshapes mineral
surfaces contributing regularly to the biogeomorphological processes at the both Poles.

734
2077
Metal Enrichment in Desert Varnish from Ice-free Areas of Coastal Antarctica

Daniel Nyvlt1 (daniel.nyvlt@seznam.cz), Ondrej Zverina2, Renata Copjakova3, Filip Hrbacek1

1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic, 2Masaryk University,
Faculty of Medicine, Department of Public Health, Brno, Czech Republic, 3Masaryk University, Faculty of Science,
Department of Geological Sciences, Brno, Czech Republic

Desert varnish is a coating that forms on the exposed surface of stones located in both hot and cold arid areas.
The semi-arid ice-free area of Ulu Peninsula, James Ross Island, represents the largest deglaciated land in
Antarctic Peninsula (AP) region that contains numerous granite and basalt cobbles and boulders with well-
developed desert varnish. It is generally accepted that desert varnish is composed of clay particles rich in iron
and manganese oxides and that iron enrichment is typical for cold environments while desert varnish enriched
in manganese is frequently associated with hot environments. Enrichment by 399 ± 239 % and 16 ± 8 % for
manganese and iron, respectively, was found at basalt clasts by in situ X-ray fluorescence. The same values for
AP granite clasts are 511 ± 644 % and 126 ± 170 % for manganese and iron, respectively. Both petrotypes show
high enrichment in manganese. Fe-rich basalts tend to enrich by iron much less than Fe-poor granites. More
variable enrichment found for granites corresponds to their larger grain-size and higher mineralogical diversity.
At the microscopic level, metal oxides enrichment is connected with quartz and feldspar dissolution and
formation of fluorapophyllite and zeolites. Our field and laboratory electron microprobe data from desert
varnish on basalt and granite clasts from Ulu Peninsula show that the original rock petrology and mineralogy is
more important for specific metal oxide enrichment than the environment.

735
2482
Wind-driven Rock Abrasion in Antarctica's Ice-free Valleys: Rates and Controls

Bernard Hallet1 (hallet@uw.edu), Michael C. Malin2, Ronald S. Sletten3

1
University of Washington, Earth and Space Sciences, Seattle, United States, 2Malin Space Science Systems, San
Diego, United States, 3University of Washington, Seattle, United States

Wind is a principal geomorphic agent in dry regions of Earth and Mars, where it transports sediments and
erodes rock surfaces, creating diverse geomorphic features, and helping generate dust and regolith. Despite its
importance, few studies have defined rates of rock abrasion under natural conditions. We report rock abrasion
rates well characterized through a comprehensive long-term (>30 year) field experiment in the hyper-arid ice-
free McMurdo Valleys, Antarctica. More than 5000 rock targets of several lithologies (dolerite, basalt, and non-
welded tuff) were installed at 5 heights above the ground (7 to 70 cm) facing the 4 cardinal directions at 10
sites. Periodic collecting of rock targets exposed to abrasion define the progressive mass loss, a simple measure
of the amount of abrasion, after 1, 5, 10, 30 and 31 years of exposure. Abrasion rates generally show striking
consistency for a given lithology at any site, but they vary considerably from site to site owing to differences in
availability of transportable sediment, wind regime, and surface roughness. For example, for dolerite, basalt,
and tuff targets facing the dominant winds, annual abrasion averaged 21, 49, and 3400 microns respectively in
central Wright Valley (site 7); in contrast, it averaged 2, 4, and 200 microns at site 8, only 23 km directly up
valley of site 7. At each site, rates primarily depend on target orientation relative to the dominant winds and,
secondarily on height above the ground.

736
1524
The Origins of Antarctic Rock Glaciers: Periglacial or Glacial Features?

Mauro Guglielmin1 (mauro.guglielmin@uninsubria.it), Stefano Ponti2, Emanuele Forte3

1
Università degli Studi dell'Insubria, DISTA, Varese, Italy, 2Università degli Studi dell'Insubria, Varese, Italy,
3
Università degli Studi di Trieste, Trieste, Italy

In extensively glaciarized permafrost areas as Continental Antarctica, rock glaciers are quite common and
considered postglacial cryotic landforms. This paper reveals that, two landforms previously mapped on
geomorphological bases as rock glaciers, located in Northern Victoria Land should have the same glacial origin.
In fact, by integrating different geophysical investigations and borehole stratigraphy, we show that both
landforms have similar internal structures and cores of buried glacier ice. Therefore, this kind of rock glacier is
possibly related to the long-term creep of buried ice rather than of permafrost creep alone. This interpretation
can be extended to the larger part of the features mapped as rock glacier in Antarctica. In addition, a high-
reflective horizon sub-parallel to the topographic surface was detected in Ground Probing Radar (GPR) data
over a large part of the study area. Combining all the available information, we conclude that it cannot be
straightforwardly interpreted as the base of the active layer but rather represents the top of a cryo-lithological
unit characterized by ice lenses within sediments that could be interpreted as the transition zone between the
active layer and the long-term permafrost table. More generally, the combined use of GPR and ERT is
extremely helpful to understand the origin of landforms that can be found also on Mars and, possibly to
contribute to understand the paleoclimatic evolution of the cryosphere.

737
SH-4 - Polar Heritage: Politics, policy, practice
20.06.2018 16:00-17:30, A Sertig

2645
Constructing the Pasts of Polar Futures: History and Heritage in Polar Conflicts

Dag Avango1 (avango@kth.se)

1
KTH-Royal Institute of Technology, Div of History of Science, Technology and Environment, Stockholm, Sweden

This paper analyses the role of history and heritage in the international competition for resources and political
influence in the Polar Regions. The paper builds on a book project contributing to a broad field of research
exploring the production of future visions about the polar regions. A striking feature of these visions is the
degree to which they are based on notions about the past. Actors involved in the competition for natural
resources and political influence there have used and produced history and heritage as a part of their strategies
to influence the future. They have done so on different arenas: through corporate and policy documents,
popular history publications, museums, and through designation, narration and management of heritage sites.
This paper discusses such practices in the Arctic and Antarctic over the course of the 20th century up until the
present. The results show that such politics of memory have played significant roles in the polar regions. By
enrolling actors from the past and the material remains of their actions into actor networks, competing actors
have populated places with allied actors and actants. These networks have played different roles, defending
national prestige, attracting tourists, creating a sense connectedness to distant polar places, as well as
legitimizing claims for influence over territories and natural resources.

738
54
Landscape in White; Archaeology and Anthropology in Antarctica

Andres Zarankin1 (zarankin@yahoo.com), Melisa Salerno2

1
Universidade Federal de Minas Gerais, Antropologia e Arqueologia, Belo Horizonte, Brazil, 2CONICET, DIPA,
Buenos Aires, Argentina

Antarctica was the last continent to be known. Human encounters with the region acquired different
characteristics over time. Within the framework of dominant narratives, the early 'exploitation' of the territory
was given less attention than late nineteenth-early twentieth-century 'exploration'. Dominant narratives on the
period refer to the captains of sealing vessels, the discovery of geographical features, the volume of resources
obtained. However, they do not consider the life of the ordinary sealers who lived and worked on the islands.
In this chapter we will try to show the power of archaeology to shed light on these 'invisible people' and their
forgotten stories. We hold that archaeology offers a possibility for reimagining the past of Antarctica, calling for
a revision of traditional narratives.
In this presentation we will discuss some of the new lines of inquiry we are working with, and some of the
results already obtained by the international project “Landscapes in White; Archaeology and Anthropology in
Antarctica”. We will focus on the archaeology of experience, and the ways in which “being-in-the place” could
be useful to discuss the life of the 19th-century sealers we are studying. Furthermore, we will present the
results of the excavations we are conducting, the use of new technologies in the research, public archaeology
and the creation of an interactive record for the archaeological sites.

739
2430
Competing Discourses and Practices at the Heritage-making Process in Antarctica

Maria Ximena Senatore1 (mxsenatore@gmail.com)

1
CONICET, UNPA-UBA, Buenos Aires, Argentina

Heritage making in Antarctica is a complex process that occurs at multiple contexts (e.g. policy making,
archaeological research and tourism), and levels (e.g. international, national, individual). In this paper, heritage
is considered a cultural process concerned with negotiating, creating and re-creating cultural memories and
values. This process involves a range of discourses and actions used to construct meanings that have relevance
and utility in the present. The aim of this paper is to present the characterization of three different competing
discourses that underlie different contexts of the heritage making process:
a) policy making in the context of the Antarctic Treaty System,
b) archaeological research and,
c) tourism visitation.
I found that competing discourses understand Heritage as “a thing”, as “a means to an end” and as “an
experience”. The actions and practices were analyzed through bibliographical review of the academic
production published form 1960 to the present identifying the main objectives and actions taken place in
Antarctica in the frame of research projects or conservation projects. I also analyzed the ATCM documents
referring to historic sites form 1960 to 2016.

740
130
Antarctic Heritage: Cooperation and Conundrums

Bryan Lintott1 (bjl44@cam.ac.uk)

1
Scott Polar Research Institute, University of Cambridge, Cambridge, United Kingdom

In recent years, there has been increased public interest in Antarctic heritage, ranging from major centennial
events to conservation projects. There has also been increasing cooperation between several Antarctic nations
in sharing experience and expertise relevant to historic site and monument (HSM) management and
conservation.
However, concerns have been raised regarding several aspects of Antarctic heritage. These include an appeal
for increased involvement with the values associated (puesta en valor / mise en valeur) with Antarctic heritage,
and broader recognition of less prominent people from Antarctica´s past. Standards of HSM management and
conservation, and the question of whether or not to retain artefacts in Antarctica - a remote location with a
hostile environment - have also arisen.
The decision, in 2015, by the Committee for Environmental protection (CEP) to have a temporary ´hold´ on
future proposals for new HSMs, and the subsequent establishment of an Intersessional Contact Group to
consider several heritage matters demonstrates that there are unresolved subjects related to Antarctic
heritage.
Since 1961, heritage has been incorporated within Antarctic diplomacy. Whilst a system of HSM designation
and protection was developed it was not entirely satisfactory. This presentation will review the history of
Antarctic heritage, and identify and discuss the major diplomatic and cultural matters that inform the current
conundrums.

741
2571
Employing Polar Heritage to Construct Antarctic Identity at the Gateway Cities

Gabriela Roldan1 (gabriela.roldan@pg.canterbury.ac.nz)

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand

Antarctica's absence of native human population poses challenges and opportunities for those communities
living in the periphery of the Southern Ocean in creating connections with the South. Unlike the Arctic
communities, people at the today-known Antarctic gateway cities had little association, if so, with Antarctica.
Once the geopolitical and economic significance of their role in facilitating access to Antarctica, and its
associated knowledge and services, is recognized by their respective nations, multiple strategies are set in place
to establish a legitimate polar connection. Cultural imaginings of Polar heritage are employed daily in public
spaces as reminders of polar explorers' past visits to the city, and of the participation of local heroes in
Antarctic expeditions. This paper examines the use of Antarctic-related public art within each city, such as
statues of polar explorers, the historical and political context in which these statues were erected, and the
current significance to the local community in constructing polar belonging and the city's relationship with
Antarctica throughout time.

742
GG-2f - Arctic and Antarctic past ice sheet dynamics and paleoclimate evolution
20.06.2018 16:00-17:30, A Schwarzhorn

1856
New Aerogeophysical Survey of Titan Dome and Ice-core Drilling Potentia

Lucas Beem1 (lhbeem@utexas.edu), Duncan Young1, Don Blankenship1, Jamin Greenbaum1, Gail Muldoon1,
Jason Roberts2, Catherine Rtiz3, Guo Jingxue4, Sun Bo4
1
University of Texas -- Institute for Geophysics, Austin, United States, 2Australian Antarctic Division, Kingston,
Australia, 3Laboratoire de Glaciologie Géophysique de I'Environment, Saint Martin d'Hères, France, 4Polar
Research Institute of China, Shanghai, China

Ice domes and divides, including East Antarctic Titan Dome and Dome C, are interior boundaries of major
glacier drainages and are thought of as stable regions of ice sheets. As a result, these regions are targets for ice-
core drilling including the search for high-resolution climatological proxies that date back 1 to 1.5 Myr.
However, subglacial processes and ice flow-reorganization over glacial-cycle timescales can belie the stability of
these regions. A new survey of Titan Dome conducted through a partnership between Polar Research Institute
of China and University of Texas-Institute for Geophysics offer constraints on the subglacial environment and
the distribution of water and heat. Though a combination of data analysis, radar and potential fields, and
hydrological modeling the basal heat budget, geological character, and drilling site potential are evaluated.
Analysis of Titan Dome observations reveal the presence and distribution of liquid water and complex internal
ice structure including locations of local drawdown, suggesting past ice flow or enhanced basal melt. Subglacial
water flow, including within the subsurface, influences the basal heat flux by up to multiple factors of assumed
geothermal flux. This analysis is aided by the context of a similar but higher density survey of Dome C. Together
they offer insights into ice sheet processes that occur at ice-sheet divides and future drilling site potential
including in service to NSF's Rapid Access Ice Drill.

743
1638
Searching for Oldest ice in Antarctica, an Ice Sheet Modelling pre-site Survey

Johannes Sutter1,2 (johannes.sutter@awi.de), Thomas Kleiner1, Klaus Grosfeld1, Nanna B. Karlsson1, Brice Van
Liefferinge3, Frank Pattyn3, Hubertus Fischer4, Olaf Eisen1,5
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2University
of Bern, Physics Institute & Oeschger Centre for Climate Change Research, Bern, Switzerland, 3Université Libre
de Bruxelles, Brussels, Belgium, 4University of Bern, Physics Institute & Oeschger Centre for Climate Change
Research, Climate and Environmental Physics, Bern, Switzerland, 5University of Bremen, Bremen, Germany

Covering the Middle-Pleistocene Transition (MPT) transition with a well resolved ice core record is the main
motive of the European Beyond EPICA - Oldest Ice (BE-OI) efforts. Pre-MPT glacial cyclicity was dominated by
obliquity (ca. 40 ka) which then shifted to 100 ka excentricity-driven glacial-interglacial cycles typical for the last
ca. 800 ka. The drivers of this transition are still obscure, hence a well resolved Antarctic ice core record
spanning this transition would provide much needed proxy information. We present transient continental scale
3D ice sheet simulations of the Antarctic Ice Sheet (using the Parallel Ice Sheet Model PISM) which span the last
2 million years to capture, both, pre-MPT as well as excentricity driven ice dynamics. Employing passive tracers,
we dynamically reconstruct the stratigraphy of existing deep ice cores and indicate potential sites of oldest ice
around Dome Fuji and Dome C. Around the latter ice core sites, we incorporate new radar derived bedrock
topographies to improve the lower boundary conditions. The ice sheet model is forced by a compilation of
different geothermal heat fluxes, sea level and climate scenarios to account for a range of potential paleo-
climate boundary conditions and their effects on ice dynamics. This study contributes to a variety of modelling
and observational efforts to establish the most promising drill site for an ice core up to 1.5 million years old.

744
1397
In situ Cosmogenic 14C and 36Cl Inform Deglacial Ice Extents in Western DML

Nathaniel Lifton1,2 (nlifton@purdue.edu), Sarah Sams1, Jennifer Newall1,3,4, Ola Fredin5,6, Neil Glasser7, Jorge
Bernales8, Marc Caffee1,2, Derek Fabel9, Jon Harbor1,3,4, Irina Rogozhina8,10, Arjen Stroeven3,4
1
Purdue University, Dept of Earth, Atmospheric, and Planetary Sciences, West Lafayette, United States, 2Purdue
University, Dept of Physics and Astronomy and Purdue Rare Isotope Measurement Laboratory (PRIME Lab),
West Lafayette, United States, 3Stockholm University, Geomorphology and Glaciology, Dept of Physical
Geography, Stockholm, Sweden, 4Stockholm University, Bolin Centre for Climate Research, Stockholm, Sweden,
5
Geological Survey of Norway, Trondheim, Norway, 6Norwegian University of Science and Technology, Dept of
Geography, Trondheim, Norway, 7Aberystwyth University, Centre for Glaciology, Dept of Geography and Earth
Sciences, Aberystwyth, United Kingdom, 8GFZ German Research Centre For Geosciences, Helmholtz Centre,
Potsdam, Germany, 9Scottish Universities Environmental Research Centre, Glasgow, United Kingdom,
10
University of Bremen, Center for Marine Environmental Sciences MARUM, Bremen, Germany

MAGIC-DML is a Swedish-US-Norwegian-German-UK collaboration focused on improving ice sheet models by

filling critical data gaps that exist in our knowledge of the timing and pattern of ice surface changes along the
western Dronning Maud Land (DML) margin, combined with advances in numerical techniques. To provide
empirical data on the timing of ice surface lowering, field studies in austral summer 2017 targeted slopes in the
Heimefrontfjella and Vestfjella nunatak ranges for in situ cosmogenic nuclide (CN) sampling at a range of
elevations above the modern ice surface. Comparing concentrations of nuclides with widely differing half-lives
in bedrock and erratic samples from such sites can provide information on complex burial and exposure
histories, and thus, past configurations of non-erosive ice. Quartz-bearing samples were analyzed for in situ
10
Be (t1/2 1.4 My), 14C (t1/2 5.7 ky), 21Ne (stable), and 26Al (t1/2 705 ky), and mafic lithologies were analyzed for in
situ 36Cl (t1/2 301 ky). In situ 14C is unique among these nuclides in that its short half-life makes it particularly
sensitive to complex histories since the Last Glacial Maximum (Marine Oxygen Isotope Stage 2). We present
preliminary in situ 14C results from selected bedrock and erratic samples across the field area, compared with
long-lived nuclide results (presented separately), as well as preliminary in situ 36Cl results from associated
glacially striated basaltic bedrock.

745
1618
Pleistocene Paleoceanographic Changes of the Southern Ocean off the Ross Sea

Sunghan Kim1 (delongksh@kopri.re.kr), Jae Il Lee1, Kyu-Cheul Yoo1, Young-Suk Bak2, Min Kyung Lee1, Hi Il Yoon1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Chonbuk National University, Jeonju,
Korea, Republic of

A 8.4 m long gravity core RS15-GC107 was collected from a seamount in the Southern Ocean off the Ross Sea
(68o04.0741´S, 178o37.9066´W, 3050 m deep). Geochemical proxies (biogenic opal, CaCO3, TOC) and oxygen
isotope of planktonic foraminifers (Neogloboquadrina pachyderma (sin.)) were measured in order to
reconstruct paleoceanographic changes of the Ross Sea Sector of the Southern Ocean. Because CaCO3 was
relatively well preserved in upper 6 m of the core, the age of the upper part was constrained through
planktonic foraminifer oxygen isotope correlation to LR-04 stack. CaCO3 became to be preserved from 6.2 m of
core RS15-GC107, whereas biogenic opal decreased from this interval. The changes at 6.2 m of core RS15-
GC107 most likely corresponded to the beginning of the Mid-Pleistocene Transition (MPT) climate change. This
means that the Ross Sea Sector of the Southern Ocean shifted from relatively more siliceous ocean to
carbonate ocean during the MPT. Oxygen isotope values became lower during the interglacial periods with
larger glacial-interglacial contrast at 1.5 m of the core, ~430 ka, which corresponds to the Mid-Brunhes Event
(mWP). Interestingly, glacial planktonic Oxygen isotope values also became relatively lighter from ~430 ka than
before. This may suggest that post-mWP glacial periods became more stratified along with increased ice
volume.

746
831
Nonlinearities in Southern Ocean Response to CO2 and Obliquity Forcing

Elizabeth D Keller1 (l.keller@gns.cri.nz), Nicholas Golledge1,2, Richard Levy1, Katrin J Meissner3

1
GNS Science, Lower Hutt, New Zealand, 2Victoria University of Wellington, Antarctic Research Centre,
Wellington, New Zealand, 3University of New South Wales, Climate Change Research Centre and ARC Centre of
Excellence for Climate System Science, Sydney, Australia

Paleoclimate records suggest an increased sensitivity of the Antarctic ice sheet to orbital forcings when
atmospheric CO2 concentrations reach above ~500 ppm. Here we present model experiments designed to
explore the relative sensitivity of atmospheric CO2 and obliquity forcing in Antarctica and the Southern Ocean
using the University of Victoria Earth System Climate Model (UVic ESCM). We focus on the Pliocene, as this
interval contains several orbital cycles and provides an example of Southern Ocean dynamics in a warmer-than-
present, high CO2 world in which the West Antarctic Ice Sheet (WAIS) is absent. We find a nonlinearity in the
system response to obliquity when CO2 is between 500-650 ppm, particularly in ocean temperature at
intermediate depths. We analyse the possible drivers of this result and the implications for future warming.

747
1135
Paleobathymetry of the Cenozoic Southern Ocean and its Various Consequences

Katharina Hochmuth1 (katharina.hochmuth@awi.de), Karsten Gohl1, German Leitchenkov2, Isabel Sauermilch3,

Joanne Whittaker3, Laura DeSantis4, Elisabetta Olivio4, Gabriele Uenzelmann-Neben1, Bryan Davy5
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2VNII
Okeangeologia, St. Petersburg, Russian Federation, 3Institute of Marine and Antarctic Studies, University of
Tasmania, Hobart, Australia, 4Institute Nationale di Oceanographica e di Geofisica Sperimentale (OGS), Trieste,
Italy, 5GNS Science, Lower Hutt, New Zealand

Although the Southern Ocean plays a fundamental role in the global climate and ocean current system, paleo-
ocean circulation models of the Southern Ocean suffer from missing boundary conditions. A more accurate
representation of the geometry of the seafloor and its dynamics over long time-scales are key for enabling
more precise reconstructions of the development of the paleo-currents, the paleo-environment and the paleo-
ice sheets of Antarctica.
The reassessment of all available seismic reflection and borehole data from Antarctica as well as its conjugate
margins of Australia, New Zealand, South Africa and South America allows us to create paleobathymetric grids
for various time slices during the Cenozoic. We generated grids from the Eocene/Oligocene Boundary, the Mid-
Miocene Climatic Optimum and the Pliocene/Pleistocene. These grids reveal changes in sediment distribution
and volume as well a local sedimentation rates.
The observation of sediment distribution and local sediment volumes opens the door towards more
sophisticated paleo-topograpy studies of the Antarctic continent and more detailed studies of the paleo-
circulation. Local paleo-water depths at the oceanic gateways or the position of paleo-shelf edges highly
influence the regional circulation patterns supporting more elaborated climate models.

748
TE-3f - Remote sensing of polar regions
20.06.2018 16:00-17:30, A Seehorn

1949
Variability in Glacier Dynamics of a Greenland Glacier Using Sentinel-1 SAR Data

Christoph Rohner1 (christoph.rohner@geo.uzh.ch), Rémy Mercenier1, Andreas Vieli1, Martin Lüthi1, David
Small1
1
University of Zurich, Department of Geography, Zürich, Switzerland

Following the general warming trend in Greenland, an increase in calving rates, retreat and ice flow can be
observed at ocean-terminating outlet glaciers. These changes contribute substantially to the current mass loss
of the Greenland Ice Sheet. In order to constrain models of ice dynamics, detailed knowledge of geometry, ice-
flow, and environmental forcing factors are needed.
Using spaceborne synthetic aperture radar (SAR) systems in conjunction with in-situ measurements, we
investigate the intra- and inter-annual variability of the flow dynamics of a medium-sized ocean-terminating
outlet glacier located in Western Greenland. The satellite datasets consist of a time series comprising more
than 150 acquisitions from ESA's Sentinel-1 SAR platform starting in 2014 as well as 20 Radarsat-2 images from
2015/2016. By applying feature tracking approaches, the data from these C-band SAR sensors allows derivation
of quasi-continuous velocity estimates at high spatial and temporal resolutions. In addition, the C-band
backscatter enables detection of surface melt and ice mélange extent as well as the position of the calving front
with almost no additional knowledge required. The availability of such data time-series stemming from one
single platform will allow investigation of the influence of environmental forcing (melt and ice mélange) on the
variability in flow and terminus dynamics, and thereby provide constraints for models of calving dynamics.

749
1991
Remote Sensing of Coastal Sea Ice Using Passive Microwave and Visible Imagery

Alice Bradley1 (alice.chapman.bradley@dartmouth.edu), Elizabeth Durham2, Rachel Obbard1

1
Dartmouth College, Thayer School of Engineering, Hanover, United States, 2Dartmouth College, Hanover,
United States

Coastlines in the Arctic are made vulnerable by longer ice-free seasons, but studying the timing of freeze-up is
limited by a lack of observations. Existing passive microwave sea ice concentration products are undefined near
shore, and limited coverage of higher-resolution products can mean missing most of the freeze-up season. This
presentation explores a new approach to remote sensing of coastal sea ice cover, loosely based on the NASA
Team algorithm. Designed specifically for pixels with partial land and partial ocean area, it uses local land pixels
as seasonally-varying tie points to control for changing land surface conditions over the course of the winter.
The approach uses polarization and gradient ratios from brightness temperature retrievals to determine ice
presence in the fraction of a pixel that is ocean. A reference dataset of visible, infrared, and SAR imagery
complements local observations (compiled through SIZOnet) to validate the passive microwave approach.

750
2042
Monitoring of Ice Dynamics and Mass Balance in Central Dronning Maud Land

Christoph Knöfel1 (christoph.knoefel@tu-dresden.de), Mirko Scheinert1, Ludwig Schröder1, Benjamin

Ebermann1, Veit Helm2, Martin Horwath1
1
Technische Universität Dresden, Institut für Planetare Geodäsie, Dresden, Germany, 2Alfred-Wegener-Institute,
Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany

Since 1991, various geodetic and glaciological research activities have been carried out in the region southeast
of Schirmacheroase, Dronning Maud Land, East Antarctica. This region is characterized by the slowly floating
Potsdam Glacier that crosses a wider area of bare blue-ice surface.
Repeated ground-based surveys (mainly GNSS) realizied during the last 25 years serve as a basis to studying the
long-term behaviour of surface heights, ice velocity, accumulation and ablation in that region. In the last few
years our ground-based measurements have been performed simultaneously with airborne radar and lidar
observations. Additionally, we incorporated satellite laser and radar altimetry data from ERS-1/2, Envisat,
ICESat and CryoSat-2. Satellite images (e.g. taken by Landsat satellites) provide optical snapshots over several
decades.
We will discuss the long-term evolution of the ice regime based on surface-height variations and flow
velocities. In terms of mass balance, the combination of ground-based, airborne and satellite-based data allows
to give a comprehensive picture of the entire region. Furthermore, the comparison leads to accuracy estimates
of the derived trends. Results based on temporarily and spatially limited GNSS observations serve as
constraints for airborne and spaceborne measurements which cover larger areas. It will be shown that the
permanent monitoring of relevant regions is essential for the derivation of reliable long-term trends.

751
2211
Estimating Melt Pond Fractions on First Year Ice with Compact Polarization SAR

Haiyan Li1,2, Will Perrie2 (william.perrie@dfo-mpo.gc.ca)

1
University of Chinese Academy of Sciences, 1. Key Laboratory of Computational Geodynamics, Chinese
Academy of Sciences, Beijing, China, 2Bedford Institute of Oceanography, Dartmouth, Canada

Melt ponds are common on Arctic sea ice. They are linked to surface albedo and energy transfer to the ocean
from the atmosphere and are important in Arctic climate studies. This paper presents a first attempt to retrieve
melt pond fractions from hybrid-polarized compact polarization (CP) SAR imagery, which will be available from
RADARSAT Constellation Mission to be launched in 2018. CP SAR has wider swath and shorter revisit time than
quad-polarization systems, like RADARSAT-2 (RS-2). The co-polarization (co-pol) ratio has been verified to
provide estimates of melt pond fractions. But it is a challenge to link CP parameters and the co-pol ratio. The
theoretical basis is presented for making this linkage with the CP parameter C22/C11 (the ratio of the elements
of the coherence matrix of CP SAR) for melt pond detection with the tilted-Bragg scattering model for the
ocean surface. An empirical formulation, the 'compact polarization and quad-pol' ('CPQP') model, is proposed
based on 2062 RS-2 quad-pol SAR images, collocated with in situ measurements. We compare the retrieved
melt pond fraction with CP parameters simulated from quad-pol SAR data and results retrieved from the co-pol
ratio from quad-pol SAR images from the Arctic-Ice (Arctic-Ice Covered Ecosystem in a Rapidly Changing
Environment) project. Results are comparable for observed melt pond data in spatial and temporal
distributions. Thus, the CP mode SAR is able to estimate melt pond fractions on first year ice.

752
2280
Variations in the Extent and Elevation of the Larsen Ice Shelf, Antarctica

Changqing Ke1 (kecq@nju.edu.cn), Jun Chen1

1
Nanjing University, School of Geography & Oceanography, Nanjing, China

Ice shelf extent is extracted from declassified aerial photographs and modern satellite images, and a very long
time series of the areal extent of the Larsen A Ice Shelf (LAIS) and the Larsen B Ice Shelf (LBIS) is compiled. In
addition, we characterize the surface elevation changes of the LAIS and the LBIS over the last two decades by
combining the Ocean Topography Experiment/Poseidon (T/P) and the Envisat Radar Altimeter-2 (RA-2) using
the collinear analysis method. The northern Larsen Ice Shelf (LIS) displayed no significant changes until the late
1980s, whereas the LAIS has retreated rapidly since 1986, and the LBIS has followed a similar pattern since the
early 1990s. The gradual retreat of the northern LIS is interrupted by several catastrophic calving events. The
LAIS and the LBIS have already diminished by approximately 14,000 km2 in total since 1968. At the same time,
the surface elevations of the LAIS and the LBIS exhibit progressive lowering from 1992 to 2010, whereas the
lowering rate of the LAIS is significantly higher than that of the LBIS. The northern LIS has warmed substantially
in all seasons, but summer displays the least warming. The warmer air temperatures and increasing surface
meltwater production and refreezing lead to continuous surface lowering by firn densification. However,
considering the continuous retreat of the northern LIS, its surface elevation is more sensitive to the collapse
and retreat of the ice shelf than atmospheric warming.

753
2381
Advance of Western Margin of the Vavilov Ice Cap Assessed by Remote Sensing Data

Irina Bushueva1, Andrey Glazovsky1 (icemass@yandex.ru), Gennady Nosenko1

1
Institute of Geography Russian Academy of Sciences, Glaciology, Moscow, Russian Federation

The Vavilov ice cap (79.30° N, 95.47° E) is situated on October Revolution Island of the Severnaya Zemlya
archipelago. In this project the images obtained from Landsat-1, 5, 7, 8, Terra (ASTER), Sentinel-1 and Corona
were applied. We found out that from 1963 to 2017 the ice cap margin advanced seaward by 11.7 km (central
line), and its area increased by 133 km2. The accelerated advance started in 2010, in summer 2016 the marginal
front terminated in sea began to disintegrate, in 2017 the advance continued but with lower velocity.
The data on ice cap velocities was taken from two sources. The first one is GoLIVE project, also we analysed the
synthetic aperture radar data from Sentinel-1 satellite. Comparison of the velocities acquired from two sources
for the same period shows that they are in a very good correlation. Maximum velocity of glacier was in 2016
and reached 25.4 m/day. From 2016 the velocity started to decrease.
To evaluate the volume changes of western part of the Vavilov ice cap we analysed ASTER DEMs of 2000 and
2015, radar data obtained during fieldwork in 2014 and topographic maps of scale 1:200 000. Above the
contour line of 100 m (2015) the main trunk of the newly formed outlet glacier thinned by at least 1.918 km3,
and at the same time its snout increased by 4.101 km3.
This study is supported by the Russian Foundation for Basic Research, grant 16-35-00333, and by the Russian
Science Foundation, grant 14-37-00038.

754
OS-2c - Interdisciplinary research on sea-ice biogeochemistry and associated ecosystems
20.06.2018 16:00-17:30, A Wisshorn

744
Physical and Biogeochemical Properties of Winter Sea Ice during Pipers, Ross Sea

Jean-Louis Tison1 (jtison@ulb.ac.be), Ted Maksym2, Jan Lieser3, Gauthier Carnat1, Celia Sapart1, Steve Ackley4,
Johannes de Jong1, Fanny Vanderlinden5, Sharon Stammerjohn6, Bruno Delille5
1
Université Libre de Bruxelles, Glaciology, Bruxelles, Belgium, 2Woods Hole Oceanographic Institution (WHOI),
Woods Hole, United States, 3University of Tasmania, Institute for Marine and Antarctic Studies (IMAS), Antarctic
Climate and Ecosystems Cooperative Research Centre (ACE CRC), Hobart, Australia, 4University of Texas at San
Antonio, San Antonio, United States, 5Université de Liège, Chemical Oceanography Unit (COU), Liège, Belgium,
6
Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado, Boulder,
United States

The PIPERS (Polynyas, Ice Production and its seasonal Evolution in the Ross Sea) cruise on N. B. Palmer into the
early winter Ross Sea took place between April 11 and June 14 2017. The main objective was to investigate the
Atmosphere-Ice-Ocean interactions in the Terra Nova Bay and Ross Ice Shelf coastal polynyas. The cruise
however extended these polynyas studies to a series of ice stations transects “in” and “out” of the Ross Sea. It
involved a large set of multidisciplinary activities aiming at the detailed documentation of processes across the
ocean-ice-atmosphere continuum. This paper presents the basic physical (Temperature, bulk salinity, brine
volume, Rayleigh number) and biogeochemical properties (water stable isotopes, Chl-a) of the sea ice cover at
27 ice stations. The cruise encountered unusual sea-ice conditions in the 2016/2017 season, where
exceptionally low sea-ice summer extent was recorded Antarctica-wide as early as November 2016, which
stayed below previous records of the satellite era for the rest of the austral summer. It is also a year where
active primary production was evidenced within the Ross Sea and Terra Nova Bay Polynya, a few weeks before
the cruise took place. We will show how these conditions have potentially affected (or not) the physical and
biogeochemical properties of the sea ice cover in the Central Ross Sea and discuss the contrasts with the sea
ice properties of the Terra Nova Bay polynya and the MIZ.

755
2021
PIPERS: Role of Polynyas on the Atmospheric Budget of Methane and Carbon Dioxide

Célia Sapart1,2 (csapart@ulb.ac.be), Brett Thornton3, Patrick Crill3, Caroline Jacques1, Bruno Delille4, Thanos
Gkritzalis5, Thomas Röckmann6, Carina van der Veen6, Elena Popa2, Sharon Stammerjohn7, Stephen Ackley8,
Brice Loose9, Sam Gartzman9, Peter Guest10, Jean-Louis Tison1
1
Laboratoire de Glaciologie/Université Libre de Bruxelles, Brussels, Belgium, 2Institute for Marine and
Atmospheric Research Utrecht (IMAU), Utrecht, Netherlands, 3Stockholm University, Stockholm, Sweden,
4
Université de Liège, Liège, Belgium, 5Vlaams Institute voor de Zee, Ostend, Belgium, 6Institute for Marine and
Atmospheric research Utrecht (IMAU), Utrecht, Netherlands, 7Lamont-Doherty Earth Observatory of Columbia
University, Boulder, United States, 8The University of Texas at San Antonio, San Antonio, United States,
9
University of Rhode Island, Rhode Island, United States, 10Naval Postgraduate School, Monterey, United States

Coastal polynyas are areas of anomalous open water and thin ice in regions that are otherwise covered by sea
ice. They frequently occur around the Antarctic continent in response to strong offshore katabatic wind
stresses. The loss of heat from the open ocean to the cold atmosphere can enormously enhance rates of ice
production. In polynya areas, the coupling between the atmosphere, sea ice and ocean is complex, and the role
of ice formation on the budget of the main climate forcing carbon gases remains unknown. During the PIPERS
expedition on the N.B. Palmer from April to June 2017, we performed continuous measurements of methane
and carbon dioxide concentrations in the atmosphere and in the surface water from New Zealand to the
polynyas of the Ross Sea. Discrete sampling was carried out in parallel to calibrate the continuous systems and
to later measure the stable isotope ratios of both gases in the water and in the air. The stable isotope data
enable unravelling the pathways involved in gas formation and removal. While the concentrations of both
gases were relatively low in the surface waters of polynyas, the preliminary atmospheric data show higher
methane and carbon dioxide levels in the atmosphere at locations where sea ice formation was most intense.
These data together with the isotopic ratios of both gases and with meteorological data will be discussed to
better understand the role of sea ice formation on the exchange of climate forcing gases.

756
414
Antarctic Landfast Sea Ice: Autotrophy vs Heterotrophy, Sink vs Source of CO2

Fanny Van der Linden1,2 (fvanderlinden@ulg.ac.be), Sébastien Moreau3, Willy Champenois1, Bernard Heinesch4,
Gauthier Carnat2, Marie Kotovitch1,2, François Fripiat5, Florian Deman6, Frank Dehairs6, Tim Haskell7, Jean-Louis
Tison2, Bruno Delille1
1
Université de Liège, Chemical Oceanography Unit, Liège, Belgium, 2Université Libre de Bruxelles, Glaciology
Lab, Brussels, Belgium, 3University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia,
4
Université de Liège, Biosystem Engineering, Liège, Belgium, 5Max Planck Institute for Chemistry, Mainz,
Germany, 6Vrije Universiteit Brussel (VUB), Analytical, Environmental and Geo-Chemistry Department, Brussels,
Belgium, 7Callaghan Innovation, Lower Hutt, New Zealand

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different
times of the year depending on its trophic status (autotrophic vs heterotrophic). In the frame of the YROSIAE
project (Year-Round survey of Ocean-Sea-Ice-Atmosphere Exchanges), carried out at Cape Evans in McMurdo
Sound (Antarctica) from Nov. 2011 to Dec. 2012, ice cores, seawater, and brines were collected at regular time
intervals. We used dissolved inorganic carbon (DIC) and chlorophyll-a
(chl-a) as proxies of net community production and autotrophic biomass, respectively. From spring, very high
chl-a concentrations (>2400µg.L-1) were observed at the bottom of the ice. This suggests high primary
production. Strikingly, at the same time, nutrients increased significantly indicating strong remineralization at
the bottom. In the ice interior, evolution of DIC was marked by a succession of autotrophic and heterotrophic
phases. The overall increase of DIC suggests that the ice interior was rather heterotroph. Such sea ice system
should expel CO2. Yet, strong under-saturation in CO2 and DIC depletion appeared at the ice surface, suggesting
that sea ice should take up CO2 from the atmosphere. On the whole, land fast sea ice in McMurdo Sound
appears as a puzzling ecosystem. High primary production and remineralization develop simultaneously at the
bottom while the top of the ice is rather heterotrophic but still able to pump CO2 from the atmosphere.

757
844
Modeling Iron Distribution in the Early Stages of Sea-ice Growth

Julie Janssens1 (julie.janssens@utas.edu.au), Sebastien Moreau1, Martin Vancoppenolle2, Klaus Meiners3,

Delphine Lannuzel1
1
Institute for Marine and Antarctic Studies, Hobart, Australia, 2Laboratoire d'Oceanographie et du climat,
Institut Pierre-Simon Laplace, Paris, France, 3Australian Antarctic Division, Hobart, Australia

Primary productivity in the Southern Ocean (SO) is affected by the release of iron (Fe) from melting sea ice.
Despite this, representation of sea ice as a source of Fe for the surface waters of the SO is poorly represented
in models. Sea-ice extent and volume are predicted to reduce in the future. The extend to which these climate-
induced changes will affect biological activity in the seasonal ice zone, and therefore primary productivity in the
SO, both having a significant role on the climate system, is currently unknown.
We implemented a one-dimensional modelling framework (LIM-1D) to identify the main processes responsible
for Fe distribution in a single ice floe during the very early stages of sea-ice growth. The model simulations are
compared with field observations carried out during in situ ice-growth experiments during Austral winter in the
Weddell Sea, Antarctica. The model successfully represented the vertical distribution of iron in newly formed
sea ice, when the processes of entrapment and adsorption were included to represent the initial physical
enrichment of particulate iron and dissolved iron. Our study is a first step towards the development of large
scale modelling tools to simulate sea-ice associated primary production and further simulate its feedback
impact on the climate, ultimately helping to forecast the response of Antarctic ecosystems to environmental
changes.

758
1081
Using under-ice Radiance Spectra to Determine Antarctic Fast Ice Algal Biomass

Pat Wongpan1 (pat.wongpan@postgrad.otago.ac.nz), Klaus Meiners2,3, Pat Langhorne1, Petra Heil2,3, Inga
Smith1, Greg Leonard4, Rob Massom2,3, Lesley Clementson5, Tim Haskell6
1
University of Otago, Department of Physics, Dunedin, New Zealand, 2Australian Antarctic Division, Department
of the Environment and Energy, Kingston, Australia, 3Antarctic Climate and Ecosystems Cooperative Research
Centre, University of Tasmania, Hobart, Australia, 4University of Otago, National School of Surveying, Dunedin,
New Zealand, 5CSIRO Oceans and Atmosphere, Hobart, Australia, 6Callaghan Innovation, Lower Hutt, New
Zealand

Fast ice is an important component of Antarctic coastal ecosystems, providing a habitat for thriving ice algal
communities. This work examines the relationships between the normalized difference indices (NDI) calculated
from under-ice radiance measurements and both sea ice algal biomass and snow depth for Antarctic fast ice.
While this technique has been calibrated to assess biomass in Arctic fast ice and pack ice, and Antarctic pack
ice, relationships are currently lacking for Antarctic fast ice. We analyze measurements along transect lines at
two contrasting fast ice sites: near (affected by platelet ice) and distant from an ice shelf, i.e. in McMurdo
Sound and off Davis Station, respectively. Snow and ice thickness, and ice salinity and temperature
measurements underpin our paired in situ optical and biological measurements. NDI wavelength pairs near the
first chlorophyll-a (chl a) absorption peak (≈440 nm) explain up to 70% of the total variability in algal biomass.
Snow depth is estimated from an NDI with a wavelength pair of 648 nm and 567 nm explaining 88% of its total
variability. Accounting for pigment packaging effects by including the ratio of chl a specific absorption
coefficients improved the NDI-based algal biomass estimation only slightly. Our new observation-based
algorithms can be applied to estimate Antarctic fast-ice algal biomass and snow depth non-invasively from
moored sensors (time-series) or to map their spatial distributions using underwater vehicles.

759
1497
On the Fate of Primary Production in the Sea Ice Zone of the Southern Ocean

Sebastien Moreau1,2 (sebastien.moreau@hotmail.com), Philip W. Boyd1, Peter Strutton1, Delphine Lannuzel1

1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Norwegian Polar
Institute, Tromso, Norway

Primary production (PP) in the Southern Ocean is of paramount importance for two main reasons. First, it
contributes to the largest biological pump on the planet, mitigating climate change. Second, it is the basis food
support for the Antarctic krill, the animal on the planet with the largest biomass, which feeds the largest
number of top predators. In the Southern Ocean, the sea-ice zone and the sea ice itself only account for 10% of
the basin-scale PP. However, sea ice is the critical habitat for overwintering krill and a reduction in its cover can
have dramatic consequences on the food-web. Moreover, the release of algae by melting sea ice is often un-
coupled from grazing activity and consequently sinks into the Ocean's interior. Hence, the sea ice zone plays
additional ecological and biogeochemical roles above its contribution to the PP of the Southern Ocean. In this
context, we present here a new algorithm to derive and demarcate the two main fates of PP - zooplankton
grazing and the export of phytodetritus and faecal pellets - from a combination of biogeochemical sensors
mounted on bio-Argo floats. We focus on floats which were profiling within the sea ice zone of the Southern
Ocean over the last 5 years. We find that ~90% of the annual PP is grazed by zooplankton, while phytodetritus,
the remaining 10%, accounts for up to 75% of the annual organic carbon export. This new proxy provides a new
tool to study remotely the fate of PP in a geographically-remote environment.

760
CR-3d - Cryosphere-Hydrosphere interactions: The water cycle at the three Poles
20.06.2018 16:00-17:30, B Parsenn

2178
Runoff Generation Processes in Extratropical Andean Catchments

James McPhee1 (jmcphee@uchile.cl), Yohann Videla1

1
Universidad de Chile, Santiago, Chile

Understanding the physical processes that dominate the volume and residence time of water stored in the
extratropical Andes is of great importance to the success in the management of the resource for around 10
million people. A lack of direct, long term process observations motivates the use of hydrological modeling for
hypothesis testing and process understanding, with the ultimate goal of achieving robust hydrological
predictions under global change scenarios. Here, we employ a physically based suite of hydrological routines to
estimate the energy and mass balance components of snow hydrology in extratropical mountain catchments,
and their contribution to runoff. The model is forced with data from the Era-Interim re-analysis for the 2000-
2016 period, which have been corrected through spacial and temporal downscaling and yield a very good
agreement with observed snowpack dynamics. Our results suggest that in this complex topography, 22% of the
snow is subject to reallocation either by wind or gravitational effects, such that meteorological elevation
gradients are not in themselves enough for explaining snow water equivalent distribution. An estimated 80% of
summer flow (DJF) comes from glacial melting, while it is shown that snow and ice melt contribute to runoff at
all times of the year, dispelling the notion of distinct accumulation and melt seasons.

761
920
Glacier Meltwater Mitigates the Impact of Severe Droughts in the Semiarid Andes

Alvaro Ayala1,2 (ayala@vaw.baug.ethz.ch), David Farias3, James McPhee4,5, Francesca Pellicciotti6, Daniel
Farinotti1,2
1
ETH Zurich/VAW, Department of Civil, Environmental and Geomatic Engineering, Zürich, Switzerland, 2WSL
Swiss Federal Institute for Forest Snow and Landscape Research, Birmensdorf, Switzerland, 3University of
Erlangen-Nürnberg/Institute of Geography and Geosciences, Erlangen, Germany, 4Universidad de Chile,
Department of Civil Engineering, Santiago, Chile, 5Universidad de Chile/AMTC, Santiago, Chile, 6Northumbria
University, Department of Geography, Newcastle, United Kingdom

Glaciers in semiarid regions have been highlighted as key reservoirs of fresh water resources with the potential
to sustain minimum flow levels in high-elevation catchments. However, few studies have quantified the glacier
contribution to runoff during severe droughts. Here, we estimate the ice loss and associated runoff
contribution of glaciers in the Maipo River catchment (semiarid Andes of Chile) in 2010-2015, the longest and
most extensive drought on local records. The Maipo River is the largest source of freshwater for the capital city
Santiago, and contains more than 800 glaciers, covering 377 km2. We use the physically-oriented TOPKAPI-ETH
hydrological model at a daily timestep and at a spatial resolution of 100 m to simulate snow processes, glacier
mass balance and runoff generation. While the average summer streamflow at the catchment outlet decreased
from 165.8m3s-1, in 2000-2009, to 97.8 m3s-1 (-41%), during the drought, our preliminary results indicate that
summer runoff from ice melt increased from 27.2 to 34.0 m3s-1 (+24.9%), providing additional 65 Mm3 y-1, and
more than doubling its summer relative contribution, from 15 to 34%. We build scenarios of extensive glacier
retreat in which we estimate the impacts that similar droughts will have on the availability of water resources
in a warming climate. Our study quantifies the impact of glacier retreat on water availability in a region where
the frequency of droughts is expected to increase with climate change.

762
1452
Quantifying Rock Glacier Contribution to Streamflow in Semiarid Catchments

Shelley MacDonell1 (shelley.macdonell@ceaza.cl), Francesca Pellicciotti2, James McPhee3, Nicole Schaffer1, Ivan
Fuentes3, Ben Robson4, Marion Réveillet1, Francisco Fernandoy5, Álvaro Ayala6
1
Centro de Estudios Avanzados en Zonas Aridas (CEAZA), La Serena, Chile, 2Northumbria University, Newcastle,
Chile, 3Universidad de Chile, Santiago, Chile, 4University of Bergen, Bergen, Norway, 5Universidad Andrés Bello,
Viña del Mar, Chile, 6ETH Zürich, Zurich, Switzerland

In high altitude areas vulnerable to climatic change, rock glaciers act increasingly as important sources of
water, especially during summer and dry periods. These cryoforms are considered to be long term water
reservoirs that support efficient water storage and slow delivery. The role of rock glaciers in the wider
hydrological system of the semiarid Andes is little known, and is the driving impetus for this study. As water
resources become increasingly scarce, and their demand increases, there is a need for improved understanding
of existing sources, and changes within the context of a warming climate. This study will take a multi-method
approach utilising a combination of glaciological, geomorphological, geophysical, geochemical and modelling
techniques to better elucidate the structure and function of the hydrological system of rock glaciers and to
subsequently evaluate rock glacier contribution to streamflow in the Elqui catchment where there are over 300
rock glaciers. In this presentation, we will highlight the methodological considerations for undertaking such a
study, will provide a first inventory of rock glaciers and their changes in the last six decades in semi-arid Andean
catchments, and compare their distribution, characteristics and potential hydrological importance to that of
glaciers in the same region.

763
1055
High Elevation Snow Depth and Importance to Streamflow in the Andes of Chile

Thomas Shaw1 (thomas.shaw@amtc.uchile.cl), James McPhee2, Álvaro Ayala3,4, Francesca Pellicciotti5, Simon
Gascoin6
1
Universidad de Chile/AMTC, Advanced Mining Technology Center, Santiago, Chile, 2Universidad de Chile,
Facultidad de Ciencias Físicas y Matemáticas, Santiago, Chile, 3ETH Zurich/VAW, Laboratory of Hydraulics,
Hydrology and Glaciology, Zurich, Switzerland, 4WSL Swiss Federal Institute for Forest Snow and Landscape
Research, Birmensdorf, Switzerland, 5Northumbria University, Department of Geography, Newcastle upon Tyne,
United Kingdom, 6CESBIO, Centre d'Etudes Spatiales de la Biosphère, Toulouse, France

Accurate quantification of snow accumulation and the contributions of snow and ice melt to river streamflow is
of critical importance for water management in the semi-arid Andes of central Chile (32-34°S). This is
particularly noteworthy because of a heightened socio-economic demand following recent drought events,
which have reached unprecedented duration. There is, however, much uncertainty regarding the spatial
distribution of snow and snow depth (dS) as a source of meltwater in the upper basins of major rivers, which is
often modelled assuming simple statistical relationships and with data extrapolated from low elevation
meteorological stations. Here we explore the appropriateness of leveraging modern satellite techniques for
derivation of dS in combination with high resolution ground-based LiDAR data in order to address some of
these uncertainties. We evaluate the representation of dS in a glacierised basin of the upper Maipo River (Rio
del Yeso, 112 km2) using recently developed techniques with optical tri-stereo imagery from the French
Pléiades satellites (resolution < 2 m). We discuss the sub-pixel variability of dS in relation to topographical
features of the landscape and compare with alternative statistical models in the literature. Finally, we begin to
present the importance of this information for seasonal hydrological forecasting when prescribed as initial
conditions in a glacio-hydrological model for the winter-summer season of 2017/2018.

764
1956
Modelling Long-term Runoff from a Glacierised Catchment in High Andes

Flavia Burger1 (flavia.burger@northumbria.ac.uk), Alvaro Ayala2,3, Shelley MacDonell4, Thomas Shaw5, Ben
Brock1, James McPhee5,6, Francesca Pellicciotti1
1
Northumbria University, Department of Geography, Newcastle upon Tyne, United Kingdom, 2Laboratory of
Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland, 3Swiss Federal Institute for Forest,
Snow and Landscape Research WSL, Birmensdorf, Switzerland, 4Centro de Estudios Avanzados en Zonas Aridas
(CEAZA), La Serena, Chile, 5Advanced Mining Technology Center, Santiago, Chile, 6University of Chile,
Department of Civil Engineering, Faculty of Physical and Mathematical Science, Santiago, Chile

Central Chile's economy relies on melt water from glaciers and seasonal snow to sustain a robust growth, as
well as to provide drinking water to major cities, particularly during dry periods. These recurrent climatic
events play an important role on glacier storage, runoff production and long-term changes in glacier mass
balance and streamflow. Here we present a modelling study that aims at reconstructing the climatic forcing,
glacier response and runoff generation from a high elevation catchment of central Chile over the past 4
decades. Recent modelling studies have considerably advanced our understanding of water storage and of the
spatial distribution of energy, mass and water fluxes in glacierised Andean catchments. However, they all have
focused on simulations of a few years or melt seasons for which extensive field datasets were available to
constrain model parameters. Very little is known about long-term fluctuations in glacier mass balance and the
resulting changes in runoff from glacierised catchments, and the partition of snow and ice contribution over
the long term. Debris-covered glaciers are an important element of the Andean cryosphere that has been to
date largely neglected in hydrological studies. These types of glaciers, common in the central Andes, are
increasingly recognized as responding in a distinctive manner to climate compared to clean ice glaciers and
have the potential to affect the hydrological regimes of catchments substantially.

765
2385
How Important Are Ice Cliffs for the Mass-balance of Debris-covered Glaciers?

Pascal Buri1, Jakob F. Steiner2 (j.f.steiner@uu.nl), Evan S. Miles3, Silvan Ragettli4, Francesca Pellicciotti5
1
ETH Zurich, Institute of Environmental Engineering, Zürich, Switzerland, 2Utrecht University, Faculty of
Geosciences, Utrecht, Netherlands, 3University of Leeds, School of Geography, Leeds, United Kingdom,
4
hydrosolutions ltd, Zürich, Switzerland, 5Northumbria University, Department of Geography, Newcastle upon
Tyne, United Kingdom

Supraglacial ice cliffs enhance locally melt and mass losses of the otherwise insulated ice on debris covered
glaciers. However, their contribution to the total glacier mass balance has never been quantified, with
inference obtained from upscaling models or observations at selected cliffs. Their overall importance remains
little understood.
From six high-resolution satellite images we derive an inventory of ice cliffs in the Langtang catchment (Nepal)
for 2006-2015 and we use it to:
i) assess the frequency and distribution of cliffs and ponds;
ii) characterize cliff geometries, pond areas and the life cycle of cliff-pond systems.
The volume losses associated with the backwasting of cliffs for the debris-covered glaciers of the Langtang
catchment are calculated with a physically-based backwasting model considering the cliff-atmosphere energy-
balance, reburial by debris and the effects of adjacent ponds. To estimate the contribution of ice cliff melt to
total glacier mass balance we compare simulated cliff melt to the distributed glacier mass balance values from
a glacio-hydrological model (TOPKAPI-ETH).
Ice cliffs vary greatly in space and time. The associated volume losses are a non-negligible term (with values
>60% on the lower sections of the debris-covered tongues) in the total glacier mass balance of debris-covered
glaciers, providing a partial explanation of the higher-than-expected mass losses of debris-covered glaciers of
High Mountain Asia.

766
BE-7 - Up- and Down-scaling approaches in Polar Ecosystem Research
20.06.2018 16:00-17:30, B Jakobshorn

524
Role of Scale in the Analysis of Arctic and Southern Ocean Benthic Functions

Heike Link1 (heike.link@uni-rostock.de), Philippe Archambault2, Joshua Kiesel3, Dieter Piepenburg4,5,6, Derya M.
Seifert4, Gritta Veit-Köhler7
1
University of Rostock, Department Maritime Systems, Rostock, Germany, 2Université Laval, Departement de
Biologie, Quebec, Canada, 3Kiel University, Institute for Geography, Kiel, Germany, 4Kiel University, Institute for
Ecosystem Research, Kiel, Germany, 5Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research,
Bremerhaven, Germany, 6Helmholtz Institute for Functional Marine Biodiversity at Oldenburg University,
Oldenburg, Germany, 7Senckenberg am Meer, German Centre for Marine Biodiversity Research, Wilhelmshaven,
Germany

Comparative ecosystem studies are acknowledged to be crucial for soundly estimating the relative importance
of physical-chemical (temperature, salinity) and biological (Chl a, faunal abundance) factors for ecosystem
functions (e.g. remineralisation). However, such studies are still scarce in polar benthic habitats, as they are
elaborate to conduct, and constraints imposed by differences in methodological approach, regional
particularities, and spatio-temporal scales are known to bias the analyses and subsequent upscaling efforts.
Here, we present the findings of comparative within-region versus across-region analyses of studies in Arctic
and Antarctic shelf waters (Canadian Arctic and Laptev Sea, as well as Weddell Sea and off the Antarctic
Peninsula). We demonstrate how the analysed scale can influence results and conclusions on the effects of
environmental and biological drivers on benthic ecosystem functions (benthic remineralisation, oxygen
consumption). The highly standardized field approach (ex situ incubations) applied in each region reduces
methodological bias and allows for a sound comparison on different spatial scales. Our results point to the
difficulties of comparative studies but also provide suggestions how to handle those issues when aiming for and
interpreting upscaling approaches in polar marine benthic systems.

767
1037
A Seascape View of Decadal Change along the Western Antarctic Peninsula

Jeff Bowman1 (jsbowman@ucsd.edu), Maria Kavanaugh2, Scott Doney3, Hugh Ducklow4

1
Scripps Institution of Oceanography, UC San Diego, La Jolla, United States, 2Oregon State University, College of
Earth, Ocean and Atmospheric Sciences, Corvallis, United States, 3University of Virginia, Charlottesville, United
States, 4Lamont-Doherty Earth Observatory of Columbia University, Palisades, United States

Located near the edge of the winter sea ice maxima, the marine ecosystem of the western Antarctic Peninsula
(WAP) is a bellwether of global climate change. The Palmer Long Term Ecological Research (LTER) project has
been documenting changes to the WAP marine ecosystem since 1993 with an annual summer cruise. To enable
a comparison between multiple years in the Palmer LTER dataset we developed a seascape unit (SU)
classification system based on temperature, salinity, nutrients, and chlorophyll a. By objectively mapping these
parameters for each cruise we were able to classify the Palmer LTER grid into 8 recurrent SUs. We used
clustering and PCA to evaluate the distribution of SUs between years, finding that years formed two statistically
significant clusters. While mean chlorophyll a concentration did not differ between clusters, the location and
SU association of chlorophyll a biomass differed. We used correlations and elastic-net regression to identify
environmental factors and modes of climate variability that might account for cluster membership and SU
abundance. We detected a strong association between early spring sea ice conditions and cluster membership,
suggesting that early spring nutrient drawdown can impact the distribution of summer chlorophyll a biomass.
Future improvements to the seascape concept for the WAP will enable further insights, and wider application
to the coastal Antarctic may lead to a unified view of marine ecosystem distribution and change.

768
487
Arctic Benthic Diversity Research with PANABIO: Scale, Sharing and Modelling

Casper Kraan1,2 (casper.kraan@awi.de), Jan Holstein1,2, Paul Kloss1,2, Thomas Brey1,2, Dieter Piepenburg1,2,3
1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany,
2
Helmholtz Institute for Functional Marine Biodiversity (HIFMB) at University Oldenburg, Oldenburg, Germany,
3
Christian-Albrechts-Universität zu Kiel, Kiel, Germany

Arctic marine biota are affected profoundly and at large scales by accelerating environmental change, such as
sea-ice decline. Moreover, increasing human activities, e.g. exploitation of natural resources, add further
cumulative pressures. Substantial shifts in ecosystem functions and services, e.g. biodiversity, are expected. To
understand, predict, and mitigate the profound ecological consequences of such shifts, it is critical to identify
and analyse the relationships between environmental drivers and ecosystem functions at regional and pan-
Arctic scales. We address this challenge by developing a pan-Arctic knowledge system on benthic biota
(PANABIO). Underpinned by international efforts to combine data and expertise, PANABIO integrates quality-
controlled and geo-referenced data on benthic communities in a public data-warehouse. This will support
(a) providing ecological baseline-data to gauge ecosystem changes,
(b) analysing coupling mechanisms between environmental drivers and ecosystem functions/services on
regional and pan-Arctic scales,
(c) developing future ecosystem scenarios in response to external forcing, and
(d) creating online stakeholder-oriented visualization and analysis tools.
The talk will demonstrate the huge up-scaling of benthic data we realised, our achievements to support data-
sharing, as well as first results of multi-variate species distribution models to discern distinct benthic sea-ice
communities.

769
1864
Physiological Models in Antarctica: Dynamic Inferences in a Changing Environment

Charlene Guillaumot1 (charleneguillaumot21@gmail.com), Antonio Aguera1, Bruno Danis1

1
Université Libre de Bruxelles, Brussels, Belgium

The Western Antarctic Peninsula is facing rapid global changes which are currently the focus of an intense
research effort to understand the potential of marine benthic populations response. Our knowledge about the
impact of environmental changes on Antarctic species physiology has mostly been gathered from short term
experimental designs and is limited by a broad range of practical constraints.
An alternative to these experimental designs is to use mechanistic models that relate species functional traits
to environmental characteristics. Dynamic Energy Budget (DEB) theory describes organisms uptake and
allocates energy throughout their entire life cycle. Their parametrisation requires observations of species life
cycle and physiology, which are often available from the literature.
In this presentation, we showcase DEB models built for a series of representative benthic Antarctic species.
Metabolic performances (growth rate, age at metamorphosis, reproductive performance, survival) will be
assessed for these species on the extent of the Western Antarctic Peninsula. Potential shifts in physiological
traits will be predicted and compared for a range of environmental scenarios (RCP scenarii, IPCC, 5th report) in
order to characterise species sensitivity in the context of a fast-changing environment.

770
267
How Universal is the Keystoneness of Krill in Southern Ocean Food Webs?

Stacey A. McCormack1 (stacey.mccormack@utas.edu.au), Jessica Melbourne-Thomas2,3, Rowan Trebilco3, Julia

L. Blanchard1, Ben Raymond1,2,3, Andrew Constable2,3
1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Australian Antarctic
Division, Department of the Environment and Energy, Hobart, Australia, 3University of Tasmania, Antarctic
Climate and Ecosystems Cooperative Research Centre, Hobart, Australia

A principal goal of ecosystem ecology is to develop and test theories regarding the nature of species
interactions and their contribution to the organisation of biological communities. In Southern Ocean
ecosystems, Antarctic krill (Euphausia superba) are widely recognised to play a keystone role in transferring
energy from primary producers, supporting large populations of marine mammals and seabirds. However, it is
not clear whether the dominant role of krill in Southern Ocean food webs is universal. An alternative
configuration is more diffuse trophic networks, where a variety of mid-trophic level organisms, other than krill,
play major roles in energy transfer.
To evaluate how universal the keystone role of krill is in Southern Ocean food webs, we used the Southern
Ocean Dietary Database to undertake the first large-scale circumpolar analysis of food web structure across the
four major oceanic sectors of the Southern Ocean. Here, we describe how we quantified the contributions of
various species and groups to energy flow within each sector, and provide a summary of our key findings.
Previous analyses of Antarctic ecosystems have focused entirely on a single web topology or have provided
qualitative descriptions of small sub-systems. We discuss how our generalised approach facilitates cross-system
comparisons, emphasises critical processes for maintaining food web structure within each sector, and can
inform the future management of Antarctic ecosystems.

771
1424
Towards Monitoring of Primary Production in Polar Regions

Gemma Kulk1 (g.kulk@rug.nl), Jacco Kromkamp2, Gerrit van der Goot1, Hugh Venables3, Mike Meredith3, Anita
Buma1,4
1
University of Groningen, Ocean Ecosystems, Groningen, Netherlands, 2Royal Netherlands Institute for Sea
Research, Estuarine and Delta Systems, Yerseke, Netherlands, 3British Antarctic Survey, Cambridge, United
Kingdom, 4University of Gronigen, Arctic Centre, Groningen, Netherlands

Active chlorophyll a fluorescence techniques have the potential to provide estimates of phytoplankton primary
production at unprecedented temporal and spatial scales. Fast Repetition Rate fluorometry (FRRf) is such a
promising technique, however knowledge of the electron requirement of carbon fixation (Φe,C) is required to
accurately estimate primary production from FRRf measurements. While the Φe,C has been studied in fast areas
of the open oceans, only a few studies have focused on polar regions. In the Arctic, the Φe,C seems to vary with
in situ light conditions and is closely related to non-photochemical processes and other physiological processes
such as cyclic electron flow. The present study assessed the Φe,C experimentally in freshly isolated Antarctic
diatom species. In addition, the Φe,C was measured in natural phytoplankton communities from Ryder Bay,
West Antarctic Peninsula, during two summer seasons. While Φe,C was influenced by species composition and
environmental conditions, results showed a linear relationship between electron transport and carbon fixation.
These results were used to estimate primary production from automated FRRf measurements in both the
laboratory and the field. Further upscaling of the chlorophyll a fluorescence technique can strongly advance
our understanding of factors that regulate primary production of marine phytoplankton in one of the most
rapidly warming regions of the world.

772
EN-1 - Environmental and community challenges in rapidly changing polar coastal zones
20.06.2018 16:00-17:30, C Sanada I

109
Collapsing Coasts in the Arctic: Environmental and Socio-economic Impacts

Michael Fritz1 (michael.fritz@awi.de)

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Periglacial Research, Potsdam,
Germany

Arctic warming is exposing permafrost coastlines, which account for 34% of the Earth's coasts, to rapid thaw
and erosion. Coastal erosion rates as high as 25 m yr-1 together with the large amount of organic matter frozen
in permafrost are resulting in an annual release of 14.0 Tg (1012 gram) particulate organic carbon into the
nearshore zone. We highlight the crucial role the nearshore zone plays in Arctic biogeochemical cycling, as here
the fate of the released material is decided.
With Arctic warming, erosion fluxes have the potential to increase by an order of magnitude until 2100. Such
increases would result in drastic impacts on global carbon fluxes and their climate feedbacks, on nearshore
food webs and on local communities, whose survival still relies on marine biological resources. Quantifying the
potential impacts of increasing erosion on coastal ecosystems is crucial for food security of northern residents
living in Arctic coastal communities. We need to know how the traditional hunting and fishing grounds might
be impacted by high loads of sediment and nutrients released from eroding coasts, and to what extent coastal
retreat will lead to a loss of habitat. Quantifying fluxes of organic carbon and nutrients is required, both in
nearshore deposits and in the water column by sediment coring and systematic oceanographic monitoring.
Ultimately, this will allow us to assess the transport and degradation pathways of sediment and organic matter
derived from erosion.

773
2168
Impacts of Sea-level Change on Antarctica

Jasmine Lee1 (jasmine.lee1@uqconnect.edu.au), Steven Chown2, Richard Fuller3, James Watson4, Aleks
Terauds5
1
University of Queensland, Centre for Biodiversity and Conservation Science, St. Lucia, Australia, 2Monash
University, School of Biological Sciences, Melbourne, Australia, 3University of Queensland, School of Biological
Sciences, Brisbane, Australia, 4University of Queensland, School of Earth and Environmental Sciences, Brisbane,
Australia, 5Australian Antarctic Division, Antarctic Management and Conservation, Hobart, Australia

Whilst much Antarctic research has been focused on determining how Antarctic ice sheets will contribute to
global sea-level rise under warming, the potential effects on Antarctica of sea-level change have not been as
comprehensively considered. Here we assess the potential effects of forecast sea-level rise and fall to Antarctic
biodiversity and human infrastructure by 2100, using multiple sea-level scenarios (0.5 m, 1 m, 2 m). Under a 2
m rise scenario, up to 60% of Antarctic Specially Protected Areas, 58% of Important Bird Areas, 68% of penguin
breeding colonies, 40% of research infrastructure, and 71% of tourist landing sites could be at risk of partial or
complete inundation. A fall in sea-level would see infrastructure and biodiversity further from the coast,
resulting in changed environmental conditions and new logistic challenges for National Programs. Simultaneous
impacts on human activity and terrestrial biodiversity will compel several forms of adaptation across both
groups, with potential for growing conservation problems. Better spatially explicit understanding of sea-level
change is therefore also pressing from a conservation perspective.

774
1166
Dendrology and Newspaper Accounts: A Novel Approach to Coastal Storm Research in
Alaska

Jon Rosales1 (jrosales@stlawu.edu)

1
St. Lawrence University, Environmental Studies, Canton, United States

Frequent interactions with indigenous communities can lead to novel approaches in studying climate change.
Such approaches generate new forms of knowledge, but also generate a fuller understanding of climate change
as it occurs in infrequently studied regions. This presentation focuses on storm intensity in one such region in
Alaska, the Bering Strait. While it is likely that storm intensity has increased and will continue to increase in this
region with additional warming, there is little evidence to support these claims. This project aims to generate
evidence of storm intensity in the region by combining natural science and traditional Siberian Yupik naming
traditions. Driftwood deposits laid to rest at the extent of the storm surge are used as indicators of a given
storm's intensity. The date of when the driftwood was deposited, however, cannot be determined precisely by
dendrochronology techniques. Traditional ecological knowledge of storm events stored in the names of
indigenous peoples in Savoonga, Alaska may reveal the dates of large storms that left the driftwood on their
beaches. This Siberian Yupik village names babies after significant events, like large storms, to retain knowledge
of those events; their birth dates are used to identify, with great precision, the date of past storms. Storm
surge maps can be generated from these sources and the direction of storm intensity change may be identified.

775
1387
Coastal Landscape Transformation in Sørkapp Land (Spitsbergen), 1899 - 2016

Wieslaw Ziaja1 (wieslaw.ziaja@uj.edu.pl)

1
Jagiellonian University, Institute of Geography and Spatial Management, Krakow, Poland

Sørkapp Land is the southern Spitsbergen peninsula - a wedge between the Barents and Greenland Seas. Its
coasts transformed under climate warming since 1899. The eastern, most glaciated and coldest, mountainous
coast (70 km long) underwent a huge change: - recession of tidewater glaciers (rapid since the 1980s) formed
the new Hambergbukta fjord and Isbukta bay, and exposed the coastline to sea abrasion and accumulation, -
hence, the plain with Davislaguna was abraded by the sea and several new plains appeared in areas abandoned
by glaciers, - recession of glaciers located above the sea-level led to formation of a new landscape (new
deposits, landforms and water-bodies), - animal colonization allowed plant succession what began soil
formation. The western - least glaciated and warmest - lowland coast (55 km long) underwent a progressive
change since 1899. It was generally ice-freed at the end of Pleistocene and covered with tundra, overgrazed by
reindeer regenerated there since the 1990s. Recession of the only tidewater glacier led to origin of the
Stormbukta bay. The coastline was modified due to shortening of a sea-ice season what intensified sea-action:
filling bays with deposits and abrasion of headlands. The northern fjord coast (55 km long) lengthened a lot
since 1899 due to recession of tidewater glaciers, which formed new lateral fjords and bays (Samarinvågen is
the longest). The southern lowland coast is 27 km long and most stable due to a shallow sea offshore.

776
1289
Building a Collaborative Framework to Support Adaptation in Coastal Alaska

Stephen Gray1 (sgray@usgs.gov), Amy Holman2, Nicole Kinsman2, Jeremy Littell1, Molly McCammon3, Karen
Murphy4, Jacquelyn Overbeck5, Karen Pletnikoff6, Aaron Poe7
1
US Geological Survey, Alaska Climate Science Center, Anchorage, United States, 2NOAA Alaska Region,
Anchorage, United States, 3Alaska Ocean Observing System, Anchorage, United States, 4US Fish and Wildlife
Service, Western Alaska LCC, Anchorage, United States, 5Alaska Department of Natural Resources, Anchorage,
United States, 6Aleutian Pribilof Islands Association, Anchorage, United States, 7US Fish and Wildlife Service,
Aleutian and Bering Sea Islands LCC, Anchorage, United States

In environments undergoing rapid change, increased adaptive capacity and resilience are only achieved with
strong, ongoing collaboration. Recognizing this challenge, decision makers working in coastal communities
across Alaska convened a series of workshops to share knowledge on current and future changes, their
impacts, and potential responses. These workshops began in late 2012 with a focus on coastal hazards, and
have continued through 2017 with a string of discussions centered on regional impacts. The 300+ participants
included Alaska Natives, local governments, and State and Federal agencies, with input from all of these groups
feeding into an assessment of the data and information needed to help communities better respond to coastal
change. Based on these ongoing efforts, we will provide a summary of key data gaps related to the
environment in these coastal zones (e.g., bathymetry, sea ice conditions, vessel traffic), and progress to date in
addressing these gaps. Moreover, we hope to present an overview of how these workshops have been used to
strengthen collaboration across stakeholder groups; consolidate and leverage research (both western and
traditional); and ensure that results reach the stakeholders who need them. Overall, we seek to present a suite
of “lessons learned” for those wishing to create a dynamic, collaborative process for identifying needs,
conducting research, and communicating in support of those living and working in Polar coastal zones.

777
1976
Mechanisms Controlling the Evolution of Rocky Coastal Zone in Polar Climates

Mateusz Strzelecki1 (mat.strzelecki@gmail.com), Michael Lim2, Marek Kasprzak1, Zuzanna Swiard3, Piotr
Migoń1, Grzegorz Rachlewicz4, Marek Jaskólski1, Lukasz Pawlowski1
1
University of Wroclaw/ Institute of Geography and Regional Development, Wroclaw, Poland, 2Northumbria
University, School of Built Environment, Newcastle Upon Tyne, United Kingdom, 3Durham University,
Department of Geography, Durham, United Kingdom, 4Adam Mickiewicz University in Poznan, Cryosphere
Research Department, Poznan, Poland

Our work aims to address deficiency in understanding of mechanisms controlling the development of rocky
coasts in polar regions. Over last few years we studied the processes controlling the evolution and behaviour of
rock coasts in representative areas of South Shetland Islands (Antarctic) and Svalbard (Arctic).
Rock surface weathering and downwearing surveys along several morphologically different coast types
demonstrated broad variety of interrelations between rock surface resistance and distance from present-day
shoreline as well as thickness of snow covers. In general, cliff surfaces were the most resistant in their lower
and middle zones which are thermally insulated by thick winter snowdrifts. Whereas the more exposed cliff
tops were heavily fractured and weathered. The differences in rock resistance and downwearing rates
observed along the shore platforms were highly dependent on thickness of sediment cover and shoreline
configuration. These characteristics favoured stronger rock surfaces in areas exposed to the longest wave
fetch, but also washing by meltwaters from decaying ice-foot. The results of ERT survey suggest that most of
the rocky capes and platforms are free of continuous permafrost and frozen ground conditions develop further
inland. The results presented in this paper emphasize the richness of microrelief features and processes
operating in polar rock coastal environments.
This paper is a contribution to NCN project UMO2013/11/B/ST10/00283.

778
BE-4f - Climate change and ecosystems: physiology, biodiversity and ecological functions
20.06.2018 16:00-17:30, C Sanada II

273
Arctic Kelp Ecophysiology in a Warming Winter Scenario

Kai Bischof1,2 (kbischof@uni-bremen.de), Lydia Scheschonk1, Huiru Li1

1
University of Bremen, Marine Botany, Bremen, Germany, 2Alfred Wegener Institute, Bremerhaven, Germany

Kelps, large brown seaweeds of the order Laminariales, are important ecosystem engineers in Arctic coastal
ecosystems. However, knowledge of seaweed ecosystem functioning under Arctic winter conditions is scarce,
but essential to understand adaptive life strategies and adaptability in an era of climate change. In high latitude
coastal systems, kelps, as perennial and primarily photoautotrophic marine plants, have to face several months
of darkness, precluding photosynthetic activity. Still, winterly growth of kelp tissue has been observed, fuelled
by the consumption of stored carbohydrates.
In the Arctic Kongsfjord (Svalbard), a pronounced increase in seawater temperature has been detected since
2006, and is expected to continue. Thus, it is essential to understand temperature related modulation of
winterly ecophysiology in Arctic seaweeds. Two species of Arctic kelps (the cold-temperate Saccharina
latissima and the endemic Laminaria solidungula) have been studied for the expression and regulation of
house-keeping physiological processes in autumn and just at the end of the polar night. In S. latissima more
than 80% of the storage carbohydrate laminaran is consumed during winter under current in situ fjord
temperature, and our data suggest that carbohydrate turn-over will further increase with temperature.
Experimentally increased temperature conditions during dark exposure point to a complex network of
physiological adjustments of kelps in a changing Arctic environment.

779
287
Spatial Variation in the Structure of Benthic Communities in Siberian Shelf Seas

Miriam Hansen1 (mhansen@ecology.uni-kiel.de), Casper Kraan2,3, Dieter Piepenburg3,4,5

1
Christian Albrecht University of Kiel, Palaeoceanography, Kiel, Germany, 2Alfred-Wegener-Institut Helmholtz-
Zentrum für Polar- und Meeresforschung, Functional Ecology, Bremerhaven, Germany, 3Helmholtz Institute for
Functional Marine Biodiversity (HIFMB) at University Oldenburg, Oldenburg, Germany, 4Christian Albrecht
University of Kiel, Kiel, Germany, 5Alfred Wegener Institute, Bremerhaven, Germany

Climate change and its consequences pressure the Arctic Siberian shelf region and impact marine benthic
organisms severely. Since polar ecosystems are used to long-time stable conditions, even small changes could
have wide-ranging consequences for benthic communities, food webs, and ecosystem functions. Yet, little is
known about the response of Arctic benthic organisms to changing environmental conditions. We address this
knowledge gap by combining data from different Arctic regions and employing recent ecological modelling
techniques and study community structure, diversity and ecosystem functions in Arctic benthos across larger
scales.
Expeditions in the Arctic seas from the years 1991, 1993, 2013 and 2014 provide the required ecological data
for the modelling approaches. Sixty-nine stations across the Arctic Sea were sampled by trawling and grab
methods within the TRANSDRIFT-framework. By employing multivariate spatial analysis tools, such as Moran's
eigenvector mapping, an answer to the following question shall be provided: whether to include relationships
between spatial structure and abiotic variables allow scientists to better detect patterns of species and
communities in the Arctic Siberian Sea. The expected result will show which environmental variables are
important at which scale, and which macrobenthic species are most associated with these distinct scales.

780
1751
Genetic Monitoring for Climate Change in Antarctic Marine Invertebrates

Nerida Wilson1 (nerida.wilson@museum.wa.gov.au)

1
Western Australian Museum, Molecular Systematics Unit, Welshpool, Australia

Climate change is expected to disproportionately affect the diversity of polar regions. In comparison, in other
areas with latitudinal scope, organisms may be able to respond by changing their distributions to suit their
physiological capacities. However this is not possible for polar species that simply have nowhere colder they
can migrate to, even if they were able to. Although some level of adaptation and response to changing
conditions is predicted, undoubtedly the loss of species diversity is ultimately expected. We show here the
importance of having baseline phylogeographic information to be able to detect when the species diversity of
Antarctic communities begin being impacted. Our study system utilises cryptic species diversity in the Antarctic
crinoid Promachocrinus, and differential species distributions to create a warning system of marine
invertebrate community change.

781
1175
Structural Protein Constraints at Low Temperature

Daniela Giordano1, Daniela Coppola1, Guido di Prisco1, Cinzia Verde1 (c.verde@ibp.cnr.it)

1
National Research Council of Italy, Naples, Italy

The main question in the debate on climate change is whether some species will be able to adapt fast enough
to keep up with the rapid pace of changing climate. Whatever the type of adaptive responses, underlying
mechanisms are due either to evolution or plasticity. Empirical evidence suggests that physiological plasticity is
often more important than genetic contribution in complex, long-living species. Of particular concern are
“tipping points” where ecosystem thresholds can lead to irreversible shifts. The biological effects of increasing
temperature on marine ecosystems are already evident. Temperature governs the rate of chemical reactions
and pathways regulating the development and decline of life. Sensitivity to temperature influences the success
of organisms in all habitats, and is caused by the susceptibility of biochemical processes, including protein
function, to temperature change. Recent studies indicate that only minor structural modifications are needed
to change the intrinsic stability of cold-adapted proteins, and that local rather than global flexibility may play an
important role. In this contribution, we first summarise how cold temperature affects the physiology, then
focus on the molecular mechanisms of cold adaptation revealed by recent biophysical, biochemical and genetic
studies of a specific group: oxygen-binding proteins.

782
468
Functional Response Traits in a Changing Polar Ocean

Laura Grange1 (l.j.grange@noc.soton.ac.uk), Jasmin Godbold1, Martin Solan1

1
University of Southampton, Ocean and Earth Science, Southampton, United Kingdom

The northern high latitudes are experiencing some of the most rapid and severe climate change recorded
globally. Changes apparent in the Arctic climate system are now well established and evidenced in observations
of substantial warming and dramatic reductions in summer sea ice extent and thickness. However, the
response of key components of Arctic ecosystems, such as benthic faunal assemblages, to environmental
change is poorly understood. Here we investigate the ecological consequences of climate change in the Arctic
by characterising and quantifying change in the functional response traits of representative benthic species
along a gradient of variable sea ice conditions. To inform our interpretations, we focus on biogeochemically
and population-relevant biological activities, including bioturbation and bioirrigation, and growth and
reproduction, respectively. Our findings detail how and when the response of benthic invertebrate species
and/or communities lead to functionally important changes in behavior that, in turn, alter important ecosystem
processes and function.

783
2
Climate and the Magnitude of Blue Carbon Storage by Circumpolar Shelf Benthos

David K A Barnes1 (dkab@bas.ac.uk), Narissa Bax2, Rachel Downey3, Christoph Held4, Camille Moreau5, Bernabe
Moreno6, Maria Paulsen7, Chester J Sands1
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Tasmania, Hobart, Australia, 3Australian
National University, Canberra, Australia, 4Alfred Wegner Institute, Bremerhaven, Germany, 5Université Libre de
Bruxelles, Bruxelles, Belgium, 6Universidad Científica del Sur, Lima, Peru, 7University of Bergen, Bergen, Norway

High latitude continental shelves provide carbon capture and storage of millions of tonnes annually. The
magnitude and variability in this biological accumulation, immobilization and ultimate sequestration of Carbon
has been little quantified. Darwin Initiative, Antarctic Circumnavigation Expedition (ACE) and ICEBERGs projects
have supported the Antarctic Seabed Carbon Capture Change project to sample shelf benthos in order to
attempt estimation of this carbon budget by region and across years. This was undertaken by using Shelf
Underwater camera System (SUCS) and video/photo-equipped trawls to estimate benthos densities and
specimens were collected to evaluate carbon per age per species. SubAntarctic continental shelf benthos seem
to play only a small role in carbon cycling, but are globally significant in terms of carbon storage and very likely
sequestration. There is considerable temporal variation in benthic carbon storage, particularly around West
Antarctica, correlated with climate forced sea-ice losses (and ice shelf disintegration). There is also evidence of
warming increasing benthic carbon storage budgets, through faster growth. SubAntarctic continental shelves
have considerable phytoplankton blooms, little sea ice and warmer sea temperatures than Antarctica; together
with polar shelves they represent one of Earth's most significant and growing negative feedbacks on climate
change.

784
Poster & Beer I
20.06.2018 17:30-18:30, Foyer

Wed_1_AC-2_62
Precipitation Measurements at Rothera Research Station in Antarctica

Steven Colwell1 (src@bas.ac.uk)

1
British Antarctic Survey, Cambridge, United Kingdom

Measuring precipitation in the Antarctic is very difficult and at present no reliable way of ground truthing the
data exists. It is a very important parameter to accurately measure so that the measurements can be used for
model verification. At the British Antarctic Survey's Rothera station on the Antarctic Peninsula at (67.5S, 68.1W)
we are comparing a selection of precipitation sensors to assess which is the most accurate.
Three optical sensors are being compared, they are a Thies Laser Precipitation Monitor (LPM), a Biral VPF-730
combined precipitation and visibility sensor and a Campbell Scientific PWS100. They all use different measuring
techniques to estimate precipitation type and intensity by analysing how the water droplets and snow particles
interfere with the optical beams.
There is also a UPG1000 - Universal Precipitation Gauge that is manufactured by Environmental Measurements
Ltd (EML). When snow falls into this gauge it is melted and then measured using a tipping bucket.
Initial results show a large difference between all of the sensors on a monthly scale but in low wind speed
conditions there is close agreement between all. More analysis of the data are being carried out to try and
ascertain which of them is most accurate for use in the Antarctic.
This presentation will look in more detail at the operation of the sensors and how the data compares in
different wind regimes.

785
Wed_2_AC-2_292
Detailed Regional Reanalysis for Russian Arctic: Strategy and Methodology

Vladimir Platonov1 (vplatonov86@gmail.com), Mikhail Varentsov1

1
Lomonosov Moscow State University, Meteorology and Climatology, Moscow, Russian Federation

There are various estimates of the trends of certain meteorological parameters in different water areas and
coastal zones of the Russian and rest Arctic regions. Taking into account the increasing number of dangerous
phenomena and outlooks for the Arctic coast, the task of providing the region detailed hydrometeorological
and climatic information with a horizontal resolution of at least several kilometers becomes particularly topical.
To get there, we will use well-known regional climate model COSMO-CLM v5.0.
The regional reanalysis for Russian Arctic, an integrated archive of hydrometeorological parameters with a
spatial resolution of less than 5 km, will be obtained for the first time after long-term simulation experiments.
Detailed hydrometeorological fields in the Arctic over a long period (1980 - 2016) will be derived by the two-
step downscaling technology with ~13 km and ~4 km domains and will cover most of Russian Artic (western
Arctic seas more detailed).
The regional reanalysis output is possible to use as inputs to modelling the ocean´s characteristics (wind waves
and dynamics), coastal ecosystems (turbulent heat fluxes, greenhouse gases), more detailed research of
individual phenomena on nested domains (extreme situations, hazardous weather events), analysis of trends in
the frequency of occurrence of extreme events and features of their spatial distribution, the
hydrometeorological regime of coastal areas studies, climatology and tracking of polar mesocyclones, etc.

786
Wed_3_AC-2_337
The New Normal: The Synoptic Situation during the ACLOUD/PASCAL Campaigns 2017

Erlend Moster Knudsen1 (eknudsen@uni-koeln.de), Bernd Heinold2, Annette Rinke3, Sandro Dahlke3,4, Marion
Maturilli3, Christof Lüpkes5, Dmitry Chechin5, Gerit Birnbaum5, André Ehrlich6, Manfred Wendisch6, Susanne
Crewell1, Mario Mech1, Andreas Macke2, Johannes Quaas6
1
University of Cologne, Institute for Geophysics and Meteorology, Köln, Germany, 2Leibniz Insititute for
Tropospheric Research, Leipzig, Germany, 3Alfred-Wegener-Institute Helmholtz-Center for Polar and Marine
Research, Potsdam, Germany, 4University of Potsdam, Potsdam, Germany, 5Alfred-Wegener-Institute Helmholtz
Center for Polar and Marine Research, Bremerhaven, Germany, 6University of Leipzig, Leipzig Institute for
Meteorology, Leipzig, Germany

The Arctic is warming twice as fast as the global average. This feature, known as the Arctic amplification, results
in and is a result of rapidly changing climate system components, where the effects of clouds remain one of our
largest unknowns.
The joint field campaign Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD)
May 22 - June 28, 2017 aimed at improving our understanding of physical processes above, below and in Arctic
clouds. It offers crucial data for the representation of clouds and atmospheric processes in weather and climate
models representing the new normal in the Arctic.
ACLOUD made use of two aircrafts based in Longyearbyen, Svalbard. Flying mostly together at different levels,
the aircrafts Polar 5 and 6 applied in situ measurement techniques and remote sensing instruments. ACLOUD
was coordinated with surface-based observations from the station in Ny-Ålesund and an ice camp north of
Svalbard operated within the joint campaign PASCAL around RV Polarstern. This allowed us to measure
properties of cloud and aerosol particles, trace gas concentration, and turbulent and radiative fluxes in the
atmospheric column over and around Svalbard.
In this presentation, the first results of ACLOUD are given, with a focus on the synoptic situation during the
campaign. We highlight the importance such field campaigns have also beyond the scientific community.

787
Wed_4_AC-2_475
ARPEGE Contribution for the Study of Antarctic Climate and SMB Change

Julien Beaumet1 (julien.beaumet@univ-grenoble-alpes.fr), Gerhard Krinner1, Antoinette Alias2, Michel Déqué2

1
Université Grenoble-Alpes, Institut des Géosciences de l'Environnement, Grenoble, France, 2Meteo France,
CNRS, CNRM, Toulouse, France

Assessing the evolution of Antarctic climate and SMB by the end 21st century is of first importance for
evaluating the potential contribution to SLR. In this frame, we evaluate the contribution of atmosphere-only
GCM, ARPEGE, with a stretched grid allowing a resolution of 45 kms on Antarctica. First, the ability to
reproduce Antarctic climate of a free AMIP simulation (1981-2010) is assessed using observational data set,
reanalysis and model inter-comparisons. Firsts results show that ARPEGE succeed in reconstructing surface
climate. The use of an intermediate-complexity snow model allows taking into account processes such as snow
sublimation and run-off. However, errors on atmospheric general circulation, particularly the underestimation
of Amundsen Sea Low affects the spatial distribution of precipitations over West Antarctica. Nevertheless,
mean 1981-2010 SMB of Antarctic Ice sheet of 2317.7 Gt.yr-1 concours with recent publications (e.g. Agosta et
al., 2013, Lenaerts et al., 2015). Then, we use ARPEGE to evaluate changes of Antarctic climate and SMB in a
RCP8.5 scenario. Thirty years simulations at the end of the 21st century (2071-2100) are realized using bias
correction of oceanic forcings coming from CMIP5 AOGCM scenarios following recommendations from
Beaumet et al., (submitted). Remaining uncertainties coming from the climate change signal for oceanic
surface conditions in different CMIP5 model are assessed independently from the bias on historical climate.

788
Wed_5_AC-2_492
The Vertical Structure of the Troposphere above the Southern Ocean during ACE

Franziska Aemisegger1 (franziska.aemisegger@env.ethz.ch), Pascal Graf1, Iris Thurnherr1, Irina Gorodetskaya2,

Josué Gehring3, Maxi Boettcher1, Stephan Pfahl1, Harald Sodemann4,5, Alexis Berne3, Martin Ralph6, Heini
Wernli1
1
ETH Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland, 2Center for Marine and
Environment Sciences, University of Aveiro, Aveiro, Portugal, 3Environmental Remote Sensing Laboratory, EPFL,
Lausanne, Switzerland, 4Geophysical Institute, University of Bergen, Bergen, Norway, 5Bjerknes Centre for
Climate Research, Bergen, Norway, 6Scripps, UCSD, San Diego, United States

Due to the poor observational constraint in the Southern Ocean, atmospheric analysis and reanalysis datasets
are associated with larger uncertainties in this region than in the Northern Hemisphere. On this poster a series
of 98 vertical soundings collected during the ship-based Antarctic Circumnavigation Expedition (ACE) in the
austral summer 2016/2017 is compared to operational analysis data of the European Centre for Medium-Range
Weather Forecasts. The ACE soundings were not assimilated and thus provide an independent validation data
set. The vertical structure of temperature, humidity, and wind is analysed. In many soundings, a good match of
the observations with the operational analysis is found for the upper troposphere (p< 500 hPa). In contrast, in
the lower troposphere, 50-100 hPa thick humid layers generally associated with clouds are either not
represented in the analysis data or shifted in space and time. Three cases of a marked isothermal mid
tropospheric dry air layer above a precipitating cloud are discussed in more detail based on a Lagrangian
analysis of the airmass history in this layer.

789
Wed_6_AC-2_666
One Year of Stratospheric Water Vapor Measurements at Thule, Greenland

Gabriele Mevi1,2, Giovanni Muscari1 (giovanni.muscari@ingv.it), Tatiana Di Iorio3, Alcide Giorgio di Sarra3,
Daniela Meloni3, Giandomenico Pace3, Marco Cacciani4
1
Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy, 2Roma Tre University, Mathematics and Physics
Department, Rome, Italy, 3ENEA, Laboratory for Observations and Analyses of Earth and Climate, Rome, Italy,
4
University of Rome 'La Sapienza', Physics Department, Rome, Italy

A new 22 GHz water vapor spectrometer, VESPA-22, was installed in July 2016 at the Thule High Arctic
Atmospheric Observatory located at Thule Air Base (76.5° N, 68.8° W), Greenland (http://www.thuleatmos-
it.it/). It was designed and built at the INGV and measures the 22.235 GHz water vapor emission line with a
bandwidth of 500 MHz and a resolution of 31 kHz. The collected spectra are inverted using an optimal
estimation algorithm in order to retrieve water vapor vertical profiles from about 25 to 75 km with an overall
uncertainty between 5 and 12%. Depending on season and weather conditions, 2 to 4 vertical profiles a day are
obtained. VESPA-22 has been operating in an autonomous mode since its installation, with very few short
periods of data gaps. This study will present water vapor stratospheric profiles over Thule obtained during a
complete yearly cycle, from July 2016 to July 2017, showing both the rapid variations measured in winter when
the polar vortex moved away from Thule and the slow seasonal variations due to the air subsidence inside and
at the edge of the polar vortex. VESPA-22 water vapor vertical profiles have been compared with version 4.2 of
concurrent Aura/Microwave Limb Sounder (MLS) profiles. In the sensitivity range of VESPA-22 retrievals, the
intercomparison between the two datasets reveals a correlation coefficient of about 0.8 or higher and an
average difference reaching its maximum of -6% or -0.2 ppmv at the top of the sensitivity range.

790
Wed_7_AC-2_680
Column Water Vapor Impact on the Surface Infrared Radiation at Thule, Greenland

Giovanni Muscari1 (giovanni.muscari@ingv.it), Daniela Meloni2, Giandomenico Pace2, Gabriele Mevi1,3, Alcide
Giorgio di Sarra2, Tatiana Di Iorio2, Marco Cacciani4
1
Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy, 2ENEA, Laboratory for Observations and Analyses of
Earth and Climate, Rome, Italy, 3Roma Tre University, Mathematics and Physics Department, Rome, Italy,
4
University of Rome 'La Sapienza', Physics Department, Rome, Italy

The absorption of longwave radiation by water vapor and clouds influences temperature at the surface creating
complex feedback cycles. Direct measurements of surface irradiance in the Arctic region are sparse and
accurate parameterizations are therefore required in order to constrain climate models and study such cycles.
This study presents an analysis of the impact of precipitable water vapor (PWV) and surface temperature on
downwelling longwave clear-sky irradiance at the surface measured at the Thule High Arctic Atmospheric
Observatory located at Thule Air Base (76.5° N, 68.8° W), Greenland (http://www.thuleatmos-it.it/). PWV
measurements are obtained with the 22 GHz spectrometer VESPA-22 and the RPG HATPRO radiometer,
whereas the longwave irradiance is measured by means of a CGR4 pyrgeometer. VESPA-22 and HATPRO PWV
measurements are intercompared with those obtained by Aqua/AIRS, and by means of a Cimel sunphotometer
(AERONET network) and a GPS receiver also installed at Thule. A new semi-empirical parameterization model is
formulated using high-time resolution observations collected from July 2016 onwards. The relative weight of
column water vapor and temperature on clear-sky longwave irradiance at the surface is investigated by means
of the MODTRAN radiative transfer model during a full annual cycle. The semi-empirical model implemented in
this study proves to be a valuable tool for parameterizing clear-sky longwave irradiance at high latitudes.

791
Wed_8_AC-2_746
Comparison Between Cloudsat and In-situ Radar Snowfall Rates in East Antarctica

Florentin Lemonnier1 (florentin.lemonnier@lmd.jussieu.fr), Jean-Baptiste Madeleine1, Chantal Claud1, Norman

Wood2, Tristan L'Ecuyer2, Gerhard Krinner3, Alexis Berne4, Claudio Duran-Alarcon3, Cyril Palerme3, Christophe
Genthon3
1
Laboratoire de Météorologie Dynamique/IPSL, École Normale Supérieure, Paris, France, 2University of
Wisconsin-Madison, Madison, United States, 3Institut des Géosciences de l'Environnement, Grenoble, France,
4
École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland

The Antarctic continent is a vast desert, the coldest and the most unknown area on Earth and contains its
largest fresh water reservoir. Current global warming could threaten this ice sheet, leading to sea level rise. The
main goal of the French-Swiss APRES3 project (Antarctic Precipitation, Remote Sensing from Surface and Space)
is to document and understand current precipitation over the south polar cap, knowing that current climate
models do not agree on snowfall amounts over the ice sheet [Palerme, Clim. Dynamics 2017]. Remote sensing
observations of the coastal regions and the continent using CloudSat radar give a snowfall rate of 153 mm/year
whereas the IPSL Climate Model gives a higher rate of 172 mm/year, knowing that CloudSat uncertainties are
hard to constrain and range from about 50% up to 175% [Wood, Thesis 2011]. We did a comparison between
CloudSat radar observations and a Micro-Rain Radar located at the French Dumont d´Urville station that brings
a better understanding of CloudSat uncertainties and leads to a reassessment of these values. We compared
these two different data sets over February 2017, when CloudSat overpassed the Dumont d´Urville radar four
times, at one vertical level and the agreement is suitable. Using different CloudSat vertical levels and additional
surface precipitation observation by a PLUVIO2 weighing gauge, we explore and analyze the vertical profile of
precipitation over Dumont d´Urville and revisit the results over the whole continent.

792
Wed_9_AC-2_782
Comparison of Arctic Precipitation from Reanalyses for 1979 - 2016

Benjamin Segger1 (benjamin.segger@awi.de), Annette Rinke1, Robert Graham2, Susanne Crewell3, Erlend
Knudsen3
1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Atmospheric Physics, Potsdam,
Germany, 2Norwegian Polar Institute, Tromsø, Norway, 3University of Cologne, Cologne, Germany

Precipitation and snowfall in particular are of great importance for the Arctic climate system due to their
implications on physical mechanisms like sea ice growth and melt, permafrost, as well as on ecosystems and
society.
Unfavorably, there are only few circum-Arctic stations and hardly any in the Central Arctic itself measuring
precipitation. Therefore, many related studies use model simulations or reanalyses. However, it is somehow
unclear how big the uncertainties from a specific product are.
Our study examines the spatiotemporal distribution and statistical characteristics of precipitation from various
reanalyses (ERA-Interim, MERRA-2, JRA-55, ASR, CFSR) in the Arctic for 1979-2016. We show that the spatial
distribution of precipitation and the timing at which the precipitation occurs are very similar across the
reanalyses, as those are mainly influenced by the large-scale circulation. However, there does exist a large
spread in the amount of precipitation caused by synoptic events as well as in the total amount.
Since the used parametrization schemes vary widely in the way they determine the precipitation phase, large
differences in the snowfall to precipitation ratio can be observed.
We analyze how the trend in the amount of precipitation and the precipitation phase can be interpreted.
This work was supported by the SFB/TR 172 “ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe
Processes, and Feedback Mechanisms (AC)³” in sub-project E04 funded by the DFG.

793
Wed_10_AC-2_805
Characteristics of Gravity Waves over Antarctica Using Radiosonde Observations

N Koushik1 (koushiknk@gmail.com), Geetha Ramkumar1, Karanam Kishore Kumar1, Kandula V Subrahmanyam1

1
Space Physics Laboratory, Vikram Sarabhai Space Centre, Indian Space Research Organisation,
Thiruvananthapuram, India

By now the momentous role of atmospheric gravity waves in shaping the thermal and dynamical structure of
the middle atmosphere is irrefutable. More observations of gravity waves in the polar stratosphere, especially
over the remote and hostile Antarctic, are required for the betterment of their representation in models. In this
regard, a study was conducted to characterize gravity waves in the Antarctic lower stratosphere using
campaign mode balloon borne radiosonde observations from the Indian research base at Antarctica, Bharati
(69oS, 76.8oE) during the austral summers of 2014-15, 2015-16 and 2016-17. The average potential energy
densities in the lower stratosphere were found to be less than 1J/kg. The gravity wave kinetic energy densities
were found to be much higher than the corresponding potential energy densities (KE/PE>1), suggestive of the
dominance of inertia-gravity waves in the wave field. Further, Stokes parameter analysis was used to extract
the propagation characteristics.The intrinsic period of the gravity waves were found to be closer to the inertial
period at the location. The deduced horizontal wavelengths were large, of the order of 1000km. The observed
waves were predominantly upward propagating which is typical of summertime Antarctic stratosphere. The
significance of the present study lies in bringing out the characteristics of gravity waves over Antarctica during
three summer seasons with different prevailing atmospheric conditions.

794
Wed_11_AC-2_859
Influence of Ozone Hole on Precipitation in the Pacific Coast of South America

Alessandro Damiani1 (alecarlo.damiani@gmail.com), Raul Cordero2, Pedro Llanillo2, Sarah Feron3, Juan Pablo
Boisier4
1
Chiba University, CEReS, Chiba, Japan, 2Universidad de Santiago de Chile, Santiago, Chile, 3Leuphana
University, Lüneburg, Germany, 4Universidad de Chile, Santiago de Chile, Chile

Both simulations and observations consistently proved that the ozone hole left a clear signature of its effects
on the surface climate of the Southern Hemisphere. Within this framework, results based on an ozone
attribution study, performed by some of the models participant to the Coupled Model Intercomparison Project
Phase 5 (CMIP5) initiative, suggest that the evolution of the ozone hole contributed to the previously identified
reduction of precipitation occurred along the Pacific coast of southern South America during the last decades.
Such ozoneinduced variations, which maximize in summer, are coupled to corresponding changes in cloud
fraction and surface temperature. The individual response of each model is shown to be dependent on the
magnitude of the ozone forcing. This influence is explained by the ozone hole impact on the general
atmospheric circulation and confirms previous results pointing to a largescale control on this region. In
particular, the response to ozone hole in the zonal winds is shown to determine the strength of uplift on the
windward side of the Andes with consequent larger humidity there and, possibly, dry conditions in the eastern
plains. Since the ozone hole is simulated to recover by the next decades, its forcing is shown to counteract the
GHG forcing under the RCP4.5 scenario. As a consequence, no evident changes in cloudiness and precipitation
affect the investigated region during this period.

795
Wed_12_AC-2_915
Overview of Stable Water Isotope Meteorology in the Southern Ocean during ACE

Iris Thurnherr1 (iris.thurnherr@env.ethz.ch), Graf Pascal1, Franziska Aemisegger1, Stephan Pfahl1, Maxi
Böttcher1, Yongbiao Weng2, Harald Sodemann2, Josué Gehring3, Alexis Berne3, Irina Gorodetskaya4, Heini
Wernli1
1
ETH Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland, 2University of Bergen,
Geophysical Institute & Bjerknes Centre for Climate Research, Bergen, Norway, 3EPFL, ENAC-LTE, Lausanne,
Switzerland, 4University of Aveiro, Centre for Environmental and Marine Studies, Aveiro, Portugal

The dynamics of the large-scale atmospheric flow strongly influences the Southern Ocean fresh water budget.
For example, the passage of cyclones is responsible for a large part of strong precipitation events, whereas
cold-air outbreaks are often associated with intense ocean evaporation. Stable water isotopes (SWI) are useful
tracers to analyse atmospheric moisture sources and transport pathways. During the Antarctic
Circumnavigation Expedition (ACE), a unique observational dataset was collected on board the vessel Akademik
Tryoshnikov from 16 Dec 2016 to 17 March 2017. These observations include measurements of SWI in
atmospheric water vapour, precipitation and surface waters, radar observations of precipitation, high-
resolution humidity measurements, and atmospheric profiles from radiosondes.
Together with different meteorological diagnostics, these observations are used to investigate key aspects of
the Southern Ocean water cycle. The meteorological conditions during austral summer 16/17 are presented
using operational analysis data of the European Centre for Medium-Range Weather Forecasts. Various tools to
identify weather systems are used to characterise the meteorology during the ACE expedition. The
encountered weather systems are then linked to the SWI composition of atmospheric water vapour. This
includes a detailed characterisation of the spatial and temporal SWI variability in atmospheric vapour along the
ship track, and the involved meteorological phenomena.

796
Wed_13_AC-2_928
Antarctic Ozone Asymmetry and Regional Climate Changes

Gennadi Milinevsky1,2 (genmilinevsky@gmail.com), Asen Grytsai1, Andrew Klekociuk3,4, Oleksandr Evtushevsky1,

Kane Stone5
1
Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, 2Jilin University, International Center for Future
Science, Changchun, China, 3Australian Antarctic Division, Hobart, Australia, 4Antarctic Climate and Ecosystems
Cooperative Research Centre, Hobart, Australia, 5Massachusetts Institute of Technology, Cambridge, United
States

The asymmetry in the Antarctic total ozone zonal distribution has changed during the last four decades,
showing an eastward shift in the zonal ozone minimum of quasi-stationary planetary wave. The satellite data
1979-2016 analyzed by the authors related to changes in the zonal asymmetry of the Antarctic ozone and to
their coupling with atmospheric parameters in the Southern Hemisphere (SH) are presented. Long-term
changes of total ozone content in the SH in spring are accompanied by changes in its asymmetric distribution.
Interannual variations of the longitudinal ozone minimum position demonstrate statistically significant relation
to the structure of the quasi-stationary planetary waves in the distribution of atmospheric parameters. The
long-term longitudinal shift of the ozone minimum is similar to shift in the zonal structure of planetary waves in
the tropospheric parameter distribution and is also accompanied by meridional displacement of the climatic
anomalies toward the equator. The obtained relationships characterize interdependence between the large-
scale tropospheric and stratospheric disturbances in the SH during the ozone hole season. Eastward movement
of the zonal ozone minimum over Antarctica has slowed and reversed to westward during the last decade that
can relate to the first sign of recovery in Antarctic ozone. The zonal ozone asymmetry behavior accompanying
ozone depletion/recovery could be associated with regional climate changes in the SH in spring.

797
Wed_14_AC-2_976
Arctic/Antarctic UV Measurements: Sodankylä 67ºN Marambio 64ºS

Kaisa Lakkala1, Outi Meinander2, Margit Aun3, Eija Asmi2 (eija.asmi@fmi.fi), Ricardo Sanchez4, Germar
Bernhard5, Britta Hamari1, Tomi Karppinen6, Rigel Kivi6, Hector Ochoa7, Alberto Redondas8
1
Finnish Meteorological Institute, Rovaniemi, Finland, 2Finnish Meteorological Institute, Helsinki, Finland,
3
University of Tartu, Tartu Observatory, Tartu, Estonia, 4Servicio Meteorológico Nacional, Buenos Aires,
Argentina, 5Biospherical Instruments, Inc., San Diego, United States, 6Finnish Meteorological Institute,
Sodankylä, Finland, 7Dirección Nacional del Antártico-Instituto Antártico Argentino, Buenos Aires, Argentina,
8
Izaña Atmospheric Research Center, Agencia Estatal de Meteorología, Tenerife, Spain

The Finnish Meteorological Institute (FMI) has collaborated with the Servicio Meteorológico Nacional,
Argentina, to establish new UV measurements in Antarctica. A GUV-2511 multifilter radiometer was installed at
Marambio (64ºS) in January 2017. The radiometer measures spectral irradiance at five UV wavelengths and one
wavelength in the visible (555 nm). An addition channel measures PAR. The new observations continue UV
measurements performed between 2000 and 2012 with a NILU-UV radiometer of the Antarctic NILU-UV
network, which is a collaboration between FMI, SMN, Spain, and DNA-IAA, Argentina. The gap between the two
UV time series can be filled with measurements of a broadband UV radiometer, which is part of the albedo
measurement setup in Marambio
The FMI measures UV radiation at seven stations in Finland. In Sodankylä (67ºN), measurements started in
1990, and the spectral UV time series is among the longest in the Arctic. Observations are made with a Brewer
spectroradiometer, which also measures total ozone. As both Sodankylä and Marambio are located in areas of
spring-time stratospheric ozone depletion at similar latitudes but in different hemispheres, it is interesting to
compare the measured UV time series. The irradiance scale of the measurements was homogenized and is
traceable to Aalto-MIKES, Finland. At Sodankylä, the maximum UV index was found to be 6 (summers 2011 and
2013). At Marambio, the maximum UV index measured between 2000 and 2010 was 12 (Nov 2007).

798
Wed_15_AC-2_992
Ozone Column Variability at Marambio Base, Eastern Antarctic Peninsula

Klára Čížková1,2, Kamil Láska1 (laska@sci.muni.cz), Ladislav Metelka2, Martin Staněk2

1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic, 2Solar and Ozone
Observatory, Czech Hydrometeorological Institute, Hradec Králové, Czech Republic

Ozone monitoring is still very important even more than 30 years after the Montreal Protocol agreement,
because the first signs of ozone layer healing have only been observed very recently. Since February 2010, the
Czech Hydrometeorological Institute monitors the total column ozone and vertical ozone profiles at the
Marambio Base (64° S, 56° W), eastern Antarctic Peninsula , by the MK-III Brewer spectrophotometer B199.
Using the eight years (2010-2017) of observed data, we have been focusing mostly on these topics:

1. Assessment of the total column ozone variability

2. Intercomparisons of the B199 total ozone column with various satellite data products
3. Validation of the B199 Umkehr vertical ozone profiles using the Finnish Meteorological Institute ozone
soundings

Our results indicate that due to dynamical processes in the stratosphere, the ozone layer recovery is more
variable in time than the ozone depletion onset. For example in 2013, a fast recovery was observed, while in
2011 the ozone hole lasted till mid-November. Moreover, we confirmed that B199 data fits very well satellite
total column ozone. The most reliable dataset seems to be OMI (TOMS) with over 95 % variability in common
with B199. On the other hand the Umkehr profiles are too smooth and overestimating the ozone amount in
days characterized by the strong ozone depletion linked with strength of the polar vortex.

799
Wed_16_AC-2_1017
Total Ozone, UV and Radio Sounding Measurements in the Sør Rondane Mountains

Alexander Mangold1 (alexander.mangold@meteo.be), Quentin Laffineur1, Roeland Van Malderen1, Christian

Hermans2, Kevin Nys3, Maarten Verbruggen3, Hugo De Backer1
1
Royal Meteorrological Institute of Belgium, Brussels, Belgium, 2Royal Belgian Institute for Space Aeronomy,
Brussels, Belgium, 3Universiteit Antwerpen, Antwerp, Belgium

Since December 2010, a Brewer ozone spectrophotometer for measuring the total ozone column and UV
spectra (283 to 363 nm) has been operated during austral summers at the Belgian research station Princess
Elisabeth (PES), in the Sør Rondane Mountains in East Antarctica (72° S, 23° E, 1390 m asl). We will present an
overview of the measurement results since 2010/11 up to 2017/18. In 2015, the Antarctic ozone hole was one
of the largest and most stable one on record and total ozone amounts showed local record minima between
170 to 180 Dobson Units for the end of November 2015. These conditions persisted until 15 December 2015.
Consequently, the UV index reached local record values up to 12.
In addition, weather balloons with radio sondes (vertical profile of temperature, relative humidity, pressure,
wind speed and direction up to 30 km) have been launched during austral summers 2014/15, 2015/16 (planned
for 2017/18). During season 2014/15 the mean tropopause height was 9607 ± 836 m asl with a corresponding
temperature of -56.6 ± 4.9 °C (9178 ± 735 m and -56.9 ± 4.1 °C in 2015/16, respectively). During summer
season 2014/15 a distinct temperature inversion at around 2500 m asl was observed during almost all launches
in January and February. However, this pattern was not observed in season 2015/16. The mean relative
humidity ranged between 30 and 50 % throughout the troposphere in 2014/15 and 2015/16. However,
February 2016 showed distinctly higher relative humidity profiles

800
Wed_17_AC-2_1058
The Interplay between Cold Air Outbreaks, Convergence Zones and Polar Lows

Annick Terpstra1,2 (annick.terpstra@uib.no), Lukas Papritz2, Clemens Spensberger2, Ian Renfrew1

1
University of East Anglia, Norwich, United Kingdom, 2Geophysical Institute, University of Bergen and Bjerknes
Centre for Climate Research, Bergen, Norway

Geographically confined, equator-ward excursions of cold air masses into ice-free regions are frequently
accompanied by the development of severe mesoscale weather phenomena, such as intense low-level jets and
polar lows. Cold air outbreaks and polar lows have both been studied independently and are known to be
closely related, though it remains unclear how often polar lows accompany cold air outbreaks. Furthermore,
polar lows tend to develop at the leading edge and outer boundaries of cold air outbreaks, yet little is known
about the temporal and structural evolution of this cold air outbreak periphery and the triggering mechanisms
for mesoscale cyclone development along these frontal structures.
In this study we utilize ERA5-reanalysis data to examine the interplay between cold air outbreaks, convergence
zone formation and mesoscale cyclone development focusing on the Nordic Seas region. We apply objective
detection methods for each of these features, and identify regions and atmospheric conditions which are
(non)-favorable for the development of polar lows during cold air outbreaks. We examine the spatial and
structural evolution of contrasting cases, i.e. with/without mesoscale development, and explore the role of
thermal and moisture gradients at the fringes of cold air outbreaks for mesoscale cyclone initiation.

801
Wed_19_AC-2_1348
On the Mean Age of Stratospheric Air and the Polar Vortex Preconditioning

Petr Šácha1 (sacha@uvigo.es), Aleš Kuchař2, Petr Pišoft2, Laura de la Torre1, Juan Añel1
1
Universidade de Vigo, Facultade de Ciencias de Ourense, Ourense, Spain, 2Charles University in Prague,
Department of Atmospheric Physics, Prague, Czech Republic

The mean age of stratospheric air (AoA) is a useful transport diagnostic. We study the hypothesis that AoA can
be used as a proxy for the polar vortex preconditioning, because it reflects the cumulative effect of transport
processes. Using a composite analysis of sudden stratospheric warming events from the CMAM specific
dynamics simulation we formulate an AoA anomaly index and study its ability to predict polar vortex events up
to one month prior to the event. The dynamical origin of these anomalies is then analysed with respect to the
anomalous planetary and gravity wave activity.

802
Wed_20_AC-2_1383
A Lagrangian Analysis of Atmospheric Rivers at Livingston Island, Antarctica

Sergi Gonzalez1 (sgonzalezh@aemet.es), Francisco Vasallo2, Pablo Sanz3, Alberto Luna3, Ana Justel4, Julio
Rodriguez4, Marcela Svarc5, Lucas Fernández5
1
Agencia Estatal de Meteorología, Grupo Antártico, Barcelona, Spain, 2Agencia Estatal de Meteorología, Grupo
Antártico, Rota, Spain, 3Universidad Autonoma de Madrid, Centro de Computación Científica, Madrid, Spain,
4
Universidad Autonoma de Madrid, Departamento de Matemáticas, Madrid, Spain, 5Universidad de San Andres,
Departamento de Matematicas, Buenos Aires, Argentina

Atmospheric rivers (AR) are long and narrow regions in the atmosphere that accounts a major horizontal
transport of moisture outside the tropics. AR are responsible for coastal heavy rainfalls in midlatitudes.
Similarly, AR contributes significantly to heavy snowfall events in coastal Antarctica. In the Antarctic peninsula,
AR events are important due to their impact on the surface mass balance of the ice sheets, that may be positive
by snow accumulation or negative by snow melting caused by liquid rain events in summer. Other significant
impacts involve their potential to transport microbial propagules from South America that may succeed into
the deglaciated areas of the Shetland Islands.
To study AR reaching Livingston Island, a climatology of 368172 trajectories (12 year between 2005 and 2016, 4
times a day and 21 levels) has been computed using the Hybrid Single-Particle Lagrangian Trajectory model
(HYSPLIT). Following the methodology described by Gorodetskaya et al (2014) to detect AR at high latitudes, we
selected the cases where AR impinged on JCI station at Livingston Island between 2005 and 2016. In this
communication we present the lagrangian analysis of these events focusing on their climatology, their moisture
sources and the synoptic settings that produces them.

803
Wed_21_AC-2_1595
Contribution of Foehn Winds to the January 2016 West Antarctic Melt Event

Xun Zou1, Julien Nicolas1, David Bromwich1 (bromwich@polarmet1.mps.ohio-state.edu)

1
Ohio State University, Byrd Polar and Climate Research Center, Columbus, United States

In January 2016, the Ross Ice Shelf (RIS) experienced one of its most prominent surface melt events since the
advent of satellite observations in the late 1970s. This event followed a pattern already seen during previous
events: the melting begins along the Siple Coast, on the eastern side of the RIS, expands to the rest of the ice
shelf, before retreating to where it started. Previous work has highlighted the role of the strong 2015-16 El
Niño event in promoting warm air advection toward western West Antarctica. While important in initiating the
melt event, this phenomenon only partially explains the spatial and temporal distribution of the melting and
ignores other important physical mechanisms. Here, we present the results of a detailed three-dimensional
investigation of the meteorology of the January 2016 event based on model output from the Antarctic
Mesoscale Prediction System (AMPS) and the ERA5 Reanalysis. Using backward trajectory analysis, we highlight
in particular the foehn effect taking place downwind of the coastal mountain ranges of Marie Byrd Land, which
acts to amplify the warm advection, especially during the early stage of the melt event. To our knowledge, the
existence of this foehn effect has thus far never been demonstrated nor its effect quantified. Our analysis
underscores the importance of high resolution for atmospheric simulations of West Antarctic surface climate,
an important aspect to consider when projecting the future of the RIS.

804
Wed_22_AC-2_1654
Snowfall Rate Retrieval and its Relation with the Antarctic Surface Mass Balance

Niels Souverijns1 (niels.souverijns@kuleuven.be), Alexandra Gossart1, Stef Lhermitte2, Irina V. Gorodetskaya3,

Stefan Kneifel4, Maximilian Maahn5,6, Francis L. Bliven7, Alexander Mangold8, Quentin Laffineur8, Andy Delcloo8,
Nicole P. M. van Lipzig1
1
KU Leuven, Department of Earth and Environmental Sciences, Heverlee, Belgium, 2Delft University of
Technology, Department of Geoscience and Remote Sensing, Delft, Netherlands, 3University of Aveiro, Centre
for Environmental and Marine Studies, Aveiro, Portugal, 4University of Cologne, Institute for Geophysics and
Meteorology, Cologne, Germany, 5University of Colorado Boulder, Cooperative Institute for Research in
Environmental Sciences, Boulder, United States, 6NOAA Earth System Research Laboratory, Boulder, United
States, 7NASA Goddard Space Flight Center, Wallpos Island, United States, 8Royal Meteorrological Institute of
Belgium, Observations department, Uccle, Belgium

The Antarctic Ice Sheet (AIS) is the largest ice body on earth. In order to understand its contribution to sea level
rise, local surface mass balance (SMB) measurements are crucial. Precipitation is generally considered the
dominant source term in the SMB budget of the AIS. Both SMB and snowfall are not well constrained in both
models and observations, and the relation between both quantities remains unknown.
At the Princess Elisabeth station (East Antarctica), a ground-based vertically pointing 24 GHz Micro Rain Radar
provides radar reflectivity measurements. When information about snow particle microphysics is available, one
can get an idea of snowfall rates. This is provided by an optical disdrometer (Precipitation Imaging Package). As
such, radar reflectivity snowfall rate relations (Z=a*SRb) are derived for the East Antarctic escarpment region
including an overview of their uncertainties.
The local SMB at the station is measured using an Automatic Weather Station and the link between snowfall
rates and accumulation at the surface was investigated. It was found that snowfall events are much more
common than accumulation events. During 38% of the snowfall cases observed, the freshly-fallen snow is
ablated by the wind during the course of the event. In this study, the conditions for ablation and accumulation
are investigated discovering a non-linear relation between snowfall and accumulation at the surface.

805
Wed_23_AC-2_1671
What Controls Deuterium Excess in Coastal Antarctica?

Sentia Goursaud1 (sentia.goursaud@lsce.ipsl.fr), Camille Bréant2, Amaelle Landais2, Valérie Masson Delmotte2,
Michel Legrand3, Martin Werner4
1
Institut des Géosciences de l’Environnement, Université Grenoble Alpes, Saint Martin d'Hères, France,
2
Laboratoire des Sciences du Climat et de l’Environnement, Gif-sur-Yvette, France, 3Institut des Géosciences de
l’Environnement, Saint Martin d'Hères, France, 4Alfred Wegener Institute Helmholtz Center for Polar and Marine
Research, Bremerhaven, France

The second-order water stable parameter deuterium excess (d-excess) can be used to understand the spatial
and temporal changes in the isotopic-temperature relationship. However, so far no simple result is obtained
from statistical analyses of continental surface measurements or from measurements in precipitation and ice
cores.
In order to make progress in understanding d-excess measured in Antarctica, we compiled an updated
database of water stable isotope data from vapour, snow surface and ice cores. We then completed this
database with new data from Adélie Land, obtained from in situ water vapor monitoring at Dumont d'Urville
during 40 days of the austral summer 2016/2017 and new high resolution measurements from one shallow ice
core drilled at 25 km from the station during the austral summer 2014/2015. Our data are combined with the
meteorological observations from Dumont d'Urville and the dry and wet back-trajectories simulated by Hysplit
and Flexpart respectively.
Our limited dataset shows the complexity of d-excess signals, and call for new datasets obtained in water
vapour, snowfall, surface snow and shallow ice. We show that coastal Antarctic d-excess variability is not
controlled by local climate variables and appears related to atmospheric circulation and moisture transport at
the local to regional scale. Further studies are needed to deconstruct the exact drivers of coastal Antarctic d-
excess and exploit this signal.

806
Wed_24_AC-2_1727
Cyclone Activity in the Arctic from an Ensemble of Regional Climate Models

Mirseid Akperov1, Annette Rinke2, Igor Mokhov1 (mokhov@ifaran.ru), Heidrun Matthes2, Vladimir Semenov1
1
A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russian Federation,
2
AWI, Potsdam, Germany

The ability of state-of-the-art regional climate models to simulate cyclone activity in the Arctic region is
assessed based on an ensemble of 13 simulations from 11 models from the Arctic-CORDEX initiative. Some
models employ large-scale spectral nudging technique. Cyclone activity characteristics simulated by the
ensemble are compared with four reanalyses in winter and summer during the 1981-2010 period. Biases in
cyclone frequency, intensity and size over the Arctic are quantified.
Variations in cyclone frequency across the models are partly related to the differences in cyclone frequency
over land. The variations across the models are largest for small and shallow cyclones for both seasons. A
connection between biases in the zonal wind at 200 hPa and cyclone characteristics is found for both seasons.
Most models underestimate zonal wind speed in both seasons, which likely leads to underestimation of cyclone
mean depth and deep cyclone frequency in the Arctic.
In general, the RCMs are able to represent the spatial distribution of cyclone characteristics in the Arctic region
but models that employ large-scale spectral nudging are in much better agreement with ERA-Interim reanalysis
than the rest of the ensemble. Trends also exhibit the benefits of nudging. Most non-nudged models cannot
reproduce cyclone trends while the opposite is true for models with spectral nudging. However, the choice of
nudged variables also affects the cyclone characteristics and trends.

807
Wed_25_AC-2_1804
Polar Mesoscale Cyclone Climatology for the Nordic Seas

Clio Michel1,2 (clio.michel@uib.no), Annick Terpstra1,2, Thomas Spengler1,2

1
University of Bergen, Geophysical Institute, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen,
Norway

Polar mesoscale cyclones (PMCs) are automatically detected and tracked over the Nordic seas using the
Melbourne University algorithm applied to the ERA-Interim reanalysis. The novelty of this study is the length of
the dataset (1979-2014) and the usage of PMC tracks to infer relationships to large-scale flow patterns.
The angle between the ambient mean and thermal wind is used to distinguish two different PMCs genesis
environments. The forward shear environment (thermal and mean wind in same direction) features typical
baroclinic conditions with a temperature gradient at the surface and a strong jet stream at the tropopause. The
reverse shear environment (thermal and mean wind in opposite direction) features an occluded cyclone with a
barotropic structure throughout the entire troposphere and a low-level jet.
In contrast to previous studies, PMC occurrence does neither feature a significant trend nor a significant link
with the North Atlantic Oscillation and the Scandinavian Blocking (SB), though the SB negative pattern seems to
promote reverse shear PMC genesis. The sea ice extent in the Nordic seas is not associated with overall
changes in PMC occurrence but influences the genesis location. Selected cold air outbreak indices and the
temperature difference between the sea surface and 500 hPa (SST-T500) show no robust link with PMC
occurrence but the characteristics of forward shear PMCs and their synoptic environments are sensitive to the
choice of the SST-T500 threshold.

808
Wed_26_AC-2_1927
Identification of a Physically Based Arctic Cold and Transition Seasons

Taneil Uttal1 (taneil.uttal@noaa.gov), Alexander Makshtas2, Christopher Cox3, Nikolay Ivanov2

1
NOAA Earth System Research Laboratory, Physical Science Division, Boulder, United States, 2Arctic and
Antarctic Research Institute of Roshydromet (AARI), St Petersburg, Russian Federation, 3Cooperative Institute
for Research in Environmental Sciences, NOAA/ESRL/PSD, Boulder, United States

Arctic 'seasons' are physically unique compared to lower latitudes and have strong latitudinal dependence
within the Arctic due sun-earth geometry. Therefore, physically-based seasons are here defined to be a long
cold season (~6 months), two short transition seasons, and a warm season. Arctic extremes and trends must be
defined using different criteria for each of these seasons. In the warm season the obvious extremes are in
changing sea-ice extent/area. Trends and extremes for transition seasons are more defined by a trend towards
earlier (latter) melt (freeze-up) dates. The Arctic cold season is therefore the most interesting for looking at
temperature trends, variability and trends. For in-situ temperature records from Tiksi, Russia, cold season
temperature trends are shown to decrease as the length of the record over which trend is calculated increases
due to a significant warm period in the 1940s. The incidence of extreme temperature events (exceeding the
95th and 99th percentiles) also show a bimodal distribution with peaks in the 1940s and the present. Results
from Tiksi are compared to
(1) various reanalysis products and
(2) other Arctic sites such as Barrow, Alaska.
It is proposed that it is the temperatures during the Arctic cold season are the most relevant for determining
linkages with global climate and weather. In addition, the seasonal partitioning described here is expected to
be useful for analysis of data from YOPP.

809
Wed_27_AC-2_1936
Characteristics and Synoptic Environment of Polar Lows over the Barents Sea

Chantal Claud1 (chclaud@lmd.polytechnique.fr), Marie Vicomte1, Maxence Rojo2, Paul-Etienne Mallet3, Gunnar
Noer4
1
CNRS/Ecole Polytechnique, Palaiseau, France, 2CEARC/OVSQ, Guyancourt, France, 3LOA, Lille, France, 4Met-
Norway, Tromso, Norway

Polar Lows are intense mesoscale maritime storms, which form over open sea during wintertime north of the
main baroclinic zone. They occur during cold air outbreaks and are generally associated with heavy snowfalls,
reduced visibility, and changing surface winds which can be in excess of 30 m/s. The degree of predictability
varies from case to case but they have always represented a challenge in terms of forecasting: their rapid
development, their small scale extent (200-600 km) and short lifetime (average 15-20 hrs), the absence or
rarity of synoptic observations and real time satellite derived winds, the poor radar coverage and, in many
cases, unreliable model fields, has led in the past to a rather low skill, with even some polar lows undetected
until they affect coastal regions.
The Barents Sea has long been known to be a prime site for the development of such storms, but climatological
aspects of Polar Lows affecting this region are poorly known. In addition, recent retreating sea ice may expose
this area to increased occurrences of extreme weather systems. The characteristics of Barents Sea Polar Lows
over more than 15 years and the synoptic environment in which they develop will be discussed.

810
Wed_28_AC-2_1974
Enhancement of Gravity Wave over Syowa Observed by Rayleigh/Raman Lidar

Masaru Kogure1 (kogure.masaru@nipr.ac.jp), Takuji Nakamura2, Yoshihiro Tomikawa2, Mitsumu K. Ejiri2,

Masaki Tsutsumi2, Takanori Nishiyama2
1
SOKENDAI (The Graduate University for Advanced Studies), Department of Polar Science, Tokyo, Japan,
2
National Institute for Polar Research, Tokyo, Japan

Typical gravity wave activities and its seasonal variations have been studied at various places around the world.
However, what causes a shorter temporal and local variations of the activities are poorly understood. To
understand this cause, we estimated the potential energy of gravity wave over Syowa Station (69°S, 40°E) from
a Rayleigh/Raman (RR) lidar observation between 2011 and 2015. We found a clear enhancement of the
potential energy during 8th-21st August 2014. The energy in this period was about two and five times as large as
the winter mean in the other years at 50 and 60 km. There are two possible causes. The first one is that some
source would exist around 45 km, but there seemed no specific source within the MERRA. The second one is
that the gravity waves would converge from the lower atmosphere at lower and higher latitudes due to the
meridional gradient of the westerly wind [Dunkerton, 1984]. The polar night jet around 40°E during the
enhancement period slanted to ~70°S from ~50°S. In such condition, the gravity waves with west-ward
wavenumber incline to converge to Syowa. We estimated paths of gravity waves in order to examine whether
the gravity waves could converge to Syowa. We found that the large-scale gravity waves could converge to 50-
55 km altitudes over Syowa in that period. This result suggests that the enhancement could be caused by the
convergence of the gravity waves. we will show these results and discuss the cause of the enhancement.

811
Wed_29_AC-2_1977
Stratospheric Ozone and Nitrogen Oxides in Antarctic Regions

Daniele Bortoli1,2 (db@uevora.pt), Fabrizio Ravegnani2, Maria Joao Costa1,3, Giorgio Giovanelli2
1
University of Evora, Institute for Earth Sciences, Evora, Portugal, 2Institute for Atmospheric Sciences and
Climate, Bologna, Italy, 3University of Evora, Department of Physics, Evora, Portugal

Since the discovery of the ozone hole phenomena in Antarctica during the spring season, the studies on the
atmospheric tracers related to the ozone chemistry are of extreme interest for the scientific community. At the
Mario Zucchelli station, since 1995, GASCOD (Gas Analyzer Spectrometer correlating Optical Differences)
equipment performs measurements of zenith sky scattered radiation, for the assessment of stratospheric NO2
and O3. In 2013 the SAMOA (Automatic Station monitoring Antarctic Ozonesphere) system is placed side by
side to the old spectrometer to assure the continuation of the time series for the above mentioned compounds
and to enlarge the monitoring capabilities. SAMOA is composed of the UV-Vis GASCOD NG1 (New Generation),
the VELOD (Vertical Looking Device) to measure the zenith sky scattered radiation and the MIGE (Multiple
Input Geometry Equipment) to perform measurements in different directions.
Here, the SAMOA station is described and the improvements with respect to the old system are highligted.
Moreover, the DOAS and MAX-DOAS algorithms are briefly introduced and the results obtained during the full
period of measurements of the GASCOD instrument are presented and discussed together with a trend analysis
for NO2 and O3 total columns. the first comparison of the observations obtained with the two systems, are
analyzed.

812
Wed_30_AC-2_1998
Characteristics of Near-surface Wind Field over Terra Nova Bay, Antarctica

Chenoli Sheeba Nettukandy1,2 (sheeba@um.edu.my), Muhammad Yunus Bin Ahmad Mazuki2, Azizan Abu
Samah1,2
1
Department of Geography, University of Malaya, Kuala Lumpur, Malaysia, 2National Antarctic Research
Center, University of Malaya, Kuala Lumpur, Malaysia

Terra Nova Bay is often affected by storms moving along the coast and katabatic flow from the continental
interior towards the coast. Data from Jang Bogo Station, other available automated weather station (AWS)
from Terra Nova Bay and ERA interim reanalysis are used as the as the primary dataset to develop the
climatology of near surface winds. In-situ surface meteorological parameters from the AWS used in the study
are wind speed, direction, temperature and pressure. The surface wind field over the Jang Bogo Station is
influenced by its complex topography. A bimodal direction in the wind regime is noted throughout the season
with wind speed greater than 10 ms-1 coming from the direction 225° to 315°. Criteria were set to classify wind
events based on the wind speed and duration. A strong wind event is defined as the event which has wind
speed more than two standard deviations. Several thresholds in terms of duration are tested to capture a
representative number of wind events for further analysis. The mesoscale and synoptic background of the
events are also investigated using reanalysis data.
Boundary layer characteristics during the SWEs were also analyzed using SODAR and Radiosonde data. Case
studies of SWEs over Terra Nova Bay was carried out to understand the interaction between and katabatic
wind and storm of the coast.

813
Wed_31_AC-2_2064
Riming in Alpine and Antarctic Precipitation

Josué Gehring1 (josue.gehring@epfl.ch), Jacopo Grazioli2, Christophe Praz1, Nikola Besic1, Christophe Genthon3
1
EPFL, ENAC-LTE, Lausanne, Switzerland, 2MeteoSwiss, Locarno, Switzerland, 3IGE, Grenoble, France

Precipitation is crucial in the Alps for water resources and hydro-power. In Antarctica, it is a key term in the
surface mass balance but it remains poorly understood because of extreme conditions making observations
very challenging. Precipitation in the Alps is better documented, thanks to past field campaigns, and
operational measurements including weather radars. However, the interactions between cloud microphysics
and orography need to be further investigated. In particular riming, the collection of supercooled water by ice
crystals, can significantly contribute to snow accumulation. It is therefore necessary to investigate riming in
Alpine and Antarctic precipitation to further its understanding in both environments.
We present results from two field campaigns in Antarctica and in the Swiss Alps. The occurrence and intensity
of riming are investigated using hydrometeor classifications from polarimetric radar data and snowflake
photographs. The results show that besides aggregates, graupel is the second most important hydrometeor
type. The vertical structure of precipitation during riming events is different in the Alps and in Antarctica. In the
Alps, the proportion of rimed particles is larger and intense riming is confined to a layer of about 1000 m. In
Antarctica, the proportion of rimed particles is less variable in the vertical, without intense riming layers. This
study contributes to document an important process for Alpine and Antarctic precipitation.

814
Wed_32_AC-2_2163
Urban Heat Island Arctic Research Campaign (UHIARC): Results and Perspectives

Pavel Konstantinov1 (kostadini@mail.ru), Mikhail Varentsov1, Alexander Baklanov2

1
Lomonosov Moscow State University, Faculty of Geography, Department of Meteorology and Climatology,
Moscow, Russian Federation, 2World Meteorological Organization (WMO), Research Branch, Geneva,
Switzerland

Now, in 2017 more than one half of Earth population lives in urbanizes areas. So, the problem of land-use and
microclimate changes in city area becomes more important in the context of inhabitants' long-term quality of
life. And good knowledge about nature of urban climate and formation of urban heat islands (UHI) became one
of important tasks.
Despite the number of big cities are located in high latitudes, especially in Russian Arctic (Murmansk with ≈300
000 inhabitants, Norilsk with ≈180 000 inh., Novy Urengoy with ≈110 000 inh. and a number of cities with more
than 50 000 inh.), the climatology of their UHIs has not been practically studied. For Arctic region such
investigation was performed only for towns in Alaska (Barrow and Fairbanks). Keeping in mind that during polar
night and polar day sunlight conditions are quite different, the idea to explore UHI climatology in Arctic
becomes more and more attractive.
After the first experience in 2013-2014, our team developed Urban Heat Island Arctic Research Campaign
(UHIARC) in five cities of Russian Arctic. Four of them are located within flat and homogeneous terrains which
makes them especially prospective places for Arctic UHI study.
Analysis of the collected data showed the existence of significant UHI with the difference between city center
and surrounding landscape up to 10-12ºC that can have strong impact on house heating strategies and
inhabitants' thermal comfort.

815
Wed_33_AC-2_2259
Representation of the Antarctic Stratospheric Vortex in a Global Climate Model

Chris Cameron1,2 (chris@bodekerscientific.com), Gregory Elton Bodeker2, Jono Conway2, James Renwick1, Jared
Lewis2, Stephen Stuart3
1
Victoria University of Wellington, Wellington, New Zealand, 2Bodeker Scientific, Alexandra, New Zealand,
3
NIWA, Wellington, New Zealand

The Antarctic circumpolar vortex (ACV) forms each winter and spring as a zone of strong stratospheric westerly
winds surrounding Antarctica. The ACV presents a barrier to transport of air masses between middle and high-
latitudes which contributes to stratospheric temperatures above the polar region dropping sufficiently low in
spring to allow for the processes leading to ozone loss. The dynamics of the stratosphere and how they may be
changing over time can also affect circulation in the troposphere and have an impact on weather and climate.
The processes controlling the permeability of the ACV, and how they are likely to respond to a changing climate
and a recovering ozone hole, have not been well studied, and as a result are not well simulated in Global
Climate Models (GCMs). This research makes use of reanalysis data and GCM data - using the UK Met Office
Unified Model (UM) - together with trajectories from Loon balloon flights over Southern Hemisphere middle
and high latitudes to determine how well the permeability of the ACV is represented in a GCM. Results are
expected to indicate how improved representation of ACV transport process can be captured in GCMs.

816
Wed_34_AC-2_2388
Comparison of Temperature Extremes between the East and Antarctica Peninsula

Aihong Xie1 (xieaih@lzb.ac.cn), Shimeng Wang1, Yicheng Wang1

1
Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences, Lanzhou City, China

On the base of daily minimum, maximum, and mean surface air temperatures (Tmin, Tmax, Tmean) at Great Wall
Station (GW, 1985-2015) and Zhongshan Station (ZS, 1989-2015) in Antarctica, changes in temperature
extremes are analyzed in the last three decades. Annual mean temperature reveals the strongly warming trend
in Tmin, slightly warming in Tmean, while cooling in Tmax, and shows different seasonal variabilities with the least
variability in summer. Annual mean of daily temperature range (DTR) has decreased by -0.39 and -0.29
℃/decade at Great Wall Station and Zhongshan Station, respectively.More importantly, we have found that the
seasaw exists East Antarctica and Antarctica Peninsula in the interannual time scale. Eleven indices of extreme
temperature are also examined. The occurrence of extreme warm days has decreased by -0.53 and -0.048
d/decade at GW Station and ZS Station, respectively, while the occurrence of extreme warm nights has shown
nonsignificant trend with much variability. The number of melting days has increased by 4.3 d/decade at Great
Wall Station. Although our analysis can explain part of the variability by changes in winds or to the coastal
icescape, an additional but unknown factor is how atmosphere has responded to changes in ocean heat.
Unraveling cause and effect, critical for predicting changes to the ocean-atmosphere-sea ice-ice sheet system,
will require more in situ observations and improved atmosphere modeling.

817
Wed_35_AC-2_2434
Long-term Ozonesonde Observations at Marambio, Antarctic Peninsula

Rigel Kivi1 (rigel.kivi@fmi.fi), Eija Asmi2, Pauli Heikkinen1, Laura Thölix2, Leif Backman2, Ricardo Sanchez3
1
Finnish Meteorological Institute, Sodankylä, Finland, 2Finnish Meteorological Institute, Helsinki, Finland,
3
National Meteorological Service, Buenos Aires, Argentina

The ozonesonde measurement program at Marambio was established in late 1980s, soon after the discovery of
the Antarctic ozone hole. The Marambio Antarctic Station is located in an island at the North of the Antarctic
Peninsula, surrounded by Weddell Sea (at 64º 14 ´S, 56º 38´W 198 m.a.s.l). The location is suitable for
observing Antarctic stratospheric ozone depletion. In addition to the springtime measurements we have also
performed regular soundings during other seasons. The soundings have been made by electrochemical
concentration cell ozonesondes, using a potassium iodide solution. The sounding system in Marambio is
DigiCORA III from Vaisala and the radiosondes are Vaisala RS92-SGP. The sondes measure ozone profiles from
surface up to the altitude of 30-35 km. The effective altitude resolution is 100-150 meters, uncertainty of the
stratospheric ozone measurements is about 5 %. Here we present results of the long term measurements. The
time series have been recalculated using the knowledge from dual ozonesonde experiments. The ozonesonde
observations are also compared to the available total ozone measurements by a ground based Dobson
instrument at Marambio and by satellite borne instruments. Finally, the reprocessed data set is used to study
trends and variability in measured ozone profiles. A statistical model is applied on the profile data, the model
includes terms for effective equivalent stratospheric chlorine and meteorological variability.

818
Wed_36_AC-2_2551
A Numerical Simulation of Strong Wind Event at King Sejong Station, Antarctica

Hataek Kwon1 (dixon409@gmail.com)

1
Korea Polar Research Institute (KOPRI), Inchon, Korea, Republic of

In this study, a strong wind event that recorded a 10-min average wind speed of about 22 m/s at King
Sejong(KSJ) station was simulated using the Polar WRF (Weather Research and Forecasting) model, which is an
optimized version of WRF. Also, sensitivity experiments of the initialization time on a strong wind simulations is
conducted. Through this, first we have evaluated the strong wind simulation performance of the Polar WRF by
carrying out cross validation by comparing with local surface observations and reanalysis data. Second, we
verified that the main cause of the strong wind event observed in KSJ Station by analyzing in detail
observations and numerical simulation results. In addition, we investigate the climatological characteristics of
the surface meteorological fields by analizing the in situ meteorolocial observations for 22 years in KSJ station.
It is revealed by in situ observations, numerical weather prediction, and reanalysis fields that the synoptic and
mesoscale environment of the strong wind event was due to the passage of a intense low pressure system with
the center pressure of 950hPa. Verifying model results from 3 km grid resolution simulation against
observation showed that high skill in simulating wind speed and surface pressure, respectively. The surface
variables of 10m wind, 2m temperature and surface pressure observed in KSJ station shows clear annual cycles
in the analysis of long-term observation from 1994 to 2015.

819
Wed_37_AC-2_2636
Urban Heat Islands in the Arctic: The First Quasi-climatological Results

Mikhail Varentsov1,2 (mvar91@gmail.com), Pavel Konstantinov1

1
Lomonosov Moscow State University, Moscow, Russian Federation, 2A.M.Obukhov Institute of Atmospheric
Physics, Russian Academy of Sciences, Moscow, Russian Federation

Urban heat island (UHI) effect is well studied for moderate and low latitudes and is considered in general as a
negative phenomenon due to its influence on human thermal comfort and energy consumption rates. For the
Arctic, on the contrary, its positive effects could be related with mitigation of severe frosts and fuel economy
for house heating. However, until nowadays the knowledge about polar UHIs was extremely poor and limited
by few studies for Alaskan towns, while the biggest Arctic cities located in Russian sector of Northern Eurasia
were the terra incognita for urban climatology.
In this study we present the first quasi-climatological estimates of UHI intensity (urban-rural temperature
difference) for Arctic winter conditions. They are based on UHIARC (Urban Heat Island Arctic Research
Campaign) seasonal-scale experimental meteorological observations in five medium-sized Russian Arctic cities
(Apatity, Vorkuta, Nadym, Novy Urengoy, Salekhard). Measurements in these cities have shown quite similar
values of UHI intensity and patterns of its temporal variation. For all of them the average winter UHI intensity
could be estimated as 1-1.5 °C, while extremes up to 6-7 °C are observed in frosty anticyclonic weather.
However, the Arctic UHIs could be strongly amplified by local orography. For Apatity this results in extremely
high (up to 12 °C) values of temperature differences between the city, located at the top of the hill, and WMO
weather station at the lowland.

820
Wed_39_AC-4_382
Gravity Wave Propagation through a Tidally Varying Wind above Davis, Antarctica

Peter Love1, Michael Taylor2, P.-Dominique Pautet2, Damian Murphy3 (damian.murphy@aad.gov.au)

1
Antarctic Climate & Ecosystems Cooperative Research Centre, Hobart, Australia, 2Utah State University, Logan,
United States, 3Australian Antarctic Division, Kingston, Australia

Gravity waves in the night-time mesosphere/lower thermosphere can be observed using infrared imagers
sensitive to emissions from the hydroxyl layer. Wave propagation directions from these imagers are often used
to infer possible lower atmosphere source regions either approximately by direct projection or using ray tracing
methods. However, it is generally assumed that the waves are propagating in an invariant wind environment.
The height region around the hydroxyl layer (near 87 km) coincides with significant increases in tidal wind
amplitudes and is thus subject to strong diurnal or semidiurnal wind fluctuations. These have the potential to
change the propagation characteristics of gravity waves just prior to their observation.
In this study, gravity-wave horizontal wavelengths, frequencies, orientations and phase propagation speeds are
extracted from images of the hydroxyl layer above Davis station, and used to seed ray tracing analyses of 3-D
wave propagation. MLS satellite observations provide daily average temperature profiles and instantaneous
wind fields were obtained using the Davis MF Radar. The influence of the wind and its variations can thus be
assessed by back tracing the observed gravity waves through a mean or tidally varying field.
The results of this study will be presented. Their implications for these and other ANGWIN measurements will
be discussed.

821
Wed_40_AC-4_385
ANGWIN: International Collaboration in Polar Atmospheric Research

Tracy Moffat-Griffin1, Jose Valentin Bageston2, Jeong-Han Kim3, Damian Murphy4

(damian.murphy@aad.gov.au), Takuji Nakamura5, Michael Taylor6, Cristiano Wrasse2
1
British Antarctic Survey, Cambridge, United Kingdom, 2National Institute for Space Research (INPE), Sao Jose
dos Campos, Brazil, 3Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 4Australian Antarctic
Division, Kingston, Australia, 5National Institute of Polar Research, Tachikawa, Japan, 6Utah State University,
Logan, United States

Atmospheric gravity waves play a fundamental role in transporting energy and momentum between
atmospheric regions and drive circulations that affect key processes like the formation of the ozone hole and
the cold summer polar mesosphere. Despite their importance, gravity-wave activity over Antarctica suffers
from a lack of comprehensive observations. The ANtarctic Gravity Wave Instrument Network (ANGWIN) is a
highly successful grassroots programme that was started in 2011. It seeks to use a network of observations to
measure gravity waves continent wide and through all levels of the atmosphere, in order to fully understand
their impact and to constrain modelling work. Although initially focused on the Antarctic, the group is now
aiming to develop collaborations in both Polar Regions.
ANGWIN is an international network, supported by activities based in Australia, Brazil, Japan, Korea, the United
Kingdom and the United States of America.
The objectives of the ANGWIN network include: Quantify the longitudinal variation in gravity-wave activity and
determine causes; Characterise wave propagation and influence; Relate observed gravity waves to sources
throughout the atmosphere; Study the interaction of gravity waves with global scale waves; Compare polar
wave observations to model parameterizations; Determine the effects of gravity waves on polar stratospheric
cloud formation.
This poster will describe the ANGWIN network, its objectives and some recent results.

822
Wed_41_AC-4_578
Simultaneous Observations for Neutral Winds and Ion Drifts at JBS, Antarctica

Geonhwa Jee1 (ghjee@kopri.re.kr), Changsup Lee1, Nikolay Zabotin2, Terry Bullett2

1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2University of Colorado, Boulder, United
States

It is well known that the thermospheric winds are mainly driven by the ionospheric plasma convection in the
polar region. However, it was observed that there are significant differences between thermospheric winds and
ion drifts in the polar cap region. The ionosphere and the thermosphere have been simultaneously observed by
Vertical Incidence Pulsed Ionospheric Radar (VIPIR) and Fabry-Perot Interferometer (FPI), respectively, at Jang
Bogo Station, Antarctica, which is located in the polar cap region. Using these unique observations, we
investigate how much the thermospheric winds are affected by ion drifts in the southern polar cap region. In
this study, we will present the response time, relative velocity and direction of thermospheric winds with
respect to ion drifts as well as the physical characteristics in the polar cap region during the observation
periods.

823
Wed_42_AC-4_640
Climatological Behaviours of the Total Electron Content over Antarctica

Nicolas Bergeot1 (nicolas.bergeot@oma.be), Jean-Marie Chevalier1

1
Royal Observatory of Belgium, Brussels, Belgium

The understanding of the impact of solar activity on polar regions upper atmosphere is not as strong as
compare to low and mid-latitudes due to lack of experimental observations, especially over Antarctica.
To characterize the differences in the ionosphere-plasmasphere total electron content (TEC) climatological
patterns over Antarctica, we reprocessed the GNSS (GPS + GLONASS) data available since 1999 up to now for
stations situated at latitudes below S50°. For that, we used the data from POLENET/IGS networks and stations
installed around the Princess Elisabeth polar Base (Utsteinen, North-East Antarctica).
The estimated TEC data set is then employed to constrain an empirical model to predict the TEC from F10.7P
solar index in entrance using a least-square adjustment. To minimize the differences between the modelled
and observed vTEC we considered: (1) an eight-order polynomial function with monthly coefficients between
the TEC and F10.7P; (2) a discretization with respect to different zones over Antarctica region to highlight
different climatological patterns; (3) different time definitions such as Solar Local Time, Magnetic Local Time,
and UTC.
From the output of this model we discuss the different climatological behaviors identified in the ionosphere-
plasmasphere TEC at these high latitudes. Finally, we show some examples of typical TEC disturbances
observed during extreme solar events.

824
Wed_43_AC-4_755
ULF Geomagnetic Activity and Atmosphere Dynamics in the Southern Polar Cap

Patrizia Francia1 (patrizia.francia@aquila.infn.it), Mauro Regi1, Marcello De Lauretis1, Gianluca Redaelli1

1
University of L'Aquila, Department of Physical and Chemical Sciences, L'Aquila, Italy

We investigated the possible coupling between geomagnetic activity and the low atmosphere dynamics in the
polar cap. To this purpose, we compared the ULF geomagnetic activity, computed from geomagnetic field
measurements at Terra Nova Bay (Antarctica, corrected geomagnetic latitude λ ~ 80°S), with several
atmospheric parameters (temperature, zonal wind, specific humidity and cloud cover) obtained from re-
analysis dataset. We used data collected in the years 2003-2007. We found a statistically significant
correspondence of temperature and zonal wind fluctuations in the stratosphere and troposphere (greatly
reduced at the tropopause height) with geomagnetic ULF power fluctuations at the ~27 day periodicity, related
to the Sun's rotation period. We observed a similar, clear relationship between the atmospheric parameters
and the polar cap potential difference.
We also found that the atmospheric parameters significantly change following the increase of geomagnetic
activity within 1-2 days. These changes are evident in particular when the interplanetary magnetic field is
oriented southward with the azimuthal component duskward. We suggest that both the precipitation of
electrons induced by ULF activity, and the intensification of the polar cap potential difference, modulating the
microphysical processes in the clouds, can affect the atmosphere conditions.

825
Wed_44_AC-4_772
ICT Framework for Field Acquisition and Processing of GNSS Data in Polar Regions

Luca Pilosu1 (pilosu@ismb.it), Giorgio Giordanengo1, Olivier Terzo1, Vincenzo Romano2, Ingrid Hunstad2,
Umberto Apponi3
1
Istituto Superiore Mario Boella, Torino, Italy, 2Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy,
3
SpacEarth Technology, Roma, Italy

The scientific research community dealing with polar regions is increasing its interest in ICT solutions allowing
to overcome the strong environmental limitations of these areas in terms of power, data exchange and
computing infrastructures.
The “Upper atmosphere observations and Space Weather” project, developed under the SCAR GRAPE (GNSS
Research and Application for Polar Environment) expert group, aims to extend the GNSS measurements to new
sites for the assessment of the delay and corruption induced by the ionosphere on satellite signals in polar
regions.
On-field data are acquired by means of an energetically autonomous prototype with pre-processing capabilities
(called GreenLab), which has been successfully installed in Antarctica, close to the italian base “Mario
Zucchelli”, which is able to send data to the base station by means of an innovative smart antenna.
Data can then be further processed exploiting the cloud computing federated infrastructure already deployed
in DemoGRAPE project and leveraging the Linux Containers technology (i.e. Docker) to run applications where
data are stored, thus avoiding to move large amounts of data.
These two main blocks, the GreenLab and the federated cloud infrastructure, constitute a complete ICT
framework for data acquisition and management, which could be a reference architecture for several scientific
topics dealing with polar regions.

826
Wed_45_AC-4_779
Scintillation Studies in the GPS Era - What Went Wrong in the Last 10 Years?

Jayachandran Thayyil1 (jaya@unb.ca), Anthony McCaffrey1

1
University of New Brunswick, Physics, Fredericton, Canada

Global Navigation Satellite Systems (GNSS), including the Global Positioning System (GPS) support a wide range
of civilian and military applications, and have become indispensable in precise positioning and time keeping. As
our society moves towards a state characterized by an increasing dependence on space technologies, and since
our environment affects our daily life like never before, understanding the Solar-Terrestrial interaction, and its
impact on the geo-space environment, has become critical to the well being of our modern technology-
dependent society.
Scintillation, random rapid fluctuations of the trans-ionosphere radio signal, is caused by the refractive and
diffractive properties of the medium, and the structures within it. Understanding the generation and dynamics
of these irregularities will in turn help model/forecast this physical phenomenon, and mitigate it if possible.
Over the last few years we have been focussing on the scintillation indices to develop a better understanding of
the underlying physics of the scintillation producing irregularities, and attempt to develop predictive models.
However, we believe that relying on such indices may very well be the wrong approach. We will show with
evidence, using very high sampling rates (50 &100 Hz), that the conventional approach relying on the
conventional indices led us down the wrong path. We will propose a new approach to study the micro-physics
of scintillation producing ionospheric structures.

827
Wed_46_AC-4_1624
Impact of Solid Earth Tide Model Error on Tropospheric Zenith Delay Estimates

Shengkai Zhang1 (zskai@whu.edu.cn), Jintao Lei1, Fei Li1, Chao Ma1, Weifeng Hao1, Dongchen E1, Qingchuan
Zhang1
1
Wuhan University, Wuhan, China

The elastic response of the crust due to the external Tide Generating Potential (TGP) is called the solid Earth
tide, which can result in periodic 3-dimension displacements of a point on Earth's surface. To demonstrate how
'error' in the modelling of the solid Earth tide affects the estimates of tropospheric zenith total delay (ZTD) and
how it propagates into long-period signal in the daily GPS time series, we analyze GPS observations collected
between 2009 and 2013 for 13 sites in the coastal regions around Antarctica using GAMIT/GLOBK 10.6
software. Satellite orbital parameters, 2-hour tropospheric zenith delays, atmospheric gradients and Earth
orientation parameters are estimated along with site coordinates. Two solutions are generated with or without
the inclusion of K1 correction in the frequency domain of IERS2003 model, while all other processing strategies
are held constant. We show the differenced time series of both the ZTD estimates and site coordinates, along
with their corresponding admittances (ratio of amplitude of output signal to amplitude of input signal). In such
a way, we conclude that ZTD differenced time series, with amplitude at the 2 mm level, have inverse
correlation with the input K1 error, and the corresponding admittances range from 6% to 14%; Propagated
spurious annual signals are evident in the vertical component of coordinate differenced time series, with
amplitudes at the mm level and admittances of around 2% to 11%.

828
Wed_47_AC-4_1772
Fast Dynamic of Polar Ionosphere from GNSS SDR High Sampling Rate Measurements

Claudio Cesaroni1 (claudio.cesaroni@ingv.it), Lucilla Alfonsi1, Luca Spogli2, Nicola Linty3, Fabio Dovis3, Antonio
Cicone4, Mirko Piersanti4, Pierre Cilliers5
1
INGV, Environment, Rome, Italy, 2INGV, Rome, Italy, 3Politecnico di Torino, Torino, Italy, 4Università di L’Aquila,
L'Aquila, Italy, 5SANSA, Cape Town, South Africa

Software Defined Radio (SDR) receivers are able to process Intermediate Frequency (IF) signals acquired by a
front-end in order to generate Global Navigation Satellite Systems (GNSS) In-phase and Quadrature amplitude
values at very high sampling rate (up to 1000 Hz). The analysis of GNSS signals at frequencies higher than the
usual 50 Hz, provided by the traditional ionospheric scintillation receiver monitor, gives the possibility to
describe the dynamics of the scintillation driven irregularities spanning a wider time scales range. In this work,
a new spectral decomposition analysis technique named Adaptive Local Iterative Filter (ALIF) is applied to the
data provided by a GNSS SDR developed by Politecnico di Torino in order to highlight the contributions to the
scintillations characterized by frequencies higher than 50 Hz. The objective is to relate such contributions to the
very fast dynamics processes typical of the ionosphere at polar regions that are not caught using the very well-
known scintillation indices S4 and sf that is calculated on 50 Hz samples. Results on scintillation case events
using data from both SDR and Septentrio PolaRxS receivers installed in the South African Antarctica station
SANAE IV (71° 40' S, 2° 50' W) in the framework of the DemoGRAPE project are here presented.

829
Wed_48_AC-4_1887
A View from Geomagnetic Observation Points along the 80°S Parallel in Antarctica

Lucia Santarelli1 (lucia.santarelli@ingv.it), Stefania Lepidi1, Lili Cafarella2, Domenico Di Mauro2

1
Istituto Nazionale di Geofisica e Vulcanologia (INGV), L'Aquila, Italy, 2Istituto Nazionale di Geofisica e
Vulcanologia (INGV), Roma, Italy

Contributions to the knowledge of the Earth's magnetism from polar regions is extremely important to
understand the magnetospheric dynamics because local field lines reach extreme magnetospheric regions
where the interactions with the solar wind occurs. The Earth's magnetic field shows temporal variations which
go from seconds to hundreds of thousands of years. We study low frequency fluctuations (approximately in the
Pc5 range, ~1-7 mHz).
INGV has a consolidated experience in Antarctic research activities and in management of permanent
geomagnetic observatories as Mario Zucchelli (MZS, at Terra Nova Bay) and Concordia (DMC, at DomeC)
stations, as well as temporary installations as Talos Dome (TLD), installed during 2007-2008 Antarctic campaign
and working for a few months. The availability of simultaneous measurements from MZS, TLD and SBA (Scott
Base), allows to make an interesting comparison in that the three stations are located approximately at the
same geomagnetic latitude (~ 80°S), with approximately 2 hours total displacement in magnetic local time. This
location is particularly useful to study the signal propagation in the azimuthal direction. We review the results
obtained so far from the analysis of diurnal variation, coherence, power and propagation direction of Pc5
pulsations observed along the 80°S geomagnetic parallel, underlying the importance of such observational
point, in anticipation of the future installation of a new geomagnetic station at TLD.

830
Wed_49_AC-4_2316
Studies of Antarctic Atmospheric Dynamics by a Large Aperture Atmospheric Radar

Kaoru Sato1, Masaki Tsutsumi2, Toru Sato3, Takuji Nakamura2 (nakamura.takuji@nipr.ac.jp), Akinori Saito3,
Yoshihiro Tomikawa2, Koji Nishimura2, Masashi Kohma1, Taishi Hashimoto3
1
University of Tokyo, Tokyo, Japan, 2National Institute of Polar Research, Tachikawa, Japan, 3Kyoto University,
Kyoro, Japan

A large-aperture atmospheric radar, PANSY (Program of the ANtarctic SYowa Mesosphere, Stratosphere, and
Troposphere/Incoherent Scatter [MST/IS] Radar) radar, was constructed at Syowa station (69S, 39E) during the
2010-11 austral summer (Sato et al., 2014). Valuable atmospheric data in Antarctic troposphere, stratosphere
and mesosphere has been being accumulated based on continuous operation using a quarter system since
early 2012 and the full system since late September 2015. Such continuous observation data set using a full
MST/IS radar system is the first of its kind in the world. It will enable us to capture various temporal- and
spatial-scale phenomena in the Antarctic atmosphere with high temporal and vertical resolutions throughout
the year and to contribute to improving global climate models for better understanding of future climate
change.
The Japanese Antarctic Research Expedition (JARE) is currently in a six-year long research project, Phase IX
(2016-2021). The main scientific theme, “Investigation of changes in the Earth system from Antarctica”, has
been launched in Phase IX. The PANSY radar is the core facility of one of the three projects in the main theme,
“The global atmosphere system explored by precise observations of the Antarctic atmosphere”, which
combines various radio and optical instruments for comprehensive understanding of the whole atmosphere. In
this paper, recent studies using the PANSY radar are reviewed.

831
Wed_50_AC-4_2561
Effects of Energetic Particles Transfer and Precipitation in High Latitude

Anand K Singh1 (aksncaor@gmail.com), Shailendra Saini1, Rashmi Rawat1

1
National Centre for Antarctic & Ocean Research (ESSO-NCAOR), Space Weather Studies, Vasco DA Gama, India

Quantitative evaluation of energy transfer in and around the auroral oval under the influence Solar plasma
ejection and the electromagnetic status of the interplanetary medium were carried out on the ground based
data collected at the stations in Dronning Maud Land, Enderby Land and Princess Elizabeth Land of Antarctica.
Geomagnetic storms with negative and positive vertical component of interplanetary magnetic field were
chosen for evaluation. This evaluation of the release and transfer of energy due to drifting or injection of
energetic particles during various geomagnetic conditions may give us ability to identify critical inputs of the
dynamics of the entry of energetic charged particles into the polar upper atmosphere. Moreover geomagnetic
quiet time enhancement of total electron content shows the indirect energy transfer in polar ionosphere from
magnetotail along the field lines. The drifted energetic particles and subsequent precipitation of energetic
particles in the sub-auroral, auroral and polar region gives the estimated time delay, span and duration of
ionospheric irregularities. Thus dynamics of energy transfer and drift of energetic charged particles in polar
upper atmosphere that involved in linking the entire system, under the influence of interplanetary magnetic
field were analysed which begins at the Sun and ends on the Earth.

832
Wed_51_AC-4_2624
Storm-time Ionospheric Convection in the Central Polar Cap

Jianjun Liu1 (liujianjun@pric.org.cn), Hongqiao Hu1

1
Polar Research Institute of China, Polar Atmospheric and Space Physics, Shanghai, China

Observations of the ionospheric convection during a storm main phase on 9th September 2011 were examined.
Measurements were obtained by three SuperDARN radars (ZHO, SYE and MCM) located in the southern
hemisphere, the conjunction of these 3 radars plays an important role in revealing the dynamic process in
magnetosphere-ionosphere coupling system. During the storm period, MCM radar scanning polar cap
ionosphere monitored sequential strong antisunward large-scale plasma irregularities, which clearly presents
the polar cap patches moving across the pole to the nightside and eventually into the the nightside auroral oval
in quasi-periodical variation. While the ZHO radar recorded intense ionospheric backscatter echo power and
moderate Doppler negative velocity in the poleward boundary of the nightside auroral oval, and simultaneous
observation by the optical auroral imager did not get aurora data. In the duskside sector, Doppler velocity
monitored by the SYE showed irregular plasma structures towards or away from the radar site. Furthermore,
ionospheric digisonde at Zhongshan station observed strong spread F during the storm main phase. For this
kind of event, coordinated observations suggest that the ionospheric convection dominates the periodical
plasma transportation during typical disturbed geomagnetic environment.

833
Wed_52_AC-4_2696
Collaboration at the NOAA Atmospheric Baseline Observatories

Brian Vasel1 (brian.vasel@noaa.gov)

1
NOAA Earth System Research Laboratory, Global Monitoring Division, Boulder, United States

The NOAA Global Monitoring Division (GMD), based in Boulder, CO, has operated four long-term atmospheric
baseline observatories for over 40-years. These sites are located at Barrow, AK; Mauna Loa, Hawaii; Tula,
American Samoa; and South Pole, Antarctica. In addition, GMD previously operated observatories at Trinidad
Head, CA and at Summit, Greenland; however, both sites were downgraded from full baseline observatories in
2017 following a GMD reprioritization of global observing networks. These long-term sites with NOAA facilities,
technical staff, baseline atmospheric measurements, and meteorology, are also available to support
cooperative research proposals from the global community. The one exception being South Pole Station, as the
site is operated by the National Science Foundation and they approve science projects at the station. This
poster will detail measurements at the four sites, focusing on Barrow and South Pole, and encourage
collaboration. In addition, it will discuss the vision for the sites to become more “green” with added renewable
technologies and backup power and safety measures to ensure continuity of operations. Often emergency
plans from remote sites can be challenging and NOAA has various plans in place for each location. Finally, other
NOAA/GMD measurements from across the Artic and Antarctic will also be highlighted, including sampling sites
in: Canada, Greenland, Norway, Russia, Finland, and the Antarctic Peninsula.

834
Wed_53_AC-7_301
Polar Lows and Climate Change

Helene Bresson1 (h.m.e.bresson@pgr.reading.ac.uk), Kevin Hodges1, Len Shaffrey1, Giuseppe Zappa1

1
University of Reading, Department of Meteorology, Reading, United Kingdom

Polar lows (PLs) are intense mesoscale cyclones (diameter of 200-600km) that form at high latitudes during
winter. Their wind speeds (above 15m/s) can substantially impact on and offshore activities. PLs may have an
impact on deep-water formation, and thus affect the Atlantic Meridional Overturning Circulation (AMOC),
which suggests that PLs are important for the climate system. However, there are still large uncertainties in
their frequency, spatial distribution and response to climate change. Previous studies showed that PLs may
experience a decrease in the future over the North Atlantic Ocean, due to a future increase in static stability
caused by a faster increase in sea surface temperatures compared to the increase in mid-tropospheric
temperatures. This decrease would imply a reduction of PLs impact on deep ocean convection with the
concomitant weakening of the AMOC. To investigate PLs possible future changes, the UPSCALE dataset is used:
a series of ensemble simulations of the HadGEM3 global atmosphere-only model at resolutions of 130, 60 and
25km for present climate conditions and a potential future climate scenario, the IPCC RCP 8.5 scenario. The aim
is to explore how PLs might respond to climate change and how this response may be affected by the model
resolution. The 25km results will be compared to the PL climatology previously analyzed from the coupled
climate model HadGEM3-CG2. Results will be presented on PLs representation for the current and future
climates.

835
Wed_54_AC-7_1211
Advanced Prediction in the Arctic and Beyond: The APPLICATE Project

Thomas Jung1 (thomas.jung@awi.de)

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

The Arctic is changing rapidly carrying the potential to influence weather and climate in mid-latitudes. It is
therefore crucial to predict these changes and their impacts. Recognizing this priority, a European consortium
of scientists set out to advance our capability to predict the weather and climate in the Arctic and beyond in
the framework of the EU-funded project APPLICATE. The project aims to improve the representation of key
processes in coupled atmosphere-sea ice-ocean models, in order to deliver enhanced numerical weather
forecast, seasonal to interannual climate predictions and centennial climate projections. The linkages between
the Arctic and mid-latitudes is explored through a coordinated multi-model approach using coupled
atmosphere-ocean models. APPLICATE will also provide guidance for the design of the future Arctic observing
system to improve our capacity to reanalyse the climate system and enhance models' predicting skills.
The APPLICATE Consortium is also engaging in clustering activities to exploit synergies with other programs. On
the European level we participate in the EU Arctic Cluster, but we also have strong links with North American
partners (e.g., US CLIVAR), and several other international projects (e.g., the Polar Prediction Project, MOSAiC).
In this presentation, we will give an overview of APPLICATE activities as part of our effort to understand
changes in the Arctic and their far-reaching impacts for both environment and communities.

836
Wed_55_AC-7_1380
Lagrangian Meteorological Simulations to Study Polar Aerobiology

Sergi Gonzalez1 (sgonzalezh@aemet.es), Francisco Vasallo2, Ana Justel3, Julio Rodriguez3, Pablo Sanz4, Alberto
Luna4, Eugenio Rico5, David Velazquez6, Pablo Almela6, Samuel Cires6, Marcela Svarc7, Lucas Fernández7, David
Pearce8, Antonio Quesada6
1
Agencia Estatal de Meteorología, Grupo Antártico, Barcelona, Spain, 2Agencia Estatal de Meteorología, Grupo
Antártico, Rota, Spain, 3Universidad Autonoma de Madrid, Departamento de Matemáticas, Madrid, Spain,
4
Universidad Autonoma de Madrid, Centro de Computación Científica, Madrid, Spain, 5Universidad Autonoma
de Madrid, Departamento de Ecología, Madrid, Spain, 6Universidad Autonoma de Madrid, Departamento de
Biología, Madrid, Spain, 7Universidad de San Andres, Departamento de Matemáticas, Buenos Aires, Argentina,
8
Northumbria University, Department of Applied Sciences, Newcastle-upon-Tyne, United Kingdom

Aerial dispersal in polar regions is a booming issue because it provides new insights on biogeography and may
allow forecasting alterations in biodiversity in a global change scenario. Moreover, it is a major challenge due
to the difficulties of gathering representative samples of airborne propagules and tracking their paths to
estimate where they come from. As a result, this issue is nowadays poorly understood. To improve our
knowledge on this topic a multidisciplinary project is being conducted to fill this gap at three different scales:
local, regional and global, in both polar regions.
There are a variety of strategies to track the airborne propagules into the atmosphere, each one with specific
advantages and disadvantages. In this communication we focus on the simulation of the trajectory of a single
particle into the atmosphere on the assumption that propagules transit altogether. Thousands of simulations
have been conducted using HYSPLIT model with different configurations and input data for each specific
requirement.
We present some of these experiments: backward trajectories at sampling sites in Byers peninsula, trajectories
of the air parcels reaching the ship during the Antarctic Circumpolar Expedition and the WindSled during the
Ice River Greenland Expedition, and a lagrangian climatology of trajectories over the Southern Ocean.
Trajectories simulated are widely dispersed with some preferential directions that will be analyzed using
clustering techniques.

837
Wed_56_AC-7_1482
The Contribution of Natural Variability to Recent Sea-ice Loss across the Arctic

Mark England1 (mre2126@columbia.edu), Lorenzo Polvani1,2, Alexandra Jahn3

1
Columbia University, Applied Physics and Applied Mathematics, New York, United States, 2Lamont-Doherty
Earth Observatory of Columbia University, New York, United States, 3University of Colorado, Department of
Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, Boulder, United States

The total extent of Arctic sea ice over the last half century has dramatically declined, at a rate of nearly 5% a
decade, with yearly Arctic sea ice minimums in each of the last five years being at least two million square
kilometres below the mid 20th century average. Focusing on the total sea extent over the Arctic polar cap,
several recent studies have shown that only approximately half of the recent loss is anthropogenically forced,
suggesting that internal (i.e. unforced) variability may be responsible for the remaining half. Analysing 40
historical runs of the CESM Large Ensemble over the period 1950-2015, we here ask whether the relative
contributions of anthropogenic forcing and natural variability to September sea ice loss over that period have a
robust regional structure. We find a large spread in regional patterns of September sea ice loss across the Large
Ensemble: however, these patterns are well captured by the leading EOFs of internal variability, highlighting
two key regions, which have experienced the largest September trends in recent decades: the East Siberian Sea
and the Barents Sea. We will discuss our findings detailing for which regions the forced response is dominant
and for which regions internal variability is more important. Implications for future trends and for potential
impacts on the mid-latitudes will be discussed.

838
Wed_58_AC-7_1799
Estimating Changes in the Collins Glacier, King George Island, Antarctica

Carina Petsch1 (carinapetsch@gmail.com), Kátia Kellem da Rosa1, Rafaela Mattos Costa1, Matthias Holger
Braun2, Jefferson Cardia Simões1
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Porto Alegre, Brazil, 2Friedrich Alexander-
Universität Erlangen-Nürnberg, Erlangen, Germany

This work proposes future scenarios for the extent of the Collins Glacier (King George Island, Antarctica) and for
hydrogeomorphological changes in its periglacial environment. We used a method based on ellipsoidal height
changes to estimate modifications in this ice mass up to 2067. We assume insignificant ice flow, refreezing and
basal melting, and the same climatic conditions of the period 1998-2009. The ice mass will continue to retreat
in all sectors, if the current regional warming trend is maintained, and the periglacial ice-free zone will increase
by 4.5 km². The current area of the glacier is 15 km² and according to this scenario can reach 10.5 km². The
local hydrological system will be strongly modify, mainly in the Maxwell Bay area, and a proglacial lake formed
in the last 30 years may disappear by then, influencing the patterns of sedimentary deposition and local
erosion. The new ice-free area may develop a new meltwater stream system at the ice margin, forming lakes
and wetlands, increasing chemical weathering, creating soils favouring the fixation and expansion of
vegetation. In short, the expected changes may cause a rapid change from proglacial to periglacial
environment.

839
Wed_59_AC-7_2026
Probabilistic Projections of Annual Runoff and Hydropower Production in Finland

Elena Shevnina1 (elena.shevnina@fmi.fi), Andrey Silaev2, Timo Vihma1

1
Finnish Meteorological Institute, Helsinki, Finland, 2National Research University Higher School of Economics,
Nizhny Novgorod, Russian Federation

Social, economic and environmental benefits of forecasts of weather and climate are obvious.Among others,
risks in hydroenergy production are usually connected to extremes, which can be estimated from projected
exceedance probability curves (EPCs) of annual runoff.The exceedance probability indicates the likelihood that
a particular annual runoff value will be exceeded. In our study the EPCs of annual runoff were applied to
evaluate the potential hydropower production in Finland. The climate related changes in hydroelectric
production of the existent plants were estimated based on the the EPCs of annual runoff at catchment and
regional scales.

840
Wed_60_AC-7_2438
Recording, Predicting and Responding to Rapid Environmental Change in Siberia

Henry Burgess1 (henry.burgess@bas.ac.uk), Terry Callaghan2,3, Aleksandr Sokolov4, Alexey Titovsky5, Sergey
Kirpotin6
1
NERC/ British Antarctic Survey, NERC Arctic Office, Cambridge, United Kingdom, 2University of Sheffield,
Sheffield, United Kingdom, 3Tomsk State University, Tomsk, Russian Federation, 4Institute of Plant and Animal
Ecology, Ural Branch, Russian Academy of Sciences, Arctic Research Station, Labytnangi, Russian Federation,
5
Government of Yamal Nenets Autonomous District, Director, Department of Science and Innovations,
Salekhard, Russian Federation, 6Tomsk State University, Head of the BioClimland Centre of Excellence, Tomsk,
Russian Federation

The pace and depth of environmental change across the largest terrestrial region of the Arctic - Siberia - is
dramatic. The impact of vegetation alteration across the taiga and tundra zones; changes in biological
productivity and hydrology; and the resulting impact on fauna, especially those relied upon by Indigenous and
local people, is combining to create environmental and human impacts with local, regional and global effect. .
More than ever there is a need for researchers, authorities and Indigenous and local people to work together
to record, predict and adapt to environmental change. Over the last two years the Siberian Environmental
Change Network of Tomsk State University, The Government of the Yamal-Nenets Autonomous District, the UK
Science and Innovation Network, and the EU INTERACT trans-national access programme together with other
international partners and senior Indigenous peoples´ representatives have brought together interested
stakeholders to put in place effective monitoring which addresses the needs and skills of local people and
researchers, most recently in the context of winter weather and climate extremes.
The Abstract will present the findings from the last two practical workshops; suggest a range of promising
approaches; identify emerging good practice; and set out the next steps. Attendees will see how international
cooperation is combining with local knowledge to create meaningful practical action and important research.

841
Wed_62_AC-6_339
Glaciological Changes on the Northern Antarctic Peninsula

Thorsten Seehaus1, Sebastian Marinsek2, Alison Cook3, Jan Melchior van Wessem4, Matthias Braun1
(matthias.h.braun@fau.de)
1
Friedrich-Alexander-Universität Erlangen-Nürnberg, Geography, Erlangen, Germany, 2Instituto Antártico
Argentino, Buenos Aires, Argentina, 3Durham University, Geography, Durham, United Kingdom, 4Utrecht
University, IMAU, Utrecht, Netherlands

During the last decades the climatic conditions along the Antarctic Peninsula have undergone significant
changes. Consequently, the glacial systems along the Antarctic Peninsula reacted with widespread retreat,
surface lowering as well as variations in flow speeds. Moreover, numerous ice shelves along the Antarctic
Peninsula retreated, started to break-up or disintegrated completely. The aim of this work is to study the
reaction of glaciers at the northern Antarctic Peninsula to the changing climatic conditions and the
readjustments of tributary glaciers to ice shelf disintegration, as well as to better quantify the ice mass loss and
its temporal changes.
We analysed time series of various satellite sensors (ERS-1/2, ENVISAT, RADARSAT-1, ALOS, TerraSAR-
X/TanDEM-X, ASTER, Landsat) to detect changes in ice dynamics of glacier along the northern Antarctic
Peninsula (< 65°). Intensity feature tracking techniques were applied on data stacks from different SAR
satellites over the last 20 years to infer temporal trends in glacier surface velocities. In combination with ice
thickness reconstructions and modeled climatic mass balance fields regional imbalance were calculated.
The detailed multi-mission time series analysis of glacier changes supports the interpretation of the ongoing
processes in this region and allows multi temporal imbalance estimates.

842
Wed_63_AC-6_350
First Detailed Quantification of Glacier Elevation Changes on South Georgia

David Farías1 (david.farias@fau.de), Christian Sommer1, Thorsten Seehaus1, Philipp Malz1, Gino Casassa2,
Matthias H. Braun1
1
Friedrich Alexander-Universität Erlangen-Nürnberg, Institute of Geography and Geosciences, Erlangen,
Germany, 2Universidad de Magallanes, Punta Arenas, Chile

Glaciers are frequently regarded as indicators of climate change, several studies indicate that most of the
glaciers worldwide are retreating. In the Southern Hemisphere glacier mass balance information is scarce.
Therefore, this gap of information generates an uncertainty about the current status of glaciers. South Georgia
is the largest subantarctic islands, lying south of the Antarctic polar front. About of 56% of the surface is
glacierized. Previous studies carried out on South Georgia have shown heterogeneous pattern of glacial
advance and retreat over time. However, mass balance data is lacking for this region. Our focus in this study is
to derive glacier surface elevation changes using SRTM-C band and TanDEM-X bistatic SAR-data for the period
2000-2012/13. This information is used to obtain the first detailed quantification and interpretation of glacier
elevation and mass change on South Georgia.

843
Wed_65_AC-6_770
Glacier Velocity and Ice Thickness Measurements on James-Ross-Island, Antarctica

Stefan Lippl1 (stefan.lippl@fau.de), Norbert Blindow1, Sebastián Marinsek2, Thorsten Seehaus1, Matthias Braun1
1
Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, 2Instituto Antártico Argentino, Buenos
Aires, Argentina

In this poster we present glacier velocities (by remote sensing and field data) as well as ice thickness
measurements (by an airborne 25 MHz ground penetrating radar) on Gourdon Glacier (James Ross Island,
Antarctica).
James Ross Island is located east from the northern Antarctic Peninsula in a region which has undergone
considerable changes in the last decades with the retreat or disintegration of several ice shelves. The glaciers of
James Ross Island have shown predominantly retreat over the last decades while some glaciers showed also
advance. In this context, we investigate the glacier dynamics and mass changes on James Ross Island using
different approaches: geodetic glacier mass balances and the flux-gate approach (input-output method).
A comprehensive set of field observation (surface mass balance, time lapse camera, automatic weather
stations, permanent GPS recorders) is run over several years. Additionally, a detailed remote sensing data
analysis of the temporal evolution of velocities is carried out.
In order to improve the ice flux estimates we started a comprehensive airborne ground penetrating radar (GPR)
campaign on Gourdon Glacier in February 2017. Ice thickness and elevation data were collected on more than
50 km of profiles with ice thicknesses of up to 350 m. Further measurements are planned for February 2018
and will include repetitions of profiles flown by previous ice thickness surveys in order to evaluate potential
changes in the accumulation area.

844
Wed_66_AC-6_1596
The 1979 Barrier to Antarctic and Southern Ocean Climate Reanalysis

David Bromwich1 (bromwich@polarmet1.mps.ohio-state.edu), Julien Nicolas1

1
Ohio State University, Byrd Polar and Climate Research Center, Columbus, United States

Since the very first global atmospheric reanalysis projects in the early 1990s, handling the ever-changing
observing system has proved an important and recurring challenge to producing temporally consistent
reanalysis datasets. The problem has been exacerbated over Antarctica and the Southern Ocean by the data
scarcity characteristic of these regions. Important changes in the type and/or availability of observations (most
notably the massive input of satellite data in the late 1970s) have produced major artifacts in the reanalysis
time series in high southern latitudes. Reanalysis projects going back to the early 1900s have sought to achieve
greater temporal homogeneity in the observing system by assimilating only a limited set of conventional
observations. In these instances, however, the prescription of unrealistic sea-ice conditions prior to 1979 and
the rapidly decreasing density of surface observations poleward of 60S prior to the 1980s have again resulted
in significant inhomogeneities and spurious trends in the time series. Overall, these issues have severely
reduced the usefulness of reanalysis products for Antarctic and Southern Ocean studies prior to 1979 and
limited our understanding of long-term climate changes in these remote regions. Here, we reassess the skills of
global reanalyses in high southern latitudes, take stock of recent improvements, and offer some
recommendations for addressing some recurring issues and ultimately helping bridge the 1979 barrier.

845
Wed_67_AC-6_1600
Surface Air Temperature Trends Across the Southern High and Middle Latitudes

Megan Jones1, David Bromwich1 (bromwich@polarmet1.mps.ohio-state.edu), Julien Nicolas1, Jorge Carrasco2

1
Ohio State University, Byrd Polar and Climate Research Center, Columbus, United States, 2Universidad de
Magallanes, Departamento Programas Antárticos y Sub-antárticos, Punta Arenas, Chile

Recent studies have concluded that overall warming trends in Western Antarctica since the 1950s, as well as
the cooling in more recent years, are within the bounds of natural variability. We want to provide a more
comprehensive and widespread picture of how surface temperatures are changing throughout recent decades
across much of the Southern Hemisphere mid- and high-latitudes. The study includes station observations from
the entire Antarctic continent, mid-latitude island stations, South America, South Africa, southern Australia,
and New Zealand. Using seasonal and yearly temperature anomalies, our goal is to determine the trends and
their statistical significance and then investigate the drivers behind them, using time periods of various lengths
to determine the longevity of said drivers. Teleconnections being considered include the Southern Annular
Mode and the El Nino Southern Oscillation, due to their known influence on the Southern Hemisphere climate.

846
Wed_68_AC-6_1725
Isotopic Composition of Atmospheric Water Vapor around Antarctica

Anna Kozachek1 (kozachek@aari.ru), Alexey Ekaykin1,2, Amaelle Landais3, Vladimir Lipenkov1, Hans Christian
Steen-Larsen4
1
Arctic and Antarctic Research Institute, Climate and Environmental Research Laboratory, Saint Petersburg,
Russian Federation, 2Saint Petersburg State University, Saint Petersburg, Russian Federation, 3Laboratoire des
Sciences du Climat et de l'Environnement, Gif-sur-Yvette, France, 4Center for Ice and Climate, Niels Bohr
Institute, University of Copenhagen, Copenhagen, Denmark

It is well-known that the isotopic composition of the ice cores is a proxy for the temperature change at the
drilling site. However, several studies showed that there are many other factors influencing the ice cores data.
One of these factors is the isotopic composition of water and water vapour at the site of the airmass formation.
In order to separate these factors we carried out continuous measurements of the isotopic composition of
water vapor over the ocean surface during the Antarctic Circumnavigation Expedition (ACE) 2016/17.
For the measurements on board of the ship, two water vapor isotope analyzers (Picarro L2120-i and Picarro
L2130-i) were used equipped with two types of calibration devices. This helped to obtain robust and accurate
results. As a by-product result we present comparative characteristics of different types of equipment.
This data is also combined with the previously published results (see review in Galewsky et al., 2016). Here we
present the results of these data analysis combined with the meteorological observations and air mass
trajectories calculations.
The research was possible due to funding from EPFL, Swiss Polar Institute and Ferring Pharmaceuticals. We
thank Picarro Inc. for providing us with the Picarro L2130-i and Standard Delivery Module.

847
Wed_69_BE-6_212
Lake Bonney High Resolution 3D Structure using an Autonomous Underwater Vehicle

Robert Spigel1, Peter Doran2 (pdoran@lsu.edu), John Priscu3, Maciej Obryk2, William Stone4
1
National Institute of Water and Atmospheric Research (NIWA), Christchurch, New Zealand, 2Louisiana State
University, Baton Rouge, United States, 3Montana State University, Bozeman, United States, 4Stone Aerospace,
Austin, United States

We used an Environmentally Non-Disturbing Under-ice Robotic ANtarctic Explorer (ENDURANCE) to make

measurements of conductivity and temperature in Lake Bonney, in Taylor Valley. The lake is divided into two
lobes - East Lobe Bonney (ELB) and West Lobe Bonney (WLB), each with unique temperature and salinity
profiles. Most of our data were collected in November 2009 from WLB to examine the influence of the adjacent
Taylor Glacier on the structure of the water column. Temperatures adjacent to the glacier face between 20-22
m were 3°C colder than in the rest of WLB, due to latent heat transfer associated with melting of the
submerged glacier face and inflow of cold brines that originate beneath the glacier. Melting of the glacier face
into the salinity gradient below the chemocline generates a series of nearly horizontal intrusions into WLB that
were previously documented in profiles measured with 3 cm vertical resolution in 1990-91. WLB and ELB are
connected by a narrow channel through which water can be exchanged over a shallow sill that controls the
position of the chemocline in WLB. A complex exchange flow appears to exist through the narrows, driven by
horizontal density gradients and melting at the glacier face. Superimposed on the exchange is a net west-to-
east flow generated by the higher volume of meltwater inflows to WLB. Both of these processes can be
expected to be enhanced in the future as more meltwater is produced.

848
Wed_70_BE-6_558
Seasonal Dynamics in the Extreme Arctic: Ward Hunt Lake, Canada

Paschale N. Bégin1,2 (paschale-noel.begin.1@ulaval.ca), Yukiko Tanabe3, Warwick F. Vincent1,2

1
Centre d'Études Nordiques (CEN), Quebec City, Canada, 2Université Laval, Biology, Quebec City, Canada,
3
National Institute of Polar Research, Tokyo, Japan

Lake ecosystems occur along the far northern coast of the Canadian High Arctic, but almost nothing is known
about their seasonal dynamics. Ward Hunt Lake is Canada's northernmost lake, located on Ward Hunt Island
(lat. 83 °05'N, long. 74 °10'W), off Ellesmere Island, Nunavut. The lake is oligotrophic, and given its extreme
northerly location, is a potentially sensitive indicator of global climate change. Our aims were to determine the
structure and functioning of this remote aquatic ecosystem, and to better understand the nature and
implications of ongoing change. A mooring installed at the deepest point of the lake (10m) recorded
temperature, oxygen, chlorophyll fluorescence and underwater irradiance. This information was coupled with
images from an automated camera system to track the seasonal variations in ice cover from July 2016 to July
2017. The annual chlorophyll a maximum coincided with open water conditions in September when there was
increased light availability and water column mixing. Contrary to expectation, oxygen concentrations dropped
rapidly after ice-up, and anoxia was recorded in the bottom waters in December. The oxygen and temperature
records also revealed an internal wave pattern during the period of ice-cover. These high-resolution
measurements indicated large-amplitude temporal variations in biogeochemical processes despite the low-
nutrient status of this High Arctic ecosystem.

849
Wed_71_BE-6_612
Characterising Seasonal Water and Melting in the Ross Sea Region of Antarctica

Simon Christopher Cox1 (s.cox@gns.cri.nz), Pierre Roudier2, Fraser Morgan3

1
GNS Science, Dunedin, New Zealand, 2Manaaki Whenua Landcare Research, Palmerston North, New Zealand,
3
Manaaki Whenua Landcare Research, Auckland, New Zealand

Increased meltwater is a feature of nearly all models of Antarctica's future, and underpins analysis of
environmental and biological domains. We characterised surficial occurrences of water, or ice re-frozen from
meltwater, throughout the Ross Sea Region (RSR) using two important new datasets:
(1) a GeoMAP GIS defining exposed bedrock and glacial cover sequences, including 869 seasonal meltwater
accumulations;
(2) an Antarctic-wide datacube of daily land surface temperatures (LST) from 2003-2015, detected by MODIS
instruments at 1 km resolution.
Local temperature statistics were assigned to water occurrences to derive empirical thresholds for melting.
Water is only observed where average annual LST is > -35°C, but with significant regional differences in
conditions of meltwater occurrence. Growing degree days (GDD) above a temperature threshold, albedo and %
rock are key factors strongly correlated with meltwater. Probability that water is present or absent is modelled
across the RSR using a variety of environmental covariates weighted by correlation strength in a training
dataset. Environmental conditions were then adjusted and models re-run to forecast future conditions under a
warmer climate (LST +2ºC, GDD +30%). As well as defining where surficial water can be expected in future, the
study highlights the importance of regional-scale datasets to characterise cryosphere-lithosphere interactions,
and role geology may play on the melting of Antarctica.

850
Wed_72_BE-6_977
Seasonal Change of Photosynthesis of Phytobenthic Communities in Antarctic Lakes

Yukiko Tanabe1,2 (ukko@nipr.ac.jp), Nobuo Kokubun1,2, Kentaro Hayashi3, Nobuhide Fujitake4, Morimaru Kida4,
Sakae Kudoh1,2
1
National Institute for Polar Research, Biology Group, Tokyo, Japan, 2SOKENDAI (The Graduate University of
Advanced Studies), Tokyo, Japan, 3Institute for Agro-Environmental Sciences, Tsukuba, Japan, 4Kobe University,
Kobe, Japan

The most luxuriant vegetation is found in freshwater lakebeds as thick phytobenthic mats in East Antarctica.
Photosynthetic activities of phytobenthic mats are measured well in many lakes on Antarctica during summer,
whereas little is known about it for a period from autumn to spring. We collected phytobenthic mat samples
from Lake West Ongul (69°01′S, 39°33′E) in Sôya Coast, East Antactica once or twice per month throughout the
year except June, and from nine freshwater lakes (69°14′S-69°30′S, 39°33′E-39°47′E) in Sôya Coast, East
Antactica in both summer and early-spring, of which two lakes were a target of continuous monitoring of PAR
(photosynthetically active radiation) and temperatures underwater by installing mooring systems. Then, we
measured photosynthetic characteristics using a chlorophyll fluorescence instrument (Phyto-PAM, Walz) as
soon as possible after arrival in the base, and rest of the samples were frozen in the dark at -20°C for analyzing
the pigments composition as an index of light-utilization and photo-community composition. The
photosynthetic activities changed seasonally and are quite different between spring and summer, in addition to
this, the community compositions contributing to photosynthesis of the benthic mats changed depending on
the season.

851
Wed_73_BE-6_1582
Sub-daily Biogeochemical Cycling in Sediment from an Ephemeral Meltwater Stream

Joel Singley1,2 (joel.singley@colorado.edu), Michael Gooseff2,3, Eve-Lyn Hinckley1,2

1
University of Colorado, Environmental Studies, Boulder, United States, 2Institute of Arctic and Alpine Research,
University of Colorado, Boulder, United States, 3University of Colorado, Civil, Environmental, and Architectural
Engineering, Boulder, United States

Glacial meltwater streams are often characterized by diel fluctuations or cessation of flow, especially in regions
where the energy balance of the source glacier is alternately positive and negative throughout a day. These
characteristics drive a highly dynamic physical environment, in which stream sediment undergoes periodic
inundation and drying as channel flow varies. The role of long-term (i.e., seasonal to inter-annual) sediment
drying-rewetting on biogeochemical cycles has been studied extensively in temperate systems characterized by
wet and dry seasons. However, these relationship have remained understudied in systems characterized by
short-term (i.e., sub-daily to weekly) flow intermittency, as often occurs in glaciated environments. To advance
understanding of how short-term variations in physical conditions alter nutrient cycling (specifically, inorganic
nitrogen availability), we present preliminary findings on the spatiotemporal variability of pore-water chemistry
during diel pulsing in an ephemeral glacial meltwater stream (McMurdo Dry Valleys, Antarctica). We present
these results in the context of a laboratory rewetting experiment, high- and low-frequency stream nitrate
concentration data from the MDV Long-Term Ecological Research Project, and results from prior studies in
Arctic and Antarctic streams. Our results will inform understanding of sediment-channel interactions that
control nutrient transport and retention in polar and alpine ephemeral streams.

852
Wed_75_BE-6_1843
North American Arctic Freshwater Biodiversity Trends in a Changing Climate

Jennifer Lento1 (jlento@gmail.com), Christian Zimmerman2, Joseph Culp3, Daniel Bogan4, Bob Brua5, Stéphane
Campeau6, Krista Chin7, Jennie Knopp8, Sarah Laske2, Isabelle Lavoie9, Heather Mariash10, Michael Power11,
Kathleen Rühland12, Emilie Saulnier-Talbot13, Rebecca Shaftel4, John Smol12, Heidi Swanson11, Matthew
Whitman14
1
Canadian Rivers Institute and University of New Brunswick, Department of Biology, Fredericton, Canada, 2U.S.
Geological Survey, Anchorage, United States, 3Environment and Climate Change Canada @ Wilfrid Laurier
University, Waterloo, Canada, 4Alaska Center for Conservation Science, University of Alaska Anchorage,
Anchorage, United States, 5Environment & Climate Change Canada, Saskatoon, Canada, 6Université du Québec
à Trois-Rivières, Trois-Rivières, Canada, 7Government of Northwest Territories, Yellowknife, Canada, 8Oceans
North, Peterborough, Canada, 9Institut National de la Recherche Scientifique, Québec City, Canada,
10
Environment & Climate Change Canada, Ottawa, Canada, 11University of Waterloo, Waterloo, Canada,
12
Queen's University, Kingston, Canada, 13Université Laval, Québec City, Canada, 14Bureau of Land
Management, Anchorage, United States

Within the North American Arctic, the effects of climate change have led to more pronounced temperature
change in the west, with substantially more warming in Alaska and the Northwest Territories than along the
eastern coast of Nunavut. Though records of increased temperatures and increased occurrence of permafrost
degradation have been noted, widespread and long-term assessment of freshwater biotic responses to the
changing climate have been lacking in North America. Assessment of trends across the North American Arctic
presents the opportunity to investigate biotic responses to different rates of warming (west to east) with
relatively little interaction from anthropogenic effects, compared to more developed regions of the
circumpolar Arctic. The biodiversity of fish, benthic macroinvertebrates, and algae in lakes and rivers was
evaluated along latitudinal transects from west to east, and biotic patterns were related to trends in abiotic
descriptors to characterize environmental drivers of change in these communities. Through the analysis of
spatially- and temporally-distributed data for the North American Arctic, this study aims to assess the current
status and historical trends in freshwater biodiversity in response to physical and chemical habitat shifts
related to climate change.

853
Wed_76_BE-6_1906
Modeling Vulnerability to Thermokarst Disturbance in Boreal Alaska

Helene Genet1 (hgenet@alaska.edu), Mark Lara2, Anthony David McGuire3, William Robert Bolton4, Eugénie
Euskirchen1, Vladimir Romanovsky4
1
University of Alaska - Fairbanks, Institute of Arctic Biology, Fairbanks, United States, 2University of Illinois,
Urbana-Champaign, Department of Plant Biology, Urbana, United States, 3U.S. Geological Survey, Alaska
Cooperative Fish and Wildlife Research Unit, Fairbanks, United States, 4University of Alaska - Fairbanks,
International Arctic Research Center, Fairbanks, United States

Recent climate change is driving permafrost degradation, threatening to mobilize vast reservoirs of ancient
carbon previously protected from decomposition. Although large scale, progressive, top-down permafrost thaw
has been well studied and represented in high-latitude ecosystem models, the consequences of abrupt and
local thermokarst disturbances (TK) are less well understood. To fill this gap, we conducted a detection analysis
characterizing 60 years of land cover change in a major wetland complex subjected to TK disturbance in Interior
Alaska, using aerial and satellite images. We observed a nonlinear loss of permafrost plateau forest associated
with TK disturbance and driven by precipitation and forest fragmentation. The results of this analysis were
integrated into a state-and-transition model that simulates land cover change associated with TK disturbance.
By 2100, the model predicts a mean decrease of 7.4% (sd 1.8%) in permafrost plateau forests associated with
an increase in TK fens and bogs. We evaluated the consequences of TK-related land cover change on the
regional carbon balance using a process-based biogeochemical model. We used long-term field observations of
vegetation and soil physical and biogeochemical attributes to develop new parameterizations for TK wetlands
and permafrost plateau forest land cover types. Preliminary simulations suggest a 7.5% (sd 3.5%) decrease in
Net Ecosystem Exchange associated with TK-related land cover change by 2100.

854
Wed_77_BE-6_1992
Validating Approaches to Determine Biodiversity Attributes of Arctic Freshwaters

Michael Power1 (m3power@uwaterloo.ca), Joseph Culp2,3, Milla Rautio4, Guillaume Grosbois5

1
University of Waterloo, Biology, Waterloo, Canada, 2Wilfrid Laurier University, Biology, Waterloo, Canada,
3
Environment and Climate Change Canada, Waterloo, Canada, 4Université du Québec à Chicoutimi, Chicoutimi,
Canada, 5Université du Québec à Chicoutimi, Biology, Chicoutimi, Canada

Improved understanding of how human-induced changes in Arctic freshwater ecosystems, e.g. climate change
and resource development, may impact the health of northern freshwater resources and the provision of
ecosystem services, e.g., sustainable fisheries, is essential. Here we discuss a research template consistent with
the Circumpolar Biodiversity Monitoring Program to determine how aquatic ecosystem function and structure
varies with spatial scale to support juvenile fish production, the diversity of other resident organisms, and the
habitats upon which fisheries health and sustainability depend. The study also aims to measure cumulative
impacts on aquatic ecosystem structure (e.g., biodiversity loss, reduced fish harvestability). Research focuses
on the Lake Greiner Watershed, Victoria Island Nunavut, is multi-trophic and will expand beyond simple, single
study of lake ecosystems to include landscape-level, watershed attributes such as tributary streams that
provide important rearing and connectivity habitats for fish. The study is timely and necessary as it has been
more than 40 years since such investigations were last conducted in the Canadian Arctic. The work will
establish and validate monitoring protocols for aquatic ecosystems in the north, thereby providing tools to
government agencies for the continued routine monitoring of Arctic freshwater systems and a means to assess
the accumulation of future ecosystem impacts (e.g., climate change, development).

855
Wed_79_BE-6_2251
Characterizing Microhabitats at Relevant Scales for Polar Terrestrial Biota

Peter Convey1 (pcon@bas.ac.uk), Stephen J. Coulson2,3, Anna Sjöblom4

1
British Antarctic Survey, Cambridge, United Kingdom, 2UNIS - University Centre in Svalbard, Longyearbyen,
Norway, 3Swedish University of Agricultural Sciences, Uppsala, Sweden, 4Uppsala University, Uppsala, Sweden

Ground temperatures in the top few centimetres of the soil profile are key in many processes yet remain very
poorly documented, especially in the polar regions or over longer timescales. They vary greatly at various scales
across the often heterogeneous polar landscapes. Meteorological air temperature records provide a poor proxy
for soil temperature profiles, while at present no biological microclimate datasets exist that are of sufficient
duration to allow comparison with large-scale climate trends. Responses of soil-associated biota both to
existing climate and to projected change cannot be understood without improved description of these
microclimates. We introduce and provide an overview of multi-annual temperature records at biologically-
relevant scale from 20 High Arctic (Svalbard) and maritime Antarctic sites. General features that are likely to
have important influences on polar terrestrial biology include
(a) summer ground and sub-surface temperatures vary much more than those of the air;
(b) winter ground temperatures are generally uncoupled from atmospheric temperatures;
(c) the ground thawing period may be considerably shorter than that of positive air temperatures;
(d) ground freeze-thaw event patterns differ between Arctic and Antarctic;
(e) rates of ground temperature change are generally low;
(f) accumulated thermal sum in the ground usually greatly exceeds air cumulative degree days.

856
Wed_80_BE-7_523
Comparative Benthic Experiments in Polar Seas - What Can we Learn from them?

Heike Link1 (heike.link@uni-rostock.de), Joshua Kiesel2, Derya M. Seifert3

1
University of Rostock, Department Maritime Systems, Rostock, Germany, 2Kiel University, Institute for
Geography, Kiel, Germany, 3Kiel University, Institute for Ecosystem Research, Kiel, Germany

To predict changes in the future, we need to identify links between parameters in the ecosystems, such as food
supply to the benthos, composition of benthic communities and effected functions. Comparative experiments
can be used to distinguish different causes for effects, particularly in regions differing in environmental
conditions such as sea-ice cover. Here we show results from benthic chamber incubation experiments, in which
the same method was applied in
(i) Arctic shelf and deep seas and
(ii) Arctic and Antarctic shelf seas.
Our results show that the comparative approach can point to challenging global assumptions such as the
largely diffusion-driven oxygen consumption rates in the deep sea and the biodiversity-driven rates of
ecosystem functions (here: remineralisation rates). We argue that experiments manipulating the biological
system (e.g. species) or environment in contrasting regions such the Arctic and Southern Ocean can elucidate
physico- and biochemical mechanisms crucial for a better state description and prediction of processes in
marine and polar ecosystems.

857
Wed_81_BE-7_529
Ecological Role of Arctic Squid Gonatus fabricii Inferred using Stable Isotopes

Alexey Golikov1 (golikov_ksu@mail.ru), Filipe Ceia2, Rushan Sabirov1, Zarina Zaripova1, Martin Blicher3, Denis
Zakharov4, José Xavier2,5
1
Kazan Federal University, Department of Zoology, Kazan, Russian Federation, 2University of Coimbra, Marine
and Environmental Sciences Centre, Coimbra, Portugal, 3Greenland Institute of Natural Resources, Greenland
Climate Research Centre, Nuuk, Greenland, 4Polar Research Institute of Marine Fisheries and Oceanography,
Laboratory of Coastal Research, Murmansk, Russian Federation, 5British Antarctic Survey, Natural Environment
Research Council, Cambridge, United Kingdom

Gonatus fabricii is the most abundant (and the only one species of) squid, living in the Arctic throughout its life
cycle. Its detailed ecological role was assessed using stable isotope analysis of its beaks in the Arctic: Western
Greenland, Eastern Greenland and the Barents Sea. The values of both δ13C and δ15N were not sex-related,
despite ontogenetic differences in life cycle. δ13C showed low ontogenetic increase while having significant
geographical differences: more eastern areas had lower values, more western areas had higher ones. Such
pattern in δ13C values, despite of not reported previously, was spotted in many taxa in the Arctic. δ15N showed
no geographical variation, while having significant ontogenetic increase (9.99‰ δ15N; 2.8 trophic levels) from
epipelagic forms (1.4-2.6 trophic levels) to bathypelagic ones (2.2-4.2 trophic levels), being comparable with
the largest fishes, seals and whales. Consequently, G. fabricii is considered the top predator invertebrate in the
Arctic, with the widest trophic niche. G. fabricii had the highest values of δ15N ever recorded in cephalopod
beaks, 14.85‰. Its trophic level was surpassed only by the Antarctic colossal squid, Mesonychoteuthis
hamiltoni: seems like in polar ecosystems squids occupy higher positions, than in the rest of the World Ocean.
As the maximum recorded mantle length of G. fabricii is 389 mm (257 mm in the studied ones), its trophic level
and predatory role would increase as our research develops.

858
Wed_82_BE-7_580
Regional Variation of Antarctic Krill Lipids and their Fatty Acid Composition

Nicole Hellessey1,2,3 (nicoleh3@utas.edu.au), Jessica Ericson1,2,3, Peter D Nichols2, Stephen Nicol1, So

Kawaguchi3,4, Nils Hoem5, Patti Virtue1,2,3
1
Institute for Marine and Antarctic Studies, Hobart, Australia, 2Commonwealth Science for Industry Research
Organisation, Oceans and Atmosphere, Hobart, Australia, 3Antarctic Climate & Ecosystems Cooperative
Research Centre, Ecology, Hobart, Australia, 4Australian Antarctic Division, Kingston, Australia, 5Aker BioMarine,
Oslo, Norway

Antarctic krill are an important trophic link between phytoplankton and higher organisms. Knowledge of their
lipid (oil) biochemistry can assist in understanding and predicting potential ecological changes and can also
inform the fishery on sustainable practices, optimising krill harvest. This study examined how the lipid and fatty
acid content and composition of Antarctic krill varied between the three major ocean basins surrounding
Antarctica (Indian, Atlantic and Pacific). Lipids were analysed from krill collected by a commercial krill fishery,
along with samples collected on the K-Axis and ACE voyages.
Krill were staged, sexed, weighed and measured before undergoing lipid and fatty acid analysis. The digestive
glands and stomachs were dissected out of samples so that a clear dietary signal could be attained and
compared to the signal detected from samples of whole krill. Fatty acid signatures from the digestive glands
and stomachs serve to show the immediate differences in diet between these regions, whilst the fatty acids of
the whole krill show which lipids are being retained by the krill between regions.
These analyses serve as a baseline of the differences at a regional scale for lipid levels, energy usage and
budgeting of krill. Knowing how krill diet and energy budgets vary around Antarctica will ensure an accurate
measurement of krill production and energy flow in ecosystem models as well as helping to ensure the krill
fishery is sustainable into the future.

859
Wed_83_BE-7_1301
A Novel High-resolution Model of Moss-bed Microclimate in Maritime Antarctica

Krystal Randall1 (klr452@uowmail.edu.au), Sharon Robinson1, Michael Ashcroft1, Melinda Waterman1, Ilya
Maclean2, Jon Bennie3, Gustavo Zuniga4, Paulo Camara5
1
University of Wollongong, Centre for Sustainable Ecosystem Solutions, Wollongong, Australia, 2University of
Exeter, Penryn Campus, Environment and Sustainability Institute, Penryn, United Kingdom, 3University of Exeter,
Penryn Campus, College of Life and Environmental Sciences, Penryn, United Kingdom, 4Universidad de Chile,
Santiago, Chile, 5University of Brasília, Departamento de Botânica, Asa Norte, Brazil

Moss communities dominate the terrestrial vegetation in Antarctica, and thus are disproportionately important
for the preservation of ecosystem services and biodiversity continent-wide. Understanding physical drivers of
moss-community-level processes in Antarctica is a key challenge due to difficulties associated with sampling at
temporal and spatial scales relevant for moss. Further, the ability to predict future impacts of climate change
on Antarctic vegetation has been hampered by a scale mismatch between coarse scale climate models and
scales biologically relevant for moss communities. Modelling at a scale appropriate for the study of mosses will
lead to novel insights into how microhabitats are distributed across micro-topography, what impact
microclimates have on community assemblages and productivity, and what changes may occur in the future.
We surveyed microclimates in 10 quadrats (1m x 1m) in maritime Antarctica in January 2017 and 2018.
Microclimatic variations were captured under different weather conditions, and moss-bed surfaces were
digitised at a 1cm resolution using structure from motion. These data were used to parameterise a novel
empirically calibrated mechanistic model that predicts moss-bed microclimates on a centimetre scale. This
model allows us to scale-down from coarse climate data to determine how processes affecting moss
composition, health and physiology vary in different microhabitats and how these might be altered under
future climate scenarios.

860
Wed_84_BE-7_1505
Winter to Summer Trophic Shift of Gondogeneia Antarctica in an Antarctic Fjord

Francyne Elias-Piera1 (francyne.ep@kopri.re.kr), In-Young Ahn1, Sun-Yong Ha1, Sergio Rossi2,3

1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Università del Salento, DiSTeBA, Lecce,
Italy, 3Universitat Autònoma de Barcelona, ICTA, Cerdanyola del Vallès, Spain

The amphipod Gondogeneia antarctica is one of species predominating shallow Antarctic coastal macrobenthic
communities. G. antarctica has been considered a key component of nearshore Antarctic food web, preyed by
a high number of predators, and relying on various food sources over a year. In order to investigate its trophic
preferences, G. Antarctica and its potential food (Suspended Particulate Matter and macroalgae) were
collected, from intertidal water at King Sejong Station (Feb-Nov 2015). The C and N stable isotopes were
analyzed in the potential food and the body of amphipods. We found similar δ13C values of G. antarctica during
the year (e.g. -19.4‰ ± 0.8: summer, -20.2‰ ± 0.5: winter), being close to those of red algae analyzed (Iridaea
cordata -21.1‰ ± 3.2, Gigartina skottsbergii -22.6‰ ± 1.5, Palmaria decipiens -19.9‰ ± 0.7), indicating that
the macroalgae were a primary food source, and SPM (-25.4‰ ± 1.2) the secondary one. The digestive tract
contained organic matter (summer) and macroalgae (winter) confirming the isotopic results. The range of δ15N
values (5.6 to 7.7‰) of the amphipod indicated omnivory when food is relatively abundant in summer, though
they generally appeared to be primary consumers in the other seasons. This seasonal trend was consistent
among different sizes & reproductive status. We further discuss about the relevance of this seasonal shift with
environmental parameters, such as seawater temperature, salinity, Chlorophyll a and sea ice cover.

861
Wed_85_BE-7_1637
Multiscale Analysis of Epibenthic Communities off the Antarctic Peninsula

Janina Arndt1 (janina.arndt@uol.de), Casper Kraan2,3, Dieter Piepenburg2,3, Julian Gutt4

1
Carl von Ossietzky University of Oldenburg, ICBM, Oldenburg, Germany, 2Alfred Wegener Institute, Helmholtz
Center for Polar and Marine Research (AWI), Department of Functional Ecology, Bremerhaven, Germany,
3
Helmholtz Institute for Functional Marine Biodiversity (HIFMB) at University Oldenburg, Oldenburg, Germany,
4
Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI), Department of Bentho-
Pelagic Processes, Bremerhaven, Germany

Patterns in epibenthic community distribution and composition are regulated by a variety of environmental
and biotic drivers. The multiscale nature of these fundamental cause-effect relationships, albeit generally
known to be very important for the understanding of ecological processes and development of conservation
and environmental management practices, has very rarely been explicitly addressed in marine polar research.
To tackle this issue, we performed an ecological survey of epibenthic communities in three regions off the
northern Antarctic Peninsula (northwestern Weddell Sea, southern Bransfield Strait and southern Drake
Passage) by means of high-resolution seabed images (n=2799 taken with the Ocean Floor Observation System
(OFOS)). We used Moran's eigenvector mapping of the epibenthic composition data to extract spatial scales at
which communities are structured (700 m to 30 km) by physical and biological environmental factors, such as
sea-ice dynamics, primary production, and water depth. The analysis indicates that at different spatial scales
the community structure is driven by different environmental variables. However, the small-scale variability in
epibenthic composition was not sufficiently explained by the measured environmental factors, very likely
because it is primarily driven by biological interactions. Our study underpins the necessity to assess the
relationship between environmental drivers and biological assemblages across a range of scales.

862
Wed_86_BE-7_1866
Dynamic Growth Model of Antarctic Macroalgae in a Fast-changing Environment

Charlène Guillaumot1 (charleneguillaumot21@gmail.com), Antonio Aguera1, Bruno Danis1, Dolores Deregibus2,

Maria Liliana Quartino2, Leonardo A Saravia3
1
Université Libre de Bruxelles, Bruxelles, Belgium, 2Instituto Antártico Argentino, Buenos Aires, Argentina,
3
Universidad Nacional de General Sarmiento, Buenos Aires, Argentina

Understanding communities functions and trophic interactions between Antarctic species has been the focus of
a lot of research over the past few years. Modeling approaches help integrate increasing information about
these communities using ecological network frameworks. Within these networks, macroalgae, as primary
producers, are strong drivers in benthic ecosystem functioning. Characterising relationships between
macroalgae growth performance and environmental parameters is an interesting approach to assess potential
ecosystem responses to fast-changing environments. In this context, we build a dynamic growth model for
Antarctic macroalgae that describes biomass changes in time and predicts macroalgae growth according to
forcing environmental variables like: light intensity, water turdidity, current speed, ice cover. Our objective is to
define a mathematical model structure that can encompass the environments observed in the Western
Antarctic Peninsula, we will obtain parameters from published studies mainly from Potter Cove, King Georges
Island (South Shetlands). After defining it we study the existence of alternative stable states with respect to
environmental variables that could produce regime shifts in these Antarctic ecosystems.

863
Wed_87_BE-7_2085
Antifouling Activity in Sessile Antarctic Invertebrates by in situ Experiments

Carlos Angulo-Preckler1 (carlospreckler@hotmail.com), Mariana Postigo2, Critina Cid2, Conxita Avila1

1
University of Barcelona, Evolutionary Biology, Ecology and Environmental Sciences, Barcelona, Spain, 2Center of
Astrobiology, Microbial Evolution Laboratory, Madrid, Spain

Competition for space is a remarkable ecological force, comparable to predation, which produces a strong
selective pressure on sessile benthic invertebrates. The settlement of organisms on the surfaces of living
organisms can be either advantageous or disadvantageous to the host. To obtain protection, many benthic
marine invertebrates, including sponges and bryozoans, contain secondary metabolites with antibacterial
properties. Here, extracts from five sponges and two bryozoans from Antarctic waters, have been shown to
exhibit selective antibacterial activity. Three replicates of each fraction treatment were tested submerging the
plates in the sea during one lunar cycle (28 days). Amplification from environmental DNA was performed
searching for bacteria, eukaryota, and archea. Different levels of bacterial and eukaryotic activity were found in
the tested extracts when compared to controls. An important activity against eukaryotic fouling were detected.
The hydrophylic fractions of Mycale tylotornota and Cornucopina pectogemma completely inhibited the growth
of eukaryotic organisms, one of the early succession stages involved in biofouling. Thus, although chemical
defenses may be quite species-specific in their ecological roles, these results suggest that different chemical
strategies exist to deal with space competition, reinforcing the importance of marine organisms in the
production of bioactive substances.

864
Wed_88_BE-7_2673
Disentangling the Coupling between Sea Ice and Tundra Productivity in Svalbard

Marc Macias-Fauria1 (marc.maciasfauria@ouce.ox.ac.uk), Bruce Forbes2, Stein Rune Karlsen3

1
University of Oxford, School of Geography and the Environment, Oxford, United Kingdom, 2University of
Lapland, Arctic Centre, Rovaniemi, Finland, 3Northern Research Institute - Norut, Tomsø, Norway

The rapid decline in Arctic sea ice poses urgent questions concerning its ecological effects, such as on tundra
terrestrial productivity. However, reported sea ice/terrestrial productivity linkages have seldom been
constrained, and the mechanism governing them remains elusive, with a diversity of spatial scales and metrics
proposed, at times in contradiction to each other. In this study, we use spatially explicit remotely sensed sea
ice concentration and high-resolution terrestrial productivity estimates (Normalised Difference Vegetation
Index, NDVI) across the Svalbard Archipelago to describe local/sub-regional and large-scale components of sea
ice/terrestrial productivity coupling. Whereas the local/sub-regional component is attributed to sea breeze
(cold air advection from ice-covered ocean onto adjacent land during the growing season), the large-scale
component might reflect co-variability of sea ice and tundra productivity due to a common forcing, such as
large-scale atmospheric circulation (North Atlantic Oscillation, NAO). Our study clarifies the range of
mechanisms in sea ice/terrestrial productivity coupling, allowing the generation of testable hypotheses about
its past, present, and future dynamics across the Arctic.

865
Wed_89_BE-7_2697
Elemental Stoichiometry Drives Nematode Life History and Genome Evolution

Byron Adams1 (bjadams@byu.edu), Bishwa Adhikari2, Xia Xue3, Breana Simmons4, Becky Ball5, Jeb Barrett6,
Diana Wall7
1
Brigham Young University, Department of Biology, Provo, United States, 2University of Arizona, Tucson, United
States, 3Brigham Young University, Provo, United States, 4East Georgia State College, Swainsboro, United
States, 5Arizona State University, Glendale, United States, 6Virginia Tech, Blacksburg, United States, 7Colorado
State University, Fort Collins, United States

The presence of bioavailable phosphorus (P) differs significantly across the Transantarctic Mountain (TAM)
landscape where it is highly correlated with age of exposure and the composition of glacial tills. Terrestrial
habitats with very old surface exposures have relatively little bioavailable phosphorus whereas as younger tills
typically are much more phosphorus rich. Thus, provenance and weathering play an instrumental role in
patterns of distribution and abundance of this important nutrient in the TAM.
Phosphorus is the most limiting element in DNA transcription and translation such that P availability is directly
coupled to high demands for the protein synthesis that is required for organismal growth and development.
Using field and laboratory approaches we show that conspecific TAM nematodes from high versus low
bioavailable P environments contain greater somatic P concentrations and have evolved 1) faster growth rates,
2) earlier reproduction, 3) shorter reproductive cycles, 4) smaller body size, 5) increased rates of transcription,
and 6) increased rRNA gene copy number. These findings have important implications on the evolution of
organismal life history traits and ultimately the development of trophic complexity in terrestrial ecosystems.

866
Wed_90_BE-7_1579
Soil Visible and Near Infrared Spectroscopy as an up-scaling Tool

Alevtina Evgrafova1,2 (alevtina.evgrafova@gmail.com), Anna Kühnel3, Christina Bogner4, Ina Haase5, Olga
Shibistova5,6, Georg Guggenberger5,6, Nikita Tananaev7, Leopold Sauheitl5, Sandra Spielvogel8
1
University of Bern, Bern, Switzerland, 2University of Koblenz-Landau, Koblenz, Germany, 3Technical University
of Munich, Munich, Germany, 4University of Bayreuth, Bayreuth, Germany, 5Leibniz University of Hanover,
Hanover, Germany, 6VN Sukachev Institute of Forest, Krasnoyarsk, Russian Federation, 7Melnikov Permafrost
Institute, Yakutsk, Russian Federation, 8University of Kiel, Kiel, Germany

The combination of partial least square regression (PLSR) and soil visible (VIS) and near infrared (NIR)
spectroscopy measurements can be used to predict soil properties and assist estimating the spatial
characteristics of soil properties from the pedon to regional scales. VIS-NIR spectroscopy was successfully used
to describe, estimate and further map the spatial patterns of soil properties in unknown locations using PLSR in
R program. The parameters such as oxalate and dithionite extracted iron, aluminum and manganese oxides and
(hydr-)oxides, soil organic carbon and total N concentrations, and pH were investigated in this research.
Moreover, the geostatistical methods (e.g. Moran´s I: spatial autocorrelation) can be used in order to better
understand the pedogenic processes pertaining to permafrost thaw. This research illustrates how VIS-NIR
spectroscopy can be implemented in order to improve the global soil spectral library as well as assist in up-
scaling of soil properties and processes in cold climate regions.

867
Wed_91_CR-2_210
Ice Table Depth, Ground Ice and its dD-d18O Composition in Cold-dry Soils

Denis Lacelle1 (dlacelle@uottawa.ca), David Fisher2, Wayne Pollard3, Alfonso Davila4, Christopher McKay4
1
University of Ottawa, Geography, Ottawa, Canada, 2University of Ottawa, Earth Sciences, Ottawa, Canada,
3
McGill University, Geography, Montreal, Canada, 4NASA Ames, Moffet Field, United States

In the ultraxerous region of the Dry Valleys of Antarctica, the very cold and dry climate ensure that dry soils
overlie icy permafrost; a characteristic unique to this region, but is the norm on Mars. Here, we present of
summary of our work in University Valley, upper Dry Valleys. In University Valley, mean annual air temperature
approximates mean annual ground surface temperature (ie, surface offset ~ 0°C); however, mean annual
relative humidity (45.5 ± 14%) is much lower than mean annual ground surface relative humidity (varying from
100 to ~ 85%ice). The ice table depth increase with distance from the glacier: from < 1 cm to ~ 60 cm, indicating
that despite being a cold and dry region, ground ice is pervasive. Excluding the two bodies of buried glacier ice,
volumetric ice contents ranged from 0 to 93%. These high ice contents suggest the cold temperatures and low
precipitation in the upper Dry Valleys are likely not limiting factors to the development of ice-rich permafrost.
Based on D-18O measurements, the ground ice has different origins: vapor-deposition, freezing of evaporated
snow meltwater or burial of glacier ice. We modeled the net water vapour flux, ice table depths and D-18O of
ground ice using the conditions measured in the valley. When ground surface conditions are used (instead of
those measured in the atmosphere), our modeling predicts that the measured ice table depths in the valley are
likely in equilibrium with contemporary conditions.

868
Wed_92_CR-2_282
Quantification of Holocene Nivation Rates on James Ross Island, Antarctica

Michaela Knazkova1 (michaelaknazkova@gmail.com), Daniel Nyvlt1, Filip Hrbacek1

1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic

Nivation encompasses a breadth of slowly operating landscape modelling processes, which have been studied
only very little in the recent years. In the semi-arid polar continental climate of James Ross Island with annual
precipitation of 300-500 mm and strong redistribution of snow by wind that causes the formation of snow-
patches, meltwater from the late-lying snow-patches is not only capable of transporting fine particles
downslope and slope profile shaping, but also controls the presence of vegetation in the landscape. The area
for this study is located on Cape Lachman. The deglaciation of this area took place 12.9 ± 1.2 ka ago. The study
site consists of ca 2 km long and 200 m wide semi-circular depression. Snow accumulations on the lee slopes
last throughout the summer and the long-term downslope transport of fine particles by meltwater has caused
significant remodelling of the slope profile. dGPS measurements on 20 transects have been used for
comparison between transects which have been affected by nivation processes and those which have been
not. Besides, a digital terrain model was constructed to quantify the scarp retreat and slope profile change
along the depression margin due to nivation and to calculate the rate of these changes since the deglaciation,
i.e. for the whole Holocene. Furthermore, grain-size changes of material in studied profiles support the removal
of fine-grained particles by meltwater from the slope and their accumulation on the depression floor.

869
Wed_93_CR-2_332
Blowing in the Wind - Where Does the Antarctic Fluvial Suspended Load Come from?

Jan Kavan1, Daniel Nyvlt1 (daniel.nyvlt@seznam.cz)

1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic

When studying fluvial transport in Antarctic streams, an obvious question arises: where does the material come
from? The sources of bedload and suspended load generally differ in most catchments. Chemical composition
of suspended material transported in Bohemian and Algal streams on Ulu Peninsula, James Ross Island (eastern
Antarctic Peninsula) didn't bring any clear answer (Kavan et al., 2017). Here we test the hypothesis that an
important source of material for fluvial transport is the material brought by strong barrier winds transporting
material from relatively vast ice-free areas of Ulu Peninsula. Two sets of passive aeolian samplers were
installed on upwind and downwind sides of Bohemian Stream braidplain with respect to prevailing southerly to
westerly barrier winds. The material was sampled for 23 days (29/01/2017-20/02/2017) without an occurrence
of significant wind storm during the period. Nevertheless, samplers ahead of the braidplain did collect 41.66
g/m2 in average, whereas only 29.09 g/m2 were sampled behind the braidplain. This suggests a significant part
of wind-blown material (>30%) was lost from aeolian transport and was stored in braidplain being available for
subsequent fluvial transport. The redistribution of aeolian material through fluvial systems causes spatially
unequal input of fine-grained material to coastal marine environment and shapes significantly the Antarctic
coastline.

870
Wed_94_CR-2_829
Inflated Soils on Earth and Mars: Cold Deserts, Old Features and Young Surfaces

Joseph Levy1 (jlevy@colgate.edu)

1
Colgate University, Geology, Hamilton, United States

How do rocky boulder pavements and oriented boulder landforms form atop dust and ice? How do they persist
through orbital/spin-axis-induced climate change? We describe silt-dominated inflated soil textures in the
McMurdo Dry Valleys of Antarctica and evaluate a class of potentially similar martian landforms on Mars
referred to as “boulder halos.” Boulder halos are circular arrangements of clasts present at martian middle to
high latitudes. They are thought to result from impacts into a boulder-poor surficial unit that is rich in ground-
ice and/or sediments and that is underlain by a competent substrate. To determine the distribution of boulder
halos and to evaluate mechanisms for their formation, we mapped boulder halos over 4,188 HiRISE images
located between 50-80° north and south latitude. Boulder halos are about three times more common in the
northern hemisphere than in the southern, and have size-frequency distributions suggesting recent Amazonian
formation (tens to hundreds of millions of years). In the north, boulder halo sites are characterized by
abundant shallow subsurface ice and high thermal inertia. Spatial patterns of halo distribution indicate that
surface processes such as inflation either promote boulder halo preservation in the north or destroy boulder
halos in the south.

871
Wed_95_CR-2_1520
Investigations of Patterned Ground in Antarctic Permafrost as a Mars Analogue

Emanuele Forte1, Rossana Raffi2, Hugh French3, Mauro Guglielmin4 (mauro.guglielmin@uninsubria.it)

1
Università degli Studi di Trieste, Trieste, Italy, 2Università degli Studi Roma La Sapienza, Roma, Italy, 3Ottawa
University, Ottawa, Canada, 4Università degli Studi dell'Insubria, DISTA, Varese, Italy

The results of a combined geophysical and geomorphological investigation of thermal-contraction-crack

polygons in Northern Victoria Land (Antarctica) are reported. An area of ~30,000 m2 characterized by random
orthogonal polygons was investigated using 10 GPR and 2 ERT surveys. The terrain consists of Holocene-age
raised beaches. The polygons are well developed only on beaches that are >14 m above current sea level. Uplift
curves for the region suggest the beaches formed between 4.2 and 6.3 ka BP. Sections were excavated through
two of the fissures that form the polygons. There was good correlation between field observations and GPR
(250 Mhz) data. It is concluded that the polygons are composite in nature because the shallow linear
depressions that outline the polygons are underlain by fissures that can contain both sandy gravel (i.e., sand
wedges) and foliated gravelly ice (i.e., ice wedges) in the same polygon network. Generally, the ice infill is less
common than the sandy gravel infill. While thermal-contraction-cracking is the principle mechanism for
polygon formation, it is suggested that local micro-site conditions, mainly snow distribution, leads to the
different type of fissure infill.

872
Wed_96_CR-2_1525
Microbial Communities in the Brines of Two Antarctic Frozen Lakes (Boulder Clay)

Maurizio Azzaro1, A Conte2, M Papale2, A.S Cabral3, G. Caruso1, E. Crisafi1, M. Dalle Fratte4, E. Forte5, Rosa Bruna
La Ferla1 (rosabruna.laferla@iamc.cnr.it), A. Lo Giudice1,2, G Maimone1, R Paranhos3, A.C. Rappazzo1, C Rizzo2, S.
Savoca2, N. Spanò2, Mauro Guglielmin4
1
National Research Council of Italy, Institute for Coastal Marine Environment (IAMC), Messina, Italy, 2University
of Messina, Messina, Italy, 3Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, 4University of Insubria,
Varese, Italy, 5University of Trieste, Trieste, Italy

During a GPR survey, two lenses of liquid brines were found at different depths in two adjacent frozen Boulder
Clay lakes (Lake-1: 2.5 m; Lake-2: 2.0) with a different salinity (0.2 and 3.6 mS/cm, respectively) and pH (8.17
and 8.76, respectively). Brines were analyzed for bacterial diversity by Ion Torrent DNA and cDNA sequencing,
microbial abundances (by image analysis and flow cytometry) and metabolic activities (by Biolog-Ecoplate™
and potential rates of ectoenzymatic activities determinations). The analysis of DNA sequences generally
showed the predominance of Bacteroidetes, followed by Proteobacteria and Actinobacteria. The highest
percentage (6.0 vs 1.7%) of active bacteria (by the analysis of RNA sequences; mainly Bacteroidetes) was
observed in Lake-1. This latter harboured microbial populations characterized by higher prokaryotic cell
abundances, volumes, biomass and virus abundance than Lake-2. Diverse cell morphotypes were observed in
the two lakes. Different metabolic responses were also determined, with higher numbers of respiring cells and
higher rates of ectoenzymatic activities, as well as the ability to better utilize carbon sources, in Lake-1 than in
Lake-2. Results highlighted differences in the analyzed cryoenvironments in terms of diversity, abundance and
metabolism, suggesting that Antarctic lakes might possess distinct microbial features in spite of their spatial
proximity

873
Wed_97_CR-2_1527
Two Microbial Assemblages in Lake Brine Pockets Separated by a Thick Ice Layer

Maurizio Azzaro1 (maurizio.azzaro@iamc.cnr.it), A Conte2, M Papale2, A.S Cabral3, G. Caruso1, E. Crisafi1, M.

Dalle Fratte4, E. Forte5, Rosa Bruna La Ferla1, A. Lo Giudice1,2, G Maimone1, R Paranhos3, A.C. Rappazzo1, C
Rizzo2, S. Savoca2, N. Spanò2, Mauro Guglielmin4
1
National Research Council of Italy, Institute for Coastal Marine Environment (IAMC), Messina, Italy, 2University
of Messina, Messina, Italy, 3Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, 4University of Insubria,
Varese, Italy, 5University of Trieste, Trieste, Italy

Two distinct hypersaline brine pockets (TF4 and TF5) separated by a 12 cm-thick ice layer were sampled from
Tarn Flat, an unexplored Antarctic perennially frozen lake. Samples were analyzed for prokaryotic (Bacteria and
Archaea) diversity (Ion Torrent sequencing), microbial abundances (image analysis and flow cytometry) and
metabolic activities (Biolog-Ecoplate™ and potential rates of ectoenzymatic activities). The two sites shared
only 22 and 18% of OTUs for Bacteria and Archaea, respectively. Shannon diversity for archaeal and bacterial
communities was higher in TF5 than TF4 (p value < 0.001). Both bacterial communities were dominated by
Proteobacteria, followed by Bacteroidetes and Actinobacteria. The Archaeal community was mainly constituted
by Euryarchaeota and Crenarchaeota. Prokaryotic and virus-like particle abundances were in the order of 109
cells/l and 1010 VLP/l, respectively, in both samples, with slightly higher counts in TF4 than TF5. However, the
VLP/PA ratio was 2.7 times higher in TF4 than in TF5. Larger cells were detected in TF5 (0.105 µm3) than TF4 (<
0.06 µm3) as well as higher values of physiological diversity, substrate richness, substrate evenness and
equitability were determined in TF5 than TF4. The prokaryotic community hydrolyzed proteins rather than
organic phosphates, and polysaccharide degradation was negligible in TF5 and high in TF4. Overall data
revealed the occurrence of highly different microbial assemblages in the studied brines.

874
Wed_98_CR-2_2018
Rock Glaciers in Antarctica Provide Evidence of Multiple Glacial Advances

Kate Swanger1 (kate_swanger@uml.edu), Esther Babcock2, Kelsey Winsor3, Regina DeWitt4, Rachel Valletta5
1
University of Massachusetts Lowell, Environmental, Earth & Atmospheric Science, Lowell, United States, 2Logic
Geophysics & Analytics, LLC, Anchorage, United States, 3Northern Arizona University, Flagstaff, United States,
4
East Carolina University, Greenville, United States, 5University of Pennsylvania, Philadelphia, United States

Rock glaciers in the Dry Valleys of Antarctica vary across the region in terms of origin and internal structure.
Based on ground-penetrating-radar data and field excavations, rock glaciers in central Wright Valley are cored
by ice-cemented sediments and recharged by meltwater, whereas those in Taylor and Pearse valleys often
contain 3+ m of clean ice buried beneath sediments. Based on field observations, the latter type of rock glacier
forms along the margins of cold-based glaciers as a mélange of glacial ice blocks, meltwater and sediments.
These clean-ice rock glaciers often show evidence of complex formational histories and can therefore be used
to map multiple glacial advances. Stable isotopic analyses of buried ice from a rock glacier in Pearse Valley
support the presence of two distinct ice bodies:
1) one from a previous advance of East Antarctic outlet Taylor Glacier, possibly dating to Marine Isotope Stage
5 and
2) another from a modern alpine glacier which is still actively supplying ice and sediments.
This study outlines the environmental conditions that foster rock-glacier formation in cold deserts with
implications for lobate flow features on Mars. The data also provide a baseline to study the geomorphic
impacts of present and future climate change. Meltwater-fed rock glaciers, such as those in Wright Valley, may
grow in response to warming, whereas clean-ice rock glaciers will likely experience degradation by thermokarst
melting and stream erosion.

875
Wed_99_CR-2_2033
Weathering Rate Study in Maritime Antarctica Using Onsite Nondestructive Methods

Jeronimo Lopez-Martinez1 (jeronimo.lopez@uam.es), Miguel Gomez-Heras1, Luis Javier Lamban2, Belen Oliva-
Urcia1, Jose A. Ortega-Becerril1, Thomas Schmid3
1
University Autonoma of Madrid, Faculty of Sciences, Geology and Geochemistry, Madrid, Spain, 2Geological
Survey of Spain-IGME, Zaragoza, Spain, 3Center for Energetic, Environmental and Technological Researches-
CIEMAT, Madrid, Spain

Periglacial processes are highly active under the maritime environmental conditions of the South Shetland
Islands. Weathering associated with such conditions influences soil and landform development. Dating of
deposits and erosive surfaces in the region poses difficulties due to the scarcity of sedimentary elements
adequate for dating. This is the case of one of the prominent geomorphological features in the studied region:
raised marine features located up to 260 m a.s.l. The aim of this work is to explore the possibilities of
discriminating exposure ages using a combination of measuring methods to study weathering. There are
studies on the use of Schmidt hammer for relative dating glacial weathered surfaces; however, there are other
onsite nondestructive techniques that could further improve the dating results. In this study, a range of
techniques including Schmidt hammer, ultrasound pulse velocity, spectroscopy and surface temperature were
applied to relatively date exposed rock surfaces in the South Shetland Islands. Measurements have included
Holocene and pre-Holocene raised beaches containing pebble sediments, and marine erosive platforms located
at different altitudes in Livingston and King George islands. In addition to onsite and laboratory measurements,
the spectral signature of these features was determined in order to characterize the spectral information from
satellite observations, which in turn can be extrapolated to further areas over a larger region.

876
Wed_102_CR-3_182
The Hydrochemal Characteristics of Ground Ice on the Qinghai-Tibetan Plateau

Tonghua Wu1 (thuawu@lzb.ac.cn), Weihua Wang1, Lin Zhao1, Ren Li1, Changwei Xie1, Xiaofan Zhu1
1
Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, State Key Lab of
Cryospheric Sciences, Lanzhou, China

The vertical distribution and controlling factors of the hydrochemistry of ground ice are critical to explore the
mechanism of salt-moisture migration during the soil freezing-thawing processes, which are of great
importance to understanding the hydrological cycles in cold regions. This study examined the characteristics of
ground ice hydrochemistry using data from nine soil profiles investigated in permafrost regions of the central
Qinghai-Tibet Plateau (QTP), which is called as the third pole. The isotopes and anion values of subsurface
water on the QTP were higher than those in Arctic polygonal ground regions. The spatial tendency of anions
was not obvious, while well-developed hydrochemical depth gradients were found within the soil profile,
presenting depleted isotopes and increased anions with depth. Cl- and SO42- concentrations in soil water
increased with depth, while NO3- concentration did not change obviously with depth. Freeze-out fractionation,
self-purification, and desalination greatly impact soil hydrochemistry. Correlation analyses showed that the
major controlling factors for the variations of soil water chemistry were soil moisture, air temperature, and
active layer thickness. The results could provide fundamental framework to understandthe ground ice origins
and the saltmoisture migration pathways in the context of permafrost changes, and should be considered in
establishing the process-based permafrost hydrologic models.

877
Wed_103_CR-3_659
Lake Volume and Groundwater Storage Variations in the Tibetan Plateau

Guoqing Zhang1 (guoqing.zhang@itpcas.ac.cn)

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

The Tibetan Plateau (TP), the highest and largest plateau in the world, with complex and competing
cryospheric-hydrologic-geodynamic processes, is particularly sensitive to anthropogenic warming. The
quantitative water mass budget in the TP is poorly known. Here we examine annual changes in lake area, level,
and volume during 1970s −2015. We find that a complex pattern of lake volume change during 1970s−2015: a
slight decrease of -2.78 Gt yr-1 during 1970s−1995, followed by a rapid increase of 12.53 Gt yr-1 during
1996−2010, and then a recent deceleration (1.46 Gt yr-1) during 2011−2015. We then estimated the recent
water mass budget for the Inner TP, 2003−2009, including changes in terrestrial water storage (TWS), lake
volume, glacier mass, snow water equivalent (SWE), soil moisture, and permafrost. The dominant components
of water mass budget, namely changes in lake volume (7.72 ± 0.63 Gt yr-1) and groundwater storage (5.01 ±
1.59 Gt yr-1), increased at similar rates. We find that increased net precipitation contributes the majority of
water supply (74%) for the lake volume increase, followed by glacier mass loss (13%), and ground ice melt due
to permafrost degradation (12%). Other term such as SWE (1%) make a relatively small contribution. These
results suggest that the hydrologic cycle in the TP has intensified remarkably during recent decades.

878
Wed_104_CR-3_681
Vapor Stable Isotopes in the Tibetan Plateau Record Moisture Transport Processes

Jing Gao1 (gaojing@itpcas.ac.cn), Tandong Yao1, H. C. Steen-Larsen2

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China, 2Niels Bohr Institute,
University of Copenhagen, Copenhagen, Denmark

The water cycle in the southern Tibetan Plateau as a crucial region in the “Asian Water Towers” impacts water
supply in downstream countries. Moisture transport processes determine the variation of regional water cycle
directly. Water vapor stable isotopes (δ18O and δD), as an integrative tracer of water phase-transition and
diffusivity process provide the potential of enhancing our knowledge of the moisture transport processes from
the moisture origins to the southern Tibetan Plateau. Continuous, in situ high-resolution measurements of
atmospheric water vapor stable isotopes have been conducted at Lhasa, Motuo and Everest, southern Tibetan
Plateau (TP), since October 2014, using the laser analyzers. Combined with local meteorological data, reanalysis
data and simulations from the iso-GCMs model, the relationships between water vapor stable isotopes and
atmospheric processes are explored at daily and seasonal scales. The changing of vapor stable isotopes is
resulted from the moisture transport processes, especially the transfer from the westerlies to the Indian
summer monsoon. Our results will improve the implications of stable isotopes in ice cores and understanding
of water cycle in this region.

879
Wed_105_CR-3_686
Characteristics of Wet Season Precipitation Gradients on the Tibetan Plateau

Lan Cuo1 (lancuo@itpcas.ac.cn), Yongxin Zhang2

1
Chinese Academy of Sciences, Institute of Tibetan Plateau Research, Beijing, China, 2National Center for
Atmospheric Research (NCAR), Research Applications Laboratory and Climate and Global Dynamics Laboratory,
Boulder, United States

The Tibetan Plateau (TP) with its vast land mass and high elevation affects regional climate and weather. More
importantly, the TP is the headwater of 9 major Asian rivers that provide fresh water for 1.65 billion people and
many ecosystems, with wet season (May - September) precipitation being the most critical component of the
fresh water. Using station observations and ERA-Interim reanalysis for 1979 - 2015, we show that wet season
precipitation on the TP displays distinctive regional variations in vertical gradients (i.e., changes with elevation).
The variations can be largely explained by considering those of vertically integrated moisture, convective
available potential energy and condensation level. The increase of precipitation with elevation for all groups is
predominantly the result of combined increasing CAPE and decreasing LCL with elevation that cancel out the
decreasing vertically integrated moisture with elevation. Below 4000 m and excluding desert, precipitation
change with elevation is mainly determined by the effects of energy and condensation level. Above 4000 m and
in the desert, condensation level dominates over energy.

880
Wed_106_CR-3_701
Hydrogeochemical Characteristics of the Gandaki River Basin in Central Himalayas

Fan Zhang1 (zhangfan@itpcas.ac.cn), Ramesh Raj Pant1, Faizan Ur Rehman1, Guanxing Wang1
1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

Hydrogeochemical Characteristics of the Gandaki River Basin of Central Himalayas was analyzed based on 165
river water samples taken during pre-monsoon, monsoon and post monsoon seasons from 55 sampling sites.
The pH, EC and TDS were measured on site while major ions (Ca2+, Mg2+, K+, Na+, Cl˗, SO42˗, NO3˗) and Si were
analyzed in the laboratory following the standard procedures. The results revealed mildly alkaline pH with the
pattern of average ionic dominance: Ca2+>Mg2+>Na+>K+ for cations and HCO3˗>SO42˗ >Cl˗ >NO3˗ for anions. Gibbs
plot and ionic relations displayed the predominance of carbonates weathering processes which is supported by
geochemical facies of water in Piper plot as Ca˗HCO3 (83.03%), mixed with Ca˗Na˗HCO3 (12.73%) and Ca˗Cl
(4.24%). Strong spatiotemporal heterogeneity was observed between upstream and downstream segments in
terms of distinct precipitation, meltwater, local geogenic sources and anthropogenic interferences. Suitability
analysis of river water for drinking as well as irrigation purposes revealed that the river has mostly retained its
natural water quality. However, increasing anthropogenic interferences could be serious threats for water
quality and ecological integrity of the river basin in the future.

881
Wed_107_CR-3_863
Coordinated Regional Climate Downscaling Experiment (CORDEX) Activity in Asia

Likun Ai1 (aili@itpcas.ac.cn)

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, International Programme Office, Third
Pole Environment, Beijing, China

CORDEX is a sub-project under WCRP (World Climate Research Program). From 2013, APN (Asian-Pacific
Network for Global Change Study) funded a regional project to support the CORDEX devlopment in Asia. The
objective of this joint CORDEX activity for Asia is to set up a more enhanced, open, efficient, and shared
collaborative platform for climate downscaling groups in Asia. In last 4 years, re-grouped and re-designed 3
sub-domains for CORDEX Asia have been conducted, which are South Asia, East Asia and Southeast Asia. This
project has set up the mechanism of sharing the data, experiences and technics on climate downscaling with all
the CORDEX groups in Asia. This APN project has also supported setting up the ESGF nodes (RCM data sharing)
in Asia by collaboration with WCRP-ESGF core group. The CORDEX Asian Empirical-Statistical Downscaling (ESD)
group was established to support the application of climate downscaling products to end-users. The science-
policy dialogues platform focusing on climate adaptation during the workshops was build up. This project has
trained more than 130 young scientists from developing countries in Asia.

882
Wed_108_CR-3_864
Third Pole Environment (TPE) Programme: History, Achivements and Future Plan

Likun Ai1 (aili@itpcas.ac.cn)

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, International Programme Office, Third
Pole Environment, Beijing, China

After the North and South Poles, the Third Pole is the highland core of Asia, and includes the Hindu-Kush,
Karakorum, Himalayas, Tibetan Plateau and all the mountain ranges that surround it. This region provides the
water resource and ecosystem services to billions of people in Asia. It is well accepted that the regional
environmental change will have huge implications for millions of people living in the Third Pole region and
downstream areas.
Formally Launched in 2009, the Third Pole Environment (TPE) program is to understand the mechanisms of the
earth system multi-sphere (atmosphere, cryosphere, hydrosphere, lithosphere, biosphere and anthroposphere)
interactions in the Third Pole region. This Poster will give brief introduction of history, achivement, onging
activities and future plan of TPE.

883
Wed_109_CR-3_884
Thermal Behaviour of Debris Covered Glaciers, Western Himalaya

Lavkush Patel1 (lavkushpatel@ncaor.gov.in), Parmanand Sharma1, Ajit Singh1, Meloth Thamban1, Vinay
Gaddam1, Bhanu Pratap1, Sunil Oulkar1
1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Polar Sciences, Vasco da Gama, India

Debris is one of the unavoidable components of Himalaya glaciers and having a critical role in glacier dynamics.
Contrasting to normal ablation pattern over glaciers, debris covered glaciers of this region has experienced
inverse ablation rate due to significant control of debris cover. Considering complex nature of debris materials,
surface temperature becomes crucial factor to estimate thermal resistance of debris to calculate ablation
under debris covered glacierized area. In this investigation, an attempt has made to quantify the thermal
resistivity of supraglacial debris of Chandra basin by using heat flux method. The ablation and temperature
(surface and subsurface) data was obtained from stake networks and T-data logger installed over glaciers in
different altitude ranging from of 4100 to 5100 m.a.s.l. during year 2016-17. The Chandra basin has 702 km2
glacierized areas and almost ~22% of this area is covered by debris with various thicknesses (10-150 cm). The
major components of the debris in this basin are Quartz, Phyllite, Mica, Slate, Gneiss and feldspar. Observation
revealed lower temperature at the debris surface and debris-ice interface during November to May and vice -
versa during June to August. There is significant diurnal variation in thermal resistance of debris, higher during
day than night may be caused by variation in vapour pressure in the debris layer under the saturated water
pressure condition.

884
Wed_110_CR-3_908
Multi-sphere Hydrological Modeling over the Third Pole Region

Lei Wang1 (wanglei@itpcas.ac.cn)

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

For improved predictive ability of regional water resources and water-related disasters in the Third Pole region
(Tibetan Plateau and its surrounding area), in recent years, we aim at developing a multi-sphere hydrological
modeling system that is applicable to the high-elevation environment.
The major achievements of our work can be summarized as follows.
(1) A distributed land surface hydrological model (WEB-DHM) was developed in 2009, which can consistently
describe the exchanges of water, energy, and CO2 fluxes in the land-atmosphere interactions at the basin scale.
The model has been widely applied into dozens of watersheds in Asia, Africa, North America, and South
America, to serve their integrated water resources management.
(2) Key cryosphere processes (e.g., snow, frozen soil, glacier) have been significantly improved under the
framework of the distributed land surface hydrological model WEB-DHM, and the physically-improved multi-
sphere (atmosphere-hydrosphere-cryosphere-biosphere) hydrological model have been extensively applied
into cold river basins for addressing critical water issues in the Third Pole Region (e.g., Floods, Droughts, Lake
area changes, and so on).

885
Wed_111_CR-3_1010
Spatio-temporal Analysis of Snowmelt in Tibet Plateau, Greenland and Antarctica

Xinwu Li1 (lixw@radi.ac.cn), Huadong Guo2, Lei Liang2, Lu Zhang2, Xingxing Yang2
1
Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, CAS Key Lab of Digital Earth
Science, Beijing, China, 2Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing,
China

As an important sensitive factor of global climate change, the surface snowmelt in Tibet Plateau, Greenland
and Antarctica is a key factor impacting the free water resources in world. Understanding the spatio-temporal
variation of snowmelt in the three areas is very important to change of water resources. Many studies for
surface snowmelt have been conducted already, but most of them only focused on one of three areas. The
climate conditions of Tibet Plateau, Greenland and Antarctica differ, and local characteristics are diverse within
their regions as well. However, linkages through atmosphere, ocean and another climate system make local
climate change in the three areas correlated. Therefore, in order to understand precisely the impact of
snowmelt on Tibet Plateau, Greenland and Antarctica to water resources, the variation of snowmelt on the
three areas should be studied as a whole system. Spaceborne earth observation provides an efficient means of
measuring snowmelt dynamics in a long term. Therefore, based on spaceborne microwave radiometer datasets
from 1978 to 2014 by using improved freeze-thaw detection algorithms and new proposed snowmelt index, we
investigate the snowmelt change on Tibet Plateau, Greenland and Antarctica in this paper by addressing the
following three questions: What is difference between the snowmelt change on the three areas? How is the
snowmelt change on whole three areas ? What is relationship between the snowmelt change in on the three
areas?

886
Wed_112_CR-3_1026
Relationship between Passive Microwave Remote Sensing and SWE in Chilean Andes

Harold Llauca1 (hllauca@ing.uchile.cl), Gonzalo Cortés2, James McPhee1

1
University of Chile, Department of Civil Engineering, Santiago, Chile, 2University of California Los Angeles,
Department of Civil and Enviromental Engineering, Los Angeles, United States

Spaceborne passive microwave remote sensing (e.g. SSM/I, AMSR-E) and its relationship with physical
properties of the snowpack has been widely studied in the last decade. Furthermore, AMSR-E measurements
from Level 2A (L2A) product, are three times more sensitive than EASE-Grid for mountainous regions. In spite
of this, advantages of passive microwaves remote sensing technologies are still unexplored for the Andean
Region, such as the Upper Maipo basin (about 7562 km2) located in the Central Andes of Chile. The aim of this
study is to examine passive microwave brightness temperature (Tb) at 36.5 GHz from L2A (14 x 8 km), and its
relationship with the snow water equivalent (SWE) in the Upper Maipo. For this, Tb observations were
processed at basin and point scales, and a recent SWE reanalysis, with a spatial resolution of 0.05°, were used
in this study. There is a high negative correlation (R=-0.80) between the minimum Tb (nighttime) of each
hydrological year (2002/03 - 2011/12) with the concurrent SWE for basin scale, and significant higher
coefficients of determination (R2>0.75) for cells above ~3500 m.a.s.l. Nevertheless, there is a high spatial
scattering between Tb and SWE due to different spatial scales of each product and other variables involved in
the radiative transfer of the snowpack. Finally, it was shown that Tb observations are sensitive to SWE in the
Central Andes of Chile, with a high empirical correlation during the accumulation period.

887
Wed_113_CR-3_1035
Interannual Variability of Snowfall Interception in Deciduous Nothofagus Forest

Marlene Huerta1 (lissp3@ug.uchile.cl), Noah Molotch2,3, James McPhee1,4

1
University of Chile, Department of Civil Engineering, Santiago, Chile, 2University of Colorado Boulder,
Department of Geography, Boulder, United States, 3Institute for Arctic and Antarctic Research, University of
Colorado, Boulder, United States, 4Advanced Mining Technology Center, Faculty of Physical and Mathematical
Sciences, University of Chile, Santiago, Chile

Native nothofagus forests in the mid-latitude regions of the Andes Cordillera are notorious biodiversity
hotspots, uniquely situated in the Southern Hemisphere such that they develop in snow-dominated reaches of
this mountain range. Spanning a comparatively smaller surface area that similar ecosystems in the northern
hemisphere, the interaction between vegetation and snow processes in this ecotone has received relatively
little attention in the scientific literature. Here, we present the first systematic study of snow-vegetation
interactions in the nothofagus forests of the Mediterranean Andes, focusing on the interplay between
interception, climate and energy exchange in determining patterns of snow water equivalent variability. The
Valle Hermoso experimental basin, located in Nevados de Chillan, was fitted with eight continuously measuring
snow depth sensors, located at varying elevations, aspect and forest cover. Also, manual measurements of
snow properties and canopy parameters as distance to canopy, leaf area index and total gap area were
obtained during end-of winter and spring seasons during three years, 2015 through 2017. We find that
interception implied a 22% - 32% reduction in snow accumulation in forested sites compared with clearings.
Differences in snow duration were not statistically significant between forested and clearing sites, indicating
that long-wave energy exchange is unable to overcome the shading induced by the forest canopy, even in
deciduous forest.

888
Wed_115_CR-3_1189
Closing the Water Budget of the Wolverine Glacier Basin, Kenai Mountains, AK

Krista Myers1,2 (kmyer19@lsu.edu), Shad O'Neel2, Louis Sass2, Joshua Koch2, Anna Bergstrom2,3, Christopher
McNeil2, Peter Doran1
1
Louisiana State University, Geology and Geophysics, Baton Rouge, United States, 2USGS, Alaska Science Center,
Anchorage, United States, 3University of Colorado Boulder, Geological Sciences, Boulder, United States

Water budgets of glacialized basins are difficult to constrain, despite the significant potential to undergo
change as ice coverage decreases and rain becomes the dominant form of precipitation. Wolverine Glacier
(WG) is a coastal mountain glacier in southcentral Alaska that has experienced 27 m w.e. a-1 mass loss since
monitoring began in 1966. A basic water budget was calculated for the WG basin using meteorological, glacier
surface mass balance, and stream discharge data from water years 2011 through 2017. The water budget was
partitioned into on-glacier and off-glacier components in order to quantify how different hydrologic
components contribute to annual stream discharge. Our results indicate the dominance of on-glacier fluxes and
a large and temporally-variable residual that likely accounts for unmeasured variables. As the glacier continues
to retreat, off-glacier components will become more important as new vegetation expands into previously ice-
covered regions, altering timing of water delivery, storage, chemistry, and evapotranspiration. Understanding
the water budget of glacierized basins will become increasingly important, as they provide delivery of
freshwater and nutrients to downstream habitats. Water source (on versus off glacier), timing, and magnitude
of basin runoff will be critical to predict impact on these diverse and economically significant ecosystems.

889
Wed_116_CR-3_1192
A Framework of Remote Sensing Products for Three Pole Studies

Rongxing Li1,2 (rli@tongji.edu.cn), Yinsheng Zhang3, Hansheng Wang4, Fei Li5, Xiaohua Tong1,2
1
Center for Spatial Information Science and Sustainable Development Applications,Tongji University, Shanghai,
China, 2College of Surveying and Geo-Informatics, Tongji University, Shanghai, China, 3Institute of Tibetan
Plateau Research, Chinese Academy of Sciences, Beijing, China, 4Institute of Geodesy and Geophysics, Chinese
Academy of Sciences, Wuhan, China, 5Chinese Antarctic Center of Surveying and Mapping, Wuhan University,
Wuhan, China

The Three Poles play an important role in the earth system and global change studies. Much of research efforts
have been made in studying the individual poles and their immediate and intermediate surroundings, while
research results of three poles as non-separate entities have been less published. We present a framework of
remote sensing product generation which will establish a collection of maps and databases to support
integrated three poles studies. These products will geographically cover all three poles and have a range of
cryospheric and hydrospheric attributes, including permafrost, sea ice, snow, albedo, ice sheets and glaciers
(mass balance, ice flow speed etc.) and others. Existing products will be evaluated and updated considering
their consistencies, errors, and spatial and temporal changes. New products will be generated to fill gaps or to
improve the quality as new data and technology become available. Models can be used to guide observations
and data collections, as well as to demonstrate the capability of uncertainty reduction of predictions. The
remote sensing products are expected to support a focused set of science applications including the anomaly
change trend of some local and regional glaciers in Tibet Plateau, change and instability of polar ice sheets vs.
sea level changes, and global sea ice change trend.

890
Wed_117_CR-3_1280
Effects of Glacial Meltwater on pCO2 and Air-sea CO2 Flux in Greenland Fjord

Daiki Nomura1,2 (daiki.nomura@fish.hokudai.ac.jp), Naoya Kanna2, Shun Yunoki1, Daiki Sakakibara2, Yasushi
Fukamachi2,3,4, Toru Hirawake1,2, Shin Sugiyama2,3
1
Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan, 2Arctic Research Center, Hokkaido
University, Sapporo, Japan, 3Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan, 4Global
Station for Arctic Research, Global Institution for Collaborative Research and Education, Hokkaido University,
Sapporo, Japan

In order to clarify effects of glacial meltwater discharge on surface water carbonate chemistry and air-sea CO2
flux, observational studies were carried out in the Bowdoin Fjord in northwestern Greenland during the
summer of 2016 and 2017. Due to the freshwater supply from the melting glacier, surface water salinity was
low down to 6.5 near the calving front of the glacier as compared to that in the outer side of the fjord
(Salinity=30.5). The dissolved inorganic carbon (DIC) and total alkalinity (TA) in surface water were also low
near the calving front while they were high in the outer side of the fjord. A relationship between salinity and
DIC/TA in surface water indicates high correlations, suggesting that variations of DIC and TA in surface water
are explained mainly by the dilution effect due to the discharge of the pure glacial meltwater. The partial
pressure of CO2 (pCO2) in surface water estimated from DIC and TA was low, especially near the calving front
down to 100 µatm as compared to that in the atmosphere (about 400 µatm). Therefore, the surface water
affected by the glacial meltwater acted as a sink for atmospheric CO2. Present results indicate that the
discharge of glacial meltwater draws down the pCO2 in surface water and enhances the air-to-sea CO2 flux.

891
Wed_118_CR-3_1762
The Subglacial Recovery Lake: New Insights from Airborne Radar Data

Anja Diez1, Kenichi Matsuoka1 (kenichi.matsuoka@npolar.no), Tom Jordan2, Jack Kohler1, Fausto Ferraccioli2,
Hugh Corr2, Arne Olesen3, René Forsberg3
1
Norwegian Polar Institute, Tromsø, Norway, 2British Antarctic Survey, Cambridge, United Kingdom, 3Technical
University of Denmark, Copenhagen, Taiwan, Republic of China

The Recovery Region, with its largest glacier Recovery Glacier, was identified as the biggest contributor to sea
level rise from East Antarctica in future. Active subglacial lakes along the glacier suggest an active hydraulic
network controlling the enhanced ice flow of Recovery Glacier. Four giant lakes (Lake A--D) were identified at
the onset of the enhanced ice flow from satellite data. Their stability and potential hydraulic link to the
downstream lakes is unknown. We conducted an extensive radar survey over these lakes in 2015/16,
complementing radar data from the region from 2013/2014. We analyze this new radar data together and
compare it to previously collected data from 2008/2009. Hence, we show that the two southern lakes, Lakes C
and D do currently not contain significant amounts of water. Within the originally-proposed area of Lake A and
B we identify one Lake/Swamp area and estimate its current area to be about 4320 km2. Water leakage from
the western boundary of this lake triggers the fastest enhanced ice flow branch of Recovery Glacier. We
suggest that this Lake is part of the system of active subglacial lakes further downstream within the Recovery
trough, affecting their multi-year cycle of filling and draining.

892
Wed_119_CR-3_2030
Water Balance and Thermal Regime of Lakes in Antarctic Oases

Elena Shevnina1 (elena.shevnina@fmi.fi), Ekaterina Kourzeneva1, Daniela Franz2, Yuriy Dvornikov3

1
Finnish Meteorological Institute, Helsinki, Finland, 2Johann Heinrich von Thünen Institute, Berlin, Germany,
3
Earth Cryosphere Institute, Russian Academy of Sciences, Saint Petersburg, Russian Federation

Connection between thermal regime and water balance for lakes in the Antarctic oases was studied. The study
based on observation on 18 lakes located in the King George Island, the Larsmann Hills and the Schirmaher
oasis in summers 2011-2018. The role of evaporation in the seasonal water balance of the Antarctic lakes are
discussed. The latent heat flux or the evaporation rate was evaluated from the lake model FLake simulations
forced by standard meteorological observations. Also, the evaporation was estimated from the empirical
equations. The sensitivity of the different methods to calculate evaporation, by the Dalton-type empirical
equation and by the atmospheric surface layer block of the FLake model, was studied. For endorheic lakes, the
sensitivity appeared to be large, up to 47% of the total seasonal water volume change, which assumes that
FLake has the potential to be used in hydrological applications to calculate evaporation.

893
Wed_120_CR-3_2038
Consequences of a Human-induced Lake Drain in Antarctic Permafrost Environment

Luis Moreno-Merino1 (l.moreno@igme.es), Juan José Duran-Valsero2, Jerónimo López-Martínez3, Adrian Silva-
Busso4
1
Geological Survey of Spain-IGME, Environmental Geology and Geo-Mathematics, Madrid, Spain, 2Geological
Survey of Spain-IGME, Geological Resources, Madrid, Spain, 3Universidad Autónoma de Madrid, Departamento
de Geología y Geoquímica, Madrid, Spain, 4Universidad de Buenos Aires, Departamento de Geología, Buenos
Aires, Argentina

Böeckella Lake, located in Hope Bay, northern Antarctic Peninsula, is a thermo-karstic lake surrounded by
morainic deposits. The area has continuous permafrost with 80-100 m mean depth. This is a relevant location
from the ecological point of view, containing one of the main Adelie penguin's colonies. The natural lake
recharge came from glacial melting water, direct precipitation and underground circulation from the
surrounding moraines. The lake discharge from the lake was mainly by underground flow in the northern sector
to the Böeckella stream. The lake has been the source of fresh water for the Argentinean Esperanza Base for
more than 30 years. In order to increase the volume of stored water in the lake, its level was artificially
increased by means of construction of a wall in the natural drain sector. During the 2009-2010 austral summer
the closure of the lake broke, due to permafrost melting, and in a few hours the lake water discharged to the
sea. The lake was replaced by a dry surface containing five ponds corresponding to the main natural lake
depocenters. In this work, the causes and consequences of the mentioned event are analyzed, including the
effects in the vegetation and animal colonies around the lake. Broader effects discussed are those connected
with exposure to the atmosphere of stored organic matter, which started an oxidation process and CO2
transference to the air.

894
Wed_121_CR-3_2073
Contributions to High Asian Runoff from Glacier Ice and Seasonal Snow

RIchard Armstrong1 (rlax@nsidc.org), Andrew Barrett1, Mary Jo Brodzik1, Alice Hill1, Siri Jodha Khalsa1, Alia
Khan1, Adina Racoviteanu2, Bruce Raup1, Karl Rittger1, Alana Wilson1, Florence Fetterer1, Betsy Armstrong1
1
University of Colorado, Boulder, United States, 2Aberystwytyh University, Aberystwytyh, United Kingdom

Realistic, accurate estimates of future availability and vulnerability of water resources across the High Asia
region are not possible without a better understanding of the current hydrologic regime. The amount, timing
and spatial patterns of snow and ice melt play key roles in providing water for downstream irrigation,
hydropower generation, and general consumption. Separating the specific contribution of seasonal snow
(renewable) versus glacier ice (non-renewable) melt is the main goal of the Contribution to High Asia Runoff
from Ice and Snow (CHARIS) project that focuses on the Ganges, Brahmaputra, Indus, Amu Darya and Syr Darya
basins. Our methodology involves the application of MODIS-derived remote sensing products to calculate
separately daily melt from snow and glacier ice. Using an automated partitioning method, we generate daily
maps of:
1) snow over glacier ice,
2) exposed glacier ice, and
3) snow over land.
These are inputs to a temperature index (TI) model that yields melt water volumes contributing to river flow.
Here we present a high-level summary of our overall methodology as well as preliminary results for the five full
CHARIS basins. The western regions of High Asia are heavily reliant on snow and ice melt sources for summer
dry season flow when demand is at a peak (15-20% specifically from glacier ice melt) whereas monsoon rainfall
dominates runoff during the summer period in the east (< 5% from glacier ice melt).

895
Wed_122_CR-3_2093
Intensity of Internal and External Water Cycle for the Tibetan Plateau

Hui Wu1 (wuhui@camscma.cn), Renhe Zhang1,2, Kun Yang3,4, Lei Wang4, Yangjun Qi1
1
Chinese Academy of Meteorological Sciences, Beijing, China, 2Fudan University, Shanghai, China, 3Tsinghua
University, Beijing, China, 4The Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing,
China

Tibetan Plateau (TP) is referred as “Asian Water Tower” for the large amount of water storage and the wide-
range influence on the downstream countries through a large network of rivers. In the water cycle, energy
released from the phase change of water during precipitation is part of the elevated thermal effect on the
weather and climate over the Northern Hemisphere. The study presents the relative contribution of internal
and external water vapor to the precipitation based on basin-scale analysis over the TP. The result shows that
the water vapor transportation varies depending on the circulation and terrain complexity. Overall, the
atmosphere conveys about 60% of the water vapor condensation into the precipitation over the TP, whereas
the local evapotranspiration contributes the rest 40%.
Noted the reanalyses produced excessive precipitation over the TP, we also compare the water cycles in
several reanalyses. The result could give some light on the errors of the reproducing the water cycle processes
in reanalyses and be helpful to improve the performance of the model over TP.

896
Wed_123_CR-3_2148
Oxygen Stable Isotope Variability on the Pine Island Glacier Ice Divide

Ronaldo Torma Bernardo1 (ronaldo.bernardo@ufrgs.br), Franciele Schwanck1, Jefferson Cardia Simões1,

Douglas Introne2
1
UFRGS, CPC, Porto Alegre, Brazil, 2University of Maine, CCi, Orono, United States

This work reports the δ18O variability in the upper 45 m of a 92 m firn-ice core recovered from the West
Antarctic Ice Sheet in the 2008/09 austral summer. The core site, called Mount Johns, is at 79°55'S; 94°23'W,
2122 m a.s.l., the 12 m temperature is -33 °C. The core was melted in a continuous melter system and the first
300 samples analyzed by IRMS at Climatic Change Institute, University of Maine. Further, 1500 samples were
measured by laser spectroscopy at the Centro Polar e Climático Isotopes Laboratory. The medium value for
these 1800 samples is 36.4 ± 1.9‰, ranging from -42.7 to -30,3‰, covering about 105 years of accumulation
(i.e., about 0.21 m in water equivalent per year). The isotopic profile recorded at Mount Johns shows a
warming trend similar to the ones observed in others West Antarctic Ice Sheet sector (WAIS) since the 1990s.
These changes are directly linked to variations in the regional atmospheric circulation, we discuss these stable
isotope ratios in term of changes in the moisture source areas.

897
Wed_124_CR-3_2232
Permafrost as a Key Factor of River Runoff Generation in Central Yakutia, Russia

Liudmila Lebedeva1 (lyudmilaslebedeva@gmail.com), Olga Makarieva1,2,3

1
Melnikov Permafrost Institute, Yakutsk, Russian Federation, 2St. Petersburg State University, St. Petersburg,
Russian Federation, 3Gidrotehproekt Ltd., St. Petersburg, Russian Federation

The study aims in estimation of role of permafrost-related processes in runoff generation in continuous
permafrost in Eastern Siberia. Terrain is elevated plain (100-500 m a.s.l.) with occasional uplands. The climate is
cold and dry. Mean air temperature varies from -9 to -11°C, precipitation ranges from 270 to 310 mm/year.
Main land cover types are slopes, uplands and thermokarst areas. Studied 18 river basins with areas 80 - 65400
km2 were classified into three groups with distinct behavior:
1) with flow larger 100 mm/year and variation coefficient (Cv) lower 0.4;
2) transitional;
3) with flow lower 24 mm/year and Cv larger 1.1.
Rivers of the 1st group do not freeze up to the bottom and do not dry. Rivers of 2nd group freeze up to the
bottom in winter but flow every year in warm season. Rivers of 3rd group could be frozen and/or dry for the
whole year. Precipitation does not explain spatial and temporal variability of flow. Land cover analysis showed
that rivers with high and stable flow have less than 4% of the watershed area subject to thermokarst. More
than a half of basin areas of rivers with low and unstable flow are occupied by thermokarst. Study showed that
permafrost conditions could play a larger role in runoff generation than hydroclimatic factors.
The study is partially supported by Russian Foundation for Basic Research, projects No 17-05-00926.

898
Wed_125_CR-3_2298
Enthalpy-based Distributed Melting Modelling of Two Glaciers on Tibetan Plateau

Baohong Ding1 (dingbh@itpcas.ac.cn), Francesca Pellicciotti2, Kun Yang1,3, Wei Yang1, Alvaro Ayala4, Thomas
Shaw5, Hui Wu6
1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China, 2Northumbria University,
Newcastle, United Kingdom, 3Tsinghua University, Beijing, China, 4ETH Zürich, Zurich, Switzerland, 5Universidad
de Chile, Santiago, Chile, 6Chinese Academy of Meteorological Sciences, Beijing, China

Glacier-climate interaction and its spatial variability over the Tibetan Plateau is still poorly understood. We
present a new distributed glacier mass balance model applied on two glaciers of the Tibetan Plateau: Parlung
No. 4 Glacier, 11.7 km2, a temperate-maritime glacier, and Zhadang Glacier, 2.0 km2, a sub-continental glacier.
Enthalpy, rather than temperature, is used in the energy budget equations to simplify the computation of
latent heat fluxes from water phase changes and the movement of liquid water in the snow. Two novel
methods are used to distribute near-surface air temperature and wind speed from a set of Automatic Weather
Stations (AWS). Further, we apply a new method to discriminate between solid and liquid precipitation based
on daily mean air temperature, relative humidity, and elevation. Model results are evaluated by in-situ mass
balance observations of the Parlung No. 4 Glacier and remote sensing products.
Our aims are to:
i) develop a novel enthalpy-based model and test its performance on the distributed simulations of glacier
mass balance and energy budget;
ii) compare the physical processes typical of the summer season on two different types of glaciers on the
Tibetan Plateau;
iii) identify the key model sensitivities at both study sites.
We present the interplay of precipitation thresholds, albedo and net radiation at these different glaciers and
discuss their implications for future mass balance modelling on the Tibetan Plateau.

899
Wed_126_CR-3_2301
Oxygen 17 Fractionation during Water Freezing in the Subglacial Lake Vostok

Alexey Ekaykin1,2 (ekaykin@aari.ru), Anna Kozachek1, Vladimir Lipenkov1, Aleksandra Skakun1, Arina Veres1,2,
Diana Vladimirova1,2
1
Arctic and Antarctic Research Institute, Saint Petersburg, Russian Federation, 2Saint Petersburg State
University, Institute of Earth Sciences, Saint Petersburg, Russian Federation

Stable water isotope content is widely used in paleo-climatology, glaciology and hydrology as a proxy of the
precipitation formation conditions, water origin etc. In particular, the concentration of heavy isotopes is
applied in hydrology for mass-balance studies, to assess contribution of different water sources and other
issues. Understanding the isotopic transformations of water during the hydrological cycle requires precise
knowledge of the fractionation coefficients. While for deuterium and oxygen 18 these coefficients are known
within satisfactory uncertainty, this is not the case for the oxygen 17 fractionation coefficients.
In this study, we use a unique opportunity provided by the hydrological system of Antarctic subglacial Lake
Vostok, where the lake water is slowly frozen in equilibrium conditions to form the accreted lake ice
underneath the Antarctic ice sheet. We have precisely measured the isotopic composition (including oxygen 17
concentration) in the accreted lake ice and water, which for the first time allowed us to directly obtain robust
values of oxygen 17 fractionation coefficients during water freezing. It has been demonstrated that the ratio
between 17O and 18O fractionation coefficients during water freezing differs significantly from the value
known for evaporation and sublimation processes. We use these new findings to re-assess the characteristics
of Lake Vostok water mass balance.

900
Wed_127_CR-3_2305
Impact of Topography on Snowfall, Assessed by a Dual-pol Radar

Nikola Besic1,2 (nikola.besic@epfl.ch), Franziska Gerber1,3, Daniele Nerini2, Yvan Chevalley1, Loris Foresti2, Jordi
Figueras i Ventura2, Marco Gabella2, Urs Germann2, Michael Lehning1,3, Alexis Berne1
1
EPFL, Lausanne, Switzerland, 2MeteoSwiss, Locarno-Monti, Switzerland, 3WSL Institute for Snow and Avalanche
Research SLF, Davos, Switzerland

In this contribution we analyse the impact of topography on snowfall, in terms of variability and microphysics,
by interpreting polarimetric radar data. The former is related to the dynamics i.e. growth and decay analysis of
the snowfall precipitation field, while the latter is related to the 3D hydrometeor classification in precipitation.
The analysis focuses on the region around the Weissfluhgipfel (WFG) radar, in the vicinity of Davos,
Switzerland.
The growth and decay analysis is based on the advection (semi-Lagrangian scheme) of the snowfall field and
the comparison with the following actual measurement. Basically, we shift the precipitation field as if it was not
affected by the local topography and then compare it with the measurement which obviously accounts for the
micro-scale influence.
The applied hydrometeor classification is a semi-supervised approach, adapted to the technical specificities of a
radar, capable of distinguishing between 9 different hydrometeor classes, among which rimed ice particles,
aggregates (AG), crystals (CR) and vertical ice.
Links of both variability (snowfall growth) and microphysics (intense riming + AG/CR co-occurrence)
observation to the local topography are assessed through multi-scale wavelet analysis. The analysis shows an
interesting correspondence between the zones of snowfall growth on one side and the zones of relatively more
intense riming and AG/CR co-occurrence on other side.

901
Wed_128_CR-3_2436
Arctic Precipitation: Observed Trends and Changes at Ny-Alesund, Svalbard

Foteini Baladima1 (foteini.baladima@univ-grenoble-alpes.fr), Hans-Werner Jacobi1, Mareile A. Wolff2, Ragnar

Brækkan2, Eirik Førland2, Herdis M. Gjelten2
1
University Grenoble Alpes / CNRS / Grenoble INP / IRD, Institute for Geosciences and Environmental Research
(IGE), Grenoble, France, 2Norwegian Meteorological Institute, Oslo, Norway

Liquid and solid precipitation are important climatic variables in the Arctic that are expected to have
undergone significant changes in the past and will undergo further changes due to the changing climate.
However, only a few in situ data sets of these variables are currently available in the Arctic. Due to the long
history of monitoring activities Ny-Alesund, Svalbard offers the possibility to generate a quality-controlled data
set that may serve as a reference of precipitation for the analysis of the impact of a changing climate on the
hydrological cycle, on cryospheric processes, on atmospheric chemistry, or on the properties of the soil.
However, it is well known that standard gauges to measure precipitation can strongly be biased especially in
the case of solid precipitation. We will present our recent work on the correction of observed precipitation in
Ny-Alesund for arctic conditions and how these corrections modify the recorded data. Moreover, the
uncorrected and corrected precipitation time series will be analyzed regarding parameters like total
accumulation, number of events, modification of precipitation phase, and strength and frequency of extreme
events.

902
Wed_129_CR-3_2449
Rapid Expansion of Glacial Lakes in the Central Himalayas

Weicai Wang1 (weicaiwang@itpcas.ac.cn)

1
Institute of Tibet Plateau Research, Chinese Academy of Sciences, Beijing, China

Glacial lake outburst floods are among the most serious natural hazards in the Himalayas. Such floods are of
high scientific and political importance because they exert trans-boundary impacts on bordering countries. The
preparation of an updated inventory of glacial lakes and the analysis of their evolution are an important first
step in assessment of hazards from glacial lake outbursts. Here, we report the spatiotemporal developments of
the glacial lakes in the Poiqu River basin, a trans-boundary basin in the Central Himalayas, from 1976 to 2010
based on multi-temporal Landsat images. Studied glacial lakes are classified as glacierfed lakes and non-glacier-
fed lakes according to their hydrologic connection to glacial watersheds. We found that lakes connected to
glacial watersheds (glacier-fed lakes) significantly expanded from 1976 to 2010, whereas lakes not connected
to glacial watersheds (non-glacier-fed lakes) remained stable during the same period. This contrast can be
attributed to the impact of glaciers. Retreating glaciers not only supply meltwater to lakes but also leave space
for them to expand. Compared with other regions of the Hindu Kush Himalayas (HKH), the lake area per glacier
area in the Poiqu River basin was the highest. This observation might be attributed to the different climate
regimes and glacier status along the HKH. The results presented in this study confirm the significant role of
glacier retreat on the evolution of glacial lakes.

903
Wed_130_CR-3_2500
Persistent Pollutants in Kongsfjorden (Svalbard) Sea Water and Coastal Sediments

Stefania Giannarelli1 (stefania.giannarelli@unipi.it), Sandro Francesconi1, Beatrice Muscatello2

1
University of Pisa, Department of Chemistry and Industrial Chemistry, Pisa, Italy, 2University of Pisa,
Department of Pharmacy, Pisa, Italy

Persistent organic pollutants (POPs) are chemicals with long-lifetime in the environment, and therefore have
the potential to be transported over long distances.
As the environmental behaviour of POPs depends on complex interaction of many factors, any significant
environmental alteration is likely to affect their distribution and fate; temperature as well as many other
mechanisms are known to influence their distribution in the environment.
Sea ice, as well snow melting, can be well considered an indicator of climate change and it is also a significant
POPs reservoir, and influences the contaminant dispersion through the sea ice trajectories.
Kongsfjorden is situated in the northern part of Spitsbergen island (Norwegian Arctic). Surface and depth
water, as well as sediments, were collected at four sites during three sampling campaigns between June and
September 2012, which means before, during and after ice and snow melting. The sampling stations were
characterized by different degrees of glacial "runoff" and different anthropogenic impact.
The present investigation reveals the results of the analysis of the samples for their PAH, OCP and PCB content.
Twelve of 16 studied PAHs, seven of 29 PCBs and four of 14 OCPs were determined in the sea waters. Total
PAH, PCB and OCPs concentrations in the sea waters were from 50 to 500 ng/L, 5 to 30 ng/L and 10 to 150 ng/L
respectively.

904
Wed_131_CR-3_2658
An Assessment of the MAR Regional Climate Model over High Mountain Asia

Melissa Linares1 (melinares2@gmail.com), Marco Tedesco1,2, Steve Margulis3, Jeyavinoth Jeyaratnam1,4, Patrick
Alexander1, Xavier Fettweis5
1
Lamont-Doherty Earth Observatory Columbia University, New Yrok, United States, 2NASA Goddard Institute of
Space Studies, New Yrok, United States, 3UCLA, Department of Civil and Environmental Engineering, Los
Angeles, United States, 4City College of New York, New Yrok, United States, 5Université de Liège, Department of
Geography, Liège, Belgium

The lack of ground measurements has made the use of remote sensing, atmospheric reanalysis and modelling
tools over the High Mountain Asia (HMA) pivotal for understanding the impact of climate change on the
hydrological cycle and on the cryosphere . Here, we show the results of the analysis of the assessment of the
outputs of Modèle Atmosphérique Régionale (MAR) model RCM over the HMA region as part of the NASA-
project 'Understanding and forecasting changes in High Mountain Asia snow hydrology via a novel Bayesian
reanalysis and modeling approach'.
We compared the MAR outputs with reanalysis data from ERA-Interim over the region bounded by the
following coordinates: 66°E to 89°E and 21°N to 39°N. In particular, we evaluated the following parameters:
surface pressure, snow depth, total cloud cover, two-meter temperature, wind speed, surface new solar
radiation, skin temperature, surface sensible heat flux, and surface latent heat flux. The level of agreement
between the RCM outputs and the reanalysis highly depend on the specific parameters. For example, in case of
surface pressure the maximum percentage error is 13.24% while the 2-m air temperature has a maximum
percentage error of 340.62%.
Lastly, we report results concerning the assessment of MAR surface albedo and surface temperature over the
region through MODIS products. Next steps are to determine whether RCMs and reanalysis datasets are
effective at capturing snow and snowmelt runoff processes.

905
Wed_132_CR-7_94
Multiyear Observations on Stable Isotopes of Surface Snow along CHINARE Transect

Tianming Ma1,2 (matianming@pric.org.cn), Yuansheng Li2, Li Li1, Chunlei An2, Guitao Shi2, Hongmei Ma2, Su
Jiang2
1
Tongji University, State Key Laboratory of Marine Geology, Shanghai, China, 2Polar Research Institute of China,
Shanghai, China

Water stable isotopes from Antarctic surface snow have long been used to understand physical processes
occurring in hydrologic cycle. In this study, a dataset including new measurements and previous observations is
presented here for the determination of water isotopic composition along the traverse from Zhongshan Station
to Dome A, East Antarctica. All 661 samples were collected in 7 field seasons by Chinese National Antarctica
Research Expedition. The spatial distribution of δ18O and δD show significantly decrease tendency from coastal
to inland regions, with a latitudinal gradient of -2.42 ‰/degree(r2=0.85), an altitudinal gradient of -1.02
‰/100m (r2=0.85), a temperature gradient of 0.95 ‰/℃(r2=0.85). In addition, the accumulation, moisture
source, transportation paths and post-depositional effects are also possible to have an association with spatial
variability of water stable isotopic ratios. To disentangle the complicated influences on water isotopic
composition of surface snow samples, the Hysplit trajectory model combining with MCIM model are used to
calculate δ values during snowfall process. The results indicate that the moisture source of each region is
completely different. Simulated experiments under various temperatures were conducted to reveal
sublimation and isotopic exchanges between snow and air. This comparison suggests the isotopic composition
of surface snow on coastal region may get a more impact by post-depositional processes than other regions.

906
Wed_133_CR-7_168
Ionic and Isotopic Variability in a Firn Core in the Antarctic Ice Sheet

Flavia Alves Tavares1 (flaviaalvestavares@hotmail.com), Nicoli Pozzebon Gerhard1, Jefferson Cardia Simões1,
Ronaldo Torma Bernado1, Isaías Ullmann Thoen1, Filipe Gaudie Ley Lindau1
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Centro Polar e Climático, Porto Alegre, Brazil

This work investigates the concentrations the major ionic and the stable isotope variability in a 42.92 m firn
core (called IC-2) collected at 88°01´21.3"S, 82°04´21.7"W (2,621 m a.s.l.) in the West Antarctic sheet, during a
Chilean-Brazilian traverse in the 2004/05 Austral summer. We subsampled the core using a continuous melting
system at the Climate Change Institute (CCI, University of Maine, USA) under a Class 100 room conditions. This
process generated 1,755 samples (about 40 samples by meter) for ionic chromatography determination Na+, K+,
Mg2+, Ca2+, MS- (CH3SO3-), Cl-, NO3- e SO42-. We used a Picarro system (Wavelength-Scanned Cavity Ring Down
Spectrometer, WS-CRDS) for determining the δ18O and δD in each sample. The mean δ18O is -46.45‰ (ranging
from -50.77‰ to -41.40‰); while the mean δD is -369.68‰ (ranging from -408.18‰ to -323.85‰). The
deuterium excess (d) varies from -5.84‰ to 9.23‰ (mean = 3.74‰). The first 800 samples (the upper 23 m)
show a mean snow accumulation rate of 0.40 m y-1 in eq. H2O, corresponding to about 32 years of
precipitation. The ionic analysis of the first 200 samples show a strong predominance of H+ (2.52 µEq L-1),
indirectly calculated through the ionic balance, indicating an acid contribution, and low concentrations of NO3-
(68.52 ± 31.39 µg L-1) (Lindau et al., 2016), probably resulting from post-depositional effects (glaze ice is
observed in the area).

907
Wed_134_CR-7_312
Spatio-temporal Variations of Firn Properties on the Western Greenland Ice Sheet

Regine Hock1 (rehock@alaska.edu), Giovanni Corti2, Federico Covi1, Takao Kameda3, Jonny Kingslake4, Sasha
Leidman5, Clement Miege5, Asa Rennermalm5, Steve Munsell6, Marco Tedesco4
1
University of Alaska Fairbanks, Geophysical Institute, Fairbanks, United States, 2Reed College, Portland, United
States, 3Kitami Institute of Technology, Koencho, Japan, 4Columbia University, New York, United States, 5State
University of New Jersey, Piscataway, United States, 6Prescott College, Arizona, United States

On the Greenland ice sheet a significant portion of surface melt percolates, refreezes, or is stored in porous
firn. However thick (>5 m) ice layers in the ice sheet, now present at lower elevations, can seal off underlying
porous firn, forcing meltwater to generate runoff instead of refreezing. Using five 20-26 m firn cores collected
40 to 100 km apart (1963 to 2355 m a.s.l.) in spring 2017 in addition to GPR data, automatic weather stations
and ice temperature profiles, we investigate stratigraphy and spatio-temporal variation of firn properties in the
Kangerlussuaq sector of the western Greenland ice sheet. We find significant spatial variability in firn
properties on both large and small scales. For firn cores extracted at the lowest elevations thick (>1 m) ice
lenses are present in the upper portion. The fraction of ice lenses for the upper 20 m of the cores ranged from
10% to 55%. A short core (5 m) drilled 16 m away from one of the longer cores shows significant small-scale
variability in the distribution of ice lenses. Comparing 2017 core data to legacy data from 1989 at one drilling
site shows a substantial increase in mean firn density and the size and number of ice lenses.

908
Wed_135_CR-7_412
Analysis of IceCube and QualitySpec Trek Derived Snow SSA Measured in Sodankylä

Leena Leppänen1 (leena.leppanen@fmi.fi)

1
Finnish Meteorological Institute, Sodankylä, Finland

Snow microstructure is important for microwave and optical remote sensing of snow. One parameter
describing it is specific surface area (SSA), which is defined as volume to surface area ratio of snow grains.
Several measurement methods are developed to measure it, including reflectance derived methods, as
reflectance at NIR and SWIR wavelengths is sensitive to grain size and therefore SSA.
IceCube (A2 Photononic Sensors, France) is developed to SSA measurements and it measures hemispherical
reflectance of 1310 nm laser from the snow sample surface. Method is presented to be accurate (10 % error)
but it needs removal of the snow from snowpack during the sampling. Recently developed hand-held
QualitySpec Trek (QST, ASD Inc., US) measures spectral reflectance of 350-2500 nm with direct contact to the
object.
The collected data set includes measurements of vertical snow profile with IceCube and QST during five days
between February and April 2017 in Sodankylä in Finland at research station of Finnish Meteorological
Institute. Some of the IceCube samples were measured also with QST.
Preliminary results shows usability of QST for SSA observations, thus error seems to be larger than for IceCube.
QST observations confirms also that reflectance measured from IceCube samples differs little from reflectance
measured directly from the snowpack at the same height.

909
Wed_136_CR-7_552
Wind-packing of Snow in Antarctica

Christian Sommer1,2 (sommer@slf.ch), Nander Wever1,2, Charles Fierz1, Michael Lehning1,2

1
WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland, 2École Polytechnique Fédérale de
Lausanne, School of Architecture, Civil and Environmental Engineering, Lausanne, Switzerland

A snowfall and subsequent drifting snow event were observed in Antarctica. The event was similar to recent
wind tunnel experiments on wind-packing of snow and could therefore be used to compare wind-packing in
Antarctica with those experiments. The results from Antarctica were similar to those from the wind tunnel.
Drifting snow is necessary for wind-packing and the hardening is more efficient at wind-exposed surfaces than
in wind-sheltered areas. The results show that the insight gained from the wind tunnel experiments are
applicable in nature. Furthermore, it is demonstrated for the first time how fresh snow gets organized in
Barchan dunes during subsequent drifting with significant increase in surface hardness at all locations on the
dune. This quantitative analysis of surface and associated hardness change improves our understanding of
Antarctic snow deposition.

910
Wed_137_CR-7_728
The Challenge of Automatic SWE Measurements in High Altitudes

Christoph Marty1 (marty@slf.ch), Charles Fierz1, Alain Geiger2, Franziska Koch3, Wolfram Mauser3, Ladina
Steiner2
1
WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland, 2ETH / IGP, Zurich, Switzerland, 3LMU,
Munich, Germany

Information about the available snow water equivalent (SWE) of a snow pack is valuable for many applications
including the validation of remote sensing data, flood forecasting, designing buildings for snow loads and
assessing changes in snow water resources in mountain catchments. The measurements of SWE are
particularly important in mountain regions where measuring winter precipitation by conventional rain gauges is
problematic due to wind under-catch. Manual measurements of SWE are time consuming and therefore often
only performed on monthly time-intervals. The automatic measurement of SWE in Alpine terrain is not reliable
despite the fact that some commercially available devices are on the market. These devices often need either
regular calibration, complicated post-processing or are limited by a maximum SWE they are able to measure.
We use a multi-year data set from the high alpine experimental site Weissfluhjoch at 2540 m asl, where the
mean maximum measured snow depth is 240 cm. On this site SWE has been measured manually in a snow pit
and simultaneously by a snow pillow, a snow scale, a ground penetrating radar and GPS receivers.
We assess the different SWE measurement methods during the typical seasonal evolution of the snow pack
and compare it with state-of-the-art parameterization and modelling approaches.

911
Wed_138_CR-7_806
Synchronizing Borehole Depths to a Temperature Time Series

Jandyr Travassos1 (wavefrontgeo@gmail.com), Mariusz Potoki2, Jefferson Simoes3, Pedro Carvalho1

1
UFRJ, COPPE, RIo de Janeiro, Brazil, 2University of Maine, Climate Change Institute, Orono, United States,
3
UFRGS, NUPAC, Porto Alegre, Brazil

The Plateau Detroit divides the warmer and moist west side from the colder and drier east side of the Antarctic
Peninsula and has a very high deposition rate. We use hydrogen peroxide concentration with a high resolution
sampling, averaging 36 samples/year from a 98m borehole as a robust seasonal marker. We found the
hydrogen peroxide concentration to be well preserved in that high accumulation site. We have also estimated a
daily temperature time series at the site by using daily records from four Antarctic Stations forming a polygon
having the borehole in its interior. Both records, hydrogen peroxide concentration and daily temperature,
follow the same seasonal variation, the passing of years, but in a different fashion. The former has a frequency
scaling in relation to the former. As the temperature has a constant spectral contents we compensate the
peroxide frequency scaling by a non--linear pairing transformation based on mathematical optimization,
without human intervention. That pairing allows for the estimation of a relation of depth to time; a chronology
for the borehole data chronology spanning from 01-Jan-1980 to 29-Dec-2010. The estimated borehole
chronology suggests that at least the first 109.29m were accumulated within a time frame spanning a mere 30
years period. This points to a deposition rate of 2.7m(weq)/year, or 2.5 times the accumulation rate found at
Gomez, further South.

912
Wed_139_CR-7_1228
Snow Microstructure Evolution in Presence of Mineral Dust

Marie Dumont1 (marie.dumont@meteo.fr), Frédéric Flin1, Pascal Hagenmuller1, François Tuzet1, Isabel Peinke1,
Philippe Lapalus1, Anne Dufour1, Jacques Roulle1, Laurent Pézard1, Sabine Rolland-du-Roscoat2
1
Météo-France - CNRS, CNRM/CEN, Grenoble, France, 2UGA - Grenoble INP - CNRS, 3SR, Grenoble, France

Light absorbing impurities in snow such as black carbon or mineral dust are known to decrease snow albedo.
This engenders several positive feedbacks generally leading to an acceleration of snow metamorphism. Though
many studies have been focused on measuring, modeling and quantifying the radiative impact of light
absorbing impurities in snow, only a few have been focused on the non-radiative impact of such impurities and
especially on the impact of the presence of impurities directly on snow metamorphism.
In this study we present 'in vivo' X-ray tomography monitoring of snow microstructure containing mineral dust
(desert sand with size distribution centered at 1 micron) under several conditions and especially under
temperature gradient metamorphism. Snow microstructure evolution along with the change in the spatial
distribution and exact location of the dust particles observed during such an experiment are especially relevant
to understand metamorphism/impurities interplays for arctic snowpacks that frequently undergo high
temperature gradient metamorphism.

913
Wed_140_CR-7_1323
Rapid Measurements of the Snow Surface Specific Area using the ASSSAP Instrument

Laurent Arnaud1, Ghislain Picard1 (ghislain.picard@univ-grenoble-alpes.fr), Eric Lefebvre1

1
Institut des Géosciences de l'Environnement, Saint Martin d'Hères, France

The surface specific area is a snow properties defined as the surface area of the air-ice interface per unit of
mass. It has become in a decade a variable of choice to predict snow optical and microwave behavior and to
quantitatively simulate snow metamorphism allowing significant progresses. The development of instruments
and protocols to rapidly take accurate measurements of SSA in the field has greatly contributed to this
emergence.
ASSSAP, the Alpine/Arctic/Antarctic Snow Specific Surface Area Profiler, is an instrument designed to measure
profiles of SSA at 1 cm resolution in 1-2 meter long boreholes. It estimates SSA from measured snow
reflectance at two wavelengths (1310 nm and 850 nm). It uses laser diodes and photodiodes as the sole optical
elements and basic embedded electronics which is very robust and is able to operate at -40°C. It allows 4
modes of operation:
i) in-situ measurements of profiles in boreholes directly
ii) measurements on samples, in the field or in the lab, with a sampler holder compatible with IceCube
iii) in-situ nondestructive 1-2 meter long transects of SSA of the snow surface,
iv) measurements of profiles along 1-m snow cores in the lab.
The profiles and transects are measured in a matter of minutes, and are equivalent to about 100 independent
measurements. Measurements on sample takes about 30 s. The accuracy has been shown to be around 15% in
a well controlled experiment but our experience suggests that this depends on conditions.

914
Wed_141_CR-7_1372
Results from COST ES1404 Action for Harmonization of Snow Measurements in Europe

Leena Leppänen1 (leena.leppanen@fmi.fi), Juan Ignacio López Moreno2, Ali Nadir Arslan3, Pavla Dagsson
Waldhauserova4, Charles Fierz5, David Finger6, Ladislav Holko7, Bartłomiej Luks8, Christoph Marty5, Ghislain
Picard9, Roberta Pirazzini3, Aynur Sensoy Sorman10, Ali Arda Sorman10
1
Finnish Meteorological Institute, Sodankylä, Finland, 2Pyrenean Institute of Ecology, CSIC, Zaragoza, Spain,
3
Finnish Meteorological Institute, Helsinki, Finland, 4University of Iceland, Reykjavik, Iceland, 5WSL Institute for
Snow and Avalanche Research SLF, Davos Dorf, Switzerland, 6Reykjavik University, Reykjavik, Iceland, 7Slovak
Academy of Sciences, Institute of Hydrology, Bratislava, Slovakia, 8Polish Academy of Sciences, Institute of
Geophysics, Warsaw, Poland, 9Université de Grenoble, St Martin d'Heres, France, 10Anadolu University,
Eskisehir, Turkey

The COST Action ES1404 entitled “A European network for a harmonized monitoring of snow for the benefit of
climate change scenarios, hydrology and numerical weather prediction” aims to enhance and harmonize the
observations of European operational services and the snow research community. This presentation illustrates
the results of the Action activities related to the harmonization of in situ snow observations and
instrumentation, to establish quality-assured and comparable regional and global observation-based data on
the variability of depth, structure and other physical properties of snow cover. Members of the Action designed
a survey carried out among European institutions on measured snow parameters and applied instrumentation.
It was answered by 125 groups from 38 European countries, providing a compilation of the measurement
practices applied by different communities and in various environments and regions. In addition, the Action
organized two field measurement campaigns in Turkey in March 2016 and in Iceland in February 2017
dedicated to the measurements of two essential snow variables, snow water equivalent (SWE) and snow depth
(HS). The results contains the comparison of SWE and HS measurement techniques including error analysis
aiming to develop instrument recommendations for range of environmental conditions. The Action included
several workshops and Short term Scientific Missions that strengthened networking and co-operation among
the participating countries.

915
Wed_142_CR-7_1471
Linking Area Extent of Melt to Changes in Snow and Firn in Greenland

Achim Heilig1 (heilig@r-hm.de), Lino Schmid2, Michael MacFerrin3, Olaf Eisen4, Konrad Steffen5
1
LMU Munich, Department of Earth and Environmental Sciences, München, Germany, 2WSL Institute for Snow
and and Avalanche Research SLF, Davos, Switzerland, 3University of Colorado Boulder, Geography, Boulder,
United States, 4Alfred Wegener Institute, Glaciology, Bremerhaven, Germany, 5WSL Swiss Federal Institute for
Forest Snow and Landscape Research, Birmensdorf, Switzerland

In recent years, increasing melt on the Greenland ice sheet (GrIS) has caused significant changes in percolation
regimes in GrIS's firn. Aquifers have grown in some regions and impermeable ice slabs are forming in others,
which directly affect runoff. The effects of refrozen melt water have been observed in firn cores, but
continuous high-resolution data has not yet been available to document the nature of these changes as they
happen. Very little is known about percolation depths, liquid water content, refreezing and seasonal mass
fluxes, and vertical versus horizontal flow of water in areas where refrozen melt water is becoming the
dominant regime in near-surface firn. To overcome this deficit and provide continuous data for model
evaluations, we installed impulse radar systems at 3 locations in various glacier regimes: at the transition zone
from accumulation to ablation (Swiss Camp), within the deep percolation regime where meltwater inputs are
steadily increasing (Dye-2), and in the dry snow zone (Summit). For summer 2016, we compare monitored
changes within snow and firn at these locations with spatial extent and duration of melt over the GrIS from
remote sensing data. Such comparisons provide valuable information on water retention and percolation at
certain glacier regimes of the GrIS. Linking the detail of in situ data at select sites with the spatial melt extent
supports a more comprehensive interpretation of changes occurring within meltwater regimes over the GrIS.

916
Wed_143_CR-7_1496
Inter-comparison of Direct Observations of Snow Grain Size

Roberta Pirazzini1 (roberta.pirazzini@fmi.fi), Charles Fierz2, Teruo Aoki3, Henna-Reetta Hannula4, Leena
Leppänen4
1
Finnish Meteorological Institute, Meteorological Research, Helsinki, Finland, 2WSL Institute for Snow and and
Avalanche Research SLF, Davos, Switzerland, 3Okayama University, Graduate School of Natural Science and
Technology, Okayama, Japan, 4Finnish Meteorological Institute, Arctic Research, Sodankylä, Finland

This work focuses on snow grain size data measured during the MicroSnow workshop held in March 2014 in
Davos, Switzerland. The workshop was motivated by the recent development of new techniques to measure
the snow microstructure, and aimed to quantify the differences among the various existing methods. The main
objective of this study is to describe direct grain size measurements techniques, which include visual grain size
estimation and calculation of the grain size from macro-photos using image processing software, and inter-
compare the obtained measurements. Each of the inter-compared method applies a specific grain size metric,
which is linked to the original application of the method: traditional visual estimations were developed by snow
scientists to characterize the snowpack, e.g. for hydrological and avalanche forecast purposes. The Aoki grain
size and the short skeleton metric are used to represent the optical properties of the snowpack when studying
its interaction with the visible and near-infrared solar radiation. Finally, grain metrics that represent the
dimension of the aggregated crystals are applied to represent the upper edge of grain size distribution in the
simulation of the radiative transfer in the snow. In this work we assess differences between the used grain
metrics, also in relation to other microstructure quantities such as specific surface area and optically equivalent
grain size, evidencing merits and shortcomings of the applied methods.

917
Wed_144_CR-7_1515
Triple Surface Snow Isotopic Composition Records Metamorphism

Mathieu Casado1,2 (mathieu.casado@gmail.com), Amaelle Landais2, Ghislain Picard3, Laurent Arnaud3, Marion
Leduc-Leballeur4
1
AWI, Potsdam, Germany, 2LSCE (UMR 8212 CEA-CNRS-UVSQ/IPSL), Université Paris Saclay, Gif sur Yvette,
France, 3IGE, Université Grenoble Alpes, CNRS, IRD, Saint Martin d'Hères, France, 4IFAC-CNR, Sesto Fiorentino,
Italy

Water isotopic composition from ice core is a key proxy for past climate reconstructions. In particular, the
longest climatic records from ice core are obtained from the low accumulation areas of the East Antarctic
Plateau. Still, the low accumulation which enables long term records implies a longer exposure of the surface
snow to the atmosphere, and thus, a more significant role of post-deposition processes. This limits the
interpretation of isotopic composition from ice core records, specifically at short time scales.
Here, we compare series of surface snow isotopic composition from East Antarctica to grain index satelitte
observations, highlighting that during intense summer metamorphism events, the climatic signal in the surface
snow isotopic composition is erased. Still, we observe a signature of these events left in surface snow 17O-
excess. We compare the evolution of surface snow isotopic composition in between precipitation events to the
first measurements of 17O-excess in the vapour in Antarctica to estimate the mass balance and the associated
fractionation. These results provide new applications for 17O-excess as a tracer of post-deposition processes.

918
Wed_145_CR-7_1921
Seismic Evidence of Anisotropy in the Firn of the Amery Ice Shelf, Antarctica

Hannes Hollmann1 (hannes.hollmann@utas.edu.au), Leo Peters1

1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia

In order to better understand the relationship between the firn layer and the underlying ice, a seismic
refraction experiment was carried out on the Amery Ice Shelf in Eastern Antarctica. The experiments aimed to
reveal a detailed view of the subsurface structures and physical properties both in the direction of flow and
perpendicular to it. Several surveys were carried out along and across the shear margin of two ice units that
originated from the Lambert Glacier and the Mawson Escarpment Ice Stream. The firn is an important
component of ice sheet dynamics, as the firns anisotropy provides an indication of where the ice is undergoing
deformation.
Seismic velocity is directly related to mechanical properties. An increase of anisotropy leads to differences in
seismic velocity when measured in different directions. We use this to determine the degree of anisotropy for
the surveyed area. The seismic velocities is calculated by applying the 1D inversion algorithm of Wiechert-
Herglotz-Bateman to the data. We find that the seismic velocity of the firn exhibits anisotropic behaviour in
both surveyed directions:
The degree of anisotropy decreases in flow-direction (along the shear margin). Across the margin (across-flow)
the degree of anisotropy is higher on the ice unit closer to the ice shelf boundary, with the highest values being
found above the shear margin. The ice unit further away from the ice shelf boundary exhibits only small
anisotropic behaviour.

919
Wed_146_CR-7_1929
Surface Mass Balance Changes during the Last Deglaciation

Marie-Luise Kapsch1 (marie.kapsch@mpimet.mpg.de), Florian Ziemen1, Virna Meccia1, Uwe Mikolajewicz1

1
Max Planck Institute for Meteorology, Hamburg, Germany

Modeling the surface mass balance (SMB) from long-term climate simulations with Earth System Models
(ESMs) remains a major challenge, specifically due to the required downscaling from coarse resolution
atmospheric data onto high-resolution topographies.
We present a sophisticated energy balance model (EBM) to calculate and downscale the SMB for multi-
millennial simulations. The EBM accounts for changes in the snow albedo due to varying snow properties (age,
depth, melting and refreezing of water) and cloud cover, as well as key physical processes like percolation and
refreezing of melt water. The atmospheric forcing is obtained from simulations with the Max-Planck Institute
Earth System Model (MPI-ESM).
To evaluate its performance, the EBM is used to calculate the SMB based on the MPI-ESM CMIP6 historical
simulation and shows good agreement with reconstructions from regional climate modeling (RACMO and
MAR). To estimate the SMB changes throughout the last deglaciation, the EBM is forced with a transient
simulation with MPI-ESM in coarse resolution. For the latter, MPI-ESM is run with prescribed ice sheets and
topography and accounts for changes in river directions, ocean bathymetry and land sea mask due to the
retreating ice sheets and isostatic adjustments. In this presentation, we not only depict the challenges of
modeling the SMB from coarse resolution climate data but also highlight the benefits of using a sophisticated
EBM for long-term simulations.

920
Wed_147_CR-7_2144
SNOWAVE: A Novel Radar Architecture for Snow Cover Monitoring

Marco Pasian1 (marco.pasian@unipv.it), Pedro Fidel Espin-Lopez1, Massimiliano Barbolini1,2, Fabio Dell'Acqua1
1
Università degli Studi di Pavia, Pavia, Italy, 2Flow-Ing, La Spezia, Italy

Snow avalanches are a persistent risk for Alpine infrastructures. Cost-effective strategies for risk mitigation
invariably require avalanche forecasting tools, based upon the knowledge of the physical parameters of the
snow cover (depth, density, liquid water content, etc.). Currently, the most common measuring method for
these parameters is the manual analysis of snow cover, through in-situ excavation of snow pits. This method,
although time-consuming, is usually very accurate, but for safety reasons it cannot be applied when and where
most needed (along critical slopes, under bad weather conditions).
To get around these constraints, systems based on microwave radars have been proposed. Such systems can
deliver a rapid, non-destructive, and possibly automatic analysis of the snow structure. While very promising,
standard radar architectures cannot deliver, without external aids, measures of the snow depth and physical
parameters at the same time, thus strongly limiting the accuracy and applicability of this approach.
This paper presents a novel radar architecture, called SNOWAVE, capable of simultaneously measuring the
propagation distance and wave speed, and possibly also attenuation in the medium. This way, snow depth,
density, and possibly liquid water can be estimated at the same time. Experimental results from field test at
elevations above 2500 m in the Italian Alps (Valle d'Aosta) are also presented to show the feasibility and
potential of this innovative approach.

921
Wed_148_CR-7_2335
Topography and Snow Accumulation in the Marginal Zone of the Greenland Ice Sheet

Nena Griessinger1,2 (nena.griessinger@slf.ch), Neige Calonne1,3, Lino Schmid1, Konrad Steffen4,5,6, Tobias Jonas1,
Martin Schneebeli1
1
WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland, 2University of Zurich, Geography,
Zurich, Switzerland, 3Montana State University, Civil Engineering, Bozeman, United States, 4Swiss Federal
Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland, 5ETH Zurich, Environmental
Systems Science, Zurich, Switzerland, 6EPFL, Architecture, Civil and Environmental Engineering, Lausanne,
Switzerland

The marginal zone is of importance for accumulation and melt of the Greenland Ice Sheet. We measured snow
water equivalent (SWE), snow depth and snow stratigraphy along a transect of 100 km length between
Crawford Point 1 and Swiss Camp. The transect extended from the edge of the dry zone to the ablation facies
(Benson, 1962). We measured the snow stratigraphy every 5 km by a high-resolution penetrometer
(SnowMicroPen), besides to conventional snow pit records every 10 km. In addition, a ground-penetrating
radar (GPR) system (1.3 GHz) was towed by skis to resolve the spatial variability of seasonal SWE along the
transect. We found that end-of-winter SWE slightly decreased from about 500 mm to 400 mm along the
transect. More surprisingly, we found quite large fluctuations of SWE between 350 and 550 mm along the GPR-
record which we analyzed by variograms. We propose that point SWE-measurements in this zone should be
complemented with GPR-measurements to arrive at unbiased SWE estimates and its spatial variation. In
addition, SnowMicroPen measurements are found to be essential to keep track of the rather complex
stratigraphy.

922
Wed_149_CR-7_2423
Sensitivity Experiments for the Impact of Metamorphism on Signals in Polar Snow

Matthias Jaggi1, Henning Löwe1 (loewe@slf.ch), Martin Schneebeli1, Ghislain Picard2, Laurent Arnaud2, Amaelle
Landais3
1
WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland, 2Institut des Géosciences de
l'Environnement, Saint Martin d'Hères, France, 3Laboratoire des Sciences du Climat et de l'Environnement, Gif-
sur-Yvette Cedex, France

Under prevailing temperature gradient metamorphism in near-surface snow, the ice matrix may undergo full
recrystallization via sublimation-deposition cycles, with potential consequences for the formation of climatic
signals in polar snowpacks. Polar field studies naturally focus on the in-situ evolution of snowpacks, thereby
facing unavoidable difficulties of discerning controls from stratigraphy, spatial variability or the atmosphere. In
contrast, ex-situ laboratory studies on metamorphism are able to reasonably constrain the forcing, but were
hitherto limited to small, homogeneous samples which hinders an understanding of stratigraphic variability. To
bridge the gap between typical lab and field conditions we developed a portable rack of macroscopic
metamorphism boxes in which large (0.4 x 0.4 x 0.3 m3), stratigraphically heterogeneous snow blocks can be
subjected to different temperature forcing under sealed conditions after excavation from the natural
snowpack. The experimental setup enables to conduct ex-situ sensitivity experiments for the evolution of
signals (microstructure, isotopes, etc) if combined with an a posteriori comparison to the concurrent in-situ
dynamics. In this contribution we present the design of the experiment and report preliminary results from the
first deployment at Dome C during the Antarctic Summer 2017/2018 to detail the role of metamorphism within
the project “Snow properties evolution in a changing climate in Antarctica”.

923
Wed_150_CR-7_2459
Post-depositional Changes of Delta O-18 in Snow

Jürg Trachsel1 (juerg.trachsel@slf.ch), Martin Schneebeli1

1
WSL-Institut für Schnee- und Lawinenforschung SLF, Davos Dorf, Switzerland

The delta O-18 records of ice cores are used as a proxy for temperature fluctuations. However, the processes
leading to the final embedding of the measured ratio of O-18 to O-16 are not completely understood: Snow
with a certain delta O-18 is deposited on the ground during snowfall. Snow close to the surface is exposed to
high temperature gradients and therefore metamorphoses by high water vapor fluxes. These fluxes alter the
ratio of stable water isotopes after deposition. It has also been shown that advective fluxes (wind) contribute
to a change in isotope ratio. Therefore, it is of high importance to better understand these processes for the
interpretation of ice core data. We investigated these effects the upper snowpack at a field site above Davos
Switzerland. From January to May 2017 we sampled weekly the top 20 cm of the snow. Monthly, we sampled
the complete profile of delta O-18 with a vertical resolution of 6 cm. In parallel, we continuously measured the
delta O-18 signal in the air. In addition, the full energy balance is known, as well as microstructural properties
of the snow (density, SSA). First results showed that delta O-18 in the surface snow is generally lower than in
the simultaneously measured air. This can be explained by equilibrium fractionation of the snow. Some events
also showed an enrichment in the snow surface in absence of precipitation. We assume this is due to
predominant fractionating sublimation.

924
Wed_151_CR-7_2464
Continuous Sensing of Snow Water Equivalent Using Natural Gamma Radiation

Jaakko Mäkinen1 (jaakko.makinen@nls.fi), Arttu Raja-Halli1, Heikki Virtanen1

1
Finnish Geospatial Research Institute, Masala, Finland

Since 2014 we have been using the Campbell CS725, an instrument based on the attenuation of the natural
gamma radiation of the soil to record the water equivalent of snow (SWE) at the Metsähovi Geodetic Research
Station, Kirkkonummi, near Helsinki, Finland. The snow in this area is seasonal, the snow cover lasting 4 months
with peak SWE of 100 mm on the average (1981-2010). The purpose of the measurements is to provide a
correction for the attraction of the snow mass to the continuous record of variation in gravity of the
superconducting gravimeter (SG) at the site. The SG has sensitivity better than 0.1 ppb for step-type changes in
gravity, corresponding to the attraction of a water layer of 2 mm. However, the presence of the laboratory
building modifies considerably the response as there is no snow under the SG and instead the snow stays on
the roof producing a component in the direction opposite to the attraction of the snow on ground. We
compare the record of the gamma device with manual sampling using the Korhonen-Melander snow sampler
and meteorological observations, and discuss whether the gravity record in turn could be used to infer changes
in SWE.

925
Wed_152_CR-8_92
New Organic Compounds in Ice Cores for Use in Paleoclimate Reconstruction

Amy King1,2 (amyking@bas.ac.uk), Chiara Giorio3, Markus Kalberer2, Liz Thomas1, Eric Wolff4
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Cambridge, Chemistry (Centre for
Atmospheric Sciences), Cambridge, United Kingdom, 3University of Padova, Padua, Italy, 4University of
Cambridge, Earth Sciences, Cambridge, United Kingdom

Despite contributing up to 50% of atmospheric aerosol concentration (Jimenez et al., 2006), detection and
understanding of organic compounds in ice cores is not as well developed as their inorganic counterparts.
Two groups of organic compounds emitted from the marine and terrestrial biosphere, fatty acids and terpene
secondary oxidation aerosols (SOAs), display characteristics suitable for ice core paleoclimate reconstruction.
Emission rates depend on ambient atmospheric conditions and/or plant species, compounds survive long-
distance transport in the atmosphere to high latitudes (Fu et al., 2013, Pokhrel et al, 2016, among others), and
some compounds are shown to survive in ice layers up to 450 yrs old (Kawamura et al., 1996).
Contamination potential for these organic compounds, from various media used in the core drilling and
analysis process, is quantified. A single, robust method of quantification for trace levels of compounds is
developed, including preconcentration of samples and analysis with high resolution liquid chromatography -
mass spectrometry (HPLC-MS).
These methods are finally used to test shallow snow and ice core samples representing both dominant
terrestrial and marine aerosol input locations (identified using back-trajectory analysis). We present a first
inventory of chemicals found in detectable amounts in locations including the Altai Mountains (Russia),
Antarctic Peninsula, and sub-Antarctic island cores collected on the recent ACE Expedition.

926
Wed_153_CR-8_183
Urban Contamination in Andean Mountains near Santiago, Chile

Fabrice Lambert1 (lambert@uc.cl), Francisco Fernandoy2, Ariel Muñoz3, Francisco Barraza1, Margit
Schwikowski4, Theo Jenk4
1
Catholic University of Chile, Physical Geography, Santiago, Chile, 2Universidad Andres Bello, Geology, Viña del
Mar, Chile, 3Catholic University of Chile Valparaiso, Geography, Valparaiso, Chile, 4Paul Scherrer Institute,
Villigen, Switzerland

Santiago, Chile is a South American mega-city with very high levels of air pollution despite the introduction of
contamination reduction measures in the past 20 years. The city relies heavily on glacier and snow melt for its
supply of fresh water during spring and summer. However, it is unclear how much of an impact the Santiago
pollution plume has on nearby high-altitude glaciers.
We have identified the major sources of air contamination, their chemical profiles, and their temporal
evolution since 1998 through analysis of urban air filters. Since 2016 we have collected tree samples from the
mountain slopes and firn cores from the glaciers on top of the mountains. The comparison of anthropogenic
contaminant profiles in tree and firn samples allows an estimation of the altitudinal reach of the Santiago
pollution plume.
Here we show contaminant measurements from several firn cores drilled in glaciers downwind from Santiago
between 4000 and 5200 m. We show that urban contaminants do reach the highest peaks near Santiago.
However, the very high recent summer temperatures produce surface melt that mixes with underlying layers in
all but the highest mountain glacier above 5000 m. We therefore compare only this high´altitude firn core
record with contaminant time series from urban air filters and mountain slope dendrochemistry
measurements.

927
Wed_154_CR-8_201
Air-snow Transfer of Nitrate in Dronning Maud Land, East Antarctica

Holly Winton1 (vicwin@bas.ac.uk), Markus Frey1, Joanna Haigh2, Robert Mulvaney1, John Pyle3, Joël Savarino4,
Rebecca Tuckwell1, Rolf Weller5, Xin Yang1
1
British Antarctic Survey, Cambridge, United Kingdom, 2Imperial College London, London, United Kingdom,
3
University of Cambridge, Cambridge, United Kingdom, 4University of Grenoble Alpes, Institut des Géosciences
de l'Environnement, Grenoble, France, 5Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und
Meeresforschung, Bremerhaven, Germany

The “Isotopic Constraints on Past Ozone Layer in Polar Ice” (ISOL-ICE) project is investigating the variability of
past ultraviolet radiation and the ozone layer over the past 1000 years using a combination of ice cores,
atmospheric measurements and numerical models. The ultraviolet radiation proxy, based on stable isotopes of
nitrate, is being applied to a new 120 m ice core that was recovered from Dronning Maud Land, Antarctica in
the 2016-17 Antarctic field season. During the field season, continuous atmospheric measurements of nitrogen
oxides, turbulent flux and down-welling irradiance were also made. The first step to apply the new ultraviolet
radiation proxy to the ice core record is to evaluate the regional air-snow transfer and post-depositional
changes in nitrate and its stable isotopic composition. Here we present the nitrate isotopic composition and
concentration of daily aerosol and surface snow from Dronning Maud Land throughout January 2017. We
compare these observations to existing data sets in Terre Adelie and Dome C, another low accumulation region
on the high elevation East Antarctic Ice Sheet.

928
Wed_156_CR-8_554
Modelling the Influence of Layering and Barometric Pumping on Firn Air Transport

Benjamin Birner1 (bbirner@ucsd.edu), Christo Buizert2, Till Wagner1, Jeffrey Severinghaus1

1
Scripps Institution of Oceanography, UC San Diego, La Jolla, United States, 2College of Earth, Ocean and
Atmospheric Sciences, Oregon State University, Corvallis, United States

Ancient air trapped in ice core bubbles is a key source of information about past climate and atmospheric
composition. Before air bubbles become isolated in ice, the atmospheric signal is altered in the firn column by
transport processes such as advection and diffusion. However, the influence of impermeable layers and
barometric pumping (driven by surface pressure variability) on firn air transport is not well understood and
cannot be captured in conventional 1-dimensional firn air models. Here we present a 2-dimensional (2D) trace
gas advection-diffusion-dispersion model that accounts for discontinuous horizontal layers of reduced
permeability. We find that layering and barometric pumping individually yield too small a reduction in
gravitational settling of trace gases to match observations. In contrast, a combination of both processes
strongly supresses gravitational fractionation. Layering focuses airflows in the 2D model and thus amplifies the
dispersive mixing resulting from barometric pumping. Hence, the representation of both factors is needed to
match the well-known observation of an interval of zero gravitational settling in the lock-in zone. Moreover, we
find robust scaling relationships between kinetic isotope fractionation of different noble gas isotope and
elemental ratios. These relationships may be used to correct for kinetic fractionation in future high precision
ice core studies.

929
Wed_157_CR-8_602
20th Century Dramatic Dust Influx to Antarctica & Associated Aridity in SSA

Laluraj C M1 (lalucm@gmail.com), Rahaman Waliur1, Thamban Meloth2

1
National Centre for Antarctic & Ocean Research, Polar Cryosphere & Ice Core Studies, Vasco da Gama, India,
2
National Centre for Antarctic & Ocean Research, Polar Sciences, Vasco da Gama, India

Atmospheric dust is known to be a significant influence to the global climatic variability. The present study uses
a high-resolution dust flux record of an ice core retrieved from the central Dronning Maud Land of East
Antarctica to identify the factors controlling the dust flux during the last century (1905-2005 AD). The results
show that there was a nearly 2.5 fold increase in the dust influx (from an average of 2.5 to 37.0 mgm-2yr-1) to
the East Antarctica between the early to late 20th century, which was similar to the elevated dust fall over the
West Antarctica. Such dramatic changes within the spatially distinct sites of Antarctica support the spacial
extent and temporal consistency attributed to regional climate variability. A common source for the
concomitant deposition of dust across the Antarctica appears to be the desert storms originating from the
southern parts of the South America (SSA). The dust influx showed significant correlations with relative
humidity, soil moisture, wind speed since the 1980's compared with air temperature of Patagonia region
supporting their the dominant role in production and transport of dust in Southern south America. The
significant correlation of dust flux in Antarctica with the anthropogenic forcing (from CCSM4/CMIP5 model)
indicates significant impact of the anthropogenic factors on the dust deposition and vice versa in Antarctica.

930
Wed_158_CR-8_684
Environmental Signals from the Dust in a High Altitude Tropical Ice Core

Filipe Gaudie Ley Lindau1 (filipelindau@hotmail.com), Jefferson Cardia Simões1, Barbara Delmonte2
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Centro Polar e Climático, Porto Alegre, Brazil,
2
University Milano-Bicocca (UNIMIB), Department of Environmental Sciences, Milano, Italy

High altitude ice cores from Central Andes are sources of information on the mechanisms leading the intense
mid-tropospheric warming of the last decades, and also provide high-resolution data for a better
understanding of the tropical-polar teleconnexions. In order to provide a proxy for atmospheric circulation
variability over tropical South America during the last century we determined the dust size and concentration
from the Illimani ice core (Bolivian Andes) recovered in 1999 at 6300 m. The content of particles with diameters
from 0,7 to 20 µm was measured using a Coulter Multisizer at the LGGE, Grenoble. The seasonal resolution
register comprises the 1919 - 1998 period and is characterized by a pronounced increase in dust concentration
during the austral winter (JJA), reaching concentrations up to 22 µg g⁻¹, which responds to the increase of
westerly winds over the Bolivian Altiplano during the dry season. The mode of the size distribution also
increases during JJA, sometimes ranging from 6 to 10 µm which indicates an important local dust contribution.
The dust concentration record suggests a slight increasing tendency as higher peaks are more frequent in the
most recent years of the time series. These highest dust peaks, however, do not correspond to the same years
of the main El Niño events. Additional methods are needed to separate the local dust from the
regional/continental environmental signal in order to obtain significant correlations with atmospheric
parameters.

931
Wed_159_CR-8_766
Ultralight Ice Coring System

Victor Zagorodnov1 (victor.zagorodnov@gmail.com)

1
Cryosphere Research Solutions LLC, Columbus, United States

Major incentives for developing lightweight drilling systems are: 1) cost reduction of field operations, and 2)
accessibility of high altitude glaciers. A new approach to field operations is use of the Ultralight ice coring
systems (ULICS), commercial flights and regular transportation in complex logistic regions instead of charter
carriers. It also allows deployment of the ULICS equipment and ice cores to and out of a drilling site by small
group of researchers. The minimal deployment total weight of the ULICS drilling equipment including power
source, fuel and shelter is about 60 kg. Operation of the ULICS requires 2 persons.
The ULICS logistics based around small ice core diameter. This implementation relies on low power drilling
equipment and lightweight high-efficiency power sources. Small diameter ice cores can be stored in portable
freezers on a drill site or/and base camp.
The ULICS prototype is built at the Cryosphere Research Solutions LLC. Current model of the ULICS equipped
with thermal-electric drill capable of producing 42 mm ice core. Estimated total deployment weight of the ULCS
capable of recovering ice cores down to 150 m depth at about 4 m h-1 production drilling rate is 25 kg. It
includes custom high altitude power generator. A suit of electro-thermal and electro-mechanical drills suitable
for the same lightweight rig to recover ice cores of 15-82 mm in diameter in temperate and polar glaciers is
currently in development.

932
Wed_160_CR-8_818
Shape and Size Constraints on Ice Core Dust Optical Properties

Marco A.C. Potenza1 (marco.potenza@unimi.it), Barbara Delmonte2, Samuel Albani3, Giovanni Baccolo2, Valter
Maggi2, Llorenç Cremonesi1
1
Univerisity of Milano, Physics, Milan, Italy, 2University Milano-Bicocca (UNIMIB), Milan, Italy, 3LSCE/IPSL, Gif-
sur-Yvette, France

Mineral dust aerosol influences global climate. It changes the radiative properties of the atmosphere through
scattering and absorption of solar (shortwave) and terrestrial (longwave) radiation. Paleoclimate modeling
studies generally assume a spherical shape for dust particles, an assumption that implies a significant deviation
of light scattering from scattering properties of real particles. Through the novel Single Particle Extinction and
Scattering (SPES) method applied to East Antarctic ice core samples from the last glacial period and the
Holocene we were able to derive information about dust particle shapes, which is critical to determine the
intrinsic optical properties of dust.
We consider the first-order impact of different sets of optical properties derived from SPES analyses on
atmospheric dust Aerosol Optical Depth (AOD), based on dust mixing ratios simulated by the Community Earth
System Model (CESM), tuned to match size and deposition at Dome C. We derive that the net effect of
considering the actual variability in particle shape can contribute to changes in AOD up to ~10%. Actually,
spatial and temporal variations in dust load, particle size distribution and shape combine together to determine
the net effects on atmospheric extinction.
Given the importance of modeling light scattering by non-spherical particles, we recommend the use of the
novel SPES technique to ice core analyses for an improved understanding of the role of dust in past climate
change.

933
Wed_161_CR-8_819
Internal Bubble Pressures and Bubble Trapping Function in Ice Cores

Ruzica Dadic1 (ruzica.dadic@vuw.ac.nz), Martin Schneebeli2, Mareike Wiese2, Nancy Bertler1, Andrey
Salamatin3, Thiemo Theile2, Richard Alley4, Vladimir Lipenkov5
1
Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand, 2WSL Institute for Snow
and Avalanche Research SLF, Davos, Switzerland, 3Kazan Federal University, Kazan, Russian Federation,
4
Pennsylvania State University, State College, United States, 5Arctic and Antarctic Research Institute, St.
Peterburg, Russian Federation

Ice core data recorded significant and abrupt past climate changes that are associated with large and rapid
changes in atmospheric greenhouse gases, such as methane. Due to the gradual close-off of gas bubbles, even
a stepwise increase in air composition is spread out into a ramp in the data, because laboratory analysis of
gases only considers the mean of all bubbles across one sample. The convolution of the distribution of trapping
ages with the history of atmospheric composition smears the measured gas record in each sample. We propose
to use the shape of the trapping function derived from bubble-pressure-distribution and site characteristics to
deconvolve bubble close-off history from the atmospheric composition record. Here, we first present a non-
destructive method that can simultaneously estimate pressure-distribution in all bubbles in a sample, not only
for present conditions, but back through time under varying atmospheric conditions. The method uses
temperature-driven air-bubble-migration as a proxy for the pressure of individual bubbles and thus the gradual
close-off of gas bubbles. We then use the pressure-distribution to model the gas trapping functions and to
constrain the age distribution of air bubbles for past conditions, which are preserved at different depths. The
trapping functions will help us to obtain a more accurate gas signal in the future that is less attenuated through
the age distribution of the gas during the close-off process.

934
Wed_162_CR-8_868
Reconstruction of Early Holocene Environmental Conditions from the RICE Ice Core

Lukas Eling1,2 (lukas.eling@vuw.ac.nz), Nancy Bertler1,2, James Lee3, Robert McKay1,2, Rebecca Pyne2
1
Victoria University of Wellington, Wellington, New Zealand, 2GNS Science, Lower Hutt, New Zealand, 3Oregon
State University, Corvallis, United States

As part of the Roosevelt Island Climate Evolution (RICE) project, a deep ice core was drilled at Roosevelt Island,
an ice rise situated at the north-eastern edge of the Ross Ice Shelf, a major drainage pathway of the marine
based West Antarctic Ice Sheet (WAIS). The RICE records provide new insights into our understanding of the
stability of the Ross Ice Shelf in a warming world and associated sea-level rise contributions of WAIS.
Here we present high precision (low to sub ppb concentrations) Ion Chromatography data from discrete
samples of the RICE core representing the Early Holocene from ~ 10.5 ka BP to ~ 7.5 ka BP in high resolution
(sub-annual to 3-5 years). This record permits the reconstruction of sea ice extent and marine primary
production in the Ross Sea Polynya using MSA- and the ratio of Na+/SO42- to estimate the frost flower
contribution. Additionally atmospheric circulation patterns are reconstructed based on K+, Mg2+ and NO3- ,
which have a continental source and are therefore related to katabatic winds, and Na+, Cl- and Ca2+ which are
marine aerosols and are associated with cyclonic activity.
This detailed picture of Early Holocene atmospheric conditions, sea ice and marine productivity in the Ross Sea
is used to link changing environmental conditions to the retreat of the Ross Ice Sheet/ Shelf, which may have
been largely complete by the mid-Holocene as suggested by recent results from marine studies, combined with
ice sheet modelling experiments.

935
Wed_163_CR-8_876
Spatiotemporal Variations of Monocarboxylic Acids in Snow in Eastern Antarctica

Chuanjin Li1 (lichuanjin@lzb.ac.cn)

1
State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese
Academy of Sciences, Lanzhou, China

The spatiotemporal distributions of formate and acetate in snow layers along a transect from Zhongshan
Station to Dome A are presented here. In the snow pit samples, the concentrations varied between 0.47 ± 0.14
ng g−1 and 3.12 ± 4.24 ng g−1 for formate and between 5.31 ± 1.55 ng g−1 and 13.29 ± 4.64 ng g−1 for acetate.
Spatially, the concentrations of both acids featured negative trends with increasing elevation and distance
inland for the initial 600 km of the transect, which implies that marine sources from the coastal oceans
dominate the acid supply. Different distribution styles of the acids in the interior section (600-1248 km) suggest
that different source region and transporting mechanism may be responsible for the acid deposition in the
interior regions. Seasonal variations in the amounts of acid in a coastal snow pit (29-A) indicate highervalues in
the summer and lower amounts in thewinter. An enlarged source region and intensifiedproduction and
transport mechanisms were primarily responsible for the higher values insummer. Lnger records from the
interior snow pits (29-L and 29-M) indicate elevated values inthe 1970s and lower values in the 1980s and early
1990s. The increases in the mono-carboxylic acids since 1999 in snow pit 29-L and since 2005 in snow pit 29-M
were temporally coincident with Chinese expedition activities in the area, suggesting that human activities
were responsible for the increases in the acid load during recent decades.

936
Wed_164_CR-8_979
Last Interglacial Climate Variability at TALDICE, East Antarctica

Barbara Stenni1,2 (barbara.stenni@unive.it), Massimo Frezzotti3, Chiara Franceschini1, Valerie Masson-

Delmotte4, Louise Sime5, Cristiano Varin1, Andrea Spolaor2, Giuliano Dreossi2
1
Ca Foscari University of Venice, Department of Environmental Sciences, Informatics and Statistics, Venezia,
Italy, 2CNR-IDPA, Venezia, Italy, 3ENEA, Laboratorio di Osservazione e Analisi della Terra e del Clima, Roma,
Italy, 4LSCE (UMR 8212 CEA-CNRS-UVSQ/IPSL), Université Paris Saclay, Gif-sur-Yvette, France, 5British Antarctic
Survey, Cambridge, United Kingdom

The last interglacial period, also known as Eemian (ca. 132-116 ka BP), characterized by global temperatures
and sea level higher than today, has been found in six East Antarctic ice cores: Vostok, Taylor Dome, Dome F,
EPICA Dome C, EPICA Dronning Maud Land and TALDICE. Here we present a new deuterium excess record
obtained from the TALDICE ice core analysing the high-resolution samples obtained from the 5 cm cuttings
between 1384 and 1414 m, corresponding to the 115-130 ka BP period. Talos Dome is a peripheral dome of
East Antarctica, located in the Ross Sea sector where the TALDICE deep ice core (1620 m) has been retrieved. A
previous study has shown that the δ18O records obtained from the East Antarctic deep ice cores depict a quite
homogeneous pattern during the present and last interglacials. However, regional differences, particularly
important in the case of the TALDICE ice core, may be related to both elevation and regional atmospheric
circulation changes. The north-western drainage area of Talos Dome is mostly below sea level (Wilkes
Subglacial Basin) and could be more sensitive to climatic and sea level fluctuations than other sectors of the
East Antarctic Ice Sheet, possibly causing a distinct δ18O signal in the TALDICE ice core. The δ18O and deuterium
excess records will be compared to high resolution ssNa and nssCa records as well as to the EPICA Dome C
isotopic records to understand the regional differences highlighted by this site.

937
Wed_165_CR-8_1024
Atmospheric Contamination on the Top of the Himalaya over the Last 500 Years

Paolo Gabrielli1,2 (gabrielli.1@osu.edu), Anna Wegner1,3, Roxana Sierra1, Beaudon Emilie1, Joel Barker1,2, Lonnie
Thompson1,2
1
Ohio State University, Byrd Polar and Climate Research Center, Columbus, United States, 2Ohio State
University, School of Earth Sciences, Columbus, United States, 3Alfred Wegener Institute, Bremerhaven,
Germany

The Dasuopu ice core was drilled in 1997 at 7200 m altitude in the Himalaya and provides the highest elevation
ice core climate record ever obtained. Due to its high altitude this site has the potential to have a large spatial
significance including long distant pollution from Europe and climatic signals influenced by the North Atlantic.
This area is heavily influenced by the monsoon regime providing seasonally and highly variable annual snow
accumulation rates. The preservation of annual layers in this low latitude - high altitude ice core has allowed for
the possibility to obtain a detailed snow accumulation record that can be used to calculate chemical fluxes to
the central Himalaya. Here we present the results of a new trace element record from the Dasuopu ice core
spanning the period between 1500 and 1993 AD. Crustal enrichment factors are used to discriminate between
the terrigenous and non-crustal contributions (e.g. anthropogenic origin). In this study we focus on two
research topics:
(1) determine the onset and origin of the earliest anthropogenic contamination from trace elements at high
elevation (7200 m) in the Himalaya and
(2) determine annual, intra-annual, and decadal variations of atmospheric trace element fluxes.

938
Wed_166_CR-8_1030
New Results from the Mineral Dust Record of the TALDICE Ice Core

Giovanni Baccolo1 (giovanni.baccolo@mib.infn.it), Barbara Delmonte1, Giannantonio Cibin2, Massimiliano

Clemenza1, Dariush Hampai3, Augusto Marcelli3, Massimiliano Nastasi1, Ezio Previtali4, Valter Maggi1
1
University of Milano-Bicocca, Milano, Italy, 2Diamond Light Source, Didcot, United Kingdom, 3INFN, Frascati,
Italy, 4INFN, Milano, Italy

Thanks to ice cores the history of the dust cycle and its tight connections with the climatic system were
reconstructed. Here we present an update of the current research on the atmospheric dust content of the
TALDICE ice core (Ross Sea sector, East Antarctica). Thanks to the application of different techniques it was
possible to characterize the mineral particles deposited in the last 150 kyr. New constraints on provenance
during the last climatic cycle will be given, showing that peripheral and inner sites, well coupled during glacial
stages, present differences in relation to the different atmospheric evolution occurred during the last climatic
transition. In addition the analysis of the elemental composition of dust allowed preparing a first and
preliminary inventory of the elemental depositional fluxes in Antarctica. This is the first step to define a robust
reference to assess the current impact of human activities on Antarctic glaciochemistry. But important results
were also achieved looking at the deep disturbed part of TALDICE. For the first time significant weathering
affecting particles entrapped in deep ice was appreciated and quantified. Chemical and physical processes alter
the composition and aggregation state of dust below a critical depth. Future projects focused on the retrieval
of very ancient ice, will need to take into account such phenomena.

939
Wed_167_CR-8_1043
X-Ray Computed Tomography System for Analysis of Full Length Ice Cores

Alexandra Khairedinova1 (khairaalex13@gmail.com), Stanislav Kutuzov2, Alexey Khomyak3, Dmitry Korost3

1
Lomonosov Moscow State University, Geography Department, Moscow, Russian Federation, 2Institute of
Geography RAS, Glaciology Department, Moscow, Russian Federation, 3Lomonosov Moscow State University,
Geology Department, Moscow, Russian Federation

A wide range of methods are available in studying ice cores nowadays. Nevertheless, most of them have a lot
of disadvantages related to destruction of samples and their melting during the analyses, which may prevent
the future sample processing.
X-ray computed tomography (CT) is a well-known and common method to obtain cross sectional images using
X-Rays. The primary use of CT doesn't affect further processing of samples. Another advantage of method is its
promptitude: the analysis cost is low, while the amount of information obtained is very substantial.
The shallow ice cores from Elbrus region were analyzed with the help of X-Ray CT scanner. RCT-180 scanner is
able to scan cores with a length of 1 m and with a diameter of 10 cm. Scanner has a 150-180 µm spatial
resolution and 100х100х1000 mm active area. For supporting the natural conditions of ice, a special
cryothermos was created, which allows to keep the sample frozen during the survey.
This method permitted us to define the inner structure of full length ice cores, to find the core disturbances; to
obtain a 3D pattern of ice density which appears to provide much more information than the visual observation
of the axial ice cutting; to obtain 3D stratigraphy for subsequent correlation; to reveal and calculate the typical
layers with contrast density and to find total porosity and individual pores.
The research was supported by the Russian Science Foundation (project no. 17-17-01270).

940
Wed_168_CR-8_1053
Leads/Lags between Antarctic Temperature and CO2 during the Last Deglaciation

Léa Gest1, Frédéric Parrenin1 (frederic.parrenin@univ-grenoble-alpes.fr), Jai Chowdhry Beeman1, Dominique

Raynaud1, Tyler J. Fudge2, Christo Buizert3, Edward J. Brook3
1
CNRS/IRD/UGA, Institut des Géosciences de l'Environnement, St Martin d'Hères, France, 2University of
Washington, Department of Earth and Space Sciences, Seattle, United States, 3Oregon State University, College
of Earth, Ocean, and Atmospheric Sciences, Corvallis, United States

Here we accurately determine the phasing between East Antarctic temperature and atmospheric CO2 variations
during the last deglacial warming based on Antarctic ice core records. We build a stack of East Antarctic
temperature variations by averaging the records from 4 ice cores (EPICA Dome C, Dome Fuji, EPICA Dronning
Maud Land and Talos Dome), all accurately synchronized by volcanic event matching. We place this stack onto
the WAIS Divide WD2014 age scale by synchronizing EPICA Dome C and WAIS Divide using volcanic event
matching, which allows comparison with the high resolution CO2 record from WAIS Divide. Since WAIS Divide is
a high accumulation site, its air age scale, which has previously been determined by firn modeling, is more
robust. Finally, we assess the CO2 / Antarctic temperature phasing by determining four periods when their
trends change abruptly.
We find that at the onset of the last deglaciation and at the onset of the Antarctic Cold Reversal (ACR) period
CO2 and Antarctic temperature are synchronous within a range of 210 years. Then CO2 slightly leads by 165 ±
116 years at the end of the Antarctic Cold Reversal (ACR) period. Finally, Antarctic temperature significantly
leads by 406 ± 200 years at the onset of the Holocene period. Our results further support the hypothesis of no
convective zone at EPICA Dome C during the last deglaciation and the use of nitrogen-15 to infer the height of
the diffusive zone.

941
Wed_169_CR-8_1261
Frequency of Large Volcanic Eruptions over the past 200,000 Years

Eric Wolff1 (ew428@cam.ac.uk), Sue Mahony2, Stephen Sparks2, Andrea Burke3, Shuji Fujita4, Frédéric
Parrenin5, Mirko Severi6
1
University of Cambridge, Earth Sciences, Cambridge, United Kingdom, 2University of Bristol, School of Earth
Sciences, Bristol, United Kingdom, 3University of St-Andrews, School of Earth and Environmental Sciences, St
Andrews, United Kingdom, 4National Institute of Polar Research, Tokyo, Japan, 5Institut des Géosciences de
l'Environnement, Grenoble, France, 6University of Florence, Firenze, Italy

Volcanic eruptions are an important component of climate forcing, and an essential component of the long-
term budget of carbon dioxide in the atmosphere. However, establishing the past frequency of eruptions of
various magnitudes is challenging. The record of episodic sulfate deposition in Antarctic ice offers the
opportunity to establish such frequencies for larger eruptions. Here, we build on recent work that has
synchronised records back to 200,000 years, between the East Antarctic sites of Dome C, Dome Fuji and
Vostok. In each record, and for each volcano, we can estimate the amount of sulfate deposited above the
background across the years following an eruption; in some cases we will use electrical conductivity data as a
surrogate for sulfate. For some eruptions we will measure the profile of mass independent fractionation of
sulfur isotopes to establish whether the eruption reached the stratosphere. By using the three records together
we can for the first time place uncertainty estimates on the amount of sulfate deposited for each eruption. We
will then use (and test) methods we have developed for making an assessment, unbiassed by diffusion and
thinning, of the frequency of eruptions above a given magnitude (in terms of sulfate deposition). Initial work
suggests that the frequency of large eruptions is rather constant through the glacial and interglacial stages of
two glacial cycles, but we hope to have fully tested this by the time of the meeting.

942
Wed_171_CR-8_1591
Taylor Glacier Ice Core Shows Dynamic Taylor Dome Accumulation during MIS 5-4

James Andrew Menking1 (menkingj@oregonstate.edu), Sarah Shackleton2, Ed Brook1, Jeffrey Severinghaus2,

Rachael Rhodes3, Joe McConnell4, Aron Buffen1, Michael Dyonisius5, Thomas Bauska3, Vasilii Petrenko5
1
Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, United States, 2Scripps
Institution of Oceanography, University of California, San Diego, La Jolla, United States, 3Cambridge University,
Department of Earth Sciences, Cambridge, United Kingdom, 4Desert Research Institute, Reno, United States,
5
University of Rochester, Department of Earth and Environmental Sciences, Rochester, United States

A new ice core retrieved from the Taylor Glacier blue ice area (McMurdo Dry Valleys, Antarctica) contains a
well-preserved record of the marine isotope stage (MIS) 5/4 transition. Methane and δ18Oatm measurements
were used to build a gas age scale for the new core by tying to preexisting, well-dated ice core records.
Measurements of particle concentration (dust) were used similarly to build an ice age scale for the new core.
The ice age-gas age difference approaches 10,000 years during MIS 4, suggesting very low precipitation or high
wind scouring at the Taylor Glacier accumulation zone near Taylor Dome. Revised gas age and ice age models
spanning the MIS 5/4 transition in the Taylor Dome ice core indicate a delta age = ~ 3000 years during MIS4,
which in conjunction with the Taylor Glacier data implies large spatial gradients in accumulation and/or wind
scouring across Taylor Dome. Curiously, the delta age relationship between Taylor Glacier and Taylor Dome at
the MIS 5/4 transition is reversed relative to the last glacial maximum (Baggenstos, 2015). This could be due to
changes in the trajectory of paleo storm tracks that effectively reversed spatial gradients in accumulation
across Taylor Dome at different times in the past (e.g., Morse et al., 1998).

943
Wed_172_CR-8_1610
Aerosols Preserved in a High-accumulation Dome Ice Core, Southeast Greenland

Yoshinori Iizuka1 (iizuka@lowtem.hokudai.ac.jp), Ryu Uemura2, Koji Fujita3, Sumito Matoba1

1
Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan, 2University of the Ryukyus, Faculty
of Science, Okinawa, Japan, 3Nagoya University, Nagoya, Japan

On May 2015, we drilled a 90.45 m ice core in a high accumulation area of the southeastern Greenland Ice
Sheet (SE-Dome; 67.18°N, 36.37°W, 3170 m a.s.l.). Then we measure physical and chemical properties of the
SE-Dome ice core. First, we propose a dating method based on matching the δ18O variations between ice-core
records and records simulated by isotope-enabled climate models. The close similarity between the δ18O
records from the ice core and models enables correlation and the production of a precise age scale, with an
accuracy of a few months. Second, we measured the major ion fluxes, and obtained records of annual ion
fluxes from 1957 to 2014. From 1970 to 2010, the trend of non-sea-salt SO42- flux decreases, whereas that for
NH4+ increases, tracking well with the anthropogenic SOx and NH3 emissions mainly from North America. The
result suggests that these fluxes reflect histories of the anthropogenic SOx and NH3 emissions. In contrast, the
decadal trend of NO3- flux differs from the decreasing trend of anthropogenic NOx emissions. We also find a
high average NO3- flux (1.13 mmol m-2 yr-1) in the ice core, which suggests a negligible effect from post-
depositional NO3- loss. Thus, the SE-Dome region is an excellent location for reconstructing nitrate fluxes. Over
a decadal timescale, our NO3- flux record is similar to those from other ice cores in Greenland high-elevation
sites, suggesting that NO3- concentrations records from these ice cores are reliable.

944
Wed_173_CR-8_1622
High Resolution East Antarctic Climate History: Ice Core Isotopic Records

Andrew Moy1,2 (andrew.moy@aad.gov.au), Mark Curran1,2, Tas van Ommen1,2, Jason Roberts1,2, Christopher
Plummer3, Tessa Vance2, Lenneke Jong1,2, Li Yuansheng4, Vincent Favier5, Diana Vladimirova6,7, Alexey
Ekaykin6,7, Barbara Stenni8,9, Ian Goodwin10, Joe McConnell11, Monica Arienzo11, Trevor Popp12, Amaelle
Landais13, Anais Orsi14, Yaping Lui15, Nerilie Abram16
1
Australian Antarctic Division, Kingston, Australia, 2Antarctic Climate and Ecosystems Cooperative Research
Centre, University of Tasmania, Hobart, Australia, 3Institute for Marine and Antarctic Studies, University of
Tasmania, Hobart, Australia, 4Polar Research Institute of China, Shanghai, China, 5University of Grenoble Alpes,
Grenoble, France, 6Arctic and Antarctic Research Institute, St. Petersburg, Russian Federation, 7St. Petersburg
State University, St. Petersburg, Russian Federation, 8Ca Foscari University of Venice, Venice, Italy, 9CNR, Venice,
Italy, 10Macquarie University, Sydney, Australia, 11Desert Research Institute, Reno, United States, 12Center for Ice
and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark, 13Laboratoire des Sciences
du Climat et de l’Environnement, Gif-sur-Yvette, France, 14Laboratoire des Sciences du Climat et de
l'Environnement, Gif-sur-Yvette, France, 15State Key Laboratory of Cryospheric Science, Northwest Institute of
Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China, 16Research School of Earth
Sciences, Australian National University, Canberra, Australia

In Antarctica, a reasonable coverage of ice core records exist for the last couple of hundred years, however
there is poor spatial coverage of high-resolution climate data over the last 2,000 years, particularly in East
Antarctica (EA). Here, we use a range of high-resolution ice cores from EA covering the last 2,000 years from
the IPICS array and PAGES Antarctic2k projects, and adding the recently recovered Aurora Basin North (ABN)
ice core. The isotopic composition of snow and ice from this site is compared with other ice core isotopic
records from Wilkes Land Coast and the transition region into the East Antarctic Plateau. The isotopic variability
at ABN shows annual cycles in the upper 50 m and longer-term variability on decadal to centennial timescales.
The ABN record shows no long-term isotopic trend over the ~2,700 year record length, whereas the isotopic ice
core records used in EA regional composite show there is a long-term cooling over the last 2,000 years. A
comparison of the preliminary dated ABN isotope record with the Law Dome (LD) isotopic record shows they
are correlated, despite differences in site-specific influences. This correlation indicates a common climate signal
at both sites and a spatial coherence in regional climate from coastal LD to the inland plateau of the ABN site.
The isotopic records from ABN in conjunction with other EA high-resolution ice core records are used to
explore, quantify and determine natural variability of key climate processes.

945
Wed_174_CR-8_1641
Development of a Method for the Measurement of δ15NH4 in Ice Core Samples

Prisca Lehmann1 (lehmann@climate.unibe.ch), Barbara Seth1, Jochen Schmitt1, Hubertus Fischer1

1
University of Bern, Climate and Environmental Physics, Physics Institute & Oeschger Centre for Climate
Research, Bern, Switzerland

Ammonium (NH4+) in Antarctic ice samples originates mainly from marine biogenic sources and is transported
in aerosol form to the ice sheet, where deposition takes place. Due to the coupling of the biogeochemical
cycles of nitrogen and carbon and isotopic fractionation, a dependence of the isotopic signature (δ15NH4) of
ammonium and the efficiency of nutrient turnover in the surface ocean is expected.
The low concentration of NH4+ in ice and only small changes in the isotopic ratio make this analysis challenging.
The basis of our new δ15NH4 system is the well-established CFA system, which provides a continuous and
contamination-free flow of meltwater containing ammonium. We are currently developing an interface that
comprises four main steps: In a first step, the dissolved NH4+ is incorporated into an organic molecule and
retained from the water phase by solid phase extraction. Secondly, this organic-N is quantitatively oxidized to
N2 using Cu/CuO as redox agents. In a third step, combustion side products (i.e. CO, CO2 and H2O) are separated
using cryotraps and gas chromatography. In the last step, the δ15N of the purified N2 is determined by isotopic
ratio mass spectrometry. We already constructed and tested the lines for step 2-4 and the oxidative conversion
works well for a NH3-gas-standard and N-containing organic compounds. The coupling towards the ammonium-
N in the water phase will be our next step and we present the current status of the analytical system.

946
Wed_176_CR-8_1721
Lead in the European Atmosphere from the Ortles Ice Cores, the Last 7000 Years

Michele Bertò1 (michele.berto@psi.ch), Paolo Gabrielli2,3, Andrea Spolaor4, Jacopo Gabrieli4, Giuliano Dreossi4,
Michela Segnana5, Carlo Barbante4,5
1
Paul Scherrer Institute, Energy and Environment Research Division, Zürich, Switzerland, 2Ohio State University,
Byrd Polar and Climate Research Center BP, Columbus, United States, 3Ohio State University, School of Earth
Sciences, Columbus, United States, 4CNR-IDPA, Venice, Italy, 5Ca Foscari University of Venice, DAIS, Venice, Italy

Four ice cores were recovered in 2011 from the Alto dell'Ortles glacier (3859 m, South Tyrol, Italy). This study
presents the results from the analyses of the ice cores #1 (73.5 m) and #3 (74.83 m) performed at the
University of Venice (Department of Environmental Sciences, Informatics and Statistics, DAIS) and at The Ohio
State University (Byrd Polar and Climate Research Center, BPCRC) that cover the last 3000 and 7000 years,
respectively. Core#1 and #3 were analyzed by Continuous Flow Analyses (CFA). The samples from core#1 were
also measured discreetly. Trace elements analyses performed at DAIS were performed by using an ICP-MS
(Agilent 7500), whereas those performed at the BPCRC by means of a ICP-SF-MS (Element2, Thermo).
The Ortles cores provide a detailed Lead contamination reconstruction of the past European atmosphere. A
first Lead enrichment was found during the time of the Roman Empire, due to intense Lead and Silver mining
activities. Afterwards Lead levels remained low except during the periods 1380- 1500 AD and 1580-1680 AD,
revealing an enhancement in European Silver mining activities. The highest Lead levels were determined during
the last century, starting in the 1920s, mostly caused by leaded gasoline.
A comparison with other local archives corroborates the results of the Ortles ice cores. A comprehensive
comparison with most of the available lead reconstructions allows obtaining a worldwide perspective of
atmospheric contamination from this toxic metal.

947
Wed_177_CR-8_1744
Coupled Production of CH4, C2H6, and C3H8 in Dust-rich Greenland Ice

Jochen Schmitt1, Barbara Seth1 (seth@climate.unibe.ch), James E. Lee2, Jonas Beck1, Jon S. Edwards2, Edward J.
Brook2, Hubertus Fischer1
1
Climate and Environmental Physics, Physics Institute, and Oeschger Center for Climate Change, University of
Bern, Bern, Switzerland, 2College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis,
United States

Air enclosures in ice samples are the only archive to reconstruct atmospheric trace gases and their isotopic
composition beyond the time where firn air samples are accessible. Reconstructing the past atmospheric
composition accurately requires that the respective trace gas is neither consumed nor produced in the ice. It is
known for decades, that CO2 production in Greenland ice compromises the atmospheric signal, and for trace
gases like N2O and methyl chloride production in dust-rich sections in Antarctic ice cores has been
documented. Here, we show that for dust-rich Greenland ice samples production of short chain hydrocarbons
(CH4, C2H6, and C3H8) occurs in significant amounts to compromise accurate reconstructions of these gases. We
found that the production of these hydrocarbons is tightly coupled to the dust concentration in these samples,
which support results from independent experiments at Oregon State Univ. (presentation J. Lee). We further
observed that these three hydrocarbon homologous occur in a stoichiometric ratio of about 20:2:1 for CH4,
C2H6, and C3H8, respectively, pointing to a shared production process, e.g. from an organic precursor molecule.
With experiments we show that the production proceeds via a rather slow process in the water phase. With
regard to the CH4 produced in glacial Greenland ice, published results require a careful reevaluation of
methane stable isotope records and reconstructions of the interhemispheric gradient during the glacial.

948
Wed_178_CR-8_1750
Towards Gas Measurements in Extremely Thinned Ice: The Mid-IR Laser Spectrometer

Bernhard Bereiter1,2 (bereiter@climate.unibe.ch), Béla Tuzson2, Philipp Scheidegger2, Lukas Emmenegger2, Lars
Mächler1, Jochen Schmitt1, Hubertus Fischer1
1
University of Bern, Physics Institute & Oeschger Centre for Climate Change Research, Bern, Switzerland, 2Swiss
Federal Laboratories for Materials Science and Technology Empa, Dübendorf, Switzerland

The European Partnership in Ice Core Sciences (EuroPICS) plans to drill an ice core extending over 1.5 million
years (Myr), nearly doubling the time span of the existing greenhouse record. The oldest section from 1-1.5
Myr is expected to be close to the bedrock and, due to glacial flow, extremely thinned. Thus, a 10,000 year
glacial/interglacial transition can be compressed in 1 m of ice, reducing the sample vertical extent to cm-scales
and its volume to 1-2 ml air STP, respectively, for a targeted century-scale temporal resolution.
Within the ERC Advanced Grant “deepSlice” we aim to unlock such atmospheric archives in extremely thinned
ice by developing a novel coupled semi-continuous sublimation extraction/laser spectroscopy system. Here we
present the custom-made laser spectrometer developed in this context whose goal is to measure
simultaneously CO2, CH4 and N2O concentrations and d13C(CO2) isotope ratios in such small air samples without
destructing it. The analytical approach is based on direct absorption using two Quantum Cascade Lasers
emitting at 4.34 and 7.87 µm, respectively. The main challenge stems from the small sample volume which
requires high precision and stability from the electronic and optical part of the system as well as low reactivity
from the inner surfaces of the absorption cell. Preliminary results will be presented which show that the high-
precision targets can be reached for all four parameters.

949
Wed_179_CR-8_1760
Alpine Ice Cores Indicate Persistently High Nitrate and Ammonium Concentrations

Margit Schwikowski1,2,3 (margit.schwikowski@psi.ch), Anja Eichler1,3, Theo M. Jenk1,3, Susanne Preunkert4,

Michael Sigl1,3, Michel Legrand4
1
Paul Scherrer Institute, Laboratory of Environmental Chemistry, Villigen PSI, Switzerland, 2University of Bern,
Department of Chemistry and Biochemistry, Bern, Switzerland, 3University of Bern, Oeschger Centre for Climate
Change Research, Bern, Switzerland, 4Université Grenoble Alpes, CNRS, Institut des Géosciences de
l'Environnement (IGE), Grenoble, France

Ice cores from glaciers in the Alps are well suited to document the effects of anthropogenic emissions on air
pollution, since they are surrounded by highly populated and industrialized countries in Europe. Concentration
records of sulfate, nitrate and ammonium covering the 20th century until 2015 from Col du Dôme (4250 m asl,
French Alps) and Colle Gnifetti (4450 m asl, Swiss Alps) ice cores agree well in absolute concentrations and
temporal trends. Sulfate originating from fossil fuel combustion peaked in the 1970-80's with a significant
downward trend in recent decades, in agreement with results from atmospheric chemical transport modelling.
In contrast to sulfate, in the case of nitrate related to traffic and energy production and ammonium to
agricultural emissions, ice core data show persistently high concentrations, which do not correspond to the
model simulations and/or data from Western Europe in the European Monitoring and Evaluation Programme
network. The good agreement for sulfate indicates that transport and atmospheric chemistry is well simulated
by the models. The discrepancy for nitrate and ammonium suggests uncertainties in the emissions estimates,
which in the case of nitrogen oxides are possibly related to underestimated car emissions. Such uncertainties
are also relevant for ammonia released from fertilizer use and animal husbandry, since it plays a significant role
in secondary aerosol formation with a corresponding negative effect on human health.

950
Wed_180_CR-8_1764
Stable Methane Isotope Data from Antarctic Ice Cores over DO7/8 and HS4

Jonas Beck1 (beck@climate.unibe.ch), Jochen Schmitt1, James Edward Lee2, Barbara Seth1, Michael Bock1,
Edward Jeremy Brook2, Hubertus Fischer1
1
University of Bern, Physics Institute & Oeschger Centre for Climate Change Research, Bern, Switzerland,
2
Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, United States

Ice cores are used to reconstruct past changes in atmospheric methane. The stable isotopes of CH4 enable us to
draw conclusions about processes behind source and sink budget changes. By measuring δD(CH4) on trapped
gas from the NGRIP ice core over the period of Dansgaard-Oeschger (DO) events 7 and 8, Bock et al. (2010)
ruled out the clathrate gun hypothesis, which calls upon the destabilization of marine CH4 hydrates to explain
the rapid CH4 increases. However, for dust-rich Greenland ice there is evidence of excess CH4 production during
the melt extraction that calls into question previous results (presentations of J. Schmitt and J. E. Lee). New δD
measurements using Antarctic ice from TALDICE show that the NGRIP δD values are likely affected by this
process. The TALDICE δD values show only small variability over the two DO events, indicating no dramatic
change in the CH4 source mix. The new data are therefore still clearly in disagreement with the clathrate gun
theory. Furthermore, we present new δD and δ13C data from the WAIS core covering a short-lived CH4
excursion documented in the very high resolution CH4 data by Rhodes et al. (2015) in Heinrich Stadial 4. Such
rapid CH4 excursions leave a characteristic imprint in both δ13C, from firn diffusion, and for δD, due to
atmospheric imbalance effects, which are visible in our record. After accounting for these transient effects, the
remaining isotope signal suggests a heavier source mix for δ13C, but little changes for δD.

951
Wed_181_CR-8_1775
Towards Gas Measurements in Extremely Thinned Ice: Sublimation Extraction

Lars Mächler1 (maechler@climate.unibe.ch), Bernhard Bereiter1,2, Bela Tuzson2, Lukas Emmenegger2, Remo
Walther1, Jochen Schmitt1, Hubertus Fischer1
1
University of Bern, Physics Institute & Oeschger Centre for Climate Change Research, Bern, Switzerland, 2Swiss
Federal Laboratories for Materials Science and Technology, Empa, Dübendorf, Switzerland

The European Partnership in Ice Core Sciences (EuroPICS) plans to drill an ice core extending over 1.5 Ma,
nearly doubling the time span of the existing greenhouse record and covering the time period of the Mid
Pleistocene Transition. The oldest section from 1-1.5 Ma is expected to be close to the bedrock and, due to
glacial flow, extremely thinned. A century-scale temporal resolution reduces the sample vertical extent to cm-
scales containing only 1-2 ml air STP.
Within the ERC Advanced Grant deepSlice project we aim to unlock such atmospheric archives by developing a
novel coupled semi-continuous sublimation extraction/laser spectroscopy system. Sublimation is the only dry
method that extracts 100% of all gas species avoiding potential issues with gas fractionation which showed to
cause offsets between ice cores/different extraction methods. With the target of reducing ice waste and
increase sample throughput, the development of our new gas extraction method aims at vertically sublimating
an ice-core section with subsequent collecting the released air via cryo trapping in a dip tube. However, there
remain several challenges: the heat transport within the sample could induce subsurface melting or lateral
sublimation, inhomogeneity in the ice or of the radiation field delivering the heat could create inhomogeneity
in the sublimation front, and CO2 adsorption, a problem to all CO2 extraction methods, particularly affects
isotope ratios.

952
Wed_182_CR-8_1874
Growth of Air-hydrate Crystals in the Bottom Section of the EPICA DC Ice Core

Vladimir Lipenkov1 (lipenkov@aari.ru), Andrey Salamatin2, Jerome Chappellaz3, Gregory Teste3

1
Arctic & Antarctic Research Institute, Climate & Environmental Research Laboratory, Saint Petersburg, Russian
Federation, 2Kazan (Volga Region) Federal University, Kazan, Russian Federation, 3University Grenoble Alpes,
IGE, Grenoble, France

The post-formation growth (Ostwald ripening) of air-hydrate crystals occurs in polar ice sheets due to the
diffusion of air molecules through the ice matrix from smaller crystals towards larger ones. The earlier studies
of this phenomenon in the Vostok (Tsyganova & Lipenkov, 2011) and Dome Fuji (Uchida et al., 2011) ice cores
have shown that, in the lower sections of these cores, the mean radii of hydrates increase linearly with their
age. The existence of a robust linear relationship between the size and age of air hydrates in very old polar ice
would imply that the geometrical properties of hydrate crystals could be used for estimating the age of ice in
the near bottom layers of the ice sheets.
Here we present the preliminary results of a study of geometrical properties of air hydrates in the bottom
section of the EDC ice core. The size distribution and the number concentration of hydrate crystals were
measured at 23 depth levels between 2802 and 3258 m using the ice samples from the low-temperature
collection stored in the undersnow cave at Concordia station. Experimentally determined correlation between
the size and age of hydrates in the well dated part of the 800-kyr old EDC ice core is used to constrain the
parameters of a mathematical model which describes the growth of air hydrates below the bubble-to-hydrate
transition (Salamatin et al., 2003). The implication of the new data for dating the disturbed section of the old
meteoric ice at Vostok is discussed.

953
Wed_183_CR-8_2007
An Extended Climate Archive from the Eastern Alps: The Mt Ortles Ice Cores

Giuliano Dreossi1 (iodio9@yahoo.it), Paolo Gabrielli2, Luca Carturan3, Barbara Stenni4, Michele Bertò5, Andrea
Spolaor1, Jacopo Gabrieli1, Carlo Barbante1,4
1
National Research Council for the Dynamics of Enviromental Processes (IDPA-CNR), Venice, Italy, 2Byrd Polar
and Climate Research Center, Columbus, United States, 3Department of Land, Environment, Agricolture and
Forestry (TESAF), University of Padua, Padua, Italy, 4Department of Environmental Sciences, Informatics and
Statistics (DAIS), Ca' Foscari University of Venice, Venice, Italy, 5Paul Scherrer Institute, Villigen, Switzerland

Oxygen and hydrogen stable isotopes have been widely used in ice cores as temperature proxies for the last 50
years. In autumn 2011 three ice cores were drilled down to bedrock on the Alto dell'Ortles glacier (3859 m
a.s.l.), Eastern Alps. The ice core chronology, based on lead-210 in the upper part and on carbon-14
measurements for the lower part, proves that this record is the most extended of the Eastern Alps and the
second most extended ice core record from the Alpine region, extending beyond 7000 years BP. The long
temporal extension of this glacial archive represents a unique opportunity to study the climate of the past in
this part of the Alps, normally characterized by low-elevation shallow glaciers, whose have been particularly
affected by the recent warming. The oxygen and hydrogen isotopic composition was measured for all the three
cores and an isotope stacked record was created combining the three isotope profiles. The composite record
shows a long warm period during the mid holocene, followed by a decreasing trend extending until the roman
period. A large negative anomaly is present during the last 500 years, suggesting the presence of a colder
period which was interrupted only in the XX century.

954
Wed_184_CR-8_2290
Dating the Aurora Basin North Ice Core with Seasonal Cycles and Volcanic Ties

Mark Curran1,2 (mark.curran@aad.gov.au), Dating Team ABN3

1
Australian Antarctic Division, Kingston, Australia, 2ACE CRC, Hobart, Australia, 3M. Arienzo, J. Chappellaz, A.
Chunlei, D. Dahl-Jensen, C. Glor, L. Jong, S. Kipfstuhl, J. McConnell, A. Moy, C. Plummer, T. Popp, S.O.
Rasmussen, J. Roberts, C. Tozer, P. Vallelonga, T. Vance, T. van Ommen, L. Yaping, ABN, Australia

The aim of the Aurora Basin North (ABN) ice core drilling project is to provide a 2000 year climate record from a
data sparse area of East Antarctica to add to the IPICS 2k array and the PAGES Antarctica2k projects. ABN is a
303m ice core from East Antarctica, 550km inland and about half way between the coastal Law Dome and
inland Dome C sites. A combination of annual layer counting and volcanic ties was used to date the record.
Annual peaks were found in many trace chemical species (e.g. sodium, sulphate, hydrogen peroxide) and other
species such as black carbon. The ABN chronology has been established to ~1900 years before present (or 120
CE) through a combination of volcanic synchronisation to DSS and WAIS divide ice cores and layer counting
between volcanic events. Below this date, annual layer counting becomes less certain and volcanic ties alone
indicate the record extends to around 2700 years before present. We will present an update of the ABN results
on this timescale for reconstructed temperatures, snow accumulation rate and aerosol concentrations,
including volcanic sulphate concentrations and fluxes. These will be compared to other Antarctic ice core
records.

955
Wed_185_CR-8_2304
Trace Elements Variation between ~600kyr BP to 800 kyr BP in Dome C Ice Core

Soon Do Hur1 (sdhur@kopri.re.kr), Tseren-Ochir Soyol-Erdene2, Chang Hee Han1, Sungmin Hong3, Hee Jin
Hwang1, Carlo Barbante4
1
Korea Polar Research Institute, Incheon, Korea, Republic of, 2National University of Mongolia, Ulaanbaatar,
Mongolia, 3Inha University, Incheon, Korea, Republic of, 4University of Venice, Venice-Mestre, Italy

Geochemical proxies were measured from the EPICA (European Project for Ice Coring in Antarctica) Dome C ice
core, covering a period from ~600 kyr BP to ~800 kyr BP, by inductively coupled plasma sector field mass
spectrometry (ICP-SFMS) and ion chromatography (IC) for trace elements and platinum group elements (PGEs)
and major ions, respectively. The main trend of trace element and other proxy concentrations match well
defined insoluble dust concentration profile. It shows that mineral dust was the dominant source of trace
elements to East Antarctica whatever the period. PGE concentrations show a less difference between glacial
and interglacial periods in comparison with crustal enriched elements and concentration ratios of Ir and Pt
indicate that PGEs in Antarctica may be originated from non-crustal sources. These geochemical evidence
suggest that changes in relative contribution of crustal dust, volcanic and extraterrestrial input to Antarctic ice
during period from ~600 kyr BP to ~800 kyr BP.

956
Wed_186_CR-8_2479
Synchronizing Ice Core Chronologies: An Automated Method

Jai Chowdhry Beeman1 (jai-chowdhry.beeman@univ-grenoble-alpes.fr), Frédéric Parrenin1, Emmanuel

Witrant2, Amaelle Landais3
1
Université Grenoble Alpes / Institut des Géosciences de l’Environnement (IGE), CNRS - UMR 5001, Grenoble,
France, 2Université Grenoble Alpes, GIPSA-Lab/CNRS, Grenoble, France, 3LSCE (UMR 8212 CEA-CNRS-
UVSQ/IPSL), Université Paris Saclay, Gif-sur-Yvette, France

Ice cores can be synchronised to other ice cores, to paleoclimate records such as speleothems or marine
sediment cores, or to orbital targets using time series measurements. Here, as part of the IceChrono dating
model (Parrenin et al., 2015), we propose a generalized Bayesian synchronisation method, built on minimising
residuals between series using a parallelized Metropolis-Hastings simulation. We test the method on the gas
phase synchronisation of the Epica Dome C and Fletcher Ice cores to the WAIS Divide chronology, using
measurements of CH 4.
Our method is able to precisely synchronise the two gas records, introducing a level of reproducibility and
objectivity unavailable in manual time series synchronisation methods. To guarantee an accurate estimate of
chronological uncertainty, we present the chronologies we produce as ensembles of all the scenarios accepted
in the Metropolis-Hastings simulation.

957
Wed_187_CR-8_2490
Astronomical Dating: An Inverse Method Applied to Antarctic Ice Cores

Jai Chowdhry Beeman1 (jai-chowdhry.beeman@univ-grenoble-alpes.fr), Amaelle Landais2, Thomas Extier2,

Lucie Bazin2, Frédéric Parrenin1, Emmanuel Witrant3, Aleksandra Skakun4, Vladimir Ya. Lipenkov4, Dominique
Raynaud1
1
Université Grenoble Alpes / Institut des Géosciences de l'Environnement (IGE), CNRS - UMR 5001, Grenoble,
France, 2LSCE (UMR 8212 CEA-CNRS-UVSQ/IPSL), Université Paris Saclay, Gif-sur-Yvette, France, 3Université
Grenoble Alpes, GIPSA-Lab/CNRS, Grenoble, France, 4Arctic and Antarctic Research Institute, St. Petersburg,
Russian Federation

The chronologies of deep polar ice cores are vital to our understanding of how climate variables and
atmospheric greenhouse gas concentrations interacted over the last 800,000 years. The most recent
chronologies of the deepest Antarctc ice cores rely in part on proxies that follow the periodicities of Earth´s
insolation, defined by its rotational and orbital parameters, which can be calculated well into the past. The
processes that link astronomical forcings to their proxies, on the other hand, operate on multiple spatial and
temporal scales and are not well-modeled; and the synchronization between a proxy and its target can be
ambiguous. This translates into significant uncertainty in astronomical chronologies. Since the alignment of
proxies with their astronomical targets is typically performed visually, this uncertainty is difficult to formally
address.
Here, we pose the synchronization of ice cores to astronomical targets as an inverse problem, based on the
calculation of a cost function that takes into account residuals between proxy and target series. We compare
the chronologies and respective uncertainties calculated by this method, using Total Air Content and d18O and
dO2/N2 isotopic ratios as tracers of Earth´s astronomical parameters, to visual astronomical chronologies, and
compare the results of the chronologies we produce using each proxy-target pair. We discuss the implications
of our work for ice core chronologies, focusing on robust uncertainty estimation.

958
Wed_188_CR-8_2517
Exploring a New Proxy for Reconstructing Past Wind Strength in Ellsworth Land

Dieter Tetzner1,2 (dietet95@bas.ac.uk), Liz Thomas1, Eric Wolff2, Claire Allen1

1
British Antarctic Survey, Cambridge, United Kingdom, 2Cambridge University, Department of Earth Sciences,
Cambridge, United Kingdom

In the last decade, several efforts have been carried to assess the causes of the current rapid recent warming
measured on West Antarctica and Antarctic Peninsula. The increase in wind strength and shifts in atmospheric
circulation patterns have shown to play a key role in driving the advection of warm air parcels from mid-
latitudes to high-latitudes. Winds are also responsible for driving basal and surface melting in the ice shelves by
enhancing the removal of surface snow and by promoting the upwelling of deep warm water, respectively. All
these combined have shown to produce substantial effects on environmental parameters, such as: sea surface
temperatures, sea ice extension, air surface temperatures and precipitation.
Even though winds are fundamental components of the climatic system, there is a lack of past records which
can help to understand completely the role that winds have played through time and the significance of the
recent warming observed in the region.
In this work, we present a record of marine diatoms preserved in an intermediate depth ice core retrieved from
the Amundsen Sea region. We explore the diatom abundance, species assemblages and total particulate
content to assess the capacity of this record to represent the local/regional variability in wind strength and
circulation patterns that influence the onshore northerly winds.

959
Wed_189_CR-8_2538
New Insights into Disruptions in the Isotopic Record from the Ronne Ice Shelf

Dieter Tetzner1,2 (dietet95@bas.ac.uk), Francisco Fernandoy3

1
British Antarctic Survey, Cambridge, United Kingdom, 2Cambridge University, Department of Earth Sciences,
Cambridge, United Kingdom, 3Universidad Andrés Bello, Facultad de Ingeniería, Viña del Mar, Chile

In the last decades, the Filchner-Ronne Ice Shelf (FRIS) region has emerged as an important location to study
the response of the West Antarctic Ice Sheets and Ice Shelves in a climate change context. Recent research has
highlighted the sensitivity of this region to current changes in the climatic conditions.
Instrumental records from this remote region are short and scarce. However, several environmental
parameters can be interpreted from proxy records preserved in ice cores. These records can be used to
produce accurate chronologies of variations in meteorological parameters.
Even though these records are valuable tools to interpret climate trends, the lack of consistent annual cycles in
a suite of chemical species, as well as the presence of peaks within the year cycle, can induce to errors in the
production of age models. Identifying the presence of these peaks and understanding the processes behind
their development is essential to improve chronologies.
In this work, we use meteorological observations, atmospheric reanalysis and stable water isotopes from firn
cores to explore the relation between atmospheric processes and disruptions observed in the stable water
isotope records from FRIS and inland. We assess the ability of synoptic scale events, atmospheric circulation
modes and post-depositional processes to generate these sporadic patterns in the isotopic profiles.

960
Wed_190_CR-8_2575
The Fidelity of Ice Core Methane Records: Excess Methane in Greenland Ice Cores

James Lee1 (leej7@oregonstate.edu)

1
Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, United States

Ice core records of methane are important indicators of the response of terrestrial biogeochemical cycles.
Recent work has greatly enhanced the detail and precision in these records (Bock et al, 2010; Chappellaz et al,
2013; Baumgartner et al, 2014; Rhodes et al, 2015), but their interpretation depends on the fidelity of ice cores
in preserving the paleo-atmospheric record. We review published data sets and observe enrichments of
methane in samples from Greenland that are correlated with the abundance of dust in the ice (Steffenson,
1997). This is the first evidence of a non-atmospheric source of methane, which we refer to as ``excess´´
methane, affecting ice core samples absent of melt layers or interaction with basal material. Enrichments of ~6
µmol CH4 per mol Ca2+ in the sample were observed which corresponds to enrichments in concentration of
several 10's of ppb and depletions in δD-CH4 up to ~10‰. The release or production of excess methane was
directly measured using a multiple melt-refreeze strategy on samples from the GISP2 Greenland Summit ice
core and the North Greenland NEEM ice core. Enrichments of methane were absent in Antarctic ice core
samples. Of several potential mechanisms, our results are best explained by the desorption of methane from
dust particles during sample analysis. Ultimately, excess methane may be adsorbed onto the dust particles
from emissions at the dust source or during methanogenesis within the ice sheet.

961
Wed_191_CR-8_2579
Water Isotope Characterization of the Styx Glacier Ice Core in East Antarctica

Yeongcheol Han1 (yhan@kopri.re.kr), Songyi Kim1,2, Sang Bum Hong1, Soon Do Hur1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Ewha Womans University, Seoul, Korea,
Republic of

The Antarctic Northern Victoria Land (NVL) is adjacent to the Ross Sea and comprises the Transantarctic
Mountains, which has both coastal and plateau environmental conditions. The Styx Glacier (SG) is a well-known
snow accumulation area with least influence of katabatic wind in NVL and forms a flat surface with an area of
>100 km2. The field campaign, a part of the Korean Antarctic research program, drilled a 210.5 m long ice core,
two firn cores and a snow pit at SG during the 2014-2015 summer season. Stable water isotopes (d18O, d17O
and dD) were determined for the uppermost 100 meters of the ice core, a firn core and the snow pit. The
results were combined with a firn densification model, electrical conductivity measurement data and firn air
composition to establish a reliable depth-age relationship and to reconstruct the snow accumulation rate. The
results were compared with ice core data from neighboring sites, and the spatial variability at the regional scale
was investigated. Statistical approaches were applied to the water isotope time series to derive climate
implications and to capture potential teleconnection influence.

962
Wed_192_CR-8_2589
Assessment of Fractionation Processes and Corrections for Noble Gas Thermometry

Sarah Shackleton1 (sshackle@ucsd.edu), Christo Buizert2, Jeffrey Severinghaus1

1
University of California San Diego, Scripps Institution of Oceanography, San Diego, United States, 2Oregon
State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, United States

Noble gas thermometry allows reconstruction of mean ocean temperature (MOT) from the noble gas content
(dKr/N2, dXe/N2, and dXe/Kr) of glacial ice. This technique promises to advance our understanding of past
ocean heat uptake, potentially narrowing uncertainty in the climate sensitivity. Since the development of this
proxy, improvements in the method have allowed for MOT reconstruction with unprecedented precision.
These significant steps forward require us to reassess the validity and sensitivity of the assumptions that go
into MOT reconstruction. Investigations into mechanisms that decouple the MOT proxies from ocean heat
content have primarily focused on processes that affect atmospheric noble gas content. Here we address
processes that decouple the noble gas content of air in glacial ice from the atmosphere and assess associated
uncertainties in the interpretation of MOT records. We analyze modern firn air and surface ice samples from
multiple polar sites, in which the air is young enough that the true atmospheric composition is known. We then
correct them for gravitational, thermal and kinetic fractionation and gas loss using several approaches. From
this we identify a 'best method' for correction of dKr/N2, dXe/N2, and dXe/Kr data, and quantify systematic
error in MOT records. Using these findings we make suggestions for identifying and correcting potential bias in
future MOT campaigns.

963
Wed_193_CR-8_1670
Radiocarbon Analyses of Dissolved Organic Carbon (DOC) in Glacier Ice

Ling Fang1 (ling.fang@psi.ch), Johannes Schindler2, Theo Jenk2, Margit Schwikowski2

1
Paul Scherrer Institute, Villigen PSI, Switzerland, 2Paul Scherrer Institute, Villigen PSI Ost, Switzerland

Dating of ice cores from high alpine glaciers is challenging due to limited glacier thickness, the complex bedrock
geometry and strong annual layer thinning. Water Insoluble Organic Carbon (WIOC) in glacier ice has been used
for radiocarbon dating for years [1]. However, this method is limited by the WIOC concentrations. The majority
of the carbon containing matter in snow and ice is present as Dissolved Organic Carbon (DOC) [2]. To
investigate the suitability of DO14C dating, we develop a high efficient and low blank extraction system. Ice
samples after cutting are further cleaned and melted under helium gas. WIOC is separated by filtration and
Inorganic Carbon (IC) is removed via acidifying and degassing. The remaining DOC in the solution is oxidized by
UV lamps. Produced CO2 is quantified after cryogenic trapping and sampled to glass vials for 14C analyses. This
setup has been applied to the Fiescherhorn ice core to estimate anthropogenic contribution of DOC to Alpine
glaciers and establish the time boundary of applying DO14C as a dating tool.
[1] Uglietti, C. et al (2016). Radiocarbon dating of glacier ice: overview, optimisation, validation and potential.
The Cryosphere, 10(6), 3091-3105.
[2] M. Legrand, et al., Major 20th century changes of the content and chemical speciation of organic carbon
archived in Alpine ice cores: Implications for the long term change of organic aerosol over Europe, Journal of
Geophysical Research: Atmospheres 118.9 (2013): 3879-3890.

964
Wed_194_EN-1_47
Ecological Architecture of Antarctica: The Usage of Natural Building Materials

K P C Hudson1 (katelyn.hudson@student.bond.edu.au)
1
Bond University, Faculty of Society and Design, Robina, Australia

Today the building industry has a strong impetus and emphasis on sustainable building, a prevalent aspect of
which is the use of endemic materials. What happens when the natural resources available aren't what is
traditionally considered usable or practical? Throughout the history of building practices in Antarctica there has
been minimal employment of materials that are available despite knowledge of the vernacular architectural
practices in Arctic regions. Snow and ice are an ever present consideration in Antarctica, whether the structure
interacts with drifting snow defensively, treating it as a negative quality, an impediment, or embraces it as a
secondary building material and potential insulator. Recent research stations, in contrast to many of the older
stations and huts, have been more cognizant of what impact they have on natural surroundings, which has
resulted in more creative and innovative structures, including one proposal which incorporates snow as a
primary building material. An interpretive-historical study of the building practices provides cultural and
environmental insight into why this practice wasn't utilized more as well as the successes and failures.

965
Wed_195_EN-1_568
Vulnerability of Ice-free Landscapes to Human Impacts, East Antarctica

Stephanie McLennan1 (stephanie.mclennan@ga.gov.au), Tanya O'Neill2, Duanne White3

1
Geoscience Australia, Environmental Geoscience Division, Canberra, Australia, 2University of Waikato, Earth
and Ocean Sciences, Hamilton, New Zealand, 3University of Canberra, Canberra, Australia

Ice-free regions of Antarctica make up only a fraction of the continent but are often the site of intensive activity
associated with national programs and tourism. Without the protection of permanent snow and ice, poorly
consolidated sediments and fragile polar landforms can be easily damaged by human activities. Natural
recovery processes in the cold, dry climate are slow and poorly understood. Over the next three years a
collaborative project between Geoscience Australia, the Australian Antarctic Division, University of Waikato
(NZ), and University of Canberra (AUS) will build on existing systematic methods for assessing impact and
recovery. Through field experiments and geomorphology mapping, we will identify chemical and physical
processes in ice-free landscapes that may influence recovery from disturbance. Preliminary remote landform
mapping in the Vestfold Hills, East Antarctica, shows a variety of potentially vulnerable sedimentary landforms
between bedrock outcrops, including muddy drainage depressions, ephemeral ponds, raised beaches, boulder
fields, dunes, moraines, and gently undulating water-lain deposits. Salt efflorescence on the surface is
common, particularly in areas with deeper sedimentary cover. We will link verified landform mapping to soil
characteristics to reveal patterns of vulnerability, aid planning and environmental management practices and
provide geoscience information to inform predictions of future environmental changes.

966
Wed_196_EN-1_1626
Penguin Guano Play an Important Role in Antarctic Coast Ecosystem

Jian Chen1 (chenjian@tio.org.cn), Dongyi Li1, Yuan Li2, Longshan Lin2

1
The Third Institute of Oceanography, State Oceanic Administration, Marine Environmental Geology, Xiamen,
China, 2The Third Institute of Oceanography, State Oceanic Administration, Marine Biology, Xiamen, China

Study shows that chlorophyll-a concentration in 80% area of the South Ocean is lower than 0.5 ug/l. Incubation
experiment has proven that addition of guano with high content of nutrients may efficiently improve
production of chlorophyll.
In south bay of the Doumer island CTD cast data show fluorescent of Chlorophyll-a in upper 100m water are
about 0.14-3.64 ug/l with average of 1.09 ug/l, and has a observable peak in depth about 20-30m with
temperature of 0.97 ℃. POC/PON in the bay is about 4.0-6.4 with average of 5.0, is remarkably lower than
FOODBANCS C/N (5.9-7.8) in east of the Anvers Island and Palmer LTER C/N (7.1-9.2) in the west Antarctic
Peninsula continent shelf, which may be explained that some guano debris are brought into the bay by melt
water, redistributed by tidal current and deposit in coastal zone. These additional input of undissolved
particulate guano reduce value of observed C/N, with a trend of being smaller in coast than inner bya.
Moreover, low concentrations of coprostanol and cholesterol were detected in the surface sediments in center
of the bay, which may be an another indicators for penguin guano effect in this area.
It can be inferred that in circumstance of global warming, the historical penguin excretion may release much
more nutrients to coastal water. These will stimulate phytoplankton community production and benefit krill
resource in the Antarctic. More attentions should be exerted to understand guano role in ecosystem nutrient
cycling.

967
Wed_197_EN-1_1686
Diversity and Ecophysiology of Vaucheria sp. in Coastal Tidal Flats of Svalbard

Claude-Eric Souquieres1, Jana Kvíderová1 (jana.kviderova@objektivem.net), Josef Elster1,2

1
University of South Bohemia, České Budějovice, Czech Republic, 2Institute of Botany, Academy of Sciences of
the Czech Republic, Třeboň, Czech Republic

The Arctic coastal zone, especially tidal flats, is the one most dynamic polar landscapes due to frequent
disturbance of the seabed and random recolonization of very unstable fine sediment in temporary system of
channels and lagoons. One of such unique areas where these processes occur is the Adventfjorden tidal flat,
located near Longyearbyen (Svalbard). The microphytobenthos carpet covers large area of several hectares
there, contributing thus significantly to tidal flat stabilization. The xanthophycean microalga Vaucheria sp.
(Vaucheriaceae, Xanthophyceae) is dominant there in various habitats ranging from freshwater to marine ones.
In summer seasons 2016 and 2017, we focused on morphological and molecular diversity of Vaucheria sp. with
respect to the area distribution, impact of tide and distance from sea on Vaucheria sp. distribution together
with chemical and physical water and sediment ecological properties. These ecological studies were followed
by measurements of photosynthetic activity of Vaucheria sp. in two types of microcosmos as well in situ using
variable chlorophyll fluorescence and gasometry approaches.

968
Wed_198_EN-1_1844
Mapping the North East Greenland Coastal Zone with Satellite Imagery

Mikkel Høegh Bojesen1 (mhb@asiaq.gl), Rasmus Eskerod Borgstrøm2, Kirsty Langley1, Eva Mätzler1, Mikkel
Lydholm Rasmussen2, Karl Brix Zinglersen3
1
Asiaq Greenland Survey, Nuuk, Greenland, 2DHI GRAS A/S, Hørsholm, Denmark, 3Greenland Insitute of Natural
Resources, Department of Environment and Minerals, Nuuk, Greenland

The North East Greenland National Park holds unique and sensitive ecosystems as well as archaeological
heritage sites, but is also generally well protected. Nevertheless, the Greenland Sea hydrocarbon licensing
round in 2011 opened up a new chapter in hydrocarbon exploration in Greenland, as previously all exploration
licenses concerned the west coast of Greenland. Our current knowledge concerning the very remote North East
Greenland coastal areas is generally poor, and thus decision support concerning emergency prevention,
preparedness and response is challenged.
This project seeks to improve our understanding of the coastal response to oil spill, by assessing potential oil
spill sensitivity and resilience. The project utilizes a remote sensing approach to map and characterize the
coastal zone in NE Greenland. We develop a Digital Elevation Model covering more than 60.000km2 at a
resolution of 8 meters, based on ArcticDEM data. In areas of special interest we further derive intertidal zones,
shallow water bathymetry and shoreline types based on both commercial VHR imagery and publically available
satellite imagery. Validation will be carried out by in situ measurements.
The obtained knowledge will enable the provision of informed planning and decision making by a number of
stakeholders, to support a sustainable management regarding exploration and potential exploitation of
hydrocarbon resources.

969
Wed_199_EN-1_1971
Svalbard Paraglacial Coasts - Processes, Landforms and the Future

Mateusz Strzelecki1 (mat.strzelecki@gmail.com), Piotr Zagórski2

1
University of Wroclaw/ Institute of Geography and Regional Development, Wrocław, Poland, 2Marie Curie
Sklodowska University, Department of Geomorphology, Lublin, Poland

Here we summarize the results of several coastal research projects carried out along paraglacial coasts of
Svalbard during the last decade. We reconstruct the post-Little Ice Age evolution of coasts in western, central
and southern Spitsbergen to illustrate the highly variable coastal zone responses to both paraglacial and
periglacial landscape transformation associated with deglaciation and intensification of extreme
geomorphological processes.
Our results show the key role of climate changes in controlling sediment fluxes from deglaciated valleys to the
coastal zone. Under intervals characterized by a warming climate, retreating local ice masses, a shortened sea-
ice seasons and melting permafrost most of studied coastal systems rapidly responded to excess of freshly
released sediments and experienced significant geomorphological changes leading to development of new
coastal landforms (e.g. spits) and progradation of existing forms (e.g beach-ridge plains, barriers). We discuss
our new data in the context of previously published coastal evolution studies from Svalbard. The study
highlights the need for a greater understanding of the controls on High Arctic coastal systems, especially given
the potential for future accelerated climate warming, decay of sea-ice, storminess and sea-level rise and rapidly
growing human impact on Arctic resources and strategic locations.
This paper is a contribution to the NCN project UMO2013/08/S/ST10/00585.

970
Wed_200_EN-1_2137
Need for an Integrated Research & Development Center in the Alaskan High Arctic

Jasper Hardesty1 (joharde@gmail.com), Mark Ivey1, Darielle Dexheimer1, Catherine Cahill2, Erika Roesler1, Fred
Helsel1
1
Sandia National Laboratories, Atmospheric Sciences, Albuquerque, United States, 2University of Alaska -
Fairbanks, Alaska Center for Unmanned Aircraft Systems Integration (ACUASI, Fairbanks, United States

Arctic research stations provide critical monitoring and research on climate change for conditions and trends in
the Arctic to address gaps in observations, infrastructure, resource management, and emergency response.
This poster proposes development of a permanent integrated US High Arctic Research Center (USHARC) at
Oliktok Point, Alaska; taking advantage of assets and infrastructure, controlled airspace, an active UAS program
and local partnerships.
To address research and technology gaps, USHARC is envisioned to partner stakeholders from science, safety
and security to develop comprehensive solutions. The Station will offer year-round use, logistic support, access
to varied ecological settings, and support testing of technologies; such as autonomous platforms, energy
microgrids, and sensors.
We propose that USHARC, combined with Toolik Field Station and Barrow Environmental Observatory, will
form a US network of Arctic Stations. Unique assets from USHARC include: access via land, sea and air; coastal
and terrestrial ecologies; controlled airspaces (land and ocean); logistic support; atmospheric observations;
connections to Barrow and Toolik; fiber-optic communications; and a University of Alaska Fairbanks UAS Test
Facility with an airstrip and hangar.
World-class Arctic research requires year-round access and facilities. A US High Arctic Station network enables
monitoring to better study, predict and understand impacts that affect people, communities and planet.

971
Wed_201_EN-1_2253
The Coastal Community Ocean Observers (C2O2) Program

Peter Winsor1 (pwinsor@alaska.edu), Tuula Hollmen2, Seth Danielson2

1
University of Alaska - Fairbanks, Institute of Marine Science, College of Fisheries and Ocean Sciences, Fairbanks,
United States, 2University of Alaska - Fairbanks, Fairbanks, United States

The Coastal Community Ocean Observers (C2O2) is a coastal science program that seeks to build a framework
for long-term community-driven monitoring of oceanic environmental variables. The C2O2 program combines
cost-efficient means for communities to collect environmental data with local interest, promoting mutually
beneficial partnerships and relationships for collecting and sharing information. The C2O2 program is currently
active in six Alaskan communities which have uniquely different climates, cultures, and local concerns, and
represents different oceans and environments. Using simple-to-operate conductivity-depth-salinity-
fluorescence profilers, each of these communities have generated a large number of hydrographic data on
weekly to months intervals which is reported in near-real time via a web interface and immediately available
on the project website for community residents, scientists and stakeholders. Here we describe the C2O2
program, focusing on data collection, results and a build-out plan for the future, including implementation of a
biological sampling component. C2O2 is interfacing with similar efforts in Canada, the Mosquito Fleet to the
south and the CROW project to the north, to create a linked network of ocean observations in a south-to-north
framework to detect and describe climate change propagation and its impact on local ecosystems and
communities. We also discuss the possibility to build this to an pan-Arctic wide network of community
observations.

972
Wed_202_EN-1_2345
Assessment of the vulnerability of Populated Sections of the Arctic Coast

Marek W. Jaskólski1 (marek.jaskolski@uwr.edu.pl), Matt C. Strzelecki1

1
University of Wroclaw/ Institute of Geography and Regional Development, Department of Geomorphology,
Wrocław, Poland

The area of the Arctic is inhabited by about 4 million people, and the vast majority of human activity in the
Arctic is focused on the coast. Over the past three decades, the climate of the Arctic has changed significantly,
the observed increase in temperature was twice as high as the global average. Modern arctic coastal
landscapes are strongly modified by accelerated degradation of permafrost and its thawing threatens the
existing infrastructure, increases inflow of deglaciation sediments resulting in shallowing of the port basins and
extending the period of open water, causing the increase of wave activity and hence increase of the erosive
activity. The warming in the Arctic led to the acceleration and intensification of geomorphological processes
that directly affect safety of human activities. Most available Arctic literature focuses on coastal zone changes
in the local context. However, there is no overall assessment of the vulnerability of the Arctic coast in a global
context, which focuses on threats for settlements at the arctic coast. The aim of our study is to show the
variability of the vulnerability of human settlements (over 500 inhabitants) along the Arctic coastline and to
identify the most endangered areas. Evaluation will be made using indexing methods, e.g. the adapted CVI
index and remote sensing tools based on the ArcGIS geographic information system.

973
Wed_203_OS-2_233
Long-term Mesoscale Variability of Sea-ice Primary Production in the Baltic Sea

Letizia Tedesco1 (letizia.tedesco@environment.fi), Elina Miettunen2, Byoung W. An3, Jari Haapala4, Hermanni
Kaartokallio2
1
Finnish Environment Institute, Marine Research Centre, Helsinki, Finland, 2Finnish Environment Institute,
Helsinki, Finland, 3National Institute of Meteorological Sciences, Jeju-do, Korea, Republic of, 4Finnish
Meteorological Institute, Helsinki, Finland

We describe a new ocean-sea ice-biogeochemical model, apply it to the Bothnian Bay in the northern Baltic Sea
for the time period 1991-2007 and provide the first long-term mesoscale estimates of modelled sea-ice primary
production in the northern Baltic Sea. After comparing the available physical and biogeochemical observations
with the model results, we show the modelled spatial and temporal variability in sea-ice physical and
biogeochemical properties and consider the main factors limiting ice algal primary production. Sea-ice
permeability in the studied area was low compared with the polar oceans, which appeared to be a major
reason for the generally low primary production rates. Although the sea ice was less saline in the northernmost
parts of the basin, these parts were characterized by sea ice with a larger amount of habitable space, higher
levels of photosynthetically active radiation and increased macronutrient availability near the coast, which
favoured higher algal growth rates. Other parts of the southern central basin were mostly co-limited by less
favourable light conditions and lower seawater macronutrient concentrations than in the coastal zones.
Although a change towards milder winters was previously detected on a half-century timescale and could
partly be seen here, analysis of the temporal evolution of sea-ice biogeochemical properties showed no
significant trends over time, though these properties were characterized by large interannual variability.

974
Wed_204_OS-2_291
Biogeochemistry of Antarctic Landfast Sea Ice and the Potential Role of Biofilm

Florian Deman1 (florian.deman@vub.be), Arnout Roukaerts1, François Fripiat2, Jean-Louis Tison3, Bruno Delille4,
Frank Dehairs1
1
Vrije Universiteit Brussel (VUB), AMGC, Brussels, Belgium, 2Max Planck Institute for Chemistry, Climate
Geochemistry, Mainz, Germany, 3Université Libre de Bruxelles, Laboratoire de Glaciologie, Brussels, Belgium,
4
Université de Liège, Unité d'Oceanographie Chimique, Liège, Belgium

Antarctic landfast sea ice exhibits a large accumulation of biomass in the bottom few centimetres of the ice,
with particulate organic carbon (POC) concentrations reaching 2 mmol C l-1 during spring bloom. Surprisingly,
fieldwork measurements (Adélie Land 2011, McMurdo Sound 2012, Prydz Bay 2015) of nitrate and phosphate
concentrations show a simultaneous increase, with values exceeding those of underlying seawater, suggesting
an intense remineralisation process within the ice. Such co-evolution of nutrients and biomass contradicts the
classical view of nutrient consumption during the growth period followed by remineralisation after the bloom
peak, and suggests an intense supply of N from the underlying water column. Results of a NPZD-model
indicates that a second nutrient pool, in addition to the brine pool, is essential to successfully model and
reproduce field observations. The presence of a biofilm attached to the ice walls could act as a water-retaining
substrate forming microenvironments with chemical gradients within the brine channels. The effect of biofilm
on nitrogen dynamics (concentration and isotopic composition) in sea ice will be discussed as well as potential
implications for other parameters (phosphate, carbon, oxygen).

975
Wed_205_OS-2_358
Cycling of DMS,P in Early-winter Ross Sea Pack Ice during the PIPERS Project

Gauthier Carnat1 (gauthier.carnat@gmail.com), Bruno Delille2, Fanny Van der Linden1, Johannes de Jong3, Célia
Sapart1, Boris Wittek1, Stephen Ackley4, Sharon Stammerjohn5, Jean-Louis Tison1
1
Université Libre de Bruxelles, Laboratoire de Glaciologie, Brussels, Belgium, 2Université de Liège, Unité
d'Océanographie Chimique, Liège, Belgium, 3Université Libre de Bruxelles, Laboratoire G-Time, Brussels,
Belgium, 4University of Texas at San Antonio, Snow and Ice Geophysics Laboratory, San Antonio, United States,
5
University of Colorado, Institute of Arctic and Alpine Research, Boulder, United States

Ice-algal assemblages are known to produce large amounts of the sulfur metabolite
dimethylsulfoniopropionate (DMSP), and of its volatile degradation product dimethylsulfide (DMS). Sea ice
DMS is subsequently released to the polar ocean and atmosphere where it plays multiple roles in the sulfur and
carbon cycle, and mediates the formation of climate cooling sulfate aerosols. Previous studies on the cycling of
DMS and DMSP in sea ice are mostly limited to the spring/summer seasons, when large blooms develop in first-
year ice due to favourable light and nutrient regimes. In contrast, there is much less information about the
production of DMS,P during the first stages of sea ice formation in light-limited early-winter. In this context, we
carried out measurements of sea ice DMS,P concentrations in the Ross Sea from April until June 2017 in the
framework of the PIPERS project. Multiple ice types and thicknesses were sampled (frazil, unconsolidated and
consolidated pancakes, first-year ice) together with sea water and brine, in contrasted areas (marginal ice
zones, polynyas, and the central Ross sea pack ice). Sea ice DMS,P concentrations (maximum of 95 and 492 nM)
were lower than values typically reported during ice-algal spring blooms, but still significantly higher than sea
water concentrations at the time of sampling (maximum of 3 and 15 nM). We present and discuss working
hypotheses to explain how these concentrations build up through the different steps of sea ice formation.

976
Wed_206_OS-2_378
Biogeochemistry at the Early Stages of Ice Tormation: Insights from PIPERS

Bruno Delille1 (bruno.delille@uliege.be), Fanny Van der Linden1,2, Gauthier Carnat2, Célia Sapart2, Jeroen de
Jong2, Marie Kotovitch1,2, Florian Deman3, Frank Dehairs3, Jean-Pierre Descy1, Daiki Nomura4, Sharon
Stammerjohn5, Steve Ackley6, Jean-Louis Tison2
1
Université de Liège, Chemical Oceanography Unit, Liège, Belgium, 2Université Libre de Bruxelles, Glaciology
Unit, Bruxelles, Belgium, 3Vrije Universiteit Brussel (VUB), AMGC Department, Brussels, Belgium, 4Hokkaido
University, Faculty of Fisheries Science, Hakodate, Japan, 5University of Colorado, Boulder, United States,
6
University of Texas at San Antonio, Snow and ice Geophysics Laboratory, San Antonio, United States

The PIPERS cruise on N. B. Palmer into the early winter Ross Sea took place between April and June 2017.
PIPERS was a unique opportunity to investigate biogeochemistry of pack ice during early stages of ice
formation. We will present insights of the dynamics of sympagic microalgae assemblages, nutrients, particulate
organic carbon and 2 potent greenhouse gases (carbon dioxide and nitrous oxide) during early ice growth.
The comparison of CO2 fluxes over consolidated and unconsolidated ice show that
1) sea ice acts as a source of CO2 for the atmosphere
2) largest fluxes occur at the earliest sea ice growth stages (i.e. frazil ice, unconsolidated grey ice, pancake ice).
Large fluxes are due to ongoing active rejection of impurities, high porosity of highly saline/high temperature
young ice, and the absence of snow. Overall, snow appears to restrict CO2 fluxes. In some cases, fluxes over
snow appears to be nil or even opposite to fluxes over bare ice. Therefore, while snow is often view as a
transient buffer for air-ice gases fluxes, the role of snow appears to be more complicated. The new
measurements of CO2 fluxes over young ice carried out during PIPERS potentially allow to complete a budget of
CO2 fluxes over Antarctic pack ice by filling a significant gap.

977
Wed_208_OS-2_464
What is the Impact of Environmental Stress in Sea Ice Brine on DMS Production?

Boris Wittek1,2 (bwittek@ulb.ac.be), Gauthier Carnat1, Jean-Louis Tison1, Nathalie Gypens2

1
Université Libre de Bruxelles, Laboratoire de Glaciologie, Brussels, Belgium, 2Université Libre de Bruxelles,
Laboratoire d'Ecologie des Systèmes Aquatiques, Brussels, Belgium

Sea ice plays a significant role in the production and exchanges of climate active gases between the ocean and
the atmosphere. One of them, dimethylsulfide (DMS), is a key precursor of sulfate aerosols which affect the
Earth radiation balance. DMS is produced by the degradation of two algal metabolites:
dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO), typically found in very high concentrations
in sea ice. Little is known about the factors driving the production of these metabolites in the stressing
environmental conditions (in particular low temperatures and high salinities) of the brine inclusions in which
sea ice algae thrive. In this context, we present results from axenic cultures experiments with two emblematic
species of the sea ice ecosystem: the diatom Fragilariopsis cylindrus, and the prymnesiophyte Phaeocystis
antarctica. We discuss changes in DMSP and DMSO concentrations in response to gradual shifts in salinity and
temperature corresponding to the typical seasonal variability encountered by these algae in the brine
inclusions (from 4°C and salinity of 34, up to -18°C and salinity of 250). Globally, we show how the outcomes of
this research project should improve our understanding and modelling capabilities of the sea ice sulfur cycle.

978
Wed_209_OS-2_506
Differing Drivers of Taxonomic versus Trophic Structure in Arctic Communities

Hauke Flores1,2 (hauke.flores@awi.de), Benjamin Lange1,2,3, Julia Ehrlich1,2, Kristin Hardge4, Carmen David1,2,
Barbara Niehoff5, Ilka Peeken5, Doreen Kohlbach1,2, Eva-Maria Nöthig5, Katja Metfies4
1
AWI, Young Investigators Group Iceflux, Bremerhaven, Germany, 2University of Hamburg, CeNak, Hamburg,
Germany, 3Department of Fisheries and Oceans Canada, Winnipeg, Canada, 4AWI, Young Investigators Group
PLANKTOSENS, Bremerhaven, Germany, 5AWI, Polar Biological Oceanography, Bremerhaven, Germany

In the Arctic Ocean, continuing sea ice decline will increase light availability, but enhanced stratification could
decrease nutrient supply to the euphotic zone. To investigate the effects of these factors on the taxonomic and
trophic structure of planktonic and sympagic communities, we sampled environmental parameters, protists
from the under-ice layer and from the water column, zooplankton and under-ice fauna in the Central Arctic
Ocean in summer 2012. We identified
1) a 'Shelf-influenced' regime with decaying sea ice, high silicate concentrations and low NOxconcentrations;
2) a 'Polar' regime with low silicate concentrations and low NOx concentrations; and
3) an 'Atlantic' regime with low silicate concentrations and high NOx concentrations. Across all communities,
the taxonomic composition primarily responded to the variability of sea ice properties.
The trophic structure of the communities, however, responded to NOx concentrations. The most heterotrophic
taxa significantly dominated in the two NOx-depleted regimes compared to the NOx-rich Atlantic regime. The
different nutrient regimes were also associated with differences in ecosystem functions, such as primary
production, secondary production and carbon export. While changing sea ice properties will affect taxonomic
composition at multiple size classes, low nutrient concentrations in the upper Arctic Ocean may induce a more
heterotrophic food web, affecting key ecosystem functions.

979
Wed_210_OS-2_708
Community Structure and Photoacclimation in Antarctic Ice-algal Communities

Maria A. van Leeuwe1 (m.a.van.leeuwe@rug.nl), Mairi Fenton2, Amber Annett2, Emily Davis2, Jacqueline
Stefels1
1
University of Groningen, Groningen, Netherlands, 2British Antarctic Survey, Cambridge, United Kingdom

Microalgal composition and production was studied in sea ice in Ryder Bay, West-Antarctic Peninsula. This area
is the fastest warming oceanic region on earth; between 1979-2007 a 41% decline relative to the mean was
recorded. The impact on biogeochemical cycles is poorly described. Development of microalgal sea-ice
communities was studied from winter to summer during three years. Over the course of spring, modest surface
communities developed with a Haptophyte pigment signature. Major biomass increases were recorded in the
bottom layers and reached a maximum concentration of more than 700 µg Chl-a l-1 in December 2014. Early in
the season, a mixed algal community inhabited the bottom layer. From November onwards, diatoms
dominated the bottom community, with Nitzschia, Fragillariopsis and Berkeley sp. as the main species. The
maximum electron transfer rate (ETR) as determined by PAM-fluorescence at the bottom gradually increased
over spring from 3 to 30. At the same time, the slope of ETR versus irradiance (alfa) increased. The value for
light saturation (Ik) hardly changed and measured ca. 150µmol photons m-2 s-1. Data will also be presented on
production rates determined by means of C13-incorporation and on 13C-POC as a tracer for sea-ice microalgae.
These times series provide unique patterns of community structure and photoacclimation in Antarctic landfast
ice-algal communities.

980
Wed_211_OS-2_811
DMSP Production and Conversion in Antarctic Landfast Ice

Jacqueline Stefels1 (j.stefels@rug.nl), Alison Webb1, Mairi Fenton2, Emily Davey2, Maria van Leeuwe1
1
University of Groningen, GELIFES, Groningen, Netherlands, 2British Antarctic Survey, Cambridge, United
Kingdom

The marginal sea-ice zone around Antarctica is one of largest sources of the climate-active gas
dimethylsulphide (DMS). DMS is produced from the enzymatic cleavage of dimethylsulphoniopropionate
(DMSP), which is an osmolyte and cryoprotectant in ice algae. The release of DMS occurs mainly during
springtime when the ice melts, but may also happen during brine drainage and when gap-layer communities
form and mix with melting snow.
Here we present the development of DMSP in sea ice of Ryder Bay, during two winter seasons: 2014 and 2016.
Ice cores were taken as soon as ice was accessible and continued until spring. Over winter only total and GF/F-
filtered DMS+DMSP was taken, together with HPLC pigments for algal biomass analyses and classification.
Bottom-ice concentrations of total DMS+DMSP increased during September/October and reached maximum
values in December: generally between 1 and 2µM, but a maximum of 15µM was observed in December 2014.
Internal- and surface communities regularly developed earlier in the season and also reaching µM-levels of
DMS(P). High DMS(P) concentrations coincided with the presence of Haptophyte algae. In spring, ice cores
were fully analyzed for DMS, DMSP and DMSO. Stable-isotope additions were used to calculate conversion
rates within the sulphur cycle. In layers with high biomass, DMSP was quickly consumed: approximately 20%
ended up in DMS. Other important pathways were uptake by organisms and demethylation.

981
Wed_212_OS-2_814
The Arctic Microbiome During the Winter-spring Transition: Nitrogen-cycle Genes

António Gaspar Gonçalves Sousa1,2 (antonio.sousa@ciimar.up.pt), Maria Paola Tomasino1, Pedro Duarte3, Mar
Fernández-Méndez3, Philipp Assmy3, Hugo Ribeiro1, Jaroslaw Surkont4, Ricardo Leite4, José Pereira Leal4, Luís
Torgo5,6, Catarina Magalhães1,2
1
CIIMAR/CIMAR - Interdisciplinary Centre of Marine and Environmental Research, Bioremediation and
Ecosystems Functioning Research Group (EcoBioTec), Matosinhos, Portugal, 2Faculty of Sciences, University of
Porto, Department of Biology, Porto, Portugal, 3Norwegian Polar Institute, Fram Centre, Tromsø, Norway,
4
Instituto Gulbenkian de Ciência, Computacional Genomics, Oeiras, Portugal, 5INESC Technology and Science,
LIAAD - Laboratory of Artificial Intelligence and Decision Support, Porto, Portugal, 6University of Porto, Faculty
of Sciences, Department of Computer Science, Porto, Portugal

Pelagic microbial communities are a key component of the Arctic Ocean when evaluating the ecological impact
of the thinner Arctic icescape, as they constitute the basis of the marine food web and biogeochemical cycles.
During the Norwegian young sea ICE expedition (N-ICE2015), that took place in drifting pack ice north of
Svalbard between January-June 2015, seawater was collected at 5, 20 or 50, and 250 m depth on 9 March, 27
April and 16 June, together with environmental data. Illumina MiSeq paired-end reads from SSU rRNA amplicon
and metagenomes were sequenced to study the composition, diversity and key nitrogen-cycling functions of
the Arctic's microbiome through the winter-spring transition. Results show that nitrifiers, aerobic ammonia
oxidizers and nitrite oxidizers, mostly affiliated with Thaumarchaeota and Nitrospinae, are abundant in
subsurface waters below the pack ice during winter-early spring (6.3-27.4%) but nearly absent in late spring
(0.1-2.0%). Urease and ammonia monooxygenase encoding genes are positively correlated with total dissolved
nitrogen (urea included) suggesting the coupling of ureolysis and ammonia oxidation. Urease encoding gene
increases along depth meaning that distinct species of thaumarchaeotes, i.e., 'Ca. Nitrosopumilus' and Marine
Group I, found at different depths in the water column have different potential to carry out ureolysis. These
results provide new knowledge about the nitrogen-cycling communities and pathways in the Arctic Ocean.

982
Wed_213_OS-2_861
Biogeochemistry of Late Summer Sea-ice in East Antarctica

Julie Janssens1 (julie.janssens@utas.edu.au), Sebastien Moreau1, Cristina Genovese1, Matthew Corkill1, Lavy
Ratnarajah2, Luis Duprat1, Viena Puigcorbe3, Montserrat Roca-Marti3, Delphine Lannuzel1,2
1
Institute for Marine and Antarctic Studies, Hobart, Australia, 2Antarctic Climate & Ecosystems Cooperative
Research Centre, Hobart, Australia, 3Edith Cowan University, Perth, Australia

The contribution of sea-ice primary productivity to the Southern Ocean biological carbon pump is not well
constrained. In this study, we partly address this gap and present concentrations of particulate organic carbon
(POC) and nitrogen (PON), chlorophyll a (Chl a), exopolysaccharides (EPS) and macro-nutrients in fast ice, pack
ice and underlying seawater collected in the East Antarctic sector in late summer 2016-2017 (Dec-Jan). Very
few sea-ice biological data exist for this time of the year where ocean-ice interactions are maximal due to ice
melt and drift.
Chl a concentration in late summer sea ice was up to 130 µg/L in fast ice and 95 µg/L in pack ice. Particulate
organic carbon concentrations in the ice were high (up to 7000 µg/L), and C:N ratios were always higher than
the Redfield ratio, suggesting carbon overconsumption in the ice. A loss of biomass during sea-ice melting and
the production of EPS, which would have retained POC in the ice, could explain the high POC:Chl a ratios
(>7000 in fast ice and >1000 in pack ice) encountered in sea ice. Preliminary results also showed that
ammonium was consistently enriched in the ice while nitrate+nitrite was predominantly depleted. Sea ice
could have been acting as an organic carbon reservoir and recycling factory at this time of the year when the
phytoplankton bloom is at its peak. These data also contribute to increase our understanding of the role of
pack-ice biogeochemistry, which is less studied than fast ice.

983
Wed_214_OS-2_1278
Inter-comparison between Chambers for CO2 Flux Measurements over Sea Ice

Daiki Nomura1,2 (daiki.nomura@fish.hokudai.ac.jp), Bruno Delille3, Jean-Louis Tison4, Gerhard S. Dieckmann5

1
Hokkaido University, Hakodate, Japan, 2Arctic Research Center, Hokkaido University, Sapporo, Japan,
3
Université de Liège, Liège, Belgium, 4Université Libre de Bruxelles, Bruxelles, Belgium, 5Alfred Wegener
Institute, Bremerhaven, Germany

In order to validate the difference of air-sea ice CO2 flux measurements by different types of CO2 chamber,
inter-comparison experiments were carried out on winter Antarctic pack ice in the Weddell Sea (R.V. Polarstern
AWECS cruise, July-August 2013). Our ultimate goal is to understand the methodological gaps for the CO2 flux
measurements betweem chamber and eddy covariance methods over sea ice as an activity for SCOR Working
Group 152 (ECV-Ice). Two kinds of CO2 chamber systems were used: semi-automated CO2 chambers developed
at Hokkaido University and automated long-term CO2 chambers (Li-8100A, LI-COR Biosciences, USA). These
chambers were installed at the same ice/snow surface conditions within a 2-m × 2-m area. Based on the
quantitative comparisons using least squares linear regression analyses, slope was 1.08, suggesting that the air-
sea ice CO2 flux from two chambers were good agreement. Therefore, our inter-comparison experiments
confirmed that there was no instrumental bias between two chambers, thereby the past data for air-sea ice
CO2 flux obtained by each chamber's group in the world polar oceans could be shared.

984
Wed_215_OS-2_1279
ECV-Ice: Measuring Essential Climate Variables in Sea Ice-SCOR Working Group 152

Daiki Nomura1 (daiki.nomura@fish.hokudai.ac.jp), F Fripiat2, B. Else3, B. Delille4, M. Fernandez-Méndez5, L.A.

Miller6, I Peeken7, J-M. Rintala8, Maria A. van Leeuwe9, F. Zhang10, K. Abrahamsson11, J. Bowman12, J. France13,
A. Fransson5, D. Lannuzel14, B. Loose15, K. Meiners16, C.J. Mundy17, H.C. Shin18, J.-L. Tison19, M. Vichi20
1
Hokkaido University, Hakodate, Japan, 2Max Planck Institute for Chemistry, Mainz, Germany, 3University of
Calgary, Calgary, Canada, 4University of Liège, Liège, Belgium, 5Norwegian Polar Institute, Tromsø, Norway,
6
Institute of Ocean Sciences, Fisheries and Oceans Canada, Victoria, Canada, 7Alfred Wegener Institute,
Bremerhaven, Germany, 8University of Helsinki, Helsinki, Finland, 9University of Groningen, Groningen,
Netherlands, 10Polar Research Institute of China, Shanghai, China, 11University of Gothenberg, Gothenberg,
Sweden, 12Scripps Institution of Oceanography, San Diego, United States, 13University of East Anglia, Norwich,
United Kingdom, 14University of Tasmania, Tasmania, Australia, 15University of Rhode Island, Kingston, United
States, 16Australian Antarctic Division, Tasmania, Australia, 17University of Manitoba, Manitoba, Canada,
18
Korean Polar Research Institute, Incheon, Korea, Republic of, 19Université Libre de Bruxelles, Bruxelles,
Belgium, 20University of Cape Town, Cape Town, South Africa

Observations over recent decades suggest that sea ice plays a significant role in global biogeochemical cycles,
providing an active biogeochemical interface at the ocean-atmosphere boundary. However, a pressing need
exists to perform methodological intercalibration experiments in order to obtain reliable measurements of
basic biogeochemical properties, including many of the Essential Climate Variables of the Global Climate
Observing System. With newly emerging techniques, and pressed by the rapid changes in sea ice, the time has
come to evaluate and improve our approach to study sea-ice systems. In 2016, the Scientific Committee on
Oceanic Research (SCOR) launched Working Group 152 on Measuring Essential Climate Variables in Sea Ice
(ECV-Ice). This working group will synthesize past intercalibration exercises and design and coordinate new
experiments. Our ultimate goal is to provide the international community with standardized protocols for
processing sea-ice samples and collecting data for key variables, including CO2 partial pressure, nutrients, algal
biomass and production, and gas exchange. We will also establish the effectiveness of new techniques to
address sea-ice heterogeneity (often referred to as “patchiness”). These tasks will directly benefit the long-
term community goal of understanding the response of polar marine environments to ongoing climate change.

985
Wed_216_OS-2_1531
Bacteria Control Virus and Nanoflagellates in Water and Sea Ice during Winter

Laura Kaikkonen1 (laura.m.kaikkonen@helsinki.fi), Sara Enberg1,2, Jaanika Blomster1, Riitta Autio3, Anne-Mari
Luhtanen2,3,4, Janne-Markus Rintala1,2
1
University of Helsinki, Aquatic Sciences, Department of Environmental Sciences, Helsinki, Finland, 2University of
Helsinki, Tvärminne Zoological Station, Hanko, Finland, 3Finnish Environment Institute, Marine Research Centre,
Helsinki, Finland, 4University of Helsinki, Programme on Molecular Virology, Department of Biosciences,
Helsinki, Finland

Water and ice samples were collected weekly in the Baltic Sea from October to May. Abundances of bacteria,
virus-like-particles and nanoflagellates as well as chl a concentration were determined and environmental
parameters were measured. The effects of environmental conditions and biological interactions on the
organisms were examined with Pearson's correlation test and a first order vector autoregressive model. All
studied organisms had clear seasonal succession patterns and the sea ice microbial community had a
wintertime succession independent of that of the water column. Accumulation of nanoflagellates and chl a
were observed in ice. Bacteria were observed to have a key role in the trophic interactions in both ice and the
water column. The results suggest that bacteria have a higher dependence on external factors than biological
pressures. Viruses and nanoflagellates, however, seemed more responsive to changes in bacterial abundance.
Our findings confirm that ice has an important role for biomass accumulation which is enhanced when the ice
melts and carbon is released from ice. While examining the possible future changes of polar ecosystems, is is
important to consider the extent to which the microbial food web during winter supports the water column
and the benthos and affects ecosystem functioning throughout the year.

986
Wed_217_OS-2_1580
The Effect of Light on 2H/1H of Highly Branched Isoprenoids (HBIs) in Diatoms

Nikolai Pedentchouk1 (n.pedentchouk@uea.ac.uk), Simon Belt2, Lukas Smik2, Thomas Brown3, Marc-Andre
Cormier2, Martin Jones4, Thomas Mock1
1
University of East Anglia, School of Environmental Sciences, Norwich, United Kingdom, 2University of Plymouth,
Plymouth, United Kingdom, 3Scottish Association for Marine Science, Oban, United Kingdom, 4University of
Newcastle, Newcastle, United Kingdom

Sea ice is a key component of the Earth's climate system. Even though changes in sea ice extent and thickness
are well documented, understanding processes that control climate in the polar regions back in time and over
longer time scales requires proxy-based paleo reconstructions.
Several highly branched isoprenoids (HBIs) have been used previously to investigate changes in sea ice extent
in the past. However, the potential of these biomarkers - particularly their 2H/1H ratios - to provide information
about other parameters of sea ice such as ice thickness and/or snow cover have not been explored.
This study focuses on investigation of 2H/1H of HBIs isolated from the diatom Pleurosigma intermedium. We
cultured this organism to test the hypothesis that d2H values would reflect different levels of irradiance. The
diatom culture was grown at different levels of light intensity in laboratory condtions. We obseved 2H-
depletion in HBIs extracted from the cultures grown at higher light intensity.
Improved understanding of the underlying mechanisms responsible for the isotopic differences in the diatom
Pleurosigma intermedium would provide key insights for interpreting d2H values of environmental samples
from the polar regions. The goal is develop a new methodological approach that could be used to estimate ice
thickness or/and snow cover, which are among the key parameters with respect to sea ice albedo and heat
exchange between the ocean and the atmosphere.

987
Wed_218_OS-2_1583
Lipid Photooxidation: A Biogeochemically Significant Process in Polar Plankton

James Collins1,2 (james.r.collins@aya.yale.edu), Helen Fredricks2, Jeff Bowman3, Collin Ward2, Carly Moreno4,
Krista Longnecker2, Adrian Marchetti4, Hugh Ducklow5, Benjamin Van Mooy2
1
University of Washington, eScience Institute and School of Oceanography, Seattle, United States, 2Woods Hole
Oceanographic Institution, Department of Marine Chemistry & Geochemistry, Woods Hole, United States,
3
Scripps Institution of Oceanography, San Diego, United States, 4University of North Carolina, Department of
Marine Sciences, Chapel Hill, United States, 5Lamont-Doherty Earth Observatory of Columbia University, Division
of Biology and Paleo Environment, Palisades, United States

Ultraviolet radiation (UVR) is one of many sources of stress to surface-ocean microbial communities in high-
latitude ecosystems. Polar phytoplankton divert a remarkably large fraction of their biomass into lipids that
perform functions such as energy storage and cell structure, making these molecules particularly susceptible to
UVR-induced degradation compared with lower-latitude species. While there is considerable evidence from the
Arctic Ocean that lipids in sinking marine particles can be degraded photochemically, we present new evidence
for lipid photooxidation in living plankton communities from the marginal ice zone (MIZ) in West Antarctica.
We use a combination of environmental data, field experiments on natural microbial communities, and
evidence from an abiotic liposome model designed to mimic the behavior of lipids in living cells to show that
UVR exposure can increase the overall oxidation state of plankton living in the MIZ. We use high-resolution
mass spectrometry and new lipidomics data analysis methods to identify a diverse suite of oxidized lipids and
oxylipins that are produced under these conditions; many of these molecules have not been previously
identified in the environment. Using contemporaneous data from the Palmer Long Term Ecological Research
study, we show that the removal and modification of intact lipids by UVR exposure can represent a carbon flux
equivalent to 22% of the strength of bacterial production in the same waters.

988
Wed_219_OS-2_1594
Arctic Sea Ice: Investigating the Origin of Nitrate using δ15N, δ18O and Δ17O

Sydney Clark1 (sydney_clark1@brown.edu), Andrea Mastorakis2, Julie Granger3, Ana Aguilar-Islas4, Meredith
Hastings1
1
Brown University, Earth, Environmental and Planetary Sciences, Providence, United States, 2Brown University,
Chemistry, Providence, United States, 3University of Connecticut, Marine Sciences, Storrs, United States,
4
University of Alaska - Fairbanks, College of Fisheries and Ocean Sciences, Fairbanks, United States

Atmospheric deposition (AD) is hypothesized to be the primary source of reactive N (Nr) to Arctic sea ice. While
advection from the Pacific Ocean delivers a significant supply of Nr, it is unclear if AD (directly or from sea ice
melt) supports primary production in the N-deplete western Arctic Ocean. Isotopes of NO3- from sea ice cores
provide an opportunity to understand whether melting sea ice represents an external supply of N to the ocean;
examination of snow provides an isotopic end-member for direct AD. Sea ice collected during the US Arctic
GEOTRACES leg between 82 and 89°N exhibits NO3- concentrations from 0.2-1.0 µM, while snow ranges from
1.1-3.7 µM. The isotopic composition of NO3- (δ15N, δ18O, Δ17O) was measured on all snow and ice samples. The
Δ17O (Δ17O=δ17O-0.52*δ18O≠0) is a diagnostic tool for atmospheric NO3- compared to other NO3- sources
because only atmospheric NO3- contains a nonzero Δ17O. Snow samples were characteristic of atmospheric NO3-
with generally negative δ15N (-5.9-2‰) and highly enriched 17O and 18O (Δ17O=27.1-33.5‰; δ18O=70.8-87.8‰).
In contrast, sea ice samples were more enriched in 15N (-0.3-15‰) and depleted in 17O and 18O (Δ17O=0-12.4‰;
δ18O=23.3-67.5‰). The presence of a Δ17O>0‰ occurs at various depths, indicating that atmospheric NO3- is
important in sea ice. However, low Δ17O and δ18O values and numerical modeling of isotope dynamics suggest
that a majority of the NO3- is derived from seawater/produced biologically in situ.

989
Wed_220_OS-2_1787
Biophysical Characterization of Arctic and Antarctic under Ice Environments

Giulia Castellani1 (giulia.castellani@awi.de), Benjamin A. Lange2, Kim Janka Müller3, Carmen David4, Fokje L.
Schaafsma5, Hauke Flores4, Jan A. van Franeker5
1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Biosciences - Polar Biological
Oceanography, Bremerhaven, Germany, 2Fisheries and Ocean Canada, Freshwater Institute, Winnipeg, Canada,
3
University of Oldenburg, Oldenburg, Germany, 4Alfred Wegener Institute - Helmholtz Center for Polar and
Marine Research, Bremerhaven, Germany, 5Wageningen University & Research, Wageningen, Netherlands

Sea ice is a highly inhomogeneous habitat varying on scales of meters to kilometers. The spatial variability of
physical factors is reflected in the variability of sea ice microbial community and of sympagic fauna.
Characterizing the biophysical environment of sea ice at scales of meters to kilometers is still a challenge. In
this work we present data collected with a Surface and Under Ice Trawl (SUIT) during three Arctic and two
Antarctic expeditions between 2012 and 2017. The SUIT is a relatively new net, which can catch organisms
residing in close proximity to the sea ice underside. The SUIT is equipped with a sensor array from which we
can retrieve key environmental properties: water salinity, temperature, chl a, sea ice thickness, under-ice light,
and ice-algal chl a. An average trawl is about 2km long, it thus covers scales that can be hardly sampled with
classic methodologies. In the present work we show results for sea ice thickness, ridges density, under ice light,
and sea-ice chl a concentration derived from the SUIT sensor array. We investigate how the presence of ridges
affect the light transmission through sea ice in both the Arctic and Antarctic region. We derive in-ice chl a
based on under ice hyperspectral measurements to characterize the food standing stocks in both regions. We
present a first habitat characterization on the kilometer scale. Moreover, this work represents the first Arctic-
Antarctic comparison of under ice environmental characteristics.

990
Wed_221_OS-2_2027
Understanding the Origin(s) of Methane in Sea Ice Using Stable Isotope Ratios

Célia Julia Sapart1,2, Caroline Jacques1 (carjacqu@ulb.ac.be), Gauthier Carnat1, Jiayun Zhou1, Bruno Delille3,
Helge Niemann4,5, Thomas Röckmann2, Carina van der Veen2, Jean-Louis Tison1
1
Laboratoire de Glaciologie/Université Libre de Bruxelles, Brussels, Belgium, 2Institute for Marine and
Atmospheric Research Utrecht (IMAU), Utrecht, Netherlands, 3Université de Liège, Liège, Belgium, 4Centre for
Arctic Gas Hydrate, Environment and Climate, Tromso, Norway, 5Royal Netherlands Institute for Sea Research,
Texel, Netherlands

In 2012, an unexpected CH4 excess has been reported above open leads in the Arctic Ocean showing that sea
ice plays a role in the ocean-atmosphere CH4 dynamics. However, the processes involved there have not yet
been identified.
We performed CH4 stable isotope (d13C and dD) analyses on sea ice samples, as well as geochemical and
physical measurements, to determine the possible pathways involved in CH4 production/removal in or under
sea ice. We present results from ice cores collected above the shallow shelf of Barrow (Alaska) from January to
June 2009 as well as in the landfast ice of McMurdo Sound (Antarctica) from September to November 2012.
We found a clear difference in isotopic signature between the two sites. The McMurdo ice was supersaturated
in CH4 and showed isotopic signatures surprisingly enriched in heavy isotopes (d13C between -47 and -12 ‰ and
dD between -87 and -350‰). No natural pathways have yet been identified with such isotopic signatures, but
we suggest that aerobic CH4 formation in or under the ice might be a candidate. In contrast, the CH4
concentrations were much larger in ice overlying the shallow shelf of Barrow and there the origin of CH4 was
clearly biogenic (d13C between -48 and -68 ‰ and dD between -180 and -250‰), thus likely originating from
the sediment. In the McMurdo ice, the seasonal evolution shows that CH4 was becoming more enriched in
heavy isotopes with time, suggesting the occurrence of aerobic oxidation processes in the ice.

991
Wed_224_OS-2_2193
RISE UP: Robotic Exploration Beneath the Ross and McMurdo Ice Shelves

Justin Lawrence1 (jlawrence@gatech.edu), Britney Schmidt1, Matthew Meister1, Jennifer Glass1, Jeff Bowman2
1
Georgia Institute of Technology, Atlanta, United States, 2University of California, San Diego, La Jolla, United
States

The NASA-funded RISE UP program (Ross Ice Shelf and Europa Underwater probe) is a three-season project to
observe ice-ocean interactions and conditions beneath McMurdo Sound, the McMurdo Ice Shelf (MIS), and the
Ross Ice Shelf (RIS) in Antarctica. In addition to traditional water column sampling and profiling methods, these
observations are being made via the AUV/ROV Icefin, designed to conduct basal ice and benthic surveys
through 30 cm boreholes in remote locations. During the 2017-19 austral summers, and in cooperation with
the Antarctica New Zealand Ross Ice Shelf Programme (PI Christina Hulbe), RISE UP will provide insight into
these largely unmapped and uncharacterized sub-ice environments.
RISEUP aims to autonomously characterize habitability and sample under-ice environments on broad spatial
scales via robotic platforms. By combining data from Icefin's sensors with CTD profiling, nutrient sampling, cell
counts, and DNA extractions, we are mapping observations from the vehicle to the biologically relevant
environmental parameters that support life. Across the gradient of field locations from the front of the RIS to
the grounding zone, we can trace circulation, ice mass balance, nutrient flux, and sub-shelf biodiversity while
refining the sensors autonomous vehicles can use to link environmental processes and habitability. Here, we
present the results of this complementary water column sampling from the first season of RISE UP beneath the
McMurdo and Ross Ice Shelves.

992
Wed_225_OS-2_2458
Sea-ice Chemistry and Influence of Glacial Meltwater in a Spitsbergen Fjord

Agneta Fransson1 (agneta.fransson@npolar.no), Melissa Chierici2, Daiki Nomura3, Mats Granskog1, Svein
Kristiansen4, Tonu Martma5, Gernot Nehrke6
1
Norwegian Polar Institute, Tromsoe, Norway, 2Institute of Marine Research, Tromsoe, Norway, 3Hokkaido
University, Hakodate, Japan, 4The University of Tromsø, Arctic University of Norway, Tromsoe, Norway, 5Tallinn
University of Technology, Tallin, Estonia, 6Alfred Wegener Institute, Bremerhafen, Germany

Several fjords on Svalbard are affected by glacier meltwater. We investigated the sea-ice carbonate (or CO2)
chemistry in Tempelfjorden, a west-Spitsbergen fjord, and the influence of different processes such as ice-brine
rejection, calcium carbonate precipitation and glacial meltwater during two winters in 2012 and 2013. The two
contrasting years clearly showed that the influence of freshwater affected the chemical and physical
characteristics of the sea ice. We found large variability of sea-ice total alkalinity (AT), total dissolved inorganic
carbon (CT), pCO2, dissolved inorganic nutrients, oxygen isotopic ratio (d18O), and freshwater fractions, from the
glacier front to the outer part of the fjord. Processes within the sea ice such as calcium carbonate formation
(ikaite) and brine rejection also affected the sea-ice carbonate chemistry. The variability in the sea ice showed
the lowest AT in 2012 near the glacier front coinciding with the highest freshwater fractions (glacial water).
Relatively high AT in relation to salinity was observed mainly in 2012, which could either be a result of ikaite
precipitation in the sea ice (dissolved during analysis) or calcite and dolomite minerals originating from the
bedrock/glacial freshwater. We found crystals of ikaite, calcite and aragonite (forms of calcium carbonate) in
the snow/frost flowers in 2013 as a result of to sea-ice processes.

993
Wed_226_OS-6_152
'Atlantification' of Arctic Ocean - Oceanic Control and Variability

Sourav Chatterjee1 (sourav@ncaor.gov.in), Roshin P Raj2, Laurent Bertino2, Øystein Skagseth3, M

Ravichandran1, Ola M Johannessen4
1
National Centre for Antarctic & Ocean Research, Ocean Sciences, Vasco-da-Gama, India, 2NERSC, Bergen,
Norway, 3Institue of Marine Research, Bergen, Norway, 4Nansen Scientific Society, Bergen, Norway

Arctic is warming at a much higher rate than the rest of the globe. Several studies have pointed out dramatical
changes in the Arctic atmosphere over the past few decades due to local as well as large scale changes in the
atmospheric circulations. However, though not as rapid as in the case of atmosphere, the Arctic ocean and its
surrounded counterparts have also been undergoing significant modifications in their role in determining the
Arctic climate. Atlantic Water transported from the Nordic Seas through the Fram Strait and Barents Sea
Opening are the major sources of oceanic heat to the Arctic Ocean. There are several evidences of warmer
atlantic water intrusion in the arctic and surrounding oceans, popularly termed as 'Atlantification'. In this study
we show that under the changing North Atlantic climate system, the transport of Atlantic water can be
significantly modified through a defining contribution from the oceanic circulations. This has significant
implications on the net oceanic heat transport towards the Arctic and also on the regional climate patterns.
The teleconnections between North Atlantic climate and monsoon, Indian Ocean also indicates to the fact that
tropical atmosphere-ocean dynamics can also indirectly influence the oceanic heat transport towards Arctic
Ocean through changes in North Atlantic atmospheric dynamics.

994
Wed_227_OS-6_247
Analysis of Storm Waves in the Antarctic Marginal Ice Zone

Clare Eayrs1 (clare.eayrs@nyu.edu), Alison Kohout2, Jhon Mojica1, Marcello Vichi3, Alessandro Toffoli4, Alberto
Alberello4, Miguel Onorato5, Keith MacHutchon6, Warren Joubert7, Diana Karam Francis1, David Holland1,8
1
New York University Abu Dhabi, Center for Global Sea Level Change, Abu Dhabi, United Arab Emirates,
2
National Institute of Water and Atmospheric Research (NIWA), Christchurch, New Zealand, 3University of Cape
Town, Department of Oceanography and Marine Research Institute, Cape Town, South Africa, 4The University of
Melbourne, Department of Infrastructure Engineering, Melbourne, Australia, 5Università degli Studi di Torino,
Torino, Italy, 6University of Cape Town, Department of Civil Engineering, Cape Town, South Africa, 7South
African Weather Service, Cape Town, South Africa, 8New York University, Courant Institute of Mathematical
Sciences, New York, United States

Southern Ocean waves are the largest on Earth, but their interaction with sea ice is a particularly poorly
understood feedback in the climate system. Limited observations of waves in the Antarctic marginal ice zone
(MIZ) show that waves can travel hundreds of kilometers into the ice and that current representations of wave
decay are inappropriate in a sea ice regime.
Waves induce floe break up, but the mechanisms of this process are poorly understood. Characterizing the
wave field in the MIZ is fundamental to modelling wave motion through sea ice, and is crucial for estimating
sea ice cover in this dynamic region. An observed southward shift in storm tracks over recent decades and a
predicted increase in wave heights at the ice edge have implications for sea ice extent under changing climate.
Two Waves-In-Ice-Observing-Systems were deployed 1.5 km apart near 62.8 S, 29.8 E on 4th July, 2017 to
measure waves in the MIZ. Deployment coincided with the arrival of a low front accompanied by winds
averaging 25 m/s. Long period (16 s) waves of nearly 8 m waveheight were recorded at a distance of over 100
km from the ice edge. We show that a significant amount of energy can be transported well into the sea ice by
ocean waves. These results provide rare measurements of waves-in-ice during winter storms in the Antarctic
MIZ.

995
Wed_228_OS-6_387
Ocean Warming of the Antarctic Continental Shelf in an Eddying Climate Model

Paul B. Goddard1, Carolina O. Dufour2 (carolina.dufour@mcgill.ca), Jianjun Yin1, Stephen M. Griffies3, Michael
Winton3
1
University of Arizona, Department of Geosciences, Tucson, United States, 2McGill University, Atmospheric and
Oceanic Science, Montreal, Canada, 3NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, United States

Ocean warming near the Antarctic ice shelves has critical implications for ice sheet mass loss and global sea
level rise. Here, we use a global climate model with an eddying ocean to quantify the mechanisms contributing
to ocean warming on the Antarctic continental shelf in an idealized 2xCO2 experiment. We find relatively large
warm anomalies both in the upper 100 m and at depths above the shelf floor, which are controlled by different
mechanisms. The near-surface ocean warming is primarily a response to enhanced onshore advective heat
transport across the shelf break. The deep shelf warming is initiated by onshore intrusions of relatively warm
Circumpolar Deep Water (CDW), in density classes that access the shelf, as well as the reduction of the vertical
mixing of heat. CO2-induced shelf freshening influences both warming mechanisms. The shelf freshening slows
vertical mixing by limiting gravitational instabilities and the upward diffusion of heat associated with CDW,
resulting in the build-up of heat at depth. Meanwhile, freshening near the shelf break enhances the lateral
density gradient of the Antarctic Slope Front (ASF) and disconnect isopycnals between the shelf and CDW,
making cross-ASF heat exchange more difficult. However, at several locations along the ASF, the cross-ASF heat
transport is less inhibited and heat can move onshore. Once onshore, lateral and vertical heat advection work
to disperse the heat anomalies across the shelf region.

996
Wed_229_OS-6_393
Circumpolar Deep Water Intrusion onto the Prydz Bay Continental Shelf

Libao Gao1 (gaolb@fio.org.cn)

1
First Institute of Oceanography, Qingdao, China

Variability of Circumpolar Deep Water (CDW) intrusion onto the Prydz Bay continental shelf was studied based
on CTDs, Moorings, and some other observations. CDW intrusion in Prydz Bay shows significantly temporal and
spacial variability. Water exchange occurs all through the year, but the temperature recorder and current
meters shows different characteristics in the Prydz Channel. The key reason which causes the different
seasonal responses of temperature and current around CDW intrusion region is documented. CDW intrusion
process and character reveal that eddy form is the dominant mode during the CDW intrusion events. Heat and
salt budgets along the Prydz channel are also studied, which help to estimate the contribution of Prydz Bay to
Southern Ocean in heat, salt and water exchange.

997
Wed_230_OS-6_562
Deep Bottom Mixed Layer Instability Drives Variability of Antarctic Slope Front

Wilma Huneke1 (wilma.huneke@utas.edu.au), Andreas Klocker1, Ben Galton-Fenzi2

1
University of Tasmania/Institute for Marine and Antarctic Studies, Hobart, Australia, 2Australian Antarctic
Division, Hobart, Australia

Ocean-driven melting plays a fundamental role in the mass loss of the Antarctic ice sheet. The ocean
temperature on the continental shelf is modulated by heat exchange across the Antarctic slope where the so-
called Antarctic Slope Front separates the cooler continental shelf seas from the relatively warm Southern
Ocean. Nevertheless, little is known about the dynamics of the Antarctic Slope Front in modulating this heat
exchange. Here we use a process model to show how downslope bottom Ekman transport of shelf water leads
to enhanced bottom mixing on the offshore side of the Antarctic Slope Front. Every few years, this enhanced
bottom mixing triggers instabilities of the Antarctic Slope Front which allows Circumpolar Deep Water to
propagate closer to the continental shelf and enhances near-bottom water mass transformation. The
mechanism exists in the model for both constant and seasonal forcing. The identified mechanism needs to be
confirmed in realistic models and in the real ocean. It could impact variability of the cross-shelf heat exchange
and basal melt rates as well as of the overturning circulation on interannual time scales.

998
Wed_231_OS-6_570
Sea Ice Drift from High Resolution Satellite Images in the Ross Sea, Antarctica

Usama Farooq1 (usama.farooq@pg.canterbury.ac.nz), Wolfgang Rack1, Adrian McDonald1,2

1
Gateway Antarctica, University of Canterbury, Christchurch, New Zealand, 2School of Physical and Chemical
Sciences, University of Canterbury, Christchurch, New Zealand

Sea ice remains one of the least explored climate components. Sea ice drift is forced by winds and ocean
currents and is an essential element in the dynamics of the polar oceans. Sea ice extent, concentration, and
thickness are heavily influenced by ice dynamics. For the accurate representation of sea ice in climate models,
realistic parameterization of the sea ice motion and deformation rates are crucial. Here we present high
resolution sea ice deformation fields of the Western Ross Sea as a basis to explore ice-atmosphere interactions.
The Ross Sea region including three main polynyas; McMurdo Sound, Terra Nova Bay and the Ross Ice Shelf
Polynya has experienced a significant increase in sea ice extent in recent decades. For this study, we used
sequential high resolution Advanced Synthetic Aperture Radar (ASAR) images from the Envisat satellite. We
downsampled the Wide Swath (WS) mode images from 75 m pixel resolution to 150m, which has a swath width
of 400km. For this case study, we focused on the month of maximum sea ice extent, October 2011. The images
are acquired roughly 24 hours apart and drift velocity is calculated in kilometres per day. We carried out the
correlation using feature tracking and pattern matching techniques. The calculated displacement vector field
has been compared with the low resolution available sea ice motion vector standard product. Uncertainty has
also been calculated as the coarse resolution product is unable to show short term variation.

999
Wed_232_OS-6_574
Turbulent Resolution Simulation of Dissolving Ice-shelves into Polar Sea Water

Bishakhdatta Gayen1 (bishakhdatta.gayen@anu.edu.au), Mainak Mondal1, Ross W. Griffiths1, Ross C. Kerr1

1
The Australian National University, Reseach School of Earth Sciences, Canberra, Australia

Precise knowledge of ocean dynamics and interactions with the grounded ice at high latitudes is very crucial for
predicting the sea-level rise and further development of adaptation strategies in a global warming climate. The
physics of these ocean-ice interactions particularly related to small scale processes, is poorly understood which,
along with limited observation constraints, leads to uncertainties in the predictions of future melt rate. We
perform direct numerical simulations to investigate dissolving of ice into cold and salty seawater in the
presence of turbulent convection. The main focus will be on the dissolving of ice as characterizes many sites
around Antarctica. Under these conditions, the diffusion of salt to the ice-water interface depresses the
freezing point and further enhances heat diffusion to the ice. Our simulation also shows boundary layer next to
the ice face turbulent motions dominant which further amplifies the basal melt rate. It is also important to
quantify the difference between the melting of a vertical ice wall and the melting of a sloping ice shelf. The
basal slope is observed to vary significantly, due to the formation of crevasses, channels, and terraces. Our
high-resolution simulations are designed for direct comparison with laboratory measurements and theory. The
temperature and density structures found under Pine Island Glacier show several layers having a vertical scale
that can also be explained by this study.

1000
Wed_233_OS-6_627
Atlantic Water and Sea Ice Variability in the 20th Century Arctic Ocean

Morven Muilwijk1,2 (morven@uib.no), Lars Henrik Smedsrud1,2, Mehmet Ilicak2,3, Helge Drange1,2
1
University of Bergen, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen, Norway, 3Uni Research,
Bergen, Norway

Both historical observations and outcome from a fully coupled earth system model show a warming trend in
core temperature of Atlantic Water entering the Arctic Ocean over the last few decades (1977-2015). The
Atlantic Water is also observed to rise systematically in the water column since the 1990's. This suggest an
“Atlantification” of the Arctic Ocean, i.e. an ongoing expansion of the Atlantic domain. A portion of this
“Atlantification” and recent warming has been attributed to the current global warming and possibly
anthropogenic activity. However, past periods of warm Atlantic Water (1930-1940) have been documented.
We believe that the Atlantic Water warming trend in the Arctic Ocean may be part of long-term multidecadal
variability, which is influenced and reinforced by strong anthropogenic forcing.
We have therefore investigated the interannual, decadal and multidecadal variability of Atlantic Water and sea
ice in the Arctic Ocean using a global ocean model. Here we present results from a simulation for the period
1871-2009 with the ocean-sea ice component of the Norwegian Earth System Model (NorESM-O) forced by a
Twentieth Century Reanalysis data set, which are compared with available hydrographic measurements of
Atlantic Water in the Fram Strait and north of Svalbard, and observations of sea ice.

1001
Wed_234_OS-6_635
Variation of Summer Surface Water and Circumpolar Deep Water in the Prydz Bay

Bingrui Li1 (libingrui@pric.org.cn), Chengxiang Wu1, Fei Zuo1, Jia Wang2

1
Polar Research Institute of China, Shanghai, China, 2NOAA Great Lakes Environmental Research Lab, Ann
Arbor, MI, United States

Based on hydrographic data obtained during four CHINARE (Chinese National Antarctic Research Expedition)
cruises (i.e., the 27th, 28th, 29th, and 31st) in the Prydz Bay (Antarctica), we analyzed the distribution of water
masses, interannual variation of Summer Surface Water (SSW), reasons for the interannual change, and
interannual variation of the characteristics of upwelling Circumpolar Deep Water (CDW). It was found that SSW
had wide ranges of temperature and salinity, especially during the 27th and 29th cruises, with temperatures up
to 1.22°C higher during the 27th cruise. There appeared to be less sea ice during the 29th cruise. The SSW was
distributed within the upper 50 m of the ocean in the sections of 73°E, 75.5°E, and 67.25°S , whereas it was
distributed within the upper 100m during the 31st cruise. The upwelling of CDW was particularly evident in the
section of 73°E during the 28th and 29th cruises. It was observed during the 28th cruise that CDW upwelled to
90m and it was found to extend southward to 67.67°S during the 29th cruise. Cyclonic circulation has
considerable effect on the transportation of the upwelling of CDW in the Prydz Bay.

1002
Wed_235_OS-6_737
Decadal Predictability of Arctic Sea Ice from Oceanic Heat Transport

Céline Heuzé1 (celine.heuze@marine.gu.se), Karin van der Wiel2

1
University of Gothenburg, Department of Marine Sciences, Gothenburg, Sweden, 2Royal Netherlands
Meteorological Institute, R&D Weather and Climate Models, De Bilt, Netherlands

The retreat of the Arctic sea ice provides an opportunity for increased economic and scientific exploration.
Those require predictions of sea ice conditions up to a few years in advance, which so far has proven
challenging. One potential cause is that the role of the ocean is still not fully understood. Using multi-ensemble
simulations of the global coupled model EC-Earth, initiated at different states of decadal variability and totalling
2000 years, we here investigate the potential for predictability of the oceanic heat transport through Fram
Strait and the Barents Sea Opening. We first determine the atmospheric and oceanic drivers of enhanced heat
transport, notably focusing on the dynamic relationship between oceanic heat transport into the Arctic and
deep water formation in the Nordic Seas, but also in the North Atlantic where it is easier to observe. We then
quantify the impact of enhanced oceanic heat transport through either Fram Strait or the Barents Sea Opening
onto the Arctic sea ice.

1003
Wed_236_OS-6_768
Three Decades of Deep Water Mass Investigation in the Weddell Sea (1984 - 2014)

Rodrigo Kerr1 (rodrigokerr@furg.br), Tiago Dotto2, Mauricio Mata1, Hartmut Hellmer3

1
Universidade Federal do Rio Grande - FURG, Instituto de Oceanografia, Rio Grande, Brazil, 2University of
Southampton, National Oceanography Centre, Southampton, United Kingdom, 3Stiftung Alfred-Wegener-
Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft, Bremerhaven, Germany

The role of Antarctic Bottom Water (AABW) in changing the ocean circulation and controlling climate variability
is widely known. However, a comprehensive understanding of the relative contribution and variability of
Antarctic regional deep water mass varieties that form AABW is still lacking. Using a high-quality dataset
comprising three decades of observational shipboard surveys in the Weddell Sea (1984-2014), we updated the
structure, composition and hydrographic properties variability of the Weddell Sea deep-layer, and quantified
the contribution of the source waters composing Weddell Sea Bottom Water (WSBW) in its main formation
zone. Shifts in WSBW hydrographic properties towards less dense varieties likely equate to less WSBW being
produced over time. WSBW is primarily composed of 71±4% of modified-Warm Deep Water (mWDW) and
29±4% of Dense Shelf Waters, with the latter composed by ~two-thirds (19±2%) of High Salinity Shelf Water
and ~one-third (10±6%) of Ice Shelf Water. Further, we show evidence that WSBW variability in the eastern
Weddell Sea is driven by changes in the inflow of Dense Shelf Waters and bottom water from the Indian Sector
of the Southern Ocean. This was observed through the rise of the WSBW contribution to the total mixture after
2005, following a twenty-year period (1984-2004) of decreasing contribution.

1004
Wed_237_OS-6_944
Observations of Ice Tongue-ocean Interaction at Shirase Glacier

Daisuke Hirano1 (hirano@lowtem.hokudai.ac.jp), Takeshi Tamura2, Shuki Ushio2, Kay I. Ohshima1, Daisuke
Simizu2, Kazuya Ono1, Tomohide Noguchi3, Shigeru Aoki1
1
Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan, 2National Institute of Polar
Research, Tachikawa, Japan, 3Marine Works Japan, Yokosuka, Japan

Shirase Glacier Tongue (SGT) is a thick floating slab of ice that forms where the glacier flows down onto the
ocean surface at the southern closed-section of Lutzow-Holm Bay (LHB) off Enderby Land, East Antarctica.
Compared with other major ice shelves/tongues around Antarctica, SGT is smaller in area but its basal melt rate
was estimated to be relatively high at a rate of ~7 m per year (Rignot et al., 2013) based on presence of warm
deep water. Detailed analysis of the winter hydrographic observations in 1990/92 suggests a 3-dimenstional
circulation, associated with the SGT-ocean interaction, that comprises: (1) warm mCDW (modified Circumpolar
Deep Water) flows southward at the deep layer of submarine canyon that leads into the region beneath SGT,
(2) mCDW meets to melt the base of SGT, and (3) mixture of mCDW and basal melt water exports northward at
subsurface layer.
To explore in detail the SGT-ocean interaction, summer comprehensive hydrographic observations in LHB were
conducted in 2016/17 under the project called ROBOTICA. The latest observation data show clear evidences
that support the suggested SGT-ocean interaction mentioned above. Basal melt signals with elevated melt
water fractions are clearly found in the temperature, salinity, and dissolved oxygen profiles, especially at
subsurface layer (Winter Water) near the northern edge of the SGT. In this talk, preliminary results from the
next hydrographic observations in 2017/18 are also presented.

1005
Wed_238_OS-6_955
Eastern Ross Sea Shelf-break Observations during 2017 OGS-Explora Expedition

Andrea Bergamasco1 (andrea.bergamasco@ismar.cnr.it), Laura De Santis2, Michele Rebesco2, Jenny Gales3,4,

Florence Colleoni5, Vedrana Kovacevic2, Cristian Florindo Lopez6, Elisabetta Olivo2, Manuel Bensi2, Laura de
Steur7, Dino Viezzoli2, Laura Ursella2
1
CNR-ISMAR, Venezia, Italy, 2OGS, Sgonico, Italy, 3NOC, National Oceanography Centre, Southhampton, United
Kingdom, 4School of Biological & Marine Sciences, Plymouth University, Drake Circus, United Kingdom, 5CMCC,
Bologna, Italy, 6NOC, National Oceanography Centre, Southampton, United Kingdom, 7Norwegian Polar
Institute, Tromso, Norway

Cold and dense water masses formed over the Ross Sea continental shelf provide a not negligible contribution
to the Antarctic Bottom Water and then, to the global thermohaline circulation. Volume and properties are
constrained by cross - slope exchange and mixing along the whole Ross sea shelf break.
In the past, different international expeditions, focused on the Cape Adare trough and Glomar Challenger
trough exchanges, have significantly advanced our understanding of the involved processes.
In this work we describe, mainly from the oceanographic point of view, some observations performed during
the 2017 Antarctic expedition, carried out on the r/v OGS-Explora, along selected transects in the eastern part
of the Ross Sea. This area, core of the PNRA WHISPERS Project, was poorly explored in the past because often
covered by the sea ice.
Data reveals that the energetic variability at small scales and strong mixing induced by overflow/down-slope
flow have a significant role on the ways the eastern shelf break of the Ross Sea impacts the deeper circulation
and abyssal water renewal.

1006
Wed_239_OS-6_957
Variability of the Thermocline Depth on the Amundsen Sea Continental Shelf

Karen M. Assmann1 (karen.assmann@marine.gu.se), Anna K. Wåhlin1, Karen J. Heywood2, Stanley S. Jacobs3,

Tae Wan Kim4, Sang Hoon Lee4, Louise C. Biddle1
1
University of Gothenburg, Department of Marine Sciences, Gothenburg, Sweden, 2University of East Anglia,
Norwich, United Kingdom, 3Lamont-Doherty Earth Observatory of Columbia University, Palisades, United States,
4
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

The West Antarctic Ice Sheet has been losing mass at an increasing rate over recent decades. The presence of
warm ocean water at the ice-ocean interface has been identified as an important contributor to this mass loss.
Access of the warm water to the ice base and grounding lines in the ice shelf cavities surrounding the
Amundsen Sea is strongly determined by the depth of the thermocline that separates the bottom layer of
warm, salty Circumpolar Deep Water from the overlying layer of colder, fresher Winter Water. Ekman pumping
has been invoked as a process controlling thermocline depth near the western shelf break and deep mixing as a
result of local surface buoyancy forcing has been shown to affect thermocline depth near Pine Island Glacier.
Hydrographic observations since 1994 indicate coherent large-scale inter-annual to decadal variability of the
thermocline across the shelf. In addition to the ship-based hydrographic observation a series of hydrographic
moorings have been deployed across the Amundsen Sea continental shelf since 2009. We make use of these to
identify common patterns and differences in the seasonal to inter-annual variability of the thermocline and to
discuss the forcing mechanisms responsible.

1007
Wed_240_OS-6_960
Inter-annual variability of Hydrodynamics between Cape Town and Antarctica

Alvarinho J. Luis1 (alvluis1@gmail.com), Vinit Ravindra Lotliker1, Shridhar D. Jawak1

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Polar Remote Sensing Division, Polar
Sciences Group, Vasco da Gama, India

Density profiles in the upper 1000m were recorded using Expendable CTD probes operated from a cargo ship
chartered for Indian Antarctic Expedition from Cape Town (38oS, 16oE) to Antarctica (70oS, 9oE) during austral
summer of 2013-2017. The vertical density structure showed deep mixed layers (~100m) in the Agulhas
Retroflection Region (ARF) due to the presence of downwelling warm-core eddies. The ARF dynamics was
monitored using 1/3o x 1/3o Maps of Absolute Dynamic Topography derived from merged altimetry data, which
showed that at least 10 warm core eddies get detached from the ARF and they enter the Atlantic during the
austral summer period. The geostrophic transport computed relative to 1000 m indicated that large westward
transport into the Atlantic ocean is associated with North Subtropical Front during 2013-2015. The hydrological
fronts meander southward in 2016 and 2017 due to enhanced and positive nature of Southern Annular Mode.
The Southern boundary of Antarctic Circumpolar Front shifted northward from 2013-2017 possibly due to
expanding sea ice extent. We discuss the role of role of air sea interaction in genesis of water masses and
evolution of mixed layer.

1008
Wed_241_OS-6_974
Marine Observations in the Ross Sea on Board r/v OGS - Explora in 2017

Vedrana Kovacevic1 (vkovacevic@inogs.it), Andrea Bergamasco2, Cristian Florindo-Lopez3, Laura de Steur4,

Laura Ursella1, Dino Viezzoli1, Manuel Bensi1, Laura De Santis1, Michele Rebesco1, Jenny Gales5, Florence
Colleoni6, Pierre-Marie Poulain1
1
Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Sgonico, Italy, 2ISMAR CNR, Venezia, Italy,
3
NOC, National Oceanography Centre, Southampton, United Kingdom, 4Norwegian Polar Institute, Tromsø,
Norway, 5University of Plymouth, School of Biological & Marine Sciences, Plymouth, United Kingdom, 6CMCC,
Bologna, Italy

We review the oceanographic data collected during the 2017 Antarctic cruise (r/v OGS-Explora). The underway
measurements provided flow velocity in the upper 700 m, and sub-surface temperature (T) and salinity (S).
While crossing the Southern Ocean, 7 autonomous floats, 10 drifters and 29 XBTs (eXpendable
BathyThermograph) were deployed. In the Ross Sea (RS), 146 XBTs were launched. The most complete
oceanographic assessment was achieved over the slope of the Hillary Canyon (HC; ANTSSS and ODYSSEA
projects) where eight closely spaced CTD (Conductivity-Temperature-Depth) casts were done. Two additional
casts were performed west of the HC where a new sediment drift was explored by geological and geophysical
surveys. The CTD system provided pressure, T, S, fluorescence and turbidity. Lowered Acoustic Doppler Current
Profiler registered the flow velocity during the CTD casts. We aimed to explore some dynamical aspects of the
down-slope flow near the shelf-break where RS bottom water descends and contributes to the Antarctic
Bottom Water formation. East of the HC, where the slope area was explored by seismic surveys (WHISPERS
project) another XBT transect was performed. Finally, XBTs provided temperature distribution along 550 km
transect near the Ross Ice Shelf front. The acquired data provide a unique opportunity to describe the present
water properties and concomitant flow patterns to be associated with the geological evidence of the past
circulation.

1009
Wed_242_OS-6_996
Fast-ice Control of Vertical Mixing and Nutrient Fluxes on the Antarctic Shelf

Mark Inall1,2 (mark.inall@sams.ac.uk), J. Alexander Brearley3, Sian Henley2

1
SAMS, Oban, United Kingdom, 2University of Edinburgh, School of Geosciences, Edinburgh, United Kingdom,
3
British Antarctic Survey, Cambridge, United Kingdom

Fast-ice isolates the ocean from kinetic energy input by the wind, a fundamental driver of the surface ocean.
We report on new, coincident vertical mixing (microstructure), ocean energy and nutrient concentration
observations made at the same Antarctic shelf site during both summer ice-free and winter fast-ice conditions.
To our knowledge these are the first combined measurements of their kind. In late summer, the water column
above Circumpolar Deep Water (the source of oceanic heat and nutrients) is temperature stratified in the
upper 75 m and turbulent mixing is elevated, then falling by an order of magnitude between 80 m and 100 m,
remaining at that lower level down to the maximum measurement depth (300 m). By way of contrast, in mid-
winter, and in the presence of continuous fast-ice, turbulence is at near-detection limit down to the maximum
measurement depth. Thus, isolating the shelf waters from wind during times of fast-ice cover fundamentally
alters the turbulent state of the upper water column. Concurrent wind speed and current profile
measurements are used to scale the dependence of mixing, in these contrasting regimes, on atmospheric and
oceanic energy levels. Nutrient profiles are used in conjunction with mixing profiles to quantify changes in
vertical nutrient supply to the euphotic zone during the spring break-up of fast-ice. Shelf-wide upscaling using
remotely sensed data is investigated.

1010
Wed_243_OS-6_1007
The Freshwater Cycle of the Southern Ocean: A Stable Water Isotopes Approach

Camille Akhoudas1 (camille.akhoudas@locean-ipsl.upmc.fr), Gilles Reverdin1, Giovanni Aloisi1, Jean-Baptiste

Sallée1, Marion Benetti2
1
LOCEAN - Sorbonne Universités - UPMC/CNRS/IRD/MNHN, Paris, France, 2Institute of Earth Sciences -
University of Iceland, Reykjavik, Iceland

The freshwater cycle of the Southern Ocean is pivotal for Earth's climate, but it is still poorly observed and
understood. Indeed, the large freshwater fluxes between the ocean and sea ice, as well as between the ocean
and the polar ice caps, directly control ocean circulation, the geography of sea-ice, the melt of the ice-caps,
with global and major consequences for global climate and sea-level rise. In particular, the relatively warm
circumpolar deep water entering in contact with ice-shelves, and the dense water formed as a result through
ocean-ice interactions is essential for establishing global ocean circulation, for the carbon cycle, and for the
thermal regulation of the planet. In this study, we aim at shedding light in the freshwater cycle of the
circulation in the Southeastern Weddell Sea, on the continental shelf, in front of the Filchner ice-shelf. As part
of the WAPITI project cruise, we acquired in Jan-Mar 2017 a new set of oxygen and deuterium isotope from in-
situ water-column sampling. Measurements have been acquired on the entire continental shelf, from the shelf
break to the ice-shelf front, and over the entire Filchner Depression (from East-to-West). We will present
preliminary results from this exciting set of observations and present longer-term plans for freshwater cycle,
ocean-ice interaction, and ocean circulation analysis of the region.

1011
Wed_244_OS-6_1012
Simulations of the Southwestern Weddell Gyre, its Shelves and Sub-iceshelf Seas

Ute Hausmann1 (uhausc@gmail.com), Jean-Baptiste Sallée1, Nicolas Jourdain2, Clement Rousset1, Pierre
Mathiot3, Gurvan Madec1, Julie Deshayes1
1
LOCEAN. UPMC, Paris, France, 2Institut des Géosciences de l'Environnement, Grenoble, France, 3Met Office,
Exeter, United Kingdom

Realistic high-resolution model simulations of the southwestern Weddell Gyre are prepared using a state-of-
the art z-coordinate ocean plus sea ice model (NEMO, LIM version 3). One of the novelties of the proposed
setup consists in the explicit resolution of the sub-iceshelf seas adjacent to the Weddell shelves, including the
cavity between the Filchner-Ronne iceshelf (FRIS), modelling the melt at the iceshelf bases, the oceanic
processes accounting for it, as well as its impact on the ocean circulation in the cavities and beyond. The
configuration is designed to explore the mechanisms of communication between the open Weddell Gyre and
the sub-iceshelf seas, and notably, the role played therein by the circulation, stratification and water mass
(trans-)formations on the Weddell shelves. Simulations are spun up from a 1⁄4◦ Nemo simulation, and carried
out at an isotropic horizontal resolution of 1⁄12◦ longitude, which ranges from about 4.5 km at the northern
boundary of the gyres, varies between 4 to 2 km over the gyre's shelves, and reaches less than 2 km in the FRIS
cavity.

1012
Wed_245_OS-6_1040
Seasonal and Interannual Variability of the Mixed Layer in Baffin Bay

Christophe Herbaut1 (ch@locean-ipsl.upmc.fr), Marie-Noëlle Houssais1, Anne-Cécile Blaizot1, Rémi Lambert1

1
Université Pierre et Marie Curie, LOCEAN, Paris, France

A better description of the seasonal and interannual variability of the mixed layer and the underpinning
mechanisms is necessary for a clearer understanding of the primary production evolution in Baffin Bay. Spring
and summer in-situ measurements are used to estimate the winter maximum of the mixed layer depth and to
establish its spatial variability. This observational study is complemented by the analysis of numerical
simulations with a ¼° ice-ocean model, which extends over the Arctic and Atlantic Ocean. The timing of the
mixed layer deepening, its maximum and its retreat is established and its variability over the period 1979-2016
is analyzed. Fresh water and heat budget are computed to evaluate the role of the surface forcing (brine
rejection by ice growth, fresh water flux due to ice melt, heat fluxes) and the advection of polar water from the
Arctic and Atlantic water from the Labrador Sea on the evolution of the mixed layer.

1013
Wed_246_OS-6_1099
Antarctic Sea Ice Trend: Insights from a Suite of Climate Models

Jade Sauvé1 (jade.sauve@mail.mcgill.ca), Carolina Dufour1, Stephen M. Griffies2, Michael Winton2

1
McGill University, Atmospheric and Oceanic Sciences, Montreal, Canada, 2NOAA/Geophysical Fluid Dynamics
Laboratory, Princeton, United States

Antarctic sea ice concentration has been observed to increase over the last 30 years, in contrast with the
decrease that most climate models show. Here, we aim to understand this disagreement by investigating the
respective roles of natural variability and anthropogenic forcing in shaping Antarctic sea ice trend. To do so, we
use a suite of three climate models of varying resolutions in the ocean that displays a range of behaviours in
natural variability with the representation of Weddell Sea polynyas, and different intensities in the decrease of
sea ice trend. We find that the disagreement between models and observations is partly due to a
desynchronized or too weak natural variability in models compared to observations. In particular, in one
model, the sea ice trend between two polynyas is found to be of similar sign and magnitude to that observed
over the satellite record. At high latitudes, all models show a surface cooling on a short time scale, followed by
a warming on a longer time scale, consistent with the delayed warming mechanism of Ferreira et al. (2015). Of
all models, the higher resolution model shows the strongest surface warming and decrease in sea ice,
suggesting an important role for eddies in the response of Antarctic sea ice to climate change.

1014
Wed_247_OS-6_1137
Seasonal Thermocline Evolution at the Weddell Sea Shelf Break-data and Dynamics

Tore Hattermann1,2 (tore.hattermann@akvaplan.niva.no)

1
Akvaplan-niva AS, Tromsø, Norway, 2Alfred Wegener Institute Helmholtz Center for Polar and Marine Research,
Bremerhaven, Germany

Observations and models suggest that access of Warm Deep Water to the Weddell Sea ice shelf cavities links
closely to variations of the Antarctic Slope Front thermocline along continental shelf break. A new monthly
climatology of the slope front hydrography based on CTD profiles from ships and instrumented seals between
1977 and 2016 shows an elevated thermocline (by about 100 m) depth during the austral summer at Kapp
Norvegia (17W). The correspondence of this signal with a seasonal warming at the Filchner Trough further
downstream (40 W), indicates a coherent evolution of the slope front structure along a larger portion of the
shelf break. The climatological cross sections also show a distinct seasonality of the slope current and upper
ocean hydrography, where downwelling of fresh Antarctic Surface Water forms a secondary front above the
Warm Deep Water interface in summer. Enhanced baroclinic growth rates at this front suggest that the
momentum input from wind, which suppresses the thermocline along the shelf break, is partially dissipated by
a shallower eddy-overturning cell when surface water is present. A simple overturning model of the southern
limb of the Weddell Sea Gyre confirms the sensitivity of the thermocline depth to the upper ocean density
changes and reproduces the observed seasonal evolution of the thermocline as a response to wind and
buoyancy forcing.

1015
Wed_248_OS-6_1176
Negative Feedback of the Beaufort Gyre Circulation on Ice-mediated Ekman Pumping

Gianluca Meneghello1 (gianluca.meneghello@gmail.com), John Marshall1, Jean-Michel Campin1, Edward

Doddridge1
1
MIT, Cambridge, United States

Motivated by observations we explore a negative feedback loop between ice-mediated Ekman pumping and
surface geostrophic currents in the Beaufort Gyre (BG). We show that anomalous anticyclonic surface stress
due to sea-ice drift leads to increased Ekman downwelling which strengthens the surface geostrophic currents.
Accelerating the geostrophic current reduces the ice-ocean relative velocity and hence the effective surface
stress. This provides a strong damping of the downwelling processes in the BG and must be a central part of
any theory of BG dynamics.

1016
Wed_249_OS-6_1291
Seasonal Quasi-circumpolar Acceleration of the Antarctic Slope Current System

Alberto Naveira Garabato1 (acng@soton.ac.uk), Jack Hooley2, Tiago Dotto2, Sheldon Bacon3, Michel Tsamados4,
Andrew Ridout4, Tom Armitage4
1
University of Southampton, Ocean and Earth Science, Southampton, United Kingdom, 2University of
Southampton, Southampton, United Kingdom, 3National Oceanography Centre Southampton, Southampton,
United Kingdom, 4University College London, London, United Kingdom

The Antarctic slope current system plays a pivotal role in the circulation and climate of the Southern Ocean. By
flowing westward around Antarctica, it mediates the flow of water masses and freshwater across the polar
Southern Ocean, and regulates the cross-slope exchange of warm deep waters offshore and recently ventilated
waters onshore - thereby influencing the melting of Antarctic ice shelves and the production of Antarctic
Bottom Water.
Despite its significance, the dynamics of the Antarctic slope current have only begun to be probed. As sea ice
often covers the Antarctic slope, in situ measurements are very sparse, and conventional remote sensing
approaches are incapable of taking ocean observations. Here, we tackle this issue by developing and analysing
a new satellite altimetric data set of the Southern Ocean, based on the SIRAL radar altimeter on board CryoSat-
2. Sea level measurements from leads between ice floes are extracted to construct a 5-year time series of the
circulation in the seasonally and perennially ice-covered ocean. Analysis of these data reveals that the Antarctic
slope current exhibits a seasonal cycle of acceleration and deceleration around much of Antarctica, with
maximum transport in April - June and minimum transport in November - February. These altimetric
diagnostics are shown to be coherent with observations gathered by a small set of near-coast mooring arrays,
and to be indicative of driving by variable winds around the Antarctic continent.

1017
Wed_250_OS-6_1307
Seasonal Chlorophyll-a Variability in the Indian Sector of the Southern Ocean

Prince Prakash1 (prakash@ncaor.gov.in), Satya Prakash2, M Ravichandran1

1
National Centre for Antarctic & Ocean Research (ESSO-NCAOR), Vasco da Gama, India, 2Indian National Center
for Ocean Information Services, Hyderabad, India

Despite being high-nutrient low-chlorophyll (HNLC) region, the Southern Ocean(SO) plays a key role in global
carbon cycle by fixing carbon and exporting it from surface to deep Ocean. The unused nutrients also control
primary productivity in the tropical ocean. Phytoplankton growth in SO is hypothesized to be limited by
availability of iron and sunlight. Recent study shows that the SO is changing now: it's warming and freshening
due to climate perturbations which may have implications to the seasonal evolution of biological properties.
The Bio-Argo floats equipped with chlorophyll sensors together with traditional CTD sensors deployed in the
frontal zone of the Indian sector of the SO provide critical imformations on phytoplankton and the deep
chlorophyll maxima. The high productivity at fronts in the open ocean is commonly attributed to availability of
sunlight during the austral summer and supply of large quantities of dissolved iron to the ocean surface
through deep mixing/plateau effect. We found that the frontal zone results obtained from the floats show a
bloom in the spring in the three frontal regions STF, SAF and PF. Our results also show that the shallowing of
MLD over the critical depth and resultant light exposure in the MLD during the spring season play a major role
in bloom initiation.

1018
Wed_251_OS-6_1335
Austral Summer-time Variability in the Prydz Bay over the Last One Decade

P Sabu1 (sabu@ncaor.gov.in), N Anilkumar1, Racheal Chacko1, Sourav Chatterjee1

1
National Center for Antarctic and Ocean Research, Ocean Science Group, Vasco da Gama, India

Prydz Bay is a large triangular-shaped embayment in the Indian sector of Southern Ocean (SO) and this region
plays a key role in SO thermohaline circulation. Compared to other coastal regions, such as Antarctic Peninsula,
Weddell Sea, and Ross Sea, relatively little attention has been paid to understand the complex physical
processes occurring in the Prydz Bay. In this study, 3-day continuous in-situ high resolution hydrographic data
collected from the Prydz Bay during Indian Southern Ocean Expeditions 2006 and 2017 has been used. During
2017, the sea surface temperature in the Prydz Bay was unusually warm (> 1°C) as compared to 2006 which
was also well noticeable in the satellite SST. As compared to 2006, wind speed was less and air temperature
was higher in 2017 resulting in a less heat loss (-8 W/m2, minus sign indicates heat loss from ocean to
atmosphere) from the Prydz Bay region in 2017 as compared (-20 W/m2) to that in 2006. Large variability in the
properties of water masses was also noticed in 2017 as compared to 2006. During 2016-17, the warming in the
Prydz Bay was started well before the austral summer and continued upto fall. Such an elongated warming
period in the upper layer may be enough to melt existing ice and/or prevent new ice forming, resulting in the
formation of heat polynyas. Using satellite derived data, model outputs and ARGO data; an attempt has been
made to illustrate possible mechanisms of this warming in the Prydz Bay over the last one decade.

1019
Wed_252_OS-6_1395
Internal Variability in the Arctic Freshwater Budget

Rory Laiho1, Alexandra Jahn1 (alexandra.jahn@colorado.edu)

1
University of Colorado Boulder, Atmospheric and Oceanic Sciences and INSTAAR, Boulder, United States

Changes in freshwater fluxes can have implications for stratification and deep convection in the Arctic and
North Atlantic. It is therefore important to understand the potential for future change in the Arctic freshwater
budget. However, on short to intermediate timescales it is challenging to separate changes due to internal
variability from those due to external forcing. To explore changes in Arctic freshwater fluxes between the 20th
and 21st centuries and quantify the respective role of these two drivers of variability, we have analyzed the
output from the CESM Large Ensemble (LE), which is forced by the strong (RCP8.5) CMIP5 forcing. We find that
individual freshwater flux terms have varying degrees of internal variability, which influences when we see the
forced signal emerge from the natural background variability. This provides information to put the observed
changes into a longer-term context, as well as provides projections as to where we are most likely to first see a
forced trend emerge. For example, based on the CESM LE, the Davis Strait liquid freshwater export to the North
Atlantic is showing full emergence from the natural variability of the background state between 2009 and 2037,
indicating that significant changes might be imminent in the near future, despite no clear trend in the short
observational record to date.

1020
Wed_253_OS-6_1439
Frontal System Changes at the High Latitudes of the Southeastern Atlantic Ocean

Martim Mas e Braga1, Ilana Wainer1 (wainer@usp.br), Mauricio Magalhaes Mata2

1
Universidade de São Paulo, Oceanography Institute, Sao Paulo, Brazil, 2Universidade de Federal do Rio Grande,
Oceanography Institute, Rio Grande, Brazil

The transition between the South Atlantic and the Southern Ocean is marked by a frontal system that includes
both the South Atlantic Current and the Antarctic Circumpolar Current (ACC). In the eastern part of the basin
the latitudinal position of these fronts is thought to control the input of warm waters into the Atlantic basin
through the Agulhas Leakage. Changes in the Subtropical and Polar regimes associated with the frontal system
that composes the boundary between the Subtropical Gyre and the ACC are investigated using the simulation
results of the ocean component of the National Center for Atmospheric Research (NCAR) Community Earth
System Model (CESM), POP2. Sea surface height gradients and specific contours are used to identify and track
the ocean fronts position. We compare the Subtropical Front position at the eastern edge of the South Atlantic
to changes in temperature and salinity as well as Agulhas Current trans- ports and the overlying wind field in
order to determine what could be driving frontal variability at this region and its consequences to mass
transport from the Indian into the Atlantic. Results suggest that the Subtropical Front is not the southern
boundary of the subtropical gyre, but it responds to changes in the "Supergyre", especially the Indian Ocean
Subtropical Gyre expansion.

1021
Wed_254_OS-6_1445
Future Changes of the Antarctic Coastal Current: A Downscaling Experiment

Marina Noro dos Santos1 (marina_noro@hotmail.com), Ilana Wainer1, Jose Edson Pereira1
1
Universidade de São Paulo, Oceanography Institute, Sao Paulo, Brazil

The Antarctic Coastal Current (ACoC) plays an important role in the hydrographic properties of Antarctic
continental shelf. This current helps to maintain the Antarctic Slope Front, and therefore the exchange
between the cold and, relatively fresh waters from continental shelf and warmer, saltier waters offshore.
However, the impact of the strengthening and shifting poleward of the southern hemisphere westerly winds
observed in the last decades in the interplay between coastal winds, coastal current and heat distribution
remains poorly understood. In order to understand this relationship, we investigated the ACoC variability and
its influence in coastal oceanography dynamics using a high-resolution regional simulation with Regional Ocean
Model System (ROMS) for the period of 1975 to 1999. The preliminary results shows that the model is capable
to reproduce the ACoC and its seasonal variability. The maximum ACoC mean transport is approximately 6 Sv in
10°W, where this current becomes part of Weddell Gyre. For the same region, the ACoC transport reaches its
maximum during austral winter (~8 Sv) and it is weaker during summer, decreasing by up to 2 Sv compared to
winter. Results for temperature-salinity diagrams show that the model reproduces satisfactory the water
masses structure in Weddell Sea, identifying predominant water masses for this region.

1022
Wed_255_OS-6_1463
The MOMA Project - In Situ Observations and Numerical Simulations of the ACC

Yuri Cotroneo1 (yuri.cotroneo@uniparthenope.it), Isabelle Ansorge2, Pasquale Castagno1, Antonio Celeste1,

Paola de Ruggiero1, Henk A. Dijkstra3, Pierpaolo Falco1, Giannetta Fusco1, Vittorio Gentile4, Michael Ghil5, Ilaria
Iermano1, Milena Menna6, Massimo Pacciaroni6, Thierry Penduff7, Stefano Pierini1, Pierre Marie Poulain6,
Giovanni Sgubin8, Enrico Zambianchi1
1
Parthenope University, Science and Technology Department, Napoli, Italy, 2University of Cape Town,
Oceanography Department, Cape Town, South Africa, 3IMAU/UU, Utrecht, Netherlands, 4e-geos, Roma, Italy,
5
École Normale Supérieure, Paris, France, 6OGS, Trieste, Italy, 7LGGE, CNRS-Université Joseph Fourier, Grenoble,
France, 8EPOC, University of Bordeaux, Bordeaux, France

The aim of the MOMA project is to describe the Antarctic Circumpolar Current (ACC) and its variability, in space
and time, south of Africa on the basis of an up-to-date high-resolution observational dataset complemented
with model simulations performed for this project.
To do this,
(i) a high-resolution observational database describing the ACC and its variability in the Southern Ocean sector
south of Africa will be obtained through dedicated activities during SANAP oceanographic cruises;
(ii) a modelling activity based on sigma-coordinate ocean general circulation model (MACC) and an analysis of a
dataset produced by a NEMO ocean/sea-ice global model provided by the LGGE-CNRS partner will be carried
out;
(iii) experimental and modelling data will be combined to achieve a deep knowledge and understanding of the
hydrographic and dynamical features of the region of interest and of the physical mechanisms that govern
locally the variability of the ACC fronts and their predictability.
The MOMA project is part of the international efforts solicited and sustained by the Southern Ocean Observing
System (SOOS) and in the First Antarctic and Southern Ocean Science Horizon Scan concerning the study of the
Meridional Overturning Circulation, the ACC variability and their impact on global climate.
MOMA is funded by the Italian “Programma Nazionale di Ricerch in Antartide” (PNRA) grant nr.
PNRA_16_00196.

1023
Wed_256_OS-6_1508
Storm Impact on Ocean Mixing and Internal Waves under Arctic Sea Ice

Amelie Meyer1, Arild Sundfjord1 (arild.sundfjord@npolar.no), Shane Elipot2, Algot Kristoffer Peterson3, Ilker
Fer4
1
Norwegian Polar Institute, Tromsø, Norway, 2University of Miami, Miami, United States, 3Geophysical Institute,
University of Bergen, Bergen, Norway, 4University of Bergen & Bjerknes Centre, Bergen, Norway

The internal wavefield under the Arctic sea ice is considered mild compared to open-water areas elsewhere.
Sea ice insulates the ocean from the atmosphere, lessening energy transfers between those systems. Yet, with
the transition in the Arctic to a first year ice regime that has a thinner and more dynamic ice cover, it is
important to understand how energy is transferred, in particular from the atmosphere to the ocean.
Here we present mixing and internal wavefield observations from the upper ocean north of Svalbard using a six
months' time series of microstructure and ADCP current data. Collected between January and June 2015 from
ice camps during the Norwegian Young sea Ice (N-ICE2015) expedition, these data cover the Nansen Basin in
pack ice, over the Yermak Plateau, through the marginal ice zone, and to the ice edge.
Our observations show that atmospheric storms strongly impact the ocean even under packed sea ice. Storms
enhance mixing in the upper ocean with dissipation rates at the ice-ocean interface 10 times larger during
storms than average unforced background values. Near-inertial signals with downward energy propagation
follow strong storms. These storms also increase the velocity power spectra in the upper water column. The
potential increase of storm frequency in the Arctic currently under debate would affect mixing intensity and
distribution, with large implications for nutrient fluxes in the water column and heat fluxes at the ocean-ice
interface.

1024
Wed_257_OS-6_1512
Water Masses Circulation and Transformation in the Southern Weddell Sea

Lucie Vignes1 (lucie.vignes@locean-ipsl.upmc.fr), Jean-Baptiste Sallée1, Elin Darelius2, Nadine Steiger2, Svenja
Ryan3, Joel Sommeria4, Samuel Viboud4
1
LOCEAN. UPMC, Paris, France, 2University of Bergen, Bergen, Norway, 3Alfred Wegener Institute, Bremerhaven,
Germany, 4LEGI, Grenoble, France

The Weddell Sea is largely fuelling the global thermohaline circulation by transforming large amount of water
masses and producing the densest waters of the world´s oceans. Water-mass transformation occurs over the
entire area covered by the subpolar gyre, but the most intense and probably the least understood fluxes are
concentrated near its southernmost fringe : at the Antarctica continental slope, on the continental shelf, and
under the floating ice shelves. In this study, we explore the impact of a continental shelf break in restraining
the flow across it, and investigate how water masses circulate and are transformed on the continental shelf,
when it is reached. We use a unique combination of in-situ observations (e.g. moorings, profiling floats,
instrumented seals and CTD casts) to investigate circulation patterns and water-mass characteristics and
transformation on the continental shelf in the Southeastern Weddell Sea, as well as novel experiments done in
a 13m diameter rotating platform to examine the dynamical constraints of the flow.

1025
Wed_258_OS-6_1555
The Southern Ocean in Global Climate: The ORCHESTRA Programme

Andrew Meijers1 (andmei@bas.ac.uk), Emily Shuckburgh1, Michael Meredith1, Yvonne Firing2, Elizabeth Kent3,
Elaine McDonagh1, Margaret Yelland2, Tim Smyth4, Melanie Leng5, Helene Hewitt6, Patrick Hyder7, George
Nurser2, Alex Brearley1, Lars Boehme8, Anna Hogg9, Povl Abrahamsen1, Huw Griffiths1
1
British Antarctic Survey, Cambridge, United Kingdom, 2National Oceanography Centre Southampton,
Southampton, United Kingdom, 3National Ocean Technology Center, Southampton, United Kingdom, 4Plymouth
Marine Laboratory, Plymouth, United Kingdom, 5British Geological Survey, Nottingham, United Kingdom,
6
MetOffice, Exeter, United Kingdom, 7Met Office, Exeter, United Kingdom, 8St Andrews, Oban, United Kingdom,
9
University of Leeds, Leeds, United Kingdom

The Southern Ocean accounts for around half of all oceanic uptake of carbon, and more than three-quarters of
the heat uptake. Despite its profound importance, the Southern Ocean is also the least measured and arguably
the least understood of the world's oceans: its remoteness and inhospitable nature have led to a dearth of
sustained, strategic measurement programmes, and the small-scale and complexity of many of the key
processes have precluded the desired advances in simulation. To address these issues, a new £10M programme
funded by the United Kingdom NERC has now commenced - 'Ocean Regulation of Climate by Heat and Carbon
Sequestration and Transports (ORCHESTRA)'. ORCHESTRA will span five years and use a combination of data
collection, analyses, and computer simulations to radically improve our ability to measure, understand and
predict the circulation of the Southern Ocean and its role in the global climate. It will make unique and
important new measurements in the Southern Ocean using a range of techniques, including basin-wide
ocean/carbon/tracer sections, as well as deployments of autonomous vehicles, meteorological aircraft, seal
tagging and other innovative techniques for collecting data. It will also involve the development and use of
advanced ocean and climate simulations, to improve our ability to predict climatic change in coming decades.
This poster will outline the rationale, plans and key results from the ORCHESTRA programme.

1026
Wed_259_OS-6_1627
Finding Mooring Datasets for Southern Ocean Scientists

David Pasquale1, Melissa Zweng2, Pip Bricher3 (data@soos.aq), Florence Fetterer4

1
University of Colorado at Boulder, Boulder, United States, 2National Centers for Environmental Information,
Baltimore, United States, 3Southern Ocean Observing System, Battery Point, Australia, 4National Snow and Ice
Data Center, Boulder, United States

Mooring data are critical for understanding dynamics in oceans because they provide long time-series of
observations from a single location. They are particularly valuable in the Southern Ocean where observations of
all kinds are spatially and temporally sparse. Many hundreds of moorings have been deployed in the Southern
Ocean in recent decades, but to date it has been difficult to find the resulting data, which are scattered across
numerous data repositories around the globe.
Now, however, the Southern Ocean Observing System and our colleagues have compiled a central list of
historic and current mooring deployments with links to the data centres that host the data. This is a low-tech,
community-driven solution to the lack of centralised data management and will improve data discovery for a
neglected data type.
As part of this project, we have also worked to rescue unpublished datasets from scientists' hard drives and
filing cabinets. This data rescue operation has involved working with individual scientists to convert their data
to an international standard and to write comprehensive discovery metadata records before curating the data
itself in international data repositories. In this presentation, we will share our progress in data rescue and invite
input on future needs for managing and sharing these valuable datasets.

1027
Wed_260_OS-6_1628
SOOSmap: Finding and Accessing Circumpolar Southern Ocean Data

Antonio Novellino1, Marco Alba1, Patrick Gorringe2, Pip Bricher3 (data@soos.aq), Wu Lizong4, Taco de Bruin5
1
European Marine Observation and Data Network, Genova, Italy, 2EuroGOOS, Stockholm, Sweden, 3Southern
Ocean Observing System, Battery Point, Australia, 4Polar Research Institute of China, Hangzhou, China,
5
Netherlands Institute for Sea Research, Texel, Netherlands

For many scientists, finding comparison data to complement their fieldwork is a persistent problem. SOOSmap
is a new way to find data from many disciplines in one convenient place. Through SOOSmap, you can find data
from many of the world's data centres and explore thematic, spatial, and temporal gaps in the existing set of
observations.
The Southern Ocean Observing System (SOOS) is tasked with finding ways to better aggregate and share
observing data from around the Southern Ocean. We are developing SOOSmap with our colleagues at the
EMODnet Physics group, who have developed data sharing infrastructure for European marine observing data
and are now expanding their horizons to support marine observation systems in other parts of the globe.
In this presentation, we will share our progress in developing SOOSmap as a tool for discovering biological,
physical, cryospheric, and other environmental data and for exploring gaps in the existing networks of
observations. Through SOOSmap, you can filter data layers and time periods to narrow your search to only the
most relevant datasets for your purpose.

1028
Wed_261_OS-6_1729
Under-ice Turbulence and Vertical Fluxes in the Arctic Ocean in 2015

Markus Janout1 (markus.janout@awi.de), Bemjamin Rabe1, Achim Randelhoff2, Jens Hölemann1, Meri
Korhonen3, Mario Hoppmann1, Myriel Horn1, Sergey Pisarev4, Anna Nikolopoulos5, Jean Phillippe Savy6, Nico
Villacieros7
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2University
of Tromsø, Tromsoe, Norway, 3Finnish Meteorological Institute, Helsinki, Finland, 4Shirshov Institute of
Oceanology, Moscow, Russian Federation, 5AquaBiota Water Research, Stockholm, Sweden, 6LEGOS/CNRS,
Toulouse, France, 7Instituto de Investigaciones Marinas, Vigo, Spain

The Arctic Ocean is a quiescent ocean due to its sea ice cover and a strong halocline, which decouple the
subsurface ocean from atmospheric processes. For a better understanding of the Arctic ocean, sea ice, and
ecosystem it is important to understand processes that drive the vertical energy and matter fluxes in the water
column. Nevertheless, direct flux measurements are difficult to obtain and therefore sparse. We present
under-ice turbulent microstructure observations from the Eurasian and Makarov Basin of the Arctic Ocean
from two expeditions in 2015. These cover periods of melt during late spring north of Svalbard and freeze-up
during anomalously cold late summer conditions across the Eurasian and Makarov basins. Long-term (4-24 h)
sampling generally showed elevated dissipation rates at the base of the mixed layer with strongest dissipation
near the Eurasian continental slope. In the Makarov Basin, the presence of Bering Sea Summer Water led to
stratification and enhanced dissipation within the upper halocline in the Makarov Basin. We discuss these
findings in the light of the anomalous conditions in the upper ocean, sea ice and atmosphere during 2015 and
present estimates of vertical fluxes of heat, salt and other dissolved substances across the Arctic Ocean.

1029
Wed_262_OS-6_1738
Subtropical Frontal Mixing and Turbulence in the Indian Sector of Southern Ocean

Anilkumar Narayana Pillai1 (anilncaor@gmail.com), George V Jenson2, M. Nuncio1, Melena Soares1, Ravi Naik1,
S. C Tripathy1
1
National Center for Antarctic and Ocean Research, Ministry of Earth Sciences, Vasco da Gama, India, 2Indian
Institute of Sciences, Bangalore, India

AbstractIn the subtropical frontal region the upper layer diapycnal mixing studies were carried out using the
microstructure shear profiles measured during one of the expeditions to Indian sector of Southern Ocean. In
the dynamic and extremely turbulent subtropical region nitrate flux was calculated with the nutrient and
turbulence measurement. The low nitrate flux indicates weak turbulence and weak vertical gradient of
nutrient. The eddy diffusivity (Kρ = 10-5 m2/s) has been computed and its application to nutrient gradient
appears that the nutrient supply in the study period may not be due to vertical diffusion and a very low
quantity of nutrients is supplied through this process. Hence it can be suggested that the vertical supply of
nutrients perhaps may be due to advection.

1030
Wed_263_OS-6_1754
Experimental Highlights of the Eddy Saturation Regime in the Southern Ocean

Milena Menna1, Yuri Cotroneo2 (yuri.cotroneo@uniparthenope.it), Pierpaolo Falco2, Pierre Marie Poulain1,
Giorgio Budillon2
1
OGS, Trieste, Italy, 2Parthenope University, Science and Technology Department, Napoli, Italy

Drifter, satellite, XBT and Argo float data are used to define the response of the Pacific Sector of the Southern
Ocean (PSSO) to the large scale climatic patterns as depicted by the Southern Annular Mode Index -SAMI- and
the Multivariate ENSO Index - MEI in the period 1995-2017.
During this period, the SAM index is predominately positive, strengthening the westerlies, but ENSO might have
played an important role producing an increase/decrease of the EKE during La Niña/El Niño events. In fact, The
interplay between SAM and ENSO generates peculiar scenarios with different ocean responses where positive
values of SAMI are positive/negative correlated with the EKE when MEI is negative/positive.
In particular, the effects of the SAMI trend are consistent with an increase of the eddy kinetic energy (EKE) field
and the ACC transport relatively constant up to the 2007.
Results confirmed that the ocean state were close to the eddy saturation regime up to 2007 underlining the
important role of eddies in modulating the ocean circulation response to the main atmospheric forcing. After
2007, the ACC transport shows a different pattern with three well defined maximums. Two of them are in
agreement with the SAMI and MEI phases whereas there is the maximum on 2012 that is still difficult to
explain.

1031
Wed_264_OS-6_1788
Horizontal Advection Critical for Maintaining an Antarctic Biological Hotspot

Josh Kohut1 (kohut@marine.rutgers.edu), Peter Winsor2, Hank Statscewich2, Matthew Oliver3, Erick Fredj4,
Nicole Couto5, Kim Bernard6, William Fraser7
1
Rutgers University, New Brunswick, United States, 2University of Alaska - Fairbanks, Fairbanks, United States,
3
University of Delaware, Lewes, United States, 4Jersalem College of Technology, Jerusalem, Israel, 5Scripps
Institution of Oceanography, La Jolla, United States, 6Oregon State University, Corvallis, United States, 7Polar
Oceans Research Group, Sheridan, United States

Along the Western Antarctic Peninsula, ecological hotspots are spatially coherent with submarine canyons and
have persisted for millennia. Palmer Deep Canyon, a representative hotspot, is known to have higher
phytoplankton biomass than the surrounding non-canyon regions. The physical mechanisms that maintain and
deliver phytoplankton and Antarctic krill biomass, potentially increasing prey availability to predators, are not
well known. To better understand these important mechanisms, we deployed a purpose built integrated polar
observatory consisting of high frequency radar, coordinated gliders, and moorings. The gliders identified a
depth dependent influence of the underlying canyon bathymetry on physical and biological variability. A series
of simulated particle release experiments in the HF radar current maps were used to estimate surface
residence time and connectivity across the canyon. With an average residence time of 2 days, our analysis
indicates that the elevated phytoplankton biomass over the central canyon is transported into and out of the
hotspot on time scales much shorter than the observed phytoplankton growth rate, suggesting that the canyon
may not act as an incubator of phytoplankton productivity as previously suggested. It may instead serve more
as a conveyor belt of phytoplankton biomass produced elsewhere, continually replenishing the phytoplankton
biomass for the local krill community, which in turn supports numerous top predators.

1032
Wed_265_OS-6_1947
Italian Mooring Observations in the Western Ross Sea from 1995 to 2016

Pasquale Castagno1, Pierpaolo Falco1 (pierpaolo.falco@uniparthenope.it), Arturo De Alteris1, Massimo De

Stefano1, Giovanni Zambardino1, Giancarlo Spezie1, Giorgio Budillon1
1
University of Naples Parthenope, Dipartimento di Scienze e Tecnologie, Naples, Italy

Antarctic Bottom Water (AABW) plays an important role in the deep ocean stratification and in the transport of
heat, carbon and nutrients throughout the global ocean. In the Pacific Sector of the Southern Ocean, the Ross
Sea is responsible for shaping the properties of approximately 25% of the world´s AABW.
The Italian Marine Observatory in the Ross Sea (MORSea) project, funded by the Italian National Program of
Research in Antarctica (PNRA), has a network of four active moorings in the western Ross Sea: two located in
the Terra Nova Bay polynya, where the AABW precursor (High Salinity Shelf Water) is formed, and two close to
the shelf break in the Drygalski and Joides troughs where the AABW is formed from the interaction of the shelf
waters and the warm circumpolar deep water and subsequently exits from the continental shelf.
This network together with 3 moorings deployed from 1998 to 2007 in the central Ross Sea have an important
role to assess the cross-shelf exchanges processes and changes in the AABW formation in the Ross Sea and how
rapidly these changes occur.
Here, we present temperature and salinity time series and the flows variability measured at the four moorings
from 1995 to 2016 to describe trends and variability of the water properties inside the Ross Sea. In particular,
the flow and water properties variability associated with the tides and mesoscale instabilities are considered to
establish their role in the cross-shelf exchange processes.

1033
Wed_266_OS-6_1972
Changes of the Mixed Layer Depth in the Greenland, Labrador and Irminger Seas

Anna Vesman1,2 (anna.vesman@gmail.com), Igor Bashmachnikov1,3, Aleksey Koldunov3, Aleksandr Fedorov3

1
Nansen International Environmental and Remote Sensing Centre, Saint-Petersburg, Russian Federation, 2Arctic
and Antarctic Research Institute, Atmosphere-sea Ice-ocean Interaction Department, Saint-Petersburg, Russian
Federation, 3Saint Petersburg State University, Oceanology, Saint-Petersburg, Russian Federation

Deep convection (DC) in the Greenland, the Labrador and the Irminger Seas form the main source of waters of
the Atlantic Meridional Thermohaline Circulation (AMOC), and presents an important component of the global
climate system. The DC is formed in highly localized mesoscale regions and is accompanied by formation of
submesoscale convective cells, instability vortices, narrow jet streams, which makes it difficult to observe in-
situ and reproduce in ocean models. In this study we analyze the DC variability using 3 complementing data-
sets: in-situ data from EN4 Hadley Centre dataset, SODA ocean reanalysis model and ARMOR3D dataset,
combining satellite and in-situ observations, data covers period from 1993 to 2015. The Mixed Layer Depth
(MLD) was calculated using Montegut (2004), Kara (2003) and Dukhovskoy (2017) methods. Interannual
variability of DC, based on analysis of all available in-situ profiles, show significantly shallower DC, as compared
to ARMOR3D and SODA data. The latter results also show the similar tendencies with various DC indices
(integral potential energy, volume of the water mass formed, etc.)
The research was supported by RSF (project No. 17-17-01151 )

1034
Wed_267_OS-6_1990
On the Response of the LEC for the Southern Ocean to Intensified Westerlies

Yang Wu1 (yang.wu@hhu.edu.cn), Zhaomin Wang1, Chengyan Liu2

1
Hohai University, College of Oceanography, Nanjing, China, 2Nanjing University of Information Science &
Technology, School of Marine Sciences, Nanjing, China

The potential impact of intensified westerlies on the Lorenz Energy Cycle for the Southern Ocean is examined
by employing a global eddy-permitting ocean-sea ice model. Two idealized sensitivity experiments are designed
for this purpose: one is driven by 1992 forcing with weaker westerlies and the other driven by 1998 forcing
with stronger westerlies. The intensified westerlies lead to the most significant increase of about 30% in the
EKE, followed by the mean kinetic energy (MKE) increase (17.9%), eddy available potential energy (EAPE)
increase (8.6%), and mean available potential energy (MAPE) increase (6.5%). In contrast, the increases in the
generations of kinetic energy and available potential energy are quite similar, ranging from 21% for EAPE
generation to 26% for MKE generation. There are considerablly increased energy transfers from MKE to MAPE
(about 75%) and from MAPE to EAPE (about 78%), reflecting greatly enhanced baroclinic instability pathway.
The conversion rates are strongly influenced by large topography; in particular, a relatively large energy
conversion from EKE to MKE exists in the regions associated with large topography, in contrast to the energy
flow from MKE to EKE over the broad Southern Ocean. Under stronger wind forcing, all energy conversions are
enhanced, and the increases in the conversion rates from EAPE to EKE and from EKE to MKE are more
prominent than the increases from MKE to MAPE and from MAPE to EAPE near large topography.

1035
Wed_268_OS-6_2122
Benefits of High Resolution Modeling of the Ocean and Sea Ice in Adelie Land

Pierre-Vincent Huot1 (pierre-vincent.huot@uclouvain.be), Christoph Kittel2, Thierry Fichefet1, Xavier Fettweis2

1
Université Catholique de Louvain (UCL), ELI/TECLIM, Louvain-la-Neuve, Belgium, 2Université de Liège, Liège,
Belgium

Benefits of high resolution modeling of the ocean and sea ice in Adelie Land
A set of regional simulations is performed in the d'Urville sea, Eastern Antarctica. This coastal area boarded by
the Antarctic Slope Front, is one of the windiest place in the world and a major spot for dense water formation.
Our goal is to assess the importance of spatial resolution and the explicit reprensation of small scale processes
in the ability of the model to reproduce sea ice state and ocean circulation. For this purpose, two resolutions -
respectively 1/4° (~10km) and 1/24° (~2km) - will be tested in the NEMO-LIM3 model during years 2010-2013.
To also evaluate the effect of interactions with the atmosphere, both configurations will be forced by DFS
(0.75° ~30km) and by outputs of the MAR atmospheric model at 8km resolution. The simulations will be
analyzed with several foci : at a regional and seasonal scale (~500 km) to evaluate the effect of resolution on
heat, momentum and freshwater fluxes. Then, at a smaller scale (~50km), we will give a closer look at the
circulation on the continental shelf and the way it is linked to sea ice, ice shelf melting and katabatics. Finally, a
focus will be given to the air-sea interface in the presence of sea ice, to investigate in which way small scale
processes could influence fluxes between the component of the polar climate.

1036
Wed_269_OS-6_2181
Under Ice Robotic Exploration of the McMurdo Sound and Ross Ice Shelf

Britney Schmidt1 (britneys@eas.gatech.edu), Justin Lawrence1, Matthew Meister1, Daniel Dichek1, Charles
Ramey1, Benjamin Hurwitz1, Joshua Lutz1, Jade Lawrence1, Anthony Spears1, Jennifer Glass1, Amanda Stockton1,
Nicholas Speller1, Donald Block1, Margaret Philleo1, Lara Kassabian1, Jeff Bowman2
1
Georgia Institute of Technology, Atlanta, United States, 2Scripps Institution of Oceanography, San Diego,
United States

The NASA-funded RISE UP program (Ross Ice Shelf & Europa Underwater Probe) is a three-season project to
monitor basal ice conditions, ice-ocean interactions, and environmental conditions from the ice to the sea floor
beneath the McMurdo sound sea ice, the McMurdo Ice Shelf, and the Ross Ice Shelf. The main feature of the
program is the novel and scientifically capable Icefin hybrid AUV/ROV vehicle that will conduct surveys from
the ice to the seafloor to provide an integrated picture of the conditions below the ice. Nominally, the project
will conduct its work in the 17/18, 18/19, and 19/20 austral summers. In cooperation with the Antarctica New
Zealand Ross Ice Shelf Programme, PI Christina Hulbe, RISE UP will also deploy Icefin through a borehole at two
positions on the Ross Ice Shelf to access previously unmapped regions of the sub-shelf water column.
I will highlight the first results of RISE UP's first field season from October 2017 to early January 2018. This
season includes data collection at three sea ice locations, two that allow us to swim Icefin underneath the ice
shelf, and one at the Erebus Glacier Tongue. Onboard Icefin, we collect data from two sonars, two cameras, a
DVL/ADCP, and sensors for conductivity & temperature, depth, pH/ORP, DO, CDOM/FDOM and turbidity. I will
describe Icefin, and provide preliminary observations of the basal ice conditions, oceanographic properties
below the sea ice and ice shelves, and seafloor conditions we observed.

1037
Wed_270_OS-6_2186
Variability of Ocean Properties along the West Antarctic Peninsula Shelf

Carlos Moffat1 (cmoffat@udel.edu), Mike Dinniman2, John Klinck2, Borja Aguiar-Gonzalez1, David Sutherland3,
Jennifer Graham4
1
University of Delaware, Newark, United States, 2Old Dominion University, Norfolk, United States, 3University of
Oregon, Eugene, United States, 4Met Office Hadley Centre, Exeter, United Kingdom

The west Antarctic Peninsula shelf has been one of the most rapidly-warming systems in the southern
hemisphere, and glaciers terminating in this coast have undergone dramatic retreat, although with a distinct
along-shore pattern: on average, those in contact with the colder waters in northern Bransfield Strait have
retreated slower than those terminating in the warmer, southern central coast. The supply of warm
Circumpolar Deep Water to this southern region is modulated by deep troughs cutting across the shelf which
steer the circulation, and provide a pathway for relatively small, warm ocean eddies to carry heat shoreward.
Here, we use the output of the highest-resolution, shelf-wide numerical model available for the wAP as well as
available hydrographic data to characterize the spatial and temporal scales of variability of the ocean
properties forcing glacier retreat along the coast. The model (ROMS) configuration is eddy-resolving at 1.5 km
horizontal resolution, includes 24 vertical levels, and was forced with realistic meteorological fields and
observed sea-ice (at the model boundaries) for two years. Results show that the deep northern shelf water
variability is dominated by seasonal inflow from the Weddell Sea and bottom-intensified synoptic variability
while in the southern wAP shelf seasonal variability in deep water properties is mostly absent. The dynamics of
exchange between these two regions and the implications for glacier retreat along the wAP are discussed.

1038
Wed_271_OS-6_2231
12-day Arctic Ice-tethered Mooring: Velocities, Particles and Plankton Migration

Anna Nikolopoulos1 (anna.nikolopoulos@hi.no), Torsten Linders2, Elin Andrée2

1
Havforskningsinstituttet / Institute of Marine Research, Tromsø, Norway, 2University of Gothenburg,
Department of Marine Sciences, Gothenburg, Sweden

Observational data of the under-ice circulation characteristics were collected in June 2017 during a twelve-day
ice drift over the northern Yermak Plateau (approx. 82°N/10°E), as part of the R/V Polarstern expedition PS106.
A top anchored mooring line equipped with three upward looking RDI Acoustic Doppler Current Profilers
(ADCP) and three SBE microCATs (CTD) was deployed through the ice with the main purpose to measure under-
ice water velocities and temperature/salinity characteristics in the upper 180 m of the water column.
Additional measurements of under-ice particle size distribution and concentration were undertaken with a
Laser In-Situ Scattering and Transmissometry (LISST) particle size analyser, both in profiling and constant-depth
mode. Supplemental data of the water properties were collected with the standard shipboard instrumentation.
Here, we present results in terms of the vertical and horizontal under-ice water motion and the consequences
for the distribution of mass and heat within and below the mixed layer. The ADCP data are additionally
interpreted as sound scattering layers used to identify vertical migration patterns of small mesozooplankton (a
few mm in size). Our study provides yet some pieces of information about the under-ice dynamics and the
vertical positioning of organisms in the spring-to-summer transition of the Arctic Ocean.

1039
Wed_272_OS-6_2282
Interannual Variability of Modern Fram Strait Outflow Revisited

Georgi Laukert1 (glaukert@geomar.de), Martin Frank1, Jan Dreyer1, Benjamin Rabe2, Dorothea Bauch1, Wilken-
Jon von Appen2
1
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, 2AWI – Alfred Wegener Institute for Polar
and Marine Research, Bremerhaven, Germany

Several studies have shown strong variability in the composition of shallow waters leaving the Arctic Ocean
through the western Fram Strait. In particular, the fraction of Pacific-derived waters has been suggested to vary
annually from dominating to absent. However, this fraction has been determined by calculations involving
dissolved nutrient relationships, which can be altered by biogeochemical processes (occurring, for example, on
the Greenland Shelf) and, hence, not always reflect water mass advection and mixing alone. An alternative
approach uses dissolved radiogenic neodymium (Nd) isotopes (expressed as εNd) to identify and quantify the
different Arctic water mass components present in the outflowing Arctic waters. This method is applied here to
review the interannual variability of the outflow composition. New dissolved εNd data obtained for the years
2014, 2015 and 2016 for the western Fram Strait are complemented by Nd isotope data previously reported for
1999, 2002 and 2012. Constant εNd signatures near -9 and Nd concentrations of ~30 pmol/kg in the core of the
outflow are observed for all investigated years and reflect nearly steady contributions of Pacific- and Atlantic-
derived waters at a ratio of ~2:3, and minor slightly varying riverine inputs. The remarkably constant Nd
characteristics argue for a stable composition of the outflowing Arctic waters, which allows us to hypothesize
that the annual outflow was more uniform in the past than previously assumed.

1040
Wed_273_OS-6_2411
Southern Ocean Stratification Delayed by Submesoscale Wind-front Interactions

Marcel du Plessis1 (marceldpl10@gmail.com), Sebastiaan Swart2, Isabelle Jane Ansorge1, Amala Mahadevan3
1
University of Cape Town, Cape Town, South Africa, 2University of Gothenberg, Gothenburg, Sweden,
3
Massachusetts Institute of Technology, Boston, United States

Ocean stratification and the upper mixed layer influence the rate and magnitude the ocean absorbs and stores
atmospheric heat and carbon. One way in which these air-sea fluxes are moderated is through the interaction
between surface winds and ocean flow fields, such as fronts and eddies. The energetics of the ocean are
particularly amplified at submesoscales (1-10 km) which manifest in regions of large horizontal density
gradients. Both strong atmospheric forcing and submesoscale features are ubiquitous in the Southern Ocean.
We use four high-resolution glider experiments to investigate the impacts of these wind-front interactions on
upper ocean processes in the Subantarctic Zone. The mixed layer is found to have a strong seasonal signal
superimposed with large submesoscale fluctuations. These periods consist primarily of MLD deepening phases
which drive an offset in the onset of summer restratification by up to 35 days. Summer restratification is
arrested when the winds orientated along the flow of fronts (down-front) induce a destabilising flux via a
horizontal Ekman buoyancy flux (EBF) towards the less dense domain of the front. By incorporating an EBF
equivalent heat flux into a 1D model, the upper ocean stratification improves significantly compared to when
the model is run using 1D forcing. This study shows the need to incorporate submesoscale processes, such as
EBF, into global climate models to correctly account for upper ocean processes that impact climate.

1041
Wed_274_OS-6_2497
Modification of Atlantic Inflow along its Northern Passage into the Arctic Ocean

Agnieszka Beszczynska-Moeller1 (abesz@iopan.gda.pl), Waldemar Walczowski1, Agata Grynczel1, Malgorzata

Merchel1
1
Institute of Oceanology PAS, Sopot, Poland

Understanding variable oceanic fluxes of volume and heat, carried by Atlantic water (AW) into the Arctic
Ocean, and their impact on ocean-atmosphere-ice interactions, ocean heat content, sea ice cover and
propagation of anomalies are key challenges to understand the new, warmer regime of the Arctic Ocean. As
the AW progress northwards, its properties are modified by ocean-atmosphere interactions, mixing and lateral
exchange. AW temperature drops from 7-10°C at the entrance to the Nordic Seas to 3-3.5°C when it leaves
Fram Strait. Warm anomalies reaching the Arctic Ocean can result from smaller heat loss during AW northern
passage towards and through Fram Strait, and/or from an increased oceanic advection. During the last two
decades the extraordinary warm Atlantic water inflow has been reported to progress into the Arctic Ocean,
however with strong interannual variations. Here we present results from 20 years of annual hydrographic
surveys, covering the Atlantic water inflow in the eastern Norwegian and Greenland seas, Fram Strait up to the
southern Nansen Basin. Observations from year-round moorings west and north of Svalbard and regularly
deployed Argo floats are also used to elucidate processes contributing to AW modifications during its passage
into the Arctic Ocean. Long-term observations reveal new details on spatial structure and temporal evolution of
warm anomalies carried into the Arctic Ocean, and their links to heat fluxes and sea ice variability north of
Svalbard.

1042
Wed_275_OS-6_2534
Contrasted Sea Ice Response to Increased Freshwater Flux from Antarctic Glaciers

Julien Le Sommer1 (julien.lesommer@univ-grenoble-alpes.fr), Nacho Merino2, Gael Durand1, Nicolas Jourdain1,

Pierre Mathiot3, Hugues Goosse4, Gurvan Madec5
1
Institut des Géosciences de l'Environnement, CNRS/Univ. Grenoble Alpes/G- INP/IRD, Grenoble, France, 2Institut
des Géosciences de l'Environnement, Grenoble University, CNRS/Univ. Grenoble Alpes/G- INP/IRD, Grenoble,
France, 3Met Office, Exeter, United Kingdom, 4Université Catholique de Louvain, Earth and Life Institute, Centre
de Recherches sur la Terre et le Climat Georges Lemaître, Louvain la Neuve, Belgium, 5Sorbonne Universités
(UPMC, Univ Paris 06)-CNRS-IRD-MNHN, LOCEAN Laboratory, Paris, France

Antarctic outlet glaciers are undergoing rapid transitions. Induced changes in freshwater release to the
Southern Ocean have been suggested to contribute to ongoing trends water mass properties and sea ice
regimes. However, ocean/sea-ice models disagree as to the quantitative response of the Southern Ocean to
changes in glacial freshwater forcing.
In this study, a series of ocean/sea-ice modeling experiments is undertaken with NEMO global 1/4° model
configuration in order to study the physical processes involved in the changes of Southern Ocean sea ice over
recent decades. Perturbation experiments are carried out with respect to atmospheric and freshwater forcing
over recent decades. The freshwater forcing scenario explicitly takes into account the observed changes in the
volume of Antarctic ice shelves, which is found to be a key component of changes in freshwater release.
Our results show that changing freshwater release overall increases Antarctic sea ice extent, but with
distinctive regional patterns and with large changes in sea-ice thickness. The processes involved in the response
differ substantially from region to region depending on the local conditions. Our results suggest that up to one
half of the observed total changes in sea ice extent over recent decades might be due to changes in freshwater
release, the other half being induced by atmospheric changes. This study emphasizes the need for improving
the representation of freshwater sources in climate models.

1043
Wed_276_OS-6_2577
Existence of the Mendeleev Gyre and its Role in Arctic Circulation

Jinping Zhao1 (jpzhao@ouc.edu.cn)

1
Ocean University of China, College of Oceanic and Atmospheric Sciences, Qingdao, China

On the basis of conductivity, temperature, and depth (CTD) and nutrient data obtained during the Korean R/V
Araon 2012 summer Arctic cruise, a gyre-like local circulation in the Chukchi Abyssal Plain is identified as the
Mendeleev Gyre (MG). Evidence supporting the existence of the MG includes uniform temperature, salinity,
and density in the central plain; a cold core surrounding the plain; a bowl-like surface steric height embedded
in the background field; and a lens structure appearing in the vertical section. The nitrate-phosphate (N-P)
relationship in the Chukchi Abyssal Plain suggests gyre-like mixing. In an ice-ocean coupled model used to
simulate the MG and its multiyear variation, a gyre-like flow pattern is shown to appear only during 2011-2014
corresponding to the sea ice retreat, particularly in 2011 and 2012. Therefore, the MG might be an
accompaniment of sea ice retreat. Lateral entrainment is suggested as the driving factor of the MG. The
eastward boundary current and the northwestward Pacific inflow provide momentum and relative vorticity by
lateral turbulent friction, which facilitates the current leaving from the isobaths to generate a gyre. The inclined
isopycnal interfaces from west to east are verified to facilitate an eastward slope flow along inclined isosteric
height interfaces. The MG plays the role of a watershed in preventing the outflow of the shelf water and
benefiting the colder and fresher shelf water transported directly to the Canada Basin.

1044
Wed_277_OS-6_2626
Pacific Waters in Eastern Chukchi Sea Observed by Chinese Cruises in Last Decade

Jiuxin Shi1,2 (shijiuxin@ouc.edu.cn), Jinping Zhao1,2, Yutian Jiao1, Longjiang Mu3

1
Ocean University of China, College of Oceanic and Atmospheric Sciences, Qingdao, China, 2Qingdao National
Laboratory for Marine Science and Technology, Qingdao, China, 3National Marine Environmental Forecasting
Center of China, Beijing, China

Multi-disciplinary observations have been conducted by the Chinese Arctic Research Expeditions (CHINARE) at
several sections in Chukchi Sea since 1999. With CTD data from 6 CHINARE cruises during 1999-2014 and
outputs from a coupled sea ice - ocean numerical model, Pacific inflows in the Chukchi Sea and their inter-
annual variations are analyzed. These sections are limited in the eastern Chukchi Sea, consist of one meridional
section along 169°W and several nearly zonal sections between the meridional section and the Alaskan coast.
The Alaskan coast water (ACW) occurred in the east end of the zonal section to the Point Hope, as a northward
coastal current. The ACW observed in 2012 and 2014 were obviously warmer than that in 2010, approaching to
10°C. At section 169°W, relative warm and fresh waters concentrated at surface layer in the Central Channel to
the south of the Herald Shoal, with two separate cores observed in some cruises (e.g. 1999, 2003 and 2010).
These waters are identified as ACW with the additional supports from numerical model outputs. The simulated
circulation shows that a branch (or two branches) of ACW flows to northwest from Point Hope, across 169°W
and reaches Herald Canyon, while most ACW still flows toward northeast along Alaskan coast and enters
Barrow Canyon. The thermohaline structure around Herald Shoal showed large inter-annual variability, which
implies the complicated interactions between different water masses, including Pacific waters.

1045
Wed_278_OS-6_2634
Circulation of the Weddell Gyre Inferred from Long-term Observations

Krissy Anne Reeve1 (kreeve@awi.de), Torsten Kanzow1,2, Gerd Rohardt1, Olaf Boebel1, Volker Strass1, Rüdiger
Gerdes1
1
Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2Bremen
University, Physics and Electrical Engineering, Bremen, Germany

The Weddell Gyre plays a fundamental role in the climate system by advecting heat poleward to the Antarctic
ice shelves and by regulating the density of water masses that feed the lowest limb of the global overturning
circulation. Profile and trajectory data between 2002 and 2015 from a fleet of Argo floats between 50 and 2000
m are exploited in order to produce a full gyre scale view of the Weddell Gyre's circulation. The data exhibit a
gradual cooling of the Warm Deep Water (WDW) as it circulates cyclonically around the gyre. A double-cell
structure of the Weddell Gyre is revealed, with a stronger eastern core that intensifies with depth, and a
weaker western core that remains invariant with depth. The deep outflow of Weddell Sea Deep and Bottom
Water (WSDW, WSBW) at the western boundary of the gyre, formed from WDW by complex modification
processes involving sea ice formation, and basal ice shelf melting, is not covered by the float observations.
Using mooring array-based observations near the tip of the Antarctic Peninsula between 1989 and 1998, and
between 2005 and 2014, a cooling of the WSBW plume is revealed over the observational period. This is in
striking contrast to the WSDW in the interior Weddell Sea which has been undergoing a decadal warming.
While the cause of the cooling of the WSBW plume is currently unclear, the mooring-based velocity
observations indicate that the volume transport of the WSBW plume of 2.5 Sv has been stable over time.

1046
Wed_279_OS-6_2644
Decadal Covariability of Arctic and Subarctic North Atlantic Freshwater Content

Myriel Horn1 (myriel.horn@awi.de), Ursula Schauer1, Benjamin Rabe1, Claudia Wekerle1

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

Significant freshwater changes have recently been observed both in the Arctic Ocean and the subpolar North
Atlantic. To investigate possible links, we compared the liquid freshwater content of the subarctic North
Atlantic with the sum of liquid and solid freshwater content of the Arctic Ocean from observations. We found a
distinct decadal anti-correlation of the freshwater anomalies in these two regions with anomalies of almost the
same magnitude. An analysis of freshwater fluxes from the global Finite Element Sea ice Ocean Model (FESOM)
and the CORE2 atmospheric forcing data set revealed that the observed freshwater variations resulted from
changing freshwater transports. Furthermore these changes are correlated with the Arctic and North Atlantic
Oscillation indices. We suggest that changing freshwater export from the Arctic Ocean to the subarctic North
Atlantic responds to multidecadal alternations of the dominant large-scale atmospheric variability. According to
the present phase of this large-scale atmospheric variability, the freshwater accumulated during the previous
decades in the Arctic Ocean might be released into the sub-Arctic Seas in the coming years. This has the
potential to impact the North Atlantic meridional overturning circulation. To further investigate the involved
processes, find the driver of freshwater transport changes and proof our hypotheses we show further results
from the FESOM simulation and an analysis of the atmospheric forcing.

1047
Wed_280_OS-6_2648
Wind Flows and Ocean Surface Currents in Marginal Ice Zone with Satellite Data

Anastasia Tarasenko1,2 (anastasiia.tarasenko@ifremer.fr), Bertrand Chapron1,2, Vladimir Kudriavtsev2, Albert

Mourtazin2, Olivier Archer1, Jean Tournadre1
1
Ifremer, Brest, France, 2Russian State Hydrometeorological University, Saint-Peterburg, Russian Federation

Marginal ice zone (MIZ) is an area of active interaction between atmosphere, ocean and sea ice. The change of
roughness and temperature over the underlying surface (ice/open water) impacts the wind speed and
direction. Accurate wind estimates are the core not only for more exact heat fluxes assessments in rapidly
changing environment, but also can help to predict the wind drift on the short time-scales. The estimates of
wind drift in MIZ can help to reconstruct the ocean surface currents speed finally.
With the lack of in situ measurements in MIZ, one of the best tools covering large areas in polar regions is
satellite data. We studied the transformation of wind flows using high resolution Sentinel-1/SAR-C data. The
wind fields were calculated from EW Sentinel-1 images with CMOD-5 geophysical model function at 500 m
horizontal grid and then compared to ECMWF ERA-INTERIM reanalysis wind data. The possible role of the fetch
when calculating wind speed with CMOD-5 is discussed. Several configuration of wind flows position according
to the sea edge were studied: on-ice/off-ice, for weak and moderate wind speeds. The estimates of wind-
driven ice drift and ocean surface currents are provided for the case studies in 2014-2017 in the Arctic.

1048
Wed_281_OS-6_2649
Variability and Drivers of the Ice-covered Ross Gyre Circulation

Tiago S. Dotto1, Michel Tsamados2 (m.tsamados@ucl.ac.uk), Alberto G. Garabato1, Sheldon Bacon1, Andy
Ridout2, Paul Holland3
1
National Oceanography Centre Southampton, Southampton, United Kingdom, 2University College London,
London, United Kingdom, 3British Antarctic Survey, Cambridge, United Kingdom

The Ross Gyre (RG) is one of the main current systems of the polar Southern Ocean, and conveys the warm
waters from the Antarctic Circumpolar Current toward the cold continental shelves of the Antarctic Pacific
sector - regulating the stability of the Ross Ice Shelf. Due to the seasonal sea ice cover, little is known on the
variability of the RG circulation and its driving forces. Here, novel altimetry data from Cryosat-2 is used to
document the variability and drivers of the RG circulation in the period 2011-2015. The variability of altimetric
sea surface height (SSH) is highly coherent with that of ocean bottom pressure inferred from the GRACE
mission, suggesting that RG variability on time scales up to interannual has a dominant barotropic component.
The ocean surface stress curl was identified as the main driver of the observed variability in the surface
circulation. Statistical analyses indicate that variations in the area and strength of the RG are regulated by ice-
mediated wind forcing via two distinct dynamical modes of SSH variability:
(1) one involving barotropic modes that either follow the continental shelf break around the entire Antarctic
continent or are trapped within the Southeastern Pacific basin;
(2) and another implicating coherent variability across all ice-covered regions of West Antarctica. This work
illustrates the potential of this new altimetric technique in uncovering the nature and dynamics of the
circulation in the ice-covered Southern Ocean.

1049
Wed_282_OS-6_2679
Remote Sensing of Eddies in the Arctic Ocean

Igor Kozlov1,2,3 (igor.eko@gmail.com), Larisa Petrenko2, Anastasya Artamonova4, Oksana Atadzhanova4,5, Alexei
Zimin5
1
Russian State Hydrometeorological University, Satellite Oceanography Laboratory, St. Petersburg, Russian
Federation, 2Marine Hydrophysical Institute of RAS, Remote Sensing Department, Sevastopol, Russian
Federation, 3Woods Hole Oceanographic Institute, Physical Oceanography Department, Woods Hole, United
States, 4Russian State Hydrometeorological University, St. Petersburg, Russian Federation, 5Shirshov Institute of
Oceanology of RAS, St. Petersburg, Russian Federation

Here we present the results of high-resolution satellite observations of oceanic eddies over the selected Arctic
regions, including the Eurasian Arctic sector, and Chukchi and Beaufort Seas. The study is based on analysis of a
large dataset of ENVISAT Advanced Synthetic Aperture Radar (SAR) images acquired in summer-autumn 2007-
2011. Detailed maps of eddies' locations, their diameters and vorticity sign are presented and discussed. This
work is supported by RFBR grant 16-29-02106 mol_a_dk, RSF grant No. 17-77-30019, and FASO Russia project
No. 0827-2014-0011. ENVISAT ASAR data used in this study were provided by the European Space Agency (ESA)
through Cat-1 Project C1F-29721.

1050
Wed_283_SH-4_25
The Sealer-Whalers' Footwear in Livingston Island: Clothing in the 19th Century

Gerusa Radicchi1 (gerusaradicchi@hotmail.com)

1
Universitat Politècnica de València, Valencia, Spain

The research discusses the cultural identity of the sealer-whalers who were in the Livingston Island (South
Shetland Islands, Antarctica) in the nineteenth century through the practices of footwear. The studies were
developed from the shoes archaeological collection rescued by the LEACH/UFMG-Brazil. Three groups of
related materiality were investigated: the footwear; the bodily practices; and the Antarctica as a place of
experience. The study of the format indicates the permanence of models and traditional construction
techniques of their shoes. However, they also incorporated the industrial production of the early nineteenth
century and, often, articulated to the supply of ships and the whaling crew. All identified units or parts come
from simple shoe models similar to “slippers”. There are no adornments or use of other aesthetic features
among the shoes of ordinary whalers. The shoes have heavy usage and repairing marks and evidence of
material removal. These data tell us about the unavailability of resources and how footwear functioned as an
interface between physical performance and the work space in Antarctica.

1051
Wed_284_SH-4_26
The Conservation Practices of Sealer-Whalers' Remains in Livingston Island

Gerusa Radicchi1 (gerusaradicchi@hotmail.com)

1
Universitat Politècnica de València, Valencia, Spain

The proposal aims to present questions about the methods of the conservation after the archaeological
excavation of the sealer-whalers sites in the Livingston Island (South Shetland Islands, Antarctica). These
objects are characterized mainly by the presence of very fragile wet organic materials; only preserved by the
specific conditions provided by the Antarctic context. The hunters were taken to the islands by whaler shipping
companies during the first half of the eighteenth century. They performed their hunting activities in the
summer months, living on the beaches in shelters built from rocks found in the region and other resources.
Since the first excavation expedition made by the (Leach/UFMG-Brazil), in 2010, an axis of research that
articulates the methodology of excavation to conservation has been developed.

1052
Wed_285_SH-4_296
Remoteness, Environmental Protection, Mobility and Antarctic Material Remains

Lize-Marié van der Watt1 (lizemarie.vanderwatt@abe.kth.se)

1
KTH Royal Institute of Technology, Division of History of Science, Technology and Environment, Stockholm,
Sweden

This presentation explores the relationship between heritage and environmental protection in Antarctica
through focusing on the potential mobility of Antarctic material remains. Using research infrastructures as an
example, I ask to what extent heritage designation can be not only geopolitically motivated but also a more
pragmatic strategy - for example, to avoid the cost of removal. This also leads to the question of whether or not
particular historical remains' heritage status can be enhanced through removal to a more accessible site - and
what value impact that has. Could the de facto exemption of pre-1958 structures from environmental
regulations be seen as a testament to different environmental regimes in the past, and of the remains'
importance to particular national narratives? Have the values of environmental protection that underlie
removal and eradication programs influenced Antarctic cultural heritage and if so, how does this reflect on our
understanding of the relationship between cultural heritage and the Antarctic environment?

1053
Wed_286_SH-4_611
Trust in the System of the Formation of Social Capacity in the Arctic Region

Lidiia Belonozhko1 (lnbelonozhko@gmail.com), Oleg Barbakov2, Anatoly Silin1

1
Industrial University of Tyumen, Department of Marketing and Public Administration, Tyumen, Russian
Federation, 2Industrial University of Tyumen, Department of Business Informatics and Mathematics, Tyumen,
Russian Federation

One of the foundations of social harmony, largely determining the dynamics of the development of the social
situation is trust which is acting as confidence in the integrity and sincerity of others or the state and public
institutions.
Sociological studies conducted by the authors in recent years in the Yamalo-Nenets Autonomous District
recorded a decrease in the level of trust among representatives of different social groups of the population.
Thus, mass surveys on representative samples in cities, shift camps and national villages showed that
indigenous people representing one northern ethnos less trust the others, and, especially, alien visitors who
live in the North constantly, are increasingly negative to shift workers from other regions.
It was found, that the greatest level of social dissatisfaction, pessimism and distrust to the authorities was
expressed by the representatives of indigenous ethnic groups (Nenets, Khanty and Selkups), who believe that
"they are all deceived". They are often afraid to answer frankly (about half of the respondents chose" difficult
to answer" option).
Meanwhile, the social situation in the Arctic and subarctic regions, the resources of which have provided the
economic stability for many years, remains largely outside the field of attention of the authorities and the
expert community. At the same time, there are still latent processes of social frustration, which can lead to
unpredictable forms of protest.

1054
Wed_287_SH-4_824
Cultural Heritage and Commercial Fishing in the Southern Ocean

Ricardo Roura1 (ricardo.roura@worldonline.nl)

1
Independent Scholar, Amsterdam, Netherlands

The cultural heritage of Antarctica reflects over two hundred years of human presence in the region, primarily
early exploration, site occupation and scientific research. The exploitation of Antarctic marine ecosystems
began early on with sealing and then whaling. In the past several decades commercial fishing for finfish and krill
has been one of the dominant forms of human presence in the Antarctic region. Although now regulated by
different instruments and bodies, sealing, whaling and some of the earlier commercial fishing resulted in over-
exploitation of target species and a lasting ecosystem legacy. Paradoxically, the material cultural record of
commercial fishing is almost entirely absent or invisible in Antarctica, including a lack of associated Historic
Sites and Monuments. Since the establishment of the Commission for the Conservation of Marine Living
Resources (CCAMR) the legacy of fishing includes a body of databases and scientific knowledge, legal
instruments, and “lines on the map” reflecting spatial management measures. Southern Ocean fishing is also
associated with some places outside Antarctica. This presentation discusses some concepts of cultural heritage
as they apply to Southern Ocean fishing. It suggests that the history and heritage of fishing requires more
public visibility. This would contribute to maintain the memory of past over-exploitation and to increase the
transparency of CCAMLR's management of Antarctic marine life.

1055
Wed_288_SH-4_880
Managing Antarctic Heritage: The Sealer Sites in the South Shetland Islands

Maria Jimena Cruz1 (jimenacrz@gmail.com), Andrés Zarankin1, Michael Pearson2

1
Universidade Federal de Minas Gerais, Anthropology, Belo Horizonte, Brazil, 2Independent Scholar, Fischer,
Australia

The concern about the protection and conservation of historical patrimony in Antarctica has been developing
during the last decades. These efforts are evidenced by the creation of guidelines and resolutions that aim to
avoid the destruction and damage of the sites caused specially by human activities.
Sealer sites of the nineteenth century identified in the South Shetland Islands are in an ambiguous position
considered part of this patrimony. Differently to other “relevant” historical sites, these places are not directly
linked to one particular nation (for example the Heroic Era huts), resulting in a lack of interest in developing
conservation strategies. As a consequence of this, several factors that impacted negatively on the conservation
of these places have been identified, the main ones being: natural causes (presence of animals and rising sea
levels), the increasing tourism activity in the area and the presence of other researcher's parties in the location.
Taking this situation as a starting point, in this presentation we seek to discuss the initial actions that have been
carried out by the Antarctic Historical Archaeology Project in order to secure the preservation of these sites. At
the same time, we aim to encourage a broad and interdisciplinary discussion between researchers from
different disciplines that can help to generate new ways of cooperation and dialogue concerning the
conservation of the historic patrimony in Antarctica.

1056
Wed_290_SH-4_2359
Shooting the Arise of the Antarctic Overwintering Social Institution

Pablo Gabriel Fontana1 (fontana.pablo@gmail.com)

1
Instituto Antártico Argentino, Social Sciences and Humanities, Buenos Aires, Argentina

In 1927 the Argentine José Manuel Moneta, head of the Meteorological Station at Laurie Island, shot there the
documentary Among Orkney Islands ice (Entre los hielos de las islas Orcadas). Through a sociohistorical analysis
of its representations, this paper considers this film as a cinematic document of a new Antarctic social
institution, which includes a series of practices internalized by scientists overwintering on permanent stations.
Since 1904 these practices were institutionalized through logistical and scientific crews that are yearly relief
and today this is one of the most characteristic features of the Antarctic science. The film shows a new form of
human activity in Antarctica in a way that differentiates from the heroic age and its most characteristic
elements. There, a scientific station becomes the space where scientific activity develops over twelve months,
repeating itself each year with a set of elements and social practices that defines it to the present. Moneta shot
the documentary during his third winter in Antarctica. He overwintered four times, so he knew very well the
details of regular overwintering scientific experience and filmed those practices in the Antarctic environment to
show them to the society. Here we will also use his book Four Years in the South Orkney Islands (Cuatro años en
las Orcadas del Sur) to complement the analyses with other media and understand how this Antarctic social
institution was perceived at that time.

1057
Wed_291_SH-4_2454
Antarctic Wintering Art of Living: AWAL

Daphné Buiron1, Elisa Dupuis2, Ann-Isabell Guyomard3, Emmanuelle Sultan4 (emmanuelle.sultan@mnhn.fr)

1
Collectif CryoSalide, Paris, France, 2Sorbonne Universités (Université 4), Paris, France, 3Oijha - Art and Ethics
from Antarctica, Paris, France, 4MNHN, DGD REVE, Dinard, France

The Antarctic Observatory CryoSalide project looks at the human presence organization in southern
environments. In this intention, the AWAL project is dedicated to the collection and the highlighting of craft
and art developed on Antarctic stations during wintering periods. In order to compensate some lack of
equipment, craft has naturally being developed, using the limited local means. These creations are unique
witnesses of the art of living in Antarctica, and it represents a precious culture heritage, which should be
known, collected, archived and valued, Focusing on both Dumont d'Urville (Adélie Land) and Dome C Concordia
(East-Antarctic plateau) stations, we offer to conduct a preliminary inventory of art and craft realisations locally
performed. Thanks to the voluntary participation of people who have wintered, the AWAL team will provide a
catalogue describing, explaining and referencing the different kind of arts (fine arts, culinary art, etc.)
developed during wintering times. This data base will be available from the Antarctic Observatory CryoSalide
under creative common license (or other to be defined). The purpose is to make this Antarctic art alive, and
systematically included in our cultural heritage. So the art of living in Antarctica will become one day a history
of the southern art.
First results of the Antarctic art and craft catalogue will be shown with the intention of demonstrating the
interest and the potential of such an effort.

1058
Wed_293_SH-5_3
Building an Arctic Urban Sustainability Index

Robert Orttung1 (rorttung@gmail.com)

1
The George Washington University, Sustainability Collaborative, Washington, United States

This presentation will discuss the progress of a multi-disciplinary, international project designed to build an
Arctic Urban Sustainability Index. The project looks at 50 cities across the circumpolar area. The index focuses
on five areas: economic, environmental, social, governance, and planning. The purpose of the Index is to help
policy makers and ordinary citizens promote sustainability and resilience by providing tools to measure
progress, identify areas of most urgent need, select verifiable best practices, examine opportunity costs, and
determine where external actors can have the greatest impact.
The presentation will examine issues related to defining "urban" and "sustainability" in Arctic conditions. It will
discuss the issues related to identifying appropriate indicators for the five areas that make up the index. It will
also discuss the issues related to gathering data to measure sustainability and the indicators involved.
In the concluding section, the presentation will present preliminary finding of the project and examine what
the next steps will be. Most important is work to define specific indicators that can be used to measure
sustainable outcomes in Arctic urban settings. This discussion will focus on the use of indicators that measure
such things as greenhouse gas emissions and the appropriateness of different types of education systems for
promoting sustainability in Arctic cities.

1059
Wed_294_SH-5_4
Antarctic's Values and Perception of Responsibility in its Protection and Care

Claudia Estrada Goic1 (claudia.estrada@umag.cl), Mariana Cabanas1, Constanza Lopez1, Camila Jalil1, Kimberly
Hechenleitner1, Ana Latorre1
1
University of Magellan, Psychology, Punta Arenas, Chile

Social identity is the part of the self that is built from the recognition of our belonging to social groups (Tajfel,
1984). Its link to different social categories which comprise the belonging to a cultural or geographical region
has been extensively studied.
The Regional Ecological Identity (IRE) tries to represent an aspect of who we are that depends on our
connection with natural environments (the environment we interact with, either in a real or a symbolic way).
We present the results of a study on this topic whose subject are inhabitants of the extreme south of
Patagonia, who are linked to the Antarctic from a scientific and logistic perspective. A set of instruments
measured IRE, the attribution of values to the Antarctic and the perception of personal responsibility in its
protection and care; some other socials and ecological variables were also applied. The results show that the
participants attribute a high general value to the Antarctic territory, particularly aesthetically and scientifically.
Their identification with this territory is strong despite little knowledge and no direct contact. Finally, the social
variables are more useful than the ecological ones in explaining the link with this territory. These results are
discussed in the background of their significance for the evolution from an anthropocentric concept of the
Antarctic to a biocentric / conservationist view.

1060
Wed_295_SH-5_18
Arctic City Resilience to Energy Infrastructure Damage from Permafrost Thaw

Katherine Weingartner1 (kweingartner@email.gwu.edu)

1
The George Washington University, Washington, United States

Thawing Arctic permafrost poses a threat to Arctic cities that are reliant on fossil fuel development by altering
the landscape on which critical energy infrastructure is built. Permafrost thaw can not only destabilize oil and
gas pipelines by shifting the underlying earth, but resulting exploding methane bubbles can create large craters
that have the capacity to damage oil and gas infrastructure. Arctic cities face potential economic, security, and
environmental risks from such damage. Many cities in the Arctic rely on oil and gas revenue to meet the needs
of their people. Disruptions in oil and gas delivery from pipeline damage may have larger energy security
implications that can impact regional and international supplies. Lastly, such damage can cause leaks which can
have negative environmental consequences for the surrounding environment. As an extension of the National
Science Foundation grant, Arctic PIRE: Promoting Urban Sustainability in the Arctic, this paper will examine the
nature of the threat of permafrost thaw on oil and gas infrastructure for a sampling of Arctic cities and discuss
if and how these cities are planning to build greater resilience into the energy infrastructure on which they
depend.

1061
Wed_296_SH-5_656
Participatory Processes in the Arctic: The Case of Urban Development

Dorothea Wehrmann1 (dorothea.werhmann@die-gdi.de), Arne Riedel2

1
German Development Institute, Bonn, Germany, 2Ecologic Institut, Berlin, Germany

The Arctic is subject to complex and in many regards interrelated environmental, social-cultural and economic
changes and in this context, the proposed presentation discusses specifically the case of urban development in
the Arctic, which is encouraged by climate change impacts and the growing development of mineral resources.
The presentation first illustrates the various interests and different say that stakeholders have in policy-making
processes that concern urban development in the Arctic. Second and under consideration of approaches from
political science and legal studies, it discusses how more inclusive policy-making can be encouraged in the
governance of Arctic regions. Thereby, the proposed presentation relates to a central criticism often
formulated by “people from the North” on the one hand (their perception of being dominated by policies
adopted in distant capital cities), and to the often stated need to include local knowledge in policy-making to
address the complex challenges in a sustainable manner, on the other. Overall, the proposed presentation
outlines different strategies how local stakeholders from remote regions in the Arctic can be better and more
effectively included in policy-making processes that affect their livelihoods. By embedding the proposed
options also in the wider debate on the governance of the Polar Regions, the proposed presentation concludes
by relating these options to local, national, regional and global levels.

1062
Wed_297_SH-5_1044
Importance of Sustainable Development: Impacts of Future Arctic Air Pollution

Julia Schmale1 (julia.schmale@psi.ch), Kathy Law2, Stephen Arnold3, Kerri Pratt4, William Simpson5, Jingqui
Mao5, Susan Anenberg6, Alevtina Evgrafova7, Pelle Tejsner8, Arja Rautio9
1
Paul Scherrer Institute, Villigen PSI, Switzerland, 2LATMOS, Paris, France, 3University of Leeds, Leeds, United
Kingdom, 4University of Michigan, Ann Arbor, United States, 5University of Alaska - Fairbanks, Fairbanks, United
States, 6George Washington University, Washington, United States, 7University of Bern, Bern, Switzerland,
8
Aarhus University, Aarhus, Denmark, 9University of Oulu, Oulo, Finland

The Arctic is warming at a rate twice as fast as the global average; sea ice-free summers are possible by 2050.
Arctic exploration and exploitation is expected to increase due to the presence of significant oil and gas
resources. Although this provides an opportunity for socio-economic development of the region,
environmental risks would also be associated with such activities. Increase in air pollution and related health
and ecosystem issues would likely result from growth in industrial, transport, tourism and domestic activities.
Given this possible future scenario, it is important to close knowledge gaps of Arctic air pollution sources, their
societal and ecosystem impacts, and conceivable future development. A transdisciplinary study design is being
developed to define the mitigation options for local Arctic scenarios to advice on sustainable development. This
design requires a focus on:
(a) physico-chemical analysis of air pollution, its atmospheric processing and transport,
(b) human exposure assessment,
(c) community-based monitoring,
(d) environmental system analysis,
(e) development of mitigation scenarios together with citizens, policy-makers and other stakeholders, and
(f) meta-analysis in order to transfer the obtained knowledge and mitigation strategies to other Arctic
locations.
This is a cross-cutting effort by the international initiative 'Air Pollution in the Arctic: Climate Environment and
Societies' (PACES) and the International Arctic Science Committee.

1063
Wed_298_SH-5_1045
Promoting Arctic Urban Sustainability: Research and Education

Luis Suter1 (lsuter@gwu.edu), Dmitry Streletskiy1, Robert Orttung2, Marlene Laruelle2, Nikolay Shiklomanov1
1
George Washington University, Department of Geography, Washington DC, United States, 2George
Washington University, Elliott School of International Affairs, Washington DC, United States

Urban sustainability is an important research topic on the global scale. Organizations including the World Bank
and UN are leading efforts to measure sustainability in many global cities. Arctic cities, which are characterized
by accelerated climate-change, boom-bust economic cycles, diverse societies, and complex governmental
structures, have been overlooked within these initiatives. This presentation describes the results of an ongoing
project focused on assessing Arctic urban sustainability.
The Arctic Partnership for International Research and Education (PIRE) project has two major components. The
first is focused on the development of research tools to measure past, present and future levels of urban
sustainability. These data-driven tools are intended to help policymakers define and implement strategies,
compare cities, and describe the interactions between pillars of sustainability. The second component focuses
on increasing student engagement with Arctic themes. Initiatives include classroom-based digital storytelling
exchanges and university-level international field courses. Such pedagogic tools promote knowledge sharing
between students of various age groups, within the circumpolar region and outside it.
These components work together to enhance the quality, accessibility, and reach of knowledge about Arctic
cities, with applications for diverse Arctic stakeholders.

1064
Wed_299_SH-5_1070
Planning for Climate Change using Vulnerability Analysis Frameworks

Grace Ferrara1 (ferrarag@uw.edu), David Fluharty1, Kristin Laidre2,3

1
University of Washington, School of Marine and Environmental Affairs, Seattle, United States, 2University of
Washington, Polar Science Center, Applied Physics Laboratory, Seattle, United States, 3Greenland Insitute of
Natural Resources, Nuuk, Greenland

The continental shelf of the Eastern Bering Sea is home to some of the most productive fisheries in the world.
Over the last few decades, winter ice cover in the Bering Sea has retreated earlier and returned later each year,
changing the landscape of this diverse region. Species that rely on sea ice for critical life stages such as marine
mammals have already begun to experience the negative effects of habitat loss associated with a warming
climate. As sea ice projections over the coming decades become even more dire, subsistence communities
must face the possibility of the loss of the species they rely so heavily on for survival. As of yet, little is known
about how the Bering Sea's marine mammal-dependent communities will be impacted by the loss of
biodiversity that is expected in this region. This study uses two vulnerability analysis frameworks to
(1) identify the vulnerability of marine mammals in the Bering Sea to climate change,
(2) determine how these changes will affect indigenous populations dependent on subsistence harvesting in
the region, and
(3) assess the management institutions in place in and their capacity to provide an adequate response in order
to adapt to and mitigate the impacts of climate change.
We demonstrate how this interdisciplinary type of analysis can be used by Native Arctic communities and
resource managers to plan ahead for the impacts of climate change and develop management solutions aimed
at reducing ecological and social vulnerability.

1065
Wed_300_SH-5_1089
Economic Valuation of Changes in Ecosystem Services of the Arctic

Hyosun Kim1 (hyosun@kopri.re.kr)

1
Korea Polar Research Institute (KOPRI), Polar Policy, Incheon, Korea, Republic of

According to the recent observation by NOAA(US National Oceanic and Atmospheric Administration), 2015 was
the warmest year based on global average temperature since 1880. The air temperatures in the Arctic have
been rising at almost twice the global average and the extent and thickness of sea ice in the Arctic have
declined. The warming process in the Arctic is accelerating rapidly. These impacts of drastic change in sea ice
caused by climate change in the Arctic threaten the eco-system service and biodiversity in the Arctic.
This study intends to estimate the economic value on changes in eco-system services and biodiversity of the
Arctic caused by climate change. The result of the valuation indicates that the total benefit from improvement
of ecosystem in the Arctic ranges from 318.6 billion won to 715.9 billion won per annum. Replication scenarios
can be explored into two broad categories: scenarios in consideration of conflicts of different stakeholders and
scenarios based on wider or narrower definition of biodiversity in the Arctic.
Finally, based on those analysis, this study puts forward some feasible policy suggestions for strengthening the
extent of sustainability in the Arctic region.

1066
Wed_301_SH-5_1212
Tthe Antarctic Bases as Communication Links between Society and Environment

Matías Germán Belinco1 (matiasbelinco@gmail.com)

1
Instituto Antártico Argentino, Ciencias Sociales y Humanidades, San Martín, Argentina

This research tries to assess if the antarctic bases studied respond or not to the needs of the users. Architecture
can be read as the expression of a way of communicating between human collectives and the environment.
Design of spaces, distribution in the land, esthetics, the functionality and the historical context can explain the
set of relationships that were looking to develop those who carried out the buildings more than 50 years ago.
Actually, those who inhabit and use these stations condense different needs from those who have built them,
that´s why it is necessary to find the incompatibilities to take them into account in order to undertake reforms.
The methodology is based on the complex systemic approach, which consists of the theoretical construction of
systems, searching for their observable features as empirical anchorage and the analysis of the relationships
that structure them. The processes are differentiated by levels, so as to integrate them through the concrete
manifestations of their mutual determinations. Institutional histories, political contexts, regulations and
ecological determinants are analyzed. Data were collected in two scientific stations by interviews and
participant observation. The human relationship with nature makes antarctic bases emerge as technical sets of
artifacts and organizations, which, when studied, reveal systemic contradictions that were developed over
time, and are difficult to identify from daily management.

1067
Wed_302_SH-5_1215
"More Swans Lately": Indigenous Perspectives of Biodiversity Change in Yakutia

Stanislav Ksenofontov1 (stanislav.ksenofontov@geo.uzh.ch), Norman Backhaus1, Gabriela Schaepman-Strub2

1
University of Zurich, Geography, Zurich, Switzerland, 2University of Zurich, Environmental Biology, Zurich,
Switzerland

Global change drivers have altered biodiversity in the Arctic. As a result, many terrestrial, freshwater and
marine species have shifted their distribution, abundance and seasonal activities. Biodiversity change has
implications for local indigenous peoples since they depend on biodiversity for their traditional activities. There
is a lack of scientific records of biodiversity change in remote Arctic areas and thereby it is vital to incorporate
indigenous perspectives to scientific research. Therefore, this paper assesses indigenous perspectives of
biodiversity change caused by global change drivers in the Arctic region of the Republic of Sakha (Yakutia) in
North-Eastern Siberia, Russia.
The results of the study demonstrate that global change drivers have significantly affected Arctic Yakutian
biodiversity. Climate change has altered species distribution. Land use change has impacted plant and animal
species. New species are competing with the native ones, thereby some species have shifted their habitats.
Global change in Arctic Yakutia has either natural or anthropogenic reasons. Interviewees attribute changes in
biodiversity to technological development (abundance of vehicles as well as shipping), and natural processes
(e.g.increasing precipitation). The narrative of the predatory but sacred swan symbolizes the quandary
indigenous people of Arctic Yakutia find themselves in, when trying to deal with global change.

1068
Wed_303_SH-5_1342
Aquamess: Portraits of Garbage at the Earth´s Poles, Clean It

Carol devine1 (carol@caroldevine.org)

1
Independent Scholar, Toronto, Canada

Aquamess is a science art exhibit and study of marine debris found in the Arctic and Antarctic. The project
explores garbage samples from Svalbard (currently exhibited in the Canada Science and Technology Museum)
and includes multimedia materials, and scientific information about how marine debris circulates in oceans. It
also highlight polar and global initiatives to research, avoid, intercept and redesign the plastic economy for
marine ecosystem and human health.
Polar oceans store anthropogenic heat and carbon dioxide and help regulate global atmospheric temperatures.
Yet oceans are the trash bins of the planet with an estimated 8 million tonnes of plastics circulating today.
What are humans doing, what can and must we do better? This presentation is a blend of visuals, scientific
facts and questions to encourage dialogue.
I helped with a cleanup in Svalbard in 2015, collecting and exhibiting a survey of the marine debris and
documented in an exhibit Aquamess with portraits of the trash and landscapes. In 2016 in Antarctica I collected
a survey of garbage found there, which has not yet been exhibited.
We´re still learning about the volume, location and impact of marine debris in polar regions and in between.
But we know it´s harmful to wildlife and to organisms and us too when it breaks down and enters the food
chain.
Aquamess is presented in the context of international frameworks and initiatives to protect marine
environments significant for planetary health.

1069
Wed_305_SH-5_1434
The Dry Valley Ecosystem Resilience Programme: Overview and implementation

Stephen Craig Cary1 (caryc@waikato.ac.nz), Charles Lee1, Kurt Joy1, Ian Hawes1, Marwan Katurji2, Jayne Belnap3
1
University of Waikato, International Centre for Terrestrial Antarctic Research, Hamilton, New Zealand,
2
University of Canterbury, Christchurch, New Zealand, 3U.S. Geological Survey, Moab, United States

Although a consensus exists internationally that Antarctica is vulnerable to invasive species, climate change,
and increasing human presence and activity, there is a notable lack of objective measures that facilitate
evidence-based environmental management and clearly articulated conservation goals. The aims of the DryVER
programme are to deliver objective, evidence-based planning and management tools for the McMurdo Dry
Valleys (MDV). This interdisciplinary project's primary output will be a comprehensive understanding of the
resilience and sensitivity of MDV habitats to human impacts and invasive species. This understanding has been
gained through fieldwork, laboratory analyses and experimentation, remote-sensing and instrument-based
data collection, and climate and ecological modelling. The information is spatially explicit for direct integration
into an interactive GIS framework that will map and predict biodiversity, productivity, and sensitivities to
impact and invasion across the entire MDV region. Specific information has been obtained on the legacy of
previous human impacts and the efficacy of remediation. Importantly, a predictive, physics-based climate
model of the MDV will underpin our GIS framework, allowing us to project outcomes under climate change
scenarios. The research direction has been informed and enhanced by direct engagement with our primary end
users ensure clear pathways for implementation of the research outputs.

1070
Wed_306_SH-5_1462
Findings from a National Survey on Gender Equity in Australian Antarctic Science

Meredith Nash1 (meredith.nash@utas.edu.au), Mary-Anne Lea2, Justine Shaw3, Matt King4, Narissa Bax2, Hanne
Nielsen2
1
University of Tasmania, Sociology, Hobart, Australia, 2University of Tasmania / Institute for Marine and
Antarctic Studies, Hobart, Australia, 3University of Queensland, Biological Sciences, Brisbane, Australia,
4
University of Tasmania, School of Land and Food, Hobart, Australia

Although 60% of polar early career researchers are women, there is little available data on gender equity in
polar science (Strugnell et al 2016). Existing research primarily tracks publications to measure women's STEMM
participation. This approach risks ignoring disproportionate rates of gender bias and sexual harassment
experienced by women. For instance, women in polar research are 3.5 times more likely to experience
harassment than men (Clancy et al 2014).
This paper reports findings from an online survey designed to1) identify socio-demographic characteristics of
women working in Australian Antarctic science and 2) detail and contextualize their experiences of scientific
research cultures/field-based research. Survey results indicate that 64% of respondents had been sexually
harassed during their career, and that most women did not report sexual harassment at the time. Other
experiences of reported gender bias included lack of appropriately fitted Antarctic clothing; fewer leadership
opportunities; lack of career mobility; and penalties associated with caring responsibilities. Such findings
indicate a pressing need to address significant structural barriers to women's career advancement and
leadership opportunities in polar research. They also highlight the problematic contextual and relational
conditions that put women at high risk of sexual harassment in the field. These findings can be used to inform
long-term responses to gendered inequality in the field.

1071
Wed_307_SH-5_1612
Leadership in Extreme and Isolated Environments: Perceptions from Antarctica

Daleen Koch1 (daleen.koch@gmail.com)

1
University of Stellenbosch, Business School, Economic and Management Sciences, Belville, South Africa

The extreme, isolated and confined environment encountered at Antarctic stations provide unique challenges
to management and leadership. The study investigated effective leadership at Antarctic stations, as well as the
difference in perceptions based on gender, expedition experience, and the occurrence of emergencies or
interpersonal conflict.
The findings were gathered from 180 returned expeditions who participated in the South African National
Antarctic Programme from 1961 to 2015. The research collected primary data, using a standardised
questionnaire as a survey instrument. The results were analysed using descriptive statistics.
The analysis showed that an effective station leader maintains a personal bond with individuals, maintains a
balance between active and passive regulation of the emotional well-being of team members, makes an effort
to create and sustain a positive team climate, and maintains a moderate involvement in professional duties of
the team. Gender, experience and events at the station influenced perceptions of the station leader's role in
maintaining a personal bond, individual well-being, the team climate and intervention in professional duties.
This research report is of value to National Antarctic Programs, space exploration missions, as well as to
organisations in distress, who find themselves in environments that are harsh and unforgiving, similar to the
isolated and extreme environments at an Antarctic station.

1072
Wed_308_SH-5_2395
The Afterlives of Mines: A Comparative Study in the Arctic

Camilla Winqvist1 (camwin@kth.se)

1
KTH Royal Institute of Technology, Division of History of Science, Technology and Environment, Stockholm,
Sweden

In this paper I will present my dissertation project within the framework of REXSAC - Resource Extraction and
Sustainable Arctic Communities. The objective of my research is to explore how stakeholders in different parts
of the Arctic have dealt with mining legacies - both material and immaterial - during different time periods and
in different places. I will compare former mining areas in three regions; Northern Sweden, Svalbard and
northern Canada. Stakeholders in all of these regions have had to deal with a multitude of legacies from
mining, from both recently closed mines as well as legacies from older mines. The operations are gone, but
their legacies still linger in the collective memories of the local communities and in the landscape. My approach
will be multidisciplinary, combining theory and method from critical heritage studies, history of technology,
economy, human geography and social/cultural anthropology. I will primarily work with methods such as
archival research and interviews, as well as archaeological field work at industrial and post-industrial sites in
the Arctic.

1073
Wed_310_TE-1_107
Autonomous Thermal Sonde for Subglacial Lakes Exploration

Pavel Talalay1 (ptalalay@yahoo.com), Youhong Sun1, Yuansheng Li2, Guoping Li3, Jingbiao Liu4, Qifeng Cui5,
Pinlu Cao1, Alexey Markov1, Jixin Wang1, Jianhua Wang1, Rusheng Wang1, Dongliang Wang5, Xiaopeng Fan1, Nan
Zhang1, Haibin Yu4, Shilin Peng4, Sheng Wu6, Yang Yang1, Bing Li1, Ting Wang1, Yongwen Liu1, Yanji Chen1,
Yunchen Liu1
1
Jilin University, Changchun, China, 2Polar Research Institute of China, Shanghai, China, 3Nanjing Institute of
Astronomical Optics & Technology, National Astronomical Observatories, CAS, Nanjing, China, 4Hangzhou
Dianzi University, Hangzhou, China, 5Research Institute of System Engineering, Shanghai Aerospace Bureau,
Shanghai, China, 6National Ocean Technology Center, Tianjin, China

To date, more than 400 relatively small subglacial reservoirs and several large lakes were discovered in
Antarctica. Certainly subglacial lakes exist in Greenland. In recent years, different approaches were taken to
access and directly sample subglacial water environments. RECoverable Autonomous Sonde (RECAS) allows to
access subglacial lake when water remains isolated from the modern ice sheet surface during sampling. The
thermal drill can melt a hole to ice sheet bottom and is able to move upwards. It includes two electrically
powered thermal drill bits located at the upper and lower ends of the sonde, heated body, control system,
sampling chamber and coiling system. All down-hole RECAS components will be sterilized prior to deployment.
The melted water is not recovered from the hole and it refreezes behind the sonde. The power and signal line
is released from the coil inside the sonde. When sampling and monitoring are complete, the coil motor is
activated and the top drill bit is powered. It is proposed that the research personnel leave the site after RECAS
deployment and the sonde operates as a fully autonomous system. The power is provided by no-live-operator
diesel engine generators. The first laboratory tests of sonde prototype are scheduled for early 2018, field tests
are planned in season 2018-2019, in the area of Chinese Antarctic station Zhongshan.

1074
Wed_311_TE-1_934
Comparing Data Derived from Animal-borne and Argo Observations

Anne M. Treasure1,2 (anne.m.treasure@gmail.com), Isabelle J Ansorge2, Marcel du Plessis2, Marthán N. Bester1,

P.J. Nico de Bruyn1
1
University of Pretoria, Mammal Research Institute, Department of Zoology & Entomology, Pretoria, South
Africa, 2University of Cape Town, Department of Oceanography and Marine Research Institute (Ma-Re), Cape
Town, South Africa

The physical structure of the Southern Ocean (SO) plays a crucial role in the global ocean and climate system.
Nevertheless, many areas of the SO have remained relatively poorly sampled. Oceanographers often rely on
ship-based measurements to track water masses; however, these data are scarce in the SO and seasonally
biased. A significant enhancement is Argo, which is a global array of temperature/salinity profiling floats.
However, Argo does have limitations in Antarctica - for example, there are few Argo profilers south of 60S due
to sea ice. An important addition to data collection methods is conductivity-temperature-depth satellite relay
data loggers (CTD-SRDLs) deployed as animal-borne platforms to sample vertical temperature and salinity
profiles. While studies have used Argo and CTD-SRDL data, little is known about how well the two data sources
complement each other both spatially and temporally, and how comparable they are in data quality. Therefore,
this study examines data from CTD-SRDLs and Argo to assess the comparative value of the data sources to
increasing our understanding of the ocean dynamics in the South African sector of the SO. This will help to
improve our confidence that seals can be used to comprehensively sample regions previously restricted to ship-
based observations.

1075
Wed_312_TE-1_376
UAS for Evaluating Retrievals and Model Performance at High Latitudes

Gijs de Boer1 (gijs.deboer@colorado.edu), Dale Lawrence1, Amy Solomon1, Janet Intrieri2, Dave Turner2, Steven
Borenstein1, Douglas Weibel1
1
University of Colorado, Boulder, United States, 2NOAA Earth System Research Laboratory, Boulder, United
States

Over the past several years, scientists have deployed to Oliktok Point, Alaska to make atmospheric
measurements as part of the Evaluation of Routine Atmospheric Sounding measurements using Unmanned
Systems (ERASMUS) and Inaugural Campaigns for ARM Research using Unmanned Systems (ICARUS)
campaigns. These deployments included operations using the University of Colorado DataHawk UAS. The
DataHawk was configured to make measurements of atmospheric thermodynamics, wind and surface
temperature.
Over these deployments, hundreds of profiles of lower atmospheric temperature have been derived between
the surface and cloud base. These profiles are being used to help evaluate the performance of retrievals
conducted using measurements from ground-based remote sensors. As a part of this presentation, we will
show results from this evaluation and provide insight into the strength of using these sorts of platforms for this
purpose.
Additionally, during a recent October deployment, the team witnessed the development of near shore sea ice.
In this presentation, we will give an overview of measurements obtained during this time and how they were
used to better understand freeze up processes in this coastal environment. Additionally, we will provide insight
into how these platforms are being used for evaluation of a fully-coupled sea ice forecast model. Finally, we will
provide details on planned 2017 Arctic unmanned aircraft operations by the US DOE, NOAA and others.

1076
Wed_313_TE-1_472
New Set-up of ALADINA for Atmospheric Studies in Polar Region

Alexander Peuker1 (a.peuker@tu-braunschweig.de), Barbara Altstädter1, Falk Pätzold1, Lutz Bretschneider1,

Konrad Bärfuss1, Stefan Nowak1, Ulf Bestmann1, Astrid Lampert1
1
Technische Universität Braunschweig, Institute of Flight Guidance, Braunschweig, Germany

The unmanned aerial system ALADINA (Application of Light-Weight Aircraft for Detecting In-situ Aerosol),
based on a funded project of the German Research Foundation, is operated for atmospheric research at the
Institute of Flight Guidance since 2013. The total amount of more than 200 measurement flights at different
locations, prove the high usability of the aircraft. In order to obtain the high quality of atmospheric boundary
layer research in harsh Arctic conditions, ALADINA was re-engineered and newly designed for the planned
campaign in Ny-Ålesund for spring 2018. The system was insulated to avoid cooling of batteries and to
guarantee a flight endurance of about 30-40 min. In addition, the modular payload is heated constantly to
temperatures of approximately 30°C, so that all instrumentation can run properly. Further, the system was
equipped with a new autopilot system as well as new telemetry to adapt the frequency limitation of less than 2
GHz, due to a sensitive radio telescope on site. Besides, a modular package for batteries was implemented in
order to change the batteries by minimal outlay and in a short time period so that flight missions can be
performed continuously. With the presentation of the new set-up, we fulfil the expertise to show a reliable
system that is optimal prepared for studies in polar region.

1077
Wed_314_TE-1_536
Remote Assesment of Albedo by Photographic Equipment Based on UAV

Nikita Kuprikov1 (nkuprikov@gmail.com), Boris Ivanov2, Danila Zhuravskiy3, Mikhail Kuprikov3, Sergey Kashin4
1
Polar Initiative, Moscow, Russian Federation, 2Arctic and Antarctic Research Institute, St. Peterburg, Russian
Federation, 3Moscow Aviation Institute (National Research University), Moscow, Russian Federation, 4Arctic &
Antarctic Scientific-Research Institute, St. Petersburg, Russian Federation

A method for determining of albedo was developed and tested with the combined use of radiation and a photo
device. The proposed original method is based on the use of available measuring techniques and is intended
primarily to reduce the time required to obtain albedo values on large areas. The theoretical possibility of using
the proposed technical solution and its testing in the field using UAV are considered. Based on the results
obtained, conclusions are drawn about the possibility of using the proposed schematic diagram, the potential
for its improvement and application for the data collection. Mean vile that simple method for determining the
albedo of the underlying surface give the opportunity to collect data in situ non-stop, what led us to big data of
underlying surface, what is a good basis for future researchers and projects. Method for determining the
albedo of the underlying surface gives the chance to work with photos for getting results. The obtained results
of the research allow to draw a conclusion about the high potential of the proposed technical solution, not only
for carrying out data collection and observing albedo, but also for designing new devices based on the
proposed principles. The change in dimensions and the possibility of installation on UAV made it possible to
develop a new method of surveying. The developed method provides the ability to quickly and qualitatively
collect data on large areas with the help of advanced aircraft technology.

1078
Wed_315_TE-1_553
Unmanned Aerial Systems over Sea Ice during the SeaState and PIPERS Expeditions

Guy Williams1,2 (guy.darvall.williams@gmail.com), Darren Turner3, Ted Maksym4, Hanumant Singh5, Stephen
Ackley6
1
University of Tasmania, Institute of Marine and Antarctic Studies, Hobart, Australia, 2Antarctic Climate &
Ecosystems Cooperative Research Centre, Hobart, Australia, 3University of Tasmania, TerraLuma UAV Facility,
Hobart, Australia, 4Woods Hole Oceanographic Institution (WHOI), Woods Hole, United States, 5Northeastern
University, Electrical and Computing Engineering, Boston, United States, 6University of Texas at San Antonio,
San Antonia, United States

In recent years we have deployed multi-rotor and fixed wing Unmanned Aerial Systems (UAS) in support of
Autonomous Underwater Vehicles (AUV) missions beneath sea ice in both the Arctic (ONR DRI SeaState -
Beaufort Sea, Oct 2015) and Antarctic (NBP1704 PIPERS - Ross Sea, Apr-Jun 2017). Despite significant logistic
and meteorological challenges in the polar environment, our UAS project has developed into a cost-effective
and integral component of the modern sea ice research expedition. Using ´off-the-shelf´ multi-rotors and a
delta-wing photogrammetry UAS developed by the TerraLuma facility at the University of Tasmania, we
achieved icebreaker-based and ice station launch and recoveries with over ten hours of missions. These
missions collected visual imagery for ice reconnaissance, floe-size distribution over marginal ice zones and 3D
surface topography of larger floes in concert with AUV ice draft mapping below. New fieldwork is planned for
the Antarctic marginal ice zone that will incorporate additional thermal IR and hyperspectral capabilities,
together with an evolution towards longer missions beyond visual line of sight, once again in tandem with long-
range AUV missions.

1079
Wed_316_TE-1_569
Intricacies of Making Measurements in Supercooled Water

Natalie Robinson1 (natalie.robinson@niwa.co.nz), Craig Stevens1,2, Brett Grant1, Matt Walkington1, Mike
Williams1
1
National Institute for Water and Atmospheric Research, Marine Physics, Wellington, New Zealand, 2University
of Auckland, Physics, Auckland, New Zealand

For the past 15 years, New Zealand researchers have been investigating interactions between the ice and
ocean, principally in McMurdo Sound, Ross Sea. During this time, the range and technical capability of
oceanographic instruments has increased dramatically. However none of the standard oceanographic
equipment has been designed to incorporate process near the phase-change limit.
Here we document our experience teasing data from ocean that is near, and often below, in-situ freezing
temperature, as a set of principles of operation. We discuss the difficulties routinely experienced, and suggest
mitigation strategies for these. We also highlight some of the curiosities of working in crystal-laden water, and
the surprising results that flow from detailed examination of these data.
Finally we introduce the 'Supercool-ometer' - a modified SeaBird CTD that incorporates a heating chamber and
second set of sensors designed to characterise the effects of ice formation (and/or melt) inside the instrument.
We will outline the development to date of the supercool-o-meter and highlight results from three recent
deployments in significantly supercooled water.

1080
Wed_317_TE-1_763
Robotic Snow-firn Sequence Density Profiler

Victor Zagorodnov1 (victor.zagorodnov@gmail.com)

1
Cryosphere Research Solutions LLC, Columbus, United States

Non-coring electro-thermal drills, often called as Hotpoint drills (HPD), allowed fast penetration rate (up to 25
m/h) at relatively low power. As lab and field experiments show penetration rate of the HPD is proportional to
snow-firn-ice density. Continuous registration of the HPD penetration rate allows one to obtain continuous
density profile up to a few dozen meters of depth. Density resolution of the HPD is close to 5 kg m-3 while
depth resolution is about 10 mm. Snow-firn density profiling system includes: 1) HPD, 2) instrumented rig, 3)
data acquisition and power source. The system is called Speedograph - penetration rate/speed recorder.
Robotic version of the Speedograph can operate as addition to glacier surface moving autonomous platform.
The robotic Speedograph can be programmed to perform density profiling as calibration option to snow-firn
radar. Required power for the robotic version of the Speedograph is 300-800 W. Estimated weight of
Speedograph is about 6 kg while total volume is about 0.02 m-3.

1081
Wed_318_TE-1_815
Wind and Turbulence Measurements with RPA during the ISOBAR Campaign

Alexander Rautenberg1 (alexander.rautenberg@uni-tuebingen.de), Stephan Kral2, Joachim Reuder2, Jens

Bange1
1
Universität Tübingen, Environmental Physics, Tübingen, Germany, 2University of Bergen, Geophysical Institute,
Bergen, Norway

The remotely-piloted fixed-wing aircraft MASC (Multi-purpouse Airborne Sensor Carrier) from the
environmental physics working group of the University of Tübingen was used to investigate physical processes
in the ABL during the ISOBAR (Innovative Strategies for Observations in the Arctic Atmospheric Boundary Layer)
campaign over the frozen Baltic Sea in northern Finland in February 2017. MASC is equipped with a high
resolution thermodynamic sensor package including a five-hole probe and IMU for wind vector measurements.
During the three week long field period also ground based weather stations, remote sensing systems (Lidar and
Sodar) and a small fixed-wing system (SUMO) for atmospheric profiles up to 1800 m were applied. Intensive
observational periods including nocturnal flights with MASC were performed. This talk will focus on results for
the wind, turbulence and flux measurements from some flights with MASC. The strategy of the measurements
as well as the quality of the data and comparisons will be addressed. Furthermore future adaptions and
developments of the measurement system and the remotely-piloted aircraft for polar use will be presented.

1082
Wed_319_TE-1_846
Advances in Sub-ice Navigation: AUV Tests in Overhead Environments

Kristof Richmond1 (kristof.richmond@stoneaerospace.com), William Stone1, Christopher Flesher1, Laura

Lindzey1, Neal Tanner1, Victoria Siegel1
1
Stone Aerospace, Del Valle, United States

Beyond the obstacles to navigation presented by underwater operations (e.g. the lack of continuous, precise
external aiding from GPS), sub-ice navigation presents unique challenges to an autonomous vehicle. The
overhead environment prevents essentially all external navigation aiding, and severely limits ingress and egress
locations for deployment, recovery, or data transfer. In such environments (e.g. under sea ice, ice shelves, or in
sub-glacial lakes), existing methods of exploration autonomy eventually break down as highly-limited sensor
range and unbounded navigation drift lead to the inability of the vehicle to return to the point of origin for
recovery, or to return to a site of interest following an initial broad survey. Groundbreaking work on
overcoming these limitations using the local environment as a navigation reference was conducted as part of
the NASA DEPTHX project (2003-2007). A distant, miniaturized successor to DEPTHX, known as SUNFISH, has
been tested by Stone Aerospace in the overhead environment of underwater caves in northern Florida, acting
as a surrogate for complex sub-glacial lakes. We present field test results of SUNFISH on new autonomous
behaviors and methods to navigate such overhead environments with sufficient precision to allow the AUV to
approach or contact objects of interest; provide a 3D map updated in real time; and to plan paths for egress
and exploration despite map inconsistency―all in the absence of any external navigational aiding.

1083
Wed_320_TE-1_923
Marine Mammals Exploring the Oceans Pole to Pole: Review of the MEOP Consortium

Anne M. Treasure1,2 (anne.m.treasure@gmail.com), Fabien Roquet3, Isabelle J. Ansorge2, P.J. Nico de Bruyn1
1
University of Pretoria, Mammal Research Institute, Department of Zoology & Entomology, Pretoria, South
Africa, 2University of Cape Town, Department of Oceanography and Marine Research Institute (Ma-Re), Cape
Town, South Africa, 3Stockholm University, Department of Meteorology (MISU), Stockholm, Sweden

Polar oceans are poorly monitored despite the important role they play in regulating Earth's climate system.
Marine mammals equipped with biologging devices are now being used to fill the data gaps in these logistically
difficult to sample regions. Since 2002, instrumented animals have been generating exceptionally large data
sets of oceanographic CTD casts (>500,000 profiles), which are now freely available to the scientific community
through the MEOP data portal (http://meop.net). MEOP (Marine Mammals Exploring the Oceans Pole to Pole)
is a consortium of international researchers dedicated to sharing animal-derived data and knowledge about the
polar oceans. Collectively, MEOP demonstrates the power and cost-effectiveness of using marine mammals as
data-collection platforms that can dramatically improve the ocean observing system for biological and physical
oceanographers. Here, we review the MEOP program and database to bring it to the attention of the
international community.

1084
Wed_321_TE-1_997
Meander-driven Export of Shelf Waters in the West Antarctic

Alexander Brearley1 (jambre@bas.ac.uk), Michael Meredith1, Hugh Venables1, Carlos Moffat2, Michael
Dinniman3
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Delaware, School of Marine Science and
Policy, Newark, United States, 3Old Dominion University, Centre for Coastal Physical Oceanography, Norfolk,
United States

The West Antarctic Peninsula (WAP) has undergone rapid atmospheric warming occurring between the 1950s
and the late 1990s, with significant reductions in the duration and thickness of sea ice and rapid thinning of ice
shelves and glaciers. Many of these changes are driven by a warming Circumpolar Deep Water (CDW) layer, the
deep water mass that originates in the open Southern Ocean and supplies heat to the WAP shelf.
Consequently, much attention has focused recently on the delivery of heat to the shelf through mechanisms
including eddies, and flow inertia, particularly at deep glacially-carved troughs such as Marguerite Trough (MT).
However, less attention has been focused on the export of colder shelf waters that compensates the inflow of
CDW. Here, we use ocean glider data from 2015 to examine the hydrographic structure of a quasi-permanent
meander found close to the mouth of MT, from which cold-core cyclonic eddies detach and export dense water
into the Southern Ocean. Rossby numbers of these features (0.05-0.1) are consistent with geostrophic
dynamics. The circulation structure observed is consistent with an onshore transport of CDW (by small 5-10 km
eddies) towards the northeastern parts of the trough, and an offshore transport of colder, fresher waters
towards the southwestern edge. Potential vorticity fields from the gliders and an ocean model are used to
determine the instability mechanisms that drive the production and separation of eddies from the boundary
current.

1085
Wed_322_TE-1_1066
Measurements of Snow Properties on Ice Sheets with a Polar Robot

Joshua Elliott1, Austin Lines1, Mary Albert2 (mary.r.albert@dartmouth.edu), Laura Ray1

1
Dartmouth College, Hanover, NH 03755, USA, Thayer School of Engineering, Hanover, United States,
2
Dartmouth College, Thayer School of Engineering, Hanover, United States

Snow specific surface area and optical grain size of snow on the polar ice sheets are key parameters for
measuring the atmospheric interactions of snow, monitoring metamorphosis in response to environmental
change, and facilitating interpretation of remotely sensed data. Making the measurement by a ground-based
robot can save time over human deployment, and eliminates the amount of fuel that would be needed if the
instrument were towed by snowmobile. We describe robotic deployment of an instrument that uses a
shortwave infrared camera with changeable optical band pass filters (centered at 1300 nm and 1550 nm) that
can be used to quickly measure the average SSA. The device and method are compared with calculations made
from measurements taken with a field spectral radiometer, and performance of the robot is documented.

1086
Wed_323_TE-1_1071
Mapping Penguins and Blue-eyed Shags at Remote Islets by Fixed Wing UAV

Christian Pfeifer1 (christian.pfeifer@think-jena.de), Hans-Ulrich Peter2, Marie-Charlott Rümmler2, Osama

Mustafa1
1
ThINK - Thuringian Institute of Sustainability and Climate Protection, Jena, Germany, 2Friedrich Schiller
University, Institute of Ecology, Jena, Germany

The rocky northwestern coast of Nelson Island and the southwestern coast of King George Island (South
Shetland Islands) is known as a breeding area for chinstrap penguins. However, due to its difficult accessibility
the last published population counts date back to the 1980s. To obtain current, accurate and complete data,
several flights with a UAV have been carried out during December 2016 and January 2017. The 30 km long
investigation area ranges from Smilets Point at Nelson Island to Sygit Point at King George Island. In that area
all larger islets have been mapped by a micro fixed wing UAV equipped with an optical camera. The images
have been processed to orthophotomosaics with a ground resolution of about 2 cm. In these mosaics more
than 200 rocks, islets or rock outcrops have been surveyed for penguin colonies or other breeding birds. We
found 26 sites with breeding chinstrap penguins (Pygoscelis antarctica) and four sites with breeding blue-eyed
shags (Phalacrocorax atriceps), some of them recorded for the first time. For all sites breeding pair numbers of
the penguin colonies were derived by counting the individuals manually from orthophotomosaics and using a
correction factor. For blue-eyed shags the breeding pair numbers were derived by counting the nests directly.
As a result the most complete and accurate dataset on the distribution and numbers of breeding chinstrap
penguins and blue-eyed shags in the investigated area was created and will be presented.

1087
Wed_324_TE-1_1115
Polar Boundary Layer Aerosol Observed with ALADINA in Ny-Ålesund

Barbara Altstädter1 (b.altstaedter@tu-braunschweig.de), Falk Pätzold1, Ralf Käthner2, Birgit Wehner2, Markus
Hermann2, Konrad Bärfuss1, Claudio Crazzolara3, Andreas Platis3, Jens Bange3, Astrid Lampert1
1
Technische Universität Braunschweig, Institute of Flight Guidance, Braunschweig, Germany, 2Leibniz Institute
of Tropospheric Research, Leipzig, Germany, 3Eberhard-Karls Universität Tübingen, Zentrum für Angewandte
Geowissenschaften, Tübingen, Germany

The unmanned research aircraft ALADINA (Application of Light-Weight Aircraft for Detecting In-situ Aerosol)
was extensively used during field studies in Melpitz (Germany) and Savè (West Africa) since 2013. The
performance of more than 200 measurement flights and several publications support the reliability of the
system. The main focus of the project is on the variability of aerosol particles depending on different
atmospheric boundary layer conditions. For future perspectives, a new aircraft campaign is planned for spring
2018 at the local airfield in Ny-Ålesund (Spitsbergen), in association with project partners of Leibniz Institute of
Tropospheric Research and Eberhard Karls University Tübingen, as well further international collaborators. The
goal of the campaign is to study the horizontal and vertical distribution of aerosol particles in the particle
diameter from around 5 nm to 5 µm between ice surfaces up to the height of around 1000 m. In addition, one
aethalometer is installed, in order to investigate black carbon mass concentrations in a generally clean
environment that is, however, temporarily affected by ship emissions. Due to harsh Arctic conditions by low
temperatures and possible icing, the sensitive aerosol instrumentation had to be adapted properly and the new
paylaod will be presented. Further, the performed campaign will be introduced and first results of the pending
application with the main focus on polar new particle formation will be shown.

1088
Wed_325_TE-1_1170
Using an AUV and a Buoyant Rover for in situ under-ice Observations

Ian Fenty1 (ian.fenty@jpl.nasa.gov)

1
NASA Jet Propulsion Laboratory, Pasadena, United States

Melting tidewater glaciers and ice shelves from the Greenland and Antarctica Ice Sheets are now substantially
contributing to global sea level rise. The most significant submarine melt acceleration has taken place deep
within ice shelf cavities near the grounding zones where glaciers begin to float beneath more than 500 m of ice
and 10-100 km or more from the open ocean. There is a need for long-range, long-duration, in situ under ice
exploration and data collection in these environments to determine how warming ocean waters are affecting
ice shelf stability. Scientists and engineers at JPL are developing new technologies to enable autonomous
exploration and data collection in these unexplored ice shelf cavities with the objective of improving our
fundamental understanding of their physical, chemical, and biological characteristics.

1089
Wed_326_TE-1_1231
Mapping of Antarctic Wildlife by Drones

Jakob Maercker1, Max Haucke1, Stefan Knetsch1, Hans-Ulrich Peter2, Christian Pfeifer1, Osama Mustafa1
(osama.mustafa@think-jena.de)
1
ThINK - Thuringian Institute of Sustainability and Climate Protection, Jena, Germany, 2Friedrich Schiller
University Jena, Institute of Ecology, Jena, Germany

Changes in size and distribution of Antarctic wildlife populations are difficult to monitor. Breeding sites of
seabirds are often located at remote and difficult to access locations while seals can be found at almost all
parts of the Antarctic coast. Therefore, by classical methods a high effort is necessary to conduct detailed
surveys of larger areas with often incomplete results. Besides, mapping or counting these populations directly
implies a significant disturbance of the animals. Thus, the use of drones provides an option to map colonies and
aggregations of seabirds and seals.
We studied the feasibility of mapping Southern Giant Petrels (Macronectes giganteus), Cape Petrels (Daption
capense) and Kelp Gulls (Larus dominicanus) as well as different Antarctic seal species by use of an electric
powered quadrocopter micro drone. While Giant Petrels often breed at remote islets and are known to be very
sensitive to disturbance, many breeding sites of Cape Petrels and Kelp Gulls are located at steep inaccessible
rocks. Seal aggregations can be found at many sites almost everywhere along the Antarctic coast. The study
was performed at different sites of Fildes Peninsula (King George Island, South Shetland Islands).
We present the results of this survey regarding quality, effort and disturbance. Advantages and disadvantages
of different methodological settings will be discussed.

1090
Wed_327_TE-1_1363
The Dry Valley Summertime Atmospheric Boundary Layer Evolution

Marwan Katurji1 (marwan.katurji@canterbury.ac.nz), John Cassano2,3, Dion O'Neale4, Peyman Zawar-Reza1

1
University of Canterbury, Geography, Christchurch, New Zealand, 2University of Colorado, Department of
Atmospheric and Oceanic Science, Boulder, United States, 3University of Colorado, Cooperative Institute for
Research in Environmental Sciences, Boulder, United States, 4University of Auckland, Department of Physics and
Te Pūnaha Matatini, Auckland, New Zealand

The Dry Valleys are snow-free polar deserts surrounded by patches of frozen lakes and glaciers. The arid
environment limits life to microbial subsurface communities, and the complex terrain allows the development
of localized meteorology modulated by surface-atmospheric energy fluxes that are largely controlled by the
insolation diurnal profile and topographic shading.
Two custom built fixed-wing small UAVs were used to sample the atmospheric boundary layer near Lake Vanda
of the Wright Valley. The objectives of the January 2017 field campaign was to understand the diurnal
variability of the mean velocity, temperature, and turbulence from the surface up to 1000m, which influence
the microclimate spatial variability of the Dry Valleys. The meteorological payloads consisted of air
temperature, pressure, relative humidity sensors, GPS and a 5-hole probe for mean wind and turbulence
measurements at 50Hz. We conducted a total of 19 vertical profiling flights over a period of 6 days covering a
wide range of stable, unstable and transitioning boundary-layers. This data provides a unique opportunity to
understand the time scales of the thermodynamic evolution of the near-surface atmosphere in a region where
mountain meteorology directly influences available melt-water for biodiversity.

1091
Wed_328_TE-1_1371
Preliminary Results of an Experimental Survey in Kongsfjorden Area (June 2017)

Viviana Piermattei1,2, Alice Madonia1,2, Simone Bonamano1,2, Riccardo Martellucci1,2, Gabriele Bruzzone3
(gabriele.bruzzone@ge.issia.cnr.it), Massimo Caccia3, Roberta Ferretti3, Angelo Odetti3, Maurizio Azzaro4,
Marco Marcelli1,2
1
University of Tuscia, Civitavecchia, Italy, 2CMCC, Lecce, Italy, 3CNR-ISSIA, Genova, Italy, 4CNR-IAMC, Messina,
Italy

During the last years polar oceans showed the effects of global climate change, with important variations of
physical, chemical and biological characteristics. Global warming causes a significant reduction in sea-ice
thickness and in tidewater glaciers extension during late summer and autumn intensifying the input of
freshwater and sediments, causing a reduction of water transparency as a consequence of increasing water
turbidity. These processes have an impact on phytoplankton biomass life cycle, especially in the Kongsfjorden
area, Svalbard Archipelago, that is relatively warmer than other Arctic areas. An oceanographic experimental
survey was performed during June 2017 to study the ice melting of the tidewater glaciers in the Kongsfjord
making use of traditional and innovative instrumentations. Two 'state of the art' probes, Idronaut 305 plus and
Cyclops-7F™ Turner Design, and a new low-cost probe were installed onboard an innovative unmanned marine
vehicle, PROTEUS (Portable RObotic TEchnology for Unmanned Surveys). The survey was carried out along
Kronebreen and Blomstrandbreen glaciers, where a series of transects extending from a support boat up to the
direct front of the glaciers allowed the acquisition of surface water temperature, conductivity, dissolved
oxygen, chlorophyll a, fluorescence and turbidity. This work shows the preliminary results of data acquired by
the different probes, with a particular focus on the comparison between traditional and innovative ones.

1092
Wed_329_TE-1_1391
ALICE - A Remotely Piloted air Sampling System for Methane Isotopic Analysis

Falk Pätzold1 (f.paetzold@tu-braunschweig.de), Thomas Krüger1, Konrad Bärfuss1, Barbara Altstädter1, Stefan
Nowak1, Ellen Damm2, Josefa Verdugo2, Astrid Lampert1
1
Technische Universität Braunschweig, Institute of Flight Guidance, Braunschweig, Germany, 2Alfred Wegener
Institute Helmholtz Center for Polar and Marine Research, Marine Geochemistry, Bremerhaven, Germany

Methane is a very effective greenhouse gas, but the role of the Polar Regions in the methane budget and its
sources there is subject to discussion. The sparse surface network data and satellite data indicate significant
source regions above the polar oceans. The remotely piloted system (RPAS) of quadrocopter type ALICE was
developed at the Technische Universität Braunschweig for taking air samples to study methane isotopic
composition related to different polar atmospheric boundary layer conditions above sea ice and open water.
The quadrocopter ALICE has a maximum take-off weight of 25 kg and a large payload capacity of 18 kg. The
thrust to weight ratio is high compared to other RPAS to operate in wind speeds up to 70 km h-1. The scientific
subsystem consists of different meteorological sensors and twelve 100 ml glass bottles for air sampling. Profiles
with high resolution meteorological data and air samples at operator selected altitudes up to 1000 m can be
obtained. The initially tested prototype was field operated for the first time during Polarstern cruise PS109
(ARK-XXXI/4), so-called GRISO (Greenland ice sheet/ocean interaction) from 12 September until 14 October,
2017. During this proof of concept expedition the safe shipborne operation and system functionality in harsh
polar environment was demonstrated successfully. In this presentation, the design of the RPAS and the
scientific payload will be introduced and functionality discussed based on flight test results.

1093
Wed_330_TE-1_1480
Micro-Tethers for Under Ice Robotics

Michael Jakuba1 (mjakuba@whoi.edu), Andrew Bowen1, Christopher German1, Louis Whitcomb2, James
Kinsey1, Masako Tominaga3
1
Woods Hole Oceanographic Institution, Engineering, Woods Hole, United States, 2Johns Hopkins University,
Mechanical Engineering, Baltimore, United States, 3Texas A&M University, Geology and Geophysics, College
Station, United States

Robotic vehicles have proven valuable scientific assets in subsea polar environments; yet the ability of fully
autonomous vehicles (AUVs) to physically interact with the seafloor or ice remains limited or non-existent.
Remotely operated vehicles (ROVs) routinely execute these activities in ice-free waters. Real-time data access,
via the ROV's tether, enables pilots to execute complex interaction tasks and to react immediately to the
unknown or unanticipated, a capability that could prove especially important in the relatively unexplored polar
environment. However, conventional tethering systems require the host vessel to hold station above the
vehicle, a constraint that makes operating conventional ROVs in ice difficult. Micro-tethers, small diameter
unarmored fiber-optic cables, alleviate this constraint. Micro-tethers transmit only communication signals and
not electrical power, thus vehicles that use them must carry their own batteries and are referred to as
AUV/ROV hybrids. We have adapted a 250 µm diameter micro-tether system, 20 km in length, to a purpose-
built under-ice hybrid ROV called NUI. In 2016 we demonstrated the ability to operate NUI on the Arctic sea
floor at 87 N, over a km away from the host vessel, on a dive that obtained high-definition (HD) video imagery
of the seafloor and acquired targeted samples using NUI´s dexterous manipulator arm. We discuss the micro-
tethering system, NUI, and potential future polar applications of each.

1094
Wed_331_TE-1_1511
Water-air Column Characterisation in Arctic Region using Unmanned Vehicles

Roberta Ferretti1, Massimo Caccia1, Angelo Odetti1,2 (angelo.odetti@ge.issia.cnr.it), Andrea Ranieri1, Federico
Carotenuto3, Alessandro Zaldei3, Angelo Pietro Viola4, Gabriele Bruzzone1
1
CNR-ISSIA, Genova, Italy, 2Università di Genova, DITEN, Genova, Italy, 3CNR-IBIMET, Firenze, Italy, 4CNR-ISAC,
Roma, Italy

Monitoring the Arctic regions allows understanding the impact of global warming on Earth's climate but some
processes affecting the climate change cannot be fully discerned because data are sparse and even missing due
to difficulties in collecting them in hazardous area. This is particularly true in the proximity of the arctic calving
glaciers that induce changes in the physicochemical and biological properties of the seawater. Unmanned
marine and aerial vehicles allow the in-situ observing of such processes. In June 2017 CNR-ISSIA, in
collaboration with other institutes of the CNR (IAMC, ISMAR, ISAC, IBIMET) and UNITUS, has conducted a
measurement campaign in the Kongsfjord, a small fiord in Svalbard. A customised octocopter (OTTO) capable
of carrying various types of heavy payloads was used. A set of low cost and high-resolution sensors were used
to analyse the column of air in order to monitor atmospheric parameters and gases (humidity, temperature,
CO, CO2, O3, NO2). A thermal camera was also installed on the drone to reconstruct a thermal map of the
sea/ice in the area surveyed by the Unmanned Marine Vehicle PROTEUS equipped with underwater sensor. The
measurements performed allowed to fully characterise the state of air-sea interface near marine glacier fronts.
A preliminary data analysis to correlate the different measured quantities shows interesting results but further
experiment need to be done to achieve a complete understanding of the processes.

1095
Wed_332_TE-1_1529
Unmanned Vehicles for Autonomous Sensing and Sampling 2017 Scientific Campaign

Angelo Odetti1,2 (angelo.odetti@ge.issia.cnr.it), Massimo Caccia1, Roberta Ferretti1, Andrea Ranieri1, Maurizio
Azzaro3, Gabriella Caruso3, Giuseppe Zappalà3, Federico Carotenuto4, Alessandro Zaldei4, Angelo Pietro Viola5,
Alice Madonia6, Marco Marcelli6, Viviana Piermattei6, Gabriele Bruzzone1
1
CNR-ISSIA, Genova, Italy, 2Università di Genova, DITEN, Genova, Italy, 3CNR-IAMC, Messina, Italy, 4CNR-IBIMET,
Firenze, Italy, 5CNR-ISAC, Roma, Italy, 6Università della Tuscia, Viterbo, Italy

The goal of the UVASS (Unmanned Vehicles for Autonomous Sensing and Sampling) project is the use of
unmanned vehicles to perform air, water and ice data sensing and sampling in dangerous places (e.g. close to
fronts of tidewater glaciers), difficult to access for human beings. The purpose of the Arctic expedition carried
out in Summer 2017 by ISSIA-CNR, in cooperation with other institutions, was the use of a little swarm of
unmanned vehicles performing simultaneous data acquisition in order to improve the understanding of
phenomena related to the global climate changes, especially ice melting. The marine autonomous vehicle
PROTEUS was equipped with sensors and samplers, i.e. multi-parametric probe and turbidimeter and towed a
small trimaran vessel hosting heavy or voluminous sensors i.e. an automatic water multisampler, a plankton
multisampler and a SeaBird CTD probe. Besides PROTEUS, two drones were also used: the OTTO drone
recorded pictures and videos of the area and was equipped with additional payload (thermal camera, humidity,
temperature and air quality sensors) to collect environmental parameters. The Splash drone was used to
record videos and images of the coordinated operations performed by PROTEUS and OTTO for documentary
and dissemination purposes. The atmospheric data coming from OTTO, together with the marine data acquired
by PROTEUS, will allow scientists to obtain a good characterisation of the whole marine-air column in the
proximity of tidewater glaciers.

1096
Wed_333_TE-1_1909
Long-term Automatic Ice Buoy System for ArcticAtmosphere-ice-Ocean Observation

Zhuoli Yuan1 (yuanzhuoli@pric.org.cn)

1
Polar Research Institute of China, Ocean Department, Shanghai, China

The interaction process of atmosphere, sea ice and ocean is a major topic of CHINARE Arctic researches.
Various types of ice buoys were utilized to observe Arctic , but few of them shall provide long-term, effective or
highly integrated observation, which limits the development of the interaction process researches.This article
offers one long-term automatic ice buoy system for Arctic atmosphere-ice-ocean observation.
System consists of main buoy, attached buoy and atmosphere tower. Main buoy is equipped with ice/snow
thickness sonar, ice temperature chain sonar and ice radiation flux sensors. Atmospheric pressure, temperature
and humidity sensors are installed on top of the main buoy body, which shall provides one-layer atmosphere
observation. Fixed profile observation module is equipped beneath the bottom of the attached buoy, profile
observation module consists CT, chlorophyll sensors and dissolved oxygen sensors, which shall provide six-layer
multiple ocean physical data observation.Atmosphere tower consists anemometers, atmospheric pressure
sensors and temperature and humidity sensors and shall provide 2-layer atmosphere physical data observation.
The material of buoy body is high-strength aluminum alloy, covered with cathodic protection. Buoys are
equipped with buoyant material, which shall keep the system alive after the ice melts and continue the
observation work.Battery of the systems shall provide system with more than 1 year long-term observation
duration.

1097
Wed_334_TE-1_2203
Arctic Observing Using Integrated Systems of Autonomous Instruments

Luc Rainville1 (rainville@apl.uw.edu), Craig Lee1, Jim Thomson1

1
University of Washington, Applied Physics Laboratory, Seattle, WA, United States

Systems of autonomous platforms offer the ability to collect sustained, collocated measurements of the ocean-
ice-atmosphere system, accessing spatial and temporal scales that have previously been difficult or impractical
to sample. The recent Office of Naval Research Marginal Ice Zone and Arctic Sea State Programs provide
examples of these systems applied to investigations of the processes that govern evolution of the rapidly-
changing seasonal ice zone in the Beaufort Sea. Autonomous platforms operating from the ice and within the
water column collected measurements across the atmosphere-ice-ocean system and provided the persistence
to sample continuously through the springtime retreat and autumn advance of sea ice. Autonomous platforms
also allowed operational modalities that reduced the field programs' logistical requirements. These programs
demonstrate effective use of light-weight logistics and integrated systems of autonomous platforms for
persistent, multi-scale Arctic observing. Networks of autonomous systems are well-suited to capturing the vast
scales of variability inherent in the Arctic system.

1098
Wed_335_TE-1_2354
Expanding Argo Float Measurements into the Arctic

Katrin Latarius1 (katrin.latarius@bsh.de), Birgit Klein1, Kjell Arne Mork2, Jari Haapala3, Waldemar Walczowski4,
Romain Cancouet5
1
Federal Maritime and Hydrographic Agency, Hamburg, Germany, 2Institute of Marine Research, Bergen,
Norway, 3Finnish Meteorological Institute, Helsinki, Finland, 4Institute of Oceanology of Polish Academy of
Sciences, Sopot, Poland, 5Institut Polaire Francais, Plouzane, France

Ice-tethered profilers have already successfully been used as part of the integrated Arctic observing system and
provide platforms for multidisciplinary ice-atmosphere-ocean observatories under stable ice conditions. But
several observations and predictions suggest that an ice-free Arctic summer is likely to occur within the next
decades and the ongoing decrease of sea ice coverage in the Arctic Ocean is already leading to extended
periods of open water in parts of Arctic. This development facilitates measurements with profiling Argo floats
in the Arctic.
The Euro-Argo ERIC, the European contribution to the international Argo program, has therefore started to
investigate the use of profiling floats in the Arctic. First deployments are intended for summer 2018 in the
Barents Sea and north of Svalbard within the national Argo programs of Finland, Norway and Poland.
In order to avoid damage to the floats by surfacing under ice-conditions it is necessary to hold them in ice-free
areas and/or to equip them with ice-sensing algorithms. Within the context of the EU funded MOCCA project
(Monitoring the Oceans and Climate Change with Argo) the Euro-Argo ERIC has started to develop such
algorithms for the hydrographic conditions in the Arctic and is coordinating the European deployments in the
area.
The talk is meant as a summary of the present state of activities within the project and a possibility to discuss
ideas and collaborations for the future.

1099
Wed_336_TE-1_2356
Vertical Profiling of Aerosol and Cloud Properties during PaCE2017

David Brus1 (david.brus@fmi.fi), Kimmo Neitola2, Konstantinos Doulgeris1, Christos Keleshis2, Panagiotis
Vouoterakos2, Gerd Schaufelberger3, Maximilian Weiss4, Jean Sciare2, Heikki Lihavainen1
1
Finnish Meteorological Institute, Helsinki, Finland, 2The Cyprus Institute, Energy, Environment and Water
Research Center (EEWRC), Nicosia, Cyprus, 3Airclip Service GmbH & Co KG, Dresden, Germany, 4Palas GmbH,
Karlsruhe, Germany

Aerosols and clouds have a large impact on the radiative balance of the earth's surface. The aerosol-cloud
interactions are still not well understood and have significant uncertainties. Especially in turbulent environment
of the boundary layer with low aerosol burden such as the sub-Arctic region of Northern Europe. The 7th Pallas
Cloud Experiment (PaCE2017) took place at the Pallas Atmosphere-Ecosystem Supersite - Sammaltunturi Global
Atmospheric Watch (GAW) station (67◦58' N, 24◦07' E). Unmanned Aerial Vehicles (UAVs) of three teams - the
Cyprus Institute, Airclip Service GmbH & Palas GmbH, and Finnish Meteorological Institute (FMI) - were
employed to perform airborne in-situ measurements of aerosol and cloud physical properties together with
meteorological parameters. The airborne measurements took place within the FMI's reserved airspace EFD431
- PALLAS that is centered around the Sammaltunturi GAW station with boundaries of 7 km and ceiling limit
FL80 (1994 m MSL). The acquired vertical profiles cover five consecutive days from Sept 24th to Sept 28th 2017,
and characterize situations under-, in- and above-clouds. The collected data were also combined with balloon
soundings, concurrent continuous ground-based observations and remote-sensing instrumentation.

1100
Wed_337_TE-3_14
Landsat-8 Satellite Data for Lithological Mapping in the Northern Greenland

Amin Beiranvand Pour1 (amin.beiranvand@kopri.re.kr), Tae-Yoon Park1, Yongcheol Park1, Jong Kuk Hong1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

Geological investigations in the Arctic confront many difficulties due to its remoteness and extreme
environmental conditions. Greenland has unique potential for discoveries of mineral ore deposits of world-
class scale. Mineral exploration activities in Greenland have been only focused on certain targets or areas with
variable intensity and density of data collection, leaving most of the parts of Greenland largely underexplored
compared to other areas with similar geology elsewhere in the Arctic. The northern Greenlandic Archean
terranes are often remote and not well-known. In north Greenland the Palaeozoic Franklinian Basin is
recognized to host several Zn-mineralization, of which the Citronen Fjord Zn-Pb deposits is the best known. In
this investigation, the application of Landsat-8 satellite remote sensing data was evaluated for lithological
discrimination and mineral prospecting in the northern Greenland. Developed image processing approach such
as specialized band rationing, image transformation techniques and directional filtering were implemented for
mapping lithological units, gossans and structural features. Geological units, the facies-border and structures
that most likely have a guiding on mineralizing systems within the Franklinian Basin in north Greenland were
mapped using Landsat-8 spectral bands. This satellite-based remote sensing approach is comprehensively
applicable for ore minerals prospecting in other inaccessible regions in Greenland.

1101
Wed_338_TE-3_15
Changing Arctic Snow Cover: Rain-on-Snow and Ice Layer Detection

Alexandre Langlois1 (a.langlois2@usherbrooke.ca), Caroline Dolant1, Ludovic Brucker2, Alain Royer1, Benoit
Montpetit3, Alexandre Roy1
1
Universite de Sherbrooke, Sherbrooke, Canada, 2NASA Goddard Space Flight Center, Greenbelt, United States,
3
Landscape Science & Technology, ECCC, Ottawa, Canada

The first and strongest signs of global climate variability and change have been observed in the Arctic over the
past three decades. Patterns in the spatial extent and mass balance of snow show a statistically significant
trend towards negative anomalies. More specifically, the currently observed warming in the Arctic leads to
winter rain-on-snow (ROS) events, which are now more frequent. Those events often leads to the creation of
ice layers that prevents ungulates from accessing their food.
We present here results from ROS detection algorithms, validated with 625 ROS observations across the
Canadian Arctic Archipelago. Three periods were studied separately and results show that despite no
significant trends in the cumulated yearly occurrence, an increase is seen in the occurrence of fall and winter
ROS events. Furthermore, an anomaly analysis suggest positive anomalies in event occurrence starting in the
late 80's. In addition to monitoring ROS, presence of ice layers is detected from satellite observations using
variability in the polarization ratio at 11, 19 and 37 GHz. Observed trends in ice layer presence and ROS
occurrences are similar. It is shown, however, that ice layers are less frequent, given that not all ice layers are
of sufficient thickness to be detected by our algorithm. Finally, a spatio-temporal analysis identified specific
areas such as Cornwallis Island, Sommerset Island and Northern Baffin Island to be more prone to ROS and ice
occurrence.

1102
Wed_339_TE-3_83
Retrieving Ice Parameters with a UAV-mounted RADAR

Daniel Kramer1 (daniel.kramer@usherbrooke.ca), Alexandre Langlois1, Alain Royer1, Donald McLennan2

1
University of Sherbrooke, Sherbrooke, Canada, 2Polar Knowledge Canada, Ottawa, Canada

To estimate the thickness of lake ice and detecting ice layers within the snowpack, a frequency-modulated
continuous-wave (FMCW) RADAR has been mounted on a small UAV. The RADAR is working at 24 GHz (Ka
band) and has an approximate retrieval accuracy of 2cm. The system will be flown in several locations in
Canada, including Cambridge Bay (Nunavut) during a winter expedition in April 2018. Additionally, the system
will be tested over sea ice to estimate the influence of brine on ice thickness retrieval accuracy.
Combined with other techniques (e.g. Snow Depth-retrieval), this platform offers the perspective to greatly
improve measurements for estimating the amount of snow and ice presence in the ecosystem.
Initial results are promising, but the potential for (arctic) applications is unclear as an underestimation was
measured in wet snow conditions and the required low flight level of less than 5m limits the area of operation.
This presentation will highlight retrieval accuracy and ice layer detection potential for Arctic areas while
discussing pros and cons of UAV operations at high latitudes.

1103
Wed_340_TE-3_184
Relationship between Radiation and Vegetation in Fildes and Ardley Peninsula

André Andrade1 (andre.medeiros@ufvjm.edu.br), Roberto Michel2, Ulisses Bremer3, Carlos Schaefer4, Jefferson
Simões3
1
Universidade Federal dos Vales do Jequitinhonha e Mucuri / INCT da Criosfera, Instituto de Ciências Agrárias,
Unai, Brazil, 2Universidade Estadual de Santa Cruz / INCT da Criosfera, Departamento de Ciências Agrárias e
Ambientais, Ilhéus, Brazil, 3Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Instituto de
Geociências, Porto Alegre, Brazil, 4Universidade Federal de Viçosa / INCT da Criosfera, Departamento de Solos,
Viçosa, Brazil

The aim of this work is to produce a simplified vegetation map of ice-free areas of the Fildes Peninsula (FP) and
Ardley Island (AI) thought object-oriented classification using a Quickbird satellite image and to evaluate the
influence of the global solar radiation (GSR) over the vegetation distribution. The vegetation data was
generated from multiresolution segmentation, and for the classification we calculated the normalized
vegetative difference index and the green normalized vegetative difference index. Two classes were created
Lichen and Moss Cushion Sub-Formation and Moss Sub-formation with 48 vegetation samples collected in 2008
and 2009. The GSR was estimated in order to evaluate the effect of meteorological phenomena and cloud
cover, and we measured the GSR using a net radiometer model CNR4 installed in FP between 2014 and 2016.
The estimate of GSR was done for seasons of 2015, in order to estimate the light compensation point and the
saturation point for the plant communities in FP and AI. The kappa index was 0.73 and the global accuracy was
0.78, showing consistency between the classification and ground truth. The area was covered by vegetation in
FP was 16.7% and in AI is 59.1%. The vegetation cover is distributed differently at FP and AI and our results
suggest GSR plays an important role in vegetation distribution and these tendencies could be related to greater
GSR demand by mosses when compared to lichens.

1104
Wed_341_TE-3_217
A Parametric Method for Snow Density Estimation Based on Ultrasonic Waves

Krzysztof Herman1 (kherman@ubiobio.cl), Tadeusz Gudra2, Dariusz Banasiak2, Krzysztof Opielinski2, Tomasz
Budzik3
1
University of the Bio Bio, Department of Electrical and Electronics Engineering, Concepcion, Chile, 2Wroclaw
University of Technology, Department of Electronics, Wroclaw, Poland, 3University of Silesia, Department of
Earth Sciences, Sosnowiec, Poland

In this paper a method for snow density estimation based on non contact ultrasound examination is described.
This ground based method involves a constant frecuency, air coupled ultrasound waves and incorporates a
parametric method for reflected energy estimation. The paper issues theoretical considerations as well as the
technolgical details of the addressed problem. Due to the fact that the amount of the reflected sound energy is
related to the snow density the acoustic data processing scheme is presented. The theoretical model was
applied to the data collected during field experiments in the vicinity of the Polish Antarctic Station Arctowski,
South Shetlands, Antarctic. The results obtained permit to develop a new autonomous sensor for
measurements of the snow ablation and density.

1105
Wed_342_TE-3_268
KOMPSAT 5 SAR Sea Ice Concentration in the Chukchi Sea in Summer

Hyangsun Han1, Hyun-Cheol Kim1 (kimhc@kopri.re.kr)

1
KOPRI, Unit of Sea Ice Prediction, Incheon, Korea, Republic of

Sea Ice concentratiosn (SIC) has been used as a primary data source for climate change prediction and ship
navigation. However, Passive Microwave (PM) SIC have an uncertainty in accuracy during summer. In this
research, we evaluated the SIC derived from PM measurements using four representative sea ice algorithms:
NASA Team (NT), Bootstrap (BT), Ocean and Sea Ice Satellite Application Facility (OSISAF) hybrid, and Arctic
Radiation and Turbulence Interaction STudy (ARTIST) Sea Ice (ASI). KOrean Multi-Purpose SATellite-5
(KOMPSAT-5) Enhanced Wide-swath synthetic aperture radar (SAR) images was used for the evaluation in the
Chukchi Sea in summer. SIC estimated from the NT and BT algorithms were largely underestimated and
overestimated, respectively, compared to KOMPSAT-5 SIC, while the OSISAF and ASI algorithms slightly
overestimated the SIC. Meanwhile, SIC estimated from the algorithms showed different error trends according
to the KOMPSAT-5 SIC range. All algorithms overestimated SIC in open drift ice zones, in marginal ice zones and
in consolidated pack ice zones SIC. The differences in SIC estimated from each algorithm were due to different
sensitivities to surface effects, atmospheric effects, and the presence of melt ponds.

1106
Wed_343_TE-3_270
High Resolution Sea Ice Motion and Deformation Measurements

Chang-Uk Hyun1, Hyun-Cheol Kim1 (kimhc@kopri.re.kr)

1
KOPRI, Unit of Sea Ice Prediction, Incheon, Korea, Republic of

Sea ice motion and deformation have generally been measured using low-resolution passive microwave
remote sensing technique to monitor wide polar regions, e.g., entire arctic ocean or polynya. This study
presents an application of multi-sensor optical satellite images for high-resolution sea ice motion and
deformation measurements. The sea ice motion was measured by using a maximum cross-correlation
technique with hierarchical approach to decrease outliers and multi-temporal images acquired from multiple
optical sensors of Korea Multi-Purpose Satellites (KOMPSATs). The sea ice motion extracted from image pairs of
short acquisition time intervals were compared with time-interpolated in-situ buoy location records. The root
mean square errors and biases of the image-derived ice motion indicate more accurate measurements than
from the sea ice motion datasets from conventional low-resolution passive microwave satellite data. In the
dense sea ice deformation grids, free drift patterns of ice floes that appear in summer were delineated. The
results demonstrate that using high-resolution multi-sensor optical images from operational satellites enabled
accurate sea ice motion and deformation measurements, thus this approach could be used for validation of
wide-range sea ice motion studies as a supplementary dataset to buoy based reference datasets.

1107
Wed_344_TE-3_271
Regional Chlorophyll Algorithms in Coastal Waters of Svalbard, Arctic

Young-Sun Son1, Hyun-Cheol Kim1 (kimhc@kopri.re.kr)

1
KOPRI, Unit of Sea Ice Prediction, Incheon, Korea, Republic of

AOP (Apparent Optical Properties) and IOP (Inherent Optical Properties) data from 2007 to 2013 were analyzed
to evaluate the performance of the ocean color algorithms to retrieve chlorophyll concentration in polar
coastal waters. Field data were collected from the Svalbard coast, Arctic, in late spring and early summer
between May and June. For the measurement of chlorophyll concentration using satellite data, we statistically
evaluated and analyzed current algorithms. Current algorithms tend to overestimate chlorophyll at low
chlorophyll concentrations, while underestimating chlorophyll at high concentrations. Bio-optical analysis of
the coastal waters in this region showed that high chlorophyll-specific absorption coefficients and suspended
sediment concentration were the main causes of chlorophyll overestimation and large size phytoplankton such
as diatoms caused chlorophyll underestimation. We proposed regionally tuned algorithms, which led to better
results in the Svalbard coastal waters.

1108
Wed_345_TE-3_276
Ice Thickness and Frontal Ablation of Nine Outlet Glaciers on Novaya Zemlya

Andrey Glazovsky1 (glazovsky@igras.ru), Ivan Lavrentiev1, Evgeny Vasilenko2

1
Institute of Geography RAS, Department of Glaciology, Moscow, Russian Federation, 2Institute of Industrial
Research 'Akadempribor', Uzbekistan Academy of Sciences, Tashkent, Uzbekistan

Knowledge of the volume and proportion of ice mass loss due to frontal ablation (the sum of ice loss through
calving and submarine melt) from tidewater glaciers on Russian Arctic archipelagoes is very limited. Meanwhile
the frontal ablation there is an important factor of current change of glaciers, as well as this knowledge is
required for iceberg hazard assessments. We present our estimations of frontal ablation for nine Novaya
Zemlya tidewater glaciers, calculated from satellite-derived ice velocities, airborne 20 MHz GPR RES
measurements of glacier ice thickness in 2014-2016, and mass change due to changes in terminus position
(MCTP). These glaciers are located in northern part on Novaya Zemlya
(5 on its western side, and 4 on eastern side).The average ice thickness at glacier fronts varies from 70 to 250
m, and average ice velocity at fluxgates varies from 40 to 840 m a-1.
The total mean rate of frontal ablation for these nine glaciers in 2015-2016 is 2.47 km3 a-1 of ice with
dominance of western side glaciers (2.08 km3 a-1). The average ratio of MCTP to frontal ablation is 2/5 on
western side and 1/5 on eastern side. The most active frontal ablation is found on Inostrantsev Glacier, where
it comprises 0.72 km3 a-1 (with gate ice flux 0.58 km3 a-1 and MCTP 0.14 km3 a-1). On Kara Sea side, the especially
active frontal ablation 0.24 km3 a-1 is on Vershinsky Glacier. RES data allows also to identify those frontal parts
of studied glaciers that are close to the flotation.

1109
Wed_346_TE-3_280
High Resolution Sea Ice Observation using Space-borne Fully Polarimetric SAR

Suman Singha1 (suman.singha@dlr.de), Malin Johansson2, Nicholas Hughes3, Sine Hvidegaard4, Henriette
Skourup4
1
German Aerospace Center (DLR), Bremen, Germany, 2UiT The Arctic University of Norway, Department of
Physics and Technology, Tromsø, Norway, 3Norwegian Meteorological Institute, Norwegian Ice Service, Tromsø,
Norway, 4Technical University of Denmark, National Space Institute, Kgs. Lyngby, Denmark

Satellite images are an essential source of information for sea ice products such as the sea ice concentration
maps issued by the national ice charting agencies. In this regard, Synthetic Aperture Radar (SAR) is especially
valuable given its all-weather capabilities. Within this study we investigate the usefulness of fully polarimetric
SAR by utilizing an automatic sea ice classification algorithm, developed for Near Real Time (NRT) services, on
two sets of spatially and temporally near coincident fully polarimetric acquisitions from the ALOS-2, Radarsat-2
and TerraSAR-X satellites acquired during the N-ICE2015 sea ice drift study.
Overlapping coincident sea ice freeboard measurements from Airborne Laser Scanner (ALS) data are used to
validate the classification results. We analyzed the usefulness of 18 different polarimetric parameters for sea
ice characterization. In order to deliver sea ice products in NRT savings in computational time are very
important and by reducing redundant parameters we can speed up the delivery time. Validation with the
coincident ALS data shows that 100 % of the open water is separated from the surrounding sea ice and that the
sea ice classes have at least 96.9 % accuracy. A notable difference between the C/X-band and the L-band
images was the high importance of entropy for the L-band sea ice classifications.

1110
Wed_347_TE-3_308
Thermodynamic Evolution of Arctic Sea Ice Using L-band SAR

Mallik Mahmud1 (msmahmud@ucalgary.ca), Stephen Howell2, Torsten Geldsetzer1, Vishnu Nandan1, John
Yackel1
1
University of Calgary, Geography, Calgary, Canada, 2Environment and Climate Change Canada, Toronto,
Canada

Selection of C-band SAR (synthetic aperture radar) as the preferred frequency for sea ice monitoring was made
in the 1980s when the Arctic sea ice regime was different (i.e. Multi-year ice [MYI]) from what it is today (i.e.
predominantly first-year ice [FYI]). Moreover, during the melt season, it has been demonstrated that C-band
fails to exhibit necessary backscatter contrast among various ice-types that make classification difficult
compared to L-band. Thus, L-band SAR is considered as an optimal choice for sea ice monitoring in the new
Arctic sea ice regime. Considering limited L-band sea ice application, this study aims to investigate the
thermodynamic evolution of snow-covered Arctic sea ice over the Canadian Arctic Archipelago using L-band
ScanSAR imagery from ALOS PALSAR. Time-series microwave backscatter signatures for both FYI and MYI are
explored using L-band SAR imagery in 2010. Seasonal evolution of L-band microwave backscatter over FYI
shows similarity with C-band, with lower intensity. However, this study reveals that seasonal evolution of L-
band MYI signature during winter to melt transition is opposite to C-band, which certainly exhibit different
scattering mechanism. The unique characteristic of L-band SAR during thermodynamic evolution of Arctic sea
ice that will be invaluable with imminent launch of future L-band missions (e.g. SAOCOM, NISAR). This study
recommend further investigation of L-band SAR interactions with sea ice compared to higher frequencies.

1111
Wed_348_TE-3_317
L-band Brightness Temperature and Snow Surface Properties at Dome C, Antarctica

Marion Leduc-Leballeur1 (m.leduc@ifac.cnr.it), Ghislain Picard2, Giovanni Macelloni1, Laurent Arnaud2, Marco
Brogioni1, Arnaud Mialon3, Yann H Kerr3
1
IFAC-CNR, Sesto Fiorentino, Italy, 2IGE, UGA-CNRS, Grenoble, France, 3CESBIO, CNES, CNRS, IRD, UPS, Toulouse,
France

The physical properties of the surface are essential for understanding the surface energy and mass budgets of
the Antarctic ice sheet and, in turn, for predicting climate change and a rise in the sea level. Several
glaciological properties are relevant, such as snow grain size, density, roughness, etc.
A careful analyse of snow surface properties at Dome C showed that an unusual event happened during the
2014-2015 austral summer. At the same time, an exceptional variation (2 events in 6 years) is observed by L-
band radiometers (DOMEX ground radiometer and the ESA's SMOS satellite). Here we present our investigation
of this period combing multiple sources of information. From November to March, a slow increase in
brightness temperature (Tb) occurred concomitantly with a decrease in surface snow density. During this
period, low wind speed made the presence of hoar and the accumulation of light snow possible. Around 20
March 2015, an abrupt decrease in Tb was observed and corresponded with a clear increase in surface snow
density. Strong wind was also observed, which could have compacted or removed the light snow presents on
the surface. Simulations performed with the WALOMIS snow-emission model indicated that L-band Tb was
affected by both the surface snow density and the thickness of the superficial layer. Future work will explore
the widespread nature of this kind of event and the interest to use them as climate indicator of change at the
continent scale.

1112
Wed_349_TE-3_406
Cloud Optical Thickness over the Arctic: Retrieval & Validation Challenges

Aku Riihelä1 (aku.riihela@fmi.fi), Karl-Göran Karlsson2, Jan Fokke Meirink3, Jeffrey Key4
1
Finnish Meteorological Institute, Helsinki, Finland, 2Swedish Meteorological and Hydrological Institute,
Norrköping, Sweden, 3The Royal Netherlands Meteorological Institute, De Bilt, Netherlands, 4National Oceanic
and Atmospheric Administration, Madison, United States

Accurate characterization of the Surface Radiative Energy Budget (SRB) of the Arctic is critically important for
understanding its key role in climate regulation. This is most cost-effectively done with satellite observations. In
particular, we know that accurate estimates of the Cloud Optical Thickness (COT) of Arctic clouds are a
prerequisite for successful SRB calculations. Yet we also know that COT retrievals over bright surfaces such as
snow or sea ice are very challenging, particularly for legacy instruments such as the Advanced Very High
Resolution Radiometer (AVHRR). Yet, utilization of the multi-instrument AVHRR timeseries offers us the single
best chance for obtaining a long SRB timeseries if the challenges can be overcome.Thus our research question:
How do AVHRR-based COT retrieval methodologies perform over the Arctic, and can we identify specific issues
that set limitations for COT retrieval accuracy?
We have spatiotemporally collocated a large multi-year dataset (N=270K+) of individual AVHRR-based COT
retrievals from the CM SAF CLARA-A2 and NOAA APP-x datasets with corresponding observations from both
CALIPSO/CALIOP and Cloudsat, based on the SNO method. We show a comparative analysis of the different
COT retrievals, taking into account the inherent limitations in each (e.g. CALIPSO's COT saturation over thick
clouds, Cloudsat's insensitivity to very low clouds, etc.). We furthermore present the findings grouped by
background surface type and cloud type.

1113
Wed_350_TE-3_420
DLR's Near-real Time Radar Information for Antarctic Research Vessels

Paul Wachter1 (paul.wachter@dlr.de), Kathrin Höppner1, Birgit Schättler2, Egbert Schwarz1, Detmar Krause1,
Erhard Diedrich1, Christine Wesche3, Robert Metzig1
1
German Aerospace Center (DLR), German Remote Sensing Data Center (DFD), Weßling, Germany, 2German
Aerospace Center (DLR), Remote Sensing Technology Institute (IMF), Weßling, Germany, 3Alfred Wegener
Institute, Logistics & Research Platforms, Bremerhaven, Germany

Sea ice coverage is one of the major challenges for ship expeditions in the Antarctic Southern Ocean. Even
icebreakers with a high ice class can get into trouble on their journeys through sea ice covered areas. Sea ice
information in near-real time independent of weather conditions and daytime are therefore highly desirable.
The German radar satellites TerraSAR-X (TSX) and TanDEM-X (TDX) are capable to provide such a near-real time
application.
The Earth Observation Center (EOC) of the German Aerospace Center (DLR) covers the entire spectrum of
remote sensing from data reception to processing, as well as developing new information products. In
combination with the German Antarctic Receiving Station (GARS) O'Higgins, which is equipped with an
operational near-real time processor for TSX/TDX data, it is possible to deliver sea ice information just about 60
minutes after the raw data has been acquired. These information products can be used by ship crews for
navigation purposes as well as for planning biological, geological or oceanographic sampling sites by scientists
aboard the supported research vessels.
Since 2015 this service has been successfully tested during several ship expeditions. Information on the
processing chain and examples of delivered products will be presented.

1114
Wed_352_TE-3_498
Add-on Value of Sentinel-2 Imagery to Map Supraglacial Rivers in the Arctic

Kang Yang1,2 (yangkangnju@gmail.com), Laurence Smith3, Manchun Li1

1
Nanjing University, School of Geographical and Oceanographic Sciences, Nanjing, China, 2Joint Center for
Global Change Studies (JCGCS), Beijing, China, 3University of California, Department of Geography, Los Angeles,
United States

Supraglacial river networks set efficacy and time lags by which surface meltwater is routed to the englacial and
proglacial portions of the ice masses and thereby have important implications for surface ice mass balance and
ice dynamics. However, these crucial hydrologic features remain poorly studied mainly because they are too
narrow to be reliably delineated from conventional moderate-resolution satellite images. This study uses 10 m
Sentinel-2 MSI images to map supraglacial rivers on the Northwest Greenland Ice Sheet, Devon Ice Cap, and
Barnes Ice Cap. Results show that Sentinel-2 images are preferable to Landsat-8 images for delineating narrow
and continuous supraglacial meltwater channels, yielding sufficient detail and higher drainage density than
Landsat-8. The Sentinel-derived rivers form different surface meltwater drainage patterns at each study area.
In northwest Greenland, supraglacial rivers drain meltwater directly off the ice sheet into proglacial rivers,
whereas on the Devon Ice Cap and the Barnes Ice Cap, numerous supraglacial rivers are interrupted by moulins
and thereby drain considerable portions of surface meltwater to subglacial systems, potentially coupling
surface melt with ice dynamics. Overall, the Sentinel-2 images raise prospects for investigating supraglacial
meltwater drainage patterns and improving our understanding of surface hydrology and ice flow of global ice
masses.

1115
Wed_353_TE-3_507
Ice Cliff Contribution to Ablation of Debris-covered Changri Nup Glacier, Nepal

Fanny Brun1,2 (fanny.brun@univ-grenoble-alpes.fr), Etienne Berthier2, Patrick Wagnon1, Joseph Shea3, Walter
Immerzeel4, Philip Kraaijenbrink4, Christian Vincent1, Camille Reverchon1
1
Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, Grenoble, France, 2LEGOS, Toulouse, France, 3University of
Saskatchewan, Centre for Hydrology, Saskatoon, Canada, 4Utrecht University; Faculty of Geosciences,
Department of Physical Geography, Utrecht, Netherlands

Ice cliff backwasting on debris-covered glaciers is recognized as an important process, potentially responsible of
the so-called “debris-cover anomaly”, i.e. the fact that debris-covered and debris-free glaciers loose mass at a
similar rate in Himalaya. In this study, we assess the total contribution of ice cliff backwasting to the ablation of
Changri Nup Glacier tongue over one year. We use three very high resolution datasets (terrestrial
photogrammetry, UAV photogrammetry, Pléiades tri-stereo) acquired simultaneously in November 2015 and
2016 to survey the glacier tongue topography. Using terrestrial photogrammetry data, we calculated the
volume losses of 12 cliffs with various size applying a full 3D method. We used these reference volume loss
estimates to assess the applicability of UAV and Pléiades data to calculate volume losses of individual ice cliffs.
We found that the total difference between the volume loss measured with the terrestrial photogrammetry
and the UAV and Pléiades was less than 3% and 7%, respectively, demonstrating the suitability of these
datasets to measure volume loss from ice cliffs. We then applied the same method to the entire glacier tongue,
and found that ice cliffs contribute to 23 ± 5 % of the total ablation of Changri Nup Glacier tongue.

1116
Wed_354_TE-3_533
The Spatiotemporal Patterns of Sea Ice in the Bohai Sea during 2000 - 2016

Fengming Hui1 (huifm@bnu.edu.cn), Lunxi Ouyang1, Lixian Zhu1, Xiao Cheng1, Bin Cheng2, Mohammed Shokr3
1
Beijing Normal University, Beijing, China, 2Finnish Meteorological Institute, Helisinki, Finland, 3Environment and
Climate Change Canada, Toronto, Canada

In this study, sea ice thickness (SIT) and sea ice extent (SIE) in the Bohai Sea from 2000 to 2016 were
investigated. A surface heat balance equation was applied to calculate ice thickness using ice surface
temperatures estimated from MODIS data with input from air temperature and wind speed from reanalysis
weather data. No trend was found in ice thickness in this period. The mean SIT and SIE during this period were
5.58±0.86 cm and 23×103±8×103 km2, respectively. The retrieved ice thickness in the winter of 2009/2010
agreed reasonably well with in situ observations at two offshore oil platforms, with RMSE of 6.42 cm and 2.26
cm. Annual variation in mean ice thickness was rather limited within a range of 3-7 cm. The SIE varied
significantly with a rather large standard deviation of approximately 8,000 km2. The largest ice thickness and
ice extent periods were observed during the second half of January and the first half of February, respectively.
The Spearman correlation coefficient between mean ice thickness and average air temperature from 21
automatic weather stations around the Bohai Sea was -0.94 (P < 0.005), and the coefficient between median
ice extent and negative accumulated temperature was -0.503 (P < 0.001). The rate of increase in air
temperature around the Bohai Sea is 0.271°C decade-1 in winter for 1979-2016 (P < 0.05), which has not
resulted in a decreasing trend in sea ice thickness and extent for the past 16 years in the Bohai Sea.

1117
Wed_355_TE-3_655
Remote Sensing of Grounding Lines - Current Methods and Data

Peter Friedl1 (peter.friedl@dlr.de), Anke Fluhrer1

1
German Aerospace Center (DLR), German Remote Sensing Data Center (DFD), Wessling, Germany

The grounding line is the boundary between the floating and the grounded part of an ice sheet or tidewater
glacier. Knowing its position is critical for assessing glacier/ice sheet stability, glacier/ice sheet mass balance
calculations and numerical modeling. However, as it is a subglacial feature, mapping of the grounding line is
challenging. Although ice sounding surveys may be capable to map grounding line positions directly, they often
do not yield satisfying results. Other field measurements try to map grounding lines indirectly e.g. by measuring
ice flexure with tiltmeters or kinematic GPS. Nevertheless, such surveys are not suitable for picking grounding
lines over large and inaccessible areas. In contrast, the continuous development of new remote sensing sensors
and techniques over the last decades enabled grounding line delineation over extensive areas at low costs.
Modern remote sensing techniques mainly use space- and airborne SAR, optical, radio echo sounding and
altimeter data to map features in the grounding zone which can be taken as grounding line proxies. We present
a state-of-the-art review of existing remote sensing techniques and data for mapping grounding lines. We
discuss the advantages and disadvantages of the methods and evaluate commonly used sensors and data. We
also give an overview of freely available grounding line products. Finally we compare grounding lines inferred
from different remote sensing methods and data in example regions.

1118
Wed_356_TE-3_733
Sea Ice Leads Detection Based on Multisensory Remote Sensing Data

Meng Qu1, Xi Zhao1 (xi.zhao@whu.edu.cn), Mohammed Shokr2, Qing Ji1, Xiaoping Pang1
1
Wuhan University, Chinese Antarctic Center of Surveying and Mapping, Wuhan, China, 2Environment Canada,
Toronto, Canada

Sea ice leads serve as prime window for heat transfer between the Arctic ocean and the atmosphere during
winter seasons. They also provide pathways for human to enter the core Arctic area. The objective of this study
is to extract sea ice leads utilizing multisensory remote sensing data and explore potential use of high-
resolution Radarsat-2 images in lead detection. We found that ice surface temperature derived from MODIS
thermal bands has capability of detecting leads prevailed by open water or thin ice, but cannot differentiate
refrozen leads from the surrounding thick ice, i.e. multi-year ice (MYI) and first-year ice (FYI). Whereas
Radarsat-2 images outperformed in discriminating several sea ice types including new ice (NI), young ice (YI)
and refrozen leads (RL). Ice surface temperature and optical reflectance from MODIS were introduced using
decision tree to reduce ambiguity in Radarsat-2 classification. We concluded that dual-polarization Radarsat-2
data could provide more details on sea ice condition in lead area compared with moderate resolution MODIS
images, especially for refrozen leads. On the other hand, could-free optical images, if available, can add
valuable information for discrimination between FYI and NI, thus improve the classification accuracy.

1119
Wed_357_TE-3_792
Estimation of Wet Snow Fraction Images for the Antarctic Continent (1978-2017)

Claudio Wilson Mendes Junior1 (claudio.mendes@ufrgs.br), Marcos Wellausen Dias de Freitas1, Juliana Costi2,
Jorge Arigony Neto2, Jefferson Cardia Simões1
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Centro Polar e Climático, Porto Alegre, Brazil,
2
Universidade de Federal do Rio Grande / INCT da Criosfera, Laboratorio de Monitoramento da Criosfera, Rio
Grande, Brazil

A Spectral Linear Mixing Model (SLMM) is proposed to estimate wet snow fraction images for the Antarctic
continent based on calibrated SMMR, SSMI and SSM/IS EASE-Grid data (25 km spatial resolution) with a daily
temporal resolution. We compared calibrated brightness temperatures of DMSP SSM/I images (19GHz-H,
19GHz-V, 37GHz-H and 37GHz-V channels) with fraction images of Wet Snow Zone (WSZ), Dry Snow Zone (DSZ)
and Rock Outcrops (RO), derived from classified ENVISAT ASAR wide swath images (150 m) acquired at 16
dates. Then, these data were used on a least squares solution to estimate the unknown spectral signatures in
brightness temperatures (Kelvin) for these three endmembers, in channels 19H, 19V, 37H and 37V,
respectively: WSZ (256.122; 269.679; 239.865; 251.192); DSZ (200.256; 227.464; 204.568; 224.161); RO
(261.514; 287.697; 215.217; 227.824). The r2 were higher than 0.98 and p-values lower than 0.00001 for all
channels. These spectral signatures and SSM/I images were then used in this SLMM to estimate WSZ fraction
images, which were compared with correspondent ASAR fraction ones at 11 dates. The average overall
accuracy was 73% for class ranges of 0.2 (i.e., each class represents 20% of one pixel). The RMSE was lower
than 0.06 for all dates, excepting for one with 0.29. The analysis of the estimated WSZ fraction images
indicated that the most persistent and intensive melt was observed on the Larsen and Wilkins ice shelves
during the period 1978-2017.

1120
Wed_358_TE-3_856
The Latest Image Mosaic of Greenland based on Landsat8

Zhuoqi Chen1 (chenzq@bnu.edu.cn), Xiao Cheng1

1
Beijing Normal University, Beijing, China

In order to support studies on landscape changes of elements like snow, ice, water bodies and vegetation, a
new and updated mosaic of Greenland is necessary. In this study, we created a 30m mosaic of Greenland from
229 individual Landsat8 scenes acquired during June to August in 2014 and 2015. There are four steps to finish
the mosaic. Firstly, planetary reflectance for three single spectral bands (red, green and blue bands) was
calculated. Since concentrations of atmospheric water vapor and aerosols are very low over Arctic regions, the
planetary reflectance is a good approximation of surface reflectance. The planetary reflectance was used as the
surface reflectance in this study. Secondly, to minimize differences of surface reflectance among scenes caused
by acquisition date, solar elevation angles and other factors, a solar elevation correction and a non-Lambertian
adjustment were applied to the surface reflectance data. Thirdly, non-linear piecewise functions were used to
convert surface reflectance values to 8-bit values ranged from 0 to 255 for each visible wave band of Landsat8
scenes. Then three 8-bit values images were combining into a 24-bit multispectral scene in order of red band,
green band and blue band. Finally, all multispectral scenes were mosaicked to finish the full image mosaic of
Greenland.

1121
Wed_360_TE-3_874
Mapping Ice Shelf Surface Melt using Object Based Image Classification

Eleri Evans1,2 (eleri.evans@utas.edu.au), Vanessa Lucieer1, Sue Cook2, Alexander Fraser2, Richard Coleman1,2
1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Antarctic Climate &
Ecosystems Cooperative Research Centre, Hobart, Australia

Surface melt features, such as supraglacial ponds, influence ice shelf stability through hydrofracture induced
iceberg calving, and change other ice shelf properties through the redistribution of mass. Accurately mapping
the pattern of surface melt at a high temporal and spatial resolution is key to understanding the surface melt
regime. Previous studies have used algorithms to successfully discriminate ice shelf surface facies using multi-
temporal Synthetic Aperture Radar (SAR) data to map the spatial-temporal patterns of surface melt, identifying
the onset of melt and refreezing. However, these studies were restricted by low resolution images and noisy
data quality which reduced classification accuracy. The work presented here investigates the application of
Object Based Image Analysis (OBIA) to classify Sentinel-1 SAR images covering the Sørsdal Glacier, a small ice
shelf in East Antarctica that experiences significant surface melt. The classification was performed using
Trimble's eCognition software, where user-defined rules are based on a priori knowledge of the relationship
between ice surface properties and radar back scatter intensity and how this relationship changes with surface
melt. The OBIA based classifications will be evaluated using classified Landsat 8 imagery. Mapping the dynamics
of the surface melt regime is key to understanding how it influences other ice shelf processes, especially
iceberg calving, and how this influence may change in the future.

1122
Wed_361_TE-3_948
Temporally Resolved Ice Velocities of Greenland Glaciers using Sentinel SAR Data

Saurabh Vijay1 (sabvj@space.dtu.dk), Kristian K. Kjeldsen1,2, Shfaqat Abbas Khan1, Anders Kusk1, Anne Munck
Solgaard3, Anders Anker Bjørk2,4,5
1
Technical University of Denmark, Copenhagen, Denmark, 2National History Museum of Denmark, Copenhagen,
Denmark, 3Geological Survey of Denmark and Greenland, Copenhagen, Denmark, 4NASA Jet Propulsion
Laboratory, Pasadena, United States, 5University of California Irvine, Department of Earth System Science,
Irvine, United States

The mass loss due to ice discharge via marine-terminating glaciers in Greenland is largely well known. Previous
studies have indicated interannual variabilities of ice velocities of different glacier systems in Greenland.
However, in most cases these studies were limited by low temporal resolution of the available data. Here, we
present ice velocities of 45 Greenland glaciers, including, 79N Gl., Helheim Gl. and Upernavik Isstrøm, with very
high temporal sampling during 2015-2017, derived from SAR offset tracking applied over Sentinel SAR data.
Moreover, we combine radar backscatter from Sentinel SAR data and air temperature recorded at various
weather stations in Greenland, to mark the onset and extent of the melt season. We also derive the changes in
the frontal positions of selected glaciers. Seasonal velocity fluctuation of most of the investigated glaciers (26)
appear to be primarily controlled by subglacial hydrology. For instance, a group of glaciers (8) speed up with
the onset of surface melt, attain maximum velocity in the middle of the melt season and slowdown afterwards.
Other glaciers (18) show comparable velocities during late winters and early melt season with significant
slowdown afterwards. Seasonal velocities of 6 glaciers appeared to be sensitive to their ice front positions. Our
results with such temporal details are crucial for calibrating models projecting the future ice dynamics of
marine-terminating glaciers and their mass loss due to ice discharge.

1123
Wed_362_TE-3_966
Gap Filling of Antarctic Sea-ice Freeboard from ICESat: Comparison of Approaches

Huan Li1 (lihuan2016@tsinghua.edu.cn), Hongjie Xie2, Yang Hong1,3, Wei Wan1, Cunguang Wang1, Siyu Zhu1
1
Tsinghua University, State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic
Engineering, Beijing, China, 2University of Texas at San Antonio, Laboratory for Remote Sensing and
Geoinformatics, Department of Geological Sciences, Texas, United States, 3University of Oklahoma, School of
Civil Engineering and Environmental Sciences, Oklahoma, United States

Due to the sparse laser-point observations by ICESat, methods are needed to get a complete Total Freeboard
(TF) of sea ice coverage over the Antarctic. Three methods, Gaussian Weight Regression (GWR), Ordinary
Kriging Interpolation (OKI), and Random Forest Regression (RFR), have been used for gap filling of TF under
6.25 km grid scale with 17 ICESat observation periods during 2003 and 2009. The TF is derived from ICESat by
the improved Lowest Level Elevation method and randomly divided into training set (80% grids) and test set
(20% grids). Gap filling grid extents are defined with average AMSR-E sea ice concentration larger than 0 in
corresponding time periods. Differing from GWR and OKI that only use TF values for gap filling, the RFR method
integrates TF values with sea ice cover, sea surface temperature, air pressure, 10 m U wind component, and 10
m V wind component from atmospheric reanalysis data ERA-Interim. With estimated RMSEs on the test set,
our primary results show that GWR and OKI have very similar prediction accuracy. By integrating several
climate parameters, the RFR shows the best accuracy during the 17 periods.

1124
Wed_363_TE-3_1063
Precipitable Water Retrieval over Antarctica from Satellite Microwave Sounders

Arantxa Triana Gomez1, Georg Heygster2 (heygster@uni-bremen.de), Christian Melsheimer2, Gunnar Spreen2,
Monia Negusini3, Boyan H. Petkov4
1
University of Bremen, Institute of Environmental Physics, Bremen, Germany, 2Institute of Environmental
Physics, University of Bremen, Bremen, Germany, 3Institute of Radio Astronomy - INAF, Bologna, Italy, 4Institute
of Atmospheric Sciences and Climate - CNR, Bologna, Italy

Atmospheric water vapor is an important constituent of the global hydrological cycle; it transports humidity
and heat and it is the most important greenhouse gas. Large-scale observations in polar regions with low water
vapor burden are difficult to obtain because of the low water vapor signal and, over sea ice and land ice, the
high and highly varying surface emissivity. A procedure has been suggested exploiting the data of the satellite
humidity sounders SSM/T2, AMSU-B and MHS aboard the DMSP, Aqua and Metop satellites or satellite series,
respectively.
The algorithm uses three channels of neighbouring frequencies around the water vapor absorption line near
183 GHz plus the 150 GHz channel. The procedure excludes the surface contribution in the satellite signal by
considering the ratio of brightness temperature differences. Moreover, the procedure has been adapted to the
microwave humidity sounders AMSU-B and MHS with slightly different channels (Melsheimer and Heygster,
2008). Results for Antarctica will be presented for the years 2006-2007. In coastal Antarctic areas, PW time
series are available from Global Positioning System (GPS) and radiosounding (RS) stations. Data from five
Antarctic sites (Negusini et al. 2016) will be used to correct the satellite based retrievals and then to extend the
PW retrieval over whole Antarctica.

1125
Wed_364_TE-3_1069
Support of Logistics by Satellite Remote Sensing in East Antarctica

Stefan Knetsch1, Stuart McFadzean2, Christian Pfeifer1, Osama Mustafa1 (osama.mustafa@think-jena.de)

1
ThINK - Thuringian Institute of Sustainability and Climate Protection, Jena, Germany, 2White Desert Ltd,
London, United Kingdom

For scientific and logistic expeditions in Antarctica, identifying safe traverse routes and safe landing areas on
snow or ice is a significant challenge. The ability to perform meaningful assessments of ground conditions
during the planning phase of an expedition is invaluable. Here we present satellite based approaches to
support traverse planning as well as exploration of a new blue ice runway in Dronning Maud Land, East
Antarctica. For traverse planning we used both optical (Landsat 8, 15 m ground sample distance (GSD)) and C-
band radar images (Sentinel-1, 10 m GSD and Radarsat-2 1.5 m GSD). Data on ice flow speed helped us to
detect shear zones with higher risk of crevasses. For the blue ice runway we used hi-res optical images (World
View 2, 0.4 m GSD) and a stereographic derived Digital Surface Model (2m GSD). By combining and analyzing
these data sets we could identify dangerous areas (e.g. crevasses, erratica, steep slopes). For the runway
exploration additionally hi-res maps on micromorphological parameters (e.g. slope, roughness) and cross
sections were created in scales up to 1:12,000. All results were delivered as interactive field maps with offline
usability. To deal with highly dynamic glacial areas, near-time support to field teams, using of the most recent
satellite images can be provided. Antarctica is a high stakes environment and our studies can identify potential
hazards during the planning phase to reduce costs, time and increase the safety of field work.

1126
Wed_365_TE-3_1131
Identifying Blooming Algae in Antarctic Remote Sensing Observations

James Blake1,2, Matthew Davey2, Andrew Fleming1, Peter Convey1, Lloyd Peck1, Andrew Gray3, Alison Smith2,
Peter Fretwell1 (ptf@bas.ac.uk)
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Cambridge, Department of Plant Sciences,
Cambridge, United Kingdom, 3University of Edinburgh, NERC Field Spectroscopy Facility (FSF), Edinburgh, United
Kingdom

The quantity, distribution and contribution to primary productivity of snow algae in Antarctica are currently
unknown. We present the first remote sensing analysis of snow algae distribution in Ryder Bay (Adelaide Island,
Antarctic Peninsula, 68°S) using a detection algorithm for World View 3 satellite data. Impurity concentration is
one of the primary inherent characteristics that determine the optical properties and albedo of snow and snow
algae are a prolific impurity that darken the snow pack and increase snow melt through absorption of solar
radiation. This analysis is supported by ground and atmospheric spectral field sampling of the same region
obtained during the 2017/18 growing season. We compare the area coverage of snow algae to other
photosynthetic organisms such as mosses, lichens and higher order vegetation.

1127
Wed_366_TE-3_1310
Copernicus Glacier Service - Monitoring Glaciers using Sentinel

Liss Marie Andreassen1 (lma@nve.no), Solveig Havstad Winsvold1,2, Andreas Kääb2, Alexandra Messerli3, Geir
Moholdt3, Torgeir Ferdinand Klingenberg4, Nils Kristian Orthe1
1
Norwegian Water Resources and Energy Directorate (NVE), Oslo, Norway, 2University of Oslo, Department of
Geosciences, Oslo, Norway, 3Norwegian Polar Institute, Tromsø, Norway, 4The Norwegian Mapping Authority,
Hønefoss, Norway

Monitoring of glaciers and glacier changes is important for many purposes. The goal of the Copernicus Glacier
Service Norway is to develop a national service for glaciers. The Norwegian Water Resources and Energy
Directorate (NVE) and Norwegian Polar Institute (NPI) are responsible for monitoring the ice masses in
mainland Norway and Svalbard, respectively. The project will mainly use optical imagery from Sentinel-2, but
also other sensors such as Landsat-8 and Sentinel-1. Glacier products that will be produced are:
1) Glacier outline, area and calving front,
2) Glacier surface type and snow line,
3) Ice velocity,
4) Glacier crevasses and surge, and
5) Glacier lake outlines.
Here we report results on geometric performance of Sentinel-2, we present ice velocity maps for Svalbard and
selected glaciers in mainland Norway, we demonstrate how combined sensors can be used for glacier snowline
mapping and we use Sentinel-2 for mapping evolution of glacier lake outlines at selected sites with potential
for glacier lake outburst floods.
The glacier products will be made available from NPI and NVE websites (as Web Map Service´s and download)
and through the CryoClim portal. Data will also be submitted to GLIMS.

1128
Wed_367_TE-3_1314
A New Approach to Ice Concentration Retrieval from MW-retrieved Refractive Index

Sang-Moo Lee1 (greatadsl@snu.ac.kr), Byung-Ju Sohn1, Jong-Min Kim1

1
Seoul National University, School of Earth and Environmental Sciences, Seoul, Korea, Republic of

This study attempts to develop a new algorithm for retrieving sea ice concentration from AMSR (Advanced
Microwave Scanning Radiometer)-retrieved refractive index. This algorithm is based on the property that the
refractive indices of ice and snows are nearly constants regardless of frequency in microwave domain, on the
other hands, refractive index of sea water highly varies with frequency. Therefore, the new algorithm gives
possibility to reduce statistical uncertainty by using difference of the retrieved refractive index from dual-
channel observations because it can reduce tie points for three different types (i.e., first-year, multiyear, and
open water) to one for open water. The tie points for sea water are found from analyzing monthly distributions
of the retrieved refractive index of water. In other words, dynamic tie points are selected in this algorithm for
considering seasonal variation of refractive index of water due to temperature change itself. The sea ice
concentration retrieved in this study is compared with those with three different algorithms (e.g., NASA Team,
bootstrap, and ASI (ARTIST Sea Ice) algorithm) and the result shows that accuracy of ice concentration
produced using refractive index is comparable to the others. In this presentation, systematic difference over
the complete AMSR period between developed algorithm and others will be presented and discussed.

1129
Wed_368_TE-3_1324
Mapping Surface Facies of Alpine Glaciers from Himalaya using WorldView-2 Image

Shridhar Jawak1 (shridhar.jawak@gmail.com), Alvarinho Luis1, Sagar Wankhede2

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Ministry of Earth Sciences, Vasco da Gama,
India, 2Mangalore University, Department of Geoinformatics, Mangalore, India

Glacier facies are distinct zones in the surface layer of an ice sheet or glacier, which are related to patterns of
accumulation and ablation. This study has attempted to map the surface facies of selected glaciers from the
Chandra Basin, in the Great Himalayan Range. The digital mapping of spatial extent of glacier facies was carried
out using object-based and pixel-based approaches on very high resolution satellite imagery. Traditional glacier
facies mapping methodologies have usually utilized data acquired during the melt season. This study however
has attempted to map glacier facies using data acquired during early winter. WorldView-2 (WV-2) imagery was
used to develop customized spectral indices using the new spectral bands in its multispectral (MS) range. Error
matrices were utilized to assess the classification accuracies of final maps. The object-based approach provided
an overall accuracy of 88.33%. Two pixel based classifiers, namely maximum likelihood (MXL) and spectral
angle mapper (SAM) were utilized, which yielded overall accuracies of 81.67% and 78.33% respectively. The
highest kappa statistics obtained for the object based strategy is 0.86 and the pixel based classifiers delivered
Kappa statistics of 0.78 and 0.74 respectively. The results indicate that the object-based classification is
superior to the pixel-based classification methods for glacier facies mapping in Himalayan environment.

1130
Wed_369_TE-3_1356
Spectral Vegetation Indices Derived by UAV Images to Map Patchy Vegetation

Maria Eliza Sotille1 (sotille@gmail.com), Ulisses Franz Bremer1, Jefferson Cardia Simoes1
1
UFRGS, Porto Alegre, Brazil

Environmental changes observed on the northern tip of the Antarctic Peninsula over the last decades have
contributed to recession in local glaciers and expansion in ice-free areas of the region, creating more adequate
conditions for vegetation grow and colonization of newly exposed ground. However, identifying vegetation
cover in areas such as the Antarctic Peninsula can be a challenge to remote monitoring due to the nature of the
typical Antarctic cryptogamic vegetation, which often appears in small patches and scattered across ice-free
areas. In this study, we use remote sensing techniques and criteria to identify this cover in very high-resolution
images, acquired by unmanned aerial vehicles (UAV). Spectral Vegetation Indices (SVI) - based on the high
absorption in the visible range and the increased reflection in the NIR by plants - were applied in the ice-free
area of Hope Bay, in the Trinity Peninsula. The results enabled an evaluation of the indices according to the
targets of the area (especially vegetation and penguins nests), and to the types of cryptogamic vegetation
(algae, lichens and mosses), in addition to a quantification of local vegetation. We found 5% of the area imaged
with some type of vegetation cover, and the best method for the automatic identification of areas with
presence of mosses and algae was the Green Normalized Difference Vegetation Index (GNDVI).

1131
Wed_370_TE-3_1358
Climate Change and the Expansion of Ice-free Areas on the Trinity Peninsula

Maria Eliza Sotille1 (sotille@gmail.com), Ulisses Franz Bremer1, Jefferson Cardia Simoes1
1
UFRGS, Porto Alegre, Brazil

Among one of the most rapidly warming regions on Southern Hemisphere, the northern tip of the Antarctica
Peninsula has been reacting to rising air temperatures over the past decades, which have led to greater-than-
average summer melting, causing changes in its ice-covered and ice-free areas. In the Trinity Peninsula, areas
not covered by ice are sparse and restricted to a few headlands, although it is assumed these could significantly
expand as a result of a warmer weather. Mapping these areas create conditions to identify and monitor the
changes occurring in these environments, checking for eventual responses to climate change. Here, we
performed a survey of variations occurred over the last three decades (1988-2017) in the ice-free areas of the
Trinity Peninsula, using Remote Sensing techniques. The study used Landsat satellite imagery to identify ice-
free area variations using the VIS, NIR and SWIR bands to differentiate ice and snow from rocks, which can be
problematic in the Antarctic environment due to extensive cloud cover and areas with shadow.

1132
Wed_371_TE-3_1370
On the Retrieval of Ice Sheet Temperature Profile by using SMOS Satellite Data

Giovanni Macelloni1 (g.macelloni@ifac.cnr.it), Francesco Montomoli1, Marion Leduc-Leballeur1, Marco

Brogioni1, Catherine Ritz2,3, Ghislain Picard2,3
1
IFAC-CNR, Sesto Fiorentino, Italy, 2UGA - CNRS, IGE, Grenoble, France, 3CESBIO (CNES, CNRS, IRD, UPS), Univ.
Toulouse, Toulouse, France

The internal ice sheet temperature is a key parameter for the understanding of the ice sheet dynamics which,
at present, is available only from glaciological models or in the few boreholes where temperature has been
measured. However, the drilling of boreholes is a very expensive activity and the state-of-the-art climate or
glaciological models are unable to determine the temperature profile at continental scale with a sufficient
accuracy. From the spatial analysis of space-borne L-band data from the ESA's SMOS, collected over Antarctica,
it was proved that they are sensitive to the ice sheet temperature profile. The latter depends on several factors
as the ice thickness, the surface temperature, the geothermal heat flux, the mean annual accumulation. The
satellite observations suggested that, by using a proper glaciological and microwave emission model it is
possible to retrieve the ice sheet temperature profile starting from SMOS data. Starting from these
considerations an inversion algorithm, which uses as inputs SMOS data and ancillary information, the ice sheet
temperature profile was derived from a large portion of Antarctica. Areas where the retrieval is not applicable
(i.e. near to the coast or where the ice sheet velocity is higher than 10m/yr) are masked out and a quality flag
with the confidence of the estimation was also provided. Secondary products are the geothermal heat flux and
snow accumulation maps at the same spatial resolution of SMOS.

1133
Wed_372_TE-3_1469
Ice Dynamics of Union Glacier from SAR Offset Tracking

Rodrigo Gomez1,2 (rgomezfell@gmail.com), Jorge Arigony-Neto2, Angela DeSantis3, Christian Gobel2, Ricardo
Jaña4, Saurabh Vijay5
1
Centro Regional Fundacion CEQUA, Punta Arenas, Chile, 2Universidade de Federal do Rio Grande / INCT da
Criosfera, Rio Grande, Brazil, 3HOPE- Humanitarian OPErations, Bruxelles, Belgium, 4Instituto Antárctico Chileno,
Punta Arenas, Chile, 5DTU Space - National Space Institute, Techical University of Denmark, Copenhagen,
Denmark

The Antarctic ice sheet is predicted to be the major contributor to sea-level rise during the XXI century.
Therefore, monitoring ice dynamics of outlet glaciers in Antarctica is of great importance to assess future sea-
level rise predictions. Union Glacier is one of the major outlet glaciers of the Ellsworth Mountains and drains
into the Ronne-Filchner Ice Shelf. We acquired high resolution Stripmap HIMAGE SAR images from the COSMO-
SkyMed satellite constellation during austral summer of 2011-2012, and applied SAR offset tracking to compute
ice velocities. Then, we compared our derived velocities with field data obtained between December 2011 and
January 2012. Mean values of ice velocity estimated for the main trunk of the glacier are 15.7 ma-1, with
maximum values of 109.9 ma-1 and 14.3 ma-1 SD, and are in agreement with previous studies and field
measurements. Higher velocities are associated with changes in elevation between the plateau and the main
valley. A model of ice thickness based on lamellar flow theory is proposed, using estimated surface ice velocity
in combination with surface slope derived from TanDEM-X as input data. Comparison of our modeled ice
thickness with radar data from published studies agree with high accuracy. Finally, we computed principal
strain rates and compared with glacier surface features as seen in high resolution COSMO-SkyMed Spotlight-2
SAR images in order to show the relation between surface features and acting strain components.

1134
Wed_373_TE-3_1570
Spatiotemporal Trend Analysis of Snowmelt on the Antarctic Continent (1978 - 2017)

Marcos Freitas1, Cláudio Mendes Jr.2 (claudio.mendes@ufrgs.br), Juliana Costi3, Jorge Arigony-Neto4, Jefferson
Simões5
1
Federal University of Rio Grande do Sul, Department of Geography, Porto Alegre, Brazil, 2Federal University of
Rio Grande do Sul, Porto Alegre, Brazil, 3Federal University of Rio Grande, Institute of Mathematics, Statistics,
and Physics, Rio Grande, Brazil, 4Federal University of Rio Grande, Rio Grande, Brazil, 5Federal University of Rio
Grande, Porto Alegre, Brazil

We performed a spatiotemporal trend analysis of snowmelt in the Antarctic continent for the 1978-2017
period based on wet snow fraction-images, calculated by the Spectral Linear Mixture Model - SLMM. This
subpixel analysis was performed using passive microwave brightness temperature data (SMMR, SSM/I and
SSMI/S) with daily resolution, and 25 km of spatial one. To measure the snowmelt surface area, we used the
total fraction melt area calculated by the sum of the total wet snow fraction-images during 90 days of the
Austral summer with the highest snow-melt (December, January and February) in seven regions of Antarctica.
Using the Mann-Kendall test, we performed a analysis that shows negative trends in the Antarctic Peninsula,
Marie Byrd Land, Amery Ice Shelf and Dronning Maud Land regions. On the other hand, positive trends are
observed in the Ross Ice Shelf/Siple Coast and Wilkes Land. Taking in consideration these results, we are able to
distinguish two different snow-melting trends according to two groups of regions in the Antarctic continent,
which show a negative trend as a whole.

1135
Wed_374_TE-3_1658
Automatic Sea Ice Drift Tracking from SAR Images

Victoria Khmeleva1 (opa300@yandex.ru), Denis Demchev1, Vladimir Volkov1, Eduard Kazakov1

1
Nansen International Environmental and Remote Sensing Centre, Saint-Petersburg, Russian Federation

The first systematic observation of the ice drift had been held more than a century ago. Spatial ice drift vector
fields can be retrieved from remote sensing data. The sea ice motion is estimated by comparing the points of
sea ice patterns in two subsequent snapshots.
We propose a feature tracking algorithm for sea ice drift retrieval from sequential satellite synthetic aperture
radar (SAR) images. The method is based on feature tracking comprising of feature detection, description and
matching steps. The Scale Invariant Feature Transform (SIFT), its alternative called ORB and A-KAZE features are
selected for the intercomparing. The approach exploits the benefits of nonlinear multi-scale image
representations using A-KAZE features, which is a method that detects and describes image features in an
anisotropic scale space that preserves important object boundaries while adaptively removing noise and small
image details.
These techniques were implemented as a part of ice drift retrieval algorithm and tested on dual polarized
Sentinel-1A C-SAR extra wide swath mode data over Arctic Seas. To evaluate the developed of sea ice drift
retrieval algorithm we performed a series of experiments over the Arctic seas. Data collection and processing is
done in real time. Validation of the results performed in parallel and includes comparisons with other statistical
and manual methods.

1136
Wed_375_TE-3_1675
Remote Sensing Mapping of Western Dronning Maud Land (Antarctica) Geomorphology

Jennifer Newall1,2,3 (jennifer.newall@natgeo.su.se), Elena Serra1, Taisiya Dymova1, Robin Blomdin1,3, Ola
Fredin4,5, Arjen Stroeven1,3, Neil Glasser6, Nathaniel Lifton2,7, Sarah Sams2, Jon Harbor1,2,3, Derek Fabel8, Irina
Rogozhina9,10, Jorge Bernales10, Olaf Eisen9,11
1
Stockholm University, Department of Physical Geography, Stockholm, Sweden, 2Purdue University, Department
of Earth, Atmospheric, and Planetary Sciences, West Lafayette, United States, 3Stockholm University, Bolin
Centre for Climate Research, Stockholm, Sweden, 4Geological Survey of Norway, Trondheim, Norway,
5
Norwegian University of Science and Technology, Department of Geography, Trondheim, Norway,
6
Aberystwyth University, Centre for Glaciology, Department of Geography and Earth Sciences, Aberystwyth,
United Kingdom, 7Purdue University, Department of Physics and Astronomy, and Purdue Rare Isotope
Measurement Laboratory (PRIME Lab), West Lafayette, United States, 8Scottish Universities Environmental
Research Centre, Glasgow, United Kingdom, 9Bremen University, Centre for Marine Environmental Sciences
(MARUM), Bremen, Germany, 10GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam,
Potsdam, Germany, 11Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven,
Germany

Given current climate trends, it is imperative that we improve our understanding of ice-sheet responses to
climate change and consequent sea-level changes. Numerical ice sheet models are central to addressing this
challenge, and are tested and refined by comparing model predictions of past ice geometries with field-based
reconstructions from geological, geomorphological, and ice core data. However, on the East Antarctic Ice
Sheet, Dronning Maud Land (DML) comprises a critical gap in the empirical data required to reconstruct
changes in ice sheet geometry. MAGIC-DML is an international collaboration working to delineate the timing
and pattern of past ice surface changes on the western DML margin and produce a comprehensive
reconstruction of the region's glacial history. Part of this work involves remote-sensing-based mapping of
western DML glacial geomorphology to recognise potential traces of a thicker ice sheet that may have covered
some or all of the mapped nunatak ranges during previous glacial maxima. High-resolution WorldView (WV)
optical satellite data was used in ArcGIS to map landforms manually across a range of scales. Observations from
two field seasons are being used to validate the remote sensing mapping. Here we present the mapping to
date, and evaluate the use of the WV datasets for geomorphological mapping and for cosmogenic nuclide site
selection.

1137
Wed_376_TE-3_1836
Wetlands Identification Methods Applied for Fildes Peninsula, Antarctica

Carina Petsch1 (carinapetsch@gmail.com), Kátia Kellem da Rosa1, Luiz Felipe Velho1, Rosemary Vieira2, Rafaela
Mattos Costa1, Jefferson Cardia Simões1
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Porto Alegre, Brazil, 2Universidade Federal
Fluminense, Niterói, Brazil

The wetlands are flat areas of low altitude that accumulate a thin layer of water and allow the vegetation
growth. So, this study compares a supervised classification and a new multicriteria method developed for the
delimitation of meltwater wetlands. The study area is an ice-free area in the south of King George Island,
Antarctica. We classified seven images of the Landsat series (1986-2017), using the QGIS 2.19.8 software, for
delimiting the wetland area. After classification tests, we concluded the vegetation location is the main factor
to determine the wetlands limits, we use different weights to develop a new processing chain, with the
following variables: vegetation (obtained with the Normalized Difference Vegetation Index - NDVI), slope,
altitude and slopes oriented north and northwest (from a Digital Elevation Model). Supervised classification
identified only lakes, but does not identify correctly wetlands areas. As most wetlands are located in vegetated
areas under 50 m of altitude and slopes less than 16%, respectively, the new method showed good results with
accuracy from 78 to 89%. The new method, however, does not work properly in shadowed areas (due to the
relief) and images with thick snow cover. In short, relief parameters added to the location of the vegetation
allow better results than a simple supervised classification.

1138
Wed_377_TE-3_1897
Impact of Tundra Snow Layer Thickness on Measured and Modelled Radar Backscatter

Nick Rutter1 (nick.rutter@northumbria.ac.uk), Mel Sandells2, Chris Derksen3, Josh King3, Peter Toose3, Leanne
Wake4, Tom Watts4, Matthew Sturm5
1
Northumbria University, Geography and Environmental Sciences, Newcastle upon Tyne, United Kingdom,
2
CORES Science and Engineering Limited, Burnopfield, United Kingdom, 3Environment and Climate Change
Canada, Toronto, Canada, 4Northumbria University, Newcastle upon Tyne, United Kingdom, 5University of
Alaska - Fairbanks, Fairbanks, United States

Microwave radar backscatter within an Arctic tundra snowpack is strongly influenced by spatial variability of
the thickness of internal layering; often comprising two dominant snow layers (basal depth hoar overlain by
wind slab). Determining the relative proportions of depth hoar and wind slab from a snowpack of a known
depth may help our future capacity to invert forward models of electromagnetic backscatter to improve
simulations of snow water equivalent.
Extensive snow measurements were made within Trail Valley Creek, NWT, Canada in April 2013 at 18 pit and 9
trench locations (trench extents ranged between 5m to 50m). Ground microstructure measurements included
traditional stratigraphy, near infrared stratigraphy, Specific Surface Area (SSA), and density. Coincident
airborne Lidar measurements were made of snow depth across the catchment, in addition to airborne radar
snow backscatter (X- and Ku-band Synthetic Aperture Radar).
Ground measurements showed the mean proportion of depth hoar was just under 30% of total snow depth
and the mean proportion of wind slab was consistently greater than 50%, which showed an increasing trend
with increasing total snow depth. Consequently, we run forward simulations of the SMRT microwave scattering
model using Lidar derived snow depths. The influence of microstructural variability on relationships between
airborne radar and simulated backscatter, with spatial aggregation between scales of 10m to 250m, was then
explored.

1139
Wed_378_TE-3_1984
Application of Multi-source Remote Sensing Data in Antarctic/Arctic Expedition

Wenjun Li1 (liwenjun@pric.org.cn), Jian Liu1, Bo Sun1, Tianle Jiang1, Yuqin Xia1
1
Polar Research Institute of China, Shanghai, China

Remote sensing is increasingly being used in the Chinese National Antarctic/Arctic Research Expedition
(CHINARE). In the 33th Chinese Antarctic Research Expedition and the 8th Chinese Arctic Research Expedition,
multi-source remote sensing data were utilized for providing support to ship ice navigation, discharge and
investigation on sea ice. The remote sensing data that used including AMSR2, Terra/Aqua MODIS, Landsat-8,
SPOT-5, Radarsat-2, Sentinel-1A, COSMO-SkyMed, etc. With the aid of the analysis results from the multi-
source and multi-temporal remote sensing data, the 33th Chinese Antarctic Expedition planned ship route
reasonably, explored land-fast sea ice and laid down a plan of discharge; and the 8th Chinese Arctic Expedition
crossed the Trans-Polar Passage successfully, chose appropriate sea ice stations. Applications of remote sensing
data saved time for scientific investigation and logistics services, ensured the safety of people, ship and
equipments.

1140
Wed_379_TE-3_2052
Influence of Gap Filling on the Accuracy of Snow Mapping Using MODIS and VIIRS

Dorothy Hall1 (dorothy.k.hall@nasa.gov), George Riggs2, Nicolo DiGirolamo2, Miguel Roman3

1
University of Maryland, Earth System Science Interdisciplinary Center, College Park, United States, 2SSAI,
Lanham, United States, 3NASA Goddard Space Flight Center, Greenbelt, United States

Global snow-cover maps have been produced from the MODerate-resolution Imaging Spectroradiometer
(MODIS) since 2000 at 500-m resolution, and from the Suomi-National Polar Program (S-NPP) Visible Infrared
Imaging Radiometer Suite (VIIRS) since 2011 at 375-m resolution. Development of an Earth system data record
(ESDR) that utilizes both MODIS and VIIRS snow maps is underway. In November 2017 the second in a series of
VIIRS sensors will be launched on the Joint Polar Satellite System-1 (JPSS-1), with the JPSS-2 satellite scheduled
for launch in 2021, providing the potential to extend NASA's snow-cover ESDR for decades into the future.
Studies are underway to investigate the continuity of time series of datasets between the MODIS/VIIRS NASA
snow-cover data products. In the present study we focus on a time series of daily Terra and Aqua MODIS and
NASA VIIRS cloud-gap filled (CGF) snow-cover maps. A MODIS CGF snow map is available every day irrespective
of cloud cover. We explore the accuracy of cloud-gap filling at different sites in North America, and also
compare the CGF maps with other available snow maps, such as for example, the cloud-free maps derived from
the National Oceanic and Atmospheric Administration (NOAA)'s Interactive Multisensor Snow and Ice Mapping
System (IMS). The advantages and uncertainties of cloud-gap filling are discussed in the context of various
applications of the moderate-resolution ESDR.

1141
Wed_380_TE-3_2108
SnowPEx-The International Snow Products Intercomparison and Evaluation Exercise

Thomas Nagler1, Gabriele Schwaizer1, Chris Derksen2 (chris.derksen@canada.ca), Richard Fernandes3, Kari
Luojus4, Oli-Pekka Mattila5, Sari Metsämäki5, Elisabeth Ripper1, Helmut Rott1, Rune Solberg6, Bojan Bojkov7,8,
Alessandro Burini7,8, Michael Kern9
1
ENVEO IT GmbH, Innsbruck, Austria, 2Environment and Climate Change Canada, Toronto, Canada, 3Natural
Resources Canada, Ottawa, Canada, 4Finnish Meteorological Institute, Helsinki, Finland, 5Finnish Environment
Institute, Helsinki, Finland, 6Norwegian Computing Center, Oslo, Norway, 7ESA, Frascati, Italy, 8EUMETSAT,
Darmstadt, Germany, 9ESA, Noordwijk, Netherlands

Seasonal snow is a main element of the global water cycle and climate system. Accurate, long-term data sets
on main snow cover parameters are crucial for climate monitoring and validation of climate models. In order to
assess the accuracy and performance of different satellite-based snow cover products of continental to global
extent, an international collaborative effort, SnowPEx, was initiated by ESA.
SnowPEx focuses on two parameters of the seasonal snow pack, snow extent (SE) from medium resolution
optical satellite data and snow water equivalent (SWE) from passive microwave sensors. 14 continental to
global snow extent products and three SWE products were evaluated. Statistical measures and spatial pattern
analysis following standardized protocols defined in the project were applied to assess the agreement between
the products in different environments and climate zones. For validation of the products reference data sets,
derived from more than 450 Landsat scenes, and in-situ data from various organisations in Europe, North
America and Asia, were used. SWE products were also compared with output from land surface models driven
by atmospheric reanalysis data. In support of climate studies the trends in the hemispheric SE and SWE time
series of the different satellite based snow products were compared. We provide an overview on the results of
SnowPEx and report on agreement and differences of multi-decadal trends of the various snow products.

1142
Wed_381_TE-3_2159
An Improved Method for Sea Ice Concentration Estimation from SSM/I and AMSR-E

Tingting Liu1 (ttliu23@whu.edu.cn), Zemin Wang1

1
Wuhan University, Chinese Antarctic Center, Wuhan, China

To improve the accuracy of the NASA Team (NT) sea ice concentration (SIC) algorithm, a new SIC estimation
method was proposed by combining the NT algorithm and a numerical optimization technique with Special
Sensor Microwave/Imager (SSM/I) data and Advanced Microwave Scanning Radiometer for EOS (AMSR-E) data
respectively. In this method, the noise was taken into consideration to improve the SIC estimation equation,
and then the fully constrained least squares was used to further optimize the estimation results from the
improved equation. Validation was performed using comparisons between the proposed method, the NT, the
Bootstrap, the NT2, the ASI and in situ data. The quantitative results from SSM/I showed that the proposed
method accurately generated SIC with smaller bias (0.2) and RMSE (9.7) than the other methods. The results
also indicated that the proposed method consistently performed better in not only summer but also winter
(with bias 2.0 in summer and 2.0 in winter, RMSE 13.3 in summer and 7.3 in winter) than the other methods.
The accuracies of all methods in summer were lower than winter, among which the accuracy of the Bootstrap
was the lowest. The accuracies of the proposed method, NT2 and ASI using AMSR-E indicated that the
performance of the proposed method was found to be better than the NT2 algorithm and ASI algorithm in
quantitative comparisons. This research demonstrated the benefit of incorporating numerical optimization into
SIC estimation.

1143
Wed_382_TE-3_2224
AIM-North: The Atmospheric Imaging Mission for Northern Regions

Ray Nassar1 (ray.nassar@canada.ca), Chris McLinden2, Chris Sioris2, Joseph Mendonca1,3

1
Environment and Climate Change Canada, Climate Research Division, Toronto, Canada, 2Environment and
Climate Change Canada, Air Quality Research Division, Toronto, Canada, 3University of Toronto, Physics,
Toronto, Canada

Low Earth orbit (LEO) satellites offer global sampling, but revisit times can be days to weeks. Geostationary
(GEO) satellites can observe a selected region multiple times per day, but have difficulty poleward of ~50°N/S.
A constellation of 2 satellites in a highly elliptical orbit (HEO) configuration can provide quasi-geostationary
observations of the high latitudes. AIM-North is a Canadian mission concept that would provide observations of
unprecedented frequency, density and quality for monitoring greenhouse gases (GHGs) and air quality (AQ)
over landmasses from ~40-80°N, using a pair of HEO satellites. AIM-North would image the GHGs CO2 and CH4,
as well as CO in the shortwave-infrared (SWIR) and AQ species: O3, NO2, SO2, HCHO, BrO, aerosol and others, in
the ultraviolet-visible (UV-vis), multiple times per day with a pixel size of 3x3 km2. Additional IR bands could
provide complementary observations for weather, climate and AQ research and operations. AIM-North would
improve our ability to monitor the delicate carbon balance of Arctic permafrost and boreal forests, and help to
quantify anthropogenic GHGs emissions at multiple scales. Its unprecedented observations could capture
emissions from wildfires, the oil sands, or cities improving our understanding and prediction of air quality in the
north. Since AIM-North would make valuable observations over many northern countries, scenarios for an
international partnership in the AIM-North mission can be explored.

1144
Wed_383_TE-3_2314
Multiyear Sea Ice Concentration Estimates Using ASCAT and AMSR2 Data

Yufang Ye1 (yufang.ye@chalmers.se), Gunnar Spreen2, Mohammed Shokr3, Georg Heygster2, Christian
Melsheimer2
1
Chalmers University of Technology, Department of Space, Earth and Environment, Gothenburg, Sweden,
2
University of Bremen, Bremen, Germany, 3Environment & Climate Change Canada, Toronto, Canada

Multiyear ice (MYI) concentration can be retrieved from passive or active microwave remote sensing
observations. One of the algorithms that combine both observations is the Environmental Canada Ice
Concentration Extractor (ECICE). In this study, data from the Advanced Scatterometer (ASCAT) and the
Advanced Microwave Remote Sensing Radiomter 2 (AMSR2) are employed to retrieve concentrations of MYI.
Combined active and passive microwave data can help to distinguish MYI from first-year ice, however, factors
such as ice deformation, snow wetness and metamorphism can cause significant changes in brightness
temperature and backscatter, leading to misidentification of MYI. Therefore, two corrections were applied to
the MYI concentration retrievals from ECICE with inputs from ASCAT and AMSR2 observations. One correction
utilizes air temperature to restore the underestimated MYI concentrations under warm conditions, whereas
the other mainly uses sea ice drift to correct the overestimated MYI concentrations. The results are compared
with the ice charts from Canadian Ice Service (CIS), sea ice age dataset from NSIDC, and sea ice type product
from EUMETSAT OSISAF. The MYI concentration from ASCAT/AMSR2 agrees well with that in the ice charts.
Compared to the ice classified as two years or older in the sea ice age dataset, the MYI concentration from
ASCAT/AMSR2 is approximately 50% or greater. Besides, SAR images from Sentinel-1 are used to evaluate the
MYI estimates in different regions.

1145
Wed_384_TE-3_2326
Low Power Wide Area Network Deployment for Science

Johan Berte1 (info@antarctiq.com), Erik Verhagen1

1
Private, Wervik, Belgium

Operations in polar regions have a high cost compromising the scope of scientific campaigns. Equipping sensors
in a distributed network with satellite links is impractical and expensive. Furthermore satellite networks are not
designed to support large scale multi-parametric studies. A new paradigm has emerged in regional scale
telecommunications, the LPWAN (Low-Power Wide Area Networks). This technology is specifically tailored for
distributed networks.
AntarctiQ´s mission is to support operations in extreme environments. AntarctiQ has a multiple-year
experience in Antarctica ranging from infrastructure design, systems engineering, science support, prototyping,
science equipment customisation, expedition planning, logistics and on-site activities.
In 2017/2018, AntarctiQ - in partnership with Sigfox (LPWAN) and Sensolus (sensors) - will demonstrate a case
of distributed low-power science sensors and LPWAN deployment in Antarctica, this for future large scale
network deployment. A vessel will be hosting an LPWAN base station, ensuring a local +50 km low-power radio
network dedicated to remote sensing. Different wireless scientific and operational sensors will be placed in the
field to demonstrate operational safety and scientific optimisation. Data will be sent to the project
stakeholders over marine satellite communications with a minimal impact on the bandwidth due to the Sigfox
communication protocol. Users will be able to collect their data and activities in real-time.

1146
Wed_385_TE-3_2382
Gravimetric Mass Balance Products for the Antarctic and Greenland Ice Sheet

Martin Horwath1 (martin.horwath@tu-dresden.de), Andreas Groh1, Alexander Horvath2, René Forsberg3, Rakia
Meister3, Valentina R. Barletta3, Andrew Shepherd4
1
Technische Universität Dresden, Dresden, Germany, 2Technische Universität München, München, Germany,
3
Technical University of Denmark, Copenhagen, Denmark, 4University of Leeds, Leeds, United Kingdom

The ESA Climate Change Initiative (CCI) projects on the Antarctic Ice Sheet (AIS_cci) and the Greenland Ice
Sheet (GIS_cci) provide Gravimetric Mass Balance (GMB) products based on satellite gravimetry data acquired
by the GRACE (Gravity Recovery and Climate Experiment) mission. Monthly solutions produced at TU Graz are
utilized to derive two different types of products for the period 2002 - 2016:
(1) GMB basin products (i.e. time series of monthly mass changes for the entire ice sheets and selected
drainage basins) and
(2) GMB gridded products (e.g. mass balance estimates with a formal resolution of about 50km). While a
regional integration approach is used by the AIS_cci project, the GMB products of the GIS_cci project are
derived using a point mass inversion.
Here we present the final version of the ESA CCI GMB products, which are freely available through data portals
hosted by the projects (data1.geo.tu-dresden.de/ais_gmb, products.esa-icesheets-
cci.org/products/downloadlist/GMB). Since the initial product release in mid 2016, the applied processing
strategies have been improved in order to further reduce GRACE errors and to enhance the separation of
signals super-imposed to the ice mass changes. The differences between both processing strategies are
investigated through the example of the GIS. Finally, mass balance estimates for both ice sheets as well as their
corresponding contributions to global sea level rise are derived from the final GMB products.

1147
Wed_386_TE-3_2384
Vegetation Identification by Image Processing at Fildes Peninsula, Antarctica

Luiz Felipe Velho1 (lfvelho@gmail.com), Carina Petsch2, Rosemary Vieira3, Jefferson Cardia Simões2
1
Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Porto Alegre, Brazil, 2Universidade
Federal do Rio Grande do Sul, Porto Alegre, Brazil, 3Universidade Federal Fluminense, Niterói, Brazil

Wetlands are common in proglacial areas and are associated with the occurrence of vegetation. Mapping these
areas is essential for environmental studies. The aim of this study is to identify vegetation fields in the Fildes
Peninsula on King George Island, Antarctica using a combination of image processing techniques. The target
vegetation was used to facilitate the identification of flooded areas by satellite images. For the image
processing, we chose a Landsat 8 OLI image from 2016. Segmentation was performed for the identification of
endmembers that are later used in the linear mixture model. Three fractions were defined: vegetation, snow,
and shade. Our results show that those areas presenting the greatest vegetation fraction are coincident with
areas of mosses and lichens in the Fildes Peninsula. We plan to compare the results with other images and field
data to verify the accuracy of the vegetation fraction.

1148
Wed_387_TE-3_2431
Digital Processing of Non-conventional Aerial Photos of Maritime Antarctica

Pedro Henrique Araujo Almeida1 (phalmeida06@gmail.com), Márcio Rocha Francelino1, Elpidio Inácio
Fernandes Filho1, Carlos Ernesto Gonçalves Reynauld Schaefer1
1
Universidade Federal de Viçosa / INCT da Criosfera, Departamento de Solos - Núcleo TERRANTAR, Viçosa, Brazil

The development of new technologies applied to cartography and digital mapping allowed the reprocessing of
old materials obtained by non-conventional techniques, such as non-metric cameras, generated at a time when
the available tools were not so accurate. In this work we reprocessed aerial photos obtained in January 2003
from a flying over Keller Peninsula, located on King George Island, South Shetland, where the Brazilian Research
Station in Antarctica is located. 56 photographs were obtained, revealed and digitized, producing a mosaic of
the entire area. A total of 50 points were evenly distributed across Keller peninsula in the form of semi-regular
grid. With these data it was possible to generate both the new MDS and the orthophotomosaic. The result was
a much less time consuming effort in the post-processing of the images, besides determination of the level of
accuracy of the data generated. This work demonstrates that past aerial photos obtained in Antarctica through
conventional techniques over the last decades can be reprocessed using these new tools and the data of this
collection assumes historical importance in monitoring the dynamics of the glaciers of that region. Allied to this
technology, the use of light aerial vehicles (VANTS) has great potential in the studies of terrestrial ecosystems
of Antarctic ice-free areas and in the monitoring of glaciers, greatly reducing the logistics and costs of this type
of work.

1149
Wed_388_TE-3_2437
Landsat Polar Remote Sensing: Data Acquisition, Access, and Quality Advancements

Christopher Crawford1 (christopher.crawford.ctr@usgs.gov), John Dwyer1

1
U.S. Geological Survey Earth Resources Observation and Science Center, Science and Applications Branch, Sioux
Falls, United States

Cryosphere measurement capabilities from instruments prior to Landsat 8 were plagued by radiance saturation
and limited Polar Region data acquisition. The long term acquisition plan (LTAP) was revised to include imaging
of all sunlit land areas with greater than 85o solar zenith with the launch of Landsat 8. This has significantly
increased polar region coverage. With Landsat 9's 2021 launch and commissioning target, the Landsat 8/9
multi-mission LTAP will substantially increase sub-weekly cloud-free measurements over the circumpolar Arctic
and Antarctica. Access to Landsat's archive is evolving with the global Analysis-Ready Data (ARD) concept.
Global ARD will deliver well-calibrated geophysical data products with known measurement traceability and
quality assurance. Here, we summarize efforts to benchmark Landsat 8's surface measurement quality over
northwestern Greenland by using NIST traceable visible-to-shortwave infrared (VSWIR) spectrometry as part of
a NASA ICESat-2 airborne campaign to the Arctic in the summer of 2015. Our July 29, 2015 flight line analysis
with near-coincident Landsat 8 acquisitions indicates that the Operational Land Imager (OLI) is measuring land
ice surface reflectance and ocean leaving reflectance at 4-30% accuracy, which is wavelength dependent and
largely attributable to atmospheric compensation uncertainty. Our goal is to define polar measurement
requirements for Landsat's next generation instruments by learning from Landsat 8 capabilities.

1150
Wed_389_TE-3_2656
Multi-decadal Arctic Sea Ice Roughness

Michel Tsamados1 (m.tsamados@ucl.ac.uk)

1
University College London, London, United Kingdom

The transformation of Arctic sea ice from mainly perennial, multi-year ice to a seasonal, first-year ice is
believed to have been accompanied by a reduction of the roughness of the ice cover surface.
This smoothening effect has been shown to
(i) modify the momentum and heat transfer between the atmosphere and ocean,
(ii) to alter the ice thickness distribution which in turn controls the snow and melt pond repartition over the ice
cover, and
(iii) to bias airborne and satellite remote sensing measurements that depend on the scattering and reflective
characteristics over the sea ice surface topography.
We will review existing and novel remote sensing methodologies proposed to estimate sea ice roughness,
ranging from airborne LIDAR measurement (ie Operation IceBridge), to backscatter coefficients from
scatterometers (ASCAT, QUICKSCAT), to multi angle maging spectroradiometer (MISR), and to laser (Icesat) and
radar altimeters (Envisat, Cryosat, Altika, Sentinel-3).
We will show that by comparing and cross-calibrating these different products we can offer a consistent multi-
mission, multi-decadal view of the declining sea ice roughness. Implications for sea ice physics, climate and
remote sensing will also be discussed.

1151
Morning Plenary II
21.06.2018 07:50-09:00, A Davos

Keynote Lecture III, IASC Medal Recipient

Governing the Polar Regions in an Era of Global Change

Oran R. Young (oran.young@gmail.com)

Bren School of Environmental Science and Management, University of California (Santa Barbara)

I address three themes: the focus of my research program, lessons learned about governance that are relevant
to the polar regions, and the consequences of the onset of the Anthropocene for polar governance. Focusing
on governance as a social function centered on steering societies toward desirable outcomes (e.g. long-term
sustainability) and away from undesirable outcomes (e.g. the tragedy of the commons), I analyze the creation
and effectiveness of governance systems. Key lessons include: (i) regime design matters, (ii) international
legally binding instruments often have drawbacks, (iii) regulation is not the be all and end all of governance, (iv)
clustering regimes into complexes makes sense under some circumstances, and (v) regimes can produce islands
of cooperation even in times of conflict. The onset of the Anthropocene, occurring at a more rapid pace in the
Arctic than anywhere else on the planet, will have major consequences for the development and
implementation of effective governance systems for the polar regions. Among other things, we will need to:
emphasize early warning; beware of the dangers of institutional reductionism; avoid institutional lock in; and
learn to live with high levels frequent surprises.

1152
Morning Plenary II
21.06.2018 07:50-09:00, A Davos

Keynote Lecture IV, Tinker-Muse Prize Recipient

Changes in Southern Ocean circulation and properties: causes and consequences

Mike Meredith (mmm@bas.ac.uk)

British Antarctic Survey BAS, Cambridge, UK

The Southern Ocean exerts significant influence over the rest of Planet Earth, and directly affects the lives and
livelihoods of its inhabitants. It is a key regulator of global climate, absorbing large quantities of heat and carbon
(including human-produced) from the atmosphere, and storing them deep in the ocean interior. It is also
increasingly seen to be a key influence on the stability of the Antarctic Ice Sheet, and is the home for diverse
marine ecosystems and species, some of which are of commercial significance. There is strengthening evidence
that the Southern Ocean circulation is changing, from the surface to the abyss, and the increasing availability of
data from innovative sources is unveiling new levels of complexity to this to change. This talk will discuss some
specific examples of Southern Ocean circulation change, its importance, and the ongoing requirement for
sustained observations from this most challenging of environments.

1153
BE-4g - Climate change and ecosystems: physiology, biodiversity and ecological functions
21.06.2018 09:00-10:30, A Schwarzhorn

1443
Local Environmental Gradients Interact to Structure Arctic Arthropod Communities

Toke Høye1 (tth@bios.au.dk), Joseph Bowden2, Oskar Hansen1, Rikke Hansen1, Thøger Henriksen1, Andreas
Niebuhr1, Mathias Skytte1
1
Aarhus University, Department of Bioscience, Aarhus, Denmark, 2Canadian Forest Service, Corner Brook,
Canada

The organization of ecological communities along local environmental gradients provides important
information about how such communities may respond to environmental change. By replicating observations
along gradients in shrub and moisture at multiple elevations and using space-for-time substitution, it is possible
to examine how arthropod communities may respond to future change. We collected and identified 4640 adult
specimens of spiders and beetles near Narsarsuaq, South Greenland during the 2014 growing season from 112
pitfall traps. The traps were arranged in plots covering local gradients in either soil moisture or tall shrub
dominance at low and high elevation. Multivariate generalized linear models revealed that community
composition was significantly related to shrub height and soil moisture, and that this relationship varied
between low and high elevation. Among the 46 species we found, more species were unique at high than at
low elevation, a finding that was most pronounced for spiders in plots along soil moisture gradients. Indicator
species analysis corroborated earlier findings of the indicator value of specific species and suggested that
beetles are better indicators of specific habitats than spiders. Placing plots along local environmental gradients
allowed us to detect fine-scale variation in arthropod communities. Together, our results suggest that Arctic
arthropod community responses to environmental change may differ among low and high elevation sites.

1154
2686
Tundra Fire Alters the Structure and Function of Microbial-invertebrate Food Web

Amanda Koltz1 (amanda.koltz@gmail.com), Ashley Asmus2, Yamina Pressler3, Gaius Shaver4, Laura Gough5,
John C. Moore3
1
Washington University in St Louis, Biology, St. Louis, United States, 2University of Minnesota, St. Paul, United
States, 3Colorado State University, Fort Collins, United States, 4Marine Biological Laboratory, Woods Hole,
United States, 5Towson University, Towson, United States

While historically rare, arctic wildfire is becoming more common due to warmer temperatures and drier
conditions. The 2007 Anaktuvuk River fire burned over 1000 km2 of the Alaskan Arctic, resulting in combustion
of most of the organic soil horizon and fundamentally altering the above- and belowground systems. We
investigated recovery of the microbial-invertebrate food web six years post-fire in order to understand how fire
alters the structure and function of these communities and how recovery varies with fire severity. We
constructed comprehensive food webs based on functional groups of microbes, protozoa, and invertebrates
from the soil, soil surface and plant canopy at three sites (non-burned, moderately and severely burned) and
used an energetic food web model to estimate C flow through the food web and group-specific rates of C and N
cycling. We found that soil and canopy invertebrate biomass was disproportionately higher at the severely
burned site compared to non-burned or moderately burned sites. Aboveground herbivory increased
significantly with burn severity but food webs at all sites were still primarily based on C derived from detrital
resources. Contributions to nutrient cycling were highest by soil-dwelling consumers and increased with fire
severity. While responses were asynchronous across microhabitats, our results demonstrate rapid recovery of
community function to wildfire and suggest that the microbial-invertebrate food web is more resilient than
expected.

1155
2325
Microbial Biodiversity in Siberian Ecosystems: Insights into Methane Cycling

Maialen Barret1, Laure Gandois1, Roman Teisserenc1, Nikita Tananaev2, Frederic Thalasso3, Karla Martinez3,
Armando Sepulveda3, Léa Cabrol4,5 (lea.cabrol@mio.osupytheas.fr)
1
Université de Toulouse, Ecolab, UMR5245, CNRS, INPT, UPS, Castanet Tolosan, France, 2P.I. Melnikov
Permafrost Institute, Yakutsk, Russian Federation, 3Universidad de Magallanes, Magallanes, Chile, 4Pontificia
Universidad Católica de Valparaíso, Valparaiso, Chile, 5Institut Méditerranéen d'Océanologie, Marseille, France

High-latitude ecosystems are strongly affected by climate change. Methane emissions resulting from the
microbial activity in soils and lakes might constitute a positive feedback. Indeed, warming may disrupt the
methane cycle, by altering the microbial community composition and the relative abundances of key players in
methane cycling, by affecting the metabolic pathways, yields and productivities of methane producers and
consumers. Surveying the microbial diversity and functionalities in these ecosystems is essential for a better
understanding of their potential feedback to climate change. In this study, 90 samples were collected from
various ecosystems in Siberian Arctic (discontinuous permafrost, including 7 peatlands, 5 lakes, and 4 taiga
ecosystems representative of the region). In each site, various samples were collected to take into account the
local heterogeneity. DNA was extracted, the bacterial and archaeal 16S rRNA genes were amplified by PCR
using universal primers. High-throughput sequencing of these amplicons was carried out with Illumina MiSeq
technology. This survey of microbial biodiversity evidenced a structuration of microbial communities as a
function of ecosystem characteristics. The relative abundance and taxonomy of methane producers
(acetoclastic / hydrogenotrophic) and methane consumers (aerobic / anaerobic) was extracted from sequences
analysis. These data improved our understanding of the CH4 cycling in such ecosystems affected by climate
change.

1156
1979
Will Rhizosphere ´Priming´ Limit Soil Carbon Sequestration in a Warmer Arctic?

Philip Andrew Wookey1 (philip.wookey1@stir.ac.uk), Thomas C Parker1, Karina E Clemmensen2, Mark H

Garnett3, Iain P Hartley4, David Johnson5, Björn D Lindahl6, Lorna E Street7, Jens-Arne Subke1, Mathew Williams7
1
University of Stirling, Biological and Environmental Sciences, Stirling, United Kingdom, 2Swedish University of
Agricultural Sciences (SLU), Department of Forest Mycology and Plant Pathology, Uppsala, Sweden, 3NERC
Radiocarbon Facility (Environment), East Kilbride, United Kingdom, 4University of Exeter, Geography, Exeter,
United Kingdom, 5University of Manchester, School of Earth and Environmental Sciences, Manchester, United
Kingdom, 6Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, Uppsala,
Sweden, 7University of Edinburgh, School of Geosciences, Edinburgh, United Kingdom

Northern high latitudes store significant amounts of carbon (C) in soil organic matter (SOM). There is major
uncertainty over the vulnerability of these C stores to both climate and land-use change. Previous research has
focused on the direct effects of warming on plant growth and/or SOM dynamics in isolation, but there is
increasing evidence that plant-soil interactions complicate these relationships dramatically. Plants not only
control litter inputs (both quality and quantity), but may also influence rates of decomposition if the amount of
C allocated to the ´rhizosphere´ (defined as the area of soil in the vicinity of plant roots in which the chemistry
and microbiology is influenced by their growth, respiration, and nutrient exchange) is positively related to
microbial activity and the breakdown of older, more recalcitrant, organic matter. This process is referred to as
rhizosphere ´priming´, and despite suggestions that it may be critical in determining ecosystem C storage, it
remains extremely poorly understood, especially in natural and semi-natural ecosystems.
Here we outline the approach underpinning a new research project ('PRIME-TIME') on rhizosphere priming,
based in Swedish Lapland, and we present our initial findings. The project deploys state-of-the-art natural
abundance 14-C methodologies, and mycorrhizal fungal community analysis, to determine the impacts of shifts
in plant (and associated mycorrhizal) functional composition on SOM dynamics and C fluxes.

1157
1514
Decomposition Rates along Two Arctic Shrub Dominance Gradients in West Greenland

Casper T. Christiansen1,2, Regin Rønn3, Daan Blok4 (daanblok@gmail.com), Bo Elberling5, Hanna Lee1,2, Anders
Michelsen5
1
Uni Research Climate, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen, Norway, 3University of
Copenhagen, Arctic Station, Qeqertarsuaq, Greenland, 4Lund University, Department of Physical Geography and
Ecosystem Science, Lund, Sweden, 5University of Copenhagen, Center for Permafrost (CENPERM), Copenhagen,
Denmark

Due to recent climate change, many Arctic tundra regions are currently undergoing a vegetation shift towards
increasing growth and ground-cover of deciduous shrubs. Canopy-forming shrubs can alter key ecosystem
functions with strong links to climatic feedbacks, such as carbon sequestration into plant biomass and energy
balance. However, we know little about the potential biological and physical feedback mechanisms by which
these shrubs may affect litter and soil organic matter decay, and thus whole-ecosystem carbon balance.
Here, we present summer and annual decomposition data, using the Tea Bag Index, from Disko Island,
Greenland (69ºN), where we incubated 800 teabags along two deciduous shrub dominance gradients (Betula
nana and Salix glauca, respectively). We incorporated landscape variation in soil temperature and moisture
regimes within our shrub gradients by establishing 25 study sites across a 4 km2 area. This allowed us to
investigate the effect of increasing deciduous shrub dominance on teabag decay rates and nutrient content -
and relate these dependent variables to multiple vegetation, and soil microclimate and biogeochemistry
parameters.
Summer data show faster decay in the tallest shrub communities, and this vegetation-specific effect appeared
unrelated to soil microclimate. Understanding the intricate feedback mechanisms between deciduous shrub
growth and decomposition rates is vital to predict the impacts of vegetation-climate feedbacks in tundra
environments.

1158
1847
The Effects of Deep Nitrogen and Root Traits on Arctic Vegetation Dynamics

Rebecca Hewitt1 (rebecca.hewitt@nau.edu), Helene Genet2, Lee Taylor3, Dave McGuire4,5, Michelle Mack6
1
Northern Arizona University, Center for Ecosystem Science, Flagstaff, United States, 2University of Alaska -
Fairbanks, Institute of Arctic Biology, Fairbanks, United States, 3University of New Mexico, Department of
Biology, Albuquerque, United States, 4United States Geological Survey, Alaska Cooperative Fish and Wildlife
Research Unit, Fairbanks, United States, 5University of Alaska - Fairbanks, Fairbanks, United States, 6Northern
Arizona University, Center for Ecosystem Science and Society, Flagstaff, United States

The release of permafrost-derived nitrogen (N) has the potential to fertilize tundra vegetation, modulate plant
competition, stimulate productivity, and offset carbon losses from thawing permafrost. To test if Arctic plants
can access deep permafrost-derived N, we characterized rooting profiles and quantified acquisition of 15N
tracer applied at the top of the permafrost table in moist acidic tundra subjected to almost three decades of
experimental warming at Toolik Lake, Alaska. We harvested roots by depth increment down to the top of the
permafrost table in ambient and warmed plots. The average thaw depth in warmed plots was close to 18 cm
deeper than in ambient plots (warmed 58.3 cm ± 6.4 S.E.; ambient 40.8 cm ± 1.8 S.E.). Across treatments the
deepest rooting species was the forb Rubus chamaemorus (warmed 50.3 cm ± 9.8 S.E.; ambient 40.8 cm ± 1.8
S.E.) followed by the sedge Eriophorum vaginatum. These species showed the greatest uptake of tracer after 24
hours. Deciduous and evergreen shrubs had more shallow rooting depths and lower tracer enrichment. We will
present a conceptual framework for integrating dynamic rooting in relation to thaw depth into a process-based
ecosystem model coupled with a dynamic vegetation model to evaluate these effects on vegetation
productivity. Future modeling experiments will contribute to more accurate predictions of vegetation change in
the Arctic modulated by belowground plant traits and changing soil resources with warming.

1159
BE-2a - Phytoplankton, productivity and carbon export dynamics
21.06.2018 09:00-10:30, A Seehorn

2265
Riding on the “Ferrous Wave”— Bacteria Are Outcompeted by Small Phytoplankton

Marion Fourquez1,2,3 (marion.fourquez@gmail.com), Matthieu Bressac2,4, Michael Ellwood5, Christel Hassler3,

Ingrid Obernosterer6, Tom Trull1,7, Phil Boyd1,2
1
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Australia,
2
Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia, 3University of Geneva, F.-
A. Forel for Environmental and Aquatic Sciences Marine and Lake Biogeochemistry, Genève, Switzerland,
4
Sorbonne Universités, Université Pierre et Marie Curie, UMR7093, Observatoire Océanologique de Villefranche-
sur-Mer, Villefranche-sur-Mer, France, 5Research School of Earth Sciences, The Australian National University,
Canberra, Australia, 6CNRS, Sorbonne Universités, UPMC Univ Paris 06, Laboratoire d'Océanographie
Microbienne, Observatoire Océanologique, Banyuls-sur-mer, France, 7CSIRO Oceans and Climate Flagship,
Hobart, Australia

Iron (Fe) is a paradox in the Modern Ocean—its sits at the heart of many life-critical enzymes but is barely
available across most of its surface. Despite inventive Fe uptake systems, recent works suggest that
heterotrophic bacteria are outcompeted by small diatoms, therefore limiting their access to Fe. To test this
hypothesis, incubation experiments were carried out in the Subantarctic Zone of the Southern Ocean (Mar.-
Apr. 2016). Experiments were designed
(1) to determine whether carbon (C), Fe, or both elements limit the bacterial growth and
(2) to investigate microbial interactions to acquire Fe.
A pronounced response in bulk and cell-specific bacterial production to single (+C) and combined (+C+Fe)
additions of C was observed, while no stimulation by Fe addition alone was detected. Moreover, for
concomitant Fe and C additions, cell-specific bacterial Fe uptake rate increased by 8-folds compared to control
and was up to 240-times larger when small phytoplankton was excluded from incubations. The results suggest
that bacterial growth was limited by labile C rather than by Fe, and that C availability enhances the bacterial Fe
demand. Consequently, the competition for Fe would arise among prokaryotes and eukaryotes when limitation
in C is alleviated. We believe that such interactions among members of the microbial community could have a
marked effect on the extent of bacterially mediated Fe and C cycling, especially towards the end of nutrient-
limited phytoplankton blooms.

1160
1281
Role of Particle-attached Bacteria in Rendering Iron and Carbon Bioavailable

Ingrid Obernosterer1 (ingrid.obernosterer@obs-banyuls.fr), Stéphane Blain1, Pavla Debeljak1, Andy Bowie2, Pier
van der Merwe2, Thomas Holmes2, Manon Tonnard2
1
CNRS/UPMC, Banyuls sur Mer, France, 2UTAS/IMAS, Hobart, Australia

Iron and carbon are essential for microbial heterotrophic activity, but the bioavailability of these elements is
low in surface waters of the Southern Ocean. In the present study we tested the hypothesis that the activity of
particle-attached heterotrophic bacteria affects microbial dynamics in surrounding waters due to the release of
bioavailable sources of iron and carbon. We performed incubation experiments with biogenic and lithogenic
particles collected during the Heard Earth-Ocean-Biosphere Interactions (HEOBI) cruise aboard the Australian
R/V Investigator (8 January -27 February 2016). Our results reveal pronounced differences in the bacterially-
mediated processing of biogenic and lithogenic particles. This contribution will present data on the chemical
composition of the particles, the taxonomic composition of the associated bacterial community and their gene
expression patterns for a better understanding of the access to particle-bound iron and carbon in the Southern
Ocean.

1161
1614
Sea Ice is a Source of Iron-free Organic Ligands

Cristina Genovese1 (cristina.genovese@utas.edu.au), Marco Grotti2, Jessica Pittaluga2, Francisco Ardini2, Julie
Janssens1, Kathrin Wuttig1, Sebastien Moreau1, Delphine Lannuzel1
1
University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia, 2University of Genoa,
Department of Chemistry and Industrial Chemistry, Genoa, Italy

The incorporation and the release of iron in forming and melting sea ice are paramount mechanisms for
primary productivity in polar environment. It is thought that iron-binding organic ligands (Lt) can help in
stabilizing dissolved iron (DFe) at surface seawater. In order to test the hypothesis that Lt control the DFe
distribution in Antarctic pack ice, we investigated iron organic speciation during the Sea Ice Physics and
Ecosystem eXperiment-2 voyage, in 2012. Concentration of Lt ranged from 4.9 nM to 41 nM, always in a higher
concentration than the corresponding DFe. Their similar profiles and strong correlation suggested that Lt
control DFe distribution in Antarctic pack ice. Both strong and weak ligands were observed, with conditional
stability constants (logK'Fe3+L = 21.7-23.0) values similar to those previously observed in land-fast ice. Organic
ligands were not saturated with iron (Lt/DFe > 1), unlike previous results for fast ice. Flux estimates show that
pack ice would release 0.45 µmol/m2/d of Lt during spring melt, 0.21 µmol/m2/d of which are free of Fe, and
therefore available for further complexation. This may suggest that the free ligands excess released from sea
ice could help in stabilizing Fe at surface, in the marginal ice zone of the Southern Ocean. Given our findings
and the fact that sea-ice extent is thought to decrease, the sea-ice capability to stock Fe during winter would
also decrease, leading to less bio-available Fe in the marginal ice zone.

1162
89
Recycling of Iron Binding Ligands in the Context of Ocean Circulation

Christel Hassler1 (christel.hassler@unige.ch), Damien Cabanes1, Sylvia Sanders2, Ronald Benner3

1
University of Geneva, Geneva, Switzerland, 2University of Otago, Dunedin, New Zealand, 3University of South
Carolina, Columbia, United States

Iron-binding ligands are paramount to maintain iron in solution and sustain primary producers. In surface water
of the open ocean, ligands are mostly derived from in situ biological activity. Microbial decomposition
processes alter and transform organic matter as it is transported at depth, leaving behind refractory humic
substances rich in carboxylated aliphatic molecules. Here we compared labile and freshly-produced dissolved
organic matter (DOM) collected from a diatom bloom with refractory DOM collected at 1000 m. Both types of
DOM contribute to the iron-binding ligand pool, with stability constants similar to those reported in the ocean.
However, only the deep DOM has a strong iron-binding humic-like signature, consistent with previous
structural characterizations. Ability to support phytoplankton iron assimilation was 4-fold greater for plankton-
derived than deep DOM. This observation reinforces the importance of biologically-produced DOM for iron
biogeochemistry in surface water. Exposure the deep DOM to full sun spectral light under controlled
temperature, showed altered molecular size and structure of the refractory DOM as well as any iron-binding
ligands within our analytical detection limit. Therefore, photodegradation of freshly upwelled iron-binding
ligands can fuel iron remineralisation and its binding to labile and highly bioavailable DOM present in surface
water. These two process thus act together to sustain primary producers.

1163
594
Nutrient Recycling Influences Microbial Communities in the Southern Ocean

Lavenia Ratnarajah1 (lavenia.ratnarajah@utas.edu.au), Ingrid Obernosterer2, Stéphane Blain2, Philipe Catala2,

Pier van der Merwe1, Kathrin Wuttig1, Thomas Holmes1,3, Manon Tonnard3, Ari Friedlaender4, Delphine
Lannuzel1,3, Andrew Bowie1,3
1
Antarctic Climate & Ecosystems Cooperative Research Centre, Battery Point, Australia, 2Université Pierre et
Marie Curie-Paris 6, UMR 7621, CNRS, Banyuls-sur-mer, France, 3Institute for Marine and Antarctic Studies,
Battery Point, Australia, 4Oregon State University, Newport, United States

Phytoplankton and bacteria are two key components of the biological carbon pump. Autotrophic
phytoplankton acts as a sink of carbon dioxide. Comparatively, heterotrophic bacteria act as a source of CO2
but also convert labile dissolved organic carbon to recalcitrant dissolved organic carbon. The widespread
scarcity of the trace element iron has been demonstrated to limit phytoplankton and heterotrophic bacterial
growth in large areas of the Southern Ocean resulting in potential competition between these groups to access
the available iron fraction. We investigated the response of the autotrophic and heterotrophic microbial
communities through incubation experiments with whale faecal additions over a 12-day period in the sub-
Antarctic Southern Ocean region, close to Heard Island. The addition of 3 types of whale faecal material to
surface seawater resulted in an increase in dissolved iron and organic carbon concentrations while major
inorganic nutrients were not enhanced. Our results demonstrated that the addition of whale faecal material
stimulated the growth of heterotrophic bacteria and heterotrophic nanoflagellates, but not autotrophic pico-
nanoeukaryotes. Similar studies in the region have demonstrated that the growth of heterotrophic bacteria is
co-limited by iron and organic carbon. Whale faecal material likely provided the heterotrophic community with
organic carbon and iron to rapidly increase in biomass.

1164
1657
Biogeochemical Cycling of Metal Micronutrient Isotopes in the Southern Ocean

Matthias Sieber1 (matthias.sieber@erdw.ethz.ch), Tim M. Conway1,2, Michael Ellwood3, Derek Vance1

1
ETH Zürich, Institute of Geochemistry and Petrology, Zürich, Switzerland, 2University of South Florida, College of
Marine Science & School of Geosciences, St. Petersburg, United States, 3Australian National University, Research
School of Earth Sciences, Canberra, Australia

The metal micronutrients iron (Fe), zinc (Zn) and cadmium (Cd) play vital physiological roles in phytoplankton
and, ultimately, their distributions control primary productivity and sequestration of carbon by the ocean's
biosphere. Dissolved stable isotope ratios of these bioactive trace metals provide useful information, both for
understanding their cycling through the oceans and tracing their influence on phytoplankton ecology.
Here, we present water column profiles of dissolved Fe (δ56Fe), Zn (δ66Zn) and Cd (δ114Cd) isotopes from the
Pacific and Atlantic sectors of the Southern Ocean, from the recent Antarctic Circumnavigation Expedition. We
compare distributions of dissolved isotopes highlighting differences and similarities between the three metals.
South of the Antarctic Polar Front δ66Zn and δ114Cd are dominated by upwelling of nutrient-rich deep waters.
Zn isotopes show no fractionation despite intense uptake by diatoms in the surface ocean. Cd does show
biological uptake of light isotopes. While Southern Ocean surface waters also carry heavy δ56Fe, indicating
uptake of light Fe by phytoplankton, the difference in fractionation between the three metals points to
important differences in metal cycling in this region.
Overall, we aim to use this data to better understand how the interaction between ocean biogeochemistry and
physical circulation affects regional cycling of these metal micronutrients in the Southern Ocean and how this
influences their global distributions.

1165
CR-6a - Glaciers and Ice Sheets: from the Mountains to the Poles
21.06.2018 09:00-10:30, A Wisshorn

2578
Thresholds for Antarctic Ice Sheet Retreat and the Paris Climate Agreement

Rob Deconto1 (robdeconto@gmail.com), David Pollard2

1
University of Massachusetts, Amherst, Geosciences, Amherst, United States, 2Pennsylvania State University,
State College, United States

New ice-sheet modeling, calibrated to past and present changes in sea-level, is painting a stark picture of the
future fate of the polar ice sheets if greenhouse gas emissions continue unabated. This is especially true for
Antarctica, where a substantial fraction of the ice sheet bed rests far below sea level. Here, we explore the
climatic thresholds capable of triggering major ice sheet retreat. We use an ice sheet-climate model that
considers changes in mass balance and sub-ice melting, ice deformation, grounding line retreat on reverse-
sloped bedrock, and previously omitted glaciological processes including hydrofracturing of ice shelves and
structural collapse of thick, marine-terminating ice margins.
The results discussed here suggest that previous estimates of the maximum potential rate of future sea level
rise might need to be reconsidered, due to ice loss through mechanical failure in addition to basal sliding and
deformation. In high emissions scenarios, we find the potential for ~2m (or more) of sea level rise by 2100. We
also find that aggressive mitigation strategies, like those discussed at the Paris Climate Conference,
substantially reduce the the risk of extreme sea-level rise, but a 3ºC temperature rise is still enough to trigger
major retreat of the West Antarctic Ice Sheet. Finally, we discuss key uncertainties in constraining climatic
thresholds, timing, and rates of major ice-sheet retreat.

1166
293
Continuous Mega-channels Across the Foundation Ice Stream Grounding Zone

Hafeez Jeofry1,2, Neil Ross3, Anne le Brocq4, Martin Siegert1 (m.siegert@imperial.ac.uk)

1
Imperial College London, Grantham Institute and Department of Earth Science and Engineering, London,
United Kingdom, 2University Malaysia Terengganu, School of Marine Science and Environment, Kuala
Terengganu, Malaysia, 3Newcastle University, School of Geography, Politics and Sociology, Newcastle Upon
Tyne, United Kingdom, 4University of Exeter, College of Life and Environmental Sciences, Exeter, United Kingdom

There is a scant knowledge on the subglacial geomorphology across the Foundation ice stream. MODIS satellite
imagery reveals surface lineations from the ice sheet onto the ice shelf, which are thought to be associated
with ice flow. While such channels are thought to be formed by organised flow of basal water from the
upstream ice sheet, measurement of discrete channels upstream that would demonstrate the process remains
elusive. Using data from various airborne geophysical, we discuss evidence from radio-echo sounding (RES)
revealing continuously measured basal channels extending from the Foundation ice stream, across the
grounding line and beneath the ice shelf. Within the zone of grounding line ambiguity, a massive channel is
observed (~800 m in height). This channel can be seen in numerous RES transects and is manifested at the ice
surface as a feature detected by MODIS. These data make it highly likely that basal water from the upstream
grounded ice sheet is responsible for the channels. While the grounded channels are too large to be 'le
Brocqian' bed channels (i.e. the flow of water necessary to maintain one of the channels is equal to the flow of
the Amazon), their explanation as sediment-filled channels is challenging to rectify against the known glacial
geomorphological record. We discuss that while the channels are undoubtedly associated with basal water, as
required to form the ice shelf channels, the nature of the channels across the grounding line is obscure.

1167
28
Multi-System, Multi-Decadal Radar Sounding of Thwaites and Pine Island Glaciers

Dustin Schroeder1 (dustinms@stanford.edu), Andrew Hilger2, Emma Mackie1, Hugh Corr3, Donald Blankenship4,
John Paden5, Julian Dowdeswell6
1
Stanford University, Geophysics, Stanford, United States, 2Stanford University, Electrical Engineering, Stanford,
United States, 3British Antarctic Survey, Cambridge, United Kingdom, 4University of Texas, Institute for
Geophysics, Austin, United States, 5University of Kansas, Center for the Remote Sensing of Ice Sheets, Lawrence,
United States, 6University of Cambridge, Scott Polar Research Institute, Cambridge, United Kingdom

Recent observational and modeling studies have shown that the behavior and stability of both Thwaites Glacier
and Pine Island Glacier in the Amundsen Sea Embayment of the West Antarctic Ice Sheet are modulated by a
combination of ocean forcing, bed topography, and basal conditions. Despite this, little research has focused on
characterizing the basal condition context for modeling current and potential interaction across their boundary.
This is due, in part, to the fact that modern radar data in this region were collected by three different radar
systems and much of the Thwaites / Pine Island boundary lies at the boundary of these data sets. These include
the 2004 survey of Thwaites Glacier by the UTIG HiCARS system, the 2004 campaign over Pine Island Glacier by
the BAS PASIN system, and the 2011 - 2016 surveys by the CReSIS MCoRDS system.
In addition to this modern data, two transects of airborne radio echo sounding data collected in the early
seventies cross the Thwaites Glacier catchment. However, the storage of these data on film have made such
comparison at the full radiometric and geometric resolution of the data difficult. To address this challenge, we
utilized a state-of-the-art high-resolution film scanning system to digitize the entire SPRI/NSF/TUD archive.
Here present results from processing, analyzing, and synthesizing four distinct data sets to characterize basal
conditions for modeling and interpretation.

1168
1303
Using Terrestrial Radar Interferometry to Understand Calving Processes

Andrea Walter1 (andrea.walter@geo.uzh.ch), Martin Lüthi1, Andreas Vieli1, Martin Funk2

1
University of Zurich, Geography, Zurich, Switzerland, 2ETH Zurich, Zurich, Switzerland

Recently, many marine-terminating glaciers of the Greenland ice sheet revealed rapid retreat, thinning and
flow acceleration. These glaciers lose mass by calving, a process which can change on short timescales. Despite
their importance for global sea level rise, major limitations in understanding the dynamics of these glaciers
remain. Terrestrial radar interferometry provides displacement and topographical data with a high spatial and
temporal resolution. We observed two Greenland outlet glaciers in one minute intervals with a spatial
resolution of 5 meters during four multi-day field campaigns in the summers 2014 to 2017. We use these data
to establish detailed calving event statistics which are compared to environmental forcing like tides or weather
conditions. By identifying source areas and ice volumes of individual calving events we quantitatively
investigate the relationship between calving front geometry, calving rate and potential drivers. We find for
example substantial differences in calving volume statistics between grounded and floating parts of the glacier
front. We further compare the observed calving volumes with data of tsunami waves which were continuously
recorded with pressure sensors between 2014 and 2017. The resulting relationship between calving volumes
and tsunami waves allows us to establish continuous calving catalogs over four years and investigate calving
periodicity.

1169
1648
Sun2Ice: Monitoring Calving Glaciers from Solar-powered UAVs

Guillaume Jouvet1 (jouvet@vaw.baug.ethz.ch), Thomas Stastny1, Philipp Oettershagen1, Eef Van Dongen1,
Michael Hugentobler1, Thomas Mantel1, Amir Melzer1, Yvo Weidmann1, Martin Funk1, Roland Siegwart1
1
ETHZ, Zurich, Switzerland

Here we present the first outcomes of ETHZ´s Sun2Ice project, which aims to use a state-of-the-art, highly-
optimized, solar-powered Unmanned Aerial Vehicle (UAV), AtlantikSolar, for long-range, and multi-day
monitoring of calving glaciers in the Arctic. The „midnight sun“ in polar summer time offers unique conditions
for solar-powered flights, including potentially energetically perpetual flight, consequently enabling frequent,
high-resolution and large-scale glacier surveys. In Sun2Ice, this cutting-edge technology is dedicated to the
monitoring of iceberg calving, a still poorly understood process which plays a major role in the observed retreat
of many ocean-terminating glaciers. The main achievement of Sun2Ice´s 2017 fieldwork was the undertaking of
the first-ever autonomous, solar-powered flights of a UAV in a polar region, including a flight of more than 12
hours duration, and the survey of the calving front of Bowdoin Glacier, Northwest Greenland. This monitoring
revealed the opening of a major crack, which led to a major calving event one week later. This presentation will
focus on the technical challenges, the glaciological outcomes, and the potential of using such a technology for
monitoring the Cryosphere with a spatial and temporal resolution not achievable by satellite remote sensing.

1170
1483
Modelling the Calving Contribution to Sea Level in Alaska and Greenland

Lizz Ultee1 (ehultee@umich.edu), Jeremy Bassis1

1
University of Michigan, Climate & Space Sciences, Ann Arbor, United States

Iceberg calving is an important mass loss process for ocean-terminating glaciers and ice shelves. Where ocean-
terminating glaciers drain ice sheets, as at the margins of Greenland, the rate of calving modulates a large
potential contribution to global sea level. Parametrizing this process for numerical modelling has been
challenging due to the widely varying spatial and temporal scales involved. We have developed a new,
physically-consistent model that captures the effect of iceberg calving for the evolution of individual glaciers
and their tributaries in both Alaska and Greenland. Here, we apply our model to Jakobshavn Isbrae,
Kangerlussuaq Glacier, and Helheim Glacier, showing that we are able to reproduce observed patterns of
terminus advance/retreat and upstream thickness change over the past decades. We then apply the model to
the 30 ocean-terminating glaciers responsible for the majority of Greenland ice sheet discharge. Using a
heuristic upstream forcing—a thinning rate that varies linearly, quadratically, or exponentially—we estimate
the dynamic contribution to sea level rise that Greenland can make in the 21st century.

1171
CR-4a - Ice sheets, ice shelves & proximal processes in past, present & future climates
21.06.2018 09:00-10:30, B Parsenn

250
Ice Shelf-ocean Interactions in High-resolution, Global Simulations: Part II

Stephen Price1 (sprice@lanl.gov), Xylar Asay-Davis1,2, Mark Petersen1, Jeremy Fyke1, Matthew Hoffman1, Darin
Comeau1, Adrian Turner1, Jon Wolfe1, Todd Ringler1
1
Los Alamos National Laboratory, T-3, Fluid Dynamics and Solid Mechanics Group, Los Alamos, United States,
2
Potsdam Institute for Climate Impact Research, Potsdam, Germany

Critical to reducing uncertainty in projections of future sea-level rise is an improved understanding of how the
Antarctic ice sheet will evolve in response to current and future climate. We discuss efforts towards simulating
Antarctic ice sheet evolution within the U.S. Department of Energy's global, coupled, Energy Exascale Earth
System Model (E3SM), which includes variable-resolution, atmosphere, land, ocean, sea ice, and land ice
components. Importantly, E3SM includes the ability to simulate ocean circulation within Antarctic ice shelf
cavities. Part I of this talked focuses on the model configuration and tuning. In part II of this talk, we focus on
analysis of global simulations aimed at understanding differences due to
(1) the presence or absence of Antarctic ice shelf cavities in global simulations,
(2) prescribed (CORE) versus fully-coupled atmospheric forcing and,
(3) low (non-eddying ocean) versus high (eddy-permitting ocean) spatial resolution.
Simulation differences and biases are discussed in the context of validation against observations of ocean
water mass properties, sea ice extent and thickness, and submarine melt rates. We also discuss short- and
longer-term strategies for applying validated, E3SM-derived submarine melt rates towards simulations of
Antarctic ice sheet evolution and future sea-level rise.

1172
2285
On Ice-ocean Interaction and Ocean Circulation under the Ross Ice Shelf

Michael Williams1, Natalie Robinson1 (natalie.robinson@niwa.co.nz), Craig Stewart1,2, Stefan Jendersie1,3, Alena
Malyarenko1,3, Michael Brewer1, Craig Stevens1,4
1
National Institute for Water and Atmospheric Research, Wellington, New Zealand, 2Scott Polar Research
Institute, University of Cambridge, Cambridge, United Kingdom, 3University of Otago, Dunedin, New Zealand,
4
University of Auckland, Auckland, New Zealand

The future fate of the Ross Ice Shelf will likely be determined by the ability of the Ross Sea to melt the ice shelf.
The Ross Sea has not yet seen the rise in temperatures or the encroachment of Circumpolar Deep Water
experienced in other sectors of Antarctica. However, ablation rates equivalent to several meters a year have
been observed for short periods near the front of the Ross Ice Shelf, as part of the significant variability
between winter and summer in the ice shelf ablation rates and ocean temperature. The observations highlight
inconsistencies in existing parameterisations of ice shelf-ocean interaction, and demonstrate the role warm
surface water subducted under the ice shelf has in enhancing ice shelf ablation. An ocean model of the Ross
Sea region places the existing observations in an inflow region to the ice shelf cavity, and demonstrates the
important role of the Ross Sea polynya in driving seasonal ocean variability both at the ice shelf front and
within the cavity. This increased understanding of the cavity oceanography asks more questions than it
answers. To better understand these questions a new mooring is planned for near the middle of the Ross Ice
Shelf in December 2017. The initial timeseries from this mooring will be important for understanding the
dominant time scales of ocean variability within the cavity, and if these can be linked to seasonal drivers
outside the cavity or if other processes are at play.

1173
1592
Modelling the Retreat of Pine Island Glacier with Bayesian Networks

Elizabeth D Keller1 (l.keller@gns.cri.nz), Annemarie Christophersen1, Nicholas Golledge1,2, Nancy Bertler1,2,

Robert McKay2, Richard Levy1, Anca Hanea3
1
GNS Science, Lower Hutt, New Zealand, 2Victoria University of Wellington, Antarctic Research Centre,
Wellington, New Zealand, 3University of Melbourne, Melbourne, Australia

The stability of marine-based sectors of the West Antarctic Ice Sheet (WAIS) under future climate change has
important implications for the potential WAIS contribution to sea level rise, yet large uncertainties still exist
surrounding the magnitude, rate and timing of change. Here we investigate the potential to use Bayesian
Networks (BNs) as an approach to model the retreat of WAIS and to explore the sensitivity of marine-based ice
sheets in a changing climate.
BNs are probabilistic, graphical models that provide an elegant way of expressing and visualising the uncertain
behaviour of a large number of interrelated variables of a system. They have been applied in hazard and risk
assessment as decision support tools and to enhance understanding of complex systems. Current modelling of
the Earth's cryosphere relies on deterministic, process-based models. BNs are a complementary approach that
provide a rigorous statistical framework in which to explore the relative sensitivity of climatic and topographic
features without the need to model detailed ice dynamics.
We focus initially on Pine Island Glacier (PIG) because it is a relatively well-studied, small outlet glacier over
retrograde-sloping bedrock, and is currently undergoing accelerated retreat. We present a prototype BN of PIG,
including as variables ocean and air temperature, precipitation, ice velocity and thickness, bed topography, and
sea ice, which can be adapted and applied to larger and more complex areas of WAIS.

1174
379
Future Research Directions in Antarctic Surface Hydrology & Ice-shelf Stability

Jonathan Kingslake1, Alison Banwell2, Robin Bell1, Alexandra Boghosian1, Julian Spergel1, Marco Tedesco1, Kirsty
Tinto1 (tinto@ldeo.columbia.edu), Luke Trusel3
1
Lamont-Doherty Earth Observatory Columbia University, Palisades, United States, 2Cambridge University,
Cambridge, United Kingdom, 3Rowan University, Glassboro, United States

We will present recent progress and future research directions in the growing field of Antarctic surface
hydrology, with a focus on how surface hydrology could affect the stability of Antarctic ice shelves. We will
report the outcomes of a scientific workshop on these topics held in February 2018 and funded by the US
National Science Foundation (NSF).
It is widely hypothesized that static meltwater ponds can expedite iceberg calving by flowing into and enlarging
fractures and trigger ice-shelf disintegration via stresses generated by melt ponds. When ice shelves collapse,
the adjacent grounded ice accelerates and thins, contributing to sea-level rise.
The flow of water across the surface of Antarctica is also increasingly recognized as important. This
phenomenon is more widespread than previously assumed and melting is predicted to increase significantly
this century. Without considering water flow explicitly, the latest ice-sheet models respond dramatically to
increased ice-shelf melting, predicting up to 1 m of sea-level contribution from Antarctica this century.
Our current knowledge of the present state and controlling dynamics of the Antarctic surface hydrological
system is poor. Drawing from the outcomes of the NSF workshop, we will summarize present knowledge and
look ahead to the key questions, most important for predicting the role Antarctic surface hydrology will play in
the ice sheet's future.

1175
1931
Water on the Antarctic Ice Sheet: Mapping Supraglacial Lake Depth and Volume

Allen Pope1 (allen.pope@nsidc.org), Mahsa Moussavi1, Luke Trusel2

1
National Snow and Ice Data Center, Boulder, United States, 2Rowan University, Glassboro, United States

Though Antarctica is Earth's coldest continent, surface melting is widespread across its ice perimeter. Melt
plays an integral role in modulating Antarctic sea level contributions via its influence on ice shelf stability and
grounding line retreat. Despite their glaciological significance, there has been no systematic study of Antarctic
lake occurrence either spatially or temporally. Here, we begin to answer the questions: When and where do
supraglacial lakes form in Antarctica? And how much water is stored in these lakes?
Put simply, supraglacial lakes are identified by how blue they are and so multispectral data are needed. While
many studies in Greenland have used MODIS sensors to track supraglacial lakes, Antarctic lakes have been
shown in one comparative study to be smaller and shallower than their Greenlandic counterparts. Accordingly,
the workhorses of this study will be the higher resolution Landsat series, complemented by Sentinel-2, and
augmented by MODIS. After lake identification, a physically-based (and open source) lake depth retrieval will
be used to calculate lake volume. The combination of these sensors will allow us to track supraglacial lake
distribution and volume in Antarctica over 30+ years, yielding an unprecedented understanding of lake
behavior in Antarctica. First, however, this presentation will show progress toward this goal by beginning with
various case study areas around the perimeter of Antarctica.

1176
696
In Search of Perennial firn Aquifers in Antarctica

Jan Melchior van Wessem1 (j.m.vanwessem@uu.nl), Michiel R. van den Broeke2, Stefan Ligtenberg1, Christian
Steger1, Willem Jan van de Berg1, Julie Miller3
1
Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht, Netherlands, 2IMAU/UU, Utrecht,
Netherlands, 3Byrd Polar and Climate Research Center, Columbus, United States

We predict the location of perennial firn aquifers (PFAs) in Antarctica using the updated regional atmospheric
climate model RACMO2.3p2, that is specifically adapted for use over the polar regions. With RACMO2 output
we force two firn models, IMAU-FDM and SNOWPACK, that explicitly calculate processes in the snowpack, such
as densification, meltwater penetration, refreezing, retention and runoff.
In this presentation, we primarily focus on the Antarctic Peninsula (AP), where conditions are favorable for the
formation of PFAs: there is both sufficient meltwater production and snowfall to store the meltwater in the firn
during winter without refreezing, as the fresh snow insulates the meltwater from the winter cold wave. These
conditions are similar to those locations where PFAs were discovered in Greenland and Svalbard. The firn
models predict the formation of PFAs on Wilkins ice shelf and on the northwestern mountain slopes of the AP.
Using observations obtained with, amongst others, satellite C-band scatterometry, we evaluate the robustness
of these findings. In addition, we try to better understand processes controlling PFA formation, longevity and
extent in Antarctica, which clearly differ from Greenland and Svalbard. In Antarctica, we distinguish multiple
types of PFAs: long living (>20 years) PFAs, PFAs that frequently disappear and reform and PFAs that are only
maintained during individual winters. Finally, we try to locate PFAs elsewhere in Antarctica.

1177
OS-3a - Sea ice extent, properties, volume & ice shelves: modern and paleo records
21.06.2018 09:00-10:30, B Jakobshorn

29
Driftwood Insights into Holocene Pan-Arctic Sea Ice Dynamics

Georgia Hole1 (georgia.hole@ouce.ox.ac.uk), Marc Macias-Fauria1

1
University of Oxford, School of Geography and the Environment, Oxford, United Kingdom

The rapid decline in Arctic sea ice extent, age and thickness is well documented, with such changes due to
cause far-reaching impacts. At present unknowns remain about the nature of the spatiotemporal Arctic sea ice
fluctuations of the Holocene preceding satellite observation, limiting the extrapolation of modern trends to
predictions of future change. Driftwood can be used as a novel and robust proxy for sea-ice reconstructions in
the Arctic, with driftwood transport and deposition determined by sea ice and surface current dynamics. The
collation of driftwood samples from across the western Arctic with spatiotemporal distribution and available
provenance data has enabled the production of a high‐resolution proxy‐based reconstruction of Holocene
Arctic Ocean surface current and sea ice dynamics. To further constrain this spatiotemporal reconstruction,
isotopic analysis of driftwood using Strontium 87Sr/86Sr radiogenic isotope ratios combined with a framework
of potential source Strontium signatures enables a spatial link between the deposited driftwood and its
originating growth site, leading to a robust reconstruction of the wood-bearing sea ice dynamics. Combined
with links between ice movement with the expansion and contraction of the Arctic Ocean circulations of the
Beaufort Gyre and Transpolar Drift, the method enables a proxy-based reconstruction of Arctic sea ice and
broader climatic states throughout the Holocene.

1178
2063
Arctic Sea Ice Export during the Globally Warm Pliocene

Stijn De Schepper1,2 (stijn.deschepper@uni.no), Caroline Clotten1,2, Kirsten Fahl3, Stein Ruediger3,4

1
Bjerknes Centre for Climate Research, Bergen, Norway, 2Uni Research Climate, Bergen, Norway, 3Alfred
Wegener Institute - Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 4University of
Bremen, Department of Geosciences, Bremen, Germany

Sea ice is an important component in Arctic and global climate, but there is limited knowledge about Arctic sea
ice extent and export throughout the geological past. Today, the East Greenland Current (EGC) is the main
exporter of sea ice into the Atlantic, yet its behavior in the Pliocene globally warm climate is poorly
documented. We reconstructed the EGC and sea ice variability in the Iceland and Labrador seas during the
Pliocene (~5-2.4 million years ago) using the sea ice proxy IP25, paleoproductivity biomarkers, alkenone-based
sea surface temperatures and dinoflagellate cysts. Our results show that sea ice first appeared in the Iceland
Sea around 4.5 million years ago when a proto-EGC developed. A more modern-like Nordic Seas circulation
developed around 4.0 Ma, when our data indicate a seasonal sea ice cover in the Fram Strait and Iceland Sea.
In the Late Pliocene, prior to 3.0 Ma, a relatively weak EGC likely caused the frequent occurrence of seasonal
sea ice in the Iceland Sea, while sea ice rarely occurred in the Labrador Sea. After 3.0 Ma, when global climate
cooled, a stronger EGC established a sea ice edge close to Greenland resulting in limited sea ice presence in the
Iceland Sea, whereas the Labrador Sea more frequently received sea ice. The changes in sea ice regime are
likely driven by oceanographic changes and may have played a role in the gradual expansion of the Greenland
Ice Sheet from the Early to Late Pliocene.

1179
646
Past Sea Ice Variability Derived from Ice Cores: The Bromine Approach

Andrea Spolaor1 (andrea.spolaor@unive.it), Niccolò Maffezzoli2, Paul Vallelonga2, Alfonso Saiz-Lopez3, Francois
Burgay4, Claudio Scarchilli5, Clara Turetta1, Federico Scoto4, Carlo Barbante1,4
1
Consiglio Nazionale delle Ricerche, Institute for the Dynamics of Environmental Processes, Venice, Italy, 2Niels
Bohr Institute, Centre for Ice and Climate, Copenhagen, Denmark, 3Consejo Superior de Investigaciones
Científicas, Institute of Physical Chemistry Rocasolano, Madrid, Spain, 4Ca Foscari University of Venice, Venice,
Italy, 5ENEA, Rome, Italy

Sea ice is a crucial parameter in the climate system, and it is declining at a faster rate than models predicted.
Bromine plays a central role in sea ice chemistry, from where it is released as BrO during springtime, enriching
its abundance in the polar atmosphere. Therefore, bromine enrichment in snow, with respect to the sodium
ratio in seawater, can be been linked to first year sea ice variability at the Poles. Measurements of Bromine
enrichment (Brenr) have been carried out in Greenland (NEEM and Renland ice cores), Svalbard, Severnaya
Zemlya and Antarctica (Talos Dome, Law Dome and Dome C). These climate ice archives investigated, cover
both the satellite era and the older climate periods back to the last glaciation. The results obtained from deep
drilling in the Arctic suggest that during the Holocene climate optimum (9- 10 ky BP) in summer time open
water was present in the Canadian Arctic, whilst multi-year sea ice was present during the last glaciation, with
rapid interstadial periods able to changes the sea ice structure. The Antarctic results (except Talos Dome) were
mainly focussed on covering the last 200 years, the Talos Dome ice core covered back to the previous glaciation
(150 ky BP). The results obtained from the Law Dome and Dome C ice core, support the idea that Br
enrichment can also be used in Antarctica and suggests that the variability of sea ice, especially in the Indian
sector, might be explained by the changes in the SAM (Southern annular mode).

1180
1257
Biogeochemical Cycling and Sea Ice Dynamics in the Bering Sea across the MPT

Henrieka Detlef1 (detlefh1@cardiff.ac.uk), Sindia Sosdian1, Simon Belt2, Lukas Smik2, Caroline Lear1, Ian Hall1,
Sev Kender3,4, Melanie Leng4, Katrine Husum5, Patricia Cabedo-Sanz2
1
Cardiff University, Cardiff, United Kingdom, 2Plymouth University, Plymouth, United Kingdom, 3University of
Exeter, Exeter, United Kingdom, 4British Geological Survey, Keyworth, United Kingdom, 5Norwegian Polar
Institute, Tromso, Norway

Today the Bering Sea is characterized by high primary productivity along the eastern shelf, maintained by CO2
and nutrient rich upwelled deep waters and nutrient release during spring sea ice melting. As such, low oxygen
concentrations are pervasive in mid-depth waters. On glacial/interglacial (G/IG) timescales sea ice formation
plays a pivotal role on intermediate water ventilation with evidence pointing to the formation of North Pacific
Intermediate Water (NPIW) in the Bering Sea during late Pleistocene glacial intervals. Additionally, sea ice plays
a significant role in both long- and short-term climate change via associated feedback mechanisms.
Here we use a multi-proxy approach to study sea ice and bottom water dynamics, across three intervals prior
to, across, and after the Mid-Pleistocene Transition (MPT, 1.2-0.7 Ma) from International Ocean Discovery
Program Site U1343. The biomarker-based sea ice record shows substantial increase in sea ice extent across
the MPT and the occurrence of a late-glacial/deglacial sea ice spike, with potential consequences for land
glacier retreat via the temperature-precipitation feedback. U/Mn of foraminiferal authigenic coatings is used to
reconstruct sedimentary redox conditions, a factor of export productivity and bottom water oxygenation. This
aids to elucidate the interactions of sea ice with biogeochemical cycling and NPIW formation on G/IG
timescales, with potential implications for the North Pacific carbon cycle.

1181
1685
Arctic Ice Sheets and Sea Ice Extent during MIS 6/MIS 5: A Biomarker Perspective

Ruediger Stein1,2 (ruediger.stein@awi.de), Anne Kremer1, Kirsten Fahl1, Frank Niessen1

1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Geosciences, Bremerhaven,
Germany, 2University of Bremen, MARUM & Faculty of Geosciences, Bremen, Germany

The Quaternary glacial history of the Arctic Ocean is characterized by the repeated build-up and decay of
circum-Arctic ice sheets on the continental shelves and related changes in ocean-circulation patterns and sea
ice cover. Here, we present new biomarker records that give insights into the interactions between the
Eurasian-Siberian ice sheets, sea ice extent and Atlantic water inflow during the Penultimate Glacial Maximum
(Marine Isotope Stage (MIS) 6) to Last Interglacial (MIS 5e) transition. Along the Svalbard and northern Barents
Sea continental margin, the MIS 6 ice sheet and sea ice conditions might have been similar to those of the LGM.
An extended Barents Sea Ice Sheet had reached the shelf edge causing polynya-like open-water conditions
(triggered by strong katabatic winds) with phytoplankton and sea ice algae production, and the deposition of
suspended (terrigenous) material along the slope, as reflected in the biomarkers from this area. Furthermore,
the seasonally open-water conditions along the Barents Sea continental margin might have been fostered by
the inflow of Atlantic Water. Biomarker records from the southern Lomonosov Ridge area close to the Siberian
continental margin support an extended (MIS 6?) East Siberian Chukchi Ice Sheet, with strong katabatic winds
and polynya-like open-water conditions in front of the ice sheet. Such a scenario would clearly contradict the
hypothesis of a MIS 6 ice shelf covering the entire Arctic Ocean.

1182
2264
Sea Ice Reconstructions Using Ancient DNA

Jessica Louise Ray1 (jessicalouiseray@gmail.com), Katrine Sandnes Skaar1, Henrik Sadatzki2, Aud Larsen1,
Christofer Troedsson1, Stijn De Schepper3
1
Uni Research Environment, Bergen, Norway, 2University of Bergen, Bjerknes Centre for Climate Research,
Bergen, Norway, 3Uni Research Climate, Bjerknes Centre for Climate Research, Bergen, Norway

Environmental ancient DNA (aDNA) as a tool in paleoceanographic studies is still in its infancy and its potential
for sea ice reconstructions is promising but not yet fully explored. To document the sea ice history of the
Greenland Sea, we characterized a sediment core using metabarcoding of aDNA, dinoflagellate cyst
assemblages and the sea ice biomarker IP25, to determine how plankton dynamics preserved in aDNA
corresponds to established proxies for sea ice reconstructions. We extracted total DNA and performed
metabarcoding analysis of the V7 hypervariable region of the eukaryotic small subunit ribosomal RNA gene
(SSU rRNA) on nine sediment samples ranging in age from modern to ~100,000 years ago. The aDNA sequences
in one sample dated ~34 ka were unique in the study interval with nearly-absent diatoms and a dominance of
dinoflagellates, cercozoans and unclassified sequences. Notably, we observed a high relative abundance of
sequence reads resembling the sea ice-associated dinoflagellate Polarella glacialis in this sample. Together with
a dinoflagellate cyst assemblage dominated by the sea-ice-associated genus Islandinium and a clear signal in
IP25, this indicates a likely seasonal sea ice cover. Our preliminary aDNA work thus demonstrates (1) the
presence of amplifiable aDNA back to ~100,000 years ago in the Greenland Sea and (2) the potential for aDNA
to complement traditional microfossil analyses in order to strengthen estimates of past seasonal sea ice cover.

1183
AC-1f - Polar and high altitude atmosphere: clouds, aerosols, climate and interactions
21.06.2018 09:00-10:30, C Sanada I

477
Aerosol Microphysical Effects on Cloud Fraction over the Nighttime Arctic Ocean

Lauren Zamora1,2 (lauren.m.zamora@nasa.gov), Ralph Kahn3, Sabine Eckhardt4, Andreas Stohl4

1
ESSIC, Univ. of Maryland, College Park, United States, 2NASA Goddard Space Flight Center, Greenbelt, United
States, 3NASA Goddard Space Flight Center, College Park, United States, 4NILU – Norwegian Institute for Air
Research, Kjeller, Norway

Cloud fraction is a key component affecting the surface energy balance in the Arctic. Aerosol microphysical
processes can affect cloud fraction, for example through cloud lifetime effects. However, the importance of
aerosol impacts on cloud fraction is not well constrained on a regional scale at high latitudes. Here a new
method is presented for identifying and comparing clean and aerosol-influenced cloud characteristics using a
combination of multi-year remote sensing data (CALIPSO, CloudSat) and the FLEXPART aerosol model. This
method is used to investigate a variety of aerosol microphysical impacts on nighttime Arctic Ocean clouds on
regional and local scales. During the polar night study period, aerosols were associated with noticeable regional
cloud fraction differences, suggesting possibly significant changes in longwave cloud radiative effects at the
Arctic Ocean surface. We present evidence for combustion aerosols acting as ice nucleating particles at the cold
temperatures of high altitude (>4 km) Arctic ice clouds. Potential mechanisms for aerosol-driven microphysical
changes on cloud fraction within lower altitude clouds will also be discussed.

1184
589
Far IR Measurements of Thin Polar Ice Clouds in View of TICFIRE Mission

Jean-Pierre Blanchet1 (blanchet.jean-pierre@uqam.ca), Quentin Libois2, Liviu Ivanescu1, Ludovick Pelletier1,

Pierre Gauthier1, Laurence Coursol1
1
Université du Québec à Montréal, Sciences de la Terre et de l'atmosphère, Montréal, Canada, 2Météo-France,
Toulouse, France

The water cycle in the dry and cold Arctic is not well understood, yet it is by far the dominant factor controlling
polar climate with strong implications on the midlatitude weather. Optically thin ice clouds (TIC) processes are
still poorly represented in atmospheric models. Furthermore, it is now recognized that anthropogenic aerosol
can alter cloud microphysics and precipitation. These ubiquitous clouds, sensitive to aerosols via ice nucleation,
can significantly modulate the amount of far infrared radiation escaping the Earth, and consequently the
temperatures in the upper troposphere, and occasionally in the UTLS region. Since TIC signature in the far
infrared is also very sensitive to their microphysical properties (crystals size and shape) and optical depth, these
quantities can be retrieved from ground-based and satellite observations. Theoretical calculations demonstrate
that the far infrared spectrum of the atmosphere could provide valuable information for weather forecast data
assimilation and climate simulations, about its water vapour content, the microphysical characteristics of ice
clouds and common light precipitation, especially in dry and cold regions. In the context of YOPP, with the
Canadian Space Agency and in collaboration with NETCARE, PAHA and AVATAR, we have initiated new
measurements in the mid and far IR range (8-50µm) to advance our knowledge of the water cycle in the High
Arctic with the deployment of the Far IR Radiometer (FIRR).

1185
703
Satellite Observations of Summer Arctic Sea Fog

King-Fai Li1,2 (king-fai.li@ucr.edu), Li Yi3, Xianyao Chen4,5, Ka-Kit Tung2

1
University of California, Riverside, Environmental Sciences, Riverside, United States, 2University of Washington,
Applied Mathematics, Seattle, United States, 3Ocean University of China, College of Oceanic and Atmospheric
Sciences, Qingdao, China, 4Ocean University of China, Physical Oceanography Laboratory/CIMST, Qingdao,
China, 5Qingdao National Laboratory of Marine Science and Technology, Qingdao, China

Under global warming, the rapid increase in open water surface area resulting from sea ice melting may lead to
an increase in fog (here defined as any cloud with a base height below 1000 ft), which may imperil ship and air
transportation in the region. There is a need for real-time monitoring of fog formation over the Arctic. Given
that ground-based observations of fog over Arctic open water are sparse, satellite observations are currently
the most effective way for real-time monitoring. We developed a fog detection algorithm using the
temperature difference between the cloud top and the surface, called ∂T in this work. A fog event is said to be
detected if ∂T is greater than a threshold, which is typically between −6°C and −10°C, depending on the time of
the day (day or night) and the surface types (open water or sea ice). As a test, we apply this method to the
coastal regions of Chukchi Sea and Beaufort Sea near Barrow, Alaska. We showed that the ∂T method can
detect Arctic fog with an optimal probability of detection (POD) of 77−84% and false alarm rate (FAR) of
13−19%. The feasibility of the ∂T method, however, critically relies on the accuracy of the physical quantities
(such as the cloud-top height) determined from the same infrared measurements.

1186
809
Interactions Between Arctic Clouds, Sea Ice, and Lower Tropospheric Stability

Patrick Taylor1 (patrick.c.taylor@nasa.gov)

1
NASA Langley Research Center, Climate Science Branch, Hampton, United States

Arctic low clouds strongly affect the Arctic surface energy budget and through this impact influence the rest of
the Arctic climate system: namely surface and atmospheric temperature, sea ice extent and thickness, and the
atmospheric circulation. Arctic clouds are in turn influenced by the Arctic climate system creating the potential
for cloud-climate feedbacks. We quantify the influence of atmospheric state on the surface cloud radiative
effect (CRE) and the covariability between surface CRE and sea ice concentration (SIC) using instantaneous,
active remote sensing satellite footprint data from the NASA A-Train. First, the results indicate significant
differences in the surface CRE when stratified by atmospheric state. Second, a statistically insignificant
covariability is found between CRE and SIC for most atmospheric states. Third, we find a statistically significant
increase in the surface longwave CRE with decreased SIC in fall. Specifically, a +3-5 W m-2 larger longwave CRE
is found over footprints with 0% versus 100% SIC. Because systematic changes of 1 W m-2 are sufficient to
explain the observed reductions in Arctic sea ice, our results (1) indicate a potentially significant amplifying sea
ice-cloud feedback that could delay fall freeze-up influencing sea ice variability under certain atmospheric
conditions and (2) suggest that a small change in the frequency of atmosphere states may yield a larger Arctic
cloud-climate feedback than any cloud response to sea ice.

1187
987
Antarctic Cloud Microphysics using the DARDAR Synergetic Satellite Products

Constantino Listowski1 (constantino.listowski@latmos.ipsl.fr), Julien Delanoë1, Tom Lachlan-Cope2

1
LATMOS, Guyancourt, France, 2BAS, Cambridge, United Kingdom

In Antarctica, surface radiation biases of several tens of watt per square meters are calculated in mesoscale
high-resolution models, which point to major problems in the simulation of the cloud phase. Antarctic clouds
need to be correctly represented in both regional and global atmospheric models, to improve daily operational
forecast as well as for future global climate predictions. Indeed Antarctic cloud microphysics affect lower
latitudes too via their impact on the North-South temperature gradient. Because of the inaccessibility of most
Antarctica to in-situ cloud science, observations are sparse, and satellite observations appear as a welcome if
not crucial complement.
DARDAR satellite products were developed in order to take advantage of both radar (CloudSat/CPR) and lidar
(CALIPSO/CALIOP) measurements which are used seamlessly to retrieve cloud properties at a horizontal
resolution of 1.7x1.4 km and a vertical resolution of 60 m. We will present results of the analysis of Antarctic
cloud thermodynamic phase using the DARDAR products over the period 2007-2010, at the continental and
regional scales, paying close attention to the supercooled liquid phase. So far unreported links between
Antarctic clouds and the Southern Annular Mode over different regions, and the atmosphere dynamics
continent-wide, will be also highlighted.
Acknowledgement: CL acknowledges the post-doctoral funding from CNES.

1188
2110
Vertical Distribution of Aerosol Properties in the Spitsbergen Region

David Cappelletti1 (david.cappelletti@unipg.it), Mauro Mazzola2, Beatrice Moroni1, Justyna Lisok3, Kris
Markowicz3, Luca Ferrero4, Marion Maturilli5, Silvia Becagli6, Traversi Rita6, Angelo Lupi2, Chiara Petroselli1,
Christoph Ritter5, Christine Boeckmann7, Angelo Viola8, Vitale Vitale2
1
University of Perugia, Perugia, Italy, 2CNR - ISAC - National Research Council, Bologna, Italy, 3University of
Warsaw, Institute of Geophysics, Warsaw, Poland, 4University of Milano-Bicocca, Milano, Italy, 5AWI - Alfred
Wegener Institute for Polar and Marine Research, Potsdam, Germany, 6University of Florence, Florence, Italy,
7
University of Potsdam, Potsdam, Germany, 8CNR - ISAC - National Research Council, Roma, Italy

Primary objective of this long-term research activity is to build a climatology of aerosol vertical profiles in and
above the Arctic Boundary Layer. To this aim since 2011 an international research team has performed yearly
field campaigns at the Ny Alesund super-site thanks the support of the Italian CNR Arctic station Dirigibile Italia
and German AWI Koldway station. Making use various aerosol payloads and tethered balloons systems (TBS)
up to date about 500 aerosol profiles have been regularly recorded in the first 2 km, providing detailed
information on black carbon concentration, aerosol size distribution, aerosol scattering coefficients and
chemical composition. Seasonal trends have been obtained for spring, summer and autumn. Case studies will
be highlighted describing the impact of ship emissions, Arctic haze and new particle formation events on the
vertical aerosol structure. In situ TBS activities have been often accompanied by parallel lidar profiling and a
closure study of aerosol microphysical property retrieval is in progress based on this data and also on a full
chemical aerosol characterization both at bulk level on filter samples and on single particles by scanning
electron microscopy.
References:
Adv. in Meteorology, Article ID 292081 (2016)
Rend. Fis. Acc. Lincei (2016).
Atmos. Chem. Phys., 16, 12601-12629 (2016)
Rend. Fis. Acc. Lincei (2016).
Atmos. Environ., 156, 135-145 (2017)

1189
OS-7a - Atmosphere-Ice-Ocean interactions in the Polar Regions
21.06.2018 09:00-10:30, C Sanada II

2418
Importance of Processes and Feedbacks in Modeling & Prediction of Arctic Climate

Wieslaw Maslowski1 (maslowsk@nps.edu), Younjoo Lee1, Robert Osinski2, Andrew Roberts1, John Cassano3
1
Naval Postgraduate School, Monterey, United States, 2Institute of Oceanology of Polish Academy of Sciences,
Sopot, Poland, 3University of Colorado at Boulder, Boulder, United States

Some of the largest changes due to warming climate have occurred in the Arctic. Historical reconstructions
from Earth System Models (ESMs) are in a broad agreement with these changes, except for the modeled rates
of change, which generally remain outpaced by observations. Such limitations imply a limited skill in ESM
projections of future Arctic System states and are likely due to a combination of coarse model resolution,
inadequate parameterizations of sub-grid processes, and a limited knowledge of physical interactions. One of
the least understood limitations are processes controlling ocean-ice-atmosphere surface momentum and
energy transfer.
We demonstrate the capability of the Regional Arctic System Model (RASM) in addressing some of the ESM
limitations in simulating observed variability and trends in arctic surface climate. RASM is an example of
limited-area, process-resolving, fully coupled ESM. Due to the constraints from boundary conditions it
facilitates detailed comparisons with observational statistics that are not possible with ESMs. This talk will
emphasize the need for fully coupled climate model simulations, high model resolution and fine-tuning of
scale-aware parameterizations of sub-grid physical processes. In support, selected RASM results will be
presented on physical processes and resulting feedbacks controlling seasonal cycle and variability of the Arctic
ocean-ice-atmosphere boundary layer.

1190
329
Multidisciplinary Drifting Observatory for the Study of Arctic Climate

Markus Rex1 (markus.rex@awi.de), Matthew Shupe2, Klaus Dethloff1, Anja Sommerfeld1

1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Atmospheric Physics, Potsdam,
Germany, 2University of Boulder, Boulder, United States

MOSAiC is an international initiative under the umbrella of IASC, designed by an international consortium of
leading polar research institutes.
Rapid changes in the Arctic lead to an urgent need for reliable information about the state and evolution of the
Arctic climate system. This requires more observations and improved modeling over various spatial and
temporal scales, and across a wide variety of disciplines. Observations of many critical parameters have, to
date, not been carried out in the central Arctic for a full annual cycle.
MOSAiC will be the first year-around expedition into the central Arctic exploring the coupled climate system.
During 2019 to 2020 the research vessel Polarstern will drift with the sea ice from the Siberian Sector of the
Arctic across the polar cap towards the Fram Strait.
The focus of MOSAiC is based on a constellation of in-situ observations of the climate processes that couple
atmosphere, ocean, sea ice, biogeochemistry and ecosystem. These measurements will be supported by
weather and sea ice predictions, and remote sensing operations to aid implementation and extend the
observational results in time and space. The project includes coordinated aircraft campaigns and expeditions by
icebreakers from MOSAiC partners. All observations will support the main scientific goals of MOSAiC:
Enhancing the understanding of the regional and global consequences of Arctic climate change and sea ice loss,
and improving weather and climate prediction.

1191
214
Improving Forecasts of Air-ice-Ocean Interactions in the MIZ during Autumn 2015

Amy Solomon1 (amy.solomon@noaa.gov), Antonietta Capotondi1, Janet Intrieri2, Ola Persson1

1
University of Colorado, Boulder, United States, 2NOAA, Boulder, United States

The United States Office of Naval Research SeaState campaign took place on the ice breaker R/V Sikuliaq Sept
28-Nov 10 2015 in the Beaufort Sea. This field program was designed specifically to understand the effects of
an increasingly dynamic sea state on autumn ice recovery. Comprehensive air-ice-ocean measurements were
taken during the campaign to quantify the coupled mechanisms responsible for fluxes at the air-ice/ocean-ice
interfaces.
During Oct 9-15 2015, it was observed that pancake ice in the marginal ice zone unexpectedly retreated. This
was unexpected because surface measurements indicated water at the freezing point and a loss of heat to the
atmosphere, demonstrating that processes other than atmospheric fluxes were responsible for the retreating
ice edge.
This modeling study investigates the relative roles of ocean mixing and ice advection in reversing the observed
seasonal ice advance during Oct 9-15 2015, and the ability of state-of-the-art forecast models to simulate the
observed retreat, with a hierarchy of ocean models (i.e., with and without ocean dynamics) at this time period
and location.
Of specific interest is the role of the Pacific intermediate water and the initial ocean conditions required to
simulate the observed variability. Results from experiments varying initial ocean conditions will be presented to
identify potential model biases and strategies to improve the coupled model forecasts.

1192
660
Arctic Climate Spatio-temporal Modes of Variability as Sources of Predictability

Juan Camilo Acosta Navarro1 (jacosta@bsc.es), Virginie Guemas1, Neven Fuckar1, Alasdair Hunter1
1
Barcelona Supercomputing Cente, Barcelona, Spain

The Arctic region has suffered a transformation in the past decades that will very likely continue in the future.
Since the late 1970s, declining trends in pan-Arctic sea ice extent and volume, and increasing trends in air and
sea surface temperature have been observed. However, the region has a large natural climate variability that
can usually be mistaken for a long-term forced response. Furthermore, this natural Arctic variability has been
linked to mid-latitude weather extremes in the northern hemisphere, both as a cause and a as response.
Disentangling natural variability and forced response is of critical importance from a climate change
perspective.
Using observational evidence and advanced statistical methods (K-mean clustering), we studied natural modes
of variability in key Arctic climate variables (i.e. sea ice concentration, sea surface and near surface air
temperature). The main objective was to identify spatio-temporal coherence in the series and lag-lead
correlations between variables after detrending them.
Sea ice concentrations show three main modes of variability, as previously found. Both atmospheric near
surface temperature and sea surface temperatures can individually affect sea ice and partly explain some
regional patterns of natural variability on seasonal timescales. Pan-arctic sea ice extent shows a delayed
response of 1-3 months to near surface air temperature and about a year to sea surface temperature
variations.

1193
2055
Satellite-derived Sea Ice Export and its Impact on Arctic Ice Mass Balance

Robert Ricker1 (robert.ricker@awi.de), Fanny Girard-Ardhuin2, Thomas Krumpen1, Camille Lique2

1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2Ifremer,
Brest, France

Sea ice volume export is affecting the Arctic ice mass balance, and certainly the multiyear ice volume variability.
Climate relevance is also given by the significant fresh water input into the North Atlantic, affecting the
thermohaline circulation. The Fram Strait represents the main sea ice export gate in the Arctic. Here, we
present the first estimates of winter sea ice volume export through the Fram Strait using CryoSat-2 sea ice
thickness retrievals and three different ice drift products for the period 2010-2017. The export rates vary
between 20 km3 and 550 km3 per month. We find that sea ice drift is the main driver of seasonal and
interannual ice volume export variability. Moreover, 79 % of the interannual variability can be explained by the
relation to the North Atlantic Oscillation index (NAO). The seasonal trend, however, is driven by the mean ice
thickness, associated with the thermodynamic ice growth, which is typically peaking in March. Considering
Arctic winter multiyear ice volume changes, 50 % of the seasonal variability can be explained by the ice volume
export through the Fram Strait.

1194
1046
Contrasting Antarctic and Arctic Atmospheric Responses to Projected Sea Ice Loss

Mark England1 (mre2126@columbia.edu), Lorenzo Polvani1,2, Lantao Sun3

1
Columbia University, Applied Physics and Applied Mathematics, New York, United States, 2Lamont-Doherty
Earth Observatory of Columbia University, New York, United States, 3NOAA, Boulder, United States

By the end of this century, annually-averaged Antarctic sea ice area is projected to decline by an amount
comparable to the one in the Arctic. However, the impact of future Antarctic sea ice loss is largely an open
question, having received very little attention to date. Here, the atmospheric response to future sea ice loss in
the Antarctic is investigated, and contrasted to the Arctic case, using the Community Earth Systems Model
Whole Atmosphere Coupled Climate Model (WACCM). Comparing time-slice model runs with historic sea ice
concentrations to runs with sea ice in each hemisphere reduced to values representative of the late 21st-
century (from a high CO2 emission scenario) allows us to disentangle the effect of future sea ice loss on the
atmosphere from other aspects of the coupled system. It is found that both Antarctic and Arctic sea ice loss act
to shift the tropospheric jet equatorward, acting as an internal negative feedback to the net poleward shift
associated with increased greenhouse gases. Furthermore, the atmospheric response to Antarctic sea ice loss is
found to be of slightly smaller amplitude, more vertically confined, and less seasonally varying than in the case
of Arctic sea ice loss. Finally, our model shows that the surface temperature response to Antarctic sea ice loss is
unable to penetrate the Antarctic continent, suggesting that the sea ice increases of recent decades cannot
explain the observed lack of warming over much of the Antarctic continent.

1195
BE-4h - Climate change and ecosystems: physiology, biodiversity and ecological functions
21.06.2018 11:00-12:30, A Schwarzhorn

365
Dynamics of Peat Frontiers in the Arctic and Antarctic under a Warming Climate

Zicheng Yu1 (ziy2@lehigh.edu), Kathleen Cleary1, Julie Loisel2, David Beilman3, Charly Massa1, Jonathan Stelling1
1
Lehigh University, Bethlehem, United States, 2Texas A&M University, College Station, United States, 3University
of Hawaii, Honolulu, United States

Amplified climate warming in the Arctic and Antarctic Peninsula in recent decades has caused a multitude of
changes, including ice/snow reduction, permafrost soil thaw, and vegetation greening. Peat-forming
ecosystems are "hotspots" of long-term carbon (C) sequestration in the high northern latitude region during
the Holocene. However, we don't know if peat-forming ecosystems are expanding under a warming climate
and whether they contribute significantly to regional C balance. Here we use some case studies from the North
Slope of Alaska and from the Antarctic Peninsula to show potential peat expansion in both polar regions. In
Arctic Alaska, we found that shallow “peat patches” (typically dominated by peat moss Sphagnum)—that may
represent the initial stage of peatland formation—are distributed across some tundra landscapes. Our results
from 6 soil cores indicate the onset of rapidly-accumulating Sphagnum peat at ~1930 AD, likely responding to
regional climate warming directly or indirectly through permafrost dynamics. In the Antarctic Peninsula, we
found rapid increase in C accumulation rates in recent decades from peat cores collected from aerobic moss-
dominated peatbanks. Furthermore, we observed the re-appearance of waterlogged peatlands responding to
rapid warming climate. The possible transformation of polar landscapes to more peat-forming ecosystems has
implications for a sustained C sink, impacting the regional and global C balance over decadal or century
timescales.

1196
2610
Linking C Sequestration Service and High Arctic Ecosystem Multi-functionality

Patrick Saccone1, Alexandra Bernardova2, Michala Bryndová2, Francesco de Bello2,3, Miloslav Devetter2,4, Tomáš
Hájek2, Ladislav Háněl4, Veronika Jílková4, Petr Kotas2, Jana Macková4, Petra Polická2, Josef Starý4, Petr Macek5
(maca@prf.jcu.cz)
1
Faculty of Science, University of South Bohemia, Centre for Polar Ecology, České Budějovice, Czech Republic,
2
Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic, 3Institute of Botany, Czech
Academy of Sciences, Trebon, Czech Republic, 4Institute of Soil Biology, Biology Centre, Czech Academy of
Sciences, Ceske Budejovice, Czech Republic, 5Faculty of Science, University of South Bohemia, Centre for Polar
Ecology, Ceske Budejovice, Czech Republic

The mechanistic response of Arctic terrestrial ecosystems to ongoing climate changes is the key of carbon (C)
sink status of the soil. The assessment of the sustainability of Arctic soils C sequestration service requires
deeper understanding of the ecological mechanisms leading to C accumulation in the soil. We explored the
links among plants, soil invertebrate and microbial communities, and the C biogeochemical cycle along
environmental gradients in different valleys of central Svalbard. This multifunctional approach integrates the
holistic aspect of the ecosystem structure and aims at stressing the association of ecosystem service resilience
with the functional links among the compartments. We sampled
(1) plant composition, abundance, above and belowground traits,
(2) soil invertebrate composition, abundance and feeding traits,
(3) soil microbial communities functional composition and activity; and
(4) soil C organic and inorganic contents.
Our preliminary analyses showed functional clustering across the compartments and also different levels of
sensitivity to environmental gradient depending upon the compartments. Analyses need to be deepen and
complete with manipulative experiments to disentangle the mechanisms but our results already illustrate a
breakthrough in functional ecology with an explicit consideration of multitrophic functionality.

1197
1882
Greening and Browning Trends in Circumpolar Arctic Tundra Vegetation

Howard Epstein1 (hee2b@virginia.edu), Uma Bhatt2, Martha Raynolds2, Donald Walker2, Leah Reichle1,
Coleman Dickerson1
1
University of Virginia, Charlottesville, United States, 2University of Alaska - Fairbanks, Fairbanks, United States

Until recently the scientific literature has seen an abundance of papers describing the “greening” of the Arctic;
from a remote sensing perspective this has meant an increase in the Normalized Difference Vegetation Index
(NDVI), or a similar satellite-based index. More recently, there have been more widespread observations of
tundra “browning.” Here, we use a circumpolar remote sensing dataset to evaluate the spatio-temporal
patterns of arctic tundra vegetation dynamics (greening and browning), and its control by summer warmth, at
the circumpolar, continental (North America, Eurasia), and tundra subzonal (i.e. latitude) scales over the past
35 years. Significant warming trends, significant greening trends, and significant inter-annual relationships
between NDVI and summer warmth were not spatio-temporally consistent. Significant warming trends tended
to occur further north, whereas significant greening trends tended to occur more in the southern tundra. Some
significant browning trends were observed in the northern tundra subzones. Significant relationships between
NDVI and SWI were more likely found in the middle tundra latitudes. Over the satellite record, the number of
years of greening was similar to the number of years of browning, with the exception of the most southern
tundra subzone (Subzone E). The spatio-temporal dynamics of tundra vegetation and the controls on greening
and browning appear to be highly complex and in need of continued study.

1198
133
Spatial Redictions of Essential Biodiversity Variables: A Bird Perspective

Nasrin Amini Tehrani1 (nasrin.aminitehrani@unil.com)

1
University of Lausanne, Geoscience and Environment Institute of Earth and Dynamic, Lausanne, Switzerland

With increasing human pressure on biodiversity, populations of sensitive species become more isolated and
decrease in size as their suitable habitats become fragmented and degraded. In this context, landscape
composition, especially the arrangement of mountain is often key for population persistence and biodiversity
conservation. Monitoring how landscape changes affect biodiversity should be a central component of
landscape planning. Biodiversity includes too many dimensions, so defining which of them are essential is key
to successful monitoring. For this reason, the concept of essential biodiversity variables (EBV) was defined, with
the intent to identify key elements to monitor. One way to derive EBVs spatially may be through the use of
species distribution models (SDM) based on quantification of species' habitat suitability, and use them to
support planning and decision-making over large areas. One can further use stacked species distribution
modelling (S-SDM) of constituent species to approximate the properties of assemblages. S-SDM outputs can
then be used to predict various EBVs spatially. We aim to develop and test new approaches based on SDMs, to
build spatial predictions of EBVs for birds in a mountain area of the Swiss Alps. We first study the power of
different environmental and geographical factors for building S-SDM predictions,then we use these to derive
bird EBVs as support to biodiversity management and help identifying priority bird conservation areas.

1199
353
Climate Warming Accelerates Increase in Plant Species Richness on Alpine Summits

Christian Rixen1 (rixen@slf.ch), Sonja Wipf1

1
WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland

Species climate envelope models predict that a large proportion of Europe's alpine flora is threatened by local
extinction in a warmer climate, as stronger competitors move to higher altitudes and might out-compete cold
climate specialists.
We study how the species composition in the Arctic and Alpine, particularly on mountain summits, has changed
over the past decades, especially during the pronounced warming since approx. 1980. We compare historical
and recent plant occurrences in a summit re-visitation study.
The comparison of historical and recent plant occurrence data from c. 250 mountain summits in European
mountain ranges showed that species richness increased considerably due to upward migration of species,
while there was little evidence for extinctions of high-alpine specialists. Fine-scale species distribution revealed
that “successful” and less successful species differ in the type of microhabitats they occupy. This spatial and
ecological segregation might explain why colonization with new, potentially highly competitive species has not
(yet) been followed by a wave of local extinctions.
Our findings shed light on processes that drive the spatial distribution of plant species in alpine terrain and thus
may, in the longer term, help to refine predictions of threats to particular plant species.

On behalf of the E Summit Flora consortium.

1200
1125
European Alpine Glacier Reveals one Millennium of Fire and Vegetation Dynamics

Sandra Brügger1 (sandra.bruegger@ips.unibe.ch), Erika Gobet2, Michael Sigl3, Dimitri Osmont3, Margit
Schwikowski3, Willy Tinner2
1
University of Bern, Physics Institute & Oeschger Centre for Climate Change Research, Bern, Switzerland,
2
University of Bern / Institute of Plant Sciences and Oeschger Center for Climate Change, Bern, Switzerland,
3
Paul Scherrer Institute, Villigen, Switzerland

Wild fires are a disturbance agent across the continents, driving ecosystem dynamics and societal hazards. We
analyze ice-core pollen and spores as proxies for vegetation composition and land use, microscopic charcoal for
fire activity, and spheroidal carbonaceous particles for fossil fuel combustion. The results derive from the
highest glacier of Europe (4452 m asl), from Colle Gnifetti. To our knowledge they provide the first long-term
and high-resolution palynological record of Europe from an ice-core.
The central position and large microfossil catchment of the Colle Gnifetti allows us to address vegetation and
societal responses to climatic change and wildfire disturbance on a subcontinental scale, presumably covering
substantial parts of Western, Central and Southern Europe. The ice core record provides an excellent
chronological control for the past millennium, particularly over the most recent 200 years, the period that
experienced important climatic changes and an increasing globalization of economy.
We reconstruct large scale impacts such as extreme weather, societal innovations, agricultural crises and
pollution in Europe. Surprisingly, pollution tracers occur in the record as early as 1750 AD. They anticipate
industrialization but coincide with a shift to large-scale maize production in Northern Italy and strongly
increased fire activity. Our multiproxy record may allow desentagling the role of climate and humans for
vegetation composition and biomass burning.

1201
BE-2b - Phytoplankton, productivity and carbon export dynamics
21.06.2018 11:00-12:30, A Seehorn

676
Southern-Atlantic Phytoplankton Community Composition Response to Light and Iron

Johannes Jacobus Viljoen1 (16487338@sun.ac.za), Susanne Fietz1

1
Stellenbosch University, Earth Science, Stellenbosch, South Africa

Understanding the response of phytoplankton communities to specific environmental drivers in different

Southern Ocean water masses is critical to improve projections under current threats of global change. We
show the importance of understanding of the role the biological pump play in the future global climate and
more specifically the effect of different phytoplankton communities. Different phytoplankton play different
roles in the ocean biogeochemical cycles, especially carbon export, and thus on climate feedback processes.
This study presents changes in the community composition across a South-Africa to Antarctic transect along
with an assessment of the effects of increased micronutrients using a series of on-board iron/light bulk
incubation experiments. Phytoplankton composition was assessed using their photosynthetic pigments.
Diatoms are dominant in the Sub-Antarctic, Polar Frontal, and - along with Phaeocystis antarctica - the
Antarctic zone. This was re-enforced when cultivated under increased light/iron conditions and the new bulk
community was diatom dominated. Incubations also revealed that P. antarctica acclimated its pigment ratios to
function more efficiently within different light and iron conditions and that community compositions in the
Antarctic zone depend more on iron availability than that of the Polar Frontal zone. We conclude that both
light and iron are significant controls on the phytoplankton community and that their effects varies regionally.

1202
693
Southern Ocean Phytoplankton Silica Uptake Relating to Leakage and Carbon Export

Ian Weir1 (ianweir1992@gmail.com), Susanne Fietz1

1
Stellenbosch University, Earth Sciences, Stellenbosch, South Africa

The silicic acid cycle is closely linked to the carbon cycle in oceans as diatoms, a dominant, siliceous
phytoplankton in the Southern Ocean (SO), are estimated to be responsible for the removal of approximately
55% of the total organic carbon in modern oceans.
The incorporation of silicic acid into the diatom cell wall structure, carbon export, productivity and biogenic
silica distribution are reported in this paper through incubation experiments and transect data addressing
pitfalls of the Silicic Acid Leakage Hypothesis. Upon iron (Fe) fertilization, the potential for the community to
utilize less silicic acid from the water column is evaluated. The study spans a winter and three summer cruises,
including the Atlantic and Indian Sectors of the SO. Biogenic silica is coupled with ancillary trace metal,
macronutrient, particulate organic carbon (POC), Chlorophyll a and community composition data.
Incubation experiments within the community illustrate a noticeable increase in biogenic silica under high iron
and light regimes, whilst transect data reiterate these limitations. Results suggest an increase in productivity
across all oceanic zones. Scanning Electron Microscopy imaging indicates that upon Fe fertilization, changes in
the thickness of the diatom cell wall are species-specific. To conclude, Fe addition drastically increases diatom
production with certain species displaying a thinning of the cell wall marking potential for excess silicic acid in
the water column.

1203
1386
Impact of Light and Iron Availability on Antarctic Phytoplankton Ecophysiology

Scarlett Trimborn1,2 (scarlett.trimborn@awi.de), Silke Thoms1, Kai Bischof2, Sara Beszteri1

1
Alfred Wegener Institute, Bremerhaven, Germany, 2University of Bremen/BreMarE, Bremen, Germany

Although iron (Fe) availability sets primarily the rate of phytoplankton growth and primary and export
production in the Southern Ocean, other environmental factors, most significantly light, also affect
productivity. Due to wind-induced vertical mixing, the total irradiance dose can be reduced, but exposing
phytoplankton also to periods of excessive irradiance when residing near the surface. As these dynamic
alterations between low and high irradiance in low Fe-waters are important drivers of species distribution, we
investigated the effects of light (20, 200 and 500 µmol photons m−2 s−1) in combination with low and high Fe
availability (0.4 and 2 nM Fe) on the physiology of the two ecologically relevant species Chaetoceros debilis and
Phaeocystis antarctica. Fe-limited cells of P. antarctica displayed similar high growth rates at all irradiances. In
comparison, Fe-limited C. debilis cells grew much slower under low and medium irradiance and were unable to
grow at the highest irradiance. Compared to C. debilis Fe-limited P. antarctica cells fixed more particulate
organic carbon at all irradiances. When exposed to short-term excessive irradiances C. debilis could cope better
than P. antarctica under low Fe conditions, but this was at the expense of lowered carbon production. Overall,
our results show that P. antarctica was more tolerant to changes in the availability of Fe and light, providing it a
competitive advantage under a dynamic light regime in Fe-deficient waters.

1204
1172
Phytoplankton Group-specific Contributions to the Subantarctic Biological Pump

Heather J Forrer1 (hjforrer@gmail.com), Thomas G Bornman2, Samantha C Waterworth3, Angela N Knapp4,

Rachel K Thomas4, Rosmary A Dorrington3, Sarah E Fawcett1
1
University of Cape Town, Department of Oceanography, Cape Town, South Africa, 2Elwandle Coastal Node,
South African Environmental Observation Network, Port Elizabeth, South Africa, 3Rhodes University,
Department of Biochemistry and Microbiology, Grahamstown, South Africa, 4Earth, Ocean and Atmospheric
Science Department, Florida State University, Tallahassee, United States

Summer Subantarctic surface waters are characterized by high concentrations of unconsumed nitrate (NO3-),
likely due to combined iron, light and silica limitation of phytoplankton growth. Phytoplankton diversity and
community structure response to such nutrient limitation is not well understood. The degree to which
phytoplankton consume NO3- (“new production”) is proportionate to net carbon (C) removal to the deep
ocean, while growth fueled by recycled ammonium (NH4+) yields no net C flux. The N isotopic composition
(d15N) of upper ocean biomass can be used as an integrative tracer of NO3- vs. NH4+ uptake; however, surface
particles include heterotrophs and detritus in addition to phytoplankton, complicating the use of bulk particle
d15N as a metric for new vs. recycled N uptake. This is overcome by coupling cytometric cell sorting (FACS) -
isolating important populations (e.g., cyanobacteria, picoeukaryotes, diatoms) - with group-specific d15N
analysis. On the summer 2016/2017 Antarctic Circumnavigation Expedition cruise across the Indian sector of
the Subantarctic Ocean, we collected particles for FACS-d15N analysis and seawater samples for analysis of
nutrients and nitrate d15N. Four phytoplankton groups appear to be dominant across the basin. Their
contribution to new production and C export will be discussed, as will that of Subantarctic island populations
occupying waters where iron and possibly silica are no longer limiting due to mesoscale upwelling and island
runoff.

1205
678
Coccolithophore Controls on the Southern Ocean Carbon Cycle

Cara Nissen1 (cara.nissen@usys.ethz.ch), Meike Vogt1, Matthias Münnich1, Nicolas Gruber1

1
Environmental Physics, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zürich, Switzerland

Southern Ocean (SO) phytoplankton biogeography impacts carbon cycling and the transport of macronutrients
to lower latitudes. The relative importance of calcifying coccolithophores is especially important, since
calcification and photosynthesis have opposing impacts on seawater pCO2 and air-sea CO2 fluxes. Further,
calcite acts as ballast material for exported organic matter, enhancing the sequestration of organic carbon.
Recent evidence suggests areas of high coccolithophore abundance in the SO, yet, the quantitative
contribution of coccolithophores to SO biogeochemistry is not well understood. Here, we address this question
using a regional high-resolution ocean circulation model for the entire SO (>24°S) with an embedded
biogeochemistry module and an explicit representation of coccolithophores (ROMS-cBEC). Comparing our
standard simulation to one without calcification by coccolithophores, we find the net air-sea flux of CO2 to
increase by 50% when neglecting calcification, making the SO a larger CO2 sink. In contrast, we find little change
in NPP and carbon transfer efficiency (< 5%), implying only a small ballasting effect. When coccolithophores are
excluded from the model's phytoplankton community, preliminary results suggest a 15% increase in the
northward transport of nitrate relative to silicate. Thus, future changes in the relative importance of
coccolithophores could substantially impact carbon cycling not only in the SO, but potentially at lower latitudes
as well.

1206
2133
Main Drivers Regulating the Strength of Carbonate Counter Pump in the SO

Clara Manno1 (clanno@bas.ac.uk), Federico Giglio2, Gabriele Stowasser1, Sophie Fielding1, Geraint A. Tarling1
1
British Antarctic Survey, Cambridge, United Kingdom, 2National Research Council CNR-ISMAR, Bologna, Italy

The Biological Carbon Pump (BCP) is counteracted by the Carbonate Counter Pump (CCP), which causes an
increase in surface ocean CO2 through the export of Particulate Inorganic Carbon (PIC). The ability to
precipitate carbonate as well as the ballasting effect change according the different plankton calcifying
structures. Thus understanding the variability in calcifying assemblage and/or their relative abundance it is
crucial in order to forecast the fate of CO2 uptake and sequestration in the deep ocean. Here, we describe a 2-
year-long series of particles flux, as measured by deep moored sediment traps located at two sites close to
South Georgia (Northern Scotia Sea). The aim of this study is to assess the specific contribution of the whole
calcifying organism compartment (pteropods, foraminfera, coccolithophores and ostracods) to the Carbonate
flux as well as their role in regulating the strength of the CCP. We found that when pteropods drive the
magnitude of Carbonate flux, the total annual reduction of CO2 transferred to the deep ocean double respect
to the other year (when conversely foraminifera and coccolithiphores are dominants). This work provides an
insight into the importance of the plankton calcifying assemblage to drive the magnitude of the CCP in a
sensitive region such as the Southern Ocean which is responsible for 40% of the global anthropogenic carbon
uptake.

1207
CR-6b - Glaciers and Ice Sheets: from the Mountains to the Poles
21.06.2018 11:00-12:30, A Wisshorn

543
Major 20th Century Contribution to Sea-level Rise from Uncharted Glaciers

Ben Marzeion1 (ben.marzeion@uni-bremen.de), David Parkes1,2

1
University of Bremen, Bremen, Germany, 2University of Innsbruck, Innsbruck, Austria

Global mean sea-level rise (GMSLR) during the 20th century was primarily caused by glacier and ice sheet mass
loss, thermal expansion of ocean water, and change of terrestrial water storage. Whether based on
observations2 or results of climate models, the sum of estimates of each of these contributors tends to fall
short of the observed GMSLR. All estimates of the glacier contribution to GMSLR rely on the application of
glacier inventory data, which are known to under-sample the smallest glacier size classes. Here we show that
missing glaciers (those small glaciers that we expect to exist today, but which are not represented in the
inventories) may have contributed 42.7±6.5 mm to GMSLR during the period 1901 to 2015, even though their
total 2015 ice mass is very small (2.4±0.4 mm GMSLR equivalent). Additionally, disappeared glaciers that
existed in 1901, but had completely melted away by 2015, and which are therefore not included in modern
global glacier inventories, may have contributed 5.3±2.4mmto GMSLR. Together, these uncharted glaciers
(missing glaciers and disappeared glaciers combined) made an estimated contribution of 48.0±8.9 mm to
GMSLR. Failure to consider these glaciers may be the cause of difficulties in closing the GMSLR budget during
the 20th century. We suggest that accounting for uncharted glaciers in some fashion is essential for accurate
historical glacier GMLSR contribution estimations.

1208
1379
Data Assimilation & Uncertainty Analysis of a Stochastic Subglacial System Model

Inigo Irarrazaval1 (inigo.irarrazavalbustos@unil.ch), Gregoire Mariethoz1, Frederic Herman1

1
University of Lausanne / Institute of Earth Surface Dynamics, Lausanne, Switzerland

The subglacial drainage system plays a crucial role not only in ice flow dynamics, but also in erosion of the
bedrock, catchment hydrology, and potential hazards related to of glacier outburst floods. The study of
subglacial drainage system is challenging due to the inaccessibility of such environments, resulting in a lack of
direct observations. Even though physical deterministic models have been built, it difficult to constrain their
outputs to observations and to perform sensitivity analysis and independent validation of these model.
In this context, we aim to infer the spatial structure and hydraulic parameters of the subglacial drainage system
based on indirect data such as water pressure and tracer experiment. To this end, we develop an approach that
uses a combination of stochastic and physical processes. An inversion procedure is used to determine a set of
possible models that all agree with the data, and to determine parameters uncertainty. The proposed
methodology incorporates three main components:
1) a stochastic channel generator to produce realistic geometries for the subglacial drainage system;
2) a physical model where distributed water pressure and mass transport are computed over the domain;
3) an inverse loop where the results (pressure, mass concentration) are compared with observed data in order
to assess the channel network geometry and hydraulic properties of the system.

1209
99
Time-lapse Thermal Imagery Used to Resolve sub-debris Glacier Melt in Alaska

Sam Herreid1 (samherreid@gmail.com), Francesca Pellicciotti1

1
Northumbria University, Newcastle upon Tyne, United Kingdom

Rock debris at the surface of a glacier often insulates the underlying ice from incoming energy fluxes thereby
reducing the local melt rate. The relation between debris thickness and melt suppression is nonlinear and
consistent throughout many field studies. Debris that is about 10-15 cm thick can reduce the local melt rate by
half and debris >50 cm thick can reduce melt to near zero. The distribution of debris cover on glaciers globally
is not explicitly known at the time of writing, but is estimated at around 17%. The impact of debris cover on
glacier melt is neglected in most large-scale glacier melt models and is likely one of the leading sources of error.
The spatial distribution of debris on glaciers is fairly simple to derive from remote sensing, yet the governing
term, the thickness of the debris, is much more difficult to resolve. We use time-lapse thermal imagery
collected in the Alaska Range coupled with classical glacier field data and satellite based thermal imagery to
(1) test the hypothesis that thermal data can be used to derive debris thickness at wide spatial scales, and
(2) develop a simple model for estimating the impact of debris cover on glacier melt at a regional scale.
Modeling efforts that are successful at a regional scale are an essential step towards larger-scale efforts. This
work is targeted towards the inclusion of a debris cover term in global glacier melt models.

1210
2124
Recent Changes to Glaciers on Northern Ellesmere Island, Nunavut, Canada

Adrienne White1 (awhit059@uottawa.ca), Luke Copland1

1
University of Ottawa, Department of Geography, Environment and Geomatics, Ottawa, Canada

Using optical satellite scenes, this study quantifies change in the extent of 1755 glaciers across northern
Ellesmere from 1999-2015. Our results show that ice coverage decreased by ~6% over the 16-year period. This
indicates an acceleration over the 3.4% loss recorded by Sharp et al (2014) between 1960-2000. Our results
show that ice shelves had the greatest losses relative to their size, a loss of ~25%. Tidewater glaciers reduced
by 3% and included the transition of two tidewater glaciers to land-terminating. 18 glaciers that were identified
as marine-terminating with an ice tongue in 1999 had their tongues disintegrate. Past studies have linked the
loss of ice shelves to warmer summer air temperatures, and the loss of the protective barrier created by multi-
year landfast sea ice (MLSI). These factors may have also played an important role in the loss of the floating ice
tongues observed in this study, particularly in Yelverton Inlet where several ice tongues have disappeared since
the recent loss of MLSI in this region. Land-terminating glaciers lost 5% of their area, including the complete
loss of three small ice caps (< 1.5 km2). This is consistent with trends observed from other regions where ice
loss has been dominated by small, remnant glaciers, due to their greater sensitivity to climate. Overall our work
suggests that the rate of ice loss has increased and that the ice masses most susceptible to accelerated loss are
glaciers with floating termini and small ice caps.

1211
2677
The 50 Year Response and Future Stability of Canada´s Arctic Reference Glaciers

Laura Thomson1 (lthomson@sfu.ca), David Burgess2

1
Simon Fraser University, Burnaby, Canada, 2Geological Survey of Canada, Ottawa, Canada

The Canadian Arctic hosts the largest area of ice outside of Greenland and Antarctica and is currently the
largest contributor to modern global sea level rise as a result of Arctic amplification. Since 1960, annual
measurements of surface mass balance have been conducted on three ice caps and one mountain glacier on
Meighen, Melville, Devon, and Axel Heiberg Island in the Canadian Arctic. Together, these records indicate a
trend of increasing mass loss over the past two decades alongside rising equilibrium line altitudes and shrinking
accumulation area ratios. The sensitivity and long-term stability of these glaciers is closely linked to ice
dynamics, and specifically the rate of ice transfer from cold, high elevations to lower, warmer elevations where
melt conditions prevail. We present a synthesis of the long-term mass balance records in the Canadian
alongside a case study from White Glacier on Axel Heiberg Island, Nunavut, to demonstrate the role of
thinning, retreat, and ice dynamics in the long-term stability of high-Arctic glacier response.

1212
421
Elevation Changes of Greenland's Glaciers using AeroDEM, ArcticDEM and TanDEM-X

Jacqueline Huber1 (jhuber@access.uzh.ch), Luisa von Albedyll2, Horst Machguth1, Michael Zemp1
1
University of Zurich, Department of Geography, Zürich, Switzerland, 2University of Bremen, Bremen, Germany

Greenland peripheral glaciers and ice caps are sensitive key indicators of climate chance but recent evolution of
ice volume along Greenland's periphery is still poorly understood. The restricted number of geodetic glacier
thickness changes on Greenland is probably related to the absence of digital elevation models (DEM) of
sufficient accurac
In this study we used the reanalyzed AeroDEM (late 1970s to mid-1980s) and the two recently released high
resolution DEMs ArcticDEM (2012-2015) and TanDEM-X (2010-2014) to calculate geodetic glacier elevation
changes. Thereby, the main challenge was to appropriately deal with the data voids and artefacts occurring in
all three DEMs. In the framework of a pilot study, the ArcticDEM was subtracted from the AeroDEM over the
Holm Land ice cap, northeast Greenland. The data voids were filled (A) by spatial interpolation and (B) by
interpolating the mean of the respective elevation bin, resulting in a mean elevation changes of −9.3 m and
−9.9 m, respectively. Based on the results of this pilot study, we are applying these approaches to calculate
glacier elevation changes for larger regions on Greenland.
This work is carried out in the framework of the Copernicus Climate Change Service
(https://climate.copernicus.eu/about-c3s) for which the World Glacier Monitoring Service (WGMS) aims at
generating glacier specific elevations changes for regions around the world.

1213
CR-4b - Ice sheets, ice shelves & proximal processes in past, present & future climates
21.06.2018 11:00-12:30, B Parsenn

1758
Ice Shelf Buttressing and Ice Sheet Flow

G Hilmar Gudmundsson1 (hilmargudmundsson@googlemail.com), Ronja Reese2, Ricarda Winkelmann2, Anders

Levermann2
1
University of Northumbria, 8ST, United Kingdom, 2Potsdam Institute for Climate Impact Research, Potsdam,
Germany

Ice shelves buttress ice at the grounding lines of the Antarctic Ice Sheet and changes in the geometries of ice
shelves can affect upstream flow. We review theoretical concepts related to ice-shelf buttressing and
grounding-line stability, and use numerical ice flow models to quantify the impact of loss of ice shelves on ice
flux across grounding lines. We give both a general overview over the sensitivity of grounding-line ice flux to
changes in ice-shelf thickness, and more specifically estimate the impact that recent thinning may have had on
ice flow in Antarctica. We find that the spatial pattern of observed current ice loss matches closely that
predicted by numerical modelling. Hence, loss of ice shelf buttressing appears to be modulating grounding line
ice flux in Antarctica today. While these findings are in good agreement with prevailing views on the
importance of ocean-induced thinning over ice shelves, this is the first time that such a link is explicitly derived
using numerical ice flow models.

1214
44
An Observation Based Approach to Calculating Ice Shelf Calving Flux

Eleri Evans1,2 (eleri.evans@utas.edu.au), Alexander Fraser2, Sue Cook2, Richard Coleman1,2, Ian Joughin3
1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Antarctic Climate &
Ecosystems Cooperative Research Centre, Hobart, Australia, 3University of Washington, Applied Physics
Laboratory, Polar Science Center, Seattle, United States

Traditionally it has been very difficult to determine the non-steady state behaviour of ice shelves from
observations. In order to define the state of an ice shelf one of the key components, the calving flux, is
required. Antarctic wide calculations of ice shelf calving fluxes have tended to ignore the smaller ice shelves
and/or smaller calving events, often assuming that the calving flux of an ice shelf is temporally constant and so
not accounting for non-steady state behaviour. An approach is needed that captures the sum total of all calving
along with the variation in calving front position between calving events. We have developed an observation
based approach that uses a combination of ice flow velocities, ice thicknesses and a time-series of calving front
positions to calculate the calving flux of an ice shelf at a high temporal and spatial resolution. The Sørsdal
Glacier of East Antarctica is used as an example. The sensitivity of the approach to the input datasets (e.g. ice
velocities and ice thicknesses) is investigated. Quantifying the calving fluxes of smaller ice shelves at a high
temporal and spatial resolution will allow a more accurate estimate of the mass loss from the Antarctic Ice
Sheet due to ice shelf calving. Using such an observation based approach to quantify the calving flux will also
give an insight into ice shelf dynamics and how these may change with changing environmental forcings.

1215
606
Nature or Nurture? Rift Generation(s) at the NE front of the Ross Ice Shelf

Martin Forbes1 (martin.forbes@postgrad.otago.ac.nz), Christina Hulbe1, Karuna Sah2

1
University of Otago, National School of Surveying, Dunedin, New Zealand, 2Dickinson College, Carlisle, United
States

Understanding the conditions that drive ice shelf rift geometry and propagation is critical to understanding
contemporary change in Antarctic systems. Rifts become the planes along which tabular icebergs calve and
thus play an important role in ice shelf mass balance and response to climate change.
We use a linear elastic fracture mechanics (LEFM) modelling approach coupled with an ice shelf model to
investigate a family of rifts at the front of the Ross Ice Shelf, between Roosevelt Island and the Shirase Coast.
This is an ideal section of the ice shelf for our study because stress conditions are straightforward and spatial
variation in ice properties appears to be relatively straightforward as well. The propagation of two generations
of rifts is recorded in images collected between 1986 and 2017 by Landsat 4, 7, and 8. Rifts originating from
very different spatial circumstances are observed to develop into similar near-front geometries. We consider
both differing origins and similar fates of these features, simulating both using the same far-field stress
conditions.

1216
1191
Study on Fracturing of Ronne-Filchner Ice Shelf using Multisource Satellite Data

Rongxing Li1,2 (rli@tongji.edu.cn), Haifeng Xiao1,2, Shijie Liu1,2, Xiaohua Tong1,2

1
Center for Spatial Information Science and Sustainable Development Applications,Tongji University, Shanghai,
China, 2College of Surveying and Geo-Informatics, Tongji University, Shanghai, China

Ice shelves play a very important role in buttressing the Antarctic ice sheet. Monitoring the stability of the ice
shelves is an integral part of the study of AIS mass changes and the associated sea level rise. We propose a new
framework of systematic fracture mapping and major calving event prediction for the large ice shelves in
Antarctica using optical imagery, SAR imagery, altimetric data, and stereo mapping imagery. It is implemented
and applied for a comprehensive study of the fracturing of Ronne-Filchner Ice Shelf using a long time dataset
dating back to 1957. New remote sensing data that have been made available in the past decade, including
Landsat 8, WV-2, ZY-3 and others, greatly enhance our abilities to detect new fractures and monitor large rifts
in three dimensions. Two large rifts, Rifts 1 and 2, were newly detected and are comparable to the Grand
Chasm that caused a major calving event in the region in 1986. Based on the results of the 2D and 3D fracture
mapping, the spatial and temporal analyses of the overall fracture changes and large rift evolutions, the level of
fracturing in RFIS was slightly increased, particularly at the front of the ice sheet. The overall fracture
observations do not seem to suggest immediate significant impacts on the stability of the shelf. However, the
most active regional fracturing activities occurred at the front of Filchner Ice Shelf. A potential upcoming major
calving event of FIS is estimated to occur around 2051.

1217
1127
MADICE - Exploring Ice Rises and Shelves of Dronning Maud Land, East Antarctica

Thamban Meloth1 (meloth@ncaor.gov.in), Kenny Matsuoka2, Project Team Madice3,4,5

1
ESSO-National Centre for Antarctic & Ocean Research, Polar Sciences, Vasco da Gama, India, 2Norwegian Polar
Institute, Fram Centre, Antarctic Glaciology, Tromso, Norway, 3Norwegian Polar Institute, Tromso, Norway,
4
ESSO-National Centre for Antarctic & Ocean Research, Vasco da Gama, India, 5University Center in Svalbard,
Longyearbyen, Norway

Ice shelves of Antarctica are rapidly changing and could largely affect the Antarctic ice sheet stability. Ice rises,
grounded ice domes, affect ice-shelf stability and are useful sites to investigate the proxy records of Antarctic
climate variability. Dronning Maud Land (DML) is characterized by small ice shelves that are punctuated by ice
rises. To fill the knowledge gap and to undertake a detailed study of ice shelves and ice rises of coastal DML, an
Indo-Norwegian project named MADICE (Mass balance, dynamics, and climate of the central Dronning Maud
Land coast, East Antarctica) was initiated. During the 2016-17 season, the first joint MADICE campaign was
under taken within the Nivlisen Ice Shelf and adjacent ice rises (Djupranen and Leningradkollen). This campaign
successfully collected a range of glaciological data using GPS and radar, and recovered two ice cores at the
summits of the ice rises (depth 122 and 51 m, respectively). The ice core from Djupranen ice rise includes
negligible melt features, whereas the ice core from Leningradkollen shows many melt features. This is primarily
caused by the difference in surface elevations (150 m). We are analyzing the stratigraphy, stable isotope other
properties of these ice cores. The second MADICE campaign is currently underway. We will present scope,
outline and initial results of this project. Details of geophysical/glaciological findings are proposed as another
presentation in the same session (Lindbäck and others).

1218
2424
Multi-disciplinary Observation Network to Monitor Rapid Changes in Antarctica

Won Sang Lee1 (wonsang@kopri.re.kr), Choon-Ki Lee1, Yongcheol Park2, Sukyoung Yun1, Christopher Zappa3,
Craig Stevens4, Don Blankenship5, Alex Forrest6, Robert Dziak7, Mechita Schmidt-Aursch8, Christine Dow9, Ted
Scambos10, Jinseok Kim1, Jiyeon Lee1, Seung Hyun Lee1, Seungtae Yoon1
1
Korea Polar Resarch Institute, Unit of Ice Sheet and Sea Level Changes, Incheon, Korea, Republic of, 2Korea
Polar Resarch Institute, Incheon, Korea, Republic of, 3Lamont-Doherty Earth Observatory Columbia University,
NY, United States, 4National Institute for Water and Atmospheric Research, Wellington, New Zealand,
5
University of Texas at Austin, Jackson School of Geosciences, TX, United States, 6University of California, Davis,
CA, United States, 7NOAA Pacific Marine Environmental Laboratory, OR, United States, 8Alfred Wegener
Institute - Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 9University of Waterloo,
ON, Canada, 10National Snow and Ice Data Center, CO, United States

The Polar Regions have been experiencing dramatic changes particularly including glacier retreating, ice
thinning, declining in sea ice extent, and so on. Recent literatures illuminate that the melting rate of ice sheets
and glaciers in the West Antarctic has accelerated, which may lead significant contributions to global sea level
rise. In an attempt to understand the complex forms of interaction between the Lithosphere, the Hydrosphere,
the Atmosphere, and the Cryosphere, Korea Polar Research Institute has been operating an integrated
Cryosphere monitoring network (EGGNet; Extreme Geophysics Group observation Network) in the Terra Nova
Bay (TNB) since December, 2010. The EGGNet consists of local broadband seismic stations, GPS stations,
AMIGOS systems, Ocean Bottom Seismometers, oceanographic moorings, and Autonomous Underwater
Hydrophones. In addition to operation of the year-round stations, we have performed magnetotelluric survey
near Mt. Melbourne, CTD castings in TNB, airborne geophysical surveys on Nansen Ice Shelf, Drygalski Ice
Tongue and David Glacier. In this presentation, we show some of interesting features observed through the
EGGNet: identification of David Glacier subglacial lakes, basal melting occurring under Drygalski Ice Tongue,
existence of super-cooled water in TNB, seismic velocity structure under Mt. Melbourne, etc. We anticipate
that these in situ observations could help to improve our understanding of physical processes for ice sheet
models.

1219
OS-3b - Sea ice extent, properties, volume & ice shelves: modern and paleo records
21.06.2018 11:00-12:30, B Jakobshorn

391
Drivers of Southern Ocean Sea Ice Trends in CMIP5 Models

Will Hobbs1 (whobbs@utas.edu.au)

1
Antarctic Climate & Ecosystems Cooperative Research Centre, Hobart, Australia

Formal change detection studies indicate that the observed trend inSouthern Ocean sea ice cover is within the
range of internal variability. However, this result depends on global coupled models that fail to capturestrong
local trends, in especially during summer in the western Ross andBellingshausen sectors. Additionally the
model response to individual forcings has not been considered except for total sea ice extent changes. In this
work optimal fingerprinting has been applied to Southern Ocean sea ice, and to the local atmosphere and
ocean, to individually explore the sea ice response to anthropogenic greenhouse gas and anthropogenic ozone
depletion. The former is characterised by a thermodynamic reduction in sea ice at all seasons andsectors; the
latter shows a seasonally and spatially-dependent response that is driven by the atmosphere and is similar to
observed patterns. The all-forcings response, which has been used in previous detection studies,is dominated
by the thermodynamic greenhouse gas forcing. This indicates that the models over-represent the thermal
response in the high latitudeSouthern Hemisphere.

1220
304
Atmospheric Influences on the Anomalous 2016 Antarctic Sea Ice Decay

Elisabeth Schlosser1,2 (elisabeth.schlosser@uibk.ac.at), Alexander Haumann3,4, Marilyn Raphael5

1
University of Innsbruck, Atmospheric and Cyrospheric Sciences, Innsbruck, Austria, 2Austrian Polar Research
Institute, Vienna, Austria, 3ETH Zurich, Zurich, Switzerland, 4Princeton University, Princeton, United States,
5
University of California LA, Los Angeles, United States

In contrast to the Arctic, where total sea ice extent (SIE) has been decreasing for the last three decades,
Antarctic SIE has shown a small, but significant increase during the same time period. However, in 2016, an
unusually early onset of the melt season was observed; the maximum Antarctic SIE was already reached as
early as August rather than end of September, and was followed by a rapid decrease. The decline of the sea ice
area (SIA) started even earlier, namely in July. The decay was particularly strong in November where Antarctic
SIE exhibited a negative anomaly (compared to the 1979-2015 average) of approximately 2 Mio. km2, which,
combined with reduced Arctic SIE, led to a distinct minimum in global SIE. ECMWF- Interim reanalysis data
were used to investigate possible atmospheric influences on the observed phenomena. The early onset of the
melt and the rapid decrease in SIA and SIE were associated with atmospheric flow patterns related to a positive
ZW3 index, i.e. synoptic situations leading to strong meridional flow. Particularly, in the first third of November
northerly flow conditions in the Weddell Sea and the Western Pacific triggered accelerated sea ice decay,
which was continued in the following weeks due to positive feed-back effects, leading to the extraordinary low
November SIE. In 2016, the monthly mean SAM index reached its second lowest November value since the
beginning of the satellite observations. SIE decrease was preconditioned by SIA decrease.

1221
609
Exploring Kinematic Contributions on Antarctic Sea-ice Extent

Petra Heil1 (petra.heil@utas.edu.au), Glenn Hyland1

1
Australian Antarctic Division, Antarctica and Global System, Hobart, Australia

The recent collapse of annual maximum extent of Antarctic sea ice brings the long-term evolution of Antarctic
sea ice into line with the polar response to global warming. For about the last two decades the Antarctic winter
ice cover had expanded, exceeding 20Mio km2 in 2014. The underlying processes for this expansion are thought
to be due to either melt-induced cold freshwater lenses at the ocean surface in the Southern Ocean or a
combination of wind-driven advective and thermodynamic changes. Here we investigate the contribution of
advection on the ice extent using SAR and MODIS imagery. Since 2001 during most years in the region off East
Antarctica, strengthened synoptic-scale surface winds increased the northern sea-ice extent. However, during
some years, including the most recent once, winds acted to compact the near-coastal sea ice, and by virtue of
deformation increased the ice thickness. In the Weddell Sea and to a lesser degree in the Ross Sea, ice
advection was found to modulate the strength of the regional northward ice export. Off East Antarctica and in
the Weddell Sea ice advection correlated with shear and has been linked to deformational thickening. A
pathway of ice advection affecting the regional sea-ice extent and ice-thickness distribution can be identified
for most Antarctic regions.

1222
2519
Sea Ice Type Distribution in the Antarctic from Microwave Satellite Observations

Christian Melsheimer1 (melsheimer@uni.-bremen.de), Gunnar Spreen1, Mohammed Shokr2, Yufang Ye3

1
University of Bremen, Institute of Environmental Physics, Bremen, Germany, 2Environment and Climate Change
Canada, Toronto, Canada, 3Chalmers University of Technology, Göteborg, Sweden

Sea ice can be classified into several types, such as young ice (YI, thin and smooth new ice), first-year ice (FYI,
formed during one cold season), and multiyear ice (MYI, ice that has survived at least one melt season). As the
physical properties of sea ice differ significantly for the different ice types, knowledge of the sea ice type is
essential, e.g., for properly modelling the ice-ocean-atmosphere system.
Here we apply a new satellite-based retrieval of sea ice type in the Antarctic. This retrieval has originally been
developed and tested for the Arctic, where it can distinguish YI, FYI and MYI. The motivation to apply the sea
ice type retrieval in the Antarctic is that there is a considerable amount of MYI in the Antarctic (albeit less and
younger than in the Arctic), and that, however, the ice type distribution in the Antarctic has not yet been
investigated much.
The retrieval method uses input data from active and passive microwave instruments (radar scatterometer and
radiometer, respectively) for the retrieval but in addition applies several correction schemes to account for the
effect of melt-refreeze processes, snow metamorphosis and sea ice drift on the sea ice type retrieval. The
needed satellite data have been available since 1999, there is daily full coverage (but no retrieval during
summer melt), and the spatial resolution is about 25 km.
We will present first results of the new retrieval applied to Antarctic sea ice and compare with results from the
Arctic.

1223
802
Sea Ice Thickness Estimates from Icebridge over the Weddell Sea in 2009-2016

Jing Li1 (jingli@lzb.ac.cn), Hongjie Xie2, Liuxi Tian2, Stephen Ackley2, Alberto Mestas-Nuñez2
1
Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China,
2
University of Texas at San Antonio, Department of Geological Sciences, San Antonio, United States

NASA's Operation IceBridge (OIB) aircraft flights aim at extending the laser altimeter time series through the
gap between the end of ICESat data collection in 2009 and the launch of the ICESat-2 lidar in 2018. OIB data is
used to estimate sea ice total freeboards and thicknesses over the Weddell Sea during 2009-2016. Local sea
level heights are extracted from the ATM (lidar) L1B over leads/thin ice mapped by the DMS images. Total
freeboard of sea ice is then derived from the ATM L2 by subtracting the nearest local sea level height. For the
2011 flights, our results are also compared with a previously published result that used the ATM L1B of the
lowest reflectance threshold (< 0.25) as local sea level. Ice thickness derived by using the empirical equations
shows reasonable spatial and temporal distributions, with thickest ice in the coastal northwest Weddell Sea.
The averaged ice thickness estimated at each track varies from 1.27m to 2.25m, with an overall increasing
linear trend of 0.035 m/yr from 2009 to 2016, although statistically insignificant (p = 0.13). Our next step is to
bring into the analysis the ICESat data (2003-2009) for the same tracks and thus generate a longer time series
(2003-2016) and more complete picture of sea ice variability in the Weddell Sea.

1224
945
Spatial Variabilities and Trend Analysis of the Antarctic Sea Ice with ICESat

Huan Li1 (lihuan2016@tsinghua.edu.cn), Hongjie Xie2, Yang Hong1,3, Wei Wan1, Siyu Zhu1, Wenbin Shi1, Yu
Fang3, Stefan Kern4, Stephen F. Ackley2, Burcu Ozsoy-Cicek5
1
Tsinghua University, State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic
Engineering, Beijing, China, 2University of Texas at San Antonio, Laboratory for Remote Sensing and
Geoinformatics, Department of Geological Sciences, Texas, United States, 3University of Oklahoma, School of
Civil Engineering and Environmental Sciences, Oklahoma, United States, 4University of Hamburg, Hamburg,
Germany, 5Istanbul Technical University, Turkey Polar Research Center (PolReC), Istanbul, Turkey

Obtaining accurate measures of the Antarctic sea-ice thickness (I) is becoming increasingly relevant given
below-average sea-ice extents observed after 2014 and the reappearance of the Weddell Sea polynya during
winter/spring 2017. Satellite laser altimeter observations of the total (sea ice plus snow) freeboard (F) have
proven to be useful in this context. However, in addition to uncertainties in F the conversion from F into I is
subject to several uncertainty sources, e.g., snow density and snow depth (S). Here we present a novel method
which combines several approaches. We derive F with the well-known lowest-level elevation method. We
avoid known uncertainties in the conversion from F into I (see above) by using a simplified buoyancy equation
in concert with the idea to consider sea ice and snow as one layer. The density of this layer required for the F-
to-I conversion can be computed as product between ice density and the ratio S/I. We derive the latter
dynamically from first guess values of I and S computed using two empirical equations based on in-situ
observations. Hereby we assume that contemporary application of these empirical equations to F results in a
smaller uncertainty in sea-ice thickness than when utilizing a potentially biased snow depth from another data
source. We show and discuss results of our enhanced sea-ice thickness retrieval method for ICESat / ICESat-2 in
a circum-Antarctic as well as regional context.

1225
AC-1g - Polar and high altitude atmosphere: clouds, aerosols, climate and interactions
21.06.2018 11:00-12:30, C Sanada I

114
Supersaturated Atmosphere on the Antarctic Plateau

Christophe Genthon1 (christophe.genthon@cnrs.fr), Etienne Vignon2, Jean-Baptiste Madeleine3, Luc Piard1,

Giuseppe Camporeale4, Paolo Grigioni5
1
CNRS, Institut des Géosciences de l'Environnement, Saint Martin d'Hères, France, 2Université Grenoble-Alpes,
Institut des Géosciences de l'Environnement, Saint Martin d'Hères, France, 3Universit é Pierre et Marie Curie
Paris 06, Laboratoire de Météorologie Dynamique, Paris, France, 4CNR, ISSIA, Genova, Italy, 5ENEA, Laboratory
for Observations and Analyses of Earth and Climate, Rome, Italy

Relative humidity with respect to ice (RHwri) is often reported close to or at saturation in the surface
atmosphere of the antarctic plateau. However, this does not exclude the possibility that the air is actually
supersaturated because conventional hygrometers cannot measure supersaturation and rather stick to their
100% instrumental ceiling. While they are frequent at high altitude, ice supersaturations do not generally occur
in the surface atmosphere where measurement is obviously much easier. Atmospheric conditions close to
those occurring at the tropopause are, however, found at the surface of the Antarctic plateau, both in terms of
temperature and humidity, and of low concentration of ice nuclei. Frequent reports of saturation probably
actually reflect poorly sampled supersaturation. Adapted sensors that can measure beyond saturation show
that at Dome C supersaturation is frequent and the norm rather than the exception (https://www.atmos-chem-
phys.net/17/691/2017/), and RHwri can occasionally reach 150% or more in winter. In summer, RHwri rises to
supersaturation as temperature decreases in the evening, then the vapor often coalesces to form surface haze.
RHwri decreases as the haze develops then as temperature increases, to reach undersaturation during the day.
This succession and chronology of events could offer a fair test for cold microphysics parameterizations
increasingly implemented in meteorological and climate models to simulate high-altitude cirrus clouds.

1226
495
Empirical Trace Gas Gradients in the Arctic and the Polar Dome Location

Heiko Bozem1 (bozemh@uni-mainz.de), Peter Hoor1, Franziska Köllner1,2, Daniel Kunkel1, Oliver Eppers1,2,
Stephan Borrmann1,2, Johannes Schneider2, Christiane Schulz2, Andreas Herber3, Hannes Schulz3, Manfred
Wendisch4, André Ehrlich4, Richard Leaitch5, Megan Willis6, Julia Burkart7, Jon Abbatt6
1
Johannes Gutenberg University Mainz, Institute for Atmospheric Physics, Mainz, Germany, 2Max Planck
Institute for Chemistry, Particle Chemistry Department, Mainz, Germany, 3Alfred Wegener Institute Helmholtz
Center for Polar and Marine Research, Climate Sciences, Sea Ice Physics, Bremerhaven, Germany, 4University of
Leipzig, Leipzig Institute for Meteorology, Leipzig, Germany, 5Environment and Climate Change Canada, Climate
Research Division, Toronto, Canada, 6University of Toronto, Department of Chemistry, Toronto, Canada, 7TU
Wien, Institute of Materials Chemistry, Vienna, Austria

The Polar Dome has long been recognized as a transport boundary for mid-latitude air travelling into the Arctic.
Measurement based identification of the Polar Dome is difficult due to the temporal and spatial variability and
a lack of consistent measurements in the lower few kilometers of the Arctic. Particularly the climatological role
of the Dome as a transport boundary for pollution tracers has not yet been fully addressed on the basis of in-
situ measurements.
We present aircraft based trace gas measurements in the Arctic during different seasons since 2014 (NETCARE
2014/2015, RACEPAC 2014, PAMARCMiP 2015/2017, ACLOUD 2017) covering an area from Spitsbergen to
Alaska. We analyze the distribution of CO and CO2 in different coordinate systems and identify the Dome
location from observed trace gas gradients. Significant differences regarding the Dome location and transport
between winter/spring and summer appear. During winter/spring the Dome is characterized by an almost
isentropic distribution of CO and CO2, whereas in summer diabatic processes introduce isentropic gradients.
Consistent with the tracer measurements the analysis of kinematic 10-day back trajectories revealed different
transport regimes with contributions of mid-latitude air ranging from 15%-55%. The North American continent
is the dominant source region of air masses in the Canadian Arctic. However, erratic WCB transport originating
in Eastern Asia affects the composition of the high Arctic troposphere.

1227
1447
Chemical Composition and Growth of Newly formed Particles at Chacaltaya, Bolivia

Claudia Mohr1 (claudia.mohr@aces.su.se), Wei Huang2, Cheng Wu1, Federico Bianchi3

1
Stockholm University, Stockholm, Sweden, 2Karlsruhe Institute of Technology, Karlsruhe, Germany, 3University
of Helsinki, Helsinki, Finland

The ability of atmospheric aerosols to act as cloud condensation nuclei (CCN) is influenced by both the
particles´ size and chemistry. For particles formed in the atmosphere via nucleation of vapors, this means that
they must undergo significant growth before they can become active as CCN. Direct atmospheric observations
at high altitudes of the life cycle and chemistry of aerosol particles from nucleation to cloud droplets are still
scarce. We present first results from a comprehensive 6-month field campaign (December 2017 - May 2018)
conducted at the GAW station Chacaltaya in the Bolivian Andes. The station is at an altitude of 5240 m a. s. l., in
the Cordillera Real, which separates the Amazon basin from the Altiplano. Regular regional new particle
formation events, the influence of the emissions from the nearby city of La Paz on an almost daily basis, and of
air masses from the Amazon during the rainy season make this a highly interesting site to study atmospheric
particle formation and growth processes. To this purpose we deploy several state-of the-art mass
spectrometers. This abstract focuses on results from a chemical ionization mass spectrometer with filter inlet
for gases (FIGAERO-CIMS), which is used to investigate the nature and relative importance of anthropogenic
and biogenic organic components contributing to the growth of newly formed particles to sizes where they can
become active as CCN.

1228
1163
The Fate of Arctic Black Carbon Aerosol from Clouds to Snow

Marco Zanatta1 (marco.zanatta@awi.de), Hannes Schulz1, Stephan Mertes2, Simonas Kecorius2, Johannes
Schneider3, Heiko Bozem4, Emma Järvinen5, Olivier Jourdan6, Regis Dupuy6, André Ehrlich7, Andreas Herber1
1
Alfred Wegener Institute, Bremerhaven, Germany, 2Leibniz Insititute for Tropospheric Research, Leipzig,
Germany, 3Max Planck Institute for Chemistry, Mainz, Germany, 4Johannes Gutenberg University, Mainz,
Germany, 5Karlsruhe Institute of Technology, Karlsruhe, Germany, 6LaMP, Clermont Ferrand, France, 7Leipzig
University, Leipzig, Germany

Black carbon (BC) aerosol is considered to play a strong role in Arctic warming. However, the lack of
measurements represents a large source of uncertainty in assessing the total radiative forcing of BC. In order to
quantify the presence and properties of BC we performed simultaneous airborne and shipborne field
experiments between Svalbard and the Fram Strait in May/June 2017. The BC particles were thereby measured
in the cloud-free atmosphere, in particle residuals of mixed-phase clouds and in snow, by means of a single
particle soot photometer. Within the ACLOUD (Arctic Cloud Observations Using airborne measurements during
polar Day) experiment, vertical distribution of BC and its presence in cloud particles were investigated.
Simultaneously, during the PASCAL (Physical feedbacks of Arctic PBL, Seaice, Cloud And Aerosol) campaign, BC
atmospheric concentration was monitored at sea level from the RV Polarstern and more than 200 snow
samples were collected over the sea ice for BC quantification. Shipborne and airborne observations showed
extremely clean Arctic conditions above 65°N, with BC mass concentration below 10 ng m-3 at sea level and
strong vertical variability (from 5 to 70 ng m-3). BC cloud residuals, sampled with a counter-flow virtual
impactor, were larger in diameter (300 nm) as compared to outside-cloud conditions (150 nm). The analysis of
snow samples will allow understanding the time evolution of BC concentration and its metamorphism during
the melting season.

1229
1381
Insoluble Brown Carbon Emitted by Marine Engines: Relevance to a Warming Arctic

Joel C. Corbin1,2 (joel.corbin@nrc-cnrc.gc.ca), Hendryk Czech3, Dario Massabo4, Fengshan Liu1, Simone Pieber2,
Juergen Orasche5, Benjamin Stengel3, Francesco Buatier de Mongeot4, Claudio Mennucci4, Amewu Mensah6,
Marco Zanatta7, Gert Jakobi5, Prem Lobo1, Ralf Zimmermann3,5, Andre Prevot2, Imad El Haddad2, Martin Gysel2
1
National Research Council Canada, Ottawa, Canada, 2Paul Scherrer Institute, Villigen PSI, Switzerland,
3
University of Rostock, Rostock, Germany, 4University of Genoa, Genoa, Italy, 5Helmholtzzentrum Munchen,
Munich, Germany, 6Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland, 7Alfred
Wegener Institute, Potsdam, Germany

The majority of ships travelling through the Arctic operate on heavy fuel oil (HFO). The exhaust associated with
HFO combustion contains light-absorbing black carbon (BC) particles but also substantial amounts of brown
carbon (brC). This brC absorbs more strongly at shorter (blue) wavelengths than at longer (red) ones, and can
dominate the total light aerosol light absorption by HFO-combustion aerosols. Here, we show that it is
fundamentally different to brC produced by sources such as biomass-burning. We show that this brC is
insoluble, thermally refractory, and absorbs in the near infrared. These properties resemble those of the tar
balls which have been previously observed from biomass combustion, rather than to the light-absorbing
organic molecules that have been the focus of recent brC research. These properties also mean that common
techniques for measuring BC may result in strongly biased estimates of aerosol light absorption. The insolubility
of this brC means that it may accumulate on snow and ice, perhaps explaining recent observations that 32% of
albedo reduction in Arctic snow is due to non-BC particles. Further field measurements are needed to quantify
these light-absorbing brC particles in order to understand anthropogenic impacts on the Arctic environment.

1230
1402
Black Carbon in the Atmosphere and Snow in the McMurdo Dry Valleys, Antarctica

Alia Khan1 (alia.khan@colorado.edu), Gavin McMeeking2, Joshua Schwarz3, Peng Xian4, Kathleen Welch5,
William Lyons6, Diane McKnight7
1
University of Colorado Boulder, National Snow and Ice Data Center, Boulder, United States, 2Handix Scientific,
Boulder, United States, 3National Oceanic and Atmospheric Administration, Earth System Research Laboratory,
Boulder, United States, 4Naval Research Laboratory, Aerosol and Radiation Section of the Marine Meterology
Division, Monterey, United States, 5Ohio State University, Columbus, United States, 6Ohio State university,
Columbus, United States, 7University of Colorado Boulder, Institute of Arctic and Alpine Research, Boulder,
United States

Measurements of light absorbing particles in the boundary layer of the high southern latitudes are scarce,
particularly in the McMurdo Dry Valleys (MDV), Antarctica. During the 2013 - 2014 austral summer near-
surface boundary layer refractory black carbon (rBC) aerosols were measured in air by a single particle soot
photometer (SP2) at multiple locations in the MDV. Near-continuous rBC atmospheric measurements were
collected at Lake Hoare Camp (LH) over two months and for shorter periods at more remote locations. Snow
samples were also collected in a 1m pit on a glacier near the camp. The range of concentrations rBC in snow
were 0.3 - 1.2 ± 0.3 ng-rBC/g-H2O, and total organic carbon were 0.3 - 1.4 ± 0.3 mg/L. At LH, the average
background rBC mass aerosol concentrations was 1.3 ng/m3. rBC aerosol mass concentrations were slightly
lower, 0.09 - 1.3 ng/m3, at the most remote sites in the MDV. Concentration spikes as high as 200 ng/m3 were
observed at LH, associated with local activities. During a foehn wind event, the average rBC mass concentration
increased to 30-50 ng m-3. Here we show the rBC increase could be due to resuspension of locally produced BC,
which may remain on the soil surface until redistributed during high wind events. Quantification of local
production and long-range atmospheric transport of rBC to the MDV is necessary for understanding the
impacts of this species on regional climate.

1231
OS-7b - Atmosphere-Ice-Ocean interactions in the Polar Regions
21.06.2018 11:00-12:30, C Sanada II

1181
Early Winter Sea Ice Dynamics and Ice Production in the Ross Sea during PIPERS

Ted Maksym1 (tmaksym@whoi.edu), Steve Ackley2, Sharon Stammerjohn3, Jean-Louis Tison4, Kathrin
Hoeppner5
1
Woods Hole Oceanographic Institution, Woods Hole, United States, 2University of Texas at San Antonio, San
Antonio, United States, 3University of Colorado Boulder, Boulder, United States, 4Universite Libre de Bruxelles,
Bruxelles, Belgium, 5German Aerospace Center (DLR), Wessling, Germany

The Ross Sea sea ice cover is one of the few regions of the cryosphere that have been expanding in recent
decades. However, 2017 saw a significantly delayed autumn ice advance and record low early winter sea ice
extent. To better understand the causes and impacts of this variability on sea ice production, we present a suite
of in situ and satellite observations made during the PIPERS (Polynyas, Ice Production and its seasonal Evolution
in the Ross Sea) cruise in April-June 2017. To assess the relative role of sea ice dynamics and thermodynamics
in sea ice production, four arrays of GPS and ice mass balance buoys were deployed in the outflows of the Ross
Ice Shelf and Terra Nova Bay Polynyas. High-resolution synthetic aperture radar imagery are used to provide
regional context. Despite high rates of ice production in the polynyas, the ice remained thin due to rapid export
and northward drift. Compared to the only prior winter observations made in 1995 and 1998, the ice was
thinner, with less ridging and snow cover, reflecting a younger ice cover. Surprisingly, granular ice was less
prevalent in 2017, particularly in the outer pack, due to less snow ice formation and less pancake ice formation
at the advancing ice edge. We discuss the relative roles of ice dynamics and thermodynamics in both the
polynyas and the main ice pack, and the dynamic interactions between these regions in governing total sea ice
production.

1232
2112
Air-sea-Ice Interaction Associated with the 2016 and 2017 Weddell Polynyas

Kent Moore1,2 (gwk.moore@utoronto.ca), Ethan Campbell3, Earl Wilson3, Casey Brayton4, Stephen Riser3,
Matthew Mazloff5, Lynne Talley5
1
University of Toronto, Physics, Toronto, Canada, 2University of Washington, Jackson School for International
Studies, Seattle, United States, 3University of Washington, Physical Oceanography, Seattle, United States,
4
University of South Carolina, Physical Oceanography, Columbia, United States, 5Scripps Institution of
Oceanography, UC San Diego, Physical Oceanography, San Diego, United States

Maud Rise, a seamount in the Weddell Sea, is a location where polynyas occasionally form. The most dramatic
of these events was the ~300,000km2 polynya that occurred over the 3-year period from 1974-1976. Another
smaller polynya developed in 1994 and there is evidence of a persistent halo of reduced ice cover in the region
that may be a signature of a Taylor Cap. The presence of a polynya can lead to vigorous air-sea interaction
resulting in a densification of the surface waters and a convective overturning of the water column. There is
still much that is unknown regarding how they form as well as the characterization of the atmospheric forcing
that occurs within them and the oceanic response. In 2016, a polynya developed in late July and persisted for
approximately 3 weeks. In September 2017, the polynya returned and has remained open through November.
Here we use new high resolution atmospheric, oceanic and cryospheric datasets to examine the air-sea
interaction that occurred within the recent polynyas. Observations from SOCCOM under-ice profiling floats
show prominent cold, fresh, high-oxygen anomalies to a depth of 1700m after the 2016 event. In addition,
there was an intermittency to the area of open water within the polynya in both 2016 and 2017 that was
associated with variability in the wind field suggesting that a coupling exists between the atmosphere and
ocean in the region.

1233
1468
Quantification of Sea-ice Production in Weddell Sea Polynyas (Antarctica)

Günther Heinemann1 (heinemann@uni-trier.de), Rolf Zentek1, Lukrecia Stulic2, Ralph Timmermann2, Stephan
Paul2, Andreas Preußer1
1
University of Trier, Environmental Meteorology, Trier, Germany, 2Alfred Wegener Institute, Helmholtz Center
for Polar and Marine Research, Bremerhaven, Germany

A multi-method approach is used to quantify sea ice production polynyas in the southern Weddell Sea for the
period 2002-2015. We use
1) a regional climate model (CCLM) with 5km and 15 km resolution (C05/15),
2) retrievals from MODIS data at a high resolution of 1-2km and
3) simulations of a sea ice-ocean Model (FESOM) with a resolution down to 3 km.
Methods 2) and 3) need atmospheric forcing, which is taken from different reanalyses (ERA-I, CSFR, JRA55,
NCEP2) as well as from CCLM data. Estimates of sea ice production and comparisons of the different methods
are presented for polynya areas of the Weddell Sea. We study the following polynyas: Antarctic Peninsula (AP),
Ronne Ice Shelf (RO), Iceberg A23a (IB), Filchner Ice Shelf (FI), Coats Land (CL) and Brunt Ice Shelf (BR). In all
methods, the largest ice production (IP) is found for RO and for BR. However, significant differences between
different methods and forcing data sets are found for polynya area (POLA) and IP. In particular, relatively too
low temperatures in JRA and C05 lead to higher IP compared to ERA in the MODIS retrievals. Estimations based
on CCLM simulations agree generally well with MODIS/ERA-I, but tend to be smaller due to the coarser
resolution of the microwave sea ice data used in CCLM. In contrast, FESOM yields a generally larger ice
production and shows also a pronounced sensitivity to the atmospheric forcing, but the effect on POLA and IP
depends on the region.

1234
264
Coastal polynyas on PIPERS: enhanced ice growth in strong katabatic wind events

Stephen Ackley1 (stephen.ackley@utsa.edu), Ted Maksym2, Sharon Stammerjohn3

1
Univ of Texas San Antonio, Snow and ice Geophysics Laboratory, San Antonio, United States, 2Woods Hole
Oceanographic Institution (WHOI), Woods Hole, United States, 3Univ of Colorado, Boulder, United States

The PIPERS cruise to the Terra Nova Bay (TNB) polynya during April-June 2017 focused on joint measurements
of air-ice-ocean wave interaction. Measurements were taken during intense katabatic wind events (over 35 ms-
1
) and temperatures of -15C. Wave amplitudes of over 2m and 7-9 sec periods built and large amounts of frazil
ice crystals grew. The frazil ice gathered initially into short plumes that were added together laterally to create
longer and wider streaks, an apparently “self-herding” characteristic of ice in small pieces, found in other
granular materials. The wave field within the wider streaks was dampened and enhanced the development of
pancake ice. Eventually, the open water areas sealed off and developed a uniform pancake ice cover. As the
waves died off, sustained katabatic wind velocities resulted in a wide area of concentrated, rafted, pancake ice
of 30 to 40cm thickness that was rapidly advected downstream until the end of the katabatic event. High
resolution TerraSar-X radar satellite imagery showed the length of the ice area produced in one single event
extended over 300km or ten times the length of the open water/frazil ice area during the polynya event. The
TNB polynya is therefore an “ice factory” where frazil ice is manufactured into pancake ice floes that are then
pushed out of the assembly line, rafted into “dragon skin” ice and advected, until the katabatic wind dies off at
the coastal source.

1235
2185
Salinity Response to Atmospheric Forcing of the Terra Nova Bay Polynya

Deborah A Le Bel1, Christopher J Zappa1 (zappa@ldeo.columbia.edu), Giorgio Budillon2, Arnold L Gordon1

1
Lamont-Doherty Earth Observatory of Columbia University, Ocean and Climate Physics, Palisades, United
States, 2Parthenope University of Naples, Naples, Italy

The density and salinity of High Salinity Shelf Water (HSSW), a key component of Antarctic Bottom Water
emanating from the Ross Sea, are intensified by brine rejection induced by ice formation within the Terra Nova
Bay (TNB) polynya. Meteorological observations from Automatic Weather Stations in conjunction with ocean
mooring data from 2007 and a satellite-derived opening of TNB polynya delineate higher-frequency water
column salinity variability linked to atmospheric forcing. Lagged correlation analysis indicates that on average
salinity response lags the polynya opening by two days and the wind forcing by four days. Closer examination
reveals stronger lag correlations of salinity with the wind in the fall and with polynya extent in the
winter/spring. A one-dimensional mixed layer model incorporating thermodynamic ice formation captures the
order ten day oscillations in salinity linked to polynya expansion and contraction. The model illustrates two
stages of the seasonal scale salinity response to forcing. The depth-integrated heat content governs the time
required for the water column to reach the freezing point as wind mixing and heat loss redistribute the salinity
and density profiles. Once the excess heat is removed from the water column, heat loss is primarily through the
latent heat released during ice formation and the time to reach complete homogenization of the water column
depends only on the integrated salinity deficit.

1236
2096
Sea Ice Deformation and Heat Fluxes through Leads in Arctic

Pierre Rampal1,2 (pierre.rampal@nersc.no), Einar Ólason1,2, Timothy Williams1,2, Abdoulaye Samaké1,3,

Véronique Dansereau4
1
Nansen Environmental and Remote Sensing Center, Bergen, Norway, 2Bjerknes Centre for Climate Research,
Bergen, Norway, 3Université de Bamako, Bamako, Mali, 4CNRS, Univ. Grenoble-Alpes, Institut des Sciences de la
Terre (ISTerre), Grenoble, France

Sea ice deformation is extremely localised in both space and time, and associated with intense fracturing, the
opening of leads and the formation of ridges. In particular, the spatial and temporal properties of lead patterns
control the surface heat fluxes between the ocean and the atmosphere, with a potentially strong impact on the
dynamics of the ocean mixed layer and the stability of the atmosphere boundary layer. In this talk, we will
present how a new generation sea ice model, called neXtSIM, is able to reproduce the statistics of Arctic sea ice
deformation, as retrieved from buoys and satellite (SAR) observations. The simulated lead fraction is also
compared to the estimates calculated from the AMSR-E satellite observations. The statistics of simulated heat
fluxes through leads are finally presented and their scaling properties investigated.

1237
BE-9a - Life distribution and responses to environmental changes in Polar ecosystems
21.06.2018 14:00-15:30, C Aspen

1842
Arctic Global Change Impacts Little Auk Foraging and Fitness in East Greenland

Françoise Amélineau1,2 (francoise.amelineau@gmail.com), David Grémillet2, Ann Harding3, Wojciech Walkusz4,5,

Rémi Choquet2, Jérôme Fort1
1
Université de La Rochelle, Laboratoire Littoral, Evironnement et Sociétés, La Rochelle, France, 2CEFE, CNRS -
Université Montpellier, Montpellier, France, 3Alaska Pacific University, Environmental Science Department,
Anchorage, United States, 4Fisheries and Oceans Canada, Winnipeg, Canada, 5Polish Academy of Sciences,
Institute of Oceanology, Sopot, Poland

Ongoing global changes apply drastic environmental forcing onto Arctic marine ecosystems: sea surface
temperatures are increasing, sea-ice is declining and anthropogenic pollution is reaching this area despite its
remoteness. To test the effects of these changes on marine ecological functioning in the Arctic, we used a 12-
year integrative study of little auks (Alle alle), which are the most abundant seabirds in the North Atlantic and
feed on zooplankton. In East Greenland, we monitored their foraging behavior, diet, fitness proxies (adult
survival and body condition), hatching date and chick growth rate. We tested linkages between these biological
variables and a set of environmental parameters from the breeding and wintering sites, as well as their
mercury contamination. Little auks showed substantial foraging plasticity, notably via an increase in foraging
effort in the absence of sea-ice. Yet, in contrast to former studies conducted over shorter time periods, their
fitness proxies were also impacted by environmental changes: adult body condition decreased across years,
and with increasing wind speed, and adult diet changed across the study period. Hatching date was gradually
delayed, and chick growth rate tended to decrease with time. However, no trend was found for adult survival
despite a high variability. Overall, our study shows how global changes affect a key Arctic species, and stresses
the importance of monitoring arctic ecological processes in the longer term.

1238
488
Divergent Trends and Unsynchronized Dynamics across a Seabird Community

Casey Youngflesh1 (casey.youngflesh@stonybrook.edu), Stephanie Jenouvrier2,3, Heather J. Lynch1

1
Stony Brook University, Ecology and Evolution Department, Stony Brook, United States, 2Woods Hole
Oceanographic Institution (WHOI), Biology Department, Woods Hole, United States, 3Centre d’Etudes
Biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique/Univ La Rochelle, Villiers en Bois,
France

Global change is evident around the globe. Understanding how ecological communities are structured and how
they might respond to these changes is of critical importance. However, in many cases, studies focus on a
single species. Taking a community perspective, we looked at both long-term and year-to-year responses for a
community of Antarctic seabirds and explored how environmental forcing might be driving demographic- and
population-level processes. Data on breeding success and abundance for six sympatrically breeding seabird
species located in East Antarctica were available from 1981-2013. Hierarchical Bayesian models were used to
assess trends in these metrics, the degree of community-level synchrony in breeding productivity, as well as
the contributions of environmental factors to this synchrony. We find a surprising discordance between trends
in abundance and breeding success, with several species showing increasing abundance even as breeding
success declines. In addition, we found little evidence for synchrony in breeding productivity, which was only
weakly correlated with environmental factors thought to contribute to breeding success. In contrast to this
overall pattern of asynchronous dynamics, exceptionally poor years were seen to drive similar negative
responses among species and accordingly, measures of population dynamics aggregated over the community
appear to provide more specific feedback on extreme environmental conditions than any individual species.

1239
735
Predicting Population Response of Emperor Penguin to Future Climate Change

Sara Labrousse1 (sara.labrousse@gmail.com), Stephanie Jenouvrier1, Marika Holland2, Jimmy Garnier3, Julienne
Stroeve4, Christophe Barbraud5, Henri Weimerskirch5, Hal Caswell1
1
Woods Hole Oceanographic Institution, Woods Hole, United States, 2National Center for Atmospheric Research
(NCAR), Boulder, United States, 3University of Savoy, Chambéry., France, 4National Snow and Ice Data Center,
Boulder, United States, 5CNRS, Chize, France

The Emperor Penguin (EP) is an Antarctic seabird threatened by future sea ice change. I present novel
approaches to predict population and species responses to future climate change using climate models
developed in the assessment report of the IPCC. The MUP (Measuring, Understanding, and Predicting)
approach, provides a general framework where an enhanced understanding of climate-population processes,
along with improved long-term data, are merged into coherent projections of future population responses to
climate change. Population forecasting studies have often been analyzed in terms of climate conditions at a
particular location. We projected that the Terre Adélie EP population will decline dramatically by 2100.
However, climate change will also produce changes in the spatial distribution of habitat quality (e.g.sea ice
change in Antarctica). We developed a species-level threat assessment using a spatially explicit model. At least
two-thirds of the EP colonies are projected to become endangered by future sea ice decline. We also recently
included complex dispersal processes in a novel meta-population model because individuals may respond to
climate change by moving permanently to other locations. For EP, relative to a scenario without dispersion,
dispersal can either offset or accelerate climate driven population declines. Finally, new population modeling
methods and remote-sensing products hold promise for reducing uncertainties to improve ecological
predictability.

1240
921
Influence of Antarctic Sea Ice Dynamic and Coastal Polynyas on Emperor Penguins

Sara Labrousse1 (sara.labrousse@gmail.com), Stéphanie Jenouvrier1, Christophe Barbraud2, Charles A. Bost2,

Florian Orgeret2
1
Woods Hole Oceanographic Institution (WHOI), Woods Hole, United States, 2Centre d’Etudes Biologiques de
Chizé (CEBC), Villiers en Bois, France

Emperor penguins breed on fast ice during the Antarctic winter when the constraint to acquire resources is
high, thus, seasonal and interannual variability in fast ice and coastal polynyas are likely to effect adult and
juvenile foraging performance at-sea, and ultimately their survival and population dynamics. Breeding emperor
penguins use polynyas as a predictable open water access for feeding by reducing the commuting time and
energy expenditure between colony and food supply. Antarctic coastal polynyas are key bio-physical features,
however, our understanding of their use by emperor penguins is largely theoretical. To tackle these issues, we
use both (i) tracking data of juvenile emperor penguin movement and behaviour at-sea over 2 years and (ii) the
longest time series available on demographic parameters of emperor penguins at the breeding colony of
Dumont d'Urville from 1952-2016. We first describe if juvenile emperor penguins use polynyas as a foraging
habitat and whether diving and foraging behaviour is affected by sea ice and its spatio-temporal variability. In a
second time, we investigate the combined roles of surface wind, polynya properties and fast ice spatio-
temporal variability on the demography of emperor penguins. The novelty of combining juvenile tracking data
with demographic data allows suggesting mechanisms by which sea ice and polynyas effect emperor penguin
demography through both their breeding success and the following juvenile performance at-sea.

1241
2196
Mechanisms of Pygoscelis Penguin Population Response to Environmental Change

Kristen Gorman1,2,3 (kgorman@pwssc.org), Tony Williams2, William Fraser3

1
Prince William Sound Science Center, Cordova, Alaska, United States, 2Simon Fraser University, Biological
Sciences, Burnaby, British Columbia, Canada, 3Polar Oceans Research Group, Sheridan, Montana, United States

Breeding colonies of Adélie (Pygoscelis adeliae), chinstrap (P. antarcticus), and gentoo (P. papua) penguins
occurring west of the Antarctic Peninsula (wAP) are demonstrating pole-ward range shifts that correlate with
long-term warming trends of the region. We examined mechanistic relationships that link marine ecosystem
variability with demographic parameters that drive population change. At Anvers Island, where reductions in
sea ice have been notable, Pygoscelis penguins became more similar isotopically throughout the breeding
season, due to depletion in d13C and d15N of blood tissue. Crèched chicks of all species occupied similar trophic
levels and the proportions of prey provisioned were similar across species within years. Crèched Adélie penguin
chicks were isotopically enriched at Avian and Charcot Islands, southern breeding colonies where sea ice is
more prominent. At the regional scale, a provisioning diet enriched in d15N resulted in heavier five-week-old
Adélie penguin chicks. Corticosterone hormone did not mediate variation in breeding performance. We found
no overall genetic structure among Adélie penguins. However, pairwise comparisons including Charcot Island
were significant. Variability in sea ice-associated food webs of the wAP is an important determinant of
Pygoscelis penguin reproductive performance, but not at the physiological level. A lack of genetic structure
suggests dispersal may importantly structure population responses to future ecosystem change.

1242
1577
Penguin Colony Responses to Climate Change and Volcanism

Stephen Roberts1 (sjro@bas.ac.uk), Patrick Monien2,3, Louise Foster1,4, Julia Loftfield2, Emma Hocking5, Emma
Pearson4, Steve Juggins4, Peter Fretwell1, Louise Ireland1, Ryszard Ochyra6, Anna Haworth7, Claire Allen1, Steve
Moreton8, Sarah Davies9, Hans-Jürgen Brumsack2, Bernhard Schnetger2, Mike Bentley10, Dominic Hodgson1, Jo
Baguet11, Elie Verleyen11
1
British Antarctic Survey, Cambridge, United Kingdom, 2Microbiogeochemistry, Institute for Chemistry and
Biology of the Marine Environment (ICBM), Oldenberg, Germany, 3University of Bremen, Bremen, Germany,
4
Newcastle University, School of Geography, Politics and Sociology, Newcastle, United Kingdom, 5Northumbria
University, Dept. of Geography, Newcastle-upon-Tyne, United Kingdom, 6Institute of Botany, Polish Academy of
Sciences, Kraków, Poland, 7Cardiff University, School of Earth and Ocean Sciences, Cardiff, United Kingdom,
8
NERC Radiocarbon Facility (Environment), Glasgow, United Kingdom, 9Aberystwyth University, Dept. of
Geography, Aberystwyth, United Kingdom, 10University of Durham, Dept. of Geography, Durham, United
Kingdom, 11Ghent University, Dept. of Protisology, Ghent, Belgium

Changes in penguin populations on the Antarctic Peninsula (AP) have been linked to several environmental
factors, but the potentially devastating impact of volcanic activity has not been considered. Genetic,
biogeochemical and modern count studies all show gentoo populations increasing during 'warmer' periods.
Using detailed biogeochemical analysis, we tracked penguin colony change over c. 8,500 years on Ardley Island,
currently home to one of the AP's largest populations of gentoo penguins. By comparing our data with sub-
fossil evidence of penguin occupation and records of past climate, sea-ice extent and volcanic activity from
across the AP, we found that the first sustained penguin colony was established on Ardley Island c. 6,700 years
ago. The colony experienced five population peaks during the Holocene, reaching its maximum, c. 4,000-3,000
years ago during a phase of regional warming, but there are no consistent relationships with local-regional
atmospheric and ocean temperatures or sea-ice conditions. Instead, three of the five phases of colony
expansion were ended abruptly by the deposition of volcanic ash from large eruptions of the nearby Deception
Island. Sustained post-eruption colony recovery took, on average, 400-800 years, and was slowest following the
most disruptive event, c. 5,500 years ago. We are currently undertaking biomarker and DNA analysis of lake
sediments and sub-fossils from the AP to better understand drivers of long-term penguin population change.

1243
AC-3a - High-Latitude Boundary Layers and Model Evaluation
21.06.2018 14:00-15:30, A Studio

1802
A New Antarctic Blowing Snow Particle Characterization Data Set

Katherine C. Leonard1,2 (katherine.leonard@epfl.ch), Yvonne Weber1, Caroline Aemisegger3, Irina

Gorodetskaya4, Ted Maksym5, Nander Wever6
1
EPFL, ENAC CRYOS, Lausanne, Switzerland, 2University of Colorado at Boulder, CIRES, Boulder, United States,
3
University of Zurich, Center for Microscopy and Image Analysis, Zürich, Switzerland, 4University of Aveiro,
Centre for Environmental and Marine Studies, CESAM - Centre for Environmental and Marine Sciences
Department of Physics, Aveiro, Portugal, 5Woods Hole Oceanographic Institution, Woods Hole, United States,
6
University of Colorado at Boulder, Boulder, United States

The rate of mass transport of blowing snow in numerical models depends quite strongly on the size distribution
of the particles being transported. Field observations of blowing snow using instruments are equally
susceptible to the anticipated particle parameters used to calibrate those instruments. The blowing snow size
distributions presented by Budd et al (1966), measured at Byrd Station, West Antarctica, can be found as the
basis of most such models.
We present a new data set, collected during blowing snow events over Antarctic sea ice. Like Budd et al, we
used formvar-coated microscope slides to collect 3d replicates of snow particles inside aerodynamic traps
during three discrete storms during the SIPEX-2 and AWECS expeditions. We then acquired high-resolution
digital scans of these formvar replicates, to allow detailed computational analysis of the particle characteristics
(size, sphericity, etc). Our method allows not only a significant advance over the 2-dimensional “equivalent
rectangle” size evaluation of Budd et al., but through the acquisition of scans at multiple focal depths (microns
separation) we can also determine the 3rd dimension for many of the measured particles. The minimum particle
size category identified using the methods employed by Budd et al was >35 microns. We find a substantially
greater number of small particles than are included in the 1966 blowing snow particle size distributions.

1244
2113
New Insights into the Atmospheric Oxidising Capacity above the Antarctic Plateau

Markus Frey1 (maey@bas.ac.uk), Holly Winton1, Joel Savarino2, Rolf Weller3, Jan-Marcus Nasse4
1
Natural Environment Research Council / British Antarctic Survey, Cambridge, United Kingdom, 2University of
Grenoble Alpes, CNRS, IRD, Institut des Géosciences de l'Environnement, Grenoble, France, 3Alfred Wegener
Institute for Polar and Marine Research, Bremerhaven, Germany, 4Universität Heidelberg, Inst. für
Umweltphysik, Heidelberg, Germany

Field studies in the high and mid latitudes have demonstrated that snowpack emissions of reactive trace gases
driven by photolysis alter regional atmospheric composition, the fate of pollutants and the polar ice core
archive of past environmental change. Of particular interest are reactive nitrogen and halogen species released
by surface snow, which in turn influence atmospheric levels of ozone and hdyroxyl radicals. Previous field
campaigns at South Pole and Dome C showed that surface-near air on the high East Antarctic Plateau in
summer is highly oxidising due to the interplay of photolytic snow emissions, a shallow boundary laye and cold
temperatures. However, open questions remain regarding the atmospheric oxidant budget. Here we present
new observations carried out at Kohnen Station (75ºS 0ºW) in summer 2017, located at a similar latitude as
Dome C. Measurements included nitrogen oxides (NO and NO2), atmospheric nitrate collected on filters,
ozone, slant-column BrO, actinic flux and atmospheric turbulence. In contrast to Dome C a distinct and strong
diurnal cycle of ozone with an amplitude of more than 10ppbv is observed. We discuss these new data with
respect to potential sinks and sources, and compare to the other sites on the Antarctic Plateau.

1245
1404
The Great Antarctic Climate Hack, Sponsored by the SCAR AntClim21 RSP

Joellen Russell1 (jrussell@email.arizona.edu), Nancy Bertler2, Thomas Bracegirdle3, Alia Khan4, Marilyn Raphael5
1
University of Arizona, Phoenix, United States, 2Victoria University of Wellington, Wellington, New Zealand,
3
British Antarctic Survey, Cambridge, United Kingdom, 4University of Colorado Boulder, National Snow and Ice
Data Center, Boulder, United States, 5University of California Los Angeles, Los Angeles, United States

In October 2017, the first, #GreatAntarcticClimateHack was held in La Jolla, CA at the Scripps Institution of
Oceanography. The aim was to bring together climate modelers, climate data users, and observational field
scientists to decide on metrics to evaluate current earth system model output. With the upcoming release of
CMIP6 and subsequent preparation for IPCC reports it is imperative that the broad Antarctic and Southern
Ocean science community is well prepared to make the next step in advancing both regional and global climate
science. A key unique goal of the workshop was to involve both specialists and non-specialists in the
development of climate model evaluation metrics that address cross-disciplinary scientific priorities. Discussion
and participation across broad Antarctic science communities was therefore a key aspect of the #GACH[BTJ1] .
Results of the workshop are metrics that will be incorporated into the Earth System Model Validation Tool
(ESMValTool), as well as a forthcoming publication.

1246
1951
A Long-term Hindcast Simulation with COSMO-CLM² over Antarctica

Alexandra Gossart1 (alexandra.gossart@kuleuven.be), Niels Souverijns1, Irina V. Gorodetskaya2, Matthias

Demuzere3, Jan T.M. Lenaerts4, Nicole van Lipzig1
1
KU Leuven, Department of Earth and Environmental Sciences, Leuven, Belgium, 2University of Aveiro, Centre for
Environmental and Marine Studies, Aveiro, Portugal, 3Ghent University, Laboratory of Hydrology and Water
Management, Gent, Belgium, 4University of Colorado Boulder, Department of Atmospheric and Oceanic
Sciences, Boulder, United States

The surface mass balance (SMB) of the Antarctic ice sheet (AIS) is crucial to understand Antarctica's
contribution to 21st century sea level rise. Therefore, it is essential to understand the large scale atmospheric
processes that affect accumulation as it is the only source term of the ice sheet.
Given the scarcity and low spatial coverage of observations over the AIS, the regional climate modeling
approach, which is not very common over Antarctica, is the adequate tool to gain insights in AIS SMB. In this
respect, COSMO-CLM 5.0 was coupled to the Community Land Model (CLM4.5) and adapted for Antarctic
conditions. ERA-Interim is used as initial and lateral boundaries for a time period of 30 year (1986-2016;
excluding 3 years of spin-up time) at a resolution of 0.22° by 0.22° over the whole Antarctic continent. Lackings
in the model representation of basic climatic variables such as temperature and wind speed were tackled by
adapting the turbulence scheme, implementing a two-moment cloud microphysics parametrization, as well as
several modifications to the Community Land Model (e.g. snow metamorphosis, wind dependent
compaction,...).
Here, we present the results of this long-term COSMO-CLM² simulation adapted for Antarctica. Results are
compared to observations from automatic weather stations, field campaigns and radiosondes. In the next steps
a blowing snow module and refined cloud-aerosol-precipitation interactions will be implemented into the
model.

1247
9
Modeling the Dynamics of the Stable Boundary-Layers over the Antarctic Plateau

Etienne Vignon1,2 (etienne.vignon@univ-grenoble-alpes.fr), Christophe Genthon2, Frédéric Hourdin3, Bas J. H.

van de Wiel4, Hubert Gallée2, Jean-Baptiste Madeleine5, Eric Bazile6, Peter Baas4
1
EPFL, LTE, Lausanne, Switzerland, 2IGE, Grenoble, France, 3LMD, Paris, France, 4Technical University,
Geoscience and Remote Sensing, Delft, Netherlands, 5UPMC/LMD, Paris, France, 6CNRM-GAME, Toulouse,
France

The 5th IPCC report states that the Antarctic Plateau is one of the regions where the near-surface temperature
is the less well constrained in climate models and re-analyses. The misrepresentation of the stable boundary
layer (SBL) may be suspected. Investigation of meteorological measurements at Dome C evidenced the extreme
nature of the SBL at this location. The summertime diurnal cycle, the very strong stratifications in winter and
the two-regime behavior of the SBL dynamics challenge our understanding of the SBL and its parametrization
by climate models. After characterizing the Dome C SBL from measurements, we present an innovative
conceptual model that provides insights into the SBL dynamics, explaining the reversed ´S-shaped´ dependency
of the near-surface inversion with the wind speed. The LMDZ General Circulation Model, involved in the next
CMIP/IPCC exercise, is then evaluated in 1D and 3D configurations. Extensive sensitivity tests to the turbulence
parametrization, resolution and surface parameters are presented. They lead to a satisfactory configuration of
the model´s physics, in which the turbulent mixing sharply decreases with increasing stability. The analysis of
simulations further sheds light on the critical roles of radiation and subsidence in the heat budget of the SBL.
Radiative and humidity issues associated to strong biases in the SBL representation are discussed, paving the
way for both observational and modeling studies in the future.

1248
1980
Wind Gust Climatology in the Antarctic ABL over the Dronning Maud Land

Gabin Urbancic1,2 (gabin.urbancic@fmi.fi), Irene Suomi1

1
Finnish Meteorological Institute, Polar Meteorology and Climatology Group, Helsinki, Finland, 2University of
Bergen, Geophysical Institute & Bjerknes Centre for Climate Research, Bergen, Norway

Extreme wind gust conditions are frequently observed in the coastal regions of Antarctica. At some locations
they can even reach hurricane force. The strong winds are typically of katabatic origin occasionally intensified
by passing cyclones. Even though the extreme wind conditions have been recognized, the wind gusts have
received only a little attention from the scientific community. To better understand the climatology and
dynamic origins of the gusts, the data from eddy covariance stations installed near the Finnish Antarctic station
ABOA during the austral summers of 2010/2011 and 2014/2015 was analyzed.
The region is located about 130 km from the coast and is primarily covered by a gently sloping glacier and has
the Basen nunatak as a defining feature. Energetic gravity waves generated by the nunatak have been
previously studied as well as the katabatic winds which are often present. The local, small scale dynamics is
predominantly influenced by the position in relation to the Basen nunatak. A comparison of an upwind site and
a site near the Basen nunatak demonstrates the spatial variability of the wind gust climatology in the Antarctic
ABL. Further analysis of the high resolution time series isolates the dynamic structure of the wind gusts and
results are supplemented by SODAR data.

1249
AC-8a - Causes and Effects of Changing Polar Climate, Cryosphere and Hydrological Cycle
21.06.2018 14:00-15:30, A Forum

27
Causes of Accelerated Warming of the Arctic in Winter

John Fyfe1 (john.fyfe@canada.ca)

1
Environment and Climate Change Canada, Victoria, Canada

Over recent decades, the rate of winter warming increased dramatically over the Arctic while plummeting to
near zero over northern midlatitudes. Climate models predicted neither. The reasons for the warming
slowdown over northern midlatitudes are well understood; the reasons for the warming acceleration over the
Arctic are not. Here we show, using a novel combination of atmospheric reanalyses and climate model
simulations, that these phenomena are linked through a large amplitude signal of internal trend variability with
opposing sign over the Arctic and northern midlatitudes. For the Arctic, we estimate that internal trend
variability accounted for 50-90% of the increased rate of Arctic warming since the early 1980s. Uncertainties in
trend estimates depend on atmospheric reanalysis, climate model, and trend period and length considered.
These results challenge the perception of a dominant influence from human activities on recent warming rates
over the Arctic, suggesting instead that multi-decadal internal variations had an impact nearly as large as, or
larger than, the human influence.

1250
907
Arctic Temperature Trends: A Role of Internal Variability and External Forcing

Vladimir Semenov1,2 (vasemenov@mail.ru), Pavel Demchenko1

1
A.M.Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russian Federation,
2
Institute of Geography RAS, Moscow, Russian Federation

Relative contributions of internal atmospheric variability, lower boundary conditions and external radiative
forcing to the recent warming trends in high northern latitudes are investigated based on large (30 members)
ensemble of numerical simulations with an atmospheric general circulation model (AGCM). The model is forced
with the same historical boundary conditions (sea surface temperatures and sea ice concentrations) for 1979-
2012 period and different initial conditions with and without time varying radiative forcing. It is found that
simulated ensemble mean Arctic temperature changes considerably underestimate the observed temperature
increase. The difference between model results and observations may not be explained by internal
atmospheric variability that is reasonably well simulated by the model. Analytical model describing climate
zonal trend uncertainty as a function of internal fluctuations of zonal temperature anomalies is suggested and
found to successfully describe AGCM results. Introducing direct radiative forcing considerably improves the
model's results in simulating Arctic temperature trends. The strongest contribution of direct radiative forcing is
found in the European part of Russia and in the Western Arctic. Comparison of the simulated trends with
observations suggests possible problems with sea ice concentration data used to force atmospheric models.

1251
731
Non-linear Impacts of Future Anthropogenic Aerosol Emissions on Arctic Warming

Srdan Dobricic1, Luca Pozzoli1 (luca.pozzoli@ec.europa.eu), Elisabetta Vignati1, Rita van Dingenen1, Julian
Wilson1, Simone Russo1, Zbigniew Klimont2
1
European Commission, Joint Research Centre, Ispra, Italy, 2International Institute for Applied Systems Analysis,
Laxenburg, Austria

Past reductions of anthropogenic aerosol concentrations in Europe and North America could have amplified
Arctic warming. In the future the impact of air pollution policies may differ, because the major anthropogenic
sources of atmospheric aerosols are increasingly in Asia. In this study numerical experiments indicate that,
while reduced carbon dioxide (CO2) emissions weaken Arctic warming, future reductions of anthropogenic
aerosol concentrations can either amplify or diminish it. Interactions between regional atmospheric aerosol
concentrations in Asia and internal climate variability may differently initiate and sustain atmospheric planetary
waves propagating into the Arctic. In a non-linear manner they may redistribute atmospheric and oceanic
meridional heat fluxes at the high latitudes. In experiments until 2050 lower anthropogenic aerosol
concentrations combined with current CO2 emissions amplified Arctic warming by increasing atmospheric
meridional heat fluxes, but when combined with lower CO2 emissions they further diminished Arctic warming
by decreasing oceanic meridional heat fluxes.

1252
2569
Does the Atlantic Windstorms Have Significant Influences on the Arctic Warming?

Baek-Min Kim1 (bmkim@kopri.re.kr)

1
Korea Polar Research Institute (KOPRI), Unit of Sea-ice Prediction, Inchon, Korea, Republic of

During the northern winter, strong Atlantic windstorms often intrude into the Arctic and play important roles
as a moisture supplier into the Arctic. Recent unprecedented Arctic warming event happened in early January
of 2016 is the best example: In this episode, the Atlantic sector of Arctic experienced tremendous warming
more than 25 DegC than its daily climatology due to the entry of strong Atlantic windstorm of 950 hPa as its
central pressure. However, quantitative assessments on the role of Atlantic windstorms on the Arctic warming
episodes are rare in the current literatures. Here we provide robust statistical evidences that strong Atlantic
windstorms tend to move northeastward to the Arctic and induce significant Arctic warming. Positive North
Atlantic Oscillation (NAO) condition and, thus, intensified upper-level winds and tropospheric instability
contribute favorable conditions for the intensification of the stronger storms. Enhanced poleward energy
transport by moisture intrusion is observed during the lifecycle of the Atlantic windstorms of strongest 10-20%
category. The increase of Arctic temperature critically depends on the strength of storm. This linkage between
strong Atlantic windstorms and Arctic warming events are well simulated by the two independent climate
model simulations.

1253
2120
Collapse of the 2017 Winter Beaufort High: A Response to Thinning Sea Ice?

Kent Moore1,2 (gwk.moore@utoronto.ca), Axel Schweiger3, Jinlun Zhang3, Michael Steele3

1
University of Toronto, Physics, Toronto, Canada, 2University of Washington, Jackson School for International
Studies, Seattle, United States, 3University of Washington, Polar Sciences Center, Seattle, United States

The winter Arctic atmosphere is under the influence of two very different circulation systems. The eastern
Arctic is impacted by extra-tropical cyclones that travel from Iceland towards the Barents Sea along the primary
North Atlantic storm. In contrast, the circulation in the western Arctic is characterized by a quasi-stationary
region of high pressure known as the Beaufort High. Both of these circulation systems play important roles in
the Arctic climate system. Here we show that the winter of 2017 featured a reversal of the normally
anticyclonic surface winds and sea ice motion in the western Arctic. We argue that this reversal can be traced
to a collapse of the Beaufort High as the result of the intrusion of low-pressure systems from the North
Atlantic, along the East Siberian Coast, far into the Arctic Basin. Thin sea ice as the result of an extremely warm
autumn of 2016 contributed to the formation of an anomalous thermal low over the Barents Sea that, along
with a northwards shift of the tropospheric polar vortex, permitted the intrusion of low-pressure systems deep
into the Arctic Basin. This collapse was associated with 2-sigma sea-level pressure, surface wind and sea ice
circulation anomalies in the western Arctic. As the Arctic sea ice continues to thin, such reversals may become
more common and impact ocean circulation, sea ice, and biology.

1254
1655
Towards a Rain-dominated Arctic

Richard Bintanja1 (bintanja@gmail.com)

1
KNMI, De Bilt, Netherlands

Climate models project a strong increase in Arctic precipitation over the coming century, which has been
attributed primarily to enhanced surface evaporation associated with sea-ice retreat. Increases in Arctic
precipitation are thus firmly linked to Arctic warming and sea-ice decline. Since the Arctic is still quite cold,
especially in winter, it is often (implicitly) assumed that the additional precipitation will fall mostly as snow.
However, little is known about future changes in the distributions of rainfall and snowfall in the Arctic. In this
study we use 37 state-of-the-art climate models in standardised twenty-first-century (2006-2100) simulations
to show a decrease in average annual Arctic snowfall, despite the strong precipitation increase. Rain is
projected to become the dominant form of precipitation in the Arctic region (2091-2100), as atmospheric
warming causes a greater fraction of snowfall to melt before it reaches the surface, in particular over the North
Atlantic and the Barents Sea. The reduction in Arctic snowfall is most pronounced during summer and autumn
when temperatures are close to the melting point, but also winter rainfall is found to intensify considerably.
Projected (seasonal) trends in rainfall and snowfall will heavily impact Arctic hydrology (e.g. river discharge,
permafrost melt), climatology (e.g. snow, sea-ice albedo and melt) and ecology (e.g. water and food
availability).

1255
SH-6a - Connecting Polar Research Across Boundaries
21.06.2018 14:00-15:30, A Sertig

1962
Science-policy Interface in the Two Poles - Comparison and Lessons Learnt

Malgorzata (Gosia) Smieszek1 (malgorzata.smieszek@ulapland.fi), Daniela Liggett2

1
Arctic Centre, University of Lapland, Rovaniemi, Finland, 2University of Canterbury, Centre for Antarctic Studies
and Research, Christchurch, New Zealand

At first sight, the two poles differ in some fundamental ways. Whilst the Arctic consists of ocean surrounded by
continents, the Antarctic is a continent surrounded by ocean; where the Antarctic has no permanent human
habitation, the Arctic is inhabited by indigenous peoples and other local communities. Those differences find a
clear expression in the distinct legal arrangements and governance mechanisms for the Arctic and the
Antarctic. At the same time, two polar regions share certain important similarities that, we argue, render their
comparison valuable. Among others, what they have in common is the paramount importance of scientific
research and informing relevant decision-making with best available scientific knowledge on changes in socio-
ecological systems and biophysical environments of the Arctic and Antarctic. How is the science-policy interface
organized in the two regions? What are the differences and similarities between them? What are the pros and
cons of present arrangements centered in case of the Antarctic around the Scientific Committee on Antarctic
Research (SCAR) and around the Arctic Council (AC), albeit in a much looser manner, in case of the Arctic? Are
there lessons that two poles could learn and benefit from each other? This paper examines the above issues. As
such presented work spans not only boundary between science and policy-making, but also between the Arctic
and the Antarctic, providing fertile ground for further research and collaboration.

1256
2011
Engaging, Involving and Empowering Stakeholders for Arctic Climate Prediction

Halldor Johannsson1 (halldor@arcticportal.org), Dragana Bojovic2, Marta Terrado2, Luisa Cristini3, Isadora
Christel2, Gerlis Fugmann4, Francisco Doblas-Reyes5
1
Arctic Portal, Akureyri, Iceland, 2Barcelona Supercomputing Cente, Barcelona, Spain, 3Alfred Wegener Institute
- Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 4Association of Polar Early Career
Scientists, Alfred-Wegener Institute, Helmholtz Center for Polar and Marine Research, Germany, Potsdam,
Germany, 5Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain

The Arctic environment is changing rapidly with new opportunities and threats, calling for enhanced
collaboration between academia and stakeholders.
The EU H2020 project APPLICATE aims to improve climate prediction, applying user engagement to share
knowledge by a three-level approach:
Engaging, Using optimum communication tools, APPLICATE targets the broader stakeholder community: (i)
scientific and intergovernmental organisations, as advanced data users that can highlight knowledge gaps; (ii)
Public and private sector, who benefit from enhanced operational predictive capacity; (iii) Society at large,
general public and local communities; (iv) relevant international projects.
Involving, Interacting with stakeholders in meetings and via the Polar Prediction Matters Blog, APPLICATE
extends discussion and knowledge exchange. A User Group composed of representatives from various
stakeholder groups, closely follows and collaborates with the project.
Empowering, Relationships with stakeholders are achieved through their participation in project meetings and
activities. Co-development of user-relevant metrics improves our understanding of impacts and opportunities
of potential changes in the Arctic and their effects. Active collaboration helps produce sound project results
and relevant products and services, supporting stakeholders decision making, training and education.
User engagement supports informative decision making and capacity to adapt to new conditions in the Arctic

1257
1642
Crossing Boundaries in Science - INTERACT Science Diplomacy

Margareta Johansson1, Terry Callaghan2,3 (terry_callaghan@btinternet.com)

1
Lund University, Lund, Sweden, 2Sheffield University, Sheffield, United Kingdom, 3Tomsk State University,
Tomsk, Russian Federation

At a time of increasing geopolitical tensions, it is important to adopt all diplomatic activities including those in
science. INTERACT is a network of 83 research stations in 18 countries (including all Arctic nations). The
Stations share activities, data and experiences independent of nationality. Funding through the EU, USA and
Canada allowed INTERACT to offer Transnational Access (TA) funding at a pan-Arctic scale for the first time. TA
has so far funded about 600 researchers to work in infrastructures outside their own national facilities. A
community of grant holders has cemented a multinational and multidisciplinary team of researchers working
throughout the North. In addition, the INTERACT experience has been used as a model within various Arctic
nations and has contributed to the establishment of national networks linked internationally. The science
diplomacy operated by INTERACT has received attention and support from various Embassies and has explicitly
improved relationships between Russian and western researchers and infrastructures. INTERACT seeks to
improve the wellness of Indigenous Peoples and other Arctic residents. For the first time, it provides a one-
stop-shop (a Red Phone) for alerting infrastructures throughout the Arctic to identify, observe and respond to
potentially hazardous environmental events. It has also worked with Russian and other local governments and
universities to improve the relevance and awareness of science to local peoples.

1258
1277
Antarctic Cities: Rethinking the Gateways

Juan Francisco Salazar1 (j.salazar@westernsydney.edu.au), Elizabeth Leane2, Daniela Liggett3, Hanne Nielsen4,
Gabriela Roldan3, Claudia Estrada5, Elias Barticevic6, Liam Magee1, Paul James1
1
Western Sydney University, Institute for Culture and Society, Sydney, Australia, 2University of Tasmania /
Institute for Marine and Antarctic Studies, Hobart, Australia, 3University of Canterbury, Christchurch, New
Zealand, 4University of Tasmania, Hobart, Australia, 5Universidad de Magallanes, Punta Arenas, Chile, 6Chilean
Antarctic Institute INACH, Punta Arenas, Chile

The five recognized Antarctic gateways cities of Cape Town, Christchurch, Hobart, Punta Arenas and Ushuaia all
stand on the Southern Ocean Rim. As all significant engagement with the South Polar Region is co-ordinated
through these cities, they have a unique opportunity to act as custodian cities of this ecologically and
geopolitically fragile region. Each city is formed by long and complex histories of engagement with the Antarctic
going back to the nineteenth century. However, until now these cities have been thought of primarily as
exit/entry points for tourists and base-personnel traveling to Antarctica. This presentation provides an
overview of the international collaborative research project Antarctic Cities and the Global Commons:
Rethinking the Gateways which is the first study to offer a systematic rethinking of both the engagement and
outlook of these cities — not as five far-flung ports competing for the same commercial opportunities but as
members of an interlinked network. This rethinking is crucial in offering ways of reorienting these cities not just
as thoroughfares, but as urban centers that can embody the cosmopolitan values associated with Antarctic
custodianship: international co-operation, scientific innovation, and ecological conservation. As the cities
envision their urban futures this project explores a possible shift in urban practices and imaginaries from
'gateway cities' to 'custodian cities'.

1259
BE-2c - Phytoplankton, productivity and carbon export dynamics
21.06.2018 14:00-15:30, A Seehorn

1075
Modelling Cross-latitude Variability in Carbon Export Efficiency

Çağlar Yumruktepe1 (caglar.yumruktepe@nersc.no), Annette Samuelsen1, Barış Salihoğlu2

1
Nansen Environmental and Remote Sensing Centre, Bergen, Norway, 2Middle East Technical University Institute
of Marine Sciences, Erdemli, Turkey

We investigate generic algorithms to improve variability in modeled carbon export by emphasizing the
influence of plankton community structure. We conducted tests on a 1D lower trophic level model set at
various time-series stations in the North Atlantic, and each community was allowed to modify the settling and
remineralization rates of detritus-based on their traits (i.e diatoms produce fast sinking particles with higher
remineralization rates, while particles from prokaryotes are slower with lower remineralization rates).
Additional tests were conducted on aggregation, mineral ballasting, and DVM. Results indicate that a
community-based scheme is superior in representing temporal and spatial changes in export and transfer
efficiencies without any region-specific parameterization. As communities adapt to different hydrography, so
does the regional export efficiency. Cross-latitude comparisons show that high latitudes, which sustain larger
plankton, receive higher export efficiencies compared to both low latitudes and experiments using constant
global rates. Such an export mechanism has important implications for regional and global models since
hydrography is thus tightly coupled to export through community structure, which may improve predictive
skills for future ocean communities and carbon export. We present experiments in 1D from subtropics to
Arctic, as well as initial tests in the Arctic in a 3D operational model.

1260
108
Autonomous Multi-trophic Observations of Southern Ocean Production and Export

Tom Trull1,2,3 (tom.trull@csiro.au), Peter Jansen1,2,3, Eric Schulz3,4, Ben Weeding5, Diana M. Davies5, Stephen G.
Bray2, Ruth Eriksen1
1
CSIRO Oceans and Atmosphere, Hobart, Australia, 2ACE CRC, Hobart, Australia, 3Integrated Marine Observing
System, Hobart, Australia, 4Bureau of Meteorology, Melbourne, Australia, 5ACE CRC, IMOS, Hobart, Australia

Spring blooms provide insight into the importance of physical versus ecological controls of ocean productivity
and export, and potential responses to climate change. We present high temporal resolution records from the
Southern Ocean Time Series south of Australia, for physical drivers (temperature, salinity, surface mixed layer
depth, currents, wind speeds, insolation, and air-sea heat fluxes) and biological responses for four (NPZD)
trophic levels commonly used in biogeochemical models (Nutrient depletions and Phytoplankton community
structure from automated sample collections; Zooplankton from four-frequency acoustics; POC and ballast
mineral Detrital fluxes from sediment traps, as well as net community production (NCP) from O2/N2).
Chlorophyll increased slightly ahead of the spring mixed layer shoaling, when zooplankton populations were
lowest. The summer zooplankton increase was accompanied by shallower daytime migrations, especially for
the high frequency (small) sound scatterers. Diatoms dominated biomass in spring, when NCP was highest, and
continued to be important in summer even after silica was depleted. Nonetheless, seasonal N/Si drawdown
shows non-diatoms were important to export and the major biogenic mineral reaching the ocean interior was
carbonate, along with global median levels of POC export, despite low dissolved iron levels. These results
suggest the current maximal state of the Si pump may not limit future Southern Ocean carbon export.

1261
1093
Effects of Sea Ice on the Biogenic Carbon Export in High-Arctic Svalbard Fjords

Gérald Darnis1 (gerald.darnis@qo.ulaval.ca), Catherine Lalande1, Steffen Swoboda2, Janne Søreide2, Finlo
Cottier3, Philipp Assmy4, Jørgen Berge5
1
Université Laval, Quebec City, Canada, 2UNIS The University Centre in Svalbard, Longyearbyen, Norway, 3The
Scottish Association for Marine Science, Oban, United Kingdom, 4Norwegian Polar Institute, Tromsø, Norway,
5
UiT The Arctic University of Norway, Tromsø, Norway

Variation in the strength, timing and composition of the biological carbon pump determines energy transfer to
higher trophic levels and the capacity of the ocean to sequester atmospheric CO2. The lack of knowledge on
sinking fluxes in Svalbard fjord ecosystems limits our understanding of the drivers of this critical process for
carbon cycling. By comparing two Svalbard fjords with different environmental settings, our aim is to assess the
nature of annual sinking fluxes in these systems and identify forcing factors and implications for food web
processes. We analyzed samples from autonomous ocean observatories with sediment traps at 100 m depth in
ice-free Kongsfjorden and in the seasonally ice-covered Rijpfjorden. The total mass and protist flux was an
order of magnitude higher in Kongsfjorden than in Rijpfjorden. However, timing of the sharp protist peak flux
was similar in the two fjords. Over three annual cycles in Rijpfjorden, the peak flux of the obligate ice-algal
diatom Nitzschia frigida preceded the peak flux of the pelagic diatom spring bloom by only one to two weeks.
Sinking flux linked to ice-algal and phytoplankton blooms appeared to be intense but brief events followed by
low post-bloom export, except in 2014 in Rijpfjorden. Drivers of the observed flux patterns are interpreted
based on oceanographic and sea-ice cover information, and surface fluorescence data as a proxy for pelagic
primary production.

1262
1699
The Gypsum Gravity Chute to the Arctic Abyss

Jutta Erika Wollenburg1, Christian Katlein2, Gernot Nehrke1, Eva-Maria Nöthig3, Jens Matthiessen4, Dieter Wolf-
Gladrow1, Anna Nikolopoulos5, Fernando Gázquez-Sanchez6, Leonard Rossmann7, Philipp Assmy8, Marcel
Babin9, Flavienne Bruyant10, Marieke Beaulieu11, Christien Dybwad12, Ilka Peeken13 (ilka.peeken@awi.de)
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, BioGeosciences, Bremerhaven,
Germany, 2Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Sea Ice Physics,
Bremerhaven, Germany, 3Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Biological
Oceanography, Bremerhaven, Germany, 4Alfred Wegener Institute Helmholtz Center for Polar and Marine
Research, Marine Geology, Bremerhaven, Germany, 5AquaBiota Water Research, Oceanography, Stockholm,
Sweden, 63Godwin Laboratory for Palaeoclimate Research, University of Cambridge, Cambridge, CB2 3EQ,
United Kingdom,, Department of Earth Sciences, Cambridge, United Kingdom, 7Alfred Wegener Institute
Helmholtz Center for Polar and Marine Research, Sea ice physics, Bremerhaven, Germany, 8Norwegian Polar
Institute, Fram Centre, Ecotoxicoloy, Tromsø, Germany, 9Université Laval and CNRS, Takuvik Joint International
Laboratory, Québec, Canada, 10Université Laval and CNRS, G1V 0A6, Takuvik Joint International Laboratory,,
Québec, Canada, 11Université de Sherbrooke, Department of Civil Engineering, Sherbrooke, Canada,
12
Universitetet i Tromsø - The Arctic University of Norway, Department of Arctic and Marine Biology, Faculty of
Biosciences, Fisheries and Economics,, Tromsø, Norway, 13Alfred Wegener Institute Helmholtz Center for Polar
and Marine Research, Polar Biological Oceanography, Bremerhaven, Germany

In the ice-covered central Arctic Ocean vertical carbon flux has been considered especially low with some
notable exceptions that highlight the importance of fast-sinking aggregates for the biological carbon pump.
Incorporation of ballast minerals into sinking aggregates can significantly increase the carbon export efficiency
from the surface ocean to depths below the pycnocline. However, little is known about the importance of
ballasting in the ice-covered Arctic Ocean, and in particular the composition of ballast minerals.
Lacking a mineral shell the haptophyte algae Phaeocystis is usually remineralised above the pycnocline. Here
we show that, during the TRANSSIZ expedition in spring 2015, gypsum crystals released from melting sea ice
were trapped by an under-ice Phaeocystis bloom. A geochemical model indicates that the gypsum crystals
formed at temperatures below -6.5°C and were subsequently released during the melting of sea ice and
coincident to the formation of the under-ice Phaeocystis bloom. This led to an accelerated and enhanced
vertical export of gypsum-ballasted Phaeocystis aggregates to the sea floor at 2147 m water depth. Our
findings suggest an important and previously unknown role of cryogenic gypsum in ballasting under-ice
Phaeocystis blooms. Current environmental changes in the Arctic likely favour this gypsum gravity chute with
consequences for carbon export and energy partitioning between pelagic and benthic Arctic ecosystems.

1263
2079
Importance of Zooplankton Grazing for Arctic Pelagic-benthic Coupling

Ingrid Wiedmann1 (ingrid.wiedmann@uit.no), Elena Ceballos Romero2, Feliciano de Soto3, María Villa-
Alfageme2, Morten Hvitfeld Iversen4
1
UiT The Arctic University of Norway, Department of Arctic and Marine Biology, Tromsø, Norway, 2Universidad
de Sevilla, Departamento de Física Aplicada II, Sevilla, Spain, 3Universidad Pablo de Olavide, Departamento de
Sistemas Físicos, Químicos y Naturales, Sevilla, Spain, 4University of Bremen, Faculty of Geosciences and
MARUM, Bremen, Germany

Field observations are always point measurements and it can be demanding to elucidate driving processes for
pelagic-benthic coupling based on only these data. We complemented therefore our field observations
(hydrography, suspended biomass, particle export estimated with short-term sediment traps modified with a
gel containing glass jar) at three contrasting Arctic sites around Svalbard with a novel microscopic simulation
for particle dynamics to reproduce the particle production, sinking and degradation and estimate the vertical
export.
Our observations showed that particle size and abundance changed with depth, suggesting that strong
zooplankton grazing on settling aggregates at the base of the mixed layer (ML) caused a change in the
attenuation mechanisms with depth. This conclusion is supported by the results of the simulations, because the
observed vertical fluxes could be reproduced if a significant depth decrease in the particle degradation rate
(e.g. three fold) below the ML was applied in the simulation.
In this work, we show the potential of the combination of field observations and process modelling, allowing to
improve the information obtained from a few points of field observation in relation to processes in the water
column and to identify potential drivers for organic carbon export from the surface ocean to the sea floor.

1264
1237
20 Years of Particle Export in West Antarctic Peninsula Coastal Waters

Rebecca Trinh1 (rtrinh@ldeo.columbia.edu), Hugh Ducklow1

1
Lamont-Doherty Earth Observatory Columbia University, Earth and Environmental Science, New York, United
States

To understand how warming in the West Antarctic Peninsula (WAP) has affected the polar ecosystem and the
global carbon cycle, a multi-decade sediment trap time-series is analyzed in relation to environmental
(temperature, sea ice duration) and biological (primary and bacterial production, zooplankton abundance)
factors. The continental shelf region of the WAP has experienced over 6°C increase in winter temperatures
since 1950. The recent warming and declines in sea ice have been associated with changes at all levels of the
WAP ecosystem, including reduction in phytoplankton biomass, shift in phytoplankton community
composition, reduction in krill abundance, as well as decline in top predators such as Adelie penguins. These
changes to the phytoplankton and krill have resulted in notable changes in particulate organic carbon (POC)
flux, as these components represent two major drivers to the biological carbon pump. The Palmer Long Term
Ecological Research program has been conducting extensive studies along the WAP for the past 25 years,
including deployment of a moored sediment trap which intercepts sinking particles at 170 m in the water
column. Data from this sediment trap time-series is unique in its longevity, allowing us to understand how POC
flux has changed seasonally and annually over two decades. Evidence of environmental changes at the ocean
surface are reflected at depth in the sediment trap data as a decrease and shift in timing of POC flux over the
past two decades.

1265
CR-6c - Glaciers and Ice Sheets: from the Mountains to the Poles
21.06.2018 14:00-15:30, A Wisshorn

165
Using Microseismicity to Study the Role of Subglacial Fluids in Basal Slip

Thomas S. Hudson1,2 (tsh37@cam.ac.uk), Alex Brisbourne1, Robert S. White2

1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Cambridge, Dept. Earth Sciences,
Cambridge, United Kingdom

Icequakes are triggered by glacier or ice sheet movement. Here, we are particularly interested in basal
icequakes, primarily induced by basal slip of ice over bedrock or sediment. The specific Icequakes investigated
in this study are associated with Skeiðarárjökull, an outlet glacier of the Vatnajökull ice cap, Iceland. To detect
and locate these icequakes, we use a network of 13 seismometers deployed on the glacier surface. The seismic
energy that travels from the icequake source to the seismometers can be used to understand the processes
that generate the icequake. We use moment tensor analysis combined with modelling to investigate whether
subglacial fluids exert influence during a basal icequake event, and to what extent they govern slip occurring.
Although these results are associated with a relatively small outlet glacier in Iceland, the glacier is sufficiently
thick and fast moving that these results are likely also relevant for ice sheet behavior. The role of subglacial
fluids in promoting basal slip observed here could therefore aid our understanding of ice sheet dynamics, both
in Greenland and Antarctica.

1266
1868
Long-term Changes of Cryosphere and Glaciers in Kaffiøyra Region, NW Spitsbergen

Ireneusz Sobota1 (irso@umk.pl), Tomasz Grajewski2, Piotr Weckwerth3, Marcin Nowak1

1
Nicolaus Copernicus University, Faculty of Earth Sciences, Department of Hydrology and Water Management,
Polar Research Center, Torun, Poland, 2Nicolaus Copernicus University, Faculty of Earth Sciences, Department of
Hydrology and Water Management, Toruń, Poland, 3Nicolaus Copernicus University, Faculty of Earth Sciences,
Department of Geomorphology and Palaeogeography of Quaternary, Polar Research Center, Toruń, Poland

Recent changes of cryosphere and glacier dynamics in north-western Spitsbergen were based on infrastructure
of the Nicolaus Copernicus University Polar Station, located in Kaffiøyra. It was mainly related to mass balance,
ablation and snow accumulation on three glaciers: Waldemarbreen, Irenebreen and Elisebreen. Changes in the
surface area and recession of the land and sea-terminating glaciers were analysed. Changes in the outflow from
Waldemarbreen were analysed in detail. The active layer of permafrost was also covered by measurements,
especially its thermals and thickness changes.
Systematically field studies of glaciers mass balance components were carried out from 1996 to 2017, and
remain some of the longest measurement series run on Svalbard. The measurements of the glaciers´ recession
and the magnitude of thawing of the active layer of permafrost on Kaffiøyra are similarly unique in terms of
their length. All the studies aimed at understanding the intensity and size of changes in the cryosphere of
north-western Spitsbergen, the Kaffiøyra region, as well as processes ruling them nowadays, as a result of
changes taking place in this part of the globe. Like other contemporarily glaciated areas, the Kaffiøyra region is
a place of wide variety of cryosphere components, which in recent years have been rapidly responding to
climate change.

1267
1312
On Various Approaches to Map Glaciers and their Changes

Liss Marie Andreassen1 (lma@nve.no), Hallgeir Elvehøy1, Bjarne Kjøllmoen1, Joaquin M. C. Belart2,3, Jessica De
Marco1
1
Norwegian Water Resources and Energy Directorate (NVE), Oslo, Norway, 2University of Iceland, Institute of
Earth Sciences, Reykjavik, Iceland, 3University Of Toulouse, Laboratoire d'Etudes en Geophysique et
Oceanographie Spatiales, Toulouse, France

Accurate glacier surveys are essential in glacier monitoring. Surface elevations are needed for glaciological
calculations, and repeated surveys are used to detect glacier changes of glaciers and to reanalyse glaciological
mass-balance series. Whereas traditionally ground surveys and aerial photogrammetry were used for glacier
surveys, today a wealth of approaches to map glaciers exists. Possibilities include laserscanning (LIDAR), aerial
photos and high resolution satellite imagery. What is suitable depends on scale, for smaller glaciers and ice
patches unmanned aerial vehicles (UAV) and ground surveys may be appropriate, for larger glaciers other
approaches are needed.
Here we report on experiences of mapping glaciers and glacier changes in mainland Norway using various
mapping techniques. Over recent years 1/3 of the glacier area has been mapped using airborne laser scanning.
We compare this data with previous laserscannings and aerial photogrammetry where available. We also
demonstrate how scanned historical aerial photos can be used to reconstruct glacier surface elevations. We
show that new satellite sensors such as Pleiades can be used for glacier change detection and reanalysis. We
also discuss the possibilities and shortcomings of using UAVs for glacier survey for our reference glaciers.
Finally, we present a geodetic mass balance estimate of all glaciers in Norway from the 1960s to the 2010s.
Results reveal an overall mass loss and area shrinkage in this period.

1268
910
IACS Working Group on Ice Thickness Estimation - What Have we Achieved?

Daniel Farinotti1,2 (daniel.farinotti@ethz.ch), Liss M. Andreassen3, Huilin Li4

1
Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland, 2Swiss Federal
Institute for Forest Snow and Landscape Research WSL, Birmensdorf, Switzerland, 3Norwegian Water Resources
and Energy Directorate (NVE), Oslo, Norway, 4State Key Laboratory of Cryospheric Sciences, Tian Shan
Glaciological Station, CAREERI, CAS, Lanzhou, China

The Working Group (WG) on Ice Thickness Estimation, hosted by the International Association for Cryospheric
Sciences, was established in 2015 with the goal of (a) performing a model intercomparison experiment for
models that estimate glacier ice thickness from surface characteristics, (b) associating a distributed ice
thickness estimate to all glaciers included in the Randolph Glacier Inventory, and (c) supporting the World
Glacier Monitoring Service in the effort of creating a database centralizing ice thickness measurements across
the Globe.
In this contribution we report from the WG's activities during its three years of existence. We highlight our
successes - particularly including the results obtained within the Ice Thickness Models Intercomparison
eXperiment (ITMIX) and the release of new versions of the Glacier Thickness Database (GlaThiDa) -, report on
the challenges faced during our work, and provide an outlook for the activities that will follow from our
endeavours.
We hope our experiences to be insightful, inspiring, and motivating for WG's yet to come.

On behalf of http://www.cryosphericsciences.org/wg_glacierIceThickEst.html

1269
1544
Estimating Changes in Glacier Sliding Velocity from Drone Images

Aurelie Gourdon1, Raphael Vallat1, Lionel Benoit1 (lionel.benoit@unil.ch), Inigo Irarrazaval Bustos1, Gregoire
Mariethoz1, Frederic Herman1
1
University of Lausanne / Institute of Earth Surface Dynamics, Lausanne, Switzerland

Glacier sliding velocity is difficult to measure because the subglacial environment is typically inaccessible. We
propose an approach to infer sliding velocity based on glacier surface velocities measured by remote sensing,
as well as the physics of ice rheology.
Until recently, measuring the spatial distribution of glacier surface velocity was challenging because it required
expensive high-resolution satellite acquisitions. Moreover, these acquisitions are often subject to cloud
obstructions, which make it challenging to acquire images at a sufficient frequency to estimate high ice
velocities. In the last years, the development of UAVs has offered the possibility to acquire images at an
unprecedented resolution and frequency, and at a fraction of the cost of satellite images. Here we use such
acquisitions to derive a high resolution surface velocity field of the Gorner glacier (Swiss Alps) and its evolution
through the 2017 summer season.
The same glacier was then modeled using a finite element ice flow model (Elmer/ice), using as inputs the
drone-derived surface DEM, a glacier bed topography available from geophysical surveys, appropriate
boundary conditions, and assuming a zero sliding velocity. The modeled surface velocities thus corresponds to
the pure deformation velocity component. Assuming that the sliding velocity corresponds to the difference
between the deformation velocity and the UAV-derived surface velocity one can finally derive the sliding
velocity.

1270
2392
Simulating the Evolution of Rhonegletscher Since 1600 with Úa and GERM

Simon Förster1 (foerster@vaw.baug.ethz.ch), Matthias Huss1, Hilmar Gudmundsson2

1
Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zürich, Zürich, Switzerland, 2British Antarctic
Survey, Cambridge, United Kingdom

At the end of the Little Ice Age (around 1850), glaciers in the Alps reached their last maximum extent. However,
it is still uncertain what caused the preceding advance and the following retreat. Several studies have
concluded that temperature alone cannot explain this behaviour. A precipitation increase of about 25% could
explain the anomaly, but this is not supported by observations. Further processes have been proposed,
including changes in solar radiation (due to either solar activity variations or aerosols in the atmosphere),
surface impurities on ice and snow, and dynamical effects in both the atmosphere and the glaciers. We will test
some of these processes in a model study and determine their relative importance by coupling the ice flow
model Úa to the mass balance part of the Glacier Evolution Runoff Model (GERM).
We simulate the evolution of Rhonegletscher between 1600 and today using the coupled model based on
different temperature and precipitation reconstructions, e.g. Casty et al. (2005), the PAGES2k database, and
Pauling et al. (2006). We compare these simulations to a simpler approach prescribing the mass balance as a
function of temperature and precipitation. Furthermore, we validate the simulations with observations of
glacier length change, flow velocity, and geometry change.

1271
EN-3_EN-4a - Geological heritage and geo-conservation in the Polar Regions &
Conservation in the Polar Regions: Challenges, Strategies and Collaborations
21.06.2018 14:00-15:30, B Pischa

619
Protection Strategies in a More Accessible Maritime Arctic

Lawson Brigham1 (lwb48@aol.com)

1
University of Alaska Fairbanks, International Arctic Research Center, Fairbanks, United States

Profound Arctic sea ice retreat is creating greater marine access and potentially longer seasons of navigation
throughout the region. Arctic natural resource developments onshore and offshore are linking the Arctic to
global markets using advanced marine transportation systems. These key drivers of change require a holistic
approach to enhancing marine safety and environmental protection in the Arctic marine environment. The
Arctic Council´s Arctic Marine Shipping Assessment (AMSA) identified 17 recommendations that covered three
critical themes: I. Enhancing Arctic Marine Safety (through International Maritime Organization measures and
international instruments/binding agreements such as for search and rescue); II. Protecting Arctic People and
the Environment (through identifying indigenous marine use, designating Arctic marine protected areas , and
addressing measures for oil spills, air emissions, invasive species, and more); and, III. Building the Arctic Marine
Infrastructure (such as establishing Arctic traffic systems, investing in hydrography and charting, and
developing enhanced response capacity). This will be a review of current and future strategies , including
ecosystems-based management, being used to address the impacts of greater marine operations and shipping
throughout the Arctic Ocean. All of the multi-faceted approaches for protection must address the serious
maritime infrastructure gap throughout the Arctic.

1272
1903
Conserving Abundance, or How to Avoid What Has Happened Everywhere Else

Henry Huntington1 (hhuntington@oceanconservancy.org)

1
Ocean Conservancy, Eagle River, United States

Many conservation approaches focus on scarcity and vulnerability. Fear of extinctions rightly drives
endangered species laws. The recognition of biological hot spots understandably leads to the designation of
protected areas. Concern about overharvesting produces fish quotas and hunting limits. These are necessary
and appropriate measures. They fall short, however, of protecting the abundance that still characterizes many
aspects of Arctic ecosystems. In a global context, Arctic fisheries are well managed, and the Arctic has vast
expanses of relatively undisturbed, connected habitats. The risk is that we take such bounty for granted,
encroaching bit by bit into more and more areas, willing to take a little more here and there, over and over.
The end result is an Arctic that looks much like the rest of the world: relic populations of large animals living in
small fragments of habitat. One alternative is to recognize and protect what remains abundant, rather than
reacting only to scarcity. Cautionary approaches to fisheries management in Arctic Canada and Alaska provide
one example, which may soon be extended to the international waters of the central Arctic Ocean. Widespread
habitat protections offer another mechanism, allowing some types of human use but extending over far larger
areas than just the most spectacular aggregations of wildlife. This presentation will suggest a new vision for
Arctic conservation, recognizing what makes the Arctic distinct in today's world.

1273
2520
A Step-wise Plan for Integrated Ecosystem Science in the Central Arctic Ocean

Jacqueline Grebmeier1 (jgrebmei@umces.edu), Henry Huntington2

1
University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, United
States, 2Ocean Conservancy, Eagle River, United States

The international waters of the central Arctic Ocean are experiencing rapid sea ice reduction and transition to a
seasonally open system that can lead to increased human usage. With these changes there is a need for better
understanding of the Central Arctic Ocean (CAO) ecosystem and its connectivity to the surrounding seas.
Multiple efforts are underway to develop an integrated ecosystem assessment for the CAO. Coincidently, the
five Arctic coastal states (Canada, Denmark/Greenland, Norway, Russian Federation, United States of America)
and five distant-water fishing jurisdictions (the European Union, Iceland, Japan, People's Republic of China,
Republic of Korea) are negotiating a closure to commercial fishing in these waters until sufficient scientific
information is available to support management decisions related to commercial fisheries within an ecosystem
approach. Recently, a series of three international “dialogue” meetings have occurred to encourage
international arctic science community discussions for an ecosystem approach to minimize unregulated
fisheries in the CAO. We propose a step-wise approach in which basic monitoring is undertaken to detect
ecosystem component status and any significant changes. This approach will facilitate determining if and when
more intensive efforts are needed to gather data on specific ecosystem components, fish population dynamics,
and potential outcomes to track ecosystem response and fish populations in the changing Arctic region.

1274
790
Towards a Representative System of Marine Protected Areas in the Southern Ocean

Cassandra Brooks1 (cassandra.brooks@colorado.edu)

1
University of Colorado Boulder, Environmental Studies, Boulder, United States

Global threats to ocean biodiversity have generated a worldwide movement to take action towards better
conservation and management. A number of international targets have recommended the adoption of marine
protected areas (MPAs) in national and international waters. While establishing MPAs in international waters
has proved to be incredibly challenging in most of the world, national governments and the Commission for the
Conservation of Marine Living Resources (CCAMLR) have succeeded in adopting multiple MPAs in the Southern
Ocean. But are these MPAs representative of Southern Ocean biodiversity and ecosystems? This talk will
present on the current status of Antarctic MPAs and future trends using existing benthic and pelagic
bioregionalizations as well as other ecological data sets as a proxy for biodiversity. Results show that currently
about 8% of the Southern Ocean is protected in MPAs. While this is a relatively large proportion of protected
areas when compared to other international waters, it falls short of existing international MPA targets. Further,
current Antarctic MPAs are not fully representative of all bioregions. Yet CCAMLR is currently negotiating a
variety of additional MPA proposals and if these are adopted in the coming years, CCAMLR may be the first
international ocean management organization that meets global ocean biodiversity targets.

1275
1198
Joining Forces in Implementing the CEP's Climate Change Response Work Program

Birgit Njaastad1 (njaastad@npolar.no), Ewan McIvor2

1
Norwegian Polar Institute, Tromsø, Norway, 2Australian Antarctic Division, Hobart, Australia

In 2015 the Antarctic Treaty's Committee for Environmental Protection (CEP) adopted a Climate Change
Response Work Program (CCRWP: www.ats.aq/documents/ATCM39/att/atcm39_att072_e.doc), to be
implemented as a matter of priority and kept under regular review. In 2017 the CEP established a subsidiary
group with the responsibility to oversee the implementation of the CCRWP, through facilitating coordination
and communication between stakeholders, by updating and by reporting on progress of implementation to the
CEP.
In this presentation, the aim is to highlight and discuss opportunities and challenges regarding the science-
management interaction in implementing the CCRWP. A large portion of the CCRWP points to knowledge gaps,
as well as research and monitoring needs that would support future conservation efforts in a changing
Antarctic environment. Knowledge about ongoing research programs/projects (from Parties, SCAR, WMO, etc.)
that seek to or will provide insight into CCRWP issues will be important in this context, and even more so
ensuring an appropriate flow of new knowledge from this work, thus facilitating the further implementation of
CCRWP actions and tasks. SCAR and the science community will play an important and active role in this
context. Furthermore, the science community will be important in supporting the SGCCR's work in developing
management advice on basis of new knowledge within the framework of the CCRWP.

1276
1321
Anthropogenic Transfer of Species between Antarctic Biogeographic Regions

Kevin A. Hughes1 (kehu@bas.ac.uk), Peter Convey2, Luis Pertierra3, Greta Vega4, Pedro Aragón3, Miguel Á.
Olalla-Tárraga4
1
British Antarctic Survey, Environment Office, Cambridge, United Kingdom, 2British Antarctic Survey, Cambridge,
United Kingdom, 3Museo Nacional de Ciencias Naturales, Centro Superior de Investaciones Científicas, Madrid,
Spain, 4Rey Juan Carlos University, Department of Biology and Geology, Physics and Inorganic Chemistry,
Madrid, Spain

The distribution of terrestrial biodiversity within Antarctica is complex, with 16 distinct biogeographic regions
currently recognised within the Antarctic Treaty area. Much of this diversity is endemic not only to Antarctica
as a whole, but to specific regions within it. Further complexity is added by inclusion of the associated sub-
Antarctic ecosystems found on islands in the Southern Ocean. Within Antarctica, scientific, logistic and tourism
activities may inadvertently move organisms over potentially long distances. Species translocation can disrupt
natural species distribution patterns and biogeography through:
(1) movement of spatially restricted indigenous species to other areas of Antarctica;
(2) movement of distinct populations of a more generally distributed species from one area of Antarctica to
another, leading to genetic homogenisation and loss of assumed local patterns of adaptation; and
(3) further dispersal of introduced non-native species from one area of Antarctic to another.
Species can be moved between regions in association with people and their cargo by ship, aircraft and overland
travel. Movement of cargo by ship between stations located in different biogeographic regions is likely to
present one of the greatest risks, particularly as coastal stations may experience similar climatic conditions,
making establishment more likely. We make practical recommendations aimed at reducing the risk of species
transfer between Antarctic regions.

1277
CR-4c - Ice sheets, ice shelves & proximal processes in past, present & future climates
21.06.2018 14:00-15:30, B Parsenn

1060
The iSTAR Research Programme on Pine Island Glacier and the Amundsen Sea

Andy Smith1 (amsm@bas.ac.uk), Karen Heywood2, Adrian Jenkins1, Andrew Shepherd3, David Vaughan1
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of East Anglia, Norwich, United Kingdom,
3
University of Leeds, Leeds, United Kingdom

The future of Earth's large ice sheets in Antarctica and Greenland represents the greatest uncertainty in
projections of future sea level, and the behaviour of the West Antarctic Ice Sheet, in particular, is difficult to
predict. The UK-NERC iSTAR Programme (www.iSTAR.ac.uk) is a 7-year effort (2010-17) to improve
understanding of West Antarctica's combined Pine Island Glacier-Amundsen Sea system. Of all glaciers
worldwide, Pine Island Glacier is the one now making the biggest single contribution to sea level rise. This
imbalance has been driven by changes in the Amundsen Sea, which have brought warm ocean waters into
contact with floating ice.
iSTAR's objectives were: understanding the transport of ocean heat towards the ice sheet, understanding the
sub-ice processes affecting ice melt; and understanding the response of the inland glacier to the ocean-induced
changes. Data acquisition campaigns focussed on the ocean, the ice shelf, the inland glacier and the ice sheet.
Data analysis, remote sensing and modelling are still on-going. We present an overall summary of the iSTAR
Programme and some of the main results and conclusions so far.

1278
854
On the Bathymetry of Getz Ice Shelf Cavity from Airborne Gravity Data Inversion

Wei Wei1 (wwei@utexas.edu), Jamin S. Greenbaum1, Donald D. Blankenship1, Tom G. Richter1, Duncan A.
Young1, Sanghoon Lee2, Wongsang Lee2, Anna Wåhlin3, Karen Assmann3
1
University of Texas, Institute for Geophysics, Austin, United States, 2Korean Polar Research Institute, Incheon,
Korea, Republic of, 3University of Gothenberg, Gothenberg, Sweden

The Getz Ice Shelf, stretches along ~500 km of coastline in the Amundsen Sea Sector of West Antarctica, is the
largest meltwater source in Antarctica. Getz Ice Shelf itself has nearly constant melt rate of 4.3 ± 0.4 meters of
water per year, which is possibly affected by intrusions of modified Circumpolar Deep Water (mCDW). The
warm, salty mCDW crosses the continental shelf break through the Dotson-Getz Trough and melts the floating
ice shelf from below. Bathymetry has significant implication for possible CDW pathways and is required as one
crucial boundary condition for cavity circulation modeling. However, no direct observation of bathymetry
under Getz Ice Shelf is available yet. Here, we perform airborne gravity data inversion with multiple geophysical
data constraints to obtain an inferred bathymetry. Our results indicate a sill between Siple Island and Carney
Island complicates flow of mCDW through the Getz Ice Shelf from east to west and may impact ice shelf basal
melt rates. To explore this further, we put the bathymetry in the context of MITgcm (MIT General Circulation
Model). A similar approach can be applied to small ice shelves from East Antarctica in the future.

1279
1759
Ice Shelf Thickness Change from 2010 to 2017

Anna Hogg1 (a.e.hogg@leeds.ac.uk), Andrew Shepherd2, Lin Gilbert3, Alan Muir3

1
University of Leeds, Centre for Polar Observation and Modelling, Leeds, United Kingdom, 2University of Leeds,
Leeds, United Kingdom, 3University College London, London, United Kingdom

Floating ice shelves that fringe the majority (74%) of Antarctica´s coastline provide a direct link between the ice
sheet and the surrounding oceans, and changes in their constitution have been shown to influence the flow of
inland ice due to their buttressing effect. This process has become increasingly important over recent decades
as Antarctic ice shelves have thinned, retreated, and collapsed - events that have been recorded largely by
European satellites. At the Antarctic Peninsula, ice shelf retreat has been observed throughout the satellite era
(18% over 50 years), and large sections of the Larsen-A, Larsen-B, and the Wilkins Ice Shelf collapsed,
catastrophically in 1995, 2002, and 2008, respectively. In the Amundsen Sea, ice shelves at the terminus of the
Pine Island and Thwaites glaciers have thinned at rates in excess of 5 meters per year for more than two
decades. Both signals are indicative of long-term changes in the regional climate, and have impacted on the ice
inland. We use CryoSat-2 to map ice thickness change on Antarctic ice shelves by exploiting the dense spatial
sampling and repeat coverage provided by the SARIn mode data acquired by CryoSat-2 from 2010 to the
present day. We find that ice shelf thinning rates exhibit large fluctuations over short time periods, and the
improved spatial resolution of CryoSat-2 enables us to resolve the spatial pattern of thinning with ever greater
detail in Antarctica.

1280
2628
Channelized Melting Drives Thinning under a Rapidly Melting Antarctic Ice Shelf

Noel Gourmelen1 (noel.gourmelen@ed.ac.uk), Dan Goldberg1

1
School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom

Ice shelves play a vital role in regulating loss of grounded ice and in supplying freshwater to coastal seas.
However, melt variability within ice shelves is poorly constrained and may be instrumental in driving ice-shelf
imbalance and collapse. High-resolution altimetry measurements from 2010 to 2016 show that Dotson Ice
Shelf (DIS), West Antarctica, thins in response to basal melting focussed along a single 5 km-wide and 60 km-
long channel extending from the ice shelf's grounding zone to its calving front. If focused thinning continues at
present rates, the channel will melt through within 40-50 years, almost two centuries before melt through is
projected from the average thinning rate. Our findings provide evidence of basal melt-driven sub-ice shelf
channel formation and its potential for accelerating the weakening of ice shelves.

1281
2175
Ice--ocean Wave Interaction on Ice Shelves

Bradley Lipovsky1 (brad_lipovsky@fas.harvard.edu)

1
Harvard University, Cambridge, United States

Distant storms, tsunamis, and earthquakes generate waves in floating ice shelves. In several instances, seismic
observations have clearly demonstrated a mechanistic link between periods of elevated wave activity and
iceberg calving. The detailed mechanical interpretation of observed seismograms is complicated, however, by
the existence of numerous types of waves that propagate in the coupled ice--ocean--earth system. Here, I
describe wave propagation in an elastic, finite-thickness, buoyantly floating ice layer above a uniform and
inviscid water layer. I place particular focus on waves with wavelength greater than the ice thickness, as have
recently been observed on the Ross, Pine Island, and Amery Ice Shelves. I show that mode uncoupling occurs at
long period such that waves occur as either symmetric or flexural modes. I calculate the stresses associated
with the seismically observed wave field on the Ross Ice Shelf. In the context of linear elastic fracture
mechanics, this stress field provides a mechanistic explanation for the occurrence of ice shelf rifting during
periods of elevated ocean swell. This theory paves the way for more realistic depictions of iceberg calving in
large scale ice sheet models.

1282
1598
Early Weakening of the Larsen B Ice Shelf Prior to Break-up

Theodore Scambos1 (teds@nsidc.org), Marin Klinger1

1
University of Colorado at Boulder, National Snow and Ice Data Center/CIRES, Boulder, United States

Precursor changes in the Larsen B Ice shelf beginning more than a decade before its disintegration have been
identified, and coincide with a trend towards reduced sea ice cover and increased foehn winds. Ice flow speeds
in the major tributary glaciers of the Larsen B increased, even in the period prior to the loss of critical areas of
the ice shelf (which began in 1998 for the Larsen B), and elevation of the ice shelf surface decreased. Ice shelf
surface lowering is interpreted as resulting from actual ice shelf thinning for this area, since field studies on
both the Larsen A and B noted the upper firn of the shelf was almost completely converted to ice. Examination
of satellite images spanning 1963 - 1997 shows that Larsen B shear margins and some suture zones evolved
significantly prior to significant ice shelf retreat. Overall, these changes suggest either increased ocean-driven
basal melt or effects of increased surface meltwater on grounded glacier outflow are a cause of early shelf
weakening that leads eventually to disintegration. Available ocean temperature data show that modified
Weddell Deep Water, having a temperature 0.1-0.4°C above the surface freezing point, is present near the
former ice fronts in some 1995-2012 profiles, but to date has not been detected within the embayments near
the glacier grounding lines or beneath the ice shelves.

1283
OS-3c - Sea ice extent, properties, volume & ice shelves: modern and paleo records
21.06.2018 14:00-15:30, B Jakobshorn

941
Examining Antarctic Coastal Exposure - Sea Ice-free Coastal Regions

Philip Reid1 (p.reid@bom.gov.au), Rob Massom2

1
Australian Bureau of Meteorology, Hobart, Australia, 2Australian Antarctic Division and ACE CRC, Hobart,
Australia

While the change and variability of Antarctic sea ice extent, area and seasonality are well documented, very
little information is available on broad-scale change and variability of sea ice-free coastal regions. This is an
important topic since there is mounting evidence of potentially strong relationships between coastal sea ice
distribution and the characteristics and stability of glacier tongues and ice shelves, such that a lack of the
protective "buffer" of sea ice could potentially enhance flexure and fatigue of exposed outer ice-shelf margins
by storm-generated ocean swells.
In this study we introduce and examine two methods that focus on sea-ice free regions: a simple, large-scale
index called the "Antarctic Coastal Exposure Index"; and a second method which determines the Coastal
Exposure Length. For this study we use satellite imagery from 1979 through to 2016 and examine temporal and
spatial occurrence and trends. Results show that the West Antarctic coastal regions are dominated by an
increase in coastal exposure, particularly in the West Antarctic Peninsular region, but also in the Amundsen
Sea. In East Antarctica, trends, when viewed as a longitude-time plot, show that a decrease in coastal exposure
around the eastern Antarctic has a distinct westward progression over the summer months. Not all increases in
coastal exposure are found within West Antarctica, with some smaller pockets of East Antarctica also showing a
positive trend.

1284
526
Influence of Continental Ice on Sea Ice Thickness Distribution in SW Ross Sea

Pat Langhorne1 (pat.langhorne@otago.ac.nz), Christian Haas2,3, Wolfgang Rack4, Gemma Brett4, Greg Leonard1,
Eamon Frazer5, Mike Williams6, Natalie Robinson6, Brett Grant6, Alena Malyarenko1,6, Madelaine Rosevear7
1
University of Otago, Dunedin, New Zealand, 2Alfred Wegener Institute Helmholtz Center for Polar and Marine
Research, Bremen, Germany, 3York University, Toronto, Canada, 4Gateway Antarctica, Canterbury University,
Christchurch, New Zealand, 5University of Aberdeen, Dunedin, New Zealand, 6National Institute for Water and
Atmospheric Research, Wellington, New Zealand, 7University of Tasmania, Hobart, Australia

Melting at the base of an ice shelf or a glacier tongue freshens and cools the fluid in the ice-ocean boundary
layer, producing Ice Shelf Water (ISW), a water mass colder than the sea water surface freezing point. If ISW
becomes in situ supercooled by pressure release, ice crystals can persist. These crystals add to the mass of the
coastal sea ice cover, forming a porous, friable layer, called the sub-ice platelet layer, which can be several
metres thick beneath the two-metres of sea ice. Consequently platelet ice formation not only causes sea ice to
be thicker, but it also alters the hydrostatic relationship between sea ice elevation and thickness, influencing
satellite altimeter determination of sea ice thickness. Here we report on the sea ice thickness distribution in the
SW Ross Sea in spring, and describe how this distribution is influenced by interaction with the ice from the
continent. The SW Ross Sea is fringed by a number of ice shelves (e.g. McMurdo, Hells Gate, Ross) and glacier
tongues (e.g. Drygalski, Erebus), features that have the potential to form ISW. We have conducted airborne sea
ice thickness surveys using electromagnetic (EM) induction sounding. These regional surveys have been
supported over smaller geographic areas by detailed on-ice sea ice and snow thickness measurements, by on-
ice EM induction transects of sea ice thickness, and by under-ice oceanographic observations that track the
heat deficit and mixing in the upper ocean at selected sites.

1285
424
Wave Propagation in Frazil/Pancake Ice: The Beaufort Sea MIZ during Fall 2015

Peter Wadhams1 (pw11@cam.ac.uk), Giuseppe Aulicino1, Flavio Parmiggiani2

1
Univerisità Politecnica delle Marche, Ancona, Italy, 2CNR-ISAC, Bologna, Italy

The wave frequency and the physical properties of the ice cover determine the way in which waves propagate
in ice. Large floes interact with waves via a scattering process which results in an exponential decay of incoming
wave energy with distance. Very small floes, like pancake ice where the individual cakes may be less than 3 m
in diameter, interact in a different manner; they behave like a continuum and can be considered as a very
viscous fluid which not only causes decay of the waves but also causes them to propagate with a different
dispersion relation. A careful analysis of in situ measurements, collected in the Beaufort Sea during fall 2015
through the use of directional wave buoys, has allowed us to examine attenuation rates, spectral spread rates
and anomalous dispersion for different ice conditions met in the MIZ during several in situ experiments.
The buoys deployments lasted 1-3 days temporally and spanned up to 100 km spatially. After inter-calibrating
the buoys, the vertical displacement (heave) time series for the buoys was hence analyzed for calculation of the
scalar wave energy spectra and bulk wave parameters (i.e., significant wave height, dominant wave period). As
expected, our measurements show that waves play an important role in inhibiting the fall freeze-up of the
Beaufort Sea, especially near the ice edge facing the prevailing easterly winds. Results on the attenuation of
waves in different MIZ conditions are presented and discussed.

1286
263
PIPERS: Overview of the 2017 Winter Cruise in the Ross Sea Pack Ice

Stephen Ackley1 (stephen.ackley@utsa.edu), Sharon Stammerjohn2, Ted Maksym3, Peter Guest4, John Cassano2
1
Univ of Texas San Antonio, Snow and Ice Geophysics Laboratory, San Antonio, United States, 2Univ of Colorado,
Boulder, United States, 3Woods Hole Oceanographic Institution (WHOI), Woods Hole, United States, 4Naval
Postgraduate School, Monterey, United States

The PIPERS cruise on N. B. Palmer into the early winter Ross Sea took place between April 11 and June 14 2017.
The keystone project was to investigate the Atmosphere-Ice-Ocean interaction in the Terra Nova Bay and Ross
Ice Shelf coastal polynyas. The cruise however involved multidisciplinary and complementary activities that
were conducted in several different phases of the cruise. These activities were: ARGO and SOCCOM Float
deployments north of the sea ice; marginal ice zone(MIZ) wave buoy deployments and sampling activities;
along track sampling for physical oceanography , trace metals, and trace and noble gasses; ice thickness,
roughness and physical property sampling at ice stations; gas fluxes(CO2, DMS, Methane) and sea ice
biogeochemistry sampling at ice stations and in polynyas; boundary layer profiling using drone aircraft and met
towers at ice stations; and atmosphere, ice and ocean investigations in the coastal polynyas. An overview of
some of the newer technologies used on the cruise and how measurements were coordinated will be described
here for these multiple phases of the cruise. Other presentations will be identified for specific details and
results.

1287
2503
PIPERS: Air-sea-Ice Interactions during a Very Anomalous Season in the Ross Sea

Sharon Stammerjohn1 (sharon.stammerjohn@colorado.edu), Stephen Ackley2, Ted Maksym3, Peter Guest4,

John Cassano1, Peter Sedwick5, Brice Loose6, Jean-Louis Tison7, Bruno Delille8, Guy Williams9
1
University of Colorado Boulder, Boulder, United States, 2University of Texas San Antonio, San Antonio, United
States, 3Woods Hole Oceanographic Institution, Woods Hole, United States, 4Naval Postgraduate School,
Monterey, United States, 5Old Dominion University, Norfolk, United States, 6University of Rhode Island,
Kingston, United States, 7Universite Libre de Bruxelles, Bruxelles, Belgium, 8Universite de Liege, Liege, Belgium,
9
University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia

The PIPERS (Polynyas, Ice Production and seasonal Evolution in the Ross Sea) project conducted a research
expedition to the southwestern Ross Sea aboard the RVIB Palmer during April-June 2017. Its main objective
was to assess the local/large-scale controls on sea ice production, water mass transformation, and
carbon/trace metal inventories during an autumn-winter transition. Between 1979 and 2015 the Ross Sea was
notable for showing strong positive sea ice trends in all seasons (strongest in autumn and spring). The PIPERS
expedition however took place prior to the lowest austral summer sea ice extent ever observed in the Ross Sea
since 1979. This anomalous 2017 summer season followed record-breaking anomalies that first emerged the
preceding winter-spring of 2016. Subsequently, during the autumn of 2017, the ice edge was slow to recover
during March-April, but by late May, the ice edge east of ~165W finally reached its climatological location,
while the ice edge between 165E to 165W remained anomalously south (by ~240km). This ice edge anomaly
then shifted eastward during winter-spring 2017. To help explain these anomalous sea ice conditions, air-sea-
ice and ice-climate interactions leading up to and during the PIPERS cruise will be described and discussed.
These regional analyses will then be compared to the ship-based observations acquired during PIPERS to help
validate and distinguish local/large-scale controls on sea ice production and thickness evolution.

1288
725
Variability of Sea Ice Production in Ross Ice Shelf Polynya

Xi Zhao1 (xi.zhao@whu.edu.cn), Xiaoping Pang1, Zian Cheng1

1
Wuhan University, Chinese Antarctic Center of Surveying and Mapping, Wuhan, China

The Ross Ice Shelf Polynya (RISP) has the highest sea ice production in the Southern Ocean. We calculated sea
ice production of RISP from 2003 to 2015 by a thermodynamical model based on sea ice concentration derived
from AMSRE, SSMIS and AMSR2, and ERA-Interim meteorological data. The result of ice production model is
sensitive to parameter variation. The value of the parameters such as the latent heat of sea ice fusion and the
bulk transfer coefficients have a great impact on the results of the model. When different parameter value are
chosen, the ice production results vary as much as 46%. The wintertime total ice productions of RISP for 2003-
2015 range 164-313 km3 with an average of 219 km3, showing no obvious temporal trend. The ocean surface
produces ice at a high rate within the distance of 20-30 km from the ice shelf front. In most high production
areas, the ice production significantly increases. Some local regions show a contrarily significant decreasing
trend as a result of ice shelf expansion and iceberg events. The monthly total RISP ice production ranges from
14 to 76 km3, showing substantial fluctuations in each month during 2003-2015. The seasonal variation of each
year also shows substantial fluctuations. Finally, the ice production by RISP is related to sea ice extent in Ross
sea section and its contributions to the increasing trend are discussed.

1289
AC-2a - Polar meteorology, climatology and stratospheric processes
21.06.2018 14:00-15:30, C Sanada I

2123
Observing the Stratosphere at South Pole with High-energy Muons in IceCube

Serap Tilav1 (tilav@udel.edu)

1
University of Delaware, Physics and Astronomy, Newark, DE, United States

The IceCube Neutrino Observatory, located at the geographical South Pole, records high-energy muons at
depths of 1450-2450m in the Antarctic ice. While the sensors look for rare astrophysical neutrinos as signal,
downgoing muons with energies above 400 GeV are able to penetrate and trigger the detector at a rate of 2.15
kHz. The bulk of the downgoing muons are created by cosmic ray interactions in the lower stratosphere and
their rate best correlates with the temperature variations around 50-150 hPa (12-20 km) layers. Here we report
on the observation of both seasonal modulation of the rates and the short term correlations with the
stratospheric temperatures.

For the IceCube Collaboration

1290
1077
The SPARC Polar Stratospheric Cloud Initiative (PSCi)

Michael Pitts1 (michael.c.pitts@nasa.gov), Lamont Poole2, Ines Tritscher3, Thomas Peter4, Reinhold Spang3,
Jens-Uwe Grooß3, Michael Höpfner5, Alyn Lambert6, Simon Alexander7, Francesco Cairo8, Terry Deshler9, Sergej
Molleker10
1
NASA Langley Research Center, Science Directorate, Atmospheric Composition Branch, Hampton, United
States, 2Science Systems and Applications, Inc., Hampton, United States, 3Forschungszentrum Jülich, Jülich,
Germany, 4ETH Zurich, Zurich, Switzerland, 5Karlsruhe Institute of Technology, IMK, Karlsruhe, Germany, 6Jet
Propulsion Laboratory, California Institute of Technology, Pasadena, United States, 7Australian Antarctic
Division, Kingston, Australia, 8CNR-ISAC, Rome, Italy, 9University of Wyoming, Laramie, United States, 10Max-
Planck-Institute for Chemistry, Mainz, Germany

After more than three decades of research, the role of polar stratospheric clouds (PSCs) in stratospheric ozone
depletion is well established. However, important questions remain unanswered that have limited our
understanding of PSC processes and how to accurately represent them in global models, calling into question
our prognostic capabilities for future ozone loss in a changing climate. A more complete picture of PSC
processes on vortex-wide scales is emerging from a suite of contemporary satellite missions: the Michelson
Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat (2002-2012), the Microwave Limb
Sounder (MLS) on Aura (2004-present), and the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on
CALIPSO (2006-present). These datasets have motivated numerous research activities that both extend and
challenge our present knowledge of PSC processes and modeling capabilities. The SPARC PSC initiative was
organized in January 2015 to address key questions related to PSCs and their representation in global models
with the following main objectives: identify key PSC parameters required by global models; identify strengths
and limitations of the PSC datasets; define a methodology to obtain the key PSC properties required by models
from the observational datasets; develop a state of the art PSC climatology; and identify remaining open
science questions. In this presentation, we describe the PSCi activities, key findings, and remaining open
questions.

1291
2412
New Satellite Climatologies of PSC: Assets for Model Improvement

Reinhold Spang1 (r.spang@fz-juelich.de), Lars Hoffmann2, Ines Tritscher1, Jesn-Uwe Grooss1, Rolf Müller1,
Michael Höpfner3, Michael Pitts4, Andrew Orr5
1
Forschungszentrum Jülich, IEK-7, Jülich, Germany, 2Forschungszentrum Jülich, JSC, Jülich, Germany, 3Karlsruhe
Institute of Technology, IMK-ASF, Karlsruhe, Germany, 4NASA Langley Research Center, Hampton, United States,
5
British Antarctic Survey, Cambridge, United Kingdom

The MIPAS instrument onboard ESA's Envisat satellite operated from July 2002 until April 2012. The infrared
limb emission measurements represent a unique dataset of day- and nighttime observations of polar
stratospheric clouds (PSC) up to both poles. The cloud detection sensitivity is comparable to spaceborne lidars
like the CALIOP instrument on the CALIPSO satellite (operating since June 2006). Both instruments allow the
differentiation of PSC types, like solid particles of ice and nitric acid trihydrate (NAT), as well as liquid droplets
of super-cooled ternary solution (STS). From the MIPAS and CALIOP measurments an unprecedented database
PSC type observations is now available for validation and improvement of PSC schemes in chemistry transport
and chemistry-climate models for a better predictability of future polar ozone loss in a changing climate.
The spatial, intra-seasonal, and inter-annual variation in the PSC type occurrence have been analysed for MIPAS
and compared to CALIOP as well as model results. Key parameters such as Volume and Area PSC, frequently
used as a proxy for ozone depletion, have been investigated in comparison with model results of the Chemical
Lagrangian Model for the Stratosphere (CLaMS). Finally, an analysis of mountain wave (MW) induced formation
of NAT and ice clouds based on measurements of the nadir looking AIRS instrument and the MIPAS climatology
- focusing on both hemispheres - will be presented.

1292
2682
Multi-decadal NDACC Measurements of Atmospheric Trace Species at Thule GR

James Hannigan1 (jamesw@ucar.edu)

1
National Center for Atmospheric Research (NCAR), Boulder, United States

To understand better the effects of changing emissions, possibly changing transport pathways and chemistry in
a rapidly changing Arctic atmospheric environment, consistent observations of key species for a duration
preceding and spanning our current time period are invaluable. Since the late 1990's observations have been
taken in the Arctic at several NDACC sites (Network for the Detection of Atmospheric Composition Change).
These FTIR (Fourier Transform Infra-Red) instruments that pass through a process of intercomparison to
maximize consistency of spectral data and retrievals, routinely acquire spectra for many species. The remotely
sensed vertical distributions provide trends and a measure of variability of species in both the tropospheric and
stratospheric and aid in evaluating transport and chemistry processes. In this presentation, we will discuss
trends in trace species and focus on carbonyl sulphide a key precursor to the stratospheric sulphate aerosol
layer with highly variable sources in a changing Arctic.

1293
1209
Analysis of Middle Atmospheric H2O and O3 Measurements at Ny-Ålesund, Svalbard

Franziska Schranz1 (franziska.schranz@iap.unibe.ch), Brigitte Tschanz1, Niklaus Kämpfer1

1
University of Bern / Institute of Applied Physics, Bern, Switzerland

The ground based ozone and water vapour radiometers GROMOS-C and MIAWARA-C have been located at the
Arctic research station AWIPEV at Ny-Ålesund, Svalbard (79°N/12°E) since September 2015. Both radiometers
were built at the University of Bern, Switzerland and are specially designed for campaigns. The instruments
measure the vertical distribution of ozone and water vapour in the middle atmosphere with a high time
resolution and under most weather conditions. GROMOS-C provides hourly ozone profiles where for
MIAWARA-C a resolution of 2-4 hours is realistic, depending on the atmospheric opacity. The unique datasets
from these instruments are used to study dynamical events and the chemistry of ozone and water vapour in
the middle atmosphere. We present an overview of the data from two years with characteristic events in
summer and winter such as effects of sudden stratospheric warmings or the tertiary ozone layer. Special
emphasis is given to the investigation of the link between ozone and water vapour concentrations in the upper
stratosphere and lower mesosphere. The specified dynamics version of the Whole Atmosphere Community
Climate Model (SD-WACCM) is used to support this investigation.

1294
1217
The Canadian Arctic ACE/OSIRIS Validation Campaigns at PEARL

Kaley A. Walker1 (kaley.walker@utoronto.ca), Kimberly Strong1, Pierre F. Fogal1, James R. Drummond2

1
University of Toronto, Department of Physics, Toronto, Canada, 2Dalhousie University, Department of Physics
and Atmospheric Physics, Halifax, Canada

Ground-based measurements provide critical data for the validation of satellite retrievals of atmospheric trace
gases and for the assessment of long-term stability of these measurements. As of February 2018, the Canadian-
led Atmospheric Chemistry Experiment (ACE) satellite mission has been making measurements of the Earth´s
atmosphere for nearly fourteen years and Canada´s Optical Spectrograph and InfraRed Imager System (OSIRIS)
instrument on the Odin satellite has been operating for sixteen years. As ACE and OSIRIS operations have
extended beyond their planned two-year missions, there is an ongoing need to validate the trace gas profiles
for the satellite instruments.
To this end, fifteen Canadian Arctic ACE/OSIRIS Validation Campaigns have been conducted during the spring
period (February - April in 2004 - 2018) at the Polar Environment Atmospheric Research Laboratory (PEARL) in
Eureka, Nunavut (80N, 86W). The spring period coincides with the most chemically active time of year in the
Arctic, as well as a significant number of satellite overpasses. A suite of as many as 12 ground-based
instruments, as well as frequent balloon-borne ozonesonde and radiosonde launches, have been used in each
campaign. This presentation will focus on an overview of the measurements made by the ground-based,
balloon-borne and satellite-borne instruments during the recent ACE/OSIRIS Arctic Validation campaigns and
highlight how these have been used for satellite validation.

1295
OS-7c - Atmosphere-Ice-Ocean interactions in the Polar Regions
21.06.2018 14:00-15:30, C Sanada II

2471
Wave-ice-Ocean Interactions during Storm-induced Sea Ice Breakup

Lucia Hosekova1 (l.hosekova@reading.ac.uk), Yevgeny Aksenov2, Stefanie Rynders2, Andrew Coward2

1
University of Reading, Department of Meteorology, Reading, United Kingdom, 2National Oceanography Centre,
Southampton, United Kingdom

The Marginal Ice Zone (MIZ), an area of transition between open ocean and sea ice is characterized by highly
fragmented ice cover and strong temporal and spacial variability. Over the last three decades, it has been
undergoing dramatic expansion in the Arctic due to sea ice retreat and increased wave activity. We present a
model development which implements surface ocean wave effects into global ocean model NEMO and sea ice
model CICE to account for a number of physical processes specific to the MIZ, in particular sea ice breakup due
to waves and the effect of floe size distribution on lateral melting of sea ice. We perform high resolution model
studies of recently documented large storm events in polar areas and investigate the impact of waves on both
sea ice and upper ocean, identifying potential mechanisms for momentum and heat exchange between waves,
ocean, sea ice and atmosphere following periods of enhanced wave activity.

1296
1206
Bridging the Scales in Sea Ice Deformation for Sea Ice Damaged by Winter Storms

Polona Itkin1 (polona.itkin@npolar.no), Annu Oikkonen2, Gunnar Spreen3, Jari Haapala2

1
Norwegian Polar Institute, Fram Centre, Tromsø, Norway, 2Finnish Meteorological Institute, Helsinki, Finland,
3
University of Bremen, Bremen, Germany

In the changing Arctic where the sea ice is getting thinner and at the same time moving faster, also ice
deformation processes are increasing. The magnitude of deformation rates are however hard to compare as
they depend on spatial and temporal scales of the measurements. Here we present results from the N-ICE2015,
an expedition to the ice covered region north of Svalbard in the first half of 2015. The deformation rates we
measured on N-ICE2015 by buoy arrays were one of the highest ever recorded in the Arctic at similar scales
(10-100 km at 1-3 hour interval). We also measured the deformation at shorter scales (100 m-5 km at 10 min
interval) from the ship radar images. To bridge between the spatial scales we will supplement these two
deformation estimates by deformation rates from satellite remote sensing (SAR) images based on sea ice drift
(1-500 km at 1 day interval). These three datasets will allow us to quantify the scaling law relationships over a
large range of spatial and temporal scales, and help us to estimate the extent and consequences of the major
deformation events observed. During N-ICE2015 the sea ice in the Atlantic sector of the Arctic was impacted by
several powerful storms. These storms penetrated deep into the pack ice and permanently damaged the ice.
We will use the deformation rates obtained from SAR sea ice drift to estimate the importance of the ice age
and distance to the ice edge for deformation and healing processes of sea ice.

1297
239
Impact of Severe Storm Conditions on the Marginal Ice Zone in the Southern Ocean

Marcello Vichi1 (marcello.vichi@uct.ac.za), Sebastian Skatulla2, Keith Machutchon2, Ehlke de Jong3, Clare Eayrs4,
Jhon Mojica Moncada4, David Holland5, Alessandro Toffoli6, Alberto Alberello6, Miguel Onorato7, Clinton
Saunders8, Anriette Bekker8, Warren Joubert9
1
University of Cape Town, Marine Research Institute, Cape Town, South Africa, 2University of Cape Town, Civil
Engineering, Cape Town, South Africa, 3University of Cape Town, Department of Oceanography, Cape Town,
South Africa, 4New York University Abu Dhabi, Center for Global Sea Level Change, Abu Dhabi, United Arab
Emirates, 5New York University, Courant Institute, New York, United States, 6The University of Melbourne,
Department of Infrastructure Engineering, Melbourne, Australia, 7University of Turin, Department of Physics,
Turin, Italy, 8Stellenbosch University, Department of Mechanical and Mechatronic Engineering, Stellenbosch,
South Africa, 9South African Weather Service, Cape Town, South Africa

The winter marginal ice zone (MIZ) in the Southern Ocean is one of the least explored regions of the world
ocean, where synoptic weather, sea-ice and oceanic processes are more tightly interlinked. Remote sensing
observations have revealed the large variability of the Southern Ocean sea ice over the past 20 years, and the
increased spatial resolution of sensors now allow to capture synoptic patterns in the ice edge. The actual
reliability of these data is however not known because of the very few in situ observations particularly during
the winter period. This contribution reports on a process study conducted in July 2017 in the Indian Ocean
sector, aimed at studying the winter MIZ, the relation with met-ocean conditions and how they impact
navigation performances. The response of the MIZ to a large-scale storm was documented by means of sea-ice
observations, ice-drift buoys, wave cameras and the ship-response to vibrations. The sea ice was composed of
pancakes of varying dimensions that did not show compaction for more than 150 km into the MIZ. The
preliminary results hint at a coherent large-scale response of the pancake ice field to wind and swell, with drifts
of up to 0.8 m/s, more typical to brash ice conditions rather than the observed semi-consolidated surface. The
results are analysed in conjunction with atmospheric reanalyses data and ocean forecasting models to provide
insights on the process dynamics and improve future polar predictions in the southern hemisphere.

1298
482
Wave-induced Floe-floe Collisions and Ocean-sea Ice Momentum Transfer

Agnieszka Herman1 (oceagah@ug.edu.pl)

1
University of Gdansk, Institute of Oceanography, Gdynia, Poland

In the marginal ice zone (MIZ), waves entering from the open ocean often induce collisions between
neighboring ice floes. Due to limited observational data, it is not known to what degree wave-induced collisions
contribute to the stress within the ice and to the dissipation of wave energy in MIZ. In this paper, wave-induced
collisions between ice floes are analyzed with a numerical, discrete-element model. The model simulates surge
motion of an ensemble of ice floes on a prescribed wave field. It is shown that the collision pattern depends on
ice concentration, wave steepness, floe size relative to wavelength, floe-size distribution, as well as the
restitution coefficient and drag between the ocean and the ice. For relatively large ice floes, the results are very
sensitive to the formulation of wave forcing and ice-water drag. If the forcing correctly takes into account floe
size relative to the wavelength, the model accurately reproduces surge RAOs of single floes, as well as
accelerations and forces of floes impacting a structure. The modelling results are used to estimate the granular
temperature, as well as covariance between ice floes' velocities and forces acting on them for a wide range of
conditions. This is crucial for developing parameterizations of source terms related to wave-induced collisions
in the granular-temperature evolution equation used in large-scale sea ice models.

1299
77
Waves, Turbulence, and Thin Sea Ice at the Autumn Air-Ice-Ocean Interface

Madison Smith1 (mmsmith@uw.edu), Jim Thomson1, Lettie Roach2

1
University of Washington, Applied Physics Lab, Seattle, United States, 2National Institute of Water and
Atmospheric Research (NIWA), Wellington, New Zealand

Winds, waves, and turbulent mixing at the air-ice-ocean interface set the exchange of momentum, heat, and
gases between the ocean and atmosphere. Surface waves and associated near-surface turbulence are
particularly tightly coupled in thin, new ice. We present observations made from drifting buoys in autumn
pancake sea ice in the Arctic and Antarctic during Sea State and PIPERS programs, respectively. Coincident
measurements of sea ice, wind, waves, and turbulence from the buoys allow quantification of feedbacks
between ice growth, attenuation of waves, and suppression of turbulence. Thin ice attenuates waves from
open water conditions, preferentially attenuating high frequency waves. Thus, the net effect of ice is to
increase the dominant wave period and length. We find that floe diameter throughout the growth process is
proportional to the ratio of wavelength squared to wave height (known as the tensile failure mode), indicative
of a feedback between ice growth and wave attenuation. Near-surface wave-breaking turbulence is
simultaneously reduced, due to decreased wind input transfer velocity. Thin ice also has the potential to
increase turbulence below the surface due to shear between the ice and ocean. As air-ocean production of
turbulence weakens, the ice-ocean interface becomes the dominant source for shallow turbulence. Our results
suggest parameters for estimating near-surface turbulence in thin pancake and frazil ice, which are ubiquitous
in autumn marginal ice zones.

1300
1298
Wave-ice Interactions during the Antarctic Circumnavigation Expedition

Alberto Alberello1, Luke Bennetts2, Susanne Lehner3, Egbert Schwarz3, Keith MacHutchon4, Konny Reichert1,
Alessandro Toffoli1 (alessandro.toffoli@unimelb.edu.au)
1
The University of Melbourne, Parkville, Australia, 2University of Adelaide, Adelaide, Australia, 3German
Aerospace Center (DLR), Hamburg, Germany, 4University of Cape Town, Cape Town, South Africa

Southern Ocean waves play a crucial role in global climate system. Besides regulating energy exchanges in the
upper ocean via turbulent mixing, waves influence sea ice formation and its break up. However, the underlying
physics involved in wave-ice interactions poorly understood. The rate of wave energy dissipation and the
intensity of the wave induced drift are still uncertain. During the Antarctic Circumnavigation Expedition waves
and their interaction with sea ice was investigated, with the wave climate monitored via an onboard wave
radar WaMoS II that provided the full two-dimensional wave spectrum and the surface current. Concurrently,
satellite images overlapped with some of the cruise track allowing a cross-comparison of onboard and remote
wave measurements. Global altimeter and SAR wave mode data as well as Sentinel-1 and TerraSAR-X scenes
were used. Compared to onboard measurements, remote sensing provides information on the metocean
conditions at a much larger areal scale. Here, we examine data collected during the crossing of an ice band
between Balleny Islands and the Mertz Glacier when a swell was coming from an easterly direction. The wave
energy dissipation is found to be frequency dependent, i.e. the ice cover acts as band pass filter where the
maximum dissipation occurs at frequency comparable with the ice floe length, corroborating previous
laboratory experiments. Moreover, the wave-induced ice drift is found to exceed predictions based on the
Stokes' drift.

1301
BE-9b - Life distribution and responses to environmental changes in Polar ecosystems
21.06.2018 16:00-17:30, C Aspen

123
Deep Scattering Layers, the Feeding Ground of Antarctic Deep-diving Predators

Camille Le Guen1 (cmmalg@st-andrews.ac.uk), Roland Proud1, Matteo Bernasconi2, Lars Boehme1, Inigo
Everson3, Paul Fernandes4, Joshua Lawrence4, Richard Sherley5, Andrew Brierley1
1
University of St. Andrews, School of Biology, St. Andrews, United Kingdom, 2Institute of Marine Research,
Bergen, Norway, 3University of East Anglia, Norwich, United Kingdom, 4University of Aberdeen, Aberdeen,
United Kingdom, 5University of Exeter, Exeter, United Kingdom

During the day, myctophids (lanternfish), krill, squid and jellyfish form layer-like aggregations in the
mesopelagic zone (200-1000m deep) to reduce exposure to visual predators. These layers can be detected by
echosounders and are known as deep scattering layers (DSLs). Myctophids are very abundant in DSLs and offer
great potential as a protein source for human consumption, but play a key trophic role as food for predators. In
the framework of the Commission for the Conservation of Antarctic Marine Living Resources, pressing
management issues arise because myctophids make up to 90% of the diet of deep-diving air-breathing
predators such as King Penguins (Aptenodytes patagonicus, dive depth >350m) and Southern Elephant Seals
(Mirounga leonina, dive depth >1500m). More data on DSLs are needed to develop a biogeographic zonation
and understand likely future responses to climate change before any large-scale exploitation begins. A unique
data set of DSL geographic variability in depth and echo-intensity (proxy for biomass) throughout the Southern
Ocean was collected during the Antarctic Circumnavigation Expedition (ACE), along with CTD data and satellite
remote sensing. We also collected position, depth and accelerometry data from predators off the coasts of
South Georgia and Kerguelen as the ACE vessel approached each island. The tracking data are co-located with
the DSL landscape to better understand predator-prey interactions and inform fisheries and conservation
management.

1302
286
Climate Change and Polar Range Expansions: Could Cuttlefish Cross the Arctic?

Jose Xavier1,2 (jccx@cantab.net), Lloyd Peck2, Peter Fretwell2, John Turner2

1
MARE, University of Coimbra, Life Sciences, Coimbra, Portugal, 2British Antarctic Survey, Cambridge, United
Kingdom

Climate change can have major effects on the distribution of species. In marine ecosystems, the cold waters of
the Arctic have restricted warmer water species from crossing between Eurasia and North America. However,
with Arctic waters becoming warmer, various marine species have expanded their distribution. Cuttlefish are
fast-growing, voracious predators and are absent in American waters. The European cuttlefish Sepia officinalis
is the most northerly distributed cuttlefish, with potential to expand its range and cross to the American
continent. Our climate model predictions suggest that the S. officinalis could potentially reach American
shores, by 2300 via the north Atlantic with medium mitigation of greenhouse gas concentrations; we predict
that adult dispersal of cuttlefish across the Atlantic sector would require a migration distance of over 1400 km
at depths below 200 m and temperatures above 7 °C (temperature below which cuttlefish cannot maintain
routine metabolic processes physiologically). If they reach American shores they could have large impacts on
coastal marine ecosystems, due to their wide diet (e.g. diet covers many shallow-water crustacean and fish
species) and its potential as prey, and due to their short life-history strategy of “live fast, die young”.
Discussions to how cuttlefish may also be present in the Antarctic in the future, and their possible impacts in
Antarctic marine coastal ecosystems is discussed.

1303
930
Feed like a Toothfish: Foraging Behavior from In Situ and Ex Situ Analysis

Laura Ghigliotti1 (laura.ghigliotti@ge.ismar.cnr.it), Simonepietro Canese2, Erica Carlig1, Davide Di Blasi1, Sara
Ferrando3, Lorenzo Gallus3, Steve Parker4, Eva Pisano1, Marino Vacchi1
1
National Research Council of Italy, Institute of Marine Sciences (ISMAR), Genoa, Italy, 2Istituto Superiore per la
Ricerca e la Protezione Ambientale (ISPRA), Rome, Italy, 3University of Genova, Genoa, Italy, 4National Institute
of Water and Atmospheric Research (NIWA), Nelson, New Zealand

In the Ross Sea, the world's largest Marine Protected Area has recently been created. In this area, the
commercially harvested Antarctic toothfish Dissostichus mawsoni, plays a key ecological role as the piscine
apex predator. Although trophic interactions have been well documented on the continental slope and
northern seamounts in the region, observations from sea-ice covered coastal margin areas are much more
limited.
Our aim is to better describe Antarctic toothfish natural history by studying the feeding ecology of this species
in sea-ice covered areas.
During field activities, conducted in November from the fast ice at McMurdo Sound (2015) and Terra Nova Bay
(2016), sampling methods, based on vertical longline fishing, were combined with low impact visual sampling
techniques, relying on the use of Baited Underwater Video cameras (BUVs).
The diet and age structure of the Antarctic toothfish sampled in sea ice covered areas, as well as hypotheses on
the feeding strategies emerging from the combination of sensory system information, feeding structure
morphology data and behavioral records, are presented.

1304
1632
Can Isoscapes of Mesopelagic Fish Predict Top Predator Hotspots?

Andrea Walters1 (andrea.walters@utas.edu.au), Rowan Trebilco2, Sophie Bestley1, Ben Raymond3, Andy Revill4,
Mark A. Hindell1, Mary-Anne Lea1, Jess Melbourne-Thomas2,3, Andrew Constable2,3
1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Antarctic Climate and
Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Australia, 3Australian Antarctic
Division, Hobart, Australia, 4Commonwealth Scientific and Industrial Research Organisation (CSIRO), Hobart,
Australia

Assessment of marine predator habitat use can reveal geographic hotspots of foraging activity, and when
linked with diet information can provide an improved understanding of biological processes and predator
dependence on trophic resources. Mesopelagic myctophid fish, as a key trophic link between the meso-
zooplankton and higher trophic levels (seabirds, penguins and marine mammals), are expected to be a good
indicator of biological hotspots in oceanic waters. To explore this idea we developed spatially-resolved
isoscapes using Southern Ocean mesopelagic fish populations. Fish were sampled along survey transects from
the Antarctic shelf to BANZARE Bank and waters to the west and east during January to February 2016. The
wide spatial range aimed to account for variability in the nutrient sources and oceanographic conditions in the
southern Kerguelen Plateau region. The mesopelagic distributions were analysed in relation to the spatial
distribution of flying seabirds and subsurface feeders (e.g. seals, penguins) based on telemetry data. We
investigated multi-species spatial overlap areas and examined the extent to which isotope mapping of prey
distributions can be used to identify important oceanic areas for marine predators in the southern Indian
Ocean. This integrative approach can provide important insights into the structure and function of Southern
Ocean ecosystems, and aid large-scale efforts to identify areas of ecological significance for marine seabirds
and mammals.

1305
2045
Range Shifts in Arctic and Antarctic Zooplankton: The Role of Themisto Amphipods

Charlotte Havermans1,2 (charlotte.havermans@awi.de), Wilhelm Hagen1, Christoph Held2, Holger Auel1

1
University of Bremen/BreMarE, Marine Zoology, Bremen, Germany, 2Alfred Wegener Institute Helmholtz
Centre for Polar and Marine Research, Bremerhaven, Germany

Both the Arctic and Southern Ocean, in particular the southwest Atlantic sector, are experiencing rapid
environmental changes. In the southwest Atlantic sector of the Southern Ocean, a long-term trend of density
changes of key pelagic species has been noted over the last decades. A decline in Antarctic krill is hypothesized,
whilst salps are on the rise and shifting their distribution poleward. A similar poleward expansion is anticipated
for a third key player, the amphipod crustacean Themisto gaudichaudii, leading to an increasing overlap of the
distributions of these three species. In Arctic waters, two congeneric amphipod species co-exist: T. libellula, a
genuine Arctic species and T. abyssorum, considered sub-Arctic boreal. Despite their overlapping distributions,
the two species seem to occupy distinct ecological niches and are preyed upon by different predators. Due to
the ongoing Atlantification of the Arctic, a range expansion of T. abyssorum concomitant with a retraction of T.
libellula's range are very likely to occur. Due to major knowledge gaps in the ecology, biology and genetic
connectivity of Themisto species, the consequences of these shifts for food web structures and biogeochemical
cycles remain largely unexplored. In this context, we carried out a comparative study of Themisto populations
at both poles. Their distribution, genetic and trophic connectivity were investigated with population genetics,
molecular diet analyses and feeding experiments.

1306
2554
Drivers of Jellyfish Diversity, Demography and Distribution in European Arctic

Maciej Mańko1 (mmanko@ug.edu.pl), Marta Głuchowska2, Agata Weydmann1

1
Insititut of Oceanography, Department of Marine Plankton Research, Gdynia, Poland, 2Institute of Oceanology
of the Polish Academy of Sciences, Sopot, Poland

Jellyfish, here as pelagic ctenophores and cnidarians, are increasingly important for the functioning of marine
ecosystems worldwide. They feed on preys ranging from unicellular protists to large fish, simultaneously, in
spite of their relatively low energy density, they also constitute a prey of choice for numerous predators even
as large as cods or seabirds. Although jellyfish are undoubtedly relevant at the global scale, still little is known
about them in polar areas, especially with regard to factors affecting their spatially and vertically structured
biodiversity and population structure.
To elucidate the role of jellyfish in the European Arctic, we have characterized their diversity, size structure and
demography in stratified vertical samples (1000 m to the surface) collected in 2012 from the two latitudinal
sections in the Fram Strait, a crucial pathway for warm and biologically rich Atlantic waters to the Arctic.
Overall, we have identified 13 taxa, with Aglantha digitale and Dimophyes arctica being the most numerous.
We have then contrasted our data on jellyfish with both environmental (salinity, temperature, depth) and
biotic (descriptors of whole plankton community, chlorophyll a) ecosystem characteristics using numerical
ecology tools to elucidate how these factors shape jellyfish diversity and distribution in the European Arctic.

1307
AC-3b - High-Latitude Boundary Layers and Model Evaluation
21.06.2018 16:00-17:30, A Studio

821
Atmosphere-surface Energy Budget Process Relationships over Central Greenland

Matthew Shupe1,2 (matthew.shupe@noaa.gov), Nathaniel Miller1,2, Christopher Cox1,2, Ola Persson1,2

1
University of Colorado Boulder, CIRES, Boulder, United States, 2NOAA Earth System Research Laboratory,
Boulder, United States

The Greenland Ice Sheet (GIS) plays important roles in global climate, impacting sea-level rise, circulation
patterns, and potentially the ocean thermohaline circulation. Variability in the GIS mass budget results from
numerous processes including surface melt, runoff and precipitation. In the context of a warming Arctic,
surface melt is increasing dramatically, making it essential to understand key processes that control variability
in surface temperature and melt. The surface energy budget, comprised of radiative, turbulent, and conductive
heat fluxes, controls surface temperature variability. To represent surface temperature and melt in current and
future climates, numerical models must accurately represent the surface energy budget, including the
partitioning of energy into individual terms and the key atmospheric drivers. This presentation draws on a
comprehensive set of surface and atmosphere measurements made at Summit, Greenland to examine the
surface energy budget. Changes in surface radiation, largely driven by the solar cycle and clouds, elicit
responses in the surface temperature, turbulent sensible and latent heat fluxes, and conductive heat flux.
Relationships are developed that relate radiative forcing terms and responding terms as they manifest over a
full annual cycle. These relationships are then used to evaluate how surface energy budget processes are
represented in model and reanalysis products, including ERA-Interim, CFSv2, and CESM.

1308
2504
On the Clear-sky Cooling during Polar Night over the Sea Ice in the Arctic

Dmitry Chechin1 (dmitry.chechin@awi.de), Christof Lüpkes1, Irina Makhotina2

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2Arctic
and Antarctic Research Institute, St. Petersburg, Russian Federation

We present a simple analytical model of the atmospheric boundary layer (ABL) over the sea ice during polar
night in clear-sky conditions. The model represents coupling between the ABL and sea ice in the presence of
leads. Both steady-state and time-dependent analytical solutions are obtained. The solutions describe air and
surface temperatures as functions of many parameters among which are wind speed and sea ice
concentration. In particular, analytical solutions describe the transition from coupled to decoupled ABL state
when wind speed is decreasing. The model demonstrates the warming effect of leads and shows that leads
might contribute to decoupling over the ice. Analytical solutions are compared to those of a more complex
numerical single-column atmospheric model coupled to the thermodynamic model of the sea ice.
Also, observations from several recent Russian „North Pole“ drifting stations are used to demonstrate the
sensitivity of the thermal regime over the sea ice to wind speed. The observations show that stronger wind
speeds are associated with warmer temperatures, while for weak winds decoupling often occurs. Analytical
solutions provide several possible explanations of the observed dependency of temperature on wind speed.

1309
2496
Evaluation of the Polar Atmosphere-ice-Ocean Interface in CNRM-CM6

Matthieu Chevallier1 (matthieuche@gmail.com), Aurore Voldoire1, David Salas y Mélia1, Lauriane Batté1,
Constantin Ardilouze1, Michel Déqué1, Clotilde Dubois2, Rym Msadek3
1
CNRM-GAME, Toulouse Cedex, France, 2Mercator Ocean, Ramonville Saint Agne, France, 3CERFACS / CNRS,
Toulouse, France

We present a polar-oriented evaluation of CNRM-CM6-1, the updated version of the atmosphere-ocean

coupled model developed at CNRM (Meteo France/CNRS) and CERFACS to contribute to CMIP6 and YOPP. The
nominal horizontal resolution is 150km in the atmosphere and 1° in the ocean. Main evolutions since CMIP5
include a fully new physics in the ARPEGE Climat atmosphere model, the version 3.6 of NEMO ocean model,
enhanced vertical resolutions in the atmosphere and the ocean, a revised atmosphere-ocean coupling strategy
in the presence of sea ice and revised sea ice parameters in the GELATO sea ice model. The focus is on the
representation of the air-ice-ocean interface, including the boundary layers, sea ice and the upper ocean. The
evaluation is done in atmosphere-only mode (with a one-dimensional version of the GELATO sea ice model
embedded into the SURFEX surface scheme), in coupled mode following the CMIP6 DECK protocol and in
seasonal prediction mode using the coupled model initialized with ocean-sea ice reanalyses produced with
Mercator Océan. Improvements include reduction of a bias in geopotential heights in both polar regions, a
more realistic representation of temperature inversions over ice-covered seas, and overall better simulations
of Arctic and Antarctic sea ice in all seasons. Seasonal predictions are used to assess predictive skill, as well as
analysing how persisting biases at the air-ice-ocean interface develop from close-to-observed initial conditions.

1310
35
The Atmospheric Boundary Layer Response to Sea Ice Fragmentation

Marta Wenta1 (marta.wenta@phdstud.ug.edu.pl), Agnieszka Herman1

1
University of Gdansk, Institute of Oceanography, Gdynia, Poland

The response of oceanic and atmospheric boundary layer (ABL) to subgrid - scale variations of sea ice
properties and fracturing has only recently attracted attention and mostly focused on the mixing occurring in
the ocean. Additionally, processes taking place on the level of individual ice floes are not fully understood and
therefore not taken into account in mesoscale Numerical Weather Prediction (NWP) models parameterizations.
In response to growing need of improving the models performance, a series of high-resolution simulations with
Weather Research and Forecasting (WRF) model is performed for different spatial sea ice distributions, ice
concentrations and ambient wind speed profiles. The model parameters are set to represent Arctic winter
conditions. The results indicate that the structure of ABL is highly sensitive to the spatial distribution of sea ice
and open water. With identical ice concentration, considerable variability of several domain-averaged
quantities like surface turbulent heat flux or ABL water vapor content for different arrangements of leads and
ice floes is found. Furthermore the formation of convective cells is determined. The structure and size of the
cells is significantly dependent on the sea ice distribution and wind speed applied to the model. We suggest
that NWP models need improvement and new parameterizations of the ABL are necessary. Our study may
provide a basis for such development and guidance for the planning of field measurements.

1311
369
Observations of Strong Gap Flows in the Nares Strait Region (Greenland)

Günther Heinemann1 (heinemann@uni-trier.de), Clemens Drüe2

1
University of Trier, Environmental Meteorology, Trier, Germany, 2University of Trier, Trier, Germany

The boundary layer structures of gap flows were studied in northwest Greenland during the aircraft-based
experiment IKAPOS (Investigation of Katabatic winds and Polynyas during Summer) in June 2010. The
measurements were performed using the research aircraft POLAR 5 of the Alfred Wegener Institute (AWI,
Bremerhaven). The aircraft was equipped with a suite of meteorological sensors, including a turbulence
measurement system on a nose boom with a sampling rate of 100 Hz.
In the area of the Nares Strait a stable, but fully turbulent boundary layer with strong winds of up to 22 m/s
was found during conditions of relatively warm synoptically induced northerly winds through the Nares Strait.
Strong surface inversions were present in the lowest 100 m to 200 m. As a consequence of channeling effects a
well-pronounced low-level jet (LLJ) system was documented. The channeling process is consistent with gap
flow theory and can be shown to occur at the topographic gap between Greenland and Canada represented by
the Smith Sound. While the flow through the gap and over the surrounding mountains leads to the lowering of
isotropic surfaces and the acceleration of the flow, the strong turbulence associated with the LLJ leads to the
development of an internal thermal boundary layer past the gap.

1312
963
The Iceland Greenland Seas Project: Meteorological Highlights

Ian Renfrew1 (i.renfrew@uea.ac.uk), Bob Pickart2, Kjetil Vage3, GWK Moore4, Tom Lachlan-Cope5, Alexandra
Weiss5, Andy Elvidge6, Annick Terpstra3, Harald Sodemann3, Joachim Reuder3, Lukas Papritz3, Denis Sergeev6,
Chris Barrell6, Shenjie Zhou6, Tom Bracegirdle5, Russ Ladkin5, Nina Petersen7, Ian Brooks8, James Pope5, Erik
Kolstad9, Thomas Spengler3
1
University of East Anglia, School of Environmental Sciences, Norwich, United Kingdom, 2Woods Hole
Oceanographic Institution (WHOI), Woods Hole, United States, 3University of Bergen, Bergen, Norway,
4
University of Toronto, Toronto, Canada, 5British Antarctic Survey, Cambridge, United Kingdom, 6University of
East Anglia, Norwich, United Kingdom, 7Icelandic Met Office, Reykjavik, Iceland, 8University of Leeds, Leeds,
United Kingdom, 9Uni Research, Bergen, Norway

A coordinated meteorological and oceanographic field campaign over the Iceland and southern Greenland Seas
is scheduled for February and March 2018. The aim being to characterise the atmospheric forcing and the
ocean response of coupled atmosphere-ocean processes; in particular cold-air outbreaks in the vicinity of the
marginal-ice-zone and their triggering of oceanic heat loss and the generation of dense water masses. We will
observe the spatial structure and variability of surface flux fields in the region and the weather systems that
dictate these fluxes, through the first meteorological field campaign in the Iceland Sea. This will be done as part
of a coupled atmosphere-ocean field campaign in winter 2018 involving a rare wintertime research cruise,
airborne observations and a host of ocean and atmosphere observing systems. We will make in situ
observations of air-sea interaction processes from several platforms. Here we will present some highlights from
the meteorological component of the field campaign - illustrated by observations from some of the research
aircraft cases.

1313
AC-8b - Causes and Effects of Changing Polar Climate, Cryosphere and Hydrological Cycle
21.06.2018 16:00-17:30, A Forum

1375
Future Emergence of Deep Convection in the Arctic and Impact on the AMOC

Camille Lique1 (camille.lique@ifremer.fr), Matthew Thomas2, Helen Johnson3, Yves Plancherel3

1
Laboratoire d'Océanographie Physique et Spatiale, IFREMER, Plouzane, France, 2Yale, New Haven, United
States, 3University of Oxford, Oxford, United Kingdom

We investigate the potential for deep Mixed Layer Depths (MLDs) to appear close to the Arctic sea ice edge
under a warming climate, using results from present day simulations of two climate models, and also from
simulations with a 4 times increase in atmospheric CO2 levels, representing a future, warmer climate. Under a
warming climate, we expect
(i) a reduction of the AMOC,
(ii) a MLD shoaling in the North Atlantic and
(iii) a northward retreat of the sea ice edge.
We document the changes affecting the MLD in the Arctic and the North Atlantic. There is a strong shoaling in
the present-day areas of deep convection in the North Atlantic, but also a deepening in the Eurasian Basin,
where MLD can episodically reach up to ~1000m. The temporal and spatial structures of the changes in ocean
surface properties reveal a strong surface warming (linked with the sea ice edge retreat) and a strong
salinization (due to Arctic gyre intensification driven by stronger surface stress as the sea ice pack is shrinking).
Together, these changes decrease stratification, triggering convective events. A quantitative Lagrangian
diagnostic of climate model output allows us to determine where the ML subduction contributes to the AMOC.
For present-day conditions, AMOC main contributors are subduction in the Labrador, Irminger and Greenland
Seas. In contrast, in the 4xCO2 simulations, the AMOC is greatly reduced and subduction in the Arctic and the
subtropical gyre contribute significantly to the AMOC.

1314
2341
Ocean Heat Transport Changes Connecting the Midlatitudes to the Arctic

Aleksi Nummelin1, Camille Li2,3 (camille@uib.no), Paul Hezel2,3

1
Johns Hopkins University, Baltimore, United States, 2University of Bergen, Bergen, Norway, 3Bjerknes Centre for
Climate Research, Bergen, Norway

Arctic amplification of global warming has many drivers, including important feedbacks related to changes in
sea ice and the vertical structure of the atmosphere. In the ocean, climate models simulate a weakening of the
Atlantic Meridional Overturning Circulation and its associated ocean heat transport at midlatitudes, but an
increase in the ocean heat transport to the Arctic Ocean. These opposing trends indicate what could appear to
be a discrepancy in the reported ocean contribution to Arctic amplification. Here, we clarify how ocean heat
transport affects Arctic climate under strong greenhouse warming using a set of the 21st century simulations
performed within the Coupled Model Intercomparison Project. The results suggest that subpolar atmosphere-
ocean interactions are key to linking midlatitude and Arctic ocean changes: future reductions in subpolar ocean
heat loss enhance ocean heat transport to the Arctic Ocean, driving an increase in Arctic Ocean heat content
and contributing to the intermodel spread in Arctic amplification. Implications for understanding the rapidly
changing Barents Sea ice cover, which has been linked to midlatitude weather extremes, are discussed. Finally,
the results caution against extrapolating the forced oceanic signal from the midlatitudes to the Arctic.

1315
1935
Changes in Arctic Hydrological Cycle in a Rapidly Warming Arctic

Hotaek Park1 (park@jamstec.go.jp), Daqing Yanag2, Xiangdong Zhang3

1
JAMSTEC, Yokosuka, Japan, 2Environment Canada, Victoria, Canada, 3University of Alaska Fairbanks, Fairbanks,
United States

The decreasing areal extent and thickness of the Arctic sea ice have apparently increased heat and moisture
fluxes from the ocean to the atmosphere in particular in autumn and early winter. These changes may locally
affect air temperature, moisture, and cloud cover, and in turn remotely cause anomalous weather, such as cold
and snowy winters, in the subarctic and mid-latitude regions. As a consequence, changes in the hydrological
regime and its thermal conditions may occur. To investigate these changes, statistical analyses have been
conducted on various observational records and modeling output. It has been identified that permafrost has
warmed due to changes in snow cover in addition to global warming effects. The warmed permafrost was also
implicated for the alternation of seasonality, variability, and magnitude of Arctic river discharge, such as an
earlier occurrence of spring peak and an increase in the annual discharge. At the same time, the warming
climate has also increased river water temperature, resulting in a larger heat flux into the Arctic Ocean when
combined with the increased discharge. The increase in heat flux from the northern rivers may have
contributed to the recently observed sea ice melt. This presentation will review sea ice-retreat-induced
processes driving intensification of Arctic water cycle in a warming climate and evaluate robustness of the
previous findings using the latest field observations and modeling experiments.

1316
2646
Coupled Climate Simulations on the Influence of Reduced Arctic Sea Ice Cover

Tido Semmler1 (tido.semmler@awi.de), Camila Campos1, Thomas Jung1

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Climate Dynamics, Bremerhaven,
Germany

The influence of Arctic sea ice cover decline on mid-latitude climate has been studied extensively in the light of
the drastic sea ice decline of the last decades. However, most previous studies focused on the atmosphere.
Here we present results of coupled climate model sensitivity simulations with the Alfred Wegener Institute
Climate Model (AWI-CM). We artificially reduced Arctic sea ice in the coupled system with various different
methods and investigated the response of the coupled system. Atmospheric responses include an AO minus
type large-scale circulation response along with a southward shift of the mid-latitude storm track. In the ocean,
the thinner and therefore weaker Arctic sea ice cover leads to an intensified Beaufort Gyre, and with a time lag
of 50-80 years to increased outflow through the Fram Strait. Ultimately, the entire Arctic and North Atlantic
ocean circulation is intensified leading to an Atlantification of the Barents Sea / Kara Sea. Surprisingly, at least
in the investigated time scale of 150 years the influence on the Atlantic Meridional Overturning Circulation
(AMOC) is limited.

1317
435
Winter Atmospheric Response to Summer Sea Ice Loss in the CNRM-CM6 climate Model

Svenya Chripko1 (chripko@cerfacs.fr), Rym Msadek2, Emilia Sanchez-Gomez1, Laurent Terray1

1
CERFACS / CECI UMR 5318, Toulouse, France, 2CERFACS / CNRS, Toulouse, France

Continuous measurements of summer Arctic sea ice over the past four decades have revealed a large year-to-
year variability superimposed on the negative trend (Stroeve et al. 2014). Excursions from the forced trend, if
big enough, could impact mid-latitude weather and climate but the mechanisms behind such linkages remain
uncertain. In this study we investigate the winter atmospheric response to summer sea ice anomalies using
coupled model experiments based on the CNRM-CM6 high-top model recently developed for CMIP6. 40-
member ensemble simulations in which sea ice albedo is reduced from realistic values to the ocean value are
run for 15 months, yielding an ice-free state during the first summer after initialization. The atmospheric
response to sea ice loss shows a classical polar warming as well as weakened westerlies that promote a
negative NAO-like sea level pressure pattern during winter. We present how sea ice loss affects wintertime
synoptic variability by looking at the position and strength of the jet stream, the frequency of blocking events
and the sinuosity of the flow. The importance of stratospheric pathways in setting the winter atmospheric
response is also discussed. Following Screen et al. (2017), we examine the respective contribution of the
dynamical and thermodynamical part of the response to sea ice loss and link it with the occurrence of cold
extremes over Northern Europe. We assess the robustness of the response by comparing our results to
previous studies.

1318
2303
Response from Arctic Sea-ice Loss - Internal Variability vs SIC Uncertainties

Jinro Ukita1 (jukita@env.niigata-u.ac.jp), Meiji Honda2, Kazuhiro Hoshi2, Tetsu Nakamura3, Koji Yamazaki3
1
Niigata University, Faculty of Science, Niigata, Japan, 2Niigata University, Niigata, Japan, 3Hokkaido University,
Sapporo, Japan

Impacts of Arctic warming on mid-latitude climate and weather have recently been studied extensively.
Simulated winter atmospheric circulation response to the Arctic sea ice loss varies among model studies. This
makes difficult to understand an observed relationship of northern midlatitudes weather and climate with the
Arctic sea ice loss. Recognizing the differences among sea ice concentration (SIC) data due to various sources
and algorithm, it became an issue whether or not SIC uncertainties contribute to varying model results. Here
we conducted a large ensemble simulation of climate impacts of the Arctic sea ice loss using 18 sea-ice
configurations derived from 6 different datasets. Based on large resembles (n=3600) we found that a mean
response to the Arctic sea ice loss, while SST being fixed across all runs, is a negative AO-like signal. However,
sea ice anomalies in the GIN Seas appear to have a control on amplitude and details of the AO-minus response.
We propose a mechanism in which sea ice anomalies in the GIN Seas modulate otherwise a mean negative AO-
like response of the BK Seas ice loss by the formation of a blocking high with upscale energy flux from transient
eddies. The results imply that
(1) both sea ice coverage in the GIN Seas and North Atlantic SST must be critically evaluated in AGCM and/or
coupled experiments, and that
(2) possible structure embedded in variability of air-sea-ice interaction over the GIN Seas must be further
quantified.

1319
SH-6b - Connecting Polar Research Across Boundaries
21.06.2018 16:00-17:30, A Sertig

1159
Svalbard Science Forum: Added Value through Cooperation

Cecilia A. M Sandström1,2 (casa@rcn.no), Helén J. Andersen1,2, Margrete N. S. Keyser1,2, Carina Leander1,2

1
Research Council of Norway, Oslo, Norway, 2Svalbard Science Forum, Longyearbyen, Norway

The Svalbard Science Forum (SSF) promotes coordination and collaborative efforts in research activities in
Svalbard. Our objective is to contribute to the development of Svalbard as a platform for international research
cooperation in the Arctic and enforce Svalbard´s position as a key location in high Arctic research.
SSFs tasks include managing the database "Research in Svalbard" (RiS) which contains information relating to
more than 3300 Svalbard related projects. RiS is established in cooperation with the Norwegian Polar Institute
and is a valuable source for information on previous, current and future research activities in the region. SSF is
always working towards helping both researchers and management and strives to simplify registration of
research projects, bookings of logistics and applications to the Governor of Svalbard by offering all services via
one portal: the RiS database.
The SSF organises workshops and administers two funding schemes targeted towards the Svalbard research
community: Svalbard Strategic Grant and Arctic Field Grant. Svalbard Strategic Grant supports seed money for
workshops and collaborative activities where the goal is to enhance international and inter-disciplinary
cooperation and/or initiate pilot studies for planning of larger projects with relevance to Svalbard. Arctic Field
Grant support costs for fieldwork by students and/or researchers conducting field work in the area of Svalbard
and Jan Mayen.

1320
SH-6b - Connecting Polar Research Across Boundaries
21.06.2018 16:00-17:30, A Sertig

1831
The Forum of Arctic Research Operators (FARO): The First 20 Years

James Drummond1 (james.drummond@dal.ca), Piotr Glowacki2, Jennifer Mercer3, Sergey Priamikov4, Hyoung
Chul Shin5
1
Dalhousie University, Physics and Atmospheric Science, Halifax, Canada, 2Polish Academy of Sciences, Polar and
Maritime Research Department, Warsaw, Poland, 3National Science Foundation Foundation, Office of Polar
Programs, Alexandria, United States, 4Arctic and Antarctic Research Institute of Roshydromet (AARI), Sankt-
Peterburg, Russian Federation, 5Korea Polar Resarch Institute, Head, Department of International Cooperation,
Yeonsu-gu, Korea, Republic of

The Forum of Arctic Research Operators, FARO, was initiated by 24 operators from 11 countries in August 1998.
Now, in 2018, FARO has 20 member countries with Arctic research activities. It acts as an international forum
for information exchange, establishment of cooperation and development of new ideas. It aims to encourage
and optimize logistics and operational support for scientific research in the Arctic. It is closely associated with
the International Arctic Science Committee (IASC) and holds its annual meeting during Arctic Science Summit
Week (ASSW).
Over the last 20 years Arctic research has changed in many ways driven by changing needs and stunning
changes in technology, but the underlying need for collaboration and information exchange across national
boundaries remains critical to the success of research endeavours. This is particularly true when a large
infrastructure commitment is needed or many observing sites are involved.
As FARO celebrates 20 years of dialogue and information exchange, we will review the past, consider the
present and anticipate the future of international collaborative Arctic research.

1321
SH-6b - Connecting Polar Research Across Boundaries
21.06.2018 16:00-17:30, A Sertig

1636
Project and Community Management in Polar Sciences: Challenges and Opportunities

Kirstin Werner1 (kirstin.werner@awi.de), Luisa Cristini1, Renuka Badhe2, Marlen Brückner3, David Carlson4, Sven
Lidström5, Alexey K. Pavlov5, Allen Pope6, Yulia Zaika7
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2European
Polar Board, The Hague, Netherlands, 3University of Leipzig, Leipzig, Germany, 4/, Bozeman, United States,
5
Norwegian Polar Institute, Tromsø, Norway, 6International Arctic Science Committee, Akureyri, Iceland,
7
Lomonosov Moscow State University, Moscow, Russian Federation

Geoscientific research often occurs via community-instigated bursts of activity. Successful attainment of
research goals thus requires skilful scientific project management. In addition to usual matching scientific
ambitions to limiting resources and on-going coordination, polar science confronts additional challenges.
Planning and implementation of polar science projects often involve many uncertainties caused by, for
example, unpredictable weather, ocean and sea ice conditions, or large-scale logistical juggling. Large amounts
of funding are needed to procure the considerable infrastructure and technical equipment required for
interdisciplinary and international polar expeditions; or permissions to enter certain regions must be
requested. Assessment of risk is key to successful polar science project management as failure can be
extremely costly. There is thus an increasing demand to employ professional project and community managers
able to support their colleagues' operations in the field. Project managers in polar science need to have
comprehensive expertise in polar sciences themselves in order to understand requirements, structures and
funding schemes that drive interdisciplinary polar research. Polar science community managers must
understand the science and the institutional landscapes that polar researchers work within. In this
presentation, we provide an overview of specific challenges of project and community management in polar
sciences.

1322
331
Co-designing a European Research Programme and the Lessons Learned along the Way

Kristina Charlotte Baer1 (kbaer@awi.de), Nicole Biebow1, Kirsi Latola2, Annette Scheepstra3
1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, International Cooperation,
Bremerhaven, Germany, 2Thule Institute, University of Oulu, Oulu, Finland, 3Arctic Centre, University of
Groningen, Groningen, Netherlands

The EU-PolarNet consortium has been tasked by the European Commission to develop an integrated European
polar research programme, which is co-designed with the European science community, international partners
and relevant polar stakeholders. Well into its fourth year and with one and a half years left to deliver the
programme, the consortium can look back on many boundaries it has bridged - to various level of success. This
presentation aims at illustrating how the members of EU-PolarNet have navigated the challenges of
“transdisciplinarily” identifying polar issues that are of high interest to the European society, and where the
outcomes of future research could have social, economic and environmental benefits. It will give insight to how
the consortium has successfully managed to get social and natural scientists to cooperate; to its efforts of
meaningfully involve stakeholders from indigenous communities, industry and national administrations; and to
its objective to provide European policy makers with relevant information on the changes affecting both the
Arctic and the Antarctic. Within this framework, different engagement strategies will be presented, which have
led to a steep learning curve within the project and which provide valuable lessons learned for researchers
seeking to connect polar research across boundaries, including online consultations, European policy briefings
and a transdisciplinary polar white paper workshop.

1323
SH-6b - Connecting Polar Research Across Boundaries
21.06.2018 16:00-17:30, A Sertig

1108
Making the Connection: A Path to Connecting Researchers and Indigenous Peoples

Meredith LaValley1 (mlavalley@arcus.org), Carolina Behe2, John Pearce3

1
Interagency Arctic Research Policy Committee, Anchorage, United States, 2Inuit Circumpolar Council- Alaska,
Anchorage, United States, 3USGS, Anchorage, United States

The US Interagency Arctic Research Policy Committee's (IARPC) Coastal Resilience Collaboration Team (CRCT)
has made progress bridging boundaries between researchers and Indigenous Peoples. As an interagency body
with a large Federal base but functionally open to all, IARPC is in a unique position to bring Arctic community
and Indigenous voices into the discussion of Federal research initiatives. The CRCT is a case study for others
interested in bridging boundaries between researchers and Indigenous Arctic communities in order to
encourage involvement of Indigenous voices more fully in the discourse on Arctic research. This will take long-
term consistent effort. The CRCT has made progress bridging boundaries by (1) devoting time and space for
Indigenous Peoples to ask questions and become familiar with IARPC; (2) continuous outreach through
Indigenous networks, setting aside specific time for engagement, and including Indigenous speakers regularly
in meeting agendas; and (3) listening and taking action. These efforts have resulted in active Indigenous
participation in several CRCT meetings and a focus placed on Indigenous concerns. Yet, uncertainty remains
about the value to Indigenous Peoples of participation in IARPC. This presentation will demonstrate IARPC's
efforts to bridge the boundary between Federal research efforts, academia, and Indigenous people and explore
ways to make further advances. It will include the Federal, academic and Indigenous community perspective.

1324
BE-11 - Using satellite imagery to study wildlife ecology in polar regions
21.06.2018 16:00-17:30, A Seehorn

1798
A Nine-year Emperor Penguin Population Assessment from VHR Satellite Imagery

Peter Fretwell1 (ptf@bas.ac.uk), Phil Trathan2, Rod Downie3

1
British Antarctic Survey, Mapping And Geographic Information Centre, Cambridge, United Kingdom, 2British
Antarctic Survey, Ecosystems, Cambridge, United Kingdom, 3WWF, Godalming, United Kingdom

Emperor penguins are a key study species if we are to understand change in the Southern Ocean. Their
dependencies upon sea-ice as a breeding platform and as a foraging environment makes them vital for
providing insights into this key part of the marine ecosystem. However, the logistical challenges of working in
the sea-ice zone means that there are few long term studies for the species. In 2012, the first census of
emperor penguins by satellite was published, assessing the major part of the population in a single breeding
season. Satellite technology provides an insight into population state irrespective of logistical difficulties with
ground-based methods. Since 2009 we have therefore continued to task Very High Resolution (VHR) satellites
to take imagery of every colony and now, using the same methodology as our 2009 study, we report on
population change at the 16 colonies located between 0° and 90° West. This nine year study of emperor
populations shows there is high inter-annual variability at most colonies, highlighting colony movements,
colony dispersal and occasional complete breeding failures. Our goal is to relate the population data, at the
scale of a colony, group of colonies, or geographic region, to sea-ice, and other environmental conditions to
better understand the relationship of emperor penguins with their environment. This will facilitate future
models of regional population trajectories for this iconic species.

1325
1914
Range-wide Adélie Penguin Abundance from 30 Years of Landsat Satellite Imagery

Christian Che-Castaldo1 (cccweb@icloud.com), Heather J. Lynch1, Mathew R. Schwaller2

1
Stony Brook University, Ecology and Evolution, Stony Brook, United States, 2NASA/Goddard Space Science
Center, Greenbelt, United States

We developed a novel approach to incorporate the existing Landsat 4, 5, 7, and 8 imagery archive into models
of Adélie penguins (Pygoscelis adeliae) distribution and abundance in Antarctica. Building on sensor-specific
algorithms to automatically retrieve Landsat pixels classified as guano, we constructed an observation model
that accounts for satellite detection failures when converting pixels into nest abundances and their associated
observation errors. Using these satellite-derived nest abundances, we refit a recently published Bayesian
population dynamics model that includes process and observation error to all known Adélie penguin
abundance data (1982-2015) in the Antarctic, covering >95% of their population globally. By comparing models
with and without satellite data, we assess how satellite derived nest abundances reduce our uncertainty of
population trends at the CCCAMLR sub-area and regional scale. In addition, our analysis of the historical
Landsat archive finds that several newly discovered Adélie penguin colonies have been in existence at least as
far back as the late 1980s. Based on these results, we believe the Landsat-8 will allow for the automated
mapping of Adélie penguin colonies over the life of the Landsat 8 program.

1326
478
Geographic Structure of Adélie Penguin Populations

David Ainley1 (dainley@penguinscience.com), Jarrod Santora1, Michelle LaRue2

1
H.T. Harvey & Associates, Los Gatos, United States, 2University of Minnesota, Minneapolis, United States

We hypothesize that regional spatial organization of Adélie Penguin colonies is dependent on proximity and
size of adjacent colonies, availability of coastal, snow-free terrain, and proximity of polynyas and submarine
canyons. The hypothesis of Furness & Burkhead (1984) was tested previously before the availability of
extensive biologging results to quantify colony foraging areas and when assessments of colony size was a
compendium of historical counts. These critical data sets are now available following 20 years of biologging and
real-time satellite assessment of colony locations and sizes continent-wide. We collated colony counts from
Schwaller et al. (2013) and Lynch and LaRue (2014) and literature on foraging ranges to determine the relative
importance of the three factors reviewed above. Indeed, colonies occur in clusters and in general large colonies
do not exist adjacent to one another, with a zone of ~180 km being the critical distance, i.e. the outer edge of
the foraging area of large colonies. Results are relevant to assessing effects of climate and other factors on
penguin population trends, it being necessary to consider entire colony clusters rather than individual colonies.

1327
1054
Intraseasonal Variability of Remotely Sensed Penguin Colony Counts

Osama Mustafa1 (osama.mustafa@think-jena.de), Jan Esefeld2, Max Firla1, Martin Senf2, Hans-Ulrich Peter2,
Christian Pfeifer1
1
ThINK - Thuringian Institute of Sustainability and Climate Protection, Jena, Germany, 2Friedrich Schiller
University, Institute of Ecology, Jena, Germany

In recent years significant progress was made in the field of satellite based detection of penguin colonies. As
single penguin nests cannot be detected reliably, the coverage of the breeding area by guano is used as a proxy
for the population size. Due to the frequent cloud coverage at Antarctic coasts, satellite images often cannot be
acquired at the desired time related to the breeding phenology of a colony. Aim of this study was to
understand how much the extent detected the guano cover changes during the breeding season. We studied
the relation between guano coverage and breeding pair numbers in the course of the breeding seasons
2014/15, 2015/16, 2016/17 and 2017/18 in a colony of pygoscelid penguins at Ardley Island (South Shetland
Islands). Data from multitemporal remote sensing images of different satellite sensors and from drones were
collected as well as data on breeding phenology. Additionally, the colony was mapped on ground for its precise
spatial extent and to obtain the exact breeding pair numbers. The analysis of this data shows that the extent of
guano coverage in a Pygoscelid penguin colony undergoes significant intraseasonal changes. Hence, the timing
of satellite image acquisition matters for the analysis of penguin populations and should be considered during
the analysis.

1328
447
Monitoring Pack-ice Seal Populations from Space with Deep Learning

Bento Collares Gonçalves1,2 (bento.goncalves@stonybrook.edu), Heather Lynch1,2

1
Stony Brook University, Ecology and Evolution, Stony Brook, United States, 2Institute for Advanced
Computational Science, Stony Brook, United States

Antarctic pack-ice seals are a fundamental component of the Southern Ocean (SO) foodweb and, as key krill
consumers (CCAMLR, 2008), reflect the spatial and temporal distribution of krill stocks. Despite their
importance to Antarctic ecology, mapping Antarctic pack-ice seals at large scale has proven challenging. In this
talk, we demonstrate how high-resolution (sub-meter) satellite imagery in concert with automated detection
algorithms provides a feasible and cost-efficient alternative to aerial surveys. Our computational pipeline
involves two Convolutional Neural Networks (CNNs) trained using TensorFlow (Abadi et al 2016) on a set of
manually-labelled images. Our training set contained two seal target classes -
(1) seals on pack-ice, and
(2) seals on fast-ice - and three additional target classes -
(3) empty pack-ice,
(4) non-pack-ice empty substrate, and
(5) emperor penguin.
Our pipeline is > 95% accurate at classifying images when compared to manual classification of images. In
addition to being immediately applicable to ongoing international efforts to monitor pack-ice seals, this
approach can be easily adapted for other large-bodied species visible from satellite imagery. Automated
“scanning” of the SO for pack-ice seals has the potential to radically expand the scale and frequency at which
we can track their populations, and demonstrates the use of deep learning methods that have not been fully
exploited for the interpretation of high-resolution satellite imagery.

1329
1179
Environmental Factors Influencing Presence of Weddell Seal Populations

Michelle LaRue1 (larue010@umn.edu), Leo Salas2, Nadav Nur2, David Ainley3

1
University of Minnesota, Minneapolis, United States, 2Point Blue Conservation Science, Petaluma, United
States, 3HT Harvey and Associates, Los Gatos, United States

Weddell seals are an important indicator of Southern Ocean health, yet are difficult to study at regional- to
continental-scales due to their reliance on inaccessible areas of fast ice particularly in the springtime. Here, we
combined citizen science with remote sensing to, for the first time, learn about the environmental factors that
explain Weddell seal presence across Antarctic regions. We employed the crowd-sourcing platform Tomnod at
Digitalglobe to select and host high-resolution satellite imagery (VHR) of the Antarctic coastline during
November 2010 and 2011 --- images made available to volunteers, who were asked to categorize maps into
seal presence and absence. We then created a 5km grid of seal presence within the extent of fast ice per year,
and determined environmental variables that explained presence. We modeled habitat suitability of seals using
a generalized linear model (GLM). Our best models included the positive influence of cracks in the fast ice, fast
ice width, distance from the continental shelf break, and proximity to emperor penguin colonies, though
covariate influence varied across regions. Our results represent an important step toward disentangling the
factors that may influence Weddell seal populations around the Antarctic coast.

1330
CR-6d - Glaciers and Ice Sheets: from the Mountains to the Poles
21.06.2018 16:00-17:30, A Wisshorn

2061
Evolution of Djankuat Glacier (Central Caucasus) under Climate Change

Oleg Rybak1,2,3 (o.o.rybak@gmail.com), Elena Rybak1,2, Victor Popovnin4, Polina Morozova5

1
Sochi Research Centre, Sochi, Russian Federation, 2Institute of Natural and Technical Systems, Sochi, Russian
Federation, 3Vrie Universiteit Brussel, Earth System Sciences & Departement Geografie, Brussels, Belgium,
4
Lomonosov Moscow State University, Department of Geography, Moscow, Russian Federation, 5Institute of
Geography, Russian Academy of Sciences, Moscow, Russian Federation

In general, Caucasus glaciers lost approximately one-third of the area and half of the volume during the 20th
century. Prediction of their further degradation in changing environment is a challenging task because rivers
fed by glacier melt water provide up to 70% of the total river run-off in the adjacent piedmont territories.
Therefore accurate assessment of future glacial run-off is a key problem of sustainable development in the
regions where hydrological regime is dependent on glacial run-off. The problem is solved by dynamical
modeling of mountain glaciers. It is feasible to focus on several reference glaciers in the region and to further
extrapolate modeling results on the whole glaciated area.
We employ a 3D higher-order ice flow model coupled with a surface mass-balance model with treatment of
debris-covered areas to perform prognostic numerical experiments aimed at simulation of future dynamics of
the reference Djankuat Glacier. It is a typical valley glacier on the northern slope of the main Caucasus chain. It
is one of the most well studied glaciers in Russia (and, perhaps, in the World) which has been monitored during
the last fifty years.
To validate the model, we utilize observations from the nearest weather stations, as well as flow velocity, radio
echo-sounding, accumulation and ablation measurements.
Predictions until the end of the 21st century are performed by downscaling of global climate modeling results
according to various climate change scenarios.

1331
1667
Impact of Climate Change on the Mountain Glaciers of Russia

Tatiana Khromova1 (tkhromova@gmail.com), Gennady Nosenko1, Stanislav Nikitin2, Anton Muraviev2, Ludmila
Chernova2
1
Insitute of Geography, RAS, Glaciology, Moscow, Russian Federation, 2Insitute of Geography, RAS, Moscow,
Russian Federation

Glaciation exists on the territory of Russia for thousands of years. At present mountain glaciers are wide-spread
on continental part of the country where it currently covers the area of about 3,480,000 km². There are 18
glacier regions. Five out of twelve Atlantic regions (Khibiny, Urals, Putorana, Byrranga and Orulgan) are situated
within subarctic latitudes and seven (Caucasus, Altai, Kuznetsk Alatau, East Sayan, Kodar, Barguzin and Baikal
Ridges) - within mid-latitudes. Six Pacific glacier regions (Chukotka, Koryak and Kolyma Plateaus, Chersky Mts.,
Suntar-Hayata Mts., Kamchatka) are located relatively close to the Pacific Ocean within 68о - 62о N.
All recent data available indicate that during the last few decades almost all glaciers in mountain areas were
retreating that manifested in decrease of their size, volume and ice mass. The paper presents the review of
results of evaluation common factors and regional features of changes in glaciation of continental Russia based
on satellite imagery interpretations and field surveys, analysis of the USSR Glaciers Inventory, topographic
maps and aerial photographs as well as published research papers.
Acknowledgements: The paper includes the results of research project № 0148-2014-0007 of the Research
Plan of the Institute of Geography, RAS and research project supported by the Russian Geographical Society
(grant number 05/2017/RGS-RFBR).

1332
953
Heterogeneous Glacier Thinning Patterns in Karakoram-Himalaya during 2000 - 2012

Saurabh Vijay1,2 (sabvj@space.dtu.dk), Argha Banerjee3, Ramachandran Shankar4, Harish Chandra Nainwal5,
Matthias Braun2
1
Technical University of Denmark, Copenhagen, Denmark, 2Friedrich Alexander-Universität Erlangen-Nürnberg,
Institute of Geography, Erlangen, Germany, 3Indian Institute of Science Education and Research Pune, Pune,
India, 4The Institute of Mathematical Sciences, Chennai, India, 5HNB Garhwal University, Srinagar, India

Regional heterogeneity of glacier elevation and mass changes in high-mountain Asia (HMA) is well known.
However, the changes in individual glaciers located in the same region can also be different primarily due to
supraglacial features (debris-cover, ponds, lakes and ice cliffs). These features coexist on glacier ablation zones
and affect the energy available for ice melt. While few studies have reported similar thinning rates of debris-
covered and debris-free glacier areas in HMA, other studies provided evidences of debris insulation and
enhanced melt due to supraglacial water bodies and ice cliffs. In order to contribute to this ongoing scientific
debate, we derive spatially detailed glacier elevation changes in the Karakoram-Himalaya regions for the period
2000-2012. For this, we employ SRTM and TanDEM-X digital elevation models. Our regional scale altitudinal
distribution of elevation change indicates the insulating effects of debris cover, whereas the debris-covered
glaciers show two different patterns. First pattern shows maximum thinning upstream indicating the insulating
effects of thick debris-cover at lower altitudes. The second pattern shows maximum thinning at the glacier
terminus, which is most likely because of enhanced ice melt due to supraglacial water bodies and ice cliffs. To
validate our assumptions, we combine debris thickness and the extents of supraglacial ponds of Satopanth
Glacier, central Himalaya. These variables were measured in the field.

1333
951
Region-wide Mass Balance Series from Snowline Observations for Central Asia

Martina Barandun1 (martina.barandun@unifr.ch), Kathrin Naegeli1,2, Robert McNabb3, Matthias Huss1,4, Martin
Hoelzle1
1
University of Fribourg, Department of Geosciences, Fribourg, Switzerland, 2Aberystwyth University, Centre for
Glaciology, Department of Geography and Earth Sciences, Aberystwyth, United Kingdom, 3University of Oslo,
Department of Geosciences, Oslo, Norway, 4ETH Zurich, Laboratory of Hydraulics, Hydrology and Glaciology,
Zürich, Switzerland

The Tien Shan and Pamir-Alay are among the largest mountain ranges on earth, hosting more than 15000
glaciers. These glaciers are important water sources for the downstream populations. Most studies focus on
region-wide, decadal mass changes and only a few address seasonal/annual mass balance series for Central
Asia. Here, we use a mass balance model coupled with repeat snowline observations throughout the melting
seasons to infer daily mass balance series over a multi-decadal study period (2000 - 2017). By integrating
snowline observations into the mass balance modelling, we produce an improved estimate at high temporal
and spatial resolution. Snowline mapping is carried out automatically based on LandSat, ASTER and Sentinel
images. We derive spatially distributed shortwave broadband albedo for the glacierized area of each scene to
discriminate snow-covered and bare-ice surfaces using an automated, multi-step classification scheme. The
mapped snowlines are used to calibrate an accumulation and temperature-index melt model.
We validate these results through comparison with geodetic mass balances calculated from ASTER images
covering the entire region. To compute digital elevation models the MicMac ASTER (MMASTER) package, an
enhanced method to process ASTER data, was used.
In this study, we present daily mass balance series supported by sub-seasonal snowline observations of glaciers
located in the Tien Shan and Pamir-Alay, validated with region-wide geodetic mass changes.

1334
1678
Ice Flow Modeling to Constrain SMB and Ice Discharge in Patagonia

Gabriela Collao-Barrios1 (gabriela.collao@univ-grenoble-alpes.fr), Fabien Gillet-Chaulet1,2, Vincent Favier1,2,

Gino Casassa3,4, Etienne Berthier5, Ines Dussaillant5, Jeremie Mouginot6, Eric Rignot6,7, Marius Schaefer8
1
Université Grenoble Alpes, IGE Institud des Géosciences de l'Environnement, Grenoble, France, 2CNRS, IGE
Institut des Géosciences de l'Environnement, Grenoble, France, 3Universidad de Magallanes, Dirección de
Programas Antárticos y Subantárticos, Punta Arenas, Chile, 4Geoestudios, San José de Maipo, Chile, 5LEGOS,
Université ́ de Toulouse, CNRS, Toulouse, France, 6University of California, Department Earth System Science,
Irvine, United States, 7Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States,
8
Universidad Austral de Chile, Instituto de Ciencias Físicas y Matematicas, Facultad de Ciencias, Valdivia, Chile

We simulate the ice dynamics of San Rafael Glacier located in the Northern Patagonia Icefield (46.7oS/73.5oW).
The model is initialized using an inverse method to infer the basal friction coefficient from observed surface
velocity. These observations are given by previous studies based on multiple synthetic aperture radar and
optical satellite data collected between 1994 and 2014. Low values of basal shear stress (< 100 kPa) are
obtained at the glacier front and are in agreement with values from other ice streams. These values are
reasonable considering the high surface velocities in this zone (up to 7.5 km/a). The modeled ice flow results
suggest that the horizontal velocities are quasi-independent of depth in the lowest zone of the glacier.
We force the 3D full-Stokes model Elmer/Ice based on San Rafael Glacier surface mass balance (SMB) given by
previous studies. We use geodetic elevation changes during the study period (2000-2012). We analyze the
influence of different SMB distributions on the glacier dynamics, ice discharge and mass balance. The analysis
of different SMB scenarios suggests that the average SMB for the entire glacier is 0.08±0.05 Gt/a and that
previous SMB estimations for San Rafael Glacier significantly overestimated the accumulation. The ice
discharge is estimated as 0.77±0.29 Gt/a representing the main source of glacier wastage.

1335
1691
Fast Recession of Patagonian Glaciers Dynamically Modulated by Calving Activity

Andres Rivera1,2 (arivera@cecs.cl), Francisca Bown1, Daniela Carrion1, Sebastian Cisternas1, Jorge Hernandez1,
Felipe Napoleoni1, Jonathan Oberreuter1, Pablo Paredes1, Sebastian Pulgar1, Jose Andres Uribe1, Rodrigo
Zamora1
1
Centro de Estudios Científicos, Glaciology, Valdivia, Chile, 2Universidad de Chile, Geography, Santiago, Chile

The Southern Patagonia Icefield (SPI) is the second ice mass in the Southern Hemisphere outside Antarctica.
With only a couple of exceptions, all its glaciers have experienced substantial frontal retreats, high thinning
rates of the ablation zones and ice flow acceleration, a pattern that is climatically triggered, but dynamically
modulated by calving activity, since the great majority the SPI outlet glaciers are calving into tidewater fjords or
freshwater lakes, where the bathymetry is playing a critical role in controlling ice dynamics. In spite of the
importance of calving in explaining recent glacier changes, very little is known about the lake or fjord waters
nearby the main glaciers fronts, especially the bathymetry, sedimentation rates, temperatures and the
consequent sub aquatic melting. In recent years we have studied this problem by conducting several on the
ground and airborne campaigns to Glaciares Jorge Montt, O'Higgins, Chico, Viedma and Upsala. In these
surveys we have detected very deep fjords of up 600 m in areas recently occupied by glaciers, water
temperatures with contrasting vertical structures and high subaquatic melting rates. Also, we have measured
high ice velocities with satellite feature tracking techniques as well as time lapse videos. The most dramatic
event recently captured with these techniques was the collapse experienced by Glaciar O'Higgins between May
and June 2017 when it front lost 2 km2 of ice in a sequence of huge calving events.

1336
EN-3_EN-4b - Geological heritage and geo-conservation in the Polar Regions &
Conservation in the Polar Regions: Challenges, Strategies and Collaborations
21.06.2018 16:00-17:30, B Pischa

2034
Challenges Associated with the Protection of Antarctic Geological Features

Jeronimo Lopez-Martinez1 (jeronimo.lopez@uam.es), Luis Carcavilla2, Kevin Hughes3, Juan Jose Duran2
1
University Autonoma of Madrid, Faculty of Sciences, Geology and Geochemistry, Madrid, Spain, 2Geological
Survey of Spain-IGME, Madrid, Spain, 3British Antarctic Survey, Cambridge, United Kingdom

Increased visitation, easier access, infrastructure construction and collection of samples for scientific purposes
can all impact the conservation of Antarctic geological features. Therefore, there is a need to identify geological
features that merit protected and possible ways to do it. The geographic location of Antarctica, its distinctive
environmental conditions and the existing system for protection of values present a unique context for
geoconservation in comparison with other regions of the world. Therefore, an adaptation of the criteria usually
used to identify and protect geological heritage in other continents may be necessary. Given the existence of
vulnerable geosites in Antarctica, the establishment of procedures to catalog and protect the Antarctic
geological heritage may be recommended. This work analyses the components involved in the identification of
Antarctic geological values and the associated risk of possible loss of values should some features not be
identified. The advantages, difficulties and viability of identifying Antarctic geological heritage are discussed
within the framework of existing experience and global protection mechanisms, including the management of
geological heritage in existing protected areas. This work is a contribution to the ongoing work of the SCAR
Action Group on Geological Heritage and Geoconservation, which aims to recommend possible measures to
protect geological heritage in Antarctica.

1337
827
Informing Conservation Planning for Terrestrial Antarctica

Aleks Terauds1 (aleks.terauds@gmail.com)

1
Australian Antarctic Division, Antarctic Conservation and Management, Kingston, Australia

Antarctic Specially Protected Areas (ASPAs) are an important conservation mechanism of the Protocol on
Environmental Protection to the Antarctic Treaty. While most ASPAs protect values that are consistent with
those outlined in the Protocol, several recent assessments have questioned the efficacy of the current set of
ASPAs. Concomitant with the increasing scrutiny of ASPAs, and sometimes critical assessment, is a suite of
research into the provision of an evidence-base for the designation of protected areas in terrestrial Antarctica.
Much of this research is underpinned by a strong focus on more holistic approaches to protected area
designation, typically incorporating continental or large-scale data and analyses
I will provide examples of empirical, continental scale analyses for terrestrial Antarctica with a focus on two key
areas - species and ecosystems. For species I will report on i) a recent synthesis of continental scale species
distribution modelling for over 30 taxa, and ii) a snapshot of Antarctic biodiversity protection. For ecosystems,
my focus will be on i) a new assessment of Antarctic terrestrial habitats, and their potential as proxies for
biodiversity and ii) the application of the IUCN Red List of Ecosystems process to terrestrial Antarctica. I will
conclude with a summary of how these analyses, both individually and together, can contribute to the
foundation of a more integrated and systematic protected area network for terrestrial Antarctica.

1338
229
Conservation and Historical Research in the McMurdo Dry Valleys, Antarctica

Adrian Howkins1 (adrianhowkins@hotmail.com), Andrew Fountain2

1
University of Bristol, Bristol, United Kingdom, 2Portland State University, Portland, United States

With particular attention to sites of past human activity, this paper explores how historical research can inform
environmental conservation efforts in the McMurdo Dry Valleys, Antarctica. Since the late 1950s scientists have
worked in the Dry Valleys every summer season making the region one of the most intensive sites of scientific
activity anywhere on the Antarctic continent. Historical research can provide information about the location of
field camps, the duration of occupation, and the nature of activities being conducted. This historical
information has then been used to inform field observations and sampling conducted as part of the work of the
McMurdo Dry Valleys Long Term Ecological Research site to provide insights into the long-term legacy of
human activity in the McMurdo Dry Valleys. Alongside a presentation of results, this paper will also consider
the challenges and opportunities of interdisciplinary conservation work in the polar regions.

1339
564
A Multi-discipline Assessment of Foot Traffic Impacts in the McMurdo Dry Valleys

Kurt Joy1 (kurtj@waikato.ac.nz), Jayne Belnap2, Charles Lee1, Stephen Cary1

1
University of Waikato, International Centre for Terrestrial Antarctic Research, Hamilton, New Zealand, 2USGS,
Southwest Biological Science Center, Moab, United States

The McMurdo Dry Valleys are recognised as a unique environment in which landscape and biodiversity are
protected as an Antarctic specially managed area. The management plan associated with such areas allow
tourist and scientific operations to occur with the minimum of environmental impact.
Yet the magnitude and longevity of impacts associated with human foot traffic are poorly quantified, particular
in respect to the identification and mapping of soils sensitive to such impacts. Therefore, gaining a greater
understanding of how Antarctic soils respond to trampling is key to ensuring such protected areas remain as
undisturbed as possible.
We present preliminary results of a combined near-target remote sensing and soil study of geomorphological
units in the McMurdo Dry Valleys and their resilience to trampling. Using structure from motion
photogrammetry and tension infiltrometery, 140 sites in the MDV ASMA have been visited, and their response
to a range of human impacts measured. Our results show that the style of foot traffic, whether it be single or
multiple pass, plays an important role in the magnitude of physical and visual disturbance observed at these
sites.
It is hoped that this technique will identify soils in polar desert regions sensitive to disturbance. By providing
environmental managers a tool to plan science and tourist visitation into ice free areas, human impacts can be
assessed and management plans to mitigate then implemented prior to visitation.

1340
2118
Assessing Risks to Polar Ecosystems: The IUCN Red List of Ecosystems Criteria

David Keith1,2 (david.keith@unsw.edu.au), Rebecca Miller3, Emily Nicholson4, Graeme Clark5

1
University of New South Wales, Centre for Ecosystem Science, Sydney, Australia, 2NSW Office of Environment
and Heritage, Hurstville, Australia, 3IUCN Ecosystem Management Programme, Cambridge, United Kingdom,
4
Deaking University, Centre for Integrative Ecology, Mebourne, Australia, 5University of New South Wales,
Evolution and Ecology Research Centre, Sydney, Australia

Polar ecosystems face an uncertain future, with threats posed by exploitation of minerals, fossil fuels, fish and
wildlife, shipping, tourism, invasive species and climate change. Understanding the relative risks to different
ecosystems is fundamental to well-informed ecosystem management. The IUCN Red List of Ecosystems (RLE)
protocol is an international standard enabling systematic assessment of ecosystems at risk of large detrimental
changes involving loss of biodiversity and functionality. Several qualities make it well suited for application to
polar ecosystems. First, it provides an adaptable and consistent framework for risk assessment across
terrestrial, subterranean, freshwater and marine ecosystems. Second, RLE assessments may be framed to
accommodate data of varying quality and abundance. Third, the RLE assessment process mobilises experts to
compile and critically review available data, identifying gaps to support strategic investment in data acquisition.
Finally, it enables scenario analysis, given plausible alternative futures for polar environments. We will briefly
explain the assessment process and review applications to selected polar ecosystems. We will explore the
potential for developing systematic Red List assessments of polar ecosystems to support decisions about design
and management of protected areas, indigenous peoples' interests, industry development, impact assessment,
reporting against global targets and climate change mitigation and adaptation.

1341
546
Conservation Issues in the High Arctic and Pole-to-Pole Comparisons

Warwick F. Vincent1 (warwick.vincent@bio.ulaval.ca), Annick Wilmotte2

1
Université Laval, Centre d'Études Nordiques (CEN), Québec City, Canada, 2University of Liège, InBios-Centre for
Protein Engineering, Liège, Belgium

With the increasing impacts of global change, conservation activities are more important than ever to protect
and preserve high latitude environments and their biota. Efforts to date in the Arctic have focused on higher
plants and animals; for example, the Red List of threatened Arctic plants is currently limited to vascular species,
and no attention has been given to lower plant and microbial communities that are often dominant features of
far northern ecosystems. One of the largest northern conservation zones in Canada is Quttinirpaaq National
Park, a 37,775 km2 region that extends to the northern coast of Ellesmere Island, Nunavut. Studies over the last
two decades at the northern coastline of this park have shown that the land, lake and fjord environments
contain diverse microbial assemblages and functions ('environmental microbiomes') and that these are
responding strongly to the current trend of accelerated warming at these extreme high latitudes (82-83N),
leading to the extinction of certain ecosystem types. In Antarctica, increased (albeit still limited) attention is
being given to protection measures for microbial ecosystems (e.g., ASPAs and SCAR codes of conduct for
activities and research in terrestrial, geothermal and subglacial aquatic environments) and a similar level of
stewardship is needed for analogous High Arctic microbial ecosystems. A Red List of vulnerable microbiomes in
High Arctic and Antarctic environments may help inform conservation efforts.

1342
SH-3 - Historical perspectives on Arctic and Antarctic connections
21.06.2018 16:00-17:30, B Parsenn

12
C. Christensen and C. Larsen: A Comparative Analysis of Two Whaling Entrepreneurs

Bjørn L. Basberg1 (bjorn.basberg@nhh.no)

1
Norwegian School of Economics, Economics, Bergen, Norway

Chr. Christensen and C.A. Larsen are usually considered among the most important pioneers in the transfer of
whaling to Antarctic waters in the early 20th century. After a period of close cooperation during the 1890s, they
took different courses and built up their Antarctic enterprises independently of each other. While Larsen
initiated the foundation of shore station whaling at South Georgia, Christensen sent a floating factory ship to
the South Shetland Islands.
The main aim of the paper is to make a systematic comparison of the two entrepreneurs and their companies,
and focus explicitly on the considerations and decisions they made when whaling was transferred from North
to South. They obviously chose different strategies, but we will ask how different they really were in their
thinking about how Southern whaling was going to develop.
Both entrepreneurs brought along their experiences from how whaling had been undertaken in the Northern
waters. It was not obvious what organizational patterns that would work in the South, and we shall study how
familiar and new ways of organizing the industry were combined - as is often the case in entrepreneurial
innovations.

1343
20
The Transfer of Sledging Technology from the Arctic to the Antarctic

Michael Pearson1 (mike.p@ozemail.com.au)

1
Independent Scholar, Canberra, Australia

Sledges have been used by northern cultures for millennia, and were adapted and modified for exploration
expeditions through the nineteenth century. When exploration in the Antarctic began, the experience of
northern explorers was drawn on in the selection of sledges best suited to Antarctic conditions. The Nansen
sledge proved to be the most popular, and the influence of Fridtjof Nansen as a model and mentor was
immense, but other designs were also used. The paper looks at the development and the sledge for northern
exploration, and its transfer to the Antarctic in the late nineteenth and early twentieth centuries.

1344
319
Why Go So Far? The Ainu with Lt Shirase's 1910 - 1912 Japanese Antarctic Expedition

Hilary Shibata1 (jhs1001@cam.ac.uk)

1
Scott Polar Research Institute, University of Cambridge (retired), Cambridge, United Kingdom

After the successful use of ponies on Shackleton's 1907-09 Nimrod expedition, Scott wasn't the only explorer
who wanted to do likewise. In Japan Lt Shirase's original plan had also been to use horses, but when his
Antarctic Expedition finally found a ship it was much smaller than he envisaged. Horses were abandoned in
favour of sledge dogs from the Japanese sub-Arctic Prefecture of Karafuto on the island now known as Sakhalin
in the Russian Far East.
Just days before the Expedition sailed the 36 dogs and their handlers arrived to join the Japanese expedition
members in Tokyo. Yasunosuke Yamabe and Shinkichi Hanamori were from the indigenous Ainu community on
Sakhalin. The Ainu were discriminated against and impoverished by Japanese settlers who flocked to develop
the north of the country after the Meiji restoration in 1868. So why did these two men volunteer for such a
dangerous mission so far from home? Why did they go so far as to risk their lives for the glory of their
oppressors?
Little is known outside Japan about Lt Shirase's Heroic Age expedition, and even less about the Ainu who set
Antarctic dog-sledging records, but never knew it.
However, when they got back to Tokyo in 1912 Yamabe took the time to write his autobiography before
returning to his community in the far north. Starting with his earliest memories and finishing with his
experiences in Antarctica, his book gives us insights into the thoughts of a leader of an indigenous sub-Arctic
community.

1345
97
Historical Exchanges and Precedence in the Production Ice Sheet Knowledge

Jean de Pomereu1 (jean@jeandepomereu.com)

1
University of Cambridge, Scott Polar Research Institute, Cambridge, United Kingdom

The cultural and scientific history of ice sheets cannot be considered from the point of view of just Greenland
or Antarctica. Although they are located at opposite poles, both regions have played central roles in the
interconnected, but not always synchronous production of ice sheet knowledge. Through examples of surface
exploration, seismic sounding, radio echo sounding (RES) and ice coring, this paper examines the processes of
exchange and precedence that have constructed our perception and understanding of ice sheets from their
earliest physical exploration in the second half of the 19th century, up until the early 1980s. In mapping the
history of where, when and how new methodologies and technologies were deployed in the study of the
Greenland and Antarctic ice sheets, it demonstrates how ice sheet knowledge was shaped as much by scientific
priorities, as by questions of accessibility, institutional and budgetary constraints, geopolitical interests, and
individual or institutional leadership. This history also provides us with new insights into collaborative
mechanisms, directions of exchange, and polar interdependence from both an exploratory and an Earth System
perspective.

1346
1779
SCAR, IASC and the Coordination of Polar Research during the Cold War

Iqra Choudhry1,2 (iqra.choudhry@postgrad.manchester.ac.uk)

1
University of Manchester, Centre for the History of Science, Technology and Medicine, Manchester, United
Kingdom, 2Scott Polar Research Institute, University of Cambridge, SCAR Secretariat, Cambridge, United
Kingdom

Established in 1958, SCAR has a much longer history of coordinating polar research than its Arctic equivalent,
IASC, which was established decades later in 1990. By using new material from the recently opened SCAR
archive, this paper sets out to investigate the events that led to the creation of an Antarctic research
committee far earlier than one for the Arctic.
I will argue that we can understand this disparity in light of the different systems of governance existing in the
Arctic and the Antarctic in the Cold War years. So, whilst for many years polar research developed in similar
ways at both poles and often through coordinated efforts (Baker, 1982), there was only one agency devoted to
its coordination. The disparity also originates in SCAR's relationship with the Antarctic Treaty System, which
was unparalleled in the Arctic. In particular, although there are specific cases in the Arctic (e.g. Svalbard) for
which sovereignty was decided, upon on the basis of international treaties (Lüdecke, 2011), the Cold War
prevented extending such legislation to the entirety of the Arctic Circle. This meant that whilst a body
coordinating Antarctic research was needed to further strengthen the ATS, the same was not possible at the
North Pole. It is thus no surprise that the potential of coordinating research in the Arctic, and also such
research as a vehicle of international diplomacy, emerged only towards the end of the Cold War.

1347
311
Polar Art and Climate Change: Perceptual Shifts in Polar History Mediated by Art

Lisa Bloom1 (lbloom2@mindspring.com)

1
University of California, Gender and Women's Studies, Berkeley, United States

This paper draws on writing done for my book project Polar Art and the Climate Crisis: Witnessing the
Anthropocene. It brings together the Arctic and Antarctic by asking in the context of climate change how we
can imagine the shift in perception from the last spaces of heroic exploration to the first places of global
decline. And how does this shift from space to place and the heroic to the climatic specify a shift in perception
and history of both these polar regions mediated by art?
Through a discussion of the work of Judit Hersko, Annie Pootoogook, and Subhankar Banerjee on both the
Arctic and Antarctic, I examine the shift from polar fantasies of the old flag-planting heroism of explorations to
“the ends of the earth” of an earlier epoch to the new critical realities of place in the present. I focus on how
these very different polar histories as mediated by art intersect and play an enormous part in replacing the
sublime aesthetic of the polar heroic regions with an alternative aesthetic that is ant-heroic, feminist and
indigenous (Inuit) one. More especially, the paper argues that art and visual culture about the polar regions in
their most capacious aspects play a very key role in our thinking on the Anthropocene.

1348
OS-3d - Sea ice extent, properties, volume & ice shelves: modern and paleo records
21.06.2018 16:00-17:30, B Jakobshorn

2017
Arctic Sea Ice Volume Variability over the Past 40 Years

Jean-Claude Gascard1 (jga@locean-ipsl.upmc.fr), Jinlun Zhang2

1
University Pierre & Marie Curie, LOCEAN, Paris, France, 2University of Washington, Polar Science Center,
Seattle, United States

We compared Arctic sea ice volume estimated from PIOMAS (Pan-Arctic Ice-Ocean Modelling and Assimilation
System; Zhang and Rothrock 2003) and Arctic sea ice volume estimations based on observed freezing
conditions expressed as Freezing Degree Days (FDD; Harpaintner et al 2001) deduced from ERA-Interim
reanalysis (Dee et al 2011, Gao 2013) for the past 40 years. During the early 80s the amount of sea ice
calculated from FDD was significantly lower than sea ice volume produced by PIOMAS in winter. This was due
to the abundance of multiyear ice (MYI) during the early 80s that FDD could not account for. During more
recent years, PIOMAS and FDD estimations are both producing a similar amount of sea ice. This is a remarkable
result due to the disappearance of MYI during recent years. But the similarity between PIOMAS and FDD sea ice
volume winter production including the long-term trend as well as the interannual and interdecadal variability
is striking. This suggests that in the northern hemisphere as a whole, the surface air temperature driving
freezing is a major factor for the sea ice volume production in winter. Since the 1980s the ice cover has
shrunken by half in both extent and thickness, leading to a total sea ice volume reduction of 75 per cent in
summer. It should only take one or two decades at most to melt away the remaining 25% of Arctic sea ice at
the end of the summer season. Most of the Arctic Ocean would then refreeze during the following winter
season.

1349
1394
Assessing Internal Variability of Arctic Sea Ice Thickness and Volume

Alexandra Jahn1 (alexandra.jahn@colorado.edu), David M. Hall2, Kerrie Dochen3

1
University of Colorado Boulder, Atmospheric and Oceanic Sciences and INSTAAR, Boulder, United States,
2
University of Colorado Boulder, Computer Sciences, Boulder, United States, 3University of Colorado Boulder,
INSTAAR, Boulder, United States

Satellite-based remote-sensing measurements of Arctic sea ice thickness provide important new constraints on
the sea ice changes in the Arctic for the last 1.5 decades. However, ICESat and CyroSat-2 campaigns did not
overlap, they (so far) provide only a short timeseries in terms of climate records, and they have sampled an
unprecedented period of rapid sea ice decline in the Arctic. Given all of these constraints, how do we best use
these sea ice thickness products for model assessment? By analyzing the variability of sea ice thickness from
the CESM large ensemble, CMIP5 (and if possible CMIP6) models, and the satellite data in novels ways, we will
show how we can interpret these short but crucial records of Arctic sea ice change in the light of natural
variability, and which insights they allow about sea ice thickness and volume biases and their sources in climate
models.

1350
644
Spatial and Temporal Patterns of Arctic and Antarctic Sea-ice Leads, 2003 - 2016

Sascha Willmes1 (willmes@uni-trier.de), Günther Heinemann1, Fabian Reiser1

1
University Trier, Environmental Meteorology, Trier, Germany

The occurrence of leads represents a key feature of the polar sea ice cover. Leads promote the flux of sensible
and latent heat from the ocean to the cold winter atmosphere and are thereby crucial for air-sea-ice-ocean
interactions and feedbacks. We use the thermal signature of leads in the MODIS ice surface temperature
product and a subsequent cloud artefact filter to infer daily and monthly composite lead maps for the sea ice
area in both hemispheres during wintertime, 2003-2016. For the Arctic, our results highlight the marginal ice
zone in the Fram Strait and Barents Sea as the primary region for lead activity. The spatial distribution of the
average pan-Arctic lead frequencies reveals distinct patterns of predominant fracture zones along the Arctic
Boundary Current, in the Siberian sector of the Arctic Ocean as well as in the well-known polynya and fast-ice
locations. For the Antarctic, we present results for the most active sea-ice regions with respect to lead
occurrences and their inter-annual variability. Hemispheric and regional peculiarities as well as methodological
issues are discussed. Results are compared to passive-microwave lead products and the potential of this data
set for an operational high-resolution sea-ice monitoring is investigated.

1351
1853
Changes in Arctic Sea Ice Dynamics: Ice Speed, Wind, and Thickness Change

Gunnar Spreen1 (gunnar.spreen@uni-bremen.de), Ron Kwok2

1
University of Bremen, Institute of Environmental Physics, Bremen, Germany, 2Jet Propulsion Laboratory,
California Institute of Technology, Pasadena, United States

Arctic sea ice has displayed significant thinning as well as an increase in drift speed in recent decades. Both
buoy observations and satellite microwave radiometer based sea ice speed estimates show a strong increase in
the Arctic-wide sea ice drift speed for the period 1979-2007 and 1992-2009, respectively. For the satellite data,
the strongest ice speed increase was observed between 2004 and 2009. During these time periods changes in
wind speed cannot explain the ice drift speed increase overall and sea ice thinning is the main driver for the ice
speed changes. During the last ten years 2007-2016, however, the ice drift speed increase got reduced and
became spatially more variable. Now the ice and wind speed trend patterns are in better agreement, and
changes in the wind forcing can explain a larger fraction of ice drift changes. At the same time the ice thickness
is at a very low level and therefore the ice drift got more susceptible to wind forcing, which is supported by a
higher correlation between the two. The sea ice thickness, however, also did not change during recent years.
The CryoSat-2 time series since 2010 shows thin ice and high inter-annual variability but no further overall
thinning. The Arctic might have reached a new state with thin ice and higher ice drift speeds.
The MOSAiC experiment in 2019/2020 will allow to observe this new Arctic for a complete seasonal cycle and
can provide new insights to the coupling between sea ice dynamics and ice thickness.

1352
1573
A New Time Series of Sonar-based Sea-ice Draft Records from the Siberian Shelf

H. Jakob Belter1 (jbelter@awi.de), Ed Ross2, Stefan Hendricks1, Markus Janout1, Stephan Paul1, Robert Ricker1,
Thomas Krumpen1, Christian Haas1,3
1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2ASL
Environmental Sciences Inc., Victoria, Canada, 3Institute for Environmental Physics, University of Bremen,
Bremen, Germany

The Laptev Sea is an important region for net ice production and a major contributor to the Transpolar Drift
System. Seasonal and interannual ice thickness variability in this shallow shelf sea is primarily controlled by ice
dynamics. Recent studies have shown increasing sea-ice area and volume export from the Laptev Sea, which is
likely related to increasing drift speeds. This increased export accelerates summer sea-ice retreat and has far-
reaching consequences for the entire Arctic sea-ice mass balance.
In order to increase the limited knowledge about seasonal and interannual variability of sea-ice thickness on
the Laptev Sea Shelf, a set of moored Ice Profiling Sonars (IPS5, ASL Environmental Sciences Inc.) were
deployed from September 2013 to September 2015. Here we present this comprehensive sea-ice draft data set
for the first time. Observed seasonal changes in ice draft are linked to atmospheric and oceanic processes and
used to validate different satellite-based sea-ice thickness products from altimeter and radiometer missions
like CryoSat-2 and SMOS. Based on the comparison between ice thickness time series obtained from IPS and
Acoustic Doppler Current Profiler (ADCP) bottom track data, we are able to extend the ice thickness time series
even further back in time. This may provide us with the opportunity to compare our data sets to sea-ice
thickness estimates obtained from ENVISAT radar altimeter data.

1353
968
The ESA CCI Radar Altimeter Sea-ice Thickness Data Set: Some Evaluation Results

Stefan Kern1 (stefan.kern@uni-hamburg.de), Louisa Bell2, Kirill Khvorostovsky3, Stephan Paul4, Henriette
Skourup5, Stefan Hendricks4, Stein Sandven3
1
University of Hamburg, Center for Climate System Research and Sustainability (CEN), Hamburg, Germany,
2
University of Hamburg, Hamburg, Germany, 3Nansen Environmental and Remote Sensing Centre, Bergen,
Norway, 4Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany,
5
Danish Technical University, Lyngby, Denmark

Sea-ice thickness (SIT) is a key to quantify variability in the hemispheric sea-ice volume. Polar-orbiting satellite
altimeters, in operation since the early 1990ties, permit to derive hemispheric-scale SIT from elevation
measurements. Unlike for sea-ice concentration, changes in sensor characteristics and data coverage are
substantial and complicate creation of a SIT climate data record (CDR) from altimeter data. We present
evaluation results for the new ESA CCI SIT CDRs based on Envisat RA-2 (RA2) and CryoSat-2 SIRAL (CS2) satellite
radar altimeter observations. The CDRs include monthly radar freeboard, ice freeboard (FB) and SIT at 25 km
(Arctic, winter only) and 50 km (Antarctic, entire year) grid resolution. The CDR's parameters are mostly
consistent across the RA2 - CS2 sensor change. Regionally, however, FB and SIT from RA2 often exceeds that
from CS2, particularly in early winter; the Ross Sea, Antarctic, seems to be especially problematic. We find a
linear regression of 0.88x+0.03 m between Arctic CS2 SIT and airborne total (sea ice + snow) thickness,
RMSE=0.73m; regression is 0.26x+1.45 m for RA2 SIT, RMSE=0.90m. Agreement between Antarctic SIT and
airborne total thickness is worse than in the Arctic. Arctic sea-ice drafts measured by BGEP ULS and estimated
from RA2 and CS2 SIT agree within ~0.5 m depending on ice type, month and snow-depth. On average, Arctic
RA2 SIT underestimates ICESat SIT by ~0.4 m, with wide-spread differences > 1.5 m on 25 km grid scale.

1354
AC-2b - Polar meteorology, climatology and stratospheric processes
21.06.2018 16:00-17:30, C Sanada I

1964
Different Propagation Characteristics of Gravity Waves over Syowa and Davis

Masaru Kogure1 (kogure.masaru@nipr.ac.jp), Takuji Nakamura2, Yoshihiro Tomikawa2, Mitsumu K. Ejiri2,

Takanori Nishiyama2, Masaki Tsutsumi2, Michael J. Taylor3, Yucheng Zhao3, P.-Dominique Pautet3, Damian
Murphy4
1
SOKENDAI (The Graduate University for Advanced Studies), Department of Polar Science, Tokyo, Japan,
2
National Institute for Polar Research, Tokyo, Japan, 3Utah State University, Center for Atmospheric and Space
Sciences, Logan, United States, 4Australian Antarctic Division, Kingston, Australia

Source, propagation and intermittency of gravity waves are only poorly understood because of the lack of
observations. To understand their source and propagation, our group has observed gravity waves over Syowa
(69°S, 40°E), Davis (69°S, 79°E) and other stations using various instruments [Kogure et al., 2017; Matsuda et
al., 2017].
We will show the ground-based horizontal phase speed spectrum over the two stations derived from OH
imagers. We analyzed the OH airglow imager data obtained from March to October in 2016 with the M-
transform [Matsuda et al., 2014]. We analyzed the data without clouds and aurora contaminations
continuously for at least one hour. The numbers of nights with such data sets are 40 at Syowa and 55 at Davis.
The seasonal variations of the nightly mean variance were very similar with winter maximum, but the variance
over Syowa was larger than that over Davis in September. In 2016, clear sky and aurora free data were
available at both station on ten nights. Comparison of phase velocity spectrum obtained on the same night
showed similarities on only one night out of ten nights. At five nights, the spectra were different. At the other
four nights, the spectral peaks with slow westward phase velocity were commonly observed but additional
spectral peaks were found over Davis and not over Syowa. We will also present comparisons of kinetic energy
and propagation direction of gravity waves derived from MF radars, and compare with the results from OH
imagers.

1355
2105
Dynamics of Extreme Stratospheric Positive Heat Flux Events in a Simple Model

Etienne Dunn-Sigouin1 (etienne.dunn-sigouin@uib.no)

1
University of Bergen & Bjerknes Centre for Climate Research, Geophysical Institute, Bergen, Norway

Extreme stratospheric positive wave-1 heat flux events are coupled to significant variability in the polar
troposphere. In particular, the events are associated with large amplitude wave-1 geopotential height
anomalies, near surface cooling over Eurasia and warming over Northern Canada. Here a dry dynamical core is
used to investigate the dynamical mechanisms driving the events. Ensemble spectral nudging experiments are
used to isolate the roles of specific dynamical components:
i) the tropospheric wave-1,
ii) the stratospheric zonal-mean flow and
iii) the higher-order planetary wavenumbers.
Nudging tropospheric wave-1 partially reproduces the events whereas they are not reproduced when nudging
stratospheric wave-1, supporting the role of upward wave coupling from the troposphere to the stratosphere
during the events. Nudging tropospheric wave-1 and the zonal-mean flow largely reproduces the events
whereas they are not reproduced when nudging the latter alone, showing that the zonal-mean flow is a
necessary but not sufficient condition in driving the upward wave coupling. Nudging the higher-order
wavenumbers and the zonal-mean flow also largely reproduces the events. Mechanism denial experiments,
whereby one component is fixed to the climatology and others are nudged to the event evolution, show that
higher-order wavenumbers play a key role in driving the tropospheric wave-1 source during the events.

1356
760
Stratospheric Polar Jet Oscillation Events and their Surface Predictability

Daniela Domeisen1 (daniela.domeisen@env.ethz.ch), Peter Hitchcock2, Mikhail Dobrynin3, Wolfgang A. Müller4,

Johanna Baehr3
1
ETH Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland, 2Laboratoire de Météorologie
Dynamique, Ecole Polytechnique, Paris, France, 3Institute of Oceanography, Center for Earth System Research
and Sustainability (CEN), University of Hamburg, Hamburg, Germany, 4Max-Planck-Institute for Meteorology,
Hamburg, Germany

The surface impacts of stratospheric sudden warming (SSW) events tend to extend up to several weeks. It is
however unclear which mechanisms lead to the long lifetime of the surface impacts on seasonal timescales.
About half of all SSW events are associated with so-called Polar Jet Oscillation (PJO) events, which are
characterized by an extended recovery of the stratospheric flow and long-lasting temperature anomalies in the
lower stratosphere. It is here investigated if this extended recovery may in part be responsible for the extended
duration of the surface impact of SSW events (though PJO events may also occur independently of SSW events)
- and therefore a possible improvement in winter predictability in the extratropical troposphere.
The hypothesis is tested using a 30-member ensemble of seasonal hindcasts initialized on November 1st of
each year from 1979 to 2014 from the seasonal prediction system based on the Max Planck Institute Earth
System Model (MPI-ESM). Evidence is found that the ensemble provides improved statistical predictability for
both SSW and PJO events in the stratosphere. In addition, the surface impact of PJO events is well represented
in the model as compared to reanalysis, and it is significantly stronger and longer-lived than for SSW events.
Prediction skill over the North Atlantic and the Arctic is significantly enhanced during years with SSW or PJO
events.

1357
1599
Arctic System Reanalysis Provides High-resolution Accuracy for Arctic Studies

David Bromwich1 (bromwich@polarmet1.mps.ohio-state.edu), Aaron Wilson1, Lesheng Bai1, Zhiquan Liu2

1
Ohio State University, Byrd Polar and Climate Research Center, Columbus, United States, 2National Center for
Atmospheric Research (NCAR), Boulder, United States

To detect and diagnose rapid climate changes occurring in the Arctic, a state-of-the-art assessment and
monitoring tool is imperative. The Arctic System Reanalysis is a university-led reanalysis of the Greater Arctic
region using blends of the polar-optimized version of the Weather Research and Forecasting (Polar WRF) model
and WRF three-dimensional variational data assimilation system. The latest is a comprehensive integration of
the regional Arctic climate for 2000-2016 (ASRv2.1). ASRv2.1 features 15 km horizontal resolution, updated
model physics including sub-grid scale cloud fraction interaction with radiation, and a dual outer loop routine
for more accurate data assimilation. Analysis reveals superior reproduction of near-surface and tropospheric
variables. Forecast precipitation and downward radiative fluxes demonstrate significant improvements over
earlier versions. The high-resolution topography and land surface, including weekly-updated vegetation and
realistic sea-ice fraction, sea-ice thickness, and snow cover depth on sea ice, resolve fine-scale processes. This
allows in-depth investigations of topographically-forced wind events, marine cold air outbreaks, and polar lows,
all important components of the Arctic climate. Thus, ASRv2.1 permits a reconstruction of the contemporary
changes in the Arctic, complements global reanalyses, and may be used in environmental models, to verify
regional processes, or aid in the siting of future observation networks.

1358
870
How Well Do we Know the Polar Energy Budgets?

Tristan L'Ecuyer1 (tristan@aos.wisc.edu)

1
University of Wisconsin - Madison, Madison, United States

While the underlying theory behind polar feedback mechanisms has been known for a long time, current
climate models still struggle to capture observed rates of sea ice decline and ice sheet mass. This may be
explained, at least partially, by a lack of observational constraints on polar energy budgets and, in particular,
the roles clouds and precipitation play in modulating them. One solution to the challenges of making sustained,
high quality atmospheric measurements in this inhospitable region, is to turn to satellites. This presentation
will introduce a new multi-satellite, multi-model dataset for probing the state of the Arctic and Antarctic
climates and documenting its representation in predictive models. Recent satellite-based reconstructions of
the polar energy budgets and their annual cycle from this dataset will be used to demonstrate that
atmospheric reanalyses and global climate models exhibit significant biases in several key energy flows at both
poles. These biases, in turn, lead to discrepancies in both the magnitude and seasonality of the implied surface
heat storage and heat transport into polar regions from lower latitudes. The significance of these biases is
illustrated by examining their influence on ice sheet dynamics and the surface mass balance of the Greenland
Ice Sheet.

1359
1098
The Variations of Tropopause and TIL in the Arctic Region during SSW2009

Rui Wang1 (wangrui@pric.org.cn)

1
Polar Research Institute of China, Shanghai, China

The mechanism to explain the variations of tropopause and tropopause inversion layer (TIL) in the Arctic region
during a sudden stratospheric warming (SSW) in 2009 was studied with MERRA reanalysis data and
GPS/COSMIC temperature data. During the prominent SSW in 2009, the cyclonic system changed to the
anticyclonic system due to the planetary wave with wavenumber 2 (wave2). The GPS/COSMIC temperature
data showed that, during the SSW in 2009, the tropopause height in the Arctic decreased accompanied with
the tropopause temperature increase and the TIL enhancement. The variations of the tropopause and TIL were
larger in higher latitudes. A static stability analysis showed that the variations of the tropopause and TIL were
associated with the variations of the residual circulation and the static stability due to the SSW. Larger static
stability appeared in the upper stratosphere and moved downward to the narrow region just above the
tropopause. The descent of strong downward flow was faster in higher latitudes. The strong downwelling in the
stratosphere was mainly induced by wave2, which led to the tropopause height and temperature changes due
to the adiabatic heating. Around the tropopause, a pair of downwelling above the tropopause and upwelling
below the tropopause due to wave2 contributed to the enhancement of static stability in the TIL immediately
after the SSW.

1360
OS-7d - Atmosphere-Ice-Ocean interactions in the Polar Regions
21.06.2018 16:00-17:30, C Sanada II

1254
Sea-ice Properties Derived from Ice Mass-balance Buoys using Machine Learning

Louisa Tiemann1 (louisa.tiemann@awi.de), Marcel Nicolaus1, Mario Hoppmann1, Marcus Huntemann1,2,

Christian Haas1
1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany,
2
University of Bremen, Institute of Environmental Physics, Bremen, Germany

Sea ice in the polar regions determines the energy, mass and momentum exchange between the atmosphere
and the ocean. However, remoteness of the polar oceans as well as the harsh weather conditions make
observations challenging and expensive. Sea Ice Mass-balance Buoys (IMBs) are autonomous instruments,
consisting of a thermistor chain, measuring vertical temperature profiles extending from the air through snow
and sea ice into the upper ocean. So far, deriving the respective interfaces between the media to investigate
the local sea ice energy and mass balance is a crucial challenge. Here we present a semi-automatic algorithm
based on supervised machine learning techniques that is capable of reliably identifying the interfaces between
atmosphere, snow, sea ice and ocean from IMB temperature and heating data. We use a random forest
classifier, based on a number of subsets of the training set to fit an ensemble of decision trees. The
classification is achieved by averaging over the ensemble and the algorithm is applied to IMBs deployed in the
Arctic and Antarctic since 2012. Our results show time series of sea-ice growth/melt, snow
accumulation/ablation, snow-ice formation and thermal conductivities. We discuss the time series and the
spatial variability in order to improve our understanding of seasonal variations in the energy and mass budgets
of sea ice and its impact on the climate system.

1361
2207
Sonar Probing of Ice Thickness and Ice-related Climate Feedbacks

Peter Wadhams1 (pw11@cam.ac.uk)

1
University of Cambridge, Applied Maths and Theoretical Physics, Cambridge, United Kingdom

Arctic sea ice retreat has been observable since 1950 and is reaching a stage where the summer ice cover will
soon disappear. The rapidity of change was masked because the decline in area (easily mapped by satellite)
was accompanied by a rapid decrease in mean thickness (less easily mapped by submarine sonar). We begin by
surveying how sonic range probing of the ice underside has developed, from use in wave recording to single-
beam then multi-beam mapping. We go on to survey the implications of the observed volume decrease, since
the retreat has feedbacks on other aspects of the climate system. The feedbacks involve
(1) albedo - as sea ice and snow on land retreat, the average albedo of the Earth is reduced, now equivalent to
adding 50% to the emissions of CO2;
(2) sea level - the retreating sea ice warms the atmosphere around Greenland in summer, speeding its melt
rate and increasing the rate of global sea level rise;
(3) methane - increasing quantities are being emitted from the Russian continental shelves, and this could
accelerate into a methane pulse with major climate implications;
(4) weather - extreme weather changes relate to the ice retreat and these threaten global food supply;
(5) weakening of the Atlantic thermohaline circulation due to a loss of sea ice from the Greenland Sea, which
reduces the warming rate of Europe while increasing that of the tropical Atlantic.
We estimate the magnitudes of the five feedbacks and their total impact on the global climate.

1362
785
PIPERS: Sea Ice Thickness Redistribution from Early Winter Deformation

M. Jeffrey Mei1,2 (mjmei@mit.edu), Ted Maksym2, Arnold Song3, Matthew Parno3, Guy Williams4, Hanumant
Singh5, Jeffrey Anderson6, Alek Razdan5
1
Massachusetts Institute of Technology, Mechanical Engineering, Cambridge, United States, 2Woods Hole
Oceanographic Institution, Applied Ocean Science & Engineering, Woods Hole, United States, 3Cold Regions
Research and Engineering Lab, Hanover, United States, 4University of Tasmania, Hobart, Australia,
5
Northeastern University, Boston, United States, 6Nature Imagery, Portland, United States

The morphology of sea ice deformation is important for the representation of deformation in sea ice models
and interpreting satellite observations of ice thickness. Deformation features in the Antarctic differ from those
in the Arctic, yet we have limited understanding of how deformation drives ice morphology. In this study, sea
ice deformation is characterized and quantified with relevant statistics using high-resolution three-dimensional
observations of ridges collected during the 2017 PIPERS cruise in the Ross Sea in early winter. These
observations primarily consist of ice draft from multibeam sonar on an autonomous underwater vehicle (AUV)
and are supplemented with terrestrial lidar for surface elevation and manual MagnaProbe for snow depth. We
quantify ridge statistics such as roughness, symmetry (skew) and linearity using computer vision techniques
and model the thickness distribution using generalized extreme value distributions. To understand how
deformation processes determine these morphologies, ridge spatial statistics are verified using a three-
dimensional Discrete Element Model, which also allows for investigating the effects of different initial floe
statistics on resultant ridge morphology. This yields improved estimates of sea ice thickness redistribution due
to ridging that will ultimately improve sea ice dynamic models, algorithms for remote sensing of ice thickness
distribution and parameterizations of ice-ocean drag.

1363
1174
Observations of Sea-ice Mediated Upwelling and Downwelling in the Beaufort Sea

Gianluca Meneghello1 (gianluca.meneghello@gmail.com), John Marshall1, Mary-Louise Timmermans2, Jeffery

Scott1
1
MIT, Cambridge, United States, 2Yale, New Haven, United States

We present observational estimates of Ekman pumping in the Beaufort Gyre region. Averaged over the Canada
Basin, our results show a 2003-2012 average of 2.5m/y downward with strong seasonal and interannual
variability superimposed: monthly and yearly means range from 30m/y downward to 10m/y upward. A clear
seasonal cycle is evident with intense downwelling in autumn and upwelling during the winter months.
Wintertime upwelling is associated with friction between the large scale Beaufort Gyre ocean circulation and
the surface ice pack, and contrasts with previous estimates of year-long downwelling; as a consequence, the
yearly cumulative Ekman pumping over the gyre is significantly reduced. The spatial distribution of Ekman
pumping is modified as well, with the Beaufort Gyre region showing alternating, moderate upwelling and
downwelling, while a more intense, year-long downwelling averaging 17.5m/y is identified in the northern
Chukchi Sea region. Implications of our results for understanding Arctic Ocean dynamics and change are
discussed.

1364
1549
The Impacts of El Niño on the Observed Sea Ice Budget of West Antarctica

James Pope1 (japope@bas.ac.uk), Paul Holland1, Andrew Orr1, Gareth Marshall1, Tony Phillips1
1
British Antarctic Survey, Cambridge, United Kingdom

We assess the impact of El Niño induced wind changes on seasonal West Antarctic sea ice concentrations using
reanalysis data and sea ice observations. A novel ice budget analysis reveals that in autumn a previously
identified east-west dipole of sea ice concentration anomalies is formed by dynamic and thermodynamic
processes in response to El Niño generated circulation changes. The dipole features decreased (increased)
concentration in the Ross Sea (Amundsen and Bellingshausen Seas). Thermodynamic processes and feedbacks
make a substantial contribution to ice anomalies in all seasons. The eastward propagation of this anomaly is
partly driven by mean sea ice drift rather than anomalous winds. Our results demonstrate that linkages
between sea ice anomalies and atmospheric variability are highly nonlocal in space and time. Therefore, we
assert that caution should be applied when interpreting the results of studies that attribute sea ice changes
without accounting for such temporally- and spatially-remote linkages.

1365
1290
Cooling and Freshening of the Southeast Pacific Driven by Sea Ice Export

Ivana Cerovecki1 (icerovecki@ucsd.edu), Andrew Meijers2, Matthew Mazloff1, Sarah Gille1, Veronica Tamistt1
1
Scripps Institution of Oceanography, University of California, San Diego, CA, United States, 2British Antarctic
Survey, Cambridge, United Kingdom

Strong cooling and freshening was observed in the southeast Pacific in 2008-2010 and 1998-2000, affecting
both the Southeast Pacific Subantarctic Mode Water (SEPSAMW) and the Antarctic Intermediate Water (AAIW)
density ranges. Both 1998 and 2008 experienced an exceptionally low Amundsen Sea Low, a strong positive
Southern Annular Mode, and a negative El Niño Southern Oscillation. In both years two varieties of SEPSAMW
were formed: a colder, fresher, denser variety in the immediate vicinity of the Subantarctic Front (SAF), and a
warmer, saltier, lighter variety further north. Results of analyses of an ocean-sea ice data-assimilating Southern
Ocean State Estimate (SOSE) and other products suggests that this bimodal structure of SEPSAMW is associated
with strong zonal wind forcing in the vicinity of the SAF and sea ice influences further poleward. In both 1998
and 2008, anomalously strong meridional winds drove strong sea ice export from the Ross Sea. The sea ice melt
propagated eastward in the subsequent two year time period, causing destruction of water in the AAIW and
SEPSAMW density ranges. Particles released along the sea ice edge in 2008 and advected by SOSE velocities
confirmed that on timescales up to three years, the strongest influence on the AAIW and SEPSAMW comes
from water that originates in the Ross Sea. Thus strong sea ice export from the Ross Sea can play an important
role in modifying the AAIW and the SEPSAMW properties during subsequent years.

1366
Poster & Beer II
21.06.2018 17:30-18:30, Foyer

Thu_1_AC-3_283
The Effect of Wind Direction on air Temperature Variability on James Ross Island

Klára Ambrožová1, Kamil Láska1 (laska@sci.muni.cz), Filip Hrbáček1, Jan Kavan1, Jakub Ondruch1
1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic

The western and eastern parts of the Antarctic Peninsula are quite different, especially due to frequent
atmospheric blocking or foehn events induced by the mountains. In order to study the influence of topographic
modification on atmospheric circulation and its impact on cryosphere, the air temperature measurements from
the northern part of James Ross Island were evaluated with respect to surface wind direction. Meteorological
parameters from 2013-2016 were observed in one-hour interval by multiple automatic weather stations, while
1000-hPa pressure level data from the ERA-Interim reanalysis were used to assess the surface wind effect.
Furthermore, near-surface temperature lapse rates were calculated and linked to boundary layer processes.
The results were analysed with respect to topographic conditions, separately for ice-free parts and glaciers of
the Ulu Peninsula. The seasonal and inter-annual variation of the selected near-surface atmospheric variables
was emphasized in the study.

1367
Thu_2_AC-3_505
A Satellite Perspective of Summer Warm-air Advection over Melting Sea Ice

Cheng You1 (cheng.you@misu.su.se), Michael Tjernström1, Abhay Devasthale2

1
Stockholm University, Department of Meteorology, Stockholm, Sweden, 2Swedish Meteorological and
Hydrological InstituteMeteorological and Hydrological Institute, Research Department, Remote Sensing Group,
Norrköping, Sweden

Some very special conditions apply in summer warm-air intrusions as compared to in winter. As long as
significant melting sea ice is present, surface temperature must remain at the melting point, in contrast to
winter when the surface temperature can respond to changes in the heat surface fluxes. Strong surface
inversion forms often accompanied by fog and the high temperature of the fog and its large longwave
emissivity brings positive net longwave surface radiation, while the inversion conditions bring a downward
turbulent heat flux. Studies based on data from the 2014 Arctic Clouds in Summer Experiment (ACSE), on the
Swedish icebreaker Oden, indicate that while low clouds and fog reduce the net solar radiation at the surface,
the combined effect on all terms in the surface energy budget leads to additional heat flux to the surface in
these conditions; the net outgoing longwave radiation at the top of the atmosphere also increases. We
hypothesize that cloud-top cooling and cloud-induced along with surface mixing eventually erodes the surface
inversion downstream and the boundary layer transforms into the often-observed well-mixed cloud-capped
boundary layer; the extra surface energy is concentrated to a zone inside the ice edge. To evaluate the
hypothesis, and to determine the time/length scales involved in the transition, we use a combination of
reanalysis, back trajectories and satellite products to extend the view from the local column observations from
the icebreaker.

1368
Thu_3_AC-3_508
Exploring Air Mass Origin in the Arctic for Clear and Cloudy Boundary Layers

Syed Mubashshir Ali1,2 (syedmuba@uni-bremen.de), Felix Pithan2

1
University of Bremen, Institute of Environmental Physics, Bremen, Germany, 2Alfred Wegener Institute,
Helmholtz Centre for Polar and Marine Research, Climate Dynamics, Bremerhaven, Germany

The observations from the Surface Heat Budget of the Arctic (SHEBA) campaign revealed the presence of two
preferred states of wintertime Arctic boundary layer, a radiatively clear state and a cloudy state with low-level
mixed-phase clouds (Persson et al. 2002). Both of these states have distinct impacts on radiative and turbulent
heat fluxes of the Arctic boundary layer. The clear state is being characterized by strong longwave cooling
under the clear sky or ice clouds and, the cloudy state by little to no surface longwave cooling (Stramler et al.,
2011). However, most climate models lack a realistic representation of the cloudy state of the Arctic boundary
layer (Pithan et al 2013).
We examine what leads to the formation of these boundary layers. In order to study that, we calculate the
back trajectories from the radiosondes data obtained from the SHEBA Ice Camp. For the calculation of these
trajectories, we use the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) by NOAA Air
Resource Laboratory.The various back trajectories provide us with an overall evaluation of the air mass
formation in the Arctic boundary layer. Furthermore, the case studies can be used to design Single Column
Experiments and Large-Eddy Simulation Models to improve the biases in climate models representing the
Arctic boundary layer. It will also help us to inform the setup of the future observational campaigns in the
context of YOPP and MOSAIC.

1369
Thu_4_AC-3_698
Application of Controlled Meteorological Balloons in Polar Regions

Lars Robert Hole1 (lrh@met.no), Tjarda Roberts2, Paul Voss3, Timo Vihma4
1
Norwegian Meteorological Institute, Bergen, Norway, 2LPC2E/CNRS, Orleans, France, 3Smith College,
Northampton, United States, 4Finnish Meteorological Institute, Helsinki, Finland

CMET balloons can fly for multiple days in the lower troposphere while changing altitude on demand. Around
20 CMET balloons have been launched from Svalbard and Antarctica during 2010-2017. In May 2011, one
balloon launched from Ny-Ålesund, Svalbard achieved a suite of 18 continuous soundings that probed the
Arctic marine boundary layer (ABL) over a period of more than 10h. Profiles were compared to model output
from ECMWF Era-Interim reanalysis (ERA-I) and to a high-resolution (15 km) Arctic System Reanalysis (ASR)
product. To the east of Svalbard over sea ice, the CMET observed a stable ABL profile with a temperature
inversion that was reproduced by ASR but not captured by ERA-I.
In January 2013, two balloons were launched from the Aboa station in Dronning Maud Land, Antarctica. They
were airborne for 60 and 106 hours with trajectory lengths of 885.8 km and 2367.4 km, respectively. The most
interesting feature deteced was a mesoscale anticyclone over the Weddell Sea and the coastal zone, which was
reproduced by the WRF model with reduced intensity. Another balloon launched from Aboa in January 2017
was airborne for 157 hours and made a trans-Antarctic flight before it landed in the Ross Sea. It made multiple
deep soundings to the surface over the interior of the continent.
The results above demonstrate that CMET balloons are a valuable approach for profiling the free atmosphere
and boundary layer in remote regions such as Polar Regions.

1370
Thu_5_AC-3_775
Annual Variability of the Temperature Profile at the THAAO Observatory

Giandomenico Pace1 (giandomenico.pace@enea.it), Tatiana Di Iorio1, Alcide di Sarra1, Antonio Iaccarino1,

Daniela Meloni1, Gabriele Mevi2,3, Giovanni Muscari2, Marco Cacciani4, Nis Jepsen5
1
ENEA, Laboratory for Observations and Analyses of Earth and Climate, Rome, Italy, 2Istituto Nazionale di
Geofisica e Vulcanologia, Rome, Italy, 3Roma Tre University, Mathematics and Physics Department, Rome, Italy,
4
University of Rome 'La Sapienza', Physics Department, Rome, Italy, 5Danish Meteorological Institute,
Copenhagen, Denmark

Surface Temperature Inversions (STIs) are typical features of the polar atmosphere. They are principally due to
a) the imbalance between outgoing longwave radiation from the surface and downwelling shortwave and
longwave radiation, leading to a surface cooling, and/or b) the advection of warm air over a cooler surface
layer. Recently, it has been suggested that STIs play an important role in the Arctic winter warming damping
the infrared cooling of the lower atmosphere, and thus constituting a positive warming feedback contributing
to the Artic Amplification.
The present study shows and discusses the variability of the vertical temperature profile retrieved by a RPG
Humidity And Temperature PROfiler (HATPRO-G2) installed at the Thule High Arctic Atmospheric Observatory
(THAAO, 76.5° N, 68.8° W, http://www.thuleatmos-it.it/, Northern Greenland) in July 2016. A statistical
retrieval is used to estimate the temperature profile from the brightness temperatures measured by HATPRO.
The retrieval accuracy in the Arctic environment is studied by comparing the obtained profiles with
radiosondes launched in summer and wintertime.
The temperature evolution and vertical structure of the atmosphere at THAOO in the period July 2016-March
2018 is discusses together with the occurrence and intensity of STIs. The relationship between and STIs and
cloud occurrence is also investigated.

1371
Thu_6_AC-3_1245
Observations and the Source Investigations of Boundary Layer BrO at Ny-Ålesund

Yuhan Luo1 (yhluo@aiofm.ac.cn), Fuqi Si1, Haijin Zhou1, Yi Liu2, Wenqing Liu1
1
Chinese Academy of Sciences, Hefei Institutes of Physical Science, Hefei, China, 2University of Science and
Technology of China, Hefei, China

Bromine monoxide is a reactive halogen species which has profound impact on the chemistry of the
tropospheric polar boundary layer. A considerable challenge for understanding enhanced BrO and the
associated ODEs is the difficulty of real-time observations. In this study, we found a typical process of enhanced
bromine and depleted ozone in Ny-Ålesund boundary layer using ground based differential optical absorption
spectroscopy (DOAS) techniques in late April 2015. BrO was observed as high as 6×1014 molecular cm-2, while
the in-situ ozone and gaseous mercury reduced by 85% and 90% separately at the same period. The largest BrO
column densities were found at elevation angle of 2° above the horizon. The vertical distribution of BrO was
present at 0.5-1km layer using radiative transfer model simulation. Although the HYSPLIT model and satellite
data showed air masses coming from the High Arctic area, which was enriched in bromine, the sea ice in the
Kings Bay area, occurred only for a short period exactly during the enhancement, was considered as the main
local source of this bromine enhancement event. The key role of bromine on the atmospheric oxidation and
the ecosystem will be further discussed.

1372
Thu_7_AC-3_1346
Multi-scale Modeling and Measurements of Arctic Clouds

Ben Hillman1 (bhillma@sandia.gov), Dari Dexheimer1, Erika Roesler1

1
Sandia National Laboratories, Albuquerque, United States

Arctic clouds are important to the radiative budget, but they are difficult to represent in atmospheric general
circulation models (AGCMs). Three approaches to improving Arctic clouds in models are presented. First, a
cloud system resolving model (CSRM) is embedded into each gridcell of a traditional AGCM to explicitly
simulate more cloud processes. Second, a variable resolution AGCM is used to understand modeled cloud
response to increasing horizontal resolution. Third, stand-alone large eddy simulations (LES) are used to
explicitly resolve cloud processes. The AGCM simulations have a negative low cloud amount bias when
compared with multi-year satellite retrievals. The Atmospheric Radiation Measurement program's (ARM) third
ARM Mobile Facility (AMF3) and the restricted airspace associated with it at Oliktok Point, Alaska, are used to
operate a tethered balloon system (TBS). Sensors deployed on the TBS are compared with the ground-based
instrumentation also at the site, and with the AGCM and LES simulations previously described. Sandia National
Laboratories is a multimission laboratory managed and operated by National Technology and Engineering
Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of
Energy's National Nuclear Security Administration under contract DE-NA0003525. SAND2017-12294 A.

1373
Thu_8_AC-3_1393
The Canadian Arctic Weather Science Project: An Overview

Stella Melo1 (stella.melo@canada.ca), Zen Mariani1, Gabrielle Gascon2, Barbara Casati3, William Burrows2,
Armin Dehghan1, Paul Joe1, David Hudak1
1
Environment & Climate Change Canada, Science and Technology, Meteorological Research Division, Toronto,
Canada, 2Environment & Climate Change Canada, Meteorological Services of Canada, Edmonton, Canada,
3
Environment & Climate Change Canada, Science and Technology, Meteorological Research Division, Montreal,
Canada

ECCC established two supersites at western and Eastern Arctic for understanding weather and climate, testing
suitable observation technology and support validation of space-borne observations of wind, aerosols, cloud
and precipitation from ADM-Aeolus, EarthCARE and Global Precipitation Mission. Winds can be localized and
impact the distribution of snow and ice affecting human activity and navigation. Aerosols from mid-latitudes
can impact the cloud/precipitation distribution affecting the radiation balance and resulting in intensification of
cold air outbreaks that affect mid-latitudes. The weather in Whitehorse is at the confluence of the Pacific
Ocean, the Western Cordillera, the North American continent and the Arctic Ocean and is challenge to predict.
Iqaluit is at the center of different Arctic large scale weather systems and Eastern seaboard of North America.
Observations at the Iqaluit (64oN, 69oW) revealed high frequency (40% daily occurrence) of multiple (4-10)
wind layers (0.2 to 4.4 km in depth) from surface to 7.2 km. These stratified wind layers are visible as shifting
wind directions with height in Doppler lidar and dual-polarization Ka-band radar range-height scans and in the
Doppler lidar and radiosonde data. Analysis showed that NWP surface variables were inaccurately predicted
during wind layer events. Surface-based inversions can exceed 10 K with depths as large as 1 km the model
appears to underestimate their intensity or fail to predict any inversion.

1374
Thu_9_AC-3_1709
The Surface wind Circulation over a Complex Terrain of Central Spitsbergen

Kamil Láska1,2 (laska@sci.muni.cz), Zuzana Chládová2,3, Jiří Hošek3, Josef Elster2

1
Masaryk University, Brno, Czech Republic, 2University of South Bohemia, České Budějovice, Czech Republic,
3
Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic

Better understanding of the Svalbard climate conditions requires a comprehensive knowledge of atmospheric
boundary-layer processes including the effects of local topography and ground surface properties. The
atmospheric boundary layer often includes large vertical gradients in air temperature, humidity as well as wind
speed, which is mainly generated by a complex interaction of a large-scale circulation and small-scale
processes. The aim of the study is to 1) compare surface wind measurements and reanalysed low-level
geostrophic winds in the period of 2013-2016, and 2) evaluate a role of topography on spatiotemporal
variability of winds within a fjord. For studying near-surface wind characteristics in central Spitsbergen
(Billefjorden area), we chose three sites differing in terrain elevation and local surface properties: Petuniabukta
terrace (15 m a.s.l.), Mimerbukta terrace (20 a.s.l.), and the top of Mumien Peak (773 m a.s.l.). Patterns of
atmospheric circulation were identified using 1000-, 925- and 850-hPa geopotential heights and geostrophic
winds based on the ERA5 reanalysis data provided by the ECMWF. Our results indicate that a large-scale flow
was often modified by channelling and drainage effects accompanied by an increase in wind speed and wind
direction frequency at the coastal sites. On the other hand, the near-surface wind at the top of the Mumien
Peak was most similar to the geostrophic wind, irrespective of the circulation type.

1375
Thu_10_AC-3_1742
Bulk Flux Parametrization for the Stable Atmospheric Surface Layer over Sea Ice

Vladimir M. Gryanik1,2, Christof Lüpkes3 (christof.luepkes@awi.de)

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Climate Sciences, Bremerhaven,
Germany, 2A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russian
Federation, 3Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Climate Sciences,
Schiffdorf, Germany

In climate and weather prediction models the near-surface turbulent fluxes of heat and momentum and
related transfer coefficients are parameterized on the basis of Monin Obukhov similarity theory (MOST). Its
application requires an iterative solution of the MOST equations. To avoid iteration many models determine
the transfer coefficients using the Louis method relating the stability parameter ζ=z/L (L is the Obukhov length
and z is height) to the bulk Richardson (Rib) number. However, the presently used methods are valid only for
larger surface roughness and weaker stability than observed over the polar oceans. In contrast to the popular
methods of polynomial fitting we propose an approximate solution that results in ζ as a function of Rib and of
the surface roughness. For the stability functions we use those based on SHEBA data (Grachev et al. 2007) and
thus on the most modern data over sea ice. Using the new ζ approximation, bulk transfer coefficients for
momentum and heat are obtained without iteration depending on stability and surface roughness. It is shown
that these coefficients reproduce the coefficients obtained by the classical, iteration based solution of the
MOST equations with a mean accuracy of 5 % for Rib between 0 and 0.3 for a large range of surface roughness.
At large Rib the new bulk transfer coefficients are much smaller than those currently used. The new non-
iterative parametrization can be easily implemented in climate and weather forecast models.

1376
Thu_11_AC-3_2010
Boundary-layer Structure during Super-cooled Fog Events at Summit, Greenland

Christopher Cox1,2 (christopher.j.cox@noaa.gov), William Neff1,2

1
Cooperative Institute for Research in Environmental Sciences, Boulder, United States, 2NOAA/Earth System
Research Laboratory/PSD, Boulder, United States

Persistent stable stratification of the boundary layer at Summit, Greenland (72.58ºN, 38.48ºW, 3210 masl)
drives the development of liquid fogs by surface radiative cooling. These fogs are most common from June
through October and are super-cooled, typically ~ -20 ºC. We present case studies from June 16th and 23rd,
2013 that are associated with the diurnal development of surface-based temperature inversions during clear
skies, each lasting ~10 hours. We analyze measurements collected by meteorological sensors, cloud particle
probes, and isotopic vapor composition from a 46 m tower, as well as a nearby high resolution minisodar and
other remote sensors. The common driving mechanism and the typical transition in the boundary-layer from
stable stratification to a shallow convective layer led to similarities between the cases in the evolution of the
fog microphysics. There were important differences too, such as in the liquid water path, which was larger on
the 16th and suppressed the surface cooling. We explore how these differences may be related the boundary-
layer structure, including Kelvin-Helmholtz instability identified on the 16th while the liquid water path was
high, and transient disturbances of the boundary layer at 10 to 20 minute intervals during the 22nd and 23rd.
Improved understanding of the physical processes that govern fogs will inform on the importance their
representation in the models used for ice sheet surface energy and mass balance projections.

1377
Thu_12_AC-3_2071
The Role of Atmospheric Rivers and Summer Surface Melting in Greenland

William Neff1,2 (william.neff@noaa.gov), Mathew Shupe1,2, Gilbert P. Compo1,2

1
NOAA/Physical Sciences Division, Boulder, United States, 2University of Colorado, CIRES, Boulder, United States

Past work implicated atmospheric rivers (ARs) in the melting of the surface of the Greenland Ice Sheet (GIS) in
2012 and 1889 (Neff et al. 2014). In this work we examine the degree of melt along the western slopes of the
GIS from 2000 to 2012. We compare three different reanalyses (ERA-I, NCEP, and 20CR) in their ability to detect
the northward transport of moisture to the west of the GIS and then compare such events with the degree of
melt for the period June-August (available through NSIDC). We assessed the three reanalyses at four locations
to the west of the GIS, between 50N and 66N, comparing wind speed and direction at 850 hPa and total
integrated water vapor (IWV). Events were detected using thresholding of wind speed and IWV at 60N and
66N. These events were compared with the fraction of melt observed in two geographical regions west of the
highest topography: from -55W to -43W and south to north 63N to 68N and 68N to 73N. Two case studies will
also be presented: One will be an AR on 18 August 2000 with extensive melt inland and temperatures just
below freezing at Summit Station and one on 24 August 2011 that produced significant rain along the coastal
glaciers (Doyle et al. 2015) with more limited melt inland. We will also explore the potential of identifying the
impact of ARs on the GIS using the 20CR back to 1880.

1378
Thu_13_AC-3_2074
The Meteorology and Chemistry of High NO Concentrations at the South Pole

William Neff1,2 (william.neff@noaa.gov), James Crawford3, Marty Buhr4, John Nicovich5, Gao Chen3, Douglas
Davis5
1
University of Colorado, CIRES, Boulder, United States, 2NOAA/Physical Sciences Division, Boulder, United States,
3
NASA Langley Research Center, Science Directorate, Hampton, United States, 4Air Quality Design, Golden,
United States, 5Georgia Institute of Technology, Earth & Atmospheric Sciences, Atlanta, United States

This presentation summarizes key results from a recent paper submitted to ACPD (doi.org/10.5194/acp-2017-
812). Our study examined the effect of the seasonal cycle in meteorology from November through December
and the effect of stratospheric ozone depletion on the photochemical production of nitrogen oxide (NO) from
nitrate in the snow at the South Pole. We found a systematic evolution of the large-scale wind system at 300
hPa over the ice sheet from winter to summer that controls the surface boundary layer and its effect on NO:
Initially in Early Spring (Days 280-310) the transport of warm air and clouds over West Antarctica dominates the
environment over the South Pole; In Late Spring (Days 310-340), of significance to NO, the winds at 300-hPa
exhibit a bimodal behavior alternating between NW and SE; In Early Summer (Days 340-375), the flow aloft is
dominated by winds from the Weddell Sea. During Late Spring, winds aloft from the SE are strongly associated
with clear skies, shallow stable boundary layers, and light surface winds from the east: it is under these
conditions that the highest NO occurs. We also found that ozone depletion which now extends into late
November- early December coincides with optimum conditions (clear skies, strong surface temperature
inversions, and light winds) for high concentrations of NO to accumulate at the surface.

1379
Thu_14_AC-3_2584
An Evaluation of the WRF Model for the Antarctic Peninsula

Elcin Tan1 (elcin.tan@itu.edu.tr)

1
Istanbul Technical University, Department of Meteorological Engineering, Istanbul, Turkey

The near-surface wind field of the Antarctica is determined by Katabatic winds which is originated by the
occurrences of the strong temperature inversion zone, whose intensity is driven by the temperature gradient
between surface and the atmospheric layer above it. Numerical weather prediction studies show that large and
mesoscale circulation pattern can be captured with reasonable accuracy by having small biases (Turner et al,
1996; Van Den Broeke, 1997; Wilson et al., 2012). In this study, The Polar WRF model is used to simulate the
atmospheric conditions of selected days of 2016 for each season. The model is configured with three nested
domains to provide high-resolution model outputs which are compared to in situ observations of the Antarctic
Peninsula. The finest domain resolution of the model is 1 km. The model offers multiple physics options for
microphysics, radiation, cumulus parameterization, boundary layer, snow surface physics and sea-ice
treatment. MODIS land use/cover data is adapted to the model to determine the snow surface characteristics
of the model more accurate. The WRF configuration is designed to have 45 terrain-following vertical levels.
Initial and boundary conditions are obtained from NCEP/NCAR Reanalysis data. The results of the WRF model
are compared to the available temperature and wind data of automatic weather stations on the Antarctic
peninsula to discuss katabatic wind patterns and their relations with temperature gradients.

1380
Thu_15_AC-3_2662
Regional Analyses of the Antarctic Atmospheric Boundary Layer during Concordiasi

Manisha Ganeshan1 (mganeshan@usra.edu), Yuekui Yang2

1
Goddard Earth Sciences Technology and Research Studies and Investigations, USRA, Greenbelt, United States,
2
Goddard Space Flight Center, National Aeronautics and Space Administration, Climate and Radiation
Laboratory, Greenbelt, United States

This study investigates characteristics of the atmospheric boundary layer (ABL) observed over continental
Antarctica during the Concordiasi campaign in spring 2010. The Concordiasi dropsondes are high-resolution
atmospheric profile measurements, valuable for studying the ABL. The surface air temperature is in good
agreement with collocated 2 m air temperature from the Antarctic Mesoscale Prediction System (AMPS).
Regional analyses show that the ABL is often well-mixed in the west and southeast regions of the continent.
Increased temperature and wind speed shear associated with synoptic disturbances is the likely cause for the
high frequency of well-mixed ABLs in West Antarctica. Higher temperatures and wind speed shear are also
associated with well-mixed ABLs in northern Antarctica. In other regions, thermal effects appear to dominate
over mechanical mixing in the ABL. Solar heating plays an important role in eroding surface-based inversions
and mixing the ABL in higher latitudes (south of 80°S). A similar effect is observed along the slopes of the east
Antarctic plateau, where adiabatic warming associated with downsloping winds appears to increase surface air
temperatures and reduce boundary layer stability. Although we do not measure cloud properties, the dewpoint
depression profiles suggest that the most pronounced saturation differences (and associated longwave
feedback) between stable and well-mixed ABLs may occur along the eastern coastal regions of Antarctica.

1381
Thu_16_AC-8_6
Sea Ice and Planetary Wave Activity over the 20th Century

Amanda Lynch1 (amanda_lynch@brown.edu), Andras Zsom2

1
Brown University, Institute at Brown for Environment and Society, Providence, United States, 2Brown
University, Providence, United States

The contrasting geographies of the Southern and Northern hemispheres play a significant role in the observed
Rossby wave regimes. In addition to differences in the continental distribution and the location of major north-
south mountain chains, the mean equator-to-pole temperature difference is significantly larger in the Southern
Hemisphere (around 70 K) than in the Northern Hemisphere (around 40 K). The evolving nature of these wave
regimes have been extensively studied in climate models and re-analyses. Planetary wave amplitude is a
challenging measurement compared to parameters such as wave propagation speed, jet strength and location,
and wavenumber. In this study, the evolution of planetary wave amplitudes over the 20th Century are analyzed
using a novel implementation of the quasi-geostrophic wave activity parameter. The trajectories of change are
distinctive between the hemispheres and can be linked to sea ice properties.

1382
Thu_17_AC-8_8
Contrast between Antarctic and Arctic Sea Ice Change

Son Nghiem1 (son.v.nghiem@jpl.nasa.gov)

1
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States

A key issue to be resolved in cryospheric science is to fully understand and explain the contrast between
Antarctic and Arctic sea ice change: Why Antarctic sea ice has been stable or even slightly increased while
Arctic sea ice has been reduced drastically in the past several decades? We discuss multiple interactions and
processes controlling the polar sea ice covers. We present results from SeaWinds scatterometer aboard the
QuikSCAT satellite and from aircraft acquired during the NASA's Operation IceBridge (OiB). Results indicate that
Antarctic sea ice cover is encapsulated by a band of circumpolar frontal ice zone (FIZ) containing older, rougher,
and thicker sea ice in the zone adjacent to the sea ice edge. This is in a stark contrast to Arctic sea ice where the
marginal ice zone (MIZ) consists of young and thin sea ice along the ice edge, which is easily reduced by melt
and by wind and wave effects. For Antarctic sea ice, topography and bathymetry, which are stable geological
factors, can have a significant role in sea ice processes that must be considered in explaining the overall
stability of Antarctic sea ice. Finally, we will describe the 2017 OiB/TanDEM-X Antarctic Science Campaign
(OTASC) to obtain extensive observations in characterizing Antarctic sea ice, by coordinating NASA Operation
IceBridge (OiB) aircraft with DLR TanDEM-X satellite SAR data acquisitions together with other multi-sourced
remote sensing data and surface field measurements.

1383
Thu_18_AC-8_16
The Warm Arctic-Cold Siberia Temperature Pattern: Has it Happened before?

Martin Wegmann1,2 (martin.wegmann@univ-grenoble-alpes.fr), Yvan Orsolini3, Olga Zolina2,4

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany,
2
University of Grenoble, Institut des Géosciences de l´Environnement, Grenoble, France, 3Norwegian Institute for
Air Research, Kjeller, Norway, 4P.P. Shirshov Institute of Oceanology, Moscow, Russian Federation

The Warm Arctic-Cold Siberia surface temperature pattern during recent boreal winter is suggested to be
triggered by the ongoing decrease of Arctic autumn sea ice concentration and has been observed together with
an increase in mid-latitude extreme events and a meridionalisation of tropospheric circulation. However, the
exact mechanism behind this dipole temperature pattern is still under debate, since model experiments do not
support this sea ice forcing. We use the early Twentieth Century Arctic warming as a case study to investigate
the link between September sea ice in the Barents-Kara Sea and the Siberian temperature evolution. Analysing
a variety of long-term climate reanalyses, we find that the overall winter temperature and heat flux trend can
be largely attributed to a reduction of September BKS sea ice. Tropospheric conditions show a strengthened
atmospheric blocking over the BKS, strengthening the advection of cold air from the Arctic to Central Siberia on
its eastern flank, together with a reduction of warm air advection by the westerlies. This setup is valid for both,
the early and the current Arctic warming period.

1384
Thu_19_AC-8_171
Impact of Permafrost Melting on the Hg Cycling in Thermokarst Pond

Martin Pilote1 (martin.pilote@canada.ca), Joao Canario2, Christian Gagnon1

1
Environment and Climate Change Canada, Aquatic Contaminants Research Division, Montreal, Canada,
2
University of Lisbon, Department of Chemical Engineering, Lisbon, Portugal

Mercury naturally occurs as elemental mercury (Hg°) and organic and inorganic species as well. Microorganism
can transform inorganic Hg to methylmercury (MeHg), and thus easily bioaccumulated in biota and
biomagnified in the food web. Melting permafrost has the potential to release a large proportion of previously
stored Hg and organic carbon that could alter the Hg cycling in permafrost zone and subarctic region. The aim
of this study is to characterize Hg levels and carbon contents in thermokarst ponds during the cold and the
growing season, to assess the contribution of allochtonous input of Hg and to evaluate their potential transport
towards the aquatic system. Thaw ponds are formed by the collapse of peat mounds in discontinuous
permafrost, eastern Canadian subarctic region. Our results suggest a strong link between MeHg production,
nutrient status and the importance of anaerobic methylation. Winter results will be compared to summer
measurements in order to assess the biogeochemical cycle of Hg in warmer months and to evaluate the
potential Hg transport towards the aquatic system. Quantifying the Hg source originating from melting
permafrost and soil leaching in subarctic and Arctic region in a changing climate is crucial of interest to assess
the Hg dynamic in the aquatic ecosystem and the food chain.

1385
Thu_20_AC-8_195
Arctic Precursors of Changing Eurasian Storm Tracks and Surface Climate

Pawel Schlichtholz1 (schlicht@iopan.gda.pl)

1
Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland

Since synoptic eddies forming midlatitude storm tracks shape the day-to-day weather and several aspects of
surface climate, seasonal predictability of their seasonal mean activity is of paramount importance to society.
While some seasonal predictability of the Pacific storm track and related climate variations in North America is
provided by atmosphere-ocean coupling in the tropics, seasonal predictability of Eurasian storm track
variations has not been demonstrated yet. Here statistical analyses of atmospheric reanalysis (NCEP/NCAR)
data and observed Arctic sea ice concentration (SIC) in the era of satellite observations (1979-2017) are used to
identify linkages of a dominant mode of interannual variability in wintertime upper-tropospheric storm tracks
over Eurasia to the concurrent surface climate anomalies and pre-winter Arctic SIC variations. This mode
explains an exceptionally large fraction (about 70% of the variance) of the North Atlantic Oscillation (NAO) and
of a leading mode of Eurasian surface air temperature variations. As more than 50% of its variance is found to
be accounted for by October SIC anomalies in the Barents/Kara Sea, we conclude that wintertime Eurasian
climate variability is to a large extent predictable. It is further shown that the predictability of the storm
track/NAO system from Arctic sea-ice anomalies might have increased after the acceleration of the Arctic sea-
ice decline in the 2000's.

1386
Thu_21_AC-8_278
Hydrometeorology of Three Arctic Catchments in Different Stages of Deglaciation

Jakub Ondruch1, Jan Kavan1, Kamil Láska1 (laska@sci.muni.cz), Daniel Nývlt1

1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic

The Arctic is regarded as one of the most vulnerable regions to climate change. Retreat and thinning of glaciers
is a prominent response, which, in turn, alters the functioning and importance of processes in proglacial and
periglacial zones. When deglaciated, fluvial (along with slope) processes substantially determine the evolution
of landscape and thus represent an important topic in climate change studies. Despite the progress in an
understanding of fluvial systems over the past decades, lack of empirical studies in various environmental
conditions has limited to address handful of questions such is the difference in importance of controls on
hydrological response of streams across catchments. In the study, we focus on a description of relationship
between meteorological factors and hydrograph during two ablation seasons in three catchments (Elsa,
Ferdinand, Bertil Streams) in Billefjorden, Svalbard. These have similar geology, geomorphology and climate;
however, they differ in an extent of glaciers. Meteorological variables are represented by air and ground
temperatures, global radiation, precipitation, wind speed and direction, all measured by automatic weather
stations with one-hour interval. Discharges were obtained in stable gorges near the outlet into the sea by
applying discharge - water stage rating curve using continuous hydrostatic pressure sensors and handheld
Acoustic Doppler Velocimeter.

1387
Thu_22_AC-8_445
Sea Ice Influence onto Eurasian Snow Revealed by Model Sensitivity Experiments

Maria Santolaria-Otin1 (maria.santolaria-otin@univ-grenoble-alpes.fr), Olga Zolina1, Fumiaki Ogawa2, Ho Nam

Cheung2, Noel Keenlyside2
1
Université Grenoble-Alpes, Institut des Géosciences de l'Environnement, Saint Martin d'Heres, France,
2
University of Bergen & Bjerknes Centre, Geophysical Institute, Bergen, Norway

Snow is a critical element of the Arctic system and is rapidly changing due to global warming with unexpected
impacts on environment, society and economy. Snow variations affect the atmosphere via changes in ther
reflectance of shortwave solar radiation (albedo), emissivity of longwave radiation, insulation of the
atmosphere from the soil below and latent-heat and water- release in association with melting. Understanding
snow processes is a crucial need. Here, we show an intercomparison of an ensemble of CMIP5 models with
observations for snow-related variables over the Arctic climate system for historical runs and future projections
in different RCP scenarios. Moreover, we perfom two different sensitivity experiment prescribing SIC and SST
with two atmospheric model CAM4 (low-top) and WACCM (high-top) to investigate the influence of sea ice on
Eurasia regarding variability and trends of snow cover and on the atmospheric circulation on the North Atlantic
sector.

1388
Thu_23_AC-8_489
A Climatology of Strong Large-scale Ocean Evaporation

Franziska Aemisegger1,2 (franziska.aemisegger@env.ethz.ch), Lukas Papritz3,4

1
ETH Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland, 2Centre for Environmental and
Climate Research, Lund University, Lund, Sweden, 3Geophysical Institute, University of Bergen, Bergen, Norway,
4
Bjerknes Centre for Climate Research, Bergen, Norway

In this presentation an object-based, global climatology (1979-2014) of strong large-scale ocean evaporation
(SLOE) is presented. This study is based on the reanalysis data set ERA-Interim from the European Centre for
Medium-Range Weather Forecasts (ECMWF). The mechanisms underlying the frequent occurrence of SLOE are
discussed as well as the typically associated climatic properties. In polar regions more than half of the total
wintertime evaporation is associated with SLOE. An analysis of the past history and fate of air parcels involved
in cold season SLOE in the North Atlantic and the Southern Indian Ocean shows that cold advection is the main
mechanism that induces these events. Extratropical cyclones thereby play an important role in setting the
necessary equatorward synoptic flow. An analysis of the interannual variability of SLOE associated with the
North Atlantic Oscillation and the Southern Annular Mode shows that SLOE is very sensitive to the location of
the storm tracks in both hemispheres. This study highlights the strong link between transient synoptic events
and the spatio-temporal variability in ocean evaporation patterns. The possible implications of this study for
our understanding of the water cycle at mid- to high latitudes and for the interpretation of deuterium excess as
a proxy for changes in climatic conditions are highlighted.

1389
Thu_24_AC-8_560
Interconnectivity and Drivers of Baffin Bay and Greenland Melt/freeze Onset

Thomas Ballinger1 (tballinger@txstate.edu), Thomas Mote2, Edward Hanna3, Jeffrey Miller4,5

1
Texas State University, Department of Geography, San Marcos, United States, 2University of Georgia,
Department of Geography, Athens, United States, 3University of Lincoln, School of Geography, Lincoln, United
Kingdom, 4NASA Goddard Space Flight Center, Greenbelt, United States, 5KBRWyle, Inc., Houston, United States

Oceanic and atmospheric warming of Greenland and surrounding areas has led to increased ice sheet spatial
melt extent and decreased sea ice coverage during the summer months. The last two decades have witnessed
increased warm air and moisture advection into the region from Greenland blocks and transient synoptic
patterns that have exasperated the background warming signal and led to several melt season anomalies and
isolated extreme melt events. The scope of the melt season is also evolving rather rapidly, particularly
throughout much of Baffin Bay and adjacent portions of the western Greenland Ice Sheet, where melt (freeze)
is occurring earlier (later) within the annual melt cycle. Less is known, however, about processes driving ice
sheet and sea ice changes at the temporal boundaries of the melt season and how these ice environments
physically interact during times of melt and freeze onset. Utilizing observational data from passive microwave
satellite sensors, in situ weather stations, and reanalysis products we look to better understand the local
sea/land ice interactions by 1) assessing relationships between the timing of melt and freeze onset, and 2)
evaluating preconditioning factors, such as heat and moisture intrusions, that influence subsequent melt
responses. Emphasis is placed on the autumn freeze onset period and how processes leading to a fluctuating
freeze date influence ice sheet and sea ice melt during the subsequent spring.

1390
Thu_25_AC-8_634
Reason for Accelerated Decline in Arctic Sea Ice in Recent Decades

Lejiang Yu1 (yulejiang@pric.org.cn)

1
Polar Research Institute of China, Shanghai, China

In recent decades, the Arctic sea ice has been declining at a rapid pace along with a significant warming in the
region at a rate of twice the global average. The underlying physical mechanisms for the Arctic warming and
accelerated sea ice retreat are not fully understood. We present evidence that the anomalous autumn Arctic
intrinsic atmospheric modes could explain as much as 50% of autumn sea ice decline for the 1979-2016 period.
The Arctic atmospheric circulation anomalies associated with anomalous sea surface temperature patterns
over the North Pacific and North Atlantic influence sea ice concentrations primarily through anomalous water
vapor advection and associated radiative feedback.

1391
Thu_26_AC-8_878
Mechanism of Sea-ice Variability in the Indian Ocean Sector of the Antarctica

Babula Jena1 (bjena@ncaor.gov.in), Avinash Kumar1, Alvarinho J Luis1, M Ravichandran1

1
National Center for Antarctic and Ocean Research, Vasco da Gama, India

The influence of global warming on the Arctic sea-ice exhibits a profound declining trend as expected. In
contrast, sea-ice around Antarctica exhibits an overall expansion with regional heterogeneity that comprises of
increasing and decreasing pattern in different sectors. Regional sea-ice variability in the Indian Ocean sector of
the Antarctica (IOSA) during 1979-2015 revealed significant expansion of sea-ice extent at an average annual
rate of 2.4%±1.2 per decade. The sea-ice expansion trend in this sector has a substantial seasonal variability
which peaks in summer (10.6%±4.1 decade-1), followed by autumn (4.0%±1.6 decade-1), winter (1.9%±0.9
decade-1) and spring (1.7%±1.2 decade-1). Result showed robust features of sea surface freshening and cooling
trend (up to ~100m depth) in the IOSA region which is conducive for expansion in sea-ice. The spatial trend
map of sea surface temperature (SST) shows wide spread cooling throughout all seasons. Analysis of Ocean
Reanalysis System 4 (ORAS4) and Met office EN4 observations shows sub-surface warming trend below ~100m
depth, possibly from advection of modified circumpolar deep water which advects warm water onto the ice-
shelf. In the present work, the mechanism of observed sea-ice expansion is analysed with respect to SST, winds,
current, heat flux, vertical thermohaline structures, and leading climate oscillator of ocean-atmospheric
coupled phenomenon.

1392
Thu_27_AC-8_933
Bi-Polar Sea-ice Trends - An Overview of Possible Teleconnections

Girija Kalyani Burada1 (girija.kalyani18@gmail.com), Alvarinho J Luis1

1
National Center for Antarctic and Ocean Research, Polar Sciences, Vasco da Gama, India

Currently, Arctic sea ice extent for Sep 2017 was 4.87 million sq km, 7th lowest in the entire satellite record
since 1979 and was 1.67 million sq km (1.24 million sq km) below (above) the 1981-2010 average (Sep record
low-2012). Antarctic sea ice has reached its maximum extent on Sep 15, at 17.98 million sq km among the
earliest maxima on record. If this extent holds, it will be second lowest daily maximum in the satellite record at
20000 sq km above 1986 record. Antarctic sea ice extent has been record low since Sep 2016 though it has
recorded highest until 2014-15. What is causing these drastic inter-annual changes? These changes are
definitely causing on longer temporal forcing of multiple teleconnections. Depending on which teleconnection
is strong on a particular time-period, which is weakening the other whilst together influencing sea-ice. We
explain how multi-decadal scale teleconnections are acting on inter-decadal, inter-decadal on decadal, thereby
annular modes and local factors. Study addresses how Pacific Decadal Oscillation (20-30 years)-Inter decadal
Pacific Oscillation(15-30)-Atlantic Multi-decadal Oscillation-North Atlantic Oscillation-El Nino Southern
Oscillation(2-7), Indian Ocean Dipole (1-2)-Annular Modes (North & South) had affected the polar climate over
a period; thereby enhancing local factors. Since both the poles are behaving anomalously in terms of sea-ice,
we focus on outlining the changes driving these on a broader scale with possible evidences.

1393
Thu_28_AC-8_980
Response to the Arctic Sea Ice Decline in a Regional Climate Model

Vladimir Semenov1,2 (vasemenov@mail.ru), Mikhail Varentsov3

1
A.M.Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russian Federation,
2
Institute of Geography RAS, Moscow, Russian Federation, 3Lomonosov Moscow State University, Moscow,
Russian Federation

Record high global temperatures in the beginning of the 21st century were accompanied by more frequent
anomalously cold spells during winter in the Northern Eurasia. A number of previous studies based on empirical
data analysis and global atmosphere general circulation models revealed a link between negative surface air
temperature anomalies and rapid Arctic sea ice reduction. A mechanism of such a link is under discussion. The
major hypothesis is based on interaction between large-scale atmospheric circulation and anomalous wave
activity induced by low troposphere heating in the areas of sea ice retreat. The response can also be explained
by regional circulation response to the modified local temperature contrasts. In order to test a possibility of the
regional response, we performed ensemble simulations with COSMO regional atmospheric model for the
region covering a part of the Northern Eurasia and Eastern Arctic. Simulations were performed for high and low
sea ice concentrations in the Barents Sea and strong and weak zonal circulations for the both low and high sea
ice cases. The model reproduced anticyclonic circulation anomaly in the southern Ural region accompanied by
negative temperature anomalies as a response to the sea ice reduction only under conditions of a weak zonal
flow. The results support a possibility of the regional response independent on interaction with stratosphere
and/or circumpolar circulation modes and highlight a role of background circulation.

1394
Thu_29_AC-8_1083
The Impacts of Greenland Ice Sheet Collapse on the Tides in Hudson Bay

Anna Hayden1 (anna-mireilla.hayden@mail.mcgill.ca), Natalya Gomez1, Sophie-Berenice Wilmes2, J.A. Mattias

Green2
1
McGill University, Earth and Planetary Sciences, Montreal, Canada, 2Bangor University, School of Ocean
Sciences, Menai Bridge, United Kingdom

In Hudson Bay, sea level changes associated with Greenland ice loss vary across the bay and differ significantly
from the change in global mean sea level equivalent due to gravitational effects. Changing water depths give
rise to changes in ocean tides, for which tidal energy dissipation and tidal amplitudes are directly linked to
ocean bathymetry (Green, 2010). In the present study, we investigate the impact of sea level changes on tides
in Hudson Bay, Canada - a region where tidal energy dissipation is strongly sensitive to bathymetry (e.g. Egbert
and Ray, 2000), and the bathymetry is in turn highly uncertain in some parts of the bay. Recent work by Wilmes
et al. (2017) indicates that regional variability in future sea level changes as a consequence of ice sheet collapse
will impact tides globally, in particular in Hudson Bay. We present simulations of the sea level changes
associated with a suite of Greenland ice loss scenarios using a gravitationally self-consistent sea level model
(Gomez et al., 2010) and consider the impact of these sea level changes on tides in the Hudson Bay using the
OTIS tidal model. We also investigate the sensitivity of our tidal calculations to uncertainty in regional
bathymetry. Our results aid in constraining the response of Hudson Bay tidal dynamics to projected sea level
changes, elucidating the feedbacks between energy dissipation and shoreline migration, and assessing the
impact of climate change on coastal regions in the Hudson Bay.

1395
Thu_30_AC-8_1273
Predicting Arctic Sea Ice Extent using Causal Effect Networks

Sha Li1 (ariel14.lis@gmail.com), Muyin Wang2, Jiping Liu3, Yuqi Bai1, Shiming Xu1, Bin Wang1,4
1
Tsinghua University, Department of Earth System Science, Beijing, China, 2University of Washington, Joint
Institute for the Study of the Atmosphere and Ocean, Seattle, United States, 3State University of New York at
Albany, Department of Atmospheric and Environmental Sciences, Albany, United States, 4Chinese Academy of
Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics
(LASG), Institute of Atmospheric Physics, Beijing, China

Chukchi and East Siberian seas play a vital role in the polar resource exploration and ship transportation. In this
study a novel data-driven approach named causal effect networks (CEN) was applied to explore the potential
factors triggering the sea-ice loss in this region. The CEN is an adjusted causal discovery method, which can
reduce data dimension by initially selected regional mean time series and avoid false correlations by
conditionally independence tests. We took September sea-ice extent (SIE) as an example to know how it
correlates with potential predictors including downward short- and long-wave radiation, sea surface
temperature, and winds. It is shown that the predictors from selected lower-latitude regions are more closely
related to September SIE than that from the local areas. The results are sensitive to parameters in the
algorithm, such as significance level, temporal resolution, and max leading time. On the monthly scale, R2
values for all the models exceed 0.97 when the max leading time is less than nine months with other
parameters fixed. If the max leading time is seven months, the best prediction model can explain 98.7% of
September SIE variance by Leave-One-Out Cross-Validation. We found the earlier zonal winds at 10 m height
near the tropical eastern Pacific and Inner Mongolia are both the most significant predictors, while the
downward long-wave radiation to the south of Greenland is an important heat source associated with
September sea-ice loss.

1396
Thu_31_AC-8_1316
Large-scale Atmospheric Teleconnection Related to Pan-Arctic Wildfire Activity

Jin-Soo Kim1 (jinddu@gmail.com), Jong-Seong Kug1, Gabriela Schaepman-Strub2

1
Pohang University of Science and Technology, Division of Environmental Science and Engineering, Pohang,
Korea, Republic of, 2University of Zurich, Department of Evolutionary Biology and Environmental Studies, Zurich,
Switzerland

The pan-Arctic has the potential for positive carbon-climate feedbacks by releasing a substantial amount of
carbon buried in the permafrost zone. Wildfires can rapidly transfer carbon to the atmosphere, thereby playing
an important role in the pan-Arctic terrestrial carbon cycle. One expected response to recent pan-Arctic
warming is an increase in wildfire activity, but satellite-based observations suggest that the interannual
variability of wildfires is much higher than a linear increase. We found diverse large-scale atmospheric
teleconnections with wildfire activity in East Siberian and North American permafrost regions. However, dipole
structures in sea-level pressure between Arctic and pan-Arctic commonly drive temperature anomalies in the
pan-Arctic region and directly modulate wildfire activity. This dipole pattern is consistent with previous studies
that showed teleconnections related to Arctic temperature variation via Rossby wave propagation.
Furthermore, some large-scale atmospheric teleconnections lead few months later to wildfire activity;
therefore, these climate variabilities could be a possible predictor for the pan-Arctic wildfire activity.

1397
Thu_32_AC-8_1700
Landscape and Climate Interaction on sub-Antarctic Marion Island

Werner Nel1 (wnel@ufh.ac.za)

1
University of Fort Hare, Department of Geography and Environmental Science, Alice, South Africa

Marion Island in the southern ocean has a hyper-maritime climate and an environment where diurnal
processes dominate the landscape. In a diurnal soil frost environment like Marion Island, the impact of climate
change on the landscape occur at a higher resolution than for seasonal and permafrost environments and
needs investigation at the synoptic time scale. Results from automated and manual measurements of the
abiotic characteristics of a variety of habitats show that the passage of synoptic scale weather systems
dominated the landscape on Marion Island. These systems influences the thermal characteristics of soil,
intensity of rainfall, snowfall, soil frost dynamics, needle ice development, aeolian erosion, the hydrochemistry
of stream water and a host of other abiotic processes and its direct and indirect interactions with the
ecosystem. This presentation reviews the current knowledge on the interaction between climate and the
landscape, the current methodologies employed to investigate these interactions and specifically addresses the
possible landscape responses under a future climate.

1398
Thu_33_AC-8_1702
Atlantic Multidecadal Oscillation Modulates the Impact of Arctic Sea Ice Decline

Fei Li1 (lifei-715@163.com), Yvan Orsolini1

1
Norwegian Institute for Air Research, Oslo, Norway

Arctic sea ice cover has been rapidly declining in the last two decades and the connection between the sea ice
decline and the Arctic Oscillation (AO) remain unclear. Here we use both observations and model simulations
to investigate how the Atlantic Multi-decadal Oscillation modulates the connection between the sea ice decline
and the AO. We find that the sea ice decline during the AMO|− induces increased Ural blocking activity and
southward-extended snowpack over Eurasia in December through enhanced cold air advection and moisture
transport from the Arctic. The increased Ural blocking activity and extended Eurasian snowpack strengthen the
upward wave propagation over the Siberia-North Pacific in the lower stratosphere and hence lead to weakened
stratospheric polar vortex and to the negative AO at the surface in February. However, corresponding to the
sea ice decline during the AMO|+, one finds extended Arctic warming, less Ural blocking activity, and reduced
snowpack over northern Eurasia in December. The stratosphere-troposphere coupling is suppressed in early
winter and no negative AO anomaly is found in February. We suggest that the AMO|− is important to regulate
the atmospheric circulation response to the Arctic sea ice decline and our study provide insight to the ongoing
debate on the connection between the Arctic sea ice decline and the AO.

1399
Thu_34_AC-8_1811
Causal Effect Networks in Arctic-midlatitude Teleconnections

Peter Yu Feng Siew1,2 (yu.siew@uib.no), Xinshu Fu3, Camille Li1,2, Stefan Sobolowski2,4, Martin King2,4
1
University of Bergen, Geophysical Institute, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen,
Norway, 3Nanjing University, Nanjing, China, 4Uni Research Climate, Bergen, Norway

Mid-latitude variability can affect and be affected by Arctic climate change. Evidence exists for mechanisms
operating in both directions, for example, sea ice decline causing cold winters in Eurasia (Mori et al. 2014), and
moisture transport from the mid-latitudes driving sea ice decline (Park et al. 2015). An essential difficulty in
investigating Arctic-midlatitude teleconnections is demonstrating causal links in a system with large internal
variability. Here, we use causal effect network analysis (Kretschmer et al. 2016) to identify robust causal links
between the mid-latitudes and Arctic, and to elucidate the characteristics of their lead-lag behavior. This
approach allows us to test a range of pathways within the same framework, using variables such as poleward
moisture transport, downward longwave radiation, surface turbulent heat fluxes, Barents-Kara seas ice cover,
vertical wave activity, and polar vortex strength. This network analysis builds a clearer picture of the physical
mechanisms linking the Arctic and mid-latitudes, as well as their relative importance in today's climate.
Kretschmer, M. et al. J.Clim. 29, 4069 (2016)
Mori, M. et al. Nat.Geosci. 7, 869 (2014)
Park, H.S. et al. J.Clim. 28, 5030 (2015)

1400
Thu_35_AC-8_1816
Impacts of Arctic storms on Atlantic Water Transports into the Arctic Ocean

Zhenxia Long1 (longz@dfo-mpo.gc.ca)

1
Bedford Institute of Oceanography, DFO, Dartmouth, Canada

The impacts of Arctic storms on the Atlantic water transports into the Arctic Ocean are investigated using a
coupled atmosphere-ice-ocean model (NEMO). In the Nordic Sea, Arctic storms play an important role on the
air-sea interactions. To understand the impacts of the Arctic storms on the water volume transports through
Fram Strait and the Barents Sea Opening, NEMO is implemented in the Arctic Ocean, forced by PHC
temperature (salinity), GLORYS currents and CORE II surface fields. Compared to PHC data, NEMO can reliably
reproduce the upper layer water temperature and salinity, suggesting a warm layer at intermediate depths. In
addition, the model simulations exhibit significant decadal variations of water volume transports through Fram
Strait and the Barents Sea Opening. Moreover, the storm activity in the eastern Arctic Ocean plays an
important role in the variability of Atlantic water inflows. In the early 1990s and 2000s, while increased storm
activity in the Greenland Sea tended to enhance the Atlantic water transport through Fram Strait, the increased
Atlantic water inflow through the Barents Sea Opening was mainly associated with the storm activity in the
northern Barents Sea. Furthermore, our results also show that the decadal variability in the storm activity is
related to decadal variations of atmospheric baroclinicity.

1401
Thu_36_AC-8_1821
The Atmospheric Circulation Response to Sea Ice Change in an Aquaplanet AGCM

Caroline Holmes1 (calmes@bas.ac.uk), Tim Woollings2, David Brayshaw3, Len Shaffrey3,4

1
British Antarctic Survey/NERC, Cambridge, United Kingdom, 2University of Oxford, Department of Physics,
Oxford, United Kingdom, 3University of Reading, Department of Meteorology, Reading, United Kingdom,
4
National Center for Atmospheric Science, Reading, United Kingdom

Despite considerable modelling efforts, there remains uncertainty about the magnitude and nature of the
sensitivity of the atmospheric circulation to sea ice change. Here, the impacts of sea ice loss on the global
atmospheric circulation are investigated using equilibrium simulations in an aquaplanet AGCM with prescribed,
zonally symmetric, sea ice.
Responses can be separated into two broad categories; for sea ice constrained to poleward of 60º, the
difference relative to a simulation with no ice is a moderate acceleration on the poleward flank of the eddy-
driven atmospheric jet stream which projects increasingly onto the annular mode. For larger extents,
anomalies are much larger relative to the magnitude of the forcing and a shift in circulation regime is evident,
with the jet and storm tracks shifting polewards and intensifying.
This is consistent with previous work in which sea ice reductions are connected to equatorward shifts in the jet.
Moreover, the apparent nonlinearity in the magnitude of the response aids our understanding of the range of
responses found in previous studies with models of varying complexity.
It is also demonstrated that jet latitude variability increases as ice extent increases, and that certain features of
changes in the jet speed are masked by looking only at the time-mean picture. These results have implications
for understanding the impact of different sea ice extents in paleoclimate, as well as the twentieth and twenty-
first centuries.

1402
Thu_37_AC-8_1829
The Role of the Aleutian Low in Seasonal Melt of the Pacific Arctic Cryosphere

Christopher Cox1,2 (christopher.j.cox@noaa.gov), Robert Stone3, Diane Stanitski4, David Douglas5

1
Cooperative Institute for Research in Environmental Sciences, Boulder, United States, 2NOAA/Earth System
Research Laboratory/PSD, Boulder, United States, 3Science and Technology Corporation, Boulder, United States,
4
NOAA/Earth System Research Laboratory/GMD, Boulder, United States, 5United States Geological Survey,
Alaska Science Center, Juneau, United States

Recent springtime climate extremes have been observed along the northern coast of Alaska. The dates when
snow melted at Barrow in 2015 and 2016 were the 4th and 1st earliest recorded, respectively, since 1901. These
early years were followed in 2017 by the latest date of snow melt since 1988, nearly seven weeks later than in
2016. Previous work implicates the northward advection of warm air circulating around the Aleutian Low
during years of early melt and blocking by the Beaufort High during years of later melt. The same circulation
patterns have been linked to the timing of the onset of ice melt in the Chukchi Sea. Here, we further investigate
how the transport of Pacific air to the Arctic is linked to the position of the Aleutian Low and its juxtaposition
with the Beaufort High. Using reanalysis, satellite and surface-based data sets we analyze how the spatial
distribution of air temperature is modified by variability in the atmospheric circulation. Anomalies are further
investigated by analysis of the resulting spatial patterns in the timing of snow melt over land areas and melt
onset over the sea ice. We introduce a new climate index that explains some of the variance in those variables.
This index is suitable for monitoring changes in regional circulation and may be useful for developing seasonal-
scale predictive tools.

1403
Thu_38_AC-8_1928
Variability of Circulation Eddy Energy Components in High Latitudes of Siberia

Elena Kharyutkina1 (kh_ev@mail2000.ru), Sergey Loginov1, Yuliya Martynova1,2

1
Institute of Monitoring of Climatic and Ecological Systems SB RAS, Tomsk, Russian Federation, 2Siberian
Research Hydrometeorological Institute of Roshydromet, Novosibirsk, Russian Federation

Acceleration of warming in the Arctic region over last decades causes reduction of sea ice cover and
intensification of heat exchange between ocean and atmosphere. Observed changes in atmospheric circulation
processes lead to climate change in the adjacent regions, for instance, winter cooling in the midlatitudes of
Eurasia.
Main goal of this study is the investigation of seasonal variability in energetic characteristic of atmospheric
circulation in West Siberia (50°-70°N, 60°-90°E), where special attention paid for its Arctic part. Statistical
estimations of climatic variables and energy characteristics (zonal and eddy components of available potential
and kinetic energy), were derived using reanalysis data (ERA-Interim, JRA-55) and climate system model
INMCM 4.0. The calculation of baroclinic instability parameter fields allowed us to reveal baroclinity zones, to
define the changes in its intensity and, as a result, to get an overview about the variability of advection over the
region of under study. It was revealed that in the beginning of XXI century the variability of eddy kinetic energy
has significant contribution to temperature variability over the territory of West Siberia. Moreover, constructed
temporal variability of relative vorticity value (anticyclonic type) showed the increase of this parameter in
winter months.
The work is supported by the grant of the RF President МК-2018.2017.5 and by RFBR, according to the research
project No.16-35-60088 mol_а_dk.

1404
Thu_39_AC-8_2002
Inter-seasonal Temperature Teleconnections in the Northern Hemisphere

Natalia Gnatiuk1,2 (natalia.gnatiuk@niersc.spb.ru), Timo Vihma3, Leonid Bobylev1,4

1
Nansen International Environmental and Remote Sensing Centre, St. Petersburg, Russian Federation,
2
Ukrainian Hydrometeorological Institute, Kiev, Ukraine, 3Finnish Meteorological Institute, Helsinki, Finland,
4
Nansen Environmental and Remote Sensing Centre, Bergen, Norway

On the basis of ERA-Interim reanalysis we analysed relationships the between Earth surface temperature (Ts) in
the Northern Hemisphere (on grid 1.5o-1.5o) and 2-m air temperature (T2m) in 13 selected study regions in
Europe, Greenland, and parts of Asia and North Africa for the period 1979-2016. Applying detrended data we
eliminated spurious correlations resulting from similar trends in the two variables.
We detected significant correlations between the surface temperature over the Labrador Sea, Canadian
archipelago and North Atlantic and 2-m air temperature in different study regions for inter-seasonal spring -
summer (MAM-JJA) and autumn - winter (SON-DJF) relationships.
Among the strongest correlations between the spring Ts and summer T2m were the positive correlations found
between Ts in the North Atlantic and T2m in Scandinavia, Ts in the Labrador Sea and T2m in Northeast Europe,
and Ts in Norther Sahara and T2m in Urals.
As well, among the strongest correlations between the autumn Ts and winter T2m were the positive
correlations found between Ts in the North Atlantic and the Labrador Sea and T2m in Scandinavia and
Northwest Africa; and the negative correlations found between Ts in the Labrador Sea and the North Atlantic
and T2m in Scandinavia, Northeast Europe, Urals, Black Sea region and Northcentral Asia.
Authors acknowledge RSF project No. 17-17-01151.

1405
Thu_40_AC-8_2012
Coupled Modes of Barents Sea Ice and Atmospheric Anomalies in Autumn and Winter

Martin King1,2 (martin.king@uni.no), Stefan Sobolowski1,2, Camille Li2,3

1
Uni Research Climate, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen, Norway, 3Geophysical
Institute, University of Bergen, Bergen, Norway

Recent studies report linkages of late autumn Barents-Kara sea ice and winter atmospheric circulation
anomalies but it is unclear what the zero-lag feedbacks and higher coupled modes do. Here, we revisit the
problem using Maximum Covariance Analysis (MCA), examining not only the first modes but also higher modes
that contribute significantly to the squared covariance fraction (SCF). Besides sea ice concentration, SLP, and
geopotential height, we also analyse heat advection and surface temperature to elucidate the climate impact
on Europe. In reanalysis/observational data, the first two atmospheric modes at zero lag advect cold/warm air
southward/northward over the Arctic-Atlantic sector, and are associated with positive/negative sea ice
anomalies. Additionally, the atmospheric modes at zero lag can cancel or reinforce, depending on the regions,
the lagged atmospheric responses to sea ice reported previously. Applying the same analysis to coupled model
simulations, we find that models can reproduce the first MCA modes, but they are far too dominant (SCF >
60%) compared to those in observational data (SCF ~ 40%). This suggests that coupled modes in models are not
as diverse as in the real world, and that the lagged coupled modes are underestimated by models. By
considering all the leading modes, we can have more complete understanding of the lagged and zero-lag
feedbacks. Additionally, examining MCA beyond the first modes can be used to assess coupled modes
simulated by models.

1406
Thu_42_AC-8_2092
Enhanced Poleward Moisture Transport Contested

Ambroise Dufour1 (ambroise.dufour@univ-grenoble-alpes.fr), Olga Zolina1

1
Université Grenoble Alpes, Grenoble, France

The catchment of the Ob, Yenisei and Lena rivers covers stretch from 46°N to 71°N and cover 7.95 million
square kilometers. The water cycle over these basins is sensitive to rising temperatures due to melting
permafrost, reduction in snow cover, increased atmospheric moisture and possible circulation changes.
Downstream, the river discharge is a major contributor to the Arctic Ocean freshwater budget. Changes in the
regional water cycle are constrained upstream by the quantity of water vapour transported by winds into the
domain, which can be monitored with atmospheric reanalyses.
Our study builds upon the work of Zhang et al. [Nature Climate Change 3.1 (2013): 47-51.] using NCEP NCAR R1.
We evaluate the robustness of their conclusions using state of the art reanalyses (ERA-Interim, NCEP CFSR, JRA
55 and MERRA 2) and prolonging the reference period from 2008 to 2015. The increasing trend in NCEP NCAR
R1 is found to be sensitive to the start and end points and is weaker or absent in the other datasets. We
confirm that the variability of the moisture convergence is a consequence of changing winds rather than
increasing moisture. Finally, we contrast this behaviour with moisture fluxes into the High Arctic (north of
70°N) where winds and humidity show opposite trends.

1407
Thu_43_AC-8_2172
What If Paris Works: Ice Sheet Surface Melting in Low and High Warming Worlds

David Reusch1,2 (david.reusch@nmt.edu)

1
New Mexico Institute of Mining and Technology, Earth & Environmental Science, Socorro, United States,
2
University of Washington, Earth & Space Science, Seattle, United States

Surface melting on the Greenland ice sheet has seen dramatic change with increasing global air temperatures,
e.g., recent melt extent often exceeds the 1981-2010 median through much of the melt season. To evaluate
potential future change, we investigate surface melting drivers under both low (~1.5 °C) and high (RCP 8.5)
warming scenarios including differences in scenario outcomes.
Melt-relevant climatologies are developed from two publicly available ensembles of CESM1-CAM5-BGC runs:
the 30-member Large Ensemble (CESM LE; Kay et al. 2015) for historical calibration and RCP 8.5 scenario and
the 11-member Low Warming ensemble (CESM LW; Sanderson et al. 2017) for the 1.5 °C scenario. For higher
spatial resolution (15 km) and improved polar-centric model physics, we also apply the regional forecast model
Polar WRF to decadal subsets (1996-2005; 2071-80) with ERA-Interim Reanalysis (ERAI) & GCMs for boundary
conditions.
Models are skill-tested against ERAI and AWS observations. For example, CESM LE tends to overpredict both
maximum (above-freezing) and minimum daily average surface temperatures vs GC-Net Swiss Camp AWS
observations.
Future (2081-2100) Greenland warms even in the LW scenario, but positive changes vs ERAI are mostly coastal
(2-3 °C) with the interior showing only minor change. Under RCP 8.5, the entire ice sheet has warmed by 2-6 °C,
or a median increase of ~5 °C vs LW. Adjusting for the CESM cold bias pushes these values closer to more
frequent melting conditions.

1408
Thu_44_AC-8_2277
Reconstruction of Autumn SIE during 1289-1993AD for Barents-Kara Seas, Arctic

Qi Zhang1, Cunde Xiao2 (cdxiao@bnu.edu.cn), Minghu Ding3, Tingfeng Dou4

1
Chinese Academy of Meteorological Sciences, China Meteorology Administration, Haidian District, China, 2State
Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China,
3
Chinese Academy of Meteorological Sciences, China Meteorology Administration, Beijing, China, 4College of
Resource and Environment, University of Chinese Academy of Sciences, Beijing, China

Using high resolution ice core and tree ring proxies for sea ice extent (SIE), we reconstructed robust time series
of autumn SIE over the Barents-Kara (B-K) sector of Arctic during 1289-1993 AD. After inter-comparison of the
results and statistical parameters of the Ordinary Least Squares Regression (OLSR), Principle Components
Regression (PCR) and Partial Least Squares Regression (PLSR) methods, the SIE time series are synthesized into
a more convincing one using weighted average method with the explained variance as the weight. The result
shows that during 13th to 18th century, autumn B-K SIE is in a high level with high oscillations and has a slight
trend of expanding. It reflects significant multidecadal oscillations during the little ice age (LIA) background. B-K
SIE starts to decline since the end of 18th century and the shrinking trend becomes very significant during the
second half of the 19th century lasting to 1930s-1940s. 1930s-1940s is a period of relative low SIE in B-K sea
and the SIE has a short period of expandation during 1940s-1970s. However, the B-K SIE has continuously been
shrinking significantly since 1970s,with industrial activities may be a dominant factor. B-K SIE retreats
significantly since 1970s with the speed 6.18 times as the former mean retreating speed, the Arctic SIE in
recent years may be the lowest one over the last millennium.
Keywords: Arctic; Sea ice; Ice core; Tree rings; Paleoclimatology; Global Warming

1409
Thu_45_AC-8_2487
Analyses of Explosive Cyclones Reaching the Antarctic Coast in 2017

Luciana Bassi Marinho Pires1 (luciana.pires@worldenvironmentalconservancy.org), Marcelo Romão1,2, Ana

Carolina Vasques Freitas1,3
1
World Environmental Conservancy, Atlanta, United States, 2National Institute for Space Research (INPE), Sao
José dos Campos, Brazil, 3Federal University of Itajubá, Itabira, Brazil

Explosive cyclones or meteorological bombs are a kind of mesoscale cyclones known for their rapid
intensification, but are not necessarily short-lived. They can produce strong winds, heavy rainfall and
dangerous oceanic conditions as a result of rapid change of central pressure. It is likely that climate change is
causing an increase in this type of event in the Antarctic coast and, if this increase is confirmed, the regime of
winds and temperatures may be changing. In the northern portion of the Antarctic Peninsula a decrease in
temperature has been recorded over the last 15 years, with a higher incidence of explosive cyclones over the
region having been noted during this period. Explosive cyclones, which change the wind patterns when they
reach certain areas, therefore may be contributing to this change in the Antarctic climate. This study is part of
the “Explosive Cyclones on the Antarctic Coast” (EXCANC) Project conducted by the World Environmental
Conservancy organization which analyzes data from 13 meteorological stations strategically scattered
throughout the coast and operated by various international Antarctic programs, and also utilizes satellite
images. Results show that through October of 2017, 96 cases of explosive cyclones in the Antarctic continent
have occurred with around 100 cases being expected through the end of the year; the greatest number of
events have been recorded at the Australian Casey station (16 cases). Intensity analyses also are shown.

1410
Thu_46_AC-8_2581
Light-absorbing Impurities in Coastal Snowpacks in Western Antarctica

Raul Cordero1 (raul.cordero@usach.cl), Penny Rowe1, Sarah Feron1, Alessandro Damiani1

1
1Universidad de Santiago de Chile, Santiago, Chile

Black carbon (BC), light-absorbing impurities plays an important role in Earth's cryosphere due to its strong
absorption of visible light. Direct absorption of solar radiation by BC leads to atmospheric warming, while BC
deposition on snow increases the fraction of solar energy absorbed accelerating in turn melting.
In this context, we focused our efforts on the measurement of the BC concentration and other light-absorbing
impurities as well as algae in snow. In the last two years, we sampled in the snow across a north-south transect
of almost 2000 km of the Chilean Andes: from at 8 locations from King George Island (62°S) to the southern
Ellsworth Mountains on the broad expanse of Union Glacier (79°S; 3030 km from the southern tip of Chile and
just about 1000 km from the South Pole). The sampling methodology was the meltwater filtration (MF)
technique, whereby our 235 snow samples (of about 2.5 liters each) were melted shortly after collection and
passed through a 0.4 mm nucleopore filter.
As expected, we found significant geographical differences in the content of light-absorbing impurities. For
surface snow, the estimate of BC-equivalent mass loading was found to be 5 ng/g on King George Island to 0.5
ng/g at Union Glacier Camp. Our measurements also showed that light-absorbing impurities as well as the
effect of algae in the snow decreased as we went south.

1411
Thu_47_AC-8_2596
Interplay of Sea Ice and Oceanic Vertical Mixing in the Arctic Warming Hotspot

Sigrid Lind1,2 (sigridl@imr.no), Randi Ingvaldsen3, Tore Furevik2

1
Institute of Marine Research, Tromsø, Norway, 2University of Bergen, Geophysical Institute & Bjerknes Centre
for Climate Research, Bergen, Norway, 3Institute of Marine Research, Bergen, Norway

The Arctic is warming twice as fast as the global mean, with the northern Barents Sea being the absolute
warming hotspot. This region has seen the largest decline in winter sea ice and the strongest surface warming,
with the warming signal extending deep into the water column and high into the lower troposphere. The
mechanisms controlling the heat transfer from the sub-surface warm Atlantic layer, and thus the sea ice cover
and the lower troposphere temperatures, are not well understood nor quantified. In this presentation, we
explore some of the mechanisms that we believe are important in the Arctic warming hotspot.
Our analysis is based on an extensive observational hydrographic data set from late summer and early autumn
1970-2016 in the northern Barents Sea. Focus for the study is the relationships between the upper ocean
stratification, vertical fluxes of heat and salt from the deep Atlantic layer, and influx of sea ice and fresh water
to the region. Year-to-year changes in the distribution of heat and salt in the water column reveal substantial
variations in vertical fluxes of heat and salt that is controlled by upper ocean salinity. Special focus is on the
freshwater input to this region, its interplay with vertical mixing, and its role in the Arctic warming hotspot.

1412
Thu_48_AC-8_2689
Properties and Predictability of Precipitation over the Mertz Glacier Region

Irina V. Gorodetskaya1 (irina.gorodetskaya@ua.pt), Katherine Leonard2,3, Annick Terpstra4,5, Claudio Duran6,

Alexandre Flouttard7, Alexis Berne2, Iris Turnherr8, Heini Wernli8, F. Martin Ralph9
1
University of Aveiro, Centre for Environmental and Marine Studies, Department of Physics, Aveiro, Portugal,
2
EPFL, Lausanne, Switzerland, 3University of Colorado Boulder, Department of Atmospheric and Oceanic
Sciences, Boulder, United States, 4University of East Anglia, Norwich, United Kingdom, 5University of Bergen,
Geophysical Institute & Bjerknes Centre for Climate Research, Bergen, Norway, 6Laboratory of Glaciology and
Geophysical Environment, Grenoble, France, 7Météo France, Toulouse, France, 8ETH Zurich, Institute for
Atmospheric and Climate Science, Zurich, Switzerland, 9University of California San Diego, Scripps Institution of
Oceanography, La Jolla, United States

Intense precipitation events are important contributors both to the surface mass balance of the Antarctic ice
sheet and Southern Ocean salinity. As they are typically associated with high wind speeds and whiteouts they
also strongly disturb local operations. Here we analyse several precipitation events affecting the Mertz glacier
region and Dumont D´Urville (DDU) station in February 2017 combining unique ship-based measurements
performed during the Antarctic Circumnavigation Expedition (ACE) and DDU station measurements.
Precipitation amounts and properties are obtained using a combination of techniques, including precipitation
radars, photoelectric particle counters, and formvar imprints of snowflakes for microphysical characterization.
Atmospheric profiles are analyzed using radiosonde measurements. The events were forecasted and closely
monitored using operational analysis of the European Centre for Medium-range Weather Forecasts (ECMWF)
model and the Antarctic Mesoscale Prediction System (AMPS)/Polar WRF model. A combination of ACE and
DDU measurements provide a unique opportunity to evaluate model performance and assess predictability of
the events at different forecast lead times.

1413
Thu_49_BE-2_55
Nitrogen uptake by Phytoplankton in the Indian Sector of Southern Ocean

Sarat Chandra Tripathy1 (sarat76@gmail.com), Sivaji Patra2, K Vishnu Vardhan2, A. Sarkar1, R.K. Mishra1, N.
Anilkumar1
1
ESSO-National Centre for Antarctic and Ocean Research, Ocean Sciences Group, Vasco-da-Gama, India, 2ESSO-
Integrated Coastal and Marine Area Management-PD, Chennai, India

This study reports nitrogen uptake rate (using 15N tracer) of phytoplankton in surface waters of different frontal
zones in the Indian sector of Southern Ocean (SO) during austral summer of 2013. The investigated area
encompasses four major frontal systems, i.e., the Subtropical Front (STF), Subantarctic Front (SAF), Polar Front-
1 (PF1) and Polar Front-2 (PF2). Analysis of nutrient ratios indicated potential N-limited conditions at the STF
and SAF but no such scenario was observed for PF. In terms of phytoplankton biomass, PF1 was found to be the
most productive followed by SAF, whereas PF2 was the least productive region. Nitrate uptake rate increased
with increasing latitude, as no systematic spatial variation was discerned for NH4+ and urea. Linear relationship
between nitrate and total N-uptake reveals that the studied area is capable of exporting up to 60% of the total
production to the deep ocean if the environmental settings are favorable. Like N-uptake rates the f-ratio also
increased towards PF region indicating comparatively higher new production in the PF than in the subtropics.
The moderately high average f-ratio (0.53) indicates potentially near equal contributions by new production
and regenerated production to the total productivity in the study area. Elevation in N-uptake rates with
declining temperature suggests that the SO with its vast quantity of cool water could play an important role in
drawing down the atmospheric CO2 through the “solubility pump”.

1414
Thu_50_BE-2_57
Plankton Production in Open Southern Ocean and Surrounding subantarctic Islands

Luca Stirnimann1 (luca.stirnimann3@gmail.com), Tommy Bornman2,3, Heather Forrer1, Kolisa Sinyanya4, Hans
Verheye5, Sarah Fawcett1
1
University of Cape Town, Oceanography, Cape Town, South Africa, 2South African Environmental Observation
Network (SAEON), Port Elizabeth, South Africa, 3Nelson Mandela Metropolitan University, Ocean Sciences
Campus, Port Elizabeth, South Africa, 4University of Cape Town, Cape Town, South Africa, 5Department of
Environmental Affairs, Oceans and Coastal Research, Cape Town, South Africa

The Southern Ocean supports a complex foodweb which is shaped by the many interactions occurring between
the planktonic system and the physico-chemical conditions of the marine environment, which affect both
primary production and net ecosystem production. Southern Ocean ecosystems are thought to be changing
rapidly due to climate change, yet much remains unknown of the “baseline” state of trophic carbon fluxes,
which is key to understanding the potential ecosystem response to ongoing or future perturbations. We
investigated ecosystem production and plankton trophic dynamics in the waters surrounding the Subantarctic
Prince Edward Island archipelago during two expeditions to the Southern Ocean - the Antarctic
Circumnavigation Expedition (ACE) in December 2016 and a SANAP cruise to Marion Island in April/May 2017.
We collected biological (e.g., plankton abundance, biomass, diversity) and chemical (e.g. dissolved organic
carbon, nutrients, chlorophyll, carbon and nitrogen) samples and measured biogeochemical rates (e.g. primary
and secondary production, net ecosystem production) in the open Subantarctic and in the vicinity of the
islands. Trophic structure, rates of production, nutrient biogeochemistry and their interactions will be
discussed, with a view to better understanding Subantarctic ecosystem carbon cycling.

1415
Thu_51_BE-2_226
Contribution of Small Cells to the Total Primary Production in the Amundsen Sea

Yu Jeong Lim1 (yjlim@pusan.ac.kr), Sang Hoon Lee2, Jisoo Park2, Dabin Lee1, Sang Heon Lee1
1
Pusan National University, Department of Oceanography, Busan, Korea, Republic of, 2Korea Polar Research
Institute (KOPRI), Incheon, Korea, Republic of

The warming ocean is anticipated to increase the importance of small phytoplankton. However, little
information has been reported in the Amundsen Sea. To understand the seasonal variation of the small
contribution to the carbon uptake rates, the 13C-15N dual stable isotope tracer techniques were carried out
during January-February 2016 and the small contributions were compared with the previous results in different
seasons. The total daily carbon uptake rate and the small contribution to the primary production averaged in all
stations were respectively 0.59 g C m-2 d-1 and 24.8 %. In the polynya region alone, the average total daily
carbon uptake rate was 0.72 g C m-2 d-1 and the average small contribution was 24.2 %. The mean proportion of
small cells to the total carbon uptake rates in the polynya region in this study was significantly different from
previous results: 50.8 % in February-March 2012 and 14.9 % in early January 2014 (one-way ANOVA; F = 15.66,
p < 0.01). Different bloom timings of large and small phytoplankton are suggested for causing the large
seasonal variation of small contribution. The total daily carbon uptake rates and the euphotic depths were also
changed largely along the season. A strong negative correlation (r = - 0.52, p < 0.01) between the small
contributions and the total daily carbon uptake rates was found in this study, whereas a strong positive
correlation was found between the small contributions and the euphotic depths (r = 0.75, p < 0.01).

1416
Thu_52_BE-2_234
In-situ Carbon and Nitrogen Uptake Rates of Arctic Melt Pond Algae

Sang Heon Lee1 (sanglee@pusan.ac.kr), Ho Jung Song1, Kwanwoo Kim1, Jae Hyung Lee1, So Hyun Ahn1, Houng-
Min Joo2, Jin Young Jeong2, Eun Jin Yang2, Sung-Ho Kang2
1
Pusan National University, Department of Oceanography, Busan, Korea, Republic of, 2Korea Polar Research
Institute (KOPRI), Incheon, Korea, Republic of

Relatively little studies on melt pond ecosystems have been conducted in the Arctic Ocean although melt ponds
are a ubiquitous feature of summer Arctic sea ice. Twenty two melt pond samples at ice camp 1 (146.17 ºW,
77.38 ºN) and 11 melt pond samples at ice camp 2 (169.79 ºW, 76.52 ºN) were obtained to measure uptake
rates of carbon and nitrogen from various melt ponds in the western Arctic Ocean. The major nutrient
concentrations were largely variable among melt ponds at the ice camps 1 and 2. The chl-a concentrations
averaged from the melt ponds at the camps 1 and 2 were 0.02-0.56 mg chl-a m-3 (0.12 ± 0.12 mg chl-a m-3) and
0.08-0.30 mg chl-a m-3 (0.16 ± 0.08 mg chl-a m-3), respectively. The hourly carbon uptake rates at the camps 1
and 2 were 0.001-0.080 mg C m-3 h-1 (0.025 ± 0.024 mg C m-3 h-1) and 0.022-0.210 mg C m-3 h-1 (0.077 ± 0.006 mg
C m-3 h-1), respectively. In comparison, the nitrogen uptake rates at the camps 1 and 2 were 0.001-0.030 mg N
m-3 h-1 (0.011 ± 0.010 mg N m-3 h-1) and 0.002-0.022 mg N m-3 h-1 (0.010 ± 0.006 mg N m-3 h-1), respectively.
These values obtained in this study are significantly lower than those reported previously. A large portion of
algal biomass caught into new forming surface ice in melt ponds appears to be a main potential reason for the
lower chl-a concentration and subsequently lower carbon and nitrogen uptake rates in this study.

1417
Thu_53_BE-2_314
Water Column Stability Drives Production/export Dynamics in Two WAP Bays

Juan Höfer1,2 (juanhofer@gmail.com), Ricardo Giesecke1,2, Emilio Alarcón2,3, Vania Carrera2, Jose Luis Iriarte2,4,
Humberto E. González1,2
1
Universidad Austral de Chile, Instituto de Ciencias Marinas y Limnologicas, Valdivia, Chile, 2Centro IDEAL,
Valdivia, Chile, 3Centro de Investigación en Ecosistemas de la Patagonia (CIEP), Coyhaique, Chile, 4Universidad
Austral de Chile, Instituto de Acuicultura, Puerto Montt, Chile

Normally the Southern Ocean is characterized by its high nutrient availability and its low chlorophyll
concentrations (High Nutrients Low Chlorophyll or HNLC). Discrepancy, which seems to be caused by the
paucity of micronutrients (e.g. Fe). Nevertheless, this general pattern does not entirely apply in coastal areas
(e.g. bays), where iron is more abundant due to meteoric water inputs (i.e. glacial melt). In the Western
Antarctic Peninsula water column stability has been proposed as the main cause for massive phytoplankton
blooms that attain very high primary production rates.
During the extremely warm summer of 2017 (January and February) we found huge phytoplankton blooms
(chlorophyll > 15 mg m-3) inside Maxwell Bay (King George Island, South Shetland Islands) and South Bay
(Doumer Island, Palmer Archipelago). Accordingly, primary production rates were very high (1.3 - 8.9 g C m-2 d-
1) agreeing with concomitant measures of low pCO2 (< 200 µatm) near surface waters. Fast winds (>70 km h-1)
mixed the water column, breaking the stability promoting phytoplankton blooms and diminishing chlorophyll
concentrations, whereas its downward vertical flux increased.
These findings suggest that bays on the Western Antarctic Peninsula may act as biological “hot spots” (i.e. CO2
sinkholes) gathering phytoplankton, when they present a stable water column, that afterwards may be
exported horizontally (nearby oceanic waters) or vertically (carbon sinking) due to fast winds forcing.

1418
Thu_54_BE-2_320
Macromolecular Compositions of Phytoplankton at the Jang Bogo Station

Kwanwoo Kim1 (goanwoo7@pusan.ac.kr), Sang Heon Lee1

1
Pusan National University, Department of Oceanography, Busan, Korea, Republic of

To obtain the monthly variation in macromolecular compositions (carbohydrates, proteins, and lipids) of
phytoplankton, surface water samples were collected at the Jang Bogo Station (74° 37.4´ S, 164° 13.7´ E)
located in Terra Nova Bay, Antarctica. Samplings were performed approximately once every second week from
February to October, 2015. The total chlorophyll a (Chl-a) concentration was 0.32 µg L-1 (S.D. = ± 0.88 µg L-1)
averaged from our observation period. The phytoplankton community was dominated by large-sized
phytoplankton (> 20 µm) accounting for 58.9 ± 18.5 % (mean ± S.D.) of the total Chl-a concentration, followed
by middle-sized (2-20 µm; 26.8 ± 10.5 %), and small-sized phytoplankton (0.7-2 µm; 14.3 ± 9.4 %). Overall,
carbohydrates were dominant components of total phytoplankton with a mean of 69.3 % (± 13.8 %) and had an
increasing trend over our study period except February 9, 2015. On the other hand, protein contribution was
lowest (9.4 ± 11.0 %) except February, 2015 and had a decreasing trend from February to October. Lipids,
however, did not show any specific trend with a few fluctuations (21.4 ± 4.4 %). In comparison, the overall
contributions of carbohydrates, proteins and lipids of small phytoplankton were 68.8% (± 12.0 %), 6.5 % (± 9.2
%) and 24.6 % (± 5.9 %), respectively.

1419
Thu_55_BE-2_559
Carbonate Sensitive Phytotransferrin Controls High-affinity Fe Uptake in Diatoms

Jeff McQuaid1,2 (jmcquaid@jcvi.org), Adam B. Kustka3, Miroslav Obornik4, Aleš Horák4, John P. McCrow1,
Bogumil J. Karas1, Hong Zheng1, Theodor Kindeberg2, Andreas J. Andersson2, Katherine A. Barbeau2, Andrew E.
Allen1,2
1
J. Craig Venter Institute, Environmental Genomics, San Diego, United States, 2Scripps Institution of
Oceanography, UC San Diego, San Diego, United States, 3Rutgers University, Earth and Environmental Sciences,,
Newark, United States, 4Institute of Parasitology and University of South Bohemia, Biology Centre ASCR, Faculty
of Science, Ceske Budejovice, Czech Republic

In large regions of the Southern Ocean the scarcity of iron controls the growth and productivity of
phytoplankton. While most dissolved iron in the marine environment is complexed to organic molecules,
picomolar amounts of unchelated ferric iron (Fe′) are maintained within the euphotic zone and are an
important source of iron for eukaryotic phytoplankton, particularly diatoms. In the model diatom
Phaeodactylum tricornutum, we show high-affinity Fe′ acquisition is mediated by phytotransferrin, a
endocytosis-dependent functional analog of transferrin. Like transferrin, phytotransferrin coordinates the
binding of iron with carbonate (CO32-), and manipulation of the carbonic acid system reveals that the synergistic
binding of [Fe′] and [CO32-] occurs at environmentally relevant concentrations of seawater carbonate, and
[CO32-] co-limits Fe′ uptake. We show phytotransferrin has broad phylogenetic distribution among marine
eukaryotes and is abundant in Southern Ocean genomic and proteomic datasets, suggesting that ocean
acidification and the decline in seawater [CO32-] will negatively impact this iron acquisition mechanism, with
possible implications for carbon export rates and marine biogeochemical cycles.

1420
Thu_56_BE-2_642
Enhancing of Biological Pump in the Chukchi Sea Based on Chinese Arctic Cruises

Jianfang Chen1 (jfchen@sio.org.cn), Haiyan Jin1, Yanpei Zhuang1, Youcheng Bai1, Hongliang Li1
1
Second Institute of Oceanography, State Oceanic Administration, Laboratory of Marine Ecosystem and
Biogeochemistry, Hangzhou, China

With decreasing of sea ice cover there would the potential for deepening of nutricline and an increasing of
annual biological pump in the Arctic Ocean because of more nutrients in the euphotic zone will be consumed in
an ice free sea or open ocean. Since 1999 (in summers, 1999, 2003, 2008, 2010, 2012, 2014, 2016), seven
Chinese Arctic Expeditions has been carried out in Chukchi Sea and Canadian Basin where upper ocean
nutrients are abundant compared with European sector of the Arctic Ocean. During those cruises, we analyzed
nutrients, DO, pH, chl a, opal and HPLC pigments in the water column, which allow us to look the variation of
nutricline and biological pump after sea ice retreat since 1999. The results showed that size fractionation of chl
a and opal, chl a-maximum depth, phytoplankton communities changed dramatically in the West Arctic Ocean,
especially along the longitudinal 170°W section since 1999. A highlight of those changes is deepening of
nutricline in summer and increasing of the depth of chl a-maximum in the shelf waters such as Chukchi Sea and
ice edge in the Canadian Basin since1999. Organic carbon, opal burial and biomarkers records in sedimentary
cores in the Chukchi Sea also indicated that increasing of organic carbon burial and relative abundance of
diatoms while the contributions of haptophytes decreased since last 250a. We will involve MOSAIC program
and future Chinese cruises in the west Arctic Ocean focusing on biological pump observation.

1421
Thu_57_BE-2_647
Sedimentary Pigments as Biomarkers of Benthic Communities in Kongs-Krossfjorden

Archana Singh1 (archana.singh199101@gmail.com), K. P. Krishnan1

1
National Center for Antarctic and Ocean Research, Arctic Division, Vasco da Gama, India

In the present study, the surface sediments from Kongsfjorden-Krossfjorden, Arctic were examined for spatial
distribution and biomarkers of benthic communities. Photosynthetic pigments (chlorophyll a and b), accessory
pigments (fucoxanthin, zeaxanthin, alloxanthin, lutein etc.), and chlorophyll a decomposition products
(chlorophyllide a, pheophorbide a, pheophytin a) from surface sediments were analyzed using high
performance liquid chromatography. The distribution of pigments was found to be spatially variable with
overall greater concentrations in Krossfjorden than Kongsfjorden. In both the fjords, the most abundant
pigment was chlorophyll-a (0.1-0.8 µg g-1) followed by pheopigments (0.06-0.6 µg g-1) with greater
concentrations recorded in mid-fjord stations, indicating the productivity distribution within the fjord. Similarly,
the concentration of β-carotene (total algal abundance) & carotenoids like alloxanthin (cryptophyta),
fucoxanthin (diatoms), lutein (Chlorophyta, Euglenophyta, Plantae) and zeaxanthin (cyanobacteria) recorded to
be elevated at middle of fjord, but peaked at outer fjord stations. The ratio Chl-a:pheo was >1 in most stations,
indicating that chlorophyll-a was preserved despite grazing and degradation pathways that accumulate
pheopigments. The overall study outlines the spatial distribution of benthic communities in the two fjords and
baseline for further ecological studies to be undertaken for the region.

1422
Thu_58_BE-2_741
The Effect of Climate Change on the Carbon Balance in Microalgae

Deborah Bozzato1 (deborah.bozzato@uni-leipzig.de), Torsten Jakob1, Christian Wilhelm1

1
University of Leipzig, Plant Physiology, Leipzig, Germany

The Southern Ocean is an important sink for the atmospheric CO2 due to the physical and the biological
(photosynthetic) activity of phytoplankton. Some studies have investigated the photosynthetic activity of the
benthic and pelagic producers, but there is only very scarce knowledge about the carbon losses due to
respiration of phytoplankton. The reason for this lack of information is principally methodological limitations. In
the light of expected changes of environmental conditions due to the climate change, the aim of the project is
to investigate the range of variability of photosynthesis over respiration ratio (rP/R) in response to different
growth conditions, namely: different temperatures, water salinity and in dependence on iron availability. In this
respect, two key species of the Southern ocean are investigated: the diatom Fragilariopsis cylindrus and the
prymnesiophyte Phaeocystis antarctica.

1423
Thu_59_BE-2_756
Particle Flux and the Biological Pump in Prydz Bay, Antarctica

Zhengbing Han1 (hzbing@sio.org.cn), Jianming Pan1, Chuanyu Hu1, Jun Zhao1, Weiping Sun1, Haifeng Zhang1,
Dong Li1, Gaojing Fan1
1
Second Institute of Oceanography, SOA, Hangzhou, China

The ''biological pump” (BP) plays a central role in the sequestration of carbon away from the atmosphere for
long time. Sea ice change, slope transport, CDW upwelling and other climate change processes will change the
Antarctic BP process and efficiency. Between 2009 to 2017, ten sets of mooring system with sediment trap
were deployed in the Prydz Bay to study the seasonal variations of particle fluxes. 6 moorings with 7 sediment
traps were successfully recovered. The annual average flux of organic carbon (OC) and biogenic silica (BSi) were
comparable to other similar Antarctic seas. The summer flux is the main contribution of the whole year flux, ca.
>80%. The major contributor to the total mass flux was BSi. Comparison of remote sensing data, there are
significant inter-annual differences. The results of carbon and nitrogen stable isotopes show that, the lowest
organic carbon flux during the summer of 2014/2015 may be caused by strong lateral transport from east,
thereby in-situ production of high organic matter cannot settle down to the trap. In deep ocean, the upper
fluxes were extremely low while the lower fluxes relatively high during winter, which may be explained by
sediment suspension or lateral transport. High fecal flux during winter suggest that strong biological process
would happened on the continental slope. This speculation requires further evidence, and it could improve a
better understanding of the link between the BP and Antarctic ecological process.

1424
Thu_60_BE-2_778
Effects of Iron Bioavailability on Plankton Communities from the Southern Ocean

Damien Cabanes1 (damien.cabanes@unige.ch), Sonia Blanco-Ameijeiras1, Scarlett Trimborn2,3, Sonja

Wiehmann2, Christian Volkner2, Dorothee Wilhelms-Dick2, Tina Brenneis2, Heike Simon4, Matthias Sieber5,
Jasmin P Heiden2,3, Florian Lelchat1, Astrid Bracher2,3
1
University of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences, Geneva, Switzerland,
2
Alfred Wegener Institute, Bremerhaven, Germany, 3University of Bremen, Bremen, Germany, 4University of
Oldenburg, Oldenburg, Germany, 5ETH Zurich, Zurich, Switzerland

Organic ligands such as saccharides and exopolymeric substances (EPS) are known to complex with iron (Fe)
and influence Fe bioavailability to phytoplankton. In this work, we addressed how Fe enrichment associated to
organic binding ligands influences productivity and biodiversity of natural phytoplankton communities from
two sites of the Drake Passage and one from the Western Antarctic Peninsula. At each station, short- (24h) and
long- (6d) term incubations were performed with the in-situ phytoplankton community without (control
treatment) and after addition of different Fe-binding ligands including: the siderophore desferrioxamine B, two
saccharides, two different bacterial EPS and a virally degraded EPS. While siderophores consistently decreased
Fe uptake rates, effects of saccharides and EPS were variable the different plankton size fractions. Additionally,
Fe speciation measurements allowed us to characterize the pool of Fe-binding ligands naturally present in the
samples, and determine the impact of the added organic ligands on Fe bioavailability and phytoplankton
productivity. Our results illustrate that the different organic ligands used have great capability to differentially
modulate Fe bioavailability for different plankton groups. The simultaneous characterization of chemical and
biological parameters provides valuable insights in the rarely carried out relationship between Fe chemistry
and Fe bioavailability.

1425
Thu_62_BE-2_914
Seasonality of Carbon Cycling in the Kerguelen Bloom Reveals by Autonomous Tools

Stephane Blain1 (stephane.blain@obs-banyuls.fr), Jacqueline Boutin2, Liliane Merlivat2, Herve Claustre3,

Mathieu Rembauville4
1
UPMC, LOMIC, Banyuls sur Mer, France, 2CNRS, Paris, France, 3CNRS, Villefranche sur Mer, France, 4UPMC,
Banyuls sur Mer, France

The central Kerguelen plateau hosts a recurrent massive phytoplankton bloom essentially sustained by natural
iron fertilization. During the past decade, this bloom has been extensively studied thanks to oceanographic
cruises but a complete view of the seasonal dynamics was still missing. The SOCLIM project has filled this gap
with the deployments of both instrumented moorings and biogeochemical Argo floats. The subsurface mooring
(40 m) was equipped with biogeochemical sensors and a remote autonomous sampler. Two sediment traps
were also deployed at 300 m at the same site. This 1D view was completed by 2 BGC argo floats that drifted
close to the moorings and captured the export events. The data collected during SOCLIM will allow to
understand the interplay between environmental factors (light, nutrients) and bloom dynamics, and how
biological activity and ecological vectors contributes to the CO2 sink and carbon storage in the deep waters.

1426
Thu_63_BE-2_922
Satellite Study on Particulate Inorganic Carbon Content within E. huxleyi Blooms

Dmitry Kondrik1 (dmitry.kondrik@niersc.spb.ru), Dmitry Pozdnyakov1, Lasse Pettersson2

1
Nansen International Environmental and Remote Sensing Centre, St. Petersburg, Russian Federation, 2Nansen
Environmental and Remote Sensing Centre, Bergen, Norway

By implementing the developed methodologies of E. huxleyi blooms identification and special processing
algorithms to the satellite data, multi-year time series of variations in occurrence, spatial extent, and content of
particulate inorganic carbon (PIC) within E. huxleyi blooming areas in the North, Norwegian, Greenland,
Barents, and Bering Seas were obtained for the time period 1998-2013. The analysis of obtained results
permitted to reveal the specific features of E. huxleyi blooming events in the studied regions. During the intra-
annual cycle, E. huxleyi blooms advance from temperate to higher latitudes along the pathways of the Gulf
Stream propagation starting from North and Norwegian Seas (in early June), and ending in the Barents Sea (in
late July-early September). The highest bloom areas in the North Atlantic-Arctic waters were registered in the
Barents Sea (up to 250,000 km2). The same pattern holds for the total PIC content within E. huxleyi blooms:
values of this parameter reached the amount of ~0.35 Mt in the Barents Sea. In the Bering Sea, the temporal
and spatial dynamics of E. huxleyi development proved to be highly irregular: before and after the 1997-2001
period of high intensity of this phenomenon, the blooms are sporadic, their extent and PIC production are
either very low or insignificant, whereas during 1997-2001, it even exceeded the values for the Barents Sea: up
to ~0.4 Mt and, on one occasion (in 2001), even about ~0.7 Mt.

1427
Thu_64_BE-2_929
Dissolved CO2 Increase within Coccolithophore Blooms in Subpolar and Polar Seas

Dmitry Pozdnyakov1 (dmitry.pozdnyakov@niersc.spb.ru), Dmitry Kondrik1, Ola Johannessen2

1
Nansen International Environmental and Remote Sensing Centre, St. Petersburg, Russian Federation, 2Nansen
Scientific Society, Bergen, Norway

Coccolithophore E. huxleyi cause less uptake of atmospheric CO2 by the ocean. A global assessment of this
phenomenon has so far not been quantified. We used Ocean Colour Satellite time series data for a 19-year
period (1998-2016) to quantify the CO2 partial pressure increase (ΔpCO2) within E. huxleyi blooms in the North,
Norwegian, Greenland, Barents, and Bering Seas. E. huxleyi outbursts in the North Atlantic and Arctic Seas
proved to occur annually, but their extent vary interannually. In the Bering Sea, during 1998-2001 there was a
splash in blooming activity followed by a drastic drop. The bloom duration in the Bering Sea in 1997/98-2001
reached 10 months, in the North Atlantic seas it was ~ 1 month. The maximum inorganic carbon content in E.
huxleyi blooms in all seas varied over the 19 years between ~ 15 and 70 Kt. When normalized to pCO2 in the
absence of bloom, the mean and maximum ΔpCO2 values within the bloom areas varied in percent between
21.0 - 43.3 and 31.6 - 62.5, respectively. Utilizing OCO2 spaceborne data on columnar pCO2, we also quantified
changes in atmospheric columnar CO2 over E. huxleyi blooms in the target seas and documented a reversion of
CO2 flux from ocean to atmosphere. As huge outbursts of E. huxleyi also occur in the southern hemisphere,
such blooms unfold in the world oceans across the entire year. Our data can serve as a baseline for assessing
the importance of the phenomenon for climatology, marine chemistry and ecology on a global scale. 


1428
Thu_66_BE-2_1319
Zooplankton Mediate Faecal Pellet Fluxes across Southern Ocean Environments

Cecilia Liszka1,2 (ceclis56@bas.ac.uk), Carol Robinson2, Gabriele Stowasser1, Clara Manno1, Geraint Tarling1
1
British Antarctic Survey/NERC, Ecosystems, Cambridge, United Kingdom, 2University of East Anglia, ENV,
Norwich, United Kingdom

The Southern Ocean (SO) is the world's greatest carbon sink and, via carbon uptake and sequestration, the SO
Biological Carbon Pump exerts a strong control over global climate. Central to its efficiency is the production
and fate of zooplankton faecal pellets (FPs), particularly the magnitude of, and processes governing, FP flux to
depth. Primary productivity and seasonal ice cover vary considerably across the SO, impacting secondary
consumption and FP production. Constraining this variability is crucial for improving SO representation in ocean
biogeochemical models.
We address this by investigating the distribution and fate of FPs over 400m, the region where attenuation is
potentially highest. We studied three sites within the Scotia Sea: i) ice-influenced; ii) comparatively
oligotrophic; and iii) within a seasonally extended phytoplankton bloom. FPs obtained from CTD bottles and
mesozooplankton from net samples were analysed to derive estimates of and investigate controls on FP flux
from the epi- to mesopelagic. Within the top 200 m, FP fluxes varied by a factor of 6 but, at 400m, by < 3. We
suggest that, whilst FP production in surface waters may vary between productivity regimes, zooplankton-
mediated controls on remineralisation and FP lability can act to narrow differences in respective levels of
export. This has implications for our understanding of carbon export at intermediate depths, and for resulting
carbon sequestration to bathypelagic depths in differing regimes.

1429
Thu_67_BE-2_1470
Low Mesoscale Kinetic Energy as a Precondition for Blooms in the Southern Ocean

Joseph Gradone1 (jgradone@udel.edu), Matthew Oliver1, Alexander Davies2

1
University of Delaware, Marine Science and Policy, Lewes, United States, 2United States Naval Academy,
Oceanography Department, Annapolis, United States

In the Southern Ocean, surface waters are typically macro-nutrient rich in the austral summer, yet they are
characterized by patchy, intense phytoplankton blooms within a generally unproductive environment. Due to
the remoteness and harsh conditions, there are a dearth of in-situ chlorophyll observations in the Southern
Ocean. Furthermore, persistent clouds and low sun-angle make remote sensing observations of chlorophyll
comparatively rare. However, we have detected a hyperbolic relationship between satellite estimates of
chlorophyll and radar-based satellite estimates of surface current kinetic energy. This is important because
satellite derived estimates of kinetic energy, which are not hampered by cloud cover, and can possibly be used
to improve estimates of total Southern Ocean biomass. While iron is a major limiting factor for Southern Ocean
phytoplankton blooms, our analysis suggests there is a low-kinetic energy pre-condition before large
phytoplankton blooms can occur. This is observed by both satellite and Argo biofloats, suggesting that kinetic
energy estimates from space serve as a proxy for ecologically relevant mixing of phytoplankton populations in
the Southern Ocean.

1430
Thu_68_BE-2_1494
Carbon Uptake in Bi-polar Regions and their Responses to Climate Change

Zhongyong Gao1 (gaozhongyong@tio.org.cn), Heng Sun1, Liqi Chen1, Di Qi1

1
Third Institute of Oceanography, State Oceanic Administration (SOA), Key Laboratory of Global Change and
Marine-Atmospheric Chemistry (GCMAC), SOA, Xiamen, China

Carbon uptake data sea were integrated from the 1999 to 2017 not only in the Antarctic, but also in the Bering
Sea and the Western Arctic Ocean. Both ere summer cruises of the Chinese National Arctic and Antarctic
Research Expedition (CHINARE). Parameters including CO2 system parameters etc., were well measured. Bering
carbon sink, Arctic carbon sink, and the Southern carbon sink were all well calculated during the past two
decades. Both Bi-polar carbon sink including Bering carbon sink were well compared with each other. Results
showed distinguished differences between the bi-polar ocean carbon sink. The Bering Basin carbon uptake was
almost remained stable compared with its adjoin spacious Pacific Ocean, however, those in Bering Slope
Current region was coincide well with climate change. Due to rapid Arctic Change, Chukchi Sea's carbon sink
was remained strong uptake during the past two decades, where nutrients was supplied well by the Pacific
inflow, however, the other regions where there were not nutrients supply was different change. In Contrast,
the Southern Ocean carbon sink was response to the climate change in December, however, there was
negative feedback was observed during Astral Summer season due to the bio-production, especially in Prydz
Bay, Antarctic.
Acknowledgement: This Work is supported by Fujian Science Fund for Leading talents of science and
technology innovation and National Natural Science Foundation of China (NO. 40976173).

1431
Thu_69_BE-2_1859
Effects of High CO2 on Pteropod Contribution to Carbonate Flux in the Ross Sea

Kirstie Jones-Williams1,2 (kirnes79@bas.ac.uk), Clara Manno1, Victoria Peck1, Robert Upstill-Goddard2, Laura
Cutroneo3, Marco Capello3
1
British Antarctic Survey, Cambridge, United Kingdom, 2Newcastle University, Newcastle-upon-Tyne, United
Kingdom, 3Universita' degli Studi di Genova, Genova, Italy

The Southern Ocean (SO) plays a key role in global climate and biogeochemical cycles. Thecosomate pteropods
(calcareous molluscs) are the main planktonic producers of aragonite in the world's oceans and in the SO they
can contribute to > 50% of the total biogenic carbonate export. Pteropods are vulnerable to the forecasted
increase in ocean acidification (OA), owing to their aragonite shell which is prone to dissolution. Understanding
pteropod flux dynamics is crucial in order to predict how a drop in their population will impact the balance
between Particulate Inorganic Carbon (PIC) and Particulate Organic Carbon (POC) export to the deep ocean.
Here we present an investigation of pteropods collected from subsurface and deep moored sediment traps in
Terra Nova Bay, Ross Sea for one year. In this region, the presence of CO2-rich water masses promotes OA.
Pteropod abundance and biomass were investigated to assess their contribution to deep carbonate export.
Level of shell dissolution was estimated by scanning electron microscope (SEM) to evaluate the impact of OA
on shell condition. Results highlight the significance of pteropods as a vector for carbon export, contributing up
to 88% of the total carbonate flux. The observation of a mass mortality of larval stage pteropods along with
extensive “in-life” shell dissolution amongst all individuals, highlights (with in situ evidence) the threat of OA to
the key role of pteropods within the SO carbonate system.

1432
Thu_70_BE-2_1975
Is There More to Diel Vertical Migration?

Vicky Dewar-Fowler1,2 (vicwle19@bas.ac.uk), Geraint Tarling1, Ryan Saunders1

1
British Antarctic Survey, Cambridge, United Kingdom, 2University of East Anglia, Norwich, United Kingdom

The Southern Ocean plays an important role in moderating our climate through the biological carbon pump
(BCP), in which atmospheric carbon is drawn down and sequestered into the deep ocean through a
combination of biological and physical processes. The zooplankton community plays a key role in BCP both
through their individual vertical migrations and also in the generation of waste matter that may rapidly sink,
both of which contribute to a process termed active flux. Vertical migration in zooplankton is a well described
phenomenon where animals migrate on mass from depth to the surface layers to feed under the cover of
darkness and return to depth during the daylight hours. However, recent studies suggest that individual
zooplankton may also make several shorter migrations into shallow waters, termed forays, over the course of
24 hours. These forays may lead to an increase in active flux and could augment the BCP. Here we aim to use
novel technology and traditional methods to look at migration behaviour at both the individual and population
level. In particular, we have developed a 2-way net trap that can be deployed in open-ocean environments
which can intercept individuals during their forays. We identify the main migrators that participate in foray
behaviour in the Scotia Sea, which is a key region of carbon drawdown in the Southern Ocean.

1433
Thu_71_BE-2_2031
Influence of Coccolithophore Species-specific Growth Rates on Calcite Production

Kyle Mayers1,2 (kyle.mayers@soton.ac.uk), Stephanie Allen1,2, Alex Poulton3

1
University of Southampton, Southampton, United Kingdom, 2National Oceanography Centre Southampton,
Southampton, United Kingdom, 3The Lyell Centre, Heriot-Watt University, Edinburgh, United Kingdom

Coccolithophores are single celled phytoplankton which produce an exoskeleton of calcium carbonate plates.
The production and export of these coccoliths play a major role in ocean carbon cycling. The rates at which
species produce coccoliths, as well as the calcite content of species can influence the flux of carbon from the
euphotic zone.
In this study, we measured the abundance, biometry and species specific growth rates of coccolithophores on
the extended Ellett line between Scotland and Iceland during June 2015. The coccolithophore community was
dominated by Emiliania huxleyi and the larger species Coccolithus pelagicus. Abundances of E. huxleyi and C.
pelagicus varied from 22-1,500 and 0.3-129 cells mL-1 respectively. However, C. pelagicus accounted for 20-95%
of daily calcite production due to its larger calcite per cell content and similar growth rates to E. huxleyi. Across
the entire cruise the average contributions to calcite production was 55 and 45% for E. huxleyi and C. pelagicus
respectively.
This research highlights the importance of species specific rates when considering biogeochemical rates, as less
abundant but larger species can dominate calcite production. How different species respond to environmental
change will also impact on regional carbon dynamics.

1434
Thu_72_BE-2_2367
Phytoplankton variability in the Indian Ocean sector of the Southern Ocean

R K Mishra1 (rajanimishra@ncaor.gov.in), Ravidas Krishna Naik2, N Anilkumar2, Babulal Jena2

1
National Centre for Antarctic & Ocean Research (ESSO-NCAOR), Southern Ocean, vasco-da-Gama, India, 2ESSO-
National Centre for Antarctic and Ocean Research, vasco-da-Gama, India

The phytoplankton communities, adaptations and variations in the frontal ecosystems of the Indian sector of
the Southern Ocean (IOSO) have been investigated along with the sea surface temperature (SST), sea surface
wind (SSW), photosynthetically active radiation (PAR), and nutrients. The in situ, model and satellite
observations during austral summer 2013 indicates that the variability of chlorophyll a (Chl-a) and diatoms
were primarily influenced by light and wind. The Chl-a was higher in the sub-Antarctic front (SAF) followed by
the sub-tropical front (STF) and the polar front (PF). However, in throughout the period during 1998-2012, the
diatoms concentration was higher at the SAF followed by the PF and STF. Dominance of diatoms at the PF may
be attributed to their adaptability for low light conditions. During a time series (1998-2014) in austral summer
the diatoms contribution to the Chl-a biomass was ≥80% at the PF. On the other hand, the chlorophytes to Chl-
a biomass showed ≥70% at the STF and gradually decreased towards the PF mainly attributed to the temperate
adaptation. The variability of flagellates and diatoms from the STF to PF is attributed to the variability of PAR,
SST and SSW.The results from this study of the frontal ecosystems would help to understand the shifting of
communities in the ecosystem, biogeochemical cycle of the IOSO.

1435
Thu_74_BE-2_2483
Trends in Primary Production under the New Arctic Sea-ice Regime

Pedro Duarte1 (pedro.duarte@npolar.no), Philipp Assmy1, Lasse M. Olsen1, Hanna M. Kauko1, Mar Fernandéz-
Méndez1, Haakon Hop1,2, Mats A. Granskog1, Gunnar Spreen3, Harald Steen1
1
Norwegian Polar Institute, Tromsø, Norway, 2Faculty of Biosciences, Fisheries and Economics, UiT The Arctic
University of Norway, Department of Arctic and Marine Biology, Tromsø, Norway, 3Institute of Environmental
Physics, University of Bremen, Bremen, Germany

Here we analyze trends in sea-ice primary production (PP) under the new thinner and more dynamic Arctic sea-
ice regime using empirical data and various biogeochemical models, ranging from analytical to numerical and
from one-dimensional vertically-resolved to three-dimensional. We argue that the traditional conceptual view
of a spring phytoplankton and ice algal bloom in the Marginal Ice Zone (MIZ) following its progression as a PP
“front”, should be replaced by a “network view”. This view does not contradict the existence of a frontal PP
zone, but it merely acknowledges the effect of the thinner and more dynamic ice cover in creating a fractal
network of refrozen light conduits, deep into the ice pack, along which phytoplankton and ice algal growth
rates may be enhanced. We further argue that this network will lead to an increase in spring phytoplankton
areal PP under the ice pack, ultimately limited by nutrient availability. However, the outcome of these light
conduits is not so obvious for ice algae. In spite of the increased growth rates, nutrient and recruitment
limitation in the expectably more frequent and extensive young sea ice along the light conduits may prevent
standing stocks from reaching the levels observed in older ice types. These bottlenecks may be partly
compensated by horizontal spreading of transmitted light to thick ice and ridges bordering the refrozen areas,
where ice algal standing stocks are higher and not recruitment limited.

1436
Thu_75_BE-2_2484
Arctic Ocean Carbon Cycle Response to Atlantification and CO2 Invasion

Tatiana Ilyina1 (tatiana.ilyina@mpimet.mpg.de), Hongmei Li1, Katharina Six1, Mikhail Dobrynin2

1
Max Planck Institute for Meteorology, Hamburg, Germany, 2Universität Hamburg, Institute of Oceanography,
Hamburg, Germany

Arctic Ocean carbon cycle is a hotspot for strong perturbations driven by rising CO2 emissions and concomitant
climate change in future projections. We investigate these perturbations with the Max Planck Institute´s Earth
System Model, focusing on the high CO2 scenario RCP8.5 extended until 2300. Model results project an SST
increase in the Arctic Ocean by 4°C in 2100 and by 10°C in 2300, respectively, accompanied by the loss of
summer and eventually also the winter sea ice. Warming enhances thermal stratification, but ice free water
favors formation of convection cells. Intensification of the Atlantic water inflow leads to erosion of the
halocline in the central basin of the Arctic Ocean. The carbon cycle responds to these complex hydrodynamic
changes, but is also directly affected by the uptake of anthropogenic CO2. We will show that while future
changes in the Arctic Ocean carbon cycle proceed at rates determined by atmospheric CO2 levels, the regional
patterns are driven by shifts in the hydrodynamic regime.

1437
Thu_76_BE-2_2582
Timing of Meroplankton in Different Arctic Primary Production Regimes

Janne E. Søreide1 (janne.soreide@unis.no), Eike I Stübner1, Tove M. Gabrielsen1, Paul Renaud2, Jørgen Berge3,
Marit Reigstad3, Slawomir Kwasniewski4, Katarzyna Blachowiak-Samolyk4, Rafal Boehnke4
1
The Univeristy Centre in Svalbard, Department of Arctic Biology, Longyearbyen, Norway, 2Akvaplan-niva AS,
Tromsø, Norway, 3UiT The Arctic University of Norway, Tromsø, Norway, 4Institute of Oceanology Polish
Academy of Sciences, Sopot, Poland

Larvae of benthic organisms that temporarily inhabit the pelagic environment (meroplankton), are important
contributors to coastal Arctic marine zooplankton communities. Their seasonal dynamics is, however, poorly
described due to their small size and limited presence in the pelagic. Here we present high resolution
meroplankton data from three different fjords in the Svalbard archipelago, one ice-free fjord and two
seasonally ice covered fjords. Among the eight main meroplankton groups that were present the most
important were Cirripedia and Bivalvia.
Based on 5 seasonal data sets from these three fjords with different primary production regimes, we conclude
that the timing of meroplankton is mainly steered by the timing of the phytoplankton bloom, and less by ice
algae and hydrography. Reduction in sea ice cover and thickness may lead to changes in the onset, duration
and magnitude of the phytoplankton bloom, and eventually the meroplankton seasonal dynamics in a future
warmer Arctic.

1438
Thu_77_BE-2_2592
Metagenomic Analysis of Antarctic Communities of Thalassiosirales Diatoms

Mariela Guajardo1 (mari.igm.bi@gmail.com), Mario moreno1, Rodrigo de la Iglesia2, Nicole Trefault1

1
Universidad Mayor, GEMA Center for Genomics, Ecology and Environment, Santiago, Chile, 2Pontificia
Universidad Católica, Facultad de Ciencias Biológicas, Santiago, Chile

Antarctic coastal regions are highly productive ecosystems characterized by temperatures below the freezing
point, complete darkness in winter and continuous day light and high UV radiation in summer. In these
systems, photosynthetic microorganism, especially diatoms, are the base of the food web, contributing in great
manner to carbon fixation and intake during spring and summer blooms. Thalassiosirales inhabiting this
environment have adapted their physiology to maintain their basic functions in these extreme conditions. In
this work, we aim to analyze the metagenomic features allowing Antarctic diatom communities to thrive in this
environment.
Metagenomes corresponding to pico and nano- phytoplankton communities from a short diatom bloom were
analyzed by standard bioinformatic analyses. Our results show that:
i) The major diatom group was Thalassiosirales order, representing 43 and 73 %, with members belonging to
Detonula, Skeletonema and Thalassiosira genus.
ii) We observed a large number of genes related to photosynthesis and genetic information processing.
iii) Functional predictions of ORFs assigned to Thalassiosirales show a substantial number of heat shock
proteins, DEAD- box, RNA helicases, fatty acid desaturases and other proteins involved in functions that are
indicative of a low-temperature-adapted metabolism.
Our results remark the special characteristic of an important Antarctic community member as Thalassiosirales,
who has a key role in this environment.

1439
Thu_78_BE-2_2639
Long Time-series of POC Fluxes over Arctic and Antarctic Margins

Leonardo Langone1 (leonardo.langone@ismar.cnr.it), Robert Dunbar2, Federico Giglio1, Clara Manno3, David
Mucciarone2, Marco Capello4, Laura Cutroneo4, Walker O. Smith5, Stefano Aliani6, Alessandra D'Angelo1,
Stefano Miserocchi1, Manuel Bensi7, Vedrana Kovacevic7
1
CNR-ISMAR, National Research Council, Bologna, Italy, 2Stanford University, Stanford, United States, 3BAS,
Cambridge, United Kingdom, 4University of Genoa, Department of Earth, Environmental and Life Sciences
(DISTAV), Genoa, Italy, 5Virginia Institute of Marine Science, Gloucester Point, United States, 6CNR-ISMAR,
National Research Council, La Spezia, Italy, 7OGS, Trieste, Italy

The export of particulate organic carbon (POC) from the sea surface is an essential part of the biological pump.
POC from the upper layers is delivered to the deep ocean, which retains CO2 for a relatively long period
compared with the epipelagic CO2 residence time.
This work summarizes POC fluxes measured in the past 25 years in the Ross Sea (Antarctica) and western
Svalbard (Arctic) by using moored sediment traps.
In the Ross Sea, fluxes of POC and total mass are well correlated implying that particle fluxes are dominated by
biogenic debris. Annual POC fluxes to below 200 m average 4.4±3.3 g C m-2 y-1. Particle fluxes are relatively low
when primary production is high (spring-summer) followed by enhanced sedimentation in late summer-fall.
The high degree of decoupling between production and sedimentation is unusual compared to records of
Antarctic Peninsula and may represent low grazing rates.
In the past decades, the decrease of sea-ice in Fram Strait (NW Svalbard) is significant. From 2002, water
temperature increases in general, while POC fluxes tend to decrease. Starting from 2010, moored sediment
traps have been deployed also in SW Svalbard slope. Here, marine POC fluxes show the typical temporal
variability of high latitudes with higher content of biogenic compounds in spring-summer linked to
phytoplankton blooms. However, most of the POC is laterally advected in late winter by occasional intrusions of
warmer, saltier, less dense and more oxygenated water.

1440
Thu_79_BE-5_144
Potential Primary Production of Microphytobenthos in the Changing Potter Cove

Ralf Hoffmann1 (ralf.hoffmann@awi.de), Angela Wulff2, Adil Yousif Al-Handal2, Ulrike Braeckman3, Dolores
Deregibus4, Frank Wenzhöfer1
1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Deep Sea Ecology and
Technology, Bremerhaven, Germany, 2University of Gothenburg, Biological and Environmental Science,
Gothenburg, Sweden, 3Ghent University, Department of Biology, Ghent, Belgium, 4Instituto Antártico Argentino,
Departamento de Biología Costera, Buenos Aires, Argentina

The retreating Fourcade glacier in Antarctic Potter Cove uncovered new space for primary production. Thought,
pelagic and macroalgae primary production does not provide enough organic carbon to feed the benthic
community. Benthic microalgae, the microphytobenthos (MPB), are proposed to partly provide the required
organic carbon. To estimate the potential primary production from MPB, we incubated 12 intact sediment
cores from three stations (8 m depth) at increasing light intensities (up to 70 µmol photons/m² s) and
measured the oxygen exchange. Further, we measured in situ photosynthetic active radiation (PAR, 400-700
nm), chlorophyll a (Chl a), and the MPB composition. The diatom Gyrosigma fasciola was the most occurring
species at all stations, while Chl a showed large intra- and inter station-specific variability. In situ PAR intensities
partially exceeded the calculated light compensation point of the MPB, which indicates MPB as a potentially
important carbon source for the heterotrophic benthic community. However, primary production differed
strongly between the stations, following the general Chl a pattern. Further, PAR availability depends on
turbidity, caused by melting related processes and its distribution in Potter Cove by wind and currents.
Therefore, our study is a first step to reveal the contribution of microphytobenthic primary production in Potter
Cove and thereby expand our understanding of how melting glaciers may alter Antarctic coastal primary
production.

1441
Thu_80_BE-5_191
Identifying Vulnerable Ecosystems in an Antarctic Coastal Marine Environment

Jodie Smith1 (jodie.smith@ga.gov.au), Kim Picard1, Ian Atkinson1, Michael Kumpis2, Ursula Harris3, Philip
O'Brien4
1
Geoscience Australia, Canberra, Australia, 2Royal Australian Navy, Canberra, Australia, 3Australian Antarctic
Division, Hobart, Australia, 4Macquarie University, Sydney, Australia

Monitoring changes in shallow-water benthic ecosystems requires baseline information against which any
future changes can be assessed. This includes information on the existing spatial extent and physical habitat
requirements of the different benthic communities.
A detailed study in shallow coastal waters of the Vestfold Hills has shown that seafloor geomorphology
information provides a physical framework for understanding benthic habitats and a broad indication of the
distribution of benthic communities in the region. Macroalgae is common in the coastal waters, inhabiting very
shallow areas with hard substrate. Areas with extended sea ice cover are dominated by invertebrates and are
devoid of macroalgae. Studies have shown that these shallow invertebrate-dominated ecosystems are
vulnerable to changes in sea ice extent which will increase light availability and drive regime shifts towards
macroalgae-dominated communities (Clark et al. 2013. DOI:10.1111/gcb.12337).
New high-resolution multibeam data collected over the broader Vestfold Hills region is being used to expand
our understanding of the spatial extent of benthic habitats across the shallow coastal environment and identify
potential habitat for macroalgae communities. Bathymetry derived from multispectral satellite imagery is used
to fill data gaps in very shallow areas and areas under sea ice. This seafloor information is useful to guide
further biological studies to determine if and when regime shifts occur.

1442
Thu_81_BE-5_400
Polynya Formation and its Associated Chlorophyll - A Variability in Antarctica

Jisoo Park1 (jspark@kopri.re.kr), Edward Shin1, Eunho Ko1, Sanghoon Lee1, Taewook Park1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

Antarctic coastal polynya is the most productive area in the Southern Ocean, therefore they play a significant
role in polar ecosystem. Change in polynya phenology can alter, or even disrupt, the polar food web. As such, it
is important to understand the polynya phenology. However, despite polynya's significance in the polar
ecosystem, there are still many unfamiliar aspects of polynya and its associated changes in ecosystem. Our aim
is to organize relevant polynya data, reveal insightful polynya characteristics: determine whether physical
polynya features have an effect on phytoplankton dynamics. We investigated to what extent the physical
polynya parameters affect polynya phenology. By looking for correlations between such parameters and
chlorophyll-a concentration of each season and their respective dates, we hope to develop a thorough
understanding of the relationship between the physical input and biological output. We focused on Antarctic
polynyas, and we are especially interested in the types of environment that contribute to distinct correlations.
We are also interested in the causation and the implications of our findings. Understanding the driving force
behind the physical parameters of polynya would allow us to predict what sort of effect a polynya can have on
its ecology. We will talk about how physical forcing could affect chlorophyll variability in Antarctic coastal
polynyas in recent decades, and whether the relation has any connection with climate change.

1443
Thu_82_BE-5_455
Shelf Ice-associated Cryo-benthos and Environmental Features

Horst Bornemann1 (horst.bornemann@awi.de), Christoph Held1, Marthán N. Bester2, Julian Gutt1, Boris
Dorschel1, Dieter Gerdes1, Rainer Knust1, Dominik Nachtsheim3, W. Chris Oosthuizen2, Nils Owsianowski1,
Joachim Plötz1, Claudio Richter1, Svenja Ryan1, Michael Schröder1, Rainer Sieger1, Daniel Steinhage1, Christine
Wesche1
1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany,
2
Mammal Research Institute, University of Pretoria, Pretoria, South Africa, 3Institute for Terrestrial and Aquatic
Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Büsum, Germany

Incidences of cryo-benthic communities beneath ice shelves are rare and recent discoveries. Combined seal-
and ROV-borne imagery and novel sampling technologies allowed for a re-assessment and augmentation of
earlier findings on a cryo-benthic isopod community (Antarcturus cf. spinacoronatus), being attached head-
down to the underside of floating shelf ice at depths of around 80-150m. The shelf ice-associated cryo-benthos
was discovered at Drescher Inlet (-72.83667 -19.15300), Riiser-Larsen Ice Shelf (eastern Weddell Sea). The inlet
constitutes a 25km long and between 2 and 4km wide crack in the surrounding shelf ice, which is associated
with certain environmental features. Here we compile all available local physical, biological, and
biogeochemical data and discuss their relevance in the wider regional context for this faunal hotspot. These
include data on shelf, sea and platelet ice, seafloor topography, hydrography and water chemistry, as well as
associated pelagic and benthic marine life, in particular affinities of the cryo-benthic isopod community to
related fauna occurring in nearby seabed communities using molecular barcoding.

1444
Thu_83_BE-5_583
Microbial Eukaryotes in Sea Water From Fildes Peninsula, Antarctica

Wei Luo1 (luowei@pric.org.cn), Huirong Li1, Yong Yu1, Yinxin Zeng1

1
Polar Research Institute of China, Shanghai, China

Data on Antarctic coastal sites remain scarce and are generally limited to microscopy; the diversity of coastal
Antarctic ecosystems has been long underestimated. The diatom-dominant community in the coastal sea
waters of the Fildes Peninsula has been described according to traditional protocols. Molecular diversity of
microbial eukaryotes (≤ 20 µm) from Great Wall Cove and Ardley Cove, Fildes Peninsula, has been determined
by Illumina MiSeq2000 sequencing. Inferred metabolisms of summer phytoplankton in the two coves are
characterised by autotrophy and heterotrophy. The frequent occurrence of such nanoflagellates as
Dinoflagellates, Cryptophyta, Stramenopiles, Pyramimonas, Telonema, and Cryothecomonas, is predicted to be
important in these Antarctic coastal communities. Seawater exchange exists between the two coves when high
tide occurs, indicating that there appears to be mixing between the microbial communities in the two coves.
Cluster analysis of the microbial eukaryote composition at the phylum and genus levels reveals a conservation
of the community composition between the two coves. The inner stations of Great Wall Cove are clustered
closely together, surrounded by islands and formed into a semi-closed body of water. The samples from the
outer stations of Great Wall Cove, are more similar to the Ardley Cove samples.Sea water exchange between
the outer basins might be the effect of their community compositions.

1445
Thu_84_BE-5_882
Lipid Composition of the Sea Ice and Water Column in Early Spring

Patti Virtue1 (virtue@utas.edu.au), Peter Nichols2

1
University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia, 2CSIRO Oceans &
Atmosphere, Hobart, Australia

To understanding the role of sea ice in the Southern Ocean ecosystem, we need to also understand the
availability of key and essential nutrients to consumers. Baseline biochemical data are therefore required in
order to gauge any impact the reduction of sea ice will have on the sea ice community. Here we compare lipid
class, fatty acid and sterol content and composition of sea ice and water column samples collected during early
spring in East Antarctica. The availability of key essential omega-3 long-chain (≥C20) polyunsaturated fatty
acids, including - 20:5w3, eicosapentaenoic acid, EPA and 22:6 w3, docosahexaenoic acid, DHA - the major
constituents of cell membranes, were found to be severely limited during late winter and early spring,
particularly in the under ice water samples. The ramifications for sea ice obligate organisms such as larval krill
are discussed.

1446
Thu_85_BE-5_893
Macrobenthic Communities along a Shelf-slope-Basin Transect in the Bering Sea

Heshan Lin1 (linheshan@tio.org.cn), Kun Liu1, Jianjun Wang1

1
The Third Institute of Oceanography, State Oceanic Administration, Xiamen, China

The study analyzed the macrobenthic community and the spatial-temporal patterns of the Bering Sea based on
a number of summer surveys. Polychaetes (Scoloplos armiger), crustaceans (Ceradocus capensis) and sea
urchins (Echinarachnius parma) were the main dominant groups in the shallow shelves. The sea star
(Ctenodiscus crispatus) and the brittle star (Ophiura sarsii) were the main dominant groups in the continental
slope, whereas small polychaetes (Prionospio malmgreni) dominated the basin. Sediment type, water depth,
and current were the major factors affecting the macrobenthic community and spatial distribution. The Bering
shelves and slope showed an extremely high-standing biomass. In particular, the northern shelf, which is
primarily controlled by Anand Water, is an undersea oasis. In contrast, a deficiency in the downward transport
of particulate organic carbon has resulted in a desert-like seabed in the basin. Compared to previous studies,
macrobenthic communities of this area have undergone significant structural changes in recent decades,
resulting in a decrease in density and an increase in biomass. In addition, populations of amphipods and
bivalves in the northern shelf have decreased significantly and have been gradually replaced by other species.
These changes might be associated with advanced seasonal ice melting, changes in organic carbon input, and
global warming, indicating that large-scale ecosystem changes have been occurring in the Bering Sea.

1447
Thu_86_BE-5_918
Dispersal of Fjord Megabenthos in Andvord Bay: A Modeling Approach

Amanda Ziegler1 (ziegler8@hawaii.edu), Craig Smith1, Lisa Hahn-Woernle1, Brian Powell1

1
University of Hawaii, Oceanography, Honolulu, United States

Dispersal is a key factor affecting the biogeography and connectivity of Antarctic benthic communities. The
potential for planktotrophic larval dispersal is typically inferred from genetic data and current distributions of
adult forms. However, these methods do not provide insights into the mechanisms behind observed patterns
nor information on processes occurring on ecologically relevant time scales. In regions of complex topography
and potentially limited circulation (e.g. in fjords), source-sink population dynamics may be very important in
assembling communities. Fjords along the West Antarctic Peninsula are known to harbor rich and abundant
benthic communities distinct from those on the open shelf and even adjacent fjords (Grange and Smith, 2013)
and are therefore likely to exhibit limited connectivity and larval dispersal. We applied the Lagrangian
TRANSport model (LTRANS) (North et al. 2005) to Andvord Bay, a fjord on the northern West Antarctic
Peninsula, to address this key question: can the abundant megabenthic populations of Andvord Bay export
larvae to adjacent fjords and the open continental shelf? The model tracked simulated larvae (i.e. particles) in a
range of dispersal scenarios over time scales representative of PLDs for a range of organisms (14-120 days).
Results indicate that Andvord Bay acts to retain larvae over 120-d time scales, and may not routinely export
larva to adjacent fjords the open continental shelf along the West Antarctic Peninsula.

1448
Thu_87_BE-5_1065
Decadal Population Trends of Two Pacific Arctic Clams as Related to Production

Christina Goethel1 (cgoethel@umces.edu), Jacqueline Grebmeier1, Lee Cooper1

1
University of Maryland Center for Environmental Science, Solomons, United States

Dynamic factor analysis of bivalve abundance and biomass, along with two covariates, sea ice extent and
bottom water temperature, have identified time-series benthic macrofaunal changes in the Distributed
Biological Observatory (DBO) in the Pacific Arctic. Station SLIP 5 in the northern Bering Sea (DBO region 1) was
determined to be a transition point for abundance and biomass of the common deposit-feeding bivalve
Macoma calcarea between three stations to the south and two to the north. In addition, an increase in the
suspension-feeding bivalve Serripies groenlandicus, has been observed during field sampling (2014-2017) in the
DBO 3 region. We determined the spatial and temporal resolution of abundance and biomass of M. calcarea
and documented the increased abundance and biomass of S. groenlandicus north of Bering Strait. We also
tracked changes in abundance and biomass of the two species at five additional sites in the DBO 3 region (north
of Bering Strait) and over two additional years. We will present results relating the potential significance of
sediment chlorophyll-a, integrated water column chlorophyll-a concentrations, and sediment parameters that
include total organic carbon content and grain size as potential drivers for these changes. We will show that
these additional covariates contribute to the assessment of abundance and biomass trends for these two Arctic
bivalve species and reflect on the overall biological productivity of the system.

1449
Thu_88_BE-5_1225
Linking Fine Scale Distribution of Zooplankton to Sea Ice Cover and Predators

Mette Dalgaard Agersted1 (metteagersted@gmail.com), Eva Friis Møller2, Norman Ratcliffe3, Anders Mosbech2
1
University of Oslo, Oslo, Norway, 2Aarhus University, Roskilde, Denmark, 3British Antarctic Survey/NERC,
Cambridge, United Kingdom

As sea ice retreats due to a warmer climate, habitats of seabirds, such as little auks (Alle alle), will change. To
understand how this affects populations of little auks, it is essential to study the relations between them, their
zooplankton prey and water mass characteristics. A study was carried out in NW Greenland in July-August, a
period where little auks depend on lipid-rich zooplankton to feed their chicks. Results suggest that the
abundance of prey integrated across the upper 50 m, which was what we were able to measure from net hauls,
may only be important if the prey items are also concentrated in the vertical plane. The use of high-resolution
acoustic echo sounders represents a method to study fine scale zooplankton distribution patterns in details and
non-invasively. This approach was used in a similar study in NE Greenland where water mass characteristics,
fine scale zooplankton distribution and little auk abundance were assessed across areas with different sea ice
cover and stratification, from shelf to off-shelf areas. Here, we will present data on zooplankton fine-scale
distribution in relation to sea ice cover, physical and biological oceanography, and furthermore discuss how this
relates to the abundance of little auks.

1450
Thu_89_BE-5_1268
Small-scale DVM of Zooplankton and Susceptibility to Light Pollution

Jørgen Berge1 (jorgen.berge@uit.no), Martin Ludvigsen2, Geir Johnsen2, Maxime Geoffroy3, Jon Cohen4, Malin
Daase5
1
UiT The Arctic University of Norway, Arctic and Marine Biology, Tromsø, Norway, 2NTNU, Trondheim, Norway,
3
Memorial University, St John's, Canada, 4University of Delaware, Lewes, United States, 5UiT The Arctic
University of Norway, Tromsø, Norway

Light is a major cue for nearly all life on Earth. However, most of our knowledge concerning the importance of
light is based on organisms' response to light during daytime, including the dusk and dawn phase. When it is
dark, light is most often considered as pollution, with increasing appreciation of its negative ecological effects.
Using an Autonomous Surface Vehicle fitted with a hyperspectral irradiance sensor and an acoustic profiler, we
detected and quantified behavior of zooplankton in an unpolluted light environment in the high Arctic polar
night, and compared the results with that from a light polluted environment close to our research vessels. First,
in environments free of light pollution, the zooplankton community is intimately connected to the ambient
light regime, and perform synchronized diel vertical migrations in the upper 30 m despite the sun never rising
above the horizon. Second, the vast majority of the pelagic community exhibits a strong light-escape response
in the presence of artificial light, observed down to 100 m. This study underscores the need to adjust sampling
platforms, particularly in dim-light conditions, to capture relevant physical and biological data for ecological
studies. It also highlights a previously unchartered susceptibility to light pollution in a region destined to see
significant changes in light climate due to reduced ice cover and increased anthropogenic activity.

1451
Thu_90_BE-5_1484
Phytoplankton Community Composition and Distribution in an Antarctic Fjord

B. Jack Pan1 (b4pan@ucsd.edu), Maria Vernet1

1
Scripps Institution of Oceanography, UC San Diego, La Jolla, United States

As the Western Antarctic Peninsula (WAP) region responds to a warmer climate, the impacts of glacial
meltwater on the Southern Ocean are expected to intensify. Because fjords provide an extreme in the
meltwater's spatial gradient from the glacio-marine boundary to the WAP continental shelf, Andvord Bay is an
ideal study site to understand the impacts of environmental conditions, particularly glacial meltwater, on
phytoplankton community composition and their spatial distribution. While meltwater processes are weaker in
Antarctic fjords in comparison to the Arctic, they can still influence phytoplankton due to the direct
entrainment into water column; meltwater is rich in macro-nutrients and iron, induces stratification, and
impacts underwater light field, but the net effect of these factors is elusive. Fluorometric chlorophyll
measurement indicates that the concentration range is ~1 order of magnitude higher in Dec. 2015, while
significant deep chlorophyll and phaeo-pigment accumulations were found in Apr. 2016. Concurrent high-
performance liquid chromatography samples were also collected; and in the context of environmental
conditions, further analyses of these samples can illustrate the spatial distribution of phytoplankton community
composition and their seasonal variability. The hypothesis being tested is the impact of meltwater presence
can shift phytoplankton community to one that is dominated by cryptophytes due to reduction in salinity and
mixed layer depth.

1452
Thu_91_BE-5_1590
Organic Carbon Budget of the in Ice-covered Arctic Ocean during Late Spring

Monika Kędra1 (kedra@iopan.gda.pl), Marcel Babin2, Christine Dybwad3, Hauke Flores4, Piotr Kowalczuk1,
Christine Michel5, Nathalie Morata6, Barbara Oleszczuk1, Marit Reigstad3, Monika Zabłocka1, Ilka Peeken4
1
Institute of Oceanology Polish Academy of Sciences, Sopot, Poland, 2Takuvik (CNRS & U Laval) and Québec-
Océan, Université Laval, Quebec, Canada, 3University of Tromsø, Tromsø, Norway, 4Alfred Wegener Institute,
Bremerhaven, Germany, 5Fisheries and Oceans Canada, Winnipeg, Canada, 6Akvaplan-niva, Tromsø, Norway

The Arctic Ocean is undergoing substantial warming and sea ice loss, which are likely to cause changes in
primary production, export fluxes and productivity of the Arctic marine ecosystems. Yet, we lack sufficient
information about the ecosystem productivity, organic carbon cycling and cryo-pelago-benthic coupling
processes in the Arctic Ocean. Such information is particularly scarce for deep Arctic basins and during the
spring to summer transition under seasonally ice-covered waters. Our aim was to provide carbon budget
estimations under different environmental regimes and bloom development stages in the region north of
Svalbard. We conducted ecological and biogeochemical early spring process studies in sea ice covered areas,
from the shelf to the basins of the European Arctic margin and on the Yermak Plateau during the TRANSSIZ
cruise PS 92 on the ice breaker R/V Polarstern in May/June 2015. We identified the potential characteristics of
carbon production of primary producers in the sea ice and water column, and secondary production of
zooplankton and benthos. We looked into the organic carbon production fate and export, including respiration
and burial, as well as identified similarities and differences in ecosystem functioning along topography- , sea
ice- and water mass-related gradients. This scientific initiative was undertaken by Arctic in Rapid Transition
(ART) International Arctic Science Committee (IASC) network .

1453
Thu_92_BE-5_1905
High Resolution Hydrographic Surveys: Fjord Ecosystem Experiment Results

Hank Statscewich1 (hank.stats@alaska.edu), Peter Winsor1, Martin Truffer1, Craig Smith2, Maria Vernet3
1
University of Alaska - Fairbanks, College of Fisheries and Ocean Science, Fairbanks, United States, 2University of
Hawai`i at Manoa, School of Ocean and Earth Science and Technology, Honolulu, United States, 3Scripps
Institution of Oceanography, University of California, San Diego, Integrative Oceanography Division, La Jolla,
United States

Fjords with tidewater glaciers occur widely at temperate to polar latitudes, and extensively along the sub-polar
Western Antarctic Peninsula (WAP). Fjord ecosystems can be heavily modulated by local conditions, causing
ecosystem structure and function to differ from the open continental shelf and to be highly sensitive to climate
warming. Fjord ecosystems remain very poorly studied along the WAP, and several lines of evidence suggest
that WAP fjords are intense hotspots of biological productivity. In December 2015 and April 2016, a series of
high resolution hydrographic surveys were conducted utilizing a towed undulating instrument platform and an
autonomous underwater vehicle to investigate phytoplankton distributions, meltwater content, and sediment
inputs to Andvord Bay, a sub-polar glacio-marine fjord on the WAP. The towed vehicle and glider completed
several transects near glacier termini, over sills and along the length of Andvord Bay. Our observations reveal
elevated chlorophyll values associated with a persistent upper water column frontal boundary near the mouth
of the fjord and limited subsurface sediment plumes near glacier termini. We hypothesize that the high
(benthic and pelagic) productivity in Andvord Bay may be facilitated by elevated turbulence associated with
bathymetric features, fjord geometry and tidally driven flow and further aided by existing conditions of low
meltwater content and the limited extent of glacial-derived sediment input.

1454
Thu_93_BE-5_2029
Inter-annual and Seasonal Sediment Trap Zooplankton Variability - Arctic Fjords

Paula Kacprzak1 (paula.kacprzak@phdstud.ug.edu.pl), Jorgen Berge2, Sanna Majaneva2, Finlo Cottier3, Agata
Weydmann1
1
University of Gdansk, Institute of Oceanography, Department of Marine Plankton Research, Gdynia, Poland,
2
The Arctic University of Norway, Department of Arctic and Marine Biology, Tromso, Norway, 3Scottish
Association for Marine Science, Oban, United Kingdom

Sediment traps may provide a useful tool to study Arctic zooplankton during the whole year, irrespective of
environmental conditions or sea ice. Year-round sediment traps were moored in 2014/2015 and 2015/2016, in
high Arctic fjords on Svalbard - Kongsfjorden and Rijpfjorden respectively, to monitor seasonal and inter-annual
variability in zooplankton community. These fjords require enhanced monitoring, because of the progressive
alteration of extent and dynamics of the relatively warm West Spitsbergen Current. Thus, fjords differ strongly
in the amount of flowing Atlantic Water, which influences the composition and distribution of zooplankton
species. Our study demonstrated the relationship between distinct water masses and zooplankton structure in
fjords. The zooplankton community was divided into several groups, strictly related to hydrological shifts and
advection in the fjords: spring, summer/autumn, and winter. The dominant species in the winter group in fjords
consisted mainly of Arctic taxa such as Oikopleura spp, Pseudocalanus spp., Metridia longa, Themisto libellula,
Limacina helicina, but also typical boreal species like Limacina retroversa and cosmopolitan Oithona similis. The
spring and summer seasons in fjords were characterized by high numbers of Copepoda eggs and nauplii, small
copepods and genus Calanus which differed in proportions within the fjords. Especially three species were
linked to the advection events in the fjords - two pteropods and O. similis.

1455
Thu_94_BE-5_2078
ART Initiated TRANSSIZ -Transitions in the Arctic Seasonal Sea Ice Zone - Cruise

Ilka Peeken1 (ilka.peeken@awi.de), Marcel Babin2, Marie Amelie Blais2, Christine Dybwad3, Hauke Flores1,
Yannick Huot4, Markus Janout5, Christian Katlein1, Monika Kedra6, Piotr Kowalczuk6, Thomas Krumpen1, Ludvig
Loewemark7, Jens Matthiessen1, Christine Michel8, Nathalie Morata9, Anna Nikolopoulos10, Allyson Tessin11,
Jean-Éric Tremblay2, Jutta Wollenburg1, All shipboard party12
1
Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI), Bremerhaven, Germany,
2
Takuvik (CNRS & U Laval) and Québec-Océan, Université Laval, Québec, Canada, 3University of Tromsø,
Tromsø, Norway, 4Universite de Sherbrooke, Québec, Canada, 5Alfred Wegener Institute, Helmholtz Centre for
Polar and Marine Research (AWI), Bremerhaven, Germany, 6IOPAN –Institute of Oceanology - Polish Academy
of Sciences, Sopot, Poland, 7National Taiwan University, Taiwan, Taiwan, Republic of China, 8Department of
Fisheries and Oceans Canada, Manitoba, Canada, 9Akvaplan-niva AS, Fram Centre/ Laboratoire des Sciences de
l'Environnement Marin (LEMAR), Tromsø/Brest, France, 10AquaBiota Water Research, Stockholm, Sweden,
11
School of Earth and Environment, University of Leeds, Leeds, United Kingdom, 12Polarstern, Bremerhaven,
Germany

The TRANSSIZ ('Transitions in the Arctic Seasonal Sea Ice Zone') cruise PS92 was carried through by the “Arctic
in Rapid Transition” (ART) International Arctic Science Committee (IASC) network on the German research
icebreaker R/V Polarstern in May/June 2015. The overall cruise goal was to use a multidisciplinary approach to
identify the potential characteristics in carbon production as well as to investigate similarities and differences
in ecosystem functioning related to gradients in topography, sea ice and water masses, and to link past and
present sea-ice transitions in the Arctic Ocean. Thus, ecological, physical and biogeochemical early spring
process studies were conducted across the shelf of the European Arctic margin and on the Yermak Plateau. At
each station R/V Polarstern was anchored for 36 hours to an ice floe. Special emphasis was given to the
quantification of the environmental preconditions for biological productivity (e.g. nutrients, stratification)
under sea ice and in open waters. With this study we gained new insights for improving predictions of the
potential annual primary production in the changing Arctic Ocean and the understanding of ecosystem
functioning and biogeochemical cycles in the transition from spring to summer in the European Arctic margin.
Investigations during TRANSSIZ will also enable reconstructions of productivity, food web carbon flux, and sea
ice and ocean circulation across the few last glacial cycles.

1456
Thu_95_BE-5_2270
Functional Patterns of Chukchi Sea Benthos

Renate Degen1 (renate.degen@hotmail.com), Bodil Bluhm2, Katrin Iken3

1
University of Vienna, Limnology and Bio-Oceanography, Vienna, Austria, 2Arctic University of Norway, Tromsø,
Norway, 3University of Alaska - Fairbanks, Fairbanks, United States

Traits - i.e. the life history, morphological and behavioural characteristics of species - provide a link between
species and multiple ecosystem-level processes, such as the fluxes of oxygen, energy and nutrients. In marine
ecosystems, trait-based approaches are often applied to detect early responses of communities to
environmental changes or stressors, to estimate ecosystem resilience or vulnerability, or to indicate overall
ecosystem functioning. They are however still rarely applied in studies from polar marine regions, albeit these
areas are facing dramatic and rapid environmental changes today. One reason is that biological trait
information of polar species is often not ready at hand, and its collation requires a time and labor intensive
survey of literature. The open access to trait databases is an important step in overcoming this obstacle. Here
we demonstrate how trait information retrieved from the online accessible Arctic Traits database is used to
analyze functional patterns of benthic communities in the Chukchi Sea, a shallow Arctic shelf sea characterized
by tight pelagic-benthic coupling. The observed community patterns are further related to environmental
parameters like water temperature and sea ice concentration in order to detect potential drivers of change in
benthic ecosystem functions.

1457
Thu_96_BE-5_2413
Sea Ice and Glacier Control of Antarctic Coastal Ecosystem Dynamics and its Fate

Hyoung Chul Shin1 (hcshin@kopri.re.kr), Sung-Ho Kang1, Hyoung Sul La1, Tae Wan Kim1, In-Young Ahn1
1
Korea Polar Research Institute, Incheon, Korea, Republic of

Bays and coves in King George Island, Antarctica represent a sentinel embayment ecosystem in South Shetland
Islands that is sea ice affected in a highly seasonal manner and subject to accelerating glacier retreats in the
region. Oceanographic measurements mostly from fixed points and the station weather logs for nearly 20 years
have been examined in order to determine the mechanisms of ecosystem responses and the critical governing
factors. Sea ice formation and break-up in the Bay appear to be controlled by physical oceanography in
offshore waters and sea ice trend in the wider region. In addition, yearly varying sea ice dynamics combined
with local meteorology seem to determine the fate of the algal blooms and the major primary producer
species. There is an inconspicuous yet consistent trend with the taxonomic group and size compositions.
Moreover, glaciers receding at high paces (most recently, around 100 m per year) are opening up new waters
and create new habitats both pelagic and benthic. This already provided for a new start of ecological
successions but also would modify key environmental features that will shape the future ecosystems and
determine the changing functions. Models that came out of this would greatly assist us in assessing the future
changes in the ocean-cryosphere boundary along the Northern Antarctic Peninsula.

1458
Thu_97_BE-5_2651
Arctic Benthic Community Structure and Functioning during Late Spring

Barbara Oleszczuk1 (oleszczuk@iopan.gda.pl), Nathalie Morata2, Emma Michaud2, Paul E. Renaud3, Aleksandra
Winogradow1, Katarzyna Grzelak1, Monika Kędra1
1
Institute of Oceanology of Polish Academy of Sciences, Sopot, Poland, 2Universite de Bretagne Occidentale –
Institut Universitaire Europeen de la Mer (IUEM), Brest, France, 3Akvaplan-niva, Tromsø, Norway

Changes in sea ice cover are affecting the bloom timing, quantity and quality of primary production, and thus
quantity and quality of organic matter reaching the seafloor. Changes in organic matter export fluxes are
predicted to influence structure and functioning of benthic communities, especially in the deep-sea. The aim of
this study was to examine meio- and macro- benthic community structure and function in relation to sea ice
cover, bloom stage and depth from the shelf to the basins of the European Arctic margin and on the Yermak
Plateau, Svalbard fjords and in the Barents Sea. Material was collected during spring cruises PS92 - TRANSSIZ in
May-June 2015, and ARCEx in May 2016, and included sediment and particulate Organic Matter (OM) samples.
OM sources and trophic position of benthic animals were determined with use of stable carbon (δ13C) and
nitrogen (δ15N) isotopes. Additionally bioturbation experiments were performed. The particulate OM
concentrations in the water column decreased with depth, and increased with the bloom progress. Benthic
density, biomass and intensity of bioturbation were the highest at the shelf stations where intensive bloom was
observed and were related to higher concentrations of fresh OM input to the sea bottom. Low benthic infaunal
diversity, abundance, and biomass were noted in fjords and deep stations where low concentrations of lower
quality OM reaching seafloor were noted.

1459
Thu_98_BE-8_38
Molt Phenology Mediates Colony Attendance and Pupping Success in Weddell Seals

Roxanne Beltran1,2 (roxanne.beltran@gmail.com), Amy Kirkham2,3, Greg Breed3, Ward Testa2,4, Jennifer Burns2
1
University of Alaska Fairbanks, Biology and Wildlife, Fairbanks, United States, 2University of Alaska Anchorage,
Biological Sciences, Anchorage, United States, 3University of Alaska Fairbanks, Fairbanks, United States,
4
National Marine Mammal Laboratory, Seattle, United States

Mammalian species have been shown to shift life history event phenology in response to environmental
change, but this response is highly variable across species. The replacement of hair (i.e. molt) is an
intermediate life history event that may affect subsequent breeding attempts; however, the magnitude of its
impact is poorly understood. Our aim was to understand the carry-over effects of molting and pupping
phenology in Weddell seals. To do so, we conducted demographic surveys of 4,252 uniquely identified seals in
Erebus Bay, Antarctica during the austral summers of 2013-2017. The start date of each animal's molt was
back-calculated based on hair loss progression, and pupping success and dates were obtained for the breeding
season prior to and following the molt. The molt in Weddell seals lasted 29 ± 8 days. Within adult females, molt
phenology was markedly different across reproductive and non-reproductive individuals, with non-
reproductive seals beginning molt 16 days earlier than reproductive seals (mean start date Jan06 and Jan22,
respectively, t-test p< 0.0001). Animals that molted later were less likely to be seen in the breeding colonies
during the following pupping period, suggesting they either did not pup that year or were deceased. By
systematically manipulating estimated transition probabilities between pupping and molting categories using a
simulation model, we demonstrate the importance of intermittent skipping of pupping to reset life history
phenology.

1460
Thu_101_BE-8_1593
How Do Hormones and the Skin Transcriptome Drive Molt in a Polar Pinniped?

Amy Kirkham1,2 (amy.kirkham@gmail.com), Roxanne Beltran2,3, Skyla Walcott2, Michelle Shero2, Donald
Thompson, Jr4, Julie Avery5,6, Jennifer Burns2
1
University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Juneau, United States, 2University of
Alaska Anchorage, Biological Sciences, Anchorage, United States, 3University of Alaska Fairbanks, Biology and
Wildlife, Fairbanks, United States, 4Louisiana State University, School of Animal Sciences, Baton Rouge, United
States, 5University of North Florida, Jacksonville, United States, 6University of Alaska Fairbanks, Water and
Environmental Research Center, Fairbanks, United States

Pinnipeds replace their fur each year in an annual pelage molt, the timing of which is tightly regulated to
conserve energy. Recent cases of disrupted molt in Arctic seals have highlighted how little is known about the
underlying mechanisms of this key life history event. To characterize the drivers of healthy molt in a polar
phocid, we examined hair cycling in 121 prime-age female Weddell seals (Leptonychotes weddellii) during the
Antarctic summer (Nov-Feb). At each handling (n=1 or 2 per female), skin biopsies were collected to determine
hair cycle phase (i.e., anagen, catagen, telogen) by histology, and serum hormone levels and body composition
were measured to test for endocrine and nutritional effects on molt. Hair follicles became active in Nov/Dec, at
least a month prior to the onset of shedding, and did not complete growth until late Jan at the earliest.
Elevated prolactin appeared to delay molt, while body condition did not impact molt timing. To identify gene
expression changes between three hair cycle phases, skin transcriptomes were profiled using Illumina RNA-Seq
(n=9). Over 4000 genes were differentially expressed between phases. These included hormone receptors and
genes involved in wound healing, suggesting skin's response to hormones and its healing capacity change
across the molt. Our novel findings on endocrine and transcriptomic control of molt indicate how this process
may be impaired, as well as how altered hair cycling may impact integumentary health.

1461
Thu_102_BE-8_1839
Environmental Influences on the Thermal Flux of a Molting Polar Pinniped

Skyla Walcott1 (skyla.walcott@gmail.com), Amy Kirkham1,2, Roxanne Beltran1,3, Jennifer Burns1

1
University of Alaska Anchorage, Department of Biological Sciences, Anchorage, United States, 2University of
Alaska - Fairbanks, College of Fisheries and Ocean Sciences, Fairbanks, United States, 3University of Alaska -
Fairbanks, Department of Biology and Wildlife, Fairbanks, United States

Antarctic pinnipeds face complex thermoregulatory challenges, as they must conserve heat in both air and
water. Primary adaptations to reduce heat loss include a thick blubber layer and the ability to limit blood flow
to the peripheries via vasoconstriction. These adaptations reduce heat flux by decreasing the temperature
gradient between the animal and the environment. During the annual molt however, heat conservation may be
compromised, as hair follicles may require more constant perfusion; this could result in higher rates of heat
loss and higher metabolic costs. In warmer summer months, the thermal gradient between the animal and
environment is reduced, providing optimal ambient conditions for molting.
Across a four-year study, surface temperature and heat flux were directly measured in-air, on adult female
Weddell seals (n=77, Leptonychotes weddellii) across the progression of the molt. Surface temperatures
increased significantly with increased ambient temperature and relative humidity and decreased wind speed
and solar radiation. Heat flux was significantly higher during the molt than prior to its onset, resulting in greater
overall heat loss in molting seals. This suggests that perfusion is increased during molt to support hair follicles
at the expense of increased thermoregulatory costs. Correlations between time-activity budgets and ambient
conditions will be measured to determine how environmental perturbations may influence summertime
molting haul-out decisions.

1462
Thu_103_BE-8_2084
Effects in Renal and Hepatic Cells by Cd, Pb, Cr and Se Found in Penguins

Ana Meseguer1, Silvia Jerez1, Andrés Barbosa2, Miguel Motas3 (motas@um.es)

1
University of Murcia, Murcia, Spain, 2Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain, 3Health
Institute Carlos III, Environmental Toxicology, Madrid, Spain

Recent studies carried out by our research group revealed high levels of Cd, Pb, Cr and Se in the kidney and
liver of three penguin species: Papua - Pygoscelis papua, Barbijo - Pygoscelis antarctica and Adelia - Pygoscelis
adeliae. According to these results, the effects on the cell cycle have been studied, that the average
concentrations found in chickens, juveniles and adults and the EC50 (effective concentration 50) provoke on
the cell lines VERO (renal) and AML12 (hepatic). The cells were treated for 24 hours with each concentration.
Subsequently using the IP fluorochrome (propidium iodide) by flow cytometry and with the ModFit computer
program, the changes produced with respect to the control were detected, by the different concentrations, in
each phase of the cell cycle. For both cell lines we observed that the concentrations of Cr, Se and the highest
Cd (adults), produce an increase in the percentage of cells in S phase, causing their blockade in this phase and
preventing cell division. In the case of lead, we find that the effect is similar for the highest concentration
(EC50), that is, blockade in S phase; however, at lower concentrations, an increase in the percentage of cells in
G2 / M phase is observed, and therefore, an increase in the percentage of cells in mitosis.

1463
Thu_104_BE-8_2101
Metals Found in Penguins Produce Oxidative Stress in Renal and Hepatic Cells

Ana Meseguer1, Silvia Jerez1, Andrés Barbosa2, Miguel Motas3 (motas@um.es)

1
University of Murcia, Murcia, Spain, 2Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain, 3Health
Institute Carlos III, Environmental Toxicology, Madrid, Spain

Antarctica is one of the last virgin regions, however studies carried out by our group have shown an increase in
the levels of certain elements, in three species of penguin: Papua - Pygoscelis papua, Barbijo - Pygoscelis
antarctica and Adelia- Pygoscelis adelie. The mean concentrations of Cd, Pb, Cr and Se and EC50 (effective
concentration 50) found in chick, juvenile and adult individuals from three penguin species of the Antarctic
Peninsula and Associated Islands, were evaluated in renal and hepatic cells (cell lines VERO and AML12). The
cells were treated for 24 hours with each concentration. Later, using the colorimetric probe DCFH-DA (dichloro-
dihydro-fluorescein diacetate) and by means of flow cytometry, the changes produced by the concentrations of
each element on oxidative stress were detected. In the VERO cell line, the results show a decrease in
fluorescence proportional to the concentration and therefore a decrease in the reactive oxygen species (EROs).
This is due to the fact that these concentrations modify the integrity of the cellular DNA, not allowing the cell to
produce EROs. Therefore, the determination of ROS is more an indicator of mortality than of toxicity for said
cell line. In the AML12 cell line, the highest concentration corresponding to the average concentration of adults
causes an increase in the EROs; for the rest of the elements no significant differences appear or, as in VERO, a
decrease in fluorescence occurs in a concentration-dependent manner.

1464
Thu_105_BE-8_2236
Adélie Penguin Diet: Comparison of Stomach Flushing with Faecal DNA Analysis

Bruce Deagle1 (bruce.deagle@aad.gov.au), Julie McInnes1, Louise Emmerson1, Michael Dunn2, Stacey Adlard2,
Andrea Polanowski1, Claire Waluda2
1
Australian Antarctic Division, Kingston, Australia, 2British Antarctic Survey, Cambridge, United Kingdom

Adélie penguin diet is studied at colonies around Antarctica as part of CCAMLR's Ecosystem Monitoring
Program (CEMP). The standard methodology involves stomach flushing of breeding birds to identify prey
species and record diet composition by mass. Due to the invasive nature of sampling, genetic approaches using
faecal samples are being investigated.
High-throughput sequencing of DNA barcoding markers recovered from faecal samples has become a common
method for assessing of diet in a wide range of animals. However, direct comparisons of DNA-based diet
analysis with traditional methods are still limited.
We report on a study carried out at Signy Island (South Orkneys) comparing stomach lavage data (n= 60;
collected in 2014/15 and 2015/16) with DNA data from concurrently collected faecal samples (n=450). For the
DNA analysis a conserved marker (18S rRNA) was used to identify broad prey groups and mtDNA markers used
to provide high resolution taxonomy of main prey groups.
Antarctic krill (Euphausia superba) and bony fish (Actinopterygii) made up >98% of the stomach content mass
and also >99% of the prey DNA sequence reads. Both datasets also identified a switch from a krill dominated
diet in 2014/15 to a nearly even split between krill and fish in 2015/16.. We discuss the strengths and
weaknesses of each approach, comparability of the datasets and the prospects for incorporating DNA diet
analysis into long-term monitoring programs.

1465
Thu_106_BE-8_2366
Adélie Penguin Telomeres: Eco-indicators of Environmental Stress?

Jilda Alicia Caccavo1 (jildaalicia.caccavo@studenti.unipd.it), Thierry Raclot2, Timothée Poupart3, Yan Ropert-
Coudert3, Frédéric Angelier3
1
Università degli Studi di Padova, Dipartimento di Biologia, Padova, Italy, 2Institut Pluridisciplinaire Hubert
Curien, UMR7178 du CNRS-Université de Strasbourg, Strasbourg, France, 3Centre d'Etudes Biologiques de Chizé,
UMR7372 du CNRS-Université de La Rochelle, Villiers-en-Bois, France

Defining the impact of anthropogenic stressors on Antarctic wildlife continues to be an active aim for
investigators. Physiological conservation has emerged as a new research topic that aims to identify key
physiological variables that can help ecologists to assess the impact of human activities in the environment.
Recently, telomeres have been suggested as a promising molecular tool to investigate the fitness of wild
vertebrates. Telomeres are well-conserved repeated sequences of non-coding DNA located at the terminal
ends of chromosomes. They shorten with advancing age and this telomere attrition is accelerated by the
occurrence of environmental stressors. Furthermore, telomere length appears to be a reliable predictor of
longevity and survival in captive and wild vertebrates. In this study, we examined the relationship between
telomere length and various degrees of long-term human exposure in Adélie penguin chicks (Pygoscelis
adeliae) from Terre Adélie, East Antarctica. Thus, telomere length was quantified and compared between
chicks from two sites with sustained and continuous human activity (Petrels Island) and two sites on
neighboring islands with little or no human presence (Lamarck and Bernard Islands). Our results will provide a
powerful insight into the long-term impacts on wildlife living in close proximity to human activity, as well as
contribute to the growing body of research on the efficacy of telomere length as an eco-indicator.

1466
Thu_107_BE-8_2338
Modelling of Ballast Water Discharge in the Arctic Ocean

Ingrid Linck Rosenhaim1 (ilinckro@awi.de), Kathrin Riemann-Campe2, Andreas Herber2, Rüdiger Gerdes2
1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2Alfred
Wegener Institute - Helmholtz Center for Polar and Marine Research, Sea Ice Physics, Bremerhaven, Germany

Sea-ice concentration in the Arctic Ocean has decreased by 9 % per decade since 1978. As a consequence,
more vessels are navigating the Arctic, increasing the risk of alien species introduction by ballast water (BW)
discharge. The ships depend on BW for stability and structural integrity. Ballast water, however, also contain
aquatic species, and in turn, these introduced species might survive and establish a reproductive population.
A tracer for BW was implemented into a high-resolution North Atlantic/Arctic Ocean-Sea Ice Model (NAOSIM).
The flow of the BW-tracer discharged in the Arctic and possible areas of accumulation were investigated. In
total, 17.407 vessels navigated the Arctic waters in 2013, with an estimated amount of discharged BW of about
13 million m3. In the model, the BW-tracer is released along the shipping routes navigated in 2013. Results
show that the seasonal cycle of the ocean mixing affects the BW-tracer distribution significantly. In winter, the
BW-tracer reaches deeper waters, than in spring, when the sea-ice starts melting and stratifies the upper
ocean. In spring and summer, the BW-tracer remains within the upper 20 m, where the availability of sun and
nutrients lead to favorable living conditions for non-indigenous species. One area of BW-tracer accumulation is
the vicinity of the Kara Gate in the Barents Sea. There, 10 % of the BW-tracer remains more than 20 days after
its release. Lower percentages of the BW-tracer remain almost three months.

1467
Thu_109_BE-9_42
Trophic and Non-trophic Connections of Potter Cove Marine Ecosystem

Vanesa Anabella Salinas1,2 (vane.salinas79@gmail.com), Fernando Roberto Momo1,3

1
Universidad Nacional de General Sarmiento, Instituto de Ciencias, Los Polvorines, Argentina, 2CONICET, CABA,
Argentina, 3Universidad Nacional de Lujan, Biology, Lujan, Argentina

Organisms eating each other are only one of many types of well documented and important interactions
among species. However, ecological interactions of coexisting species involve much more than just feeding.
Within an ecosystem, species interact with each other in many different ways including predation, competition
and facilitation. These interactions can be modelled as trophic and non-trophic networks which constitute a
group of links that mediates ecological communities' response to perturbations, such as exploitation and
climate change. Here we expose the trophic and non-trophic interactions of the marine ecosystem of Potter
Cove (62°14´S, 58°40´W, King George Island, Antarctica) expressed in four different networks depending on the
type of interaction: trophic (+/-), commensalism (+/0) and amensalism (-/0), mutualism (+/+) and competition
(-/-). Conducting a preliminary analysis, we argue the importance of incorporating both direct and indirect non-
trophic and trophic interactions and their ecological context, suggesting that it is the key to predicting
community dynamics, thus it stability.

1468
Thu_110_BE-9_158
Snow Does Not Mirrow Air Microbial Communities as Shown on Transects in Iceland

Nora Els1,2 (nora.els@uibk.ac.at), Birgit Sattler1,2

1
University of Innsbruck, Institute of Ecology, Lakes and Glacier Research, Innsbruck, Austria, 2Austrian Polar
Research Institute, Austria, Austria

Snow and ice surfaces host viable and diverse bacterial and fungal communities. These originate partly from
wet and dry aerial deposition. However, the impact of short or long distance air transport, meteorological
features, selective deposition and colonization processes remain unclear in their role with air and snow
microbial diversity. Rapidly changing climate patterns in polar regions evoke a pressing need to investigate such
air-snow community dynamics.
Eighteen air samples, comprising 56m³ of air, were taken at 15 sites along three transects in northern Iceland,
covering distances of 50 to 120km with MD8 Air Port (Sartorius) and Coriolis µ (Bertin) air samplers. In two
transects 11 snow sites were sampled. Airborne and snow-associated bacterial and fungal diversity, abundance
and ice nucleation potential were investigated for temporal and spatial variation and correlated with multiple
environmental factors.
Bacteria and fungi feature some ubiquituous core phyla, but show significant differences between air and snow
on taxa level. Local aerosolisation sources, geographical and meteorological features impact on small scale
spatial variability. Temporal site variation amongst the respective habitat was low.
Results hint towards a high contribution to snow microbial diversity from other than single cell deposition,
suggesting snow inoculators originate from wet deposition, particle-associated microbe input or airborne, rare
but highly successful colonizers.

1469
Thu_111_BE-9_159
Snow and Photosynthetically Active Radiation in Lakes of the McMurdo Dry Valleys

Madeline Myers1 (mmyer11@lsu.edu), Peter Doran1, Krista Myers1

1
Louisiana State University, Geology and Geophysics, Baton Rouge, United States

The role of snow on underwater photosynthetically active radiation (UWPAR) in the McMurdo Dry Valleys
(MDVs) has been understudied due to lack of a detailed snowfall record. Research has shown that a
relationship between snow cover and UWPAR exists, but the extent has never been evaluated in great detail.
Although annual snowfall values in the MDVs are low (3 to 50 mm water equivalent annually), trends of
increasing snowfall on the continent under future warming conditions could lead to an increased role for snow
in regulating UWPAR (and associated primary productivity). Here, we discuss evidence from the snowfall
record, surface PAR, and UWPAR, of the influence of snowfall on UWPAR in the major lakes of Taylor Valley. A
new, detailed record of snowfall over the last 10 years created from camera and satellite imagery, and ground-
based instruments will be presented. Statistical analysis of snow events within the record reveals the nature of
their role in governing UWPAR rebound at Lake Hoare. In one large snowfall event in November 2016, UWPAR
took 41 days to recover to levels equivalent to before the snowfall at Lake Fryxell which is more proximal to the
coast. At the more distal West Lobe Bonney the recovery time was only 9 days. We will also present progress
on a spatial model of UWPAR which will aid in evaluating the annual light budget under the lake and provide
insight on snow as an ecological disturbance and the implications for lacustrine primary productivity.

1470
Thu_112_BE-9_186
Climate Variability Positively Affects East Antarctic Moss Communities

Michael B Ashcroft1 (ashcroft@uow.edu.au), Diana H King1, Johanna Turnbull1, Jane Wasley2, Jessica Bramley-
Alves1, Taylor Benny1, Rebecca E Miller1, Sharon A Robinson1
1
University of Wollongong, Centre for Sustainable Ecosystem Solutions, Wollongong, Australia, 2Australian
Antarctic Division, Antarctic Conservation and Management Program, Kingston, Australia

Polar regions are characterised by microclimates that are highly variable in space and time. Such high climate
variability is expected to negatively impact biodiversity as it increases the probability that conditions will
exceed species' physiological limits or the thresholds to ecosystem resilience. Not all microhabitats are equally
variable, but few studies have examined how spatial differences in variability can affect the distribution of
biodiversity. We surveyed 60 quadrats of Antarctic mosses over 10 years to determine if the health or
composition were affected by the mean or variability of available water. We found that higher climate
variability was associated with more green, photosynthetically active moss and a greater proportion of the
endemic species Schistidium antarctici, compared to the cosmopolitan species Ceratodon purpureus. The
healthiest quadrats were those with the highest mean water availability, but variability in water availability also
positively affected species composition, especially where the mean water availability was low. Antarctic mosses
can dehydrate and become physiologically inactive during drier periods to prevent damage, so our results
suggest that periodic flooding is more beneficial for moss health and endemic species than having moderate,
stable conditions. These results are especially important as 21st century climates are expected to be more
variable and this could therefore impact ecosystems regardless of changes in mean climate.

1471
Thu_113_BE-9_205
Age, Density, Prey, and Climate Drive the Demographics of an Apex Predator

Nathan Pacoureau1 (nathan.pacoureau@cebc.cnrs.fr), Karine Delord1, Christophe Barbraud1

1
CNRS, Centre d'Étude Biologique de Chizé, Villiers-en-Bois, France

Ecologists widely acknowledge that a complex interplay of endogenous (density-dependent) and exogenous
(density-independent) factors impact demographic processes and that individuals respond differentially
according to their age, ultimately shaping the population dynamics of wild species. Here we provide an insight
of the mechanisms affecting four vital rates (survival probability, probability of breeding, probability of a
successful breeding with one, and with two chicks) of an apex Antarctic marine predator by combining
longitudinal time series of know-age individuals, abundance data, climatic and prey abundance covariates. We
found evidence for age-related changes in the four vital rates. Traits at younger ages were smaller and had
larger temporal variance than those of older age-classes for all parameters. Results clearly evidenced an impact
of extrinsic factors, with a direct influence of local climate (sea ice concentration) and of available prey
resources (penguins), and of intrinsic factors with an influence of the size of the breeding population. More
covariate effects were found on reproductive traits than on survival traits, and age classes responded
differentially to these effects, the younger age classes being more sensitive than the older ones. Using a half a
century dataset, we provide a compelling evidence to support the importance of considering multiple causal
effects when studying demographic process in seabirds and the impact of environmental variability.

1472
Thu_114_BE-9_374
Multi-million Year Antarctic Presence within the Moss Genus Schistidium

Elisabeth M. Biersma1,2 (elibi@bas.ac.uk), Jennifer A. Jackson1, Michael Stech3,4, Howard Griffiths2, Katrin
Linse1, Peter Convey1
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Cambridge, Department of Plant Sciences,
Cambridge, United Kingdom, 3Naturalis Biodiversity Center, Leiden, Netherlands, 4Leiden University, Leiden,
Netherlands

Schistidium is the most species-rich plant genus in the Antarctic, as well as containing most Antarctic endemic
moss species. To assess the diversity, richness and relative age divergences within the genus in Antarctica we
applied phylogenetic and molecular dating methods, using the nuclear Internal Transcribed Spacer, on all
known Antarctic species with available samples. We additionally investigated the continent-wide genetic
diversity within the common and widespread endemic species Schistidium antarctici. Most previously
described Antarctic Schistidium species were genetically distinct, confirming their specific status. All species
had separated from each other at least ~1 Mya. In particular, S. antarctici diverged from other Antarctic
Schistidium species as early as the late Miocene, thereby being the oldest extant plant species currently known
in Antarctica, and providing strong support for vegetation survival through multiple glacial periods. Genetic
patterns within S. antarctici suggest the mountainous spine on the Antarctic Peninsula has formed a strong
barrier to gene flow over time, while the increased genetic diversity in this species in the northern Maritime
Antarctic indicates likely glacial refugia in this area. This study provides an important first step towards
assessing the evolutionary history of the largest plant genus in the Antarctic, and provides an insight into their
adaptive potential to climate change over both past and contemporary timescales.

1473
Thu_115_BE-9_657
Sensitivity of Coccolithophores to Ocean Warming and Acidification

Shramik Patil1 (shramik@ncaor.gov.in), Rahul Mohan1, Suhas Shetye2, Sahina Gazi1, Syed Jafar1
1
National Center for Antarctic and Ocean Research, Antarctic Science Division, Vasco-da-Gama, India, 2National
Institute of Oceanography, Panaji, India

Coccolithophores are an important component of the Earth system and represents an essential footing to the
marine ecosystem. This study presents the results of 10 year observational investigations on coccolithophore
ecology and morphology in the Southern Indian Ocean (SIO). Samples were collected during four SIO
Expeditions and three Antarctic Expeditions (December-April). Our data evidently indicates a pronounced
seasonality in coccolithophore biogeography and noticeable size variation in E. huxleyi. The E. huxleyi show
highest production in the STF and SAF region during the early austral summer and is more prone to dissolution
at South of the SAF regions despite of high pH saturation. Whereas, during mid-austral summer, E. huxleyi
population expands southwards forming heavily calcified morphotypes despite of low pH saturation. The study
indicates it is unlikely that the increase in PAR and probable shifts in carbonate chemistry could cause E. huxleyi
shift in high latitudes. We documented over-calcification in E. huxleyi when conditions were most acidic
contrary to the earlier predictions. However, the occurrence of large E. huxleyi cells with numerous coccoliths
in mid austral summer period indicates slowed cell division to cope with low pH conditions. On the contrary
rapid increase in heterotrophs and subsequent grazing on coccolithophores in the late austral summer period
raises further questions about the fate of coccolithophores in the future high-CO2 world.

1474
Thu_116_BE-9_658
Ecoregionalisation of the Southern Ocean in the Context of Climate Change

Salomé Fabri-Ruiz1 (salome.fabri-ruiz@u-bourgogne.fr), Thomas Saucède1, Bruno Danis2

1
Laboratoire Biogéosciences UMR CNRS 6282, Dijon, France, 2Marine Biology Lab, Brussels, Belgium

Understanding species distribution in the Southern Ocean is challenging in many aspects. Sampling in this
region is logistically difficult because of its remoteness and extreme environmental conditions. Today, species
distribution models (SDM) can be used to provide spatial projection of species distribution and quantify the
relationship between species occurrence and their environment, and can fill knowledge gaps in data deficient
areas. Based on the SDM approach, ecoregionalisation aims at defining ecoregions for conservation purposes
that is, biogeographic entities that differ in their biotic and abiotic characteristics. In the context of rapid
climate change, ecoregionalisation can provide a direct prediction of species assemblages that are linked to
environmental features in under-sampled areas. In addition, projection of ecoregions in future environmental
conditions can help identify regions that might be particularly at risk. In this framework, we proposed an
ecoregionalisation of the Southern Ocean for echinoid species, which are common benthic organisms in the
Southern ocean benthic communities. We first developed individual SDM for each species and then combined
them using a Gaussian mixture model and a clustering approach using R to define ecoregions.

1475
Thu_117_BE-9_688
Southern Ocean Influence on Robertson Bay, Northern Victoria Land

Gary Wilson1 (gary.wilson@otago.ac.nz), Craig Cary2, Morgan Coleman3, Vonda Cummings4, Ian Hawes2, Soon
Gyu Hong5, Marwan Katurji6, Christina Riesselman1, Fiona Shanhun7, Craig Stevens4, Olivia Truax1
1
University of Otago, Marine Science, Dunedin, New Zealand, 2University of Waikato, Hamilton, New Zealand,
3
Landcare Research, Lincoln, New Zealand, 4NIWA, Wellington, New Zealand, 5Korea Polar Research Institute
(KOPRI), Incheon, Korea, Republic of, 6University of Canterbury, Christchurch, New Zealand, 7Antarctica New
Zealand, Christchurch, New Zealand

Robertson Bay lies to the west of Cape Adare at the North Western corner of the Ross Sea (71.5°S 170°E). It is
500 m deep at its deepest and open to the North. A temperature inversion in the summer months results from
strong offshore winds, linked to cyclonic storms, drawing warmer deep water into the bay. In the winter and
spring months, the winds are decoupled from the ocean by the formation of sea ice. At the surface, water
circulates in a clockwise gyre, developing a South-North long-shore current along the Adare Peninsula of a few
knots. Flora and fauna are strongly coupled to the marine environment. The shallow benthos is diverse with
many ophiuroids, anenomes, and sponges, and common macroalgae (also observed at Cape Hallet but no
further south). The water column is also rich with plankton. Within 5-km of Ridley Beach, at the tip of Cape
Adare, diversity and density of benthos drops off due to the presence of the million strong Adelie penguin
colony. The penguin colony also dominates the terrestrial flora and microbial signature. At Robertson Bay,
rather than deep warm water incursion driving change in the environment, the strong South / South East
cyclonic winds dominate and drive ocean circulation. This phenomenon has recently been reported further
west in East Antarctica where the cyclonic winds also influence the extent of sea ice. But the extent of sea ice
does not seem indicative of circulation at depth where warm water is being drawn onto the continental shelf.

1476
Thu_118_BE-9_707
Social Structure of Leopard Seals at Livingston Island, Antarctica

Carolina Bonin1 (carolina.bonin@hamptonu.edu), Michael Goebel2, Douglas Krause2, Eric Lewallen3, Nefertiti
Smith1, Isaiah Milton1, Joseph Hoffman4
1
Hampton University, Marine and Environmental Sciences, Hampton, United States, 2Southwest Fisheries
Science Center, Antarctic Ecosystem Research Division, La Jolla, United States, 3Hampton University, Biological
Sciences, Hampton, United States, 4University of Bielefeld, Department of Animal Behaviour, Bielefeld, Germany

The rapid environmental change occurring in the Antarctic Peninsula region has led to changes in the biota and
community structure. Changes in top predator populations include shifts in distribution, abundance and the
relative importance of top predators within the ecosystem. As ice-habitat in the Peninsula region has
decreased, Leopard seals (Hydrurga leptonyx) have been dramatically increasing on land at Cape Shirreff,
Livingston Island. Animals hauling out are primarily large females and juveniles. Remarkably, there is no
published information on the social structure of leopard seals. Therefore, we set out to investigate the social
structure of Leopard seals, via the estimation of genetic relatedness and parentage analyses. A preliminary
assessment (17 samples; 10 microsatellite markers) revealed two pairs of mother-offspring, suggesting some
level of individual association in hauling out behavior. However, genetic diversity was relatively low
(heterozygosity, HE= 0.57), so more genetic markers are needed to increase statistical power in our analyses.
Despite this caveat, our results suggest that kinship associations are common and likely an important aspect of
hauling out patterns in Leopard seals. We are currently expanding the scope of our study to add more samples,
including animals from other areas, so we can better understand this species' behavior and population
dynamics.

1477
Thu_119_BE-9_727
What´s in a Size? Phenotypic Variation across Acutuncus antarcticus Populations

Katherine Short1 (katort80@bas.ac.uk), Sandra McInnes1, Davide Pisani2, Peter Convey1

1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Bristol, Biological Sciences, Bristol, United
Kingdom

Tardigrades, are one of the most diverse and common groups of animals found throughout continental
Antarctica and play an important role in biological processes in its challenging terrestrial ecosystems.
Acutuncus antarcticus is currently thought of as a truly pan-Antarctic species which can survive in most
terrestrial habitats in Antarctica, although it is most commonly found within algal mats. Previous studies into
phenotypic variation between continental populations of this species showed little difference. Here we build
on these studies by measuring phenotypic variation over a geographical area expanded to include the sub- and
maritime Antarctic. Principal component analysis of morphological data obtained identified distinct regional
variation and suggested two alternative explanations for the variation seen. Firstly, local adaptation to their
environment in individual populations or second, the early stages of speciation across different geographical
areas. These alternatives will be addressed with molecular phylogenetic analyses. Knowing the history and
colonisation routes of these animals in Antarctica could contribute to predicting future changes to biodiversity
associated with climate change.

1478
Thu_120_BE-9_800
Three Decades of Plant Succession at Rip Point, Nelson Island, Antarctica

Daniela Schmitz1 (danni_schmitz@hotmail.com), Jair Putzke2, Carlos Ernesto Gonçalves Reynaud Schaefer3
1
Federal University of Viçosa, Núcleo Terrantar, Deptartment of Plants Biology, Viçosa, Brazil, 2Federal
University of Pampa, Núcleo de Estudos da Vegetação Antártica, São Gabriel, Brazil, 3Federal University of
Viçosa, Núcleo Terrantar, Deptartment of Soils, Viçosa, Brazil

Long-term studies of plant succession are still negligible in Antarctica. Such evaluations allow correlations
between plant development, climatic change and ecological consequences in specific areas of Antarctica. We
compared the phytosociological data collection carried out in 1990 with recent data from 2017 Austral Summer
at Rip Point, Nelson Island - Maritime Antarctica. Ten areas dominated by mosses selected in 2017, which out
of 17 areas studied in 1990. The Braun-Blanquet square methodology was adapted to the Antarctic conditions,
in which we compared vegetation differences through frequency and coverage data and analyzed the plant
community succession in the area. The results indicate that varying water availability influences local
vegetation, reducing cushion forming mosses and Warnstorfia spp. community, more dependent on
waterlogging. This was attributed to lower snow cover, remaining in the area compared with data 1990, the
general species composition revealed the appearance of Brachythecium sp. not observed in the earlier study.
Sanionia spp. carpets área now increasing growing and vigour, except in áreas under intense human impact,
where the community is reducing. Even though the decreasing water availability with time, Polytrichum
piliferum Hedw. is being completely overgrown by S. uncinata. Some areas showed the appearance or
increasing growing of muscicolous lichens, indicating a process of plant succession at Rip Point.

1479
Thu_121_BE-9_832
Efficiency of the Antarctic Protected Areas Conserving the Terrestrial Diversity

Oscar Ramos1 (ojramos@unisalle.edu.co), Maria Fernanda Lozano2, Gelys Mestre1, Mayerling Sanabria3
1
University of La Salle, Department of Basic Sciences, Bogota, Colombia, 2University of La Salle, La Salle
Museum, Bogota, Colombia, 3University of La Salle, Faculty of Engineering, Bogota, Colombia

The Antarctic Specially Protected Areas and Managed Areas (ASPA/ASMA) are Antarctic zones defined to
protect scientific, historic and environmental values, including the conservation of the fauna and flora. The
delimitation of these areas is reviewed regularly during the workshops of the Antarctic Treaty Meetings.
However, information of the geographic distribution of the Antarctic biodiversity has not been considered
strictly to delimit these areas. Thus, to produce a baseline to support this kind of decisions, this study was
focused to estimate how the terrestrial biodiversity is distributed within the protected areas and how it
changes as the distance from their current limit increase. To achieve this, first, we estimated the geographic
distribution of the terrestrial Antarctic biodiversity using stacked distribution models of 68 species. Each
species distribution was obtained from a consensus model, combining MaxEnt, GARP, GAM and SVM models.
After, we estimated how the biodiversity changes as the distance to the current ASPA/ASMAs increased:
evaluating dissimilarity due to species replacement and species loss in ring buffers located at different
distances to the protected areas. Finally, we ranked all the ASPA/ASMAs from the most efficient to the less one
based on the replacement and loss of species. The maps of change in biodiversity and the efficiency ranking
obtained constitute a key baseline to redefine the limits of the Antarctic protected and managed areas.

1480
Thu_122_BE-9_839
Closely Related Antarctic Octopus Show Different Spatial Genetic Structures

Jan Strugnell1 (jan.strugnell@jcu.edu.au), Louise Allcock2, Phillip Watts3

1
James Cook University, Townsville, Australia, 2National University of Ireland, Galway, Galway, Ireland,
3
University of Oulu, Oulu, Finland

Determining whether comparable processes drive genetic divergence among marine species is relevant to
molecular ecologists and managers alike. Sympatric species with similar life histories might be expected to
show comparable patterns of genetic differentiation and a consistent influence of environmental factors in
shaping divergence. We used microsatellites to quantify genetic differentiation across the Scotia Arc in three
octopod species; Pareledone turqueti, P. charcoti, and Adelieledone polymorpha. The relative importance of
environmental factors in shaping genetic structure was investigated. Isolated populations of P. turqueti and A.
polymorpha at these species' range margins were genetically different to samples close to mainland Antarctica;
however, these species showed different genetic structures at a regional scale. Samples of P. turqueti from the
Peninsula, Elephant and Signy Islands were genetically different, and this divergence was associated primarily
with depth. By contrast, weak or nonsignificant spatial genetic structure was evident across the Peninsula,
Elephant and Signy Island regions for A. polymorpha. P. charcoti exhibited no genetic differentiation between
samples from a small region of the Scotia Arc. Thus, closely related species with similar life history strategies
can display contrasting patterns of genetic differentiation depending on spatial scale; moreover, depth may
drive genetic divergence in Southern Ocean benthos.

1481
Thu_123_BE-9_964
What Drives the Distribution of Antarctic Krill at the South Orkney Islands?

Sally Thorpe1, Angelika Renner2 (angelika.renner@imr.no), Emma Young1, Olav Rune Godø2, Thor Klevjer2,
Eugene Murphy1
1
British Antarctic Survey, Cambridge, United Kingdom, 2Institute of Marine Research, Tromsø, Norway

Antarctic krill is a key species in the marine ecosystem of the Southern Ocean and the target of a commercial
fishery. Determining the physical and behavioural drivers for krill distribution, including the formation,
maintenance and distribution of krill aggregations, is essential to understanding the ecosystem, its function,
and sensitivity to climate change and human impacts. This is particularly important as the fishery for krill is
increasingly geographically focussed on local krill hotspots.
Here we present modelling results from two related projects investigating the distribution of Antarctic krill at
the South Orkney Islands (~60oS, 45oW). One of the main fishing grounds for krill, this region is also critical for
determining the overall availability of krill across the wider Scotia Sea. Modelling studies using state-of-the-art
ocean-sea ice models at differing spatial resolutions allow us to understand temporal and spatial variability in
krill flux into and out of the South Orkney region, and the relationship to sea ice conditions. Individual-based
models incorporating key behavioural characteristics permit further investigation into the role of krill behaviour
on retention and dispersal of krill in the region. Such insights and predictive tools are essential for a sound
implementation of a feedback management system for Antarctic krill, which is currently being developed under
the auspices of the Commission for the Conservation of Antarctic Living Resources (CCAMLR).

1482
Thu_124_BE-9_978
Physical Forcing of Marine Ecosystems in the Prince Edward Islands Region

Anne M. Treasure1,2 (anne.m.treasure@gmail.com), James J. Ruzicka3, Evgeny A. Pakhomov4, Coleen L.

Moloney5, Isabelle J. Ansorge2
1
University of Pretoria, Mammal Research Institute, Department of Zoology & Entomology, Pretoria, South
Africa, 2University of Cape Town, Department of Oceanography and Marine Research Institute (Ma-Re), Cape
Town, South Africa, 3Oregon State University, Cooperative Institute for Marine Resources Studies, Newport,
United States, 4University of British Columbia, Department of Earth and Ocean Sciences, Vancouver, Canada,
5
University of Cape Town, Department of Biological Sciences and Marine Research Institute (Ma-Re), Cape
Town, South Africa

The Southern Ocean (SO) plays a crucial role in the global ocean and climate system. Its ecosystems affect
global biogeochemical cycles, sustain globally important marine biodiversity and will be important in
maintaining food security. Somewhat alarming therefore is the rapid rate of environmental change being
experienced by the region with resultant impacts to ecosystems and food webs. Understanding the impacts of
a changing physical environment on biological systems is a key question in marine ecology. However, linking
ecosystem changes to physical ones remains difficult. Ecosystem models allow computational exploration of
disruptions on ecosystems that would otherwise be impossible experimentally. However, much research to
date has focused on species-specific research. Therefore a great emphasis has been placed on the need for the
development of modelling strategies that span all levels of the biotic system, from end to end. While integrated
whole ecosystem views of the SO from nutrients through primary producers and consumers to top predators
are starting to emerge, models integrating physics and biology are lacking. Therefore we use physical
oceanographic data to drive biological ecosystem models of the sub-Antarctic Prince Edward Islands. Physical
oceanographic processes are of considerable importance to the marine ecosystem in the vicinity of these
islands and therefore changes to these processes are predicted to have significant impacts on species and
communities.

1483
Thu_125_BE-9_1018
Integrating Niche Modelling to Assess Spatial Risks of an Invasive Midge

Luis R. Pertierra1 (luis.pertierra@gmail.com), Jesamine Bartlett2, Grant Duffy3, Greta C. Vega1, Kevin Hughes4,
Scott Hayward2, Pete Convey4, Miguel Angel Olalla-Tarraga1, Pedro Aragón5
1
Universidad Rey Juan Carlos, Mostoles, Spain, 2University of Birminham, Birmingham, United Kingdom,
3
University of Monash, Melbourne, Australia, 4British Antarctic Survey, Cambridge, United Kingdom, 5Museo
Nacional de Ciencias Naturales, Madrid, Spain

Eretmoptera murphyi, a flightless midge endemic to the sub-Antarctic island of South Georgia, was
inadvertently introduced to Signy Island (South Orkney Islands) in the 1960s, establishing an alien population
that has since been expanding locally. In order to identify future expansion risks, different modelling
techniques are explored here. Mahalanobis distances were calculated based on the species' current realized
distribution, as an indication of environmental distances to the species niche centroid at different sites. In
addition, ecophysiological experiments were performed on E. murphyi larvae to identify those temperatures
most beneficial for survival to build into mechanistic models. Potential range distribution scenarios are
generated for current and predicted future scenarios up to 2100. Increasing risk of invasion into Antarctic
locations further south is predicted over time. Sites in synergy with high visitation at the South Shetland Islands
and northern Antarctic Peninsula are likely to be at particularly high risk. How the endemic maritime Antarctic
midge (Belgica antarctica) will be affected in the event of southwards range spreading and range overlap with
E. murphyi remains to be assessed. Human activities in the this region should follow particularly strict
biosecurity protocols if visiting Signy Island or South Georgia and then traveling to other maritime Antarctic
locations, in order to minimize the risk of assisted dispersal to such highly vulnerable sites.

1484
Thu_126_BE-9_1020
Antarctic Sponges as Prokaryotic Diversity and Biotechnology Hot-spots

Angelina Lo Giudice1 (alogiudice@unime.it), Gabriella Caruso1, Stefania Giannarelli2, Concetta Gugliandolo3,

Annarita Poli4, Rosabruna La Ferla1, Stefano Amalfitano5, Ermanno Crisafi1, Maurizio Azzaro1
1
Institute for Coastal Marine Environment (IAMC), National Research Council, Messina, Italy, 2University of Pisa,
Department of Chemistry and Industrial Chemistry, Pisa, Italy, 3University of Messina, Department of Chemical,
Biological, Pharmaceutical and Environmental Sciences, Messina, Italy, 4Institute of Biomolecular Chemistry
(ICB), National Research Council, Pozzuoli (Naples), Italy, 5Water Research Institute (IRSA), National Research
Council, Roma, Italy

Polar Regions are experiencing multiple environmental stressors and the increasing contaminant influxes are
likely becoming more severe. As filter-feeders, in Porifera ingestion becomes the primary route in the uptake
and accumulation of particle-associated contaminants, which may accumulate in animal tissues. Porifera also
provide an important habitat for aquatic prokaryotes that colonize outer surfaces and interstices of ostia and
oscula, and may be particularly responsive against contaminants accumulated in the sponge tissues. Symbiotic
microorganisms can adhere to the sponge surfaces by forming biofilm with complex 3D-structures, composed
by microbial consortia encased in an extracellular polymeric substances. The exopolymeric substances possess
high biotechnological potentialities with applications in biomedical, cosmetic, food and environmental fields.
Despite Porifera are abundant invertebrates in Antarctica, the associated prokaryotic communities and their
biotechnological potentialities were largely disregarded. Funded by the Italian PNRA, the P3 project "Antarctic
Porifera: Hot-spots for Prokaryotic diversity and biotechnological Potentialities”" (PNRA16_00020) will aim at
linking the ecological traits (e.g., phylogenetic diversity and metabolic activities) and biotechnological potential
(e.g., biofilm production, pollutant degradation) of prokaryotes associated with Antarctic Porifera by applying a
multidisciplinary approach.

1485
Thu_127_BE-9_1025
Peracarids of the Larsen-C Shelf Area Compared with Non-ice Covered Regions

Angelika Brandt1 (angelika.brandt@senckenberg.de), Katrin Linse2, Huw Griffiths3

1
Senckenberg Institute and Natural History Museum, Frankfurt, Germany, 2British Antarctic Survey, Cabridge,
United Kingdom, 3British Antarctic Survey, Cambridge, United Kingdom

The Larsen-C PEARL Project (The influence of Larsen-C ice-cover on macrobenthic peracarid crustacean
assemblages on the Antarctic shelf) compares and analyses the benthic peracarid distribution in ice covered
(Larsen-C, calved iceberg A 68) and ice-free Southern Ocean areas. The project's governing hypothesis is: H:
"Until the calving of the Larsen-C iceberg, A68, the benthic fauna on the seabed beneath ice shelf has likely
comprised oligotrophic assemblages resembling deep-sea Weddell Sea assemblages. The calving of A68, and
the exposure of the seabed to open-marine and sea-ice conditions will initiate a rapid colonisation by new
species that will transform the benthic ecosystem significantly within a short timeframe." Larsen-C Pearl will
focus on peracarid crustaceans and analyse biodiversity and assemblage structure of the epi- and suprabenthic
peracarid crustaceans and compare the occurrence of species from the Larsen-C area with that of the deep sea
of the Weddell Sea as well as the Filchner Trough and South Orkney area.

1486
Thu_128_BE-9_1091
An Investigation into Social-biology of Penguins in Antarctica

Prabir G Dastidar1 (prabirgd11@gmail.com)

1
Ministry of Earth Sciences, Delhi, India

Presentation will be made on Social Networks of animals to understand animal behaviour, animal cognition and
the dynamics of animal societies in extreme environments like Antarctica. And its role in the designing the
instinctive layer of social systems.
Social structure of penguins¾a group of primitive flightless birds living in the coastal regions of Antarctica
continent will be explored.
These primitive birds living in the earth for more than 60 million years by withstanding extreme evolutionary
challenges. Various adaptive strategies in their daily life are examples of highest level of cooperative behaviour,
and reasons for their survival for such a long time; while majority of animals of that period are now extinct and
no longer exist in earth. All this made possible with a very primitive brain structure.
Importance of multidisciplinary studies will be explored to understand the structure and dynamics of their
social system; biological and mathematical characteristics responsible for developing into a well-structured
organised society. Adaptive features of their anatomy, physiology and cognition will be presented.
The studies into the social network of penguins will make it possible to understand instinctive nature and
robustness of their social systems functioning with a primitive and simple brain, body and social structure. The
role of biotic and abiotic factors in shaping up animal societies will also be discussed.

1487
Thu_130_BE-9_1155
Are there Barriers for Microbial Dispersal in Antarctica? Clues from Rotifers

Nataliia Iakovenko1,2,3 (rotifer1@gmail.com), Jerzy Smykla4,5, Eva Kašparová3, Karel Janko3,6,7

1
University of Ostrava, Biology and Ecology, Ostrava, Czech Republic, 2Schmalhausen Institute of Zoology NAS of
Ukraine, Invertebrate Fauna and Systematics, Kyiv, Ukraine, 3Institute of Animal Physiology and Genetics,
Liběchov, Czech Republic, 4University of North Carolina, Biology and Marine Ecology, Wilmington, United States,
5
Institute of Nature Conservation, Biodiversity, Krakow, Poland, 6University of Ostrava, Ostrava, Czech Republic,
7
Centre for Polar Ecology, České Budějovice, Czech Republic

According to the recent biogeographical classification (Terauds et al. 2012, Terauds & Lee 2016), ice-free
regions of Antarctica are divided into 16 Antarctic Conservation Biogeographic Regions (ACBRs), each of those
with characteristic fauna including microscopic organisms (fungi, algae, microarthropods and other
invertebrates). Various historical and contemporary drivers may underlay the observed biodiversity patterns,
including population isolation during glacial maxima, physical and/or atmospheric connectivity barriers.
Our research aims at discovering the patterns of isolation/long-distance dispersal in the populations of 5
species of Antarctic rotifers: (1)Adineta editae, (2)A. emsliei, (3)A. grandis, (4)Macrotrachela cf musculosa,
(5)Philodina gregaria. Species were collected in 7 ACBRs of maritime (1,4) and continental Antarctica (1,2,3,5).
Sequences of mtCOX1 partial gene were used for AMOVA, Mantel test and building TCS haplotype networks.
The analysis has shown significant patterns of local isolation in the populations of all species, and long-distance
dispersal for (4).

1488
Thu_131_BE-9_1204
Under Sea-ice and under Protection: Low Impact Sampling of Antarctic Toothfish

Davide Di Blasi1 (davide.diblasi@ge.ismar.cnr.it), Simonepietro Canese2, Erica Carlig1, Laura Ghigliotti1, Steven J.
Parker3, Eva Pisano1, Marino Vacchi1
1
National Research Council, Institute of Marine Sciences (ISMAR), Genoa, Italy, 2Istituto Superiore per la Ricerca
e la Protezione Ambientale (ISPRA), Rome, Italy, 3National Institute of Water and Atmospheric Research (NIWA),
Nelson, New Zealand

The Antarctic toothfish (Dissostichus mawsoni) is the largest notothenioid fish inhabiting high Antarctic waters
where it is a keystone species in the food web as apex predator, and commercially fished. The life cycle of the
species is only partially known since large amount of data is available from open waters, where the toothfish
resides as adult, whereas information from sea-ice covered areas is still poor. This leaves in the field of
uncertainty a significant portion of the species life cycle, including the sub-adult phase. Where and how the
sub-adults toothfish forage in the water column and to what extent they are able to perform vertical migration
in sea-ice sheltered areas are among the issues that still remain uncovered.
In this frame, and taking into account the conservation goals of the recently established Ross Sea Region
Marine Protected Area (RSRMPA), low environmental impact methodologies for the visual survey of Antarctic
toothfish are being developed for collecting data from under sea-ice areas. The work, performed under the
umbrella of the scientific scholarship 2017 of the Commission for the Conservation of Antarctic Marine Living
Resources (CCAMLR), aims at contributing to refine the sustainable management of the Antarctic toothfish, and
to develop a standardized protocol for non-invasive sampling to be used for monitoring in the RSRMPA.

1489
Thu_132_BE-9_1255
Retarded Ice Growths in Antarctic Lichen Thalli

Kazimierz Strzalka1 (kazimierzstrzalka@gmail.com)

1
Jagiellonian University, Malopolska Centre of Biotechnology, Krakow, Poland

Antarctic lichens are resistant to low temperatures and to deep dehydration. The understanding of that
requires the knowledge on the formation of tightly and of loosely bound water fractions at different steps of
hydration process.
The thalli of fruticose lichen Cetraria aculeata (Schreb.) Fr. were collected in maritime Antarctica.1H-NMR
spectra were collected on Bruker Avance III 300 spectrometer (Bruker Biospin),. DSC scans were performed on
Perkin Elmer DSC 8000 calorimeter.
1
H-NMR experiments allow us to distinguish besides the signal from lichenized fungus tissue also the signal
from tightly bound (immobilized) water and the signal from loosely bound (more mobile) water fraction.
1
H-NMR spectra temperature dependence reveals two processes of bound water immobilization, i.e. coherent
ice freezing and gradual non-coherent immobilization of water molecules. Besides these two mechanisms
observed by us in other biological systems/living organisms, e.g. in wheat photosynthetic membranes, a novel
effect was discovered using DSC, namely ice crystallites growth inside the Antarctic Cetraria aculeata thallus
was retarded by diffusion of supercooled liquid water molecules. The retardation is probably
correlated/induced by morphological diversity of the thallus, consisting of fungus and of isolated algal cells.
However, there is a question to what extent this phenomenon creates an evolutionary advantage of lichenized
fungi.

1490
Thu_133_BE-9_1266
Substrate Colonization in the Ross Sea, Antarctica: The ANT-BIOFILM Project

Gabriella Caruso1 (gabriella.caruso@iamc.cnr.it), Maurizio Azzaro1, Ombretta Dell'Acqua2, Angelina Lo Giudice1,

Stefano Fazi3, Carmela Caroppo4, Filippo Azzaro1, Rosabruna La Ferla1, Giovanna Maimone1, Pasqualina
Lagana'5, Flavia Marinelli6, Francesca Berini6, Giorgia Letizia Marcone6, Gérard Pichon7, Mariachiara Chiantore2
1
Institute for Coastal Marine Environment (IAMC), National Research Council, Messina, Italy, 2University of
Genoa, Department of Earth, Environment and Life Sciences (DISTAV), Genoa, Italy, 3Water Research Institute
(IRSA), National Research Council, Rome, Italy, 4Institute for Coastal Marine Environment (IAMC), National
Research Council, Taranto, Italy, 5University of Messina, Department of Biomedical and Dental Sciences and
Morphofunctional Imaging, Messina, Italy, 6University of Insubria, Department of Biotechnology and Life
Sciences (DBSV), Varese, Italy, 7Barbier Group, Sainte Sigolène, France

Microbial biofilms play a key role in substrate colonization in aquatic environments, as hot spots of biodiversity
and sources of secondary metabolites with biotechnological potential. In Terra Nova Bay (Ross Sea, Antarctica),
microbial biofilm communities are under-explored in their structure and functions; particularly, their response
to environmental and/or anthropogenic forcings remains to be elucidated yet. Funded by National Antarctic
Research Program (XXXIII Italian expedition), the ANT-Biofilm project "Microbial colonization of benthic
ANTarctic environments: response of microbial abundances, diversity, activities and larval settlement to natural
or anthropogenic disturbances and search for secondary metabolites" (PNRA16_00105) includes short and long
term (3-12 months) experiments in two bays (Road Bay and Tethys Bay) characterized by anthropogenic (i.e.
sewage) and natural (i.e. low salinity) stressors, respectively. Total, viable and respiring prokaryotes, culturable
bacteria, potential enzymatic activity rates, physiological community profiles, microalgae and macrobenthic
community are studied. Selected biofilm samples will be sequenced and analyzed by hybridization (i.e. Card-
FISH) and bacterial isolates screened for antibiotic resistance and metabolite production. Physical-chemical
environmental characterization will be performed. This contribution reports the preliminary results obtained by
the four Research Units during the short term experiments.

1491
Thu_134_BE-9_1357
Environmental Drivers of Mesopelagic Community Structure on the Kerguelen Axis

Rowan Trebilco1 (rowan.trebilco@utas.edu.au), Andrea Walters2, Jess Melbourne-Thomas3, Sophie Bestley4,

Martin Cox3, Sven Gasteur1, Michael Sumner3, Andrew Constable3
1
Antarctic Climate & Ecosystems CRC, University of Tasmania, Hobart, Australia, 2Institute for Marine and
Antarctic Studies, University of Tasmania, Hobart, Australia, 3Australian Antarctic Division and ACE CRC,
Kingston, Australia, 4CSIRO Oceans & Atmosphere, Hobart, Australia

In January - March 2016, the Antarctic Climate and Ecosystems CRC led an integrated ecosystem survey voyage
on the Southern Kerguelen Axis - a productive region spanning from Banzare Bank on the southern Kerguelen
Plateau towards Prydz Bay in East Antarctica. The voyage track encompassed an 8850 km path including 9
transects, designed to encompass major environmental transitions that may drive ecosystem structure in the
region. A primary goal was to characterize the pelagic foodweb structure and major energy pathways, with a
strong focus on the mesopelagic community. The mesopelagic community was sampled at 36 stations, from
the surface to 1000m in 200m depth strata, using an IYGPT net equipped with a multiple cod-end MIDOC
device. Calibrated acoustic data were also collected throughout the voyage, using SIMRAD EK60 echosounders,
operated at 38, 120 and 200 kHz. We present a summary of the mesopelagic community results from this
voyage, including abundances key nekton groups, and analyses examining the relationship between catch
composition, total acoustic backscatter, and key environmental drivers. This work provides new information on
a poorly represented ecosystem component and pilots methodologies for future ecosystem observation and
monitoring.

1492
Thu_135_BE-9_1405
Assessment of Ground versus UAS Flight Surveys on Antarctic Predator Behavior

Douglas Krause1 (douglas.krause@noaa.gov), Jefferson Hinke1, Wayne Perryman2, Michael Goebel1, Donald
LeRoi3
1
NOAA Fisheries/Southwest Fisheries Science Center, Antarctic Ecosystem Research Division, La Jolla, United
States, 2NOAA Fisheries/Southwest Fisheries Science Center, Marine Mammal and Turtle Division, La Jolla,
United States, 3Aerial Imaging Solutions LLC, Old Lyme, United States

Accurate population counts are fundamental to wildlife management. The recent proliferation of unmanned
aerial systems (UAS) has provided new opportunities for collecting census and distribution data that are as, or
more, accurate than traditional ground surveys. Reports on the effects of UAS on wildlife, however, vary
widely. Wildlife response differs depending on many factors including species, type and size of UAS, method of
operation, amplitude and frequency of noise, etc. We compared the effects of UAS flights to ground surveys by
assessing the behavioral responses of chinstrap penguins (CP), Antarctic fur seals (AFS), and leopard seals (LS)
to flights at specific altitudes. For CP & AFS we also controlled for differences in human exposure history and
stage of reproduction. Flights were conducted Jan-Mar 2017. Observations for all three species were recorded
by a UAS camera, a lateral camera with a sound meter and visual observers. We conducted 35 flights over CP
(N=272), AFS (N=68) and LS (N=10). Lateral camera and visual observations were also made for ground surveys
of CP (N=130) at the same location. During flights as low as 8 m < 1% of CP, 10% of LS, and < 15% of AFS
responded to UAS. No animals moved their location. By comparison >85% of CP and 100% of LS left their
location during ground surveys. Our studies indicate that a UAS, operated within guidelines appropriate to the
situation, can have less impact on wildlife than traditional survey methods.

1493
Thu_136_BE-9_1406
Modelling the Diet of Leopard Seals at Cape Shirreff, Antarctic Peninsula

Douglas Krause1 (douglas.krause@noaa.gov), Carolyn Kurle2

1
NOAA Fisheries/Southwest Fisheries Science Center, Antarctic Ecosystem Research Division, La Jolla, United
States, 2University of California San Diego, Division of Biological Sciences, La Jolla, United States

Leopard seals are a widespread and important predator in Antarctic coastal ecosystems. Previous studies have
identified a broad range of prey items; however, due to anecdotal or otherwise limited information leopard
seal diets remain largely unresolved by seal sex, inter-individual variability, age class, region, or season. As a
result, leopard seals are commonly reported as generalist predators. Over three summer field seasons we
collected visual, scat and stable isotope tissue (blood and plasma) data from nineteen adult female and two
adult male leopard seals foraging near mesopredator breeding colonies at Cape Shirreff. We summarized a
priori diet information and applied a three isotope (δ13C, δ15N and δ34S), four source (fish, fur seal, krill,
penguin) Bayesian mixing model to examine temporal variability in both prey sources and leopard seal tissues,
and define their trophic position within the local food web. The distribution of the four prey groups in isospace
appears to explain the entire leopard seal diet. Rather than a generalist diet pattern, posterior probabilities of
prey proportions identified two distinct groups among female diets. One diet was dominated by Antarctic fur
seal pups and krill, while the other was predominately penguin and demersal fish. The diet of the two males
was mostly krill. Additionally, δ15N values were consistently enriched for plasma versus red blood cells implying
a seasonal diet change for both female groups.

1494
Thu_137_BE-9_1413
Parsing Environmental Stressors in the Southern Ocean Ecosystem

Casey Youngflesh1 (casey.youngflesh@stonybrook.edu), Fiona Jones2, Tom Hart2, Grant Humphries3, Ron
Naveen4, Heather J. Lynch1
1
Stony Brook University, Ecology and Evolution Department, Stony Brook, United States, 2University of Oxford,
Zoology Department, Oxford, United Kingdom, 3Black Bawks Data Science, Fort Augustus, United Kingdom,
4
Oceanites, Inc., Chevy Chase, United States

Ecological systems are being impacted by a wide variety of environmental stressors. Changes in the abiotic
environment and resource extraction are two areas of particular concern in the Southern Ocean. Parsing the
impacts of these stressors, however, has proven difficult. Not only is resource extraction in the region difficult
to quantify, impacts of both abiotic and biotic stressors may result in similar ecological responses in metrics
commonly measured by researchers. Using data on penguin demographics, krill catch, and abiotic
environmental conditions such as sea ice dynamics, we assess the impact of these drivers on penguin
reproductive performance. We combined data on Pygoscelis penguin reproductive success from a network of
remote time-lapse cameras positioned across the Antarctic Peninsula and previously unanalyzed high-spatial
and temporal resolution krill catch data obtained from Aker BioMarine. A hierarchical Bayesian state-space
model was used to estimate penguin chick survivorship as a function of both abiotic environmental conditions
and krill catch across both space and time. Through the integration of multiple sources of data over large
spatial scales, we identify key drivers of penguin breeding success, which has important implications for
management efforts and our understanding of the Southern Ocean marine ecosystem.

1495
Thu_138_BE-9_1414
Environmental Change and Ecosystem Monitoring of the Ross Sea Region

David Bowden1, Vonda Cummings2 (vonda.cummings@niwa.co.nz), Matt Pinkerton1, Melissa Bowen3, Malcolm
Clark1, Rochelle Constantine3, Moira Decima1, Andres Gutierrez Rodriguez1, Mike Harvey1, Richard O'Driscoll1,
Arne Pallentin1, Mike Williams1
1
NIWA, Wellington, New Zealand, 2National Institute of Water and Atmospheric Research, Wellington, New
Zealand, 3University of Auckland, Auckland, New Zealand

The Ross Sea region of the Southern Ocean is a significant focus of global research. Important unanswered
questions remain on the drivers and extent of oceanographic change and on the response of marine
ecosystems to a changing environment. Managing and mitigating the effects of human activities (especially
fishing and tourism) against this backdrop of environmental change is challenging and has led to the
establishment of the world´s largest Marine Protected Area in the Ross Sea region. Ongoing stewardship
requires an understanding of environmental-ecosystem interactions and the development of an effective
approach to monitoring.
This presentation outlines the first results from a New Zealand research voyage to the Ross Sea region in 2018.
New information will be presented on the main science questions:
1. How has the export of Antarctic Bottom Water from the Ross Sea changed over the past two decades?
2. What are the key interactions between aerosols and cloud formation?
3. How do marine microbial planktonic communities vary across the Ross Sea region?
4. What is the structure, and key environmental drivers, of benthic and demersal habitats and faunal
communities of the Pacific-Antarctic Ridge in the Ross Sea sector?
5. Is the Ross Sea region ecologically critical for key species of Antarctic whales?
6. How is the distribution, abundance and trophic ecology of mesopelagic fishes and zooplankton in the Ross
Sea region related to the oceanographic environment?

1496
Thu_139_BE-9_1441
Complementary eDNA and Micropaleontological Foraminiferal Record from Ross Sea

Ewa Demianiuk1 (ejdemianiuk@gmail.com), Wojciech Majewski1, Mateusz Baca2, Danijela Popović2, Lindsay
Prothro3, Lauren Simkins3, John Anderson3
1
Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland, 2University of Warsaw, Centre of New
Technologies, Warsaw, Poland, 3Rice University, Department of Earth, Environmental & Planetary Sciences,
Houston, United States

The seafloor morphology of the western Ross Sea has been shaped by glacial and post-glacial processes,
including subglacial deposition, erosion of paleo-ice streams, and iceberg scouring. The similarities of
repeatedly recycled sediments pose a problem with distinction between sedimentary facies. However, in most
of these records, foraminiferal microfossils are present, carrying significant information.
During the NBP15-02A cruise, we collected samples from megascale glacial lineations (MSGLs), Grounding Zone
Wedge (GZW) topsets, foresets and slope deposits for micropaleontology and next-generation sequencing of
environmental DNA (eDNA). In sediments from different geomorphological features, we found various
assemblages of fossil foraminifera, which are complemented by information from foraminiferal DNA. Species
detected by molecular methods were dominated by monothalamids, which are absent in the fossil record.
Information derived from eDNA increases our knowledge of true foraminiferal diversities as well as supports
the interpretation of in-situ character of investigated assemblages. The distribution of biogenic remains fits
well with environmental interpretations based on sedimentology and geomorphology. It shows an absence of
eDNA in sediments from GZW topsets and MSGLs paired with low microfossil abundances. In contrast, in GZW
foresets, eDNA is accompanied by numerous foraminiferal tests.

1497
Thu_140_BE-9_1550
How C. quitensis Can Cope with Global Warming: A Focus on Photosynthesis

Laura Bertini1 (lbertini@unitus.it), Francesca Focaracci1, Fabiana Canini1, Silvia Proietti1, Leon Bravo2, Carla
Caruso1
1
University of Tuscia, Ecological and Biological Sciences, Viterbo, Italy, 2University of La Frontera, Ciencias
Agronomicas y Recursos Naturales, Temuco, Chile

The West Antarctic Peninsula is one of the areas on Earth mostly affected by global warming which is inducing
a temperature rise at an alarming rate. This makes the Antarctic Peninsula an open-air laboratory where the
study of the genetic and molecular traits of the adaptation of living organisms to rapidly changing
environmental conditions may allow the disclosure of molecular biomarkers for efficient climate change
monitoring. The two plants species native to Antarctica, Deschampsia antarctica Desv. and Colobanthus
quitensis (Kunth) Bartl., are exposed to high light and low temperature during their natural growing season
which alter their photosynthetic yield and make them more susceptible to photooxidative damage.
In this work, we investigated the influence of the temperature rise on the C. quitensis photosynthetic
performance. To this, we compared the expression level of key genes of the photosynthetic pathway in plants
grown in natural conditions versus plants grown for one year inside small greenhouses open on the top (Open
Top Chambers) which determine an increase of about 4 °C during midday, mimicking the effect of global
warming.
Interestingly, we found that higher temperatures induce a general over-expression of the genes involved in the
photosynthetic process, but plants seem to be less protected from high irradiation since the genes involved in
the non-photochemical quenching appear to be down-regulated.

1498
Thu_141_BE-9_1552
Assessment of Housekeeping Genes for qPCR Data Normalization in C. quitensis

Laura Bertini1 (lbertini@unitus.it), Francesca Focaracci1, Fabiana Canini1, Silvia Proietti1, Leon Bravo2, Claudia
Rabert2, Carla Caruso1
1
University of Tuscia, Ecological and Biological Sciences, Viterbo, Italy, 2University La Frontera, Ciencias
Agronomicas y Recursos Naturales, Temuco, Chile

The areas along the Antarctic Peninsula are warming faster than any other part of the world hard testing the
native organisms which often live at their physiological limits. This makes particularly interesting to study the
genetic and molecular traits of the local plants to assess the molecular basis of adaptation to low temperatures
and their ability to respond to climatic changes. The use of molecular tools, such as qPCR, to perform
differential gene expression studies requires the identification of the most stable houesekeeping genes (HKG)
to normalize the data and obtain robust and consistent results.
In this work, we identify and validate new reference genes for qPCR data normalization in the Antarctic plant
Colobanthus quitensis (Kunth) Bartl. under various abiotic stresses (temperature, nitrogen and salinity). In
particular, we selected a set of eight candidate HKG whose stability was evaluated using the freely available
RefFinder web tool that uses 4 different software (NormFinder, BestKeeper, ΔCt and geNorm) to calculate the
geometric mean of weights for the comprehensive ranking order recommended and to determine the best
reference gene or pair of genes.
In addition, to test the reliability of the selected reference genes, expression analysis of catalase was
presented. Ultimately, our data provide a useful set of reference genes that can be used in qRT-PCR to analyze
gene expression in C. quitensis under different experimental procedures.

1499
Thu_142_BE-9_1615
Small-sexual Segregation Despite Large Scale Overlap in Wandering Albatross

Jorge M. Pereira1, Vitor H. Paiva1, José Abreu1 (abreu.jose@ua.pt), Richard A. Phillips2, José C. Xavier1,2
1
Marine and Environmental Sciences Centre - University of Coimbra, Departamento Ciencias da Vida, Coimbra,
Portugal, 2British Antarctic Survey, Cambridge, United Kingdom

Sexual segregation in foraging habitat occurs in many marine predators and is usually attributed to intra-
specific competition or habitat specialisation associated with sexual size dimorphism. We studied habitat use,
diet and feeding ecology of female and male wandering albatrosses Diomedea exulans, fitted with GPS and
stomach-temperature loggers during the chick-rearing period at South Georgia. During this period, when
oceanographic conditions were unusual and prey availability was low in Antarctic waters, tracked wandering
albatrosses showed high consistency in foraging areas at a large spatial scale. Despite consistency in overall
habitat use, males and females showed different foraging behaviours in response to oceanographic conditions.
Males appeared to be more opportunistic, exploiting oceanic and less productive waters mostly to scavenge for
offal or non-target fish discarded by fishing vessels. In contrast, females commuted directly to natural
productivity hotspots; most prey ingestions were on the outbound part of the trip, returning directly to the
chick and fed on a wide variety of fish and cephalopods. The consistency in habitat use at a large scale, and sex
differences in feeding ecology and behaviour at finer scale, indicate that males and females adopt different
strategies in core foraging areas when prey availability is low. This leads to differences in diet composition
between sexes in the absence of large-scale sexual segregation.

1500
Thu_143_BE-9_1724
Selection of Food Concentrating Surface Convergent Zones by Penguins

Matthew Oliver1 (moliver@udel.edu), Josh Kohut2, Kim Bernard3, William Fraser4, Peter Winsor5, Hank
Statscewich5, Erick Fredj6, Megan Cimino7, Donna Patterson-Fraser4, Filipa Carvalho8, Cordielyn Goodrich1
1
University of Delaware, School of Marine Science and Policy, Lewes, United States, 2Rutgers University, New
Brunswick, United States, 3Oregon State University, Corvalis, United States, 4Polar Oceans Research Group,
Sheridan, United States, 5University of Alaska Fairbanks, Fairbanks, United States, 6The Jerusalem College of
Technology, Jerusalem, Israel, 7Scripps Institution of Oceanography, San Diego, United States, 8National
Oceanography Centre, Southampton, United Kingdom

Discovering the environmental predictors of foraging locations can be challenging and is often the critical
missing piece for interpreting the ecological significance of the observed movement patterns of marine
predators. This is especially true in dynamic coastal marine systems, where food resources are diffuse and must
be either physically or biologically concentrated to support top trophic levels. At Palmer Canyon, a known
biological hotspot in the West Antarctic Peninsula, we deployed an integrated polar observatory consisting of
high frequency radar, coordinated gliders, and moorings. Lagrangian coherent structures (LCS) derived from
surface currents measured by high frequency radar were used to estimate the location of convergent ocean
features relative to penguin foraging locations. Acoustic scattering measurements from an underwater glider
suggest that krill may be more prevalent within convergent LCS, suggesting they are important for penguin
foraging behavior. We found that shallower foraging (< 50 m) Adélie penguins selected for surface convergent
features, while the deeper diving (< 100 m) gentoo penguins did not demonstrate the same preference,
suggesting that these species are selecting for different dynamic habitats. Changes in the location of
convergent LCS appear to explain historic patterns in Adélie penguin foraging behavior, suggesting that the
frequency and location of surface convergent features are important ecological drivers in this region.

1501
Thu_144_BE-9_1757
Facilitating Southern Ocean Population Genomics - A RADseq Pilot Experiment

Henrik Christiansen1 (henrik.christiansen@kuleuven.be), Bruno Danis2, Franz M. Heindler1, Bart Hellemans1,

Quentin Jossart3, Marc Kochzius3, Frederik Leliaert4, Francesca Pasotti4, Tasnim Patel5, Henri Robert5, Anton P.
Van de Putte1,5, Ann Vanreusel4, Marie Verheye5, Filip A. M. Volckaert1, Isa Schön5
1
KU Leuven, Laboratory of Biodiversity and Evolutionary Genomics, Leuven, Belgium, 2Université Libre de
Bruxelles, Marine Biology Laboratory, Brussels, Belgium, 3Vrije Universiteit Brussel (VUB), Department of Marine
Biology, Brussels, Belgium, 4Ghent University, Marine Biology Research Group, Ghent, Belgium, 5Royal Belgian
Institute of Natural Sciences, OD Nature, Brussels, Belgium

The Southern Ocean (SO) is subject to (local) rapid environmental changes and increasing anthropogenic
perturbation. Consequently, major efforts are under way to protect, manage and/or sustainably use the living
marine resources. Such aspirations depend on knowledge of spatio-temporal distribution and diversity patterns
of Antarctic organisms. Reduced representation sequencing such as RADseq enables cost-efficient
characterization of genome-wide SNP markers in non-model species. Large numbers of SNPs facilitate
population genomic studies to investigate intra- and interspecific genetic differentiation, as well as
evolutionary adaptation potential. Obtaining useful amounts of SNPs at appropriate sequencing depth,
requires carefully optimized experimental designs, particularly in species lacking genomic resources. Here, we
present a pilot experiment to determine if and how RADseq approaches can be applied to a variety of SO taxa
(Bivalvia, Amphipoda, Asteroidea, Perciformes and Aves). We perform computational in silico digestion of
simulated genomes and genomes of related taxa with a variety of restriction enzymes and size selection
combinations to determine the expected number of markers. Results are compared to empirical data from
actual DNA digestions and promising combinations are used to prepare pilot sequencing libraries. We present
this approach as it will likely be useful and applicable to other target organisms, ultimately advancing SO
conservation efforts.

1502
Thu_145_BE-9_1801
Sea Stars Comparative Evolutionary Patterns in the Southern Ocean

Camille Moreau1 (mr.moreau.camille@gmail.com), Quentin Jossart2, Bruno Danis1, Marc Eléaume3, Chester
Sands4, Thomas Saucède5
1
Université Libre de Bruxelles, Biomar, Brussels, Belgium, 2VUB, Bruxelles, Belgium, 3Muséum National d'Histoire
Naturelle, Paris, France, 4British Antarctic Survey, Cambridge, United Kingdom, 5Université de Bourgogne
Franche Comté, Dijon, France

Ecological traits such as the dispersal ability will influence the biogeographical patterns of benthic organisms in
a significant way over local to large scale in space and time. When biogeographical observations are based on
morphological identification of specimens, conclusions assume morphology accurately reflects evolutionary
processes. In order to test the fit of morphologically based biogeographic patterns recently identified in
Antarctic sea stars with contrasting reproductive modes (here used as a proxy for dispersal ability), we re-
examine the dataset with the addition of mitochondrial sequence data. We identified diversity and divergence
patterns of 1500 specimens across five genera of Southern Ocean asteroids with contrasted dispersal abilities.
Using a comparative phylogeographical approach we were able to test for shared historical processes as
phylogeographic congruence among lineages. These outcomes were critically compared to the interpretation
of the former study.

1503
Thu_146_BE-9_1807
Accepted Taxonomy versus Real Specific Diversity in Southern Ocean Sea Stars

Camille Moreau1 (mr.moreau.camille@gmail.com), Guillaume Achaz2, Bruno Danis1, Marc Eléaume2,

Christopher Mah3, Thomas Saucède4, Quentin Jossart5
1
Université Libre de Bruxelles, Biomar, Brussels, Belgium, 2Muséum National d'Histoire Naturelle, Paris, France,
3
Smithsonian National Museum of Natural History, Washington, United States, 4Université de Bourgogne
Franche Comté, Dijon, France, 5VUB, Bruxelles, Belgium

Studying and estimating species diversity of given taxonomic groups has been an ongoing process for centuries.
First based on a morphological characterisation of specimens, the study of diversity is nowadays more powerful
than ever with the democratisation of molecular tools such as the DNA barcoding. Correlatively with the
enhancement of genetic analysis is observed a decrease of experimented systematicians to fulfil the work of
morphological characterisation of species.
We propose in this work via the analysis of asteroids barcode sequences a powerful tool to highlight the gap
between the accepted taxonomy and the real specific diversity. COI sequences of over 2,500 specimens of sea
stars collected in the Southern Ocean were analysed following a genus-by-genus approach. Procedures like the
ABGD, GYMC or PTP could rapidly help taxonomists into pinpointing taxonomic groups to focus on. The
Southern Ocean certainly is a particularly adapted laboratory for such a study as it is the theatre of various
diversification processes leading to the presence of cryptic/unrecognized diversity.
This study is the perfect example of the interest of this kind of analyses as it demonstrates the large gap
between what is described in books and what is observed at the molecular level.

1504
Thu_147_BE-9_1809
Kerguelen Asteroid Fauna Diversity and Biogeography with the Southern Ocean

Camille Moreau1 (mr.moreau.camille@gmail.com), Bruno Danis1, Marc Eléaume2, Charlène Guillaumot1,

Quentin Jossart1, Thomas Saucède3
1
Université Libre de Bruxelles, Biomar, Brussels, Belgium, 2Muséum National d'Histoire Naturelle, Paris, France,
3
Université de Bourgogne Franche Comté, Dijon, France

Marine fauna of the isolated archipelago of Kerguelen has been studied for decades as it might represent a
crucial link for benthic biogeography of the Southern Ocean. Its pivotal position in the sub Antarctic (between
South America - the Scotia Arc and the Macquaries) and the possible links with high Antarctic might play an
important role in the global biogeography of the region.
Compiling data from three research projects (POKER, Proteker and ACE - ASCCC) we conducted diversity,
phylogeographic as well as multivariate analyses to better characterize the Kerguelen Plateau in term of
asteroids assemblages (Echinodermata).
Mitochondrial gene COI sequences of hundreds of specimens were used to understand the relationships of the
Kerguelen Islands with the surrounding Southern Ocean. Gene sequences from the Kerguelen's specimens were
compared with thousands from the whole Southern Ocean allowing a better understanding of the role of the
Kerguelen Islands in the frame of the Southern Ocean.
This work brings new insight in term of the possible origin of the asteroid fauna on the Kerguelen Plateau but
also in term of the role of this sub Antarctic area as a source for post-LGM recolonization.

1505
Thu_148_BE-9_1832
Remote Characterization of Microbial Mats in Taylor Valley, Antarctica

J. E. Barrett1 (jebarre@vt.edu), Eric Sokol2, Lee Stanish2, Mark Salvatore3

1
Virginia Tech, Department of Biological Sciences, Blacksburg, United States, 2Battelle Ecology, Inc., National
Ecological Observatory Network (NEON), Boulder, United States, 3Northern Arizona University, Department of
Physics & Astronomy, Flagstaff, United States

Microbial mat communities, consisting primarily of cyanobacteria, are the most abundant and widely
distributed terrestrial phototrophs in the McMurdo Dry Valleys of Antarctica. Prior work has shed light on the
niche preferences and eco-physiology of these communities, but the combination of low photosynthetic rates
and patchy distribution has limited assessment of microbial mat dynamics to habitat-scale investigations. We
present data using high-resolution multispectral remote sensing techniques linked with field sampling
campaigns in Taylor Valley to examine the sensitivity of these microbial mat communities to environmental
variation. Our work demonstrates that:
1. microbial mat communities can be identified from orbit;
2. satellite images can be captured throughout a season and can be synchronized with in-situ measurements;
and
3. the temporal resolution is sufficient to discern temporal variation in microbial mat activity.
Our results highlight the opportunity for using remote sensing in coordination with field-based campaigns to
systematically study the base of terrestrial Antarctic food webs, i.e., microbial mat communities, at scales
relevant to quantify spatial distribution and detect the influence of hydroclimate variability on temporal
dynamics of microbial communities.

1506
Thu_149_BE-9_1875
A Synergistic Approach to Understand the Ecological Impacts of Climate Change

Rachel Cavanagh1 (rcav@bas.ac.uk), Eugene Murphy1, Nadine Johnston1, Thomas Bracegirdle1, Andrew
Constable2,3, Stuart Corney2, Susie Grant1, John Turner1, Claire M Waluda1
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Tasmania, Institute for Marine and
Antarctic Studies (IMAS), Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), Hobart,
Australia, 3Australian Antarctic Division, Hobart, Australia

Understanding potential climate change impacts on Southern Ocean ecosystems requires the inclusion and
interpretation of climate model projections. The use of global climate models in ecological studies is growing,
but drawing meaningful conclusions is difficult. Issues of temporal and spatial scale are amongst the key
challenges. For instance, these models do not sufficiently represent ecologically important features such as the
marginal ice zone since it is relatively small in area and comprises a complex variety of sea ice types. Using
Southern Ocean sea ice as an example, given its crucial role for the biology of the region, we initiated a joint
study comprising ecologists, biogeochemists, climate modellers and fishery scientists, to explore the use of
these models for ecological insights. With an emphasis on ecologically-relevant criteria (sea ice extent and
seasonality) we selected a subset of available global climate models that reliably reproduce extant sea ice
distributions. Whilst the mean of this subset is similar to the model ensemble, there is a marked reduction in
the range. This improved the precision of projected future sea ice distributions by approximately one third, and
means they are more amenable to ecological interpretation. Our study demonstrates how multidisciplinary
evaluation of climate models can enhance their ecological application, and is a first step towards a set of
community-agreed future scenarios for Southern Ocean ecosystems.

1507
Thu_150_BE-9_2004
Local Rapid Expansion of the Antarctic Hair Grass in the Maritime Antarctic

Christina Braun1 (chr.braun@uni-jena.de), Hans-Ulrich Peter1

1
University of Jena / Institute of Ecology and Evolution, Polar & Bird Ecology Group, Jena, Germany

During the past decades, the western and northern parts of the Antarctic Peninsula (Maritime Antarctic) have
experienced the largest warming trend of atmospheric temperatures. This climatic change strongly affects
biotic and abiotic components of Antarctic ecosystems on different levels.
Fildes Peninsula and Ardley Island, King George Island, South Shetland Islands, represent one of the largest ice-
free areas in the Maritime Antarctic and are characterized by a high biodiversity. The terrestrial ecosystem host
a diverse range of breeding bird species, high numbers of seals and locally the best-developed and most
extensive plant communities in the South Shetland Islands. The only vascular plant present in this area is the
Antarctic hair-grass Deschampsia antarctica. Repeated assessments of its distribution have been carried out in
1984/85, 2000/01, 2007/08 2004-06, and recently in 2016-18. The data revealed a considerable expansion of
the distribution of D. antarctica over the past three decades. The grass has spread at many known sites and has
additionally colonised further suitable areas. The distribution is widely connected to associations with mosses
and lichens, but also includes fresh moraine material in areas newly exposed by glacier retreat. Apparently,
entry of nutrient by birds and seals have a strong impact on the growth of D. antarctica. Moreover, regional
warming seems to be crucial for the considerable expansion for vascular plants in the Maritime Antarctic.

1508
Thu_151_BE-9_2015
Latitudinal Consistency of Food Web Topology in Subtidal Rocky Bottoms

Luis Cardona1, Elena Lloret1, Conxita Avila1 (conxita.avila@ub.edu)

1
University of Barcelona, Evolutionary Biology, Ecology and Environmental Science, Barcelona, Spain

The potential impact of latitude on the structure of the food web of shallow sublittoral rocky bottoms was
assessed using stable isotopes of C and N. Samples were collected at five sites along a gradient from King
George Island (South Shetland Islands; 62°11′04″S 58°54′14″W) to Adelaide Island (western Antarctic Peninsula;
67°34′06″S 68°07′33″W). Phytoplankton, encrusting red algae, brown macroalgae (Himantothallus grandifolius,
Desmarestia menziesii and Desmarestia anceps), red algae (Palmaria decipiens), sponges (Dendrilla antarctica),
snails (Margarella antarctica), limpets (Nacella concinna), holothurians, sea urchins (Sterechinus neumayeri),
nemerteans (Parborlasia corrugatus) and starfishes (Odontaster validus and Diplasterias brucei) were collected
at each site. Results revealed short food webs, supported by a diversity of carbon sources. Phytoplankton was
the main source of C for holothurians, sea urchins relied primarily on macroalgae and encrusting red algae
were the staple food of limpets. Sponges were more depleted in 13C than any other animal group, thus
revealing a unique niche. The starfish Odontaster validus was usually the top predator of the ecosystem. No
latitudinal differences in food web topology were observed, but sites differed in the stable isotope baseline and
the diversity of C sources, thus highlighting that local processes are more relevant for benthic communities
than any potential latitudinal gradient.

1509
Thu_152_BE-9_2114
Polar Cod Population Structure: Connectivity in a Changing Ecosystem

Sarah Maes1 (sarahmaeske@gmail.com), Henrik Christiansen1, Felix C. Mark2, Magnus Lucassen2, Anton P. Van
de Putte3, Filip A.M. Volckaert1, Hauke Flores2
1
KU Leuven, Leuven, Belgium, 2Alfred Wegener Institute for Polar and Marine Research, Bremerhaven,
Germany, 3Royal Belgian Institute of Natural Sciences, Brussels, Belgium

Climate-induced changes put an increasing pressure on the Arctic ecosystem and its populations, including the
most abundant circumpolar marine fish polar cod (Boreogadus saida). As a keystone species, changes in its
abundance and distribution will impact the entire Arctic food web. Despite polar cod's significance, its
population structure is largely undescribed. The genetic diversity and population connectivity of polar cod living
in fjords of West-Spitsbergen and the Eurasian Basin were investigated using eight microsatellite loci. On a local
scale, polar cod from Arctic (Billefjorden, Hornsund) and Atlantic (Kongsfjorden) influenced fjords were
compared, and on a larger scale also specimens from the Amundsen and Nansen Basin were included. Results
revealed significant population structuring on both local and large scale, suggesting reduced gene flow
between these areas. Juvenile polar cod track sea ice drift and consequently, the under-ice distribution
depends on coastal populations where sea ice originates (David et al., 2015). Hypothetically, polar cod hatched
in the Kara and Laptev Sea drift into the Nansen and Amundsen Basin, respectively, and join populations in
downstream areas by following the Transpolar Drift System. Understanding polar cod's population spatial and
temporal dynamics, population diversity and adaptive divergence is critical for making predictions about its
future distribution and for protecting this key species in the Arctic.

1510
Thu_153_BE-9_2126
Hierarchical Bayesian Modeling of Continental-scale Pygoscelid Penguin Abundance

Christian Che-Castaldo1 (cccweb@icloud.com), Casey Youngflesh1, Stephanie Jenouvrier2, Mathew R.

Schwaller3, Heather J. Lynch1
1
Stony Brook University, Ecology and Evolution, Stony Brook, United States, 2Woods Hole Oceanographic
Institution, Woods Hole, United States, 3NASA/Goddard Space Science Center, Greenbelt, United States

We present a hierarchical Bayesian model of pygoscelid penguin abundance and distribution at all 509 known
pygoscelid colonies. This model incorporates both presence-absence data and abundance estimates, collected
from all known publically accessible data on pygoscelid penguin abundance and distribution, including nest and
chick data derived from ground counts, aerial surveys, satellite imagery, and citizen science efforts. Our model
provides abundance estimates for each population in each year since the 1979/80 season, including years for
which no data are available, and allows us to both estimate species-specific trends at each penguin breeding
site and understand how sites co-vary in their interannual dynamics. We investigate whether Allee effects,
stemming from skua predation on penguin chicks and eggs, were mitigated for small Adélie or chinstrap
populations embedded in larger gentoo colonies. Our model provides the best global-scale model for
pygoscelid penguin population dynamics, and provides a means by which to assess the impact of climate
change and other hypothesized drivers of population change.

1511
Thu_154_BE-9_2143
Dive Behavior and Stable Isotopes: Index of Foraging Specialization in Seals

Daniel Costa1 (costa@ucsc.edu), Luis Huckstat1, Kimberly Goetz1, Michelle Shero2, Jennifer Burns2
1
University of California Santa Cruz, Ecology & Evolutionary Biology, Santa Cruz, United States, 2University of
Alaska Anchorage, Biology, Anchorage, United States

Understanding the response of marine organisms to climate change requires a set of indices that can be
obtained on a routine cost effective basis. While electronic tagging provides considerable insight into the
foraging behavior ecology of marine vertebrates, it can be expensive and is applicable to those species where
instruments can be deployed and recovered. Stable isotope analysis (SIA) can be carried out from tissues
obtained by remote biopsy methods, from carcasses, from preserved or ancient material. However, alone at
best SIA can provide an estimate of diet, but no information on the foraging behavior of the animal sampled.
Here we determine the efficacy of using SIA data to infer the foraging behavior of the Weddell seals in the Ross
Sea. Over a three year period (2010-2012) the foraging behavior and movement patterns of 63 Weddell seals
was examined by instrumenting them with Satellite Relay Data loggers near Ross Island Antarctica. At capture
tissues samples (hair, blood and whiskers) were collected and later analyzed for Carbon and Nitrogen isotope
levels. The SIA data provided information on distinct differences between individuals and their diet that
correlated with the individual specific diving behavior. This approach suggest that with sufficient validation SIA
analysis can provide information not only on diet, but also on individual specific foraging patterns.

1512
Thu_155_BE-9_2157
Myctophid (Gymnoscopelus nicholsi) Population Dynamics from Otoliths

Angela Klemmedson1 (aklemmedson@sandiego.edu), Christian Reiss2, Ronald Kaufmann1, Michael Goebel2,

Emmanis Dorval3
1
University of San Diego, Environmental and Ocean Sciences, San Diego, United States, 2NOAA
Fisheries/Southwest Fisheries Science Center, Antarctic Ecosystem Research Division, San Diego, United States,
3
NOAA Fisheries/Southwest Fisheries Science Center, Fisheries Resources Division, San Diego, United States

Myctophids are ecologically important in the Southern Ocean, where they constitute an important energy
resource to higher predators and serve as an alternative to krill in trophic pathways. Given the changes
predicted for Southern Ocean ecosystems owing to climate change and the recovery of top predators,
understanding the population dynamics of key prey species like myctophids is critical for ecosystem-based
management. Due to challenges associated with sampling mesopelagic fishes, there is a lack of information on
their life histories and population dynamics. Using biological samplers, such as piscivorous mammals, may
provide large amounts of information about myctophid demographics. Here we reconstruct age, growth and
length of Gymnoscopelus nicholsi using sagittal otoliths recovered from scats of Antarctic fur seals
(Arctocephalus gazella) at Cape Shirreff (Livingston Island). We derived a 16-year time series (2000-2015) and
found that G. nicholsi in the diets of fur seals ranged from 2 to 6 years of age. Additionally, we found that G.
nicholsi mean age declined significantly during this time frame. This study demonstrates the utility of biological
samplers to assessing population dynamics of mesopelagic fishes. The results presented here show that
myctophids in waters off the South Shetland Islands exhibit dynamics that have yet to be understood,
especially given the environmental changes and ecosystem regime shifts occurring in this region.

1513
Thu_156_BE-9_2169
Use of the Thermal Structure of the Water Column by Multiple Predator Species

Malcolm O'Toole1 (malcolm.otoole@locean-ispl.upmc.fr), Cedric Cotté1, Yves Cherel2, Charles-André Bost3,

Christophe Guinet2, Henri Weimerskirch2, Mark A Hindell4,5, Francesco d'Ovidio1
1
Université Pierre et Marie Curie, Laboratoire d'Oceanographie et du Climat (LOCEAN-IPSL), Paris, France,
2
Centre d'Études Biologiques de Chizé, Chizé, France, 3Centre d'´Etudes Biologiques de Chizé, Chizé, France,
4
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 5Antarctic Climate and
Ecosystems CRC, Hobart, Australia

Animals that feed in a dynamic environment should adopt strategies that will optimise energy acquisition. The
use of top predators as a bio-samplers is a complementary approach to understand how physical changes in
the environment may influence their foraging success. The thermal structure of the water column is a key
physical feature in pelagic waters that likely affect the vertical distribution of micronekton (fish, crustacean),
and ultimately the foraging efficiency of their predators. Here, for the first time, we examine how this
information links predator foraging behaviour with access to their pelagic prey. During the MYCTO-3D-Map
campaign performed off the eastern side of Kerguelen (Southern Indian ocean), in situ conductivity-
temperature-depth (CTD) profiles, acoustics, and net sampling of micronektonic organisms (prey) have been
combined with bio-logging tracks of seabirds and marine mammals (predators). This information is then
exploited for identifying potential foraging hotspots in outputs of ocean models (MERCATOR). Our aim is to
determine the threshold of each species based on their access to prey along the horizontal and vertical axes. A
better understanding of the links between ocean physics and the trophic food web has strong implications for
predicted environmental shifts in the face of future climate change.

1514
Thu_157_BE-9_2222
Bacterial Community Structure in Glacier Ice and Subglacial Streams, Antarctica

Corina Itcus1,2 (corina.itcus@gmail.com), Constantin Marin3, Soon Gyu Hong4, Paris Lavin5, Cristian Coman6, Iris
Tusa7, Manuela E. Sidoroff7, Cristina Purcarea2
1
National Institute of Research and Development for Biological Sciences, Arctic and Antarctic Research,
Bucharest, Romania, 2Institute of Biology, Romanian Academy, Microbiology, Bucharest, Romania, 3Emil
Racovita Institute of Speleology, Biospeleology and Karst Edaphobiology Compartment, Bucharest, Romania,
4
Korean Polar Research Institute, Division of Life Science, Incheon, Korea, Republic of, 5University of
Antofagasta, Antofagasta, Chile, 6Institute of Biological Research, Taxonomy and Ecology, Cluj-Napoca,
Romania, 7National Institute of Research and Development for Biological Sciences, Bioinformatics, Bucharest,
Romania

Antarctic glacier retreat is expected to have an important impact on the microbial communities embedded in
perennial ice. In this context, our study focused on investigating the bacterial diversity from glacier ice and
subglacial streams of King George Island, NW Antarctica, in relation with the spatial distribution and substrate
geochemistry.
Samples were collected from Barton, Weaver and Potter Cove areas. Physicochemical measurements indicated
a low mineral content and slightly alkaline pH in glacier ice relative to subglacier water. All ice samples showed
a reduced organic carbon content and a homogenous Na-HCO3 type chemistry, while stream water was more
heterogeneous, belonging to Na-Ca-HCO3 and Na-Cl types, with a high Al, Fe and Sr content.
Illumina MiSeq sequencing of 16S rRNA gene highlighted variations of bacterial diversity with the type of
habitat, locations and geochemical characteristics. Phyla distribution in the two types of habitats showed the
dominance of Proteobacteria followed by Bacteroidetes, with spatial variations of other phyla representation
between the peninsulas. High content of Proteobacteria characterized both the ice and stream microbial
communities, with a major presence of Acinetobacter mainly in glaciers.
Analysis of the distribution pattern of bacterial communities in ice and subglacial streams, in relation with the
habitat geochemistry, contributes to unravel the impact of melting glaciers on the resilience of the embedded
microbiome.

1515
Thu_158_BE-9_2234
Levels of Heavy Metals in Rocky Bottom Organisms along the Antarctic Peninsula

Luis Cardona1, Paula de Castro1, Conxita Avila1 (conxita.avila@ub.edu)

1
University of Barcelona, Evolutionary Biology, Ecology and Environmental Science, Barcelona, Spain

Previous research has revealed the existence of a latitudinal gradient in the levels of several heavy metals in
pelagic predators foraging along the Antarctic Peninsula. To assess the generality of that pattern, samples of
benthic organisms were collected at five sites along a latitudinal gradient from King George Island (South
Shetland Islands; 62°11′04″S 58°54′14″W) to Adelaide Island (western Antarctic Peninsula; 67°34′06″S
68°07′33″W). Phytoplankton, brown algae (Desmarestia menziesii and Desmarestia anceps), red algae
(Palmaria decipiens), limpets (Nacella concinna) and starfishes (Diplasterias brucei and Odontaster validus)
were collected at each site. Levels of Cr, Pb and Hg were assessed in each organism. Results revealed much
higher levels of heavy metals in macroalgae than in phytoplankton or any animal organism considered, thus
suggesting a minor role of Desmarestia antarctica, Desmarestia anceps and Palmaria decipiens as sources of
organic matter for limpets and starfishes. On the other hand, levels of Hg increased from Nacella concinna to
both starfish specie, thus suggesting biomagnification. Levels of Cr, Pb and Hg differed among sites, but no
latitudinal gradient existed. This suggests that local processes are more important that regional patterns in
determining the levels of heavy metals on benthic organisms and that the existence of permanent scientific
research stations might be a relevant factor.

1516
Thu_159_BE-9_2242
Genetic Identification and the Southern Ocean CPR Survey: A Useful Combination?

Bruce Deagle1, Laurence Clarke1,2 (laurence.clarke@aad.gov.au), John Kitchener1, Andrea Polanowski1, Andrew
Davidson1
1
Australian Antarctic Division, Kingston, Australia, 2Antarctic Climate & Ecosystems Cooperative Research
Centre, University of Tasmania, Hobart, Australia

Plankton surveys using the continuous plankton recorder (CPR) have characterised biodiversity along open
ocean transects covering thousands of kilometres in Polar Regions. We investigated the potential to use DNA
metabarcoding (species identification using high-throughput DNA sequencing) in the Southern Ocean CPR
survey. Samples (n= 53) were collected in two transects and metazoans identified using standard microscopic
methods and by sequencing a mitochondrial COI marker. DNA increased the number of metazoan species
identified and provided high resolution taxonomy of groups problematic in conventional surveys (e.g. larval
echinoderms and hydrozoans). Metabarcoding also generally produced more detections than microscopy, but
this sensitivity may make cross-contamination during sampling a problem. In some samples, the prevalence of
DNA from large plankton such as krill masked the presence of smaller species. Overall, the genetic data
represents a substantial shift in perspective, making direct integration into current long-term time-series
challenging. We discuss a number of hurdles that exist for progressing DNA metabarcoding from the current
snapshot studies to the requirements of a long-term monitoring program. Given the power and continually
increasing efficiency of DNA metabarcoding, it is almost certain this approach will play an important role in
characterising polar marine ecosystems.

1517
Thu_160_BE-9_2258
Spring Bloom of Corethron in Coastal Waters of the Western Antarctic Peninsula

Deneb Karentz1 (karentzd@usfca.edu), Joe Grzymski2

1
University of San Francisco, Departments of Biology and Environmental Science, San Francisco, United States,
2
Desert Research Institute, Division of Earth and Ecosystem Sciences, Reno, United States

Corethron is a cosmopolitan taxon and one of the most abundant diatom genera in the world ocean (Malviya et
al. 2016). C. pennatum is often a dominant species in polar plankton communities with historical bloom events
preserved in sediments (Leventer et al. 2002). During austral late winter/early spring 2011, observations of
phytoplankton species succession in coastal waters of the Antarctic Peninsula documented the inception and
development of a C. pennatum bloom. Cell densities increased from 100 (Sept) to 11,000 (Nov) cells/L,
representing 25-100% of the net phytoplankton. Eighty-three phytoplankton taxa (including several abundant
picoplankton species) were recorded, and C. pennatum comprised the bulk of the phytoplankton biomass
during the study period. Cell diameters of C. pennatum ranged from 6-74 µm. From early Sept to mid-Oct mean
cell diameter decreased from 29±9 to 19±8 µm. Doublets ranged from 9-32% of cells, with the maximum
proportion of cells dividing in mid-Oct coinciding with sexual reproduction and auxospore formation. Up to 4%
of cells observed at this time were male gametangia or auxospores. Enlargement of cells after auxosporulation
resulted in a mean cell diameter of 33±11 µm by mid-Nov. Sequencing of the transcriptome indicates
correlation between the occurrence of doublets and proteins involved in DNA replication (e.g., helicases),
providing additional insights on the physiological state of C. pennatum during bloom formation.

1518
Thu_161_BE-9_2281
Ross Island Adélie Penguin Population Responses to Variability in Sea Ice Extent

Fiona Shanhun1 (f.shanhun@antarcticanz.govt.nz), Natalie Robinson2, Kerry Barton3, Phil Lyver4, Rebecca
McLeod1
1
Antarctica New Zealand, Christchurch, New Zealand, 2National Institute for Water and Atmospheric Research,
Wellington, New Zealand, 3BartonK Solutions, Nelson, New Zealand, 4Landcare Research, Lincoln, New Zealand

Adélie penguins (Pygoscelis adeliae) are an indicator species used to detect and monitor the effects of
environmental change on Antarctic marine ecosystems. Since the early 1980s, New Zealand has conducted an
annual census of Adélie penguins in the Ross Sea region, with data submitted to the Commission for the
Conservation of Antarctic Marine Living Resources (CCAMLR) Ecosystem Monitoring Programme (CEMP).
Changes in the number of breeding pairs are considered in relation to environmental factors, allowing
hypotheses about population responses due to natural versus anthropogenic changes to be tested.
Sea ice conditions in McMurdo Sound in November 2016 and 2017 were significantly different. Extensive and
persistent sea ice cover in McMurdo Sound in 2016 led to many abandoned Adélie penguin nests at colonies on
Ross Island. The number of breeding pairs at Cape Royds, Cape Bird and Cape Crozier decreased by 44%, 23%
and 8%, respectively, compared to 2015 numbers. The early breakout of sea ice in the 2017 austral summer
provides a complete contrast. This inter-annual variability is considered in terms of the short-term impact on
Adélie penguin populations on Ross Island, with a view to predicting longer-term effects of changing
environmental conditions on Adélie penguin populations in the Ross Sea.

1519
Thu_162_BE-9_2309
Alpha Amylase from Geomyces sp. Isolated from Antarctic and Arctic

Abiramy Krishnan1,2 (abiramy.krishnan@gmail.com), Peter Convey3, Zazali Alias2, Marcelo Gonzalez Aravena4,
Siti Aisyah Alias1,5
1
University of Malaya, National Antarctic Research Centre, Kuala Lumpur, Malaysia, 2University of Malaya,
Institute of Biological Science, Kuala Lumpur, Malaysia, 3British Antarctic Survey, Cambridge, United Kingdom,
4
Instituto Antárctico Chileno, Punta Arenas, Chile, 5University of Malaya, Institute of Ocean and Earth Science,
Kuala Lumpur, Malaysia

Geomyces sp., a soil microfungi deserve a very special place in the polar ecosystem. This species is reported to
be positive for various hydrolase enzymes which makes it a successful decomposer in the polar region.
Objective of this study is to compare alpha-amylase from Geomyces sp. from Arctic and Antarctic. Soil samples
were collected from King George Island, Antarctic during 2007 Austral summer and Svalbard, Arctic during
boreal summer in 2006 and 2010. Soil microfungi were screened for amylase activity. One strain with highest
relative enzyme activity from each region were chosen for further enzyme activity analysis. Alpha amylases
were purified using forced affinity chromatography column. The purified enzymes were run on SDS PAGE to
confirm the molecular weight. Twenty five of 33 Antarctic and 4 of 4 Arctic Geomyces sp. showed significant
relative amylase activity in the preliminary screening. From this, one best amylase producer from each region
were chosen for enzyme activity assessment. Purified alpha amylase of both isolates showed optimum
temperature for enzyme activity at 10°C and the optimum pH was 6.6. SDS PAGE showed both alpha amylase
had molecular weight around 70kDa. Alpha amylase from Antarctic Geomyces showed higher enzyme activity
in comparison with Arctic Geomyces. This is probably because, relatively harsher environment of Antarctic
prepared these fungi to perform maximally when the optimum temperature provided.

1520
Thu_163_BE-9_2329
Polyphasic Characterization of Terrestrial Leptolyngbya on Signy Island

Ranina Alya Mohamad Radzi1 (raninaalya@gmail.com), Faradina Merican1, Paul Broady2, Peter Convey3
1
Universiti Sains Malaysia, School of Biological Sciences, Penang, Malaysia, 2University of Canterbury, School of
Biological Sciences, Canterbury, New Zealand, 3British Antarctic Survey, Cambridge, United Kingdom

Studies of members of the genus Leptolyngbya are mostly reported from tropical and temperate regions.
Although the genus often dominate microbial communities in Antarctic soils, their diversity and ecological
significance are not well understood. We have investigated four Leptolyngbya strains obtained from soil
collected from Signy Island, South Orkney Islands, and maritime Antarctic. Morphologically, all four strains in
culture showed diacritical characteristics consistent with the genus Leptolyngbya. However, 16S rDNA analysis
showed that three of the strains were closely related to the genus Wilmottia while one was a close relative of
the new cyanobacterial genus Nodosilinea. At present, only two Wilmottia species, Wilmottia murrayi and
Wilmottia sp., have been characterized from Antarctica. Under the most recent classification system, Wilmottia
is recognised as a special genus (Wilmottia gen. nov.) because of it similarities with Leptolyngbya and
Phormidium while Nodosilinea includes members with unique ability to form nodules along the length of the
filament and has mostly been recorded from environmentally extreme locations. Polyphasic characterization is
now being used to evaluate the taxonomic positions of these four strains. Moist plate enrichment culture of
the soil, transmission electron microscopy (TEM) and physiological studies such as pigment tests and salinity
tolerance assessment are being used to aid in species identification.

1521
Thu_164_BE-9_2363
Marine Ecosystem Assessment of the Southern Ocean: Outcomes of MEASO2018

Andrew Constable1 (andrew.constable@aad.gov.au), Jessica Melbourne-Thomas1, Rowan Trebilco2, Michael

Sumner1, Philip Boyd3, So Kawaguchi1, Klaus Meiners1, Kerrie Swadling3
1
Australian Antarctic Division and ACE CRC, Kingston, Australia, 2Antarctic Climate & Ecosystems Cooperative
Research Centre, Hobart, Australia, 3University of Tasmania / Institute for Marine and Antarctic Studies, Hobart,
Australia

Status and trends of Southern Ocean ecosystems are being assessed to update the SCAR Antarctic Climate
Change and Environment Report and to provide inputs to the Sixth Assessment Review of the IPCC. These
assessments are also intended to provide scientific inputs on marine ecosystems important to the Committee
on Environmental Protection under the Antarctic Treaty and to the Commission for the Conservation of
Antarctic Marine Living Resources. Interpretable measures of change in habitats, species and food webs are
being synthesised for four sectors of the Southern Ocean (East and West Pacific, Atlantic and Indian), and
divided into assessments for coastal/sub-polar and subantarctic areas. Results from the recent Marine
Ecosystem Assessment for the Southern Ocean (MEASO) conference in Hobart in April 2018 will be presented
on behalf of many scientists from ICED, SCAR Life Sciences, AnT-ERA, AntEco and SOOS. We summarise the
conclusions and gaps in the assessments for each sector and highlight directions for the next MEASO.

1522
Thu_165_BE-9_2370
Seasonal Ecology of High Arctic Ice Cap

Archana Dayal1,2 (adayal1@sheffield.ac.uk), Andrew J. Hodson1,2, Arwyn Edwards3

1
University of Sheffield, Geography, Sheffield, United Kingdom, 2University Centre in Svalbard (UNIS), Arctic
Geology, Longyearbyen, Svalbard and Jan Mayen, 3Aberystwyth University, Institute of Biological, Rural and
Environmental Sciences, Aberystwyth, United Kingdom

Snow packs are important interfaces with global climate and biogeochemistry (Wadham et al., 2013) and form
a biologically productive microbial habitat (Hodson et al., 2008). However, far less attention has been paid to
supraglacial snow packs compared with snow covers on top of soil and aquatic ecosystems (Jones 1991). In
addition, snow packs are getting wetter and less persistent globally in response to warming air temperatures.
More importantly, supraglacial snow packs are well-connected to marine and terrestrial systems, therefore any
changes will result in ecological implications downstream. Therefore, in order to understand the variation in
space and time of microbial diversity and biogeochemistry of a supraglacial snow pack, samples were collected
monthly for four months on seven areas of a High Arctic ice cap (Foxfonna, Svalbard). This work will therefore
establish the changing ecology of snow with the evolution in the snowpack's physical condition during melt and
hence present the systematic change expected in resident microbial communities and nutrient dynamics
through the summer, both spatially and temporally. In summary, this work will present a seasonal 'album' for
ecology of glacial snow packs.

1523
Thu_166_BE-9_2380
Changing Light Regimes in Polar Deserts: A Metatranscriptome Analysis

Kathryn Coyne1 (kcoyne@udel.edu), Jill Sohm2, Andrew Kalmbach3, Troy Gunderson2, Christopher R. Main1,
Doug Capone2, Edward Carpenter3, Craig Cary1,4
1
University of Delaware, Lewes, United States, 2University of Southern California, Los Angeles, United States,
3
Romberg Tiburon Center for Environmental Studies, Tiburon, United States, 4University of Waikato, Hamilton,
New Zealand

Microbial communities in Antarctic Dry Valleys are dominated by cyanobacteria that provide the heterotrophic
community with photosynthetic carbon as well as nitrogen through diazatrophic activities. Diazatrophic
heterotrophs also contribute to nitrogen input, but are a carbon sink rather than a source. Little is known about
the seasonal effects of changing light intensity on the dynamics of these two groups of microbes. The
objectives of this study were to investigate the transcriptional response of the microbial community to changes
in light regime. Plots along a stream in Taylor Valley were shaded to reduce light by 10%, 50% and 100% and
samples were collected at the initial time point and after 11 days. The transcriptomes were paired-end
sequenced and assembled, producing approximately 55,000 transcripts with an N50 of 2,098. Reads from each
treatment were mapped to the assembled transcripts for differential expression analysis. Analysis is ongoing,
but shows that metatranscriptomes generated from samples collected on day 11 were significantly different
from the initial time point, and also that samples collected from the 50% and 100% reduced light treatments on
day 11 were significantly different from the 10% treatment. Here, we will present an analysis of transcriptional
changes affecting carbon and nitrogen cycling. Results of this research will contribute to our understanding of
microbial dynamics and community responses to changing light regimes in polar deserts.

1524
Thu_167_BE-9_2417
Tardigrades from King George Island, Antarctica: Taxonomy of Dactylobiotus sp

Ji-Hoon Kihm1,2 (jhkihm@kopri.re.kr), Tae-Yoon S. Park1, Sanghee Kim3

1
Korea Polar Research Institute (KOPRI), Division of Polar Earth-System Sciences, Incheon, Korea, Republic of,
2
University of Science and Technology-Korea, Polar Sciences, Daejeon, Korea, Republic of, 3Korea Polar Research
Institute (KOPRI), Division of Polar Life Sciences, Incheon, Korea, Republic of

Phylum Tardigrada is a minute, hydrophilous animal group with a five segmented body which consists of a head
and four trunk segments. This phylum is famous for the ability to survive the severe conditions such as cold,
dry, or high radiation environments. The limno-terrestrial tardigrades are one of the dominant animal groups in
the terrestrial ecosystem of Antarctica. However, due to their limited morphological characteristics and
restricted access to the habitats, taxonomic study on Antarctic tardigrades is difficult to carry out. KOPRI
ecology team collected several species of tardigrades from King George Island, Antarctica during 2014-2015
season expedition. Among the collected tardigrades, one species shows a bucco-pharyngeal apparatus with 10
peribuccal papillae reminiscent of Macrobiotus-type and the cuticular connection between claws, which are
characteristics of the genus Dactylobiotus. This species is large in size (600-700 µm) with smooth cuticle and no
conical papillae between 3rd and 4th limbs. Key morphological characters of bucco-pharyngeal apparatus and
claws are being measured, and pt ratio (the ratio of the length of a given structure to the length of the buccal
tube) are compared to that of other Dactylobiotus species to see whether the species is a previously reported
Dactylobiotus species documented in other regions around the world, or a new species.

1525
Thu_168_BE-9_2441
Insights into Tundra Fern Physiology from Remote Sensing and Leaf Gas Exchange

Marius W. Rossouw1 (marius.w.rossouw@gmail.com)

1
Stellenbosch University, Stellenbosch, South Africa

We have deployed, for the first time, a close-distance remote sensing system to study leaf level physiological
processes of Blechnum penna-marina at fine time scales (minute x minute) on Marion Island, over an annual
cycle. Combined with this, standard leaf gas exchange approaches were also employed. We placed the remote
sensing stations at a range of elevations, and these collected micrometeorological data, as well as an index
which indicates levels of plant stress. Experiments using a LICOR 6400xt gas exchange system were performed
on low altitude plants, which were acclimated for 3 days at different treatment temperatures. Field data
suggested that plants experienced stress above 11°C, and leaf gas exchange information allowed us to explore
this relationship in more detail. We used structural equation modelling, to identify the major meteorological
factors that influence plant stress response. Machine learning was used to characterize the archetypical diurnal
conditions, which in turn allowed us to further understand how plant physiology reacts to the abiotic
environment. We argue that this mix of techniques allows the exploration of crucial aspects of how the abiotic
environment affects plant function. In conclusion, a multi-tiered approach using both remote sensing and gas
exchange will be valuable in future to understand the complex interaction climate has with organisms.

1526
Thu_169_BE-9_2465
Phototrophic Picoeukaryotes and their Antarctic Winter Niche

Carla Gimpel1 (cgimpel@hawaii.edu), Christian S. Reiss2, Elliot L. Weiss3, B. Greg Mitchell3, Alison E. Murray4
1
University of Hawai`i at Manoa, Daniel K. Inouye Center for Microbial Oceanography: Research and Education,
Honolulu, United States, 2Southwest Fisheries Science Center, Antarctic Ecosystem Research Division, La Jolla,
United States, 3Scripps Institution of Oceanography, University of California, San Diego, La Jolla, United States,
4
Desert Research Institute, Division of Earth and Ecosystem Sciences, Reno, United States

Reduced photoperiod, absence of picocyanobacteria, low surface temperatures and a highly variable sea ice
ecosystem shape the polar winter, which has become increasingly warmer and shorter. A survey was
conducted off the South Shetland Islands (SSI) during three consecutive late winter seasons. The expected low
chlorophyll a concentrations in the system correlated with phototrophic picoeukaryote (PPE) abundances in
the upper mixed layer (UML), characterized by Winter Water and varying sea ice types. To further address the
ecological significance of Antarctic PPE, we also quantified contemporaneous bacterioplankton populations.
The highest microbial abundances where detected north of the SSI and PPE counts correlated with chlorophyll
a concentrations stronger than with prokaryotes in the UML. High throughput amplicons of the hypervariable
V4 region of the 16S and 18S rRNA marker gene were used to better comprehend the diversity and potential
functional networks of the microbial community, revealing a strong presence of Bathycoccus in open waters.
Multivariate statistical analyses were used to test the significance of the influence of inherent physical
properties of the ocean on the diversity and plasticity of Antarctic picoplanktonic assemblages. The interannual
nature of this study contributes to revealing the ecosystem biological baseline and explores its resilience given
the current changes in the ecosystem.

1527
Thu_170_BE-9_2508
Elevated Salinity Alters Biotic Interactions in McMurdo Dry Valley Soils

E. Ashley Shaw1 (elizabeth.shaw@colostate.edu), Diana H. Wall1

1
Colorado State University, Department of Biology, Fort Collins, United States

The McMurdo Dry Valleys (MDV), Antarctica are relatively simple soil ecosystems compared to temperate soils.
Soil microbes and a few species of nematodes, rotifers, tardigrades, and micro-arthropods occur in the MDV;
however, soil food web structure varies landscape-wide. Nearly 95% of the area is dry soil (< 3% gravimetric
moisture) dominated by an endemic microbivore nematode, Scottnema lindsayae. Wet soil habitat is generally
limited to lake and stream margins and contains greater invertebrate biodiversity. Climate change is predicted
to alter hydrological connectivity across the MDV, shifting soil salts and solutes and changing dry and wet soil
habitat distribution. It is unknown how this will affect the distribution, abundance, and interactions of soil
biodiversity.
MDV Long Term Ecological Research data show nematode populations are negatively associated with soil
salinity, but responses to soil moisture are species-dependent. We tested the effect of increased salinity and
moisture on four different soil communities in a laboratory microcosm experiment (full factorial: 2 salinity x 2
moisture x 4 biota treatments). Elevated moisture significantly reduced adult S. lindsayae abundance, while
elevated salinity significantly reduced the total S. lindsayae population. In the presence of S. lindsayae, total
microbial abundance was significantly lower, but this effect was diminished under the high salinity treatment,
possibly due to a release of predation pressure.

1528
Thu_171_BE-9_2615
Fine-scale Population Genetic Diversity of S. thompsoni in the Southern Ocean

Angelika Słomska1 (angelika.slomska@ug.edu.pl), William Goodall-Copestake2

1
University of Gdansk, Institute of Oceanography, Marine Plankton Research, Gdynia, Poland, 2British Antarctic
Survey, Cambridge, United Kingdom

The need for information about population structure is most acute for ecologically key species like salps
because they play a key role in the marine ecosystem, and are likely to be heavily influenced by climate change.
This impact is believed to be positive in the Antarctic waters, with pronounced expansion of pelagic tunicates
under favorable environmental conditions. This study as one of the first shows a different approach to research
on Antarctic salps population and possible could fulfil the gap in knowledge about their evolution and
expansion in the Southern Ocean.
Oozoids caught off South Georgia, the Antarctic Peninsula and Polar Front area generated barcodes consisting
of a few different DNA sequences and reveal some signals of inter and intra-population variation. Analysis of
the prominent barcode sequence data yielded high haplotype (h: 0.7198-0.9346) and low nucleotide (p:
0.0099) diversities, and reveal statistically significant evidence for genetic structure between studied
population (Fst= 0.37748 with P value= 0.0000) as assessed using analysis of molecular variance. Negative
Tajima's D and Fu and Li's D statistics indicates excess of new mutation as a result of evolutionary forces, such
as selective sweeps or population grow. It could be as well an evidence for heteroplasmy arising from a
dynamic mitochondrial genome.

1529
Thu_172_BE-9_335
Morphometric Analysis of Antarctic Foliose Lichens Using 3-D Digital Microscopy

Alla Orekhova1 (asp.sniish@mail.ru), Miloš Barták1, Romana Gašparová1

1
Masaryk University, Faculty of Science, Department of Experimental Biology, Brno, Czech Republic

Recently, digital microscopy is an emerging technique that combines the tools of classic light microscopy with a
computerized imaging system. Here we present application of the method in morphometric analysis of
Antarctic lichen thalli. The main goal of the study was to evaluate changes in 3-D structute of thalli as
dependent on hydration status, and interspecific differences as well. Another goal was to provide quantitative
biometrical data on size and shape of morhological structures such as fruiting bodies. Lichen thalli collected
from several sites on deglaciated northern part of James Ross Island were analysed using a digital VHX-900F
microscope (Keyence, Japan) with a maximum resolution of 19.5 megapixels. The microscope with built-in LEDs
allowed accurate measurements of lichen surface structures viewed in real time depth composition at the
magnificion ranging from 20 to 200. Data forming a 3-D view of the upper cortex were used to analyze the size
of lobes, outgrowths, and fruiting bodies, respectively. Using a VHX software, we applied processing tools: 1)
height profile along a selected line placed across a thallus, 2) DFP method (Depth From Defocus) which
compiles different focal planes. We studied Placopsis contortuplicata, Dermatocarpon polyphillizum,
Rhizoplaca melaophthalma and other species. Gained resuts on a 3-D structure are discussed: interspecific,
hydration-, and developmental stage-dependent differences. Thank to support from CzechPolar, ECOPOLARIS.

1530
Thu_173_BE-11_582
Relating Antarctic Krill Lipids and Fatty Acids to Environmental Parameters

Nicole Hellessey1,2,3 (nicoleh3@utas.edu.au), Jessica Ericson1,2,3, Peter D Nichols2, Robert Johnson4, Stephen
Nicol1, So Kawaguchi3,5, Nils Hoem6, Patti Virtue1,2,3
1
Institute for Marine and Antarctic Studies, Hobart, Australia, 2Commonwealth Science for Industry Research
Organisation, Oceans and Atmosphere, Hobart, Australia, 3Antarctic Climate & Ecosystems Cooperative
Research Centre, Ecology, Hobart, Australia, 4Australian Bureau of Meteorology, Hobart, Australia, 5Australian
Antarctic Division, Kingston, Australia, 6Aker BioMarine, Oslo, Norway

Antarctic krill are at the centre of the Antarctic ecosystem, linking phytoplankton and higher organisms.
Knowledge of their lipid (oil) biochemistry can assist in understanding and predicting potential ecological
changes and can also inform the fishery on sustainable practices, optimising krill harvest. Knowing how krill will
respond to environmental changes is difficult to predict or explore at large scales through typical
experimentation. The use of satellite imagery can help look at krill production by using their lipids and fatty
acids as a proxy for their health and ability to reproduce.
This study examined how the lipid and fatty acid content and composition of Antarctic krill was linked to large
scale environmental parameters determined through satellite imagery. Lipids were analysed from krill collected
by a commercial krill fishery over 3 years, allowing for long-term environmental and seasonal shifts to be seen,
as well as from the K-Axis and ACE voyages, allowing for regional differences to be seen.
The fluorescence levels, chlorophyll a, irradiance, sea surface height and temperature from the same collection
dates and locations was used to compare krill lipids and fatty acids to their environment. Whilst this link has
been studied on small scales and with few samples, this study describes differences seen temporally (over 3
years in the Scotia Sea) and spatially (in 3 ocean basins) in krill lipids with their relationship to environmental
conditions.

1531
Thu_174_BE-11_838
Hyperspectral Mapping of Sentinel Organisms from Ground, UAS, and Satellite Data

Joseph Levy1 (jlevy@colgate.edu), Kurt Joy2, Charles Lee2, Craig Cary2

1
Colgate University, Geology, Hamilton, United States, 2University of Waikato, Hamilton, New Zealand

As the primary producers in Antarctic terrestrial and fluviol ecosystems in the McMurdo Dry Valleys (MDV), the
distribution and areal extent of microbial mats is hypothesized to reflect changes to water and nutrient
availability. Therefore, observations of “sentinel” microorganisms such as Nostoc, Phormidium, and other
Cyanobacteria can be used a proxy for environmental change. In order to utilize such biological proxies, it is
necessary to produce a baseline census of mat distributions and compositions to compare to future change.
Here we report on observations collected in 2016-2017 of microbial mat occurrences in Wright Valley that link
ground-based hyperspectral and molecular measurements with a UAS-enabled hyperspectral airborne survey
(600-1000 nm with 4 nm band spacing). We compare these observations to near-concurrently collected,
satellite-based Worldview-2 imagery in order to identify diagnostic microbial mat absorptions that can be
mapped using multispectral data. Initial observations suggest that the targeted mats are low-reflectivity at
visible wavelengths and bright in the near-IR portion of their reflectance spectra, consistent with reflectance
from photosynthetic pigments. NIR-bright mats can be detected in ground-based and airborne (UAS)
hyperspectral observations. Space-based mat detection is hampered by the need to generate scene-specific
atmospheric corrections due to large polar phase angles and subpixel mixing of mat, sediment, and rock
spectra.

1532
Thu_176_BE-11_1087
Penguin Watch: Using Citizen Science to Aid Large-scale Penguin Conservation

Fiona Jones1 (fiona.jones@gtc.ox.ac.uk), Tom Hart1

1
University of Oxford, Zoology, Oxford, United Kingdom

Historically, large-scale monitoring (both spatially and temporally) of Antarctic and sub-Antarctic penguin
colonies has been impracticable, owing to technological restraints and the remote locations involved. A remote
camera network, comprising ~100 time-lapse devices positioned across the Falkland Islands, South Georgia and
the Antarctic continent, aims to fill this data gap. However, with each camera capturing ~8000 images per year,
we are presented with another issue - how to efficiently process the photographs and automatically extract
meaningful phenological data. Here we discuss Penguin Watch, an online citizen science project (part of the
Zooniverse platform) which asks volunteers to 'tag' penguins in time-lapse images. To date, over six million
images have been classified by nearly 48,000 registered volunteers. Annotations are clustered and filtered (to
allow removal of erroneous classifications), and used to create time-series data, which in turn can be used to
extract phenological information such as date of adult arrival and date of chick hatching.

1533
Thu_177_BE-11_1094
King Penguin Population Monitoring through Remote Sensing

Catherine Foley1 (catherine.foley@stonybrook.edu), Tom Hart2, Heather Lynch1

1
Stony Brook University, Department of Ecology & Evolution, Stony Brook, United States, 2Oxford University,
Department of Zoology, Oxford, United Kingdom

Over the past century, king penguin colonies have been increasing in number and spatial area across the island
of South Georgia. Monitoring these populations has proven difficult due to limited access and the large
numbers of individuals within the major breeding colonies. Additionally, the unique multi-year breeding cycle
of the king penguin complicates survey efforts, since there is no single point at which the number of individuals
engaged in breeding can be directly assessed. Remote sensing methods have been used for other species of
seabirds and marine mammals that colonize regions with limited access for on-the-ground censusing. To
monitor populations of king penguins, we used high-resolution (sub-meter) satellite imagery to estimate the
distribution and abundance of king penguins in South Georgia. To accommodate for the complex phenological
challenges of translating counted individuals into an estimate of the breeding population, we developed an
individual-based simulation model that allows us to correct for availability bias in direct or remotely-derived
counts completed throughout the austral summer. These methods, which were used to estimate the total
number of king penguins currently breeding in South Georgia, represent a first step in a more-regular
monitoring scheme tracking the total abundance of king penguins in South Georgia and identifying changes in
abundance that are relevant to their conservation.

1534
Thu_178_BE-11_1110
Weddell Seal Count: Citizen Science for the Ross Sea Region MPA

Stuart Grayson1 (stuart.l.grayson@gmail.com), Regina Eisert1

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand

Weddell seals (Leptonychotes weddellii) are a focal species for research & monitoring in the new Ross Sea
region Marine Protected Area. Weddell seals have a pronounced diel or quasi-diel haul-out cycle that affects
their availability for counting. We investigated two potential drivers of haul-out behaviour, solar altitude and
ocean tides, as a basis for effective monitoring of Weddell seals in the Ross Sea region by remote sensing.
Using two autonomous survey cameras activated at 10-minute intervals, we collected ca. 10,000 static images
of the Turtle Rock seal colony, McMurdo Sound (77°44´38.22"S, 166°46´33.42"E), from Nov 2014-Jan 2015.
Turtle Rock is surrounded by sea ice and seals access the water through tidal cracks. Seals in images were
counted by two methods: (a) citizen science ('Zooniverse'); (b) automated image processing using machine
learning. We compared both methods for efficacy and for accuracy relative to images counted by the authors.
Preliminary results indicate that during a 20-day period from 28 Nov 2014, the activity pattern of Weddell seals
appeared to be correlated both with solar altitude and with the tides, with peak haul-out at low tide/solar
noon. Given the unusual tide cycle in McMurdo Sound (low tides largely coincide with solar noon during
summer), further research at different latitudes and/or times of the year may be required to disentangle the
relative importance of solar altitude and tides as zeitgebers for Weddell seal haul-out behaviour.

1535
Thu_179_BE-11_1151
Multi-modal Survey Reveals the Danger Islands as a Seabird Hotspot

Heather Lynch1 (heather.lynch@stonybrook.edu), Alex Borowicz1, Philip McDowall1, Casey Youngflesh1,

Thomas Sayre-McCord2, Gemma Clucas3, Rachael Herman1, Steven Forrest4, Melissa Rider4, Mathew
Schwaller1, Tom Hart5, Stephanie Jenouvrier2, Michael Polito6, Hanumant Singh7
1
Stony Brook University, Ecology & Evolution, Stony Brook, United States, 2Woods Hole Oceanographic
Institution (WHOI), Woods Hole, United States, 3University of New Hampshire, Durham, United States,
4
Antarctic Resource, Inc., Denver, United States, 5Oxford University, Oxford, United Kingdom, 6Louisiana State
University, Baton Rouge, United States, 7Northeastern University, Boston, United States

Despite concerted international effort to track and interpret shifts in the abundance and distribution of Adélie
penguins, ecologically significant populations of Adélie penguins continue to be identified. Here we report on a
major hotspot of Adélie penguin abundance discovered in the Danger Islands off the northern tip of the
Antarctic Peninsula (AP). We present the first complete census of Pygoscelis spp. penguins in the Danger
Islands, estimated from a multi-modal survey consisting of satellite imagery, direct ground counts, and
computer-automated counts of unmanned aerial vehicle (UAV) imagery. Our survey reveals that the Danger
Islands host 751,527 pairs of Adélie penguins, more than the rest of AP region combined, and include the third
and fourth largest Adélie penguin colonies in the world. Our results validate the use of Landsat medium-
resolution satellite imagery for the detection of new or unknown penguin colonies and highlight the utility of
combining satellite imagery with ground and UAV surveys. The Danger Islands appear to have avoided recent
declines documented on the Western AP and, because they are likely to remain an important hotspot for avian
abundance under projected climate change, deserve special consideration in the negotiation and design of
Marine Protected Areas in the region.

1536
Thu_180_BE-11_1152
Is the Antarctic Petrel Breeding Colony on Mt. Biscoe the Largest in the World?

Heather Lynch1 (heather.lynch@stonybrook.edu), Mathew Schwaller2, Arnaud Tarroux3, Brandon Prehn4

1
Stony Brook University, Stony Brook, United States, 2Stony Brook University, Ecology & Evolution, Stony Brook,
United States, 3Norwegian Polar Institute, Fram Centre, Tromso, Norway, 4University of British Columbia,
Vancouver, Canada

We recently developed an algorithm to retrieve Antarctic petrel (Thalassoica antarctica) colonies from Landsat-
8 Operational Line Imager data, and applied the algorithm in a continent-wide search for new and existing
breeding locations. One of the results of this survey suggests that the breeding population at Mt. Biscoe
(66˚13´S 51˚21´E), currently reported to be in the 1000s, may actually be on the order of 400,000 breeding
pairs. If verified, this colony would be the largest known Antarctic petrel breeding community in the world, and
a colony of this size would nearly double the known breeding population of this species. Our results also
suggest other testable hypotheses: we provide geographic coordinates of a previously suspected but
undetected breeding colony on Mt. Provender, and we make predictions on how the diet of the Antarctic
petrel (and therefore the chemistry of its guano) may affect the detection of colonies in satellite remote
sensing. We lay out a way forward for verifying the results of our survey, for algorithm improvement, and for
employing such improvements in a successively more precise understanding of the distribution and abundance
of the Antarctic petrel with remote sensing techniques.

1537
Thu_181_BE-11_1180
Learning about Weddell Seals: Engaging Citizen Scientists with New Technologies

Michelle LaRue1 (larue010@umn.edu), Melissa Dozier2, Jon Saints2, Leo Salas3, Jean Pennycook4, Sharon
Stammerjohn5, David Ainley4, Kostas Stamatiou2
1
University of Minnesota, Earth Sciences, Minneapolis, United States, 2DigitalGlobe, Inc., Westminster, United
States, 3Point Blue Conservation Science, Petaluma, United States, 4HT Harvey and Associates, Los Gatos, United
States, 5University of Colorado Boulder, Boulder, United States

To understand habitat use by Weddell seals, it is imperative to know where and when they are present around
the continent. The necessary data to date have been impossible to gather across such a large geographic area.
We established our project, Satellites Over Seals (SOS), in late 2016 as a crowd-sourced method of gaining
information about presence and abundance of Weddell seals on fast ice around Antarctica - To engage citizen
scientists, we used a novel technology: the online platform at Tomnod to select and host high-resolution
satellite imagery (VHR) for “the crowd” to search, using VHR from November 2010 and 2011, covering the Ross,
Amundsen, Bellingshausen and Weddell Sea regions. More than 318,000 citizen scientists searched 550 images
covering 105,124 km2 of fast ice to determine locations of seals. Seal presence ranged from 0.5% - 2% on all
maps (n = 778,447) searched. When detecting presence/absence of seals on a map (i.e., not seal abundance)
rate of false negative detections was 0%, though false positive rates were high (80%); this highlights the
importance of training for image interpretation to ensure differentiation among seals and landscape features.
We provide recommendations on image resolution, quality, training and outreach for future implementation of
citizen science methods to learn about Southern Ocean ecology.

1538
Thu_182_TE-3_1780
Combining Satellite Datasets to Track Changes in the Vegetation of Kerguelen

Damien Fourcy1 (damien.fourcy@inra.fr), Jean-Louis Chapuis2, Marc Lebouvier3, Marc Robin4

1
INRA, UMR 985 ESE, Rennes, France, 2MNHN, UMR 7204 CESCO, Paris, France, 3CNRS, UMR 6553 Ecobio,
Rennes, France, 4Université de Nantes, UMR 6554 LETG, Nantes, France

The Kerguelen Islands (49°30´ S, 69°30´ E) are among the most isolated islands in the world, located in the sub-
Antarctic region 2000 km from Antarctica and 3800 km from Africa. The vegetation of these uninhabited islands
is very little diversified (only 22 native phanerogams) and undergoes changes that increase since the last two
decades. The structure and the composition of the plant communities are strongly affected by the combined
effects of climate change and the introduction of animal and plant species.
In order to track changes in plant communities over large spatial and temporal scales, we have developed a
mapping method based on satellite images from different sources. High resolution SPOT images were used to
characterize the evolution of vegetation cover from 1995 to 2016, i.e. since the observation of the first
significant changes in plant communities . In addition to SPOT, Sentinel-2 imagery, thanks to its easy access,
allowed to expand temporally and spatially this general monitoring. For the most recent years, very high
resolution Pléiades images allowed a mapping of all the different plant communities. Moreover, fine data on
the evolution of floristic composition of the communities were recorded from field surveys carried out since
1995.
This mapping approach, based on multi-source satellite data and combined with field data, provides a better
understanding of the current dynamics and is a valuable tool for managing these fragile ecosystems.

1539
Thu_183_BE-11_2631
Camera Derived Phenology of Pygoscelid Penguins in Relation to Fishing

Tom Hart1 (tom.hart@zoo.ox.ac.uk), Fiona Jones1, Beccy Wilebore1, Grant Humphreys2, Caitlin Black3, Heather
Lynch4, Byron du Preez1, Ron Naveen5
1
University of Oxford, Oxford, United Kingdom, 2Black Bawks Data Science, Edinburgh, United Kingdom,
3
University of Cambridge, Zoology, Cambridge, United Kingdom, 4Stony Brook University, Stony Brook, United
Kingdom, 5Oceanites, Inc., Washington, United States

On the Antarctic Peninsula, chinstrap and Adélie penguins are in decline while gentoo populations are
expanding in size and range. Potential drivers of these changes include climate change, winter sea ice extent,
ocean productivity, tourism, fishing and prey competition with other predators. However these drivers are
usually confounded in space and time, presenting a challenge that cannot be answered by conventional remote
monitoring. Here we show that a combination of time-lapse cameras, citizen science and machine learning
allows us to elucidate the timing of breeding and nest-based reproductive success. We show differences in the
timing of breeding, reproductive success and crèching behaviour across the breeding range of these penguin
species. We also report remotely monitored Automatic Identification System (AIS) derived spatio-temporal
patterns of fishing, their overlap with foraging ranges during the penguin breeding season, and the potential
impact on penguin reproductive success. A proposal for an Antarctic Peninsula Marine Protected Area (MPA) is
already being discussed in CCAMLR and, once extant catch limits expire after the 2020/21 fishing season, it is
expected that there will be pressure to increase krill fishing quotas in the region. We consider our paper a first
step towards a more sophisticated analysis to investigate the influences of fishing pressure on krill predator
reproductive success and to disentangle the confounding stressors in the region.

1540
Thu_184_BE-12_40
Opportunistic Fungi in the Contaminated Soils of the Kola Peninsula

Maria Korneykova1 (korneykova.maria@mail.ru)

1
Institute of the Industrial Ecology Problems of the North, Kola Science Center Russian Academy of Sciences,
Ecology of Microorganisms, Apatity, Russian Federation

The opportunistic fungi (OF) were studied in the soils contaminated by the industrial plants emissions, as well
as their virulence was estimated on the basis of protease, phospholipase activity, and the growth capability at a
temperature of 37C°.
51 species of the fungi belonging to the OF group, were isolated in the soils of the Kola Peninsula. The share of
the OF increases to 15-20%, compared to the background soil, under the anthropogenic impact (oil products,
the aluminum and copper-nickel plant emissions).
The most dangerous for a human being are considered to be 7 fungi strains from the checked 75 ones:
Amorphotheca resinae st.1, Aspergillus fumigatus st.1, A. niger, Paecilomyces variotii st.1, Penicillium
commune, P. purpurogenum, Trichoderma viride. 55% of the investigated fungi strains isolated from the soils
contaminated by the aluminum plant emissions had the pathogenicity properties, compared to the strains of
the same species isolated from the clean soil (25%). A. fumigatus, Paec. variotii, P. aurantiogriseum showed
both protease and phospholipase activity. A. resinae, Cephalotrichum stemonitis, Cladosporium herbarum
revealed protease activity and the growth capability at a temperature of 37C°. The fungi isolated from the soil
can constitute a danger to the human being´s health, as most of them reveal the pathogenicity properties, to a
greater or lesser extent. The regular monitoring research should be fulfilled to determine potentially-
dangerous fungi species.

1541
Thu_185_BE-12_169
Does Arctic Warming Affect Lichen- and Bryophyte Microbiota and their Functions?

Ingeborg Klarenberg1,2 (ingeborg@unak.is), Oddur Vilhemsson1,3

1
University of Akureyri, Faculty of Natural Resource Sciences, Akureyri, Iceland, 2University of Iceland, Faculty of
Life and Environmental Sciences, Reykjavík, Iceland, 3University of Iceland, Biomedical Center, Reykjavík, Iceland

Lichens and bryophytes are an essential part of the vegetation in Arctic ecosystems. In addition to the
mutualistic association of a fungus and an alga and/or a cyanobacterium, lichens are also known to harbour
species-specific bacterial communities, typically dominated by Proteobacteria. Similarly, bryophytes possess
their own microbiome. Among the potential functional roles of these bacteria are inorganic phosphate
mobilization and nitrogen fixation. In the light of climate change and the effect on Arctic ecosystems, the
question rises what the effect will be on lichen and bryophyte associated microbiomes and their functions.
The main aim of this study is to characterise and compare the composition of lichen- and bryophyte-associated
bacterial communities differentially impacted by a long-term warming experiment. Active and resident
bacterial communities are assessed by taxonomic analysis of MiSeq libraries of 16S-rDNA and -rRNA targeted
amplicons. Also, expression of different genes involved in N-fixation are measured by RT-qPCR.
The lichen and bryophyte-associated microbiota are strongly dominated by Proteobacteria, with members of
Rhizobiales, Sphingomonadales and Burkholderiales particularly prominent. Changes in abundance of individual
taxa are expected to reflect the different living conditions expected in the warming Arctic. In addition, some
microbial functions might emerge, others disappear, with consequences for the biogeochemical cycles in Arctic
ecosystems.

1542
Thu_186_BE-12_417
What is the Best Practice for Microbial C and N Assessment in Subarctic Soils?

Mikhail Maslov1 (maslov.m.n@yandex.ru), Olga Maslova1

1
Lomonosov Moscow State University, Moscow, Russian Federation

The aim of our work were to assess the comparability of the results of determiningmicrobial carbon (C) and
nitrogen (N) in organogenic Subarctic soils by different methods under maximally standardized conditions. Four
methods of microbial C and N pools assessment were considered to subarctic soils in the European part of
Russia: fumigation-extraction (FE), fumigation-incubation (FI), rehydration-extraction (RE) and rehydration-
incubation (RI). We studied organogenic horizons of soils under 4 types of vegetation in the mountain tundra, 2
vegetation types in the lowland tundra, soils of birch and spruce forests, and swamps. FI and RI methods
require a substantial amount of time and little use for subarctic soils (including due to low pH and
predominance of fresh litter). FE and RE methods are more rapid and gives good reproducible results, but FE
method usually gives higher values of microbial biomass C and N in comparison with the RE method. The
microbial C:N ratio, determined by these methods in almost all soil is the same. The greatest differences are
characteristic of the horizon containing fresh litter. Obviously, fumigation with chloroform leads to greater
mobilization of carbon and nitrogen of plant residues compared with the drying.Concentration of microbial C
and N (determinate by FE and RE methods) more comparable for horizons with a lower content of fresh litter.
The study was supported by the Russian Science Foundation (grant No. 17-76-10020).

1543
Thu_187_BE-12_471
Ecophysiological Characteristics of Cyanobacteria from Biological Soil Crusts

Katerina Trnková1 (katka.trnkova@mail.muni.cz), Miloš Barták1, Peter Váczi1

1
Masaryk University, Faculty of Science, Department of Experimental Biology, Brno, Czech Republic

Biological soil crusts (BSCs) are biological communities inhabiting the uppermost layer of soil. They are
frequently formed in polar regions, where the severe environmental conditions limit the growth of higher
plants. The intact BSCs represent complex communities of cyanobacteria, algae, fungi, lichens, bryophytes,
bacteria and even small invertebrates. Generally, BSCs show high resistance to stress factors common in
Antarctica, i.e. low and freezing temperatures, desiccation, high UV-B doses in austral spring, high global
radiation in austral summer and no radiation in winter. In this study, the tolerance to these stress factors was
tested in single-species cultures of cyanobacteria isolated from the BSCs collected during Czech Antarctic
expeditions to James Ross Island, Antarctica (2016, 2017). We tested Leptolyngbya sp. and Nostoc sp.
cultivated on agar plates to evaluate their physiological activity under a variety of temperature and irradiance
treatments. The species showed temperature- and radiation-dependent changes in chlorophyll fluorescence
parameters derived from slow Kautsky kinetics and quenching analysis (Fv/Fm, Quantum Yield, NPQ). We
concluded that the isolated cyanobacterial species showed different sensitivity of their photosynthesis to
temperature and irradiance. The results present activity limits of cyanobacterial component of the Antarctic
BSCs.
Acknowledgements: The authors thank CzechPolar and ECOPOLARIS project for support.

1544
Thu_188_BE-12_599
Functional Potentials of Supraglacial Cryoconite Hole Microbial Communities

Aritri Sanyal1 (aritri@gmail.com), Runa Antony1, Meloth Thamban1

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Vasco da Gama, India

Dust particles on the glacier surface melts into the ice and forms nutrient rich melt water holes called
cryoconite holes that provide refuge for diverse and active microbes. We show here that cryoconite holes from
Antarctica and a Himalayan glacier (Sutri Dhaka) harbour genes responsible for carbon fixation
(Betaproteobacteria, Basidiomycota), nitrogen fixation (Actinobacteria, Betaproteobacteria), ammonia
oxidation (Betaproteobacteria, Basidiomycota), nitrate reduction (Actinobacteria, Alphaproteobacteria,
Betaproteobacteria), denitrification (Alphaproteobacteria, Actinobacteria, Betaproteobacteria, Basidiomycota),
dissimilatory nitrate reduction (Actinobacteria, Betaproteobacteria) and anaerobic ammonium oxidation
(Actinobacteria), indicating that they have good potential for cycling C and N in these ecosystems. Microcosm
experiments show that resident microbes are able to degrade carboxylic acids, such as lactate, acetate,
formate, propionate and oxalate found within the cryoconite hole environment. In addition, microbial
communities are also capable of metabolizing a diverse array of compounds, such as, proteins, lipids,
carbohydrates, cellulose and lignin that are documented to be present within cryoconite holes, thereby
influencing the chemistry of these environments. It is proposed that, in the event of glacier melting, these
microbes can act as important colonizers that can influence biogeochemical processes in downstream
ecosystems.

1545
Thu_189_BE-12_700
Are High-alpine Microbial Communities Able to Deal with Temperature Extremes?

Petra Lulakova1 (petrica@centrum.cz), Carla Perez-Mon2, Joel Ruethi2, Beat Frey2

1
University of South Bohemia, Faculty of Science, Ceske Budejovice, Czech Republic, 2Swiss Federal Research
Institute WSL, Birmensdorf, Switzerland

The response of microbial communities to the predicted rising temperatures in the alpine regions may be an
important part of the ecosystem ability to deal with climate change. Soil microbial diversity, community
structure and activity might be significantly affected by higher temperatures which influence the ecosystem
functioning of high-alpine soils. To evaluate the potential of the permafrost microbiome to adapt to
temperature extremes we set up an incubation experiment with permafrost soils (collected at a soil depth of
160 cm) and an active soil layer from a high-alpine mountain ridge of Schafberg, Switzerland. Soils were
incubated to increasing temperatures (4 - 40 °C) for two weeks as a pre-treatment before exposing them to a
heat shock of 40 °C for 5 days. All the samples were then evaluated for the changes of the bacterial and fungal
communities and their functional abilities by measuring respiration, enzyme activities and carbon utilization
patterns. Results revealed a different ability of the microbial communities to withstand and regenerate after
the heat shock according to the origin of the soils and also partly due to the pre-treatment. The adaptability of
the permafrost microbiome to the temperature rise and the heat shock will be discussed.

1546
Thu_190_BE-12_830
Parasitic Marine Alveolate DNA Dominates Southern Ocean

Laurence Clarke1 (laurence.clarke@utas.edu.au), Sophie Bestley2, Andrew Bissett2, Bruce Deagle3

1
University of Tasmania, Antarctic Climate and Ecosystems Co-operative Research Centre, Hobart, Australia,
2
Commonwealth Scientific and Industrial Research Organisation (CSIRO), Hobart, Australia, 3Australian
Antarctic Division, Kingston, Australia

Polar ocean plankton communities are extremely important for global biogeochemical processes. However,
recent efforts to survey marine eukaryote diversity focussed on tropical and temperate plankton communities,
with limited sampling of the polar oceans. We sequenced 18S ribosomal DNA to characterise eukaryotic
diversity in 284 size-fractionated plankton samples collected across 52 sites south of the Kerguelen plateau,
one of the most productive regions in the Indian Sector of the Southern Ocean.
We show that a single parasitic Marine Alveolate group I (MALV I) operational taxonomic unit comprised more
than half the reads in samples from several locations near the sea ice edge. Although an identical MALV 18S
sequence was previously found to be associated with a Northern Hemisphere radiolarian, we find the sea-ice
associated cercozoan, Cryothecomonas sp., is the likely host in the Southern Ocean samples.
Parasitic MALV are also known to be abundant in marine and sea ice ecosystems in the Arctic and Western
Antarctic Peninsula. Parasites divert energy and nutrients from the phytoplankton - krill - marine predator food
chain to the microbial loop but are rarely included in marine ecosystem models. Our findings indicate MALV
parasites have the potential to influence the abundance of a key sea-ice organism, influencing biological and
geochemical processes in polar marine and sea ice ecosystems.

1547
Thu_191_BE-12_873
Key Parameters for Modeling of Dissolved Oxygen Concentration in Antarctic Lakes

Peter Váczi1 (vaczi@sci.muni.cz), Miloš Barták1

1
Masaryk University, Faculty of Science, Department of Experimental Biology, CzechPolar2/ECOPOLARIS Project
Group, Brno, Czech Republic

Freshwater terrestrial water ponds and small basins are important aquatic habitats for autotrophs in
deglaciated Antarctic areas. Since 2011, we have been monitoring physical properties (temperature regimes
continuous data, supplementary conductivity, pH, photosynthetic active radiation-PAR, dissolved oxygen
concentration-DOC courses during summer period) in two selected water ponds in the northern part of James
Ross Island. The two ponds differ in size, morphology, and origin. First one is located in a depression of
sedimentary rock (10 m a.s.l.), the other one on stony glacier surface (220 m a.s.l.). In both of them, Nostoc and
Leptolyngbya are dominant autotroph species in microbiological mats forming a bottom cover. The ponds
freeze during winter, temperature decreases to -15 to -20°C. In austral summer, a long ice-free period (5-10
weeks) occurs. Daily courses of DOC recorded in summer showed frequent supersaturation. However, a strong
variability in DOC was found. DOC changes within a day and season were dependent on PAR, pH, and lake area
to depth ratio (positive correlations). Water temperature and electrical conductivity were negatively
correlated. These parameters, supplemented with chlorophyll concentration, serve as inputs for a multiple
regression model. An analysis of the dynamics of the ecosystem and prediction of autotrophs activity are done
using the model.
Acknowledgements: The study was supported by the CzechPolar infrastructure and the ECOPOLARIS project.

1548
Thu_192_BE-12_927
In a Search for Ancient Marine Virus and Bacteria in Lake Cadagno, Switzerland

Jaspreet Singh Saini1 (jaspreet.saini@etu.unige.ch), Marion Fourquez1, Rachel Cable2, Francesco Danza3,4,
Samuele Roman3, Mauro Tonolla3,4, Evgeny Zdobnov5, Melissa Duhaime2, Christel Hassler1
1
University of Geneva, Institute F.-A Forel for Earth and Environmental Sciences, Geneve, Switzerland,
2
University of Michigan, Department of Ecology and Evolutionary Biology, Ann Arbor, Michigan, United States,
3
University of Applied Sciences and Arts of Southern Switzerland (SUPSI), Laboratory of Applied Microbiology
(LMA), Department for Environmental Constructions and Design (DACD), Manno, Switzerland, 4University of
Geneva, Microbiology Unit, Department of Botany & Plant Biology, Geneva, Switzerland, 5University of Geneva,
Department of Genetic Medicine and Development, Genève, Switzerland

Lake Cadagno, an alpine meromictic lake originated around 10,000 years ago. It has a persistent oxic and anoxic
layers separated by a bacterial biofilm and are known to inhabit ancestral microorganisms. Although
photosynthetic and heterotrophic bacteria have been studied extensively, however, nothing is known about
viruses in this Lake. To fulfill this gap, we have collected samples at different depths of the lake to isolate
'Bacteriophages' (viruses that infect bacteria) and to investigate their relations with host microbial
communities. Virus/host abundance was investigated using Flow Cytometry and metagenomics analyses were
employed to characterize the viral diversity in the lake, which may probe the presence of 'ancient' virus-host
models. Also, results will be put in relationship with chemical gradients as well as bacterial and phytoplankton
biodiversity and productivity. Our study is the first step towards an exploration of the role of viruses in the
ecological functioning of Lake Cadagno.

1549
Thu_193_BE-12_1011
Heat Shock Response of Glacier Microbiome

Antonio Mondini1 (tonio.mondini@gmail.com), Muhammad Zohaib Anwar2, Carsten Suhr Jacobsen2, Catherine
Larose3, Cristina Purcarea1
1
Institute of Biology, Romanian Academy, Department of Microbiology, Bucharest, Romania, 2Aarhus University,
Department of Environmental Sciences, Copenhagen, Denmark, 3Université de Lyon, École Centrale, Lyon,
France

Glacier ice occupies a significant area of the planet and is currently experiencing one of the most rapid and
severe melting rate, associated with possible changes of microbiome composition due to exposure to
temperature variations when passing to adjacent soil. Our study investigated the thermal response of total and
active ice-contained microbiome from a Svalbard glacier ice core and using a psychrophilic model bacterium, in
order to identify an enzymatic biomarker. Glacier melted ice samples were submitted to a 7-day heat/freeze
cycling experiment, and the total DNA and RNA was extracted and analyzed. Changes in the total and active
microbiome composition after heat shock treatment are currently investigated by Shotgun metagenomics and
metatranscriptomics. Quantitation by qPCR of the aspartate transcarbamoylase (ATC) expression, a key enzyme
of pyrimidine nucleotides biosynthesis, revealed associated changes in the microbiome DNA synthesis. Thermal
response of pyrimidine gene expression was investigated in a parallel bacterial model experiment using
psychrophilic Glaciibacter superstes. Analysis of the ATCase gene expression pattern in the psychrophilic
bacterium and ice microbial community is currently carried out in order to propose an enzymatic biomarker for
ice microbiome response to temperature variations when changing habitats due to glaciers melting.
Acknowledgement: This project was funded by H2020 Marie Skłodowska-Curie ITN 675546 grant.

1550
Thu_194_BE-12_1242
Induction of Cryptic Secondary Metabolites from Rare Antarctic Marinobacter

Katherine Bauman1, Jeremy Carter1, Miller Judge1, Khan Kim1, Lauren McLean1, Jill Mikucki2, Katherine Novey1,
Lesley-Ann Giddings1 (lgiddings@middlebury.edu)
1
Middlebury College, Chemistry & Biochemistry, Middlebury, United States, 2University of Tennessee,
Microbiology, Knoxville, United States

Microbes from extreme environments represent untapped sources of novel, bioactive metabolites with unique
molecular frameworks, as they have evolved genes, many of which are cryptic or silent under standard
fermentation conditions, required for survival in unusual environments. Only recently have microbiological
samples been obtained from cold, dark isolated ecosystems in Antarctica. Blood Falls, one of the better-
characterized subglacial environments in Antarctica, is a cold (-7 °C), iron-rich (~3.4 mM) subglacial brine (8%
NaCl) that leaks out from below the Taylor Glacier. A moderately halophilic, heterotrophic psychrophile was
recently isolated from the Blood Falls brine that clusters within the Marinobacter genus. Bioinformatic analysis
of this strain's genome indicated the presence of at least four gene clusters involved in secondary metabolism
with low sequence identity (~30%) to other known genes in GenBank. These gene clusters are most similar to
those that produce aryl polyenes and terpenes, which function as pigments/antioxidants, protecting bacteria
from reactive oxygen species. To identify uncharacterized, cryptic secondary metabolites with potential
bioactivity, we used culture-dependent and -independent methods to induce the expression of cryptic
biosynthetic gene clusters. Our data provide insight into the Marinobacter metabolome and its role in cold
environments, such as those found in Antarctica.

1551
Thu_195_BE-12_2116
Functional Resilience of Antarctic Microbiomes to Climate-induced Changes

Maria Monteiro1 (mrcgm1@students.waikato.ac.nz), Charles Lee1, Ian McDonald1, Ian Hawes1, Craig Cary1
1
University of Waikato, International Centre for Terrestrial Antarctic Research, Hamilton, New Zealand

The biological productivity of McMurdo Dry Valley ecosystems is composed primarily of microbial processes,
which are limited by the availability of liquid water and extreme weather conditions. Climate models predict an
increase in temperature for the next decade, which will likely impact the hydrology and consequently the
biodiversity and functionality of the ecosystem. Facing a regime of change, it is critical to understand to what
extent microbial communities are able to retain their functions, thereby maintaining ecosystem services and
the status quo. Using a “space-for-time” approach to approximate resilience, four wetness transects were
sampled from the edges of Lake Brownworth and Lake Vanda, Wright Valley. We hypothesize that systems
without historical hydrological changes (Lake Brownworth) harbor microbiomes well adapted to the
permanently wet/dry conditions and that these microbiomes are structurally and functionally different to
systems subjected to annual hydrological changes (Lake Vanda) where the microbiomes are more functionally
heterogeneous and potentially more resilient to hydrological changes. Using a combination of metagenomics
and metatranscriptomics, the levels of functional redundancy present in communities from both stable and
dynamic systems will be examined, and the capacity of current microbiomes to engage with future
environmental change will be discussed. Work of this type will help us to understand the fragility and resilience
of polar ecosystems.

1552
Thu_196_BE-12_2191
Distribution and Diversity of Heterotrophic Diazatrophs in McMurdo Dry Valleys

Kathryn Coyne1 (kcoyne@udel.edu), Jill Sohm2, Alex Parker3, Andrew Kalmbach4, Troy Gunderson2, Charles
Lee5, Rosa Leon6, Doug Capone2, Edward Carpenter4, Craig Cary1,5
1
University of Delaware, Lewes, United States, 2USC, Los Angeles, United States, 3California State University
Maritime Academy, Vallejo, United States, 4Romberg Tiburon Center for Environmental Studies, Tiburon, United
States, 5University of Waikato, Hamilton, New Zealand, 6Willamette University, Salem, United States

Melt-water streams in McMurdo Dry Valleys (MDV) harbor a diverse assemblage of mat-forming cyanobacteria
that play a key role in nitrogen cycling due to their diazatrophic activity. Prior research showed that
heterotrophic diazatrophs may also contribute over 50% of nitrogen fixation in some mats. Our goals were to
survey heterotrophic diazatrophs across the MDV to identify factors that regulate distributions. We collected
samples from wetted, adjacent hyporheic, and dry regions at 23 sites, with and without visible mat. 16S rRNA
genes were sequenced from 69 samples and nifH was sequenced from samples with positive amplification.
Results show that the heterotrophic and cyanobacteria community structures were significantly correlated.
Assemblages from several mat-free sites were more closely correlated with those from dry sites, regardless of
the presence of water, suggesting that mats play an important role in structuring bacterial communities. NifH
sequence analysis also showed that diazatrophs were highly and significantly correlated to the bacterial
community as a whole. In addition, nifH genes were not amplified from samples collected in mat-free areas,
suggesting a metabolic coupling between phototrophic and heterotrophic diazatrophs. This work contributes to
our understanding of key drivers of bacteria community structure in polar deserts and informs future efforts to
investigate the contribution of nitrogen fixation to community diversity and resilience in the MDV.

1553
Thu_197_BE-12_2223
Permafrost Thaw and Resource Additions Alter Arctic Stream Microbial Communities

Natasha Griffin1 (natasha.a.griffin@gmail.com), Benjamin Abbott1, Zachary Aanderud1

1
Brigham Young University, Plant and Wildlife Sciences, Provo, United States

As permafrost thaws across the Arctic, more of the organic carbon stored in permafrost soils is becoming
available for transport to aquatic ecosystems. The response of arctic stream microbial communities to the
effects of permafrost thaw will help determine how much added carbon is taken up or released, but this is a
poorly characterized part of the Arctic carbon cycle. Deeper water movement through the thawing soil profile
and thermokarst formation will increase terrestrial resource subsidies to aquatic microbial communities, and it
may also alter the inoculation of soil microbes to streams, impacting community composition and function.
To assess the effects of thaw depth on stream microbial communities, we sampled streams during the early
and late growing season throughout three watersheds on Alaska's North Slope: the Kuparuk, a tundra stream;
the Oksrukuyik, a lake-influenced tundra stream; and Trevor Creek, a mountain stream. To investigate how
nutrient additions alter community composition and rates of dissolved organic matter decomposition, we also
incubated a subset of streamwater samples with combinations of N, P, and C amendments. We characterized
in-stream and incubation bacterial communities via a target metagenomic approach. We hypothesized that
increased thaw depth will create greater soil-stream community connectivity, with diversity decreasing
downstream, and that concurrent carbon and nutrient additions will most affect incubated stream
communities.

1554
Thu_198_BE-12_2267
Microbial Communities along Consecutively Connected Habitats in East Antarctica

Klemens Weisleitner1 (klemens.weisleitner@uibk.ac.at), Alexandra Perras2, Christine Moissl-Eichinger2, Dale T.

Andersen3, Birgit Sattler1
1
University of Innsbruck, Institute of Ecology, Innsbruck, Austria, 2Medical University of Graz, Department of
Internal Medicine, Graz, Austria, 3Carl Sagan Center, SETI Institute, Mountain View, United States

The ultraoligotrophic Lake Untersee is the largest and deepest surface lake of Central Queen Maud Land in East
Antarctica. It is located in a cirque-like valley which is dammed by the Anuchin glacier at its northern tip which
provides the only known water source for the lake. Water-loss only occurs through ablation and sublimation of
the perennially lake ice cover. Lake Untersee pelagic and benthic microbial communities are relatively well
studied. However, the Anuchin glacier is still unexplored even though its potential role as major contributor of
nutrients and biota to the lake ecosystem.
Based on 16s rRNA gene targeted PCR and subsequent Illumina tagged sequencing, we show that aerial
deposition of biota on the glacier leads to distinct microbial communities in glacier ice and cryoconite holes.
These communities ultimately become part of the lake Untersee ecosystem. Significant differences in microbial
diversity were also recorded between supraglacial habitats and the lake ice cover, suggesting a shift in glacier
microbial communities once they melt into the lake. The highest relative abundant phyla in lake, glacier and
aerosol samples belong to Actinobacteria, Cyanobacteria, Bacteriodetes, Firmicutes, and Proteobacteria.
The glacier can be considered as a vector for the colonization of Lake Untersee and hence shapes the lake
Untersee ecosystem. The microbial input from deeper depths of the glacier to the lake is unknown and requires
further investigation

1555
Thu_199_BE-12_2444
Contrasted Methanogenic Activity of Sub-Polar Wetlands in Climate Change Context

Céline Lavergne1 (celine.lavergne@pucv.cl), Bruna Martins Dellagnezze2, Polette Aguilar Muñoz1, Patricia Bovio
Winkler2, Sebastian Olivares1, Natalia Calle1, Maria Soledad Astorga España3, Armando Sepulveda Jauregui3,
Karla Martinez Cruz3, Frederic Thalasso4, Claudia Etchebehere2, Maialen Barret5,6, Léa Cabrol1,7
1
Pontificia Universidad Católica de Valparaíso, School of Biochemical Engineering, Valparaiso, Chile, 2Instituto
de Investigaciones Biológicas Clemente Estable, Bioquímica y Genómica Microbiana, Montevideo, Uruguay,
3
University of Magallanes, Ciencias y Recursos Naturales, Punta Arenas, Chile, 4Centro de Investigación y de
Estudios Avanzados del Instituto Politécnico Nacional, Biotecnología y Bioingeniería, Mexico, Mexico,
5
University of Toulouse, Laboratoire Ecologie Fonctionnelle, Castanet-Tolosan, France, 6CNRS/EcoLab,
Laboratoire d'Écologie Fonctionnelle et Environnement, Castanet-Tolosan, Chile, 7Aix Marseille University,
Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France

Due to organic matter accumulation and anaerobic microbial processes, wetland ecosystems are known to
contribute greatly to global warming through methane emissions. Polar wetlands are more strongly affected by
climate change, resulting in expected modifications of microbial community structure and methanogenesis
activity rate, leading to a positive feedback on regional methane budget and global warming. Yet, the outcome
of temperature increase on methanogenic communities and processes in Sub-Antarctic wetlands in comparison
with their Sub-Arctic counterparts has not been investigated to date.
In this study, the screening of methane production rate in lake sediments and peatlands from 10 Sub-Antarctic
ecosystems (Patagonia to Cape Horn, Chile) and 15 (sub)Arctic ecosystems (Denali to Toolik, AK, US) collected
in austral summer, highlighted the heterogeneity of methanogenic activities between the considered
ecosystems, with regional specificities and higher potential in lake sediments. In controlled microcosm
incubations, methane production pathway was mainly acetoclastic and increased temperature (5-10-15-20°C)
resulted in enhanced methane production rate. The most temperature-sensitive samples were identified by
comparison of modeled energy activation. The quantification of functional genes involved in methanogenesis in
in-situ and microcosm samples and microbial diversity evaluated by sequencing will be investigated.

1556
Thu_200_BE-12_2492
What Determines the Microbial Succession on the Glacier Foreland?

Binu Tripathi1, Hye-Ryeon Gyeong1, Mincheol Kim1, Ji Young Jung1, Yoo Kyung Lee1 (yklee@kopri.re.kr)
1
Korea Polar Research Institute, Incheon, Korea, Republic of

Glacier forelands are ideal places to study the ecological succession but microbial succession is relatively poorly
understood. We conducted a meta-analysis of bacterial communities using six different successional soils
datasets, scattered across different regions, with different pH conditions in early and late successional soils. We
found that extreme acidic or alkaline pH conditions lead to the assembly of phylogenetically more clustered
bacterial communities through deterministic processes, whereas pH conditions close to neutral lead to
phylogenetically less clustered bacterial communities with more stochasticity. We suggest that the influence of
pH, rather than successional age, is the main driving force in producing trends in the phylogenetic assembly of
bacteria. We also investigated the microbial succession along the chronosequences in front of two different
glaciers (Austre Lovénbreen & Blomstrandbreen) in Svalbard. Ordination analysis revealed that all microbial
communities shifted from early to the later successional stage following deglaciation in both glacier forelands.
The main factor of the bacterial succession was soil pH, whereas fungal communities differed more by
vegetation type and coverage. The successional age since glacier retreat is not a single driver of community
convergence at the later stage of succession, but alternate factors such as geochemistry and geomorphology
could also lead to distinct convergence pattern of microbial communities.

1557
Thu_201_BE-12_2553
Functional Metagenomic of Microbial Communities Associated to Antarctic Sponges

Nicole Trefault1 (nicole.trefault@umayor.cl), Mario Moreno-Pino1, Mariela Guajardo1

1
Universidad Mayor, GEMA Center for Genomics, Ecology and Environment, Santiago, Chile

Marine sponges harbor diverse and abundant microbial communities, that perform fundamental processes
related to biogeochemical cycling and nutritional coupling with the host, forming what is called the sponge
holobiont. Most studies about sponge holobionts have focused on the bacterial component and come from
temperate and tropical environments, and functional roles of sponge symbionts from Polar Regions remain
largely unknown. Here, we use a combination of metagenomic and culture-based approaches, with the aim to
explore the functional potential from microbial communities associated to Antarctic sponges.
Our analyses indicate that Antarctic sponge holobionts display a particular taxonomic signature, with the
absence of Cyanobacteria and Poribacteria, two common phyla in temperate and tropical sponges. Functional
potential analysis shows genes involved in nitrogen, carbon, sulfur and phosphorus cycles. Protein-coding
genes related to vitamin synthesis and host-microbe interactions are enriched inside the sponges compared to
planktonic communities. Genomic features of bacterial strains isolated from Antarctic sponges showed several
genomic signatures related to symbiotic lifestyle. To our best knowledge, this work is the first insight into the
functional potential of sponge-associated microbial communities from the Antarctic environment and reveals
that fundamental biogeochemical, defense and nutritional processes are transversal across sponge-holobionts.

1558
Thu_202_BE-12_2698
Impact of Increased Snow Melt on the Development of Cryospheric Communities

Birgit Sattler1 (birgit.sattler@uibk.ac.at), Klemens Weisleitner1, James Bradley2, Arwyn Edwards3

1
University of Innsbruck, Institute of Ecology, Austrian Polar Research Institute, Innsbruck, Austria, 2University of
Southern California, Department of Earth Sciences, Los Angeles, United States, 3Aberystwyth University, Centre
for Glaciology, Aberystwyth, United Kingdom

The vast snow covers of the cryosphere are covering up 35% of the Earth´s surface and exert substantial impact
on the biosphere. Hence, it has been addressed merely as a physical component that, due to hostile conditions
has long been regarded as devoid of life. However, snow and ice microbial communities have gained increasing
interest due to their potential to contribute to the labile carbon which is available after snow melt. Nowadays,
the general picture of snow merely being a repository for wind-transported and snow-trapped microorganisms
has changed dramatically even to breeding chambers for microbial life once liquid water is available. Here we
show a study from Svalbard, where the impact of the snow pack has been investigated over glacier ice, lake ice
and soil, respectively, during the period of snow melt. All three habitats show distinct responses to the input of
ions, biological particles and nutrients which causes an enhancing effect for microbial productivity during these
few weeks. With ongoing increase in temperature which implies more liquid water, snow melt is a crucial
process for the adjacent habitats in terms of increased productivity, activity and metabolism. Hence, with
global warming the periods of dormancy are reduced leading to higher carbon turnover rates over large areas
potentially altering the carbon budget of high altitude and high latitude regions.

1559
Thu_203_CR-4_50
Glacier Monitoring in Bhagirathi River Basin using Remote Sensing

Har Amrit Singh Sandhu1 (haramritsingh.pec@gmail.com), H.S Gusain2, Manoj Kumar Arora3
1
PEC University of Technology, Civil Engineering Department, Chandigarh, India, 2Snow Avalanche and Study
Establishment, Chandigarh, India, 3PEC University of Technology, Chandigarh, India

The Bhagirathi river basin is an important basin of central Himalaya and is a source of the river Ganges, which
feed water to most of the northern Indian states. Here, glaciers of this basin are monitored using remote
sensing for more than a decade and status of the glaciers are presented. The area has been divided into six sub-
basins i.e. Bhagirathi, Bhilangna, Pilang, Jahnvi, Jalandhri and Kaldi. The glaciers were selected from all the sub-
basins with different area, altitude, orientation etc. to make representation of the basin. In the present study,
Landsat satellite images from the year 2000 to 2015 were used to monitor 20 glaciers. The snout elevation
varies approx. from 3800m m.s.l to 5200m m.s.l. ASTER GDEM V2 has been used for extraction of glacier terrain
features e.g. elevation, slope, area, orientation etc. It is observed that Bhagirathi sub-basin has maximum
glacierised area about 35% followed by Jalandhri, Jahnvi, Bhilangna, and Pilang with 13%, 9%, 4.5% and 3.2%
respectively. Kaldi is the only sub-basin having no glacier. it is also observed that 4 glaciers has more than 70%
area towards North, while 10 glaciers has area in the range of 50%-70% towards North, while 06 glaciers shows
having area less than 50% North. 17 glaciers have shown retreat, while 3 glaciers have shown advancement
during last 15 years. The recession has been observed from 62m to 913m, while three glaciers have shown
advancement of 3m to 239m.

1560
Thu_204_CR-4_164
An Overview of Deep Ice Core Drilling Project at Dome A in Recent Two Seasons

Zhengyi Hu1 (huzhengyi@pric.org.cn), Guitao Shi1, Yuansheng Li1

1
Polar Research Institute of China, Shanghai, China

Recently, the news that 2.7-million-year-old ice core drilled in Antarctic had been detected, which causes the
human attention. Although the ice age exceeds 1.9 million years than the previous record-holder, the record is
not continuous and difficult to explain climate change. Dome A is the place, where more than one million years
of continuous ice most likely to be found. Therefore the process of deep ice core drilling at Dome A received a
high degree of attention in many countries.
During the Antarctic field season of 2015/2016 and 2016/2017, 9 scientific research team members from 4
different organizations had been dispatched to Antarctic by Polar Research Institute of China (PRIC), to perform
“Deep Ice Core Drilling Project at Dome A”, near to which China's Antarctic Kunlun Station sits. After two
expedition seasons, a total of 117+93 drilling roundtrip was implemented, 6400+3600 liters drilling fluid was
injected, 18+12 drums ice chips was collected within 12 days. What's more, 353.3+145.86 meters ice core has
been extracted, 351.5+146.21 meters borehole has been penetrated by these nine drill crews with the deep ice
coring drill. So far the total depth of the bore hole has been drilled to 800.93 meters, which is the first time to
drill through shallow ice layer and this depth is also the deepest glacier drilling depth in China.

1561
Thu_205_CR-4_167
Subglacial Conditions of Antarctic Ice Sheet between Zhongshan Station to Dome A

Xueyuan Tang1 (tangxueyuan@pric.org.cn), Bo Sun1

1
Polar Research Institute of China, Shanghai, China

A radar dataset was collected by using a ground-based radar system, along a 1083 km traverse line from
Zhongshan station to DT401, in 2004/2005. The internal layering structure and subglacial conditions were
revealed along the radar profile. The continuous internal layers, disturbed layers and Echo Free Zones (EFZ)
along the profile were identified and classified, and its spatial distribution was presented. Basing on the recent
surface ice velocity, we found that the internal layers at depth 200-300 m in the upper ice sheet are continuous
and smooth, and nearlly parallel to the ice surface topography. The thick band of the continuous layers changes
little with increasing latitude. Below the depth of 300 m, the geometric structure of the internal layers and the
vertical width of the EFZ band were influenced by the surface ice velocity and the bed topography. The
relatively high disturbance, discontinuity of the layers and the larger width of the EFZ band correspond directly
to higher surface ice velocity and sharper bed topography. In particular, two areas are identified as that,
Zone 1: at km 60-70, there exists a concave zone with a 200 m depth of surface depression;
Zone 2: at km 650-950, the Lambert Glacier Rift at the Gamburtsev Mountains with faster ice flow, where the
radar system failed to obtain the echo signal from its bed, the revealed internal layers are disturbed or broken,
and the maximal vertical width of the EFZ band is likely more than 2000 m.

1562
Thu_206_CR-4_394
Ice Retreat History in Pine Island Bay, Revealed by Sedimentary Be-10 Records

Yusuke Suganuma1 (suganuma.yusuke@nipr.ac.jp), Gerhard Kuhn2, Claus-Dieter Hillenbrand3, Albert

Zondervan4
1
National Institute of Polar Research, Tachikawa, Japan, 2Alfred Wegener Institute, Bremerhaven, Germany,
3
British Antarctic Survey, Cambridge, United Kingdom, 4GNS Science, Lower Hutt, New Zealand

Reconstruction of the past dynamics of the Antarctic ice sheets by studying records from their margin is
essential to evaluate their stability and their contribution to future sea level rise. Recently, the first direct
evidence for a paleo-subglacial lake on the Antarctic continental shelf was reported from a sediment core from
a small bedrock basin in Pine Island Bay (PIB), West Antarctica. Here we report further evidence for this paleo-
subglacial lake based on down-core changes in Be-10 concentrations in the sediments. Very low Be-10
concentration in the lower part of the core indicate limited input of meteoric Be-10, suggesting deposition of
the corresponding sediments in isolation from the open ocean. The Be-10 concentration shows a drop within a
sand, silt and mud interval in the middle part of the core that was interpreted to result from deposition during
the transition from the subglacial lake to a sub-ice shelf cavern caused by grounding line retreat in PIB around
11 kyrs B.P.. The Be-10 concentration increases significantly toward the top of the core, indicating the
establishment of an open marine setting later during the Holocene. In addition, we report new Be-10 data from
marine sediment cores in other parts of PIB. Our results demonstrate that Be-10 concentration changes in
marine sediments from glaciated margins are a valuable recorder of ice sheet - ice shelf transitions.

1563
Thu_207_CR-4_547
Ice Shelf-ocean Interactions in High-resolution Global Simulations: Part I

Mark R. Petersen1 (mpetersen@lanl.gov), Stephen F. Price1, Xylar Asay-Davis1,2, Darin S. Comeau1, Jeremy G.
Fyke1, Matthew J. Hoffman1, Todd D. Ringler1, Adrian K. Turner1, Jon Wolfe1
1
Los Alamos National Laboratory, Los Alamos, United States, 2Potsdam Institute for Climate Impact Research,
Potsdam, Germany

The ability to include ocean cavities below ice shelves is a new feature of the U.S. Department of Energy's
Energy Exascale Earth System Model (E3SM). This capability is critical for projecting Antarctica's potential
future contributions to global sea level, which is one of E3SM's primary science drivers. In part I of this talk we
describe the model configuration and tuning, while part II describes analysis and comparison to observations.
E3SM is a coupled climate model with variable-resolution components, which allows global simulations to
include enhanced-resolution regions below ice shelves. The ocean, sea ice, and land ice components use the
Model for Prediction Across Scales (MPAS) framework for unstructured horizontal meshes based on Voronoi
Tessellations.
In order to gain confidence in our implementation of ice shelf cavities, we have performed a series of standard,
idealized test cases as well as comparisons of global simulations with and without ice shelf cavities. Validation
uses observed sub-marine melt rates and other relevant oceanographic features, and the identification and
minimization of coupled model biases. Here we present the results from a large number of global simulations
at modest resolution (30 to 60 km grid cells), most of which include static ice-shelf cavities. Based on these
simulations, we attain a tuned moderate resolution state that we use as a control configuration for a smaller
number of sensitivity experiments at higher resolution.

1564
Thu_208_CR-4_615
Structural Glaciology at Minna Bluff: Crevasses Gone Wild (or not)

Christina Hulbe1 (christina.hulbe@otago.ac.nz), Martin Forbes1

1
University of Otago / Te Whare Wananga o Otago, National School of Surveying / Te Kura Kairuri, Dunedin,
New Zealand

A complex crevasse field forms offshore of Minna Bluff, along the western coast of the Ross Ice Shelf. Tracking
the crevasses downstream is equivalent to tracking propagation history in time and thus provides a unique
opportunity to investigate the evolution of secondary features around a system that is analogous to strike-slip
faults in Earth's crust. A primary population of mode II (shear) fractures propagate into the shelf and arrest at
the edge of a relict flow boundary. A subset of these open into through-cutting rifts and continue to propagate
as mode I (opening) fractures until they also arrest at a relict flow boundary. We characterise relationships
between the primary rifts and associated secondary crevasses, and compare these to other strike-slip systems.
Secondary crevasses form on both the extensional and compressional sides of the primary rifts but unlike
elsewhere, the largest splays form in the compressional regime. Also unlike other settings, splay faulting
appears to be initiated mainly by a change in fracture toughness of the ice rather than misalignment of the
propagating tip with respect to far-field principal stresses. Correct understanding of these features will provide
important insight into the role of ice properties in mediating crevasse and rift formation.

1565
Thu_209_CR-4_632
Early Warnings of Further Disintegration of Pine Island Glacier's Ice Shelves

Stef Lhermitte1 (s.lhermitte@tudelft.nl), Christopher Shuman2, Bert Wouters3

1
Delft University of Technology, Department of Geoscience & Remote Sensing, Delft, Netherlands, 2UMBC Joint
Center for Earth Systems Technology, Greenbelt, United States, 3Utrecht University, Institute for Marine and
Atmospheric Research (IMAU), Utrecht, Netherlands

Pine lsland Glacier (PIG) is among the fastest changing outlet glaciers of West Antarctica, with strong changes in
acceleration, retreat, and thinning in recent decades. If these changes continue, PIG is expected to have an
even larger impact on accelerated future retreat and contribute to increasing mass losses from West
Antarctica. Therefore, understanding evolving PIG behavior is crucial for improved future sea level rise
estimations.
In this study we highlight some early warning signs of further weakening of PIG's floating ice tongue and
adjacent ice shelves by combining multi-source satellite data (optical, altimeter and SAR radar) and analysing
derived acceleration, retreat, and thinning time series.
The early warnings of further PIG disintegration include changes in calving patterns and rifting dynamics. For
example, over the last decade calving frequency has increased and the calved icebergs have disintegrated more
rapidly as a result of changes in the rifting patterns likely caused by warm waters in Pine Island Bay. The rifting
patterns have shifted from rifting in the shear zone near the northern ice shelf to internal rifting once this zone
retreated. Satellite imagery since 2016 shows that a new rift zone is developing in the southern shear zone
which may be related to changes in glacier velocity. This rifting may be part of a positive feedback loop which
could result in a further decoupling from the southern ice shelf and which may initiate further disintegration.

1566
Thu_210_CR-4_702
A New Grounding-line Proximal Sedimentary Record from Inner Pine Island Bay

Victoria Afanasyeva1,2 (afanasyeva.vk@gmail.com), Gerhard Kuhn3, Claus-Dieter Hillenbrand4, Johann Philipp

Klages3, Witold Szczuciński5, Thomas Frederichs6, German Leitchenkov1,2
1
VNII Okeangeologia, St. Petersburg, Russian Federation, 2St. Petersburg State University, St. Petersburg,
Russian Federation, 3Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven,
Germany, 4British Antarctic Survey, Cambrige, United Kingdom, 5Adam Mickiewicz University in Poznan, Poznan,
Poland, 6Bremen University, Bremen, Germany

Pine Island Glacier (PIG) is one of the fastest changing ice streams of the West Antarctic Ice Sheet. Its ice shelf
underwent major calving events throughout recent years. The main factor for the considerable mass loss of PIG
is sub-ice shelf melting caused by the advection of warm deep water into Pine Island Bay on the shelf of the
southeastern Amundsen Sea Embayment (ASE). Unique ice conditions during expedition PS104 with RV
“Polarstern” to the ASE in February-March 2017 allowed to recover a 7.59 m-gravity core in an area that had
been covered by the PIG ice shelf until 2015. The sediment core PS104_008-2 was taken at a water depth of
698 m near the eastern margin of the ice shelf. The new sedimentological data from the core will provide
insights into sub-ice shelf environmental conditions and the Holocene history of meltwater plume deposition
and oceanic ice-shelf melting. We will present results of our new multi-proxy study, including down-core
lithological changes, grain size distribution and excess 210Pb data. Occasional occurrence of calcareous benthic
foraminifera shells in the lower part of the core will allow the application of radiocarbon dating. Coupled with
the excess 210Pb data, the AMS 14C ages will provide constraints on sub-ice shelf sediment accumulation rates
and the discharge rates of subglacial meltwater plumes.

1567
Thu_211_CR-4_749
History of Larsen C Ice Shelf Reconstructed from Sub-ice-Shelf Sediments

James Smith1 (jaas@bas.ac.uk), Keith Nicholls1, Keith Makinson1, Claus-Dieter Hillenbrand1, Thomas
Frederichs2, Werner Ehrmann3, Paul Anker1, Cristina Subt4, Brad Rosenheim4, Eugene Domack4
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Bremen, Department of Geosciences,
Bremen, Germany, 3University of Leipzig, Institute for Geophysics and Geology, Leipzig, Germany, 4University of
South Florida, College of Marine Sciences, St. Petersburg, United States

The Larsen C Ice Shelf is the largest ice shelf on the Antarctic Peninsula. Radar and satellite data show that the
ice shelf has been thinning from above and below which has been driven by a combination of decreased
snowfall/warmer atmospheric temperatures together with basal melting/ice flow divergence, respectively.
Continued thinning and retreat of the ice shelf front could push the ice shelf beyond a critical threshold, leading
to rapid retreat and this subsequent discharge of continental ice. Ice shelves, however, can respond over a
range of times-scales from decades to millennia so it is critical to disentangle short-term variability from long-
term trends. Collapse of Larsen B Ice Shelf in 2002 for example, was at least partly related to ocean-driven
thinning over many thousands of years (Domack et al., 2005). This highlighted the need to understand the long-
term history of ice shelves. Here we present new insight into the Holocene (past 11,500 years) history of Larsen
C Ice Shelf based on the analyses of sediment cores recovered from beneath the ice shelf. This is combined
with new dating constraints on cores recovered from the continental shelf, seaward of the current calving
front, to reconstruct the timing of grounding line retreat and subsequent development of an ocean cavity. We
conclude by placing our findings in the context of modern ice shelf retreat.

1568
Thu_212_CR-4_860
Tidal Grounding Line Migration at the Darwin Glacier

Oliver J. Marsh1 (oliver.marsh@canterbury.ac.nz), Dana Floricioiu2, Christian T. Wild1

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand, 2German Aerospace Center (DLR),
Wessling, Germany

The Darwin Glacier is a small outlet glacier draining the East Antarctic Ice Sheet through the Transantarctic
Mountains. Its motion is affected by ocean tides yet largely shielded from climate-driven variability, allowing
observations of short-term grounding line (GL) behaviour without the added complexity of contemporary mass-
imbalance. We conducted a detailed study of the glacier grounding zone in the 16/17 field season, mapping
surface and internal flexure, GL migration, sub-daily velocity fluctuation and ice thickness. This high-resolution
data is used to re-interpret a sequence of twelve TerraSAR-X interferograms. Double-difference tidal flexure
fringes are heavily modified by migration of the GL across a two-kilometre ´ice-plain´ at the glacier´s upstream
margin, despite relatively steep basal topography.
The asymmetric vertical displacement is re-interpreted by separating the four-image interferograms using
flexural modelling with a migrating GL and homogeneous rheology. In the flexure zone, a neutral bending layer
is found in the upper third of the ice column suggesting stiffer or cooler ice near the surface. We show that GL
migration is proportional to the bed slope in the migration zone, but that it does not equal the rate expected
from a simple flotation criterion. This simultaneous analysis of multiple interferograms reveals new information
on GL and ice properties that can help predict future GL retreat associated with glacier thinning or sea level
rise.

1569
Thu_213_CR-4_865
Hot Water Drill Project at the Amery Ice Shelf, East Antarctica

Guitao Shi1 (gt_shi@163.com), Yuansheng Li1

1
Polar Research Institute of China, Shanghai, China

Mass loss of ice shelf is of great significance to a better understanding of the ice sheet dynamics and a more
precise prediction of global sea levels. However, the melting processes and ocean currents beneath the ice
shelf remain poorly understood. The hot water drill, a highly efficient drill technique, provides an opportunity
to investigate the physical and chemical processes beneath the ice shelf. With the financial support from the
Ministry of Science and Technology of China, a hot water drill system has been successfully developed. Drilling
test results show that the average drilling speed is >30 m h-1, and the diameter of the obtained borehole is >35
cm. The length of the main hose is 2200 m. In the following five years (2018-2023), the hot water drill will be
employed on Amery Ice Shelf to penetrate the ice at 9 sites with thickness varying from ~600m to 1800m (near
the grounding line). Through the borehole, seawater and sediment beneath the ice shelf will be sampled. The
ice core will be recovered from three layers of the ice shelf (i.e., the upper, middle and lower layers). In
addition, CTD and ADCP will be installed beneath the ice shelf. Besides, the automatic weather station, surface
mass balance observation system and the GPS will be set up near the drilling site. The data logging to a local
disk will be performed, and the disk will be replaced annually.

1570
Thu_214_CR-4_871
Sea Ice Loss and Ocean Swell as a Trigger for Antarctic Ice Shelf Disintegration

Rob Massom1 (r.massom@utas.edu.au), Ted Scambos2, Luke Bennetts3, Phillip Reid4, Vernon Squire5, Sharon
Stammerjohn6
1
Australian Antarctic Division and ACE CRC, Hobart, Australia, 2University of Colorado Boulder, National Snow
and Ice Data Center, Boulder, United States, 3University of Adelaide, School of Mathematical Sciences, Adelaide,
Australia, 4Australian Bureau of Meteorology, Hobart, Australia, 5University of Otago, Dunedin, New Zealand,
6
University of Colorado Boulder, INSTAAR, Boulder, United States

Understanding the causes of catastrophic disintegration of ice shelves on the Antarctic Peninsula over the past
few decades is crucial to: i) the improved representation of complex ice sheet-ocean-atmosphere interaction
processes in Earth system models; ii) determining the impact on sea level rise; and iii) assessing the
vulnerability of remaining shelves to environmental change. While progress has been made towards
understanding melt-related and glaciological processes that precondition and weaken ice shelves, the
mechanisms responsible for triggering their disintegration remain largely unknown. In this work, we combine
satellite observations, wave hindcast data from WAVEWATCH III and ice shelf-sea ice-wave modeling to show
possible linkages between regional decrease in sea ice coverage (both pack and fast ice), resultant enhanced
impingement of ocean swells, and the disintegration events of the Larsen A and B and Wilkins ice shelves since
1995. In so doing, we highlight the potential role of regional sea ice loss in both i) contributing to
preconditioning the shelves for collapse; and ii) determining the nature and timing of eventual disintegration of
shelves weakened by multiple factors. The new results underline the need to consider sea ice (change) as a
factor affecting ice-shelf stability, depending on the ice shelf.

1571
Thu_215_CR-4_877
Chinese Dome A Deep Ice Core Project: The Main Progress and Perspectives

Yuansheng Li1 (liyuansheng@pric.org.cn), Guitao Shi1, Chunlei An1, Zhengyi Hu1, Nan Zhang2, Xiaopeng Fan2,
Pavel Talalay2
1
Polar Research Institute of China, Shanghai, China, 2Polar Research Center, Jilin University, Changchun, China

Dome A deep ice core project was started in 2009-2010, when the main drill trench was constructed. In 2010-
2011 season, the drilling slot construction was finished, then a 121 m deep pilot hole was drilled in 2011-2012.
In 2012-2013 season, the deep ice core drill, i.e., the modified version of Japanese deep electromechanical drill,
was installed. After surface and borehole testing the drilling fluid (n-butyl acetate) was dumped into the hole,
and three runs were done from the depth of 112.3 m to 122.75 m with average core length of 3.66 m. During
the season 2014-2015, the deep ice core drilling was continued, reached the depth of 304 m. In the season of
2015-2016, 354 m ice core was obtained, with the borehole depth extended to 654 m. Then, another 146 m ice
core was recovered in 2016-2017, and the depth reached 801 m. The main scientific objectives of this project
were to extend available climate records from ice cores, to investigate the main mechanisms of climate change,
and to investigate the subglacial processes. In order to achieve the objectives, the deep ice core, with the
diameter of 95 mm, will be divided into 6 parts, for the measurements of physical properties, gas
concentrations and isotopes, major ions and nitrate isotopes, water isotopic compositions and biological
signature. In general, an international cooperation on analysis of the deep ice core is essential, and the groups
abroad are welcome to join and contribute to Dome A deep ice core project.

1572
Thu_216_CR-4_894
A Glimpse Beneath the Ekstroem Shelf: First Results from Wide Angle Seismic Data

Tanja Fromm1 (tanja.fromm@awi.de), Maximilian Merl1, Ursula Schlager1

1
Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

Drilling into marine sediments and their subsequent basement provides sound constraints on the geological
history of a region. Although marine sediments have been successfully cored globally, the most valuable
information about the paleo ice sheet evolution of East Antarctica is hidden in the inaccessible sub ice shelf
deposits in our research area. Drilling of the presumably Cretaceous-Cenozoic sediments and the underlying
basaltic basement is planned at the Ekstroem Ice Shelf. Thus, in the austral summer season 2016/17 an over-ice
seismic presite survey was conducted to gain information on the sediment and basement structures.
In this context, a precise depth estimate of the target horizons/basement is of critical importance for selecting
the best drill sites. To achieve this, we installed seismic recording stations along several seismic reflection lines
to record the refracted seismic energy at long offsets. In total, we setup 14 stations along 8 profiles. The
number of stations per profile varied between 1 and 5 with a spacing of 7 to 13 km. Each station was equipped
with a Reftek 130 recorder and 9 geophone chains consisting of six 4 Hz vertical components. The source was a
9-ton EnviroVibe vibrator with a maximum pressure of 57 kPa emitting a 10 s linear sweep within a frequency
range of 10 to 220 Hz. The shotpoint distance was 120m. Here we present technical details and challenges of
the experiment, the data processing and the first preliminary results.

1573
Thu_217_CR-4_899
Totten Glacier - Southern Ocean Interactions during the Late Quaternary

Liam Holder1 (lholder@grapevine.net.au), Brad Opdyke1, Yair Rosenthal2, Amy Leventer3, Meghan Duffy3, Rushi
Perera1, Philip O'Brien4, Leanne Armand1
1
The Australian National University, Research School of Earth Sciences, Canberra, Australia, 2Rutgers University,
Department of Marine and Coastal Sciences, New Brunswick, United States, 3Colgate University, Department of
Geology, Hamilton, United States, 4Macquarie University, Department of Environment and Geography, Sydney,
Australia

This research examines the interactions between the Totten Glacier and the Southern Ocean during the Late
Quaternary using a 350kyr sediment archive on the Sabrina Coast continental margin. Stable isotope and trace
metal analyses were conducted on planktonic foraminifera Neogloboquadrina pachyderma (s) to reconstruct
hydrographic changes in this region. Lithological and assemblage observations, sediment physical properties
and ice rafted debris mass accumulation rates were combined to develop a conceptual model of climate
induced depositional changes.
The Sabrina Coast record exhibits a muted oxygen isotope (d18O) signal across the MIS 5/6 transition where the
observed isotopic shift is ~20% of the expected 1.0 per mil shift from global ice volume. Mg/Ca ratios suggest
that Antarctic surface waters cooled by 2.4 ± 0.8°C between the Holocene and MIS 3, which indicates that
changes in d18Ocal are primarily influenced by d18Osw. Other Late Quaternary d18O records from the Antarctic
Margin appear to exhibit similar trends. We discuss possible mechanisms buffering the d18Osw ice volume signal
including changes in deep water upwelling and increased [CO32-] concentrations under permanent sea ice.
Peak ice rafted debris is associated with glacial stages and deglacial transitions. The last glacial period is
punctuated by a series of IRD spikes which could indicate millennial scale variability in the Totten.

1574
Thu_218_CR-4_1021
Ice Velocity Mapping in Antarctica, 1960s to 1980s, Based on Historical Images

Gang Qiao1 (qiaogang@tongji.edu.cn), Rongxing Li1, Yuan Cheng1, Wenkai Ye1, Xuwen Ma1, Song Guo1, Guanjie
Tang1, Zeyang Wang1, Tengfei Gao1, Yong Huang1, Xuewei Li1, Yixiang Tian1, Shijie Liu1, Xiaohua Tong1
1
Tongji University, College of Surveying and Geo-Informatics, Shanghai, China

Ice flow velocity is an important parameter for estimating mass changes in glaciers. Long-time observations on
the surface velocity are of great significance for assessing the relationship between Antarctic ice sheet and
global climate change. Existing research on Antarctica ice velocity based on modern satellite remote sensing
dated back to 1970s, the early film-based ARGON satellite photographs extended the timeline back to 1960s.
This research presents a rigorous geometric processing method for estimating Antarctica ice flow velocity fields
by using ARGON/Landsat satellite images. In view of various image configurations in Antarctica, two different
methods are developed and implemented. The first method proposes a novel parallax decomposition
technique that separates the effect of the terrain relief from the ice flow motion is proposed for the ARGON
stereo image pairs. The second method deals with images with longer time baselines and ortho-rectifies the
images and then calculate ice flow velocity based on the feature matching technique. The above methods for
estimating ice flow velocity are applied in mapping the major glaciers of East Antarctica (Totten, Amery,
Rayner, etc.) from 1960s-1980s for the first time. Comparison with recent Antarctic ice velocity products from
2000-2010 shows different change patterns in different glaciers. The initial results and a discussion of the
speed change and the associated cryosphere environment are introduced.

1575
Thu_219_CR-4_1031
Evaluation of Antarctic Ice Sheet Surface Mass Balance over the Last Millennium

Quentin Dalaiden1 (quentin.dalaiden@uclouvain.be), Hugues Goosse2, François Klein2, Jan Lenaerts3

1
Université catholique de Louvain / Earth and Life Institute, ELIC, Louvain-la-Neuve, Belgium, 2Université
catholique de Louvain / Earth and Life Institute, Louvain-la-Neuve, Belgium, 3University of Colorado Boulder,
Boulder, United States

Improving our knowledge of the variability of the Antarctic surface mass balance (SMB; i.e. the difference
between the incoming and outgoing mass at the surface of the ice sheet) is crucial to reduce the uncertainties
of past, present and future Antarctic contribution to sea level rise. Here, we present an evaluation of the SMB
simulated by those global climate models that have a last millennium simulation available. In the first phase,
we focus on the last four decades, for which we present a detailed comparison with in-situ observations,
atmospheric reanalysis, and regional atmospheric climate models. The goal is to estimate the ability of the
models to reproduce the spatial distribution of the SMB, its temporal (seasonal and inter-annual) variations
and the potential links with standard modes of large-scale climate variability such as Southern Annular Mode.
In a second step, we analyse the SMB over the last millennium as simulated by the GCMs following the PMIP3
(Paleoclimate Modelling Intercomparison Project Phase 3) protocol and compare it to ice core records
synthesised in the framework of the Antarctica2K working group. In this exercise, we focus particularity the
spatial structure, the main drivers of the SMB variability and the analysis of the natural climate variability role
in SMB changes.

1576
Thu_220_CR-4_1036
Using Damage Mechanics to Model Calving from Tidewater Outlet Glaciers

Rémy Mercenier1 (remy.mercenier@geo.uzh.ch), Martin P. Lüthi1, Christoph Rohner1, Andreas Vieli1

1
University of Zurich, Department of Geography, Zurich, Switzerland

Many ocean terminating glaciers in the Arctic are undergoing rapid retreat, thinning and strong acceleration in
flow. The calving process plays a crucial role for the dynamical mass losses and occurs when the stresses at the
calving front exceed the fracture strength of ice, leading to the detachment of blocks from the glacier front.
However, the understanding of the processes involved in calving as well as the capability of flow models to
represent this mechanism remain limited.
We use a transient 2d finite-element flow model coupled to a damage model to model break-off at the front of
tidewater glaciers. The flow model computes velocities and the resulting stresses, which are in turn used to
calculate the evolution of the glacier geometry and damage. The damage variable is defined by a change of
rheological properties with increasing material degradation. Elements are removed once damage reaches a
critical threshold. We use observations from glaciers in the Arctic to constrain the material properties. We
further assess the sensitivity of the glacier evolution to external forcings such as submarine frontal melting or
surface mass balance changes.
The coupled ice flow/damage model allows for reproduction of calving front geometries typically observed for
different tidewater glaciers in the Arctic. The proposed approach should be applicable to model calving on any
glacier, and thus be used to analyse the evolution of tidewater glacier variations from the past to the future.

1577
Thu_221_CR-4_1074
Glaciological Characteristics of Ice Rises at Nivlisen Ice Shelf East Antarctica

Katrin Lindbäck1 (katrin.lindback@npolar.no), Kenichi Matsuoka1, Geir Moholdt1, Bhanu Pratap2, Thamban
Meloth2
1
Norwegian Polar Institute, Tromsø, Norway, 2National Centre for Antarctic and Ocean Research (ESSO-NCAOR),
Goa, India

The coastal region of the East Antarctic Ice Sheet has numerous ice shelves and ice rises, consisting of locally
grounded ice that controls ice dynamics and mass balance of the region. An Indo-Norwegian joint project,
called MADICE, is investigating dynamics and evolution of the Nivlisen Ice Shelf and adjacent promontory-type
ice rises by means of geophysical field surveys, satellite remote sensing, ice-flow models and ice cores. We
have conducted two field seasons in 2016-17 and 2017-18. Two ice rises, Djupranen and Leningradkollen, have
dome shaped summits with elevations of 325 m and 170 m above sea level, respectively. Low-frequency radar
data show relatively flat subglacial beds below the summits, with subglacial elevations of 100 and 150 m below
sea level, respectively. Well-developed Raymond arches indicate that the summits have been stable the last
hundred years, except for one ridge where the arches have migrated landward (south) in the shallower ice.
Farther south from the ice domes towards the ice sheet, the subglacial topography drops 500 m at a 2 to 3 km
narrow through aligned in the east-west direction, comprising a distinct margin between smooth beds in the
north (seaward) and rougher subglacial terrains in the south (landward).

1578
Thu_222_CR-4_1078
Going against the Flow: Small-scale Pinning Points within the Ross Ice Shelf

Holly Still1 (holly.still@otago.ac.nz), Christina Hulbe1, Adam Campbell1

1
University of Otago, School of Surveying, Dunedin, New Zealand

The flow of the Ross Ice Shelf (RIS) is limited by regions of localised grounding termed pinning points. While
pinning points are common features within the RIS and are generally assumed to have a stabilising effect, the
mechanics of these features have not been studied in detail. This study focuses on a collection of small pinning
points (and overlying ice rumples) located downstream from the outlets of the MacAyeal and Bindschadler Ice
Streams within the eastern sector of the RIS.
Here we use high spatial resolution ice velocity derived from Landsat 8 imagery and thickness inferred from
satellite laser altimetry to investigate the momentum balance and mass flux in the region. Drag forces exerted
by the pinning points on the surrounding ice shelf are computed using a force budget approach and are
compared to the forces expected for a similar ice shelf with no pinning points. The pinning points have
contrasting effects on the surrounding flow field. Upstream, compressive stresses act to resist ice flow from the
MacAyeal Ice Stream, supporting thicker ice than would otherwise exist. As the ice flows over and around the
pinning points, its speed decreases and mass flux declines, creating a wake of thinner ice downstream. At the
ice rumple boundaries, lateral shearing creates bands of heavily crevassed ice that advect downstream, further
modifying the flow field. This analysis improves understanding of how small-scale pinning points regulate the
flow of the RIS.

1579
Thu_223_CR-4_1248
Current Status and past Evolution of Blåskimen Island, Dronning Maud Land

Vikram Goel1,2 (vikram.goel@outlook.com), Joel Brown1,3, Carlos Martin4, Kenichi Matsuoka1

1
Norwegian Polar Institute, Tromsø, Norway, 2National Center for Antarctic and Ocean Research, Goa, India,
3
Aesir Consulting LLC, Missoula, United States, 4British Antarctic Survey, Cambridge, United Kingdom

The ice-shelf-fringed coast of Dronning Maud Land in East Antarctica contains numerous ice rises that influence
the dynamics and mass balance of the region. However, only a few of these ice rises have been investigated in
detail. We present glaciological settings and late Holocene evolution of Blåskimen Island, an isle-type ice rise
adjacent to Fimbul Ice Shelf. This ice rise is largely dome-shaped, with a pronounced ridge extending to the
southwest from its summit (410 m a.s.l.). Its bed is mostly flat and about 100 m below the current sea level.
Shallow radar-detected isochrones dated with a firn core reveal that the surface mass balance is higher on the
southeastern (upwind) slope than the northwestern (downwind) slope by ∼37%, and this pattern has persisted
for at least the past decade. The mass balance estimated using the Input-Output method show that this ice rise
has thickened by 0.12-0.37 m ice equivalent per year over the past decade. To investigate longer-term
evolution, we applied a thermo-mechanically-coupled Elmer/ICE model to a profile going across the summit
and along flowlines on either side. Constraining the model results with present-day flow speeds and englacial
stratigraphy, it is likely that the ice rise is thickening with a rate of 0.4 m i.e. per year for at least a century. Also,
we found a larger-than-present north-south imbalance in the surface mass balance sustained over several
centuries in the past.

1580
Thu_224_CR-4_1275
Predicting the Oldest Ice Optical Signal using a Marine Dust Record

Jessica Ng1 (jyn002@ucsd.edu), Jeffrey Severinghaus1, Ryan Bay2

1
University of California, Scripps Institution of Oceanography, San Diego, United States, 2University of California,
Physics, Berkeley, United States

The marine sediment record shows that glacial-interglacial cycles transitioned from regular ~41,000 year cycles
to irregular ~100,000 year cycles approximately 1 million years ago, an event known as the Mid-Pleistocene
Transition. However, the ice core record only extends 800,000 years into the past, severely limiting our
understanding of this major change in the climate system and thus of fundamental climate forcings and
feedbacks. A primary goal of the International Partnership in Ice Core Sciences is therefore to retrieve a 1.5
million year old continuous ice core, yet complex glacial processes, limited bedrock data, and surprisingly
young basal ice in previous cores necessitate careful reconnaissance studies before extracting a full core.
Ice borehole optical logging reflects ice dust content and may be used to date ice quickly and inexpensively.
Here I develop a transfer function between the 800,000 year optical dust log of the EPICA Dome C ice core and
a 4 million year marine dust flux record from a sediment core in the subantarctic zone of the South Atlantic,
which lies along the path of dust sources to Antarctic ice. I then use the transfer function to predict the optical
signal in 0.8-1.5 million year old ice from the marine dust record. In future field seasons, I will extract the
optical log at potential old ice sites using the newly developed Rapid Access Ice Drill (RAID) and apply the
transfer function to evaluate these sites for 1.5 million year old ice.

1581
Thu_225_CR-4_1400
A Minimal Model of Tidewater Glacier Evolution

Martin Luethi1 (martin.luethi@geo.uzh.ch), Andreas Vieli1, Remy Mercenier1

1
University of Zurich, Dpt. of Geography, Zürich, Switzerland

The iceberg calving process influences the geometry of a tidewater glacier, and is in turn controlled by the
terminus geometry through the stress field which controls damage and fracture of the ice. We analyze the
feedbacks in this intricately coupled process with an explicitly formulated model, consisting of evolution
equations for three state variables representing glacier geometry. The simplicity of the model allows for formal
investigation of stability of glacier states on different basal geometries during advance and retreat. This model,
complemented with a simple parametrization of glacier calving rates, can also be used to understand tidewater
glacier change rates. Model runs on realistic bathymetries yield evolution histories which compare favorably
with recorded tidewater glacier histories.

1582
Thu_226_CR-4_1458
Correlation of Recent Calving Front Retreat at Pine Island Glacier to Bathymetry

Jan Erik Arndt1 (jan.erik.arndt@awi.de), Robert D. Larter2, Peter Friedl3, Karsten Gohl1, Kathrin Höppner3
1
Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, 2British Antarctic Survey,
Cambridge, United Kingdom, 3Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany

Pine Island Glacier (PIG) currently experiences the largest negative mass balance in comparison to other outlet
glaciers in Antarctica and hence is the largest contributor to modern sea-level rise. Due to the glacier's
topographic setting, a bed that deepens beyond the grounding line to the deep interior basin of the West
Antarctic Ice Sheet (WAIS), it has been suggested that this increased ice loss may be a precursor of WAIS
collapse. Despite the increased mass loss, however, the calving front of PIG remained more or less stable since
the earliest observations in the mid-20th century. Large icebergs where calved at intervals of a few years but
subsequently the calving front re-advanced close to or even beyond its former position. This pattern changed in
2015 when a calving event resulted in a reoriented (45°-25° clockwise compared to previous calving lines) and
most retreated calving line position ever observed. This new calving geometry was confirmed by a calving
event in September 2017. In February 2017 we were able to access the formerly ice-shelf covered area during
RV Polarstern expedition PS104. Bathymetric data from this area revealed a bathymetric ridge that has acted as
a pinning point of PIG in the past. We use these bathymetric data in combination with satellite data from the
last decades to investigate the correlation of bathymetric features to the calving dynamics of Pine Island
Glacier.

1583
Thu_228_CR-4_1597
Present ENSO Modulation of Summer Surface Melting of Amundsen Sea Ice Shelves

Pranab Deb1, Andrew Orr1, David Bromwich2 (bromwich@polarmet1.mps.ohio-state.edu), Julien Nicolas2

1
British Antarctic Survey, Cambridge, United Kingdom, 2Ohio State University, Byrd Polar and Climate Research
Center, Columbus, United States

Enhanced surface melting over Antarctic ice shelves is known as an important precursor of ice-shelf break-up.
Although the marked ice-shelf thinning along the Amundsen Sea (AS) coast observed in recent years has been
mainly attributed to ocean-related sub-ice shelf melting, future climate model projections point toward
increased summer surface melting in this area in the coming decades. A better understanding of atmospheric
conditions promoting ice-shelf surface melting in the present-day climate can provide insight into the future of
West Antarctic ice shelves. Here, we present the results of a 15-km resolution simulation of West Antarctic
summer climate spanning 1979-2015 carried out with the polar-optimized version of the Weather Research
and Forecasting model (Polar WRF) and complemented with melt data derived from satellite passive
microwave observations. Consistent with previous studies, we find that a westward shift of the Amundsen Sea
Low (toward the Ross Sea) favors warmer conditions and enhanced melting along the AS coast. The impact of
the El Niño-Southern Oscillation (ENSO) is significant only when focusing on strong ENSO events, with surface
melting being significantly enhanced during strong El Niños compared to strong La Niñas. In this context, the
increase in the frequency and intensity of El Niño events projected for the twenty-first century could expose
the AS coast to enhanced surface melting and thus to an enhanced risk of ice-shelf disintegration.

1584
Thu_229_CR-4_1649
Bathymetry and Bed Conditions of Subglacial Lake CECs, West Antarctica

Alex Brisbourne1 (aleisb@bas.ac.uk), Andrew Smith1, Andres Rivera2, Rodrigo Zamora2, Felipe Napolioni2
1
British Antarctic Survey, Cambridge, United Kingdom, 2Centro de Estudios Científicos, Valdivia, Chile

Under favourable conditions, the sediments within Antarctic subglacial lakes provide unique records of ice
sheet history and microbial life. Subglacial Lake CECs, in West Antarctica, has the potential to host such an
environment. However, key to record preservation are the lake volume and depositional environment. The lake
lies beneath 2650 m of ice in a topographically-steep subglacial region to the west of the Ellsworth Mountains.
The lateral extent of the lake has been delimited by surface radar measurements. However, no constraints
have been placed on the bathymetry or bed conditions within the lake. In December 2016, a series of seismic
reflection profiles was acquired across the lake to determine the water column thickness and bed properties.
Profiles indicate a maximum water column thickness of 300 m at the widest part of the lake. The relative
reflection strength from the ice-base and lake-bed have been used to investigate the bed material. The lake-
bed is likely formed of fine-grained silts or clays, consistent with a low-energy sedimentary environment. The
volume of water and low-energy depositional environment indicate that Lake CECs is a suitable candidate for
deep exploration.

1585
Thu_230_CR-4_1673
Recent Research Advances on Subglacial Lake CECs in West Antarctica

Andres Rivera1,2 (arivera@cecs.cl), Rodrigo Zamora1, Jose Andres Uribe1, Andy Smith3, Margit Schwikowski4,
Pablo Paredes1, Jonathan Oberreuter1, Felipe Napoleoni1, Jorge Hernandez1, Alex Brisbourne3, Francisca Bown1
1
Centro de Estudios Científicos, Glaciology, Valdivia, Chile, 2Universidad de Chile, Geography, Santiago, Chile,
3
British Antarctic Survey, Cambridge, United Kingdom, 4Paul Scherrer Institute, Villigen, Switzerland

Subglacial Lake CECs (79º15´S / 87º34´W) is a near 20 km2 fresh water body located underneath 2650 m of ice
in West Antarctica. Recently collected seismic, radar and GPS data have allowed a more detailed delineation of
the lake and the surrounding subglacial topography, including the pathways of water flow potentially coming in
and out the lake. The repeat survey of 30 metal poles deployed in 2014 indicates a mean ice surface velocity of
83 cm per year and a surface snow accumulation of 23 cm water equivalent per year. This surface snow
accumulation value is very close to the mean accumulation between 1986 and 2014 obtained by glaciochemical
and stable isotope analyses of 2 shallow firn cores retrieved from the area. An automatic weather station
(AWS) installed on the ice sheet surface at 2057 meters above sea level, close to the centre of the lake, has
discontinuously recorded data since 2014. Thanks to power improvements carried out in December 2016, the
station was able to measure and transmit data in real time during the entire Antarctic winter when an absolute
minimum air temperature of -59ºC was reached. Data collected at a permanent GPS station installed next to
the AWS showed vertical movement commensurate with the surface mass balance, without any indication of
elevation changes resulting from possible water volume changes within the lake. All these new insights confirm
the advantages of this subglacial lake as a target for a deep exploration program.

1586
Thu_231_CR-4_1680
Melt Characteristics of Antarctic Ice Shelves

Stan Jakobs1 (c.l.jakobs@uu.nl), Carleen Reijmer1, Michiel R. van den Broeke1, Gert König-Langlo2
1
Institute for Marine and Atmospheric research Utrecht (IMAU), Utrecht, Netherlands, 2Alfred-Wegener-
Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany

The piling up of surface meltwater on ice shelves can lead to hydrofracturing, a process that severely damages
the structural integrity of an ice shelf and could possibly lead to its collapse. Thorough analysis of the Surface
Energy Balance and its individual components can provide insight in their separate contributions to surface
melt.
In this presentation, we will present the results from running an Energy Balance model forced by 25 years of
meteorological observations from Neumayer Station, located on the Ekström ice shelf in Dronning Maud Land,
Antarctica. The model calculates the turbulent fluxes for sensible and latent heat, as well as subsurface
processes such as meltwater percolation and densification of snow and firn. The melt season at Neumayer is
limited to December and January in most years, with melt occurring on approximately 20 days on average. We
will also comment on limitations due to measurement and modelling uncertainties.
In addition, we have forced the model by meteorological data from two additional automatic weather stations
on Antarctic ice shelves (one on the Riiser-Larsen ice shelf and one on the King Baudouin ice shelf) in order to
assess the spatial variability of the melt season. Furthermore, these results could be used to evaluate the ability
of regional climate models to calculate the Surface Energy Balance.

1587
Thu_232_CR-4_1698
Challenge in Determining the Impact of Warming Limited to 1.5/2°C for Antarctica

Christian Rodehacke1,2 (christian.rodehacke@awi.de), Tido Semmler1, Madlene Pfeiffer1, Özgür Gurses1,

Thomas Kleiner1
1
Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, 2Danish Meteorological
Institute, Copenhagen, Denmark

To assess the impact of various future climate scenarios (1.5°C, 2°C, RCP4.5, RCP8.5) on the Antarctic ice sheet
and its contribution to the global sea level, we exploit a large ensemble of ice sheet simulations. It covers the
period from 1850 to 5000 to determine short-term and long-term implications of different future climate
paths. To sample the uncertainty range, we use atmospheric and oceanic output of 3 CMIP5 models, two initial
ice sheet states, and different ways in applying the climate forcing. Two major challenges are detected: First,
the oceanic and atmospheric conditions of global climate models are too warm for pre-industrial and present-
day climates. Hence the forcing cannot be applied directly, while our simulations driven by the widely
established method of anomaly forcing are generally more realistic. Second, we detect a very large uncertainty
of near future projections up to 2100 and more so for the far future projections. This uncertainty makes
conclusions on the impact of global climate warming limitation difficult to impossible. Some ensemble
members lose the West Antarctic Ice Sheet or even parts in the east, while others do not. Ultimately,
realizations with instabilities project sea level rises significantly larger than CMIP5 estimates. On the other
hand, some of the realizations even show a negative sea level contribution due to mass accumulation in the
interior of the Antarctic.

1588
Thu_233_CR-4_1870
The Paraglacial Response in the Ice-free Terrains of the Antarctic Peninsula

Jesús Ruiz-Fernández1 (ruizjesus@uniovi.es), Marc Oliva2, Nicoletta Cannone3, Cristina García-Hernández1,

Mauro Guglielmin4, Filip Hrbáček5, Daniel Nývlt5, Matěj Roman5, Susana Fernández6, Jerónimo López-Martínez7
1
University of Oviedo, Department of Geography, Oviedo, Spain, 2University of Barcelona, Department of
Geography, Barcelona, Spain, 3Università degli Studi dell'Insubria, Department of Science and High Technology,
Varese, Italy, 4Università degli Studi dell'Insubria, Department of Theoretical and Applied Sciences, Varese, Italy,
5
Masaryk University, Department of Geography, Brno, Czech Republic, 6University of Oviedo, Department of
Geology, Oviedo, Spain, 7Universidad Autónoma de Madrid, Department of Geology and Geochemistry, Madrid,
Spain

The Antarctic Peninsula (AP) is the warmest region of the Antarctic continent. This work studies the paraglacial
response in this region. Past glacial retreat since the LGM has reshaped the configuration of the AP, favouring
the emergence of new lands and the exposure of formerly glaciated environments. The shrinking and spatial
retreat of the glaciers has favoured glacio-isostatic uplift, which has redefined the coastlines, with the
development of new islands, peninsulas, etc. These changes occurred during the paraglacial stage promoting
changes in the distribution of wildlife and flora, mainly distributed along the coastal fringes. Glacial retreat has
also conditioned environmental dynamics, which has been more or less intense according to topography,
geomorphological setting and permafrost existence/absence. The pronounced warming trend recorded during
the second half of the 20th century has accelerated some of these processes. The abundance and variety of
records (glacial, periglacial, permafrost, alluvial, coastal) as well as observations on ecological processes, has
shown evidence of the rapid paraglacial readjustment of AP environments in the transition from glacial to ice-
free conditions. High uplift rates have continued to reshape coastlines, permafrost degradation in newly
exposed areas is accelerating mass wasting, sediment redistribution and changing hydrological processes, and
wildlife and flora are rapidly fitting within the new environmental setting.

1589
Thu_235_CR-4_2005
Pre-site Study for Deep Geological Drilling below Ekström Ice Shelf, Sub-EIS-Obs

Gerhard Kuhn1 (gerhard.kuhn@awi.de), Olaf Eisen1, Christoph Gaedicke2, Nikola Koglin2, Andreas Läufer2,
German Leitchenkov3, Emma Smith1, Ralf Tiedamann1, Frank Wilhelms1
1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Geosciences, Bremerhaven,
Germany, 2BGR - Bundesanstalt fur Geowissenschaften und Rohstoffe, Polar Geology, Hannover, Germany,
3
Institute for Geology and Mineral Resources of the World Ocean (VNIIOkeangeologia), St. Petersburg, Russian
Federation

During the last seasons and ongoing, pre-site seismic surveys have taken place in the Ekströmisen region of
Dronning Maud Land, with the primary of building a stratigraphic age framework of the under-ice-shelf
sediments. These sediments are overlying the Explora Wedge, a syn- or post-rift volcanic deposit. Expected
ages range from Late Mesozoic to Quaternary. From new vibroseismic profiles we will select sites for short core
seafloor sampling through Hot Water Drill (HWD) holes of the oldest and of the youngest sediment sequences
to confine their age time span. There is further potential for drilling deeper sediment cores with the support of
international partner. Deep drilling should recover the sediments overlying the Explora Escarpment, in order to
discover the nature of the Explora Wedge. We expect the overlying sediment sequences to reveal the history of
polar amplification and climate changes in this part of Antarctica, the build-up of the East Antarctic Ice Sheet
during past warmer climates, and its Cenozoic and future variability.
Having HWD holes through the shelf ice and sampling the sea floor will provide the unique opportunity for
further piggy back experiments consisting of multi-disciplinary nature. Experiments and measuring setup for
oceanography, sea and ice shelf physics, geophysics, geology, hydrography, biogeochemistry could be planned
to characterize the ocean-ice-sediment interactions, processes and ecosystem observations.

1590
Thu_236_CR-4_2150
Seasonal Control on Totten Ice Shelf Dynamics by Sea Ice Buttressing

Chad A. Greene1 (chad@chadagreene.com), Duncan A. Young1, David E. Gwyther2, Benjamin K. Galton-Fenzi3,4,

Jamin S. Greenbaum1, Donald D. Blankenship1
1
University of Texas Institute for Geophysics, Austin, United States, 2Institute for Marine and Antarctic Studies,
University of Tasmania, Hobart, Australia, 3Australian Antarctic Division, Hobart, Australia, 4Antarctic Climate &
Ecosystems Cooperative Research Centre, Hobart, Australia

Previous studies of Totten Ice Shelf have relied upon surface velocity measurements to investigate its mass
balance and sensitivities to interannual climate forcing. However, short-term displacement measurements
cannot be used to characterize long-term flow rates where ice velocity fluctuates with the seasons. Quantifying
annual mass budgets or analyzing interannual changes in ice velocity requires knowing when, whether, and
where observations of glacier velocity may be aliased by short-term variability. Here, we analyze 16 years of
velocity data for Totten Ice Shelf, which we generate at sub-annual resolution by applying feature tracking
algorithms to several hundred MODIS satellite image pairs. We find the ice shelf is characterized by a seasonal
cycle of spring to autumn speedup of more than 100 m/yr close to the ice front. The amplitude of the seasonal
cycle diminishes with distance from the open ocean, suggesting the presence of a resistive backstress at the ice
front that reaches a maximum in winter. Springtime acceleration precedes summer surface melt and is not
attributable to thinning from basal melt. We find that the ice shelf accelerates each spring in response to lost
buttressing from the breakup of seasonal landfast sea ice.

1591
Thu_237_CR-4_2200
Antarctic Ice Sheet Volume Sensitivity to Boundary and Initial Conditions

Liz C Logan1 (liz.curry.logan@gmail.com), Sri Hari Krishna Narayanan2, Ralf Greve3, Patrick Heimbach1
1
University of Texas at Austin, Institute for Computational Engineering and Sciences, Austin, United States,
2
Argonne National Laboratory, Argonne, United States, 3Hokkaido University, Institute for Low Temperature
Science, Sapporo, Japan

Ice sheet model outputs require inputs from uncertain initial and boundary conditions, and other parameters.
We show how one particular ice sheet model, SICOPOLIS (SImulation COde for POLythermal Ice Sheets),
depends on these inputs through comprehensive adjoint-based sensitivity analyses. SICOPOLIS discretizes the
shallow-ice and shallow-shelf approximations for ice flow, and is well-suited for paleo studies of Antarctica. The
adjoint model of SICOPOLIS was developed via algorithmic differentiation, facilitated by the source
transformation tool OpenAD. While model sensitivity to various inputs can be computed by costly methods
involving input perturbation simulations, the time-dependent adjoint model of SICOPOLIS delivers model
sensitivities to initial and boundary conditions throughout time at lower cost.
Here, we explore the sensitivity of the Antarctic Ice Sheet's entire and regional volumes to: initial ice thickness,
precipitation, basal sliding, and geothermal flux over the Holocene epoch. The West Antarctic Ice Sheet (WAIS),
in particular, is well known to be sensitive to changes in basal melting, and we use the SICOPOLIS adjoint model
to make quantifiable the WAIS' sensitivity to these controls. Sensitivity studies such as described here are now
accessible to the modeling community, based on the latest version of SICOPOLIS that has been adapted for
OpenAD to generate correct and efficient adjoint code.

1592
Thu_238_CR-4_2213
Bedrock Roughness in Antarctica: Connections to Subglacial Water and Basal Slip

Duncan A. Young1 (duncan@ig.utexas.edu), Jamin S. Greenbaum1, Lucas H. Beem1, Donald D Blankenship1, Gail
R. Muldoon1,2, Scott D Kempf1, Jason L. Roberts3,4, Catherine Ritz5, Martin J Siegert6, Tas van Ommen3,4
1
University of Texas at Austin, University of Texas Institute for Geophysics, Austin, United States, 2University of
Texas at Austin, Department of Geological Sciences, Austin, United States, 3Australian Antarctic Division,
Kingston, Australia, 4ACE CRC, Hobart, Australia, 5Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, Grenoble,
France, 6Imperial College London, Grantham Institute - Climate Change and Environment, London, United
Kingdom

Over the last twenty five years, extensive ice penetrating radar (IPR) coverage of Antarctica has been obtained,
at lines spacings down to 1 km in some cases. However, many glacial processes occur at finer scales, so infering
likely landscape parameters is required for a useful interpolation between lines.
Here we present a compilation of IPR-derived profile roughness data covering three great basins of Antarctica:
the Byrd Subglacial Basin in West Antarctica, and the Wilkes Subglacial Basin and Aurora Subglacial Basins in
East Antarctica; and treat these data using root mean squared deviation (RMSD). Coverage is provied by a
range of IPR systems with varying vintages with differing instrument and processing parameters; we present
approaches to account for the differences between these systems. We use RMSD to investigate the self-affine
behaviour of the bed at kilometer scales and extract fractal parameters from the data to predict roughness and
uncertainties in ice thickness measurement, and compare to simulations from subaerial topography.
We further compare these data to inferences of subglacial hydrology from specularity content, lithology from
airborne gravity, and inferences from basal slip and find a good match between a distinct quantifiable
roughness parameter and subglacial "canal" systems, low density anomalies, and regions of high basal slip. This
map can be used a a tool in modeling ice sheets.

1593
Thu_239_CR-4_2216
Modeling Ice Shelf Weakening with Damage Mechanics and the Material Point Method

Alex Huth1 (ahuth@uw.edu), Benjamin Smith1

1
University of Washington, Seattle, United States

Thinning and fracture of Antarctic ice shelves reduces their ability to restrain discharge of grounded ice into the
ocean. Implementing these weakening processes in models of ice sheet-ice shelf systems could improve
projections of ice sheet evolution and sea level rise. However, current models at this scale cannot accurately
represent fracture-induced weakening despite attempts with damage mechanics. These damage models fail
because they often lack a strong physical basis and they encounter numerical diffusion when damage is
advected with the ice flow. Here, we overcome these issues by developing a modeling framework that
incorporates a thermodynamically consistent and anisotropic damage model and is based on an implicit
material point method (MPM) to ensure error-free advection of damage. In MPM, a set of Lagrangian particles
discretize the ice domain, carry all variables, and advect with the flow. Similar to the finite element method,
model equations are solved on an Eulerian grid, but the particles serve as moving integration points. We test
our methods with a shallow shelf model of the Larsen C ice sheet-ice shelf system. We initialize the model using
high resolution Cryosat-2 data for ice geometry and by conducting a dual inversion for the basal friction and
damage parameters that minimize mismatch between modeled and Landsat-derived velocities. We simulate
potential triggers of ice shelf collapse and discuss the resultant implications for stability of the ice shelf.

1594
Thu_240_CR-4_2378
Water on the Antarctic Ice Sheet: Quantifying Surface Melt via Radar Satellites

Luke Trusel1 (trusel@rowan.edu), Allen Pope2, Mahsa Moussavi2, Sarah Das3, Laura Stevens3
1
Rowan University, Glassboro, United States, 2National Snow and Ice Data Center (NSIDC), Boulder, United
States, 3Woods Hole Oceanographic Institution (WHOI), Woods Hole, United States

Surface melting is an important precursor for Antarctic ice shelf collapse owing to its ability deplete firn air
content and generate complex surface hydrological features including meltwater lakes. Recent ice sheet-
climate modeling suggests intensified surface melting may initiate rapid change in the ice sheet system over
this century. Accurate prediction of future melt evolution, and thus sea-level rise estimates, requires a robust
observational baseline for melt owing to important nonlinearities in the melt response to a warming
atmosphere. Here, we present new investigations of Antarctic ice sheet surface melt using satellite radar
remote sensing and field observations. We focus on extending a legacy 10-year melt intensity record from the
QuikSCAT satellite with more recent scatterometer missions. Next, we assess the capabilities of high spatial
resolution satellite synthetic aperture radars in recording variability in ice shelf surface melt. Satellite data are
evaluated against in-situ estimates of meltwater production derived from observations of the surface energy
balance. We further evaluate satellite observations against field observations of refrozen melt stratigraphy
resulting from a widespread 2016 West Antarctic melt event. Our resulting observations provide important
insights into the coupling between the atmosphere, meltwater production, firn conditions, and ice sheet
surface hydrology, all processes critical to quantify for improved sea-level projections.

1595
Thu_241_CR-4_2410
Morphology and Mass Balance of Land-terminating Ice Cliffs in North Greenland

Rainer Prinz1,2 (rainer.prinz@uni-graz.at), Jakob Steiner3, Jakob Abermann4

1
University of Graz, Graz, Austria, 2Austrian Polar Research Institute, Vienna, Austria, 3University of Utrecht,
Utrecht, Netherlands, 4Asiaq Greenland Survey, Nuuk, Greenland

Wide parts of the ice sheet in North Greenland terminate as cliffs on land. However, the characteristics of this
feature and its response to a changing climate have so far received little attention. While land-terminating ice
cliffs are studied in other regions, detailed investigations in Greenland were carried out only more than six
decades ago in the Thule area (Red Rock, Northwest Greenland). These studies showed a continuous advance at
one location over multiple years, despite the local mass balance was reported negative.
The purpose of our study is twofold. First, we extend the morphological analysis to the complete Northern ice
margin employing high resolution digital terrain models (Arctic DEM). We focus on main characteristics of the
land-terminating ice margin in Northern Greenland, its slope and aspect distribution and comparison to spatial
datasets of flow velocity and mass balance. Results show that the advance at Red Rock is long-term, continuing
unabated today at rates of up to several meters per year. Similar magnitudes were found for large other
stretches along the ice margin. Second, we investigate processes and drivers of the ice cliff evolution. With data
from our recent field experiment we show that under the same atmospheric forcing the mass balance response
of the cliff front is different to the horizontal glacier surface above the cliff. Hence, the cliff morphology
determines different energy balance regimes with specific sensitivities to climate.

1596
Thu_242_CR-4_2530
The Imitation Game: Reconstructing the Greenland Ice Sheet (GrIS)

Michael Cullum1 (michael.cullum@northumbria.ac.uk), Leanne Wake1, John Woodward1

1
Northumbria University, Geography, Newcastle-upon-Tyne, United Kingdom

Model parameters control the sensitivity of ice sheets to external forcings, and introduce uncertainty to model
output due to poor understanding of their optimum, or true values. The complexity of model physics means
few studies have explored parameter interactions. This study aims to
(1) Quantify the influence of model parameters, and their interactions on GrIS evolution, and
(2) Determine parameter ranges that reproduce a GrIS target state assumed to represent the its extent at the
Medieval Warm Period (MWP) onset.
A parameter sensitivity analysis, using principal component data reduction and Bayesian approaches is
performed using the Parallel Ice Sheet Model (PISM). For a suite of parameter settings, the GrIS is spun up from
125 to 1ka using grid sequencing to gradually increase spatial resolution from 40 to 5km. Modelled output at
1ka is compared with target model E-W ice thickness transects across the GrIS to
(1) quantify sensitivity of ice sheet profile to parameter set-up and
(2) to identify parameter values that best allow the GrIS to evolve into an assumed MWP extent.
(3) Produce a posterior probability distribution of each influential parameter
(4) Determine if posterior probability distributions of parameters are spatially variable
Identifying influential parameters and a probability distribution of their values allows for the development of a
parameter scheme that closely reproduces target ice sheet extents and simultaneously quantifies their
interactions.

1597
Thu_244_CR-4_88
Morphodynamical Changes and Predictions of Amery Ice Shelf, Eastern Antarctica

Avinash Kumar1 (avinash@ncaor.gov.in), Babula Jena1, Rahul Mohan1, M Ravichandran1

1
ESSO - National Centre for Antarctic & Ocean Research, Ministry of Earth Science (Govt. of India), Vasco, India

The Amery ice shelf (AIS) plays a critical role in Earth's climate system and its morphology is controlled by the
physical forcing and global human interventions. The coastline changes of AIS are investigated for about 460
km into three different sectors and each-sector into a number of transects at uniform intervals between 2001
and 2016 using multi-dated MODIS satellite images. Further, past coastline positions were constructed and
future positions are estimated for 5- and 10- years. The rate of change in AIS coastline positions were
estimated using the statistical methods—end point rate, average of rates and linear regression—and cross-
validated with correlation coefficient and root-mean-square error (RMSE) methods. About 51% of transects
exhibit ±200 m RMSE values, indicating better agreement between the estimated and satellite-based ice-shelf
positions, and the transects closer to the sectors boundaries exhibit 47% uncertainties in coastline change rate
estimations. Based on correlation coefficient and RMSE, the influence of physical/natural processes and global
anthropogenic activities on coastline changes has been calculated. The AIS ice sheet are gaining mass (5.4 ± 3.1
Gt/yr) due to increased accumulation of snow in this region. Significant morphological changes in AIS have
been recorded at every 5-years and attempted to link with the ice mass change and climate indices, such as El-
Niño Southern Oscillation (ENSO) and Southern Annular Mode (SAM) at different sectors.

1598
Thu_245_CR-5_115
Absolute Gravimetric Studies of GIA in Antarctica and in Fennoscandia

Jyri Näränen1 (jyri.naranen@nls.fi), Jaakko Mäkinen1, Mirjam Bilker-Koivula1, Hannu Koivula1, Hannu
Ruotsalainen1
1
Finnish Geospatial Research Institute, Masala, Finland

Finnish Geospatial Research Institute (FGI) has a long history in studying the Fennoscandian glacial isostatic
adjustment (GIA) in Finland through modelling and different kinds of measurements. Absolute gravimetry (AG)
has been done in Finland since 1980´s, first through international collaboration and then with our own
gravimeters. FGI has also participated in seven Finnish Antarctic Research Program expeditions since 1989. The
main research theme has been the study of the Antarctic glacial isostatic adjustment utilizing AG and constant
GPS measurements. Absolute gravity measurements have been carried out at five research stations located in
Dronning Maud Land, Antarctica. Repeated absolute gravity measurements can bring multiple benefits to
geodynamical work, when used together with vertical rates or even in standalone mode. At individual stations,
gravity rates can be used to control observed vertical rates and predictions from GIA models. In a regional
approach, plotting gravity rates versus vertical rates at a number of stations provides a slope that gives
information on the mechanism behind the vertical rates (e.g., GIA) and an intercept that can be used to control
the reference frame of the vertical rates. Along with the above mentioned geodynamics studies, absolute-
gravity stations are an important part of the global geodetic infrastructure. We review the FGI absolute gravity
reseach in Fennoscandia and in Antarctica and present latest results.

1599
Thu_246_CR-5_153
Seismic Signals from Ice and Ocean: Results from ICE-VOLC Project

Andrea Cannata1,2 (andrea.cannata@unipg.it), Flavio Cannavò2, Peter Danecek3, Paola Del Carlo4, Alberto
Delladio3, Giuseppe Di Grazia2, Salvatore Gambino2, Gaetano Giudice5, Giovanni Giuffrida5, Paolo Grigioni6,
Graziano Larocca2, Marco Liuzzo5, Eugenio Privitera2, Laura Spina1, Luciano Zuccarello2
1
Università degli Studi di Perugia, Dipartimento di Fisica e Geologia, Perugia, Italy, 2Istituto Nazionale di
Geofisica e Vulcanologia, Osservatorio Etneo, Catania, Italy, 3Istituto Nazionale di Geofisica e Vulcanologia,
Roma, Italy, 4Istituto Nazionale di Geofisica e Vulcanologia, Pisa, Italy, 5Istituto Nazionale di Geofisica e
Vulcanologia, Palermo, Italy, 6ENEA, Roma, Italy

Thanks to the complete lack of anthropic noise, Antarctica can be considered a perfect natural laboratory to
investigate seismic signals generated by atmosphere-cryosphere-hydrosphere interaction. In the framework of
the ICE-VOLC project (www.icevolc-project.com) funded by the Italian PNRA, Antarctic ice-quakes and
microseisms were studied.
In particular, by a temporary installation of two seismic stations in Tethys Bay close to Mario Zucchelli Station
in 2016, three icequakes were detected, with dominant low frequencies (below 2 Hz), located in the David
Glacier area with local magnitude of 2.4-2.6. These events were likely to be generated at the rock-ice interface
under the glacier.
As for microseism study, we quantitatively investigated the relationship between microseisms recorded on the
coasts of the Ross Sea, sea ice concentration in the Ross Sea and significant wave height in the southern
hemisphere. We show how, according to the different seismic station and frequency band, the areas
characterised by the strongest anti-correlation between microseism amplitude and sea ice concentration are
distinct. Accordingly, we present an algorithm to infer the sea ice distribution on the basis of the microseismic
amplitudes. Finally, we note how the oceanic areas, whose wave activity mostly affects the microseisms
recorded in the Ross Sea, are the Antarctic coasts close to Ross Sea and the Drake passage.

1600
Thu_247_CR-5_238
Antarctic GIA Estimated by Combining GRACE, ICESat and GPS

Zemin Wang1, Baojun Zhang1 (bjzhang@whu.edu.cn), Hong Geng2, Jiachun An1

1
Wuhan University, Chinese Antarctic Center of Surveying and Mapping, Wuhan, China, 2Wuhan University,
School of Resource and Environmental Sciences, Wuhan, China

Based on the significant difference between ice/snow density and lithospheric density, a new iterative method
is proposed to simultaneously estimate the present-day glacial isostatic adjustment (GIA), ice/snow mass
change and corresponding elastic vertical crustal deformation over the AIS by combining GRACE, ICESat and
GPS datasets. The influence of active subglacial lakes on GIA estimates, which is up to 1.5 mm/yr with all
datasets applying a 400 km Gaussian smoothing filter, are mitigated for the first time through additional
processing of ICESat data. The inferred GIA shows that the strongest uplift is found in the Amundsen Sea sector
and subsidence mostly occurs in Adelie Terre and the East Antarctica inland. The total GIA related mass change
estimates for the entire AIS, West Antarctica Ice Sheet, East Antarctica Ice Sheet, and Antarctic Peninsula Ice
Sheet are 43 ± 38, 53 ± 24, −23 ± 29 and 13 ± 6 Gt/a, respectively. The most significant ice mass loss and most
significant elastic vertical crustal deformations are concentrated in the ASE and northern Antarctic Peninsula.
Ice/snow mass loss rate in the northern Antarctic Peninsula and Amundsen Sea sector is more than 10 cm/a
EWH. For the corresponding elastic vertical crustal deformation rates, in the Amundsen Sea sector is more than
4.5 mm/a and the Northern Antarctic Peninsula is about 2 mm/yr.

1601
Thu_248_CR-5_297
How to Give Accurate Surface Mass Balance Projections for the 21st Century?

Vincent Favier1 (vincent.favier@univ-grenoble-alpes.fr), Gerhard Krinner1, Charles Amory2, Julien Beaumet1,

Hubert Gallée1, Cecile Agosta2
1
IGE, Grenoble, France, 2ULg, Liège, Belgium

Climate models still fail to accurately reproduce the temporal Surface Mass Balance (SMB) trends at a regional
scale, mainly because complex processes are still insufficiently considered, such as:
1) atmospheric circulation changes related to complex ocean/ice/atmosphere interactions,
2) specific polar atmospheric features (cloud microphysics, wind scouring and impact on stable surface
boundary layers),
3) surface firn physics involved in surface drag variations, or in firn air depletion and albedo feedbacks.
We propose an approach based on 1) bias corrections of future sea surface conditions coming from AOGCM
scenarios. These corrections are then used as boundary conditions for a modeling with a stretched grid
atmospheric GCM (LMDZ4), whose systematic errors in atmospheric circulation are corrected using tendency
errors from nudged simulations. These outputs are then used to force the regional atmospheric model (MAR)
to assess future regional scale SMB variations in Antarctica. The MAR is adapted to account for interactions
between drifting snow and surface drag over sastrugi fields by introducing a specific formulation for the
roughness length. This formulation accounts for the relationship existing between snow-surface temperature
and microrelief erodibility caused by the sintering of surface crystals. This adaptation is necessary to reproduce
the seasonal variations in drifting snow frequency and horizontal snow mass transport as evidenced from
observations.

1602
Thu_249_CR-5_404
GIA-induced Crustal Deformation around Syowa Station, East Antarctica

Jun'ichi Okuno1,2 (okuno@nipr.ac.jp), Koichiro Doi1,2, Yuichi Aoyama1,2, Takeshige Ishiwa1, Akihisa Hattori2
1
National Institute of Polar Research, Tachikawa, Japan, 2Graduate University for Advanced Studies,
Department of Polar Science, Tachiakawa, Japan

Geodetic and geomorphological surveys in Soya Coast area, East Antarctica have been conducted by Japanese
Antarctic Research Expedition (JARE) in order to evaluate the crustal deformation induced by Glacial Isostatic
Adjustment (GIA) in various time scales. In particular, several geodetic observations (e.g., Global Navigation
Satellite Systems: GNSS and continuous gravity observations) have been carried out on outcrop rocks in this
area since the 1990s to monitor recent crustal movements. These observations include the components of the
GIA induced by last deglaciation and elastic deformation due to recent surface mass balance. Therefore, it is
important for the separation of the components of viscous and elastic signals to compare these observations
with numerical predictions using GIA model. In this presentation, we will show the geodetic signals calculated
by GIA model based on the previously published deglaciation histories, and the results of geodetic observations
obtained by JARE for about 20 years. We intend to discuss the separation of the components between recent
ice mass change and last deglaciation, and estimate influences of recent Antarctic ice sheet mass changes on
the geodetic measurements in Soya Coast area.

1603
Thu_250_CR-5_456
20th Century Vertical Land Motion due Changes of the Greenland Ice Sheet

Kristian Kjeldsen1,2 (kkkj@space.dtu.dk), Shfaqat Abbas Khan1

1
DTU Space - National Space Institute, Division of Geodesy, Kgs. Lyngby, Denmark, 2Natural History Museum of
Denmark, Centre for GeoGenetics, Copenhagen, Denmark

Quantifying the contribution from ice sheets and glaciers to past sea level change is of great value for
understanding sea level projections into the 21st century. However, quantifying and understanding past
changes are equally important, in particular understanding the impact in the near-field where the signal is
largest.
We assess the impact of 20th century mass balance of the Greenland Ice Sheet on land motion using results
from Kjeldsen et al, 2015. These results suggest that the ice sheet on average lost a minimum of 75 Gt/yr, but
also show that the mass balance was highly spatial- and temporal variable, and moreover that on a centennial
time scale changes were driven by a decreasing surface mass balance.
Here we present and discuss land motion during the 20th century due to mass balance-, surface mass balance-,
and ice dynamics changes.
Kjeldsen, K. K. et al. (2015), Spatial and temporal distribution of mass loss from the Greenland Ice Sheet since
AD 1900, Nature, 396, 528, doi:10.1038/nature16183

1604
Thu_251_CR-5_590
Sea-level Fingerprinting as a Reconstruction of AIS History during MIS 2

Takeshige Ishiwa1 (ishiwa.takeshige@nipr.ac.jp), Jun'ichi Okuno1,2

1
National Institute of Polar Research, Tokyo, Japan, 2SOKENDAI (Graduate University of Advanced Studies),
Department of Polar Science, Tokyo, Japan

Sea-level fingerprinting by GIA model is useful to detect ice-sheet change scenarios. Regardless of lacking direct
ice-sheet data in near-field, sea-level fingerprinting can reconstruct timing and amplitude of ice-sheet change.
Marine Isotope Stage 2 (MIS 2) is the latest glacial period (29,000-15,000 years ago), including the Last Glacial
Maximum (LGM) at the timing of global ice volume maximum. Further understanding of the glacial earth
climate system requires a comparison of various paleoclimatic records with sea-level and ice-sheet change in
this period. However, Antarctica Ice Sheet (AIS) history during MIS 2 is still less understood due to lack of field
data. Here we demonstrate AIS history during MIS 2 using sea-level fingerprinting analysis on observations in
far- and intermediate-field. Our results indicate that far- and intermediate-field relative sea-level records
provide the new insight of AIS history during MIS 2 through sea-level fingerprinting analysis.

1605
Thu_252_CR-5_820
Changes of Ice Surface Heights Between 1912 and 2017 in Southern Greenland

Wilfried Korth1 (korth@beuth-hochschule.de), Thomas Hitziger2

1
Beuth Hochschule Berlin, FB III, Berlin, Germany, 2BTU Cottbus, Cottbus, Germany

In 1912 a Swiss expedition, leaded by the meteorologist Alfred de Quervain, crossed the inland ice of
Greenland on a track from Disko Bay to Tasiilaq. It was the second successful crossing of the ice cap after
Nansens expedition in 1888. De Quervain provided first good height data of the glacier surface. The accuracy of
the heights is in the range of 2 m about 10 m. There are only a few such data sets available which are measured
more than 100 years ago.
In 2002 a series of six geodetic expeditions started on the same traverse as 1912. The last measurements were
made in August 2017. In result there are a lot of information available:
- very precise height changes for the last 15 years along a 700 km profile,
- height differences measured on more than 20 camp sites of the 1912 expedition
- very dense (spacing of some meters) profiles of heights of the rim of the inland ice.
The results can be used to answer different questions: Are there significant differences in the height changes
and mass loss resp. between the 100 years after 1912 and the last decade? Is the speed of mass loss more or
less stable or increasing? How the surface topography is changing (an analysis of remote sensing data is
included)? An observed height change is mainly a mass change or a change of snow density?
And last but not least the data are usable for direct verification of altimetry data such as IceSat. Both the IceSat
heights and the height changes can be compared.

1606
Thu_253_CR-5_837
Processes of 21st Century Ice Sheet Melt and their Global Consequences

Nicholas Golledge1,2 (nicholas.golledge@vuw.ac.nz), Natalya Gomez3, Elizabeth Keller2, Kaitlin Naughten4,

Gabriel Tseng3, Jorge Bernales5
1
Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand, 2GNS Science, Lower
Hutt, New Zealand, 3McGill University, Montreal, Canada, 4University of New South Wales, Sydney, Australia,
5
GFZ German Research Centre for Geosciences, Potsdam, Germany

Both external and internal processes drive ice sheet evolution over decadal to centennial timescales, yet the
partitioning between these drivers is often hard to quantify. Here we present a new suite of high-resolution
simulations of ice sheet evolution from present-day to 2100 based on CMIP5 climatologies. Our results predict
the magnitude of possible sea level rise under different climate scenarios, but also highlight the spread of
values that arises from differing parameterisations of key physical processes, such as grounding line behaviour
or the calculation of surface melt. By quantifying mass changes in individual ice sheet drainage basins that arise
from environmental processes such as surface and basal melt, we then derive an estimate of the dynamic
component of the total discharge signal. In this manner we are able to attribute spatially-variable changes to
regional differences in climate forcing and ice sheet dynamics.

1607
Thu_254_CR-5_862
Solid Earth-Cryosphere Interaction with a Focus on East Antarctica

Anya Reading1,2 (anya.reading@utas.edu.au), Matt King2,3, Lenneke Jong2, Doreen Warjri2, Jacqueline Halpin2,
Joanne Whittaker2, Isabel Sauermilch2, Tobias Staal2,4, Alessandro Maritati2, Jason Roberts5, Steven Phipps2,
Zanna Chase2, Taryn Noble2, Lea Pesjak2, Sian Tooze2
1
University of Tasmania, Mathematics and Physics, Hobart, Australia, 2University of Tasmania / Institute for
Marine and Antarctic Studies, Hobart, Australia, 3University of Tasmania, Geography and Spatial Sciences,
Hobart, Australia, 4University of Tasmania, Earth Sciences, Hobart, Australia, 5Antarctic Climate & Ecosystems
Cooperative Research Centre, Hobart, Australia

This contribution focuses on the interplay between the solid Earth and the cryosphere with the aim of
progressing knowledge of ice extent and retreat history, and Antarctica´s contribution to sea level change, via
observation and modelling. Solid Earth-cryosphere interaction research requires an interdisciplinary approach
which is facilitated through the Antarctic Gateway Partnership research program centred in Hobart, Tasmania,
Australia. New observations are provided through onshore and marine basement rock and sediment sampling,
and GPS, seismic and airborne geophysics data collection. These observations are carried out in the context of
ice sheet modelling at both basin scale and continental scale.
We investigate the Earth deformation, including horizontal motion, associated with ice sheet evolution. We
also improve constraints on geothermal heat as an ice sheet model input by combining information from
geological, plate tectonic and geophysical inputs. The present day research findings are placed in the context of
paleo ice sheet models which consider a coupled ice sheet / ocean / solid Earth framework. With a focus on
East Antarctica, we find that the major ice sheets and their basement catchments behave with contrasting sets
of controls. Through our combined approaches, we are better able to constrain model inputs, understand the
impact of uncertainty in model inputs and investigate the impact of feedbacks between Earth systems.

1608
Thu_255_CR-5_1000
Multi-year Analysis of Antarctica GNSS Data in the Frame of the VLNDEF Project

Antonio Zanutta1, Monia Negusini2 (negusini@ira.inaf.it), Leonardo Martelli1, Luca Vittuari1, Paola Cianfarra3,
Francesco Salvini3, Francesco Mancini4, Paolo Sterzai5, Marco Dubbini6, Angelo Galeandro4, Alessandro Capra4
1
University of Bologna, DICAM, Bologna, Italy, 2National Institute of Astrophysics, IRA, Bologna, Italy, 3Roma Tre
University, Dipartimento di Scienze Geologiche, Roma, Italy, 4University of Modena and Reggio Emilia, DIEF,
Modena, Italy, 5Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Dipartimento di Geofisica della
Litosfera, Trieste, Italy, 6University of Bologna, DiSCi, Bologna, Italy

Victoria Land (Antarctica) is located at the boundary between the Western Antarctic Rift System and East
Antarctic Craton. This region is characterized by a complex tectonic architecture mainly dominated by NW-SE
regional right-lateral strike-slip faults, block faulting, tilting along NE striking, and SE dipping extensional faults.
In order to estimate the neo-tectonic geodynamics of the region, in 1999 Victoria Land Network for
DEFormation control (VLNDEF) was established and repeatedly surveyed during the Australian summer
seasons. The network nowadays is constituted by 27 sites in a region which extends over 500 km North-South
and 300 km East-West, including the “Mario Zucchelli Station” Italian base. In this paper, GPS observations of
VLNDEF, collected from DOY 349 of 1998 to DOY 365 of 2017, together with all free available geodetic
observations for Antarctica (IGS and POLENET sites) were processed with Bernese 5.2 Software, using a classical
double difference approach. Almost 100 IGS stations were used as a global frame and the IGS14 core network
was adopted to align Antarctica´s stations into ITRF2014 reference frame. GPS time series for more than 80
Antarctic sites were analyzed to remove outliers and to estimate trends, annual/semiannual signals
components and eventually offsets parameters. Finally, the principal component analysis (PCA) was applied to
filter out the common mode component (CMC) of the calculated GPS time series.

1609
Thu_256_CR-5_1057
Calibrated Projections of Jakobshavn Isbræ's Contribution to Sea Level Rise

Johannes H. Bondzio1 (jbondzio@uci.edu), Mathieu Morlighem1, Helene Seroussi2, Michael Wood1, Jeremie
Mouginot1
1
University of California Irvine, Earth System Science, Irvine, CA, United States, 2Jet Propulsion Laboratory,
California Institute of Technology, Pasadena, CA, United States

Jakobshavn Isbræ (JI), West Greenland, has become a major contributor to global sea level rise since the
disintegration of its floating ice tongue in the early 2000's. Calving controls the evolution of the ice stream, but
no robust calving rate parameterization for large-scale ice sheet models exists to date. Therefore, large
uncertainties remain concerning the future evolution of this glacier.
Here, using the Ice Sheet System Model (ISSM), we perform a model sensitivity study on JI. We estimate its
future evolution and mass loss by calibrating a calving rate parameterization based on a von-Mises yield stress
criterion with available observations over the 1985-2017 period. First, we perform a large ensemble of model
runs over the past 30 years, in which we vary several parameters that influence calving. Second, we introduce
metrics to evaluate the agreement between model runs and observations of JI, and determine the parameter
combinations that best reproduce the observed dynamic changes. Finally, we project JI's future evolution for
each of the selected parameter combinations for the next 100 years.
We discuss the robustness of our results, the sensitivity of the glacier to the respective calving parameters, and
future pathways for observations and model development. This ensemble study explores scenarios of JI's
potential evolution and yields an informed estimate of JI's contribution to global sea level rise for the next
century.

1610
Thu_257_CR-5_1064
High-resolution, Global Ice Sheet/RSL Simulations using the Higher-order ISSM

Eric Larour1 (eric.larour@jpl.nasa.gov), Erik Ivins1, Surendra Adhikari1

1
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States

Relative sea-level rise is driven by processes that are intimately linked to the evolution of glacial areas and
polar ice sheets. So far, most Earth System models capable of projecting the evolution of RSL on decadal to
centennial time scales have relied on offline interactions between RSL and ice sheets. In particular, grounding
line and calving front dynamics have not been modeled in a way that is tightly coupled with Elasto-Static
Adjustment (ESA) and/or Glacial-Isostatic Adjustment (GIA). Here, we present a new simulation of the entire
Earth System in which both Greenland and Antarctica ice sheets are tightly coupled to an RSL model that
includes both ESA and GIA at resolutions and time scales compatible with processes such as grounding line
dynamics for Antarctica ice shelves and calving front dynamics for Greenland marine-terminating glaciers. The
simulations rely on the Ice Sheet System Model (ISSM) SESAW module, which models RSL using an anisotropic
meshing apprach, as opposed to the more classic spherical harmonics appraoch. Using such an approach, one
can show the impact of higher-order ice flow dynamics and coupling feedbacks between ice flow and RSL. We
quantify the exact impact of ESA and GIA inclusion on grounding line evolution for large ice shelves such as the
Ronne and Ross ice shelves, as well as the Agasea Embayment ice streams, and demonstrate how offline vs
online RSL simulations diverge in the long run, and the consequences for predicting sea-level rise.

1611
Thu_258_CR-5_1226
Calving-induced Tsunami Analyzed through Seismic Signals and Numerical Codes

Filippo Zaniboni1 (filippo.zaniboni@unibo.it), Stefania Danesi2, Simone Salimbeni2, Andrea Morelli2, Stefano
Urbini3, Stefano Tinti1
1
Università di Bologna, Bologna, Italy, 2Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy, 3Istituto
Nazionale di Geofisica e Vulcanologia, Roma, Italy

The dynamics of sizeable outlet glaciers in Greenland has been studied through the analysis of seismic data
collected by the regional Greenland Ice Sheet Monitoring Network (GLISN), of satellite images and of local tide
gauge data. With a particular focus on the Jakobshavn Glacier, West Greenland, major calving events have
been identified by automatically detecting the ground flexure in response to sea waves generated by iceberg
detachments.
In addition, numerical techniques simulating the propagation of a tsunami in the Ilullisat fjord have been
applied. The tsunami source has been simply represented by means of a single, instantaneous sea-surface
bump, localized approximately in the area where the calving event takes place. The main interest in this
preliminary phase is focused on the assessment of the main tsunami features in the basin: propagation time,
sea-surface maxima and minima distribution and frequency characterization of the waves reaching the fjord
coasts.
The comparison of the seismograms spectra associated to calving events in the low-frequency window against
the spectra of the simulated tsunami is encouraging and opens new perspectives in the study of the interaction
between glaciers, fjords and oceans.

1612
Thu_259_CR-5_1616
Glaciers and Sea Surface Change Around Kara Sea in Russian Arctic

Keiko Konya1 (conya@jamstec.go.jp), Kazuyoshi Suzuki2

1
JAMSTEC, iace3, Yokohama, Japan, 2JAMSTEC, Yokohama, Japan

One of the recent climate changes is the temperature and precipitation increase in the Arctic. In an area of East
Russia Arctic, loss of sea ice is large and glaciers shrink due to the temperature increase and sea ice decrease.
We analyzed sea ice area, land weather and glacier mass balance of three areas in western Russian Arctic to
evaluate the influence of sea ice distribution on glaciers.
The study area has three islands. Franz Josef (FJ), Severnaya Zemlya (SZ), Novaya Zemlya (NZ). FJ and SZ are
surrounded by sea ice and has ice cap on the land. NZ is covered by a large ice cap. We used monthly mean
temperature observed in July and NCEP reanalysis data for summer mean temperature as a climate indicator.
The GRACE data was converted to water storage on land and regarded it as glacier mass change. Also, Sea ice
distribution and sea surface temperature were analyzed with the satellite data.
The glacier mass balance has decreased during 2002-2004 in FJ and NZ, and 2011-2012 in all area. For 2004-
2010, NZ showed the gradual mass balance decrease and FJ and SZ showed small change. NZ showed open
seawater in early July, which is earlier than usual year. After 2011, sea ice was separated to coastline of NZ.
Higher summer temperature was shown in FJ in 2011, SZ in 2004 and 2012, and NZ in 2004 and 2007-2008 and
after 2011. Glacier mass loss and high air temperature was seen in the same period in all areas.

1613
Thu_260_CR-5_1784
Geothermal Anomaly Onfluences Subglacial Meltwater Flow at South Pole

Tom A. Jordan1 (tomj@bas.ac.uk), Carlos Martin1, Fausto Ferraccioli1, Kenichi Matsuoka2, Hugh Corr1, René
Forsberg3, Arne Olesen3, Martin Siegert4
1
British Antarctic Survey, Cambridge, United Kingdom, 2Norwegian Polar Institute, Tromsø, Norway, 3National
Space Institute, Technical University of Denmark, Lyngby, Denmark, 4Grantham Institute and Department of
Earth Sciences and Engineering, Imperial College London, London, United Kingdom

New radar data from the PolarGAP project reveal a broad area upstream of South Pole where >400m has been
lost from the ice sheet due to enhanced basal melting. We estimate by modelling dated englacial layers that
the geothermal heat flux required is 120 ±20 mW/m2, indicating a previously undetected geothermal anomaly.
Hydrological models show that subtle changes in the ice sheet can switch melt water flow from this region
between glacial catchments. We propose that this mechanism helps explain past variability in flow deep in the
ice sheet interior.

1614
Thu_261_CR-5_1812
Mass Change in Greenland and Antarctica Derived from LAGEOS and GRACE

Ulrich Meyer1 (ulrich.meyer@aiub.unibe.ch), Krzysztof Sosnica2, Rolf Dach1, Adrian Jäggi1

1
University of Bern, Astronomical Institute, Bern, Switzerland, 2Wrocław University of Environmental and Life
Sciences, Institute of Geodesy and Geoinformatics, Wroclaw, Poland

Large scale continental mass change in polar regions is sensed by Earth observation satellites dedicated to
gravity field determination like the GRACE mission (2002 - 2017) and its successor GRACE-FO (scheduled for
launch in spring 2018). But also other low Earth orbiters (LEOs) with high-latitude orbits may be used to assess
the mass transport in polar regions. The spatial and temporal resolution of the derived mass estimates is much
coarse then what we get from GRACE, but they may serve to extend the time-series before the start of GRACE
and to bridge the gap to GRACE-FO. Satellite Laser Ranging (SLR) observations to the LAGEOS satellites allow
polar mass change estimates back to the early 1990s. They indicate that major ice melting in Greenland started
around 2002, so GRACE was launched just in time.
We present and compare time-series of Greenland and Antarctica mass changes derived by SLR and from
GRACE and discuss limitations in temporal and spatial resolution. We also address the problem of spectral
leakage due to the limited spatial resolution and of signal separation, because satellite gravimetry senses the
integrated mass change including global isostatic adjustment (GIA), snow cover and ice dynamics.

1615
Thu_262_CR-5_1863
Analysis of the Ice Dynamics of the Amundsen Sea Embayment from 2009 to 2017

Jasmine Siena Sarling Hansen1 (jasmine.hansen@colorado.edu), Michael John Willis1

1
University of Colorado at Boulder, Cooperative Institute for Research in Environmental Sciences (CIRES),
Boulder, United States

POLENET GPS sites located in the Amundsen Sea Embayment (ASE) of the West Antarctic Ice Sheet (WAIS) are
recording some of the fastest uplift rates seen anywhere in the world. This data strongly indicates that the
glaciers in the ASE are undergoing drastic dynamic changes, having a significant impact on the WAIS
contribution to sea level change. We use high resolution optical stereo imagery from the DigitalGlobe satellite
cluster, co-registered with laser altimetry and RADAR data collected during the NASA IceBridge and ICESat
missions, to generate a time series of digital elevation models (DEMs) spanning the time period between 2009
and 2017. These optically derived DEMs are extracted using the SETSM algorithm and are used to identify
glacier surface elevation (dh/dt) changes. Volume changes (dV/dt) are calculated by combining dh/dt values
and bed elevations from Bedmap2. GoLIVE data is used to identify surface velocity speeds of glaciers in the ASE
using a fixed fluxgate. We expect to see significant changes in the surface elevation, velocity and mass balance
of glaciers in the ASE and will compare our results with data obtained from studies using Cryosat-2 and ICESat.
Establishing the nature of load changes in the vicinity of the POLENET GPS sites will enable the identification of
the extent to which uplift is dominated by instantaneous elastic response due to ice mass changes.

1616
Thu_263_CR-5_2024
Investigating the Greenland Ice Sheet and its Interaction with Solid Earth

Mirko Scheinert1 (mirko.scheinert@tu-dresden.de), Christoph Knöfel1, Susanne Lunz1, Martin Horwath1, Ludwig
Schröder1, Undine Strößenreuther1, Matthias Willen1, Benjamin Ebermann1, Lutz Eberlein1, Andreas Groh1
1
TU Dresden, Dresden, Germany

Since 1995 our group has been working in Greenland. In Northeast Greenland, between 72 and 81 North,
geodetic GNSS measurements on bedrock were started in 2008 and carried out lastly in 2016 and 2017 during
campaigns based on the German research vessel “Polarstern” as well as on a field camp. Results of the GNSS
data analysis will be presented together with the inferred correction for the immediate elastic response to
recent ice-mass changes in order to link the vertical uplift rates to glacial-isostatic adjustment (GIA). A focus will
be given to Nioghalvfjerdsbraen, the northern branch of the major outlet of the Northeast Greenland Ice
Stream (NEGIS). This region is subject to a new joint research project “Greenland Ice Sheet - Ocean Interaction“
(GROCE) that a number of German universities and research centres are cooperating on. We will shortly
introduce this project that aims at investigating in detail the processes which interlink atmosphere, ocean and
ice sheet. Within the GROCE project our group deals with GIA, mass balance and dynamics of the Greenland Ice
Sheet in that focus area. The GIA effect will be determined also by the combination of satellite altimetry and
gravimetry, which then can be compared to the results of the in-situ GNSS measurements. We will discuss the
benefit of utilizing additional methods and observations to support the separation of the effects of surface
mass balance and ice dynamics.

1617
Thu_264_CR-5_2142
Geothermal Heat Flux and Predictability of West Antarctic Ice Sheet Evolution

Slawek Tulaczyk1 (stulaczy@ucsc.edu), Carolyn Branecky Begeman1, Andrew Fisher1

1
University of California, Santa Cruz, Earth and Planetary Sciences, Santa Cruz, United States

Climate changes are overall the primary driver of West Antarctic Ice Sheet (WAIS) variability over time.
However, climate sensitivity of a marine ice sheet should be strongly modulated by the magnitude and spatial
pattern of subglacial geothermal heat flux (GHF). Low GHF values favor development of slow-moving ice rises
and inter stream ridges which are frozen to their beds and offer buttressing for ice shelves and ice streams.
High GHF values hinder or prevent development of such slow-moving features because they make it hard, or
impossible, to reach freezing conditions at the bed. In general, high GHF values will favor marine ice sheet
instability. A number of recent publications reported data and modeling results indicating zones of high GHF
beneath the WAIS, purportedly related to subglacial volcanic or magmatic activity in the West Antarctic Rift
System (WARS). Diffuse continental rift zones, such as the WARS, are characterized by elevated and spatially
highly variable GHF. For instance, GHF within the Basin and Range Province has a modal value close to the
average continental GHF (ca. 60 mW per meter squared) but also a long tail of high values that reach over 300
mW per meter squared. Regional differences in GHF of such large magnitude should play a significant role in
evolution of fast/slow ice flow patterns during WAIS thinning, making it necessary to incorporate realistic GHF
fields in predictive ice sheet models.

1618
Thu_265_CR-5_2284
Measurements of GIA with Absolute Gravimeter and GNSS by JARE

Yuichi Aoyama1 (aoyama@nipr.ac.jp), Koichiro Doi1, Jun Nishijima2, Hiroshi Ikeda3, Akihisa Hattori4, Jun'ichi
Okuno1, Yoichi Fukuda5
1
National Institute of Polar Research/SOKENDAI, Tachikawa, Tokyo, Japan, 2Kyushu University, Fukuoka, Japan,
3
University of Tsukuba, Tsukuba, Ibaraki, Japan, 4SOKENDAI, Tachikawa, Tokyo, Japan, 5Kyoto University, Kyoto,
Japan

The Antarctic ice sheet plays a key role in control of the global climate and sea level. Then its ice mass changes
have been estimated from in-situ geodetic observations, satellite observations such as satellite gravimetry and
satellite altimetry as well. These estimations, however, include an uncertainty arising from the effects of GIA,
where GIA is the rheological response of the solid Earth to the ice mass changes.
With objective of observing the GIA effects, JARE (Japanese Antarctic Research Expedition) have conducted the
repeated absolute gravity (AG) and continuous GNSS measurements and other geodetic observations in
Dronning Maud Land (DML), East Antarctica. Especially, the repeated AG and continuous GNSS measurements
at Syowa Station have been carried out since 1995, and these data reveal the temporal variations in both
gravity and crustal deformation due to the GIA. JARE also succeeded the AG measurement at Langhovde during
2011/2012 austral summer, which was the first outdoor measurement in the JARE activity. Subsequently, we
performed the outdoor AG measurement at Selungen, the central parts of the Sør Rondane Mts., during 2013
austral summer. Furthermore, we plan to conduct the combination of repeated AG and GNSS measurements at
several sites on the bare rock area around Lutzow-Holm Bay, DML in 2017/2018 austral summer. In this
presentation, we will report the geodetic observations by JARE.

1619
Thu_266_CR-5_2311
Temporal Variability of the Antarctic Ice Sheet Observed from Sattelite Geodesy

Anthony Mémin1 (anthony.memin@geoazur.unice.fr), Matt King2, Jean-Paul Boy3, Frédérique Rémy4

1
Université Nice Sophia Antipolis, Géoazur, Valbonne, France, 2University of Tasmania, School of Land and Food,
Hobart, Australia, 3Ecole et Observatoire des Sciences de la Terre, Strasbourg, France, 4LEGOS/OMP, CNRS,
Toulouse, France

Quantifying the Antarctic Ice Sheet (AIS) mass balance remains challenging as several processes compete to
differing degrees at the basin scale with regional variations, leading to multiple mass redistribution patterns.
For example, analysis of linear trends in surface-height variations from 1992-2003 and 2002-2006 shows that
the AIS is subject to decimetric scale variability over periods of a few years. Every year, snowfalls in Antarctica
represent the equivalent of 6 mm of the mean sea level. Therefore, any fluctuation in precipitation can lead to
changes in sea level. Besides, over the last decade, several major glaciers have been thinning at an accelerating
rate. Understanding the processes that interact on the ice sheet is therefore important to precisely determine
the response of the ice sheet to a rapid changing climate and estimate its contribution to sea level changes.
We estimate seasonal and interannual changes of the AIS between 01/2003 and 10/2010 and 09/2016 from a
combined analysis of surface-elevation and surface-mass changes derived from Envisat data and GRACE
solutions, respectively. While we obtain a good correlation for the interannual signal between the two
techniques, differences in amplitude, phase, and spatial pattern are obtained for the seasonal signal. We
investigate these discrepancies by comparing the crustal motion observed by GPS and those predicted using
monthly surface mass balance derived from the regional atmospheric climate model RACMO.

1620
Thu_267_CR-5_2349
Greenland and Antarctica Mass Changes by Multiple-satellite and Land Uplift Data

Rene Forsberg1 (rf@space.dtu.dk), Sebastian Simonsen1, Louise Sørensen1, Valentina Barletta1, Thomas
Nagler2, Marcus Hetzenecker2
1
Technical University of Denmark, DTU Space - National Space Institute, Kongens Lyngby, Denmark, 2ENVEO,
Innsbruck, Austria

Understanding the long-term changes in the ice sheets of Greenland and Antarctica has global climate
significance, especially on long term global sea level rise predictions. We present results of satellite-derived ice
sheet change time series of Greenland and Antarctica, covering up to a 25 year time span, and highlight the
dynamic nature and of the ice sheet changes, including the large interannual variations and regional
accelerations of major ice mass loss regions. We also highlight, using satellite data from a.o. the ESA Climate
Change Initiative, how the combination of multiple satellite measurement types, such as mass change, ice
velocities, elevation changes and solid earth land uplift from GNET and ANET, may improve the overall spatial
and temporal monitoring the ice sheet changes.

1621
Thu_268_CR-5_2446
Laboratory Observations of the High Temperature Creep of Polycrystalline Ice

Adam Treverrow1 (adam.treverrow@utas.edu.au), Bridie Le'Gallais2, Jason Roberts3

1
Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Australia,
2
University of Tasmania, Hobart, Australia, 3Australian Antarctic Division, Hobart, Australia

The largest source of uncertainty in predictions of future sea level is the contribution arising from the discharge
of ice from the polar ice sheets. A key factor in reducing this uncertainty is to improve the numerical models
used to predict ice sheet evolution. One important aspect of model development is to improve the constitutive
relationship that describes the rheological properties of ice.
Factors influencing creep deformation rates include: the magnitudes of the stresses causing ice to deform;
strain-induced anisotropy of polycrystalline ice, and temperature. Creep rates at high temperatures, within 2
degrees (K) of the melting point, are constrained by a relatively small number of laboratory observations due to
the inherent difficulties in conducting experiments at such temperatures.
We present results from a series of laboratory ice deformation experiments conducted in simple shear at
temperatures between -2°C and -0.3°C at 0.1 MPa (octahedral shear stress). Unlike previous experimental
studies conducted at temperatures close to the melting point, these experiments were continued through to
high shear strains (>10% strain) to ensure that anisotropic flow, compatible with the stress configuration, had
developed.
These data contribute to the continued development of a constitutive relationship for polycrystalline ice that
will improve the accuracy of ice sheet models and are relevant to model studies utilizing inverse methods to
infer the spatial extent of basal sliding.

1622
Thu_269_CR-5_2550
The Influence of Close-field Snow and Ice on Absolute-gravity Measurements

Jaakko Mäkinen1 (jaakko.makinen@nls.fi), Jyri Näränen1, Antero Kukko1, Hannu Koivula1

1
Finnish Geospatial Research Institute, Masala, Finland

Often it is assumed that the change in gravity observed with absolute gravimeters in the Antarctic primarily
depends on solid earth motion caused by Glacial Isostatic Adjustment and/or by elastic deformation due to
changes in contemporary regional ice mass balance. However, variation in the close-field snow and ice masses
can be caused for instance by local wind ablation/accumulation and does not necessarily reflect the regional
mass balance. As the gravity stations typically are on nunataks well above the surrounding glaciers, the
variation in the gravity effect by local masses may be considerable and it can mask the large-scale solid-earth
phenomena of interest. The Finnish Geospatial Research Institute maintains time series of absolute gravity at
five stations in Dronning Maud Land, starting at the Finnish base Aboa in 1994 and continuing later at Sanae IV,
Novolazarevskaya, Maitri and Troll. We describe the various measurements used to monitor the near-field
masses, from tachymetry and snow stake lines to GNSS, altimetry and Lidar, the calculation of corrections to
observed gravity, and the influence of these corrections on the time series.

1623
Thu_270_CR-6_82
Geophysical Characterization of Boulder Clay Glacier (Victoria Land, Antarctica)

Stefano Urbini1 (stefano.urbini@ingv.it), Gianluca Bianchi Fasani2, Paolo Mazzanti3, Michelina Serafini1, Luca
Vittuari4
1
Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy, 2ENEA, Rome, Italy, 3Università Sapienza,
Department of Earth Sciences, Rome, Italy, 4University of Bologna, Department of Civil, Chemical,
Environmental and Materials Engineering (DICAM), Bologna, Italy

The Boulder Clay Glacier is a partially debris-covered glacier belonging to the Northern Foothills (Victoria Land,
Antarctica) placed close to the Italian base Mario Zucchelli Station. In the frame of XXIX, XXX and XXXI Italian
Antarctic Expeditions (from 2013-14 to 2015-16 summer seasons), several investigations, such as Ground
Penetrating Radar (GPR), Geodetic Global Positioning System (GPS) network, multi-temporal satellite SAR
interferometry (by means of Differential Interferometric Synthetic Aperture Radar, D-InSAR, methodologies),
were carried out with the main aim of determining the general assessment of this glacier. The scientific tasks
assigned to each single technique were: i) GPR: to investigate the main glacier features (i.e. superficial frozen
lakes, shear zones and ice thickness) ; ii) GPS: to determine the ice flow speed vectors over 12 points spread
over the moraine covered area; iii) D-InSAR: to estimate deformation trends and surface displacements
evolution.
The image provided by the integration of the results pointed out that glacier deformation behavior is
dependent, other than the bedrock shape, by also the relationship between the glacier, the moraine (that
exhibits different deformation patterns) and the interaction with the ablation due to the strong katabatic winds
blowing in the area.

1624
Thu_271_CR-6_100
Radio Echo Sounding and Seismic Observations at the David Glacier, Antarctica

Stefania Danesi1 (stefania.danesi@ingv.it), Simone Salimbeni1, Stefano Urbini2

1
Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy, 2Istituto Nazionale di Geofisica e Vulcanologia,
Roma, Italy

Integrated geophysical observations in polar regions make it possible to study the interaction between
lithosphere and cryosphere and their evolution in the framework of a global climate system.
We have collected Radio Echo Sounding (RES) measurements combined with passive continue seismic
observations in the area of the David Glacier (Victoria Land, Antarctica) in order to improve our knowledge
about changes in basal conditions due to melting processes.
This work provides detailed maps of the bedrock morphologies, ice thickness and physical condition at
ice/bedrock interface in the domain of the David Glacier.
The inferred 3D structural model of the ice and bedrock is integrated into the inversion algorithm in order to
improve the accuracy of local seismicity location. In continuity with previous seismic monitoring experiments in
the area, we analyze the seismicity induced by the glacier flow and we discuss the characteristic of seismic
occurrences in terms of location, frequency and possible seasonal cycling.

1625
Thu_272_CR-6_143
Consistency between Changes in Simulated Climate and European Glacier Length

Hugues Goosse1 (hugues.goosse@uclouvain.be), François Klein2, Ben Marzeion3, Fabien Maussion4, Paolo
Pelucchi5, Anouk Vlug3
1
Université Catholique de Louvain (UCL), ELIC/TECLIM, Louvain-la-Neuve, Belgium, 2Université cathlique de
Louvain (UCL), ELIC/TECLIM, Louvain-la-Neuve, Belgium, 3Univ. Bremen, Bremen, Germany, 4Univ. of Innsbruck,
Innsbruck, Austria, 5Imperial College, London, United Kingdom

It is standard to compare climate model results covering the past millennium to reconstructions based on
various archives to test the ability of models to reproduce the observed climate variability in conditions close to
the present ones. Up to now, glacier length fluctuations have not been used in this framework while it offers
information on multi-decadal to centennial variations complementary to other records. One reason is that
glacier length depends on several factors and so cannot be simply linked to simulated climate. However,
climate model skill can be evaluated by comparing the glacier length provided by a global glacier model driven
by the simulated temperature and precipitation to observations. This is done here using the version 1.0 of
Open Global Glacier Model (OGGM) forced by fields derived from a range of simulations with global climate
models over the past millennium. The focus is first on European glaciers. Sensitivity experiments are performed
to estimate the uncertainty that can be related to the glacier model itself compared to the one that is due to
the forcing derived from the climate model. These experiments are dealing with the initialisation of the glaciers
in 850 CE, the uncertain creep parameter needed to compute ice dynamics, key parameters in the surface mass
balance model, the way climate model biases are taken into account and the downscaling of model results at
the location and altitude of the glaciers.

1626
Thu_273_CR-6_154
Ice Front Retreat of Two Adjacent Glaciers in the Antarctic Peninsula

Carolina Lorenz Simoes1 (carolina.lsimoes@gmail.com), Rafaela Mattos Costa1, Jefferson Cardia Simoes1, Kátia
Kellem da Rosa1
1
UFRGS, Geography, Porto Alegre, Brazil

This study uses aerial photographs and LANDSAT and Sentinel 2 satellites images to determine the retreat
dynamics of two tidewater glaciers from 1957 to 2016, Drummond (66°40´S, 65°43´W) and Widdowson
(66°43´S, 65°46´W), in the Antarctic Peninsula western coast. A modified digital elevation model AsterDEM2
was used to characterize the morphology and the morphometry of their drainage basins. The two ice fronts
have retreated during the period; however, the Widdowson Glacier had a more significant loss (36.37 km²,
16.97% of the original area) and a higher snow line elevation (200 m a.s.l. in 2016) than the Drummond Glacier
(19.11 km2, 4.33% of the original area; snow line at 100 m a.s.l. in 2016). These differences, of two ice masses
side by side and with the same flow orientation, are attributed to different surface slopes and proportion of
accumulation areas. The smaller glacier has been more sensitive to environmental changes (e.g., increase in the
regional mean annual temperature), and reached a stabilization point (supported to the lateral bedrock) only in
2001, while the Drummond front stabilized in 1974. The Widdowson Glacier has a steeper frontal sector, which
may have influenced on the calving rate and generated a more efficient basal slip. The dynamics of these
glaciers is also influenced by changes in ocean forcing, precipitation rates, surface melting and bedrock
morphology.

1627
Thu_274_CR-6_170
Glacier Flow Acceleration in Response to the Local Climate Change

Songtao Ai1 (ast@whu.edu.cn), Zemin Wang1, Jiachun An1, Yuande Yang1

1
Wuhan University, Chinese Antarctic Center of Surveying and Mapping, Wuhan, China

Based on in-situ collected GPS data, high-precision ice velocities of a Svalbard glacier, Austre Lovénbreen, were
observed over a decade during 2005-2017, including both horizontal and vertical annual surface ice velocities.
GPS results indicate that the mass balance of this glacier is negative, which is identical to other neighbor
glaciers. GPS data analysis revealed that the surface ice flow was stable in the beginning surveyed years,
however, the ice flow velocities increased in recent two years.
A 3D finite element simulation proves that the ice flow acceleration is a response of the glacier to the warming
local climate, but the glacier ice flow will slow down soon in the next decade suppose the current climate
keeping steady.
Acknowledgement: This work was supported by the National Natural Science Foundation of China (41476162,
41531069) and the Chinese Polar Environment Comprehensive Investigation and Assessment Programmes
(CHINARE2017).
References:
[1] S. Ai, Z. Wang, D. E, K. Holmén, Z. Tan, C. Zhou, W. Sun. Topography, ice thickness and ice volume of the
glacier Pedersenbreen in Svalbard, using GPR and GPS. Polar Research, 33(2014)
[2] S. Ai, Z. Wang, Z. Tan, D. E & M. Yan. Mass change study on Arctic glacier Pedersenbreen, during 1936-1990-
2009. Chinese Science Bulletin, 58(2013)
[3] S. Ai, Z. Wang, D. E & M. Yan. Surface movement research of Arctic glaciers using GPS method. Geomatics
and Information Science of Wuhan University, 37(2012)

1628
Thu_275_CR-6_266
Chukotka: Climate and Glacier Change

Maria Ananicheva1 (maria_anan@rambler.ru)

1
Institute of Geography RAS, Glaciology, Miscow, Russian Federation

The paper presents the assessment the current state of the Chukotka highlands' glaciers by satellite images at
the background of climatic change, projection of glacier evolution in the near future. It also gives the general
description of the regional socio-economic drivers of the region of study as a part of AACA-BCB (AMAP) cluster.
Trends of the mean annual and summer temperature for entire Chukotka Peninsula within 1966-2012 are
positive. Precipitation trends of annual sum and for cold period are negative in coastal regions, and positive on
the continent between the Cross Gulf of Anandyrskiy estuary. Thus, climate processes occurring over Chukotka,
do not contribute into the development and extension of glaciation.
Estimation of the evolution of the Chukchi Highlands' glacier was an objective to assess possible variant of
evolution of the Chukotka glaciers consisted in construction of balance schemes for each glacier system by
climatic data, which is the only available for this poorly studied region and in involving climate scenario, in our
case for the time period up to 2030 (Ensemble of 31 scenario from SMIP5, RCP4.5).
Up to this time the glaciation of the Iskaten ridge and Provedensky Massif will greatly reduce, and glaciers of
the Pekulney Range will disappear; the glaciers of Chantalsky Ridge (Amguema River Basin) will save their area
by maximum.

1629
Thu_276_CR-6_275
Chinese Radioglaciological Studies on the Antarctic Ice Sheet in the past Decade

Xiangbin Cui1 (cuixiangbin@pric.org.cn), Bo Sun1, Jingxue Guo1, Xueyuan Tang1, Lin Li1
1
Polar Research Institute of China, Shanghai, China

Radioglaciological studies commenced relatively late in China.. During CHINARE 21 (Chinese National Antarctic
Research Expedition, 2004/05), Chinese glaciologists traversed to Dome A from the coastal Zhongshan Station
for the first time and were able to survey the region on a detailed surface RES gird. Since then, different kinds
of radar systems have been deployed for both fine-scale surveying networks in the Dome A and along the
traverse route for multiple scientific purposes, such as mapping subglacial conditions, distinguishing crystal
orientation fabric types, measuring internal layers and freeze-on ice. Significant motivation has been to search
for the oldest ice on Earth and to map the unknown bedrock topography of the Gamburtsev Subglacial
Mountains and infer the early origin and evolution of the AIS and the GSM. In 2015, China deployed its first
fixed-wing airplane named “Snow Eagle 601” for Antarctic expeditions, and an international campaign of
International Collaborative Exploration of the Cryosphere through Airborne Profiling in Princess Elizabeth Land
was initiated. It has great implications for investigation of ice sheet expansion, stability and the subglacial
geology of East Antarctica. In future, we will engage in and make Chinese contributions to more science issues,
such as subglacial water and lakes, subglacial canyons and channels and the subglacial hydrological system,
basal processes across grounding zones, bathymetry under ice shelves etc.

1630
Thu_277_CR-6_305
Recent Glacier and Proglacial Dynamics Changes in King George Island, Antarctica

Kátia Kellem da Rosa1 (katia.rosa@ufrgs.br), Carina Petsch2, Cleiva Perondi2, Manoela Araújo Gonçalves2,
Rosemary Vieira3, Jefferson Cardia Simões2
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Geography, Porto Alegre, Brazil, 2Universidade
Federal do Rio Grande do Sul / INCT da Criosfera, Porto Alegre, Brazil, 3Universidade Federal Fluminense, Porto
Alegre, Brazil

This paper investigates the current dynamics in proglacial geomorphology systems and glacier fluctuations in
King George Island (KGI), South Shetland Islands, Antarctica, since 1956. The glaciological, sedimentary and
remote sensing data analyses evidenced recent environmental changes. COSMO-SkyMed (Constellation of
Small Satellites for Mediterranean Basin Observation), Wordview 2 and Sentinel 2 imagens were used for
temporal analysis of glaciers outlines and recognition ice-marginal geomorphological features. From 1956 to
2017, the glaciers in Kraków and Warszawa Ice Fields presented a continuous retreat processes. Due to its
small size and thermal conditions, these glaciers respond rapidly to climatic changes. The marine terminating
outlet glaciers presented more lost area than land-terminating glaciers. A rapid ice-marginal evolution is
evidenced in land-terminating glaciers as consequence of the glacial retreat processes. The geomorphological
map of the recent ice-marginal areas showed several types of glacial deposits, such as frontal and lateral
moraines, flutes, meltwater channels and erosional features like rock moutonnés, striations and U-shaped
valleys. The results evidenced recent changes in proglacial and periglacial successional patterns for Wanda,
Potter, Ecology, Znosco and Collins Glaciers. The Znosco Glacier changed the marine-land terminating for land-
terminating conditions in last decade and reveal the rapid ice-marginal evolution.

1631
Thu_278_CR-6_309
Monitoring Recent Glacier Changes in Melimoyu Mount - Chile

Filipe Daros Idalino1 (filipe.daros.idalino@gmail.com), Kátia Kellem da Rosa1, Francisco Ferrando Acuña2,
Bijeesh Kozhikkodan Veettil3, Jefferson Cardia Simões3, Enoil de Souza Jr.4
1
Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Geografphy, Porto Alegre, Brazil, 2Universidad
de Chile, Santiago, Chile, 3Universidade Federal do Rio Grande do Sul / INCT da Criosfera, Porto Alegre, Brazil,
4
University of Manitoba, Winnipeg, Canada

This work analysed the application of Sentinel-2 MultiSpectral images and GLIMS data in retreat mappings for
to detect and estimate glacier area changes, between 1970 and 2017, in Melimoyu Mount, located in northern
Patagonia, Chile. The results presented a decreased glaciers area of approximately by 35.61% in analysis period
and there is an overall trend of glacial retreat. Majority of area loss has been identified for glaciers with mean
elevation around 1700-1725 m. The decreasing trend in mean annual precipitation presented a possible
connection with the recent glaciers changes in the study area, which indicates a large sensibility for
meteorologicals variabilitys on the region. This sensitivity also influenced by hypsometry, slope of the terrain
and total area of glaciers. The glacier mapping using sentinel 2 data in 2017 provided conditions for new
observations of rock glaciers in study area. Analysis of outline glaciers by manual delineation showed
satisfactory results with application of Sentinel-2 MSI data to these environments, and use of these enables the
continuity of retraction monitoring with greater accuracy of mapping.

1632
Thu_279_CR-6_603
Topographical Influences on Glaciers in the Jankar Chhu Watershed, NW Himalaya

Suresh Das1 (sureshdas088@gmail.com), Milap Chand Sharma1

1
Jawaharlal Nehru University, Centre for Study of Regional Development, School of Social Sciences, New Delhi,
India

This paper examines the influences of topographical factors on glaciers between 1971 and 2016 for 127 glaciers
in Jankar Chhu watershed, north-west (NW) Himalaya using satellite remote sensing data and limited field
observation. Change detection was done based on Corona KH-4B (1971), Landsat ETM+ (2000) and Sentinel 2A
(2016) imageries restricted only to a set of 127 glaciers due to cloud masking. The relationship between the
magnitude of glacier changes and a set of local factors was carried out using multivariate statistical techniques.
Cumulative influence of this factors was evaluated for each glacier using Topographic Influence Index (TII)
proposed by Garg et al., (2017). Our result show that:
(1) glacier area decreased by 7.48 ± 2.17% between 1971 to 2016; whereas glacier retreated at an average rate
of ~4.82 ± 0.35 m a¯¹;
(2) The debris cover area increased by 56.77 ± 3.33%, and the average ELA changed to ~20 m;
(3) Δ Area (%) and Δ retreat (m) of glacier are strongly affected by local factors while Δ ELA does not show any
significant relationship, indicating that it may be controlled by climatic factors and;
(4) More than 75% of glaciers show moderate to high influence of local factors on Δ area based on TII values.
This study provides important insight into the local controls on recent de-glaciation which are of critical
importance to assess the future glacier dynamics on a regional scale.

1633
Thu_280_CR-6_610
Snow Accumulation, Melting and Ice Thickness Variability on a Himalayan Glacier

Bhanu Pratap1 (bhanu@ncaor.gov.in), Parmanand Sharma2, Lavkush Patel2, Ajit Singh2, Vinay K Gaddam2, Sunil
Oulkar2, Meloth Thamban3
1
National Center for Antarctic and Ocean Research, Himalayan Cryosphere, Vasco, India, 2National Center for
Antarctic and Ocean Research, Himalayan Cryosphere, vasco, India, 3National Center for Antarctic and Ocean
Research, Polar Cryosphere, vasco, India

Knowledge of different aspects of glacier dynamics is significant to understand the variety of glaciological
processes and its characteristics. In this study, an attempt has been made to relate accumulation and ablation
rate, and ice thickness pattern over Sutri Dhaka Glacier in Chandra basin, Western Himalaya. To investigate ice
thickness, ground based radar survey has conducted using 16 MHz frequency in a distance mode. The radar
derived ice thickness varies from 65 m to 310 m for the surveyed area on this glacier, respectively. Transverse
profile of the survey formed the higher order of parabola due to friction forces at the margin against bedrock
constraints. The study also revealed that the tributaries margin of the glacier had a greater thickness as
compared to its main valley margin. The frequent avalanches on the side valley have a strong influence on the
glacier behavior and ice thickness.
Sutri Dhaka is a debris free glacier and the observed snow accumulation rate during the last one decade at
5500 m asl varies from 16 cm to 34 cm w.e. and the standard deviation is 5.6 cm w.e. The Glacier has strong
mass wasting during four consecutive negative balance years (2013-17) with the average melting of 0.74 m w.e.
a-1. Overall, the signature of accumulation, ice volume and mass balance reflect enhanced melting rate of Sutri
Dhaka Glacier during last decade.

1634
Thu_281_CR-6_617
Variability of Thermal Regime and Snow Water Equivalent of Glaciers in Svalbard

Parmanand Sharma1 (pnsharma@ncaor.gov.in), Lavkush Kumar Patel1, Ajit Singh1, Thamban Meloth1
1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Polar Science, Vasco da Gama, India

Many Arctic glaciers have been experiencing enhanced melting in response to ongoing global warming and are
predicted to shrink faster over the next few decades. Vestre Broggerbreen (VB) and Feiringbreen (FB), two
valley glaciers in Ny-Ålesund, Svalbard, Arctic have been monitored for annual mass balance, ice flux, surface
ice movement and terminal retreat since last six years . As part of this, both the glaciers have been mapped for
snow and ice thickness, sub glacier channel and distribution of warm and cold ice across the glacier tongue by
using radar. Apart from radar derived snow depth, variability in snow accumulation pattern over both the
glaciers has also been measured by snow pits, snow cores and snow probe. Results reveal that both the glaciers
having mostly cold ice (below 0oC), except in the interior part of the glacier. There is small area (12% area) with
warm ice (at 0oC) in the deep interior where ice is thicker than 130m and is warmed to the pressure melt point.
We have also observed that while the glacier terminal has retreated, the warm ice area has reduced
significantly (30%) during last six years. The mean average Snow Water Equivalent (SWE) for VB and FB were
600 ± 172 kgm-2 during 2012-2017 and 382 ± 187 kgm-2 during 2015-16 respectively. The strong correlations
between snow depth and SWE for both the glaciers reflect the significant control of snow depth and altitude on
SWE across the Svalbard valley glaciers.

1635
Thu_282_CR-6_774
Glaciological Investigations on the Mocho-Choshuenco Ice-cap, 40 °S, Chile

Marius Schaefer1 (mschaefer@uach.cl), Gino Casassa2,3, Eduardo Flandez4, Duilio Fonseca4, Pablo Iribarren4,
Matthias Scheiter5
1
Austral University of Chile, Institute of Physics and Mathematics, Valdivia, Chile, 2Geoestudios, Los Vertientes,
Chile, 3University of Magallanes, Punta Arenas, Chile, 4Austral University of Chile, Valdivia, Chile, 5Technische
Universität Bergakademie Freiberg, Freiberg, Germany

In this contribution we summarize our glaciological investigations on the ice cap, which is covering the Mocho-
Choshuenco Volcanic Complex located in the Northern Patagonian Andes. The climate on Mocho Ice Cap is
relatively mild (+2.6°C annual mean temperature near the equilibrium line) and is marked by very high rates of
accumulation. The Annual Surface Mass Balance of Mocho Glacier (one of the catchments of the ice cap) shows
very high interanual variability. On average the balance is negative which coincides with the observed thinning
and retreat of the glacier. Our research on the Mocho-Choshuenco Ice Cap includes surface mass balance and
energy balance modelling, observation of the formation and drainage of glacial lakes and ice-flow modelling.
Due to its easy access the ice cap is an ideal research laboratory for Patagonian Glaciers, which are usually hard
to reach because of their remoteness and the extreme weather conditions.

1636
Thu_283_CR-6_794
Simulating the Surface Mass Balance of Ice Sheets in the ModelE2 GCM

Patrick Alexander1,2 (pma2107@ldeo.columbia.edu), Marco Tedesco1,2, Allegra N. LeGrande2, Elizabeth Fischer3,

Maxwell Kelley2,4, Xavier Fettweis5, Gavin Schmidt2, Sophie M. J. Nowicki6
1
Lamont-Doherty Earth Observatory of Columbia University, Marine Geology and Geophysics, Palisades, United
States, 2NASA Goddard Institute for Space Studies, New York, United States, 3Columbia University, Center for
Climate Systems Research, New York, United States, 4SciSpace LLC, New York, United States, 5University of
Liège, Liège, Belgium, 6NASA Goddard Space Flight Center, Greenbelt, United States

Simulating the surface mass balance (SMB) of ice sheets in General Circulation Models (GCMs) is a challenge
because of the coarse resolution and simple physics used to efficiently simulate global processes. However,
algorithmic advances have allowed for a more sophisticated physical representation of ice sheets in GCMs. We
have applied two improvements to the ice sheet surface in the NASA GISS ModelE2 GCM: an elevation class
scheme, in which the surface model is run at multiple elevations within a single grid cell, and a sophisticated
multi-layer snow model. We compare surface mass balance simulated for the Greenland ice sheet with state of
the art regional climate model (RCM) simulations from the Modèle Atmosphérique Régionale (MAR), and
satellite measurements. The simulated SMB is particularly sensitive to the representation of surface albedo and
refreezing. Using a more realistic surface albedo consistent with satellite measurements more than doubles
surface melt. Refreezing can prevent 50% of meltwater from leaving as runoff, but can also warm the
snowpack, increasing the likelihood of melt. The addition of elevation classes has a more muted impact on
SMB, resulting in changes of less than 10%. Over the Antarctic ice sheet, sublimation and precipitation play a
more important role because runoff is a minor component of overall mass balance, highlighting the need for
accurately capturing all components of SMB in a global model.

1637
Thu_284_CR-6_883
Land Surface Temperature Analyses of Miyar and Gangotri Glacier (2000 - 2016)

Ishita Manna1 (mannaishita9@gmail.com), Milap Chand Sharma1, Elora Chakraborty2

1
Jawaharlal Nehru University, Center for Study of Regional Development, School of Social Sciences, New Delhi,
India, 2Jawaharlal Nehru University, New Delhi, India

In the absence of weather stations in the remote areas of the Lahaul District of Himachal Pradesh, satellite
derived Land Surface Temperature data can supplement for the lack of data. The MOD11B3V6 images were
processed for 17 years (2000-2016). The aim of this paper is to bridge the aspects of Temperature and the
Frontal changes noted in the Glaciers of the Miyar Basin. Iso-lines showing temperature pattern of each year
have been interpolated according to LST values of 78 geographical points on the Miyar and Bhagirathi
watershed map. Major Findings- 1. Extent of Miyar Glacier shows a decrease of 0.11sqKm, a retreat of 0.15% in
16 years; Gangotri Glacier decreased by 0.07sqKm. 2. The LST shows a decreasing trend in the yearly averages
at the Miyar Accumulation Area; negatively sloped graph at the R2 value of 0.13. Similarly, the Miyar Snout
region shows a land surface temperature of -6.54°C in the year 2009 and the trend is negative with the R2
value of 0.12. Similarly in all of the tributary glaciers this trend has been seen. The range of temperature
however has increased in the recent years and the R2 value is calculated to be 0.10 at the accumulation area
and at the Miyar Glacier Snout, it is 0.08 with a positively sloped trend over the years. In Gangotri Glacier a
there is little or no change, near accumulation area slight negative trend of 0.008 and 0.002 at snout. The study
will be very helpful in understanding the glacier dynamics in relation temperature variation.

1638
Thu_286_CR-6_932
Modeling the Effect of Water-filled Crevasses on the Flow of Calving Glaciers

Eef van Dongen1 (vandongen@vaw.baug.ethz.ch), Guillaume Jouvet1, Daniel Farinotti1,2

1
ETH Zurich/VAW, D-BAUG, Zürich, Switzerland, 2WSL Swiss Federal Institute for Forest Snow and Landscape
Research, Birmensdorf, Switzerland

Observations in Greenland show that large-scale occasional calving events often contribute more to the mass
loss of tidewater glaciers than small frequent events (Medrzycka et al., 2016). Large-scale calving events
primarily result from the propagation of fractures triggered by high stresses and sustained by the presence of
water, which causes the crack to deepen (Benn et al., 2007).
Here, a 2D Shallow Shelf Approximation (SSA) model is implemented with an ad-hoc boundary condition that
accounts for the effect of water-filled crevasses on the ice flow and is applied to the calving front of Bowdoin
glacier, North-West Greenland. Using the SSA instead of the more computationally expensive 3D Full Stokes
(FS) model is justified since the contribution of the ice deformation to the total motion is small compared to
the basal motion for the calving front of Bowdoin glacier. The SSA model is validated against the FS velocity
field computed with Elmer/Ice and ice flow fields inferred by Unmanned Aerial Vehicle photogrammetry and
feature-tracking techniques (Jouvet et al., 2017).
D. I. Benn et al. Calving processes and the dynamics of calving glaciers. Earth-Science Reviews, 82:143-179,
2007.
G. Jouvet et al. Initiation of a major calving event on the Bowdoin glacier captured by UAV photogrammetry.
The Cryosphere, 11(2):911, 2017.
D. Medrzycka et al. Calving behavior at Rink Isbræ, West Greenland, from time-lapse photos. Arctic, Antarctic,
and Alpine Research, 48(2):263-277, 2016.

1639
Thu_285_CR-6_652
Seasonally Predicting European Glacier Mass Balance using the Arctic Oscillation

Matthias Huss1,2 (huss@vaw.baug.ethz.ch), Daniel Farinotti1,3

1
ETH Zurich, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), Zurich, Switzerland, 2University of
Fribourg, Department of Geosciences, Fribourg, Switzerland, 3Swiss Federal Institute for Forest, Snow and
Landscape Research WSL, Birmensdorf, Switzerland

Estimates of the magnitude of glacier melt during the coming summer season are highly beneficial for water
resource management but predicting meteorological conditions with a lead time of several months is
challenging. Here, we explore the potential of large-scale atmospheric indices to explain and predict observed
variations in long-term mass balance of Swiss glaciers. We rely on a comprehensive 70-year data set of
seasonal mass balance observations from up to a dozen Swiss glaciers. Monthly indices of the major
atmospheric/ocean modes (NAO, AO, AMO, ENSO) are available for the entire study period. By correlating
aggregates of the indices over various combinations of months against observed winter, summer and annual
glacier mass balance anomalies, we investigate the skill of the large-scale indices to explain mass balance
variability. No significant correlations with Alpine winter mass balances were found. Also, indices averaged over
the summer season or annual periods did not correlate with annual or summer balances. However, we found a
significant correlation between the January-to-May Arctic Oscillation Index (air pressure differences in the
North Atlantic) and glacier melt during the subsequent summer season. Fitting a regression model based on the
AO index over 1948-2008 enables to correctly predict the sign of summer balance anomalies of the last decade
in 90% of the cases and with a lead time of four months.

1640
Thu_287_CR-6_1161
Response of Glaciers on James Ross Island to Regional Climate Variability

Kamil Láska1 (laska@sci.muni.cz), Zbyněk Engel2, Daniel Nývlt1, Zdeněk Stachoň1, Jan Kavan1, Michael Matějka1
1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic, 2Charles University,
Faculty of Science, Department of Physical Geography and Geoecology, Praha, Czech Republic

Air temperature records from the Antarctic Peninsula (AP) region show prominent warming trend over the
second half of the 20th century and a significant temperature decrease over last 10 years. Magnitude of
interannual to decadal-scale climate variability, however, differs significantly between western and eastern
side of the AP, reflecting the extreme internal variability of regional atmospheric circulation. In order to
describe a response of glaciers to climate variability, we analyse surface mass-balance, equilibrium line altitude
and air temperature data from Whisky Glacier and Davies Dome in the northern part of James Ross Island on
the eastern side of the AP. The surface mass-balance changes were estimated using the glaciological method
based on ablation stake measurements over the seven years period (2009/10-2016/17). Our results indicate a
change from surface mass loss that prevailed on James Ross Island during the late 20st century to
predominantly positive surface mass balance after 2009/10. We attribute the deceleration of the mass loss and
the spatial pattern of surface mass-balance distribution to the snow redistribution by wind on both glaciers
rather than to temperature changes.

1641
Thu_288_CR-6_1185
Quantifying Greenland Water Budget from Top to Bottom using Radar Sounding

Winnie Chu1 (wchu28@stanford.edu), Dustin Schroeder1

1
Stanford University, Department of Geophysics, Stanford, United States

On the Greenland ice sheet, drainage of surface meltwater produces complex velocity changes that vary
temporarily and spatially. These differential responses likely relate to what happens to the water once it enters
the ice and its interaction with both the englacial and subglacial drainage systems. However, most hydrologic
studies using radar sounding focus on what happens at the bed, neglecting the role of the englacial system.
Also, most radar observations only provide information at a single snapshot in time. The absence of continuous
observations, along with separate treatment of different hydrologic components, makes comprehensive
assessments of melt influence on velocity difficult. Here we demonstrate the application of a high-resolution
ground-based radar system in Store Glacier in western Greenland to continuously measure hydrologic changes
through the ice column to the bed. We capture the development of englacial water storage from spring to
winter. We show how these seasonal changes in englacial storage coincide with basal drainage. We also
present new techniques to quantify and constrain the amount of basal water storage from airborne radar
sounder by merging reflectivity and specularity content of the bed echoes in their subglacial hydrologic
context. By comparing bed echo properties with surface runoff models, we place observational constraints on
the portion of surface water that is drained to the bed versus stored englacially along west coast of Greenland.

1642
Thu_289_CR-6_1262
Assessing Patterns and Drivers of Surface Elevation Change on Devon Ice Cap

Claire Bernard-Grand'Maison1 (cbern085@uottawa.ca), Luke Copland1, David Burgess2

1
University of Ottawa, Geography, Environment and Geomatics, Ottawa, Canada, 2Natural Resources Canada,
Geological Survey of Canada, Ottawa, Canada

Strongly negative mass balances have been observed for glaciers and ice caps in the Canadian Arctic over the
past three decades, with a notable increase since 2005. Major uncertainties in current climate assessment
reports include how glacier dynamics will change under these conditions, and the representativeness of in-situ
surface mass balance point data extrapolated over broad spatial scales. In this study, we co-register a suite of
digital elevation data of various resolutions (i.e. ArcticDEM, TanDEM-X, CryoSat-2, IceSAT and NASA airborne
laser altimetry) available for Devon ice cap. From these datasets, we calculate volume change and estimate the
geodetic mass balance of Devon ice cap for distinct time periods over the past 20+ years. Our focus is primarily
over the northwest basin of the ice cap where in-situ surface mass balance has been measured since 1961. An
integrated analysis of available ice surface velocities and derived surface elevation change is used to isolate
thickness change solely due to surface mass balance (accumulation and melt), providing an independent
validation to the long-term glaciological mass balance dataset. Results from this study will increase our
knowledge of the reliability of this historical mass balance dataset, and associated estimates of the
contribution of Devon ice cap to non-steric sea level rise since the 1960s.

1643
Thu_290_CR-6_1276
Concurrence of Quaternary Glaciations of the Third Pole with S and N Poles

Chaolu Yi1 (clyi@itpcas.ac.cn)

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

Choosing the Puruogangri ice field in central Tibet where tectonic is stable, surface erosion is low and
Quaternary glacial relicts are well preserved, and using calibrated 10Be surface exposure dating techniques, we
compare the dates of Quaternary glaciations of the Puruogangri with those of cold records from the ice core
and Quaternary glaciations in the Arctic and Antarctic and find that the major events were coeval in three
regions, suggesting that they are controlled by the same mechanisms in a same climatic system.

1644
Thu_291_CR-6_1283
Reconstructing the Evolution of Glacier Surface using Mass Balance Data

Javier Lapazaran1, Jaime Otero1, Darlington Mensah1, Cayetana Recio-Blitz1, Francisco Navarro1
(francisco.navarro@upm.es)
1
Universidad Politécnica de Madrid, Mathematics Applied to ICT, Madrid, Spain

The availability of sufficiently accurate surface topography of glaciers is essential for a variety of glaciological
studies, including glacier dynamics modelling and mass balance studies. In particular, for glacier dynamics
modelling the surface topography data is necessary for inferring the bed topography from ice-thickness data
collected using ground-penetrating radar. For surface mass balance estimates (SMB) using the glaciological
method, surface topography is required for integrating to the entire glacier the observations performed at
individual points (mass-balance stakes, snow-probing points, snow pits). However, quite often the dates of
these observations do not coincide with that of the surface topography, which implies errors in the derived
estimates. We present a method to estimate the elevation at any point on the glacier surface and at any date
between those of two existing surface topographies, using the seasonal SMB data during the time period
between the two available topographies. From the spatial interpolation of the surface elevation data at the
initial and final dates, the proposed method reconstructs the surface elevation at any date within that period,
in two steps: first, it estimates the elevation change due to the SMB, and second, it estimates the elevation
change due to glacier dynamics.

1645
Thu_293_CR-6_1466
Snow Accumulation Processes on a Retreating Antarctic Tidewater Glacier

Shelley MacDonell1 (shelley.macdonell@ceaza.cl), Martin Sharp2

1
Centro de Estudios Avanzados en Zonas Aridas (CEAZA), La Serena, Chile, 2University of Alberta, Edmonton,
Canada

The glacier complex on King George Island in the South Shetland Islands has been exhibiting accelerated rates
of retreat over the last decade. Several studies have investigated the response of the upper parts of the ice cap,
but the outlet glaciers have received less attention. The Ecology Glacier is a polythermal outlet glacier of the
Warzawa ice field, which is located in the southern quadrant of King George Island. Even though a positive
surface mass balance has been recorded, this glacier has been retreating at a relatively high rate, and analysis
of bathymetry data suggests that there is an overdeepening at the current front of the Ecology Glacier, which
might lead to enhanced retreat rates. As the glacier is sensitive to changes in climate and oceanic conditions, it
is necessary to understand mass balance sensitivities. This study aims to understand accumulation processes
on the Ecology Glacier during a winter season using a multi-method approach. We combine accumulation
stake, snow probing, snowpit, glaciochemical and meteorological datasets taken over the course of one year
with results from related mass balance modelling to understand snow deposition patterns, accumulation
processes and biogeochemical cycling.

1646
Thu_294_CR-6_1510
Spatial and Temporal Changes of the Snow Cover in Greenland

Martin Schneebeli1 (schneebeli@slf.ch), Sascha Bellaire1, Masashi Niwano2, Konrad Steffen3

1
WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland, 2MRI/ JMA, Climate Research
Department, Tsukuba, Japan, 3Swiss Federal Institute for Forest- Snow and Landscape Research WSL,
Birmensdorf, Switzerland

The Greenland ice sheet (GrIS) is known to have the potential to contribute to sea level rise in a warming
climate. The snow cover on the ice sheet, which is the direct link between a potentially warmer atmosphere
and the ice itself, is, however, poorly investigated and little is known about the microstructure and especially
about the spatial and temporal variability of the snowcover, except from indirect evidence from remote
sensing. The dataset gathered during two campaigns in spring 2015 and 2016 are analyzed in detail. It
represents the first detailed spatially distributed observation of the GrIS snowpack since the 1950ies. The
current dataset consists of high-resolution snow profiles located at stations of the Greenland Climate Network.
We link snow physics with snow cover modeling through the evaluation of the snow cover models with high-
resolution snow microstructure measurements. Further, the measured variables are essential for remote
sensing applications (e.g. correlation length for microwave remote sensing, snow surface SSA) and therefore
provide the unique opportunity to unambiguously investigate the microwave emission as well as the albedo of
the snowpack on an ice sheet.

1647
Thu_295_CR-6_1539
Tidewater Glacier Retreat Throughout the Canadian Arctic Archipelago since 1958

Alison Cook1 (alison.cook@durham.ac.uk), Luke Copland2, Brice Noel3, Chris Stokes1, Mike Bentley1, Martin
Sharp4
1
Durham University, Geography, Durham, United Kingdom, 2University of Ottawa, Geography, Ottawa, Canada,
3
Utrecht University, IMAU, Utrecht, Netherlands, 4University of Alberta, Earth and Atmospheric Sciences,
Edmonton, Canada

Recent studies of post-2000 observational data have shown variability in the dynamic ice discharge of
tidewater glaciers throughout the Canadian Arctic Archipelago (CAA). Expanding this to all tidewater glaciers in
the region on a decadal time scale can help identify when glacier retreat began, and determine longer-term
temporal trends in mass balance.
Our study shows that over 94% of 300 tidewater glaciers in the CAA (from southern Baffin Island to Ellesmere
Island, excluding those on the northern coast) have retreated since the earliest observational records (1958-
1960). Mean overall length change between the 1950s and 2015 is -9.3 ma-1 (± 1.38 SE) for the 211 glaciers in
the Queen Elizabeth Islands, and -7.1 ma-1 (± 0.72 SE) for the 89 glaciers on Baffin and Bylot Islands. Length
change rates have been calculated across 6 time intervals, and results indicate a similar trend throughout the
CAA: glaciers show slow retreat in early years, followed by acceleration in retreat rates since the early 2000s.
To understand the primary control behind regional changes, the results have been analysed alongside ocean
temperature records and surface mass balance from the latest atmospheric climate model. Statistical analysis
reveals that on a regional scale ocean temperatures have had little control on the frontal change rates. The
clear correlation with ablation and runoff, however, shows the significant impact that atmospheric
temperature has had on glacier fronts in this region.

1648
Thu_296_CR-6_1647
Features of the Kolka Gllacier Recovery after the Karmadon Disaster

Gennady Nosenko1 (gnosenko@gmail.com), Oksana Rototaeva1, Stanislav Nikitin1

1
Institute of Geography Russian Academy of Sciences, Dept. of Glaciology, Moscow, Russian Federation

There were events that attracted attention by the grand scale of the glacial catastrophe and itsconsequences in
the North Ossetia (Caucasus Mountains) in 2002. The Kolka Glacier was completely thrown out of its bed. The
recovery of a new glacier in the empty circus of the Kolka glacier began almost immediately. This report
describes the next stage of the state of the new Kolka glacier - relative stabilization - and analyzes the features
of the process of its recovery based on the field observations data, modern space images and the data of
changes in summer air temperatures and winter precipitation on the glacier area at the beginning of the 21st
century. In recent years, the rate of increase in the area of the glacier does not exceed 0.015 km2 per year. By
September 2016, its area reached 1.11 km2, the volume - about 0.044 km3. The conditions for the formation of
a new glacier on the empty bottom of the circus differ significantly from the previous ones. In addition to
increase in the summer air temperatures, the thermal balance in the circus has changed due to the increase of
the open surface area of the bed and the lateral moraine. At the same time, the growth of the debris cover on
the glacier restrains the melting process. Fumarolic activity in the crown area of the starboard side of the circus
is preserved and this circumstance the restoration of the Kolka glacier.

1649
Thu_297_CR-6_1674
Modeling the Artificially Triggered Flood of the Mauvoisin Ice Dammed Lake, 1818

Mauro A. Werder1 (werder@vaw.baug.ethz.ch), Matthias Huss1, Martin Funk1

1
ETH Zurich/VAW, D-BAUG, Zürich ETH-Hönggerberg, Switzerland

Almost exactly 200 years ago, on 16 June 1818, the ice-dammed Mauvoisin lake drained catastrophically
causing 44 fatalities and considerable damage in the Rhone Valley, Switzerland. We take the opportunity of this
anniversary to analyze this remarkable glacier lake drainage with numerical simulations.
The Mauvoisin lake formed due to the advance of the Gietro glacier, which is located in a hanging side-valley of
the Val de Bagnes. This advance caused ice avalanches to built up a regenerated glacier behind which a lake
started to form in spring 1818. The authorities of the Canton Valais, under the lead of the engineer and early
glaciologist Ignaz Venetz, decided to artificially drain the lake with a tunnel dug through the ice dam. The early
phase of this mitigation measure was successful: the lake started draining through the tunnel on 13 June 1818
and its level lowered by 10m until 16 June. However, a backward incision of the spillway led to the failure of
the ice dam and subsequent catastrophic drainage of the remaining lake water. The flood wave propagated
down the Val de Bagnes and then down the Rhone valley.
We first give an overview over the historical events. We then present a model of the hydraulics of the lake
drainage based on the melt enlargement and the backward incision of the spillway. We compare model results
for a lake drainage with and without artificial tunnel to assess the effectiveness of the mitigation measures.

1650
Thu_298_CR-6_1795
Glacier Changes in Western Greenland Derived from New Satellite and DEM Data

Frank Paul1 (frank.paul@geo.uzh.ch), Philipp Rastner1

1
University of Zurich, Department of Geography, Zurich, Switzerland

The region to the NW of Jacobshavn Isbrae (Disko Island to Svartenhuk Peninsula) in western Greenland is
hosting >1000 glaciers and ice caps that receive comparably little attention. With the now available image as
well as DEM data from the mid1980s (Landsat TM, Greenland Orthomap and AeroDEM) and ~2015 period
(Landsat 8, Sentinel 2, TanDEM-X DEM and ArcticDEM), it is now possible to study past glacier fluctuations in
detail. However, the region is well known for its surge-type glaciers of which the largest one had a massive
surge in 1995/96 (advance >10 km). Their changes have to be excluded when interpreting length, area or
volume changes in climatic terms as they easily dominate the overall change for the entire region.
In this study, we present a new glacier inventory derived from Landsat 8 and Sentinel 2 satellite scenes (2015-
2017), as well as area and volume changes since the mid1980s using the above datasets. Glaciers were mapped
with the band ratio method and subsequent manual correction (debris, water, shadow, seasonal snow, sea ice).
Drainage divides and topographic data for all glaciers are derived from the TanDEM-X DEM. DEM artefacts
required analysing elevation changes on selected glaciers only. We found generally retreating valley glacier
tongues, a strong area decrease for ice caps at higher elevations, and volume loss (and/or gain) being strongest
for glaciers that have surged. Their elevation changes (>150 m) can be well recognized despite DEM artefacts.

1651
Thu_299_CR-6_2000
Behaviour, Pattern and Dynamics of Vestre Breggerbreen Glacier, Svalbard, Arctic

Sandip Kumar Roy1 (sroy845@gmail.com), Prakash Kumar Shrivastava2, Ashit Kumar Swain2
1
Geological Survey of India, Faridabad, India, 2Geological Survey of India, Gangtok, India

Glaciers cover about 36600 sq km area of the Svalbard Archipelago. Amongst the various types of glaciers
present in the region, the most dominant ones are the continuous ice masses/sheets which are divided into
smaller ice-streams by ridges, nunataks etc. Vestre Broggerbreen (VB) (~4.69 sq km) glacier has been studied
over the period 2009 to 2016. Traditional methods of monitoring/mass balance estimation applied to studying
the glacial dynamics and nature of ice body. Over the last seven years, VB-I shows negative mass balance with a
striking similarity in pattern to that of Austre Broggerbreen. The moraines depicts that a probable recession of
1.2 km of VB snout has taken place over a century. Recent data also show regular retreat of the order of 12
m/yr, giving credence to the fact that low altitude glaciers are shrinking faster. The data show the variable
surface velocity vector with the highest of 5m/yr at the central part of the glacier. The ice thickness estimated
over large areas on VB-I glacier shows a maximum ice thickness of 105m. Basal stress pattern shows differential
stress distribution developed within the glacier. Snow pit data shows numerous refreeze layers which could be
correlated with the local temperature variations. The glacial melt water analysis shows possibility of the
presence of elements like Th, U, which can be aid to thermal heating of the sub-surface of glaciers thereby
adding to the list of causes for their diminishing in this area.

1652
Thu_300_CR-6_2059
A 3D-assessment of Basal Freeze-on for a Greenland Ice-sheet Ablation Region

Gwendolyn J.-M. C. Leysinger Vieli1 (gwendolyn.leysinger@geo.uzh.ch), Mauro A. Werder2, Andrea Walter1,2,

Martin P. Lüthi1, Andreas Vieli1
1
University of Zurich, Geography, Zurich, Switzerland, 2ETH Zurich/VAW, Zurich, Switzerland

Recent ground penetrating radar observations have revealed plume-like englacial structures, rising from the
ice-sheet base reaching up to half of the ice sheet thickness. Such structures are found in the interior as well as
at the margin of the Antarctic and Greenland ice sheet and coincide with a rise in basal topography along ice
flow. We undertake a detailed spatial analysis of basal water flow paths and the 3D-radar-structure of a plume-
like feature in the ablation area of Eqip Sermia in West Greenland and suggest that this structure originates
from basal freeze-on of ascending water flowing along the hydraulic gradient at the ice-sheet base. As the
water at the base is abundant in the ablation region, the amount of water available for freeze-on may be quite
substantial. By means of numerical modelling we investigate the effect of basal-freeze-on and the resulting 3D-
structure. Further, this allows us to make some estimates about the total mass added due to basal freeze-on
and to put it in the context of the catchment mass balance. Such refreezing of melt water at the base is
currently not accounted for in traditional mass-balance assessments.

1653
Thu_301_CR-6_2067
Marginal Lake Drainage and Implications at a Tidewater Glacier in Greenland

Andreas Vieli1 (andreas.vieli@geo.uzh.ch), Martin Luethi1, Philipp Rastner1, Christoph Rohner1, Luc Moreau2,
Remy Mercenier1, Andrea Walter1,3, Nick Beaird4
1
University of Zurich, Department of Geography, Zurich, Switzerland, 2Laboratoire CNRS EDYTEM, Chamonix,
France, 3ETH Zurich/VAW, Zurich, Switzerland, 4Woods Hole Oceanographic Institution (WHOI), Woods Hole,
United States

In summer 2014 a lake at the margin of the Greenland ice sheet drained irreversibly into the relatively shallow
fjord of tidewater outlet glacier Eqip Sermia. Using time series of high resolution digital elevation models from
the ArcticDEM project and UAV surveys, we investigate the evolution of the lake level, the geometric
adjustment of the bounding calving front and the thinning trend of the main outlet glacier trunk between 2011
and 2014. We combine these data with time series of meteorological data, ground surface temperatures,
satellite imagery, time-lapse photographs and fjord surface temperatures in order to reconstruct the timing
and discharge rates of the drainage event and investigate potential triggering mechanisms.
We find that the lake level dropped by 70m and drained subglacially a volume of 70 Mio m3 within 1 to 3 days.
The lake drainage is unprecedented in the satellite era and seems to be preconditioned by the recent rapid
thinning of the outlet glacier Eqip Sermia and triggered by a strong precipitation event. The large pulse of
freshwater and entrained sediment had a profound impact on the circulation and water properties of the fjord
and likely enhanced oceanic melt at the calving front. Further, the drainage event provides an excellent natural
experiment for studying the geometric adjustment of the calving front that bounds the lake to sudden changes
in lake level.

1654
Thu_302_CR-6_2115
East-Antarctic Ice Stream Dynamics Inferred from Monitoring Icequake Activity

Denis Lombardi1 (lombardi@ipgp.fr), Thierry Camelbeeck2, Lionel Benoit3, Olivier Martin4

1
Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Paris, France, 2Royal Observatory of Belgium,
Brussels, Belgium, 3Université de Lausanne, Lausanne, Switzerland, 4Institut National de l'Informaton
Geographique et Forestiere, Paris, France

In Antarctica, investigations of the interactions of fast moving ice streams with the underlying bedrock and
coastal ice shelves provide crucial information about the ice sheet dynamics. Monitoring cryo-seismic activity
sheds new perspectives on cryosphere studies. Since 2010 a permanent seismic station is installed at the
Princess Elisabeth base, in the eastern Dronning Maud Land, East-Antarctica. During the 2014 campaign, 5
other temporary stations were deployed in the nearby Sør Rondane Mountains. Most of the recorded
seismicity is of small magnitude (ML< 1.5) and restricted to the few small outlet glaciers cutting through the
mountain chain. It is associated with largest ice flow speed and significant ice surface topography suggesting a
source origin related to surface crevassing. Two other spots of seismicity are found 80 km westwards along a
30 km wide and flat ice stream. They are distributed upstream and downstream of a 1000 m high bedrock
topography associated with a 75% ice flow speed decrease over an along-flow 25 km distance. While the
seismicity upstream of this bedrock topography may be caused by the ice flow resistance on hard bedrock, the
one downstream may be linked to the rapid increase of ice load over a sediment-covered bed. Investigations of
time occurrence of seismic events confirm two distinct patterns and highlight seasonal variations of the ice
stream dynamics.

1655
Thu_303_CR-6_2306
Regional Modeling of the Antarctic Surface Mass Balance from Multiple Reanalyses

Cécile Agosta1,2,3 (cecile.agosta@gmail.com), Xavier Fettweis1, Christoph Kittel1, Charles Amory1, Hubert Gallée2
1
Université de Liège, Laboratory of Climatology, Liège, Belgium, 2Université Grenoble Alpes / Institut des
Géosciences de l’Environnement (IGE), CNRS - UMR 5001, Grenoble, France, 3LSCE (UMR 8212 CEA-CNRS-
UVSQ/IPSL), Université Paris Saclay, Paris-Saclay, France

Given the scarcity of ground-based observations of the Antarctic surface mass balance (SMB) and the lack of
remote sensing products covering the entire continent, outputs from regional climate models (RCM) have been
extensively employed for mass balance studies of the Antarctic ice-sheet.
The most reliable and used products are currently from the RCM RACMO2 at 27km resolution forced by ERA-
Interim. Here we set up the polar-oriented regional climate model MAR for the Antarctic region at 35 km
resolution and used 6 reanalyses as lateral boundary conditions (ERA-Interim, MERRA2, JRA-55, NCEP1, NCEP2
and 20CRv2) for 1979-2015.
Spatial differences in SMB between reanalyses and RCMs are primarily driven by differences in precipitation.
Whereas SMB patterns are significantly divergent between reanalyses, this is no longer the case after the
downscaling step with RCMs, which all show similarly good performances against ground-based SMB
observations. Regional climate modeling is consequently a valuable step to obtain realistic Antarctic SMB
patterns. A major uncertainty remain in katabatic channels at the ice-sheet margins, where MAR is significantly
dryer than RACMO2 but where there is hardly no observation.
Finally, we show that the interannual and seasonal variability of RCM-downscaled SMB is mostly driven by the
forcing reanalyses, with agreeing results between ERA-Interim, MERRA2 and JRA-55, whereas NCEP1, NCEP2
and 20CRv2 show dissimilar (spurious) temporal variabilities.

1656
Thu_304_CR-6_2425
Echo-free Zone and Internal Radar Reflections around Dome Fuji, Antarctica

Daniela Jansen1 (daniela.jansen@awi.de), Anna Winter1, Nanna Karlsson2, Tobias Binder1, Graeme Eagles1, Veit
Helm1, Sonja Schwerdhelm1, Olaf Eisen1,3
1
AWI – Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, 2Geological Survey of
Denmark and Greenland, Copenhagen, Denmark, 3University of Bremen, Bremen, Germany

We present data from an array of airborne radar lines collected in the 2016/2017 Antarctic season in the region
around Dome Fuji, Antarctica.
The radar campaign is part of the Beyond EPICA - Oldest Ice (BE-OI), and aims to determine a suitable drilling
location to reach undisturbed ice older than 1.5 Ma to extend the record of climate proxies derived from ice
cores.
The nearly 20,000 km of radar lines cover an area of about 170,000 km2, with a spacing of 10 km for most lines
and 15 km for the five southernmost lines. The data were measured with the AWI Electromagnetic Reflection
(EMR) system on board the DC-3 aircraft Polar 6, with a 600 ns pulse at a frequency of 150 MHz. The processed
and filtered radargrams were used to handpick prominent internal reflectors, and the upper boundary of the
echo-free zone, a depth in which most internal radar reflections are lost, leaving a transparent layer between
this depth and the bedrock.
The setup of the radar system results in a vertical resolution of about 50m, with excellent returns from the
bedrock, and also good results for internal reflections. Several consistent reflectors could be picked throughout
most of the lines, allowing for tying in the results to the ice core at Dome F.
Preliminary results show a varying thickness of the echo-free zone over the survey area, with an approximate
thickness of 400 m in regions with thicker ice, and approximately half of this over the more rugged terrain with
thinner ice.

1657
Thu_305_CR-6_2467
A 30-year Mass Balance Data Set from the Hofsjökull Ice Cap, Central Iceland

Thorsteinn Thorsteinsson1 (thor@vedur.is), Tómas Jóhannesson1, Bergur Einarsson1, Oddur Sigurðsson1

1
Icelandic Meteorological Office, Reykjavík, Iceland

Temperate ice caps cover 10% of Iceland. They are located mainly in high-precipitation regions in the central
highlands or near the southern coast and their total volume corresponds to a sea-level equivalent of 9 mm. A
mass-balance program has been operated annually on Hofsjökull in the period 1989-2018. Standard
measurements of winter and summer mass-balance have been conducted on three ice-flow basins comprising
40% of the ice cap, which currently has a total area of 825 km2 and an estimated volume of 186 km3. The
annual mass balance has been negative in all but five of the thirty years of measurements and mass loss
occurred every year in the 20-year period 1995-2014. In total, Hofsjökull has lost more than 10% of its total
volume since 1989. In recent years, digital elevation models of the ice cap have allowed more precise estimates
of volume changes of the ice cap during 2-13 year time windows in the period 1986-2015. Comparison with the
mass balance data set indicates that the traditional winter snow thickness and summer ablation measurements
at ground locations overestimate the annual mass balance by 0.4 m w.eq. on average. We describe main
results from the mass balance program, including data from snow-radar studies which have increased our
knowledge of the precipitation distribution over Hofsjökull and helped explain the origin of the bias in ground-
based measurements.

1658
Thu_306_CR-6_2542
Mass Balance Modelling of Austre Grønfjordbreen Glacier, Svalbard

Nelly Elagina1 (nelly.e.elagina@gmail.com), Stanislav Kutuzov1, Robert Chernov1, Ivan Lavrentiev1, Bulat
Mavlyudov1, Arseniy Kudikov1
1
Institute of Geography, Russian Academy of Sciences, Department of Glaciology, Moscow, Russian Federation

Recent efforts by the Institute of Geography RAS have been aimed at establishing mass balance observation at
Austre Grønfjordbreen (7,6 km2) located 16 km south of Barentsburg. The Arctic archipelago Svalbard consists
of a vast glacierized area which contributes significantly to the sea level rise outside of Greenland and
Antarctica due to recent warming. The glaciers of Svalbard have already experienced an unprecedented
increase in average summer temperatures, melt periods, and rainfall in late autumn and early summer.
Noteworthy a full absence of Austre Grønfjordbreen accumulation zone was pointed out in recent years.
Current goal is to determine the most suitable approach for mass balance simulations and its application for
long time periods assessments.
The physical and mathematical modelling of the internal and external mass transfer of Austre Grønfjordbreen
glacier were carried out using the field work data and remote observations. The dependence of the mass
balance from the certain climatic factors is revealed. We apply spatially distributed model A-MELT (Rets et al.,
2012) using all available glaciological and meteorological measurements carried out since 2012 and energy
balance determination according to spatial grid. The snow line level has been reconstructed using all available
satellite images from 1986 to 2016.
The obtained mass balance gradients are compared with the results of temperature-index simulations and
traditional glaciological methods.

1659
Thu_307_CR-6_2590
Reconstructing the Deglaciation of Ice-free Areas in the Antarctic Peninsula

Marc Oliva1 (marcoliva@ub.edu), Dermot Antoniades2, Santi Giralt3, Ignacio Granados4, David Palacios5, Sergi
Pla-Rabes6, Jesús Ruiz-Fernández7, Jorge Sanjurjo8, Manuel Toro9, Gonçalo Vieira10
1
University of Barcelona, Department of Geography, Barcelona, Spain, 2Université Laval, Department of
Géographie & Centre d'Études Nordiques, Québec, Canada, 3CSIC, Institut of Earth Sciences Jaume Almera,
Barcelona, Spain, 4National Park of Guadarrama, Madrid, Spain, 5Complutense University of Madrid,
Department of Geography, Madrid, Spain, 6CREAF-CSIC, Centre de Recerca Ecològica i Aplicacions Forestals,
Blanes, Spain, 7University of Oviedo, Department of Geography, Oviedo, Spain, 8University of A Coruña, Institute
of Geology, A Coruña, Spain, 9CEDEX, Centre for Hydrographical Studies, Madrid, Spain, 10Universidade de
Lisboa, Centro de Estudos Geográficos-IGOT, Lisboa, Spain

The chronology of the deglaciation of the ice-free environments in the Maritime Antarctica has significant
geomorphological and ecological implications. In the Antarctic Peninsula, most research has focused on lake
sediment records to reconstruct the onset of deglaciation. This is the case for Byers (Livingston Island) and
Barton peninsulas (King George Island). The dating of basal sediments collected from different lakes from these
peninsulas enables inferences of the age of formation of each lake. The integration of multiple ages based on
radiocarbon dating and thermoluminescence permits the reconstruction of regional spatial and temporal
deglaciation patterns. In both peninsulas the deglaciation started at 8 ka cal BP, with the central parts
progressively deglaciated at 5-6 ka cal BP. Finally, during the Late Holocene, glacier fronts remained confined to
their current positions defined by the present frontal moraines, with minor advances and retreats. We are also
conducting research in different ice-free areas using a multiple-dating approach combining absolute
(cosmogenic, lichenometry) and relative dating techniques to reconstruct the spatio-temporal patterns of
glacial oscillations since the Last Glacial Maximum. We will discuss the potential of these techniques as well as
of key areas (nunataks) that will allow comparisons between present and past glacial thinning rates in order to
evaluate the significance of recent patterns within the paleoenvironmental record.

1660
Thu_308_CR-6_2640
Modelling the Drifting Snow Climate of the Antarctic Ice-sheet

Charles Amory1 (charles.amory@uliege.be), Christoph Kittel1, Hubert Gallee2, Xavier Fettweis1, Cécile Agosta3
1
University of Liège, Liège, Belgium, 2Université Grenoble Alpes / Institut des Géosciences de l'Environnement
(IGE), CNRS - UMR 5001, Grenoble, France, 3LSCE (UMR 8212 CEA-CNRS-UVSQ/IPSL), Université Paris Saclay,
Paris-Saclay, France

Drifting snow is an important component of the Antarctic near-surface climate, particularly pronounced in
windy coastal regions of the ice sheet. However, drifting snow measurements suffer from a high scarcity both
in space and time, making it difficult to evaluate model results. This study evaluates the ability of the regional
atmospheric model MAR to reproduce the drifting snow climate of Antarctica. MAR has been run at a fine
spatial (15 km horizontal and 1 m vertical) resolution over the entire continent and forced by ERA-Interim
(1979-2016) at its lateral and ocean boundaries. Model results are evaluated against a compilation of recent
drifting snow data including visual observations, sensor-based measurements and continent-wide remote
sensing products. Seasonal cycle, intra- and inter-annual variability of drifting snow frequency and, when
available, horizontal snow mass transport are discussed.

1661
Thu_309_CR-6_2687
Importance of Snow Cover for Changes in Glacier Geometry, Hansbreen, Svalbard

Mariusz Grabiec1 (mariusz.grabiec@us.edu.pl), Michał Laska1, Aleksander Uszczyk1, Leo Decaux1, Dariusz
Ignatiuk1, Tomasz Budzik1
1
University of Silesia, Faculty of Earth Sciences, Sosnowiec, Poland

Snow is the material forming glaciers and ice caps, hence its supply, spatial distribution, metamorphism and
decay are factors influencing geometry changes of ice masses all over the world. Regular studies on
interseasonal snow depth variability have been carried out using radar sounding on Hansbreen since 2011. The
results show strongly irregular snow distribution, with the thickest snow cover in the western section of the
glacier. The conditions of snow deposition on remaining parts of the glacier are less favourable, but, at the
same time, interseasonal variability of the snow depth is smaller there.
Asymmetric pattern of snow cover distribution on Hansbreen is not reflected in observed in the years 2011-
2014 changes of surface geometry. Despite the fact that the western section of Hansbreen gets maximum
snow accumulation, the actual reduction of the elevation in this area is the greatest. This demonstrates that
the winter mass balance is not a decisive factor determining changes in glacier surface geometry. Hence, the
change in geometry is largely controlled by spatially variable summer ablation and glacier dynamics.
Asymmetric snow distribution only modifies the influence of the above factors on the glacier shape.

1662
Thu_310_CR-6_85
Dynamics of the Antarctic and Greenland Ice Sheets - Evolution of the Geosphere

Alexey Markov1 (am100@inbox.ru)

1
Jilin University, Polar Research Center, Changchun, China

Based on measurements obtained from the deep ice wells, radar and space-based geodetic observations in
Antarctica and Greenland, a number of phenomena of mass transfer in ice were registered which did not fit
into the traditional, albeit hypothetical, ideas of monotonous uniform change in the dynamics of ice sheets.
The availability of new experimental data calls for a review of the existing models of ice sheet dynamics, taking
into account the following features:
1) The ice flow is characterized by sub-horizontal pullback according to the structure, properties and velocity of
ice movement;
2) radar cross sections reflect “isochronous” as well as “isorheological” surfaces;
3) the upper layer of firn “runs down” the lower stratum;
4) the lower masses of ice in the ice sheets move faster, which leads to, among other things, formation of
discharge structures;
5) the bottom third cross section contains structures of the infolded turbulent ice flow;
6) the general spreading of ice sheet represents an array of local glacial streams.

1663
Thu_311_CR-6_1090
Understanding the Spatial Pattern of the Glacier Changes in the Tibetan Plateau

Ninglian Wang1 (nlwang@nwu.edu.cn)

1
Northwest University, Xi'an, China

In recent years, the Karakoram Anomaly has attracted much attention. In order to better understand the
causes of this phenomenon, the spatial pattern of the variations of the glaciers in the whole Tibetan Plateau
should be explored on a longer time scale. During the Little Ice Age (LIA), the glaciers over the Tibetan Plateau
advanced and formed easily recognizable end and lateral moraines, which could be used to identify the extents
of glaciers. We recognized the distributions of the LIA's moraines of about 2000 glaciers over the Tibetan
Plateau. It was found that the glacier areas have reduced by larger than 25% in the southeast Tibetan Plateau
and the northeast margin of the Tibetan Plateau while less than 10% in the northwest Tibetan Plateau
(including the Karakoram) since the LIA. A similar spatial pattern of the shrinkages of the glaciers was also
revealed over the past decades. It's noted that the summer freezing level is much higher than the glacier
median elevation in the southeast Tibetan Plateau while much lower in the northwest Tibetan Plateau, and the
summer freezing level showed a decreasing trend in the northwest Tibetan Plateau (including the Karakoram)
while increasing in the southeast Tibetan Plateau over the past decades. These imply that the summer freezing
level play an important role in the spatial variations of the glaciers over the Tibetan Plateau.

1664
Thu_312_EN-3_566
High Resolution SfM Models of Foot Traffic Impacts in the McMurdo Dry Valleys

Kurt Joy1 (kurtj@waikato.ac.nz), Jayne Belnap2, Charles Lee1, Stephen Cary1

1
University of Waikato, International Centre for Terrestrial Antarctic Research, Hamilton, New Zealand, 2USGS,
Southwest Biological Science Center, Moab, United States

One important but underestimated anthropogenic impact observed in polar deserts such as the McMurdo Dry
Valleys is that of human movement. The unique glacial and lacustrine sediments found within the valley floors
are typically associated with well-developed lag gravels and desert pavements. As footprints and walking tracks
disrupt and break though these protective surfaces, the underlying fine-grained material is exposed and
becomes susceptible to erosion and transport by wind. Therefore, the method in which field parties' travel
across these surfaces is directly related to the long-term impact that may be observed.
To quantify such disturbances, we apply structure from motion photogrammetry (SfM) to map surficial
impacts. A computation technique that analyses groups of overlapping input images, SfM creates a 3D point
cloud of elevation values, similar to those produced from scanning laser systems. Combined with accurately
measured ground control points, SfM-MVS allows high resolution, low error 3D models to be created at a 1:1
scale at a low cost.
Our initial results show that extremely high resolution digital terrain models (DTMs) of human impacts can be
produced, from SfM-MVS derived clouds of up to 120 million points per square metre, using simple
methodologies and equipment. The production of such DTMs at the sub-millimetre vertical scale can provide a
wealth of information about the distribution of surface clasts and post disturbance morphology.

1665
Thu_313_EN-3_1144
The Polar Rock Repository: Preservation of Geological Samples from Antarctica

Anne Grunow1 (grunow.1@osu.edu)

1
Ohio State University, Byrd Polar and Climate Research Center, Columbus, United States

Geological field expeditions in polar regions are logistically difficult, financially expensive and can have a
significant environmental impact on pristine regions. The scarcity of outcrop in Antarctica (98% ice-covered)
makes previously collected rock samples very valuable to the science community. Samples from areas of
unique geological heritage and sites of special scientific interest are available for research from the Polar Rock
Repository (PRR), helping to lessen the impact of proposing additional field work in these distinctive and
potentially fragile areas. The PRR was created by the US National Science Foundation, who recognized the need
for preserving rock, dredge, and terrestrial core samples from polar areas. The PRR curates geological samples
collected primarily from Antarctica and the southern oceans, providing full and open access to both samples
and metadata via the PRR website. More than 44,000 samples are available from the PRR for scientific analysis
to researchers around the globe. In addition to the samples and their basic metadata, the PRR archives
supporting materials from the collector, images of the samples, field maps, air photos, thin sections and any
associated bibliography/DOI's. An advanced search engine for the PRR website allows scientists to “drill down”
into search results using categories and look-up object fields similar to websites like Amazon.

1666
Thu_314_GG-1_2170
Cambrian Palaeontology in North Greenland and the Early Animal Evolution

Tae-Yoon Park1 (typark@kopri.re.kr), Ji-Hoon Kihm2,3, Jusun Woo2, Arne T. Nielsen4, Jakob Vinther5
1
Korea Polar Research Institute, Division of Polar Earth-System Sciences, Incheon, Korea, Republic of, 2Korea
Polar Research Institute, Incheon, Korea, Republic of, 3University of Science and Technology-Korea, Daejeon,
Korea, Republic of, 4University of Copenhagen, Copenhagen, Denmark, 5University of Bristol, Bristol, United
Kingdom

Peary Land of North Greenland is a land of the highest latitude in the northern hemisphere, but has received
limited attention due to its extreme remoteness. Nevertheless, this area holds a celebrated Cambrian fossil
locality, Sirius Passet (82° 47.603′ N, 42° 13.394′ W), which is a conservation Lagersttäte, producing soft-bodied
marine animal fossils of ca. 520 Ma. Since the first discovery of Sirius Passet in 1984, there have been only
seven times of palaeontological expeditions to the area. In 2016 and 2017 seasons, expeditions led by Korea
Polar Research Institute collected ca. 1.5 tons of fossil slabs from the outcrop and the scree of the Lower
Cambrian Buen Formation. The fossils include various metazoans, such as sponges, arthropods, stem-group
arthropods, primitive mollusks, annelids, cycloneuralians including priapulids and loriciferans, primitive
deuterostomes, and possible chordates, which would help reveal the aspect of the 'Cambrian explosion' of the
animals. This area is part of the Northeast Greenland National Park which is the world's largest protected land
area with almost no permanent human settment. North Greenland needs to be more understood in terms not
only of geology, but also of ecology and other research fields. Korea Polar Research Institute is planning to visit
the area for the next two years, which would bring more information on the paleontology, geology, and
ecology of this remote part of the world.

1667
Thu_315_EN-4_43
Geospatial Analysis of Protected Areas in Arctic Regions of Russia

Vladimir Kudrjashov1 (vakudrjashov@rambler.ru)

1
Russian State Hydrometeorological University, Department of Ecology, Saint Petersburg, Russian Federation

Geospatial analysis of the Russian Arctic protected areas (PA) has been carried out by specially developed
information analysis system (IAS). Information support of PA system in the arctic region of Russia was fulfilled
by the IAS. Performance of the IAS can be carried out under management of several operating systems. The IAS
was characterized by the four structural organization levels connected with work flows and information
exchange in the system. Geoinformation system (GIS) was applied as a background and intelligence core of the
IAS. Spatial data base (DB) of the PA system was designed in terms of three freeware DB:
(i) WDPA World Database on Protected Areas of UNEP-WCMC,
(ii) CAFF DB of Conservation Arctic Flora and Fauna organization,
(iii) DB of organizations: Russian Social and Ecological Union, World Wildlife Fund, World Resources Institute,
and the Transparent world. It was fulfilled through retrieving, processing, analysis and modeling on the spatial
and attributive data of the PA. Protected areas were divided into the six arctic physical geography provinces.
The PA system was described by means of the data analysis classical methods such as descriptive statistic
parameters and several models of cluster-analysis with bootstrap replication approach. Artificial neural
networks (ANN) were also used for the analysis, classification and modelling of the PA system.

1668
Thu_317_EN-4_188
The Footprint on Antarctica

Shaun Brooks1 (stbrooks@utas.edu.au)

1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia

Antarctica is the least developed and populated continent on Earth. But does the degree of human activity and
impacts present challenge the imagination and preconceptions of a continent of wilderness? Continually
increasing accessibility has seen research stations, historic sites, runways, field huts, weather stations, tourism
landing areas, maintained traverse routes, and even lighthouses spread across the continent. Occupying these
are a peak population of nearly 5 000 national program personnel and in excess of 35 000 tourists landing per
year resulting in substantial human activity. The history of activity at these sites vary, with some exceeding 115
years. This human presence has resulted in localised modification to the environment with impacts to
biological, scientific, aesthetic and wilderness values. This paper presents the first continent-wide
measurement of these impacts, in the form of spatial datasets of the disturbance and building footprint. These
pioneering data will help to present the actual scale of human impacts on protected Antarctic values, and will
have implications and wide-reaching application for management of conservation and protected areas, policy,
future development, and operations.

1669
Thu_318_EN-4_592
An Analysis of Environmental Incidents for a National Antarctic Program

Shaun Brooks1 (stbrooks@utas.edu.au), Julia Jabour1, Andy Sharman2, Dana Bergstrom2

1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Australian Antarctic
Division, Hobart, Australia

Research stations in Antarctica are concentrated on scarce ice-free habitats. Operating these stations in the
harsh Antarctic climate provides many challenges, including the need to handle bulk fuel and cargo increasing
the risk of environmental incidents. We examined 195 reports of environmental incidents from the Australian
Antarctic Program, spanning six years, to investigate the impacts and pathways of contemporary
environmental incidents. Fuel and chemical spills were most common, followed by biosecurity incursions. The
majority of reports were assessed as having insignificant actual impacts. Either the incidents were small or
rapid response and mitigation procedures minimised impact. During the period only one spill report (4000 l)
was assessed as a 'high' impact. This is despite over 13 million litres of diesel utilised. The majority of incidents
occurred within the existing station footprints. The pathways leading to the incidents varied, with technical
causes predominately leading to spills, and procedural failures leading to biosecurity incursions. The large
number of reports with inconsequential impacts suggest an effective environmental management system with
a good culture of reporting environmental incidents. Our findings suggest that the key to continual
improvement in an ongoing environmental management system is to learn from incidences and take action to
prevent them occurring again, with an end-goal of minimising the residual risk as much as possible.

1670
Thu_319_EN-4_788
Leadership in Conserving the Global Commons: Protecting the Ross Sea, Antarctica

Cassandra Brooks1 (cassandra.brooks@colorado.edu)

1
University of Colorado Boulder, Environmental Studies, Boulder, United States

In October of 2016, nations made history by coming together to adopt the world's largest marine protected
area (MPA) in the Ross Sea, Antarctica. This feat required the consensus of the Commission for the
Conservation of Antarctic Marine Living Resources (CCAMLR), comprised of 24 countries plus the European
Union, and took five years of intense international negotiations, and more than 10 years of scientific planning.
But what actually led to consensus in 2016? I will present on a five-year case study of the Ross Sea MPA process
to reveal what conditions led to success in the ultimate adoption of the MPA. Some key factors included high-
level diplomacy between Russia and the United States, a decade of scientific effort that involved hundreds of
scientists from all over the world, and a wave of targeted international media and the resulting pressure from
millions of global citizens. This talk will also reflect on CCAMLR's ability to find the political will to protect 1.55
million km2 of the Ross Sea region, demonstrating international leadership and inspiring hope that despite
political tensions in other parts of the world, the Antarctic continues to be a global commons dedicated to
peace, science and conservation.

1671
Thu_320_EN-4_1208
Development of a CCAMLR Marine Protected Area in the Antarctic Weddell Sea

Katharina Teschke1,2, Hendrik Pehlke1,2, Thomas Brey1,2 (thomas.brey@awi.de)

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2Helmholtz
Institute for Functional Marine Biodiversity (HIFMB) at University Oldenburg, Oldenburg, Germany

The Antarctic Ocean may contribute considerably to the global network of Marine Protected Areas (MPA), as
proposed by the World Summit on Sustainable Development in 2002. The Commission for the Conservation of
Antarctic Marine Living Resources (CCAMLR) is responsible for establishing Antarctic MPAs. Within the CCAMLR
framework, Germany leads the initiative to establish a MPA in the Weddell Sea region and our group develops
the scientific foundation for this task.
Here, we describe the development of the Weddell Sea MPA proposal within the political context, albeit with
emphasis on its scientific foundation. Our intention is twofold, (i) to explain the science involved and its
specifics in the Antarctic region, and (ii) to visualize how our scientific work is embedded in the political
framework constituted by the diverse interests present within CCAMLR. We will highlight those issues and
steps in particular that represent the most sensitive obstacles on the road towards a CCAMLR Weddell Sea
MPA.

1672
Thu_321_EN-4_1328
Proposal for a MPA in the West Antarctic Peninsula and the Southern Scotia Arc

Mercedes Santos1 (mws@mrecic.gov.ar), Andrea Capurro1, César Cárdenas2, Esteban Barrera Oro1,3, Lorena
Rebolledo2, Enrique Marschoff1
1
Instituto Antártico Argentino/Dirección Nacional del Antártico, Buenos Aires, Argentina, 2Instituto Antártico
Chileno, Punta Arenas, Chile, 3National Scientific and Technical Research Council, Buenos Aires, Argentina

Since 2011, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) has been
working on a development of a representative network of Marine Protected Areas (MPA) around the southern
oceans, with the main objective of the protection of biodiversity. In order to achieve this, during CCAMLR´s
annual meeting 2017, Argentina and Chile introduced a preliminary proposal for a MPA in the West Antarctic
Peninsula and the southern Scotia Arc (D1MPA). The D1MPA proposal is the outcome of an inclusive,
multinational process that started in 2012, based on 143 spatial data layers and associated conservation
objectives and conservation targets. Priority Areas for Conservation have been identified taking into account
potential threats posed by climate change and krill fishery. Preliminary boundaries for the D1MPA were
introduced, in order to assist with the planning process and future management of the area. The aims of this
presentation are to introduce the D1MPA to a wider scientific community, and to look for synergies amongst
different actors/stakeholders involved in the Antarctic Treaty System.

1673
Thu_322_EN-4_1421
RAS: Understanding the Taxonomic Diversity in Antarctica and the Southern Ocean

Hsun-Yi Hsieh1 (hhsunyi@naturalsciences.be), Ben Raymond2, Peter Convey3, Bruno Danis4, Simone-N
Brandão5, Claude De Broyer6, Andrew Clarke3, Rachel Downey7, Hauke Flores8, Ian Hogg9, Christian D.
Jersabek10, Philippe Koubbi11, Sandra Mclnnes3, Thomas Saucède12, Siegel Volker13, Cath Waller14, Elise
Biersma3, Faradina Merican15, Bart Vanhoorne16, Leen Vandepitte16, Anton P. Van de Putte1
1
Royal Belgian Institute for Natural Sciences, Brussels, Belgium, 2Australian Antarctic Division, Tasmania,
Australia, 3British Antarctic Survey/NERC, Cambridge, United Kingdom, 4Université Libre de Bruxelles, Brussels,
Belgium, 5Universidade Federal do Rio Grande do Norte, Department de Geologia (UFRN), Lagoa Nova (Natal),
Brazil, 6Belgian National Committee on Antarctic Research, Brussels, Belgium, 7Australia National University,
Research School of Earth Sciences, Canberra, Australia, 8Alfred Wegener Institute Helmholtz Center for Polar
and Marine Research, Bremerhaven, Germany, 9University of Waikato, Hillcrest, Hamilton, New Zealand,
10
Universität Salzburg, Salzburg, Austria, 11Université Pierre et Marie Curie (UPMC), Paris, France, 12Université
de Bourgogne Franche-Comté, Dijon, France, 13Johann Heinrich von Thünen-Institut, Braunschweig, Germany,
14
University of Hall, School of Environmental Sciences, Hull, United Kingdom, 15Universiti Sains Malaysia, School
of Biological Sciences, Penang, Malaysia, 16Flanders Marine Institute, Oostende, Belgium

The register of Antarctic Species (RAS) is an essential taxonomic compilation system, which serves the scientific
community by providing all authorised taxonomic information for Antarctic and the Southern Ocean biota. RAS
builds upon the Register of Antarctic Marine Species (RAMS) and forms an integral Antarctic component of
World Register of Marine Species (WoRMS).
Here we highlight our recent achievements in harmonising and updating the taxonomy in RAS by cross-
referencing information from databases of species. Information from the Oceanic Biogeographic Information
System (OBIS), Global Biodiversity Information Facility (GBIF) and ANTarctic Algae DATAbase (ANTADATA) are
currently being examined by the taxonomic editors of WoRMS, Interim Register of Marine and Nonmarine
Genera (IRMNG) and RAS for this purpose.
RAS is the most complete and thorough authorised compilation of the taxonomic diversity of Antarctica and
the Southern Ocean. With a cleaned-up authorised backbone, it aims to serve the scientific community by, for
instance, providing knowledge on the taxonomic accumulation at a spatiotemporal scale, identifying taxonomic
groups that are under-represented, and offering an open source analytical tool for scientists with similar
interests in this and other regions.

1674
Thu_323_EN-4_1477
Antarctic Marine Spatial Protection in Black and White

Ricardo Roura1 (ricardo@antarcticocean.org), Claire Christian1, Nicole Bransome2

1
Antarctic and Southern Ocean Coalition, Washington, DC, United States, 2The Pew Charitable Trusts,
Washington, DC, United States

Spatial protection is one of the tools used to protect polar marine environments. In the Southern Ocean, the
Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and related technical bodies
use several forms of area-based instruments to meet the objectives of the 1980 CAMLR Convention. These
include Small Scale Research Units (SSRUs), Vulnerable Marine Ecosystem (VME) areas, and Marine Protected
Areas (MPAs), the latter having been considered by CCAMLR since 2009. Two CCAMLR MPAs have been
adopted, and three more have been proposed. Some of these instruments provide temporary closures, and
some include zoning approaches that regulate activities like research and fishing. Overall, marine spatial
protection schemes apply across a range of spatial and temporal scales, target species, and activities. Aside
from inherent scientific complexities, the adoption and implementation of further protection measures (such
as MPAs) has proven to be increasingly difficult due to political and economic considerations. In this
presentation, we attempt to present this complex arrangement in black and white. We address basic questions
concerning the application of these tools in the Southern Ocean. What activities are covered by these
instruments, and when? What are the gaps in marine spatial protection? We provide an overview of the
current status of Southern Ocean area protections, and make recommendations for improvements.

1675
Thu_324_EN-4_1500
TARDSS: A Decision Support System for Antarctic Environmental Management

Fraser Morgan1 (morganf@landcareresearch.co.nz)

1
Landcare Research, Auckland, New Zealand

Providing the Antarctic policy community the tools and knowledge to support environmental management is
critical for both the health of the Antarctic environment but also the Antarctic Treaty itself. This paper will
introduce a tool that has been designed to provide context to, and assist, the Antarctic Policy community in the
planning, permitting, and implementation of Antarctic activities. The tool, which has been developed with input
from the Antarctic Policy community, leverages new and existing insights into the environmental pressures
facing the Antarctic continent through a range of climate, biological, human activity, geological and soil
perspectives.
The resulting tool is based on the established principle of a 'spatial decision support system', an interactive
approach that provides knowledge to support management using analysis of spatially explicit data. We expect
that this tool would be utilised to enable the conservation of the Antarctic continent through activities such as:
Investigating a NNS incursion and the likelihood of continued incursions in areas based on current and future
climate as well as current and predicted future human activity; The comparison of multiple sites for future
activities or to provide a set of baseline environmental data to support area protection; and supporting a CEP
Member to undertake Environmental Impact Assessment of activities in context with regional scale
environmental patterns.

1676
Thu_325_EN-4_1566
Marine Conservation Incentives: Interdisciplinary Dimensions of Climate Change

Linda Fernandez1 (lmfernandez@vcu.edu), Brooks Kaiser2, Melina Kourantidou2, Jan Sundet3, Niels
Vestergaard2
1
Virginia Commonwealth University, Environmental Studies and Economics, Richmond, United States, 2Southern
Denmark University, Esberg, Denmark, 3Institue of Marine Research, Tromso, Norway

Arctic marine resources overlap is increasing (in space and time) as climate change narrows the availability of
appropriate habitat ranges for existing species to survive, and new species enter and compete. This challenges
the management of both commercial and ecosystem-valued species. Two invasive crab species (snow crab and
red king crab) offer a platform to explore adaptive conservation challenges for Arctic countries facing dynamic
and spatial changes in new (crab) and existing (benthic and commercial) resource productivity. Shifting supply
(US, CAN, NOR, RUS) and increasing demand (esp. Asia) add economic uncertainty to the ecological changes.
Ongoing sovereign and international policy interests matter, as they evolve in ongoing legal cases. The crabs
differ in their uncertainty, biology, economic, climatic and political factors. We exploit these differences using
quantitative and qualitative data in a bioeconomic framework that spans time and space dimensions. The crab
invasions in the Barents Sea region serve as a building block for broader pan Arctic conservation issues in the
Year of Polar Prediction and beyond. Optimal decision-making regarding commercial species such as crab in
ecosystems must incorporate how strategic institutional shifts, occurring in response to the economic
incentives, asymmetrically affect local and global stakeholders in addition to standard concerns over ecological
and economic damages amidst climate change.

1677
Thu_326_EN-4_1588
Ex-situ Conservation of Polar Cyanobacteria in the BCCM/ULC Collection

Annick Wilmotte1 (awilmotte@ulg.ac.be), Kim Beets1, Veronique Simons2, Yannick Lara1,3,4, Benoit Durieu1, Luc
Cornet3,5, Denis Baurain5, H Dail Laughinghouse6
1
University of Liège, InBios-Centre for Protein Engineering, Liège, Belgium, 2Université catholique de Louvain
(UCL), BCCM/MUCL, Louvain la Neuve, Belgium, 3Univesity of Liège, UR-Geology—Paleo-Biogeology-Botany-
Palynology, Liège, Belgium, 4University of Liège, Microbial Processes and Interactions - GemblouxAgroBioTech,
Gembloux, Belgium, 5University of Liège, InBioS—PhytoSYSTEMS, Eukaryotic Phylogenomics, Liège, Belgium,
6
University of Florida/IFAS, Fort Lauderdale Research and Education Center, Fort Lauderdale, United States

The BCCM/ULC public collection is funded by the Belgian Science Policy Office (BELSPO) and aims to gather a
representative portion of Polar cyanobacterial diversity from different ecological origins (limnetic microbial
mats, soil crusts, cryoconites, endoliths, etc.) and ensure their ex-situ conservation in a context of global
change. These strains are available for researchers to study the biodiversity, taxonomy, evolution, adaptations
to harsh environmental conditions, and genomic make-up of Polar cyanobacteria. Currently, there are 120
cyanobacterial strains of Polar origin in the collection (catalogue: http://bccm.belspo.be/catalogues/ulc-
catalogue-search). The strains are kept living and their cryopreservation is currently tested. The collection is ISO
9001 certified for depositing and distributing strains, as part of the multi-site certification of the Belgian
Coordinated Collections of Microorganisms (BCCM) consortium.
Morphological and molecular identification (based on 16S rRNA sequences) indicate that the strains belong to
the orders Chroococcales, Chroococcidiopsidales, Nostocales, Oscillatoriales, Pleurocapsales, and
Synechococcales. This broad genotypic distribution makes the BCCM/ULC collection particularly interesting for
phylogenomic studies. The genomes of several strains are currently being sequenced and the first genome of
an Antarctic cyanobacterial strain, Phormidesmis priestleyi ULC007 was recently published.

1678
Thu_327_EN-4_1814
Krill for All: What the Antarctic Krill Fishery Can Learn from Other Systems

Nicole Bransome1 (nbransome@pewtrusts.org), Rodolfo Werner2,3

1
The Pew Charitable Trusts, Protecting Antarctica's Southern Ocean, Washington, D.C., United States, 2Antarctic
and Southern Ocean Coalition, Washington, D.C., United States, 3The Pew Charitable Trusts, Washington, D.C.,
United States

The notion that marine predators (seabirds and mammals) and fisheries compete for the same resources (i.e.,
small pelagic fish) has been of interest to the marine conservation community for decades. In the Southern
Ocean, fishing grounds for Antarctic krill (Euphausia superba) overlap with foraging ranges of krill-dependent
predators. Combined with the impacts of climate change, competition for resources in the Southern Ocean
could compromise conditions for Southern Ocean species, particularly as the fishery grows. To address these
challenges, the Scientific Committee of the Commission for the Conservation of Antarctic Marine Living
Resources has agreed to advance ecosystem-based management for the krill fishery in its 2017-2021 work plan.
Here, we provide an overview of Antarctic krill fisheries management. Next, we review practices for detecting
and managing for competition between marine predators and fisheries, focusing on two recent synthesis
workshops. These workshops evaluated three approaches to understand fisheries impacts on seabirds and
other predators:
1) models including food web models that parameterize biomass
2) Experimental manipulation of fisheries (e.g., time-area closures) in the vicinity of seabird colonies or marine
mammal rookeries and
3) observational studies.
We share best practices including data requirements and method variations, and hope to initiate a dialogue
where practitioners from Antarctica and other systems can share lessons learned.

1679
Thu_328_EN-4_2009
Persistent Anthropogenic Pressure on Fildes Peninsula

Christina Braun1 (chr.braun@uni-jena.de), Jan Esefeld1, Hans-Ulrich Peter1

1
University of Jena / Institute of Ecology and Evolution, Polar & Bird Ecology Group, Jena, Germany

Fildes Peninsula, King George Island, South Shetland Islands, Antarctic, is characterized by a high biodiversity
and hosts six permanent stations and an airport turning the region into a major logistic hub for the Antarctic
Peninsula. It is the scene of a multitude of human activities including scientific research, station operations,
transport logistics and tourism. Consequently, the human pressure on the local ecosystem affects natural and
historical values. Numerous provisions and guidelines, in particular the Madrid Protocol, have been developed
in order to reduce negative impacts of human activities on fauna and flora. Most of the legally binding and non-
binding provisions have relevance on Fildes Peninsula due the unique concentration of different human
activities.
Human activities and environmental impacts on Fildes Peninsula have been documented and quantified since
2003/04 and have repeatedly revealed substantial shortcomings in the implementation of some aspects of the
Madrid Protocol by resident national Antarctic programmes. Various improvements are in opposition with
current observations of persistent breaches of the legal requirements for environmental protection. Sadly, the
lack of consensus of the local stakeholders hampers the immediate implementation of effective management
measures along with an accompanying monitoring scheme, which is required to prevent a further degradation
of the habitat and to safeguard scientific and environmental values in the area.

1680
Thu_329_EN-4_2095
A Unified Approach to Distribution Modeling of Benthic Habitats at South Georgia

Oliver Hogg1,2,3 (olgg@bas.ac.uk), Veerle Huvenne2, Huw Griffiths1, Katrin Linse1

1
British Antarctic Survey, Cambridge, United Kingdom, 2National Oceanography Centre, Southampton, United
Kingdom, 3University of Southampton, Southampton, United Kingdom

The waters around South Georgia and the South Sandwich Islands are home to some of the highest levels of
marine biodiversity in the Southern Ocean. In 2012 the regional government established a large IUCN category
IV marine protected area for the conservation of this diversity. With the MPA currently in a period of review, a
detailed assessment of the benthic biogeography of the region is paramount, if the importance of its benthic
habitats are to be reflected in spatial planning policy for the region. There is however a mismatch between the
size of this very large MPA and the biological data available to underpin its establishment and inform on its
zonation.
Here we present the findings of a three-year project to map benthic habitats around South Georgia from
coastal waters to deep-sea. Habitat mapping has increasingly been adopted as a means of addressing paucity in
biological data, through use of environmental proxies and biological surrogates. We integrated biological,
geophysical and oceanographic data to evaluate the application of landscape mapping and an ensemble
approach to predictive distribution modelling, in assessing the benthic community structure of the region. This
ambitious synthesis of multi-disciplinary information enabled, for the first time in the Southern Ocean, a
biotopic characterisation of an entire archipelago's benthic habitats and provided a framework for policy
makers to set priorities for its future management.

1681
Thu_330_EN-4_2164
Conserving Terrestrial Antarctic Biodiversity in the Face of Multiple Threats

Jasmine Lee1 (jasmine.lee1@uqconnect.edu.au)

1
University of Queensland, Centre for Biodiversity and Conservation Science, Brisbane, Australia

Like many corners of the globe, Antarctica is subject to multiple threatening processes, including climate
change, invasive species and an expanding human footprint. Prioritising management actions in the face of
these multiple threats is a challenging, yet essential goal for progressing biodiversity conservation in the region.
One method of prioritising management actions for taxonomic groups or regions is using a Priority Threat
Management (PTM) approach, which relies on expert elicitation to derive a cost-efficient outcome. We applied
the PTM approach to terrestrial Antarctic biodiversity in an international workshop that brought together over
twenty-five biodiversity experts, logistics managers and policymakers in Belgium, in July 2017. Here I will
present the results from this workshop, including the identification of management strategies and priority
actions to be employed across the Antarctic region. This work represents a substantial leap for conservation
planning in the region and will be of great use to future management decisions.

1682
Thu_331_EN-4_2351
Analyzing Ballast Water Convention and Polar Code for Arctic Navigable Water

Tanzer Satir1 (tsatir@itu.edu.tr), Burcu Ozsoy1, Ozgun Oktar1

1
Istanbul Technical University, POLREC-Polar Research Center, Istanbul, Turkey

The problem of invasive species in ships' ballast water is getting large over the last few decades due to the
expanded trade and traffic volume. Quantitative data show an alarming rate of increasing bio-invasions in new
areas. The International Convention for the Control and Management of Ships' Ballast Water and Sediments
(BWM Convention) is a new international convention to prevent the potentially devastating effects of the
spread of harmful aquatic organisms carried by ship ballast water has been adopted by the International
Maritime Organization (IMO). IMO has also adopted the International Code for Ships Operating in Polar Waters
(Polar Code). The Polar Code is intended to cover the full range of shipping-related matters relevant to
navigation in waters surrounding the two poles - ship design, construction, and equipment; operational and
training concerns; search and rescue; and, equally important, the protection of the unique environment and
Eco-systems of the polar regions.
Considering that the shipping traffic already increased in Arctic because of the new routes, operations in the
Arctic and even Antarctic environments are exposed to a number of unique risks. In this work, authors analyze
and compare Polar Code and BWM, also evaluates the new requirements for marine environmental protection
and safety of ships for these remote and sensitive areas.

1683
Thu_332_EN-4_2396
A Comparative Study: Polar Regions

Meric Karahalil1 (merickrhll@gmail.com), Burcu Ozsoy1

1
Istanbul Technical University, Polar Research Center, Istanbul, Turkey

While Arctic and Antarctic have some similar geographic aspects, they exhibit differences such as
administration and legal status conditional to their location. On the basis of scientific predictions, Arctic is
warming faster than the global average. The annual minimum Arctic sea ice extent has declined by 50% since
late 1970's. On the other hand the giant iceberg broke free from Antarctica's Larsen C ice shelf which was the
largest ever recorded.
According to sea ice modeling scenarios; Arctic region, is under risk to have larger openings in the future, might
provide a wider area for shipping operations. Unfortunately, several collisions occured in the Arctic already
during such operations. Those incidents have been caused through the special conditions which underlines the
special need for appropriate ship safety infrastructure in form of ports of distress, maritime salvage stations
and bases for search and rescue operations. Arctic is surrounded by land however Antarctica surrounded by the
Southern Ocean which means search and rescue operation standarts can not be same. IMO has adopted the
Polar Code which includes existing regulations on ship safety and pollution prevention of Polar Regions.
However, there is still a debate if it provides significant additional protection for Antarctic waters. In this study
we will discuss the lack of any significant new provisions in Polar Code.

1684
Thu_333_OS-3_53
Establishing the Sea Ice Proxy IPSO25 at the Western Antarctic Peninsula

Maria-Elena Vorrath1 (maria-elena.vorrath@awi.de), Juliane Müller1, Oliver Esper1, Gesine Mollenhauer1,

Christian Haas1, Jens Hefter1, Frank Lamy1
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

Sea ice proxies are important and useful tools to reconstruct the climate and environmental history in polar
regions. In the Southern Ocean, the biomarker IPSO25, a highly branched isoprenoid (HBI) diene produced by
sea ice diatoms (Belt et al., 2016), is not well established yet. To evaluate the advantages and limitations of
IPSO25, recent ocean surface sediments from the southern Drake Passage and the Western Antarctic Peninsula
(WAP) were used for an analysis of several biomarkers (HBIs, sterols, alkenones, GDGTs) and diatom
assemblages.
The concentrations of IPSO25 are significantly high along the WAP and on the shelf, pointing to a spring sea ice
cover. In contrast, IPSO25 is absent in Drake Passage sediments. Similary, the distribution of open marine and
sea ice diatoms suggests a seasonal sea ice coverage at the shelf, along the Bransfield Strait and a reduced sea
ice extent towards the continental slope up to 61° S. These proxy-based sea ice estimates are in good
agreement with satellite-derived sea ice data. The further consideration of e.g. higher unsaturated HBIs
alongside IPSO25 proves helpful and supports the application of IPSO25 as a suitable tool for sea ice and
environmental studies of the past in the Southern Ocean and Antarctica.
Belt et al., 2016. Nature Communications, v. 7, p. 12655.

1685
Thu_334_OS-3_78
Sediment Trap Particles (2014 - 2016) in the Terra Nova Bay of the Ross Sea

Boo-Keun Khim1 (bkkhim@pusan.ac.kr), Hyeong Jeek Kim2, Kyu-Cheul Yoo3, Hyun Cheol Kim3, Sunghan Kim3,
Sangbeom Ha1, Ho Il Yoon3
1
Pusan National University, Busan, Korea, Republic of, 2Korea Advanced Institute of Science and Technology,
Ansan, Korea, Republic of, 3Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

KOPRI mooring system has been operated at Site X1 (74º50.27'S, 166º15.89'E, 1,050 m) during March 2014 to
Dec. 2016 and at Site X2 (74º33.13'S, 167º38.92'E, 850 m) during Feb. 2015 to Jan. 2017, respectively, in the
trough of Drygalski Basin adjacent to Jangbogo Station of the Terra Nova Bay in the southwestern Ross Sea. The
bottom-tethered mooring system was deployed at 550 m below sea level (mbsl) at Site X1 and 350 mbsl at Site
X2, consisting of a Seaguard RCM current meter, a SBE Micro CAT conductivity/temperature recorder, and a 13-
cup time-series sediment trap. However, sediment trap system was not operated at Site X1 during a year of
2015. All flux data (total mass, CaCO3, organic carbon, and biogenic opal) of sediment trap particles show the
distinct seasonal and inter-annual variations. Biogenic opal flux occupies more than half of total mass flux,
indicating that the seasonal diatom bloom is a key process to contribute to the biogenic opal composition.
Higher flux occurred seasonally during a short time of March to May at both sites, but a peculiar high total flux
continued from Feb. to June 2015 at Site X2. During this period, the abnormally high CaCO3 flux was observed.
Inter-annual variation is also distinct, showing that the total flux in April 2016 was remarkably high particularly
at Site X1. These preliminary analytical results will be discussed in terms of physical and sea ice data which have
been organized.

1686
Thu_335_OS-3_248
Analysis of Synoptic Variability of the Antarctic MIZ with in Situ Observations

Ehlke de Jong1 (djnehl001@myuct.ac.za), Marcello Vichi1, Carolin Mehlmann2, Piotr Minakowski2, Thomas
Richter2
1
University of Cape Town, Oceanography and Marine Research Institute, Cape Town, South Africa, 2University of
Magdeburg, Institute of Analysis and Numerics, Magdeburg, Germany

Our knowledge of sea ice variability, which contributes to the detection of climate change trends, stems
primarily from remotely sensed information. However, sea ice in the Southern Ocean is characterised by large
variability that remains unresolved and limits our confidence in the remotely sensed products. Although one of
the biggest seasonal changes on Earth is the annual advance and retreat of the Antarctic sea-ice cover,
relatively little attention has been given to the processes by which the marginal ice zone (MIZ) edge forms and
responds to synoptic events. The objective of this study was to compare sea-ice observations from the SA
Agulhas II to high resolution satellite imagery when transecting the MIZ. The location of the ship was tracked,
allowing a more quantitative description of spatial sea-ice characteristics, specifically focusing on the MIZ and
its edge. SAR as well as ASI-AMSR2 data were used to retrieve sea-ice properties. Extent and concentration
were investigated to evaluate the quality of satellite retrievals with respect to on-board observational
estimates, based on the ASPeCt protocol. To maximize the retrieval of information from previous cruises not
specifically dedicated to sea-ice observations, an algorithm was developed to automatically retrieve sea ice
concentration from still images and videos. This method can be used to obtain quantitative sea-ice data from
vessels of opportunity without the need to have trained personnel on-board.

1687
Thu_336_OS-3_410
Antarctic Sea-ice Lead Frequencies and Regional Distribution from Satellite Data

Fabian Reiser1 (reiser@uni-trier.de), Günther Heinemann1, Sascha Willmes1

1
University of Trier, Environmental Meteorology, Trier, Germany

Leads are elongated cracks within the pack ice more than 50 m in width and up to several hundreds of
kilometers in length. Since sea-ice leads influence the lower atmosphere as well as the ocean it is crucial to
specify their temporal and spatial patterns. They are caused by mechanical forcing such as ocean currents or
wind stress and are therefore short-lived and fast moving objects. Sea-ice leads influence e.g. the fluxes of
moisture and sensible heat from the ocean to the atmosphere as well as the ice production. The characteristics
of leads require a temporally and spatially accurate monitoring. Satellite thermal imagery from the MODIS
sensor is used to produce daily potential lead maps for the entire southern ocean at a spatial resolution of 1.5
km. Data are analyzed for the winter periods from 2002 to 2017. Digital image processing and advanced
filtering techniques are used. In particular, fuzzy logic is applied to minimize errors induced by a
misclassification of leads caused by clouds. A variety of lead characteristics e.g. the object eccentricity is taken
into account to distinguish between leads and artifacts. Here we present improvements of the filtering
algorithms and preliminary results of potential lead occurrences in the Southern Ocean.

1688
Thu_337_OS-3_428
SAR Pancake Ice Thickness in the Southern Ocean during the PIPERS Project

Giuseppe Aulicino1 (g.aulicino@staff.univpm.it), Peter Wadhams2, Flavio Parmiggiani3

1
Università Politecnica delle Marche, Ancona, Italy, 2Univerisità Politecnica delle Marche, Ancona, Italy, 3CNR-
ISAC, Bologna, Italy

Pancake and frazil ice represent an important component of the Arctic and Antarctic cryosphere, especially in
the Marginal Ice Zones. The retrieval of its thickness by remote sensing is, in general, a very difficult task. A
processing system has been developed and refined by these authors in the framework of the EU SPICES project;
it is meant for routinely deriving ice thickness in frazil-pancake regions using the spectral changes in wave
spectra from imagery provided by space-borne SAR systems. This methodology has been successfully tested in
the Beaufort Sea through comparison with ground truth collected during fall 2015.
In the present study, this technique has been adapted and applied to Antarctic frazil/pancake icefields. Several
case studies have been identified using different SAR products (CosmoSkyMed, Sentinel-1, TerraSAR-X). Our
retrievals have been analyzed and validated through the comparison with co-located in situ observations
collected by international research cruises realized in different sectors of the Antarctic region (i.e., Ross Sea,
Weddell Sea). Particular attention has been addressed to in situ information collected in the framework of
2017 PIPERS cruise in the Terra Nova Bay and its polynya.
A broad agreement was found between measured thicknesses and those retrieved from the SAR imagery.
Results and statistics are presented and discussed in details.

1689
Thu_338_OS-3_459
Increase of the Antarctic SIE is Highly Significant only in the Ross Sea

Minghu Ding1 (dingminghu@foxmail.com)

1
Chinese Academy of Meteorological Sciences, Institute of Polar Meteorology, Beijing, China

In the context of global warming, the question of why Antarctic sea ice extent (SIE) has increased is one of the
most fundamental unsolved mysteries. Although many mechanisms have been proposed, it is still unclear
whether the increasing trend is anthropogenically originated or only caused by internal natural variability. In
this study, we employ a new method where the underlying natural persistence in the Antarctic SIE can be
correctly accounted for. We find that the Antarctic SIE is not simply short-term persistent as assumed in the
standard significance analysis, but actually characterized by a combination of both short- and long-term
persistence. By generating surrogate data with the same persistence properties, the SIE trends over Antarctica
(as well as five sub-regions) are evaluated using Monte-Carlo simulations. It is found that the SIE trends over
most sub-regions of Antarctica are not statistically significant. Only the SIE over Ross Sea has experienced a
highly significant increasing trend (p = 0.008) which cannot be explained by natural variability. Influenced by
the positive SIE trend over Ross Sea, the SIE over the entire Antarctica also increased over the past decades,
but the trend is only at the edge of being significant (p = 0.034).

1690
Thu_339_OS-3_479
PIPERS:Ross Sea Ice Freeboard and Thickness Retrieve from IceBridge ATM Data

Liuxi Tian1 (liuxi.tian@my.utsa.edu), Hongjie Xie2, Stephen Ackley1, Jiakui Tang3, Jing Li4
1
University of Texas at San Antonio, San Antonio, United States, 2University of Texas at San Antonio, san
antonio, United States, 3University of Chinese Academy of Sciences, beijing, China, 4State Key Laboratory of
Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences,
lanzhou, China

Ross Sea ice thickness is an important indicator of Antarctic climate change but needs to be evaluated over
several seasons to define any trends. In November (20,21,27 and 28) 2013, NASA'S IceBridge mission flew over
the Ross Sea, Antarctica and collected important surface sea ice data with airborne lidar(ATM) and digital
camera imagery( DMS) for the first time. An automatic lead-classification method based on DMS images is
developed in this paper. Using the leads only, we were able to derive the sea surface height anomaly by
subtracting geoidal mean sea surface height product DTU15 from ATM L1B (~1m resolution) retrieved surface
elevations. We then computed total freeboard (over the sea ice) by subtracting the derived sea surface
anomaly from the difference between ATM L2 retrieved surface elevation (80 m sample width 40 m spacing
along track) and mean sea surface height product DTU15. Preliminary results are, apparent reflectivity values of
leads in Ross Sea are mostly less than 0.15; Track 1 and 4 (the two most near the coast) shows the thickest ice
thickness, which can be as great as three meters. For all tracks (except one) mode thicknesses vary between
0.35-0.45 meter. Track 3 (east-west) shows the thinnest mode ice thickness (0.35 m) and mean ice thickness
(0.48 m). An ATM and DMS mission using the NSF C-130 with the Icepod system was flown in 2016 and will be
repeated in 2017. Using the 2013 mission shown here as a baseline will assist in defining any trends.

1691
Thu_341_OS-3_724
East Siberian Sea Fast Ice: Linkage with Atmospheric Forcing

Valeria Selyuzhenok1 (valeria.selyuzhenok@niersc.spb.ru), Thomas Krumpen2, Matti Leppäranta3, Rüdiger

Gerdes2
1
NIERSC, St. Petersburg, Russian Federation, 2AWI, Bremerhaven, Germany, 3Finnish Meteorological Institute,
Helsinki, Finland

By using operational sea ice charts (Arctic and Antarctic Research Institure, Russia)we analyzed seasonal and
interannual variability of fast ice extent in the East Siberian Sea between 1999 and 2015. We identified key
events in each annual fast ice cycle and linked the occurrence of these events to freezeup and melt onset and
air temperature (FDDs and TDDs). The analysis reveals that fast ice in the region is sensitive to the
thermodynamic processes throughout a season. On the interannual time scale we found a tendency towards
shorter fast ice season. The duration of fast ice season reduces by 1.5 d/y which is in agreement with Arctic-
wide trend. Analyzing fast ice annual cycle in the East Siberian Sea we describe two modes of fast regime
charactered by small (S-mode) and large (L-mode) extent. By liking the occurrence of the modes to
thermodynamic and dynamic factors we suggest the large fast ice extent forms during seasons with
atmospheric circulating favoring sea ice import to the East Siberian Sea. This likely results in a higher rate of sea
ice deformation and formation of grounded sea ice ridges which stabilize extensive fast ice cover. To confirm
this hypotheses, the processes of ice ridging in the East Siberian Sea further investigated.

1692
Thu_343_OS-3_851
Sea Ice Leads Detection using High-resolution SAR Imagery

Yu Zhang1 (yuzhang_spl@whu.whu.cn), Fei Li1, Shengkai Zhang1, Tingting Zhu2

1
Wuhan University, Chinese Antarctic Center of Surveying and Mapping, Wuhan, China, 2Wuhan University,
Collaborative Innovation Center for Territorial Sovereignty and Maritime Rights, Wuhan, China

From sea ice monitoring, the line feature like sea ice leads due to winds and ocean currents not only influences
the exchange of heat between ocean and atmosphere, and it is of great significance for ship navigation. SAR is
sensitive to surface roughness of sea ice with different dielectric properties and polarization feature, and it can
be utilized for detecting leads from SAR imagery. A line operator based edge detection method is proposed for
leads detection in high-resolution SAR imagery. Co-polarization of different polarization channels and
frequencies is investigate to measure the energy distribution of leads from different orientation and
wavelength. Histogram of gradient is calculated, and the linear feature of leads can be extracted after a
segmentation procedure, where the bounding line of leads has the largest gradient with lowest energy. Spatial
smoothing procedure is carried out to connect the segmentation of leads into a curvilinear line. Algorithm is
validated on Sentinle-1 SAR imagery with a pixel spacing of 40 meters and GF-3 SAR imagery in Beaufort Sea.
Main work is listed: 1) A line segmentation based edge detection method is proposed for high-resolution SAR
imagery. 2) The assessment of the proposed segmentation based method and classification based algorithm
has been presented. 3) The preferable parameters sets including incident angle correction, the polarization
ratio threshold and spatial smoothing window size have been discussed.

1693
Thu_344_OS-3_919
The Northern Sea Route under New Ice Conditions

Elena Shalina1 (elena.shalina@gmail.com), Leonid Bobylev1

1
NIERSC, St. Petersburg, Russian Federation

Arctic sea ice area has been decreasing over the last decades and increased area of open waters releases new
possibilities for navigation along the Northern Sea Route (NSR). Model simulations indicate an accelerated
Arctic climate change in the next decades with a potential total loss of Arctic sea ice in summer season around
the middle of this century. Increased area of open water will cause generation of larger waves in the marginal
seas that can make an area dangerous to navigation. Here, we analyze changes in sea ice and wave conditions
in the NSR over the period of satellite observations. The study is done for several standard navigation routes
suggested by NSR Advisory. The decline in the Arctic sea ice extent at the end of melt season has been
estimated at about 10% per decade over the period of satellite observations. In the seas of the Russian Arctic
the similar trend was from -9% per decade in the East-Siberian Sea to -25% per decade in the Kara Sea over the
same period. Satellite data demonstrate almost complete NSR opening in September for the period from 2008
and 2012 and from 2014 to 2017. In 2013 the passage was blocked by the ice in the Vilkitsky Strait, which is
known to be a bottleneck of the whole NSR. Ice conditions in the Kara Gates, Long Strait and Vilkitsky Strait has
been studies separately. In the Vilkitsky Strait, where ice conditions were the heaviest and most changeable,
the average ice concentration has decreased at about 10% per decade.

1694
Thu_345_OS-3_939
Evaluation of the EUMETSAT OSI SAF - ESA CCI Sea-ice Concentration Data Set

Stefan Kern1 (stefan.kern@uni-hamburg.de), Louisa Bell2, Georg Heygster3, Thomas Lavergne4, Leif T.
Pedersen5, Roberto Saldo5, Atle M. Sørensen4, Rasmus T. Tonboe6, Stein Sandven7
1
University of Hamburg, Center for Climate System Research and Sustainability (CEN), Hamburg, Germany,
2
University of Hamburg, Hamburg, Germany, 3University of Bremen, Bremen, Germany, 4Norwegian
Meteorological Institute, Oslo, Norway, 5Danish Technical University, Lyngby, Denmark, 6Danish Meteorological
Institute, Copenhagen, Denmark, 7Nansen Environmental and Remote Sensing Centre, Bergen, Norway

Surface sea-ice area fraction (sea-ice concentration or SIC) data sets derived from satellite microwave
radiometry have been among the backbones to quantify amplification of global climate change in the Arctic
with its remarkable sea-ice cover reduction contrasted by a yet to be understood Antarctic sea-ice cover
variability. For this purpose SIC data sets require the accuracy level of a climate data record (CDR). They should
be insensitive to sensor drift or change. They should include retrieval uncertainties to ease usage for climate
applications. Retrieval limitations should be understood well. We present the maturity of the joint EUMETSAT
OSI SAF and ESA CCI CDRs of daily global SIC at 25 km grid resolution. We find the SIC, its retrieval uncertainty,
and the filters applied to be consistent across sensors. Open water (SIC=0%) is retrieved with a bias < 0.1%.
Pack ice (SIC=100%) is retrieved with a bias < 2% during winter. Associated precisions fall into the retrieval
uncertainty range of 2 - 4%. Retrieval uncertainties reflect seasonal variations of atmospheric and surface
properties. CDR SIC agrees within 3% with SIC derived from ~ 400 Landsat optical images. Over < 0.2 m thick ice
SIC is biased low by up to 20%. Pan-Arctic (regional) SIC differences to 1 minus open-water fraction derived
from nine summers of MODIS data are < 5% (< 20%) but CDR SIC exceeds MODIS net ice surface fraction by up
to 30% during peak melt. Grid resolution 25 km vs. 50 km will be discussed.

1695
Thu_346_OS-3_972
Evaluation of Passive Microwave Sea-ice Concentration Products with Landsat Data

Stefan Kern1 (stefan.kern@uni-hamburg.de), Louisa Bell2, Thomas Lavergne3, Maybritt Meyer2

1
University of Hamburg, Center for Climate System Research and Sustainability (CEN), Hamburg, Germany,
2
University of Hamburg, Hamburg, Germany, 3Norwegian Meteorological Institute, Oslo, Norway

Evaluation of a sea-ice area fraction (sea-ice concentration or SIC) climate data record (CDR) obtained from
satellite microwave (MW) radiometry - like the joint EUMETSAT OSISAF - ESA CCI SIC CDRs - against
independent data is one of the key activities required to quantify its maturity. Optical imagery acquired by the
Landsat satellites provides an independent, high-resolution SIC estimate under clear-sky conditions with
daylight.
In this contribution, we use Landsat optical imagery in bands 2, 3 and 4 of Landsat 5 TM, Landsat 7 ETM, and
Landsat 8 OLI. We compute the broadband surface albedo and classify the scenes into surface types (open
water, thin sea ice, and thick >~ 0.3m sea ice). The resulting Landsat ice maps (with 30 m resolution) are co-
located with the CDR SIC, having grid resolutions between 12.5 km and 50.0 km depending on the MW
frequencies used for the SIC retrieval.
We compare CDR SIC and Landsat SIC of more than 400 clear-sky Landsat images, from both hemispheres, from
years 2002 to 2015. We document a bias between Landsat SIC and the CDR SIC of about 2% to 4%. We discuss
this bias in relation to the type of ice in the scene (thin vs thick), the MW frequencies used in the SIC CDR, and
the Landsat SIC estimation accuracy.

1696
Thu_347_OS-3_1109
Early Holocene Sea Ice Variability in Moubray Bay, Antarctica

Greer Gilmer1 (greer.gilmer@otago.ac.nz), Christina Riesselman1, Kyu-Cheul Yoo2, Jae Il Lee2, Min Kyung Lee2,
Robert M. McKay3
1
University of Otago, Dunedin, New Zealand, 2Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic
of, 3Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand

Laminated diatom oozes collected from Antarctic coastal basins provide an opportunity to create high-
resolution paleoclimate records of ocean-atmosphere variability. The relationship between sediment
geochemistry, diatom assemblages, and related environmental conditions can be utilised to reconstruct a
range of climatic conditions at a particular site through time.
We present results from a unique marine sediment core, LC-62 (4.82m long), collected from Moubray Bay, Ross
Sea, Antarctica. The upper portion of LC-62 comprises a laminated diatomaceous ooze with the horizontal
layering differentiated by changes in colour, texture and density. The lower half of the core is composed of
ooze of the same colours and textures but in undulating and interweaving layers. Overall, δ13C values in LC-62
are more negative than typical Antarctic values (-24-25‰). At the base of the core δ13C is very negative (-33‰)
but becomes more positive up core (-27 to -30‰). Core top samples contain diverse and well-preserved diatom
assemblages characterized by sea-ice associated species. Section break samples are dominated by assemblages
associated with a shallow mixed layer and rapid export and burial, and by variable abundances of sea-ice
associated species. This record will provide a new point of comparison to high-resolution ice and sediment
cores from Antarctica and sediment cores from the mid-latitudes of the Southern Hemisphere.

1697
Thu_348_OS-3_1247
New Insights into the Application of the PIP25 Index in the Arctic Ocean

Jung-Hyun Kim1 (jhkim123@kopri.re.kr), Jong-Ku Gal2, Lukas Smik3, Melanie Wary4, Simon Belt3, Kyung-Hoon
Shin2, Johan Etourneau5, Maria Fernanda Sanchez Goñi4, Seung-Il Nam1
1
Korea Polar Research Institute, Incheon, Korea, Republic of, 2University of Hanyang, Ansan, Korea, Republic of,
3
University of Plymouth, Plymouth, United Kingdom, 4EPOC, University of Bordeaux, Bordeaux, France, 5CSIC-
Universidad Granada, Granada, Spain

In this study we investigated suspended particulate matter (SPM) collected along a transect from the East Sea
of Korea to the Bering Sea from 18 to 28 July in 2015, a multicore (ARA01B-3MUC) retrieved from the Chukchi
shelf region, and a piston core (MD95-2009) taken from the Nordic Seas. We analyzed the samples for the
Arctic sea ice proxy IP25 together with a tri-unsaturated highly branched isoprenoid (HBI triene) and two sterols
(epi-brassicasterol and dinosterol) to assess the suitability of these compounds for the so-called PIP25 index in
the Arctic region as a proxy for sea ice change in the past. Our results highlight that the use of HBI triene, epi-
brassicasterol, and dinosterol, as strict phytoplankton markers for the PIP25 index (i.e. PTIP25, PBIP25 and PDIP25,
respectively), might result in misleading outcomes. Accordingly, our study highlights that more work is needed
to better constrain the use of HBI triene, epi-brassicasterol, and dinosterol, as strict ice-free, open ocean
phytoplankton biomarkers when applying the PIP25 index for reconstructing past sea ice changes.

1698
Thu_349_OS-3_1251
Application of IPSO25 for Reconstructing Sea Ice Conditions in the Amundsen Sea

Nele Lamping1 (nele.lamping@awi.de), Juliane Müller1, Oliver Esper1, Jens Hefter1, Gesine Mollenhauer1,
Gerhard Kuhn1
1
Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany

A continuous decline in sea ice extent has recently been observed in the Amundsen Sea, standing in stark
contrast to observations of an increasing trend in other regions around Antarctica. Polar sea ice plays a key role
in Earth´s global climate system as it has a strong influence on atmospheric and oceanic processes.
Reconstructions of sea ice extent and the understanding of sea ice-induced mechanisms are therefore of
crucial importance.
Here, we apply organic geochemical proxies in order to reconstruct the paleoenvironment in the Amundsen
Sea. Several samples from the Amundsen Sea Shelf will be investigated with a main focus on the reconstruction
of sea ice conditions via a specific organic biomarker, a highly branched isoprenoid (HBI), called IPSO25, which is
produced by sea ice diatoms and well preserved in marine sediments (Belt et al., 2016). For surveying IPSO25 as
a sea ice proxy, surface sediment samples will be investigated, while the analysis of two sediment cores
(PS104/014-3 and PS69/274-1) give insight into the environmental and climatic conditions across the last
deglaciation.
First measurements show highly variable concentrations of IPSO25 at both core sites. Further biomarkers, such
as HBI trienes, GDGTs (TEX86) and sterols will be investigated for reconstructions of SSTs and primary
productivity. Comparisons to diatom assemblages and diatom-derived sea ice concentrations are intended for
an evaluation of both approaches to reconstruct sea ice conditions.

1699
Thu_350_OS-3_1302
Record Low Antarctic Sea Ice Area in Springtime of 2016: Forcing and Responses

Zhaomin Wang1 (zhaomin.wang@hhu.edu.cn)

1
Hohai University, College of Oceanography, Nanjing, China

Antarctic sea ice area reached record lows for the season in the springtime of 2016. The analysis of sea level
pressure from two reanalysis datasets revealed that the atmospheric forcing at southern high latitudes
appeared to be extremely strong during the first three months of 2016, and in June and September 2016,
characterized by record low daily and monthly mean sea level pressure at southern high latitudes. Satellite sea
ice concentration data, winds from ERA-Interim, and results from a global high resolution ocean-sea ice model,
were analyzed to investigate the responses of sea ice and near-surface ocean to such atmospheric forcing. It
was found that the patterns of sea ice anomalies in June and September 2016 were controlled by both the
thermal and dynamical effects of atmospheric forcing. The anomalously strong cyclonic wind forcing at
southern high latitudes associated with extreme atmospheric conditions generated warmer near-surface
oceanic states from April 2016 onwards than in previous years.

1700
Thu_351_OS-3_1327
Sea Ice Reconstruction Over the Last 3ka BP in the Ross Sea (Antarctica)

Tommaso Tesi1 (tommaso.tesi@bo.ismar.cnr.it), Leonardo Langone1, Simon Belt2, Lukas Smik2, Caterina
Morigi3, Karen Gariboldi3, Antonella Gandolfi4, Ester Colizza5, Federico Giglio1, Patrizia Giordano1, Furio
Finocchiaro5, Lucilla Capotondi1, Andrea Gallerani1
1
ISMAR CNR, Bologna, Italy, 2Plymouth University, School of Geography, Earth and Environmental Sciences,
University of Plymouth, Plymouth, United Kingdom, 3Department of Earth Sciences, University of Pisa, Pisa,
Italy, 4Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Ferrara, Italy, 5University of
Trieste, Trieste, Italy

Reconstruction of past changes to sea ice extent is central to understanding the factors that control its
distribution and informs how changes in sea ice might occur in the future. Such reconstructions are often
hindered, however, by poor age control (or resolution) in marine archives, or the absence of robust proxy
signatures. Here, we show preliminary results from a 14.6 m long piston-core collected in the Edisto inlet (Cape
Hallett, Ross Sea, Antarctica). The aim of the project was to obtain a continuous and highly resolved record of
sea ice dynamics and other environmental parameters during the late Holocene. With this goal in mind, the
coring site was chosen in the inner bay where the Holocene unit is particularly expanded (up to 60 m thick).
Bottom core AMS 14C dating of the acid insoluble organic fraction (2820 cal. aBP after reservoir correction)
indicates an average annual sedimentation rate of ca. 0.5 cm/y. X-ray radiographs show well-preserved
laminated sediments dominated by diatom oozes alternating with dark-like sediments likely supplied from the
inner bay. In this abstract, we present high resolution bulk organic carbon geochemistry (δ13C and carbon
content), XRF core scanning data, diatom assemblages and lipid biomarker results. Specific focus will be placed
on the di-unsaturated highly branched isoprenoid biomarker IPSO25, which has been recently proposed as a
proxy of Antarctic landfast sea ice.

1701
Thu_352_OS-3_1362
Southern Ocean SST & Sea Ice Changes: Southern Oceanand Indian Monsoon Linkages

Abhilash Nair1 (abhi00777@gmail.com), Rahul Mohan1, Xavier Crosta2, Manoj M.C3, Thamban Meloth1, Arto
Miettinen4
1
National Centre for Antarctic & Ocean Research (ESSO-NCAOR), Vasco da Gama, India, 2Universite Bordeaux,
Bordeaux, France, 3Birbal Sahni Institute of Paleosciences, India, Lucknow, India, 4Norwegian Polar Institute,
Tromsø, Norway

Here we present the Southern Ocean (SO) pastsea ice (SI) duration and summer SST estimates utilizing
2sediment cores.SSTs and SIreconstructionis based on diatom transfer function and is compared with other
climatic records from SO and Arabian Sea. SIrecords reconstructed here reveal that the SI presence at the core
siteswasdiscontinuous during the past. SIwas largely absent at the core site during the interglacial stages.
Nonetheless, the winter SIpresence of 1 month/year at the core sites was evident during glacial periods. The
advance phases of SI coverage which occurredduring the glacial periods (MIS 2, 3 and 4) apparently coincided
with the drop in summer SSTs. On comparing our records of SSTs and SI with ISM reconstruction, it was seen
that the weakening of ISMduring glacial period was in phase with the equatorward shift of Antarctic SI. In
addition to the SI, the SO fronts werealso likely to have shiftedequatorward during the glacial period,this in
turn is in compliance with the equatorward shift of the southern hemisphere westerly winds. Such latitudinal
changes in the westerly wind belt during glacial-interglacial periodswas recorded to have been in phase with
thenorth-south shift of Intertropical Convergence Zone, thereby hinting at a possible modefor SO and ISM
linkages in the past. Hence there is a need to understand how such modesimpacted the variation of the
thermal gradient developed between the Indian landmass and southern tropical ocean.

1702
Thu_353_OS-3_1408
Modelling the Annual Cycle of Antarctic Sea Ice Extent

Marilyn Raphael1 (raphael@geog.ucla.edu), Mark Handcock2

1
UCLA, Geography, Los Angeles, United States, 2UCLA, Statistics, Los Angeles, United States

Satellite-observed, total Antarctic sea ice extent (SIE) experiences a distinct annual cycle, peaking in September
and troughing in March on average. The amplitude and phase of the annual cycle also varies regionally. What
forces the observed annual cycle and its variations is not completely understood. The average annual cycle may
be calculated by simply taking the average SIE for each day of the year. However, while simple and transparent,
this method produces a value that is subject to substantial variation since it is based on fewer than 40
numbers, one for each year of observed data. It also disguises the fact that the annual cycle might be slowly
changing phase and that the amplitude as well as shape of the daily extent might vary. Here, we present a
model that allows the mathematical and stochastic representation of the proximate forces that lead to the
observed annual cycle of sea ice extent. Our methods allow amplitude and phase dilation and contraction.
Thus, the annual cycle is not constrained to be a fixed cyclical pattern rather, it is a pattern that allows both
temporal dilation and contraction as well as amplitude modulation. We use this model in an ensemble
interpolation to reconstruct missing daily data in the early part of the satellite- observed sea ice data set.
Results are presented and discussed.

1703
Thu_354_OS-3_1653
Comparing Pre-industrial and Late Pleistocene Antarctic Sea Ice Trends

Juliane Müller1,2 (juliane.mueller@awi.de), Gesine Mollenhauer1, Oliver Esper1, Gerhard Kuhn1, Frank Lamy1
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2University
of Bremen, Bremen, Germany

The Antarctic sea ice proxy IPSO25, a highly branched isoprenoid (HBI) alkene (Belt et al., 2016; Massé et al.,
2011), constitutes a promising palaeoceanographic tool for the community of Antarctic polar marine geologists.
In particular, where (or when) the application of diatoms is limited due to silica dissolution, this biomarker
approach seems highly valuable to gain insight into sea ice-ocean-atmosphere interactions. Here, we target at
HBI-based sea ice reconstructions covering the pre-industrial time interval and the last interglacial. Pursuing a
multi-proxy approach, sediment cores obtained during RV Polarstern cruises PS97, PS104 and PS111 in the
southern Drake Passage, the Amundsen and Weddell Sea, respectively, will be investigated for, amongst
others, their biomarker inventory and diatom assemblages to reconstruct sea ice and ocean temperature
changes and associated fluctuations in primary productivity. These records will provide the base for an
assessment of how sea ice variability may have been linked to shifts in atmospheric circulation (ENSO, SAM)
and ocean warming - two of the main drivers of recent environmental changes in the Southern Ocean.
Belt et al., 2016. Nature Communications, v. 7, p. 12655.
Massé et al., 2011. Antarctic Science, v. 23, no. 5, p. 487-498.

1704
Thu_355_OS-3_1824
Comparison of Ice/Water Classification from C- and L-band SAR Imagery

Wiebke Aldenhoff1 (wiebke.aldenhoff@chalmers.se), Céline Heuzé2, Leif E.B. Eriksson1

1
Chalmers University of Technology, Department of Space, Earth and Environment, Gothenburg, Sweden,
2
University of Gothenburg, Department of Marine Sciences, Gothenburg, Sweden

In this article an algorithm for ice/water classification of C- and L-band dual polarization synthetic aperture
radar data is presented. A comparison of the two different frequencies is made in order to investigate the
potential to improve classification results with multi frequency data. The algorithm is based on backscatter
intensities in co- and cross-polarization and autocorrelation as a texture feature. The mapping between image
features and ice/water classification is made with a neural network.
Accurate ice/water maps for both frequencies are produced by the algorithm and the results of the different
frequencies generally agree very well. Differences are found in the marginal ice zone, where the time
difference between acquisitions causes motion of the ice pack.
C-band reliably reproduces the outline of the ice edge, while L-band has its strengths for thin ice/calm water
areas within the icepack.
The classification shows good agreement with ice/water maps derived from met.no ice-charts and radiometer
data from AMSR-2. Variations are found in the marginal ice zone where the generalization of the ice charts and
underestimation of ice concentration from radiometer data limit accuracy. Usage of high resolution dual
frequency data increases timeliness and resolution of sea ice cover information for navigation and modelling.

1705
Thu_356_OS-3_2058
Environmental Sensitivity of Diatom Biomarker Lipids Linked to Ice Edge Dynamics

Lukas Smik1 (lukas.smik@plymouth.ac.uk), Camille Visinand1, Simon Belt1, Katrine Husum2, Phillip Assmy2,
Anette Wold2, Claire Widdicombe3, James Fishwick3, Claire Allen4
1
University of Plymouth, Plymouth, United Kingdom, 2Norwegian Polar Institute, Tromsø, Norway, 3Plymouth
Marine Laboratory, Plymouth, United Kingdom, 4British Antarctic Survey, Cambridge, United Kingdom

In recent years, the source or environmental specificity of certain C25 Highly Branched Isoprenoid (HBI) alkenes
has led to their use as organic geochemical proxies for seasonal sea ice reconstruction. Thus, a mono-
unsaturated C25 HBI termed IP25 provides a useful proxy measure of the past occurrence of Arctic sea ice, a di-
unsaturated HBI (IPSO25) has been proposed as an equivalent proxy for Antarctic sea ice, while a tri-
unsaturated C25 HBI counterpart (HBI III) has been suggested as a possible proxy indicator of the retreating ice
edge during spring in both the Arctic and the Antarctic. Here, the environmental sensitivity of one of these
diatom lipids, HBI III, to ice edge dynamics has been investigated further, through analysis of water column
samples collected from two consecutive annual sampling events north of Svalbard, corresponding to a transect
that tracks the retreating ice margin. Preliminary results show that, within this study area at least, biosynthesis
of HBI III is indeed favoured in locations close to the retreating ice edge, consistent with the sedimentary
distribution of this biomarker in the nearby region. To provide further context to the findings, we also
measured the occurrence of HBI III from a temperate location in the English Channel
(www.westernchannelobservatory.org) spanning three contrasting seasons (spring-autumn). Some new
sedimentary HBI III data from the Antarctic will also be presented.

1706
Thu_358_OS-3_2161
Extraction Method of Arctic Sea Ice and its Multiscale Change Characteristics

Tiantian Feng1 (fengtiantian@tongji.edu.cn), Xiaomin Liu1, Huizi Chen1

1
Tongji University, Shanghai, China

The extent of polar sea ice is one of the key parameters of cryosphere and polar environmental change, which
plays an important role in the study of global climate change. According to the recently research results from
NASA, the extent of Arctic sea ice showed obvious decreasing trend with the average loss of 13.3% per decade,
and decreased significantly since 2007. In this study, a new extraction method of Arctic sea ice is proposed
based on multi-source remote sensing data. The accuracy of extraction results is validated using sea ice
concentration products estimated by microwave data, such as SMMR. On the other hand, the temporal change
analysis results of Arctic sea ice extent are also included. The change characteristics in various time scales, such
as decade, annual, seasonal, are presented by using the extent products from 1979 to 2017, downloaded from
the website of the National Snow and Ice Data Center (NSIDC). Moreover, this study would present the
seasonal changes in the recent 20 years, and the correlation of sea ice changes in long-term and medium-term
is revealed. In the further, we would like to improve the accuracy of extraction results and strive to the
reasonable prediction of the future tendency of Arctic sea ice according to the sequential analysis. These
results could provide important support for the research on global climate change.

1707
Thu_359_OS-3_2226
Sea Ice Volume in the Greenlanad, Irminger and Labrador Seas, 1978 - 2016

Valeria Selyuzhenok1 (valeria.selyuzhenok@niersc.spb.ru), Igor Bashmachnikov1,2, Aleksandra Mushta1

1
NIERSC, St. Petersburg, Russian Federation, 2Saint Petersburg State University, St. Petersburg, Russian
Federation

Deep convection in the Greenland, the Irminger and the Labrador Seas is an inherent part of the Atlantic
Meridional Overturning Circulation (AMOC), which modulates its intensity. Interannual variations in the
intensity of deep convection, among other factors, are thought to be controlled by variations in the intensity of
freshwater fluxes to these regions and the overall sea-ice extent in winter. In this study we investigate the role
of sea ice transport and melting in the freshwater balance of the Greenland, the Irminger and the Labrador
Seas between 1978 and 2016. The study is based on time series of sea ice volume and velocity from Pan-Arctic
Ice Ocean Modeling and Assimilation System (PIOMAS). The analysis revealed variation of the sea ice volume
with periods of 3 and 6-8 years in the Greenland Sea and 8-10 years in the Irminger and Labrador Seas. The 6-8
years cycle in the Greenland Sea lags between a quarter and a half of the period the corresponding variations
in the Irminger and Labrador Seas. The links to the corresponding cycles in oceanic and atmospheric regional
indexes (NAO, AO, AOO, etc.) are analyzed.
The research was supported by RSF project 17-17-01151

1708
Thu_360_OS-3_2291
Antarctic Sea Ice Response to Climate Changes in a Model Study

Doroteaciro Iovino1 (dorotea.iovino@cmcc.it), Verena Haid2, Simona Masina1,3

1
Euro-Mediterranean Center on Climate Change, Ocean Modelling and Data Assimilation, Bologna, Italy,
2
Laboratoire d'Océanographie Physique et Spatiale (LOPS), CNRS, Plouzané, France, 3Istituto Nazionale di
Geofisica e Vulcanologia (INGV), Bologna, Italy

In a warming climate, observations indicate that sea ice surrounding Antarctica has been slowly expanding
since 1979. Changes in the melt rates of Antarctic ice shelves and in atmospheric dynamics are both considered
key drivers of sea ice variability. We present a sensitivity study with a global eddy-permitting ocean-sea ice
model, which aims to investigate how modifications of regional/local climate conditions (freshwater discharge
and wind fields) can affect sea ice properties around Antarctica. Numerical exercises with modified surface
runoff shows that enhanced freshwater supply can increase the sea ice extent. However, a very strong increase
of freshwater will eventually invert the trend. In our runs, the freshwater spatial distribution largely affects sea
ice dynamics and regional sea ice concentration and thickness. Numerical runs with idealised changes of ERA-
Interim wind velocities show that both zonal and meridional wind modifications do only slightly impact regional
properties of sea ice.

1709
Thu_361_OS-3_2353
Interannual Dynamics of the Ice Regime of the Sea of Azov in the XX-XXI Century

Natalia Yaitskaya1,2 (yaitskayan@gmail.com), Anastasia Magaeva1

1
Southern Scientific Centre of the Russian Academy of Scinces, Rostov-on-Don, Russian Federation, 2Sochi
Research Centre, Laboratory of Mathematical Modeling of Natural Processes, Sochi, Russian Federation

Ice regime of the Sea of Azov over the period XX-XXI centuries on the basis of the author´s GIS "Ice regime of
the Southern Seas of the Russia" was investigated. The long-term dynamics of the ice cover, the duration, the
beginning and the end of the ice period was considered. The analysis of the data showed that the average long-
term value of the ice cover of the Sea of Azov is 33% for the period 1950-2015. The average area of fast ice is
6.3% of the total sea area. The duration of ice cover in the coastal weather stationswas reduced by 5 to 9 days.
Typification of winters in terms of severity was carried out for three coastal weather stations: the Taganrog, the
Genichesk, the Kerch. Typification showed that the winters with moderate characteristics are prevail in the
Azov region. A total allocated of 15 severe winters, 70 moderate and 40 soft winters. New classification of
winter periods,which combined all the ice regime parameters and typification winters in terms of severity, was
developed. It is shown that the moderate winter periods are prevalence. A total allocated of 9 severe winter
period, 36 moderate and 21 soft winter periods for GMS «Taganrog» and 8 severe winter period, 41 moderate
and 17 soft winter periods for GMS «Kerch».

1710
Thu_362_OS-3_2555
The Role of Northern Sea Ice Variability during Abrupt Glacial Climate Changes

Henrik Sadatzki1 (henrik.sadatzki@uib.no), Trond Dokken2, Sarah Berben1, Francesco Muschitiello2,3, Ruediger
Stein4,5, Kirsten Fahl6, Eystein Jansen1,2
1
University of Bergen & Bjerknes Centre for Climate Research, Bergen, Norway, 2Uni Research Climate, Bergen,
Norway, 3Lamont-Doherty Earth Observatory of Columbia University, Palisades, United States, 4Alfred Wegener
Institute for Polar and Marine Research, Bremerhaven, Germany, 5University of Bremen, Bremen, Germany,
6
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

Changes in sea ice cover in the Nordic Seas likely played a crucial role in amplifying ocean circulation and
climate changes of the Dansgaard-Oeschger (D-O) cycles during the last glacial. We investigate the role of sea
ice for abrupt Greenland climate changes, using high-resolution sea ice records from two Norwegian Sea cores
covering four D-O cycles at 32-40 ka. These records are based on the sea ice diatom biomarker IP25, open-water
phytoplankton biomarkers (sterols and alkenones) and semi-quantitative phytoplankton-IP25 (PIP25) sea ice
estimates. Our biomarker records indicate that the Norwegian Sea was characterized by a near-perennial sea
ice cover during cold stadials and enhanced open-ocean conditions during warmer interstadials. These changes
in sea ice likely facilitated shifts in atmospheric circulation, potentially contributing to far reaching atmospheric
teleconnections transmitting the D-O climate signals. Moreover, we find that initiation of sea ice retreat
systematically preceded Greenland warming and major deep mixing in the Nordic Seas, acting as a precursor of
oceanic reorganizations that likely generated much of the atmospheric warming of the Greenland D-O events.
We thus conclude that the glacial sea ice variability acted as positive feedback mechanism for abrupt ocean
circulation and Greenland climate change during D-O cycles.

1711
Thu_363_OS-3_1576
Multivariate Biomarker Methods for Reconstructing Arctic Sea Ice Conditions

Deniz Can Koseoglu1 (deniz.koseoglu@plymouth.ac.uk), Simon Belt1, Jochen Knies2,3, Katrine Husum4
1
University of Plymouth, Petroleum and Environmental Geochemistry Group, Plymouth, United Kingdom, 2CAGE
– Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geology, UiT the Arctic University of
Norway, Tromsø, Norway, 3Geological Survey of Norway, Trondheim, Norway, 4Norwegian Polar Institute, Fram
Centre, Tromsø, Norway

The discovery of the C25 Highly-Branched Isoprenoid (HBI) termed IP25 provided a direct geochemical biomarker
approach for reconstructing Arctic sea ice. Subsequent introduction of the PIP25 index, based on the ratio of the
sympagic IP25 and certain pelagic biomarkers (e.g. sterols) facilitated semi-quantitative reconstructions of paleo
spring sea ice concentration (SpSIC).
Despite these developments, the objective selection of appropriate marine open-water biomarkers as pelagic
counterparts to IP25 is challenging, and the same biomarkers may not be applicable in different Arctic regions.
Further, the PIP25 threshold values previously used to classify different sea ice conditions, ranging from open
water (PIP25 < 0.1) to extensive sea ice cover (PIP25 > 0.75) were not based on a reproducible classification
procedure, but arbitrarily estimated using linear regression.
To adress these limitations, we constructed a classification tree (CT) model based on a multivariate set of
sympagic and pelagic HBI biomarkers, including IP25, in ca. 200 surface sediments encompassing the Barents
Sea. The CT model was used to classify sea ice conditions as marginal (< 10% SpSIC), intermediate (10-50%
SpSIC), or extensive (>50% SpSIC) in sediment cores from the Barents Sea spanning the last ca. 13 cal. ka BP.
Comparison of CT model results to PIP25-based SpSIC estimates showed consistent results, supporting the
application of multivariate statistical methods for reconstructing paleo sea ice.

1712
Thu_364_SH-3_84
Ice, Snow, or Canvas? Best Protection against Harsh Weather Conditions

Cornelia Lüdecke1 (c.luedecke@lrz.uni-muenchen.de)

1
University of Hamburg, Hamburg, Germany

Hans Gazert (1870-1961), physician of the German South-Polar Expedition (1901-1903), evaluated various
types of clothes, headgear, gloves, shoes as well as sleeping bags, tents, ice and snow huts and their use during
the exploration of Antarctica around 1900. To demonstrate the historical value of Gazert's manuscript that
contains his findings I will present his thoughts about the best means of protection against harsh weather
conditions in polar regions during sledging excursions.
Particularly interesting is his review of pros and cons of European tents made from canvas or silk of dark or
light colors, ones differing both in size and shape from tents commonly constructed for summer use in the
Arctic by Inuit people. Gazert describes contemporary types of tents developed by Fridjtof Nansen for the
Arctic, or Frederick Cook and Roald Amundsen, as well as Robert Falcon Scott for Antarctic use. Arctic igloos,
Gazert found are very warm, and therefore seem to be very useful for overwintering or to establish a
secondary observing station. He recommended a simpler version to be built each day during sledging trips. Ice
houses were more stable and lasted longer than igloos and were, he said, very good for observatories, but too
cold as accommodation. Apart from Gazert's findings the present paper will also illustrate and discuss further
developments of tents designed by Nansen and Alfred Wegener for use as stations around the year 1929.

1713
Thu_366_SH-3_295
Antarctic Research and the Evolution of Arctic Institutions, c. 1940 -1960

Lize-Marié van der Watt1 (lizemarie.vanderwatt@abe.kth.se), Roberts Peder1, Julia Lajus2

1
KTH Royal Institute of Technology, Division of History of Science, Technology and Environment, Stockholm,
Sweden, 2Higher School of Economics, St Petersburg, Russian Federation

Institutions play a central role in the production of knowledge, and in the maintenance of cultures that
facilitate that production. We argue that the study of research institutes can be used as a window into the
changing nature of science and politics. We study the evolution of four distinct but comparable Arctic research
institutes during the early Cold War: the bi-national Arctic Institute of North America (AINA, US-Canadian), the
Scott Polar Research Institute (SPRI, UK), the Norwegian Polar Institute (NP) (Norway) and the Arctic Research
Institute (ARI, USSR). Using these institutional histories, we show how research in Antarctica - particularly in
connection to the International Geophysical Year (IGY) of 1957/58 - had repercussions for Arctic research. We
demonstrate how this bipolarity can be seen as part of the interplay between logistical and geopolitical
frameworks and choices in polar research agendas. Moreover, focusing on these institutes can reveal how the
relationship between the state, the individual scientists and these institutions as nodes in an international
network were negotiated during the early Cold War.

1714
Thu_367_SH-3_1350
From the Archives of the Unknown Explorer

Judit Hersko1 (jhersko@csusm.edu)

1
California State University San Marcos, Art, Media and Design, San Marcos, United States

This paper explores the research on polar history that shapes my “Unknown Explorer” series. Structured
around objects from the archives of a fictitious, female explorer, Anna Schwartz, this project builds on my
collaboration with scientists and my experience in Antarctica as a recipient of the NSF Antarctic Artists and
Writers Grant. It intersects with the history of both Arctic and Antarctic exploration and science.
The archival structure allows for a layered narrative that explores the bipolar research on climate change as
well as the contrasting histories of exploration at the two poles, with the presence of native populations in the
north and their absence in the south. While the character of Schwarz is fictitious, the archives contain factual
materials from the past and the present. For example, Schwartz who has family ties to the 19th century Austro-
Hungarian North Pole expedition is a photographer and a naturalist who grows obsessed with the microscopic
planktonic snail, the Limacina helicina, through a chance meeting with the son of Admiral Scott in 1935. Her
quest to find this organism in its habitat connects her with Vilhjalmur Stefansson, the Arctic explorer who helps
her join admiral Byrd's Antarctic Expedition in 1939. The archives also incorporate materials pertaining to
Schwartz daughter who follows in her mother's foot-steps and finds that her mother's beloved planktonic snail
functions as the canary in the coalmine when it comes to ocean acidification.

1715
Thu_368_SH-3_1416
Whaling, Claims and a Doctoral Thesis from 1940

Ursula Rack1 (ursula.rack@canterbury.ac.nz)

1
Canterbury University, Gateway Antarctica, Christchurch, New Zealand

Whaling has been a business in the Arctic and Antarctic. Over time, it has also become a political issue,
especially amongst Britain, Norway and Germany. The Northern Sea was mainly controlled by the British
(economy) and the Norwegians (whaling in the North and also in the South). The inter-war period brought
great hardship for Germany because of failed industrial and agricultural developments, the political and
financial pressure from the allied countries and the global financial crises. The so called “fat gap” (lack of
providing enough food for the population) became a political issue for Germany. The attempts of the German
“Schwabenland Expedition” 1938/39 to secure whaling grounds in the South failed. In 1940, a PhD candidate,
Hans-Georg Baare-Schmidt researched the whaling business, science and claims in the Antarctic, mainly by the
British. This thesis shows the political background, economic pressure and national ambitions in the Antarctic.
This paper will explore the complexity of whaling, science and claiming sectors of the Antarctic, as outlined in
the 1940 doctorial research and how the thesis unintentionally provided a vision for, then future,
developments in economic, political and scientific terms, which followed the decades after the Second World
War.

1716
Thu_369_SH-3_1660
Probing Antarctic Ice in the Arctic: Connections in Radioglaciology´s History

Simone Turchetti1 (simone.turchetti@manchester.ac.uk)

1
University of Manchester, Centre for the History of Science, Technology and Medicine, Manchester, United
Kingdom

In the 1960s polar explorers started using airborne radar to measure the depth of the Antarctic ice. There are
several studies (e.g. Turchetti, Dean, Naylor and Siegert, 2008) showing how the development of radio-echo
sounding (RES) was pivotal to establishing morphological profiles of its ice-sheet. RES is still widely used today
to further refine ice depth maps and charts.
Yet the set of crucial experiments catering for the adoption of RES in Antarctica took place at Camp Century,
one of the heavily militarized U.S. bases north of the Arctic Circle. Promoted by the SCAR, two "international
experiments" were completed in the spring of 1962 and 1963. Crews of engineers from several countries tested
a variety of airborne (and land-based) instruments thus gaining a novel understanding of their merits in
penetrating Greenland's ice-sheet and paving the way to their adoption in Antarctica.
In this presentation I re-appraise the history of these land-marking trials in light of a fresh analysis of
unpublished diaries and reports of one of the protagonists: the US Army Signal Corps radio engineer Amory H.
(Bud) White. These papers are revealing of the tests' utility in perfecting the instruments utilized. But also of
their progeny in the context of surveillance-driven Cold War research...
Lit. cited: S. Turchetti, K. Dean, S. Naylor and M. Siegerts, “Accidents and Opportunities: A History of the Radio-
Echo Sounding of Antarctica, 1958-1979,” BJHS 41/3 (2008), pp. 417-444.

1717
Thu_371_SH-3_2420
Sealing in Antarctic during the Nineteenth Century. Three Decades of Archaeology

Maria Ximena Senatore1 (mxsenatore@gmail.com)

1
CONICET, Buenos Aires, Argentina

The main goal of this paper is to show the analytical power that material culture studies have for
understanding the sealers' presence in the history of Antarctica. This paper poses the following general
question: What has the study of material remains meant to our knowledge of the historical sealing industry in
Antarctica? The sealers presence in Antarctica represents the process of exploration and of the incorporation
of an unknown and remote place. From this perspective, I am interested in learning about the particularities of
this process by posing specific questions that help characterize the strategies used by sealers.
This paper presents a summary and meta-analysis of the data produced during three decades of archaeological
research on the topic, addressing specific questions regarding the decisions involved in the uses of space, the
selection of the economic activities developed, the organization of onshore activities and possible temporal
changes in these choices. More specifically, this paper examines whether the sealer strategies were expansive
or focalized in terms of their use of space, were opportunistic or specialized in terms of the resources exploited
and were flexible or rigid in terms of their organization as well as to what degree they changed through time
during the nineteenth century. The data to answer these questions were gathered through a deep review of all
the currently published information.

1718
Thu_372_SH-3_2545
Isla Observatorio and its Significance for Antarctic Expeditions in 1900s

Gabriela Roldan1 (gabriela.roldan@pg.canterbury.ac.nz)

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand

Following the conclusions of the International Geographical Congresses of 1885 and 1899, Argentina built in
1902 a magnetic observatory, a meteorological station and lighthouse at Isla Observatorio, Tierra del Fuego, to
cooperate with international Antarctic expeditions. Although its use only spans a few decades, it was the
required stop for calibrations, meteorological information and even sledge dogs training for polar expeditions
heading South. Its past significance was marked by the visits from well-known polar explorers, such as
Nordenskjold and Charcot, who spent time on the island before and after their Antarctic expeditions. This
paper analyses the international significance of Isla Observatorio in the support for science expeditions at the
beginning of the 20th century, and examines the reasons for the state of disrepair and abandonment of this
National Historic Monument, and the newly discovered interest by the regional and national governments of
Argentina.

1719
Thu_373_SH-3_2556
History of French Polar Shuttles

Emmanuelle Sultan1 (emmanuelle.sultan@mnhn.fr), Daphné Buiron2, Stephane Degast3, Elisa Dupuis4

1
MNHN, DGD REVE, Dinard, France, 2Collectif CryoSalide, Paris, France, 3Degast Reporter, Paris, France,
4
Sorbonne Universités (Université 4), Paris, France

Focus on the French polar fleat from the "Pourquoi Pas? " of Charcot early 1900´s to the brand new Astrolabe,
this paper will demonstrate how those vessels are tools to connect poles, oceans and people using corpus of
memories. To illustrate that point the Astrolabe is used as a case study. The initial corpus is based on the one
used in the book «L´Astrolabe , le passeur de l´Antarctique 1988-2018 » (Buiron and Degast Oct 2017, E/P/A)
build from a collabortive gathering of memories in the framework of the retirement of the « old Astrolabe ».
This corpus points out the evolution of this ship from a simple supply to a platform for research, heritage and
creative solution to logistic issues that concern different polar countries and initiatives. More than a shuttle this
boat is also a bridge between French Polar activities and Tasmanian one as discovered through a pilote study
conducted in Hobart in July 2017 by collecting some memories about this ship which is a second corpus in the
framework of this ongoing work.

1720
Thu_374_SH-6_105
The Surface Ocean-Lower Atmosphere Study in the Polar Oceans

Lisa A. Miller1 (lisa.miller@dfo-mpo.gc.ca), Maurice Levasseur2, Jun Nishioka3, Jacqueline Stefels4, Jessica Gier5
1
Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, Canada, 2Université Laval, Département de
Biologie (Québec-Océan), Québec, Canada, 3Hokkaido University, Institute of Low Temperature Science,
Sapporo, Japan, 4University of Groningen, Groningen Institute for Evolutionary Life Sciences, Groningen,
Netherlands, 5SOLAS International Project Office, GEOMAR Helmholtz Center for Ocean Research, Kiel, Germany

The Surface Ocean-Lower Atmosphere Study (SOLAS) is an international science coordination and capacity-
building body established “to achieve quantitative understanding of the key biogeochemical-physical
interactions and feedbacks between the ocean and the atmosphere, and of how this coupled system affects
and is affected by climate and environmental change.” The new SOLAS science plan places particular emphasis
on air-sea exchange in the polar oceans, including the roles of sea ice and fresh water. Specific high-latitude
activities sponsored by SOLAS include the Biogeochemical Exchange Processes at Sea-Ice Interfaces (BEPSII) and
Cryosphere and Atmospheric Chemistry (CATCH) research communities, and other workshops and working
groups. These polar initiatives integrate research on all five core SOLAS themes: Greenhouse gases and the
oceans; Air-sea interface and fluxes of mass and energy; Atmospheric deposition and ocean biogeochemistry;
Interconnections between aerosols, clouds, and marine ecosystems; and Ocean biogeochemical control on
atmospheric chemistry. The SOLAS Science & Society task team also explores topics such as impacts of
increasing ship-plume emissions on Arctic Ocean biogeochemistry, blue carbon, open-ocean stewardship, and
implications of proposed geoengineering strategies. As a grass-roots science organization, SOLAS encourages
involvement of new people with new ideas for studying air-sea exchange processes and their implications for
the global system.

1721
Thu_375_SH-6_571
Antarctic Sun Lines: Connecting Antarctic Gateway Cities through Art

Adele Jackson1 (adele.jackson@pg.canterbury.ac.nz)

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand

The cities of Cape Town, Christchurch, Hobart, Punta Arenas and Ushuaia can be described as Antarctic
Gateway Cities. Although supporting international Antarctic operations is something these cities have in
common, each city has its own diverse history, culture and political concerns. The significance of the sun is one
unifying factor: the austral summer season is the narrow window of time when Antarctic activity is at its peak.
In October 2017, I established Antarctic Sun Lines working with the Antarctic Gateway Cities research network,
COMNAP, Gateway Antarctica researchers, and the UK and NZ Antarctic Heritage Trusts. Each gateway city and
several Antarctic research and heritage sites hosted a 'Solar Collector' pinhole camera throughout the summer
season. Up to 4 months of sunlight and the ebbing of the summer sun were captured in a single image at each
site. Founded on international collaboration and requiring the active participation of key stakeholders, the
work bridged cultural and political boundaries and created connections.
In this paper I examine the role art can have in supporting international Antarctic relationships. I argue that this
project contributed to shaping a sense of shared identity and offers opportunities for further shared gains:
inspiring new research and continuing creative collaborations; shared international cultural events such as
exhibitions; and opportunities for public engagement.

1722
Thu_376_SH-6_643
ARICE: Arctic Research Icebreaker Consortium

Veronica Willmott1 (veronica.willmott@awi.de), Nicole Biebow1

1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, International Cooperation,
Bremerhaven, Germany

The recent changes and the increased economic activity in the Arctic region have triggered a societal demand
for accurate sea-ice and weather predictions, information on the status of the Arctic Ocean (AO) and its marine
life, and complex predictions of future scenarios. To address these issues and to develop policy
recommendations for a sustainable usage of the AO and its resources, the international Arctic science
community must have access to world-class research icebreakers (RIs) to access the ice-covered AO. The new
EU infrastructure project ARICE joins the efforts of 14 partners from 12 different countries to provide Europe
with better capacities for marine-based research in the AO. ARICE will develop strategies to ensure the optimal
use of the existing polar research vessels and will work towards an International Arctic Research Icebreaker
Consortium which shares and jointly funds operational ship time on the available RIs.
ARICE will also provide transnational access to six key European and international RIs for European scientists,
based on scientific excellence of submitted proposals. Amongst others, it will give access to the winter
experiment MOSAiC on board the PRV Polarstern.
ARICE is partnering with the maritime industry on a “ships and platforms of opportunity” programme and will
improve the research icebreakers' services by exploring into new key technologies which could lead to an
improvement of ship-based and autonomous measurements in the AO.

1723
Thu_377_SH-6_962
International Collaboration at Ny-Ålesund Research Station in Svalbard, Norway

Christina A. Pedersen1 (christina.pedersen@npolar.no), Kai Bischof2, Jack Kohler1, Maarten J. J. E. Loonen3,

Roland Neuber4
1
Norwegian Polar Institute, Fram Centre, Tromsø, Norway, 2University of Bremen, Bremen, Germany, 3University
of Groningen, Groningen, Netherlands, 4Alfred Wegener Institute, Potsdam, Germany

The Ny-Ålesund Arctic Research Station in Svalbard, Norway, is a location for true international research
collaboration. Ny-Ålesund is located at the northernmost point of the warm Atlantic Ocean inflow, and hosts a
sophisticated infrastructure enabling observations of relevant parameters in the ocean, on land, and in the
atmosphere. The site is thus, among other, ideally positioned for research and monitoring of contemporary
environmental changes related to climate change issues. With its long-term data series, the station represents
one of the most important environmental monitoring site in the Arctic, and hosts numerous international
multidisciplinary collaborative science projects from institutions from more than ten nations. With so many
actors and initiatives, it is essential creating coordination tools for increased and enhanced collaboration.
The Ny-Ålesund Science Managers Committee (NySMAC) was established some twenty years ago to enhance
cooperation and coordination between institutions, and includes representatives from all parties with major
vested interests in Ny-Ålesund.
The research in Ny-Ålesund is coordinated through four flagship programs: Atmosphere, Marine System,
Terrestrial Ecosystem and Glaciology. The flagship's chair and science committees are working on establishing
meeting-places for scientific discussions and collaboration, coordinating field-activities, and generally
increasing information flow between the individual research groups.

1724
Thu_378_SH-6_1085
Knowledge Production in Polar Research: Science, Creativity and Infrastructure

Luke Bohanon1 (lukebohanon@ucla.edu)

1
University of California LA, Information Studies, Los Angeles, United States

Remote polar research stations and field camps may embody a long-term combination of extreme weather,
physical boundedness, and blurred boundaries among work, play, and sleep as personnel necessarily work, live,
and socialize within the same, fairly-restricted space. Many of those personnel document and share their
experiences through creative work including writing, visual and performing arts, and craft. This creative
documentation appears to be a common practice in remote research settings and a significant, yet overlooked,
form of knowledge production. In addition to these creative documentation practices, there seems also to be a
more pragmatic type of creativity operating as scientists, engineers, and support staff manipulate station
infrastructure and use limited materials to facilitate their work and domesticate an austere living environment.
Thus, it appears that in these remote research settings, science, creativity, and infrastructure function together
in unexpected and exciting ways; yet, despite the critical implications of polar science, the creative processes at
work in polar research settings have received little scholarly attention. The proposed work uses archival
research and semi-structured interviews to expand scholarly understanding of the roles of creativity in
knowledge production and to advance infrastructure studies by exploring how science and creativity interact
through material, technical, and social infrastructures in remote research settings.

1725
Thu_379_SH-6_1123
Efficacy of Outreach Efforts: An Insight from Stakeholders

Swati Nagar1 (swati23n@gmail.com), Rahul Mohan2

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Antarctic Science Division, Vasco da Gama,
India, 2National Centre for Antarctic & Ocean Research (ESSO-NCAOR), Antarctic Science Division, Vasco da
Gama, India

The role of science in sound decision making is vital. Scientific awareness helps people to see the socio-
scientific problems in different way and try to find their solution or how they can contribute in solving the
problem.
Outreach efforts at NCAOR have been made to link the science with its stakeholders. The pervasiveness of
science is well explained by organizing public lectures and events like Open Day, Antarctic Day, educational
tours, etc for students and/or community. The main aim of such efforts is to make students/ community aware
about the polar sciences with respect to Indian endeavors in Polar Regions and also global socio-scientific
issues like climate change etc. Moreover, the engagement of community creates a sense of appreciation for the
scientist which is a source of motivation and encouragement for scientists.
Although the increased response received from schools and colleges indicates its success. However, a survey
has been conducted to understand and assess the efficacy of outreach activities. The survey included the
opinions and suggestions of school and college teachers, school and college students etc. based on their
experiences either in events or educational tours to NCAOR. The survey indicated increasing interest of
audiences in Polar sciences, which is also a motivation for the team to further improve the outreach activities
so that more and more number of audiences can be approached. This is an attempt to inculcate a scientific
outlook in them.

1726
Thu_380_SH-6_1214
The State of Environmental Science in Svalbard - The SIOS Optimisation Report

Vito Vitale1,2, Sebastian Mernild2,3, Roland Neuber2,4, Piotr Glowacki2,5, Pascal Morin2,6, Ole Jørgen Lønne2,7, Kim
Holmén2,8, Jens Debernard2,9, Øystein Godøy2,9 (data@sios-svalbard.org)
1
Institute of Atmospheric Sciences and Climate (ISAC) Italian National Research Council (CNR), Bologna, Italy,
2
Svalbard Integrated Arctic Earth Observing System (SIOS), Longyearbyen, Norway, 3Nansen Environmental and
Remote Sensing Centre, Bergen, Norway, 4Alfred Wegener Institute Helmholtz Center for Polar and Marine
Research, Potsdam, Germany, 5Institute for Geophysics, Polish Academy of Sciences, Warsaw, Poland, 6French
Polar Institute, Paul-Emile Victor, Brest, France, 7University Centre in Svalbard, Longyearbyen, Norway,
8
Norwegian Polar Institute, Longyearbyen, Norway, 9Norwegian Meteorological Institute, Oslo, Norway

The State of Environmental Science in Svalbard (SESS) is an annual report produced by the Svalbard Integrated
Arctic Earth Observing System (SIOS). It summarises the state of current knowledge of key Earth System
Science parameters in and around the Norwegian High Arctic archipelago of Svalbard. The SESS report outlines
the work that has been done in the previous years within the SIOS cooperation to optimise the observing
system and recommends research priorities for the following year(s).
The report contains information about the long-term monitoring data that form the core of the SIOS observing
system. It will also cover new, innovative monitoring and research that has been carried out through SIOS. The
focus is on integrating datasets, encouraging new thinking about connections between measured parameters
and pursuing quantitative links. In addition to evaluating the state of current knowledge, the SESS report
highlights the questions that remain unanswered and recommends solutions.
SIOS promotes scientific innovation and sees cooperation across nations and disciplines as an important means
to this end. By improving access to new and existing monitoring data, prioritising investment in new research
infrastructure and strengthening collaboration, SIOS will use the SESS report to promote innovative solutions to
answering the big questions in Earth System Science.
The preliminary findings of the first SESS report are presented here. It will be published in autumn 2018.

1727
Thu_381_SH-6_1238
Disaster Diplomacy in the Arctic: Advancing Research and Bridging Boundaries

Katia Kontar1,2 (yekaterina.kontar@tufts.edu), Paul Berkman1,2, Patrizia Duda3, Tuyara Gavrilyeva4,5, Alik Ismail-
Zadeh6,7, Ilan Kelman8,9, Ester Sztein10, Yulia Zaika11
1
Tufts University, Fletcher School of Law and Diplomacy, Medford, United States, 2Science Diplomacy Center,
Boston, United States, 3University College London, Institute for Risk & Disaster Reduction, London, United
Kingdom, 4North-Eastern Federal University, Institute of Engineering & Technology, Yakutsk, Russian
Federation, 5Yakutian Scientific Center of the Russian Academy of Sciences, Department of Regional Economic
and Social Studies, Yakutsk, Russian Federation, 6Karlsruhe Institute of Technology, Karlsruhe, Germany,
7
Russian Academy of Science, Moscow, Russian Federation, 8University College London, Institute for Risk &
Disaster Reduction and Institute for Global Health, London, United Kingdom, 9University of Agder, Kristiansand,
Norway, 10National Academies of Sciences, Engineering, and Medicine, Board on International Scientific
Organizations (BISO), Washington, D.C., United States, 11Lomonosov Moscow State University, Department of
Geography, Moscow, Russian Federation

Disasters are destructive anywhere, but in the Arctic, the disruption is further intensified by the region's unique
features. Lack of preparation for the weather, vast distances, limited physical and communication
infrastructure, and seasonal lack of daylight pose significant obstacles to emergency response in the region.
Collaboration between disaster scholars and practitioners across the Arctic countries could significantly reduce
the adverse impacts of disasters. Examples of collaborative initiatives include search and rescue exercises, and
exchange of best practices in disaster risk and crisis management among emergency managers and Arctic
populations. Benefits of international and interdisciplinary research and practice collaborations include
advancement in risk assessment and monitoring, and disaster risk reduction. Faced with shared risk, opposing
parties are often eager to collaborate to find solutions. Fostering disaster diplomacy in the Arctic would help to
bridge the boundaries between diverse communities with shared risk, and advance scientific understanding of
disasters. The effectiveness of disaster diplomacy was evident in the 2015-2016 collaboration between US and
Russian scientists, emergency managers, regional administration, and communities' leaders to reduce adverse
impacts of spring floods in Alaska and the Sakha Republic (Siberia). This and other examples of effective
disaster diplomacy in the Arctic will be discussed.

1728
Thu_382_SH-6_1308
Young Researchers Develop Lists of Sustainable Practice in Arctic Communities

Josefine Lenz1,2 (josefine.lenz@awi.de), Emily Choy3, Elena Kutnetzowa4, Kristina Brown5, Louis-Philippe Roy6,
Robert Way7
1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Periglacial Research Section,
Potsdam, Germany, 2University of Alaska - Fairbanks, Water and Environmental Research Center, Fairbanks,
United States, 3University of Manitoba, Winnipeg, Canada, 4Norwegian Institute of Science and Technology,
Trondheim, Norway, 5Woods Hole Oceanographic Institution, Woods Hole, United States, 6Yukon College, Yukon
Research Centre, Whitehorse, Canada, 7University of Ottawa, Ottawa, Canada

Pairing scientific and traditional knowledge approaches is crucial to understanding the fate of environmental
systems under ongoing climate change; however creating a bridge between non-local, non-indigenous research
scientists and traditional knowledge holders in northern communities brings its own challenges. In an IASC
cross-cutting initiative, Fellows of the Terrestrial, Cryosphere and Marine Working Groups organized a
workshop on “Community-based Research: Do`s and Don`ts of Arctic Research” bringing together young
researchers with resident Arctic representatives and experts to discuss best practices in the exchange of
traditional and scientific knowledge and in conducting research in northern communities.
The format and organization of the workshop allowed an interactive and fruitful discussion, generating a
diverse list of Arctic Research considerations and sustainable practices. An extensive list of positive (Do`s) and
few negative recommendations (Don`ts) was generated together with the young researchers and Arctic
representatives, including considerations of
(1) the research design and early planning,
(2) the contribution of science to northern communities,
(3) the relationship of researchers and indigenous people,
(4) the communication and overall impression of visiting scientists and
(5) ways to get involved with local people.
This study is a good example of bottom-up strategy development to enhance knowledge transfer between
scientists and indigenous communities.

1729
Thu_383_SH-6_1536
Research Vessel Aranda - Experienced, Refitted and Again Ready for Polar Work

Juha Flinkman1 (juha.flinkman@ymparisto.fi), Paula Kankaanpää1

1
Finnish Environment Institute SYKE, Marine Research Center, Helsinki, Finland

Finnish research vessel Aranda has undergone a major conversion and refit during 2017-2018. In this update
the vessel´s ability and capacity for polar work has been significantly improved and enhanced.
Since commissioning in 1989, Aranda has completed two expeditions to the Antarctic, and several to Arctic
Seas. Aranda was originally designed as a polar r/v, and these properties have been further enhanced in the
conversion/refit. Aranda is oceanic class research vessel, and has very good capacity for 3 season ice edge work
in the Arctic Seas. Aranda is one of very few mid-size polar capacity research vessels, with a very good
capacity/cost ratio, especially in ICES/European Arctic area.
Presentation will give a full description of Aranda´s conversion/refit, and describe her capacity for polar work in
different diciplines, most important of which is arctic biological oceanography, environmental research and
food web studies. Aranda is also very environmentally friendly r/v, with very low noise emission to sea, high
fuel efficiency, and capacity for using biofuels.

1730
Thu_384_SH-6_1644
Year of Polar Prediction - Bridging Boundaries to Improve Environmental Safety

Kirstin Werner1,2 (kirstin.werner@awi.de), Thomas Jung1,2, Helge Goessling1,2, Winfried Hoke1,2, Katharina
Kirchhoff1,2
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2WMO-
WWRP International Coordination Office for Polar Prediction, Bremerhaven, Germany

The Year of Polar Prediction (YOPP) has been initiated by the World Meteorological Organization's World
Weather Research Programme resulting from the ongoing changes in polar regions and increasing new
opportunities such as raising economic, touristic, transportation, and scientific activities. Scheduled from mid-
2017 to mid-2019, YOPP is a major international activity to significantly advance our environmental prediction
capabilities for the polar regions and beyond on a wide range of time scales from hours to seasons. Supporting
improved weather and climate services, various international stakeholders such as the interdisciplinary polar
science community, the operational centres providing but also those using polar forecast products are involved
when it comes to the various YOPP activities such as intensive observing, modelling, prediction, verification,
user-engagement and education. The International Coordination Office for Polar Prediction hosted by the
Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, not only oversees everyday
activities and fosters communication and outreach but also coordinates, plans and prepares details of the
different work packages together with the YOPP steering group and several task teams. Engaging such a wide
range of interdisciplinary and international stakeholder groups, YOPP will contribute to the knowledge base
needed to managing the opportunities and risks that come with polar climate change.

1731
Thu_385_SH-6_1666
Towards the Marine Arctic Component of the Pan-Eurasian Experiment (PEEX)

Timo Vihma1 (timo.vihma@fmi.fi), Petteri Uotila2, Stein Sandven3, Dmitry Pozdnyakov4, Alexander Makshtas5,
Vladimir Ivanov5, Alexander Pelyasov6, Finn Danielsen7, Roberta Pirazzini1, Hanna Lappalainen2, Anna Albin7, Bin
Cheng1, Tuukka Petajä2, Ivan Frolov5, Markku Kulmala2
1
Finnish Meteorological Institute, Helsinki, Finland, 2University of Helsinki, Department of Physics, INAR -
Institute for Atmospheric and Earth System Research, Helsinki, Finland, 3Nansen Environmental and Remote
Sensing Centre, Bergen, Norway, 4Nansen International Environmental and Remote Sensing Centre, St.
Petersburg, Russian Federation, 5Arctic and Antarctic Research Institute, St. Petersburg, Russian Federation,
6
Center for the Arctic and Northern Economies, Council for Research for Productive Forces, Moscow, Russian
Federation, 7Nordic Foundation for Development and Ecology, Copenhagen, Denmark

The recent rapid climate change in the marine Arctic has strong environmental and socio-economic impacts,
which calls for enhancement of cross-disciplinary research. We present a plan for a marine Arctic component of
PEEX. The plan is based on
(a) evaluation of the state and change of the marine Arctic climate and environmental system,
(b) identification of the actual research needs and the state of existing observations in relation to the needs,
(c) evaluation of the information available on the basis of atmospheric and ocean reanalyses,
(d) and evaluation of the relevant socio-economic and cultural aspects that both affect and are affected by the
climate and environmental changes.
Among the first practical steps is establishment of a coherent, coordinated, comprehensive observation
system. It is a pronounced technological and logistical challenge, but advance is possible via international
collaboration, new observation technology, community-based coastal observations respectful for knowledge
holders, better data management, and better reanalyses supporting observations. The marine Arctic
component of PEEX is aimed to be integrated with the well-established structure and activities of the terrestrial
and atmospheric components of PEEX. This requires particular attention to the linkage and feedback processes
between the marine Arctic and Eurasian continent. These include atmospheric transports in and out of the
Arctic, river discharge, and various other coastal processes.

1732
Thu_387_SH-6_1852
Rapid Response to Environmental Emergency Alerts. An INTERACT Initiative

Alexandra Bernardová1 (alex.bernardova@gmail.com), Marie Sabacka1, Josef Elster1, Terry Callaghan2,3

1
University of South Bohemia in Ceske Budejovice, Faculty of Science, Centre for Polar Ecology, Ceske
Budejovice, Czech Republic, 2University of Sheffield, Sheffield, United Kingdom, 3Tomsk State University, Tomsk,
Russian Federation

INTERACT - International Network for Terrestrial Research and Monitoring in the Arctic is an infrastructure
project funded by the EU. Its main objective is to build capacity for identifying, understanding, predicting and
responding to diverse environmental changes throughout the wide environmental and land-use envelopes of
the Arctic. It encompases a circum Arctic network of 82 terrestrial field bases in Europe, Russia, US, Canada and
stations in northern Alpine regions.
Rapid response to environmental emergency alerts, the “Red Phone”, is a work package within INTERACT with
a main goal to help protect Arctic and global residents from the hazards of potential future environmental
emergencies by identifying and responding to any upcoming environmental hazards and disasters. Relevant
agencies and organisations (such as GEO, Arctic council, SAON, COOPEUS, CLINF, etc) are planned to be
contacted to help with rapid response actions.
The Red Phone's main output will be the development of protocols for monitoring of any potential
environmental risks and hazards and a subsequent implementation of an alert system for Arctic research
stations and adjoining territories.
The whole project is dependent on efficient networking throughout the Arctic, for which INTERACT provides a
great platform with its comprehensive net of research stations where sampling and observations can be carried
out simultaneously and comparatively across a wide range of territories, often in remote regions.

1733
Thu_388_SH-6_1876
Polar Research Center - Together Conducting Research in Svalbard

Ireneusz Sobota1 (irso@umk.pl)

1
Nicolaus Copernicus University, Faculty of Earth Sciences, Polar Research Center, Toruń, Poland

Polar Research Center is an independent unit of the university´s Faculty of Earth Sciences of Nicolaus
Copernicus University in Torun.
Main tasks of Polar Research Center are:
- Initiating and leading interdisciplinary research in polar regions and other glaciated areas,
- Encouraging interdisciplinary research projects,
- Supporting Polish Nicolaus University Polar Station. Kaffiøyra, Spitsbergen,
- Cooperation with Polish and foreign polar research institutions,
- Cooperation with non-academic partners interested in polar research and exploration,
- Promoting knowledge about polar regions and their important role in our life and global provesses.
Our research in Svalbard has essentially covered all components of the geographic environment, however with
a particular focus on glaciology, glacial geomorphology, permafrost and periglacial processes, as well as
climatological and biological studies. The glaciology studies cover: mass balance of glaciers, glaciers geometry
change processes, glacier dynamics, glacier surge, glacier-climate interactions, polar hydrology, subaqual extent
change records in the forefields of marine-type glaciers and others.
For us Svalbard is a unique natural research laboratory. It is a place where we can witness processes which
once shaped the surface features of Poland. As such, it provides a perfect educational base for research
fellows, academic staff, and doctoral, postgraduate and undergraduate students.

1734
Thu_389_SH-6_2225
Connecting Polar Research across Boundaries at the Snow Remote Sensing Example

Igor Appel1 (iappel@earthlink.net)

1
TAG, Washington, United States

The presentation considers opportunities of communication, coordination, and collaboration to help span
disciplinary, institutional, international, and sector boundaries at the example of snow remote sensing.
The NASA snow algorithms are capable to provide daily global snow output including subpixel snow fraction at
500 m resolution. Snow fraction information improves downstream remote sensing products: vertical
atmosphere profiles, soil moisture, heat fluxes, etc. The global snow observation is an important component of
land surface and hydrologic models estimating water storage and runoff from melting snow for agricultural and
other activities. Snow cover influences not only the terrestrial water cycle but
climate change too.
Recent developments show increasing interest to fractional snow cover, confirmed by the decisions made by
European Space Agency and Japan Aerospace Exploration Agency to derive snow fraction using visible
observations from Sentinel-3 and GCOM-C respectively. The collaboration between several parties tackling the
same problem can be very promising and successful.
After the SCAR Working Group, SnowAnt, made its first successful action - organizing Snow Science Winter
School, it is recommended that the group contributes efforts aimed at the key goal - improve the knowledge on
processes in Antarctic snow and its feedbacks to the climate system; develop a snow classification for
Antarctica - the tasks impossible without implementing snow remote sensing.

1735
Thu_390_SH-6_2245
Studying the Poverty of Local Communities in the North: Ways of Cooperation

Tuyara Gavrilyeva1,2 (tuyara@list.ru), Nikita Bochkarev2

1
North-Eastern Federal University, Institute of Engineering & Technology, Yakutsk, Russian Federation, 2Yakut
Scientific Centre of Siberian Branch of the Russian Academy of Sciences, Department of Regional Economic and
Social Studies, Yakutsk, Russian Federation

The interdisciplinary project “Comparative analysis of the sources of incomes and the problem of poverty in
traditional communities of northern regions of Russia, the USA and Canada” is running with funding of the
Russian Foundation for Basic Research in 2017-2019. It aims at a comprehensive study of the phenomenon of
poverty among native communities of the northern regions and the development of effective mechanisms to
overcome it.
The first stage of 2017 consists in the analysis of the structure and size of incomes, poverty level as well,
retrospective analysis of the spatial transformation, accessibility to lands and natural resources for the local
people and the evolution of the social policies in designated northern countries. Regional factors that affect
poverty and its long-term retention are studied in conjunction with other factors (institutional, demographic,
and economic). Surveys in selected settlements were implemented on this basis.
Thereby, subjects of presentation and discussion are:
- common issues and national features of poverty including inefficient and redundant mechanisms of social
protection;
- cases of industrial projects affecting the sustainability of the traditional economy and communities of the
indigenous peoples of the Russian North;
- benefits and risks of the local communities under implementation of the model Guaranteed Annual Income or
Basic Income;
- cross-country studies and surveys.

1736
Thu_392_SH-6_2252
The INTERACT Fieldwork Guidebook - A Brief Introduction

Fiona Tummon1 (fiona.tummon@apecs.is), Gerlis Fugmann2, Elmer Topp-Jørgensen3, Morten Rasch4, Ruth
Vingerhagen5, Morgan Seag5, Gwenaelle Gremion6
1
University of Tromsø, Tromsø, Norway, 2APECS Directorate/Alfred Wegner Institute, Potsdam, Germany,
3
Aarhus University, Aarhus, Denmark, 4University of Copenhagen, Copenhagen, Denmark, 5University of
Cambridge, Cambridge, United Kingdom, 6Université de Québec à Rimouski, Rimouski, Canada

The Horizon-2020 INTERACT (International Network for Terrestrial Research and Monitoring in the Arctic) aims
for a geographically comprehensive and excellent state-of-the-art terrestrial research infrastructure
throughout the Arctic and in adjoining forest and alpine regions. The project will help to identify environmental
change, to facilitate understanding and prediction of future change, and to inform decision makers about
societally-relevant impacts. INTERACT uniquely unites 83 research stations offering access to the Arctic and
surrounding regions and stimulating new collaborations and information flow.
Effectively carrying out research in the field means being well-prepared in relation to planning and safe
execution of the field activities. Together with the Association of Polar Early Career Scientists (APECS),
INTERACT is developing a fieldwork planning handbook and a general practical field guide. The handbook will
include recommendations for preparing for fieldwork, covering a wide range of topics such as health and
safety, environmental issues, outreach, and country-specific sections on obtaining relevant permits. The field
guide will be a practical guide to be carried into the field, providing recommendations on practical issues
related to conducting field work at research stations. The handbook and field guide will be developed in
cooperation with INTERACT station managers to make use of their wealth of expertise.

1737
Thu_393_SH-6_2318
Early Career Engagement Bridges Polar Boundaries: A Case Study from Horizon 2020

Jilda Alicia Caccavo1 (jildaalicia.caccavo@studenti.unipd.it), Alexander E. Thornton2, Jean Holloway3, Alice

Bradley4, Ruth Hindshaw5, Fiona Tummon6, Gerlis Fugmann7
1
Università degli Studi di Padova, Dipartimento di Biologia, Padova, Italy, 2University of Alaska Fairbanks,
Fairbanks, United States, 3University of Ottawa, Ottawa, Canada, 4Dartmouth College, Hanover, United States,
5
University of Cambridge, Cambridge, United Kingdom, 6University of Tromsoe, APECS International Directorate,
Tromsø, Norway, 7APECS Directorate/Alfred Wegner Institute, Potsdam, Germany

Early Career Researchers (ECRs) comprise a significant portion of the workforce in the Arctic and Antarctic
communities, yet remain an underutilized resource in many large polar research projects. A key goal of the
Association for Early Career Polar Scientists (APECS) is to develop opportunities for ECRs, and part of that is
achieved by integrating ECRs into polar research and coordination activities from the outset. Benefits to
projects who welcome ECRs include gaining unique perspectives from passionate, skilled minds as well as
having an active role in training future leaders of these groups. APECS also serves as an institutional partner to
support early career involvement to reduce a project's organizational risk of working with ECRs given, for
example, inherent and relatively unpredictable career transitions. This poster will describe opportunities
available to ECRs through APECS' engagement in large consortia like the EU Horizon 2020 funded projects
APPLICATE, INTERACT, ARICE, and NUNATARYUK. APECS is uniquely qualified to plan digital and in-person
training experiences, as evidenced through our long-term webinar series and the Polar Prediction School 2018
as part of APPLICATE. Successful collaborations have depended on early engagement with APECS as a partner in
order to integrate education, outreach, and training activities within these projects. APECS looks forward to
working with other polar research groups to include ECRs through every phase of development.

1738
Thu_394_SH-6_2377
RoSES - Role of the Southern Ocean in the Earth System: A NERC Funded Programme

Elaina Ford1 (eakf@bas.ac.uk)

1
British Antarctic Survey, Cambridge, United Kingdom

The Role of the Southern Ocean in the Earth System - RoSES - is a programme funded by the UK's Natural
Environment Research Counci (NERC) and aims to substantially reduce uncertainty in 21st century global
climate change projections through improved assessment of the Southern Ocean carbon sink. It is a five-year
programme, funded from 2017 to 2022. RoSES (@RoSES_ocean, www.roses.ac.uk) currently consists of three
projects (with a fourth to be funded in due course):
- CUSTARD: Carbon Uptake and Seasonal Traits in Antarctic Remineralisation Depth. Principal Investigator: Dr
Adrian Martin, National Oceanography Centre. #RoSES_CUSTARD
- PICCOLO: Processes Influencing Carbon Cycling: Observations of the Lower limb of the Antarctic Overturning.
Principal Investigator: Prof Karen Heywood, University of East Anglia coPI Tom Bell, Plymouth Marine
Laboratory. #RoSES_PICCOLO
- SONATA: Southern OceaN optimal Approach to Assess the carbon state, variability and climatic drivers.
Principal Investigator: Prof. Corrine Le Quere, University of East Anglia. #RoSES_SONATA
Here we present the aims and objectives of these three projects, and their links to the ORCHESTRA programme
- Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports. @ORCHESTRAproj,
www.bas.ac.uk/projects/orchestra.

1739
Thu_395_SH-6_2525
Arctic Pedagogic Landscape Inquiry Bridging the Polar to the Peak

Bin Li1,2 (bin.li@aho.no)

1
Oslo School of Architecture and Design, Urbanism and Landscape, Oslo, Norway, 2The Arctic University of
Norway, Tromso, Norway

Synthesis of high latitude and high altitude, territories of high peaks expand from Arctic polar regions to the
Third Pole Hindu Kush-Himalayan regions, storing snow and ice and facing climate change, industrial challenge,
infrastructure development, resource management, traveler pressure and indigenous need. Landscape
researchers situated in Tromso been inquiring into Arctic challenges, are expeditioners to Mount Gongga of the
third pole region, observing and mapping similar social and ecological challenges, referencing Arctic cases,
providing alternatives to the high altitude. Perceptional and motional mapping from ground into both the polar
and the peak, high walking routes and high ecological lines, and representational images of both start to bridge
the high polar to the high peak. The paper is a critical reflection on the bridging value of Arctic pedagogic
landscape inquiry to Third Pole high peaks.

1740
Thu_396_SH-6_2531
International Cooperation in Arctic: The Role of the UK Arctic Office

Henry Burgess1 (henry.burgess@bas.ac.uk)

1
NERC/ British Antarctic Survey, NERC Arctic Office, Cambridge, United Kingdom

The biggest questions in Arctic research need the best partnerships and the most joined-up research
communities. The UK Arctic Office, funded by the Natural Environment Research Council, exists to:
- support UK-based researchers in the High North;
- provide advice to policy makers; and
- develop new international research initiatives across the Arctic
Since 2010 the UK Arctic Office has supported a wide range of initiatives and is ambitious to do even more. This
Abstract provides attendees with the opportunity to hear about the role of the Office; to discover new
international initiatives, such as the UK-Canada Bursaries Programme (2017 & 2018); and see how a small team
can add value in building new collaboration.

1741
Thu_397_SH-7_61
British Science and the Forge of Antarctic Politics: 1895 - 1961

Ignacio Cardone1,2,3 (icardone@usp.br)

1
Universidade de São Paulo, Instituto de Relações Internacionais, Sao Paulo, Brazil, 2King's College London,
Brazil Institute - Defense Studies, London, United Kingdom, 3Nucleo de Pesquisa em Relações Internacionais, Sao
Paulo, Brazil

The United Kingdom has always been a key player in Antarctic politics. Almost all studies regarding the politics
of the white continent on the period previous to the Antarctic Treaty have taken into consideration the British
policy on those latitudes. Much of those studies have centered their attention into the geopolitical variables
that influenced the British imperial ambitions, and when considering the role of 'science', they usually have
ascribed it a merely 'instrumental' —when not absolutely accessory— role. Based on the idea that scientists
and scientific institutions have played a significant role in shaping the Antarctic politics, we contend that
'science' could not be reduced to being instrumental to the imperialist policy, and that exerted important
influences on the political agenda setting and further structuring of southern polar politics, particularly in
determining the shape of the final arrangement of the 1959 Antarctic Treaty. In order to contrast those ideas
and adopting a pluralistic approach informed on the Historical Sociology, we will apply a process tracing of the
British Antarctic history through archival material, paying special attention to the involvement of scientist and
scientific institutions, alongside other geopolitical, economic and ideational variables.

1742
Thu_399_SH-7_539
The Policy Relevancy of Arctic Marine Scientific Research: A PRS Case Study

Akiho Shibata1 (akihos@kobe-u.ac.jp), Naomi Harada2, Hajime Kimura2

1
Kobe University, Polar Cooperation Research Centre (PCRC), Kobe, Japan, 2Japan Agency for Marine Science
and Technology, Yokohama, Japan

Many of the challenges facing modern societies today like climate change cannot be adequately addressed
without the input from science and scientific advice. At the same time, the science necessary to solve societal
problems and the expensive scientific activities to support it, more often than not, need to be prioritized and
selected because of, for example, budgetary reasons. The Policy-Relevant-Science (PRS) study, embarked upon
by Kobe University PCRC and JAMSTEC under the Japanese ArCS project, tries to explore academically the ways
in which to support such decision making by public entities regarding the prioritization and selection of
scientific activities.
In our examination, we utilize the Value Tree Analysis (VTA) as a methodological tool for identifying the degree
of policy relevancy of Arctic marine observation activities. In applying the VAT, we analyze the Arctic strategies
of major Arctic marine research countries so as to clarify the key policy objectives in each of the major
international Arctic policy areas. The policy relevancy is the subjective value to be achieved in our PRS Study.
We then examine the key scientific outcomes that would support and realize the key policy objectives. The
degree of policy relevancy of a particular Arctic marine observation activity would be evaluated by examining
how much such activity supports the multiple key scientific outcomes that in turn support to achieve the key
policy objectives of the international community.

1743
Thu_400_SH-7_648
Importance and Interest on Arctic and Svalbard Treaty

Y. Barbaros Buyuksagnak1 (ybbuyuksagnak@pirireis.edu.tr), Burcu Ozsoy2

1
Piri Reis University, Istanbul, Turkey, 2ITU, Istanbul, Turkey

As the Arctic is increasingly becoming one of the focus points of international community, Svaldbard Islands,
with its location, rich wildlife, arctic nature, and old mining towns also draw attention of the states which are
interested in the region. The 1920 Svalbard Treaty confers full and absolute sovereignty on Norway.
Nevertheless, under the Treaty, Norway is obliged to give the citizens and companies of the signatory nations
equal rights in certain areas, such as; entrance to and residence in Svalbard; fishing, hunting and trapping;
maritime, industrial, scientific research, mining and commercial activities; acquisition and utilization of
property and mineral rights.
More than 40 states have signed the treaty since 1920. Turkey, a maritime country surrounded by sea on three
sides, with its 80-million population as having seventeenth largest economy and being close interest to global
affairs is not among signatory states. Besides, Turkey has signed the Antarctic Treaty in 1996. In a very short
period, launching the initiatives to become a party of the Svalbard Treaty will be evaluated.
This study aims to reveal the position of Turkey in Arctic related issues within the concept of Svalbard Treaty.
Keywords: Arctic, Svalbard Treaty, Turkey

1744
Thu_401_SH-7_1193
The Diplomacy of Science in Antarctica

Annebelle Davis1 (annebelle.davis@anu.edu.au)

1
Australian National University, Asia-Pacific College of Diplomacy, Deakin, Australia

Antarctic diplomacy seen through the lens of States negotiating The Antarctic Treaty after World War II and the
environmental protections of the 1990s has to date emphasised traditional diplomatic practices and
approaches. Much of what is known outside Ministries for Foreign Affairs about the dynamics of Antarctic
diplomacy behind the scenes comes to us via the recollections of diplomats in conference papers, and the
personal insights of Antarctic decision-makers published after they left office. No matter their starting point, or
whether these negotiations were about State interests exclusively or preserving the continent untouched in
keeping with collective interests, many of these decision-makers took opportunities inside and outside
diplomatic tracks to reiterate that Antarctica and its management constitute a special case in international
engagement. 'Specialness' is prominent in the diplomatic lexicon of Antarctica. This presentation is responding
to the challenge that this specialness poses by exploring what is unique, different, replicable or generalisable
about Antarctic diplomacy. It focuses on whether Antarctic diplomacy has a signature that sets it apart from
mainstream diplomacy, and what this means for managing Antarctica seen through the lens of science
diplomacy as an evolving and necessary adjunct to international engagement on Antarctica and Antarctic
issues.

1745
Thu_403_SH-7_1983
How Can My Research Data Be Useful for Conservation and Policy-making?

Kevin Hughes1 (kehu@bas.ac.uk), José C Xavier1,2, Daniela Liggett3, Gabriela Roldan3, Annick Wilmotte4
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Coimbra, Marine and Environmental
Sciences Centre (MARE-UC), Department of Life Sciences, Coimbra, Portugal, 3University of Canterbury, Gateway
Antarctica, Christchurch, New Zealand, 4University of Liège, InBios-Centre for Protein Engineering, Liège,
Belgium

Biodiversity conservation is a main goal of the Protocol on Environmental Protection to the Antarctic Treaty.
Policy should be based on the best scientific data available, and policy-makers are eager to have access to up-
to-date and high quality information. Scientists are on the frontline to gather relevant data, though their
primary aim is to publish in international refereed journals. However, once the data, and resulting information,
have been scrutinized and quality-checked during the review process, their usefulness for policy-making should
be also considered as they may have the potential to inform conservation measures or document processes
affecting biodiversity.
However, it is not always simple to find out how to convey this information to policy-makers. In this poster,
three main pathways are presented, through
(a) the Scientific Committee on Antarctic Research (SCAR) and its Standing Committee on the Antarctic Treaty
System (SCATS: see www.scar.org/policy/scats/);
(b) your National Delegates to the Committee on Environmental Protection (see:
www.ats.aq/devAS/cep_authorities.aspx); or
(c) writing a summary for the Antarctic Environments Portal (www.environments.aq). The latter publishes short
articles presenting state-of-the-art research findings after a thorough review process.
Hopefully, this description will encourage scientists to consider the value of their research data for
conservation of Antarctic biodiversity.

1746
Thu_404_SH-7_2243
An Assessment of South Korean-New Zealand Cooperation in Antarctica

Patrick Flamm1 (p.flamm@auckland.ac.nz)

1
University of Auckland, Auckland, New Zealand

While the Antarctic Treaty System intended to keep Antarctica an area of international cooperation and science
free from politics and militarization, it is not protected from global and regional power transformations today.
Among the emerging players from Asia, South Korea has already been identified as likely key challenger to the
status-quo polar order. This raises questions about what South Korea wants from its presence in Antarctica and
how challenging Seoul's demands are perceived to be for the existing Antarctic order. This paper is an role
theoretical assessment of Antarctic cooperation between South Korea and its main partner, New Zealand. This
cooperation is crucial for South Korea not only for the politics and logistics in relation to the newly established
Jang Bogo research station in Terra Nova Bay, but also scientifically between the Antarctic agencies Antarctica
New Zealand and the Korean Polar Research Institute (KOPRI). How was this cooperation experienced so far
and how is it valued especially with regard to an increasingly less engaged US Antarctic program and an
growing Chinese polar presence? How do especially the NZ government and Antarctica New Zealand perceive
South Korea in the role of a ´challenger´? Does Wellington see any chance in socializing Seoul through
engagement into something else than a challenger to the Antarctic order?

1747
Morning Plenary III
22.06.2018 07:50-09:00, A Davos

Keynote Lecture V
The Emerging Importance of the Humanities and Social Sciences in Polar Research

Peder Roberts (Peder.roberts@abe.kth.se)

Division of History of Science, Technology and Environment, KTH Royal Institute of Technology, Stockholm,
Sweden

The humanities and social sciences are increasingly recognized as central components of Antarctic as well as
Arctic research. This presentation provides an overview of emerging trends with a particular focus on critical
heritage studies, human relationships to physical geographical environments, and the construction of
governance structures. Specific examples discussed include 1) processes for identifying, managing, and in some
cases re-using the material legacies of human presence; 2) how the construction and implementation of fauna
management regimes reflect particular conceptions of how humans should interact with the natural world; and
3) how changing social expectations can be accommodated within polar governance structures. In each case,
emphasis is placed upon exploring the assumptions that underpin human activity in the polar regions and how
these can (and indeed) have changed through time. The presentation concludes with brief reflections on how
the significant differences between the Arctic and Antarctic have shaped research agendas, while nevertheless
including substantial opportunities for bi-polar comparisons.

1748
Morning Plenary III
22.06.2018 07:50-09:00, A Davos

Keynote Lecture VI
Dating West Antarctic ice sheet collapse using genomic data

Jan Strugnell (jan.strugnell@jcu.edu.au)

Department of Marine Biology and Aquaculture, James Cook University, Australia

West Antarctica has been identified as one of the fastest warming places on the planet. Large parts of the West
Antarctic Ice Sheet (WAIS) are predicted to melt as a result of climate change. Reducing uncertainties over the
rate of that melt has been identified as a key research priority in the 5th IPCC Assessment Report. It is well
understood from geological reconstructions that there are times in the past when average temperatures were
only ~2-3°C warmer than today, but global sea levels may have been up to 20 m higher. Determining which of
these times may have been accompanied by a widespread collapse of the WAIS is needed to provide critical
insights into the potential rate and magnitude of sea-level rise over the coming decades and centuries. It is
unknown whether there was a collapse of the WAIS during the Last Interglacial, 125,000 years ago – the last
time Earth was +1°C warmer than the pre-industrial period. A recent ice sheet model implies Antarctica may
have contributed up to 5m of the 6-9m of global sea-level rise known from geological evidence. Confirming this
is particularly important for constraining future sea level projections. The complete collapse of the WAIS would
lead to the existence of trans-west Antarctic seaways linking the present day Ross, Weddell and Amundsen
Seas. Such seaways would allow marine animal migration across newly opened straits, and a genetic signature
of that historical connectivity will persist in the genomes of benthic animals present in Antarctica today. I will
describe how we are using this information to distinguish between hypotheses to determine when the WAIS
last collapsed.

1749
BE-9c - Life distribution and responses to environmental changes in Polar ecosystems
22.06.2018 09:00-10:30, C Aspen

1
The Influence of Abiotic Factors on the Plant Growth in the High Arctic

Krzysztof Migała1 (krzysztof.migala@uwr.edu.pl), Magdalena Opała-Owczarek2, Piotr Owczarek3, Bartek Luks4,

Daniel Kepski4, Wojciech Szymanski5, Mariusz Szymanowski6, Bronislaw Wojtun6
1
University of Wrocław, Institute of Geography and Regional Development, Wrocław, Poland, 2University of
Silesia, Faculty of Earth Sciences, Sosnowiec, Poland, 3University of Wroclaw, Institute of Geography and
Regional Development, Wrocław, Poland, 4Institute of Geophysics, Pol. Acad. of Sciences, Warszawa, Poland,
5
Jagiellonian University, Institute of Geography and Spatial Management, Krakow, Poland, 6University of
Wroclaw, Wrocław, Poland

The aim of our studies was to comprehensively evaluate the abiotic factors that influence changes in the
annual growth rates of selected species of tundra plant. The study was conducted on Wedel Jarlsberg Land, SW
Spitsbergen.
It is argued that the spatial and seasonal variability of annual growth is determined by the rate at which snow
cover disappears, and also by soil moisture, which determines the plants' access to water. Soil moisture
depends on soil particle size distribution and weather; it is regulated by the supply of snowmelt water and
rainfall and also the depth at which the top layer of permafrost is situated (thaw depth), which determines the
level of groundwater during the growing season. The spatial characteristics of the process of seasonal snow
cover disappearance are co-determined by the morphology of the substrate and the physical properties of the
soil. An important but also destructive role is played by thawing episodes, which are increasingly frequent in
the winter season. The observed trend towards warming in polar areas does not inevitably lead to an increase
in biomass production. An increase in temperature during the growing season does not necessarily promote
plant growth, but rather is an indicator of drought stress caused by the lowering of groundwater levels related
to the increase in the depth to which the active permafrost layer thaws.

1750
437
Remote Sensing of Spatial Structure of the Circumpolar Tundra-taiga Transition

Wenkai Guo1 (wg241@cam.ac.uk), Gareth Rees1

1
Scott Polar Research Institute, University of Cambridge, Cambridge, United Kingdom

The tundra-taiga ecotone (TTE) or the arctic treeline is the world's longest vegetation transition zone, the
configuration, composition and dynamics of which vary greatly across the circumarctic region. Overall, the TTE
responds positively to global temperature changes with a net global treeline advance, although showing
significant regional diversities in movement patterns, which are linked to different controlling factors of tree
growth. Despite its high ecological significance, currently available derivation of the TTE suffers from low spatial
resolution and high dependence on arbitrary vegetation coverage thresholds. This study uses texture analysis
of Landsat Vegetation Continuous Field data to separate the TTE from other land cover types trained using a
collection of ground truth sites with known types. We also further explore the detailed texture differences
within the treeline class which greatly influences treeline response to climate change. Using the FOurier-based
Textural Ordination (FOTO) technique, treeline areas are separated into abrupt, diffuse and islands forms which
correspond to different levels of treeline vulnerability to climate change. Thus, this study identifies the TTE and
further divides it into ecologically significant categories, which may serve as a global map of treeline
vulnerability and provide the basis for future studies into the detailed correlation between treeline processes
and spatial characteristics.

1751
1051
Marginal Population Hotspots of Cold-adapted Species in a Warmer World

Simone Orsenigo1, Milena Cere2, Thomas Abeli2 (thomas.abeli@unipv.it)

1
University of Milan, Department of Agricultural and Environmental Sciences - Production, Landscape,
Agroenergy, Milano, Italy, 2University of Pavia, Department of Earth and Environmental Sciences, Pavia, Italy

We know little about factors shaping geographical location of margin ranges in plant species. However,
understanding factors and processes allowing populations to survive at the range edge or migrate is crucial to
trace the effect of past climate changes and to predict future species distribution and evolution. This is
particularly important for cold-adapted species that are predicted to be affected by global warming more than
other species, especially at the southern range edge.
Consequently, identification of areas where arctic-alpine, circumpolar and circumboreal species reach their
southernmost ends of their distribution and group together (marginal hotspots) will present a unique
opportunity to highlight uncover processes that shaped current biogeographical patterns, as well as prepare for
future scenarios and set conservation management.
We identify areas where southernmost populations of 183 cold-adapted taxa, are clustered in north America
and Europe, based on the number of species reaching their southern range edge in each cell of a 50×50 km
grid. Marginality hotspot partially correspond to known refugia, in other cases high latitude areas are
extremely important.
From an applied conservation perspective, we detected areas where studies and monitoring of cold-adapted
species are best performed to maximize the knowledge gain and where conservation efforts should be directed
to allow marginality hotspots to continue their function of refugia in a warmer world.

1752
462
Micodiversity across Altitudinal Gradient and Solar Exposure in Antarctic Rocks

Laura Selbmann1 (selbmann@unitus.it), Claudia Coleine1, Silvano Onofri1, Laura Zucconi1

1
University of Tuscia, Dept of Ecological and Biological Sciences (DEB), Viterbo, Italy

Rocky outcrops support the highest standing biomass in the Antarctic ice-free areas; along the Victoria Land,
the largest ice-free area of the McMurdo Dry Valleys, together with mountain tops and nunataks hanging from
the ice sheet, represent significant examples. In some of these locations, conditions approach the limits of
tolerability for most organisms and endolithic communities are the predominant life-forms. This study focused
on sandstone, the best substratum for endolithic colonization, collected in 3 locations over an altitudinal
gradient from 800 to 3100 m asl; both north/south sun expositions were considered. Rock samples were
analyzed with a meta-barcoding approach on Illumina MiSeq platform, targeting the Internal Transcribed
Sequence 1 (ITS1) region for fungi. Taxonomic results, alpha-diversity and statistical analysis were performed to
investigate microbial diversity and community structure related to environmental changes. Preliminary results
show a large predominance of Ascomycota in all the sites studied, the classes Lecanoromycetes and
Dothideomycetes prevailed. Among the localities considered, species richness varied between 80 and 106. All
the biodiversity indexes (Shannon, Pielou and Simpson) clearly showed that the number of predominating
species decreases with the environmental pressure, indicating a higher specialization of the community, and
that sun exposition is the parameter that influences fungal community composition most.

1753
1922
Physiological Responses and DNA Repair in Pseudogymnoascus spp. Fungi toward UV

Hao Jie Wong1,2 (maccus92_1@hotmail.my), Nuradilla Mohamad-Fauzi1,3, Mohammed Rizman-Idid1, Peter

Convey4,5, Siti Alias1,5
1
University of Malaya, Institute of Ocean and Earth Sciences, Kuala Lumpur, Malaysia, 2University of Malaya,
Institute of Graduate Studies, Kuala Lumpur, Malaysia, 3University of Malaya, Institute of Biological Sciences,
Kuala Lumpur, Malaysia, 4British Antarctic Survey/NERC, Cambridge, United Kingdom, 5University of Malaya,
National Antarctic Research Centre, Kuala Lumpur, Malaysia

Solar radiation drives almost all biological activities on Earth and regulates morphological, biochemical and
developmental processes in many organisms. Soil microorganisms such as fungi within the polar regions can be
continuously exposed to considerable solar UV radiation in the summer. This could negatively impact their key
functions, for instance in regulating nitrogen and carbon cycles. We examined the responses of four polar
strains of Pseudogymnoascus spp. (isolated from Hornsund, Svalbard, and King George Island, Antarctic),
assessing growth, pigmentation, conidia production, post-UV DNA lesion changes and expression of DNA repair
genes. Cultures were irradiated with 6.1 kJm-2d-1 UV-B dosage and 12 h of PAR at 15°C for 10 d in the
laboratory. All strains showed growth rate reduction of between 21.74 and 35.52%. Coloured pigment
production was not induced by exposure to UV-B, suggesting no dependence on pigments for protection. UV-B
exposure also reduced conidia production. We are now targeting genes involved in photoreactivation and
nucleotide excision repair, primary DNA repair pathways responsible for maintaining DNA integrity under UV.
The expression levels of genes will be determined after UV exposure in dark and light conditions, and UV-
induced DNA lesions, CPDs and 6-4PPs will be quantified. Preliminary ELISA results suggest that
Pseudogymnoascus HND16 R4-1 sp.1 is able to reduce UV-B induced CPDs significantly after 2 h in both dark
and light conditions.

1754
1886
Environmental vs Ecological Drivers of Microbial Adaptation to Frozen Ecosystems

Catherine Larose1 (catherine.larose@ec-lyon.fr), Benoit Bergk Pinto1, Adrien Boniface1, Rose Layton1, Romie
Tignat Perrier2, Laura Sanguino1, Lorrie Maccario1, Aurélien Dommergue2, Timothy M. Vogel1
1
University of Lyon, Ecully Cedex, France, 2University Grenoble Alpes, Grenoble, France

Similar to abiotic particles, microorganisms from marine and terrestrial environments are transported via the
atmosphere to glaciers all over the world through dry or wet (snowfall or rain events) deposition, sometimes
carried over thousands of kilometers. Once deposited, these organisms can survive in the snow and interact
with their environment even at sub-zero temperatures. However, in order to colonize some of these new
niches, microorganisms must either already be equipped with, or rapidly acquire, the necessary functions.
Since cryosphere environments are undergoing rapid change, they are ideally suited for understanding the
dynamic and rapid adaptation of microbial communities. Based on our cold environment metagenomic
research performed over the last ten years, different drivers of adaptation lead to dynamic shifts in microbial
community structure and function in Arctic environments and strategies used to acquire genes critical for
ecosystem functioning. This field and laboratory-based research in snow and ice ecosystems, including sea-ice
and terrestrial snow packs, has examined multiple habitats that present steep environmental gradients. As
climate change continues, we need to improve our knowledge about the biotic system in order to predict its
response to environmental forcing. Microorganisms are both sentinels and bioindicators of change, but the
information they encode is rapidly being lost as habitats disappear.

1755
EN-7a - Biogeochemical cycling in the Polar Regions: Terrestrial and Ocean interactions
22.06.2018 09:00-10:30, A Studio

1103
High Fe Lability of Particles Sourced from Glacial Erosion, Heard Island

Pier van der Merwe1 (pvander@utas.edu.au), Kathrin Wuttig1, Thomas Holmes2, Manon Tonnard2,3, Zanna
Chase1,2, Tom Trull1,2,4, Andrew Bowie1,2
1
University of Tasmania, Antarctic Climate & Ecosystems Cooperative Research Centre, Hobart, Australia,
2
University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia, 3Universite de Bretagne
Occidentale - Institut Universitaire Europeen de la Mer (IUEM), Laboratoire des sciences de l'Environnement
MARin (LEMAR)., Brest, France, 4CSIRO Oceans & Atmosphere, Hobart, Australia

Iron (Fe) is a critical micronutrient that controls phytoplankton growth in the Southern Ocean. As part of the
Heard Earth-Ocean-Biosphere Interactions (HEOBI) voyage in January/February 2016, we surveyed suspended
particles in the water column and underlying sediments at 11 stations over the southern Kerguelen plateau
close to Heard and McDonald Islands (HIMI) to assess the sources of natural phytoplankton iron fertilisation in
the region. Heard is glaciated, while McDonald is ice-free. These characteristics should, we hypothesise, ensure
unique fertilisation in the downstream waters of these highly productive island hotspots. Glacial erosion and
fluvial outflow into surrounding waters near Heard proved to be an important source of highly labile
nanoparticulate Fe oxides. In contrast, proximal to diffuse gasohydrothermal sites near McDonald, only highly
refractory titanium and iron bearing minerals (Ilmenite) were found. We conclude that glacial erosion of Heard
Island is an important mechanism of Fe supply to downstream waters and therefore critical to the productivity
of the area near-shore and downstream of the Kerguelen plateau. Conversely, shallow gasohydrothermal
sources seem less efficient at delivering labile Fe. As our climate warms and our glaciers retreat, this source of
labile Fe may temporarily increase and then dramatically decrease into the future.

1756
2255
Sources and Transport of Iron and Organic Carbon in the Lena River

Per Andersson1 (per.andersson@nrm.se), Don Porcelli2, Liselott Kutscher3, Catherine Hirst4, Carl-Magnus
Mörth3, Trofim Maximov5
1
Swedish Museum of Natural History, Stockholm, Department of Geosciences, Stockholm, Sweden, 2University
of Oxford, Department of Earth Sciences, Oxford, United Kingdom, 3Stockholm University, Department of
Geological Sciences, Stockholm, Sweden, 4Swedish Museum of Natural History, Department of Geosciences,
Stockholm, Sweden, 5North-Eastern Federal University, International Center for BioGeoScience Education and
Scientific Training (BEST), Yakutsk, Russian Federation

The Lena River basin, which is one of the largest contributors of organic carbon (OC) and Fe to the Arctic Ocean,
is mainly underlain by continuous permafrost. This area is vulnerable to climate driven permaforst thawing,
with possible future changes in OC and element fluxes.
Filtered water (< 0.22 µm) with colloids and particle fraction (>0.22 µm) have been separated in samples from
the Lena River main channel and major tributaries collected during 2012 to 2017. The particles in river water
are dominated by authigenic Fe primarily in the form of chemically reactive ferrihydrite with a wide size range,
between 20 to 1 µm. The ferrihydrate constitute about 70% of the particulate Fe transported in the Lena River
and tributaries, and thus is an important carrier for trace elements and adsorbed carbon.
The annual export and fluxes of organic carbon, based on concentration data of DOC (dissolved organic C) and
POC (particultae organic C) and long term discharge data, showed large geographical variations related to
differences in precipitation and catchment topography. The δ13C and C/N ratios showed that the primary
sources of DOC were terrestrial plant debris and soil organic matter (SOM), while POC was a mixture between
SOM and aquatic primary production. These results, from a large areal, show that the contribution to the river
water concentrations and composition primarily depend on the water flow pathways in a permafrost
dominated region.

1757
362
Tracing Controls on Iron Export from High Latitude Peat Soils (Keynote Speaker)

Sophie Opfergelt1 (sophie.opfergelt@uclouvain.be)

1
Université catholique de Louvain (UCL), Earth and Life Institute, Louvain-la-Neuve, Belgium

Incipient warming of peatlands at high latitudes is expected to modify soil drainage and hence the redox
conditions, which has implications for Fe export from soils. To disentangle the complex biogeochemical
interactions in soils controlling the sources and processes which govern this vital function, understanding the
controls on stable isotope fractionation of Fe in peat soils is essential. This study uses Fe isotopes to assess the
processes controlling Fe export in a range of Icelandic soils including peat soils derived from the same parent
basalt, where Fe isotope variations principally reflect differences in weathering and drainage. An additional
constraint on soil weathering is provided by Si stable isotopes. Si supersaturation in solution with respect to
amorphous silica is reached upon freezing when Al availability to form aluminosilicates is limited by the affinity
of Al for metal-organic complexes. Therefore, the precipitation of amorphous silica in peat soils indirectly
supports the formation of metal-organic complexes in poorly drained soils. The influence of organic matter on
metals is confirmed using Zn stable isotopes. These observations highlight that in a scenario of decreasing soil
drainage with warming high latitude peatlands, Fe export from soils as Fe-organic complexes will increase,
which in turn has implications for Fe transport in rivers, and ultimately the delivery of Fe to the oceans.

1758
816
Iron and Nutrient Flux to the Southern Ocean from McMurdo Dry Valleys Antarctica

Sydney Olund1, Susan Welch1, Anthony Lutton2, Wm Berry Lyons1 (lyons.142@osu.edu)

1
Ohio State University, School of Earth Sciences and Byrd Polar and Climate Research Center, Columbus, United
States, 2Ohio State University, School of Earth Sciences, Columbus, United States

Primary production in the Southern Ocean is thought to be limited by the micro-nutrient iron (Fe). Numerous
investigations over the past decade have attempted to quantify the major sources and chemical speciation of
Fe into the Southern Ocean. The potential sources include icebergs, atmospheric deposition, deep-water
upwelling, melting glacier and sea ice, and groundwater/subglacial inflow. Our initial work demonstrated that
as glaciers retreat and ice-free areas in Antarctica expand, streams could also be a major source of Fe into the
coastal ocean. We have expanded our work, and have examined streams flowing directly into the ocean from
the McMurdo Dry Valleys (MDV). In addition to the filterable Fe (passing 0.4 µm filter), we have analyzed a
number of these samples for biologically important metals such as Mo and V. We have also compared the
stoichiometry of the stream waters (N:P:Si:Fe) to that of phytoplankton, and conclude that these streams
provide excess Fe and P, relative to fixed N and Si, needed by plants. Our results support the idea that
increased cryospheric loss should increase the flux of Fe and other macro and micro-nutrients into the coastal
Southern Ocean.

1759
2540
Impact of Ice-ocean Interactions on Nutrient Fluxes in Barilari Bay, Antarctica

Mattias Cape1 (mcape@uw.edu), Maria Vernet2, Erin Pettit3, Martin Truffer3, Craig Smith4, Amy Leventer5, Julia
Wellner6, Eugene Domack7
1
Applied Physics Laboratory, University of Washington, Seattle, United States, 2Scripps Institution of
Oceanography, University of California, San Diego, La Jolla, United States, 3University of Alaska - Fairbanks,
Fairbanks, United States, 4University of Hawai`i at Manoa, Honolulu, United States, 5Colgate University,
Hamilton, United States, 6University of Houston, Houston, United States, 7University of South Florida, St.
Petersburg, United States

The West Antarctic Peninsula (WAP) is home to a thriving marine ecosystem whose dynamics are closely linked
to the physical environment. Recent studies along the WAP continental shelf have suggested that the seasonal
input of iron-rich glacial melt from the continent may serve to regulate primary production. Export of glacial
meltwater occurs primarily through coastal bays and fjords, which serve as the link between the large-scale
ocean and the ice sheet. Limited observational datasets have identified these systems as hotspots of primary
and secondary productivity, suggesting that input of meltwater may have important consequences for both
local and regional carbon cycling. In this study, we provide insight into glacier-ocean interactions along the AP
by examining physical, chemical and biological properties of Barilari Bay, a coastal embayment where glacier
fronts have experienced net retreat since the 1960s. We show that warm, Upper Circumpolar Deep Water,
thought as the primary source of heat for submarine melting of the ice sheet, reaches and interacts with the
glacier front in this system. In turn, delivery of meltwater affects local ocean circulation, enriching the fjord
with macro-nutrients by entraining deep nutrient-rich water through upwelling at the glacier front. Linking
these observations to phytoplankton community composition, biomass and productivity provides insight into
glacial contributions to local and regional carbon cycling.

1760
601
Scales of Southern Ocean Productivity Responses to Iron Inputs

Thomas William Trull1,2 (tom.trull@csiro.au), Alice Della Penna3, Bozena Wojtasiewicz4, Melanie Grenier5
1
CSIRO Oceans and Atmosphere, Hobart, Australia, 2ACE CRC, Hobart, Australia, 3University of Washington, Air-
Sea Interaction and Remote Sensing, Applied Physics Laboratory, Seatlle, United States, 4CSIRO Oceans and
Atmosphere, Perth, Australia, 5University of British Columbia, Vancouver, Canada

Inputs of iron, the nutrient limiting Southern Ocean photosynthesis, are expected to increase in future. To
assess possible productivity responses, we examined biomass dynamics (using satellite ocean colour,
autonomous profiling floats, and shipboard bio-optics) near the Kerguelen plateau, which has elevated iron
inputs from volcanism, glaciers, sediment resuspension, and deep water upwelling. Low iron loss rates (1-2%
per day) during downstream transport in the Antarctic Circumpolar Current in winter can explain the overall
length scale (1000 km) of the elevated biomass plume. Mesoscale (10-100 km) biomass variations close to the
plateau are also reasonably described by Lagrangian transport, provided Fe loss rates are higher in spring (3-5%
per day), and recycling or resupply processes modulate Fe influence offshore. Surprisingly, at small scale (1-10
km) close to the Heard and MacDonald islands, phytoplankton biomass is low despite elevated iron and high
photosynthetic competency. Multiple processes may contribute, including short residence times and removal
by grazing and/or settling induced by lithogenic particle inputs. These varying responses emphasize the
difficulty of assessing future Southern Ocean productivity changes from local studies, the importance of
considering iron removal processes (noting that first-order removal implies the scope of responses will scale
with the logarithm of supply), and the usefulness of comparisons across scales.

1761
AC-8c - Causes and Effects of Changing Polar Climate, Cryosphere and Hydrological Cycle
22.06.2018 09:00-10:30, A Forum

1646
Sea Ice Retreat and Cold European Winter Revisited

Ida Margrethe Ringgaard1,2 (iri@dmi.dk), Shuting Yang2, Jens Hesselbjerg Christensen1, Eigil Kaas1
1
University of Copenhagen, Copenhagen, Denmark, 2Danish Meteorological Institute, Copenhagen, Denmark

Arctic sea ice has been retreating during most of the satellite era. In recent years, Arctic sea ice experienced a
dramatic reduction: the summer extent in 2012 and 2016 was only half of the 1979-2000 average. With such
dramatic changes in the current sea ice coverage as a point of departure, several studies have linked reduction
in wintertime sea ice in the Barents-Kara Seas to cold weather anomalies over Europe and through large scale
tele-connections to regional warming elsewhere. Here we aim to investigate the interaction between sea ice
changes in the Barents-Kara Seas and mid-latitude dynamics. Particular focus will be if, and how, Arctic sea ice
impacts European winter weather, i.e. if the Arctic sea ice works as the ´cold heart´ of European weather.
Additionally, the potential for the atmosphere to precondition the sea ice conditions in the Barents-Kara Seas is
also investigated. To understand the effects of the sea ice reduction on the full climate system, a fully-coupled
atmosphere-ocean-sea ice global climate model, EC-Earth, is used. A new method for assimilating sea ice using
the sensible heat flux is implemented in the coupled climate model. Using this method, experiments are
performed with reduced sea ice cover in the Barents-Kara seas. Results indicate an increase in extreme cold
winters over Europe as a response to this reduction in sea ice cover. Here we present some preliminary analysis
of the chain of processes responsible for this apparent teleconnection.

1762
668
Cold Winters in Midlatitudes Coincident with, Not Caused by, Low Arctic Sea Ice

Russell Blackport1, James Screen1 (j.screen@exeter.ac.uk)

1
University of Exeter, Exeter, United Kingdom

Rapid Arctic warming has coincided with a spate of cold winters over midlatitude continents. Previous work has
proposed two distinct influences of Arctic warming: warm conditions over the Barents-Kara Sea are associated
with cold winters across East Asia, whereas severe winters over North America are related with anomalous
warmth in the East Siberian-Chukchi Sea. However, this work is based upon correlation and causality has not
been established. Here we use physical arguments based on the direction of the surface heat flux over the
Arctic regions to elucidate whether low Arctic sea ice is a cause of cold midlatitude winters. We make use of
large ensemble simulations with two coupled ocean-atmosphere models under present day conditions. The
models are able to accurately capture the two observed modes of interannual variability between low sea ice
and cold midlatitude winters, and the anomalous large-scale circulation patterns in which they are embedded.
However, these associations are only present during winters when low sea ice coincides with a downward
turbulent heat flux, implying the atmosphere is driving the ocean-ice. No midlatitude cooling is found during
winters where low sea ice coincides with an upward turbulent heat flux anomaly. This strongly suggests that
low sea ice loss is not a cause of severe midlatitude winters, but instead that anomalous large-scale
atmospheric circulation simultaneously drives cold midlatitude winters and contributes to Arctic warmth.

1763
721
The 'Warm Arctic Cold Continents' Pattern during 1901 - 2010

Linling Chen1,2 (linling.chen@nersc.no), Edward Hanna3, Jennifer Francis4

1
Nansen Environmental and Remote Sensing Centre, Bergen, Norway, 2Bjerknes Centre for Climate Research,
Bergen, Norway, 3University of Lincoln, Lincoln, United Kingdom, 4Rutgers University, New Jersey, United States

The 'Warm-Arctic Cold-Continents' (WACC) winter weather pattern is investigated using the European Centre
for Medium-Range Weather Forecasts 20th Century reanalysis data (ERA20C) spanning 1901-2010. Both the
1920-1940 and 1990-2010 periods are characterized by Arctic Amplification (AA) and mid-latitude cooling,
although the Arctic warming signal for 1990-2010 is almost twice as strong as that for 1920-1940. Compared to
the reference period of 1951-1980, significant weakening in mid-latitude poleward temperature gradient and
zonal wind, wavier upper level flow character, and strong regional blocking frequency/intensity changes are
detected during both AA periods. These results based on statistical analyses highlight the possible role of AA in
affecting mid-latitude weather patterns, but further work is needed to quantify the influence of AA on
particular mid-latitude dynamical features.

1764
575
Significant Contribution of Stratospheric Pathway to “Warm Arctic Cold Siberia”

Yutian Wu1 (yutianwu@ldeo.columbia.edu), Pengfei Zhang2

1
Lamont-Doherty Earth Observatory of Columbia University, Palisades, United States, 2Purdue University, West
Lafayette, United States

Previous studies have extensively documented the impact of Arctic sea ice melting on the midlatitude
circulation in winter. However, whether and how sea ice retreat affects the adjacent continent cooling is still
unclear and controversial among the scientific community. Here we use a state-of-the-art atmospheric general
circulation model, that has been extended into the stratosphere and above, to provide evidence of “Warm
Arctic Cold Siberia” pattern. In particular, we explicitly show that an active stratosphere plays a key role in the
cold conditions in northern Asia in the subsequent winter following sea ice loss over the BKS. The mechanism
involves two-way stratosphere-troposphere coupling and the downward effect from the stratosphere
significantly enhances the ridge over East Europe and trough over East Asia, which causes cold air advection
and increased frequency of extreme cold air outbreaks over Siberia. The results suggest that it is necessary to
use a well-resolved stratosphere model to understand the full impact of Arctic sea ice retreat.

1765
1537
Mechanisms for the Influence of Arctic Sea-ice Loss on Mid-latitudes

Christine McKenna1,2 (christine.mckenna@bas.ac.uk), Tom Bracegirdle1, Emily Shuckburgh1, Peter Haynes2,

Manoj Joshi3,4
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Cambridge, Department of Applied
Mathematics and Theoretical Physics, Cambridge, United Kingdom, 3University of East Anglia, Centre for Ocean
and Atmospheric Sciences, Norwich, United Kingdom, 4University of East Anglia, Climatic Research Unit,
Norwich, United Kingdom

To explore the mechanisms linking Arctic sea-ice loss to changes in mid-latitude surface temperatures, we
conduct idealised modelling experiments. In these, we use an intermediate general circulation model and
confine sea-ice loss of two different magnitudes to the Atlantic or Pacific sectors of the Arctic (respectively the
Barents-Kara or Chukchi-Bering Seas). Extending previous findings, in the Atlantic and Pacific experiments there
are opposite effects on the winter stratospheric polar vortex, for both large-magnitude (end of twenty-first
century) and moderate-magnitude sea-ice loss. Accordingly, there are opposite tropospheric Arctic Oscillation
(AO) responses for moderate-magnitude sea-ice loss. However, there are similar strength negative
tropospheric AO responses for large-magnitude sea-ice loss, suggesting that tropospheric mechanisms become
relatively more important than stratospheric mechanisms as the sea-ice loss magnitude increases. The mid-
latitude surface temperature response for each loss region and magnitude can be understood as the
combination of an 'indirect' part induced by the large-scale circulation (AO) response, and a residual 'direct'
part that is local to the loss region. Additional experiments designed to definitively quantify the relative role
played by stratospheric and tropospheric mechanisms in the tropospheric AO responses will also be discussed.

1766
2328
How Does Arctic Change Affect European Weather and Climate?

Timo Vihma1 (timo.vihma@fmi.fi), Halldor Björnsson2, Linling Chen3, Klaus Dethloff4, Jennifer Francis5, Rune
Graversen6, Edward Hanna7, Dörthe Handorf4, Richard Hall7, Alexey Karpechko1, James E Overland8, Nicholas
Tyrell1, Petteri Uotila9
1
Finnish Meteorological Institute, Helsinki, Finland, 2Icelandic Meteorological Office, Reykjavik, Iceland, 3Nansen
Environmental and Remote Sensing Centre, Bergen, Norway, 4Alfred Wegener Institute, Helmholtz Center for
Polar and Marine Research, Potsdam, Germany, 5Rutgers University, Department of Marine and Coastal
Sciences, New York, United States, 6University of Tromsø, Department of Physics and Technology, Tromsø,
Norway, 7University of Lincoln, School of Geography, Lincoln, United Kingdom, 8NOAA, Pacific Marine
Environmental Laboratory, Seattle, United States, 9University of Helsinki, Department of Physics, INAR - Institute
for Atmospheric and Earth System Research, Helsinki, Finland

During the period of Arctic amplification since the mid-1990s, air masses originating from the Arctic have
become warmer, but the direct advective effects from the marine Arctic to Europe are limited. However,
changes in the Arctic affect large-scale circulation regimes that further affect European weather. Important
circulation regimes include the positive and negative NAO patterns, a circulation pattern resembling the East-
Atlantic West-Russia pattern, and a high-pressure system over Scandinavia with a tongue towards northern
Siberia (SCA). During the Arctic amplification period, based on daily data, the frequency of occurrence of SCA
has increased in December and January, and the negative NAO pattern has become more common in February
and March. Sea ice decline in the Barents and Kara seas has favoured intensification of SCA, which interferes
with the Atlantic wave train in autumn. The wave train contributes to strengthening of the Siberian High,
generating increased vertical wave flux up to the stratosphere, and further to weakening of the Polar vortex in
December - February. Downward feedback to the troposphere perpetuates strong Siberian High, favouring
cold-air advection to eastern Europe. In addition, Arctic amplification affects the jet-stream latitude and speed,
the occurrence of split jets, and the persistency of weather. Greenland Blocking affects European weather both
directly and indirectly via forcing on the jet stream.

1767
TE-2a - Advancing Polar Engineering and Sustainable Infrastructure Development
22.06.2018 09:00-10:30, A Sertig

891
Chinese Deep Ice Core Drilling at Dome A, Antarctica: Progress and Problems

Nan Zhang1 (znan@jlu.edu.cn), Guitao Shi2, Xiaopeng Fan1, Chunlei An2, Zhengyi Hu2, Chuanjin Li3, Pavel
Talalay1, Yuansheng Li2
1
Jilin University, Polar Research Center, Construction Engineering College, Changchun, China, 2Polar Research
Institute of China, Shanghai, China, 3Northwest Institute of Eco-environment and Resources, Chinese Academy
of Sciences, Lanzhou, China

During last six years, five seasons were realized at Dome A, East Antarctica within the Chinese Deep Ice Core
Drilling Project DK-1. The tasks of the first two seasons were to construct pilot-hole and to install drilling
system. From the very end of the second season (January 2013), the deep ice core drilling was commenced
from ~120 m to 800.73 m recorded in January 2017. As the hole became deeper, more drilling data were
obtained which allows to analyze the drilling process with depth and gives useful reference to improve the
drilling technology. At the same time, drilling team gained more experience. Nevertheless, drilling problems
often occurred due to technological reasons and human factor. In general, drilling parameters' variation
exhibits some certain regular pattern, however, unusual service condition often came across because of the
indeterminacy of ice structure and complicated situation at the bottom. Even the drilling system was always
operated according with certain regulations, the rig, ice and operations form a complicated time varying
system. Some key drilling parameters collected in the last three seasons, problems met in the field, experience
of drilling system repairing and drilling accident treatment are analyzed and discussed.

1768
764
Lightweight Ice Coring Systems

Victor Zagorodnov1 (victor.zagorodnov@gmail.com)

1
Cryosphere Research Solutions LLC, Columbus, United States

In mid-1970th a few portable shallow ice core drills were designed and successfully used for study of polar ice
sheets. Later, shallow ice core drills were employed for mountain glaciers research.
Depending on ice core diameter and depth capabilities of the drilling system its weight can be 200-300 kg,
including power source. Considering personnel involved in an ice coring field operation, total depth of drilling
and duration of stay of a drilling site, the total weight of drilling and camping equipment, including food and
fuel, can reach 3 ton. This deployment weight is not a big burden for transportation by avionic or surface
vehicles but is prolonged and expensive for high altitude coring operations.
Major goals of new ice coring and non-coring drills development are: reduction of its weight, increasing depth
capabilities and production drilling rate. These modifications will reduce costs of field operations, as well as
reduce environmental impact of thereof. All mentioned modifications are suitable and applicable to high
altitude and Polar glacier research.

1769
1072
New Drilling Technology for Agile Sub-ice Rock Coring

Tanner Kuhl1, Chris Gibson1, Kristina Slawny1, Mary Albert2 (mary.r.albert@dartmouth.edu)

1
University of Wisconsin - Madison, Ice Drilling Design and Operations, Madison, United States, 2Dartmouth
College, U.S. Ice Drilling Program Office, Hanover, United States

Evidence of sea level under paleoclimate conditions that were warmer than the present is important for
prediction of sea level rise anticipated under current climate change. Cosmogenic nuclides in rock beneath ice
sheets can reveal former ice sheet extent and the timing and duration of past exposure periods. Under ice less
than 700m thick, nimble methods for reconnaissance recovery of small rock cores would be useful for use near
outcrops and near the ice margins. This was previously not possible because a drill capable of drilling the core
did not exist. A development project in the Ice Drilling Program Office - Ice Drilling Design and Operations
(IDPO-IDDO) group has succeeded in developing such a drill. The Agile Sub-Ice Geological (ASIG) drill is capable
of drilling through 700 meters of ice and then retrieving 8 meters of 39-mm diameter rock core. The drill was
successful in the first field season of its use, when IDDO retrieved 8 meters of rock core from under 150 meters
of ice at Pirrit Hills, Antarctica during the 2016-17 field season. This is the first time that a rock core more than
a meter long has been retrieved from beneath glacial ice. In this presentation characteristics of the drill are
described, along with a description of the drill performance in the field at Pirrit Hills.

1770
128
Movable Drilling Rig for Coring in Antarctic Traverses

Xiaopeng Fan1 (heaxe@163.com), Pavel Talalay1, Youhong Sun1, Pinlu Cao1, Nan Zhang1, Yuncheng Liu1
1
Jilin University, Changchun, China

Drilling to bedrock of ice sheets and glaciers offers unique opportunities to research processes acting at the ice
sheets bed for paleo-environmental reconstructions, subglacial geology, tectonics, geophysics, microbiology. To
drill through the ice and bedrock a novel movable drilling rig and cable-suspended electromechanical core drill
are designed. All drilling equipment is installed inside a movable, sledge-mounted, temperature-controlled, and
wind-protected drilling shelter and workshop connected by steel pathway. The drilling shelter (without the
sledges and mast) has overall dimensions of 7.8×4.8×3.0m. The shelter is set on two transverse frames with
four 3.05×0.8 m skis. Four hand screw jacks with a travel of 300 mm are located on the corners of the shelter.
The mast can be folded during transportation. The workshop has the same basic design and dimensions as the
drilling shelter. It is divided into two rooms: one room for generators and one that serves as a logging/
glaciological laboratory and workshop. Drilling shelter and workshop are transported with crawler tractors and
could be ready for drilling operations 2-3 days after arrival at the chosen site. Drilling is carried out with
electromechanical drill that permits the accomplishment of three different tasks: a large-diameter auger for dry
core drilling in the upper snow-firn layers; ice-core drilling with near-bottom fluid circulation; and bedrock core
drilling.

1771
1233
Intermediate Depth Drill Design Innovations

Jay Johnson1 (jay.johnson@ssec.wisc.edu), Tanner Kuhl1, Chris Gibson1, Grant Boeckmann1, Zachary
Meulemans1, Josh Goetz1, Kristina Slawny1
1
University of Wisconsin - Madison, IDDO, Madison, United States

In response to a call from the International Partnership in Ice Core Sciences group (IPICS) for ice core records to
contribute toward the 2k array and 40k network, the U.S. science community identified the retrieval of cores to
depths of 1000-1500 meters as a high priority. In response, the Ice Drilling Program Office - Ice Drilling Design
and Operations (IDPO-IDDO) group developed a new Intermediate Depth Drill (IDD) system that was
successfully utilized for the South Pole Ice Core (SPICEcore) project from 2014-2017 to drill a 1750 meter core.
The drill, which is based on the Danish Hans Tausen (HT) drill design, was paired with new IDDO component
designs for the winch and surface systems that focused on improved core quality and ease of use. This
presentation focuses on the new and innovative features of the IDD system and ever-important lessons learned
from the SPICEcore project.

1772
514
Direct Laser Ice Penetrators: A Breakthrough in Subglacial Access Technology

Victoria Siegel1 (vickie.siegel@stonaerospace.com), William Stone1, Bartholomew Hogan1, John Harman1,

Alberto Lopez1, Kristof Richmond1
1
Stone Aerospace, Del Valle, United States

The exploration of sub-glacial lakes on Earth presently requires an extraordinary logistics footprint (up to 1,000
tonnes of equipment) to use either traditional drilling technology or hot water drilling approaches. Stone
Aerospace has investigated alternative methods to make access to sub-glacial lakes both routine and, critically,
allow for persistent science. An ideal access method should allow for any length of time for downhole
instrumentation and vehicles to make temporal measurements, investigate areas far from the access hole, and
be recoverable to the surface on demand at the conclusion of a mission. With NASA funding we have
developed an entirely novel ice penetrating technology using focused laser light carried by an optical fiber and
emitted from the nose of an ice penetrator. Photons are used to directly melt the ice in front of the descending
vehicle at near 100% efficiency. Laboratory tests show that this approach could lead to unprecedented ice
penetration rates and enable access to any Antarctic sub-glacial lake. The design is bi-directional and could
melt its way to the surface at conclusion of a mission.

1773
GG-1a - Magmatic, tectonic, and geodynamic investigations of the Polar Regions
22.06.2018 09:00-10:30, A Schwarzhorn

1229
A New Volcanic Province: An Inventory of Subglacial Volcanoes in West Antarctica

Maximillian Van Wyk de Vries1, Robert G. Bingham1 (r.bingham@ed.ac.uk), Andrew S. Hein1

1
University of Edinburgh, Edinburgh, United Kingdom

The West Antarctic Ice Sheet overlies the West Antarctic Rift System about which, due to the comprehensive
ice cover, we have only limited and sporadic knowledge of volcanic activity and its extent. Improving our
understanding of subglacial volcanic activity across the province is important both for helping to constrain how
volcanism and rifting may have influenced ice-sheet growth and decay over previous glacial cycles, and in light
of concerns over whether enhanced geothermal heat fluxes and subglacial melting may contribute to instability
of the West Antarctic Ice Sheet. Here, we use ice-sheet bed-elevation data to locate individual conical edifices
protruding upwards into the ice across West Antarctica, and we propose that these edifices represent
subglacial volcanoes.We used aeromagnetic, aerogravity, satellite imagery and databases of confirmed
volcanoes to support this interpretation. The overall result presented here constitutes a first inventory of West
Antarctica's subglacial volcanism. We identified 138 volcanoes, 91 of which have not previously been identified,
and which are widely distributed throughout the deep basins of West Antarctica, but are especially
concentrated and orientated along the >3000 km central axis of the West Antarctic Rift System.

1774
1569
Melting of the West Antarctic Ice Sheet (WAIS), Accelerates Subglacial Volcanism

John C Behrendt1,2 (john.behrendt@colorado.edu)

1
University of Colorado at Boulder, Institute of Arctic and Alpine Research (INSTAAR), Boulder, United States,
2
US Geological Survey, Boulder, United States

Melting of the West Antarctic Ice Sheet (WAIS) would raise global sea level ~ 3 m. WAIS flows through the
volcanically active West Antarctic rift system (WARS), possibly associated with a mantle plume. Heat flow is
high beneath WAIS. Satellite altimetry shows rapid retreat of ice shelves bordering WAIS resulting from the
warming ocean resulting from climate change. GRACE satellite data indicate accelerating mass loss from WAIS,
reducing basal pressure. Aeromagnetic and radar ice sounding surveys (5 by 5 km line spacing) over the central
WAIS revealed >1000 high-amplitude magnetic anomalies having mostly < 200 m bed relief, indicative of the
late Cenozoic-recent age subglacial volcanic rocks at its base.17 anomalies have 600-2000 m edifices beneath
the ice. Increased volcanic activity resulting from decompression mantle melting beneath a thinning WAIS may
serve as a positive feedback mechanism that could further destabilize WAIS. In both Iceland, and on midocean
ridges, dated volcanism suggests decompression mantle melting associated with reductions in either ice or
water loads drives significant volcanism. Acceleration of volcanic activity as the WAIS thins, could enhance the
rate of ice loss and accelerate global sea level rise.

1775
197
Subglacial Water Flow Adjacent to Mt. Melbourne Volcano, Antarctica

Choon-Ki Lee1 (cklee@kopri.re.kr), Yong Cheol Park1, Won Sang Lee1, Joohan Lee1, Hyangsun Han1, Hyeon Tae
Ju1, Seung Hyun Lee1, Mi Jung Lee1, Su Kyung Yun1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

The volcano-ice interaction is very important to understand the glacial process adjacent to volcanoes. In order
to investigate the influence of volcano on glacier, we deployed three GPS stations on the Campbell Glacier
nearby the Mt. Melbourne, Antarctica. From year-round GPS records, we observed a sudden elevation change
probably caused by the draining of subglacial water reservoir. The elevation change was propagated
downstream in company with a phase change from draining to filling. Immediately after the draining, the
velocity of ice flow was suddenly increased at downstream area, while it was significantly decreased at the
reservoir. The sequential velocity change implies that the ice velocity of Campbell Glacier is partly controlled by
the draining of subglacial water flow. Previous seismic records and InSAR velocity changes also indicate the
presence of dynamic changes in this area, although they are not concurrent with the GPS events. Since there
was no significant change in elevation and ice velocity at the GPS station upstream of Mt. Melbourne, the
source of subglacial water seems to be the water melt by the geothermal heat from Mt. Melbourne. Further
long-term monitoring of ice flow at the Campbell Glacier would give more valuable information on the
activities of Mt. Melbourne volcano and subsequent volcano-ice interactions.

1776
156
Melbourne and Rittmann Volcanoes: Results from ICE-VOLC Project

Andrea Cannata1,2, Danilo Contrafatto2, Paola Del Carlo3 (paola.delcarlo@ingv.it), Giuseppe Di Grazia2, Angelo
Ferro2, Salvatore Gambino2, Gaetano Giudice4, Giovanni Giuffrida4, Alessandro La Spina2, Graziano Larocca2,
Marco Liuzzo4, Giuseppe Salerno2, Letizia Spampinato2, Luciano Zuccarello2
1
Università degli Studi di Perugia, Dipartimento di Fisica e Geologia, Perugia, Italy, 2Istituto Nazionale di
Geofisica e Vulcanologia, Osservatorio Etneo, Catania, Italy, 3Istituto Nazionale di Geofisica e Vulcanologia,
Pisa, Italy, 4Istituto Nazionale di Geofisica e Vulcanologia, Palermo, Italy

Melbourne and Rittmann volcanoes are located in the Victoria Land. While Rittmann's last eruption dates back
probably to Pleistocene, those of Melbourne occurred between 1862 and 1922, thus suggesting that it is still
active. At present, Melbourne and Rittmann show fumarolic fields. Despite the limited knowledge on both
volcanoes (particularly for Mt. Rittmann), the Antarctic uncontaminated framework (characterised by absence
of anthropic noise) and the proximity to the Italian Mario Zucchelli Station make them ideal sites for studying
volcano seismic sources, geothermal emissions and volcanic gas impact on the environment.
In the framework of the ICE-VOLC project (www.icevolc-project.com), multiparametric investigations have
been performed during the XXXII and XXXIII Italian expeditions in Antarctica (2016-2017). During the
campaigns, different kinds of research activities were carried out, in particular: i) acquisition of seismic signals
by two temporary stations on different sites of both volcanoes; ii) collection of rock samples from Mt. Rittmann
and Melbourne; iii) sampling of ash layers within glaciers nearby Melbourne; iv) sampling of fumaroles gases on
both volcanoes; v) remote sensing measurements of volcanic gases in atmosphere; and vi) prospection,
exploration and mapping of ice-caves on both volcanoes. Results gathered in the first phase of the project
allowed us to shed new light into the state of activity of these poorly-known volcanoes.

1777
598
Holocene Volcanic Activity of Mt. Melbourne Recorded in Talos Dome Ice Core

Mi Jung Lee1 (mjlee@kopri.re.kr), Philip R Kyle2, Jong Ik Lee1

1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2New Mexico Institute of Mining and
Technology, Socorro, United States

Tephra layers in Antarctic ice cores are valuable time planes and are useful for reconstructing the eruptive
history of young volcanic centers. An ice core drilled at Talos Dome in northern Victoria Land contains many
tephra layers and some have been attributed to eruptions from Mt. Melbourne. Three young englacial tephra
layers are exposed on the flanks of Melbourne volcano. The youngest tephra is inferred from snow
accumulation rates to be between 100 and 300 years old. The other two tephra are over 1 m thick and closely
spaced to each other and probably represent two significant eruptions from the same vent. We geochemically
analyzed the two older tephra and young lavas from the summit area of Melbourne to try and identify the
source vent for the tephra. The tephra have a strong geochemical correlation with the Talos Dome tephra layer
TD85, which suggests they are the same. This is an important finding as it indicates that significant eruptions of
Melbourne occurred at 1280 CE. The youngest tephra on Melbourne is not found in the Talos Dome ice core,
suggesting the eruption was smaller than that for the 1280 CE tephra or the wind direction did not disperse the
tephra towards Talos Dome.

1778
1095
Petrogenesis of the Lithospheric Mantle Beneath the Erebus Volcanic Province

Adam Martin1 (a.martin@gns.cri.nz), Alan Cooper2, Richard Price3, Philip Kyle4, John Gamble5
1
GNS Science, Dunedin, New Zealand, 2University of Otago, Department of Geology, Dunedin, New Zealand,
3
University of Waikato, Science and Engineering, Hamilton, New Zealand, 4New Mexico Institute of Mining and
Technology, Department of Earth & Environmental Science, Socorro, United States, 5Victoria University of
Wellington, School of Geography, Environment and Earth Sciences, Wellington, New Zealand

Cenozoic alkalic igneous rocks of the Erebus volcanic province (EVP) are extensive in the southwest Ross Sea
and provide insight into the nature of the underlying upper mantle. Younger basanites also host numerous
xenoliths of spinel lherzolites, harzburgites, crustal granulites, and rare dunites, glimmerites and plagioclase-
bearing spinel lherzolites. The latter are thought to have formed via metamorphic reaction and refertilisation.
Pyroxenite and crustal xenoliths show an atypically hot EVP geotherm of 50-100 °C/km with heat potentially
from advective transfer from melt refertilisation over the past 24 Ma. A deca-kilometre-scale mantle H2O, trace
element and Sr-Nd-Pb isotopic heterogeneity is demonstrated and it has been variously suggested that the
lithosphere has been refertilised and metasomatised by carbonatite, N-MORB or alkalic melts. Isotopic data for
primitive basanites define trajectories between DMM and HIMU, with enriched EMI and EMII components also
evident at White Island and Mount Morning. Erebus volcano samples also record a HIMU component on U/Th
and 230Th/232Th versus Pb isotope plots. Some pyroxenites at Mount Morning share trace element and isotopic
characteristics with eclogite. Despite this complex regional history, oxygen fugacity averaging -1 FMQ at Mount
Morning (from Mössbauer spectroscopy), overlap with the global median in rifted settings (-0.9 FMQ).

1779
SH-6c - Connecting Polar Research Across Boundaries
22.06.2018 09:00-10:30, A Seehorn

375
Acting upon what we Know: Making Arctic Connections across Boundaries

Robert Rich1 (bob@arcus.org), Helen Wiggins1

1
Arctic Research Consortium of the United States, Fairbanks, United States

The Arctic Research Consortium of the United States (ARCUS) has been making connections across boundaries
in support of Arctic research since 1988. There are many recent activities that have strengthened
communication, coordination, and collaboration across disciplines, organizations, sectors, nations, and
knowledge systems. This presentation will describe a process for planning and implementing collaborations and
will highlight recent case studies.
Building cross-cutting connections requires a carefully planned and strategic approach. Examples of successes
and failures will be drawn from ARCUS' portfolio of projects, including activities focused on co-production of
knowledge with Arctic Indigenous communities and researchers, cross-disciplinary research collaborations, and
education and outreach efforts.
As a real-time exercise in making connections and networking, attendees of this presentation will have the
opportunity to use online polling technology to share their own efforts at brokering connections in support of
Polar research.

1780
245
NERC Changing Arctic Ocean: Implications for Marine biology and Biogeochemistry

Kirsty Crocket1 (kirsty.crocket@sams.ac.uk)

1
Scottish Association for Marine Science, Dunstaffnage, United Kingdom

The Changing Arctic Ocean is a 5 year (2017-2022) research programme to investigate the effects of climate
change on the marine biology and biogeochemistry of the Arctic Ocean. The programme has 4 large projects
(Arctic PRIZE, ARISE, ChAOS, DIAPOD) that form the core of the programme, funded by the UK's Natural
Environment Research Council (NERC), and a further 10 smaller projects co-funded by NERC and the German
Federal Ministry of Education and Research. An important aspect of the CAO programme is the strength of its
international collaboration, reflected by the links established with over 60 international partner institutions.
The topics covered by this international collaboration span the full scope of the science in the programme, as
well as addressing societal challenges specific to the Arctic and the provision of evidence to feed into decision
and policy making. The forms of this collaboration range from the level of communication between individual
researchers, data sharing, exchange of staff on respective cruises, to representation of CAO investigators by
collaborators at Arctic committees and other international bodies. Ultimately, the aspiration of the CAO
programme is to forge lasting engagement with the international Arctic community beyond the funded lifetime
of the programme. In this talk, I outline the scope of the programme and describe our activities in encouraging
science-to-policy translation.

1781
2146
Early Career Involvement Prepares Workforce for the Future of Polar Research

Alexander Eliot Thornton1, Jean Holloway2, Alice Bradley3 (alice.chapman.bradley@dartmouth.edu), Gerlis

Fugmann4
1
University of Alaska Fairbanks, College of Fisheries & Ocean Sciences, Fairbanks, United States, 2University of
Ottawa, Ottawa, Canada, 3Dartmouth College, Hanover, United States, 4Association of Polar Early Career
Scientists, Alfred-Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany

The Association of Polar Early Career Scientists (APECS) bridges disciplinary, institutional, national, and sector
boundaries in the Arctic and Antarctic communities. APECS is an interdisciplinary organization for early career
professionals (ECPs) interested in Earth's polar regions and the wider cryosphere, with a global membership of
nearly 3,000 actively-engaged ECPs from 67 countries. Our network creates opportunities for international
collaborations and information exchange amongst both ECPs and established mentors from a range of
disciplines. We aim to recruit, retain, increase cooperation amongst, and promote future polar experts. APECS
facilitates the involvement of skilled ECPs in the working groups and committees of our partners, including
those of the International Arctic Science Committee (IASC) and Scientific Committee on Antarctic Research
(SCAR). This provides ECPs with an opportunity to practice career skills and to work with senior scientists to
synthesize information and identify emerging research questions. In this presentation, we discuss how APECS
contributes to training diverse, future leaders in the Arctic and Antarctic research and policy communities.
Support of ECPs through APECS develops a workforce more adept in interdisciplinary, international, and
collaborative work and is, therefore, an investment in the future of the Arctic and Antarctic science and policy.

1782
2276
Evaluation of Costs and Societal Benefits of Arctic Observing Systems

Srdjan Dobricic1 (srdan.dobricic@ec.europa.eu), Luca Pozzoli1, Fabio Monforti-Ferrario1, Julian Wilson1

1
European Commission, Joint Research Centre, Ispra, Italy

Observing the Arctic system is difficult due to the extremely harsh environmental conditions and long distance
from the major research facilities. A number of past and existing EU research projects and international
stakeholder initiatives have evaluated the present observational system in the Arctic, but still an overall picture
on present and future observational requirements regarding the needs of stakeholders and costs for
maintenance and investments has not been fully established. In order to support investments in observing the
rapidly changing Arctic environment, taking also into consideration the expansion of a number of human
activities in the area foreseen for the next decades, this study estimates costs and societal benefits of existing
and future observational systems in the Arctic. The first part of the presentation gives an overview of
investment and running costs of observational systems in the Arctic, the second shows the methodology based
on the value tree analysis connecting observational systems and societal benefit areas and the third evaluates
benefits for selected activities and societal benefit areas.

1783
2248
An Agent-based Mobilities Assessment for Enhanced Arctic Climate Services

Berill Blair1 (berill.blair@wur.nl), Machiel Lamers1

1
Wageningen University & Research, Environmental Policy Group, Wageningen, Netherlands

Recent developments in safe navigation, such as the passing of the Polar Code, have addressed important
issues in marine transportation in Arctic waters. Yet contrary to a global downward trend, shipping losses have
steadily increased in the past decade in this region due to expanded shipping operations and increasing spatial
and temporal variability of Arctic weather patterns and sea ice hazards. The availability and quality of climate
services in support of Arctic shipping operators therefore is an important factor in reducing hazards.
SALIENSEAS (Enhancing the saliency of climate services for marine mobility sectors in European Arctic seas), an
ERA4CS project has undertaken the development of user-focused demonstration services based on an
assessment of sector-specific user needs for climate services. Following an initial round of stakeholder
interviews, the project's first phase produced an integrated assessment model of mobilities, risks and
vulnerabilities in the European maritime sectors. The model integrates spatial and temporal variables that
impact stakeholder interests, and delineates the critical infrastructures and key resources that drive risk-
informed decisions. We discuss the role of this model in an iterative, participatory research framework, and the
model's scalability in the assessment of other types of spatial data infrastructures.

1784
CR-8a - Latest highlights from high altitude and polar ice cores
22.06.2018 09:00-10:30, A Wisshorn

1513
Archival Processes of Water Stable Isotope Signal in East Antarctic Ice Cores

Mathieu Casado1,2 (mathieu.casado@gmail.com), Amaelle Landais2, Ghislain Picard3, Thomas Munch1, Thomas
Laepple1, Barbara Stenni4, Giuliano Dreossi4, Alexey Ekaykin5, Laurent Arnaud3, Christophe Genthon3, Alexandra
Touzeau2, Valérie Masson-Delmotte2, Jean Jouzel2
1
AWI, Potsdam, Germany, 2LSCE (UMR 8212 CEA-CNRS-UVSQ/IPSL), Université Paris Saclay, Gif sur Yvette,
France, 3IGE, Université Grenoble Alpes, CNRS, IRD, Saint Martin d'Hères, France, 4Ca Foscari University of
Venice, Venice, Italy, 5Arctic and Antarctic Research Institute, Saint Petersburg, Russian Federation

The oldest ice core records are obtained from the East Antarctic plateau. Water isotopes records are key to
reconstructing past climates. The accuracy of climate reconstructions depends on knowledge of all the
processes affecting water vapour, precipitation and snow isotopic compositions. However, a quantitative
understanding of processes potentially altering the snow isotopic composition after the deposition is still
missing. In low accumulation sites, such as those found in Antarctica, these poorly constrained processes are
likely to play a significant role and limit the interpretation of isotopic composition.
Here, we combine observations of isotopic composition in the vapour, the precipitation, the surface snow and
the buried snow from Dome C, a deep ice core site in Antarctica. At the seasonal scale, we suggest a significant
impact of metamorphism on surface snow isotopic signal compared to the initial precipitation signal.
Particularly, in summer, exchanges of water molecules between vapour and snow are driven by the
sublimation/condensation cycles at the diurnal scale. Using snowpits in five Antarctic sites, we identify
common patterns, despite different accumulation rates, which cannot be attributed to the seasonal variability
of precipitation. Altogether, the difference in the signals observed in the precipitation, surface snow and buried
snow isotopic composition constitute evidences of post-deposition processes affecting ice core records in low
accumulation areas.

1785
427
Probing the Evolution of the past CH4 Budget - The Power of Stable Isotopes

Jochen Schmitt1 (schmitt@climate.unibe.ch), Barbara Seth1, Jonas Beck1, Hubertus Fischer1

1
Climate and Environmental Physics, Physics Institute, and Oeschger Center for Climate Change, University of
Bern, Bern, Switzerland

Reconstructions of atmospheric methane mixing ratios using ice cores have been available since decades. The
large dynamic range, 350 to 800 ppb, and the abruptness of these CH4 changes at DO events and during the
final deglacial phases suggest that CH4 is a powerful parameter to constrain past climate conditions, e.g.
inferring the extend of wetlands. However, based on CH4 concentrations alone, the methane source budget is
notoriously underdetermined and allows numerous hypotheses to be accommodated with the CH4 records. For
example, catastrophic CH4-clathrate releases have been suggested to cause CH4 jumps, likewise, continuous
geologic CH4 emissions were thought to comprise a large fraction of the glacial CH4 budget. Recent studies
applying δ13C, δD and 14C of CH4 were able to reject many hypotheses and concluded that low-latitude
wetlands dominate the past budget and no additional source type is needed to explain CH4 jumps. We provide
an overview on the past CH4 budget using δ13C and δD (Bock et al. 2017) and present a δ13C record extended by
additional 120,000 years covering MIS7 to MIS10. As already visible in previous data, the δ13C evolution of our
new interval shows a remarkable covariation with CO2 for inceptions and glacials. By contrast, the δ13C trend
departs from this covariation for deglaciations and interglacials, with the anomaly from the general δ13C-CO2-
covariation being proportional to the size of the interglacial CH4 peak.

1786
834
Constraining the Sources of Abrupt CH4 Rise in the past with CH4 Triple Isotopes

Michael Dyonisius1 (mdyonisi@ur.rochester.edu), Vasilii Petrenko1, Andrew Smith2, Benjamin Hmiel1, Jonas
Beck3, Barbara Seth3, Quan Hua2, Bin Yang2, Christina Harth4, Ross Beaudette4, Jon Edwards5, James Lee5,
Tobias Erhardt3, Edward Brook5, Ray Weiss4, Jeffrey Severinghaus4, Hubertus Fischer3
1
University of Rochester, Earth and Environmental Sciences, Rochester, United States, 2Australian Nuclear
Science and Technology Organisation, Kirrawee DC, Australia, 3University of Bern, Physics Institute, Bern,
Switzerland, 4Scripps Institution of Oceanography, UC San Diego, San Diego, United States, 5Oregon State
University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, United States

Methane (CH4) is the third most important greenhouse gas in the atmosphere after water vapor and CO2.
Understanding how the natural CH4 budget has changed in response to changing climate in the past can
provide insights on the sensitivity of the natural CH4 emissions to the current anthropogenic warming. CH4
isotopes (Δ14CH4, δ13C-CH4, and δD-CH4) from ice cores can be used to fingerprint the sources of CH4 increases
in the past. Here we present CH4 triple isotopes data from Taylor Glacier horizontal ice cores, Antarctica
spanning the Oldest Dryas-Bølling transition (~14.7ka) - the first abrupt warming and CH4 rise since the LGM.
Among the CH4 isotopes, our Δ 14CH4 data during this transition are novel and unique in their ability to
unambiguously distinguish between “old” CH4 sources (e.g. marine clathrate, geologic sources) and “modern”
CH4 sources (e.g. tropical wetlands). The Δ14CH4 data unambiguously rule out marine clathrate and old
permafrost as the sources of the abrupt CH4 rise. Our stable isotopes data (δ13C-CH4, and δD-CH4) agrees well
with existing CH4 stable isotopes dataset from other polar ice cores. Moreover, our CH4 stable isotopes data
provides the highest resolution paleoatmospheric CH4 stable isotopes dataset that is currently available for this
specific ~150 year timespan. Methane isotopes box modeling combined with interpolar CH4 concentration
gradient suggest that tropical wetlands were the dominant driver for the OD-BØ CH4 rise.

1787
1423
Atmospheric CO2 Variations on Millennial-scale during MIS 6

Jinhwa Shin1 (jinhwa.shin@univ-grenoble-alpes.fr), Christoph Nehrbass-Ahles2, Roberto Grilli1, Jérôme

Chappellaz1, Grégory Teste1, Loïc Schmidely2, Jochen Schmitt2, Thomas Stocker2, Hubertus Fischer2
1
CNRS, Univ. Grenoble-Alpes, Institut des Géosciences de l'Environnement (IGE), Grenoble, France, 2Climate and
Environmental Physics, Physics Institute, and Oeschger Center for Climate Change, University of Bern, Bern,
Switzerland

Understanding natural carbon cycle / climate feedbacks on various time scales is highly important for
predicting future climate changes. Paleoclimate records of Antarctic temperatures, relative sea level and
foraminiferal isotope and pollen records in sediment cores from the Portuguese margin have shown climate
variations on the millennial time scale over the Marine Isotope Stage 6 (MIS 6; from approximately 135 to 185
kyr BP). These proxy data suggested that an intensified hydrological cycle and iceberg calving in the North
Atlantic may impact the Atlantic Meridional Overturning Circulation. This leads to cooling of the Northern
hemisphere and warming of Antarctica, which is explained by the bipolar seesaw mechanism in the ocean
(Margari et al., 2010). Atmospheric CO2 reconstruction from Antarctic ice cores can provide key information on
how atmospheric CO2 concentrations are linked to millennial-scale climate changes. However, existing CO2
records lack of suitable temporal resolution and precision. In this work, we present improved CO2 data,
obtained from the Dome C ice core (75°06´S, 123°24´E) spanning the MIS 6 period, using dry extraction
methods. This new CO2 data show variabilities which are similar with those of temperature in Dome C. Further
investigations on those millennial-scale features will be conducted, with the aim of linking them to other
possible atmospheric proxies.

1788
CR-8a - Latest highlights from high altitude and polar ice cores
22.06.2018 14:00-15:30, A Wisshorn

103
Sub-Antarctic Ice Core Drilling

Elizabeth Thomas1 (lith@bas.ac.uk), Joel Pedro2, Mariusz Potocki3, Amy King1, Bradley Markle4
1
British Antarctic Survey, IDP, Cambridge, United Kingdom, 2Centre for Ice and Climate, Copenhagen, Denmark,
3
University of Maine, Maine, United States, 4University of Washington, Seattle, United States

The sub-Antarctic islands (SAI) are uniquely located to capture changes in the globally significant circumpolar
westerly winds and the Antarctic circumpolar current, key to the mixing and ventilation of the world´s deep
oceans. The glaciers on a number of these SAI's potentially contain an inimitable record of past climate,
atmospheric circulation, westerly winds and pollution from this data sparse region. Here we present the first
results from seven new shallow (10-20 m) ice cores collected as part of the Antarctic Circumnavigation
Expedition (ACE), including the first ever records from Bouvet Island, Peter 1st Island and the Balleny Islands.

1789
SH-7a - Science, Policy, and Politics at the Poles
22.06.2018 09:00-10:30, B Pischa

64
China as a Polar Great Power

Anne-Marie Brady1 (anne-marie.brady@canterbury.ac.nz)

1
University of Canterbury, Political Science and International Relations, Christchurch, New Zealand

In the last five years China has emerged as a member of the unique club of nations who are powerful at both
poles. Polar states are global giants, strong in military, scientific, and economic terms. The concept of a polar
great power is relatively unknown in international relations studies. Yet China, a rising power globally, is now
widely using this term to sum up its aspirations and symbolise the significance of the polar regions to China's
national interests. Chinese Communist Party General Secretary Xi Jinping first referred to China as a polar great
power when he visited Australia in November 2014. China's focus on becoming a polar great power represents
a fundamental re-orientation—a completely new way of imagining the world. In setting its sights on the polar
regions now, China is looking to the mid to long term and planning for its future economic, political, and
strategic needs. The Chinese government´s stated core national interests in the current era—to maintain
China's social system and state security, to preserve state sovereignty and territorial integrity, and the
continued stable development of the economy and society—all require access and engagement in the polar
regions. China has global interests and is well on the way to becoming a global great power. To succeed in this
evolution it must be powerful in the polar regions.

1790
368
Renaissance of the Russian Arctic: Geopolitical, Economic, Environmental Factors

Violetta Gassiy1 (vgassiy@mail.ru)

1
Kuban State University, Public Administration, Krasnodar, Russian Federation

The Arctic is the most important region that will ensure the future of Russia. Already, the largest Russian
projects are being implemented there. For the last hundred years, Russia for the third time begins a large-scale
industrial advancement to the Arctic. In addition, climate change is no longer scientific assumptions, but a
reality. The ice is melting and new commercial opportunities are opening up in the Arctic, non-Arctic countries
appear as investors and economic partners of Russia. Today the NSR is considered as the main Arctic shipping
line in Russia and the government tries to make the NSR a competitive transport corridor of global importance
as well as to strengthen geopolitical influence and Russia´s national security in the Arctic and a state program
for the creation of stationary points for the development of the Arctic is proof of this. Industrial development in
the Arctic is connected with preservation of the indigenous peoples, the traditional economy of nature. Also,
the key priority remains the protection of the unique natural environment of the North, environmental security
issues. Elimination of accumulated environmental damage throughout the Arctic zone, is a long-term process
that requires considerable material and financial resources. In this regard, it can be argued that effective
development of the Arctic can be achieved through an open, equitable and effective approach aimed at
strengthening international political, economic, social dialogue.

1791
1961
Korea's Arctic Policy and Implications through Comparison with That of Japan
Hyunkyo Seo1 (shkshk@kopri.re.kr)
1
Korea Polar Research Institute, Policy Division, Incheobn, Korea, Republic of

Korea has started to conducted basic survey and research on the Arctic in 1993 and the full-scale Arctic
researches after the Korea's Arctic Dasan Research Station was opened in 2012.
Based on these Scientific activities and outputs, Korea joined the Arctic Council Observer with Japan, China,
India, etc in 2013 and set the 5 years' Arctic Master plan(2013-2017) as an after-action on that year, which was
a governmental platform for implementing the comprehensive Arctic Policy for the first time in history. The
2nd phase master plan(2018-2022) by the inter-ministerial work in 2017 is under way. Also, The Korean
president offered Russia to cooperate on a range of projects, including NSR, shipbuilding, and others including
the NSR at East Economic Forum in september of 2017: Arctic (Northern) policy of the new government is
strengthened in various points.
This research will focus on change of Korea's Arctic policy through the comparison between the 1st and 2nd
master plan and will do the policy-analysis on Arctic policy of Japan, a neighbor country on the Korean
perspectives and draws implications for the improvement of Korea's Arctic policy.

1792
SH-7a - Science, Policy, and Politics at the Poles
22.06.2018 11:00-12:30, B Pischa

2147
Polarnomics: A Geo-economic Framework for Systemic Analysis of Polar Affairs

Mikaa Mered1 (mikaa.mered@gmail.com)

1
Institut Libre d'Etude des Relations Internationales, Paris, France

While humanities and social sciences are increasingly represented, supported and well considered in Polar
research and policy circles, the sub-discipline known as “geoeconomics” remains largely underrepresented and
overlooked. As an example, none of the EU H2020-funded projects do explicitly provide geoeconomics analyses
as part of their research steps or their research objectives. Moreover, geoeconomists are often mistaken with
economists, logistics or even geopolitics experts. This misunderstanding of geoeconomics studies applied to
Arctic and Antarctic research has a direct impact on both the quality of the governance of the Polar regions and
on the effective environmental stewardship of both Polar regions. The fact that policy-makers don't have
access to a wide number of Polar geoeconomics research prevents them from approaching Polar affairs in the
most comprehensive way possible. This lack of capacity may lead them to overlook some foreseeable negative
policy externalities, and even allow for socio-economic, diplomatic and/or future environmental so-called black
swan events to happen. It is therefore important to raise the profile of geoeconomics as a useful research
discipline in Polar policy-making. This presentation aims at laying down the foundations of a widespread
discussion on the use of geoeconomics in Arctic and Antarctic policy; and to that aim, proposes a
geographically-bounded framework for systemic analysis of both Arctic and Antarctic affairs: Polarnomics.

1793
SH-7a - Science, Policy, and Politics at the Poles
22.06.2018 09:00-10:30, B Pischa

2608
Geopolitical and Security Challenges in the Arctic

Barbora Padrtova1,2 (b.padrtova@gmail.com)

1
Masaryk University, Dept. of International Relations and European Studies, Brno, Czech Republic, 2Polar
Research and Policy Initiative (PRPI), London, United Kingdom

The geopolitics in the Arctic has been influenced by the current international relations' developments and
increasing tensions between Russia and the West. Additional drivers for geopolitical challenges are the
availability and accessibility of energy resources (mainly oil and gas) and opening of new transportation routes
for destination and transit shipping. The geopolitics of the Arctic is also influenced by the security
developments. There are two major types of security issues facing the Arctic: issues related to military security
of individual Arctic states and those relating to the common security of multiple regional states - including
piracy, terrorism and environmental disasters. The aim of the presentation is to provide overview of
geopolitical and security challenges which the Arctic faces in relation to climate change and current trends in
international relations. The author will focus on how geopolitics transforms into policy and what are the key
variables that influence the relations of cooperation/competition among states in the Arctic region.

1794
CR-4d - Ice sheets, ice shelves & proximal processes in past, present & future climates
22.06.2018 09:00-10:30, B Parsenn

315
Simplified Kamb Ice Stream Flowline Models with Differing Subglacial Conditions

Laurine Nathalie van Haastrecht1 (laurine.vanhaastrecht@vuw.ac.nz), Nicholas Golledge1,2, Huw Horgan1

1
Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand, 2GNS Science,
Wellington, New Zealand

The subglacial environment exerts an important control on ice sheet velocity and on the volume of ice
discharged across the grounding zone. Many subglacial processes and conditions, such as sediment porosity
and the subglacial deformation profile, are still poorly constrained. For example, basal friction from ice-
sediment contact can slow and thicken ice, whereas an increase in basal meltwater may accelerate flow. These
processes are particularly important beneath ice streams, where deforming basal till allows fast ice motion in
the absence of high driving stresses, ultimately controlling whether ice streams are flowing or stagnant. The
importance of these processes means that there is still a need to focus on characterising the subglacial
environment from observations.
Here we present flowline model results from PISM (a thermodynamic, coupled ice-sheet/shelf model)
simulations that investigate variability using seismic estimates of basal conditions from the Kamb Ice Stream
(KIS) as boundary values and tuned parameters. Seismic constraints are provided by an active-source seismic
profile collected across the grounding zone of the KIS. Reflection coefficients along the seismic line signals a
change in acoustic impedances, which can be used as a proxy for porosity and effective pressure. In our model
experiments we varied subglacial conditions (deformation behaviour, basal roughness) and quantified the
impact of each on ice stream velocity, discharge and grounding line location.

1795
828
Post-stagnation Retreat of Kamb Ice Stream´s Grounding Zone

Huw Horgan1 (huw.horgan@vuw.ac.nz), Christina Hulbe2, Richard Alley3, Sridhar Anandakrishnan3, Becky
Goodsell4, Sam Taylor-Offord4, Matthew Vaughan5
1
Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand, 2Univesity of Otago,
Dunedin, New Zealand, 3Pennsylvania State University, University Park, United States, 4Victoria University of
Wellington, Wellington, New Zealand, 5University of Otago, Dunedin, New Zealand

Grounding zone processes include the interaction of subglacial sediment and water with the overlying ice.
These processes regulate accommodation space in the ice shelf cavity, supply and deform sediment, and
determine the grounding zone´s location. Despite the importance of grounding zone sedimentation for ice
sheet stability and ice sheet history, evidence for sedimentary deposits beneath West Antarctica´s modern
grounding zone remains sparse. Recent seismic surveying shows that Kamb Ice Stream has no detectable
grounding zone deposit. As grounding zone deposition relies strongly on ice flow, the absence of a deposit
suggests that the transition from the ice stream to the ice shelf has moved after stagnation of Kamb Ice Stream.
Further support for a recent grounding zone occupation comes from satellite imagery of sub-ice shelf channel
features that likely originated at previous grounding-zone locations. These features begin 25 km seaward of the
current grounding zone and cut across ice flow streak lines. We estimate that retreat to the modern grounding-
zone position was abrupt at rates >0.2 km a−1.

1796
1756
Controls and Change of Enhanced Ice Flow in the Recovery Region, East Antarctica

Anja Diez1, Kenichi Matsuoka1 (kenichi.matsuoka@npolar.no), Fausto Ferraccioli2, Tom Jordan2, Hugh Corr2,
Jack Kohler1, Arne Olesen3, René Forsberg3
1
Norwegian Polar Institute, Tromsø, Norway, 2British Antarctic Survey, Cambridge, United Kingdom, 3Technical
University of Denmark, Copenhagen, Taiwan, Republic of China

The Recovery Region in East Antarctica has remained poorly explored, despite representing the largest
potential contributor to future global sea level rise on a centennial to millennial timescale. The region,
consisting of Recovery, Bailey and Slessor Glaciers, currently discharges 5 % of the total fresh water outflow of
Antarctica into the Filchner Ice Shelf, which is subject to extensive sub-shelf melting under ongoing climate
change. No direct ice thickness data were available within 200 km in this region, which was identified as one of
two 'poles of ignorance' by BEDMAP2. We use new airborne radar data to investigate the bed topography and
controls of fast-ice flow in this region. We show that Recovery Glacier is underlain by an 800 km long trough. Its
fast flow is strongly controlled by topography in its downstream region and the presence of subglacial water in
its upstream region. Recovery Glacier is connected with the adjacent Slessor Glacier via the newly-discovered
Recovery-Slessor Gate. Fast flow of Slessor Glacier occurs over a rougher bed and is controlled by an inferred
channelized hydrological system. Englacial layer studies suggest changes in direction of past fast flow likely
occurred within Slessor and Bailey glaciers. Similar changes could also reoccur here in future. Our findings
refine the knowledge of the Recovery Region and provide a more precise understanding of past ice dynamics
and potential of future change of this region.

1797
1264
Active Seismics at the Grounding Line of Support Force Glacier, Antarctica

Coen Hofstede1 (coen.hofstede@awi.de), Daniel Steinhage1, Hugh Corr2, Emma Smith1, Angelika Humbert1,3,
Olaf Eisen1,3
1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2British
Antarctic Survey, cambridge, United Kingdom, 3University of Bremen, Department of Geosciences, Bremen,
Germany

We report on a high-resolution seismic reflection survey, conducted across the grounding line and ice shelf of
Support Force Glacier, an ice stream feeding into the Filchner Ice Shelf, Antarctica. Two longitudinal profiles
were acquired in the ice-flow direction: a 43 km profile crossing the grounding line, parallel to a nearby ice
shelf channel and a 10 km profile in the ice shelf channel. These are connected by three cross-profiles at 2, 8
and 33 km from the grounding line. The data indicate the grounded ice flows over a flat bed from which the top
20 m most likely are consolidated sediments. The ice becomes uncoupled from the bed 3 km upstream of the
grounding line. Downstream of the grounding line we observe disturbed sedimentation at the seabed,
increasing to a 300 m thick sequence at 6 km distance from the grounding line. At 10 km distance, the
sedimentation sequence is undisturbed and stratified. We interpret the disturbed sedimentation as deposits
from a possible subglacial water conduit upstream of the ice shelf channel although past changes at the
grounding line position cannot be ruled out at this stage. The three cross-profiles show the ice shelf channel at
2 km and 8 km downstream of the grounding line. While the shape of the channel does not change, it widens
22% between 2 and 8 km and increases its height by 12% further downstream between 8 km and 33 km.

1798
2560
Using Radar to Evaluate the Thermal Stabilization of Ice Stream Shear Margins

Nicholas Holschuh1 (holschuh@uw.edu), David Lilien1, Knut Christianson1, Liz Bagshaw2

1
University of Washington, Seattle, United States, 2Cardiff University, Cardiff, United Kingdom

Ice-stream shear margins define highly localized transitions in ice-flow behavior. To reproduce these
transitions, models typically impose lateral variability in either the substrate properties, the subglacial
hydrologic system, or the thermally controlled rheology of the ice. Identifying the relative impact of these three
mechanisms is critical to predicting shear-margin evolution, but attempts to identify the dominant process
using ice penetrating radar suffer from unresolvable tradeoffs between ice temperature, bed roughness, and
basal water availability. To improve our understanding of shear-margin dynamics and aid in radar-data
interpretation collected over ice streams, we use Elmer/Ice to model the thermal state of ice-stream shear
margins as a function of the shear-strain rate, the margin width, and the magnitude of cross-marginal ice flow.
We show that lateral variability in ice temperature across shear margins is controlled by the balance of heat
production and advection, making it possible to estimate temperature gradients across shear-margins using
surface velocity observations alone. Finally, we compare temperature estimates derived from surface velocities
with radar observations across the shear margin of the Northeast Greenland Ice Stream.

1799
736
On-ice Vibroseis: Sediment Features below Ekström Ice Shelf, East Antarctica

Emma C Smith1 (emma.smith@awi.de), Reinhard Drews2, Todd Ehlers2, Dieter Franke3, Christoph Gaedicke3,
Coen Hofstede1, Gerhard Kuhn1, Astrid Lambrecht4, Christoph Mayer4, Ralf Tiedemann1,5, Olaf Eisen1,5
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Glaciology, Bremerhaven, Germany,
2
University of Tübingen, Geosciences, Tübingen, Germany, 3BGR, Federal Institute for Geosciences and Natural
Resources, Hannover, Germany, 4Bavarian Academy of Sciences and Humanities, Geodesy and Glaciology,
Munich, Germany, 5University of Bremen, Geosciences, Bremen, Germany

An extensive grid of seismic reflection data collected on Ekström Ice Shelf, East Antarctica, between 2010-2018,
using an on-ice vibroseis source and snowstreamer, are used to reconstruct the glaciological and tectonic
history of this region.
The data clearly image the outcrop and sub-ice extent of the volcanic Explora Wedge (generated through
Jurassic rifting and seafloor spreading). The wedge is overlain by a sequence of truncated, dipping marine-
sediment layers. The sediment were likely truncated by former ice advance and subsequent retreat; which has
also left evidence in the form topographic over-deepening and glacial debris deposits at the sea floor. The
debris deposits range from elongated bedforms in a topographic trough (indicating probable former ice-stream
flow) to layered sediment wedges at the current ice-shelf front (indicating the likely former extent of grounded
ice).
A series of sub-ice shelf geological drilling campaigns in the area will take place (2017-2019) to recover
sediments from the sea floor. Combining the topography and material characteristics from vibroseis data with
stratigraphic evidence from sediment cores allows a robust reconstruction in this area. Future integration of
these results with numerical models will provide a better understanding of past and present interactions
between the ice sheet and the solid Earth in Dronning Maud Land, which will in turn improve understanding of
future contributions of this region to sea-level rise.

1800
OS-4a - Sea ice modeling and prediction: Sea ice Projections
22.06.2018 09:00-10:30, B Jakobshorn

1426
Arctic Sea Ice in a 1.5 °C Warmer World

Laura Niederdrenk1 (laura.niederdrenk@mpimet.mpg.de), Dirk Notz1

1
Max Planck Institute for Meteorology, Hamburg, Germany

We examine the seasonal cycle of Arctic sea ice for different levels of global warming and quantify the possible
variations around this seasonal cycle caused by internal variability. To do so, we combine observations with
simulated internal variability from a very large ensemble, the MPI-ESM Grand Ensemble. We use the observed
sea ice sensitivity to global warming to recalibrate the sensitivity of the modelled sea-ice evolution.
We show that for a global warming of 1.5 °C above pre-industrial levels, it is unlikely that September Arctic sea
ice vanishes. The internal variability causes a range of about ±0.2 °C to the global warming magnitude at which
September Arctic sea ice is lost. For a 2.0 °C warming, the Arctic Ocean becomes virtually certainly ice free in
August and September. In March, for a 1.5 °C global warming, sea-ice area is reduced to about 85% and for a
warming of 2.0°C to about 80% of pre-satellite levels.

1801
1392
For Arctic Summer Sea Ice, Staying Below 2.0°C Global Warming Matters

Alexandra Jahn1 (alexandra.jahn@colorado.edu)

1
University of Colorado Boulder, Atmospheric and Oceanic Sciences and INSTAAR, Boulder, United States

What impact would the IPCC target of limiting global warming to 1.5° to 2°C have on Arctic summer sea ice? To
answer that question, we analyze five initial-condition Community Earth System Model (CESM) ensembles with
global warming ranging from 1.5°C to 4°C by 2100. We find that if warming can be limited to 1.5°C, 45% of the
time September sea ice extents will still be higher than the minimum observed to date by 2100, and there is a
30% probability for an ice-free September. If warming reaches 2°C, September sea ice extents will only be
above the minimum to date 2% of the time, and we find a 100% probability of at least one occurrence of ice-
free conditions. If warming exceeds 2.5°C, the sea ice extents will always be far below the minimum to date
and ice-free conditions will occur frequently in the summer. Hence, for preserving Arctic summer sea ice,
staying below 2.0°C global warming matters.

1802
1663
Polar Amplification and Sea Ice Changes in NorESM Low Warming Scenarios

Jens Boldingh Debernard1 (jens.debernard@met.no), Øyvind Seland2, Ingo Bethke3, Mats Bentsen3, Lise Seland
Graff2, Trond Iversen2
1
Norwegian Meteorological Institute, Research and Development, Oslo, Norway, 2Norwegian Meteorological
Institute, Research and development, Oslo, Norway, 3Uni Research Climate, Bergen, Norway

The differences in polar amplification and consequences for sea ice were studied with the Norwegian Earth
System Model (NorESM) during the multi-model project HAPPI, whose main focus was to evaluate differences
in impacts between scenarios of 1.5- and 2.0-degree warming above pre-industrial. Simulations from an
updated version of the fully coupled model (NorESM1-Happi) have been evaluated. Compared to earlier
versions of the NorESM, the simulated Arctic sea ice is greatly improved. In addition, slab ocean (SO) versions
of the model, specially designed to be comparable to the AMIP-style experiments used in the HAPPI-protocol,
have been analysed to look at differences in polar amplification and sea ice properties. We find large
differences in the polar amplification in the Northern and Southern Hemisphere depending on fully coupled, or
slab ocean set-ups of the model. Ocean heat transport seems to be the main contributor to this difference
between the hemispheres. Also, in the SO experiments designed to have similar ocean heat transport changes
as the CMIP5 multi-model ensemble, we find very large changes in the September sea ice extent in the Arctic
between the 1.5- and 2.0-degree warming scenarios. These large changes are sensitive to the simulated
present-day sea ice cover in the model, and the sensitivity of this is discussed in light of model assumptions and
uncertainties.

1803
799
Sea-ice Cover Timing in the Pacific Arctic: The Present and Projections

Muyin Wang1,2 (muyin.wang@noaa.gov), Qiong Yang1,2, James Overland2, Phyllis Stabeno2

1
University of Washington, JISAO, Seattle, United States, 2Pacific Marine Environmental Laboratory, Seattle,
United States

With the sea-ice cover in the Arctic fast declining, changes to the timing of sea-ice break-up and freeze-up is an
urgent economic, social, and scientific concern. Based on daily sea-ice concentration data we assess the dates
of sea-ice break-up and freeze-up, and the annual sea-ice duration in the Pacific Arctic. The simulation results
from the coupled climate models from the Coupled Model Intercomparison Project (CMIP5 and CMIP6) are the
major source for this study. Based on CMIP5 results, the length of sea-ice duration is shrinking, with the
strongest downward trend occurring for the period 1990-2014; this downward trend is projected to continue
through mid-century. Comparisons made at eight Chukchi Sea mooring sites maintained by PMEL and eight
Distributed Biological Observatory (DBO) regions show consistent results. The 30-year averaged trend for
annual sea-ice duration in the southern Chukchi Sea is projected to be -0.68 (-0.74) days/year to -1.20 (-1.17)
days/year for 2015-2044 under RCP8.5 (RCP4.5) emissions scenarios. This is equivalent to a reduction of 20 to
36 days in the annual sea-ice duration. Models project both earlier break-up dates and later freeze-up dates,
and that a later freeze-up contributes more to the overall shortening of annual sea-ice duration. Up to a 60-day
reduction of the annual sea-ice duration in the Chukchi, East Siberian, and Beaufort Seas, and less than 20 days
in the Bering Strait area is projected near the middle of the 21st century.

1804
1178
Arctic Sea Ice Melt Season Length in the CESM Large Ensemble and CMIP Models

Abigail Ahlert1 (abigail.ahlert@colorado.edu), Alexandra Jahn1

1
University of Colorado Boulder, Boulder, United States

Melt season length—the difference between the sea ice melt onset date and the sea ice freeze onset date—
plays an important role in the radiation balance of the Arctic and the predictability of sea ice cover. Using the
CESM Large Ensemble and CMIP5 model simulations, we explore three sources of uncertainty in the
assessment of melt season length in climate models: definition choices, internal variability and model
differences.
There are multiple possible definitions for sea ice melt and freeze onset in climate models, and none of them
exactly correspond to the remote sensing definition. We first show how the mismatch between model and
remote sensing definitions of melt and freeze onset limits the utility of melt season remote sensing data for
bias detection in models. Then, by using the CESM Large Ensemble, we account for the role of internal
variability, allowing us to assess the comparability of different melt and freeze onset definitions. Finally, we
expand our analysis to CMIP5 models to study how model differences affect projections of melt and freeze
onset. If possible, we will also include CMIP6 simulations in that analysis. Our study of CMIP5 models (and
CMIP6 models when available) will explore the hypothesis that an underestimation of the melt season length
trend is one factor contributing to the generally underestimated sea ice loss in climate models.

1805
801
Arctic Sea Ice-free Season Projected to Extend into Fall

Marion Lebrun1 (marion.lebrun@locean-ipsl.upmc.fr), Martin Vancoppenolle1, Gurvan Madec1, François

Massonnet2,3
1
Sorbonne Universités (Université Pierre et Marie Curie Paris 6), LOCEAN-IPSL, CNRS/IRD/MNHN, Paris, France,
2
Université Catholique de Louvain, Earth and Life Institute, Louvain-la-Neuve, Belgium, 3Barcelona
Supercomputing Cente, Earth Sciences Department, Barcelona, Spain

The recent Arctic sea-ice reduction is associated with an increase in the ice-free season, with comparable
contributions of earlier retreat and later freeze-up. Here we show that within the next decades, the trends
towards earlier freeze-up should progressively exceed and ultimately double the trends in ice retreat date.
Such asymmetry is due to the response of ice and ocean thermodynamics to warming: the extra solar heat
reaching the ocean due to earlier ice retreat is absorbed at a higher rate than it is released until freeze-up.
Based on climate change simulations, we envision an increase and a shift of the ice-free season towards fall,
which will affect Arctic ecosystems and navigation.

1806
AC-2c - Polar meteorology, climatology and stratospheric processes
22.06.2018 09:00-10:30, C Sanada I

86
The Local water Cycle Associated with Marine Cold Air Outbreaks

Lukas Papritz1,2 (lukas.papritz@uib.no), Harald Sodemann1,2

1
Geophysical Institute, University of Bergen, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen,
Norway

At high latitudes marine cold air outbreaks (CAOs) are the dominant weather systems injecting moisture into
the atmosphere - yet their role in the water cycle is not well understood and their representation in coarse
resolution models is subject to substantial biases. We present a numerical process study of one of the most
intense CAOs that occurred in the Nordic Seas in recent years. To that end we perform a set of simulations with
the limited area weather prediction model COSMO at resolutions from coarse to convection resolving. Using
tagged water tracers transported within a secondary water cycle built into the model, we follow the moisture
that evaporates into the CAO air mass from evaporation to precipitation.
Based on these simulations we characterize the water cycle associated with the CAO. Specifically, we quantify
the amount of moisture injected into the atmosphere by the CAO and analyse the footprint of the CAO in
surface evaporation and precipitation, as well as moisture pathways. Most importantly, we show that the CAO
is associated with a local water cycle, where moisture origin and precipitation are close together and take place
on a time scale of less than 3 days. This contrasts other weather systems that are associated with rather long-
range moisture transport, such as frontal systems. This local nature of the water cycle associated with CAOs
allows to study limitations of parameterised processes regarding evaporation and convection within a limited-
area model.

1807
135
Atmospheric Variability in the Subpolar North Atlantic: A Long-term Perspective

Erica Madonna1,2 (erica.madonna@uib.no), Camille Li1,2, Clio Michel1,2, Lukas Papritz1,2

1
Geophysical Institute, University of Bergen, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen,
Norway

Understanding the interannual atmospheric variability in the polar and subpolar regions is essential for
detecting and understanding future changes in these regions. Unfortunately, observations at high latitudes are
sparse and the records are short, making it difficult to assess changes.
The Arctic is dynamically linked to the mid-latitudes, for example via the poleward transport of heat and
moisture in extratropical cyclones. Moreover, in the North Atlantic, the position of the eddy-driven jet stream
is related to the occurrence of blocking, and accounts for a large portion of the internal (natural) variability in
the region. The jet stream´s position also influences the occurrence of cold air outbreaks (CAOs), which
contribute substantially to the oceanic heat loss in the Arctic due to air-sea heat exchanges.
The aim of the study is to investigate interannual variability and trends in the frequency of the jet
configurations at mid-latitudes over the past century, and the implications for the conditions in the polar and
subpolar regions. We use the long term (1900-2010) wintertime ECMWF ERA-20C reanalysis for the North
Atlantic. First, we identify the North Atlantic jet configurations, which are closely related to the quasi-stationary
states of the atmosphere, so called weather regimes. We then characterize each jet configuration with respect
to cyclones, blocking and CAOs frequencies and study their long-term variability.

1808
439
Temporal and Spatial air Temperature Changes in the Arctic, 1951 - 2015

Rajmund Przybylak1 (rp11@umk.pl), Przemysław Wyszyński1

1
Nicolaus Copernicus University, Department of Meteorology and Climatology, Toruń, Poland

Detailed research into air temperature tendencies in the Arctic based on instrumental data for the periods
1951-2015, 1976-2015 and 1996-2015 revealed the predominance of positive trends, statistically significant at
the level of 0.05. In the two later periods the rate of warming was on average 2-3 times faster than in the
entire study period. This is particularly true for mean annual values for the entire Arctic, and also for seasonal
means (DJF, MAM, etc.) for the period 1976-2015. In the most recent 20-year period very large increases in
both seasonal and annual means were observed in the Atlantic and Siberian climatic regions (after Atlas Arktiki
1985), while in the rest of the Arctic the rate of warming was usually weaker than trends for the period 1976-
2015. In particular, there was a large fall in the rate of warming in spring, with near-zero trends (Baffin Bay and
Canadian regions) and even a negative trend (-0.34°C/10 years, Pacific region). The scale of warming for the
recent 20-year period relative to the reference period 1951-1990 ranges from 1.3°C (Baffin Bay region) to 1.7°C
(Atlantic region). The average anomaly for the entire Arctic reached 1.6°C. The greatest warmings were for
autumn (1.9°C) and winter (1.7°C), while the smallest was in summer (0.9°C).
The research work was supported by a grant entitled 'Causes of the early 20th century Arctic warming', funded
by the National Science Centre, Poland (Grant No. 2015/1.9/B/ST10/02933).

1809
531
Increasing Frequency and Duration of Arctic Winter Warming Events

Robert M. Graham1, Lana Cohen1, Alek A. Petty2 (alek.a.petty@nasa.gov), Linette N. Boisvert2, Annette Rinke3,
Stephen R. Hudson1, Marcel Nicolaus4, Mats A. Granskog1
1
Norwegian Polar Institute, Tromso, Norway, 2Goddard Space Flight Center, National Aeronautics and Space
Administration, Greenbelt, United States, 3Alfred Wegener Institute, Potsdam, Germany, 4Alfred Wegener
Institute, Bremerhaven, Germany

Near-surface air temperatures close to 0°C were observed in situ over sea ice in the central Arctic during the
last three winter seasons. Here we use in situ winter (December-March) temperature observations, such as
those from Soviet North Pole drifting stations and ocean buoys, to determine how common Arctic winter
warming events are. Observations of winter warming events exist over most of the Arctic Basin. Temperatures
exceeding −5°C were observed during >30% of winters from 1954 to 2010 by North Pole drifting stations or
ocean buoys. Using the ERA-Interim record (1979-2016), we show that the North Pole (NP) region typically
experiences 10 warming events (T2m > −10°C) per winter, compared with only five in the Pacific Central Arctic
(PCA). There is a positive trend in the overall duration of winter warming events for both the NP region (4.25
days/decade) and PCA (1.16 days/decade), due to an increased number of events of longer duration.

1810
557
Modification of Polar Low Development by Sea Ice and Svalbard Orography

Denis Sergeev1 (d.sergeev@uea.ac.uk), Ian Renfrew1, Thomas Spengler2

1
University of East Anglia, School of Environmental Sciences, Norwich, United Kingdom, 2University of Bergen,
Bergen, Norway

The life cycles of intense high-latitude mesoscale cyclones, polar lows, are uniquely shaped by their local
geographical features. Our research focuses on the influence of Svalbard mountains and sea ice cover in the
Norwegian and Barents Seas on polar low formation.
We present a modelling study of two typical polar lows that were in the Norwegian Sea during a northerly cold
air outbreak. Each case is simulated using the UK Met Office Unified Model with grid spacing of 2.2 km.
Compared to satellite cloud imagery and wind estimates, the model captures key features of the mesoscale
vortices with reasonable accuracy. A series of sensitivity runs is conducted with artificially changed land mask,
orography, and sea ice cover.
Besides its role in blocking stably stratified air from the ice-covered Arctic Ocean, Svalbard acts as an additional
source of low-level cyclonic vorticity that helps polar lows to intensify. The change in the sea ice cover,
especially west of Svalbard, results in larger changes in polar low intensity, particularly in the convectively-
driven case.
The cases analysed in our study exemplify that polar mesoscale cyclones, originating from small vorticity
clusters advected by synoptic-scale weather systems, often have stochastic nature.
To make broader conclusions about statistically significant influence of sea ice cover in the region, in the
second part of our study we compile a climatology of mesocyclones in the vicinity of Svalbard using the ERA5
reanalysis.

1811
717
Arctic CO2 Variability Induced by the Madden-Julian Oscillation

King-Fai Li1,2 (king-fai.li@ucr.edu)

1
University of California, Environmental Sciences, Riverside, United States, 2University of Washington, Applied
Mathematics, Seattle, United States

Variability of atmospheric CO2 must be well understood in order to better characterize the surface sources of
anthropogenic CO2 release. Previous studies have revealed the influence of the tropical Madden-Julian
oscillation (MJO) to tropical mid-tropospheric CO2 via convection. In this work, the observation by NASA's
Atmospheric Infrared Spectrometer (AIRS) is used to further study the MJO impact on the CO2 concentration
over the Arctic. A composite analysis shows that CO2 north of 60°N varies with an amplitude of ±0.6 ppm over
the MJO cycle. An empirical correlation analysis is applied to explore some possible mechanisms through which
the MJO perturbs the Arctic CO2 concentration remotely. The spatial pattern of the MJO-related Arctic CO2
anomalies is found to resemble that of the isentropic potential vorticity (PV) anomalies at 475 K. A potential
role of the lower stratospheric tropics-extratropics exchange is discussed.

1812
OS-7e - Atmosphere-Ice-Ocean interactions in the Polar Regions
22.06.2018 09:00-10:30, C Sanada II

2609
Local Surface Mass and Energy Balance Processes in East Antarctica

Hendrik Huwald1 (hendrik.huwald@epfl.ch), Nander Wever1,2, Francesco Comola1, Michael Lehning1,2

1
Ecole Polytechnique Federale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering,
Lausanne, Switzerland, 2WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland

In Antarctica, direct observations of key processes shaping the surface mass balance such as precipitation and
snow deposition, wind transport of snow, and sublimation, are sparse due to the extreme environment and
related difficulties in measuring the variables of interest. The ongoing project 'Local Surface Mass Balance in
East Antarctica' (LOSUMEA) is designed to address these processes at the local scale with the objective of
gaining insight on the dominant surface mass and energy balance components and their link to near-surface
atmospheric dynamics and surface and sub-surface snow properties. To this end, two measurement stations
have been installed near the Princess Elisabeth Station, Antarctica, in December 2016. Besides standard
meteorological data the stations are equipped with snow particle counters and 3-D sonic anemometers relating
wind, turbulence and mass flux. Pre- and post-storm Terrestrial Laser Scans (TLS) record the resulting surface
morphological changes. While preliminary data is being analyzed, the full data set of the year 2017 is retrieved
in early 2018. Addition of moisture sensors in 2018 is expected to provide valuable information on latent heat
fluxes related to sublimation. This contribution presents an overview of the project experiments, the data
obtained to date as well as their analysis and some first results.

1813
2028
Energy Exchange between the Ground and Atmosphere at PEARL

Alexey Tikhomirov1, Glen Lesins1, James Drummond1 (james.drummond@dal.ca)

1
Dalhousie University, Physics and Atmospheric Science, Halifax, Canada

Energy exchange between the ground and the atmosphere in the Arctic is of great interest to understand the
amplification of global warming that is being experienced in that region. At very high latitudes the absence of
sunlight in the prolonged Arctic night leads to conditions very different from most of the rest of the planet. In
particular convection is suppressed though the presence of a very persistent inversion and this means that a
major mechanism for energy exchange is turned off and other mechanisms (conduction, radiation, etc) are
responsible for the exchange.
At the Polar Environment Atmospheric Research Laboratory (PEARL), Eureka, Nunavut, Canada, a research
station at 80N latitude we have been studying this situation through the Polar night. We have used many in situ
measurements including a microbarometer to watch small pressure fluctuations and a drone to measure the
temperature gradient over a significant spatial area and through the lowest levels of the atmosphere.
This talk will introduce some of the results from this work showing a strong spatial heterogeneity and
significant variations in the conditions through the night. From these measurements we can begin to piece
together a picture of the energy exchange in these unusual conditions.
PEARL is currently supported by the Natural Sciences and Engineering Research Council, Environment and
Climate Change Canada and the Canadian Space Agency.

1814
512
Cloud Role in Surface Radiation in Moisture and Sensible Heat Flux into Arctic

Yinghui Liu1 (yinghuil@ssec.wisc.edu)

1
CIMSS, University of Wisconsin at Madison, Madison, United States

Previous studies show the impact of moisture and sensible heat into the Arctic on the surface energy budget,
the Arctic sea ice concentration, and other atmospheric parameters. This study investigates how the moisture
and sensible heat advection into the Arctic in the winter time affects the Arctic cloud. Composite analysis of
radiation, cloud properties, air temperature, column integrated water vapor, and atmosphere circulation are
performed using data from ECMWF Interim Re-Analysis (ERA-Interim), the Moderate Resolution Imaging
Spectroradiometer (MODIS), and cloud profiling radar (CPR) onboard CloudSat. Results from ERA-Interim show
greater downward longwave radiaton (DLR), clear-sky downward longwave radiation (DLR_CLR), and cloud
radiative forcing (CRF_LW), with CRF_LW accounting for approximately 40% of the total positive anomalies in
the surface energy. Greater DLR_CLR can be attributed to higher air temperature, and higher column
integrated water vapor; greater CRF_LW are results of greater cloud amount, and higher cloud ice and liquid
water content. Changes in cloud properties are more obvious in the low-level clouds. Composite analysis from
MODIS cloud shows similar spatial pattern as that from EAR-Interim. Composite analysis from CloudSat CPR
shows moisture flux impact on the cloud vertical distribution stronger in the low-level, and stronger on the
Atlantic side than that on the Pacific side of the Arctic Ocean.

1815
1210
Micrometeorology Controlling Snow and Ice Ablation Processes

Rebecca Mott-Grünewald1 (rebecca.mott-gruenewald@partner.kit.edu), Michael Warscher1, Sebastian

Schlögl2,3, Thomas Grünewald2, Michael Lehning2,3
1
Atmospheric Environmental Research, Institute of Meteorology and Climate Research, Karlsruhe Institute of
Technology (KIT/IMK-IFU) KIT-Campus Alpin, Garmisch-Partenkirchen, Germany, 2WSL Institute for Snow and
and Avalanche Research SLF, Davos, Switzerland, 3Laboratory of Cryospheric Sciences, School of Architecture,
Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland

Changing micrometeorology during an ablation season strongly affects melt dynamics of seasonal snow covers,
perennial ice fields and small glaciers as complex boundary layer development over heterogeneous land-
surfaces significantly alter the local air temperatures (and humidities). Micrometeorological processes such as
advective heat transport, cold-air pooling or thermal wind systems are important meteorologic drivers for the
mass balance of very small glaciers, by strongly affecting their sensitivity to an increase in the ambient air
temperature.
In this study, we experimentally and numerically investigate the relative contribution of micrometeorological
processes to the melt dynamics of seasonal snow-covers in alpine catchments and to the mass balance of the
lowest perennial ice field of the Alps, the Eiskapelle. Measurements indicate that the well-developed katabatic
wind system significantly modifies the local air temperature field over the ice-field by decoupling the near-
surface air from the warmer ambient air. For seasonal snow-covers we could evidence a high frequency of
developing shallow stable internal boundary layers over snow patches, coinciding with atmospheric decoupling
causing a shut-down of turbulence close to the snow surface. As a counteracting process, the advective
transport of warm air is revealed to significantly increase the mean air temperature over snow resulting in 20-
40% larger catchments mean daily depletion rates.

1816
2332
The Role of Particle Cohesion in the Wind-driven Erosion of Snow Surfaces

Francesco Comola1 (francesco.comola@epfl.ch), Johan Gaume1,2, Michael Lehning1,2

1
Ecole Polytechnique Federale de Lausanne, Civil and Environmental Engineering, Lausanne, Switzerland, 2WSL
Institute for Snow and and Avalanche Research SLF, Davos, Switzerland

Snow particles in a sintering snowpack develop cohesive bonds that significantly affect the predisposition of
the snow surface to wind erosion. A better understanding of how cohesive bonds affect surface entrainment
mechanisms is crucial to improve quantifications of the surface mass balance in polar regions. Given that
particle cohesion is difficult to measure in experimental and field studies, this investigation relies on numerical
models. Here, we use the discrete element method (DEM) to investigate the role of cohesive bonds in the
granular splash process, which is the most efficient surface entrainment mechanism in wind-driven snow
transport. Our granular splash simulations show a non-linear decrease of the number of ejected grains with
increasing cohesion. The ejection speed, however, increases with increasing cohesion seemingly due to the
smaller dissipation of elastic energy in frictional rearrangements. The interplay between number and velocity
of ejected grains balances the cumulative kinetic energy of the splashed particles across a wide range of
cohesion values. We further perform DEM simulations of wind-driven snow transport to show that the
conservation of kinetic energy in the splash process can sustain the saltation mass flux over highly sintered
snow beds. Our results may improve current surface parameterizations in larger scale models of snow
transport and help us quantify, e.g., the amount of snow transported from the Antarctic ice sheet to the ocean.

1817
2451
Revisiting the Thorpe-Mason model for calculating sublimation of saltating snow

Varun Sharma1 (varun.sharma@epfl.ch), Francesco Comola1, Michael Lehning1,2

1
EPFL, Lausanne, Switzerland, 2WSL Institute for Snow and and Avalanche Research SLF, Davos, Switzerland

Sublimation of drifting and blowing snow has been recognized as an important component of the mass budget
of polar and alpine regions. The Thorpe and Mason (TM) model is the basis of all existing small and large-scale
estimates of drifting snow sublimation. We revisit this model to test its validity for calculating sublimation from
saltating snow grains.
Through simple numerical experiments, it is highlighted that the TM model is a steady-state model that
reconciles well with the solution of the unsteady mass and heat balance equations of an individual snow grain,
albeit after a transient regime. Next, we simulate snow saltation using high-resolution large-eddy simulations
of the atmospheric surface layer with lagrangian snow particles, coupled with statistical models of
aerodynamic, splash and rebound entrainement of particles from an underlying snow surface. It is found that
the residence time of a typical saltating particle is shorter than the period of the transient regime, implying that
using the TM solution might be erroneous.
In simulations with similar air and surface temperatures, these errors range between 25% for low-wind and
low-saturation conditions and 40% for high-wind and high-saturation conditions. With a small temperature
difference of 1 K between the air and the snow surface, the errors due to the TM model are already as high as
100% with errors rapidly increasing for larger temperature differences.

1818
BE-9d - Life distribution and responses to environmental changes in Polar ecosystems
22.06.2018 11:00-12:30, C Aspen

1896
Ecosystem Monitoring for Conservation: When to Monitor and Use Biodindicators

Justine Shaw1 (j.shaw6@uq.edu.au), Rachael Alderman2, Melissa Houghton1, Aleks Terauds3, Hugh Possingham4
1
The University of Queensland, Centre for Biodiversity Conservation Science, Brisbane, Australia, 2DPIPWE,
Wildlife Management, Hobart, Australia, 3Australian Antarctic Division, Hobart, Australia, 4The Nature
Conservancy, Washington, United States

Ecosystem monitoring is not high impact, novel research to undertake in Antarctica or the sub-Antarctic, as
such it is often not supported. Yet in order to understand ecosystem change and detect climate change impacts
or assess conservation targets, monitoring must occur. Due to economic and logistic constraints and a desire to
minimise our footprint we have to rationalise when, where, what and how we monitor in the region.
On sub-Antarctic Macquarie Island we are developing an optimal monitoring strategy to determine the current
ecosystem state and track change into the future following invasive species eradication and under climatic
change. We will quantify if conservation targets are being achieved. In order to do this we must identify when,
what and how we monitor the terrestrial ecosystem. Firstly, management objectives for the region were clearly
define. Secondly, temporally and spatially explicit historic data were located and compiled from various
sources. This provided us with a suite of taxa and ecosystem variables that could be monitored into the future.
We then had to consider which were suitable as bio-indicators, with which to detect change. A gap analysis was
undertaken to determine if management objectives could be determined with this suite of bio-indicators or if
new monitoring had to be initiated to ensure greater coverage of taxa and features. Finally, we are determining
how monitoring can be in repeatable, low impact and cost effective into the future.

1819
185
Species on the Move in East Antarctic Terrestrial Communities

Sharon Robinson1 (sharonr@uow.edu.au), Melinda Waterman1,2, Diana King1, Johanna Turnbull1, Jessica
Bramley-Alves1, Michael Ashcroft1, Ellen Ryan-Colton1, Jane Wasley1,3, Quan Hua2
1
University of Wollongong, Centre for Sustainable Ecosystem Solutions, School of Biological Sciences,
Wollongong, Australia, 2Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia,
3
Australian Antarctic Division, Department of Environment, Kingston, Australia

Antarctica has experienced major changes in temperature, wind speed and stratospheric ozone levels over the
last 50 years. Whilst West Antarctica and the peninsula showed rapid warming and associated ecosystem
change, East Antarctica appeared to be little impacted by climate warming, thus biological changes were
predicted to be relatively slow. Detecting the biological effects of Antarctic climate change has also been
hindered by the paucity of long-term data sets, particularly for organisms that have been exposed to these
changes throughout their lives. We monitored vegetation communities in the Windmill Islands, East Antarctica
from 2000 to 2014 and found significant changes in species composition. In addition, we have shown that
radiocarbon signals preserved along shoots of the dominant Antarctic moss flora can be used to determine
accurate growth rates over a period of several decades, allowing us to explore the influence of environmental
variables on growth. Stable isotopic measurements suggest that the observed effects of climate variation on
growth are mediated through changes in water availability and most likely linked to the more positive phase of
the Southern Annular Mode and changing westerly wind patterns. For cold remote locations like Antarctica,
where climate records are limited and of relatively short duration, this illustrates that mosses can act as
microclimate proxies and have the potential to increase our knowledge of coastal Antarctic climate change.

1820
1985
Vascular Plants and Moss Responses to Passive Warming in Antarctica

Angelica Casanova-Katny1 (angecasanova@gmail.com)

1
Universidad Catolica de Temuco, Escuela de Veterinaria Facultad de Recursos Naturales, Concepcion, Chile

In contrast to vascular plants, bryophytes are major components of green landscapes of Antarctica's small ice-
free areas. Mosses, with more than 100 species, extend from maritime Antarctica well into the continent.
However, only two vascular plants colonized Antarctica, the native Deschampsia antarctica and Colobanthus
quitensis. After long term passive warming, we found that vascular plants grew faster producing more seeds. In
mosses, an increase of sporophyte production after passive warming both in monoecius (Bartramia patens)
and dioecious (Polytrichastrum alpinum) was found. Sanionia uncinata is a dominant and pioneer moss on
glacier moraine and covers most part of the ice-free areas on the South Shetland Archipelago. We found that S.
uncinata facilitates the growth of the vascular plant D. antarctica in the field and we observed that
experimental warming did not change this positive interaction. We study heat resistance, antioxidant capacity.
We observed no change in photochemical efficiency between passive warming and control after seven years of
treatments, however lipid peroxidation rises in warmed mosses during the experiment, indicating that S.
uncinata has been affected by the long term treatment. We suggest that S. uncinata will be able to support the
future scenario of warming, but desiccation will be important for the success of this moss and this will affect
the interaction with other component of the tundra ecosystem.

1821
1014
Traits Determining Invasiveness of Temperate Plant Species in Polar Regions

Luis R. Pertierra1 (luis.pertierra@gmail.com), Inger G. Alsos2, Pedro Aragon3

1
Universidad Rey Juan Carlos, Mostoles, Spain, 2University of Tromsoe, Tromsoe, Norway, 3Museo Nacional de
Ciencias Naturales, Madrid, Spain

There are several ecological traits that could explain the capabilities of invasive species for the colonization of
new areas. Traits that promote invasiveness may largely vary due to the prevailing ecological limiting factors
across climatic regions. Temperate and Tropical areas are subjected to a stronger biotic competition than in
Polar Regions, while in contrast abiotic conditions of polar areas may result particularly stressful for plant
invaders. The present study compiles and analyzes climatic, mechanistic and physiological traits from 70
reported non-native plants of 4 different plant families historically found at nine biogeographic areas within
Arctic and Antarctic/Sub-Antarctic high latitudes. General invasiveness was related to wide macroclimatic
tolerances observed from temperature and precipitation ranges. Furthermore, the number of sites colonized
per species was related to other factors such as plant height, seed production and/or human facilitation. The
observed patterns are discussed in light of global change scenarios, taxonomic relationships and cold areas
regionalization.

1822
713
Predicting Plant Invasion Risks to the Subantarctic Islands

Michelle Greve1 (michelle.greve@up.ac.za), Rabia Mathakutha1, Christien Steyn1, Izak Blom1, Steven L. Chown2,
Barnabas H. Daru3, Brad S. Ripley4, Wayne Dawson5, Franz Essl6, Holger Kreft7, Anche Louw8, Jan Pergl9, Petr
Pyšek9, Patrick Weigelt7, Marten Winter10, Mark van Kleunen11, Peter C. le Roux1
1
University of Pretoria, Department of Plant and Soil Sciences, Pretoria, South Africa, 2Monash University,
Monash, Australia, 3Harvard University, Cambridge, United States, 4Rhodes University, Grahamstown, South
Africa, 5Durham University, Durham, United Kingdom, 6University of Vienna, Vienna, Austria, 7University of
Göttingen, Göttingen, Germany, 8Stellenbosch University, Stellenbosch, South Africa, 9Academy of Sciences of
the Czech Republic, Průhonice, Czech Republic, 10German Centre for Integrative Biodiversity Research, Leipzig,
Germany, 11University of Konstanz, Konstanz, Germany

Worldwide, alien invasive species constitute one of the greatest threats to biodiversity. Therefore, to prevent
and manage invasions, it is of utmost importance to understand invasion risks. The remote Sub-Antarctic
Islands harbour a unique flora and fauna. Although they are mostly considered to be fairly pristine and little
impacted by humans, a number of alien species have established and spread on the islands. Indeed, along with
climate change, invaders are considered the greatest threat to the native biodiversity of the islands. In this
study, we first assess the risk of invasion for all Sub-Antarctic Islands. We use a global pool of invasive plant
species to assess which global invaders have a high probability of establishing on the islands. Second, using a
trait-based approach, we assess what characteristics of plants make them successful invaders once they arrive
in the Sub-Antarctic. Our assessment indicates which species pose the greatest invasion risk and which islands
are most at risk to invasion. Furthermore, we find that weedy, generalist species with few specialised defences
against extreme weather are particularly effective invaders. Worryingly, these species are predicted to become
significantly more successful with climate change, at the expense of the native species. Our results allow us to
make recommendations on which species pose the greatest risk to the islands and to prioritise the eradication
of alien plant species on Sub-Antarctic Islands.

1823
37
Mechanistic Models to Improve Antarctic Biosecurity

Greta C. Vega1 (greta.vega@urjc.es), Grant Duffy2, Rachel Leihy2, Miguel Ángel Olalla Tárraga1, Steven L.
Chown2
1
King Juan Carlos University, Department of Biology and Geology, Physics and Inorganic Chemistry, Madrid,
Spain, 2Monash University, School of Biological Sciences, Melbourne, Australia

Invasive species are one of the most important threats to Antarctic terrestrial biodiversity. While Species
Distribution Models (SDMs) are a useful tool to assess the suitability of non-occupied areas for invasive species,
the uniqueness of the Antarctic environment has proven a challenge. We apply a new mechanistic modelling
approach that allows the inclusion of prior physiological data to predict the distribution of species, providing
strong predictive power. Six non-native Collembola species have been recorded from the Antarctic Peninsula
and many more from the Southern Ocean Islands, some identified as invasive. We therefore use this group as
an exemplar for the model. In particular, Ceratophysella denticulata is an invasive species on several Southern
Ocean Islands, and a high risk to others and to the continent. Therefore, we apply our approach to C.
denticulata SDM using its native range and physiological characteristics, and validate our results with high
resolution sample data from Marion Island (South Africa). The projection of our model shows a strong
congruence with field-collected sample data. The projection of the model to seven other Southern Ocean
Islands shows that C. denticulata would find suitable environments on four of them, resulting in a potential
threat to the native soil fauna. Our results support the rigorous implementation of biosecurity protocols to
prevent the arrival and establishment of alien species on the Southern Ocean Islands and Antarctica.

1824
EN-7b - Biogeochemical cycling in the Polar Regions: Terrestrial and Ocean interactions
22.06.2018 11:00-12:30, A Studio

2056
Geochemical Constraints on Particle Flux Processes in the Western Arctic Ocean

Melissa Sophia Schwab1 (melissa.schwab@erdw.ethz.ch), Joerg Dominik Rickli2, Jurek Blusztajn3, Steven
Manganini3, H. Rodger Harvey4, Robie W. Macdonald5, Derek Vance2, Cameron McIntyre6, Timothy Ian
Eglinton1
1
ETH Zürich / Geological Institut, Zürich, Switzerland, 2ETH Zürich / Geochemistry & Petrology Institute, Zürich,
Switzerland, 3Woods Hole Oceanographic Institute, Falmouth, United States, 4Old Dominion University / Ocean,
Earth & Atmospheric Sciences, Norfolk, United States, 5Department of Fisheries & Oceans / Institute of Ocean
Sciences, Sidney, Canada, 6Scottish Universities Environmental Research Centre, Glasgow, United Kingdom

A growing body of evidence suggests that delivery of particulate matter, including associated biogeochemically-
relevant materials to the interior Canada Basin in the central Arctic Ocean is dominated by lateral inputs. The
magnitude and origin of lateral inputs has substantial implications for central Arctic Ocean biogeochemical
processes and the ecosystem they support, as well as on records preserved in underlying sediments.
Coupled measurement of organic and inorganic tracers provides a promising approach to unravel the sources
and cycling of particulate matter in the western Arctic Ocean. In this study we used carbon (13C, 14C) isotopes,
as well as strontium and neodymium isotopes to constrain terrestrial and marine organic carbon sources and
detrital sediment provenance, respectively. Potential implications of future changes in the flux and provenance
of materials supplied laterally to the central Arctic Ocean in relation to ongoing ocean and climate change are
assessed.
Our data show a predominance of marine organic carbon in the Bering and Chukchi Sea whereas the Beaufort
Sea and the Canada Basin is more strongly influenced by terrestrial inputs, with Beaufort Sea Nd and Sr isotopic
signatures suggesting the Mackenzie River as major contributor of detrital particles whereas the Chukchi Sea
receives a mixture of Aleutian Arc and Mackenzie derived material.

1825
19
Increase in Acidifying Water in the Western Arctic Ocean

Di Qi1 (qidi@tio.org.cn)
1
Third Institute of Oceanography, SOA, Xiamen, China

The uptake of anthropogenic CO2 from the atmosphere by the ocean has decreased seawater pH and
carbonate mineral saturation state, a process known as Ocean Acidification (OA). It has been reported that the
Arctic Ocean is particularly sensitive to climate change and that the aragonite mineral saturation state (Ωarag)
will become undersaturated sooner than in other oceans. The extent and expansion rate of OA, however, are
still unknown. Here we show that low Ωarag waters were largely confined to 50-150 m depth and south of 80ºN
in the 1990's, but data from multiple trans-western Arctic Ocean cruises show that the extent of low Ωarag
waters has since expanded to 50-250 m and to 85ºN. The vertical distribution of the Ωarag< 1 water has
increased by about six-fold between the 1990's and 2010. Tracer data and model simulations suggest that the
recent increase in Pacific Winter Water (PWW) transport, driven by anomalous circulation pattern and sea-ice
retreat, is primarily responsible for the rapid expansion of the low Ωarag water. Local carbon recycling and
anthropogenic CO2 uptake have also played roles in increasing the extent of the affected area. Our new results
indicate that rapid acidification has happened in the Arctic Ocean and is far more serious than that in the
Pacific and Atlantic Oceans where decadal OA trends have recently been reported.

1826
416
Glaciers, Icebergs and Silicon: Preliminary Findings from the ICY-LAB Expedition (Invited
Speaker)

Katharine Hendry1 (k.hendry@bristol.ac.uk), Hong Chin Ng1, Rebecca Pickering2, Malcolm Woodward3, Melanie
Leng4,5, Jacob Opher6, Alexander Brearley6
1
University of Bristol, School of Earth Sciences, Bristol, United Kingdom, 2University of South Alabama, Dauphin
Island Sea Lab, Dauphin Island, United States, 3Plymouth Marine Laboratory, Plymouth, United Kingdom,
4
University of Nottingham, School of Biosciences, Nottingham, United Kingdom, 5NERC Isotope Geosciences
Laboratory, Keyworth, United Kingdom, 6British Antarctic Survey, Cambridge, United Kingdom

The supply and distribution of dissolved silicon (Si) in the oceans is a key factor in the growth of marine
diatoms, which precipitate biogenic silica (or opal). Rivers and groundwater have long been considered the
major inputs of dissolved Si, which is released during the weathering of silicate rocks. Glaciers are known
sources of both dissolved and particulate Si phases, but the impact on oceanic systems needs further
quantification to produce a more robust global budget. The aim of the ICY-LAB project is to investigate the role
of high-latitude processes on the Si marine cycle. Expedition DY081 (RRS Discovery, summer 2017) focused on
characterising the physical and chemical properties of the shelf and slope waters off Southwest Greenland, and
investigating the impact of meltwater dynamics and circulation on biological production and ecosystems. Here,
we present some of the initial results from the project, including the distribution of dissolved nutrient phases
and tracers of meltwater components in the water column. We use observational and experimental
approaches to explore the role of both continental runoff and shelf sediments in glaciated regions in supplying
dissolved nutrients into the offshore waters. Our findings improve the understanding of the Si cycling between
terrestrial sediments, shelf processes and seawater in glaciated regions, which represents an important but
understudied component of internal cycling as well as a key input into the oceanic Si budget.

1827
1120
Pulsed Iron input from Svalbard to the Arctic Ocean over the past 180 ka

Allyson Tessin1 (a.c.tessin@leeds.ac.uk), Christian Maerz1, Johan Faust1, Mattias Forwick2, Jens Matthiessen3,
Matt O'Regan4, Bernhard Schnetger5
1
University of Leeds, School of Earth and Environment, Leeds, United Kingdom, 2UiT The Arctic University of
Norway in Tromsø, Tromso, Norway, 3Alfred Wegener Institute, Helmholtz Centre for Polar and Marine
Research, Bremerhaven, Germany, 4Stockholm University, Department of Geological Sciences, Stockholm,
Sweden, 5Institut für Chemie und Biologie des Meeres, Universität Oldenburg, Oldenburg, Germany

Climate warming in high latitude terrestrial regions has the potential to significantly influence ocean
biogeochemical cycling through increased delivery of freshwater, nutrients, and organic material. Changes in
iron (Fe) input from terrestrial regions is especially important because Fe is a bioessential micronutrient, can
control the sedimentary cycling of macronutrients (phosphorus), and can increase sedimentary preservation of
organic carbon. Sedimentary records of past biogeochemical cycling are, therefore, important to evaluate and
predict the effects that changes in the input of Fe-rich terrigenous material to the Arctic Ocean will have on
nutrient cycling and organic carbon burial.
During a 2015 Polarstern expedition, sediment cores were retrieved north of Svalbard, on the Yermak Plateau.
Based on preliminary age constraints, the PS92/39-2 core includes sediments from the penultimate glaciation
(MIS 6) to the Holocene. Here we present XRF analyses to quantify and evaluate changes in biogeochemical
cycling in this region during the past two glacial cycles. Initial results indicate a series of high Fe delivery events
during the record with Fe concentrations of up to 9.8 wt.%. Pulsed delivery of Fe is likely associated with
increased delivery of material from northern Svalbard, which is dominated by Fe-rich Devonian red beds. Tight
coupling between Fe and P concentrations throughout the record suggests dynamic nutrient delivery and burial
in the region.

1828
1606
Constraining Silicate Weathering Fluxes in a High-arctic River using Li-isotopes

Melissa Murphy1 (melissa.murphy@ucl.ac.uk), Emily Stevenson2, Phillip Pogge von Strandmann1

1
University College London, London Geochemistry and Isotope Centre (LOGIC), London, United Kingdom,
2
University of Cambridge, Department of Earth Science, Cambridge, United Kingdom

Silicate weathering is an important driver in both the inorganic and organic C-cycles. CO2 is removed from the
atmosphere by the weathering of silicate rocks at the Earth's surface, and is transported via rivers as
bicarbonate (HCO3-) to the oceans, and locked up as marine carbonates. Silicate weathering also delivers
nutrients to the oceans, promoting organic carbon burial.
Understanding how cryospheric weathering processes and the presence of glaciers and permafrost may affect
physical and chemical weathering fluxes in high-Arctic rivers, and thus CO2 removal in such high-latitude
regions, remains poorly understood. In order to investigate this, we sampled rivers draining into the glacially
fed, permafrost-dominated Zackenberg River Basin, NE Greenland.
Based on dissolved major element chemistry, we can identify a silicate-rich end-member draining easily
erodible Cretaceous sandstones and Tertiary basalts, and a carbonate-rich end-member draining from the
Lindemanselven. Tributaries fed by the A.P. Olsen glaciers, and melt water streams that drain the Caledonian
granitic gneissic basement are also geochemically distinct.
Riverine lithium isotopes are a unique tracer of silicate weathering processes that are unaffected by biology,
carbonate weathering or primary lithology. Dissolved and suspended particulate Li isotopes will be presented
for rivers draining into the Zackenberg River to assess the role of silicate weathering, and ultimately CO2
drawdown, in this region.

1829
AC-8d - Causes and Effects of Changing Polar Climate, Cryosphere and Hydrological Cycle
22.06.2018 11:00-12:30, A Forum

2565
On the Relative Roles of Feedbacks and Heat Transport in Polar Amplification

Kyle Armour1 (karmour@uw.edu)

1
University of Washington, Seattle, United States

Here we present evidence that zonal-mean climate and its changes can be understood in terms of a moist
energy balance model (MEBM) that represents atmospheric heat transport as a simple diffusion of latent and
sensible heat - as a down-gradient transport of moist static energy with constant diffusivity, as supported by
comprehensive models and atmospheric reanalyses. Given patterns of local radiative feedbacks, radiative
forcing and ocean heat uptake, the MEBM accurately predicts the evolution of zonal-mean temperature and
atmospheric heat transport (moist and dry) as simulated by the ensemble of CMIP5 GCMs. These results
suggest that, despite all of its dynamical complexity, the atmosphere essentially responds to energy imbalances
by simply diffusing latent and sensible heat down-gradient.
It further provides insights into
(i) the mechanisms of polar amplification and
(ii) how uncertainty in the spatial pattern of radiative feedbacks, forcing, and ocean heat uptake project onto
uncertainty in polar warming.
In the absence of any spatial structure in feedbacks or forcing, polar amplification emerges due to enhanced
poleward atmospheric heat transport associated with latent heat. When the full spatial structure of radiative
feedbacks are accounted for, polar amplification emerges due to the feedbacks and is damped from a decrease
in atmospheric heat transport into the Arctic. These results suggest that polar amplification is an inevitable
feature of climate change.

1830
1177
The Two Major Sources of Uncertainty in Antarctic Climate Change Projections

David Schneider1 (dschneid@ucar.edu)

1
NCAR, Boulder, United States

Some of the largest uncertainties in projected anthropogenic climate change impacts occur in or are tied to
Antarctica and the Southern Ocean. Projected changes in Antarctic surface mass balance, sea ice extent, and
surface temperature differ widely among current-generation climate models, and this uncertainty largely stems
from two major sources, internal variability and structural uncertainty. In this presentation, I will highlight
recent work with the Community Earth System Model that aims to characterize the range of structural (model
physics) uncertainty in Antarctic climate change projections and to determine its importance relative to
Antarctica's large natural climate variability. In particular, I will present results from new experiments that
address how the Southern Ocean sea ice and sea surface temperature responses to stronger westerly winds
differ according to the model's ocean temperature and salinity structure.

1831
787
The Signature of Ozone Depletion in Recent Antarctic Precipitation Change

Jeremy Fyke1, Jan T. M. Lenaerts2 (jan.lenaerts@colorado.edu), Brooke Medley3

1
Los Alamos National Laboratory, Los Alamos, United States, 2University of Colorado, Boulder, United States,
3
NASA Goddard Space Flight Center, Greenbelt, United States

Precipitation as snow is a primary control on Antarctic Ice Sheet (AIS) mass balance and its contribution to sea-
level rise, with regional trends in snowfall at the interannual scale linked to patterns of broader atmospheric
circulation variability. Long-term historical AIS precipitation trends and their underlying external climate
drivers, however, remain inconclusive. Here, using a pair of climate model simulation ensembles, we uncover a
strong spatial signature of ozone depletion-forced Antarctic precipitation change characterised by an overall
increase in snowfall. Distinct areas of little change or precipitation decrease, arising from interaction between
ozone depletion-forced atmospheric circulation changes and ice sheet topography, are outweighed by large-
scale precipitation increases. This signature bears notable similarities to a new ice core-based reconstruction of
Antarctic surface mass balance change and drives a significant increase in annual integrated precipitation (38
+/- 10 Gt over the 1986-2005 period or 51 +/- 11 Gt over the 1991-2005 period) that has the same magnitude
as observed Antarctic mass loss and thus strongly dampens recent Antarctic sea-level rise contributions.

1832
1004
Dynamical Mechanisms of Anomalous Moisture Transport towards East Antarctica

Annick Terpstra1,2,3 (annick.terpstra@uib.no), Harald Sodemann2, Irina Gorodetskaya3

1
University of East Anglia, Norwich, United Kingdom, 2University of Bergen, Geophysical Institute & Bjerknes
Centre for Climate Research, Bergen, Norway, 3University of Aveiro, Centre for Environmental and Marine
Studies, Aveiro, Portugal

During the last decade Antarctic ice sheet accumulation patterns exhibited large regional differences. While the
total ice-sheet mass of Antarctica declined, East-Antarctica experienced increases in ice mass. During 2009 and
2011, this increase was caused by only a handful of intense precipitation events. In this study, we investigate
such an episodic accumulation event, thereby exploring linkages between oceanic evaporation in subtropical
regions and Antarctic ice-sheet accumulation.
We use both Eulerian and Lagrangian analysis to demonstrate that moisture transport towards East-Antarctica
was facilitated by several cyclones of different scales. Moisture transport occurred in coherent air-streams,
manifested initially as intense low-level jets embedded in the warm sector of the cyclone(s), followed by a
transition to slantwise (isentropic) ascent before reaching the continent. Water vapor loading of this air-stream
was driven by low-level convergence in the warm sector along the advancing cold-front, whereas the slantwise
ascent phase of the moisture transport was characterized by moisture removal (precipitation). Oceanic
evaporation along the filamentary structured, anomalous moisture transport area was virtually absent,
indicative for long-range moisture transport during the event. In addition to the moisture transport
mechanisms we identified moisture source regions associated with the event.

1833
2674
Impact of Sea Ice Anomaly on Antarctic Precipitation and its Source Attribution

Hailong Wang1 (hailong.wang@pnnl.gov), Jeremy Fyke2, Jan Lenaerts3, Jesse Nusbaumer4, David Noone5, Philip
Rasch1
1
Pacific Northwest National Laboratory, Atmospheric Sciences and Global Change, Richland, United States, 2Los
Alamos National Laboratory, Los Alamos, United States, 3University of A Colorado, Department of Atmospheric
and Oceanic Sciences, Boulder, United States, 4NASA Goddard Institute for Space Studies, New York, United
States, 5Oregon State University, Corvallis, United States

Modeling and experimental evidence suggests that Antarctic Ice Sheet (AIS) surface mass balance (SMB)
increases in a warming climate due to increased precipitation. We use the Community Earth System Model
(CESM) with an explicit water tagging capability to partition the causes of increased precipitation in high
latitudes. Sensitivity experiments have been conducted to understand the impact of sea ice anomalies on
regional evaporation, moisture transport, and source-receptor relationships for regional precipitation over the
Antarctica. Three composites of sea ice concentrations (SIC), constructed from the 1800-year CESM Large
Ensemble Project using mean, 10% lowest, and 10% highest southern hemispheric SIC years (and
corresponding sea surface temperatures), respectively, have been employed to drive three atmosphere-only
simulations. Moisture sources in twenty-five geographical regions are explicitly tracked using the water tagging
capability to establish source-receptor relationships of vapor and regional precipitation over the Antarctica.
Results show that vapor sources for Antarctic precipitation primarily originate from lower latitudes; however,
the tagged vapor source regions in high latitudes have discernable changes in their contributions to regional
precipitation over the Antarctic in response to the SIC changes. There is also a strong regional and seasonal
variability in vapor source attributions.

1834
TE-2b - Advancing Polar Engineering and Sustainable Infrastructure Development
22.06.2018 11:00-12:30, A Sertig

1067
Risk Assessment of Climate-change Impacts on Infrastructure in the Arctic

Dmitry Streletskiy1 (strelets@gwu.edu), Luis Suter1, Nikolay Shiklomanov1

1
George Washington University, Department of Geography, Washington DC, United States

The Arctic is home to a population of about four million and is experiencing significant economic and
environmental transformations as a result of ongoing natural resource development and climate-change.
Mitigation and/or adaption efforts will be necessary to maintain the proper functioning of infrastructure over
intended lifespans. This study examines the spatial distribution of risks from projected climate-change to built
infrastructure in the Arctic and examines the economic costs of climate-change impacts on human
development.
Changes in environmental variables such as temperature, precipitation, permafrost, freeze-thawing cycles, and
ground subsidence are estimated in order to evaluate the risks of various types of infrastructure including
roads, railways, pipelines, and buildings. The areas of significant climate-change driven risks are determined
across the circumpolar region. The costs of mitigation and adaption efforts are used to provide quantitative
estimates of climate change impacts. The results of this assessment can be used as a tool for businesses,
policymakers, and urban planners in order to guide sustainable development in the Arctic.

1835
1716
SmartICE: A Sea-ice Monitoring System for Arctic Communities and Industries

Trevor Bell1,2 (tbell@mun.ca)

1
Memorial University, Geography, St. John's, Canada, 2SmartICE, Inuit Nunangat, Canada

SmartICE (smartice.org) is a northern social enterprise that puts into the hands of communities the technology
that helps them adapt to unpredictable sea-ice changes, resulting from climate change. Inuit knowledge of sea
ice has been acquired from millennia of observation and use. But in the last decades this traditional knowledge
has become less effective in the face of unprecedented environmental changes. SmartICE is an award-winning
(Arctic Inspiration Prize 2016, UN Momentum for Change 2017) climate change adaptation tool that integrates
on-ice technology, remote sensing and Inuit knowledge to generate near real-time information on sea-ice
conditions. It maintains a network of in situ and mobile sensors that measures and transmits sea-ice thickness
data from community trails. It also maps sea-ice surface conditions from satellite imagery to inform safe travel
choices. It uses information technology to generate accessible products that match the needs of community
users. The SmartICE information system directly benefits public safety, food security, health and wellbeing,
while supporting economic activities for communities (e.g., ice-based fisheries and tourism), especially during
highly dynamic freeze-up and break-up periods. Through technological innovation and science, SmartICE strives
to integrate and augment Inuit knowledge about local sea-ice conditions, not replace it, through involvement
of Inuit in all aspects of its operation and decision-making.

1836
288
A Vision for Safe and Sustainable Arctic Maritime Transport

Martin Bergström1 (martin.bergstrom@aalto.fi), Pentti Kujala1, Mihkel Körgesaar1, Floris Goerlandt1, Giles
Thomas2
1
Aalto University, School of Engineering, Department of Mechanical Engineering, Marine Technology, Aalto,
Finland, 2University College London, Department of Mechanical Engineering, London, United Kingdom

In the face of an expected increase in Arctic ship operations, driven by climate change, improvements in ship
technology, and a high demand for Arctic natural resources, the understanding and management of related
risks is paramount. Our vision for safe and sustainable Arctic maritime transport is based on a holistic design
approach incorporating the goal-based regulations (GBRs) of the recently enforced Polar Code. In contrary to
traditional design rules, GBRs do not determine the required solution, but determine instead the required
function(s) to meet the goal(s). This gives designers more freedom to apply new and innovative solutions,
where a high (and known) level of safety and sustainability is achieved without compromising cost efficiency.
However, to ensure that the goals of the Polar Code are met, it is first necessary to determine appropriate
performance measures and acceptance criteria for all critical safety and sustainability functions of a ship, and
to develop and validate related performance assessment methods. This requires comprehensive understanding
of Arctic ship operations, the applied technologies, and their interactions. Thus, we are working towards our
vision both by increasing the knowledge about specific technologies (e.g. cold-resistant steel), and by
developing a holistic design framework for Arctic ships, considering both operational and regulatory demands.
The overall aim is to enable better-informed design decisions, reducing the level of risk.

1837
2317
Mechanical and Thermal Ice Borehole Reamers

Nikolai Vasilev1 (vasilev_ni@spmi.ru), Alexey Bolshunov2, Andrei Dmitriev1, Sergei Ignatiev3, Aleksei Podoliak1
1
Saint Petersburg Mining University, Well Drilling, Saint Petersburg, Russian Federation, 2Saint Petersburg
Mining University, Mechanics, Saint Petersburg, Russian Federation, 3Saint Petersburg Mining University,
Ingeneering Graphics, Saint Petersburg, Russian Federation

Various stages of deep-hole drilling in ice require local enlargement of boreholes in order to perform different
technological operations, e.g. installation of a casing string or sidetracking. Such tasks are accomplished using
dedicated mechanical and thermal borehole reamers.
The paper provides a brief analysis of existing designs of mechanical and thermal reamers, which was used as
the basis to specify requirements for new reamer designs. Based on these requirements, innovative designs of
mechanical and thermal reamers have been developed. The paper presents schematic diagrams of these
reamers and describes their design features, principles of action and operation practice in details.

1838
80
Building a Modern Heavy Icebreaker: Balancing Security and Science Capabilities

Kenneth Boda1 (kenneth.j.boda@uscg.mil)

1
U.S. Coast Guard, Office of Cutter Forces, Washington, United States

The United States Coast Guard is designing and building new heavy polar icebreakers to replace aging and
increasingly obsolescent ships. We have developed and evaluated icebreaker operational requirements,
seeking the greatest capability within the bounds of affordability. These ships must conduct the missions of
U.S. Coast Guard (which include safety, security, and stewardship of U.S. waters) while serving the survey and
science needs of our partner agencies across the federal government. In this presentation, I will outline the
icebreaker acquisitions process, highlighting our outreach with the U.S. Navy, industry and international
partners. I will discuss the concept of icebreaker operations in both the Arctic and Antarctic. I will present the
key performance capabilities required of the vessel in terms of icebreaking, endurance, and interoperability,
and the resulting design implications. I will discuss the capabilities that support U.S. Coast Guard maritime
missions such as boat and aviation operations. Finally, I will detail the survey and science capabilities required
of these icebreakers to increase our knowledge of the remote Polar Regions.

1839
2198
Antarctic Near-shore and Terrestrial Observation System: Technology Overview

Charles Lee1 (charles.lee@waikato.ac.nz), Kurt Joy1, Doug Calvert2, Tom Nylen3, Vonda Cummings4, Craig Cary1
1
University of Waikato, International Centre for Terrestrial Antarctic Research, Hamilton, New Zealand, 2Hoskin
Scientific Limited, Edmonton, Canada, 3UNAVCO, Boulder, United States, 4National Institute for Water and
Atmospheric Research, Wellington, New Zealand

ANTOS (Antarctic Near-shore and Terrestrial Observation System), a SCAR Expert Group, is a biology-focused
initiative to coordinate and harmonize efforts to assess environmental variability and change across the
Antarctic continent and National Antarctic Programs. The primary aim for ANTOS is to foster and facilitate
autonomous collection and sharing of long-term climate and associated environmental observations using
standardized protocols and instrumentation in terrestrial and coastal habitats. The ANTOS draft technical
guidelines include specifications for three tiers of ANTOS stations with increasing complexity and cost. The
three-tiered approach aims to enable the widest possible deployment of ANTOS-compliant automatic weather
stations across Antarctica and the broadest participation by National Antarctic Programs and Antarctic
researchers.
Leveraging decades of development and experience from polar engineers and scientists, ANTOS platforms will
be integrations of off-the-shelf products to maximize reliability and the ease of procurement and replacement.
By presenting a technology overview of ANTOS to an audience of polar engineers and field scientists, we seek
feedback on the current draft technical guidelines and wish to explore possible inclusion of emerging
technologies. We particularly hope to collect information on the performance of various new battery and
power technologies (e.g., LiFePO4 and methanol fuel cells) in polar settings.

1840
GG-1b - Magmatic, tectonic, and geodynamic investigations of the Polar Regions
22.06.2018 11:00-12:30, A Schwarzhorn

1819
The Laurentia-East Antarctica Connection Revisited

Ian Dalziel1 (ian@ig.utexas.edu)

1
The University of Texas at Austin, Institute for Geophysics, Jackson School of Geosciences, Austin, United States

Following the suggestion of Canadian geologists Bell and Jefferson, who compared the Proterozoic stratigraphy
of southeastern Australia and western Canada, Moores and Dalziel published separate papers in 1991
proposing that the Pacific margins of East Antarctica-Australia and Laurentia had been juxtaposed prior to the
opening of the Pacific Ocean basin in the Neoproterozoic. Following Moores, this became known as the
Southwest United States-East Antarctica, 'SWEAT', hypothesis. Over the past quarter century several variations
of the proposed juxtaposition have been suggested, and some authors have put forward reconstructions with
Asian crustal blocks interposed between East Antarctica-Australia and Laurentia.
In a series of publications between 2004 and 2017, Goodge, Fanning and coilleagues have demonstrated that
morainal material originating under the East Antarctic ice sheet bears compelling similarity to the Laurentian
craton. Detrital zircons in the Beacon Supergroup also have a distinctly Laurentian signature. There is, however,
a significant difference between the reconstructions stemming from these studies and one taking into account
the apparently Laurentian nature of the Mesoproterozoic volcanic rocks in Coats Land reported by Loewy and
colleagues. The latter indicates that the ca. 1.0 Ga type- Grenvillian orogeny of Laurentia continues into the
Maud orogen along the eastern margin of the Weddell Sea. The purpose of the presentation is to explore this
discrepancy.

1841
704
Integrated 3D Lithosphere Model of Antarctica

Folker Pappa1 (folker.pappa@ifg.uni-kiel.de), Ebbing Jörg1, Fausto Ferraccioli2, Wouter van der Wal3, Bas Blank3
1
Kiel University, Institute of Geosciences, Kiel, Germany, 2British Antarctic Survey, Cambridge, United Kingdom,
3
Delft University of Technology, Delft, Netherlands

We present a new 3-dimensional model of the Antarctic lithosphere, integrating seismological and gravity
gradient data in a self-consistent manner. Current studies on the lithospheric structure, in particular the Moho
depth, of the Antarctic continent contradict each other in many cases, depending on the applied geophysical
method. This has huge implications for considerations regarding the isostatic state of the continent despite
ongoing glacial isostatic adjustment (GIA). We attempt to reduce inconsistencies and ambiguities from separate
geophysical methods by combining multiple observational data in a thermodynamically self-consistent 3D
model, considering temperature and petrology of the lithosphere, seismic body wave velocities, and isostasy.
Gravity gradient data from ESA's GOCE satellite mission are used to constrain the density distribution within
the lithosphere.
Our results indicate that Antarctica is largely in isostatic equilibrium, however, the topography of some regions
seem to have components which cannot be explained by pure isostasy. The subsurface thermal field of our
model can be used to derive the mantle's viscosity for the purpose of GIA modelling. Our forward-calculated
surface heat flow estimations may serve as background values for modelling basal melt rates of Antarctica's ice
sheets.

1842
780
India-Antarctic Breakup: Constraints from New Geophysical Data

Wilfried Jokat1 (wilfried.jokat@awi.de), Tabea Altenbernd1, Wolfram Geissler1, Masakazu Fujii2, Graeme
Eagles1, German Leitchenkov3, Karsten Gohl1
1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Geophysics, Bremerhaven,
Germany, 2National Institute for Polar Research, Tokyo, Japan, 3VNII Okeangeologia, St. Petersburg, Russian
Federation

The India-Antarctica separation is still an open problem due to the absence of critical geophysical data. So far
no wide-angle data existed along the conjugate margins of East India and the Enderby Land off East Antarctica
to define the position and composition of the continent-ocean boundary - a pre-requisite for any sound
reconstruction. Furthermore, along both margins only old marine magnetic random track data are available for
identifying seafloor spreading anomalies to describe the drift of both continents in the Cretaceous. The
Kerguelen Plateau, located just north of the East Antarctica coast, however, has been drilled several times
providing the only reliable age constraint on the formation of this huge magmatic plateau. In general, the poor
information resulted a wide variety of kinematic models for the drift of the India.
In the last years several newly acquired geophysical data provide new constraints on its drift. Two deep seismic
sounding lines off Prydz Bay and across the Princess Elisabeth Trough show that oceanic crust is already present
much closer to the present-day shelf break than previously known. Magnetic data acquired parallel to these
lines provide excellent timing constraints for the initial breakup of India. Finally, marine magnetic data
gathered in 2017 south of Sri Lanka indicate that here the oceanic crust is definitely younger than magnetic
chron M0, questioning several kinematic models for the Indian Ocean.
The latest results will be presented.

1843
855
Defining Blocks and Boundaries within the Gondwanan Kuunga Orogen

Jacqueline Halpin1 (jahalpin@utas.edu.au), Nathan Daczko2,3, Ian Fitzsimons4, Joanne Whittaker1, Jacob
Mulder1, Tobias Staal1,5
1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Macquarie University,
Department of Earth and Planetary Sciences, Sydney, Australia, 3Macquarie University, ARC Centre of Excellence
for Core to Crust Fluid Systems and GEMOC, Sydney, Australia, 4Curtin University, Department of Applied
Geology, Perth, Australia, 5University of Tasmania, School of Physical Sciences (Earth Sciences), Hobart,
Australia

The East Antarctic region between Princess Elizabeth and Wilkes lands occupies a critical position in tectonic
reconstructions, encapsulating part of the enigmatic Kuunga Orogen. Here, crust of broadly Indian affinity and
Australian affinity is generally thought to have been juxtaposed during Ediacaran-Cambrian (~550-530 Ma)
Gondwana amalgamation. However, a lack of identified ophiolite or consensus on the location and geometry of
any sutures makes it difficult to incorporate the Kuunga Orogen into models of Gondwana evolution.
If Indo-Antarctica and Australo-Antarctica had distinct geological histories, then a suture zone should juxtapose
crust of different protolith age. This approach can constrain suture location from geochronology of available
outcrop even when the suture itself is not exposed. Although this boundary might not be the only suture or the
final suture, it is a fundamental paleo-plate margin and an important first step in determining the overall
orogenic architecture.
Here we explore the implications of approaching this problem via integration of geological and geophysical
data in a plate reconstruction framework. We present new zircon and monazite U-Pb geochronology, together
with zircon Hf-isotope data, to examine the crustal evolution and affinity of rare coastal exposures of the
Kuunga Orogen. Based on these integrated datasets, we suggest a fundamental terrane boundary intersects
the Queen Mary Land coast, east of Mirny and west of Alligator Island.

1844
639
Crustal Structure off Enderby-Wilhelm II Lands: Implication for Gondwana Breakup

German Leitchenkov1,2 (german_l@mai.ru), Yulia Guseva3, Viktor Gandyukhin3, Alexander Golynsky1, Andrey
Kazankov3
1
VNII Okeangeologia, St. Petersburg, Russian Federation, 2St. Petersburg State UnIversity, Institute of Erth
Sciences, St. Petersburg, Russian Federation, 3Polar Marine Geosurvey Expedition, St. Petersburg, Russian
Federation

The history of rifting and sea-floor spreading between India and Antarctica remained vague long time mainly
because of data scarcity and insufficient depth resolution of seismic data off both continents. Revision of all
available geophysical data (including recently derived) in the region off Enderby-Wilhelm II Lands (Antarctic
sector between 35E and 100E) and published information on crustal structure of the eastern India margin
based on commercial seismic data give much better understanding of break-up history of East Gondwana. The
rifted continental margin off Enderby-Wilhelm II Lands shows variable crustal characteristics. Off eastern
Enderby Land, it is 300-400 km wide and includes a 100-km-wide continent-ocean transition zone consisting
mostly of exhumed mantle. The western Enderby Land, Princess Elizabeth Land and Wilhelm II Land margins
are narrower and range in width from 50 to 200 km. The sea-floor spreading started in the eastern part of
studied region (76E-100E) at about 130 Ma. Off western Enderby Land (55E-76E), early oceanic opening was
compensated by mantle exhumation. The pole of rotation was located close to Gunnerus Ridge. The southern
Kerguelen Plateau was the part of the India margin and was attached to the Antarctic plate due to a ridge jump
at about 124 Ma. The sea-floor spreading between 36E and 66E occurred during CNS. It started at about 120
Ma off eastern Enderby Land and later off western Enderby Land.

1845
1412
New Model Bathymetry and Tectonic Boundary Beneath Ross Ice Shelf, Antarctica

Christine Siddoway1 (csiddoway@coloradocollege.edu), Kirsteen Tinto2, Matthew Tankersley1, Robin E. Bell2

1
Colorado College, Geology, Colorado Springs, United States, 2Columbia University, Lamont -Doherty Earth
Observatory, Palisades, United States

A new tectonic boundary has been discovered beneath the Ross Ice Shelf (RIS), a 476,000 km2 floating icesheet
that obscures the seafloor topography and crustal structure of the West Antarctic rift system. Mapping of
magnetic and gravity anomalies by the ROSETTA-Ice airborne survey (2015-2017) reveals a major break
between cratonic East Antarctica and accreted crust of West Antarctica, midway across the Shelf ~300 km east
of the Transantarctic Mountains. The Central High, a fault-riven block formerly identified and drilled in the Ross
Sea, is found to span the tectonic boundary and continue south as a basement high separating two distinct
crustal regions beneath the Ice Shelf. The modeled bathymetry shows a deep, smooth Ross-EAIS sector of
dense crust that displays subdued, long wavelength magnetic anomalies. This contrasts with the shallow, more
complex seabed in the ROSS-WAIS sector, comprising less dense crust with high amplitude, short wavelength
magnetic anomalies. Modeling of geophysical data allows the identification of glacially-carved and sediment-
filled troughs, faults, and tectonic transfer zones, together with magma conduits and centers. A revision of the
existing tectonic framework for the Ross Embayment is needed to accommodate these new findings from the
fuller characterization of sub-RIS extended crust. The presence of shallow and deep sectors have consequences
for ocean circulation beneath Ross Ice Shelf and modes of past and future ice sheet retreat.

On behalf of the Rosetta-Ice Team, Columbia University, Lamont -Doherty Earth Observatory

1846
BE-5a - Productivity, Biodiversity & Ecosystem Shifts at Cryosphere-Ocean Boundaries
22.06.2018 11:00-12:30, A Seehorn

551
Melting Glaciers and their Impact on Coastal Productivity in Greenland

Lorenz Meire1 (lome@natur.gl), John Mortensen1, Mikael Sejr2, Søren Rysgaard3

1
Greenland Climate Research Center, Greenland Institute of Natural Resources, Nuuk, Greenland, 2Aarhus
University, Aarhus, Denmark, 3Arctic Research Centre, Aarhus University, Aarhus, Denmark

The Greenland Ice Sheet is melting at an unprecedented rate, and as a result, fjords and continental shelves
around Greenland are exposed to an increasing freshwater runoff. Yet the impact of high meltwater input on
the biogeochemistry and productivity remains largely unquantified. To resolve the effect on Greenland's fjord,
sampling was conducted in several fjords impacted by melting glaciers in Greenland and physical, chemical and
biological gradients were studied from close to the glaciers towards the open sea. Hydrographic and
biogeochemical data from several fjord systems adjacent to the Greenland ice sheet, suggest that ecosystem
productivity is very differently regulated in fjords influenced by either land-terminating or marine-terminating
glaciers. Our data shows that rising subsurface meltwater plumes originating from marine-terminating glaciers
entrain large volumes of ambient deep water to the surface and consequently supply upwelling of nutrient-rich
deep water. This sustains sustains a high phytoplankton productivity throughout summer in the fjord with
marine-terminating glaciers. In contrast, fjords with only land-terminating glaciers lack this upwelling
mechanism, and are characterized by lower productivity. These results suggest that a switch from marine-
terminating to land-terminating glaciers can substantially alter the productivity in the coastal zone around
Greenland with potentially large ecological and socio-economic implications.

1847
324
Fjord Marine Ecosystem Response to Ice Shrinking in KGI: A Case of Marian Cove

In-Young Ahn1 (iahn@kopri.re.kr)

1
Korea Polar Research Institute (KOPRI), Division of Polar Ocean Sciences, Incheon, Korea, Republic of

King George Island (KGI) is located at the northern tip of the Antarctic Peninsula, one of the most rapidly
warming regions on earth. About 90% of the island is covered by glaciers, and significant glacier retreat has
been observed in many coastal areas including a small embayment, Marian Cove (~4.5 km long and ~1.5 km
wide). Fast and consistent glacier retreat (ca. 1.9km during 1956-2017) has been reported in MC. Recent
studies revealed a suite of environmental parameters with distinct gradients which were apparently developed
by glacier retreat and consequent processes. These studies also demonstrated that spatial pattern of benthic
communities was significantly associated with these environmental suites, suggesting MC as a model
ecosystem for assessing and predicting climate impacts. As a follow-up, this year we started a new integrative
and interdisciplinary project, CHAMP2050 (CHAnges in Coastal Marine Systems of the Antarctic Peninsula: A
2050 Outlook). In this presentation, we introduce latest findings from a long-term dataset on hydrology and
phytoplankton communities, which also revealed strong influence of glacier retreat and melt-water processes.
We also present further findings on the benthic communities, and suggest that current distribution of
megabenthos reflect somehow successional processes in the past, which in turn may provide insight into future
scenario in the Antarctic fjords.

1848
943
Impacts of Greenland Ice Sheet Melt on Marine Carbon Cycling in Adjacent Fjords

Johnna Holding1 (johnna@bios.au.dk), Mikael Sejr1

1
Aarhus University, Arctic Reseach Centre, Aarhus C, Denmark

The Greenland Ice Sheet (GIS) is melting at unprecedented rates increasing the freshwater content of the Arctic
Ocean. Freshwater run-off influences circulation patterns and stratification in Greenland fjords and also
introduces inorganic particles, which can limit light availability to photosynthetic organisms. Furthermore,
recent glaciological studies have documented that GIS melt water contains significant amounts of bioavailable
organic carbon, which are likely to impact microbial carbon cycling and thus potentially transform the coastal
ecosystem around Greenland. In this presentation we will show the results of recent studies in a Greenland
fjord influenced by land-terminating glaciers as a model for future glacier retreat, where primary production is
limited by both light and vertical flux of nutrients due to strong stratification of the water column by freshwater
run-off. Additionally, We will present the results of an experimental study, which follows the incorporation of
allochthonous carbon from freshwater run-off into the microbial loop. As glaciers retreat, Greenland fjord
ecosystems are likely to become less productive and dominated by heterotrophic processes. This may have
consequences for the metabolic balance of the ecosystem that has a major role in contributing to the uptake of
CO2 in the Arctic Ocean as well as affect the commercial and subsistence fisheries that take place in Greenland
fjords.

1849
2239
The Glacial Influence on Fjord Ecosystems of the Western Antarctic Peninsula

Martin Truffer1, Forrest McCarthy1 (forrestmccarthy@hotmail.com), Peter Winsor1, Douglas Brinkerhoff2

1
University of Alaska - Fairbanks, Fairbanks, United States, 2University of Montana, Missoula, United States

Glacially influenced fjord ecosystems on the Western Antarctic Peninsula are unusually productive, compared
to their counterparts in the northern hemisphere. We hypothesize that this is due to low levels of glacial
freshwater runoff, which leads to reduced burial of benthic organisms from turbid glacial waters. The mass loss
of most of these glaciers occurs as a flux of solid ice into the ocean. A two-year study of Andvord Bay used
timelapse cameras and remote sensing to derive a time series of ice flux, calving and sea ice cover. The biggest
ice flux contributor to the bay, Bagshawe Glacier, is characterized by maximum flow velocities of 7 m/d and an
ice flux of ~1.5 km3/yr. Calving events are episodic: in 2015/16, the majority of summer calving occurred in
three big calving events that released large tabular ice bergs. These calving events were separated by a few
much smaller events. Submarine melting has not been quantified, but is expected to be low due to cold water
and little subglacial freshwater discharge to drive ocean circulation. This is also corroborated by the absence of
a plume near the glacier front. The northern location of this glacier makes it subject to fundamental changes,
should regional warming continue. At present, these glaciers do not have ablation areas. Future warming could
lead to significant amounts of glacial runoff, with invigorated water circulation in the fjord and more subglacial
sediment, with profound consequences for the fjord ecosystem.

1850
1343
A Model to Predict Fast ice Timing in Coastal Fjord Ecosystems

Santiago Raúl Doyle1,2,3 (sdoyle@ungs.edu.ar), Leonardo Ariel Saravia1, Tomás Ignacio Marina3,4,5, Dolores
Deregibus6, Irene Schloss6,7, Sharon Stammerjohn8, Fernando Roberto Momo1,2,3, Doris Abele9
1
Universidad Nacional de General Sarmiento, Área de Biología y Bioinformática, Instituto de Ciencias, Los
Polvorines, Argentina, 2Universidad Nacional de Luján - CONICET, Instituto de Desarrollo Sustentable, Luján,
Argentina, 3Universidad Nacional de Luján, Departamento de Ciencias Básicas, Luján, Argentina, 4Consejo
Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de General Sarmiento, Área
de Biología y Bioinformática, Instituto de Ciencias, Los Polvorines, Argentina, 5Universidad Nacional de Luján,
Instituto de Desarrollo Sustentable, Luján, Argentina, 6Instituto Antártico Argentino, Dirección Nacional del
Antártico, CABA, Argentina, 7Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro
Austral de Investigaciones Científicas (CADIC), Ushuaia, Argentina, 8University of Colorado, Institute of Arctic
and Alpine Research, Boulder, United States, 9Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine
Research, Dept. Functional Ecology, Bremerhaven, Germany

In the coastal fjords of the West Antarctic Peninsula (WAP), especially in the northernmost area of Bransfield
Strait, fast ice conditions have shown high variability within the past 25 years, resulting in year-to-year changes
of coastal ecosystem productivity. In some recent years, late fast ice break-up resulted in exuberant blooms,
potentially related to the variability of fast ice timing and duration. To resolve ice dynamics, we generated a
model that uses local and regional sea ice cover, air temperature, wind direction and intensity as predictors for
Potter Cove, King George Island (WAP). Daily sea ice cover data were obtained from digital photographs taken
with a still camera at Carlini Station from 2009 to 2015. In-situ meteorological data were obtained from NCDC
Surface Data Hourly Global dataset, and daily regional sea ice data from NSIDC Sea Ice Concentration dataset.
An information-theoretic model selection scheme showed coastal ice duration was best predicted by models
including all predictors, and that start and finish of the longest fast ice period responded differently to these
variables. The fit of the models was consistently good, suggesting that coastal sea ice timing can be predicted
using a combination of regional and local data. Since all analyses are automated and input data are freely
available, this modeling tool can be used to analyze how coastal sea ice is linked to inshore bloom dynamics
and coastal productivity in WAP fjordic systems.

1851
1489
Ecosystem Physics of a WAP Fjord: A Modeling Study of Key Controlling Factors

Lisa Hahn-Woernle1 (lisahw@hawaii.edu), Brian Powell1, Oyvind Lundesgaard1, Craig Smith1, Mark Merrifield1,2
1
University of Hawaii at Manoa, SOEST, Honolulu, United States, 2Scripps Institution of Oceanography, UC San
Diego, San Diego, United States

The FjordEco Project is evaluating the role of physical oceanographic processes and glacial input in fjord
ecosystems along the Western Antarctic Peninsula (WAP). Between Dec 2015 and Mar 2017, three research
cruises to Andvord Bay, a WAP fjord, were conducted to measure physical properties as well as the structure
and function of pelagic and benthic biological communities. The sparse in situ oceanographic measurements
allow estimates of processes such as nutrient upwelling and seasonal temperature variability. However, a lack
of long-term measurements limits the identification of key controlling factors from observations alone.
Therefore, we built a high-resolution numerical model (350 m) of Andvord Bay using the Regional Ocean Model
System (ROMS) to explore physical processes influencing fjord ecosystem dynamics. The model includes tidal
forcing as well as atmospheric forcing from the Regional Atmospheric Climate Model. Initial conditions and
oceanic boundary conditions are based on observations. Key controlling factors of fjord dynamics and
climatology were determined using adjoint sensitivity analysis. Results provide insights into the influence of sea
ice and icebergs on the heat budget and light availability below the sea surface. Our sensitivity studies have
improved understanding of the key controlling factors in the fjord and indicate potential ecosystem
consequences of climate warming along the WAP.

1852
CR-8b - Latest highlights from high altitude and polar ice cores
22.06.2018 11:00-12:30, A Wisshorn

1749
Mean Global Ocean Temperatures during the Last Glacial Transition

Bernhard Bereiter1,2,3 (bereiter@climate.unibe.ch), Sarah Shackleton1, Daniel Baggenstos1,2, Kenji Kawamura4,

Jeff Severinghaus1
1
Scripps Institution of Oceanography, University of California, San Diego, GRD, La Jolla, United States,
2
University of Bern, Physics Institute & Oeschger Centre for Climate Change Research, Bern, Switzerland, 3Swiss
Federal Laboratories for Materials Science and Technology Empa, Dübendorf, Switzerland, 4National Institute of
Polar Research, 10-3, Tokyo, Japan

Due to a lack of robust reconstructions and limited observations, little is known about the ocean temperature's
response to climate perturbations. While it is observed that the ocean takes up most of the 'excess' heat from
the current global warming, its changes before the first observations (ca. 1865 CE) and in the future are
uncertain. Considering the slow overturning time of the global ocean (centuries to millennia) which determines
the responsiveness of global ocean temperatures to changing climate, much interest exists in reconstructing
ocean temperatures for pre-industrial periods. Here, using a novel ocean temperature proxy based
atmospheric noble gases derived from trapped air in ice cores, we show that mean ocean temperature
increased by 2.57 +/- 0.24°C over the last glacial transition (20,000 to 10,000 years ago) - a period of major
global climate change. Our noble gas based reconstruction provides unprecedented precision and temporal
resolution for the integrated global ocean and is not suffering any depth-, region-, organism- and/or season-
specific effects intrinsic to such proxies/estimates available thus far. We find that mean ocean temperature is
closely correlated with Antarctic temperature and has no lead or lag with atmospheric CO2, thereby confirming
the important role of southern hemisphere climate for global climate trends. We also reveal an enigmatic 700-
year warming during the early Younger Dryas that surpasses estimates of modern ocean heat uptake.

1853
1763
An Attempt to Reconstruct Planetary Radiative Imbalance over the Last 40,000 Yrs

Daniel Baggenstos1 (baggenstos@climate.unibe.ch), Marcel Häberli1, Jochen Schmitt1, Hubertus Fischer1

1
Climate and Environmental Physics and Oeschger Centre for Climate Change Research, University of Bern,
Switzerland, Bern, Switzerland

Global climate change arises from an energy imbalance at the top of the atmosphere (TOA). The direct
measurement of TOA radiative fluxes is difficult even today, such that most assessments of it are based on
changes in the total energy content of the Earth system. We apply the same approach to estimate the long
term evolution of the planetary radiative imbalance in the past.
The energy budget of the climate system is dominated by the ocean's heat capacity. On Pleistocene timescales
the latent heat changes associated with the waxing and waning of the large ice sheets are of similar magnitude
as the ocean heat uptake. Ice core noble gas thermometry allows us to estimate changes in ocean heat
content, while sea level reconstructions provide a measure for the contribution of the ice sheets from their
latent heat release or consumption. The temporal derivation of the sum of these two dominant components
should yield the planetary radiative imbalance.
We present measurements of noble gas derived mean ocean temperature from the EDC ice core covering the
past 40,000 years. We infer TOA radiative imbalance as described above. As expected from the relatively
stationary climates of the last glacial maximum and the Holocene, the radiative imbalance is close to 0.0 W/m2
in those periods. During the deglaciation a positive imbalance is maintained for ~10,000 years, with two distinct
peaks that reach up to 0.4 W/m2, highlighting the importance of internal variability in the climate system.

1854
518
Long-term Change in Ocean Heat Content using Ice Core Noble Gas Thermometry

Marcel Haeberli1 (haeberli@climate.unibe.ch), Daniel Baggenstos1, Hubertus Fischer1, Jochen Schmitt1, Thomas
Kellerhals1
1
University of Bern, Bern, Switzerland

Oceanic heat uptake carries the lion's share of glacial/interglacial changes in the planetary heat content, and is
thus the most integrative and representative parameter for quantifying long-term changes in the Earth's
energy budget.
Here, we are focusing on peak glacial and interglacial conditions over the last 800,000 years, i.e. covering the
last eight glacial and interglacial intervals. The only proxies for ocean temperatures during this time period so
far were marine sediment cores which show strong variability of ocean temperatures both between and even
within individual ocean basins as well as with depth.
The novel method of ice core noble gas thermometry allows us to reconstruct a global mean ocean
temperature (GMOT) on the basis of physical principles. The xenon/krypton ratio in the atmosphere is a direct
proxy for GMOT because of the temperature dependence of their solubility coefficients. The GMOT in past
times can therefore be estimated using high-precision measurements of noble gas elemental ratios from gases
trapped in glacial ice after appropriate correction for archive-specific effects.
We performed Xe/Kr analyses on around 100 ice core samples from the EPICA EDC and EDML ice cores from
East Antarctica over up to the last 800,000 years. The measurements imply warmer ocean temperature during
interglacials and significantly colder temperatures during glacial times quantitatively in line with deep ocean
temperature reconstructions from sediment cores.

1855
279
The Spatial Structure of the 128 ka Antarctic Sea Ice Minimum

Max Holloway1,2 (maxllo15@bas.ac.uk), Louise Sime1, Claire Allen1, Claus-Dieter Hillenbrand1, Pete Bunch3, Eric
Wolff3, Paul Valdes2
1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Bristol, Bristol, United Kingdom, 3University
of Cambridge, Cambridge, United Kingdom

Sea ice is an important amplifier in the climate system, affecting the surface energy budget by reflecting
incoming solar radiation and regulating the atmosphere-ocean exchange of heat and CO2. Our understanding
of the long term (i.e. beyond the satellite era) interplay between sea ice and the climate system can be
improved by examining how sea ice responded during a range of past climates. In particular, the last
interglacial (LIG; 130,000 to 115,000 years ago) allows investigation of the sea ice response to warmer than
present conditions. We compare multi-ice core data with δ18O model output for the early last interglacial
Antarctic sea-ice minimum. The spatial pattern of δ18O across Antarctica is sensitive to the spatial pattern of
sea-ice retreat. Local sea ice retreat increases the proportion of winter precipitation, depleting δ18O at ice core
sites. However, retreat also enriches δ18O because of the reduced source-to-site distance for atmospheric
vapour. The joint overall effect is for δ18O to increase as sea ice is reduced. Our data-model comparison
indicates a winter sea-ice retreat of 67, 59 and 43 % relative to pre-industrial in the Atlantic, Indian and Pacific
sectors of the Southern Ocean. A compilation of Southern Ocean sea-ice proxy data provides weak support for
this reconstruction. However, most published marine core sites are located too far north of the 128,000 years
BP sea ice edge, preventing independent corroboration for this sea ice reconstruction.

1856
209
Using Ice Cores and Emulation to Reconstruct Last Interglacial Ice Sheets

Louise Sime1 (lsim@bas.ac.uk)

1
British Antarctic Survey, Cambridge, United Kingdom

Far-field sea level records have provided evidence that parts of the Antarctic Ice Sheet and Greenland ice sheet
were likely lost during the Last Interglacial (LIG) period, 116-129 thousand years ago. Reconstructing ice sheet
changes within the LIG however remains a difficult problem. Sediment cores from beneath the West Antarctic
Ice Sheet (WAIS) support the view that parts were lost within the last 1.3 million years but the timing of the
loss is unknown. This lack of knowledge about the ice sheet changes during the LIG hampers our ability to
calibrate models of potential ice sheet loss in the future.
Ice cores provide amongst the best dated proximal evidence of LIG change across the Antarctica and
Greenland, it is therefore very helpful to use ice core measurements to provide constraints on the rate and
timing of ice sheet changes. Holloway et al. (2016) explored the ice core signal of WAIS change; we found that
ice sheet meltwater and/or ice sheet morphology changes would be recorded in the polar ice cores. Here we
present our recent progress on reconstructing ice sheet changes. We simulate how LIG ice sheet and sea ice
changes would be imprinted on Antarctic and Greenland ice cores using isotopically enabled climate model
simulations of the LIG, and present initial results from applying an emulator (statistical) based approach to this
problem, exploring the impact of ice sheet, meltwater, and sea ice changes on the ice core record.

1857
490
The Effect of Northern Hemisphere Ice Sheet Topography on West Antarctic Climate

Tyler Jones1 (tyler.jones@colorado.edu), William Roberts2, Eric Steig3, Kurt Cuffey4, Bradley Markle3, James
White5
1
University of Colorado, Institute of Arctic and Alpine Research, Boulder, United States, 2University of Bristol,
BRIDGE, School of Geographical Sciences, Bristol, United Kingdom, 3University of Washington, Quaternary
Research Center and Department of Earth and Space Sciences, Seattle, United States, 4University of California,
Department of Geography, Berkeley, United States, 5University of Colorado, Institute of Arctic and Alpine
Research and Department of Geological Sciences, Boulder, United States

The behavior of the Pacific climate system across the last deglaciation is widely debated. Resolving these
debates requires long-term and continuous climate proxy records. Here, we investigate multi-year climate
variability for the last ~31 ka using an ultra-high resolution and continuous water isotope record (dD, d18O, dxs)
from the WAIS Divide ice core (WDC) in the Pacific sector of West Antarctica. We document an abrupt decline
in the amplitude of dD and d18O multi-year climate variability at ~16 ka. Using the HadCM3, we demonstrate
that the climates of both West Antarctica and the Indo-Pacific were substantially altered at ~16 ka by the same
forcing mechanism: the lowering topography of the Laurentide and Cordilleran Ice Sheets (LCIS). In the tropics,
the LCIS topography affects the rainfall patterns, which explains the Indonesian deglacial shift from expanded-
grasslands to rainforest-dominated ecosystems. Similarly, the LCIS affects the tropical Pacific-to-West Antarctic
teleconnection strength, which changes WDC multi-year climate variability. The dxs shows a different
amplitude pattern than dD and d18O, for example, 3-7 yr dxs variability declines slowly from ~16 to 6 ka,
whereas 3-7 yr dD and d18O variability declines abruptly at ~16 ka and reaches a minimum at ~10 ka. Initial
results suggest that dxs could provide information about pan-Pacific changes in rainfall location, as well as the
extent and movement of sea ice during deglaciation in West Antarctica.

1858
SH-7b - Science, Policy, and Politics at the Poles
22.06.2018 11:00-12:30, B Pischa

852
Regional Cooperation in Antarctica: the Cases of Asia, Europe and South America

Andrea Colombo1 (andrea.colombo@pg.canterbury.ac.nz)

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand

International cooperation, with the aim to facilitate research in the Antarctic harsh and extreme environment,
plays a pivotal role for the logistic support and for the deployment of scientific projects run by multiple nations.
These cooperation can either be intra- continental or external; while inter-Antarctic cooperation are based on
Antarctic regional area, external ones find their fundaments in the geographical and political boundaries of
every country.
This paper analyses the current situation of three different regional groups that find their roots, in an
oversimplified way, in Asia, Europe and South America.
The Asian Forum for Polar Sciences (AFoPS), the European Polar Board (EPB) and the Reunión de
Administradores de Programas Antárticos Latinoamericanos (RAPAL) are operating in Antarctica, and with the
exclusion of the latter in both Poles, are an excellent example of logistic and scientific cooperation in Antarctica
based on a regional scale.
My presentation attempts to further analyse the concept of regional cooperation in Antarctica and underline
the importance of joint projects to fulfil scientific research that a single country might not be able to achieve on
its own.

1859
2426
Turning Observer Science into Policy in the Arctic; Lessons from the Antarctic

Hyoung Chul Shin1 (hcshin@kopri.re.kr), Sung-Ho Kang1, Won-Sang Seo1, Ji Hoon Jung1
1
Korea Polar Research Institute, Incheon, Korea, Republic of

Accelerating changes and enhanced accessibility of the Arctic call for policymaking based on more and better
science. Many of the observer states to the Arctic Council focus on science as the most significant element in
their plans. We have mapped scientific capacities of national research programs over the Arctic spatial domain
and examined the movement and usage of mobile and fixed research platforms. The scientific endeavors of
observer states already form a critical link in the overall observation network and represent significant sources
of the data required for sustainable development of the Arctic. There are mounting challenges in need of sound
Arctic science, such as the Northern Sea Route, fisheries, or ocean acidification among many others. It is a
legitimate question to ask how the Arctic as a whole is institutionally prepared to incorporate all available
science, particularly that from observers. There are notable cases of scientific findings turned into policy in the
Antarctic, for example the ozone-hole depletion, alien species, and others. In the Antarctic, institutional tools
are present and in operation that allow for deliberations and decision-making processes engaging a whole
range of stakeholders. Existing and even new arrangements in the Arctic may be inviting but are not inclusive
enough, as we will illustrate in the presentation. More solid and embracive mechanisms are warranted to make
the most use of observer contributions for the benefit of all.

1860
2279
The Impact of Arctic Scientific Cooperation Agreement on Non-Arctic States

Han Liu1 (liuhan@pric.org.cn)

1
Polar Research Institute of China, Shanghai, China

At the 10th Arctic Council Ministerial Meeting in May 2017, the third binding agreement Agreement on
Enhancing International Arctic Scientific Cooperation was adopted, which would lower the barriers in
international Arctic scientific cooperation, such as the difficulties in accessing research facilities and data
.However, it seems that only the eight Arctic States benefit from such improved environment while non-Arctic
States may be relegated to an inferior category in Arctic science . With the ratification of the Agreement in Oct.
2017 and the upcoming 2nd Arctic Science Ministeral Meeting in Oct. 2018, the degree of benefits to non-
Arctic States under the Agreement needs to be carefully considered. Therefore, the main goal of this report is
to discuss the influence of the Agreement on non-Arctic states´ approaches to Arctic scientific cooperation.In
the first place ,this report tries to critically analyze the main articles of the Agreement according to the
international law as well as provides a description of its purposes and rule-making process. It then seeks to the
influence of the Agreement on non-Arctic states´ participation in international Arctic scientific cooperation. The
Sino-Russian Arctic scientific cooperation will be evaluated as a case study to explore the possibility of scientific
cooperation between Arctic and non-Arctic states. In concluding, this report looks into the future and discusses
challenges and opportunities for non-Arctic states.

1861
2278
IASC and its Role in Bridging Arctic Science with Decision-making

Malgorzata (Gosia) Smieszek1,2 (malgorzata.smieszek@ulapland.fi)

1
Co-Chair of IASC Action Group on Communicating Arctic Science to Policy-Makers (CASP), Rovaniemi, Finland,
2
Arctic Centre, University of Lapland, Rovaniemi, Finland

The need to better connect Arctic science with decision-making is well recognized. Initiatives like ICARP-III and
the Arctic Science Ministerial stress that Arctic science must be communicated beyond Arctic research
community and underline the utmost importance of scientific information to advance constructive decision-
making. To respond to those calls, in 2017 the International Arctic Science Committee (IASC) established Action
Group on Communicating Arctic Science to Policy-Makers (CASP) - to enhance IASC capacity to provide advice
on issues of science in the Arctic and the communication of scientific knowledge to policymakers. Arguably,
IASC is very well positioned to serve as the primary source of information about Arctic science. It is the leading
international Arctic scientific organization, which brings together all countries active in Arctic research and
representatives of disciplines across humanities, social and natural sciences spectrum. The challenge to
communicate Arctic science is, yet, paramount. Not only because of the unprecedented scale and pace of
changes in the region, but also because of extremely dispersed nature of Arctic research. What is the role IASC
can and should play in communicating Arctic science to decision-makers? What are its assets and limitations?
CASP Action Group will deliver results of its work to IASC Council at the meeting in Davos. This paper builds
upon its efforts, reflects on the CASP process and considers the next steps to take.

1862
73
How Does Science Get into Policy in the Antarctic Treaty System?

David Walton1 (dwhw@bas.ac.uk)

1
British Antarctic Survey, Cambridge, United Kingdom

Governments declare that they want evidence based policy and scientists are asked to show how their science
can be used for policy. Whilst there is now an apparently well defined route through SCAR Working and
Information papers for the community into the CEP, ATCM and CCAMLR and another through national
delegations it was not always so. What then are the key drivers that make some science more effective in
Antarctic policymaking and how should you define outcomes when describing the effectiveness of the transfer?
Using examples I will describe how topicality, risk, political expediency, practicability and affordability will
always interact to determine if your efforts will result in a recognisable policy outcome and how and why this
process can take some time.

1863
2563
Canada´s Diplomatic and Juridical Foreign Policy: Continental Shelf in the Arctic

Julia Schmied1 (j.schmied@utoronto.ca)

1
University of Toronto, Munk School of Global Affairs, Toronto, Canada

Canada submitted in 2013 a complete process for the expansion of its continental shelf in the Atlantic Ocean,
and a partial process to expand its continental shelf in the Arctic. Canada now has an extension to further their
research and present a complete process to Commission on limits of the Continental Shelf (CLCS).
In this sense Canada will present the United Nations Convention on the Law of the Sea with a focus as the most
relevant issues to the expansion of the Canadian continental shelf in the Arctic.
Around the world, Governments have taken steps to include the most extensive adjacent sea areas in their
jurisdictions, acting to exercise their rights onto overseas neighbours, assess the capabilities of its waters and
the floor of the continental shelf. The praxis of States, in almost every aspect, has been implemented in line
with the Convention, especially after entry into force and rapid acceptance by the international community as a
parameter to all actions dealing with oceans and the Law of the Sea.The definition of the territorial sea
contributed to the slowing of conflicting requirements. Navigation by the territorial sea and maritime Straits
now is backed by legal principles. Coastal States already benefit from provisions that give them extensive
economic rights over an area of 200 miles wide along their shoreline.

1864
CR-4e - Ice sheets, ice shelves & proximal processes in past, present & future climates
22.06.2018 11:00-12:30, B Parsenn

813
Antarctic Ice Sheet Evolution Explained by CO2 Changes and Obliquity Sensitivity

Richard Levy1 (r.levy@gns.cri.nz), Stephen Meyers2, Nicholas Golledge3, Timothy Naish3, James Crampton1,
Robert McKay3, Robert DeConto4, Laura De Santis5, Ed Gasson6, David Harwood7, Bruce Luyendyk8
1
GNS Science, Paleontology, Lower Hutt, New Zealand, 2University of Wisconsin - Madison, Department of
Geoscience, Madison, United States, 3Victoria University of Wellington, Antarctic Research Centre, Wellington,
New Zealand, 4University of Massachusetts, Amherst, United States, 5Istituto Nazionale di Oceanografia e di
Geofisica Sperimentale, Trieste, Italy, 6University of Sheffield, Sheffield, United Kingdom, 7University of
Nebraska, Lincoln, United States, 8University of California Santa Barbara, Santa Barbara, United States

Since at least 34 million years ago, polar ice sheets have served as an important component of the Cenozoic
climate system, yet many details of that history remain enigmatic, and a coherent model for cryosphere
evolution remains elusive. Here, we establish a novel measure of Earth system sensitivity to obliquity forcing,
quantified through the analysis of δ18O data, which highlights distinct intervals in Earth system evolution and
ice sheet history. We integrate this measure with direct records of Antarctic ice sheet (AIS) variability including
sediment cores and seismic data. The results identify an increase in obliquity sensitivity associated with
favourable astronomical configurations and key planetary thresholds in CO2 concentrations and tectonics. The
emergence of marine-based ice around Antarctica is coeval with enhanced obliquity sensitivity, and based on
this, we establish a three phase AIS model (terrestrial-based ice sheet, marine-based ice sheet, and marine-
based ice sheet with extensive sea ice). Long-term climate variability, and continental scale AIS expansion and
retreat, is broadly commensurate with the 2.4-My-long eccentricity cycle. Maximum ice extent typically occurs
during episodes of low obliquity variance and medium-to-high eccentricity. This integration of ice proximal and
distal records provides a new coherent model for AIS evolution, with implications for future behaviour.

1865
875
Evolution of the Ross Ice Shelf since the Last Glacial Maximum

Daniel Lowry1 (dan.lowry@vuw.ac.nz), Nicholas Golledge1,2, Nancy Bertler1,2

1
Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand, 2GNS Science, Lower
Hutt, New Zealand

Given the position of the Ross Ice Shelf, which buttresses both the West and East Antarctic ice sheets, the
potential future sea level contribution of its grounded ice drainage basins could be substantial. Here, we
perform regional ice sheet model simulations to investigate past grounding line migration of the Ross Ice Shelf
using the Parallel Ice Sheet Model (PISM) to better understand how the ice shelf system responds to
environmental drivers. The regional simulations, performed at 10 km resolution, include both the Ross Ice Shelf
and its grounded ice drainage basins, allowing for the grounding line to evolve through time. Climate forcing
experiments are performed using different combinations of the temperature and accumulation reconstructions
of the West Antarctic Ice Sheet (WAIS) Divide and EPICA Dome C ice cores, the output of two transient climate
model simulations, and multiple SST and sea level proxy reconstructions. Differences in the pattern and timing
of retreat between the model experiments highlight the relative impacts of atmospheric and oceanic changes
and bathymetry on Ross Ice Shelf grounding line retreat. Our simulations are analysed in the context of the
Roosevelt Island Climate Evolution (RICE) ice core and sediment cores from the Ross Sea and wider region.
Together, these results provide insight into the environmental conditions that most strongly control grounding
line changes, allowing inferences to be made for future controls on sea level rise.

1866
1076
Extensive Holocene WAIS Grounding Line Retreat and Uplift-driven Readvance

Reed Scherer1,2 (reed@niu.edu), Jonny Kingslake3, Torsten Albrecht4, Jason Coenen1, Ross Powell1, Ronja
Reese4, Nathan Stansell1, Slawek Tulaczyk5, Martin Wearing6, Pippa Whitehouse7
1
Northern Illinois University, Dept. of Geology & Environmental Geosciences, DeKalb, United States, 2Northern
Illinois University, Institute for the Study of the Environment, Sustainability & Energy, DeKalb, United States,
3
Lamont-Doherty Earth Observatory Columbia University, Geosciences, Palasades, United States, 4Potsdam
Institute for Climate Impact Research (PIK), Potsdam, Germany, 5University of California Santa Cruz, Earth &
Planetary Sciences, Santa Cruz, United States, 6Lamont-Doherty Earth Observatory Columbia University,
Palisades, United States, 7Durham University, Geography, Durham, United Kingdom

Numerical models used to project future ice-sheet contributions to sea-level rise exploit reconstructions of
post-LGM ice loss to tune model parameterizations. In the Weddell and Ross Sea sectors, reconstructions of
West Antarctic Ice Sheet (WAIS) grounding line (GL) retreat history have been limited by lack of data south of
the ice shelf calving fronts. We present new evidence from
(1) ice-penetrating radar showing Holocene ice rise evolution,
(2) the prevalence of subglacial radiocarbon and
(3) glacio-isostatic adjustment (GIA) modeling that collectively challenge prevailing views of Holocene WAIS
behavior.
We show that the GL retreated more than 200 kilometers inland of its present position in these sectors, driven
by climatic warming and sea-level rise, followed by GL re-advance to its current position, driven by GIA and ice
rise formation. We explain these observations using an ensemble of ice-sheet simulations, using the PISM
model suite. These simulations reproduce widespread post-LGM GL retreat well inland of its current location
and later re-advance. These findings overturn the assumption of progressive Holocene GL retreat in the
Weddell and Ross Seas and suggest that climate-initiated ice loss was reversed by GIA-driven stabilizing
processes. Whether these processes could reverse present-day loss elsewhere in Antarctica on millennial
timescales depends on poorly-known bedrock topography, mantle viscosity, climatic forcing and future ice-
shelf stability.

1867
2580
Weddell Sea Embayment Ice Stream Till Can Be Used to Trace Past Ice Flow Paths

Kathy Licht1 (klicht@iupui.edu), Liana Agrios1, Trevor Williams2, Sidney Hemming2, Stefanie Brachfeld3
1
Indiana University Purdue University Indianapolis, Indianapolis, United States, 2Lamont-Doherty Earth
Observatory Columbia University, Palisades, United States, 3Montclair State University, Montclair, United States

Till from the margin of the major ice streams of the Weddell Sea Embayment contains detrital minerals with
distinct age populations. These differences mean that they can be used as provenance tools to reconstruct past
ice stream dynamics and determine the origin of iceberg-rafted debris (IRD) in the marine sediment record.
Distinctive zircon age populations for each ice stream include - Institute Ice Stream: 560 Ma and 1070 Ma
(dominant), Foundation/Academy Ice Streams: 505 Ma (dominant) and 1030 Ma, Recovery Glacier: 530 Ma
(southern margin) and 1610Ma (northern margin), and Slessor Glacier: 2260 Ma, 2345 Ma, and 2415 Ma.
Many, but not all of these peaks are consistent with local bedrock sources suggesting measurable input from
unexposed subglacial sources. Ar-Ar ages from detrital hornblende and biotite from the Foundation/Academy
Ice Stream are typically younger than zircons, whereas till from the northern margin of Recovery Glacier has
similar Ar-Ar age peaks as the zircon data. Comparison of these data with offshore U-Pb zircon and Ar-Ar
signatures in tills from the Ronne (west), Hughes (central), and Filchner (east) sectors allow us to constrain LGM
ice flow paths. The data suggest the Foundation Ice Stream flowed east of Berkner Island at some time during
the LGM and that input from the Slessor/Bailey Glaciers was very limited in extent. If the Recovery Glacier bed
is underlain by rocks of the Beacon Supergroup, the Recovery extended into the eastern Filchner trough.

1868
729
Diverse Landscapes Beneath Pine Island Glacier Influence Ice FLow

Robert G. Bingham1 (r.bingham@ed.ac.uk), David G. Vaughan2, Edward C. King2, Damon Davies1, Stephen L.
Cornford3, Andrew M. Smith2, Robert J. Arthern2, Alex M. Brisbourne2, Jan De Rydt2, Alastair G.C. Graham4,
Matteo Spagnolo5, Oliver J. Marsh6, David E. Shean7
1
University of Edinburgh, Edinburgh, United Kingdom, 2British Antarctic Survey, Cambridge, United Kingdom,
3
Swansea University, Swansea, United Kingdom, 4University of Exeter, Exeter, United Kingdom, 5University of
Aberdeen, Aberdeen, United Kingdom, 6oliver.marsh@canterbury.ac.nz, Christchurch, New Zealand, 7University
of Washington, Seattle, United States

The retreating Pine Island Glacier (PIG), West Antarctica, presently contributes ~5-10% of global sea-level rise.
PIG's retreat rate has increased in recent decades with associated thinning migrating upstream into tributaries
feeding the main glacier trunk. To project future change requires modelling that includes robust
parameterisation of basal traction, the resistance to ice flow at the bed. However, most ice-sheet models
estimate basal traction from satellite-derived surface velocity, without a priori knowledge of the key processes
from which it is derived, namely friction at the ice-bed interface and form drag, the resistance to ice flow that
arises as ice deforms to negotiate bed topography. Here, we present high-resolution maps, acquired using ice-
penetrating radar, of the bed topography across parts of PIG. Contrary to lower-resolution data currently used
for ice-sheet models, these data show contrasting topography across the ice-bed interface. We show that these
diverse subglacial landscapes impact on ice flow, and present a challenge for modelling ice-sheet evolution and
projecting global sea-level rise from ice-sheet loss.

1869
2566
A Varied Subglacial Landscape under Thwaites Glacier, West Antarctica

Knut Christianson1 (knut@uw.edu), Nicholas Holschuh1, John Paden2, Sridhar Anandakrishnan3

1
University of Washington, Seattle, United States, 2University of Kansas, Lawrence, United States, 3Pennsylvania
State University, University Park, United States

Deglaciated landscapes, whether subaerial or submarine, are often host to a rich panoply of subglacial
landforms. These landforms are formed and shaped by interactions between the ice and underlying substrate,
and thus have implications for the flow of the overlying ice. Robust interpretations of the relationship between
the ice and its substrate based on subglacial landforms that remain after deglaciation have been inhibited by a
dearth of high-resolution observations of currently glaciated subglacial landscapes. Here we present two
detailed gridded subglacial topographies, obtained using 3-dimensional radar tomography, from Thwaites
Glacier, West Antarctica, where ice flows over a highly variable bed. One grid is located ∼170 km downstream
from the ice divide where ice is moving ∼100 m/yr. Here the ice advects over a broad basin and then flows into
a subglacial ridge. A deep canyon (~400 m) cuts through this ridge. Relatively soft sediments on the
downstream side of the basin suggest that a large subglacial lake may have formed in this location. Multiscale
glacial lineations are also observed in the subglacial basin. The second grid is located ∼300 km downstream of
the ice divide where the ice is moving ∼350 m/yr. A large crag and even more extensive multiscale subglacial
lineations are observed here. Our results suggest that multiple subglacial landforms form in close geographic
proximity due to heterogeneous basal conditions.

1870
OS-4b - Sea ice modeling and prediction: Sea ice process understanding
22.06.2018 11:00-12:30, B Jakobshorn

1459
Quantifying Drivers of Internal Variability of Sea Ice

Dirk Olonscheck1 (dirk.olonscheck@mpimet.mpg.de), Thorsten Mauritsen2, Dirk Notz1

1
Max Planck Institute for Meteorology, Ocean in the Earth System, Hamburg, Germany, 2Max Planck Institute
for Meteorology, Atmosphere in the Earth System, Hamburg, Germany

The rapid decline of Arctic sea ice in the last decades is superimposed by strong interannual variability. The
mechanisms that cause internal variability of sea ice are debated. Many studies suggest that sea-ice variability
is driven considerably by radiative feedbacks (e.g. Hall 2004, Letterly et al 2016, Kashiwase et al, 2017), ocean
or wind forcing (e.g. Arthun and Eldevik 2012, Ogi et al 2010, Park et al 2015), while others suggest
atmospheric temperature variability as the key driver (e.g. Deser et al 2000, Ding et al 2017).
To resolve this contradiction, we here quantify how much the suggested drivers contribute to the total sea-ice
variability in the fully coupled global climate model MPI-ESM-LR. We perform and analyse experiments in which
the radiative effects of clouds, water vapour and surface albedo, and the forcing by surface winds and
meridional oceanic heat transport are decoupled from the overall climate.
Our experiments show that radiative feedbacks, ocean and wind forcing are not the key drivers of Arctic sea-ice
variability. In total, they cause about 1/4 of the total variability. We show that sea-ice variability instead is
primarily driven by direct thermal coupling to tropospheric temperature, which is consistent with other global
climate models, reanalysis and observations.

1871
1822
Production of Stable Land-fast Ice Bridges in the VP and MEB Models

Mathieu Plante1 (mathieu.plante@mail.mcgill.ca), Bruno Tremblay1, Martin Losch2

1
McGill University, Atmospheric and Oceanic Sciences, Montreal, Canada, 2Alfred Wegener Institute - Helmholtz
Center for Polar and Marine Research, Bremerhaven, Germany

Land-fast ice is an important component of the Arctic system, yet its representation in large-scale sea ice
models remains a challenge, partly due to the difficult parameterization of ice fracture that governs the
stability of ice bridges. This study aims at improving our understanding of how the ice bridges are maintained
by the formation of ice arches at the land-fast ice edge. In particular, the process at which arching fractures are
developed is investigated and their sensitivity to the yield curve parameters is discussed. We also stress that
the model configuration and the coast morphology are also largely influential in determining the timing and
shape of the arching fractures.
Using an ideal channel configuration, we perform a range of experiments in which the model material
parameters are varied to determine their relation to the strength of the ice cover. These experiments are made
using both the Maxwell Elasto-Brittle and the Viscous-Plastic rheology, which are implemented using the same
numerical framework. This allows us to isolate the differences in the modelled ice bridges (and ice fractures)
that are due to the different choice of rheology from those that are introduced by the different model
parameters, such as the time resolution and discretization.

1872
500
Interplay between Arctic Sea Ice Dynamics and State in HighResMIP

David Docquier1 (david.docquier@uclouvain.be), François Massonnet1,2, Neil F. Tandon3, Jeremy P. Grist4,

Thierry Fichefet1
1
Université catholique de Louvain (UCL), Earth and Life Institute, Louvain-la-Neuve, Belgium, 2Barcelona
Supercomputing Center, Earth Sciences Department, Barcelona, Belgium, 3Environment and Climate Change
Canada, Climate Research Division, Toronto, Canada, 4National Oceanography Centre, University of
Southampton Waterfront Campus, Southampton, United Kingdom

Sea ice area, thickness and volume have substantially decreased in the Arctic Ocean since the beginning of the
satellite era. As a result, sea ice strength has been reduced, allowing more deformation and leading to
increased sea ice drift speed. We investigate the links between sea ice dynamics and what we call 'sea ice state'
(concentration and thickness) using a process-oriented approach. Our methodology is applied to various global
climate models coupling the atmosphere, ocean and sea ice, and participating to the High Resolution Model
Intercomparison Project (HighResMIP), within the framework of the EU Horizon 2020 PRIMAVERA project.
Model results are compared to different observation datasets. We show that some models can capture the
observed relationships between sea ice drift speed, concentration and thickness with more or less accuracy.
The domain choice for computing diagnostics and metrics is crucial for our analysis. The impact of model
resolution is also assessed and reveals lower Arctic sea ice area and volume with finer grid size, but the effect
on the volume depends on the model used. This is correlated to higher northward ocean heat transport with
finer grid size. In terms of sea ice dynamics, the impact of resolution on drift speed is less straightforward and
really depends on the month of the year. Further analysis is needed to understand the root causes of the
model differences.

1873
1817
Evaluating Sea Ice Processes in CMIP5 Models Using Concentration Budgets

Caroline Holmes1 (calmes@bas.ac.uk), Thomas Bracegirdle1, Paul Holland1

1
British Antarctic Survey/NERC, Cambridge, United Kingdom

The ability of coupled climate models to recreate observed sea ice behaviour is a natural subject of scrutiny,
given their use in projecting future sea ice change. The contrasting trends of Arctic and Antarctic sea ice during
the satellite era, and difference in ability of CMIP5 climate models to represent them, means it is crucial to
work towards a process-based understanding of sea ice biases.
We seek to understand the thermodynamic and dynamic origins of biases in the seasonal cycle of sea ice area,
in both hemispheres, in the CMIP5 multi-model ensemble. This question will be addressed through the use of
sea ice concentration budgets calculated from daily sea ice and drift diagnostics, evaluated against a recent
eight-year budget derived from observations.
I will present a novel evaluation of the budget terms in the available ensemble. These will be discussed in the
context of biases in the underlying drift fields, possible sources in oceanic or atmospheric processes, and the
implications for seasonal biases in sea ice area. Previous work based on a single model family has suggested a
compensating error whereby too-strong model ice dynamics may be balanced by excess melt. I will discuss the
impact of sampling uncertainty- in time, physical space, and 'model space'- on the robustness of this
conclusion.

1874
898
Impacts on Antarctic Sea Ice in CESM1(CAM5) from Time-dependent Freshwater Input

Andrew G. Pauling1,2, Inga J. Smith2 (inga.smith@otago.ac.nz), Patricia J. Langhorne2, Cecilia M. Bitz1

1
University of Washington, Atmospheric Sciences, Seattle, United States, 2University of Otago / Te Whare
Wananga o Otago, Department of Physics, Dunedin, New Zealand

Earth System Models do not reproduce the observed increase in Antarctic sea ice extent which may be due to
the unrealistic representation of ice shelves. We investigated the response of sea ice to increasing freshwater
input from ice shelves using the Community Earth System Model with the Community Atmosphere Model
version 5 [CESM1(CAM5)]. We conducted model experiments adding fresh water as if from ice shelf melt with a
linear increase in the rate of input over the period 1980-2013.We found that an increase in the rate of change
of freshwater input of ∼45 Gt yr−2 was sufficient to offset the negative trend in sea ice area in CESM1(CAM5),
although the freshwater input by the end of the experiment was larger than observed at that time.

1875
1769
Variability & Trends of Antarctic Sea-ice in HighResMIP Simulations with AWI-CM

Thomas Rackow1 (thomas.rackow@awi.de), Thomas Jung1,2, Dmitry Sein1, Tido Semmler1

1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Climate Dynamics,
Bremerhaven, Germany, 2University of Bremen, Department of Physics and Electrical Engineering, Bremen,
Germany

Climate models struggle to capture observed Antarctic sea-ice extent trends, which has critical consequences
for sea-ice projections. To tackle this, it is often suggested to develop models at high spatial resolution. In this
study we focus on the September sea-ice extent in prototype simulations for the “High Resolution Model
Intercomparison Project” (HighResMIP). Scenario simulations (RCP8.5) are performed with the AWI Climate
Model (AWI-CM) at “high-resolution” in both ocean and atmosphere (HR) and “low-resolution” (LR) under the
same protocol.
Compared to LR, HR predicts a much weaker warming signal around Antarctica in austral winter for the end of
this century (2070-2099) relative to 1976-2005. This may partly be explained by the different sea-ice mean
states in LR and HR. However, we also observe increased extent variability and strongly reduced rates of sea-ice
decrease. Specifically, HR shows excessive polynya-like features in the Weddell Sea in the pre-satellite era,
followed by a stable September sea-ice extent until ~2050. “Mixed-resolution” runs (HR ocean with LR
atmosphere, and vice versa) attribute this difference in trends and variability to the HR ocean, independent of
the atmospheric resolution.
In light of the observed stable Antarctic September sea-ice extent and the recent return of the Weddell
polynya, we will discuss possible common mechanisms and implications for other modelling centres
participating in HighResMIP.

1876
AC-2d - Polar meteorology, climatology and stratospheric processes
22.06.2018 11:00-12:30, C Sanada I

136
Late Autumn Boundary Layer Observations in the Ross Sea from the PIPERS Project

John Cassano1 (john.cassano@colorado.edu), Peter Guest2, Kelly Schick1

1
University of Colorado, CIRES / ATOC, Boulder, United States, 2Naval Postgraduate School, Monterey, United
States

The Polynyas, Ice Production and seasonal Evolution in the Ross Sea (PIPERS) project spent mid-April to mid-
June 2017 in the western Ross Sea observing the atmosphere, ocean, and sea ice states to estimate sea ice
production and water mass transformation in the Ross Sea. The meteorological observations during PIPERS
included a ship-based weather station, radiometers, and ceilometer, a flux tower deployed during ice stations,
and radiosonde and unmanned aerial system (UAS) measurements. Ship-based and radiosonde observations
were made during transects through Terra Nova Bay during a strong katabatic wind event with winds in excess
of 30 m s-1. Bulk estimates of the turbulent fluxes during this event ranged from several hundred to over 1000
W m-2. A sequence of radiosonde measurements during the transects provide detailed observations of the
downstream evolution of the katabatic air mass as it passed over the Terra Nova Bay polynya, documenting a
downstream decrease in wind speed and an increase in boundary layer temperature and depth. UAS profiles
through the lowest 1000 m of the atmosphere, repeated at hourly to several hour frequencies, documented
the temporal evolution of the boundary layer during multiple ice stations. Both well mixed and inversion
conditions were observed and the time evolution from these UAS profiles will be used in conjunction with the
flux tower measurements to describe boundary layer processes occurring over the sea ice covered Ross Sea.

1877
449
Low-level Sublimation of Antarctic Snowfall Due to Katabatic Winds

Alexis Berne1 (alexis.berne@epfl.ch), Jacopo Grazioli2, Jean-Baptiste Madeleine3, Christophe Genthon4, Richard
Forbes5, Hubert Gallée4, Gerhard Krinner4
1
EPFL, LTE, Lausanne, Switzerland, 2MeteoSwiss, MDR, Locarno-Monti, Switzerland, 3UPMC/LMD, Paris, France,
4
IGE, Grenoble, France, 5ECMWF, Reading, United Kingdom

Over the Antarctic continent, precipitation (snowfall) is the most important input of the ice sheet mass budget.
The margins of Antarctica are characterized by persistent katabatic winds, supplying the low level of the
atmosphere with air masses of low relative humidity, originating from the elevated Antarctic plateau. Despite
the importance of these winds for the climate of coastal regions, their interaction with snowfall has not been
quantified so far. In this contribution, we show, using unprecedented remotely-sensed data (X-band and long
series of K-band radar data) collected in Dumont d'Urville on the coast of Adélie Land, that katabatic winds lead
to a significant low-level sublimation of snowfall. At the scale of individual precipitation events, sublimation is
inversely proportional to the intensity of precipitation, because more developed systems can extend further
into the continent and eventually saturate the low levels of the atmosphere. This phenomenon is reproduced
as well with the simulations of three different atmospheric models, that are used to extend our findings to the
entire continent. In quantitative terms, sublimation in the lowest kilometer of the atmosphere, before
deposition, accounts for about 17% of total snowfall over the entire continent and up to 35% on the margins of
East Antarctica.

1878
739
Parameterizing Antarctic Snowfall in the IPSL Climate Model Using Radar Data

Florentin Lemonnier1 (florentin.lemonnier@lmd.jussieu.fr), Jean-Baptiste Madeleine1, Chantal Claud1, Frédéric

Hourdin1, Gerhard Krinner2, Alexis Berne3, Claudio Duran-Alarcon2, Christophe Genthon2
1
Laboratoire de Météorologie Dynamique/IPSL, École Normale Supérieure, Paris, France, 2Institut des
Géosciences de l'Environnement, Grenoble, France, 3École Polytechnique Fédérale de Lausanne, Lausanne,
Switzerland

Precipitation over Antarctica is poorly known but was recently re-examined thanks to new radar instruments
deployed by the APRES3 team (Antarctic Precipitation, Remote Sensing from Surface and Space), which gave
access to precipitation profiles over the French coastal station of Dumont d´Urville. These precipitation events
are characterized by sublimation of snow in lower atmospheric layers [Grazioli et al., Cryosphere 2016, PNAS
2017]. The understanding of these events is essential to improve our knowledge of the Antarctic climate and to
obtain reliable estimates of snowfall over coastal areas. We modelled these events using the IPSL climate
model and nudged simulations zoomed over the Dumont d´Urville area reaching a 25 km resolution. We
observed in our simulations that the altitude where sublimation starts to dominate is too high compared to the
field observations. Furthermore, the modeled snowfall sublimation process is not as strong as observed.
Concerning our analysis over the whole Antarctic continent, we find that the IPSL climate model tends to
underestimate the snowfall rates but to overestimate the occurrence of precipitation events. The model thus
predicts a realistic annual accumulation rate by a compensation of the two biases. In this study, we will explore
the sensitivity of the model to new parametrizations of cloud to snow conversion, sublimation, sedimentation
and riming of snowflakes.

1879
1472
High Precipitation Events across the Antarctic Continent

John Turner1 (jtu@bas.ac.uk)

1
British Antarctic Survey, Cambridge, United Kingdom

A knowledge of the processes responsible for precipitation over the Antarctic is essential for the correct
interpretation of the signals in ice core. While the many depressions that ring the Antarctic are responsible for
most of the precipitation in the coastal region, in the interior of the continent there is an almost daily fallout of
clear-sky precipitation or diamond dust. It has been known for some time that there can be significant falls of
precipitation on the Antarctic plateau from short-lived intrusions of maritime air, however, the broadscale
distribution and frequency of such events has not been documented. I will present fields of occurrence of high
precipitation events based on high resolution model output and show that they can make a significant
contribution to the annual total precipitation even on the high interior plateau and that their variability
dictates the inter-annual variability of total precipitation.

1880
1661
A High-resolution Climatological Snowfall Map for Antarctica

Niels Souverijns1 (niels.souverijns@kuleuven.be), Alexandra Gossart1, Stef Lhermitte2, Irina V. Gorodetskaya3,

Susanne Crewell4, Mario Mech4, Jacopo Grazioli5, Alexis Berne5, Claudio Duran-Alarcon6, Brice Boudevillain6,
Christophe Genthon6, Claudio Scarchilli7, Nicole P.M. van Lipzig1
1
KU Leuven, Department of Earth and Environmental Sciences, Heverlee, Belgium, 2Delft University of
Technology, Department of Geoscience and Remote Sensing, Delft, Netherlands, 3University of Aveiro, Centre
for Environmental and Marine Studies, Aveiro, Portugal, 4University of Cologne, Institute for Geophysics and
Meteorology, Cologne, Germany, 5Ecole Polytechnique Federale de Lausanne, Environmental Remote Sensing
Laboratory, Lausanne, Switzerland, 6Université Grenoble Alpes, Grenoble, France, 7ENEA, Laboratory
Observation and Analyses of Earth and Climate, Rome, Italy

Precipitation is the dominant source term in the surface mass balance of the Antarctic Ice Sheet (AIS).
However, direct observations of this quantity are scarce and often limited to proxies. In 2006, the Cloudsat
satellite was launched carrying a 94-GHz nadir-looking radar on board, able to detect precipitation profiles. This
instrument allowed to get a first coherent observational dataset of radar reflectivity, snowfall rates and ice
water content for the whole AIS. However, these data products have not yet been evaluated over the AIS and
only a very coarse-resolution snowfall map for the AIS is currently available (Palerme et al., 2014).
In this study, the individual tracks for the whole Cloudsat record are geostatistically interpolated (kriging).
Microwave scattering information obtained from satellites in the A-train is used as an external parameter in
the interpolation, in order to capture the spatial structure of the precipitation systems. As such, a high-
resolution (0.1° x 0.2°) climatological snowfall map for the whole AIS is obtained. The product is evaluated
against three ground-based vertically pointing 24 GHz Micro Rain Radars and shows adequate matches for both
individual event evaluation as for long-term records including significant improvements compared to previous
studies. It therefore has the potential to be used by the modeling community for the evaluation of their climate
models and small-scale process evaluation as e.g. snowfall shadow zone detection.

1881
2587
Spectral Measurements of Radiation on King George Island (Antarctic Peninsula)

Raul Cordero1 (raul.cordero@usach.cl), Alessandro Damiani1, Sarah Feron1

1
Universidad de Santiago de Chile, Santiago, Chile

Double monochromator-based instruments developed according to the specifications defined by the World
Meteorological Organization (WMO) and the Network for the Detection of Atmospheric Composition Change
(NDACC), can produce high quality spectral measurements with relatively low uncertainties.
These instruments are able carry out absolute measurements of the solar spectrum, and therefore they are
useful as a reference for calibration or validation of other instruments, satellite products, and radiative transfer
models.
Since the solar spectrum is modulated by the ozone, clouds, albedo and aerosols, our measurements can be
exploited in order to track the temporal evolution of these parameters.
We present a summary of spectral measurements carried out since 2011 at our station on King George Island
(62oS; Antarctic Peninsula/Southern Ocean) by using a Double monochromator-based instrument that
complies with specifications of NDACC.
The measurements have been exploited in order to retrieve the ozone Column, the aerosol column, and the
cloud modification factor. The latter is particularly important since this area is known to have one of the high
cloud fraction in the planet. Spectral measurements carried out at the Izaña Observatory (Tenerife, Spain), in
Hannover (Germany) and in Chajnantor (Atacama Desert), were used for further comparisons.

1882
OS-7f - Atmosphere-Ice-Ocean interactions in the Polar Regions
22.06.2018 11:00-12:30, C Sanada II

1396
A Physical Wave Mixing Parameterisation for the Polar Regions

Stefanie Rynders1 (s.rynders@noc.ac.uk), Yevgeny Aksenov1, Gurvan Madec2, George Nurser1, Daniel Feltham3
1
National Oceanography Centre, Southampton, United Kingdom, 2L'OCEAN Sorbonne Universités, Paris, France,
3
University of Reading, Reading, United Kingdom

Breaking waves cause mixing of the upper water column and present mixing schemes in ocean models take this
into account through surface roughness. Sea surface roughness in the polar regions depends on significant
wave height and sea ice bottom roughness. Surface roughness is commonly parameterised using significant
wave height from local wind speed, ignoring the effect of sea ice. We present results from simulations using
modelled surface roughness instead, which accounts for the presence of sea ice and the effect of swell. The
simulations use the NEMO ocean model coupled to the CICE sea ice model in a one-degree configuration, with
wave information from the ECWAM model of the European Centre for Medium-Range Weather Forecasts
(ECMWF). The new mixing formulation affects vertical heat fluxes to and from the sea ice, which in turn affects
sea ice concentration and ice thickness. The mixed layer depth under sea ice is improved, without affecting
mixed layer depth in ice-free regions.
Wave heights in a large part of the Arctic are increasing and expected to increase further due to sea ice retreat
and a larger wave fetch. Therefore wave mixing and other aspects of wave and sea ice coupling will become
more important in the future.

1883
2208
Heavy Footprints of Upper Ocean Turbulence on Sea Ice

Georgy Manucharyan1, Andrew Thompson1 (andrewt@caltech.edu)

1
California Institute of Technology, Environmental Sciences and Engineering, Pasadena, United States

Signatures of mesoscale and submesoscale ocean eddies, fronts and filaments are ubiquitously manifested in
sea ice patterns, particularly in marginal ice zones. However, localized and intermittent sea ice heating and
advection by ocean eddies are currently not accounted for in climate models and may contribute to their biases
and errors in sea ice forecasts. Here we use a submesoscale-resolving global ocean-sea ice model to
demonstrate that a substantial sea ice area in both Arctic and Southern Oceans is strongly affected by ocean
eddies that induce large sea ice vorticity, redistribute its mass via Ekman dynamics, and impact its melt rates
via lateral and vertical advection of warm waters. When the sea ice weakens as its concentration falls below
about 60%, the sea ice vorticity starts to correlate with the underlying ocean vorticity at spatial scales of about
5-50 km. The increasing similarity between the sea ice and the ocean currents dramatically diminishes the ice-
ocean drag. This implies that the sea ice can no longer dissipate ocean eddies, and the combined sea ice--eddy
system nearly conserves its energy and angular momentum. Our results suggest that a continuing sea ice melt
should lead to an intensification of the upper ocean turbulence, which could affect the underlying large-scale
circulations as well as vertical heat and tracer fluxes.

1884
1446
Mixed Layer Regimes and Submesoscale Fluxes under Sea Ice from Seal Data

Louise Biddle1 (louise.biddle@marine.gu.se), Sebastiaan Swart1

1
University of Gothenburg, Department for Marine Science, Göteborg, Sweden

The Marginal Ice Zone in Antarctica can have an area of up to 18 x106 km2 in winter, influencing the upper
layers through brine rejection and increased drag from sea ice movement. The freshwater flux associated with
sea ice processes is a strong buoyancy forcing on upper ocean mixing, and can cause submesoscale instabilities.
However, despite its large extent, this region remains poorly undersampled, and is the biggest missing link in
climate models. Here, we present tagged elephant seal data from the Bouvet Island - Dronning Maud land
region, over the austral winter of 2008. We show tagged seal data is an underused, and viable, dataset to
estimate wintertime submesoscale fluxes in the Marginal Ice Zone. We assess the resolution of the seal data,
and find that the peak sampling rates are 10 m vertical, 8 km horizontal and 6 hours spacing. Using this data,
we estimate submesoscale fluxes between March and September, revealing four distinct regimes: summer
stratification, sea ice formation/brine rejection, open lead events and wintertime stable mixed layer. Short
time-scaled events, such as the opening of leads, are compared to regional wind forcing and local sea ice
concentrations to identify air-sea ice-ocean momentum fluxes. This improved understanding of upper ocean
processes under sea ice will help to identify the drivers of sea ice variability in the region.

1885
2235
Upper Ocean Evolution Across the Beaufort Sea Marginal Ice Zone

Craig M. Lee1 (craig@apl.washington.edu), Luc Rainville1, Jason Gobat1, Lee Freitag2, Sarah Webster1
1
University of Washington, Applied Physics Laboratory, Seattle, United States, 2Woods Hole Oceanographic
Institute, Applied Ocean Physics and Engineering, Woods Hole, United States

The observed reduction of Arctic summertime sea ice extent and expansion of the marginal ice zone (MIZ) have
profound impacts on the balance of processes controlling sea ice evolution.
Four long-endurance autonomous Seagliders followed the retreating Beaufort Sea ice edge to repeatedly
occupy sections that extended from open water, through the marginal ice zone, deep into the pack during
summer 2014. Gliders penetrated up to 200 km into the ice pack, under complete ice cover for up to 10
consecutive days. Sections reveal strong fronts where cold, ice-covered waters meet waters that have been
exposed to solar warming, and O(10 km) scale eddies near the ice edge. In the pack, Pacific Summer Water and
a deep chlorophyll maximum form distinct layers at roughly 60 m and 80 m, respectively, which become
increasingly diffuse as they progress through the MIZ and into open water. The isopynal layer between 1023
and 1024 kgm-3, just above the Pacific Summer Water, consistently thickens near the ice edge, likely due to
mixing or energetic vertical exchange associated with strong lateral gradients in this region. This presentation
will discuss the upper ocean variability, its relationship to sea ice extent, and evolution over the summer to the
start of freeze up.

1886
718
Linking Ocean Convection to the Recent ice Edge Retreat along East Greenland

Kjetil Våge1 (kjetil.vage@uib.no), Lukas Papritz1, Lisbeth Håvik1, Mike Spall2, GWK Moore3
1
University of Bergen, Geophysical Institute, Bergen, Norway, 2Woods Hole Oceanographic Institution, Woods
Hole, United States, 3University of Toronto, Toronto, Canada

Warm subtropical-origin Atlantic water flows, as an extension of the Gulf Stream, northward across the
Greenland-Scotland Ridge into the Nordic Seas where it relinquishes heat to the atmosphere and gradually
transforms into dense Atlantic-origin water while circulating around the basin. Before returning southward as
part of the East Greenland Current, a major contributor of dense water to the Denmark Strait overflow, the
Atlantic-origin water subducts beneath a layer of cold, fresh surface water and sea ice. Here we show, using
measurements from autonomous ocean gliders deployed from fall 2015 to spring 2016, that the Atlantic-origin
water was re-ventilated while transiting the western Iceland Sea in winter. This re-ventilation is a recent
phenomenon made possible by the retreat of the ice edge toward Greenland, which had previously insulated
the waters of the East Greenland Current from the atmosphere. The fresh surface layer that characterizes this
region in summer is diverted toward the Greenland shelf by enhanced onshore Ekman transport induced by
stronger northerly winds in fall and winter. Severe heat loss from the ocean to the atmosphere offshore of the
ice edge subsequently triggers convection which further transforms the Atlantic-origin water. This re-
ventilation is a counterintuitive occurrence in a warming climate, and highlights the difficulties inherent in
predicting the behaviour of the complex coupled climate system.

1887
808
The Iceland Greenland Seas Project: Oceanographic Highlights

Robert Pickart1 (rpickart@whoi.edu), Kjetil Våge2, Leah McRaven1, Frank Bahr1, Ian Renfrew3, Kent Moore4
1
Woods Hole Oceanographic Institution (WHOI), Physical Oceanography, Woods Hole, United States, 2University
of Bergen, Bergen, Norway, 3University of East Anglia, Norwich, United Kingdom, 4University of Toronto,
Toronto, Canada

A coordinated meteorological and oceanographic field campaign over the Iceland and southern Greenland Seas
is scheduled for February and March 2018. The main goal is to document the ventilation of the densest water
feeding the lower limb of the Atlantic meridional overturning circulation (AMOC) and to quantify the associated
atmospheric forcing. Particular focus will be on cold-air outbreaks and their forcing of oceanic convective
overturning in the vicinity of the marginal ice zone. We will characterize the spatial variation and temporal
evolution of the oceanic mixed layer in relation to the hydrography and the circulation of the region, including
the presence of boundary currents and interior gyres. We will also investigate the exchange of water between
the Greenland and Iceland Seas across the West Jan Mayen Ridge. Finally, the connection between the newly
ventilated water and the pathways providing dense water to Denmark Strait will be addressed.

1888
EN-7c - Biogeochemical cycling in the Polar Regions: Terrestrial and Ocean interactions
22.06.2018 14:00-15:30, A Studio

1317
Sr and 87Sr/86Sr in Antarctic Lakes: Chemical Weathering in Extreme Environment

Mohammad Nuruzzama1 (nuruzzama95@ncaor.gov.in), Waliur Rahaman1, Rahul Mohan1, Shramik Patil1

1
National Center for Antarctic and Ocean Research, Vasco da Gama, India

Chemical weathering is an important process for regulating biogeochemistry of Antarctic lakes and coastal
oceans surrounding the Antarctica and atmospheric CO2 consumption. There are about ten thousand surface
and subglacial lakes where these processes could play an important role in supplying nutrients to the organism
and CO2 consumption in silicate weathering reactions. However, this process in extreme environments,
particularly in the Antarctic lakes, is less studied compared to tropical river basins.
Sr isotopes are generally less affected by physical and biological processes, hence, used as a robust proxy for
chemical weathering. To study chemical weathering processes and assess its role, water samples were
collected from 10 lakes in the Larsemann Hill oasis, East Antarctica. These samples were analyzed for major
ions, dissolved [Sr] and its isotopes (87Sr/86Sr). Dissolved [Sr] and 87Sr/86Sr ranges from 0.09 to 0.69 µM and
0.71104 to 0.7121 respectively. All the data in the mixing plot between 87Sr/86Sr and 1/Sr shows three clusters
which indicate three possible sources such as weathering of silicate, sea spray, and atmospheric dust. We have
made an attempt to fingerprint the sources and their apportionments using dissolved Sr, 87Sr/86Sr together with
the inverse model. This study would improve our understanding of chemical weathering processes in extreme
environments and its role in CO2 sequestration and regulating biogeochemistry in Antarctic lakes.

1889
2391
Weathering in Siberia and Li Isotopes in the Lena and Yenisey Rivers

Don Porcelli1 (donald.porcelli@earth.ox.ac.uk), Per Andersson2, Mel Murphy1,3, Oleg Pokrovsky4, Philip Pogge
von Strandmann3, Joachim Katchinoff1,5, Liselott Kutschner2,6, Catherine Hirst2,6, Trofim Maximov7, Anatoly
Prokushkin8
1
Oxford University, Earth Sciences, Oxford, United Kingdom, 2Swedish Museum of Natural History, Geosciences,
Stockholm, Sweden, 3University College London, Earth Sciences, London, United Kingdom, 4CNRS, Toulouse,
France, 5Yale University, Geology and Geophysics, New Haven, United States, 6Stockholm University, Geological
Sciences, Stockholm, Sweden, 7North-Eastern Federal University, 74International Center for BioGeoScience
Education and Scientific Training, Yakutsk, Russian Federation, 8Russian Academy of Sciences, Sukachev
Institute of Forest, Krasnoyarsk, Russian Federation

The Lena River drains a vast area (2.5Mkm2) in eastern Siberia that is largely underlain by permafrost, and is a
major contributor of nutrients, trace elements, and water to the Arctic Ocean basin. The Yenisey River drains a
similar area in western Siberia, though the extent of permafrost coverage varies widely and includes
permafrost-free areas. These watersheds have been sampled as part of programmes to understand weathering
and the hydrological transport of nutrients and trace elements to the Arctic Ocean.
Lithium isotopes are widely used as a measure of the extent of clay formation and so incongruent weathering
processes of silicate weathering in a watershed, and so provide valuable information on how weathering in
cold regions occurs. Data has been collected for waters from tributaries across both the Lena and Yenisey
basins and draining smaller watersheds representing a range of different conditions, including underlying
lithology, topography, extent of permafrost, and mean annual temperature. A wide range of Li concentrations
and isotope compositions were found, which likely reflect a range of weathering and lithological controls and
variations in water-rock interaction time, parameter that are likely to be sensitive to active layer processes.
However, the overall range of values was similar to that found in other major global rivers, so that the effects
of climate on Li isotope compositions and concentrations are complex.

1890
1719
Seasonal Change of Geochemical Sources and Processes in the Yenisei River

Ruth Hindshaw1 (ruth.hindshaw@gmail.com), Théo Le Dantec2, Nikita Tananaev3, Roman Teisserenc2

1
University of Cambridge, Cambridge, United Kingdom, 2Université de Toulouse, ECOLAB, Toulouse, France,
3
Melnikov Permafrost Institute, Yakutsk, Russian Federation

The Yenisei River has the highest annual discharge of all the rivers draining into the Arctic Ocean and therefore
changes in the chemical flux composition would have a profound effect on the nutrient input to the ocean. The
hydrological cycle of this region is predicted to change due to changing precipitation patterns and thawing
permafrost. By studying the seasonal changes in the geochemistry of the river, information on which end-
member sources are important under different hydrological conditions can be gained and therefore provide a
basis to model future change.
In this study 50 water samples were collected throughout 2012 from Igarka, 670 km from the river mouth, and
analysed for their major ion composition. To further investigate the sources and processes affecting the
geochemical composition of the stream water, a subset of 10 samples, covering the full range in discharge,
were analysed for Sr, Mg and Li isotopes. The radiogenic Sr isotopic composition is higher in summer compared
to winter, indicating a change in the relative contribution of sources. There is negligible seasonal variation in
Mg isotopes and a 4 permil variation in Li isotopes with lower values at high discharge. In this contribution we
will discuss the potential sources and processes contributing to the observed variation (or lack of) in the three
isotope systems and how this knowledge can be used to inform models of future changes in the major element
fluxes from the Yenisei to the Arctic Ocean.

1891
2050
Biogeochemical Importance of High-latitude Dust in the Arctic and Antarctica

Joanna Bullard1 (j.e.bullard@lboro.ac.uk), Cliff Atkins2

1
Loughborough University, Geography, Loughborough, United Kingdom, 2Victoria University of Wellington,
School of Geography, Environment and Earth Sciences, Wellington, New Zealand

Estimates from field studies, remote sensing and modelling all suggest around 5% of global dust emissions
originate in the high latitudes (≥50°N and ≥40°S), a similar proportion to that from the USA (excluding Alaska)
or Australia. This paper identifies contemporary sources of dust within the high latitudes and their role within
local, regional and hemispherical environmental systems. Field data and remote sensing analyses are used to
identify the environmental and climatic conditions that characterize high latitude dust sources in both
hemispheres. Examples from the Arctic and Southern Ocean-Antarctica regions are used to demonstrate and
explain the different regional relationships among dust emissions, glacio-fluvial dynamics, sea-ice and snow
cover. The relative timing of dust input to high latitude terrestrial, cryospheric and marine systems determines
its short to medium term environmental impact. This is highlighted through quantifying the importance of
locally-redistributed dust as a nutrient and sediment input to high latitude soils in the Arctic and marine
systems around Antarctica.

1892
1665
Modeling the Local Effect of Subsea Permafrost Thawing on Arctic Biogeochemistry

Elizaveta Protsenko1,2 (elizaveta.protsenko@niva.no), Trond Kristiansen1, Øystein Varpe3,4, Philip Wallhead5,

Evgeniy Yakushev1,2, Shamil Yakubov2,6, Anastasia Zagovenkova7
1
The Norwegian Institute for Water Research (NIVA), Oslo, Norway, 2Shirshov Institute of Oceanology, Moscow,
Russian Federation, 3University Centre in Svalbard (UNIS), Longyearbyen, Norway, 4Akvaplan-niva, Fram Centre,
Tromsø, Norway, 5The Norwegian Institute for Water Research (NIVA), Marine Biogeochemistry and
Oceanography, Bergen, Norway, 6Helmholtz-Zentrum Geesthacht, Geesthacht, Germany, 7Lomonosov Moscow
State University, Oceanology, Moscow, Russian Federation

Methane is as a strong greenhouse gas and its emission from thawing permafrost could cause an accelerating
effect on global warming and acidification in the ocean. To better understand the consequences for Arctic
marine environments, we used a complex biogeochemical model to explore the local effects of methane seeps
caused by permafrost thawing. Permafrost found in the outer part of Eastern Siberian Arctic Shelf (ESAS) has
mostly degraded, and represents an area where methane fluxes are very high. For that reason, we focused on
simulating the biogeochemical changes in the water column resulting from methane seeps for the ESAS region.
Bubbles from a single seep area tend to dissolve at about the same depth above the seafloor, resulting in the
formation of methane-rich layers within the water column. At the same time, parts of ESAS are seasonally
covered by ice, serving as an almost impermeable lid for methane fluxes and promoting the formation of
methane-rich layers in the surface waters. To explore the state of the water column we used a 1D Ice-Pelagic-
Benthic transport model coupled to the biogeochemical models Bottom RedOx Model and the European
Regional Seas Ecosystem Model.
The results show significant local impacts of the subsea methane source on marine biogeochemistry on
seasonal timescales. As subsea permafrost thawing is expected to continue, our modelling approach may also
be useful for parameterizing long-term impacts on Arctic marine biogeochemistry.

1893
2477
Controls on Fluxes of Labile DOC from the Kuparuk River to the Arctic Ocean

Rose Cory1 (rmcory@umich.edu), Tyler King2, George Kling3, Beth Neilson4

1
University of Michigan, Earth and Environmental Sciences, Ann Arbor, United States, 2Utah State University,
Logan, United States, 3University of Michigan, Ecology and Evolutionary Biology, Ann Arbor, United States,
4
Utah State University, Civil and Environmental Engineering, Logan, United States

Thawing permafrost soils may increase export of dissolved organic carbon (DOC) to rivers, where this DOC may
be converted to CO2 or partially degraded by sunlight as it is transported to the Arctic Ocean. The
concentration, composition, and lability of DOC to complete and partial photo-degradation were quantified in
the Kuparuk River (arctic Alaska) during ice-free summer seasons of 2011-2017. DOC characterization,
supporting water chemistry and hydrological measurements were conducted along a 350 km transect from the
Kuparuk River headwaters in the Brooks Range to its mouth at the Arctic Ocean, and from major tributaries
entering the river. River surveys were done each year during the freshet, the height of summer, and later in
summer when thaw depth was maximum. Seasonal variability in downstream trends in DOC composition and
lability indicated influences of water residence time, prior light exposure, and different sources of DOC. DOC
composition suggested a greater proportion of DOC in the Kuparuk River from deeper mineral soils towards the
end of the summer coincident with maximum thaw depth. Overall, there was little change in DOC lability to
complete and partial degradation from the headwaters to the Arctic Ocean. This finding suggests that in-stream
degradation of DOC to CO2 may be offset by inputs of fresh, labile DOC with distance downstream, indicating
that coastal waters of the Arctic Ocean may receive DOC labile to conversion to CO2.

1894
GG-1c - Magmatic, tectonic, and geodynamic investigations of the Polar Regions
22.06.2018 14:00-15:30, A Schwarzhorn

641
Imprints of Neoproterozoic Orogeny in Princess Elizabeth Land, Antarctica

Naresh Pant1 (pantnc@gmail.com), Devsamridhi Arora1, Aditya Naik1

1
University of Delhi, Department of Geology, Delhi, India

East Antarctic shield preserves a history of ~ 4 billion years that includes remnants of every major orogenic
event. One way of characterizing these events is by studying the metamorphic evolution of the limited coastal
outcrops and nunataks.
Larsemann Hills and Brattstand bluff are present along the coast of Princess Elizabeth Land (PEL) and form a
fragment of the extensive granulitic East Antarctic shield. It was considered to be a Grenvillian tectonic belt
until recent geochronological data which proves it to be a significant Pan African belt. The time frame between
1000 and 500 Ma is obscure and possesses no firm age data except for few published detrital zircon ages of
750-900Ma.
Our investigations of metapelites from Larsemann hills indicate metamorphic assemblage developed at ~500
Ma as estimated from chemical geochronology of texturally constrained monazite. No Grenvillian age has been
recorded, which supports the idea of Pan African dominance in the area. Monazite ages obtained from the
pelitic granulites of Brattstrand bluff and adjacent Svenner Island are 820±56 Ma and 734±31 Ma; partially
reset at 486±21 Ma and 494±56 Ma respectively. The 700-800 Ma orogeny represents a hitherto less
recognized mountain building event in this sector. The resetting can be ascribed to the Pan-African event which
formed the Larsemann hills. This work substantiates evidence of ~800 Ma event in Brattstrand bluff and
adjacent islands.

1895
1315
United Plates of Dronning Maud Land Revealed by Connecting Geology & Geophysics

Joachim Jacobs1,2 (joachim.jacobs@uib.no), Andreas Läufer3, Antonia Ruppel3, Synnøve Elvevold2, Graeme
Eagles4, Wilfried Jokat4, Marlina A. Elburg5
1
University of Bergen, Department of Earth Science, Bergen, Norway, 2Norwegian Polar Institute, Tromsø,
Norway, 3Federal Institute for Geosciences and Natural Resources (BGR), Hannover, Germany, 4Alfred-Wegener-
Institute Helmholtz-Zentrum für Polar und Meeresforschung, Bremerhaven, Germany, 5University of
Johannesburg, Department of Geology, Johannesburg, South Africa

Integrating geophysics with geology, and specifically geochronology, reveals the complex tectonic history of
Dronning Maud Land, East Antarctica, which is a crucial element for Rodinia and Gondwana reconstructions.
We recognise three major tectonic provinces: a westernmost part with Kalahari, Africa, affinities and an
easternmost part from about 35°E with Indo-Antarctic affinities; sandwiched in between these two blocks, is an
extensive region with juvenile Neoproterozoic crust (ca. 990-900 Ma), the Tonian Oceanic Arc Super Terrane
(TOAST) that shows very limited signs of a pre-Neoproterozoic history. We have tested the spatial extent of the
TOAST by a regional moraine study that confirm the lack of older material inland, though latest
Mesoproterozoic juvenile rocks frequently do occur in the glacial drift and probably record a slightly earlier
precursor of the TOAST inland. The TOAST records 150 Ma of almost continuous tectono-metamorphic
reworking at medium- to high-grade metamorphic conditions between ca. 650 to 500 Ma. This long-lasting
overprinting history is thought to record protracted accretion of ocean island arc terranes and the final
amalgamation of East Antarctica along the major East African-Antarctic Orogen. There is no sign of significant
metamorphic overprint immediately after the formation of TOAST. Therefore, these island arcs may have
formed independent of or peripheral to Rodinia and may reveal major accretionary tectonics outboard of
Rodinia.

1896
1168
Plate Tectonics and Basin Formation at South Pole

Fausto Ferraccioli1 (ffe@bas.ac.uk), Tom Jordan2, Rene Forsberg3, Arne Olesen3, Graeme Eagles4, Kenichi
Matsuoka5, Tania Casal6
1
British Antarctic Survey/NERC, Geology and Geophysics, Cambridge, United Kingdom, 2British Antarctic
Survey/NERC, Cambridge, United Kingdom, 3DTU Space - National Space Institute, Lyngby, Denmark, 4Alfred
Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 5Norwegian Polar
Institute, Tromsø, Norway, 6European Space Agency/ESTEC, Noordwijk, Netherlands

The tectonic boundary between East and West Antarctica is one of the most fundamental features of the
continent but is particularly poorly understood between the Weddell Sea Rift and South Pole.
During the 2015-2016 Antarctic campaign we flew an extensive aerogeophysical survey, collecting 30,000 line
km of radio echo sounding, airborne gravity and aeromagnetic data over the region. Linear gravity lows within
the Pensacola-Pole Basin reveal a system of interconnected and glacially overdeepened grabens flanked by
horst blocks. The grabens likely originated within the Jurassic Transantarctic rift system, and may have been
reactivated in response to Cretaceous-Cenozoic far-field stresses, which also affected the East and West
Antarctic rift systems respectively.
The magnetic data reveal a composite Precambrian crustal block northeast of the Pensacola Pole Basin. We call
it the Recovery Block, and suggest that it may form the “missing link” between the subduction-related Ross
Orogen and a Pan-African age collisional and transpressional suture zone identified in the Shackleton Range.
Overall, we interpret our new gravity and magnetic data compilations to reveal a wider and more distributed
Mesozoic plate boundary zone between East and West Antarctica, which included several smaller microplates.
We propose that this was a strike-slip dominated distributed plate boundary, which kinematically linked the
eastern margin of the Weddell Sea Rift System with the Pensacola-Pole Basin.

1897
2233
Crustal Terranes in the Gondawanan Lützow-Holm Complex of East Antarctica

Daniel J. Dunkley1,2,3 (kwaidanother@gmail.com), Kazuyuki Shiraishi2, Yoichi Motoyoshi2, Yoshikuni Hiroi2,4,

Tomoharu Miyamoto5, Tomokazu Hokada2, Monika A. Kuisak3
1
University of Silesia, Faculty of Earth Sciences, Sosnowiec, Poland, 2National Institute for Polar Research,
Tachikawa, Japan, 3Institute of Geological Sciences, Polish Academy of Sciences, Warsaw, Poland, 4Chiba
University, Department of Applied Geology, Chiba, Japan, 5Kyushu University, Department of Earth and
Planetary Sciences, Fukuoka, Japan

The Lützow-Holm Complex (LHC) of east Antarctica was assembled during and metamorphosed at high-T during
the formation of Gondwana. The intense nature of orogenesis obscures geological relationships, especially in
Lützow-Holm Bay, where recumbent folding was extensively reworked by ductile shearing. Ion microprobe
dating and Hf isotopic analysis of zircon in gneisses across the LHC provides a window into pre-orogenic
geological history, revealing a juvenile late Archean igneous basement in the south of the bay that was
marginally affected by ca. 2.1-1.8Ga magmatism. The remainder of the LHC is composed of juvenile late-
Mesoproterozoic igneous crust with minor volcanism at ca. 630Ma. The boundary between these domains is
completely transposed by Gondawanan orogensis; however, geological independence is suggested from
detrital zircon in metasediments deposited on either domain, which have no common provenance. We suggest
that these domains represent different geological terranes, herein named the Skallen and Ongul Terranes for
the older and younger basements, respectively. A high-T metamorphic history is shared by the terranes, from
ca. 610Ma to ca. 510Ma, an extended period of orogensis typical of long-lived high-T orogens that assemble
large continental blocks. Evidence of earlier orogenesis is lacking except in a couple of localities on the Prince
Olav Coast, where ca. 1020Ma arc magmatic rocks and metasediments were metamorphosed at high T around
960Ma.

1898
2521
A New Thermochronometric Evaluation of Central Transantarctic Mountain Formation

Stuart N. Thomson1 (thomson@email.arizona.edu), Peter W. Reiners1, Kathy J. Licht2, Sidney R. Hemming3,

Christine M. Kassab2
1
University of Arizona, Department of Geosciences, Tucson, United States, 2Indiana University Purdue University
Indianapolis, Department of Earth Sciences, Indianapolis, United States, 3Lamont-Doherty Earth Observatory
Columbia University, Earth and Environmental Sciences, Palisades, United States

The Transantarctic Mountains (TAM) form one the longest mountain belts on Earth, but are unusual as they
have been dominated by extension tectonics related to development of the West Antarctic Rift System since
~100 Ma. A lack of a post-Jurassic onshore stratigraphic record means that TAM uplift and erosion history has
been informed largely indirectly by thermal histories recorded by apatite fission track (AFT)
thermochronometry. Traditionally these results are interpreted as recording erosion related to episodic rift
flank faulting and uplift in the Early and Late Cretaceous, and Paleogene. However, more recent studies have
proposed alternative explanations for TAM formation, including a vast Mesozoic sedimentary basin that buried
the TAM until Paleogene rift-related inversion; Cretaceous extensional collapse of a high elevation “Altiplano-
like” plateau; and that central TAM peak elevations increased by ~50% owing to isostatic rebound in response
to post-Eocene glacial incision. To help resolve this debate, we present new results from multiple
thermochronometers (apatite and zircon FT and (U-Th)/He dating) in the central TAM. Thermal histories that
best predict our initial results favor slow cooling through the Mesozoic, a period of elevated heat flow coeval
with onset of rifting at ~100 Ma, and onset of glacial incision-related accelerated cooling at ~34 Ma. Our initial
data also rule out episodic cooling episodes, and long-term burial beneath a Mesozoic sedimentary basin.

1899
1955
Zircons from the Granite Harbour Intrusives, Northern Victoria Land, Antarctica

Martina Menneken1 (martina.menneken@fu-berlin.de), Timm John1, Andreas Läufer2, Jörg Giese1

1
Freie Universitaet Berlin, Earth Sciences, Berlin, Germany, 2Bundesanstalt für Geowissenschaften und Rohstoffe
(BGR), Hannover, Germany

The Wilson Terrane in northern Victoria Land appears to be the leading edge of the East Antarctic craton and
was intruded by the calcalkaline magmatic arc of the Early Paleozoic Ross Orogen, i.e. the Cambro-Ordovician
Granite Harbour Intrusives (GHI). Previous data suggested that subduction processes started at least at ca. 550-
530 Ma, but may have started much earlier at 580-560 Ma based on arc-derived detrital zircon ages (1). In this
study, zircons and their host rocks from the GHI have been investigated with respect to regional evolution of
continental crust as well as the reliability of zircon as a recorder of crustal formation.
We present a combination of U-Pb, δ18O, trace element and inclusion data of zircons from these granitoids, as
well as geochemical analyses of accessory apatite. With careful evaluation of zircon-U-Pb-age data and related
isotopic, chemical, and mineralogical features, our study shows that even I-type granitoids do not have a simple
formation history. Instead our results present a history of early (from about 580 Ma onwards) magmatic- and
fluid alteration events, in contrast to simple inheritance. Our data thus supports that magmatic arc evolution in
the Wilson Terrane was related to Andean-style, long-lived, migrating accretionary processes at the East
Gondwana active continental margin.
1 Goodge, J.W., 2007, Geological Society of America, Special Paper 419, 2007 p. 185-203

1900
BE-5b - Productivity, Biodiversity & Ecosystem Shifts at Cryosphere-Ocean Boundaries
22.06.2018 14:00-15:30, A Seehorn

1682
Drivers of Phytoplankton Biomass and Composition in a Changing Arctic Fjord

Willem Hendrik van de Poll1 (w.h.van.de.poll@rug.nl), Gemma Kulk1, Corina P.D. Brussaard2, Anita G. J. Buma1
1
University of Groningen, Ocean Ecosystems, Energy and Sustainability Research Institute Groningen,
Groningen, Netherlands, 2Royal Netherlands Institute for Sea Research, Department of Marine Microbiology
and Biogeochemistry, Den Burg, Netherlands

Kongsfjorden on the west coast of Spitsbergen has undergone significant changes over the last decades.
Warmer Atlantic advection has decreased wintertime sea ice formation and increased melting of marine
terminating glaciers. This raises the question how this affects phytoplankton productivity and composition.
Drivers of phytoplankton productivity and composition in central and inner Kongsfjorden were assessed using
four years of pigment monitoring (2014-2017) and detailed observations during spring (2014) and summer
(2015). Increasing irradiance correlated to chl-a of all taxonomic groups from February to mid-April that
increased from the low values observed during the polar night. Stratification was initiated during April and
May, coinciding with a diatom dominated surface bloom in inner Kongsfjorden. This suggested that spring
blooms are initiated further into the fjord due to reduced sea ice cover. Surface depletion of winter nutrients
characterized the post bloom period from June to October, where flagellates of diverse taxonomic groups
dominated. Nutrient addition experiments showed that nitrate rapidly simulated biomass growth, but did not
change phytoplankton composition. Furthermore, variability in biomass correlated to episodic wind mediated
nutrient upwelling near the glaciers. Overall, our research suggest that the recent changes in Kongsfjorden
cause spatial changes in phytoplankton biomass and composition, whereas temporal changes are less clear.

1901
683
Arctic Sensitivity? Shifting Distributions due to Changing Environmental Drivers

Paul Renaud1 (pr@akvaplan.niva.no), Philip Wallhead2, Jonne Kotta3, Maria Wlodarska-Kowalczuk4, Richard
Bellerby5, Dag Slagstad6, Piotr Kuklinski4
1
Akvaplan-niva, Tromsø, Norway, 2Norwegian Institute for Water Research, Bergen, Norway, 3University of
Tartu, Estonian Marine Institute, Tartu, Estonia, 4Institute of Oceanology, Polish Academy of Sciences, Sopot,
Poland, 5East China Normal University, State Key Laboratory for Estuarine and Coastal Research, Shanghai,
China, 6SINTEF, Trondheim, Norway

Arctic marine ecosystems are commonly assumed to be highly sensitive, and their structure and function are
predicted to suffer significantly from ongoing climate change. Community shifts are likely to result from
changes in key physico-chemical drivers, such as increased temperature and CO2, but there is little
autecological data on most Arctic species to support any specific predictions as to how sensitive they are, or
how future communities may be structured. Lacking such empirical data, we extracted collection records for 90
Arctic and boreal taxa from the Barents Sea region from the OBIS database. A coupled climate-ocean model
(SINMOD) was used to both hindcast and project temperature and carbonate saturation states (omega) for
sample locations. These data provided ´realized niche´ distributions in three dimensions (depth, temperature,
omega) for each benthic taxon, and this niche space was compared with projected values for these variables in
the region for 2090-2099. Preliminary results indicate that, contrary to many predictions, calcifying taxa are no
more sensitive to changing environmental conditions than non-calcifiers. In addition, Arctic taxa were similarly
no more susceptible to predicted changes than boreal taxa. These results highlight the weakness of general
statements regarding sensitivity of taxa on biogeographic or physiological grounds, and suggest that more basic
biological data on Arctic taxa are needed for improved projections of climate impacts.

1902
748
Zooplankton in Changing Arctic Seas: Examples from West Greenland Ecosystems

Eva Friis Møller1 (efm@bios.au.dk), Mikael Sejr2, Anders Mosbech1, Torkel Gissel Nielsen3
1
Aarhus University, Roskilde, Denmark, 2Aarhus University, Aarhus, Denmark, 3Technical University of Denmark,
Lyngby, Denmark

With reduced sea ice cover, increased melt water discharge and pelagic primary production the transfer to
higher trophic levels through zooplankton will change; e.g. species composition, phenology and productivity of
the zooplankton community may be altered. In this presentation, we use dataset from coastal waters of west
Greenland to discuss the impact of melting ice (glacial and sea ice) and primary productivity on the zooplankton
community. Data from Disko Bay (69.23°N, 52.52°W) sampled with high temporal resolution during spring
blooms in the period 1996 to 2012 are used to evaluate phenology and species changes within the dominant
zooplankton genus Calanus on a decadal scale. Further north along the Greenland west coast the arctic species
Calanus hyperboreus dominate, and we use distribution data (from 71- 76°N) to discuss how difference in ice
cover/glacial impact influence their productivity and phenology, and how this may impact higher trophic levels
exemplified by the dominant avian predator Little Auk (Alle alle).

1903
1079
Zooplankton Productivity in Arctic Estuarine Habitats under a Changing Climate

Alexei Pinchuk1 (aipinchuk@alaska.edu), Leandra Sousa2, Johanna Vollenweider3

1
University of Alaska - Fairbanks, College of Fisheries and Ocean Sciences, Juneau, United States, 2North Slope
Borough, Wildlife Management, Barrow, United States, 3NOAA, Fisheries, Juneau, United States

The low-lying North American Arctic coast is characterized by numerous lagoons that are utilized by marine
mammals, waterfowl, and seabirds, and many of which have been providing important subsistence resources
for local peoples for centuries. Arctic lagoons are poorly described because of their remoteness and difficultly
to access by survey vessels. Food webs in the Arctic lagoons are thought to be dominated by benthic
detritivores dependent on microbial processing of terrestrial carbon. Recent findings of dense aggregations of
lipid-rich, fast-growing omnivory copepods in the brackish water estuarine habitats suggest high levels of
pelagic primary and secondary production in summer and, therefore, an efficient pelagic food web. We
synthesized data on composition and distribution of zooplankton, fish diets and physical processes that may
influence estuarine communities in the coastal Chukchi and Beaufort seas to address the following
fundamental question: how may changing climate conditions structure and influence trophic diversity in Arctic
lagoons during ice-free summer time.

1904
1082
Is the Shallow Kitikmeot a Marine Zoogeographic Barrier in the Canadian Arctic?

Gérald Darnis1 (gerald.darnis@qo.ulaval.ca), Caroline Bouchard2, Maxime Geoffroy3, Catherine Lalande1, Cindy
Grant1, Philippe Archambault1, Mathieu Leblanc1, Louis Fortier1
1
Université Laval, Quebec City, Canada, 2Greenland Climate Research Center, Greenland Institute of Natural
Resources, Nuuk, Greenland, 3Fisheries and Marine Institute of Memorial University of Newfoundland, St.
John's, Canada

Lack of information on large-scale spatial patterns of zooplankton, fish and benthos distribution limits our
knowledge of ecological connectivity within the Canadian Arctic marine ecosystem and, thus, the ability to
develop predictions about the ecosystem response to the multiple effects of Arctic warming and increased
human activity. We used data collected from 2005-2017 as part of the ArcticNet annual expeditions across the
Canadian Arctic Archipelago and the Kitikmeot Marine Ecosystems Study to map the distribution of Arctic cod
(Boreogadus saida), zooplankton and benthos from the Beaufort Sea in the west to the mouth of Lancaster
Sound in the east. Arctic cod larvae and adults were rare, and the large copepods Calanus hyperboreus, C.
glacialis and Metridia longa much less abundant in all years in the shallow (< 100 m) south Kitikmeot,
compared to deeper areas to the west and east where these organisms usually dominate in terms of biomass.
By contrast, benthos biomass and diversity were relatively high compared with surrounding areas. Low biomass
of Calanus species can partly explain the limited populations of vertebrate predators such as the Arctic cod,
seabirds and the bowhead whale in the south Kitikmeot. The combination of shallow depths, slow water
circulation and late sea-ice breakup suggests that this region acts as a significant barrier reducing West-East
exchange among populations of pelagic fish like the Arctic cod and of key oceanic zooplankton.

1905
1912
Phytoplankton Production in Arctic and Sub-Arctic Oceans: The Role of Diatoms

Diana E. Varela1 (dvarela@uvic.ca), David W. Crawford2, Karina E. Giesbrecht3, Jennifer E. Long2, Ian A.
Wrohan3, Adrian O. Cefarelli4, Shea N. Wyatt2, Lucianne M. Marshall2
1
University of Victoria, Department of Biology, and School of Earth and Ocean Sciences, Victoria, Canada,
2
University of Victoria, Department of Biology, Victoria, Canada, 3University of Victoria, School of Earth and
Ocean Sciences, Victoria, Canada, 4Universidad Nacional de La Plata, División Ficología, Facultad de Ciencias
Naturales y Museo, La Plata, Argentina

This presentation will address spatial and temporal patterns in phytoplankton production and nutrient
concentrations in the Arctic and sub-Arctic marine waters surrounding North America. Results from the
International Polar Year Canada-3-Oceans project and other programs (e.g. GEOTRACES, Distributed Biological
Observatory) conducted during the last decade show that phytoplankton production in marine Arctic and sub-
Arctic waters is highly variable from region to region, with hotspots of activity in the Chukchi Sea, the Canadian
Arctic Archipelago and Baffin Bay. These high production sectors markedly contrast with the oligotrophic
waters of the Canada Basin. We will zoom into those Arctic hotspots and describe the role of diatoms in total
phytoplankton production, nutrient cycling and particle dynamics in the pan-Canadian Arctic from the NE
Pacific to the NW Atlantic Oceans. We will present results from experimental manipulations in the eastern and
western Arctic using the radioisotope 32Si and a novel fluorescent probe (PDMPO) as tracers of whole-
assemblage and genus-specific diatom production. Despite the dominance of diatoms in several Arctic regions,
the rates of silicon, nitrogen and carbon production were several times higher in the western Arctic (Chukchi
Sea) than in the eastern production hotspots. These studies provided benchmark data against which future
estimates can be compared to better predict the effects of climate change on high-latitude marine ecosystems.

1906
CR-8c - Latest highlights from high altitude and polar ice cores
22.06.2018 14:00-15:30, A Wisshorn

886
Ice Cores Deformation Tests and Borehole Data Inform on Flow Properties

Dorthe Dahl-Jensen1 (ddj@nbi.ku.dk)

1
University of Copenhagen, Niels Bohr Institute, Copenhagen, Denmark

Deformation tests on ice from the Greenland ice cores GRIP, GISP, NGRIP and NEEM reveal that ice from the
glacial and interglacial have very different flow properties. By combining with repeated measurements of the
deformation of the deep boreholes in Greenland the different flow properties of ice is discussed.
The discussion is broadened out to discuss the basal processes of the deep ice and conditions for oldest ice in
Greenland and Antarctica to be stratigraphic and not folded and disturbed.

1907
709
An Andean Ice-core Based Holocene Biomass Burning Record of the Amazon Basin

Dimitri Osmont1,2,3 (dimitri.osmont@psi.ch), Michael Sigl1,3, Margit Schwikowski1,2,3

1
Paul Scherrer Institute, Laboratory of Environmental Chemistry, Villigen PSI, Switzerland, 2University of Bern,
Department of Chemistry and Biochemistry, Bern, Switzerland, 3Oeschger Centre for Climate Change Research,
University of Bern, Bern, Switzerland

The Amazon Basin is known to be one of the most important worldwide contributors to biomass burning
emissions. However, past fire activity is still poorly known due to the complex linkages between fires, climate
and humans. Biomass burning proxies such as black carbon (BC) measured in ice cores can improve our
understanding and bring new constraints on models. BC consists of aggregates of carbonaceous spherules
produced by the incomplete combustion of fossil fuels and biomass from both anthropogenic and natural
origin. Here, we present the first Andean BC ice-core record, derived from Illimani glacier, Bolivia, which spans
the entire Holocene back to the last deglaciation 13 000 years ago. A strong seasonality, with BC peaking in the
dry season, can be observed due to the combined effects of biomass burning emissions from the Amazon
Basin, transport and deposition. Slightly increasing BC concentrations are visible in the 20th century, potentially
reflecting an anthropogenic contribution. Long-term BC variations follow regional climatic trends along the
Holocene, with higher concentrations during dry/warm periods such as the mid-Holocene (8500-5500 BP) or
the Medieval Warm Period and lower values during cold/wet periods like the last deglaciation or the Little Ice
Age. Except for the 20th century, a similar temporal variability was observed in a BC record from two Antarctic
ice cores, for which South America is assumed to be the dominant source area.

1908
402
Ice-core Evidence of Earliest Copper Metallurgy in the Andes 2700 Years Ago

Anja Eichler1,2 (anja.eichler@psi.ch), Gabriela Gramlich1,2,3, Thomas Kellerhals1,2, Leonhard Tobler1,2, Thilo
Rehren4,5, Margit Schwikowski1,2,3
1
Paul Scherrer Institute, Laboratory of Environmental Chemistry, Villigen, Switzerland, 2Oeschger Centre for
Climate Change Research, University of Bern, Bern, Switzerland, 3University of Bern, Department for Chemistry
and Biochemistry, Bern, Switzerland, 4University College London, Institute of Archaeology, London, United
Kingdom, 5HBKU Doha, College for Humanities and Social Sciences, Doha, Qatar

The importance of metallurgy for social and economic development is indisputable. Advances in agriculture,
warfare, transport, cookery, and the entire Industrial Revolution are impossible without metal. Historically,
Andean copper (Cu) in particular was an essential resource of wealth for pre- and post-colonial societies and
still plays a central economic role in many South American countries today. Despite of this importance the
onset of extensive Cu metallurgy in South America is still debated.
Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from
Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South
America. We find earliest anthropogenic Cu pollution exceeding the natural background range during the Early
Horizon period ~700-50 BC. This work highlights the importance of considering changes in the natural
background of heavy metal deposition to deduce earliest stages of prehistoric extractive metallurgy from
natural archives. Our results imply that the onset of intensified Cu smelting in South America occurred during
the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time
substantial evidence for extensive Cu metallurgy already during these early cultures. In our work we further
provide archeological artefacts to document changing Cu metallurgy in South America during the past 2700
years.

1909
1297
Heterogeneous Reduction of Glaciers in the High Mountains of Asia during HCO

Shugui Hou1 (shugui@nju.edu.cn), Chaomin Wang1, Wangbin Zhang1, Margit Schwikowski2, Yetang Wang3,
Shuangye Wu4, Chiara Uglietti2, Theo Manuel Jenk2, Koji Fujita5, Hongxi Pang1, Hao Xu1
1
Nanjing University, School of Geographic & Oceanographic Sciences, Nanjing, China, 2Paul Scherrer Institute,
Laboratory of Environmental Chemistry, Villigen PSI, Switzerland, 3Shandong Normal University, College of
Geography and Environment, Jinan, China, 4University of Dayton, Department of Geology, Dayton, United
States, 5Nagoya University, Graduate School of Environmental Studies, Nagoya, Japan

Glaciers in the high mountains of Asia (HMA)—encompassing the Himalayas, Karakoram, Kunlun Shan, Tian
Shan and Qilian Shan mountains — form the headwaters of major river systems that provide fresh water for
over 1.4 billion people in Asia. Their future changes and consequent impact on water resources are hindered
mainly due to a paucity of past glacier variation data. Here we provide 14C age of bottom ice of eight glaciers in
the HMA, and estimate that, during the Holocene climate optimum (HCO), glaciers in the Qilian Shan
Mountains almost disappeared completely, while lost over 80% of its present glacier area in the Himalayas, and
over 40% in the central Tibetan Plateau and in the Tian Shan Mountains. Remarkably, glaciers in the west
Kunlun Mountains showed a negligible reduction during the HO, implying that the recent “Karakoram anomaly”
identified by remote sensing data may persist on millennial time scale. Thus we suggest that most part of the
present glaciers in the HMA excluding the west Kunlun and Karakoram regions might develop since the
Neoglaciation. Our results suggest that the modern spatial variations of glacier in the HMA are an enduring
feature on millennial time scale, thus providing a wide application for the water resource management and
adaption in the HMA.

1910
237
Investigating the Microscopic Location of Trace Elements in Glacier Ice

Sven Erik Avak1,2,3 (sven.avak@psi.ch), Marcel Guillong4, Oscar Laurent4, Thorsten Bartels-Rausch1, Margit
Schwikowski1,2,3, Anja Eichler1,3
1
Paul Scherrer Institute, Laboratory of Enivronmental Chemistry, Villigen PSI, Switzerland, 2University of Bern,
Department of Chemistry and Biochemistry, Bern, Switzerland, 3University of Bern, Oeschger Centre for Climate
Change Research, Bern, Switzerland, 4ETH Zurich, Institute of Geochemistry and Petrology, Zurich, Switzerland

Past atmospheric pollution can be reconstructed from high-alpine ice core trace element records. Due to the
current global temperature increase glaciers at high altitudes are in danger to melt, strongly altering the
information originally stored in these archives. The preservation of impurities with respect to meltwater
percolation depends on their microscopic location in firn and ice, i.e. segregation to grain surfaces versus
incorporation into the lattice. Here, we present for the first time a comprehensive study on the microscopic
location of trace elements in glacier ice using two different approaches.
Firstly, we indirectly assessed the location of trace elements by analyzing their concentration records in an ice
core from the Swiss Alps affected by an inflow of meltwater using ICP-MS. Our results suggest that atmospheric
concentration levels of the investigated trace elements are a major driving force explaining their microscopic
location in ice. Abundant pollutants such as Ca, Mg, Mn, Na and Zn are mostly segregated to grain boundaries,
prone to meltwater relocation. Rare elements including Ag, Bi, Cs, Sb and W are rather incorporated into the
ice lattice, indicated by a strong preservation of these species. Secondly, we directly analyzed the microscopic
location of trace elements in ice using cryocell laser ablation ICP-MS. This study aims to evaluate the potential
of trace elements as environmental proxies in glaciers partially affected by melting.

1911
516
A Revised Chronology of the Dome Fuji Ice Core from O2/N2 of Trapped Air

Ikumi Oyabu1 (oyabu.ikumi@nipr.ac.jp), Kenji Kawamura1,2,3, Kyotaro Kitamura1

1
National Institute of Polar Research, Tokyo, Japan, 2SOKENDAI (The Graduate University of Advanced Studies),
Tokyo, Japan, 3Japan Agency for Marine Science and Technology, Tokyo, Japan

Accurate ice core chronology is essential to examine the sequences, durations and phasing of climatic records.
A chronology for the Dome Fuji (DF) ice core (DFO-2006, for 340 kyr BP) was constructed by synchronizing
variations in O2/N2 of occluded air with local summer insolation, with stated 2σ error of about 2 kyr (Kawamura
et al., 2007). However, it was found that DFO-2006 at ~100 kyr BP and ~129 kyr BP (end of Termination II) are
older by ~3 kyr and ~2 kyr, respectively, than U-Th radiometric dating of Chinese speleothems with stated 2σ
error of < 1 kyr (Cheng et al., 2009; Fujita et al., 2015). Poor quality of the O2/N2 data due to diffusive gas loss
during core storage in “warm” freezer (-25 °C) may be responsible for the discrepancies. Here, we re-analyzed
O2/N2 to improve the DF chronology for 80 - 165 kyr BP, using the samples stored at -50 °C. After careful tests,
we found that ~1-cm-thick surface layer must be removed to eliminate the effect of gas loss for ~20 years. With
our new O2/N2 data, the DF chronology was revised with the matching technique of Kawamura et al. (2007).
The new DF chronology agrees with the speleothem chronology within 1.2 kyr. In particular, the DF age at the
end of Termination II agrees with the speleothem chronology and the AICC2012 ice core chronology within ~1
kyr. The results suggest that O2/N2 in the DF core faithfully records local summer insolation, and that the
revised chronology greatly improved from DFO-2006.

1912
OS-4c - Sea ice modeling and prediction: Sea ice prediction
22.06.2018 14:00-15:30, B Jakobshorn

173
700 Predictions: Update on the SEARCH Sea Ice Outlook from 2008 to 2017

Lawrence Hamilton1 (lawrence.hamilton@unh.edu), Julienne Stroeve2

1
University of New Hampshire, Sociology Department, Durham, United States, 2National Snow and Ice Data
Center, Boulder, United States

Each Arctic summer since 2008, the Sea Ice Outlook (SIO) has invited researchers and the engaged public to
contribute predictions regarding the September extent of Arctic sea ice. The public character of SIO, focused on
a number whose true value soon becomes known, brings elements of constructive gamification and
transparency to the science process. Updating earlier analyses, we look back on the performance of almost 700
predictions made over a full decade of SIO activity. In 2017, statistically-based methods outperformed coupled
ice-ocean-atmosphere modeling, but in past years that was not always the case. Past retrospectives noted a
pattern of easy and difficult years, corresponding roughly to dominance by climate or weather. Difficult years,
in which most predictions are far from the observed extent, tend to be those exhibiting large positive or
negative excursions from the overall downward trends. 2017 was a difficult year, with September ice extent
more than half a million square kilometers above its quadratic trend. The observed extent fell outside the
interquartile range of SIO predictions as a whole, although well within the IQR of statistical predictions made in
July and August. Close prediction remains elusive, but the median of SIO predictions demonstrably outperforms
naive methods including linear and quadratic trends, or persistence. Prediction has been difficult because
summer weather strongly affects September ice extent, in this transitional Arctic era.

1913
1554
Regional Arctic Sea-ice Prediction: Potential versus Operational Forecast Skill

Mitch Bushuk1 (mitchell.bushuk@noaa.gov), Rym Msadek2, Michael Winton1, Gabriel Vecchi3, Tony Rosati1,
Xiaosong Yang1, Rich Gudgel1
1
Geophysical Fluid Dynamics Laboratory, Princeton, United States, 2CNRS / Cerfacs, Toulouse, France, 3Princeton
University, Princeton, United States

Seasonal predictions of Arctic sea ice on regional spatial scales are a pressing need for a broad group of
stakeholders, however, most forecast skill assessments to date have focused on pan-Arctic sea-ice extent (SIE).
In this work, we present a direct comparison of potential and operational seasonal prediction skill for regional
Arctic SIE. This assessment is based on two complementary suites of seasonal prediction ensemble experiments
performed with a global coupled climate model. First, we assess the operational prediction skill for detrended
regional SIE using a suite of retrospective initialized seasonal forecasts spanning 1981-2017. These
retrospective forecasts are found to skillfully predict regional winter SIE at lead times of 3-11 months and
regional summer SIE at lead times of 1-4 months, owing partially to subsurface ocean temperature and sea-ice
thickness initial conditions, respectively. Second, we present a suite of perfect model predictability
experiments with start dates spanning the calendar year, which are used to quantity the potential regional
prediction skill of this system. These perfect model experiments reveal that regional Arctic SIE is potentially
predictable at lead times beyond 12 months in many regions, substantially longer than the current operational
skill of this system. The skill gap identified in this work indicates a promising potential for future improvements
in regional SIE predictions.

1914
1607
Subseasonal Forecast of Arctic Sea Ice Concentration via Statistical Approaches

Lei Wang1, Xiaojun Yuan1 (xyuan@ldeo.columbia.edu), Cuihua Li1

1
Columbia University, Lamont-Doherty Earth Observatory, Palisades, United States

Subseasonal forecast of Arctic sea ice has received less attention than the seasonal counterpart, as prediction
skill of dynamical models generally exhibits a significant drop in the extended range (>two weeks). The
predictability of pan-Arctic sea ice concentration is evaluated by statistical models using weekly time series for
the first time. Two statistical models, the Vector Autoregressive model and Linear Markov model, are evaluated
for predicting the 1979-2014 weekly Arctic sea ice concentration (SIC) anomalies at the subseasonal time scale,
using combined information from the sea ice, atmosphere and ocean. The Vector Autoregressive model is
slightly inferior to the Markov model for the subseasonal forecast of Arctic SIC. The cross-validated forecast
skill of the Markov model is found to be superior to both the anomaly persistence and damped anomaly
persistence at the lead time > 3 weeks. Surface air and ocean temperatures can be included to further improve
the forecast skill for lead time > 4 weeks. The long-term trends in SIC due to global warming and its polar
amplification contribute significantly to the subseasonal sea ice predictability in summer and fall. Both
statistical models also exhibit much better skill than the NOAA operational dynamical model in most cases
except for the 1-week lead in summer.

1915
2350
Predictive Skills Evaluation of Subseasonal to Seasonal Arctic Sea Ice Forecasts

Lorenzo Zampieri1 (lorenzo.zampieri@awi.de), Helge Goessling1, Thomas Jung1,2

1
Alfred Wegener Institute - Helmholtz Center for Polar and Marine Research, Climate Dynamics Section,
Bremerhaven, Germany, 2University of Bremen, Institute of Environmental Physics, Bremen, Germany

Seasonal sea ice forecasts are becoming a demanding need since human activities in the Arctic are increasing.
This study evaluates the predictive skills of the forecast systems contributing to the Subseasonal to Seasonal
Prediction Project, focusing on the sea ice edge position. As verification metric, we employ the Spatial
Probability Score and its decompositions. This is designed to quantify the correctness of the forecasted sea ice
spatial distribution when compared to the observations. Moreover, the SPS allows a probabilistic description of
both forecasted and observed sea ice.
Our findings reveal that some of the forecast systems are promising, exhibiting better predictive skills than the
observation-based climatology and persistence of the initial condition. The results also point to critical biases
concerning the data assimilation procedure and the tuning for some of the models. Comparing different
versions of the ECMWF forecast system, we show the improvements brougth by the employment of a fully
coupled sea ice model instead of an approach based on the sea ice prescription. Given the increasing
availability of new and better sea ice observations and the potential future development of the forecast
systems, the formulation of reliable Arctic sea ice predictions at the considered time scales appears to be a
realistic target for the scientific community.

1916
1706
Evaluating Roughness as a New Source of Arctic Summer Sea Ice Predictability

Jack Landy1 (jack.landy@bristol.ac.uk), Michel Tsamados2,3, Julienne Stroeve2,3, Jens Ehn4, David Barber4, Randy
Scharien5
1
University of Bristol, School of Geographical Sciences, Bristol, United Kingdom, 2Centre for Polar Observation
and Modelling, London, United Kingdom, 3University College London, Earth Sciences, London, United Kingdom,
4
University of Manitoba, Centre for Earth Observation Science, Winnipeg, Canada, 5University of Victoria,
Department of Geography, Victoria, Canada

Although melt ponds on Arctic sea ice evolve in stages, ice with smoother surface topography typically allows
the pond water to spread over a wider area, reducing the ice-albedo and accelerating further melt. We have
quantified this relationship between premelt surface roughness and summer sea ice albedo using simulations
of meltwater distributed on statistical topographies. Our method, applied to ICESat observations of the winter
sea ice roughness, could account for 85% of the variance in summer ice albedo observed by AVHRR during the
2000s [Landy et al., Albedo feedback enhanced by smoother Arctic sea ice, GRL 2015]. Thus, winter sea ice
roughness offers an exciting route for potentially bridging the reported May-June barrier in summer sea ice
predictability.
Here we present ongoing efforts through the ScIMiTaR project (forecasting summer Sea Ice MelT from winter
ice Roughness) to develop a new multi-decade sea ice surface roughness product from various data sources,
including ICESat, Cryosat-2 and MISR. To improve the resolution of roughness measurements to ~1 km, we are
developing a facet-based radar scattering model to simulate Cryosat-2 return echoes from LiDAR scans of sea
ice topography. Finally, we will discuss plans to initialise the Los Alamos sea ice model: CICE with winter surface
roughness data, benefiting from the added predictability offered to forecast summer sea ice conditions (ice
melt rate, breakup timing) from the roughness data at a lead time >6 months.

1917
2155
Monthly Antarctic Sea Ice Forecast

Sandra Barreira1 (barreira.sandra@gmail.com), Federico Orquera1

1
Naval Hydrographic Service, Meteorology, Buenos Aires, Argentina

Since 2001, we have been forecasting the climatic fields of the Antarctic sea ice (SI) at the Argentine Naval
Hydrographic Service with different techniques that have evolved with the years. Forecast is based on the
results of Principal Components Analysis applied to SI series (S-Mode) that gives patterns of temporal series
with validity areas and, to SI fields (T-Mode) that give us the form of the SI fields anomalies based on a
classification of 16 patterns. Each T-Mode pattern has unique atmospheric fields associated to it. Therefore, it
is possible to forecast whichever atmosphere variable we decide for the Southern Hemisphere. The forecast
gives the probability of occurrence of the different patterns. Only those with higher value are used to compose
the fields to obtain the final result. S-Mode and T-Mode are monthly updated with new data. We used Monthly
Polar Gridded Sea Ice Concentrations database derived from satellite information generated by NASA Team
algorithm provided monthly by the National Snow and Ice Data Center. Data begins in November 1978. During
2016 we introduced multilayer Perceptron (neuronal network) with supervised learning and a back-
propagation algorithm to improve the forecast. It was implemented through the use of surface air temperature
and pressure anomalies fields that were associated with the different sea ice anomaly patterns to simplify the
density of input data and avoid a non-converging solution.

1918
AC-2e - Polar meteorology, climatology and stratospheric processes
22.06.2018 14:00-15:30, C Sanada I

1140
The Antarctic Record Maximum Temperature: 19.8°C, Signy Island, 30 January 1982

John King1 (jcki@bas.ac.uk), Daniel Bannister1, Scott Hosking1, Steve Colwell1

1
British Antarctic Survey, Cambridge, United Kingdom

Signy Island (60.7S, 45.6W) is one of the smaller islands in the South Orkney Islands group. The island is low-
lying, but is situated just a few km south of the much larger Coronation Island, which rises to over 1200 m
elevation. A UK research station was established on Signy Island in 1947 and operated a basic climatological
observing programme from 1947 to 1996. On 30 January 1982, a daily maximum temperature of +19.8°C,
recently recognised by the World Meteorological Organisation as a record for the Antarctic region, was
reported by the station.
Examination of global atmospheric reanalysis fields shows that the record temperature was associated with
southward advection of an exceptionally warm air mass from the subtropical South Atlantic. However, during
the southward passage of this air mass over the cold Southern Ocean, there was rapid cooling of the lowest
kilometre of the atmosphere, leading to near-surface temperatures that were not exceptional for this region.
At the time of the observed record temperature, the wind at 1 km had a strong northerly component and was
thus blowing across the high topography of Coronation Island towards Signy Island. Using a high-resolution (1
km horizontal grid spacing) simulation made with the WRF model, we demonstrate that the flow across
Coronation Island generated a föhn wind that brought relatively unmodified warm air down towards the
surface over Signy Island, giving rise to the observed record high temperature.

1919
1361
Ross Sea Climate Variability from MODIS Air Temperature and Climate Simulations

Marwan Katurji1 (marwan.katurji@canterbury.ac.nz), Hanna Meyer2, Pierre Roudier3, Thomas Nauss2, Peyman
Zawar-Reza1
1
University of Canterbury, Geography, Christchurch, New Zealand, 2Philipps-Universität Marburg, Geography,
Marburg, Germany, 3Landcare Research, Palmerston North, New Zealand

Regional and local atmospheric circulation patterns influence the near-surface air temperature variability of the
Ross Sea Region (RSR). Providing meteorological context to spatio-temporal patterns of air temperature allows
for a better interpretation of climate variability that impact biodiversity, ecology and hydrology. We utilize
multi-scale datasets, which are capable of resolving synoptic and mesoscale meteorological processes
controlling the near-surface air temperature variability of the RSR.
This work uses a MODIS and machine learning based daily air temperature dataset (1 and 10km resolution from
2002 to 2016) and mean sea level pressure data from regional climate simulations. Self-organizing maps are
used to reveal intra-annual patterns of the synthesized datasets that are supported by atmospheric circulation
forcing. This includes cases from the localized McMurdo Dry Valley warming episodes caused by foehn winds,
and regional scale West Antarctic and Transantarctic Mountain coastline warming episodes resulting from
cyclonic-induced northerly air streams. This research presents a unique approach of synthesizing satellite,
ground based, and numerical climate datasets to study surface climate variability at a high spatial resolution
across the entire Ross Sea region. This work is the basis to investigate inter-annual variability and sensitivity of
near-surface air temperature associated with changes of circulation patterns.

1920
1464
Evaluation of Models using Radio Sounding Observations on the Antarctic Plateau

Gerit Birnbaum1 (gerit.birnbaum@awi.de), Konstantin Krueger1, Christof Luepkes1, Michael Schaefer2, Jan
Melchior van Wessem3, Gert Koenig-Langlo1, Bernd Loose1
1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2University
of Leipzig, Leipzig, Germany, 3University of Utrecht, Utrecht, Netherlands

Three global reanalysis products, the regional climate model RACMO and the weather forecast system AMPS
were evaluated against profiles obtained from radio soundings on the Antarctic plateau. Measurements at
Kohnen Station, which represent independent in situ data, were performed in Jan 2006, Dec 2013 and Jan 2014
four times a day. JRA-55 had the most accurate temperature profiles, MERRA-2 the best relative humidity
profiles and ERA-interim the smallest errors in wind speed profiles. Biases and root mean-square errors vary
considerably with altitude in the troposphere and in the tropopause region. Surface or elevated inversions in
the lowermost 1000 m are captured quite differently. ERA-interim always shows a surface inversion with
thickness and temperature increase that hardly vary in the course of a day. The frequency of surface and
elevated inversions is better captured at 00 and 06 UTC compared to 12 and 18 UTC in JRA-55 and MERRA-2 as
well as in the two regional models, which indicates that processes in the boundary layer, which lead to an
erosion of a surface inversion are still poorly represented in the models. All reanalyses and regional models are
able to simulate a low-level jet. However, ERA-interim, RACMO and AMPS underestimate the frequency at all
four times. Similar evaluations were performed using routine radio soundings at South Pole and Dome C in
2016. Results indicate that processes in the boundary layer are also not captured well during Austral winter.

1921
1521
Impact of Anthropogenic Forcing on High Latitude Southern Hemisphere Circulation

James Pope1 (japope@bas.ac.uk), Andrew Orr1, Gareth Marshall1, Luke Abraham2

1
British Antarctic Survey, Cambridge, United Kingdom, 2NCAS Chemistry, Cambridge, United Kingdom

We examine the impact of the individual and combined effects of three anthropogenic forcings on high-latitude
Southern Hemisphere circulation through a novel suite of climate model simulations. Using the UK Met Office
Unified Model (UM) coupled to the UK Chemistry and Aerosols (UKCA) interactive climate-chemistry model, we
investigate the climatic response due to ozone depletion, and increases in both greenhouse gases and
anthropogenically-produced aerosols. A suite of experiments, comprising a 'control' and seven further
'perturbed' runs, covering all possible individual and combinations of the three different forcings. The control-
run is forced by pre-industrial concentrations of greenhouse gases, ozone depleting substances, and aerosols,
while the perturbed experiments comprise the control simulation plus fixed present-day values of one or more
of the forcings. We focus our results on the effect of the forcing(s) on the Southern Hemisphere Annular Mode
(SAM), which is the principal mode of atmospheric variability at southern high latitudes, although we also look
at changes in meridional circulation around Antarctica, which play a major role in climate variability across the
continent. Individual forcing responses in our model are consistent with previous studies. However, in contrast
to some other studies, we find that the effect of the individual forcings are not linear when compared to the
simulation combining all three forcings.

1922
2643
Ship-based Radiosonde Observations of Atmospheric Rivers over the Southern Ocean

Irina V. Gorodetskaya1 (irina.gorodetskaya@ua.pt), Franziska Aemisegger2, Annick Terpstra3,4, Iris Turnherr2,

Maria Tsukernik5, Pascal Graf2, Meredith Fish6, Heini Wernli2, F. Martin Ralph6
1
University of Aveiro, Centre for Environmental and Marine Studies, Dept of Physics, Aveiro, Portugal, 2ETH
Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland, 3University of East Anglia, Norwich,
United Kingdom, 4University of Bergen, Geophysical Institute & Bjerknes Centre for Climate Research, Bergen,
Norway, 5Brown University, Providence, United States, 6University of California San Diego, Scripps Institution of
Oceanography, La Jolla, United States

Atmospheric rivers (AR) transport large amounts of moisture from subtropics to mid- and polar latitudes. Their
important role in intense precipitation and anomalous snow accumulation has been already demonstrated for
East Antarctica (Gorodetskaya et al, 2014). Such extreme events are particularly challenging for both weather
prediction and climate models, especially in the Polar regions where measurements are very sparse. The
Antarctic Circumnavigation Expedition (ACE) provided a unique opportunity to perform continuous radio
soundings of the atmosphere onboard a ship as it circumnavigated Antarctica during December 2016 - March
2017. In this study we target several AR events observed during ACE that brought intense precipitation over the
Southern Ocean and the ice sheet coastal areas. Using vertical profiles of temperature, humidity and wind from
radiosondes we calculate moisture fluxes and locate levels of warm and moist advection, study low level jets,
identify cloud boundaries, and follow the profiles evolution along with cyclone development. The data allow
the first-ever direct observation of the vertically integrated water vapor amount and transport in an AR over
the Southern Ocean. These measurements give a unique opportunity to evaluate models, reanalysis and
satellite products. Possible mechanisms that feed the ARs with moisture as well as the large-scale forcings
favoring convergence and the strong coherent moisture advection are explored.

1923
BE-9e - Life distribution and responses to environmental changes in Polar ecosystems
22.06.2018 14:00-15:30, C Sanada II

140
Upper Slope Processes and the Distribution of Life on the Antarctic Seafloor

Alix Post1 (alix.post@ga.gov.au), Phil O'Brien2, Leanne Armand2,3, Stuart Edwards4

1
Geoscience Australia, Canberra, Australia, 2Macquarie University, Sydney, Australia, 3Australian National
University, Canberra, Australia, 4CSIRO Oceans & Atmosphere, Hobart, Australia

The seafloor of the Antarctic upper continental slope is a dynamic and varied environment. The upper slope is
influenced by oceanographic processes, including export of dense shelf waters, upwelling of Circumpolar Deep
Waters and strong along slope flow and mixing associated with the Antarctic Shelf Front. These features can
enhance the productivity of the surface waters and influence the food supply to the seafloor. The interplay
between oceanographic and glacial processes over long time periods has created a complex morphology of
dense gully networks, rugged submarine canyons and broad sediment ridges.
The upper slope is of biological significance as an area often proposed as a refugia for shelf biota during glacial
cycles and as the interface between shelf and deep sea species. This study draws on case studies from the East
Antarctic margin to understand the processes that drive the modern distribution of benthic biota on the upper
slope. These studies illustrate how the seafloor biota are shaped by oceanographic, glacial and sedimentary
processes. Flow of dense shelf waters through shelf incising canyons off the George V margin influences the
occurrence of Vulnerable Marine Ecosystems, while variations in gully types on the Sabrina upper slope creates
heterogeneity in the occurrence and diversity of sessile suspension feeders and mobile fauna. The upper slope
provides a unique setting for understanding how the benthic biota respond in a dynamic environment.

1924
259
El Niño and La Niña Signals in the Reproduction of Antarctic Echinoderms

Laura Grange1 (l.j.grange@noc.soton.ac.uk), Lloyd Peck2, Amanda Bates1, Paul Tyler1

1
University of Southampton, Ocean and Earth Science, Southampton, United Kingdom, 2British Antarctic Survey,
Cambridge, United Kingdom

Ongoing impacts of climate change are well established and predicted to continue at an unprecedented rate.
Superimposed on this backdrop of environmental change is an increase in the frequency and severity of
extreme weather events. Fluctuations in extreme events have been implicated as major mechanistic drivers of
ecological responses to climatic trends, often being more relevant than variances in mean climate. They are,
however, infrequent and underestimated. In addition, ecologists have historically focused on quantifying the
effects of locally measured components of weather as opposed to regional modes of climate variability that
integrate over multiple local variables, and facilitate a more holistic approach when researching climate change
effects. Here we investigate the impact of local and large-scale climate cycles on reproduction in two Antarctic
echinoderms over 17 years of monthly samples. We report long-term trends in reproductive performance,
measured as gonad index and egg size, and observe extreme El Niño and La Niña signals in the reproduction of
both polar taxa. We identify the complex interplay between food supply, seawater temperature, and faunal
energy allocation strategies as key drivers of reproductive responses, where climate extremes underpin long-
term trends in biological flexibility. The infrequency of extreme weather events thus underscores the need for
long-term biological time series to better predict faunal responses to future climate change.

1925
349
More Losers than Winners in a Century of future Southern Ocean Seafloor Warming

Huw Griffiths1 (hjg@bas.ac.uk), Andrew Meijers1, Thomas Bracegirdle1

1
British Antarctic Survey, Cambridge, United Kingdom

The waters of the Southern Ocean are projected to warm over the coming century, with potential adverse
consequences for native cold-adapted organisms. Warming waters have caused temperate marine species to
shift their ranges poleward. The seafloor animals of the Southern Ocean shelf have long been isolated by the
deep ocean surrounding Antarctica and the Antarctic Circumpolar Current, with little scope for southward
migration. How these largely endemic species will react to future projected warming is unknown. By
considering 963 invertebrate species, we show that within the current century, warming temperatures alone
are unlikely to result in wholesale extinction or invasion affecting Antarctic seafloor life. However, 79% of
Antarctica's endemic species do face a significant reduction in suitable temperature habitat (an average 12%
reduction). Our findings highlight the species and regions most likely to respond significantly (negatively and
positively) to warming and have important implications for future management of the region.

1926
711
Benthic Biodiversity of the Larsen-C Shelf Previously Covered by Iceberg A68

Katrin Linse1 (kl@bas.ac.uk), Phil Trathan1, Huw Griffiths1, Sophie Fielding1, Adrian Glover2, William Reid3,
Ursula Witte4, Dieter Piepenburg5
1
British Antarctic Survey, Cambridge, United Kingdom, 2Natural History Museum London, London, United
Kingdom, 3University of Newcastle, Newcastle, United Kingdom, 4University of Aberdeen, Aberdeen, United
Kingdom, 5Alfred Wegener Institute, Bremerhaven, Germany

On 12 July 2017, the Larsen-C Ice Shelf calved one of the largest icebergs originating from the Antarctic
Peninsula ever recorded, leaving an area of 5,800 km2 of seabed newly exposed to open marine conditions.
The calving of A68 offers a unique scientific opportunity for fundamental research to address questions
focussed on the mobility and colonisation capacity of benthic fauna. In early 2018 an international,
multidisciplinary science group on-board the RRS James Clark Ross investigating the benthic biodiversity
beneath the Larsen-C, will address the hypothesis that: “Prior to the calving of iceberg A68, the benthic fauna
beneath the ice shelf probably comprised oligotrophic assemblages resembling deep-sea Weddell Sea systems.
The calving of A68 will now lead to rapid colonisation by new species that will significantly transform the
benthic ecosystem within 3 to 5 years.” Our survey, including stations both outside and inside the pre-calving
ice front, coupled with stations in the region of Larsen-A&B will comprise trawls, corers, towed camera
systems, CTD, and echo-sounders. We will sample from the surface to the seafloor. Our holistic approach will
enable us to collect information on the assemblage structure, biodiversity and abundance of the in-, epi-, and
supra-benthic meio-, macro- and mega-fauna, setting a baseline for future research. In this presentation we
will report our preliminary results from the expedition.

On bealf of the ship-Board Party of Royal Research Ship James Clarke Ross, JR17003a, Cambridge, United
Kingdom

1927
1106
High Beta Diversity of Microbes in Southern Ocean Abyssal Water Masses

Swan Li San Sow1,2 (swanlisan.sow@csiro.au), Levente Bodrossy1, Thomas W. Trull1,3, Phillip W. Boyd2,3, Eric J.
Raes4, Jodie van de Kamp1, Mark V. Brown5, Andrew Bissett1
1
Commonwealth Scientific and Industrial Research Organisation (CSIRO), Oceans and Atmosphere Flagship,
Hobart, Australia, 2University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia,
3
Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Australia,
4
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 5University
of New South Wales, School of Biotechnology and Biomedical Sciences, Sydney, Australia

The Southern Ocean (SO) is known to be an important site for carbon dioxide sequestration and dominates
many key biogeochemical nutrient cycles through microbially driven processes. The pelagic dark ocean hosts up
to 60% of heterotrophic activity, but knowledge on the community structure of these heterotrophic microbes
and their interaction with the surface community is still scarce. This study greatly expands our understanding of
SO microbes within the deeper water masses with interest on the roles of ocean circulation in structuring
microbial biogeography. At two multi-latitudinal transects from the Indian (71-99°E) and Pacific sector (170°W)
of the SO, we sampled seawater from the full water column at 8 depth points and examined bacterial, archaeal
and eukaryotic community compositions through high resolution 16S and 18S rRNA tag sequencing. We found
the biogeographical distribution of microbes were explained in part by distinct water masses hydrographies,
but bacteria and archaea from deeper (Antarctic bottom-lower circumpolar) water masses, which spread
across a wide range of latitudes, displayed niche communities with varying abundances of specific phylotypes
that were not explained by hydrography or geographical distance. The abrupt changes in phylotype
abundances corresponded with crossing frontal zones in surface waters, suggesting that the varying
communities of surface water masses influences community compositions in deeper water masses.

1928
1047
Distributional Shifts of Two Antarctic Metazoans under Climate Change Scenarios

Evgeny Pakhomov1,2,3 (epakhomov@eoas.ubc.ca), Gabriel Reygondeau2, Angus Atkinson4, Simeon Hill5, Volker
Siegel6
1
University of British Columbia, Earth, Ocean and Atmospheric Sciences Department, Vancouver, Canada,
2
Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, Canada, 3Hakai Institute,
Heriot Bay, Canada, 4Plymouth Marine Laboratory, Plymouth, United Kingdom, 5British Antarctic Survey,
Natural Environment Research Council, Cambridge, United Kingdom, 6Thuenen Institute of Sea Fisheries,
Hamburg, Germany

Distributional range shift is a well-known species response to climate fluctuation and has been documented for
various taxonomical groups in different parts of the global ocean. Circum-Antarctic habitats of the Antarctic
krill, Euphausia superba, and pelagic tunicate, Salpa thompsoni, were modelled using presence only
environmental niche models. KRILLBASE and the Southern Ocean CPR data were used. An ensemble suit of
models, including species range envelope, non-parametric probabilistic ecological niche, boosted regression
trees and maximum entropy models, were used to predict the past, present and future distributions of both
species. Habitat shifts of both species and their potential contemporary and projected overlap were
investigated under two IPCC: RCP2.6 and 8.5. The overlap in krill and salp niches/habitats appear to be
significant in the Scotia Sea and Indian Sector of the Southern Ocean as well as in coastal regions, except
perhaps the Ross Sea. Both species showed a southward shift in distribution under climate change scenarios,
which was most profound under the RCP8.5 scenario. Predictions demonstrated that since 1950s the habitat
overlap increased and stabilized. This suggested the persistence of the habitat overlap under climate change
projections with a potential increase in inter-species interactions and in competition for limited space between
both species. Potential “winners” and “losers” with implications for the high Antarctic ecosystem are discussed.

1929
EN-7d - Biogeochemical cycling in the Polar Regions: Terrestrial and Ocean interactions
22.06.2018 16:00-17:30, A Studio

604
Microbial Loop and Organic Carbon Dynamics in Kongsfjorden during June 2011

Bhaskar Parli1 (bhaskar@ncaor.gov.in), Jane Theophline Paul-Bhaskar2, Nuncio Murukkesh1, K.P. Krishnan2, S
Rajan3
1
NCAOR, Ocean Science Group, Vasco da Gama, India, 2NCAOR, Vasco da Gama, India, 3INCOIS, Hyderabad,
India

Depthwise vertical distribution of microbial components including samples of bacterioplankton, phytoplankton

assemblages, heterotrophic nanoflagellates and picoplankton and water samples for chlorophyll a (chl a) and
organic carbon were analysed at nine stations in Kongsfjorden during Arctic summer in 2011. Phytoplankton
abundance (excluding picoplankton) decreased with depth and their surface abundance ranged from 2.56 x
103cells L-1 at K1 (mouth) to a maximum of 16.76 x 103cells L-1 at K7 (outside Ny-Ålesund). On the other hand,
picoplankton abundance ranged from 0.3 x 103 cells L-1 (K4 & K7) to 8 x 103 cells L-1 (K7). Heterotrophic bacterial
and nanoflagellate abundance ranged from 7.4 x 106 (K1 and K2) to 665 x 106 cells L-1 (K4) and 2.6 x 103 cells L-1
(K7) to 21.6 x 103 cells L-1 (K3), respectively. Prymnesiophyceae (44.5%), Dinophyceae (30.4%) Chlorophyceae
(10.9%) and Bacillariophyceae (9.1%) were the major phytoplankton groups. Dominance of dinoflagellates
indicated post-spring bloom scenario. Column integrated biomass of picoplankton, nanoflagellate and
heterotrophic bacteria ranged from 3.3 x 10-5 to 8.3 x 10-3 µM-C, 5 x 10-3 to 0.01 µM-C and 3.3 to 27 µM-C,
respectively. Multivariate analyses of the data indicate that abiotic factors like light availability played
important role in controlling the phytoplankton community distribution. The dynamics of carbon and its
partitioning within microbial loop is also discussed.

1930
463
Organic Carbon Sources in Arctic and Subarctic Atlantic Fjord Sediments

Johan Faust1 (j.faust@leeds.ac.uk), Jochen Knies2,3

1
University of Leeds, Leeds, United Kingdom, 2Geological Survey of Norway, Trondheim, Norway, 3CAGE - Centre
for Arctic Gas Hydrate, Environment and Climate, Department of Geology, UiT the Arctic University of Norway,
Tromsø, Norway

During the past decade fjords attract notice as important shelf areas for carbon burial due to relatively high
sedimentation rates as well as high organic matter (OM) input. As terrigenous derived OM is more resistant to
remineralization than marine OM, a comprehensive knowledge of the carbon source is crucial to better
constrain OM burial rates in fjords sediments. Recent findings indicate that the majority of the OM in fjord
sediments globally to be terrigenous derived. However, these findings are based only on a very few studies
from the North Atlantic region. To improve the understanding of the controlling factors on OM sedimentation
in mid- and high-latitude fjord systems we investigate the OM sources of highly productive arctic fjords off the
Lofoten Islands, northern Norway and compare our results with available and new Corg/Norg and δ13Corg data
from various arctic and subarctic fjord systems in Mid-Norway, western Svalbard and East Greenland. Our
results show that in Northern Norwegian fjords the sedimentary OM is primarily controlled by marine
productivity variations and marine Corg values of up to 4.4 wt.% indicate that this region is a hotspot for marine
Corg burial. Moreover, the amount of terrigenous OM is generally higher in Arctic fjords compared to Norwegian
(Boreal) fjords and marine water inflow versus freshwater runoff seems to be an important controlling factors
of the OM composition in fjord sediments.

1931
87
Errors in Marine vs. Terrestrial Carbon Sequestration Budget for Arctic Region

Manish Tiwari1 (manish@ncaor.gov.in), Vikash Kumar2

1
National Centre for Antarctic & Ocean Research, Vasco-da-Gama, India, 2National Centre for Antarctic & Ocean
Research, Headland Sada, India

The Arctic region holds a disproportionate importance in the global carbon cycle. The changing sea cover due
to the global warming may likely change the relative marine vs. terrestrial organic carbon deposition in the
region. It is therefore important to have an accurate estimate of relative carbon burial flux for which the carbon
isotope ratio (δ13C) and carbon to nitrogen ratio (C/N) of the sedimentary organic matter (SOM) are the most
widely used tracers. These proxies that are so reliable in other parts of the world have significant limitations in
the Arctic region due to various proxy-specific uncertainties resulting in gross differences in relative burial flux
calculations. This allowed us to better constrain the marine and terrestrial end-member carbon isotopic
composition, which we found to be anomalously more depleted (marine δ13C ~−24‰) and enriched (terrestrial
δ13C ~−22.5‰), respectively, than usually assumed. This particular result also provides the explanation for the
high δ13C of SOM from central Arctic despite a high terrestrial input that remained a puzzle since reported. We
find that the bound inorganic nitrogen (ammonium attached to the clay minerals) forms a significant
proportion of total nitrogen concentration and should be removed to avoid an underestimation of terrestrial
contribution. Using these new values, we find that the terrestrial contribution to the organic carbon deposition
in the Arctic has been severely underestimated.

1932
2268
Transport of Inorganic Carbon and Nutrients across the Eurasian Shelf

Alexander Polukhin1 (polukhin@ocean.ru), Alexander Osadchiev2

1
Shirshov Institute of Oceanology, Ecology of the seas and oceans, Moscow, Russian Federation, 2Shirshov
Institute of Oceanology, Physics of the sea and land waters, Moscow, Russian Federation

One of the main features of Eurasian Arctic Seas is the huge amount of fresh water coming from great Siberian
rivers: Ob, Yenisei, Lena whose input is about 2000 km3/year into the Arctic Ocean basin. Depending on annual
discharge and wind stress riverine water can either accumulate on the shelf or according to Carmack et al
(2015) transformed riverine water moves eastward along the Eurasian shore as a narrow and shallow flow. This
flow contains huge amount of organic and inorganic matter coming to the Arctic Ocean with continental runoff
(Gordeev et al, 1996). Thus, the existing mechanism moves the nutrient and carbon in the Arctic and our goal is
to determine the volume of the transported substance and the possible degree of impact on the Eurasian
coastal ecosystem.
In August-September 2017 Shirshov Institute of Oceanology (SIO) organized cruise of RV “Academician
Mstyslav Keldysh” to East-Siberian Sea. Along the vessel course (through the Kara and Laptev Seas) direct
measurements of temperature and salinity were conducted as well as sampling from the surface layer.
Chemical analysis of the samples included nutrients (P, Si and N in dissolved forms) and carbonate system
parameters (alkalinity and pH). We also calculated concentration of DIC, Ωca and Ωar and pCO2 in surface water.
The primary analysis of the data confirmed the existence of the eastern fresh water transfer and determined
the possibility of estimating the content of nutrients and carbon in these waters.

1933
2361
Small Scale Distribution and Composition of Organic Carbon in Arctic Soils

Carsten W. Mueller1 (cmueller@wzw.tum.de), Sebastian Zubrzycki2, Isabel Prater1, Lena Zoor1, Janet
Rethemeyer3, Jenny Kao-Kniffin4
1
TU Munich, Chair of Soil Science, Freising, Germany, 2University Hamburg, Hamburg, Germany, 3University
Cologne, Institute of Geology and Mineralogy, Cologne, Germany, 4Cornell University, Department of
Horticulture, Ithaca, Germany

Tremendous amounts of organic carbon (OC) are stored in permafrost-affected soils in the Arctic. The ongoing
warming will change the accessibility and bioavailability of the previously frozen soil organic matter (SOM).
Although OC stocks and C fluxes in the Arctic are extensively studied, there is only scarce information on the
small scale (pedon scale) distribution and composition of organic matter in differently stabilized fractions.
However, this information is crucial to understand and model the fate of differently bioavailable SOC. By
combining bulk analytical methods (e.g. C and N analyses, 14C, NMR spectroscopy) with state of the art
spectromicroscopic techniques (e.g. NanoSIMS) it is possible to unravel processes stabilizing organic carbon
reaching from the formation of organo-mineral associations to soil aggregation. We will present results from
Alaska and Siberia demonstrating the distribution of distinct SOM fractions with soil depth. Using NMR
spectroscopy, we were able to demonstrate that free SOM particles showed larger amounts of rather labile C
(O/N alkyl-C) in comparison with SOM particles occluded in mineral soil structures. Soil OM directly associated
with minerals showed rather similar chemical compositions due to comparable effects on SOM sorption by
minerals. These results clearly indicate that mechanisms like soil aggregation and the formation of organo-
mineral associations play also a role for SOM bioavailability in permafrost-affected soils.

1934
2473
Source and Age of Soil Carbon in the Sør Rondane Mountains of East Antarctica

Lori A. Ziolkowski1 (loriz@sc.edu), Steffi Lutz2, Liane G. Benning2,3,4, Jenine McCutcheon4

1
University of South Carolina, School of Earth, Ocean, and the Environment, Columbia, United States, 2GFZ
German Research Centre for Geosciences, Section 4.4: Interface Geochemistry, Potsdam, Germany, 3Free
University of Berlin, Department of Earth Science, Berlin, Germany, 4University of Leeds, School of Earth and
Environment, Leeds, United Kingdom

On Antarctica, cold temperatures and months of darkness create a near inhospitable environment. Yet,
microbial life has been shown to thrive in some regions of this polar desert leading to the production of organic
carbon. The highest abundances of organic carbon are found in lakes and where microbes inhabit rocks
(endoliths), with less known about the organic carbon within soil. Presently, it is not well constrained if soil
organic carbon is produced locally within the soil or produced elsewhere and subsequently transported to the
soils. In an effort to further our understanding of the processes contributing to Antarctic soil organic carbon,
we studied the microbial community and organic carbon abundance and composition in soils collected in the
Sør Rondane mountains, 200 km inland, in East Antarctica. Using a suite of samples that range from lake-side
soils with deposits of macroalgae to dry high elevation soils devoid of visible life, we will report on the organic
carbon abundance, isotopic (13C, 14C) composition, and microbial composition of soil organic carbon in order to
determine variations in the carbon composition. Additionally, the microbial community composition of the soils
will provide insight into the relative contribution of autotrophic and heterotrophic organisms. This work will
provide the first estimates of carbon abundance and age as linked to the microbial community in soils from a
previously understudied region of East Antarctica.

1935
GG-1d - Magmatic, tectonic, and geodynamic investigations of the Polar Regions
22.06.2018 16:00-17:30, A Schwarzhorn

1715
Polyphase Brittle Tectonics in North Victoria Land and Gondwana Fragmentation

Andreas Läufer1 (andreas.laeufer@bgr.de), Laura Crispini2, Frank Lisker3, Axel Gerdes4, Antonia Ruppel1
1
Federal Institute for Geosciences and Natural Resources (BGR), Hannover, Germany, 2Università di Genova,
Dipartimento di Scienze della Terra, dell'Ambiente e della Vita (DISTAV), Genova, Italy, 3Univ. Bremen, FB
Geowissenschaften, Bremen, Germany, 4Goethe University Frankfurt, Institute of Geosciences, Frankfurt am
Main, Germany

Antarctica was at a centre position within Gondwana and holds a key position for any plate tectonic
reconstruction related to its break-up history. North Victoria Land (NVL) is located at the Pacific end of the
Transantarctic Mountains (TAM), which represent the uplifted western shoulder of the West Antarctic Rift
System. The basement of the TAM formed during subduction of the Palaeopacific Ocean under E Gondwana
during the Ross Orogeny. Major uplift of the TAM commenced around the Eocene-Oligocene boundary
following sediment accumulation within the wide “Mesozoic Victoria Basin”. This long-lasting geological history
led to highly anisotropic crust that is susceptible to repeated reactivation. We present evidence for a polyphase
structural evolution of NVL after initial break-up of Gondwana at ca. 180 Ma coeval with the Ferrar volcanic
event. Mainly Neogene NW-SE striking dextral strike-slip tectonics with local transtension and transpression
controls the present structural architecture of NVL. It may be interpreted as dynamic response to intra-oceanic
fracture zones between Australia and Antarctica extending into NVL and the Ross Sea. Dextral strike-slip
overprints two older increments:
(i) WNW-ESE striking sinistral tectonics of possibly late Mesozoic-early Paleogene age within a transform
margin setting between Australia and Antarctica,
(ii) ENE-WSW directed extension of NVL continental crust possibly coeval to Adare Trough spreading in Eocene-
Oligocene times.

1936
2403
The Distribution of Crustal Heating in West Antarctica from Aeromagnetics

Enrica Quartini1,2, Duncan Young1 (duncan@ig.utexas.edu), Donald D Blankenship1

1
Univerisity of Texas at Austin, University of Texas Institute for Geophysics, Austin, United States, 2Univerisity of
Texas at Austin, Department of Geological Sciences, Austin, United States

West Antarctica hosts the large West Antarctic Rift System (WARS), a region of continental extension which has
formed during several stages of rift reactivation from the Cretaceous through the Cenozoic.
Anomalously high geothermal flux has been reported within WARS at the WAIS Divide ice core drilling site and
Subglacial Lake Whillans, which is consistent with estimates in the Thwaites Glacier (THW) catchment from
airborne radar based techniques. Together, these observations suggest that elevated geothermal flux
characterizes large sectors of WARS. Moreover, subglacial volcanic activity has been recently documented
along the ECR, where a swarm of deep long-period earthquakes was registered in 2010 and 2011 by the
POLENET seismic network.
Here we analyze magnetic anomalies in the context of other aerogeophysical data in central WARS, along THW,
Pine Island (PI), and eastern Marie Byrd Land (MBL), in order to evaluate the distribution of potential hotspots
in the region. We identify three different regions with distinct magnetic character and correlate each one of
them to specific stages of tectonic and magmatic activity in WARS. Our interpretation supports both the
hypothesis that MBL was tectonically and magmaticaly reactivated multiple times during the Cretaceous and
that a hotspot was emplaced there later in the Cenozoic, therefore pointing to a hotter MBL compared to THW
and PI.

1937
690
A Multi-domain Lithospheric Model of East Antarctica

Tobias Staal1,2 (tobias.staal@utas.edu.au), Anya M Reading1,3, Jacquline Halpin1, Joanne Whittaker1

1
University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia, 2University of Tasmania /
Earth Sciences, Hobart, Australia, 3University of Tasmania / Mathematics and Physics, Hobart, Australia

The geology of East Antarctica is poorly constrained and covered by ice which can be several kilometers thick,
however, these hidden and inaccessible rocks are of major interest in interdisciplinary studies linking the solid
Earth and cryosphere. Subglacial geothermal heat flux is an important parameter for ice sheet models and
depends on heat production within the crust, but also the deep geothermal gradient that is defined by the
lithospheric structure.
Seismic tomography studies derive lithosphere thickness and structure, but the resolution is relatively low, and
the smoothed models don't reflect the amalgamation of lithospheric terranes that formed the continent. We
combine geophysical constraints from seismic properties and potential field data, with geological knowledge
from the sparse Antarctic outcrops and from Gondwanan neighbours in a plate reconstruction framework. We
use Bayesian inference to suggest the most probable boundaries by using a multivariate prior. The boundaries
form a segmentation of the Antarctic lithosphere and can be weighted with probabilistic significance and
location.
The result is presented as a first draft of a multi-domain tessellated terrane map of the East Antarctic
lithosphere. We believe that this approach will be useful in estimating both basal lithosphere and crustal
contributions to heat flux, and is a robust stepping stone towards more refined models.

1938
436
Crustal and Lithospheric Structure Beneath the Antarctica Based on Gravity Data

Ravi Kumar Muppidi1 (mravi@iigs.iigm.res.in), Bijendra Singh1, D.S Ramesh1, V.M Tiwari2, C.D Reddy1, Ajay
Dhar1
1
Indian Institute of Geomagnetism, Solid Earth Group, Navi Mumbai, India, 2National Geophysical Research
Institute, Hyderabad, India

Investigation of deep crustal and lithosphereric structures is essential to understand the nature of
geodynamical processes beneath the Antarctica Plate. We present a hybrid approach comprising isostasy and
spectral analysis to decompose the observed gravity field into its deep crustal and lithospheric components and
derived density cross sections beneath the Antarctica plate using integrated 2D modelling of gravity,
topography and geoid data incorporating constraints from seismic information. We also present new crustal
and lithospheric thickness maps based on integrated modeling of elevation and geoid and thermal analysis.
This approach assumes local isostasy, thermal study state, and linear density increase with depth in the crust
and temperature-dependent density in the lithospheric mantle and our result compares well with the depth of
Moho and LAB derived from seismic and tomographic models. It is observed that most of the east Antarctica
high topographic region is isostatically compensated by thick crust based on Airy model. For example, depth of
the Moho discontinuity beneath the Gamburtsev Sub glacial Mountain is inversely correlated with surface
topography. Our new lithospheric thickness map derived from 3D inversion of lithospheric field component
brings out distinct features like thin lithosphere in the west (100-150Km) and thickening of the lithosphere in
the east Antarctica (160-220Km) and therefore east Antarctica appears to similar to other stable cratons.

1939
1274
Mantle Seismic and Viscosity Structure Beneath Antarctica and Adjacent Oceans

Douglas Wiens1 (doug@wustl.edu), Andrew Lloyd1, Hejun Zhu2, Jeroen Tromp3, Andrew Nyblade4, Richard
Aster5, Terry Wilson6, Samantha Hansen7
1
Washington University in St Louis, Earth and Planetary Sciences, Saint Louis, United States, 2University of Texas
at Dallas, Dept of Geosciences, Dallas, United States, 3Princeton University, Dept of Geosciences, Princeton,
United States, 4Pennsylvania State University, Dept of Geosciences, University Park, United States, 5Colorado
State University, Dept of Geosciences, Fort Collins, United States, 6Ohio State University, School of Earth
Sciences, Columbus, United States, 7University of Alabama, Dept of Geological Sciences, Tuscaloosa, United
States

We develop a new seismic structure model for Antarctica and surrounding oceans to depths of 700 km using
more than 300 far-southern hemisphere seismic stations. We calculate full-waveform synthetics for 3D earth
models using a spectral element method, and fit the entire 3-component waveforms. The new model
overcomes the limitations of previous spatially- and depth-limited regional models and low-resolution global
models. In East Antarctica, the results reveal fast seismic velocities extending to 250 km depth beneath Wilkes
Land and the Gamburtsev Mtns. In contrast, fast velocities extend to only 100-150 km depth beneath the
Lambert Graben, Enderby Land, and portions of Dronning Maud Land, consistent with younger or tectonically
disrupted lithosphere. The West Antarctic coast from Marie Byrd Land to the Antarctic Peninsula is underlain
by low velocity mantle. The slow anomalies along the Amundsen Sea coast connect to an offshore velocity
anomaly beneath elevated bathymetry, suggesting a thermal anomaly that is associated with a larger
geodynamic process. We estimate the mantle viscosity structure from the seismic structure assuming
laboratory-derived relationships between seismic velocity, temperature, and rheology. The results indicate
several orders of magnitude variation in viscosity, with extremely low viscosity (< 1019 Pa s) beneath the
Amundsen Sea coast, consistent with low viscosity inferred by glacial isostatic uplift models constrained by GPS
data.

1940
1042
Deep Structure and Geodynamics of the Antarctic Plate with the Tomography Data

Rudolf Greku1 (r.greku@gmail.com), Alexander Litvinov1, Tatyana Greku1

1
Institute of Geological Sciences / National Academy of Sciences of Ukraine, Geology and Geoecology of
Antarctica, Kiev, Ukraine

This article contains the tomographic modeling results of the Antarctic Plate up to the depth of 5,300 km.
Density anomalies were calculated relative to PREM with the EGM2008 geoid model using the gravity
tomography method (www.uac.gov.ua/SitePages/Home/atlas.aspx).
The hot and ascending Ross Plume, the cooled and subducted Kerguelen-Conrad Plate masses and the
Antarctic Continent are the main structures of the Antarctic Plate bounded by the mid-ocean ridges. The Ross
Plume extends from the depth of 2,800 km up to the surface within some sectors of the marginal ridges.
Surface-continental density anomalies have a radial orientation from the South Pole. Distribution of density
anomalies within the oceanic lithosphere is determined by the movement of divergent and transform
spreading centers. The density anomalies of the Antarctic Peninsula and the Continental East Antarctic are
shown up to the depths of 2,800 km.
The cross-section along the ridge of the Plate boundary for a distance of 40,000km is shown. Intraplate and
interplate geodynamics is shown along cross-sections and lateral slices up to the depths of 2,800 km.
Coupling of Arctic and Antarctic can be seen only at the layers of the mantle-core. The slice at the 5,300 km-
deep consists of four symmetrically located density anomalies of different signs. They come together both in
Arctic and Antarctic. That is shown on the global maps with the Lambert Projection.

1941
BE-5c - Productivity, Biodiversity & Ecosystem Shifts at Cryosphere-Ocean Boundaries
22.06.2018 16:00-17:30, A Seehorn

1587
Infaunal Benthic Diversity, Trophic Sensitivity and On-going Changes in Sea Ice

Monika Kędra1 (kedra@iopan.gda.pl), Lee Cooper2, Mengjie Zhang2, Dana Biasatti3, Jacqueline Grebmeier2
1
Institute of Oceanology Polish Academy of Sciences, Sopot, Poland, 2University of Maryland Center for
Environmental Science Chesapeake Biological Laboratory, Solomons, United States, 3University of Notre Dame,
Notre Dame, United States

Reductions in seasonal ice and changes in organic carbon fluxes are influencing benthic communities in Arctic
shallow shelves, which can have critical consequences for ecosystem productivity. We describe multi-year
changes of macrobenthic communities in the “hot-spot” areas of benthic biodiversity and biomass in the
northern Bering and Chukchi Seas identified in the Distributed Biological Observatory. Our goal was to assess
benthic vulnerability to increasing temperature and ice decline, and its effect on the food webs and ecosystem
productivity. We examined potential implications of changes in ice cover for trophic positions of selected
species and potential food sources along a latitudinal gradient and in relation to environmental data. Benthic
organisms were collected from southwest of St. Lawrence Island, in the Chirikov Basin, the southeast Chukchi
Sea, and Barrow Canyon, at the same stations from 2007 to 2015. Samples for compound-specific stable
isotope analysis of amino acids were collected in each 'hot-spot' in 2015. Changes observed include a decline of
biomass, a switch in some dominant species, and an increase in species diversity in recent years. Variation in
δ13CAA and δ15NAA values reflect differences in food source and trophic level shifts. The compound specific
isotope analysis is consistent with the capacity of some benthic species to shift from deposit to active
suspension feeding as environmental conditions change.

1942
1187
High Export Flux and Benthic Biomass Indicate Warming Sensitivity in a WAP Fjord

Craig R. Smith1 (craigsmi@hawaii.edu), Andrew Sweetman2, McKenna Lewis1, Maria Vernet3, Lindsey Ekern3,
Clifton Nunnally4, Amanda Ziegler1
1
University of Hawaii at Manoa, Oceanography, Honolulu, United States, 2Heriot-Watt University, The Lyell
Centre for Earth and Marine Science and Technology, Edinburgh, United Kingdom, 3University of California San
Diego, SIO, San Diego, United States, 4Louisiana Universities Marine Consortium, Chauvin, United States

Rapidly-warming West Antarctic Peninsula (WAP) fjords are hotspots of pelagic and benthic
biomass/biodiversity. The drivers of fjord productivity, and benthic sensitivity to climate warming, remain
poorly known. Our FjordEco Project integrates field/modeling studies in Andvord Bay to explore how (1) glacial
and oceanographic processes enhance fjord productivity and biodiversity, and (2) increased
meltwater/sediment inputs from climate warming may alter these ecosystems. Field studies in Andvord Bay in
Dec 2015 and Apr 2016 indicated intermittently high primary production throughout the fjord but did not
resolve the location of highest seasonal export flux. We use benthic ecosystem parameters to integrate
summer seafloor POC flux and identify fjord areas of high benthic food availability. Sediment Chl-a was low
throughout the fjord in Dec, but 10-fold greater in Apr, with highest levels in the inner fjord 1-km from fast-
flowing glaciers. Seafloor carbon respiration also was enhanced in Apr, with highest rates near glaciers.
Megabenthic abundance matched the patterns of food availability with an inner fjord peak, while macrofaunal
abundance/biomass peaked in mid fjord, 10 km from glaciers. We hypothesize that macrofauna are more
sensitive than megafauna to the burial stress in the inner fjord due to lower mobility/body size. Our results
suggest that warming enhanced meltwater/sediment input near tidewater glaciers will alter inner-fjord
hotspots of productivity/biodiversity.

1943
1534
Seasonality and Spatial Variability of Epifaunal Recruitment in the Arctic

Marta Ronowicz1 (martar@iopan.pl), Anna Sowa2, Katarzyna Walczyńska2, Piotr Bałazy1, Janne Søreide3, Piotr
Kukliński1,4, Agata Weydmann2
1
Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland, 2University of Gdansk, Gdansk, Poland,
3
University Centre in Svalbard, Longyearbyen, Poland, 4Natural History Museum London, London, United
Kingdom

Recruitment process is one of the first steps of community development and has a substantial consequence for
population dynamics and structure.
The main aim of the project was to investigate seasonal variability of larvae recruitment in the Arctic fjord -
Isfjorden (West Spitsbergen) in relation to location (two sites under the influence of Atlantic versus
transformed fjordic waters), depth and predation impact. Samples were collected every third month (July 2016,
October 2017, January 2017, April 2017, July 2017), at two sites and two depths with the use of SCUBA. At each
site two experimental constructions with panels were deployed: first one covered with a cage and second one -
uncovered, to assess the predatory impact on recruiting epifauna. Meroplankton was collected with three
different types of gear in order to examine the larvae occurrence in different layers of water column: on the
bottom using vacuum pump manipulated around and under rocks, 2 m above the bottom - net towed
horizontally by divers and WP2 net. In addition the influence of environmental factors (temperature, salinity,
suspension concentration, sedimentation flux, light penetration) on colonization was studied. The study shows
that larvae are present in the water column all year round with a peak of occurrence in summer season. The
recruitment pattern follows the trend of meroplankton abundance and recruitment was the highest in summer
months.

1944
911
Intense Seafloor Pulses and Rapid Processing of Phytodetritus in Andvord Bay

Amanda Ziegler1 (ziegler8@hawaii.edu), Craig Smith1

1
University of Hawaii, Oceanography, Honolulu, United States

Fjords along the West Antarctic Peninsula (WAP) are productive ecosystems where seasonal phytodetritus
pulses sustain rich benthic communities. However, the timing and intensity of phytodetritus pulses, and
benthic community response, remain unevaluated. We used a calibrated seafloor camera to study the arrival
and utilization of phytodetritus over a 9-month period (Dec 2015 - Sept 2016) in Andvord Bay, a typical
northern WAP fjord. We developed automated color-recognition methods to quantify phytodetritus on the
seafloor and measured fecal cast production by the dominant deposit feeder, an ampharetid polychaete. An
intense phytodetritus pulse led to a rapid, 5-fold increase in deposit-feeding rate, indicating tight coupling
between plankton blooms and benthic detritivores in the fjord. Nonetheless, ampharetids fed throughout the
time-series, suggesting that phytodetritus can sustain fjord benthos into winter, consistent with the
“foodbank” hypothesis (Mincks et al. 2005). Despite high ampharetid feeding rates, the bulk of phytodetritus
was not consumed by deposit feeders but appeared to degrade by microbial processes or macrofaunal not
visible in images. This contrasts with similar depths (~500 m) on the open shelf where phytodetritus was
consumed rapidly by mobile megafauna (Sumida et al. 2014), highlighting substantial differences in pelagic-
benthic coupling and carbon cycling in WAP fjords versus the less productive open shelf.

1945
1835
Exploring Life-cycle Adaptations in a Sympagic Amphipod: Is it Truly Sympagic?

Erin Kunisch1 (erin.kunisch@uit.no), Magnus Drivdal2, Jørgen Berge1, Bodil Bluhm1, Malin Daase1, Rolf
Gradinger1, Haakon Hop1,3, Igor Melnikov4, Øystein Varpe3,5, Mikko Vihtakari3
1
UiT The Arctic University of Norway, Tromsø, Norway, 2Akvaplan-niva, Tromsø, Norway, 3Norwegian Polar
Institute, Fram Centre, Tromsø, Norway, 4Shirshov Institute of Oceanology, Moscow, Russian Federation,
5
University Center in Svalbard, Longyearbyen, Norway

Sea ice supports a diverse range of sympagic species found within brine channels and at the sea ice-water
interface. Apherusa glacialis (an Arctic gammarid amphipod) is typically found under sea ice and considered an
important trophic link between primary producers and upper trophic-level predators. While much is known
about its distribution and behavior when associated with sea ice, its potential ability to occur away from sea ice
is less clear, and adaptive roles of a pelagic stage have been hypothesized (Berge et al. 2012). Pan-Arctic pelagic
catch data was analyzed in order to determine the occurrence of A. glacialis away from sea ice to better
understand how ocean currents can be used for transport to better ice conditions. We found A. glacialis
present in depth-stratified net hauls (range: 13-3400 meters) throughout the Arctic Ocean, and at different
times of year. In Svalbard waters during the polar night, a small number of deep-water net hauls (n=8, range:
200-2000 meters) found gravid females in good body condition. Assuming A. glacialis indeed conduct vertical
migrations, particle trajectories from a coupled ocean-sea ice model were incorporated to evaluate the
possible distribution and migration patterns of this species. We assess how A. glacialis might use the Arctic
Ocean spatially (both in horizontal and vertical dimensions) and throughout the year, and discuss potential
responses and consequences during a period of diminishing sea ice coverage.

1946
2603
Tracing Sources of Carbon: Trophic Web Overlap between Antarctic Seals

Luis Huckstadt1 (lahuckst@gmail.com), Matt McCarthy2, Birgitte McDonald3, Paul Koch4, Daniel Crocker5, Daniel
Costa1
1
University of California Santa Cruz, Ecology and Evolutionary Biology, Santa Cruz, United States, 2University of
California Santa Cruz, Ocean Sciences, Santa Cruz, United States, 3Moss Landing Marine Labs, Moss Landing,
United States, 4University of California Santa Cruz, Earth and Planetary Sciences, Santa Cruz, United States,
5
Sonoma State University, Department of Biology, Rohnert Park, United States

We investigated the trophic ecology of two species of Antarctic phocids along the western Antarctica
Peninsula: the southern elephant (Mirounga leonina) and crabeater seal (Lobodon carcinophaga) using stable
isotope analyses (SIA). Our objectives were
(1) to evaluate what trophic webs of the western Antarctica Peninsula are impacted by these species, and
(2) to accurately define the trophic position (TP) of both species.
Crabeater seals consistently having significant lower values for both δ¹³C and δ¹⁵N than elephant seals. Despite
their more restricted spatial ranges, crabeater seals showed larger variability in their isotopic values, likely a
result of seasonal shifts in the composition of the coastal phytoplankton community. Using SIA of amino acids
we were able to discriminate between three food webs that are impacted by crabeater and elephant seals: a
coastal, intermediate and oceanic food web. As predicted, most crabeater seals occupy a coastal trophic web,
whereas elephant seals are fueled by both oceanic and coastal trophic webs. Most individuals occupy similar
TPs when comparing values within species (TP crabeater seal coastal = 2.12, TP elephant seal oceanic = 3.21),
however, the TPs of both species of seals is similar for those individuals in the intermediate trophic web (TP
crabeater seal intermediate = 2.96, TP elephant seal intermediate = 3.29), which could indicate krill
consumption by elephant seals.

1947
CR-8d - Latest highlights from high altitude and polar ice cores
22.06.2018 16:00-17:30, A Wisshorn

1216
The IceCube Neutrino Observatory as an Instrument for Glaciology

Martin Rongen1 (rongen@physik.rwth-aachen.de)

1
RWTH Aachen University, III. Physikalisches Institut, Aachen, Germany

The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice below the geographic South
Pole with 5160 optical modules to register the Cherenkov light of passing relativistic, charged particles.
After discovering a diffuse flux of high-energy cosmic neutrinos in 2013, there is now an on-going search to
identify the astrophysical sources.
This effort relies heavily on an ever more precise understanding of the optical scattering and absorption
properties of the instrumented ice. In turn IceCube can now provide a unique insight into the glacier which,
due to the large distances observed, is in many ways complimentary to ice cores.
Most notably we observe a dependence of the scattering length on the propagation direction of the photons,
with the direction of least scattering being aligned with the local flow direction of the ice. In this talk a depth
dependent measurement of the strength of this anisotropy will be presented and possible explanations of the
effect in the context of the distribution of scattering impurities in the crystal fabric are going to be discussed.
This contribution is presented on behalf of the IceCube collaboration.

1948
126
Glacial Dust Sources: Constraints from Radiogenic Isotopes and Raman Mineralogy

Barbara Delmonte1 (barbara.delmonte@unimib.it), Chiara Ileana Paleari1, Sergio Andò1, Biancamaria Narcisi2,
Giovanni Baccolo1, Mélanie Baroni3
1
University Milano-Bicocca (UNIMIB), Milano, Italy, 2ENEA, Rome, Italy, 3CEREGE, Aix-en-Provence, France

We investigate dust provenance during the last glacial period in central East Antarctica (Dome B) by coupling
the radiogenic isotope composition of dust (87Sr/86Sr, 143Nd/144Nd) with single-grain Raman mineralogical
analyses of a statistically-significant number of dust particles. This latter technique allows identifying mineral
species and polymorphs within the samples. Through these two powerful complementary approaches,
complemented by microscopic observations, we confirm the southern South American provenance of glacial
dust in Antarctica. In addition, for the first time we highlight the important role of the exposed Patagonian
continental shelf and glacial outwash plains of southern Patagonia at the time when sea level reached its
minimum, as evidenced by the presence of abundant aragonite particles in some samples along with diatom
valves of marine benthic/epiphytic species as well as freshwater species living today in the northern Antarctic
Peninsula and southern South America (Delmonte et al., 2017). Our study also demonstrates that the variable
dust particle sorting recorded in central East Antarctic ice cores reflects transport variability from a unique
source area. Thus, through this proxy the evolution of the past atmospheric circulation in central East
Antarctica during Holocene is going to be investigated in tandem with local temperature, humidity sources,
volcanic forcing and solar activity in the framework of the Franco-Italian SOLARICE ice core project.

1949
1634
Lead Isotopes from the Oldest Two Climate Cycles in the EPICA Dome C Ice Core

Changhee Han1,2 (hch@kopri.re.kr), Laurie J. Burn-Nunes3, Tseren-Ochir Soyol-Erdene4, Yeongcheol Han1, Soon
Do Hur1, Paul T. Vallelonga5, Paolo Gabrielli6, Carlo Barbante7, Claude F. Boutron8, Sungmin Hong2
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Inha University, Department of Ocean
Sciences, Incheon, Korea, Republic of, 3Curtin University, Department of Imaging and Applied Physics, Perth,
Australia, 4National University of Mongolia, School of Chemistry and Chemical Engineering, Ulaanbaatar,
Mongolia, 5University of Copenhagen, Centre for Ice and Climate - Niels Bohr Institute, Copenhagen, Denmark,
6
Ohio State University, School of Earth Sciences and Byrd Polar Research Center, Columbus, United States,
7
University of Venice, Institute for the Dynamics of Environmental Processes - CNR, Venice, Italy, 8Laboratoire de
Glaciologie et Géophysique de I'Environment, Saint Martin d'Heres, France

Pb isotopic compositions are recovered from the oldest two glacial-interglacial cycles recorded in the EPICA
Dome C ice core on the East Antarctic plateau providing 800,000-year climatic records. This is to trace the
origin of the dust that into the Antarctica during the period before the Mid-Brunhes Event (~43 kyr BP). All
sample handling and analytical operations were performed inside a Class 10 clean room provided with High-
Efficiency Particulate Air (HEPA) multi-staged filtration (Curtin University) and under class 10 laminar airflow
bench or booth in class 1000 clean laboratories (KOPRI). Pb isotopic compositions have been determined using
thermal ionization mass spectrometry (TRITON, Thermo Scientific). Pb isotopic compositions show variations in
changing climate due to relative proportions of mineral dust and volcanic Pb. Similar to previous studies, it was
confirmed that the main source of Antarctic dust was Patagonia during glacial period. The results also
demonstrate that Pb in EDC ice was influenced by less radiogenic non-crustal Pb when the contribution from
volcanic emissions appears to be important. This suggests that radiogenic volcanoes of the Antarctic interior
were not active during the period before MBE. Our data also indicate that the source of less radiogenic non-
crustal Pb is oceanic island including New Zealand.

1950
796
A Global Perspective of Ice Core Fluorescent Organic Matter

Juliana D'Andrilli1 (juliana@montana.edu), Joseph McConnell2, Brent Christner3, Rachel Joyce3, Rachel Kohn3,
Amanda Sapp3
1
Montana State University, Land Resources & Environmental Sciences, Bozeman, United States, 2Desert
Research Institute, Division of Hydrologic Sciences, Reno, United States, 3University of Florida, Microbiology and
Cell Science, Gainesville, United States

Reconstructing atmospheric composition during distinct climate periods is a central focus of ice core research,
and incorporation of fluorescent organic matter (OM) characterization is improving our understanding of
Earth's paleoecological history. Polar and alpine ice contain significant records of preserved carbon as OM, thus
identifying OM origin and reactive nature become essential targets, not only for atmospheric reconstructions,
but also to project potential impacts upon release in a warming climate. We present the OM fluorescent
characterizations from Antarctic (West Antarctic Ice Sheet), Arctic (Greenland and Canada), and high alpine
(Wyoming, USA) ice cores, encompassing OM fluctuations over long- and short-term time and spatial scales.
Variability of ice core OM fluorescence signatures among datasets reflected ecosystem changes as a function of
climate. Complex, terrestrially derived fluorescent OM was a signature of the youngest Antarctic and
Greenland ice cores only. More-labile fluorescent OM was reported over spatial and temporal scales for all ice
cores, indicating simple, low molecular weight, and less aromatic chemical species preserved ubiquitously.
Outspreading ice core research to routinely incorporate fluorescent OM characterization in polar and alpine
studies is still in its infancy, but has value to the cryosphere community and other aquatic and terrestrial fields
as disintegrating icy reservoirs of OM release their contents in a warming climate.

1951
537
High-resolution Analyses of Black Carbon and Dust in a Greenland Ice Core

Kumiko Goto-Azuma1,2 (kumiko@nipr.ac.jp), Yoshimi Ogawa-Tsukagawa1, Yutaka Kondo1, Remi Dallmayr1,3,

Motohiro Hirabayashi1, Jun Ogata1, Kyotaro Kitamura1, Kenji Kawamura1,2, Hideaki Motoyama1,2, Sumito
Matoba4, Moe Kadota4, Teruo Aoki5, Nobuhiro Moteki6, Sho Ohata6, Tatsuhiro Mori7, Makoto Koike6, Yuki
Komuro8, Akane Tsushima9, Naoko Nagatsuka1
1
National Instiutue of Polar Research, Tokyo, Japan, 2SOKENDAI (The Graduate University of Advanced Studies),
Hayama, Japan, 3Present affiliation: Alfred Wegener Institute for Polar and Marine Research, Bremerhaven,
Germany, 4Hokkaido University, Sapporo, Japan, 5Okayama University, Okayama, Japan, 6University of Tokyo,
Tokyo, Japan, 7Tokyo University of Science, Tokyo, Japan, 8Yamagata University, Yamagata, Japan, 9Research
Institute for Humanity and Nature, Kyoto, Japan

An ice core to the depth of 225 m was drilled at the SIGMA-D site, Northwest Greenland, in 2014 under the
SIGMA (Snow Impurity and Glacial Microbe Effects on Abrupt Warming in the Arctic) project (Matoba et al.,
2015). We analyzed the ice core to the depth of 113 m using a Continuous Flow Analysis (CFA) system, which
was recently built at the National Institute of Polar Research (NIPR), Japan. The NIPR CFA system allows high
resolution analyses of black carbon (BC), stable isotopes of water, microparticles, electric conductivity, and
trace elements (Na, K, Mg, Ca, Fe, and Al). We used a recently developed Wide-range SP2 (Single Particle Soot
Photometer, Droplet Measurement Technologies) for BC analysis. While a normal SP2 detects BC particles in
the size range between 70 and 800 nm, the Wide Range SP2 enabled us to detect BC particles in the size range
between 70 and 4000 nm (Mori et al., 2016).
Here we report the variability of BC and dust species over the past 350 years. BC concentrations started to
increase in the 1890s, reached its maximum in the 1930's - 1940's, and decreased again since then. The
increase is likely due to anthropogenic input. We also find anthropogenic changes in size distribution of BC as
well as seasonality. Dust-originated species Ca, Fe and Al show higher concentrations during the first half of the
19th Century, which might be related to cooler climate during that period.

1952
2415
A Comprehensive Study of the Drivers of Surface Snow Isotopes in Greenland

Hans Christian Steen-Larsen1 (hanschr@gfy.ku.dk), Maria Hoerhold2, Martin Madsen3, Sepp Kipfstuhl2, Jason
Box4, Anne-Katrine Faber5, Diana Vladimirova3, James White6, Emilie Capron3, Mari Jensen5, Iben Koldtoft3,
Kerim Nisancioglu5, Helen Pilar3
1
University of Bergen, Geophysical Institute & Bjerknes Centre for Climate Research, Bergen, Norway, 2Alfred
Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, 3Center for Ice and Climate, Niels
Bohr Institute, University of Copenhagen, Copenhagen, Denmark, 4Geological Survey of Denmark and
Greenland, Copenhagen, Denmark, 5University of Bergen & Bjerknes Centre for Climate Research, Bergen,
Norway, 6University of Colorado at Boulder, INSTAAR, Boulder, United States

Ice cores from polar ice sheets can be used to reconstruct past climate. However, an increasing number of
studies highlight the influence of post-depositional processes altering the isotopic composition of surface snow
on top of polar ice sheets. These processes are not accounted for by interstitial molecular diffusion and re-
distribution of snow and will influence the mean annual isotopic composition of the ice core record and hence
the paleo-climate interpretation.
To quantify these drivers we carried out a comprehensive study of surface snow and water vapor isotopes at
the new deep drilling site in North-East Greenland, EastGRIP. To balance the water stable isotope budget of the
surface snow we combine precipitation and daily snow surface and sub-surface isotope observations with
water vapor isotope flux measurements obtained from eddy-covariance and near-surface atmospheric vapor
isotope-gradient measurements.
These combined observations document snow fractionation during sublimation resulting in an enrichment of
the snow surface isotopes. Further, we observe that the change in the snow surface isotopes during clear-sky
days is comparable to the estimated cumulative water vapor isotope flux. This gives us confidence that we can
balance the water isotope budget for the snow surface and conclude that post-depositional processes are
influencing the deposited mean snow isotopic composition, specifically the second order isotope parameter,
the d-excess.

1953
OS-4d - Sea ice modeling and prediction: Sea ice Model Development
22.06.2018 16:00-17:30, B Jakobshorn

1270
Exploring the Feasibility of a Sea-ice Satellite Simulator

Clara Burgard1 (clara.burgard@mpimet.mpg.de), Dirk Notz1, Rasmus Tonboe2, Leif Toudal Pedersen3
1
Max Planck Institute for Meteorology, Ocean in the Earth System, Hamburg, Germany, 2Danish Meteorological
Institute, Copenhagen, Denmark, 3Technical University of Denmark, Copenhagen, Denmark

Sea-ice concentration is usually retrieved from satellite by analysing surface passive microwave brightness
temperatures. However, different algorithms, based on slightly different assumptions, result in different values
for the retrieved sea-ice area. Not knowing which of these retrievals is closest to reality has consequences for
both model evaluation and model initialization for seasonal hindcasts.
In our study, we investigate the drivers of sea-ice microwave surface brightness temperatures. This is a first
step to assess the possibility to obtain synthetic brightness temperatures from the output of a General
Circulation Model (GCM). Ultimately, comparing simulated to observed brightness temperatures could remove
the uncertainty introduced by a satellite retrieval algorithm and might hence allow for a more reliable
evaluation of both GCMs and retrieval algorithms.
As brightness temperatures are a combination of emissions by different media (sea ice, ocean, snow,
atmosphere), we explore the importance of various parameters for simulating realistic brightness
temperatures. Using a thermodynamical ice model combined with an emission model, we conduct sensitivity
experiments to understand which simplifications of the vertical temperature and salinity profiles in the ice
most strongly affect the simulated brightness temperature. First results suggest that simplifying the salinity
profiles introduces the largest error into the simulated brightness temperature.

1954
142
Process-informed Modelling of the Sea Ice Floe Size Distribution

Lettie Roach1,2 (lettie.roach@niwa.co.nz), Samuel Dean1, Christopher Horvat1,3, Madison Smith4, Cecilia Bitz5
1
NIWA, Wellington, New Zealand, 2Victoria University of Wellington, Wellington, New Zealand, 3Brown
University, Providence, United States, 4University of Washington, Applied Physics Lab, Seattle, United States,
5
University of Washington, Atmospheric Sciences, Seattle, United States

The lateral size of sea ice floes is receiving increasing attention as an important variable for the polar climate
system. Sea ice floe size distributions, which can include floe sizes orders of magnitude smaller than the grid
resolution, can now be simulated in global sea ice models. This allows inclusion of additional model physics,
including alternative sea ice growth pathways and fracture of ice by ocean surface waves.
Floe size distributions are difficult to observe at sufficiently high resolution and sufficiently large spatial and
temporal scales for global model validation. However, individual model processes can be observationally
constrained. Here, we present results from a model-motivated observational study from images captured by
wave buoys in the autumn Arctic Ocean.
These results inform our implementation of a joint sea ice floe size and thickness distribution in the Los Alamos
sea ice model, CICE, coupled to a dynamic ocean. Our process-based approach to model development allows us
to investigate the impacts of each process individually. We find a strong contribution of sea ice growth
processes to power-law behaviour in the floe size distribution.
A key remaining question is whether such alterations to model physics affect larger-scale sea ice properties.
We will present coupled model results that investigate this question, and discuss future possible work that may
cause significant impacts on the polar climate system.

1955
2053
Physics of Refreezing Melt Ponds in CICE

Lucia Hosekova1 (l.hosekova@reading.ac.uk), Danny Feltham1, David Schroeder1, Daniela Flocco1

1
University of Reading, Department of Meteorology, Reading, United Kingdom

Realistic representation of melt ponds in sea ice models has been demonstrated to have a significant impact on
summer melts by enhancing the albedo feedback mechanism. In addition to this effect, it has been shown that
melt ponds play a role in delaying the winter basal growth of sea ice during the period of melt pond refreezing.
In order to assess the impact of these processes on Arctic variability and predictability in sea ice models, one
needs to be able to correctly represent the temperature profile throughout the ice layer during and after the
formation and refreezing of trapped ponds. We present a modification of the vertical thermodynamics and
melt pond scheme in CICE that allows us to model multiple concurrent phases relevant to melt pond physics
(i.e. the refreezing pond, ice beneath the pond, the ice lid) with a goal to realistically account for the heat
transfer and heat storage of refreezing melt ponds, and test its ability to provide more skillful sea ice
predictions of the summer sea ice extent.

1956
2641
New Insight from CryoSat-2 Sea Ice Thickness for Sea Ice Modelling

David Schroeder1, Michel Tsamados2 (m.tsamados@ucl.ac.uk), Daniel Lee Feltham1, Andrew Ridout2, Rachel
Tilling3
1
Reading University, Reading, United Kingdom, 2University College London, London, United Kingdom, 3Leeds
University, Leeds, United Kingdom

Estimates of Arctic sea ice thickness are available from the CryoSat-2 radar altimetry mission during the ice
growth seasons since 2010. We derive the sub-grid scale ice thickness distribution (ITD) with respect to 5 ice
thickness categories used e.g. in the sea ice component CICE of HadGEM3 climate simulations. This allows us
both to verify the simulated cycle of ice thickness and to initialize the ITD in stand-alone simulations with the
sea ice model CICE . We find that a default CICE simulation strongly underestimates the ice thickness, in spite of
doing a reasonable job regarding the inter-annual variability of summer sea ice extent. We can identity the
underestimation of winter ice growth being responsible and show that using ice and snow conductivity values
on the upper end of the observed range makes sea ice growth more realistic and generally improves the model
simulation. Sensitivity studies provide insight on the role of ice strength, momentum and heat turbulent fluxes
on the annual cycle of sea ice thickness. We show that the width of ITD plays an important role for the summer
lead fraction and basal ice melt. Furthermore, a major discrepancy is revealed regarding the annual cycle of
sub-grid scale thick sea ice. According to Cryosat-2 there is a strong formation of thick ice during winter, but
hardly any thick ice survives the summer. CICE simulations only show a weak seasonal cycle, indicating that
both the formation and the melting of thick is underestimated.

1957
869
Antarctic Sea Ice and Southern Ocean Simulations using the ACCESS-CM2 Model

Siobhan O'Farrell1 (siobhan.ofarrell@csiro.au), Dave Bi1, Arnold Sullivan1

1
CSIRO Oceans & Atmosphere, Climate Science Centre, Aspendale, Australia

The ice component of the ACCESS-CM2 climate model has been updated in preparation for the CMIP6
experiments with multi-layer ice thermodynamics and pond dynamics that were provided by the UK
Meteorological Office Hadley Centre with the Unified Model (UM) upgrade that has been adopted in the
atmospheric component of the coupled model.
The sea ice model used is the CICE5.1 model from Los Alamos with adaptions to couple to the UK Met office
atmospheric model and it is coupled to the MOM5 GFDL Ocean GCM.
The Southern ocean has a warm bias which has been reduced over the latest upgrades of UM atmospheric
model, however, the ACCESS-CM2 model still does not have extensive enough ice cover in the Antarctic winter,
and the ice does not survive the summer season.
This is due to the summer ocean mixed layer being too shallow in the MOM ocean model compared to the
NEMO ocean model used by the MOHC and we have tested a number of ocean mixing schemes in an attempt
to improve our summer ice results.
Another sensitivity test we have done is to include the effect of the fresh water land ice flux from the UM in the
form of a pseudo iceberg flux which has been implemented as a freshwater and latent heat loss from the ocean
in a region of the coast off Antarctica and Greenland though avoiding the key bottom water formation areas.
Early results from these tests have allowed the ice to survive through the summer season and gives more
realistic autumn ice extents in the model.

1958
2269
A Robust Solver for Viscous Plastic Sea Ice Models in a Finite Element Framework

Carolin Mehlmann1 (carolin.mehlmann@ovgu.de), Thomas Richter1

1
Universität Magdeburg, Magdeburg, Germany

Subject of this talk are the mathematical challenges and the numerical treatment of large scale sea ice
problems. The model under consideration goes back to Hibler (Hibler 1979) and is based on a viscous-plastic
description of the ice as a two-dimensional thin layer on the ocean surface.
We present a new efficient Newton solver. The idea of the solver is to combine a fixed-point iteration (Picard
solver) with a Newton method. We analytically derive the Jacobian and show its positive definiteness. The
positive definiteness guarantees global convergence of a properly damped (e.g. line search) Newton iteration.
The Jacobian is split into a positive definite part, which is assumed to give stable convergence and a negative
semidefinite part, which might be troublesome. The negative semidefinite part is adaptively damped if
convergence worsens and the Newton solver turns towards a Picard iteration. We show the improved
robustness of the modified Netwon solver and compare it to a full Newton scheme. In every Newton step a
linear system of equations must be solved. We introduce a geometric multigrid solver as preconditioner to
accelerate the solution of the linear problems.
C. Mehlmann, T. Richter, A Finite Element Multigrid-Framework for Discretizing Sea Ice Dynamics, Journal of
Computational Physics 348, p. 847-861, 2017.
C. Mehlmann, T. Richter, A modified Newton solver for viscous-plastic sea ice models, Ocean Modeling 116, p.
96-107, 2017.

1959
OC-3 - The role of museums in promoting polar heritage and advancing polar science
22.06.2018 16:00-17:30, C Sanada I

1417
How Nations Research, Collect and Communicate their Antarctic History

Ursula Rack1 (ursula.rack@canterbury.ac.nz)

1
Canterbury University, Gateway Antarctica, Christchurch, New Zealand

This paper will illustrate results from research on how to communicate the past in order to keep the balance
among national efforts, the international importance of Antarctic history, and today's Antarctic activity on the
southern continent. The research was made possible due to the New Zealand Winston Churchill Memorial
Fellowship 2018, which I was awarded in order to investigate how nations research, collect and communicate
their Antarctic history. The Fellowship award allowed me to work in the USA, the UK and Germany, in order to
examine archives and museums, to understand outreach programs to bring awareness of the Antarctic history,
so to understand the importance of the Antarctic to each of those nations. Many of the current National
Antarctic Programs have their foundations on this history. New countries are now participants in the Antarctic
research community, and there is a need for them to be aware of their own history in that regard. The wider
public too plays a role, as, often, the general public are not conscious of their own history. Museums play a
great part in education and in communicating the past so that people can understand developments in the
present. Personal stories, sometimes collected in oral history programs, diaries, photos and artifacts are a great
resource that can be used to connect with the wider public.

1960
63
Argentine Museums Cooperation in Antarctic Study - Inspiring and Educating

Carlos Vairo1 (director@museomaritimo.com)

1
Museo Maritimo de Ushuaia, Museo Antartico Jose Maria Sobral, Ushuaia, Argentina

Doing research in Antarctica turned out to be a difficult task. We started using a sailing boat (the 47-feet ketch
Callas) in 1994. It was quite an adventure. Still, the size of the sailing boat did not allow us to take the
necessary equipment on board. Our aim was finding the sunken and abandoned ships of whalers that sailed
around the Antarctic Peninsula (Le Maire and Gerlache straits) between 1906 and 1930. We conducted a
mapping. Then, we organized other voyages aboard the Irizar, an icebreaker of the Argentine Navy. This was
equipped with all we needed, but it is so big that we could not approach sites. Then came voyages on tourist
icebreakers - the Academik IOFFE and the MIKIEV. This only served to visit new places. Thanks to a group of
businessmen that bought a small icebreaker at Moss (148 feet long), a joint venture was made with the
National Naval Museum, the Maritime Museum of Ushuaia, the Antarctic Museum José María Sobral, and the
Itinerant Museum Ice Lady Patagonia. Expeditions were conducted until 2007. The Museum heritage was
increased. And now we got the final results involving six partners: a new museum, and cooperation among
museums and research institutes resulted in books, TV cartoons, and magazines for students. These engaging
materials inspire and educate citizens on polar regions and their issues.

1961
622
Antarctic Legacy of SA Collaborates to Celebrate South Africa's Polar Heritage

Anche Louw1 (anchelouw072@gmail.com)

1
University of Stellenbosch, Botany and Zoology, Stellenbosch, South Africa

In 2017 the Antarctic community celebrated International Polar Week from the 18th to the 24th of September,
together with all involved in polar research over the world. South Africans also celebrate our rich heritage in
September, whereby we celebrate the various cultures that constitute our heritage. ALSA (Antarctic Legacy of
South Africa) saw this as an opportunity and coincided heritage and Polar Week celebrations by creating the
slogan 'Celebrating SA's Polar Heritage'.
South Africa has a rich Polar Heritage, due to our involvement in Antarctica (SANAE Base) since 1959 and in the
sub-Antarctic since 1947 when the Prince Edward Islands became South African territory. ALSA plays a crucial
role in archiving this history and was invited to exhibit SA's Polar Heritage at the Iziko Museum of South Africa
in Cape Town in September when we celebrated our Polar Heritage. Celebration efforts was focussed on the
Marion Island Exhibition in the Iziko Museum, enabling ALSA to fulfil the role of preserving and promoting
South Africa's involvement in the Polar region.
This presentation will focus on the role of ALSA to collaborate with the Iziko Museums of South Africa in
promoting polar heritage and advancing polar science in South Africa.

1962
1838
Polar Lab: Connecting Across Borders

Julie Decker1 (jdecker@anchoragemuseum.org)

1
Anchorage Museum, Executive, Anchorage, United States

The Anchorage Museum's Polar Lab program connects across disciplines and across the Circumpolar North.
Focusing on people and the environment, the Museum works with artists, designers, scientists, historians,
social scientists, Indigenous communities and others to examine a complex and changing landscape. The Arctic
region is changing rapidly, in ways that dramatically affect people's lives and ecosystems. Polar Lab places the
museum in the role of a convener, to operate across sectors and disciplines. The Museum brings designers and
scholars from Alaska and around the world to the Arctic landscape for long-term, multi-year research projects
that connect to scientific research and Indigenous knowledge related to the environment. By supporting non-
traditional research, we create new investigations, new collaborations, and new knowledge, that is informed by
centuries of adaptation. Current artists, designers and scholars-in-residence through Polar Lab are investigating
everything from the global migration of Arctic terns, pingos, place names and language, polar bear dens, food
security, changes to Arctic animal species, walruses, timekeeping in remote places, and other areas that enrich
our understanding of place and environment. This presentation will explore the role of museums in polar
heritage and advancing polar science through non-traditional collaborations and residencies and bold programs
that redefine standard museum practice.

1963
1259
The Centre for Arctic Knowledge & Exploration at the Canadian Museum of Nature

Jeffery M. Saarela1 (jsaarela@mus-nature.ca)

1
Canadian Museum of Nature, Centre for Arctic Knowledge & Exploration, Ottawa, Canada

For over 100 years, the Canadian Museum of Nature (CMN) has been a leader in exploring and documenting
the natural history and natural science of Canada's Arctic. Today, the museum's Centre for Arctic Knowledge &
Exploration (CAKE) aims to transform people's understanding of Canada's Arctic and to position the CMN as a
global museum leader in Arctic knowledge and exploration. The CAKE is an interdisciplinary hub dedicated to
research, collections development and care, data sharing, public programs, exhibits, galleries, and mentoring of
students. Current Arctic research programs focus on Arctic biodiversity in botany, phycology, palaeontology,
and invertebrate and vertebrate zoology. A core function of the museum is the collection, preservation,
stewardship and curation of natural history specimens, facilitating access to these specimens, and using the
collection to engage and educate the public. Among the 14.6 million specimens housed by CMN are about
260,000 Arctic specimens, the largest natural history collection from the Canadian Arctic. These collections
represent a substantial component of the global Arctic natural history record. The CMN recently opened the
signature Canada Goose Arctic Gallery, comprising sections about Arctic geography, ecosystems, sustainability
and climate change, and including the Northern Voices Gallery, which provides an opportunity for Northern
communities to share their own perspectives about the Arctic and their relationship with the land.

1964
2107
Putting Natural History Collections of Antarctic Museums to Work

Stefano Schiaparelli1,2 (stefano.schiaparelli@unige.it), Maria Chiara Alvaro2, Matteo Cecchetto1,2, Diego

Fontaneto3, Claudio Ghiglione2, Alice Guzzi1,2, Paola Piazza2
1
Università degli Studi di Genova, DISTAV, Genova, Italy, 2Museo Nazionale dell'Antartide 'Felice Ippolito' (Sez.
di Genova), Genova, Italy, 3National Research Council, Institute of Ecosystem Study, CNR-ISE, Verbania Pallanza,
Italy

Museums and other natural history collections (NHCs) worldwide house millions of specimens, contributing to
science in a variety of ways. Given the expected environmental changes that will likely affect Antarctica, NHCs
of Antarctic organisms will become increasingly important in the future. In order to provide a good service to
the scientific community, all the materials stored and curated by Antarctic NHCs should be made accessible and
available, virtually leaving 'no jar behind'.
With this idea in mind, at the Italian National Antarctic Museum (MNA, Section of Genoa), the institution
hosting all the biological materials collected by the Italian PNRA, we have pinpointed five operational targets to
accomplish this mission: i) give a name to all the species/specimens present in our collections (~20,000 units);
ii) validate and publish distributional records in form of datapapers (e.g. in Zookeys); iii) publish all the available
images in the Antarctic Field Guide (http://afg.biodiversity.aq), iv) provide a freely accessible database of DNA
sequences from museum materials and v) publish a synthesis on the “Marine, Terrestrial and Limnetic fauna
and flora of Terra Nova Bay” (3 volumes). By following these steps (some of which already accomplished), all
the materials stored at the MNA and related information will be made permanently available to the scientific
community. The synthesis volumes will summarize more than 30 years of Italian research in the Terra Nova Bay
area.

1965
BE-9f - Life distribution and responses to environmental changes in Polar ecosystems
22.06.2018 16:00-17:30, C Sanada II

597
Breaking Down the Barrier: Biological Dispersal to the Antarctic

Ceridwen Fraser1 (ceridwen.fraser@anu.edu.au)

1
Australian National University, Fenner School of Environment and Society, Acton, Australia

Antarctica has long been considered to be biologically isolated. Indeed, many Antarctic organisms are endemic,
found nowhere else on the planet, and many have probably remained and evolved in the Antarctic for millions
of years. Yet molecular studies are starting to show some post-Gondwanan biological connections between
Antarctica and other parts of the world, suggesting that - at least occasionally - movement into and out of
Antarctica has occurred. Recent observations of floating marine organisms drifting on either side of the
Antarctic Polar Front also challenge the assumption that the Southern Ocean is an impassable barrier to
dispersal.
In this talk, I will present evidence that Antarctica is not biologically isolated - that organisms can, and
frequently do, cross the Southern Ocean and reach Antarctica. The unique ecosystems of Antarctica are
thererfore probably more a consequence of environmental extremes in the region than of isolation. With
global warming, we should expect to see successful establishment of numerous non-Antarctic species, even
without human-mediated transport of organisms to the region.

1966
2346
Benchmarking Southern Ocean Ecosystems in 2022-2023: A Proposal from MEASO2018

Andrew Constable1, Rowan Trebilco2 (rowan.trebilco@utas.edu.au), Huw Griffiths3, Julian Gutt4, Mark Hindell5,
Eileen Hofmann6, Philippe Koubbi7, Jessica Melbourne-Thomas1, Eugene Murphy3, Louise Newman8, Keith
Reid9, Yan Ropert-Coudert10, Jan Strugnell11, George Watters12
1
Australian Antarctic Division and ACE CRC, Kingston, Australia, 2University of Tasmania, Antarctic Climate &
Ecosystems CRC, Hobart, Australia, 3British Antarctic Survey, Cambridge, United Kingdom, 4Alfred Wegener
Institute, Bremerhaven, Germany, 5University of Tasmania / Institute for Marine and Antarctic Studies (IMAS) -
Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), Hobart, Australia, 6Old Dominion
University, Norfolk, United States, 7University of Pierre-and-Marie-Curie University, Paris, France, 8Southern
Ocean Observing System, Hobart, Australia, 9CCAMLR Secretariat, Hobart, Australia, 10CNRS - Chize, Chize,
France, 11James Cook University, Townsville, Australia, 12AMLR Program, SW Fisheries Centre, La Jolla, United
States

Circumpolar assessments of change in the Southern Ocean ecosystem have been advancing over the last two
decades. The Census of Antarctic Marine Life during the International Polar Year (leading to the SCAR
Biogeographic Atlas of the Southern Ocean) and Southern Ocean GLOBEC made substantial progress in unifying
approaches to characterising these ecosystems. The Fifth Assessment Review by Working Group II of the IPCC
highlighted that long term observations to measure ecosystem change are a priority. To date, long-term whole-
of-system biological observations in the Southern Ocean have been mostly concentrated in the Antarctic
Peninsula and Scotia Arc. The scientific communities of IMBER's ICED program, the Southern Ocean Observing
System and SCAR Life Sciences have been designing a program of work to advance these earlier programs to
have sustained circumpolar measurements of the Southern Ocean ecosystem for assessing change. A program
of co-ordinated circumpolar measurements of the ecological state of the ecosystem in 2022-2023 is to be
considered at the MEASO2018 conference in April 2018. The plans arising from these discussions will be
summarised in this presentation on behalf of contributors so far, with invitations to participate in further co-
ordination and implementation of the program along with synthesis of results.

1967
596
Comparing Methods for Ecoregionalisation using Sub-Antarctic Demersal Fish

Nicole Hill1 (nicole.hill@utas.edu.au), John McKinlay2, Scott Foster3, Piers Dunstan3, Skipton Woolley3, Dirk
Welsford2, Craig Johnson1
1
University of Tasmania/Institute for Marine and Antarctic Studies, Hobart, Australia, 2Australian Antarctic
Division, Kingston, Australia, 3Commonwealth Scientific and Industrial Research Organisation (CSIRO), Hobart,
Australia

Understanding the distribution of species and their relationship with the environment is a central goal in
ecology. Mapping these patterns also facilitates ecoregionalisation, the delineation of ecologically meaningful
spatial units to assist the planning and evaluation of management and conservation options. Statistical models
that link sparse biological data with more prevalent environmental data are fundamental in modelling and
mapping species' distributions and have successfully been used for key species in the Southern Ocean.
However, a suite of recently developed statistical methods identify and model patterns in the distribution of
multi-species assemblages; thus facilitating ecoregionalisation. We briefly review these methods, which
encompass algorithmic distance-based, machine learning, and GLMs with latent variables. Methods also differ
in how they define assemblages and predict into geographic space. We apply a selection of these methods to a
sub-Antarctic demersal fish dataset, comparing the resulting ecoregions and their interpretation in light of our
knowledge of this region. We discuss the relative dis/advantages of the approaches from a statistical,
ecological and pragmatic viewpoint. Taking into account the role of ecoregionalisation in conservation
management, we recommend the methods most appropriate to particular circumstances in describing and
capturing the relationships between environment and species distributions in the Southern Ocean.

1968
1165
Response of Antarctic Krill to Rapid Regional Warming over the Last 90 Years

Angus Atkinson1 (aat@pml.ac.uk), Simeon Hill2, Evgeny Pakhomov3,4, Volker Siegel5, Christian Reiss6, Valerie
Loeb7, Deborah Steinberg8, Frances Perry1, Katrin Schmidt9, Geraint Tarling2, Laura Gerrish2, Sevrine Sailley1
1
Plymouth Marine Laboratory, Plymouth, United Kingdom, 2British Antarctic Survey, Cambridge, United
Kingdom, 3University of British Columbia, Department of Earth, Ocean & Atmospheric Sciences, Vancouver,
Canada, 4Hakai Institute, Vancouver, Canada, 5Theunen Institute of Sea Fisheries, Hamburg, Germany,
6
Southwest Fisheries Science Center, La Jolla, United Kingdom, 7Moss Landing Marine Labs, Moss Landing,
United Kingdom, 8Virginia Institute of Marine Science, Gloucester Point, United States, 9University of Plymouth,
Plymouth, United Kingdom

Productive, high latitude ecosystems comprise some of the fastest warming marine habitats on the planet.
Stenothermal polar species might be sensitive to rising temperatures and loss of sea ice, but solid evidence is
still scarce and conflicting. Long-term, temporal-spatial coverage is a key to understanding climate change
responses, and Euphausia superba is one of the very few species with the necessary intensity of sampling, due
to its role in commercially exploited food chains. Within the KRILLBASE project we have rescued and compiled
all available net sampling data on krill spanning the period 1926-2016. KRILLBASE now comprises three
databases, on abundance of the larval stages, on postlarval abundance and on postlarval length, sex and
maturity stage. This has allowed a comprehensive analysis of long-term trends in abundance, distributional
range and body size. We have identified a strong bottom-up control on krill population dynamics, with the
Southern Annular Mode (SAM) influential in modulating recruitment across the SW Atlantic sector. This
presentation will discuss the implications of the ongoing trends that we are observing, in the context of future
access to spawning grounds, linkages to the rest of the food web, biogeochemical cycling and fisheries
management.

1969
1239
Climate Model Projections of under Ice Habitats for Antarctic Krill Larvae

Stuart Corney1, Jess Melbourne-Thomas1,2, Klaus Meiners1,2, Rowan Trebilco1, Roshni Subramaniam3
(roshni.subramaniam@utas.edu.au), Andrew Constable1,2
1
Antarctic Climate & Ecosystems Cooperative Research Centre, Hobart, Australia, 2Australian Antarctic Division,
Hobart, Australia, 3University of Tasmania, Institute of Marine and Antarctic Studies, Hobart, Australia

Overwintering of larvae underneath Antarctic pack ice is an important stage in the life cycle of Antarctic krill.
Previous work based on simplified climate change scenarios has demonstrated that simple assumptions for the
important characteristics of under ice habitats for larval krill can reveal surprising predictions for available
habitat under climate change: reductions in overall ice extent may not necessarily lead to less larval krill
habitat. Here we extend that approach using the ensemble of CMIP5 models. Despite variability in future
projections (and varying model skill in representing ice), all models project a significant decrease in sea ice
cover over the coming century across a range of scenarios. However, even at the resolution of GCMs,
reductions in total area do not necessarily lead to reductions in projected habitat. In this presentation, we
consider some of the regional differences in projected habitat change, including considering whether strength
of dependence of larval krill on winter sea ice may vary between regions of Antarctica. We also discuss
limitations to using GCM output for such analyses; specifically, that required variables are not retained from
runs of most models. We suggest that better dialogue between climate modellers and ecologists will help
maximise the utility of future GCMs for understanding the ecological implications of physical changes.

1970
1841
Sea Ice Dynamics on West Antarctic Peninsula Underlying Ecosystem Alterations

Oscar Schofield1 (oscar@marine.rutgers.edu), Hugh Ducklow2, Josh Kohut3, Deborah Steinberg4, William Fraser5
1
Center for Ocean Observing Leadership, COOL, Marine and Coastal Sciences, Rutgers, New Brunswick, United
States, 2Columbia University, Lamont-Doherty Earth Observatory, Palisades, United States, 3Rutgers University,
Marine and Coastal Sciences, Rutgers, New Brunswick, United States, 4Virginia Institute of Marine Science,
Gloucester Point, United States, 5Polar Oceans Research Group, Sheridan, United States

The sea ice of the West Antarctic Peninsula (WAP) has experienced significant change over the last fifty years.
Using 25-year spatial time series collected by the Palmer Long Term Ecological Research program, we assess
long-term patterns in sea ice, upper mixed layer depth and food web dynamics (phytoplankton, zooplankton,
higher trophic levels). Over decadal time scales, the heating on the WAP has been driven by subsurface
intrusions of the warm Antarctic circumpolar current onto the shelf that is topographically steered to the coast
terminating in regions of abundant penguin colonies presumably fueled by high productivity phytoplankton
blooms. Sea ice has steadily declined from the 1980's until a recent reversal that began in 2008. In the southern
WAP, upper ocean mixed layer depth has shallowed significantly and associated with the shallower mixed layer
is enhanced phytoplankton carbon fixation. Associated with the recent increases in sea ice has been a large
increase in the photosynthetic efficiency in both the northern and southern. Using a decade of glider data,
shallower mixed layers appear to promote phytoplankton blooms. There was significant inter-annual variability
in phytoplankton blooms, but high chlorophyll years, associated with diatoms, were associated with high krill
recruitment suggesting a tightly coupled ecosystem and strong bottom-up control of the food-web. Results
demonstrate the close fidelity between the biology and physics on the WAP.

1971
Poster & Beer III
22.06.2018 17:30-18:30, Foyer

Fri_1_EN-2_48
Diisopropylnaphthalene in Sediments of Arctic Fjord: Environmental Significance

Neelu Singh1 (neelu.singh0387@gmail.com), Rajan Sivaramakrishnan2, Krishnaiah Chikkamadaiah3

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Vasco da Gama, India, 2Indian National
Center for Ocean Information Services, Pragathi Nagar, India, 3Mangalore University, Mangalore, India

This study addresses the tracking of the presence of a synthetic aromatic compound, diisopropylnaphthalene
(DIPN) in the surface sediments of Kongsfjorden, an Arctic fjord fringing the International Arctic Research
Facilities of Ny-Ålesund, Svalbard. Increasing anthropogenic impacts in the form of Persistent Organic
Pollutants (POPs), related to human activities and increased use of fossil fuels have been observed at many
places along the Arctic regions. Our studies suggest that the source of DIPN to the fjord could be a result of
human activities at Ny-Ålesund and its environs While its present-day concentrations may not be alarming,
considering the increasing activities at Ny-Ålesund, it might be prudent to exercise caution to ensure that the
levels do not increase over time. This is the first such report of DIPN in the sediments of Kongsfjorden

1972
Fri_3_EN-2_174
Citizen Scientists: Marine Litter Pollutes Arctic Beaches and Affects Wild Life

Birgit Lutz1 (birgit@birgit-lutz.de), Melanie Bergmann1, Mine Tekman1, Lars Gutow1

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany

Recent data indicate accumulation areas of marine litter in Arctic waters and significant increases on the
seafloor over time. Beaches on remote Arctic islands may be sinks for marine litter and reflect pollution levels
of the surrounding waters particularly well.
We provide the first quantitative data from surveys carried out by citizen scientists, which participated in
sailing cruises around Svalbard in 2016. Litter quantities on six beaches varied from 9 - 524 g m-2 and were
similar to those from densely populated areas. Plastics accounted for > 80% of the overall litter, most of which
originated from fisheries. Photographs provided by citizens show deleterious effects of beach litter on Arctic
wildlife including polar bears (Ursus maritimus), which is already under strong pressure from global climate
change. Our study highlights the potential of citizen scientists to provide scientifically valuable data on the
pollution of sensitive remote ecosystems. Similar programmes could be adopted in other poorly sampled areas
of the world to increase our knowledge base and to stimulate a sense of connectedness with the environment
visited.

1973
Fri_4_EN-2_235
Perchlorate in Surface Snow along a Traverse Route in East Antarctica

Su Jiang1 (jiangsu@pric.org.cn), Jihong Cole-Dai2, Yuansheng Li1, Chunlei An1, Guitao Shi1
1
Polar Research Institute of China, Shanghai, China, 2South Dakota State University, Brookings, United States

Perchlorate in the environment is of significant interest because of potential threat to human health. Recent
research suggests that perchlorate is naturally formed in the atmosphere and atmospheric formation
constitutes a significantly large portion of perchlorate in the current environment. By virtue of its geographical
position and meteorological conditions, Antarctic ice sheet provides chronological records for atmospheric
deposition of different substances. Surface snow samples collected along a traverse route from Zhongshan
Station to Dome A in East Antarctica were used to assess the spatial variability of perchlorate along the
traverse route, to explore possible sources of perchlorate in Antarctic snow and to determine what
atmospheric and glaciological factors influence spatial variability of perchlorate in snow. Results show that the
perchlorate concentrations vary between 32 and 200 ng kg-1, with an average of 104.3 ng kg-1. Perchlorate
concentration profile presents an apparent decreasing relationship with increasing distance inland in the
coastal region and a generally increasing trend approaching the dome in the inland region. Perchlorate in
Antarctic snow is probably formed in the atmosphere and deposited in snow. Different rates of atmospheric
production, dilution by snow accumulation and re-deposition of snow-emitted perchlorate (post-depositional
change) are the three possible factors influencing the spatial variability of perchlorate over Antarctica.

1974
Fri_5_EN-2_253
High Altitude Lake Environments: Sinks for Chemical Pollutants?

Julia Kleinteich1 (julia.kleinteich@ifg.uni-tuebingen.de), Sven Seidensticker1, Kurt Hanselmann2, Andreas

Kappler1, Elif Koeksoy1, Jens Brückmann1, Maria-De-Lourdes Prieto-Espinoza1, Maria Schindler1, Nelly Wang1,
Christiane Zarfl1
1
University of Tuebingen, Center for Applied Geosciences, Tübingen, Germany, 2ETH Zurich, Microbial Ecology,
Zürich, Switzerland

The melting of alpine glaciers mobilizes compounds from anthropogenic origin such as persistent organic
pollutants that had been stored in the perennial ice for the last decades. Similarly, hydrophobic polyaromatic
hydrocarbons (PAHs), which are potentially carcinogenic and are released by combustion processes, are
compounds with the potential for long range transport to remote regions. These compounds that were
released decades ago may now be found in glacier ice and glacial streams. Since glacier-fed meltwater often
passes through several smaller and larger lakes in alpine glacier forefields, the hydrophobic PAHs can be
retained in the sediments of these lakes. We hypothesize that these sites serve as sinks for PAHs. During two
field seasons and at three different glaciers we quantified the concentrations of PAHs in sediments of lakes
along spatial gradients from the glaciers. We found PAHs in all samples, albeit in the lower concentration range
and three orders of magnitude less than in polluted streams in Germany. PAH concentrations decreased with
increasing distance from the glacier. Contrary to our hypothesis, we found higher concentrations of PAHs in
lakes, which were not directly fed by glacial meltwater but by snowmelt, rain and permafrost. This may be
caused by the temporal dynamics of input rates, the age of the lakes, but also due to other biotic and abiotic
factors that influence PAH distribution, such as the sediment composition and bacterial degradation.

1975
Fri_6_EN-2_323
Air Dispersion Modeling Application for Impact Assessment in the Antarctic

Sergey Kakareka1 (sk001@yandex.ru), Svetlana Salivonchyk1

1
Institute for Nature Management, National Academy of Sciences of Belarus, Minsk, Belarus

In the paper modelling results of air impacts of Mount Vechernyaya Belarusian Antarctic station using AERMOD
as well as available from Comprehensive Environmental Evaluations (CEE) of construction and operation of the
Antarctic research stations are considered. It is shown that emission dispersion models application for impact
assessment in Antarctica is limited: from 12 known cases of air impact assessment for CEE no dispersion
modeling was done in 6 cases; ICS3 model was applied in 2 cases; SYMOS97, OND-86 and AERMOD were
applied in other 4 cases. Among these results both short-term and long-term predicted concentrations were
obtained only for two stations: Jang Bogo Station, Korea and Mount Vechernyaya, Belarus. There is a number
of reasons of such limited application, first of all high time- and resource-consuming and lack of input data. But
more wide application of dispersion modeling in impact assessment in Antarctica is important as it allows to
get qualitative estimates of impacts and make projections.
Study have shown that taking into account restrictions it is possible to provide acceptable accuracy of pollution
dispersion model results, applying non-standard methods of interpolation of meteorological data. Air
dispersion can be combined with geochemical models for analysis of pollutants migration in soils and waters
and estimation of critical loads and thresholds. Possibilities of retrospective modelling for estimation of
cumulative impacts is also discussed.

1976
Fri_7_EN-2_372
Trace Elements in an Ultraclean Snow Pit on the King George Island

Nicoli Pozzebon Gerhard1 (nicoligerhard@gmail.com), Jefferson Cardia Simões1, Francisco Adolfo Ferron2,
Ronaldo Torma Bernardo1, Alexandre Lima Correia3, Franciéle Schwanck Carlos4
1
UFRGS, Porto Alegre, Brazil, 2Waters, Milan, Italy, 3USP, São Paulo, Brazil, 4The University of Maine, Orono,
United States

This work reports the analysis of 4.5 m pit sampled under ultra-clean conditions on the King George Island ice
cap (62°07'42.2”S and 58°36'39.9” W, 700 m a.s.l.), collected in 1997 and representing one year of snow
accumulation. We analysed 25 samples for trace elements, ionic content and stable isotopes in a site that
suffers intense post-depositional phenomena, with superficial melting, followed by percolation and refreezing.
Here we evaluate the anthropogenic and natural contributions for the concentrations in 47 trace elements,
determined by ICP-MS at the Laboratoire des Mecanismes et Transferts en Geologie in Toulouse (France). The
crustal enrichment factors are low for Al, Si, Ti, V, Cr, Mn, Fe, Co, Ga, Ge, Zr, Nb, Cs, Ba, Ce, Nd, Sm, Tl, Pb, and
Bi and the ocean enrichment factors are low for Na, Mg, Cl, K, Br, Sr, and I. The elements Li, C, P, S, Sc, Rb, Ta,
and U show mixed source (crustal and oceanic) and contributions of volcanic and/or biogenic source. Ni
(129.29 ± 163.48 pg g-1), Cu (93.51 ± 106.26 pg g-1), Zn (214.76 ± 124.14 pg g-1), As (8.93 ± 7.54 pg g-1), Se (63.10
± 42.37 pg g-1), Mo (10.18 ± 3.63 pg g-1), Ag (6.38 ± 6.79 pg g-1), Cd (399.36 ± 880.65 pg g-1), Sn (17.65 ± 10.99 pg
g-1), Sb (4.17 ± 3.51 pg g-1), W (15.74 ± 11.05 pg g-1) and Hg (1.19 ± 0.71 pg g-1) show high enrichment factors,
suggesting anthropogenic inputs and/or local contamination.

1977
Fri_8_EN-2_411
PBDEs vs Biological Traits in Boreogadus saida from NE Greenland

Alice Marri1, Kim Præbel2, Alessandra Cincinelli1, Tania Martellini3, Davide Baroni1, Simonetta Corsolini1
(simonetta.corsolini@unisi.it)
1
University of Siena, Department of Physics, Earth and Environmental Sciences, Siena, Italy, 2UiT The Arctic
University of Norway, Norwegian College of Fishery Science, Tromsø, Norway, 3University of Florence,
Department of Chemistry 'Ugo Schiff', Florence, Italy

Polybrominated diphenylethers (PBDEs) are flame retardants used worldwide. Their physical-chemical
properties allow them to reach the Polar Regions and enter into the food webs. Boreogadus saida is a key
species in high Arctic marine ecosystems, connecting lower and higher trophic levels in the food web. In NE
Greenland B. saida forms populations with differentiated life histories in fjords and offshore waters,
respectively. The main aim of this study was to elucidate whether PBDEs accumulate differentially in these
populations. We collected B. saida specimens inside a fjord (Scorebysund Fjord, n=50) and at the NE Greenland
continental shelf (n=40) during the TUNU II expedition. We measured biological parameters and 24 PBDE
congeners and we correlated PBDEs and biological traits; we calculated Fulton´s condition factor,
hepatosomatic index, gonadosomatic index.
The ∑PBDE concentrations were 0.33±0.16 and 0.31±0.08 ng/g wet weight in fish muscle from the shelf and the
fjord, respectively. BDE183>BDE47>BDE28 were the most abundant in all specimens, with BDE99 in individuals
from the fjord representing the lowest concentration. Positive and significant correlations between PBDEs vs
length and PBDEs vs weight were observed in fish from fjord (p< 0.05), while these correlations were negative,
but still significant (p< 0.05), for B. saida inhabiting the shelf.
To our knowledge, this is the first study on the correlation between contaminants and biological parameters in
B. saida.

1978
Fri_9_EN-2_522
Geographic Variability in Gentoo Penguin Mercury Burdens

David Schutt1 (david.schutt@ucdenver.edu)

1
University of Colorado Denver, Integrative Biology, Denver, United States

Numerous studies have shown increases of mercury throughout the environment as a result of increased
anthropogenic pollution. As contaminant loads continue to rise, investigations have turned toward monitoring
mercury throughout the isolated southern polar region, often using penguins as biomonitors in both the
Antarctic and sub-Antarctic region. The utility of penguins as biomonitors of contaminants throughout the
Southern Hemisphere has been demonstrated due to their confinement within relatively localized geographic
ranges, their widespread distribution, their status as high trophic predators, and their unique simultaneous
molt that produces homogeneous feathers. Gentoo penguins (Pygoscelis papua) in particular occupy the widest
latitudinal breeding range of any penguin species and may be characterized as highly pragmatic biomonitors
across both the sub-Antarctic and the Antarctic, however numerous studies have shown Gentoo penguins have
high inter-population variability in their mercury burdens. For this study, we investigate mechanisms that
generate differences in Gentoo penguin mercury burdens between South America and Antarctica through the
use of multi-tissue mercury and stable isotope analyses in contemporary samples. We also reconsider the
feasibility of estimating Gentoo mercury exposure trends in relation to the high inter-population mercury
variability of this widely distributed species.

1979
Fri_10_EN-2_555
Accumulation of Crude oil in Arctic Marine Zooplankton

Mette Dalgaard Agersted1 (metteagersted@gmail.com), Eva Friis Møller2, Kim Gustavson2

1
University of Oslo, Oslo, Norway, 2Aarhus University, Roskilde, Denmark

A future increase in oil and gas activities in the Arctic will increase the risk for accidental oil spills. Due to high
lipid content in polar organisms, bioaccumulation of lipophilic contaminants, which are present in crude oil, is
more prone to take place. In Disko Bay, West Greenland, we conducted crude oil exposure experiments with
three co-existing ecologically important zooplankton species; the lipid rich Arctic copepod Calanus
hyperboreus, the smaller and less lipid rich Atlantic copepod C. finmarchicus and larvae of the shrimp species
Pandalus borealis, which has the lowest lipid content of the three species. Our results show that lipid rich
zooplankton species accumulate heavy hydrocarbon groups, despite that the crude oil they were exposed to
mainly consisted of light hydrocarbon groups. Results also indicate that grazing activity in lipid rich zooplankton
may be less directly affected by short-term crude oil exposure compared to less lipid rich species. Furthermore,
data reveal that elimination rates of crude oil model compounds are minimal and that even short-term
exposure may result in long-term bioaccumulation and internal exposure of oil compounds in lipid rich
zooplankton. Slow elimination and depuration of oil components indicate a risk for transfer of oil component
up the Arctic food web to pelagic fish, seabirds and baleen whales.

1980
Fri_11_EN-2_726
Plastic Pollution in the Southern Ocean and its Impact on Antarctic Wildlife

Liliana Keslinka1 (liliana.keslinka@gmail.com)

1
Institute of Biochemistry and Biophysics, Department of Antarctic Biology, Warszawa, Poland

The microplastic pollution of the marine ecosystem is a growing issue that is repetitively reported. Antarctica,
once believed to be pristine, is also threatened by microplastic pollution, however not enough data exists to
estimate the size of the damage and the impact of microplastic on the Antarctic environment, especially
Antarctic wildlife.
The aim of the project is to collect and analyze water samples south and north of the polar front in the
Southern Ocean in order to establish the extent of microplastic pollution. The samples will be collected at
Drake Passage, in the Southern Ocean off the east coast of South America and along the Antarctic Peninsula,
north and south of the polar circle, within 100 meter water column, what corresponds to the depths at which
gentoo penguins forage. Further, sampling of juvenile gentoo penguin's digestive systems (carcasses found in
colonies) is planned in order to find out, whether at the earliest stage of life parents are feeding the chicks with
a) food contaminated by microplastic b) big plastic particles, in order to assess the impact of the plastic
pollution on the Antarctic biota. Sampling and analyzes will be conducted according to standardised method
scheme provided by the NOAA Marine Debris Program. The surveying will take place on board of mv Ocean
Diamond in cooperation with Quark Expeditions Inc. between January and March 2018. The preliminary results
and conclusions will be presented in June at the POLAR 2018 conference.

1981
Fri_12_EN-2_742
Polybrominated Diphenyl Ethers (Pbdes) in Indoor Environments from Antarctica

América Metzdorff1 (merirebe@gmail.com), Karla Pozo2, José Luis Roscales3, Elena Cerro3, Begoña Jiménez3,
Cristóbal Galbán-Malagón4, Elisa Bergami1, Matias Poblete5, Ruben Avendaño5, Petra Přibylová2, Jordi Dachs3,
Simonetta Corsolini1
1
University of Siena, Department of Physical, Earth and Environmental Sciences, Siena, Italy, 2Masaryk
University, Faculty of Science, Research Centre for Toxic Compounds in the Environment, Brno, Czech Republic,
3
Consejo Superior de Investigaciones Científicas, Instituto de Química Orgánica General, Madrid, Spain,
4
Universidad Andres Bello, Departamento de Ecología y Biodiversidad, Facultad de Ecología y Recursos
Naturales, Santiago, Chile, 5Universidad Andres Bello, Laboratorio de Patología de Organismos Acuáticos y
Biotecnología Acuícola, Viña del Mar, Chile

Polybrominated diphenyls ethers (PBDEs) are nowadays widely used as flame retardants in electronic
components, plastics, textiles and buildings materials. Their commercial mixtures Penta-BDE and Octa-BDE
were banned in the European Union because of their toxic effects. Due to their physical-chemical properties,
PBDEs can be found in the indoor dust. In this study dust samples were collected from two Antarctic research
bases, the Gabriel de Castilla and Prof. Julio Escudero Stations, and a research vessel, the R/V James Clark Ross
of the British Antarctic Survey. The PBDE concentrations ranged from 0.1 to 69 ng/g dust. Sample from the
Gabriel de Castilla Base showed the highest levels of the ∑PBDEs, 302 ng/g, followed by those from the James
Clark Ross Base, 166 ng/g, and the Julio Escudero Base, 80 ng/g. BDE99 was the most abundant congener in the
Gabriel de Castilla Base sample (48 ng/g, contributing ~50% of the total BDE burden) followed by BDE47 (41
ng/g, ~40% of ∑PBDEs), and BDE100 (10 ng/g, ~10% of ∑PBDEs).

1982
Fri_13_EN-2_936
Melting Glaciers Stimulate Hg Cycling in High Altitudes in the Tibetan Plateau

Qianggong Zhang1 (qianggong.zhang@itpcas.ac.cn)

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

Glaciers at high-altitude mountains have been receding globally at an accelerated rate in recent decades. The
glacial melt-induced release of pollutants (e.g., mercury) and its potential impact on receiving environments
has drawn increasing concerns. During 2011-2015, we performed intensive sampling on diverse waters in a
typical glacierized basin - Qugaqie Basin (QB), in the inland Tibetan Plateau, to investigate the export and
transport of mercury from glacier to downstream environment. The total mercury (THg) concentrations in
waters showed a decreasing order of glacier snow, glacier, meltwater, glacial runoff, and wetland. Particulate
Hg was the predominant form in all sampled waters except for that of wetland. THg in runoff showed a clear
diurnal variation and is closely linked to glacier melt intensity. We estimated that annual Hg exports by the
glacier, the upper river basin and the entire QB were 8.76, 7.3 and 157.85 g, respectively, with respective yields
of 4.61, 0.99 and 2.74 µg m-2 yr-1. Unique landforms and significant gradients in mountain regions can promote
weathering and erosion, thereby controlling the transport of Hg. In comparison with other glacier-fed river
basins globally, QB has a small Hg export yet remarkably high Hg yield, underlining the significant impact of
melting alpine glaciers on regional Hg cycles. Such impacts are expected to be enhanced in high altitude regions
under the changing climate.

1983
Fri_14_EN-2_984
The Impact of Nanoplastics on Antarctic Krill Euphausia superba

Elisa Bergami1 (bergami@student.unisi.it), Clara Manno2, Maria Luisa Vannuccini1, Claire M. Waluda2, Simone
Cappello3, Ilaria Corsi1
1
University of Siena, Dep. of Physical, Earth and Environmental Sciences, Siena, Italy, 2British Antarctic Survey,
Cambridge, United Kingdom, 3National Research Council of Italy, Institute for Coastal Marine Environment,
Messina, Italy

Under current climate change scenarios, Antarctic krill (Euphausia superba) is facing multiple stressors which
could affect its abundance and distribution. Microplastics have been recently reported in Antarctic waters,
representing an additional potential impact on krill population. In this study we investigated the effects of
model nanoplastics (< 1 µm) on krill juveniles through short-term exposure (48h) of polystyrene nanoparticles
(PS NPs) with different surface charge. The behaviour of anionic (60 nm PS-COOH) and cationic (50nm PS-NH2)
NPs in Antarctic natural seawater (NSW, 34‰, 2°C) was also investigated by Dynamic Light Scattering. PS-COOH
formed nanoscale aggregates (average size of 862nm) in Antarctic NSW, while PS-NH2 maintained their nominal
size. No mortality was observed upon exposure to 2.5µg/ml PS NPs after 48h. However, krill exposed to PS-NH2
showed lower motility than individuals exposed to PS-COOH and were characterised by significant up-
regulation of cb6 gene involved in new cuticle formation. Similar findings reported for other microcrustaceans
have been associated with mortality over long-term exposure. Both PS NPs also accumulated in faecal pellets
(FPs), which were characterised by lower density and sinking rate compared to control. Our findings
demonstrate that PS NPs are able to affect swimming behaviour, cuticle formation and FPs properties of
Antarctic krill, with potential serious consequences on Southern Ocean food web and biogeochemical cycle.

1984
Fri_15_EN-2_1073
Antibiotic Resistance in Escherichia coli Strains from Antarctic Seawater

Nancy Calisto Ulloa1 (nancy.calisto@umag.cl), Claudio Gómez Fuentes1

1
Universidad de Magallanes, Departamento de Ingeniería Química, Punta Arenas, Chile

Antimicrobial resistant bacteria are widespread in aquatic environments. The aim of the present study was to
obtain information on the occurrence of bacteria with antimicrobial resistance in seawater surrounding
Antarctic stations.
Escherichia coli strains were isolated from seawater. The samples were collected from sites distributed around
the sewage outfalls of six Antarctic stations. Antibiotic susceptibility patterns were determined with the disk
diffusion method, using different groups of antibiotics: penicillins, carbapenems, aminoglycosides, quinolones,
tetracycline, phenicols, and trimethoprim. Escherichia coli ATCC 25922 was used as the control for the tests.
A total of 213 samples were analysed. E. coli were detected in 58 % of the samples. The highest bacterial
counts were found in seawater surrounding the sewage outfalls. However, the bacterial counts decreased
rapidly with increasing distance from the outfall. Seventy strains isolated were studied to determine antibiotic
susceptibility. The strains studied showed resistant to 16 out of the 18 antibiotics tested. Thirty-seven strains
were susceptible to all the antibiotics tested, and 21 showed susceptibility or intermediate susceptibility to
Ampicillin. Thirty-three were resistant to at least one antibiotic, and 11 were multidrug resistant.
The presence of bacteria with antimicrobial resistance in the Antarctic environment is indicative of how
widespread the global antibiotic resistance situation has become.

1985
Fri_16_EN-2_1258
Total Petroleum Hydrocarbons in Sediment Around Four Antarctic Stations

Claudio Gómez-Fuentes1 (claudio.gomez@umag.cl), Nancy Calisto-Ulloa1

1
Universidad de Magallanes, Ingeniería Química, Punta Arenas, Chile

Total petroleum hydrocarbons (TPH), pH and nutrients were analyzed in intertidal sediment samples for three
years (2014 to 2016). The samples were taken at increasing distances from the discharges of 4 Antarctic
stations, located in Bahía Fildes and Bahía Potter.
The maximum average values, considering the three years analyzed, were 1576 and 1180 (mg TPH / kg) for
Bahía Fildes and Bahía Potter respectively. The results show that the differences between the years analyzed
are not significant, suggesting that the impact of the TPH on the environment remains approximately constant
over time. Statistically significant differences are observed between both bays. The points of greatest impact
correspond mainly to the places where maneuvers are carried out with boats. In Fildes Bay, these points
coincide with the wastewater treated discharges from two stations.
The cluster statistical analysis shows that the samples are grouped according to the activities carried out on the
coast, separating the points without human activities in a distinct cluster.
The results of nutrients (nitrogen and phosphorus) in the sediments do not show relationship with the
discharges or with the maneuvering sites of boats. These results seem to be more influenced by local
situations, such as the presence of backwaters and algae.
This study shows that the maximum pollution detected, with high local values TPH, are confined to places
where boat maneuvering and wastewater discharges occur.

1986
Fri_17_EN-2_1399
Occurrence of PBDEs in the Greenland Shark Somniosus microcephalus

Salvatore Cotronei1 (salvatorekr82@hotmail.it), Karla Pozo2,3, Jiří Kohoutek2, Petra Přibylová2, Julius Nielsen4,
Simonetta Corsolini1
1
University of Siena, Department of Physics, Earth and Environmental Sciences, Siena, Italy, 2Masaryk University,
Research Centre for Toxic Compounds in the Environment, Brno, Czech Republic, 3Universidad Católica de la
Santísima Concepción, Facultad de Ciencias, Concepción, Chile, 4University of Copenhagen, Department of
Biology, Copenhagen, Denmark

Polybrominated-diphenyl ethers (PBDEs) include a class of brominated flame retardants (BFRs) that are added
to many products (e.g. plastics, household textiles, etc.) to reduce their flammability. The top predator
Greenland shark Somniosus microcephalus is an important cold-water species with slow growth and it is also
the longest-lived vertebrate known, for these reasons it is vulnerable to bioaccumulation of POPs.
PBDE concentrations in the muscle and liver of fifteen Greenland sharks were evaluated and then correlated to
the tissue lipid content and age/sex of sharks. ∑PBDEs ranged from 0.143 to 82 ng/g (mean 20 ± 25) lipid wt in
the liver and from 2.49 to 57 ng/g (mean 14.1 ± 15.2) lipid wt in the muscle. The percentage contribution of the
PBDE congeners showed the following patterns: BDE-47 > BDE-28 > BDE-154 >BDE-209 > BDE-99 > BDE-100 >
BDE-85 > BDE-66 > BDE-153 > BDE-66 > BDE-183 in the liver, and BDE-47 > BDE-99 > BDE-100 >BDE-28 > BDE-
209 > BDE-154 > BDE-153 > BDE-66 > BDE-85 > BDE-183 in the muscle. Our results showed that sex and
age/size may not be the main factors affecting the BDEs bioaccumulation in liver and muscle, since no
significant differences were observed between males and females or age groups.

1987
Fri_18_EN-2_1401
POPs in Cod Fish and Greenland Halibut from NW Greenland

Salvatore Cotronei1 (salvatorekr82@hotmail.it), Karla Pozo2,3, Ondřej Audy2, Jiří Kohoutek2, Petra Přibylová2,
Julius Nielsen2, Simonetta Corsolini1
1
University of Siena, Department of Physics, Earth and Environmental Sciences, Siena, Italy, 2Masaryk University,
Research Centre for Toxic Compounds in the Environment, Brno, Czech Republic, 3Universidad Católica de la
Santísima Concepción, Facultad de Ciencias, Concepción, Chile

The Atlantic cod Gadus morhua, the Greenland cod Gadus ogac and the Greenland halibut Reinhardtius
hippoglossoides are particularly sensitive to persistent organic pollutants (POP) exposure, playing an important
role in monitoring the potential effects of these chemicals in Arctic marine ecosystems.
DDTs, PCBs, PBDEs and HBCDs were determined in the muscle of five cod and five Greenland halibut specimens
collected in the Uummannaq Fjord (NW Greenland). The lipid content ranged 14.5-50% in cod fish and 46-82 in
the Greenland halibut. No significant relationship was observed correlating lipid content and POP
concentration in these species. The POP contribution to the total residue was PBDEs > PCBs > DDTs > HBCDs in
both the cod fish and PCBs > DDTs > PBDEs > HBCDs in the Greenland halibut. The ratio ΣDDTs/ΣPCBs was
significantly lower than 1 in cods (0.384-0.989 ng/g lw) respect to the Greenland halibut (0.793-1.47 ng/g lw),
suggesting a higher POP contribution of industrial and agricultural origin in the two species, respectively,
and/or a different inter-specific DDT and PCB bioaccumulation processes. Further investigations are needed
since these fish species are commonly eaten by humans and are thus considered an important economic
resource.

1988
Fri_19_EN-2_1422
Source Assessment of Trace Elements in the Polar Regions by Isotopic Analysis

Francisco Ardini1 (ardini@chimica.unige.it), Marco Grotti1, Andrea Bazzano1,2, Frank Vanhaecke2, David
Cappelletti3, Rita Traversi4, Silvia Nava5, Mery Malandrino6
1
University of Genoa, Department of Chemistry and Industrial Chemistry, Genoa, Italy, 2Ghent University,
Department of Analytical Chemistry, Ghent, Belgium, 3University of Perugia, Department of Chemistry, Biology
and Biotechnologies, Perugia, Italy, 4University of Florence, Department of Chemistry Ugo Schiff, Sesto
Fiorentino, Italy, 5University of Florence and INFN-Firenze, Department of Physics, Sesto Fiorentino, Italy,
6
University of Turin, Department of Chemistry, Turin, Italy

A thorough assessment of the exposure of the Polar environments to contaminants from local and distant
areas requires the identification of their sources and transport patterns and the capability to distinguish
between natural and anthropogenic inputs. In this context, lead and strontium isotope ratios proved to be very
powerful, providing information not easily achievable otherwise. In particular, the 208Pb/207Pb and 206Pb/207Pb
values differ significantly between crustal and ore Pb deriving from various locations and mining areas, whereas
natural variations of 87Sr/86Sr can be used for tracing the geographical sources of mineral dust.
In the framework of PNRA (National Program for Antarctic Research) and RIS (Research in Svalbard) projects we
have developed and have successfully applied novel analytical procedures based on both single- and multi-
collector inductively coupled plasma-mass spectrometry, thus obtaining interesting information on the sources
and transport pathways of trace elements in various environmental compartments.
Representative results concerning the marine environment of Kongsfjorden (The Arctic), the atmospheric
particulate reaching Ny-Ålesund (The Arctic) and Terra Nova Bay (Antarctica), and the surface snow
accumulating at Dome C (Antarctica) will be presented and discussed, together with preliminary results of the
ongoing SIDDARTA project, the aim of which is studying present-day sources and transport processes of
mineral dust to the Antarctic plateau.

1989
Fri_20_EN-2_1437
Orographic and Anthropogenic impact at Antarctica and POPs Contamination

Tanu Jindal1 (tjindal@amity.edu)

1
Amity Uinversity, Amity Centre for Antarctic Research and Studies and Amity Institute of Environmental
Toxicology, Safety and Management, Noida, India

Over the past decades, research in Antarctica has built a new understanding of Antarctica, its past, present and
future. Human activities and long range pollutants are increasing on the Antarctic continent. Research on
Persistent Organic Pollutants (POPs) have been carried out internationally by several countries having their
permanent research stations to explain the impact of an ever increasing range of POPs in Antarctic ecosystem.
POPs have been detected in Antarctica despite its geographical isolation and almost complete absence of
human settlements. Presence of POPs in different abiotic (atmosphere, water bodies, sediments, soil, sea ice)
and biotic components (mosses, lichens, krill, penguins, skua etc.) in Antarctica have been studied and
documented around for decades and have either been banned or strictly regulated but are still found in the
environment. This review focuses on recent research pertaining to sources and occurrence of POPs in Antarctic
lake water, soil, sediment, lichen, mosses and other Antarctic marine community. The talk proposes to
summarize the current state of research on POPs in Antarctica environment and draw the earliest conclusions
on possible significance and impact of POPs in Antarctica based on presently available information from related
Antarctic environment.
Keywords: Persistent Organic Pollutants (POPs), Biotic and Abiotic Compounds, Ecotoxicology and Antarctic
Pristine Environment.

1990
Fri_21_EN-2_1609
Organic Compounds Emitted by Ships as Potential Contaminants in Polar Regions

Simone Pieber1 (simone.pieber@hotmail.com), Yunliang Zhao2, Dogushan Kilic1, Benjamin Stengel3, Joel
Corbin4, Jürgen Orasche5, Felix Klein1, Imad El Haddad1, Hendryk Czech3, Urs Baltensperger1, Allen Robinson2,
Ralf Zimmermann5, Jay Slowik1, André Prévôt1
1
Paul Scherrer Institute, Villigen, Switzerland, 2CMU, Pittsburgh, United States, 3University Rostock, Rostock,
Germany, 4National Research Council Canada, Ottawa, Canada, 5Helmholtz Zentrum Munich, Munich, Germany

Maritime transport is a globally important source of submicron particulate matter and gaseous pollutants. Ship
engines typically combust low-grade fuels without application of exhaust gas after-treatment systems. Hence,
they may constitute an important source of air pollution in Polar Regions. The composition of gas phase organic
species and the identification of important precursors for secondary organic aerosol (SOA) formed from ship
emissions itself remain largely uncharacterized. We investigate the semi-, intermediate- and volatile primary
organic carbon (S-/I-/VOC) emitted from a ship engine operated with heavy fuel and marine gas oil. VOC
analysis is performed using proton-transfer-reaction mass spectrometry. This is complemented by analysis of
sorbent and filter samples using gas chromatography-mass spectrometry. We find a large fraction of aromatic
and polycyclic aromatic hydrocarbons in the emissions, present emission factors of those species and an
estimated SOA potential providing relevant information also for assessments in Polar Regions.

1991
Fri_23_EN-2_1834
Characterization of HMW TPH Patterns from Soil at McMurdo Station, Antarctica

Stephen Sweet1 (sweet@gerg.tamu.edu), Klein Andrew2, Yina Liu1, Terry Palmer3, Jose Sericano1, Terry Wade1
1
Texas A&M University, GERG, College Station, United States, 2Texas A&M University, Geography, College
Station, United States, 3Texas A&M University-Corpus Christi, Harte Research Institute for Gulf of Mexico
Studies, Corpus Christi, United States

McMurdo Station is located in an approximately 4 km2 ice free area at the southern tip of the Hut Point
Peninsula on Ross Island, Antarctica. The summer population of over 1000 people makes it by far the largest
population center on the continent. Human occupation at the site dates back to 1902. Spatial patterns of Total
Petroleum Hydrocarbons (TPH) measured in the terrestrial environment surrounding McMurdo Station during
the period from 1999 through 2015 as part of a long-term environmental study indicated many areas with little
to no impact. There are areas with elevated TPH which are found associated with helicopter operations,
refueling operations, vehicular usage and near parking/vehicular maintenance operations. Petroleum
hydrocarbons in impacted McMurdo Station soils are characterized by a low molecular weight (LMW)
gasoline/JP5/AN8, residual weathered petroleum TPH signature and a HMW signature that has not been
characterized. The LMW TPH pattern suggests relatively freshly released petroleum in surficial soils with n-
alkanes resolved on an unresolved complex mixture hump. The high molecular weight compounds are spatially-
linked and generally restricted to vehicular operations such as historical roadways and parking areas. However,
the actual composition of this HMW component has not yet been explored. This research explores the
composition of this HMW pattern using GCxGC TOF/MS and Ion Mobility Q-TOF LC/MS which should provide
better insight into its origins.

1992
Fri_24_EN-2_1930
Inputs of Halobenzenes to Ice Cores at Svalbard and Antarctica

Mark Hermanson1 (markhermanson@me.com), Elisabeth Isaksson2, Camilla Teixeira3, Derek Muir3

1
Hermanson & Associates LLC, Minneapolis, United States, 2Norwegian Polar Institute, Tromso, Norway,
3
Environment & Climate Change Canada, Burlington, Canada

Inputs of industrial organic contaminants were measured at Holtedahlfonna, Svalbard, and Site M, Antarctica.
The Holtedaholfaonna core was drilled in 2005 and covered 52 years from 1953 - 2005, and at Site M in 2004
and covered a 47-year period from 1957. Both cores were analyzed by the same lab for 15 halobenzene
compounds, including 10 chlorobenzenes, 2 bromobenzenes, 2 chloromethoxybenzenes, and
pentachloroanisole (PCA). These compounds are all highly volatile and, in general, would not be expected to
condense except under extreme cold conditions, or under situations where the atmospheric concentrations are
very high. The Antarctica results show flux and core burden dominated (70%) by 1,3-dichlorobenzene (1,3-
DCB), hexachlorobenzene (HCB), 1,2,4-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, and 3,4,5-
trichloromethoxybenzene. PCA was not detected. Holtedahlfonna is dominated (90+%) by 3 DCBs (1,4-, 1,3-,
1,2-), PCA and HCB. Quantitatively, all 15 contaminants in Antarctica contribute 30.8 ng, or 0.66 ng yr-1, while at
Holtedahlfonna, 1894 ng, or 36.4 ng yr-1. The difference appears extreme because Holtedahlfonna is dominated
80% by 1,4-DCB, and without that contribution, the total is 363 ng or 7.0 ng yr-1. The halobenzene input at
Holtedaholfonna is at least 10 times greater than Site M during this period. This result is consistent with
investigations of organic contaminants in Svalbard glaciers suggesting Eurasian sources that do not exist at
Antarctica.

1993
Fri_26_EN-2_2022
Anthropogenic Impact on Soil Prokaryotic Communities of Fildes Peninsula

João Pereira Santos1, Hugo Ribeiro1, António Gaspar Gonçalves Sousa1,2 (antonio.sousa@ciimar.up.pt), Ana
Padeiro3, João Canário3, Catarina Magalhães1,2
1
CIIMAR – Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Matosinhos,
Portugal, 2FCUP - Faculdade de Ciências, Universidade do Porto, Porto, Portugal, 3CQE, Instituto Superior
Técnico, Universidade de Lisboa, Lisboa, Portugal

The Antarctica continent is characterized by its extreme environmental conditions and low anthropogenic
pressures. However, throughout the year´s many research stations have been implemented in the few ice-free
regions of the continent. One of these areas is on the Fildes Peninsula (King George Island). The human
footprint in the region has led to the increase of pollution issues around the area such as elevated levels of
heavy metals and persistent organic pollutants. In this study, we aim to understand how these human activities
are shaping the soil prokaryotic communities of these regions. We collect a total of 20 soil samples along a
transect with decreasing human impact at Fildes Peninsula. At a preliminary stage, the structure of bacterial
communities was achieved through automated approach for ribosomal intergenic spacer analysis (ARISA), and
based on the community fingerprinting profile of ARISA, nine samples were chosen to sequence massively the
V4-5 region of 16S rRNA gene to capture all the prokaryotic diversity. The structure of the prokaryotic
communities was correlated with the heavy metal contents and persistent organic pollutants measured for
each site. Strong relations were identified between the prokaryotic communities and the pattern of distribution
of the contaminants analyzed in the present study, alerting us to the risks that anthropogenic activities pose on
this pristine environment.

1994
Fri_27_EN-2_2043
Soil Contamination at Impacted Sites in the McMurdo Dry Valleys

Andrew Klein1 (klein@tamu.edu), Stephen Sweet2, Terry Wade2, José Sericano2, Terence Palmer3
1
Texas A&M University, Geography, College Station, United States, 2Texas A&M University, Geochemical and
Environmental Research Group, College Station, United States, 3Texas A&M University-Corpus Christi, Harte
Research Institutute, Corpus Christi, United States

From 1999-2015, an environmental monitoring program has characterized spatial patterns and temporal trends
in anthropogenic contamination of the local terrestrial near McMurdo Station. Soil samples were also collected
annually at control sites in areas experiencing minimal human impacts and were analyzed for Total Petroleum
Hydrocarbons (TPH) and selected metals. TPH concentrations at the control sites were generally at near
background levels and show no evidence of changing significantly over the study period. Trace metals
concentrations are similarly low though the impacts of varying parent material among sites are evident. In 2013
and 2015, the monitoring program was expanded to encompass established field camps at Lakes Bonney,
Fryxell and Hoare and a temporary campsite in the Meirs Valley within the McMurdo Dry Valleys. Samples were
also collected at sites of suspected contamination in the Barwick and Balham Valleys Antarctic Specially
Protected Area. This research synthesizes this sampling along with historical sampling conducted as part of
operational environmental operations by the United States Antarctic Program to characterize typical levels of
contamination at impacted sites in the McMurdo Dry Valleys in comparison to levels found at the well-
characterized control sites. It also proposes effective sampling design strategies for characterize soil
contamination to inform management decisions in the McMurdo Dry Valleys Specially Managed Area (ASMA).

1995
Fri_28_EN-2_2190
Effect of Copper Contamination on SOD Activity of Polar & Tropical Chlorella sp

Emienour Muzalina Mustafa1,2 (emie@umt.edu.my), Siew Moi Phang2, Siti Aisah Alias2, Peter Convey3, Stephen
Coulson4,5, Ben Matthew Wallis6
1
Universiti Malaysia Terengganu, School of Fisheries and Aquaculture Sciences, Kuala Terengganu, Terengganu,
Malaysia, 2University of Malaya, Institute of Ocean and Earth Sciences, Kuala Lumpur, Malaysia, 3University of
Cambridge, British Antarctic Survey, Cambridgeshire, United Kingdom, 4Swedish University of Agriculture
Sciences, Swedish Species Information Centre (ArtDatabanken), Uppsala, Sweden, 5University Center in Svalbart
(UNIS), Department Arctic Biology, Longyearbyean, Norway, 6Ocean-expeditions.com, RV Australis, - Ormond St,
Bondi Beach, Australia

Environmental conditions affect many aspects of cellular metabolism. Superoxide dismutase (SOD) is the most
important enzymes in the front line of defense against oxidative stress; where SOD catalyzes dismutation of
two superoxide anion into hydrogen peroxide & molecular oxygen. Algae are notable bioindicator species in
environmental pollution studies. In view of this, efforts are made to investigate the use of SOD activity, DNA
damage level, growth responses and biochemical composition as biomarker for evaluation on how microalgae
responses and adapt to copper contamination occurred at Arctic, Antarctic & Tropical region. Results showed
that the carbohydrate, protein, lipid and AP-site content decreased with increasing concentration of copper.
The SOD activity in the exposed algae increased with increasing copper concentration until the threshold,
beyond which the cells lost their resistance and died. Levels of these SOD enzymes; DNA damage, growth,
biochemical composition in microalgae & correlation with physical-chemical characteristics of water quality at
Polar and Tropical region measured; will allow the establishment of baseline data that will be used for
developing a monitoring programed. The findings of the present study may contribute to the understanding of
how the Arctic, Antarctic and Tropical algae respond to environmental stress, and to use SOD enzymes levels to
monitor the impact of climate change and increased contamination of the polar and tropical habitats.

1996
Fri_29_EN-2_2337
Comparative Analysis of Pollutants in Polar, High- and Low-altitude Cryoconites

Ramya Bala Prabhakaran1 (pramyabala@gmail.com), Gael Le Roux1

1
EcoLab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France

Rapid industrialization in the Asian countries is one of the greatest contributors of anthropogenic pollutants
such as Black Carbon (BC). These pollutants accumulate on the surface of glaciers and in lake ice. Microbes glue
these pollutants together with dust in the form of cryoconites in a process called biological darkening,
accelerating the melting of glaciers, snow and ice-caps. The Himalayan Mountain range is the second largest ice
mass after the Polar region. Anthropogenic fossil fuel combustion and production of non-ferrous metals,
leading to bulk release of trace metals such as, As, Cr, Cu, Ni and Zn into the atmosphere, have an adverse
impact on the Himalayan ecosystem. There have been very few studies on the Himalayan cryoconites with the
first one in 2017 showing high As levels; an element of concern for downstream human populations.
Cryoconites in other regions, such as the Hans glacier, reveal high concentrations of anthropogenic Pu, Cs, Sr
while those in Alpine glaciers are heavily enriched in artificial radionuclides. Simultaneous monitoring and
comparison of various pollutants in polar, high- and low-latitudes will be important in understanding pollutant
cycling. With this intent, we are undertaking a multidisciplinary assessment of the mineral, organic and
biological components of cryoconites from the Arctic expedition, the Pyrénées and the Himalayas with a special
focus on inorganic micropollutants such as artificial radionuclides, Hg and other trace metals.

1997
Fri_31_EN-2_2343
Environmental Relationships of the Heavy Metals in a Periglacial Landscape

Marcio Rocha Francelino1 (marcio.francelino@gmail.com), Elpidio Inácio Fernandes Filho2, Adriano Luis
Schunemann3, Martin Meier1, Carlos Ernesto Schaefer1
1
Universidade Federal de Viçosa / INCT da Criosfera, Solos, Viçosa, Brazil, 2Universidade Federal der Viçosa, Soil,
Viçosa, Brazil, 3Universidade Federal do Pampa - UNIPAMPA, São Gabriel, Brazil

Although only 8.8% of King George Island are ice-free areas, they represent key hot spots where biodiversity is
maximum, and greater anthropogenic impacts occur. In the Admiralty Bay of King George Island, four research
stations are located, and generate local environmental impacts to different degrees. The objective of this work
was to identify the relationship between heavy metal contents and environmental and anthropogenic
covariates in Keller peninsula, where the Brazilian station is located. Soil sites located far away from the station
were used as control for serving as reference for comparison between anthropogenic and non-affected soils.
Categorical covariates such as landforms, lithology, soils and morphometric covariates (from a digital elevation
model with spatial resolution of 1 m) were used. Soil samples were collected in 57 points distributed in grid
form, in two depths (0-10cm and 10-20cm). The samples were analyzed by X-ray fluorescence spectrometry
and the contents of zinc, copper, nickel, cadmium, mercury cobalt, arsenic and chromium were determined.
We used the functions “findCorrelation” and “recursive feature elimination”, both using the R software. The
model with the lowest number of variables was chosen, which obtained 97%, the highest value of Kappa. This
interpretation was very useful to illustrate the general behavior of heavy metals in Antarctic landscapes.

1998
Fri_32_EN-2_434
Plastic Debris in Antarctic Marine Organisms: First Results of PLANET Project

Ilaria Corsi1, Elisa Bergami1 (elisa.bergami4@gmail.com), Martina Grattacaso1, Lisa Vaccari2, Silvia Olmastroni1,3
1
University of Siena, Physical, Earth and Environmental Sciences, Siena 1, Italy, 2Elettra-Sincrotone, Trieste, Italy,
3
National Museum of Antarctica 'F. Ippolito', Siena, Italy

For decades plastic debris accumulated in the world's oceans and recently their presence and impact has been
documented in one of the most remote and pristine region on Earth as Southern Ocean around Antarctica.
Increasing local human impacts (fishing, tourism and scientific bases) and transportation from transboundary
sources will differentially affect occurrence, spatial patterns and biological impact of plastic debris in Antarctic
waters. The PLANET project (PLastics in ANtarctic EnvironmenT) launched in 2015 by the Italian Antarctic
Research Programme is an international network of researchers sharing the common aim to address the
impact of plastic pollution on Antarctic marine organisms with particular regard to the smallest debris as micro
(< 5mm) and nanoplastics (< 100 nm). An initial monitoring study in 2016 revealed the presence of microplastic
in several marine species from the Ross Sea. They resulted more abundant in scallops and fish than in
phytoplankton, krill and blood and faeces of seabirds (penguins and skua). Rayon fibers of a size below 100 µm
(µ-FTIR) were the most present thus raising concern in terms of toxicity since approaching the nano-scale but
also chlorinated polyethylene, poly(butylene terephthalate) and melamine/alkyd resin were identified. Cross-
contamination underline the need to standardize protocols for sample handling, digestion and polymer
identification in order to properly assess micro and nanoplastic occurrence in Antarctic biota.

1999
Fri_33_EN-2_2509
Long-range Transport of Pollutants to Antarctica

Stefania Giannarelli1 (stefania.giannarelli@unipi.it), Roger Fuoco1, Alessio Ceccarini1, Marco Termine1, Andrea
Brongo1
1
University of Pisa, Department of Chemistry and Industrial Chemistry, Pisa, Italy

Antarctica is considered a pristine ecosystem; nevertheless it is influenced by Persistent Organic Pollutants

(POPs), mainly driven by long-range atmospheric transport. Antarctic ice-free areas, where rare lakes are
located, are influenced by such sources. In this work, we determine polychlorinated biphenyls (PCBs), polycyclic
aromatic hydrocarbon (PAHs) and pesticides (banned and still in use) in water and sediment samples of 7
shallow lakes in Northern Victoria Land during the austral summer season.
POPs concentrations in lakes resulted low and rather similar across the sites despite their distance.
There is always a higher presence of low molecular weight PAHs both in comparison between the various
expeditions, and comparing water and sediment of the same campaign. Phenanthrene is the predominant
compound in all the sampled sites (single PAHs concentration is in the range 0,1-0,4 ng/L).
The 6 PCBs marker (28, 52, 101, 138, 153, 180) are quantifiable and comparable (single PCBs concentrations are
in the range 0,01-0,3 ng/L).
Among the pesticides, simazine is most represented for the azine class, especially in aqueous matrices.
Endosulfan sulfate is present in all samples often at high concentrations.
p, p´-DDT isomer is the most concentrated isomer, but we have found also o,p-DDT and their metabolites.
Hexachlororobenzene and BHC-g (Lindane) are present in most samples.
Iprodione is present in most of the aqueous analyzed samples, while in sediments it is less represented.

2000
Fri_34_EN-2_2691
Using DGT to Assess the Risk of Metal Contaminants in Polar Environments

Darren Koppel1,2,3 (djk146@uowmail.edu.au), Merrin Adams2, Catherine King3, Dianne Jolley1

1
University of Wollongong, School of Chemistry, Wollongong, Australia, 2Commonwealth Scientific and
Industrial Research Organisation (CSIRO), Land and Water, Lucas Heights, Australia, 3Australian Antarctic
Division, Human Impacts, Kingston, Australia

Metal contaminants, such as those that leach from historical Antarctic waste, are known to cause toxicity to a
wide-range of organisms. The development of environmental quality guidelines will help environmental
managers to understand the risk of contaminants. However, a lack of environmental toxicological data and
environmental monitoring tools is limiting the development of guidelines. Diffusive Gradients in Thin-films
(DGT) have been established as a robust method for analysing the biologically-available contaminants in situ
and is well-positioned to assess the toxicity of metal contaminants.
This study uses DGT to assess the toxicity of Cd, Cu, Ni, Pb, and Zn singly and in mixtures, to two common
Antarctic marine microalgae, Phaeocystis antarctica and Cryothecomonas armigera. DGT devices were
optimised for use in Antarctic conditions by determining metal diffusion coefficients and quantifying the DGT's
metal-binding capacity. Preferential binding of metals was observed prior to reaching the metal-binding
capacity with Cd, followed by Pb, and Zn, outcompeted by Cu and Ni. DGT measurements were then used to
predict toxicity to two algal species exposed to a mixture of the metal contaminants. This research
demonstrates the applicability of DGT to identify contaminated sites which may pose a risk to Antarctic
organisms.

2001
Fri_35_EN-5_361
PANGAEA® - Data Publisher for Earth and Environmental Science

Stefanie Schumacher1 (stefanie.schumacher@awi.de), Amelie Driemel1, Hannes Grobe1, Rainer Sieger1

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, PANGAEA, Bremerhaven, Germany

PANGAEA - Data Publisher for Earth & Environmental Science (www.pangaea.de) is an Open Access data-library
aimed at archiving, publishing and distributing georeferenced data from earth and environmental science. The
development of the system started with the beginning of the Internet and since then offers data curation
services to national and international projects, institutes and individual scientists. The World Data Center
PANGAEA is member of the World Data System (WDS) of the International Council for Science (ICSU).
Observational and analytical data files are stored together with their metadata in a relational database. Each
data set includes a bibliographic citation and is persistently identified using a Digital Object Identifier (DOI).
Data are archived as a supplement related to an article or as an independent citable data-publication.
PANGAEA is a recommended repository for supplements in several hundred journals related to earth system
research.
PANGAEA currently provides more than 368 000 data set, consisting of >12 billion data points. This includes
important collections from international Antarctic and Arctic research programs, e.g. the Cape Roberts Project,
ANDRILL, EPICA project, and data of the first and last International Polar Year (IPY 1882-1883 and 2007-2008).
Additionally, the full data amount of combined high and low latitude research projects, e.g. JGOFS, WOCE,
DSDP/ODP/IODP and German expeditions are archived and published.

2002
Fri_36_EN-5_665
How, what, where, when: Expedition Metadata and Data Collection

Jenny Thomas1 (jenny.thomas@epfl.ch), Carles Pina Estany2

1
Swiss Polar Institute, Lausanne, Switzerland, 2ACE Foundation, Lausanne, Switzerland

Three months of data and sample collection on the Antarctic Circumnavigation Expedition during the southern
summer of 2016/17 required a system to collect metadata and data during the research cruise.
A network was established on board the R/V Akademik Tryoshnikov, to automatically store data streams from
ship-based instruments, access the local intranet and allow for communications on board. An intranet with
event-logging and data-entry system was prepared to allow scientists and data managers on board to record
the cruise metadata, database ship-based data streams and perform in-situ checks on the generic data streams
being collected during the expedition. This allowed extensive checking of metadata and completion of
metadata records of raw data sets whilst on board.
This presentation will describe the system used as well as the particular advantages and disadvantages of the
systems used on a multi-disciplinary research cruise.

2003
Fri_37_EN-5_673
Making the Most of ACE Data

Jenny Thomas1 (jenny.thomas@epfl.ch), Julia Schmale2

1
Swiss Polar Institute, Lausanne, Switzerland, 2Paul Scherrer Institute, Villigen, Switzerland

Over 30,000 samples and 30 TB of data were collected during the Antarctic Circumnavigation Expedition. ACE
was a unique expedition to the Southern Ocean, sub-Antarctic and Antarctic islands during the austral summer
of 2016/17. The scientific potential of resulting data sets depends on good data management and investment
in methods to ensure the integrity of these data sets, as well as careful data processing and checking.
In addition, once initial analyses have been done on the quality assured data sets, there is huge potential to
combine them in new ways and apply data science and machine learning techniques to explore the vast
linkages between disciplines.
This presentation will explore the potential of the ACE data sets, from the basis of their archiving, the extent of
the data sets and how they will be made available to all. Finally, we will discuss how data science methods will
be used as part of the project, "Delivering Added-value To Antarctica", ACE-DATA, to explore air-sea
interactions.

2004
Fri_38_EN-5_853
The United States Antarctic Program Data Center (USAP-DC): Recent Developments

Frank O. Nitsche1 (fnitsche@ldeo.columbia.edu), Robert Bauer2, Neville Shane1, Steve Richard1, Suzanne
Carbotte1, Ted Scambos2
1
Columbia University, Lamont-Dohert Earth Observatory, Palisades, United States, 2National Snow and Ice Data
Center, Boulder, United States

Polar data are valuable, unique research assets that are acquired under substantial and expensive logistical
effort. Historically, data management for the US Antarctic Program (USAP) has made use of existing disciplinary
data centers. However, disciplinary repositories do not exist for all USAP generated data types and often it is
unclear what repositories are appropriate, leading to datasets being served locally from scientist's websites or
not available at all. The USAP Data Center (www.usap-dc.org) contributes to the broader preservation of data
acquired with funding from NSF's Office of Polar Programs by providing a repository for diverse Antarctic data.
In Spring 2016, USAP-DC and the NSIDC began a new collaboration to consolidate data services for Antarctic
investigators and to integrate the NSF-funded glaciology data at NSIDC with the collection hosted by USAP-DC.
Investigator submissions for NSF's Glaciology program now make use of USAP-DC's web submission tools,
providing a uniform interface for Antarctic investigators. The tools have been redesigned to collect a broader
range of discovery and preservation metadata. Each data submission is reviewed and verified by a specialist
from the USAP-DC/NSIDC team depending on disciplinary focus of the submission. A recently updated web
search interface is available to search data by title, NSF program, award, dataset contributor, large scale project
(e.g. WAIS Divide Ice Core) or by specifying an area in map view.

2005
Fri_39_EN-5_879
Providing High-quality Long-term Data Management at the McMurdo Dry Valleys LTER

Renée F. Brown1 (rfbrown@unm.edu), Byron J. Adams2, John E. Barrett3, Peter T. Doran4, Adrian J. Howkins5,
Diane M. McKnight6, Rachael M. Morgan-Kiss7, John C. Priscu8, Cristina D. Takacs-Vesbach1, Michael N. Gooseff6
1
University of New Mexico, Department of Biology, Albuquerque, New Mexico, United States, 2Brigham Young
University, Department of Biology, Provo, Utah, United States, 3Virginia Tech, Department of Biological
Sciences, Blacksburg, Virginia, United States, 4Louisiana State University, Department of Geology and
Geophysics, Baton Rouge, Louisiana, United States, 5University of Bristol, Department of History, Bristol, United
Kingdom, 6University of Colorado, Institute of Arctic and Alpine Research, Boulder, Colorado, United States,
7
Miami University, Department of Microbiology, Oxford, Ohio, United States, 8Montana State University,
Department of Land Resources and Environmental Sciences, Bozeman, Montana, United States

Established in 1993, the McMurdo Dry Valleys Long Term Ecological Research Program (MCM LTER) is an
interdisciplinary effort focused on the long-term study of aquatic and terrestrial ecosystems in a cold desert
region of Antarctica. The McMurdo Dry Valleys are located on the western coast of the McMurdo Sound,
forming the largest relatively ice-free region on the Antarctic continent. MCM represents one of twenty-eight
sites in the United States (U.S.) LTER Network funded by the U.S. National Science Foundation (NSF).
Like all LTER sites, MCM is a data-intensive endeavor with a diverse set of monitoring and experimental studies
that span temporal and spatial scales. Data generation largely occurs through the intensive laboratory analyses
of biogeochemical parameters and biotic composition of field-collected samples. Additional high-frequency
datasets are obtained using automated technologies that include environmental sensor networks and satellite
imaging. MCM data standards and access policies are set by the U.S. LTER Network in accordance with NSF
guidelines, and were recently revised in the spirit of open science to promote enhanced data quality, visibility,
and accessibility.
Here, we describe the complete data life cycle at MCM, focusing on both the technological and human aspects
of collecting, curating, and preserving high-quality, publicly available long-term datasets for use by researchers,
educators, and policy-makers alike.

2006
Fri_40_EN-5_1263
Liberating Arctic Botanical Biodiversity Data at the Canadian Museum of Nature

Jennifer C. Doubt1, Lisa C. Gualtieri1, Cassandra M. Robillard1, Lyndsey A. Sharp1, Paul C. Sokoloff1, Jeffery M.
Saarela1 (jsaarela@mus-nature.ca)
1
Canadian Museum of Nature, Centre for Arctic Knowledge & Exploration, Ottawa, Canada

Core to the polar research information spectrum are the millions of biological and geological specimens in
natural history collections. These specimens represent biodiversity data documenting the distribution of
species in time and space; they serve as vouchers for the datasets that underpin scientific conclusions, allowing
future workers to confirm or revise identifications; and they are sources of new data, such as genetic
information. Most natural history museums face the massive “big data” challenge of databasing and imaging
their collections, allowing them to be widely discovered, shared, used and reused in research and outreach.
Many also possess backlog material: specimens collected and stored, sometimes many decades ago, that have
never been accessioned or prepared for long-term use, and that are consequently not discoverable or available
for study. The Canadian Museum of Nature houses over 300K Arctic specimens - the largest Arctic natural
history collection in Canada - but data for only a subset are currently accessible online. To correct this, the
National Herbarium of Canada is engaged in a project to digitize, georeference and image its Arctic plant, moss
and lichen specimens, according to global standards that facilitate collection data sharing and integration. We
are also processing important Arctic backlog material, including 3025 Canadian Arctic specimens collected in
the 1970s to the 1990s at great expense that were never mounted or formally acquired.

2007
Fri_41_EN-5_1545
Developing a Metadata Portal for Researchers

Marten A Tacoma1 (marten.tacoma@nioz.nl), Taco F de Bruin1

1
NIOZ Royal Netherlands Institute for Sea Research & Utrecht University, Den Hoorn Texel, Netherlands

One of the challenges when developing a portal is how to get the researchers to work with it. Scientists
complain about the number of systems, being from their home institution, funding agency or international,
they are required to provide with information and the amount of time this costs. Time they can´t use to
perform research.
For the Netherlands Polar Program (NPP) we developed a portal to provide access to all data and information
from the NPP. We worked with the researchers to make it as easy as possible for them to provide information
about their projects, data sets and publications. In this talk we will show the tools we created and how easy it is
for researchers to add information. The portal was built using open standards and only requires free software
to run, this way it can easily be incorporated into other national polar programs. The source code for the portal
is freely available to the community via Github.

2008
Fri_44_EN-5_2321
Enhancing Polar Decision Making: Data Sharing through Active Collaboration

Peter Pulsifer1 (peter.pulsifer@colorado.edu), Anton Van de Putte2, Phillippa Bricher3, Colleen Strawhacker1,
Maribeth Murray4
1
University of Colorado, National Snow and Ice Data Center, Boulder, United States, 2Royal Belgian Institute of
Natural Sciences, Brussels, Belgium, 3Southern Ocean Observing System, Hobart, Australia, 4University of
Calgary, Arctic Institute of North America, Calgary, Canada

Recent conferences, workshops and meetings have confirmed that there are many projects and programs that
are active in polar data management and stewardship at multiple scale. These initiatives have a mandate or
desire to contribute to regional or international coordination of effort and activities. These programs have
resources available and are making progress towards an envisioned connected, interoperable polar data
system. The international polar data community is eager to improve cooperation and coordination of their
efforts.
In the spring of 2018, more than ten active programs and initiatives came together to focus on work planning
and coordination of effort. This meeting complemented past workshops and fora (e.g. IPY, Polar Data Forums
etc.) that have been effective in defining important community challenges and technical issues. The focus of
the meeting was to generate detailed plans on how best to mobilise existing and pending funded activities to
develop a particular international data sharing case study.
The meeting was co-led and co-organized by key polar data projects and programs associated with polar
science and observing coordinating bodies, international initiatives, regional, national and disciplinary
programs, and Indigenous organizations. Here we report details of the planning process, the established case
study, established interoperability mechanisms and a discussion of the collaborative process involved in
bringing together a diverse group of data.

2009
Fri_45_EN-5_2357
Using Concept Analysis and Visualization to Mediate Data for Different Audiences

Peter L. Pulsifer1 (peter.pulsifer@colorado.edu), Colleen Strawhacker1, Noor Johnson1, Brendan Billingsley1

1
University of Colorado, National Snow and Ice Data Center, Boulder, United States

The volume and variety of data available for research, decision making and local, community-driven projects
and programs is rapidly increasing. These data may be produced using different methods, epistemologies and
overall world views. At a more technical level, the data are often stored in different formats using a range of
different vocabularies that are specific to a natural language or particular domain.
Drawing on examples from the Exchange for Local Observations and Knowledge of the Arctic, the activities of
the Arctic Data Committee, and other related projects, data and information generated from different
perspectives and managed using different techniques are analyzed and linked through the analysis of concepts
and related categories. The results of the analysis are visualized to provided insights into how disparate data
and information might be mediated for use between and among actors from different communities, domains
and communities of practice. The challenges of representation using visualization to represent non-spatial
concepts are discussed as are possible opportunities.

2010
Fri_46_EN-5_2435
Biogeographically-linked Resource to Share Polar Microbial & Environmental Data

Alison Murray1 (alison@dri.edu), Anton P. Van de Putte2, Bruno Danis3, Lea Cabrol4,5, Maialen Barret6
1
Desert Research Institute, Earth and Ecosystem Sciences, Reno, United States, 2Royal Belgian Institute of
Natural Sciences, Brussells, Belgium, 3University Libre de Bruxelles, Laboratoir de Biologie Marine, Brussells,
Belgium, 4Pontificia Universidad Católica de Valparaíso, Valparaiso, Chile, 5Institut de Recherche pour le
Développement, Institut Méditerranéen d'Océanologie, Marseille, France, 6Université de Toulouse, Ecolab,
UMR5245, CNRS, INPT, UPS, Castanet Tolosan, France

The microbial Antarctic Resource system (mARS; mars.biodiversity.aq) is an information system dedicated to
facilitating the discovery, access and analysis of molecular microbial diversity and 'omics (meta)data generated
by researchers. Here we report on the expansion of the geographic coverage of mARS to include all polar and
subpolar regions. This enhancement is envisioned to facilitate comparative studies between the poles and
serve as a collaborative, networking resource for polar scientists. mARS incorporates standardized
environmental context data into a custom MySQL database in which users can search by latitude/longitude
coordinates, environmental temperature, salinity, depth, or elevation etc., so that studies submitted by other
researchers can be discovered which may be relevant for comparative diversity and metagenome or
transcriptome studies. Visualization tools have also been created to capture the sequence coverage of different
studies, geographic coverage, and in the future, phylogenetic coverage of data sets that are reflected in mARS.
The mARS team partnered with the ERANET/LAC-supported METHANOBASE project which has characterized
archaea and bacteria in permafrost, wetland and lake ecosystems in subarctic and Antarctic, and sub-Antarctic
sites over the past two years. This large project, which collected over 480 samples from diverse ecosystems,
served to help improve the mARS infrastructure and its usability by the user community of microbial scientists.

2011
Fri_47_EN-5_2661
The CCADI Initiative: Advancing Arctic Research with Connected Data

Shannon Vossepoel1 (shannonv@ucalgary.ca), Julie Friddell2, Christine Barnard3

1
University of Calgary, Arctic Institute of North America, Calgary, Canada, 2University of Waterloo, Canadian
Cryospheric Information Network/Polar Data Catalogue, Waterloo, Canada, 3Université Laval, Centre d'Etudes
Nordiques, Quebec, Canada

The Canadian Consortium for Arctic Data Interoperability (CCADI, http://ccadi.ca) is an emerging initiative to
advance collaboration, nationally and internationally, through the development of an integrated Canadian
Arctic data management system that will facilitate information discovery, establish metadata and data sharing
standards, enable interoperability among existing data infrastructures, and provide accessible data to a broad
audience of users, from researchers to the general public.
Importantly, the Consortium aims to connect a broad variety of information types ranging from bibliographic
records and research licenses, to metadata and raw data sets. Connecting these various kinds of data grants
users the ability to build a holistic view of research, from inception and throughout the data lifecycle, and
provides enhanced opportunities to recreate scientific studies and review them from different angles. It also
provides countless opportunities to compare and link data, both qualitative and quantitative, across disciplines.
The CCADI also aims to include Inuit Knowledge and is working with regional Inuit organizations and Inuit
Tapiriit Kanatami to ensure that indigenous data is included ethically, with full Inuit involvement in the design
of systems, and in the management and use of their data.
The CCADI is composed of six Canadian universities, two Canadian federal agencies, two Inuit organizations,
and three non-profit partners.

2012
Fri_48_EN-6_34
Source, Processes & Productivity-investigation through Lake Sediment, Antarctica

Shabnam Choudhary1 (shabnam.geology@gmail.com), G. N. Nayak1, A.K. Tiwari2, N. Khare3

1
Goa University, Department of Marine Sciences, Taleigao Plateau, Goa, India, 2National Centre for Antarctic
and Ocean Research (ESSO-NCAOR), Vasco, Goa, India, 3Ministry of Earth Sciences, New Delhi, India

Two sediment cores retrieved, one each from lake GL-1 of Schirmacher Oasis and lake L-12 of Larsemann Hills,
East Antarctica were investigated at 2 cm interval for sedimentological and geochemical parameters viz. grain
size, total organic carbon, total nitrogen, total phosphorus, biogenic silica and bulk metal concentration. High
sand content (>72%) in the major portion of the cores revealed predominant mechanical weathering process,
which resulted in coarse-grained material from the rocks in the catchment area of the lakes. Relatively, higher
biogenic silica along with high total organic carbon associated with high clay in the upper portion of both the
lakes indicated deposition of finer particles from suspension in recent years which facilitated high primary
productivity due to exposure of the lakes to the ice-melt water influx. C/N ratio for both the lakes was found to
be < 10 which indicated that the major source of organic matter was autochthonous. However, N/P and N/Si
ratios were lower than Redfield ratio indicating N and Si were limiting elements in the lakes. In these lakes, TOC
and TN exhibited a poor correlation indicating their different source. Cd in both the lakes was found to be of
mainly biogenic origin, whereas Pb in these lakes was found to be of lithogenic origin. Silt and organic matter in
core GL-1 and organic matter along with the Mn-oxide in core L-12 regulated the distribution of metals.

2013
Fri_49_EN-6_429
Long-term Growing Season Dynamics Inferred from Birch Leaf Cuticle

Fabian E Z Ercan1 (f.e.z.ercan@uu.nl), Wim Z Hoek1, Daan Blok2, F Wagner-Cremer1

1
Utrecht University, Physical Geography, Utrecht, Netherlands, 2Lund University, Department of Physical
Geography and Ecosystem Science, Lund, Sweden

A significant lengthening trend of the Northern Hemisphere growing season increasingly affects vegetation
dynamics. Growing season length data, however, are currently restricted back to 1982, when satellite based
vegetation monitoring began. All forward modelling of potential consequences to date are restricted to this
short reference period. Sound evaluation of positive or negative effects for ecosystem performance requires
longer time-series data to place ongoing changes into ba broader temporal context. Palaeobotanical
investigations provide a tool to generate long-term growing season records beyond the short-term satellite
records. Our novel growing season length proxy is capable of accurately reconstructing past growing degree
days and spring onset data. In this study, micro-phenological data from modern and fossil leaf cuticles are
tested against historical meteorological data, and validated by field climate manipulation experiments. Growing
season signals from historical and fossil leaves are subsequently used to estimate spring thermal properties
over the past century. We here focus on Disko Island, Greenland and Kevo, Finland, both extremely sensitive to
seasonal temperature changes. The generated time-series records of spring dynamics will support the
understanding of ongoing climate change on time scales beyond the instrumental record.

2014
Fri_51_EN-6_548
Holocene Environmental Change Around the Lutzow-Holm Bay using Penguin Rookery

Hideki Miura1 (miura@nipr.ac.jp)

1
National Institute of Polar Research, Tokyo, Japan

Adelie penguin carries pebbles to rookery during summer breeding season, so pebbles deposit thickly year by
year with relics such as feces, egg shells, feathers and bones.
Prior to the start of summer nesting of Adelie penguin, I excavated sediments of rookery of Adelie penguin that
existed around the Lutzow-Holm Bay in Antarctica, and described the sections of feces, bones, feathers and
eggs from the basement to the surface layer, and took the radiocarbon dating and nitrogen isotope
measurements.
In this research, based on this result, I examine the following four contents: 1) Geographical distribution of
Adelie penguin rookery and their formation history, 2) History of change of the sea level change and Antarctic
ice sheet , 3) Penguin´s food content, and discuss Holocene environmental change around the Lutzow-Holm
Bay region.

2015
Fri_52_EN-6_618
Diatom Variation Reconstructed from Two Lake Sediment Cores from East Antarctica

Mahesh Badanal1 (mahe687@gmail.com), Abhilash Nair2, Anish Kumar Warrier3, Rahul Mohan2
1
National Centre for Antarctic & Ocean Research, Antarctic Science Division, Vasco da Gama, India, 2National
Centre for Antarctic & Ocean Research, Antarctic Science, Vasco da Gama, India, 3Manipal University,
Department of Civil Engineering, Manipal, India

Biogenic proxies such as diatoms retrieved from sedimentary deposits are a good tool to decipher and
understand climate changes in the cold environments of Antarctica. The use of diatoms as a paleoclimate
indicator in lacustrine systems of Antarctic ice free areas is well documented. In this study, we report diatom
abundance and species variation for two sediment cores collected from two freshwater lakes viz., Mochou Lake
(ML) and LH-73 of Broknes Peninsula in Larsemann Hills, East Antarctica. The cores were collected at different
elevation (ML: 2 m & LH-73: 22 m asl) and distance (ML: 350 m & LH-73: 250 m) from the coast. The ML core
spans the last 28.6 kyr while the LH-73 covers the last 25.8 kyr. In the time-series, the appearance of diatoms
was recorded at 15.63 ky BP in ML record while it appears at 19 ky BP in LH-73 records wherein the
deglaciation in Antarctic ice-core records is at 19 ky BP. This suggests that the lakes became ice-free after the
deglaciation in Antarctica aiding growth of diatom community though at different times. This difference is most
likely due to the geographical setting of both the lakes. The late-Holocene records higher diatom abundance as
compared to the down-core indicating a favorable condition for the diatom community to flourish. The most
abundant species in both the records is Stauroforma inermis followed by Planothidium quadirpunctatum,
Amphora veneta, Diadesmis australis and Psammothidium abundance.

2016
Fri_53_EN-6_786
A Land Mammal Tibia from the Eocene of Marambio/Seymour Island, West Antarctica

Javier N. Gelfo1,2 (jgelfo@fcnym.unlp.edu.ar), Marcelo Reguero1,2,3

1
CONICET, Buenos Aires, Argentina, 2Universidad Nacional de La Plata, División Paleontología Vertebrados,
Museo de La Plata, La Plata, Argentina, 3Instituto Antártico Argentino, San Martín, Argentina

Despite Antarctica is the only continent without terrestrial mammals, in the past it played a key role in the
evolutionary history of Southern Hemisphere mammalian communities. Sometime between the Late
Cretaceous and the latest Paleocene, before the complete break-up of Gondwana, West Antarctica functioned
as a land bridge for the dispersal of metatherians and monotremes, from Southern South America to Australia
in the first case, and in the other way round in the last. Fossil land mammals in Antarctica are mostly
constrained to the dental remains from the Eocene of La Meseta and Submeseta Formations in Marambio
Island. Here we described and discuss the implications of the first mammalian long bone, represented by an
almost complete right tibia (MLP 94-III-15-6). The remain came from the lower conglomeratic shell bed from
Cucullaea I Allomember at La Meseta Formation (Telm 4) in the locality DPV 2/84. The minimum length of the
tibia is approximately of 230 mm; the prominent cnemial crest and most of the proximal epiphysis are cracked
and with most of its surface were reconstructed. Proximally, the medial condyle is broken as well as most of
the tibial malleolus. The distal third of the bone is the best preserved, particularly the astragalar articular
surface. The distal moiety of the shaft resembles some Proterotheriidae litopterns for being more trihedral and
less oval in section suggesting Sparnotheriodontid affinities.

2017
Fri_54_EN-6_798
First Cranium of the Giant Penguin Anthropornis from Marambio/Seymour Island

Carolina Acosta Hospitaleche1,2 (acostacaro@fcnym.unlp.edu.ar), Nadia Haidr3, Marcelo Reguero2,4

1
Universidad Nacional de La Plata, División Paleontología Vertebrados, Museo de La Plata, La Plata, Argentina,
2
CONICET, La Plata, Argentina, 3IBIOMAR-CONICET, Puerto Madryn, Argentina, 4Instituto Antártico Argentino,
Buenos Aires, Argentina

Anthropornis, described more than a century ago, is one of a fascinating species of fossil penguins. The
robustness and massiveness of its bones caught the attention of Carl Wiman in 1905, and made him worthy of
the name Anthropornis, which means "man-bird". Both species of this genus were only known through isolated
bones (tarsometatarsi), until a few years ago, when the reinterpretation of some articulated bones Only
isolated bones were described for both species of this genus until that new articulated skeletons from the
Antarctic Eocene allowed the reinterpretation and assignment of associated limb remains to Anthropornis sp.
A new skeleton found in Priabonian levels of the Submeseta Formation, Marambio (Seymour) Island, Antarctic
Peninsula, constitutes the first specimen with a complete tarsometatarsus (that allowed the assignment to
Anthropornis grandis), and the cranium, besides many fragments of other bones. The importance of this finding
is that it is the first fossil cranium of Antarctica that can be assigned to any of the known species of penguins
since all findings of cranial elements constitute isolated remains. Anthropornis grandis has an extremely
elongated and slender bill and a small neurocranium, compared to modern penguins. Dimensions of the
occipital condyle and the foramen magnum, however, are congruent with a large cranium and neck. These
proportions seem to be the rule among large and giant penguins during the Paleogene.

2018
Fri_55_EN-6_917
Reconstructing Temp in Antarctica over the past Based on Water Stable Isotopes

François Klein1, Nerilie J. Abram2, Mark A. J. Curran3, Hugues Goosse1 (hugues.goosse@uclouvain.be), Sentia
Goursaud4, Valérie Masson-Delmotte4, Raphael Neukom5, Anaïs Orsi4, Jesper Sjolte6, Nathan Steiger7, Barbara
Stenni8, Martin Werner9
1
Université catholique de Louvain (UCL), Louvain-La-Neuve, Belgium, 2Australian National University, Canberra,
Australia, 3University of Tasmania, Hobart, Australia, 4Laboratoire des Sciences du Climat et de l'Environnement,
Gif- sur-Yvette cédex, France, 5University of Bern, Bern, Switzerland, 6Lund University, Lund, Sweden, 7Columbia
University, New York, United States, 8Ca' Foscari University of Venice, Department of Environmental Sciences,
Venice, Italy, 9Alfred Wegner Institute, Bremerhaven, Germany

Full title: Reconstructing air surface temperature in Antarctica over the past millennium based on water stable
isotopes. Last millennium temperature changes over Antarctica are still relatively uncertain. This has several
origins:
1) The number of high resolution ice cores is small, in particular on the Antarctic Plateau;
2) The instrumental records are short which limits the calibration period for reconstructions and the
assessment of the methodologies;
3) The link between isotope records from ice cores and local climate are usually complex and dependent on the
spatial and time scales investigated.
Here, we assess the potential of statistical reconstructions methods and data assimilation-based methods to
obtain better understanding of last millennium temperature changes over Antarctica. This is first achieved in a
pseudo-proxy framework. A long simulation performed with an isotope-enabled model is sampled at the same
spatial and temporal resolution as existing data to provide the pseudo-data of surface temperature over the
recent past and of stable oxygen isotopes over the past millennium. The performance of the statistical and data
assimilation reconstructions based on those pseudo-data is then assessed by comparing the reconstructed
temperature with the simulated one. In a second step, the data assimilation method tested and improved in
this idealized framework is applied to real data and the results compared to available reconstructions based on
statistical methods.

2019
Fri_56_EN-6_938
Hunting for Dansgaard-Oeschger-type Variability in the Earliest Pleistocene

Rebecca Parker1 (rp501@exeter.ac.uk), Deborah Ray1, Anieke Brombacher2, Stephen Obrochta3, Paul Wilson2,
Ian Bailey1
1
University of Exeter, Penryn Campus, Camborne School of Mines, College of Engineering, Mathematics &
Physical Sciences, Penryn, Cornwall, United Kingdom, 2University of Southampton, Waterfront Campus, National
Oceanography Centre Southampton, Southampton, United Kingdom, 3Akita University, Graduate School of
International Resource Science, Akita, Japan

Geological studies indicate the Earth's climate system is capable of undergoing abrupt and profound change
when surface temperature is cooler than present (Dansgaard et al., 1993). It is now known that these co-called
Dansgaard-Oeschger (DO) events likely occurred during a range of intermediate ice-volume states for the past
1.3 million years (Birner et al., 2016). Yet, it remains unknown when DO-events were first a feature of North
Atlantic climate during the Quaternary. To shed new light on this issue, we present new suborbital
palaeoceanographic records that track variability in surface and intermediate water properties of the northeast
North Atlantic Ocean during the onset of major Northern Hemisphere glaciation, 2.5 million years ago.
Birner, B., Hodell, D.A., Tzedakis, P.C. and Skinner, L.C (2016), Similar millennial climate variability on
the
Iberian margin during two early Pleistocene glacials and MIS 3, Paleoceanography, 31, 203-217
Dansgaard, W., Johnsen, S.J., Clausen, H.B., Dahl-Jensen, D, Gundestrup, N.S et al. (1993). Evidence for general
instability of past climate from a 250-kyr ice-core record. Nature 364, 218-220

2020
Fri_57_EN-6_1032
Subdecadal Holocene Climate Reconstruction of Byers Peninsula (Antarctica)

Santiago Giralt1 (sgiralt@ictja.csic.es), Dermot Antoniades2, Ignacio Granados3, Emma Liu4, Sergi Pla-Rabes5,
Manuel Toro6, Marc Oliva7
1
Institute of Earth Sciences Jaume Almera (ICTJA-CSIC), Barcelona, Spain, 2Centre d'Études Nordiques, Université
Laval, Québec, Canada, 3Parque Nacional Sierra de Guadarrama, Centro de Investigación, Rascafría, Spain,
4
University of Bristol, Bristol, United Kingdom, 5Centre de Recerca Ecològica i Aplicacions Forestals (CREAF-CSIC),
Bellaterra, Spain, 6Centro de Estudios Hidrográficos (CEDEX), Madrid, Spain, 7University of Barcelona, Barcelona,
Spain

Byers Peninsula (Livingston Island, South Shetland Islands) is one of the few glacier-free areas in Antarctica that
allow the high-resolution characterization of Holocene history based on paleolimnological studies. Several lakes
on the peninsula with sedimentary infills up to 5 m of thickness provide excellent opportunities to conduct
multidisciplinary environmental reconstructions. The complete sedimentary infill of five lakes was retrieved in
2003 and 2008 (Limnopolar) and November 2012 (Chester, Escondido, Cerro Negro and Domo). Sediments
ranged from nearly completely mineral to an alternation of mosses and mineralogical layers. The age model of
these five sedimentary records was built using 53 AMS 14C and 4 TL dates covering the last ca. 8,000 cal years
BP. Past climate and environmental changes are here inferred using the results obtained with an X-ray core
scanner and x-ray diffraction analysis. Our results are related to the main Holocene climate fluctuations in this
area. However, the comparison of the obtained reconstructions for each lake allowed for dintinctions between
local ontogenic processes controlled by the catchment and lake internal dynamics and those caused by regional
climate fluctuations.

2021
Fri_58_EN-6_1224
New Wet Extraction Technique to Measure CH4 and N2O Mole Fractions in Ice Cores

Loïc Schmidely1 (schmidely@climate.unibe.ch), Michael Bock1, Christoph Nehrbass-Ahles1, Jochen Schmitt1,

Hubertus Fischer1, Thomas Stocker1
1
University of Bern, Physics Institute & Oeschger Centre for Climate Change Research, Climate and
Environmental Physics, Bern, Switzerland

Reconstructions of past greenhouse gases (GHG) concentrations from polar ice cores are highly valuable to
study the coupling between GHG and the climate system. A detailed understanding of their past natural
variability and feedback mechanisms with temperature is crucial to constrain the future evolution of the
climate.
We present a new gas extraction technique coupled to a gas chromatograph. It is characterized by a continuous
vacuum extraction of the gases during the ice melting and subsequent collection on an active charcoal
adsorber. Our efforts are currently devoted to the reduction of possible sources of contamination connected
with desorption and/or outgassing phenomena connected to the ice extraction line.
The goal is to provide precise measurements to increase the temporal resolution of the EPICA Dome C Antarctic
CH4 and N2O records. Our new data will allow for a better quantification of the phasing between CH4, N2O and
CO2 during rapid climate changes along with better estimates of the magnitudes and rates of change of these
GHG fluctuations.

2022
Fri_59_EN-6_1428
Records of the Southern Hemisphere Westerlies from the Cape Horn Archipelago

Bianca Perren1 (biaper@bas.ac.uk), Steve Roberts1, Dominic Hodgson1, Frank Lamy2, Helge Arz3, Rolf Kilian4
1
British Antarctic Survey, Cambridge, United Kingdom, 2Alfred Wegener Institute Helmholtz Center for Polar and
Marine Research, Bremerhaven, Germany, 3Leibniz Institute for Baltic Sea Research Warnemünde (IOW),
Warnemünde, Germany, 4Universität Trier, Trier, Germany

Recent changes to the strength and latitudinal range of the Southern Hemisphere Westerly winds (SHW) have
highlighted their importance in regulating atmospheric CO2, sea ice extent, and the stability of Antarctic ice
shelves. Despite their critical role in global climate and mitigation of anthropogenic climate impacts, little is
known about their long term natural variability. Here we present efforts to reconstruct past SHW intensity and
associated late Glacial and Holocene climate variability from two islands in the Cape Horn Archipelago, Isla
Hermite (55º50'S, 67º40'W), the westernmost in the archipelago, and Isla Hornos (55º56'S, 67º16'W), the
southernmost. Combining peat and lake records from a suite of low-lying, westerly-facing sites on Isla Hermite,
and a lake sediment record from a headwater cirque lake on Isla Hornos, we aim to reconstruct past aerosol
deposition and westerly wind intensity using a novel diatom- and geochemistry-based multiproxy approach.
Here we present our latest radiocarbon age-depth models, diatom reconstructions, and micro-XRF scanning
results from the cores. These records form part of a larger project to reconstruct late glacial-Holocene SHW
intensity from sedimentary records from the sub-Antarctic islands, in an effort to understand past migration
and changes in intensity to the SHW, and ultimately how these variations affect CO2 sequestration on multi-
millennial timescales.

2023
Fri_60_EN-6_1453
Diatoms as Indicator of Regional Climatic Variability in Antarctica

Anna Oaquim1,2 (oaquim.bia@gmail.com), Gleyci Moser3, Heitor Evangelista2

1
Federal Fluminense Univesity, Chemestry, Niterói, Brazil, 2State University of Rio de Janeiro, Biology, Rio de
Janeiro, Brazil, 3State University of Rio de Janeiro, Oceanography, Rio de Janeiro, Brazil

The use of diatoms as micropaleontological indicators has been used in the last decades, once these organisms
that are sensitive to environmental changes, having their frustules preserved in the sediments which enables
paleoclimatic reconstructions. In this context, the present study reconstruct regional climatic variations in the
west coast of the Antarctic Peninsula, using fossil records of diatoms in a sedimentary corer with 50 cm
sampled at the Glubokoe Deepe Lake, King George Island. 25 layers (period 2013 to 1737) was submitted to
qualitatively analysis where 19 taxa was considered as frequent and there relative abundance was correlated
with environmental variables to established three reconstruction models. The first reconstruct the temperature
in Antarctica Peninsula based on the relative abundance of Brachysira minor and Pinnularia sp. and presented
an associated error of 13%. The second reconstruct the energy of cyclones occurring between 50 ° and 70 ° S
based on the relative abundance of Nitzschia cf. Kleinteichiana, Pinnularia borealis, Gomphonema sp. and has
an average error of 2%. And the last one reconstruct the ozone content in the atmosphere using Planothidium
australe, Pinnularia borealis, Gomphonema sp. and Humidophila tabellariaeformis relative abundance with a
mean associated error of 11%. The results corroborate with other models proposed thereby allowing to
concluded that diatom assemblages can be used as paleoclimatic reconstructors for this region.

2024
Fri_61_EN-6_1603
Pliocene-Pleistocene Paleoproductivity on the Wilkes Land Margin, Antarctica

Grace Duke1 (grace.duke@otago.ac.nz), Christina Riesselman1,2, Briar Taylor-Silva1

1
University of Otago / Te Whare Wananga o Otago, Geology Department, Dunedin, New Zealand, 2University of
Otago / Te Whare Wananga o Otago, Marine Science Department, Dunedin, New Zealand

Although the East Antarctic Ice Sheet (EAIS) is considered relatively stable, the Wilkes Land Margin (WLM) is
susceptible to global warming because its marine-based glaciers are at risk of contact with warm mid-depth
waters. Unstable ice sheets cause sea-level rise and threaten coastal communities, but our understanding of ice
variability and response to climate change is poorly constrained due to a lack of data. We present a Plio-
Pleistocene biogenic silica (wt% BSi) stratigraphy, diatom assemblages, and bulk sedimentary stable isotope
data from a marine sediment core collected from IODP site U1361A, located on the WLM continental rise.
Characterizing Southern Ocean conditions from 1.8 - 3.8 Ma allows us to examine the shift from the warm
Pliocene, which is an analog for future warming conditions, to the cooler Pleistocene, and may improve the
parameterization of EAIS response to climate forcings. High wt% BSi intervals are interpreted to reflect
interglacial episodes of elevated diatom productivity, while lower wt% BSi intervals are interpreted to reflect
glacial episodes of decreased productivity and/or increased terrigenous input. Diatom assemblages from mid-
and late-Pliocene interglacial intervals indicate the onset of cooler interglacial surface ocean temperatures
around 3.3 Ma, punctuated by short-lived warm water incursions. Work is underway to extend this
reconstruction into the early Pleistocene.

2025
Fri_62_EN-6_1620
Preliminary Study on the Geochemistry and Diatom of Core Sediments in Ross Sea

Younho Noh1 (ss112@kopri.re.kr), Ho Il Yoon1

1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

The paleoenvironments, XRF, biostratigraphy, and age dating of the piston cores (RS14-GC04) collected from
Ross sea Strait, Antarctica are studied by the micropaleontological studies based on diatoms.
As a result of dating, the age of the core represents about 6,000 years. The variation of sediment core including
diatoms were analyzed from the drilled core which was obtained from the Ross sea for the purpose of
reconstruction of the environmental variations during the Holocene.
A total of 25 species and varieties belonging to 58 genera are identified from the Core RS14-GC04. The range of
diatom valves per gram of dry sediment was approximately0 to 26.3* 107/g in quantitative diatom assemblage
analysis.
The diatom assemblages from RS14-GC04 are dominated by Fragilariopsis curta, Thalassiosira antarctica cold
type, Eucampia Antarctica var, recta. A minor species appeared as F. obiquecostata, F. turgiduloide, proboscia
alata, Rhizosoleni styliformis and Stellarima microtrias.
Ba is a good correlation with TOC, suggesting their relation to biogenic debris, precipitation from seawater, or
hydrothermal input.

2026
Fri_63_EN-6_1645
Implications of Biogenic Sulfur Species from GV7 Firn Core, East Antarctica

Sangbum Hong1 (hong909@kopri.re.kr), Joo-Hong Kim1, Seong-Joon Jun1, Yeongcheo Han1, Jangil Moon1,
Chang-Kyu Lim1, Chae-Won Chang1, Jung-Ho Kang1, Soondo Hur1, Seong-Joong Kim1, Roberto Udisti2, Silvia
Becagli2, Rita Traversi2, Mirko Severi2
1
Korea Polar Research Institute, Incheon, Korea, Republic of, 2University of Florence, Florence, Italy

The concentrations of ionic species in conjunction with stable isotopes were measured from firn core drilled in
the austral summer of 2014 at the GV7 site (70° 41´S, 158° 52´E, 1950m a.s.l.) conducted as a scientific
cooperation between ENEA from Italy and KOPRI from Korea. This study presents the snow chemistry of a short
firn core covering a time period of at least 35 years (1979-2013). The concentration variations of biogenic sulfur
species were studied in detail to investigate their implications as proxies to indicate the long-term perspective
on the change of oceanic environmental in the past. The seasonal concentrations of methanesulfonic acid
(MSA) were determined according to the age-depth relationship based on the annual layer counting using the
variations of oxygen isotope ratio, nssSO42-, Cl-/Na+, and Pinatubo volcanic record. The correlation analyses with
satellite-derived sea ice area and firn core MSA were systematically conducted. Variations of MSA during
austral summer season were found to be positively correlated with sea-ice area (~60-65°S) between the 150°E
and 150°W sector during spring season and the correlation between them at each 10° sector was strongest at
180° (p< 0.05).

2027
Fri_64_EN-6_1867
Morphology and Sediments of the Confined Outwash Fan in the High Arctic Region

Piotr Weckwerth1 (pweck@umk.pl), Katarzyna Greń2, Ireneusz Sobota3

1
Nicolaus Copernicus University in Toruń, Faculty of Earth Sciences, Department of Geomorphology and
Palaeogeography of Quaternary, Polar Research Center, Toruń, Poland, 2University of Warsaw, Faculty of
Geography and Regional Studies, Warsaw, Poland, 3Nicolaus Copernicus University in Toruń, Faculty of Earth
Sciences, Department of Hydrology and Water Management, Polar Research Center, Toruń, Poland

Controls affecting the morphology and surficial lithology of a confined outwash fan of the Waldemar River (NW
Spitsbergen, Svalbard) were analysed on the basis of geomorphological and sedimentological researches which
indicate multiple correlations between the shape of distributary channels and textural features of fluvial
deposits. The statistical techniques were used to find relations between the morphological and sedimentary
features of a confined outwash fan developed in High Arctic conditions. The ability of these techniques to
detect relationships was analysed and threshold values for changes in relations between fan slope, channel
morphology, sediment distribution and confined outwash fan width were detected. The results of our research
indicate that the morphology and surficial lithology of the confined outwash fan developed under High Arctic
conditions are closely related to the existence of permafrost. Changes in the confined fan slope, width and rate
of sediment supply (as a result of lateral, mechanical and thermal erosion and degradation of the uppermost
part of permafrost) control the distributive channels bed lithology. Thus, the evolution and determination of
the rate and dynamics of transformations of confined outwash fans in High Arctic regions, affected by climate
warming, can be considered as an indicator of polar environment changes resulting from climate fluctuations.
This also will help us to understand the outwashes evolution during the Pleistocene.

2028
Fri_65_EN-6_1986
Last Decades Warming Evidences in the NW Barent Sea (Arctic)

Viviana Gamboa Sojo1,2 (vi_gs1283@hotmail.com), Caterina Morigi1,3, Renata G. Lucchi4

1
Università di Pisa, Dipartimento di Scienze della Terra, Pisa, Italy, 2Università degli Studi di Firenze, Firenze,
Italy, 3Geological Survey of Denmark and Greenland, Department of Stratigraphy, Copenhagen, Denmark, 4OGS
– National Institute of Oceanography and Experimental Geophysics, Trieste, Italy

The Arctic area is responding more rapidly to global warming than most other areas on our planet. The
Kveithola Trough located in the NW Barents Sea has an interesting sedimentary record due to its geographical
conditions and its dynamic glacial history formation. Its location allows the input and interaction of two of the
main water masses, the cold, fresh Arctic Water coming from the north and the warm, salty Atlantic Water
flowing from the south.
Four sediment cores collected in the Kveithola Trough area during the oceanographic cruise EUROFLEETS2-
BURSTER were analysed with regard to benthic foraminiferal assemblages and sedimentological parameters in
order to elucidate past variability of the water masses, the organic matter flux and oxygen concentration to the
sea floor during the last decades. The foraminiferal assemblages composition and and taxonomic abundance
allow inferring significant environmental differences between the evolution of the inner and outer shelf areas.
The dominant foraminiferal species recurrent in the study area may indicate that during the last 45 years a
higher influence of warm water and an increase in the anoxic conditions has been established along of the
Kveithola Trough area. These evidences need to be confirm by further multidisciplinary analysis including
biological, sedimentological and chemical data.

2029
Fri_66_EN-6_2057
Early Holocene Shallow Marine Mollusc Palaeodiversity, Billefjorden, Svalbard

Martin Lulak1,2 (nitram.kalul@gmail.com), Martin Hanacek1,2, Daniel Nyvlt1, Slavomir Nehyba3

1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic, 2University of South
Bohemia, Centre for Polar Ecology, Ceske Budejovice, Czech Republic, 3Masaryk University, Faculty of Science,
Department of Geological Sciences, Brno, Czech Republic

Species communities of marine molluscs from two geochronologically identical early Holocene sites with
different positions in the northern part of Billefjorden were compared. Kapp Ekholm (KE) site is situated in the
main fjord and the terrace surface lies at ~25 m a.s.l. Mimerdalen 1 (MD1) site has a terrace surface at 28 m
a.s.l. and is situated in a valley, which represented a shallow cove. Although both sites are identical in
morphostratigraphy and geochronology, they bear species compositions, which correspond to different
biostratigraphical levels according to classical concept. The species community on KE is correlated to the
morphologically highest, i.e. the oldest Holocene terraces. On the contrary, species composition on MD1 is
correlated with morphologically lower and younger terraces. This diversity is caused by different palaeodepths
on both sites. According to the sediment architecture, the depth of the sea floor inhabited by studied
organisms was ~20 m on KE and ~5 m on MD1. The results indicate that past species communities do not have
to correlate necessarily with the morphostratigraphy of terraces. They depends more on the palaeogeographic
position within the fjord than on chronostratigraphic position within the early Holocene. Species-poor
community does not indicate only temperate conditions shortly after the LGM, but can also occur later in
connection with ecological conditions at specific locations.

2030
Fri_67_EN-6_2166
Reconstruction of Sedimentary Environment in Western Ross Sea Since Early LGM

Xibin Han1 (hanxibin@sio.org.cn), Panpan Long1, Linggang Tang2, Lehui Song3, Geng Liu1
1
Second Institute of Oceanography, State Oceanic Administration, Key Laboratrory of Submarine Geosciences,
Hangzhou, China, 2South China Sea Institute of Oceanology,Chinese Academy of Sciences, Guangzhou, China,
3
Nanjing University, Geographic and Oceanographic Sciences, Nanjing, China

The Western Ross Sea is an important drainage channel for the Ross Ice Shelf（RIS）and paleo-ice sheet, and
its sedimentary records reflect the retreat history of the RIS and the changing processes of the local ocean
circulation. The lithologic feature, internal structure, physical characteristics and organic molecular
geochemistry of the gravity sediment core ANT31-JB03 in the Central Basin, western Ross Sea revealed that
two stage sedimentary environmental change: (Phase I) and (Phase II) in the early Last Glacial Maximum (LGM)
and since the Holocene with the boundary of 78cm depth below sea floor. The missing sediment matter during
the two stages maybe eroded by the glacial drift flow during the Last Deglaciation followed the LGM. The
sedimentary environment of Phase I was glacial-marine sediment still under RIS extension, with two age
reversal events which means that the sediment on the Ross Sea shelf were prone to slide migration and mixing
effected by ice shelf drainage flow because of sea water temperature rise or the ice-sea interacts strengthening
with each other weak reducing-reducing environment. Since the Holocene, with the rising of the sea level, and
the retreating of RIS, the sediments grainsize became thinner, the biological activity increased, the productivity
increased, the source of organic matter increased, and the influence of ocean circulation increased gradually. In
the meanwhile, three events with increased density and reduced porosity.

2031
Fri_68_EN-6_2240
Greenland NEEM Ice Core Records of Trace Metals during the 1710~1970

Khanghyun Lee1 (leekh@kopri.re.kr), Seung Mi Lee1, Jangil Moon1, Yeongcheol Han1, Soon Do Hur1, Sungmin
Hong2
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Inha University, Incheon, Korea, Republic
of

In this research, we present high resolution record of Al, As, Ba, Cd, Co, Cr, Mn, Mo, Pb, Rb, Sr and V from
Greenland NEEM ice core samples covering the period from 1710 to 1970. To our knowledge, long-term trends
of these elements except Cd and Pb have never been reconstructed from Greenland ice cores at such a high
resolution. The ice core records of the trace metals concentrations are characterized by large fluctuations. The
ratios between maximum and minimum concentrations range from 69 for Sr to 1596 for As indicating a stark
variation in concentration with depth. To help understanding long-term changes in atmospheric trace metals,
individual data points were averaged for a decadal period. The main features of long-term changes are all
categorized into three groups. Al, Ba, Mn, Rb, Sr and V show no distinct peaks in their concentrations over the
whole period. Meanwhile, Co, Cr and Mo concentrations are largely peaked from the mid-1830s to the mid-
1850s and steadily increase for the 20th century. For As, Cd and Pb, two concentration peaks are appeared
around 1800 AD and 1900 AD. The different patterns in the periods reaching peaks in concentrations are likely
due to the primary anthropogenic sources for the different element. Our first comprehensive and reliable time
series for various trace metals from Greenland NEEM ice core provide valuable insights into significant
enrichments of these elements due to human activities from the early-19th to the mid-20th century.

2032
Fri_69_EN-6_2364
Reconstructed Plutonium Fallout in the GV7 Firn Core from East Antarctica

Heejin Hwang1 (heejin@kopri.re.kr), Yeongcheol Han1, Jungho Kang1, Sangbum Hong1, Khanghyun Lee1, Soon
Do Hur1, Massimo Frezzotti2, Biancamaria Narcisi2
1
Korea Polar Research Institute, Incheon, Korea, Republic of, 2ENEA, Casaccia Research Centre, Rome, Italy

Atmospheric nuclear explosions during the period from the 1940s to the 1980s are the major anthropogenic
source of plutonium (Pu) in the environment. In this work, we analyzed fg g-1 levels of artificial Pu, released
predominantly by atmospheric nuclear weapons tests. We measured 351 samples which collected a 78 m-
depth fire core at the site of GV7 (S 70°41´17.1", E 158°51´48.9", 1950 m a.s.l.), Northern Victoria Land, East
Antarctica. To determine the Pu concentration in the samples, we used an inductively coupled plasma sector
field mass spectrometry coupled with an Apex high-efficiency sample introduction system, which has the
advantages of small sample consumption and simple sample preparation. We reconstructed the firn core Pu
fallout record for the period after 1954 CE shows a significant fluctuation in agreement with past atmospheric
nuclear testing. These data will contribute to ice core research by providing depth-age information.

2033
Fri_70_EN-6_2486
Anthropogenic Contaminants in the Last Hundred Years of Antarctic Ice

Stefania Giannarelli1 (stefania.giannarelli@unipi.it), Roger Fuoco1, Sandro Francesconi1, Chiara Tiribilli1

1
University of Pisa, Department of Chemistry and Industrial Chemistry, Pisa, Italy

The deposition of contaminants, transported by the aerosol, occurs mainly through snowfalls and therefore the
ice-cores represent an archive of notions of the variation of trace chemicals. From the stratigraphy of the ice
cores, the ice-layers can be temporally related. Antarctica is the ideal site to perform basic studies on
contamination: it provides an atmospheric environment free of local sources or anthropogenic contamination,
giving a low background of native-pollution which is essential for transportation studies. As the ice
compartment represents a reservoir of historically deposited POPs, quantification of concentrations in
Antarctic continental ice is particularly relevant in order to predict the possible future POP re-emission into the
atmosphere and oceans through ice melt.
In this work we investigated the presence of Organo Chloride Pesticides (OCPs) in a 50-m deep snow/firn core,
collected at the peripheral site GV7 in East Antarctica during the 2013-2014 XXIX Italian expedition, to elucidate
historical deposition rates of OCPs.
The concentration depth profile was obtained on the basis of the total concentration of twenty-two OCPs
individually detected by GC-MS QqQ.
SOCPs showed linear and constant trend from 1890 till 1960 (with an average value of 0,01 ng/l), then an
increase, in the period 1960-2010, from about 0.01 to 0.20 ng/l (200% increase).

2034
Fri_71_EN-7_33
Soil Organic Carbon Variability Along a Latitudinal Transect in Arctic Siberia

Anna Bobrik1 (ann-bobrik@yandex.ru), Georgy Matyshak1, Olga Goncharova1, Dmitry Petrov1

1
Lomonosov Moscow State University, Department of Soil Science, Moscow, Russian Federation

The aim of our study was to assess variability in the soil organic carbon pool from the peatlands and bog soils in
taiga and tundra zones along the latitudinal transect in Arctic West Siberia (Russia).
The taiga research site is located in discontinuous permafrost zone (N65º18´, E72º52´). The average active layer
thickness was 163±8 (August 2015). The CO2 efflux from the peatlands was low (202 ± 37 mgСО2/m2hr). The
upper horizons of the peatland soils statistically differed from those of the bog in the contents of the total,
labile and microbial carbon.
The tundra research site is located in continuous permafrost zone (N 67°48; E 76°69'). Soils of this research site
are characterized by low active layer thickness, CO2 efflux and content of microbial carbon (August 2016). The
spatial distribution of CO2 efflux and content of water-extractable organic carbon are strongly correlated with
hypsometric levels (r = -0,33, and r=-0,42 respectively, p-level < 0,05) in tundra ecosystems.
Despite the wide array of changes in both physical (soil temperature, soil moisture) and biological conditions
(vegetation composition, content of labile and microbial soil carbon), our results showed that soil CO2 flux did
not vary significantly throughout transect (taiga- tundra). But depth of permafrost table differed significantly. It
explains the necessity of adequate assessment of the spatial variability on the active layer thickness as a
significant factor influencing regional CO2 emission.

2035
Fri_72_EN-7_41
Fire Effects on Greenhouse Gas Emissions on Wetlands in the YK Delta, Alaska

Darcy L. Peter1 (darcy.peter@akijp.org), Emily M. Bristol2, Paul James Mann3, John D. Schade4
1
Alaska Institute for Justice, Research and Policy, Anchorage, United States, 2University of Alaska Southeast,
Sitka, United States, 3Northumbria University, Tyne, United Kingdom, 4National Science Foundation, Alexandria,
United States

Climate change is increasing both fire frequency and fire intensity, especially in Arctic regions. Fire leads to
increased soil temperature, which increases the likelihood of permafrost thaw. Permafrost soils in northern
latitudes store large amounts of carbon, and thawing of this permafrost will alter carbon cycling processes,
which may substantially impact ecosystem processes in aquatic ecosystems. One potential consequence of
altered aquatic ecosystem processes is changes in carbon emissions resulting from altered carbon inputs from
thawing permafrost. Aquatic ecosystems are known to be hotspots of greenhouse gas emissions, so changes in
greenhouse gas fluxes from them may have important impacts on global climate. In this work, we focused on
CO2 and CH4 fluxes from plateau and lowland ponds, fens and bogs in the Yukon-Kuskokwim (YK) Delta in
southwest Alaska. The YK Delta experienced unprecedented fires in summer 2015, presenting an opportunity
to assess the impacts of permafrost thaw on greenhouse gas fluxes from aquatic ecosystems. We sampled in
sites that had burned in 2015 as well as from similar sites where there have been no recorded fires in the past
75 years. We found little difference in gas flux between aquatic sites in burned and unburned sites, with the
exception of channel fens, which showed substantially higher CH4 and CO2 flux in burned sites. Results may
indicate the response of aquatic ecosystems to fire may lead to positive feedbacks on climate change.

2036
Fri_73_EN-7_261
Estimating pCO2 in Cambridge Bay Nunavut Using an Autonomous Sensor Platform

Patrick Duke1 (pjduke@ucalgary.ca), Brent Else1, Richard Dewey2, Kim Juniper2, Lisa Miller3, Akash Sastri2,
Oksana Schimnowski4, Helmuth Thomas5
1
University of Calgary, Geography, Calgary, Canada, 2Ocean Networks Canada, Victoria, Canada, 3Department
of Fisheries and Oceans Canada, Sidney, Canada, 4Polar Knowledge Canada, Winnipeg, Canada, 5Dalhousie
University, Halifax, Canada

Continuous monitoring platforms contribute to our understanding of long term ocean change, offering
increased temporal resolution and ability to resolve variability compared to occasional measurements. We will
present pCO2 time series data from on-board an Ocean Networks Canada cabled seafloor platform at sub-tidal
depth in Cambridge Bay, Nunavut. The platform, which supports a Pro-Oceanus sensor for measuring pCO2 and
instruments for measuring temperature, salinity, ice thickness, oxygen, chlorophyll, current velocity, and pH
was deployed from August 2015 to August 2017. We will quantitatively distinguish influencing oceanographic
processes on pCO2 daily, seasonally, and annually for this unique marine biogeochemical time series. This work
contributes to quantifying pCO2 cycling in the Arctic Ocean, influencing climate modelling and future
projections of the Arctic Ocean carbon cycle. We will also review the performance of the pCO2 sensor
operating in near continuous subzero seawater.

2037
Fri_74_EN-7_277
Terrestrial - Atmosphere Mercury Exchange in the Arctic Tundra

Martin Jiskra1 (martinjiskra@gmail.com), Jeroen E. Sonke1, Daniel Obrist2, Yannick Agnan3, Christine Olson4,
Christopher Moore5, Dominique Colgrove6, Jaques Huber6, Detlev Helmig6
1
CNRS / Geosciences Environment Toulouse, Toulouse, France, 2University of Massachusetts Lowell, Lowell,
United States, 3Sorbonne Universités (Université Pierre et Marie Curie Paris 6), Paris, France, 4Desert Research
Institute, Reno, United States, 5Gas Technology Institute, Des Plaines, United States, 6University of Colorado,
Boulder, United States

Mercury (Hg) is a global pollutant of great concern for human and ecosystem health. The Arctic is particularly
vulnerable because of the high dietary exposure of indigenous populations to Hg in fish and mammals.
Atmospheric Hg deposition to Polar Regions has been extensively studied in coastal zones with the goal to
better understand the nature and relevance of halogen-driven atmospheric mercury depletion events
(AMDE´s). Little attention has been given so far to the interior, continental Arctic. We will present a
comprehensive Hg stable isotope mass balance of the arctic tundra made at Toolik Field station, AK and
compare our findings with extensive terrestrial - atmosphere Hg0 flux measurements conducted at the same
site. The Hg stable isotope results agree well with micro-metrological flux measurements. Both independent
approaches suggest that vegetation uptake of gaseous elemental Hg represents the dominant Hg flux between
the atmosphere and Arctic tundra soils. The Arctic tundra thus represents a globally important sink for
anthropogenic Hg emissions. Changes in environmental conditions, such as warming and thawing of permafrost
due to climate change or could however lead to a remobilization of a large Hg pool stored in Arctic tundra soils
to the Arctic Ocean.

2038
Fri_75_EN-7_313
Tracing the Iron Cycle in the Southern Ocean during the ACE Voyage

Michael Ellwood1 (michael.ellwood@anu.edu.au), Christel Hassler2, Samuel Jaccard3, Tim Conway4, Julie
Janssens5, Maureen Soon6, Roger Francois6, David Jenssen3, Matthias Sieber7, Damien Cabanes2, Phillipe
Arpagaus2, Derek Vance7, Nolwenn Lemaitre7, Gregory de Souza7
1
Australian National University, Research School of Earth Sciences, Canberra, Australia, 2University of Geneva,
Geneva, Switzerland, 3University of Bern, Bern, Switzerland, 4University of South Florida, St Petersburg, United
States, 5University of Tasmania, Hobart, Australia, 6University of British Columbia, Vancouver, Canada, 7ETH
Zurich, Zurich, Switzerland

Incubation and mesoscale enrichment experiments demonstrate that iron is a key micronutrient limiting the
growth of phytoplankton in Southern Ocean waters. It is the size of the bioavailable iron pool that shapes the
phytoplankton community and hence their draw-down atmospheric carbon dioxide.
During project 15 of the Antarctic Circumnavigation Expedition (ACE) we collected trace metals samples from
Indian, Pacific and Atlantic sectors of the Southern Ocean. Preliminary results reveal that the dissolved iron
concentration in open ocean waters is sub-nanomolar in concentration. Near continental features such as the
Kerguelen Plateau, iron concentrations are elevated which is consistent with continental supply. In contrast,
there was latitudinal surface gradient in the concentration for dissolved zinc, copper, nickel and cadmium.
Concentrations for these elements were high in surface waters south of the Antarctic Polar Front consistent
with a deep-water supply whereas concentrations declined as surface waters are advected northward in the
Subantarctic zone. Using this data, our goal is to develop a mechanistic understanding of the role iron, zinc,
copper, nickel and cadmium play in regulating plankton communities in the Southern Ocean.

2039
Fri_76_EN-7_591
Export of Particulate Organic Carbon in the Dalton, Mertz and Ninnis Polynyas

Lavenia Ratnarajah1 (lavenia.ratnarajah@utas.edu.au), Sebastien Moreau2, Julie Janssens2, Cristina Genovese2,

Matthew Corkill2, Luis Duprat2, Viena Puigcorbé3, Montserrat Roca-Martí4, Delphine Lannuzel1,2
1
Antarctic Climate & Ecosystems Cooperative Research Centre, Battery Point, Australia, 2Institute for Marine
and Antarctic Studies, Battery Point, Australia, 3Edith Cowan University, Perth, Australia, 4Autonomous
University of Barcelona, Barcelona, Spain

Photosynthetic production of particulate organic carbon (POC) by marine phytoplankton is a key mechanism
for the uptake of carbon dioxide that enters the surface ocean, which is then cycled through the complex
marine food web. Sinking of POC from surface waters to the deep ocean represents a major pathway in the
long-term storage of carbon. However, only a small fraction of the surface POC is sequestered in the deep
ocean. We examined the fate of POC throughout the water column in the Dalton, Mertz and Ninnis polynyas in
the Southern Ocean towards the end of the summer bloom. POC concentration in surface waters (2-10m) of
coastal polynyas are higher (162 to 274 mg m-3) than the Antarctic open water reference station (114 mg m-3).
Compared to the Dalton where POC concentration decreased with depth, POC concentration in the Mertz and
Ninnis polynyas increased (>300 mg m-3) between 10-50m before decreasing. Background POC in the twilight
zone was also higher within the polynyas. Large fraction of the organic carbon in the sinking particles is
subjected to a range of processes such as bacterial remineralisation, abiotic disaggregation and fragmentation
into smaller, slower sinking particles by the zooplankton community during its transit through the water
column. Seawater ammonia concentrations suggest active bacterial remineralisation in surface seawater.
Biologically productive polynyas are hotspots for elevated surface POC, and could play an important role in
carbon export.

2040
Fri_77_EN-7_613
Nutrient Cycling in Supraglacial Ecosystems at Larsemann Hills, East Antarctica

Gautami Samui1 (gautamisamui@gmail.com), Runa Antony1, Meloth Thamban1

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Polar Cryosphere and Ice Core Studies,
Vasco, India

Microbial communities in supraglacial ecosystems like cryoconite holes and surface snow strongly influence
nutrient cycling in these environments. In order to understand carbon flow within these systems, we carried
out in-situ measurements of primary (PP) and bacteria production (BP) in cryoconite holes and surface snow at
Larsemann Hills, East Antarctica during 2016-17 season. The rates of PP and BP in six cryoconite hole water
samples were 0.09±0.03 µgCL-1d-1 and 10.26±7.18 ngCL-1d-1, respectively, with higher rates observed in the
sediment (PP=5.88±3.77 µgCL-1d-1; BP=138.40±86.25 ngCL-1d-1), suggesting that sediments play a crucial role in
the carbon cycling of the cryoconite holes ecosystem. In snow, mean rate of PP was 0.08±0.02 µgCL-1d-1
whereas BP was below detection limit. To understand the photochemical and microbial transformations of
dissolved organic matter and ionic constituents associated with snow and cryoconite holes, in-situ field
experiments were carried out in the presence of: microbes under dark, microbes+light and only light (no
microbial activity) conditions. Significant changes in DOC and major ions (Na⁺, Cl‾, Mg2⁺, Ca2⁺, SO42‾, K⁺, NO3‾,
Ac‾, Fo‾, Oxy2‾ and HCO3‾) concentrations were observed after 30 days incubation. Observations made in this
study are crucial for an improved understanding of the nutrient cycling in supraglacial ecosystems of polar
regions.

2041
Fri_78_EN-7_740
Microelements in Soils of Oases of Thala Hills, Enderby Land, East Antarctica

Tamara Kukharchyk1 (tkukharchyk@gmail.com), Sergey Kakareka1, Yuri Giginyak2, Vladislav Myamin2

1
Institute for Nature Management, National Academy of Sciences of Belarus, Minsk, Belarus, 2The Scientific and
Practical Centre for Bioresources, National Academy of Sciences of Belarus, Minsk, Belarus

The paper is devoted to the studies of spatial and temporal patterns of microelements content in soils of
Vecherny oasis (Thala Hills, Enderby Land) and their connections to human impact. The paper is based on the
results of soils investigation during Belarusian Antarctic Expeditions in 2011-2017.
General description of soils features of the oasis in comparison with others oases of Enderby Land is provided.
It is shown, that the most developed soils with profile up to 50-60 cm can be found at bottoms of hollows; such
sites are usually partially covered by lakes or snowfields. Their area varies from less than 1 m2 to several
hundred meters. Soils are acidic or slightly acidic, characterized by low humus content and low sorption
capacity; soils properties and intensity of radial and horizontal microelements migration are highly impacted by
the hypsometric level of a site location.
Certain connections of microelements content in soils with human impacts in this area is found. Among
microelements sources are: erosion of old mechanisms, constructions, waste fuel oil barrels as well as fuel
leaks. Generally, detected levels of microelements content can be considered as not very high. No common
area of soils contamination was found due to high level of soils fragmentation.
The results of soils study will be used for model of heavy metals migration in soils parametrization to provide
the forecast of soil pollution taking into account climate change and human activities.

2042
Fri_79_EN-7_754
Dynamics of Inorganic Components in Terra Nova Bay Lake Ecosystems (Antarctica)

Eleonora Conca1 (econca@unito.it), Mery Malandrino1, Agnese Giacomino2, Isabella Zelano3, Sandro Buoso1,
Andrea Ruo Redda2, Carmela La Gioia1, Ornella Abollino1
1
University of Turin, Chemistry, Torino, Italy, 2University of Turin, Drug Science and Technology, Torino, Italy,
3
Centre de Recherches Pétrographiques et Géochimiques, Nancy, France

A large suit of inorganic analytes was determined in water collected from six shallow Antarctic lakes of Terra
Nova Bay (Northern Victoria Land, Antarctica), as well as in algae, mosses and suspended particulate material
(SPM). The sampling campaigns took place between 2007 and 2012 (and one in 2002) within the framework of
the Italian National Program of Research in Antarctica (PNRA). The purpose of this work was to gain insight into
the natural processes regulating species distribution, define natural background values and detect possible
present or future local and/or global anthropogenic contamination.
The results were processed with multivariate chemometric techniques. Lake water composition was found to
be mainly influenced by marine spray and meltwater input, i.e. natural phenomena. The obtained results were
compared with older literature data from the same lakes. A considerable variability was observed in metal
concentrations, but no clear trend was identified; no evidence of an increase of metal concentrations over time
was found for water or vegetation samples. Seasonal variability was also evaluated for each analyte, and
explained considering the natural transport processes involving each species. Higher element concentrations
were found in SPM than in water, suggesting that weathering plays an important role on the chemistry of these
lakes. The exam of the SPM samples with a SEM showed the presence of many diatoms belonging to different
species.

2043
Fri_81_EN-7_1015
Microbial Metabolism in Front of Kongsfjorden Glaciers

Maurizio Azzaro1 (maurizio.azzaro@iamc.cnr.it), Giuseppe Zappalà1, Rosabruna La Ferla1, Stefano Miserocchi2,

Tommaso Tesi2, Giovanna Maimone1, Gabriella Caruso1, Massimo Caccia3, Roberta Ferretti3, Angelo Odetti3,
Filippo Azzaro1, Alice Madonia4, Simone Bonamano4, Viviana Piermattei4, Marco Marcelli4, Daniele Piazzolla4,
Alessandro Cosenza1, Rappazzo Alessandro Ciro1, Furnari Michele1, Gabriele Bruzzone3
1
CNR-IAMC, Messina, Italy, 2CNR-ISMAR, Bologna, Italy, 3CNR-ISSIA, Genova, Italy, 4University of Tuscia,
Civitavecchia, Italy

Understanding how the climate change affects the microbial community in the Arctic Sea and the ongoing
heating results in cascading effects on the earth delicate climatic equilibrium is an important challenge of
recent research performed in vulnerable ecosystems such as the Svalbard Islands. Within the UVASS
(Unmanned Vehicles for Autonomous Sensing and Sampling) project, an unmanned marine vehicle (PROTEUS,
Portable RObotic TEchnology for Unmanned Surveys), equipped with an automatic water multisampler,
designed and built by ISSIA-CNR and IAMC-CNR respectively, were exploited to study the response of
planktonic communities, particularly prokaryotes, in the extreme environment of Kongsfjorden. In June 2017
seawater samples were collected by those automatic systems along three transects extending from glaciers
fronts to the open sea. The samples were analyzed for nutrients, organic matter and its utilization by microbial
activity using Biolog-Ecoplates™ and extracellular enzymatic activity rates (leucine aminopeptidase, beta-
glucosidase and phosphatase activities). Richness and Shannon-Weaver index and Principal Component
Analysis were used to depict differences in the microbial catabolic potential. Variations in organic matter
distribution and in functional diversity of microbial assemblages were observed. Freshwater runoff from ice
melting was found to increase the amount of terrestrial organic matter to the fjord and microbial processes
allowed organic matter decomposition.

2044
Fri_82_EN-7_1201
Sediment Transport in the Northwestern Laptev Sea

Stefan Buettner1 (sbuettner@ecology.uni-kiel.de), Jens Hoelemann2, Markus Janout2

1
Christian Albrecht University of Kiel, Institute for Ecosystem Research, Kiel, Germany, 2Alfred Wegener Institute
Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany

Arctic summer sea ice extent is continuously declining, affecting the hydrography and biogeochemical cycles on
the seasonally ice-free shallow Siberian shelves. The prolongation of the open-water season during summer
causes higher sediment resuspension and coastal erosion due to larger wind fetch and wave heights. This
impacts the optical properties of the water column and hence biological productivity in this region. In order to
link changes in sediment distribution with ecosystem consequences under a warming climate, detailed studies
of sediment transport and pathways are required.
On the central and eastern Laptev Sea shelf, suspended particulate matter (SPM) transport is mainly
characterized by two nepheloid layers, originating from bottom resuspension, erosion of thawing permafrost
coasts and the input of turbid river water from the Lena River. In the northwestern Laptev Sea, SPM dynamics
and transport mechanisms from the Kara Sea through Vilkitsky Strait and into the Eurasian Basin remain largely
unknown due to the inaccessibility of the region. Nevertheless, several ship expeditions and deployments of
long-term oceanographic observations were carried out in the western Laptev Sea from 2013 until 2015 to
investigate year-round SPM distribution and dynamics. This study presents first results of year-round SPM
distribution, obtained by combining optical backscatter data, ADCP echo intensity data and filtration
measurements from summer expeditions.

2045
Fri_83_EN-7_1246
Antarctic Derived Dust in the South West Ross Sea

Cliff Atkins1 (cliff.atkins@vuw.ac.nz), Gavin Dunbar1, Juliet Sefton2

1
Victoria University of Wellington, Wellington, New Zealand, 2Durham University, Durham, United Kingdom

Dust in the SW Ross Sea Region is transported by katabatic winds from ice-free areas, offshore onto ice shelves
and sea ice where it is released into the ocean. The dust contributes sediment to the Antarctic shelf and is one
source of iron (Fe) involved in triggering vast phytoplankton blooms which regulate the oceanic biological
pump, drawing down atmospheric CO2. However, the source, distribution and impact of the dust is still poorly
constrained. Although some modelling studies suggest that the McMurdo Dry Valleys is an important source of
dust, our field data indicate that most of the dust flux comes from relatively small areas around the coast, in
particular an area of unconsolidated debris on the McMurdo Ice Shelf.
We present new major element X-ray florescence analysis from a comprehensive suite of samples from
potential source areas in Victoria Land as well as samples from extensive areas of sea ice and ice shelves
fringing the coast and also from sea floor grab samples from across the SW Ross Sea. The results shows clear
compositional patterns suggesting that dust can be geochemically traced from various onshore sources to
offshore Ross Sea sink. This provides constraints on the modern dust flux, transport processes and impact on
sedimentation and biogeochemical cycling in the Ross Sea. The data will contribute to the new international
High Latitude and Cold Climate Dust Network database, www.hlccd.org.

2046
Fri_84_EN-7_1293
Illuminating Dissolved Organic Matter Diversity in Antarctic Lakes and Streams

Morimaru Kida1 (m.kida@stu.kobe-u.ac.jp), Taichi Kojima1, Yukiko Tanabe2,3, Kentaro Hayashi4, Sakae Kudoh2,3,
Nagamitsu Maie5, Nobuhide Fujitake1
1
Kobe University, Kobe, Japan, 2National Institute of Polar Research, Tachikawa, Japan, 3SOKENDAI (The
Graduate University for Advanced Studies), Tachikawa, Japan, 4Institute for Agro-Environmental Sciences,
NARO, Tsukuba, Japan, 5Kitasato University, Towada, Japan

Dissolved organic matter (DOM) exists ubiquitously in water and is involved in various biogeochemical
processes. In Antarctica, most of DOM is considered to be originated from lower plants. This unique feature of
Antarctica is ideal to unveil structural properties and functionality of DOM, which depend on the source
materials and environmental processing. In this study, we present the diversity in the properties of DOM
obtained from various lakes and streams at Soya Coast, East Dronning Maud Land, East Antarctica (n = 81).
Water samples were collected from streams, and the center or shore of lakes. They were filtered with a pre-
combusted glass fiber filter (< 0.3 µm), and the absorbance and excitation emission spectroscopy (3D-EEM)
were measured immediately. Some portion of water samples were stored in a glass bottles and transferred to
Japan, where DOM in the samples were fractionated into humic substances (HS) and non-HS. Optical indices
such as SUVA254, S275-295, FI, BIX, and HIX were calculated from the absorbance and 3D-EEM data to elucidate
the structural properties and origin of DOM. We further analyzed 3D-EEMs by parallel factor analysis
(PARAFAC) to deconvolute them into distinct fluorescent components. It was suggested that Antarctic DOM
increases its molecular weight, aromaticity, and degree of humification along glacier melt-lake water-pore
water spectrum, and these changes are attributed to be driven by the activity of primary producers.

2047
Fri_85_EN-7_1385
Meltwater as a Source of Iron to Terra Nova Bay Polynya (Ross Sea, Antarctica)

Paola Rivaro1 (paola.rivaro@unige.it), Francisco Ardini1, Pasquale Castagno2, Pierpaolo Falco2, Rosabruna La
Ferla3, Maurizio Azzaro3, Angelina Cordone4, Maria Saggiomo5, Olga Mangoni4
1
University of Genova, Genova, Italy, 2Parthenope University, Napoli, Italy, 3CNR, National Research Council,
IAMC Institute of Marine and Coastal Environment, Messina, Italy, 4University of Napoli Federico II, Napoli, Italy,
5
Stazione Zoologica Anton Dorhn, Napoli, Italy

Iron (Fe) availability and its influence on phytoplankton community structure and nutrient cycling has been
recognized in the Ross Sea. This region is one of the most productive of the Southern Ocean, thus
significantlycontributing to the CO2 sink.The most investigated source of Fe is sea ice melting, but recent
studies in the Central and Southern Ross Sea also identified the importance of the CDW intrusion and the
glacial melt water. The Fe input evaluation due to glacial melt water in the western Ross Sea is one of the goals
of CELEBeR (CDW Effects on glaciaL mElting and on Bulk of Fe in the Western Ross sea) project. To this purpose,
CELEBeR carried out ship measurements during a cruise in the austral summer 2016-17, as part of the Italian
National Program of Research in Antarctica (PNRA). Dissolved and particulate Fe data were collected in 18
stations sampled in Terra Nova Bay polynya together with physical, chemical (O2, H218O/H216O ratio, nutrients,
CO2 system variables) and biological (phytoplankton and prokaryotic biomass, characterization of bacteria at
DCM) parameters. Water mass characterized by temperature below the surface freezing point and associated
with Fe contribution was detected in the intermediate layers of the water column. Particulate Fe
concentrations were on average an order of magnitude higher than those of dissolved Fe. The Fe distribution
will be discussed taking into account the chemical, physical and biological characteristics of the area.

2048
Fri_86_EN-7_1389
Dissolved Organic Matter (DOM) and Microbial Enzymes in the Ross Sea

Antonietta Specchiulli1 (antonietta.specchiulli@ismar.cnr.it), Gabriella Caruso2, Pasqualina Laganà3, Lucrezia

Cilenti1, Pasquale Castagno4, Paola Rivaro5, Maurizio Azzaro2
1
CNR, National Research Council, Institute of Marine Sciences, Lesina (FG), Italy, 2CNR, National Research
Council, IAMC Institute of Marine and Coastal Environment, Messina, Italy, 3University of Messina, Messina,
Italy, 4Parthenope University, Napoli, Italy, 5University of Genova, Genova, Italy

In the Ross Sea the dissolved organic matter and the role of culturable heterotrophic microbes in its
degradation are almost unknown. In the carbon cycle, dissolved organic carbon (DOC) concentration and its
optically significant fraction, the chromophoric component (CDOM) are important for DOM budget estimates.
Within the CELEBeR project [Circumpolar Deep Water (CDW) Effects on glaciaL mElting and on Bulk of Fe in the
Western Ross sea - PNRA], DOC and CDOM, culturable heterotrophic bacteria and the enzymatic activities,
expressed by bacterial isolates, were examined in the Ross Sea during the austral summer 2017, in relation to
CDW contribution. The covered areas were the Drygalski Ice Tongue and the nearby Terra Nova Bay polynya (A)
and the continental Shelf Break area near Cape Adare (B). Within the area A, the lowest DOC (38.33 µM),
CDOM (a280 of 0.27 m-1) and SUVA254 (0.54 L mg-1 m-1) were measured at 225 m (CDW); the highest DOC (63.29
µM), CDOM (a280 of 1.39 m-1) and SUVA254 (1.6 L mg-1 m-1) were recorded at the northernmost area B (DCM),
also characterized by the lowest spectral slopes (SR= 1.37). Heterotrophic bacteria ranged from 5.0x101 (CDW)
to 7.0x103 CFU/ml (DCM); aminopeptidase and alkaline phosphatase were the most expressed enzymes. Based
on microbial cells counting, the distribution of heterothrophic bacteria seems to be not affected by DOC
concentration and its composition, as highlighted by the lack of correlations between the two variable sets.

2049
Fri_87_EN-7_1460
Extracellular Enzymatic Activities in the Ross Sea (CELEBeR Project)

Renata Zaccone1 (renata.zaccone@iamc.cnr.it), Filippo Azzaro1, Rosabruna La Ferla1, Pasquale Castagno2, Paola
Rivaro3, Maurizio Azzaro1
1
CNR, National Research Council, IAMC Institute of Marine and Coastal Environment, Messina, Italy,
2
Parthenope University, Napoli, Italy, 3University of Genova, Genova, Italy

The microbial community uses extracellular enzymatic activities (EEA) to initialize degradation of high
molecular weight organic matter in all the ocean.
The intrusion of the warm Circumpolar Deep Water (CDW) into the Antarctic shelf area is one of the recognized
drivers of ice shelf melting, playing an important role on the shelf physical and biological processes. The
investigated areas covered: a) the Drygalski Ice Tongue and the nearby Terra Nova Bay polynya; b) the coastal
area between the Mariner and Aviator glaciers; c) the Antarctic continental Shelf Break area near Cape Adare
(North Victoria Land).
During an oceanographic cruise performed in the framework of the CELEBeR (CDW effects on glacial melting
and on bulk of Fe in the Western Ross Sea) project (funded by Italian PNRA), the EEA distribution was studied in
order to investigate the spatial and depth patterns in the Ross Sea. In particular rates of leucine-
aminopeptidase -LAP, β-glucosidase -GLU and alkaline phosphatase -AP were measured. The contribution of
free enzymes fraction in some stations was also determined and the relationships with the main environmental
parameters were analyzed.
Results suggested the potential capability of the microbial community to decompose proteins, carbohydrates
and organic phosphates. In the Shelf Break area LAP values showed higher values than Terra Nova Bay at
surface. The decreasing trend with increasing depth was confirmed. Hydrology had also effect on EEA
distribution.

2050
Fri_88_EN-7_1498
Drivers of Phytoplankton Biomass in Three East Antarctica Polynyas

Sebastien Moreau1,2 (sebastien.moreau@hotmail.com), Julie Janssens1, Peter Strutton1, Lavenia Ratnarajah1,

Delphine Lannuzel1
1
University of Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Norwegian Polar
Institute, Tromso, Norway

In the Southern Ocean, polynyas have the highest primary productivity rates and represent one of the largest
CO2 sinks. As a consequence, top predators favour these biomass rich areas. Three contrasting polynyas were
visited in East Antarctica in January 2017: the Dalton, the Mertz and the Ninnis polynyas. The average
phytoplankton biomass was ~ twice as high in the Mertz and Ninnis (411 and 466 mg Chl-a m-2) than in the
Dalton (266 mg Chl-a m-2) Polynya. Sea surface ΔO2/Ar was also significantly higher in the Mertz and Ninnis (5
to 12%) than in the Dalton (-8 to 8%) Polynya. These strong regional differences were further explored using
physiological and physical parameters. First, the maximum yield of photosystem II was not significantly
different and > 0.4 in all the polynyas. The higher productivity in the Mertz and Ninnis could be due to higher
stratification and iron-rich sea-ice meltwaters. This scenario is supported by the significantly lower surface
salinity in the Mertz and Ninnis (33.18 ± 0.33) than in the Dalton polynya (34.01 ± 0.33). In contrast, the major
driver of primary productivity in the Dalton Polynya seemed to be the outflow of Ice Shelf Water from the
neighbouring Moscow University Ice Shelf. Alternative hypotheses included a trophic cascade due to less top
predators in the Dalton and differences in the phytoplankton composition of the three polynyas. Our study
highlights the role of cryosphere-ocean interactions on carbon cycling in Antarctic polynyas.

2051
Fri_89_EN-7_1502
Dissolved Cr Redox Speciation and Isotope Composition in the Southern Ocean

Jörg Rickli1 (joerg.rickli@geo.unibe.ch), David J. Janssen1, Micheal Elwood2, Christel Hasler3, Samuel L. Jaccard1
1
University of Bern, Institute of Geological Sciences & Oeschger Centre for Climate Change Research, Bern,
Switzerland, 2Australian National University, Research School of Earth Sciences, Canberra, Australia, 3University
of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences, Geneva, Switzerland

Variations in stable chromium isotopes (δ53Cr) may serve as a useful tool for understanding biological and
physical processes in the modern and past oceans. For example, the redox activity of Cr and the isotope
fractionation and solubility changes associated with Cr redox transformations have led to the use of Cr for
inferring the paleoredox state of seawater. Additionally, recent data showing the scavenging of dissolved Cr
onto growing phytoplankton suggests that δ53Cr in marine sediments may yield constraints on changes in
marine biological productivity in the past.
To help assess δ53Cr as a productivity proxy and better understand the as yet poorly constrained marine Cr
cycle, samples for dissolved Cr concentration, redox speciation and δ53Cr were collected during the Antarctic
Circumnavigation Expedition (ACE) as a component of project 15. These samples, collected across strong
gradients in macro- and micronutrient concentrations and in primary productivity, will provide insights into the
relationship between Cr speciation, δ53Cr and primary production in varying oceanographic regimes and will
help determine the potential of the proxy in modern and paleoceanographic settings. Additionally, the samples
will add significantly to the global body of δ53Cr data and help to further a mechanistic understanding of Cr
cycling in the global ocean.

2052
Fri_90_EN-7_1532
Automatic Sampling Near an Arctic Glacier: First Microbial Results

Maurizio Azzaro1 (maurizio.azzaro@iamc.cnr.it), Rosabruna La Ferla1, Giovanna Maimone1, Filippo Azzaro1,

Gabriella Caruso1, Anderson S. Cabral2, Rodolfo Paranhos2, Ermanno Crisafi1, Massimo Caccia3, Roberta
Ferretti3, Angelo Odetti3, Giuseppe Zappalà1, Gabriele Bruzzone3
1
CNR-IAMC, Messina, Italy, 2UFRJ, Institute of Biology, Rio De Janeiro, Brazil, 3CNR-ISSIA, Genova, Italy

In the frame of the ARCA project (ARctic: present Climatic change and pAst extreme events) aimed at studying
the hydrological cycle in the boreal hemisphere, a first prototype of automatic equipment was specifically
designed to perform discrete sampling of waters in the area close to a glacier. The Shark USSV (Unmanned
Semi-Submersible Vehicle), designed and built by CNR-ISSIA, was the first to reach and autonomously collect
samples of water near the front of a glacier, the Kronebreen in the Kongsfjorden. Shark towed, through an
adequate rope, a small catamaran carrying an Automatic Water Multisampler built by CNR-IAMC. In June 2015,
surface water samples were collected by the automatic Multisampler along a transect subdivided into 9
sampling stations and extending from the glacier front to the open sea. This research reports the results of the
first in situ application of this device related to the study of the distributions of prokaryotes, virus-like particles
and nutrients. Viral and prokaryotic abundances were significantly correlated with each other and their spatial
distributions resulted not to be affected by the presence of the glacier. A low viruses abundance was found
compared to the other marine ecosystems and it might be explained by adsorption on particles. The low
virus/prokaryotes ratio suggested a lysogenic phase of virus. High nutrient concentrations were detected but
they appeared to be not linked to microbial patterns.

2053
Fri_92_EN-7_1825
Biogenic Matter in Surface Sediments of the Weddell Sea Continental Shelf

Enrique Iisla1 (isla@icm.csic.es)

1
Institut de Ciències del Mar-CSIC, Marine Geosciences, Barcelona, Spain

The organic carbon (OC) and biogenic silica (bSi) contents in the upper 5 cm of the seabed were investigated in
more than 60 sediment cores from several regions along the continental shelf of the Weddell Sea and the
northern Antarctic Peninsula. The results showed that the shelf on the western flank of the Filchner Trough has
the lowest contents in OC, 1.2 mg g-1, in contrast to the northwestern Weddell Sea where values of up to 16
mg g-1 were found. In the case of bSi the lowest values were also observed in sediment from the western flank
of the Filchner Trough, 5 mg g-1, whereas the highest concentrations were measured in samples from the
Bransfield Strait, 114 mg g-1. The lowest values corresponded to regions where sea ice distribution drastically
reduces primary production at the sea surface and consequently there is a relatively small export flux of
biogenic matter such as in the cases of the western flank of the Filchner Trough and the Larsen A, B and C
continental shelves. In contrast, in regions where the typical ice-free seasonal summer conditions take place,
such as Bransfield Strait and the northwestern Weddell Sea at the vicinities of the Antarctic Peninsula and the
eastern Weddell Sea off Kapp Norvegia, the biogenic matter contents in the sediment are higher. Ongoing
climate change directly affects sea ice distribution and most likely will transfer this signal to the chemical
characteristics of the seabed sediment.

2054
Fri_93_EN-7_1845
Reactivity of Glacially Derived Particles in West Greenland Coastal Environments

Minik T. Rosing1 (minik@snm.ku.dk), Sneha Ray Sarkar1, Nicholas M. Rose1

1
Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark

The Greenland Ice Sheet (GRIS) creates large amounts of fine-grained mineral particles by bedrock erosion. This
glacial rock flour (GRF) is transported to the ocean via a series of intermediate environments: pro-glacial river
valleys, lakes, estuaries and fjords. GRF in estuaries of meltwater rivers is very fine-grained as exemplified by
Ilulialik in West Greenland: D90=24, D50=4, D10=0.7 (microns).
The migration of GRF from land to open ocean is accompanied by export of dissolved carbon and alkalinity,
nutrients, trace elements and isotopes, and by change in turbidity and ocean albedo. GRF behaviour is highly
dependent on its fine grain size, which allows high-residence time in the water column before settling, and high
reactivity in aqueous solutions. We report experimental results on GRF reaction rates in freshwater and
saltwater in order to develop a predictive model quantifying these effects and to determine the ultimate fate
of glacially derived rock particles during transit through the photic layer in Arctic marine environments.
We propose that the export rate, settling velocity and reactivity of GRF affects the primary productivity and CO2
drawdown capacity of Greenland near-shore environments, and potentially the whole North Atlantic region.
Increased melting of GRIS has caused increased sediment export (Bendixen et. al., 2017: Nature 550, 101-104:
doi:10.1038/nature23873). We address some of the potential effects of this increase on the Arctic marine
environment.

2055
Fri_94_EN-7_1869
Source and Sunlight Influence Dissolved Black Carbon Signature in the Cryosphere

Alia Khan1 (alia.khan@colorado.edu), Sasha Wagner2, Rudolf Jaffe3, Peng Xian4, Mark Williams5, Richard
Armstrong1, Diane McKnight6
1
University of Colorado Boulder, National Snow and Ice Data Center, Boulder, United States, 2University of
Georgia - Savannah, Skidaway Institute of Oceanography, Marine Sciences Department, Savannah, United
States, 3Florida International University, Southeast Environmental Research Center and Department of
Chemistry and Biochemistry, Miami, United States, 4Naval Research Laboratory, Monteray, United States,
5
University of Colorado Boulder, Geography, Boulder, United States, 6University of Colorado at Boulder, Institute
of Arctic and Alpine Research, Boulder, United States

Black carbon (BC) is derived from the incomplete combustion of biomass and fossil fuels and can enhance
glacial recession when deposited on snow and ice surfaces. Here we explore the influence of environmental
conditions and the proximity to anthropogenic sources on the concentration and composition of dissolved
black carbon (DBC), as measured by benzenepolycaroxylic acid (BPCA) markers, across snow, lakes, and streams
from the global cryosphere. Data are presented from Antarctica, the Arctic, and high alpine regions of the
Himalayas, Rockies, Andes, and Alps. DBC concentrations spanned from 0.62 µg/L to 170 µg/L. The median and
(2.5, 97.5) quantiles in the pristine samples were 1.8 µg/L (0.62, 12), and non-pristine samples were 21 µg/L
(1.6, 170). DBC is susceptible to photodegradation when exposed to solar radiation. This process leads to a less
condensed BPCA signature. DBC across the dataset was comprised of less-polycondensed DBC. However, DBC
from the Greenland Ice Sheet (GRIS) had a highly-condensed BPCA molecular signature. This could be due to
recent deposition of BC from Canadian wildfires. The high concentration measured in supra-glacial melt on the
GRIS also suggests DBC can be mobilized across ice surfaces. Overall, variation in DBC appears to be driven by a
combination of photochemical processing and the source combustion conditions under which the DBC was
formed, and was found to persist across the global cryosphere in pristine and non-pristine areas.

2056
Fri_95_EN-7_2013
Composition and Transformation of Dissolved Organic Matter in Antarctic Snow

Runa Antony1 (runa@ncaor.gov.in), Amanda S. Willoughby2, Amanda M. Grannas3, Rachel L. Sleighter2, Meloth
Thamban1, Patrick G. Hatcher2
1
National Center for Antarctic and Ocean Research, Goa, India, 2Old Dominion University, Virginia, United
States, 3Villanova University, Pennsylvania, United States

The processing of dissolved organic matter (DOM) in glacier systems is an important part of the global carbon
cycle. We applied ultrahigh-resolution mass spectrometry and other chemical and biological approaches to
understand the molecular composition of DOM along two coast to inland (up to 300 km from the sea) transects
in East Antarctica. We also carried out in situ field incubations to understand photochemical and biological
(photo-biochemical) transformation of DOM on the ice surface. DOM composition in Antarctic snow was
mainly related to autochthonous production by resident microbial communities, with significant inputs from
marine and long range atmospheric transport. We present strong evidence of extensive photo-biochemical
alteration of both autochthonous and allochthonous DOM on the coastal Antarctic ice sheet surface, resulting
in major shifts in the composition and bioavailability of nitrogen, sulfur, and phosphorous bio-molecules. In
some cases, photo-biochemical processing appears to result in altered compounds that are photo- and bio-
labile. The opposite is also observed, converting some components of the DOM to photo- and bio-resistant
forms. Thus, the biogeochemistry of DOM is highly complex and closely connected with microbial and
photochemical processes. The new insights on the interactions between microbes, light and specific DOM
molecules highlight the need for focused studies on supraglacial carbon biogeochemistry and its response to a
changing climate.

2057
Fri_96_EN-7_2069
Carbon Export by the Mackenzie River during Spring Freshet

Melissa Sophia Schwab1 (melissa.schwab@erdw.ethz.ch), Robert G. Hilton2, Negar Haghipour1, Timothy Ian
Eglinton1
1
ETH Zürich / Geological Institut, Zürich, Switzerland, 2Durham University / Geographic Institute, Durham,
United Kingdom

Rapid ongoing warming and accompanying hydrological changes in the Arctic influence the mobilization and
fate of terrestrial organic carbon transported along the land-to-ocean continuum, with implications for regional
and global carbon cycles. The Mackenzie River is the largest supplier of sediment and particulate organic
carbon to the Arctic Ocean, with a majority of the annual sediment load being exported during the spring
freshet. However, thus far, relatively few studies have attempted a comprehensive quantification and
characterization of organic carbon exported by the Mackenzie during the spring freshet.
We collected water column samples for analysis of dissolved inorganic and organic carbon, and depth profiles
of suspended particulate matter, as well as bank and channel sediments from the main channel of the
Mackenzie River, the Peel River and the Arctic Red during the spring freshet in 2017. We present a
comprehensive data set comprising sedimentological characteristics (grain size, mineralogy mineral-specific
surface area), bulk geochemical properties (e.g., %OC, d13C-OC, D14C-OC) and molecular signatures (i.e. long-
chain n-alkanes and fatty acids) to constrain sources and derive fluxes of terrestrial organic carbon during the
freshet. We compare these data from the 2017 freshet with complementary information available from
previous studies in order to assess potential temporal changes in the nature of materials exported by the river
system.

2058
Fri_97_EN-7_2076
Modern Sediment Distribution and Composition in Kongsfjorden, Svalbard

Stefano Miserocchi1, Leonardo Langone1 (leonardo.langone@ismar.cnr.it), Alessandra D'Angelo1,2, Fabrizio Del

Bianco3, Federico Giglio1, Tommaso Tesi1, Stefano Aliani4
1
CNR-ISMAR, National Research Council, Bologna, Italy, 2Università degli Studi di Siena, Siena, Italy,
3
Proambiente Scrl, Bologna, Italy, 4CNR-ISMAR, National Research Council, La Spezia, Italy

The Kongsfjorden is a small fjord located in western Svalbard. 12 short sediment cores were sampled in 2011 to
describe modern sediment distribution and geochemical composition. Core locations were chosen based on a
high resolution seismic survey in order to delineate surficial seismostratigraphic features.
Based on the different acoustic response, seismic reflectors are continuously or irregularly laminated,
transparent-chaotic, or continuous and highly reflective. Maximum sediment thicknesses (~10 m) were
recorded close to the calving line of ice tongues.
Sedimentation rates, based on seismic and radionuclide profiles, resulted in high values (up to 10 cm/y) in the
laminated fine mud near the glaciers, and lower sedimentation rates (0.2-0.6 cm/y) in the bioturbated muddy
sediment of the outer fjord.
Organic carbon content of surface sediments showed values decreasing toward the inner fjord, reflecting the
higher accumulation rates and the lower biological production in the turbid water near glacial fronts. High Br/Cl
in outer fjord sediments reveals the presence of organic matter of marine origin consistent with the bulk
organic carbon data.
High Ca/Ti ratios measured in inner fjord sediments prove the deposition of Ca-rich sediments supplied by the
catchment of Kronebreen-Kongsvegen glaciers. In contrast, Ca/Ti is lower in the outer fjord. However, the
down core distribution suggests the occurrence of past events during which the glacier influence extended
further seaward.

2059
Fri_98_EN-7_2081
Changes in Ocean Chemistry from 6 Year Time Series in Arctic Outflow Waters

Melissa Chierici1,2 (melissa.chierici@imr.no), Agneta Fransson3, Paul Dodd3, Mats Granskog3, Colin Stedmon4,
Svein Kristiansen5
1
Institute of Marine Research, Oceanography and Climate, Tromsø, Norway, 2University Centre in Svalbard
(UNIS), Longyearbyen, Norway, 3Norwegian Polar Institute, Tromsø, Norway, 4Danish Centre for Marine
Research, Copenhagen, Denmark, 5The Arctic University of Norway, Tromsø, Norway

The Fram Strait is the main gateway for the exchange of warm and saline Atlantic water and the cold and fresh
outflow waters from the Arctic Ocean. For six years, we collected data on the chemical (carbonate chemistry,
nutrients) and physical (salinity and temperature) data along a section at ~79 °N across Fram Strait from 2011
to 2016. In this study, we focus on the change of the outflow waters in the top 400 m on the NE Greenland
shelf between 12°W and 4°W. The largest variability and change in physical-chemical characteristics were
observed in the top 100 meters, where temperature and salinity generally increased in the study period. Except
for in 2012, total alkalinity (AT), total dissolved inorganic carbon (DIC) and CO2 (fCO2) showed a clear increase in
the whole water column throughout the period. Simultaneously, pH and calcium carbonate (CaCO3) saturation
decreased, and we found indications of a deepening and spread of the lower aragonite saturated waters. This
confirms recent findings in the Arctic Ocean that the low CaCO3 saturated waters are spreading horizontally at
depth. The study shows that even a relatively short time-series such as six years gives important information on
the present changes in the chemical and physical environment in the Arctic Ocean. We discuss and compare
results from previous studies and discuss possible causes for the observed changes in the carbonate chemistry
and ocean acidification state.

2060
Fri_99_EN-7_2082
Effects of Arctic Sea-ice and Biogeochemical Drivers on Under-ice Water fCO2

Agneta Fransson1 (agneta.fransson@npolar.no), Melissa Chierci2, Ingunn Skjelvan3, Are Olsen4, Philipp Assmy1,
Algot K Peterson5, Gunnar Spreen6, Brian Ward7
1
Norwegian Polar Institute, Tromsoe, Norway, 2Institute of Marine Research, Tromsoe, Norway, 3Bjerknes
Centre for Climate Research, Uni Research Climate, Bergen, Norway, 4Geophysical Institute, University of
Bergen, Bergen, Norway, 5Geophysical Institute, University of Bergen, Tromsoe, Norway, 65Institute of
Environmental Physics, University of Bremen, Bremen, Germany, 7School of Physics and Ryan Institute, National
University of Ireland, Galway, Ireland

The ice cover in the Arctic Ocean has decreased during the last decades, manifested in particular as an
extensive transition from thicker multiyear ice to thinner first-year ice. As the summer sea-ice cover is
decreasing, larger areas with open water will be exposed to the atmosphere. This will have implications for the
carbonate chemistry and sea-air carbon dioxide (CO2) exchange. We present measurements of CO2 fugacity
(fCO2) and estimates of the effects biogeochemical processes in the under-ice water, driving the sea-air CO2
fluxes. The data was obtained from January to June 2015 during the Norwegian young sea ICE (N-ICE2015)
expedition, where the ship drifted with four different ice floes and covered the deep Nansen Basin, the slopes
north of Svalbard, and the Yermak Plateau. This unique winter-to-spring data set includes the first winter-time
under-ice water fCO2 observations in this region. The observed under-ice fCO2 was undersaturated relative to
the atmospheric fCO2. Although the sea ice partly prevented direct CO2 exchange between ocean and
atmosphere, frequently occurring leads and breakup of the ice sheet promoted sea-air CO2 fluxes. In winter,
the main drivers of the change in under-ice water fCO2 were dissolution of CaCO3 (ikaite) and vertical mixing. In
June, in addition to these processes, primary production and sea-air CO2 fluxes were important.

2061
Fri_100_EN-7_2138
Methane Cycling in Peatlands Ponds of the Cape Horn Region, Southern Chile

María Soledad Astorga-España1 (msoledad.astorga@umag.cl), Armando Sepúlveda-Jauregui1, Karla Martínez-

Cruz1, Celine Lavergne2, Lea Cabrol2,3, Maialen Barret4, Frederic Thalasso5
1
University of Magallanes, Department of Science and Natural Resources, Punta Arenas, Chile, 2Pontificia
Universidad Católica de Valparaíso, School of Biochemical Engineering, Valparaíso, Chile, 3Mediterranean
Institute of Oceanography (MIO), Institut de Recherche pour le Développement (IRD), Marseille, France, 4INPT-
ENSAT - Ecole Nationale Supérieure d'Agronomie Toulouse, ECOLAB - Laboratoire d'Ecologie Fonctionnelle et
Environnement, Toulouse, France, 5(CINVESTAV) Centro de Investigación y de Estudios Avanzados del Instituto
Politécnico Nacional, Ciudad de Mexico, Mexico

Navarino Island (55º S) is the southernmost territory of the sub-Antarctic Magellanic ecoregion, which is a part
of the world where ecosystems have been understudied and from which methane cycling and emissions in
lakes have never been reported before. The Island is populated by less than one inhabitant per square
kilometer. This pristine environment is dominated by evergreen Magellanic forest, peat bogs with various
species of sphagnum moss, and peatland ponds which are the prevailing aquatic ecosystem of the region. In
the present work we characterized, for the first time, the methane cycle of two characteristic peatland ponds
located close to the northern coast of the Island. Both studied ponds, of 17,900 and 7,600 m2 , were bordered
by forest on the north and south shores while large sphagnum bogs were present at the east and west sides of
the ponds. Our study included winter and summer quantification of methane and carbon dioxide
concentrations. In addition, several physicochemical parameters were measured together with methane
oxidation (methanotrophy) activity. The results indicate that peatland ponds were net sources of methane to
the atmosphere with a relatively low seasonal variation. these results will be discussed in a global context.

2062
Fri_101_EN-7_2286
Soils and Landforms of Elephant Island, South Shetland Islands

Daniela Schmitz1 (danni_schmitz@hotmail.com), Carlos Schaefer2, Antônio Pereira3, Roberto Michel4, Flávia
Ferrari1, Luca Aquino1
1
Universidade Federal de Viçosa/ INCT da Criosfera, Departamento de Biologia Vegetal, Viçosa, Brazil,
2
Universidade Federal de Viçosa/ INCT da Criosfera, Departamento de Solos, Viçosa, Brazil, 3Universidade
Federal do Pampa - UNIPAMPA, NEVA, São Gabriel, Brazil, 4Universidade Estadual de Santa Cruz / INCT da
Criosfera, Departamento de Ciencias Agrárias e Ambientais, Ilhéus, Brazil

Elephant Island geology is basically metamorphic rocks (gneiss, schists) from Meso-Cenozoic subduction
complex, great contrast with the volcanic nature of Shetland´s Archipelago. Soil formation in different
geomorphic settings following the Holocene glacial retreat at Stinker point was analyzed. Twenty-three pedons
were selected dug, sampled and analyzed. Soil pH, exchangeable nutrients and soil texture were determined.
Soils from till and glacial deposits can be separated by age of exposure: older soils are skeletic, shallow depth,
acid reaction and moderate contents of P, SOC and base saturation; recently exposed till have soils with
moderate depth, alkaline reaction and very high base saturation. Soils at the mid platforms are shallow, coarse,
skeletic textured, with elevated P contents, low pH Ca and Mg. Soil weathering is controlled by the foliation of
parent material. The ornithogenic influence is variable, but there are either recent or abandoned areas of birds
influence. Soils from the present day beaches are alkaline, very coarse with no horizon differentiation, whereas
soils on Holocene beaches are acid and nutrient rich due to the or past influence of the fauna (seals, penguins).
Soils from Stinker point are generally shallow, skeletic and strongly related to the geomorphological position on
the landscape. Compared with South Shetlands soils, soil development is less pronounced, due metamorphic
nature parent material with greater resistance to weathering.

2063
Fri_102_EN-7_2336
The Importance of Aeolian Dust Inputs into Oligotrophic Lakes in West Greenland

Joanna E. Bullard1 (j.e.bullard@lboro.ac.uk), N. John Anderson1, Suzanne McGowan2, Amanda O'Byrne3, Clay
Prater1, Michael J. Watts4, Erika J. Whiteford5
1
Loughborough University, Physical Geography, Loughborough, United Kingdom, 2University of Nottingham,
Nottingham, United Kingdom, 3University of Amserdam, Amsterdam, Netherlands, 4British Geological Survey,
Keyworth, United Kingdom, 5Nottingham Trent University, Nottingham, United Kingdom

Biogeochemical cycling in aquatic environments is strongly tied to elemental inputs from terrestrial sources.
However, while most previous work has focused on nutrient delivery via hydrological inputs, the effects of
atmospheric dry deposition are comparatively understudied. This paper examines the influence of aeolian
derived elements on water and sediment nutrient chemistry of oligotrophic lakes in West Greenland. Estimates
of dust elemental composition and seasonal deposition rates are combined with seasonal lake nutrient
concentration measurements to establish connections between glaciofluvial dust and lake biogeochemistry of
downwind lakes. Further, elemental profiles of lake sediment cores are used to explore historical changes in
elemental deposition in this region. Together, these analyses demonstrate the importance of atmospheric dust
deposition on lake biogeochemistry in arid high-latitude environments and demonstrate the need to better
understand the role of aeolian deposition in cross-system nutrient transport in polar regions.

2064
Fri_103_EN-7_2352
Vegetation Determines the Fate of Soil Organic Matter on Antarctic Islands

Isabel Prater1 (i.prater@tum.de), Filip Hrbacek2, Lars Arne Meier3, Christina Braun4, Daniel Nyvlt2, Carsten W.
Mueller1
1
TU Munich, Chair of Soil Science, Freising, Germany, 2Masaryk University, Faculty of Science, Brno, Czech
Republic, 3Eberhard-Karls Universität Tübingen, Soil Science and Geomorphology, Tübingen, Germany, 4Friedrich
Schiller University, Institute of Ecology, Jena, Germany

With a low degree of ecosystem interactions and thus unique conditions for soil development, Antarctica offers
the opportunity to disclose basic soil biogeochemical processes. We studied soils from vegetation-free and
vegetated sites on King George Island (KGI) with a maritime cold climate, and on James Ross Island (JRI) with an
arid continental cold climate. The autochthonous vegetation mirrors the climatic differences; while it solely
consists of cryptogams on JRI, on KGI vascular plants are also endemic. This permits the study of the complex
interplay between soil organic matter (SOM) sequestration and soil structure development with respect to the
varying presence of vegetation. Main aim of the study is to decode the mechanisms determining the fate of
SOM in maritime Antarctica and to understand how the scarce vegetation drives SOM distribution within
specific physical soil fractions and its chemical composition. The distance to vegetation patches was reflected in
variations in the distribution of carbon and nitrogen and in a decrease in labile SOM constituents as revealed by
13C-CPMAS NMR spectroscopy, while mineral associated SOM of the clay sized mineral fractions dominated
the carbon storage throughout all sites. The ongoing climate change is assumed to significantly alter the
vegetation distribution and thus drive the storage and composition of SOM. This will also affect soil microbial
activity and land-ocean transitions on the studied islands.

2065
Fri_104_EN-7_2355
Characteristics of Soils Derived from Olivine-basalts in Antarctica

Mayara P Daher1, Carlos Ernesto Schaefer2, Elpidio Inacio Fernandes Filho2 (elpidio.solos@gmail.com), Andre
Thomazini2, Eduardo O Senra2, Marcio Rocha Francelino2
1
Universidade Federal de Viçosa / INCT da Criosfera, Solos, Viçosa, Brazil, 2Universidade Federal de Viçosa /
INCT da Criosfera, Solos, Vicosa, Brazil

It was collected 26 soil profiles distributed through Barrientos Island, Robert Island (Maritime Antarctica) and
James Ross Island (Antarctic Peninsula) formed by olivine-basalts. The samples were submitted to chemical and
physical analyses such as: texture, pH in water, H+Al, exchangeable bases, phosphorus and total organic carbon
(TOC). Clay fraction mineralogy was assessed by X-ray diffraction. Due to the warmer and wetter climate of
Maritime Antarctica, permafrost is generally absent in the soils collected and were classified as Entisols. The
islands are fully vegetated by mosses and lichens and the presence of bird populations result in physical and
chemical changes in soils. The soils have some degree of chemical weathering and leaching bases, with acid pH
values and high values of P, TOC and H+Al. On the other hand, the drier and cooler climate of James Ross Island
favor the presence of permafrost and soils were classified as Gelisols. The vegetation and bird populations are
virtually absent. The soil weathering is predominantly by physical processes. The soils have neutral to alkaline
pH values, low values of P and H+Al, and devoid TOC. Meanwhile, the 26 soils pedons have characteristics in
common attributed to olivine-basalts and show little transformation in relation to the parent material as the
amounts of exchangeable Ca and Mg high, coarse texture (sandy loam) and the clay fraction is mainly
composed of feldspar, illite, quartz, kaolinite and vermiculite.

2066
Fri_105_EN-7_2397
Benthic Nutrient Fluxes at Greenland Coast under the Setting of Melting Glaciers

Hong Chin Ng1 (hn9381@bristol.ac.uk), Katharine Hendry1

1
University of Bristol, School of Earth Sciences, Bristol, United Kingdom

Greenland glaciers play an important role in providing nutrients, dissolved silicon (DSi) in particular, to its
coastal area. Given predictions of accelerated melting of the Greenland glaciers, an increase in coastal DSi
supply is expected to facilitate production of biogenic opal by Si-precipitating phytoplankton, and the
subsequent remineralisation of nutrients at depth will have an impact on the benthic ecosystem. As yet there is
little understanding of benthic nutrient fluxes at coastal Greenland, which hinders quantitative examination of
the evolving nutrient cycles in the light of enhanced glacial melting. Here, we address this issue through the
analysis of sediment pore water and core incubation experiments carried out on a set of mega-cores recently
acquired from coastal Greenland. Down-core profiles of pore water DSi concentrations and isotope
composition mainly reflect biogenic opal dissolution for the upper ~15cm. Beneath that, precipitation of
authigenic Si increases with increasing depth. There is also some evidence of glacier influence which provide
greater amount of Si to sites proximal to the coastal fjord. Results from core incubation experiments enable us
to quantify the flux of DSi at the sediment-water interface. Together, the new results contribute to the
evaluation of benthic Si fluxes at coastal Greenland, which have significant implications in the biogeochemical
cycling of Si and other nutrients in the polar regions.

2067
Fri_106_EN-7_2447
High-arctic Weathering, Sulfide Mineral Oxidation and the Zackenberg River

Emily Stevenson1 (eis22@cam.ac.uk), Mel Murphy2, Tenna Riis3, Ed Tipper1, Sasha Turchun1
1
University of Cambridge, Earth Sciences, Cambridge, United Kingdom, 2University College London, London,
United Kingdom, 3Aarhus University, Bioscience, Aarhus, Denmark

The impact of weathering on atmospheric CO2 depends upon the balance between
(1) alkalinity generation by carbonate and silicate mineral dissolution, and
(2) sulfuric acid generation by the oxidation of sulfide minerals.
In regions of high physical erosion, (e.g., mountainous and glaciated terrains), increased exposure and
oxidation of sulfide minerals, such as pyrite, may change the balance of (1) to (2), leading such regions to
become short term sources of CO2[1].
To test the influence of glacial erosion and permafrost freeze-thaw cycles in high-Arctic environments, we
sampled from the Zackenberg River (NE Greenland), and surrounding tributaries, which individually integrate
different lithologies, and are fed by either glacial rivers, seasonal snowmelt or seasonal permafrost thaw. Major
cation and anion data revealed a major tributary, Aucellaelven, has an extremely high concentration of sulfate
(SO42-), the highest in the region (>2mmol L-1). Here we present coupled sulfur and oxygen isotope data (δ34SSO4
and δ18OSO4) measured in SO42- to constrain the source of sulfur to the river system. Determining if the source of
SO42- is from either evaporate mineral (sulfate containing) dissolution, or oxidative sulfide weathering, is vital to
determining the importance of sulfuric acid in silicate weathering reactions in terrestrial Arctic environments,
and the impact on inorganic carbon cycling in the region.
[1]
Torres et al. (2016) EPSL 450 381-391

2068
Fri_107_EN-7_2544
Sea Water and Sediments Biogeochemistry Studies in the Templefjord, Spitsbergen

Maria Pogojeva1 (pogojeva_maria@mail.ru), Evgeniy Yakushev2

1
Zubov State Oceanographic Institute, Moscow, Russian Federation, 2Norwegian Institute for Water Research,
Oslo, Norway

The aim of this work was to assess the current chemical regime of sea water and bottom sediments exposed to
coastal runoff and glacial melting and an analysis of the possible consequences associated with climate
warming (melting of glaciers, permafrost thawing). The work is based on chemical studies of sea water, fresh
water, sea ice, fresh ice, glacier, bottom sediments, soil and permafrost, carried out at different intervals within
the framework of the Norwegian Research Council POLRES program Norwegian-Russian grants CARSIC
(http://www.niva.no/carsic) and POMPA (https://pompaproject.wordpress.com ). Totally there were
performed 5 expeditions: in February 2011, in September 2011, in March 2014, in June 2015 and in June 2017.
We studies distributions of nutrients, carbonate system parameters, metals, including mercury and methyl
mercury, and POPs. Chemical analyses were made in parallel in Norwegian and, when possible, in Russian
laboratories. The data received allowed to estimate the characteristic ranges or concentrations of the studied
parameters, estimate their seasonal changes, that can be used for the model validations.

2069
Fri_108_EN-7_2583
Changing Nutrients and Primary Production in the Baffin Bay/Labrador Sea Complex

Jean-Eric Tremblay1,2 (jean-eric.tremblay@bio.ulaval.ca), Pierre Coupel3, Igor Yashayev4, Simon Bélanger2,5,

Michel Gosselin2,6,7
1
Université Laval, Biology, Quebec, Canada, 2Québec-Océan, Quebec, Canada, 3Université Laval, Biologie,
Quebec, Canada, 4Bedford Institute of Oceanography, Fisheries and Ocean Canada, Bedford, Canada,
5
Université du Quebec a Rimouski, Geographie, Rimouski, Canada, 6Institut des Sciences de la Mer de Rimouski,
Rimouski, Canada, 7Université du Quebec a Rimouski, Rimouski, Canada

The western subarctic Atlantic collects large amounts of water from the North though the Baffin Bay/Labrador
Sea complex and is directly affected by changes occurring in the Arctic Ocean (AO) and its remote source
waters. Because it carries the cumulated impact of biogeochemical changes in source regions, the nutrient
properties of this water can be used to diagnose shifting contributions by different water masses or alterations
in micro-algal productivity and microbial processes. These changes potentially impact biological productivity
and the contribution of different phytoplankton functional groups, both regionally, through the influence of the
Labrador Current along the eastern North American seaboard, and globally though lateral exchange with the
subpolar gyre and the central Labrador Sea, where deep convection occurs. Using historical data and time-
series of observations collected during ArcticNet, the Atlantic Zone off-shelf Monitoring Program and other
program, we present trends in productivity and nutrient concentrations for waters entering Baffin Bay and
propagating to the western Labrador Sea, with a focus on probable causes and consequences.

2070
Fri_109_EN-7_2635
Temporal Variability of Particle Fluxes in Kongsfjorden (Svalbard) in 2010-2017

Leonardo Langone1 (leonardo.langone@ismar.cnr.it), Alessandra D'Angelo1,2, Federico Giglio1, Stefano

Miserocchi1, Anna Sanchez-Vidal3, Stefano Aliani4, Tommaso Tesi1, Angelo Viola5, Mauro Mazzola6
1
CNR-ISMAR, National Research Council, Bologna, Italy, 2Università degli Studi di Siena, Siena, Italy, 3Universitat
de Barcelona, Barcelona, Spain, 4CNR-ISMAR, National Research Council, La Spezia, Italy, 5CNR-ISAC, National
Research Council, Roma, Italy, 6CNR-ISAC, National Research Council, Bologna, Italy

Over the last decades, the Arctic has experienced faster environmental changes than any other regions on
Earth in response to global warming. The Arctic amplification may be due to feedback mechanisms from loss of
sea ice and changes in atmospheric and oceanic circulation.
Kongsfjorden is a small Svalbard fjord whose glaciers are rapidly retreating. However, how the land-to-ocean
fluxes of particulate matter are changing in the fjord remains elusive.
Here, we show results from a mooring deployed in the inner fjord since 2010 that collected multiannual time-
series to monitor the interaction between the entering Atlantic water (AW), melting glacier water and local
winter water.
Thermohaline properties reveal a large seasonal and interannual variability (θ = -1.91/6.87°C, S = 34.10/35.28)
with greater AW intrusion in November. Middle and bottom water temperatures generally follow the same
pattern, although periods of water stratification occur. Bottom temperatures show a consistent increasing
trend of 0.16 °C y-1. Currents are generally < 10 cm/s.
The average total mass flux (TMF) is 20 g m-2 d-1, with higher peaks in summer (~100 g m-2 d-1) and reduced
fluxes in autumn-winters (~7 g m-2 d-1). Notably, in summer 2013, TMF reached ~330 g m-2 d-1. Lithics and clastic
carbonates by glacier and iceberg melting are the most abundant components. During May-June, higher
contents of bSiO2 and OC with heavier δ13C show a higher fraction of marine organic matter by diatom
production.

2071
Fri_110_EN-7_2657
Terrestrial-marine Connections in the Coastal Ross Sea during the Mid-Pliocene

Tirzah Abbott1,2 (tirzah.abbott@northwestern.edu), Justin Dodd1, Reed Scherer1

1
Northern Illinois University, Geology and Environmental Geosciences, DeKalb, United States, 2Northwestern
University, NUANCE - EPIC, Evanston, United States

Orbital frequencies are well documented in a number of terrestrial and marine climate records throughout the
Cenozoic; however, assessing the feedbacks and timing of terrestrial-marine systems on glacial-interglacial
timescales is often challenging. This is particularly the case in high-latitude, near-shore environments where
traditional proxy records like benthic foraminifera are absent. Here we present a combined oxygen (δ18O and
δ17O) and silicon (δ30Si) isotope record from marine diatom silica in the mid-Pliocene (3.5 - 4.7Ma) section of
the AND-1B core from McMurdo Sound, Antarctica. Diatom silica δ18O values range between +28.1 and
+36.4‰ VSMOW, and have an inverse relationship with the stacked benthic foraminifera δ18O record. We
interpret the diatom δ18O values as a record of terrestrially-sourced cryogenic brine flux to McMurdo Sound;
density-driven transport of these brines from the McMurdo Dry Valleys to the marine costal environments
during the warm mid-Pliocene is a potentially overlooked terrestrial source of hypersaline waters. The δ30Si
values range from +0.5 to +2.2‰ and appear to correlate with the benthic stack. The considerable variability in
δ30Si values may record large-scale changes in silicon and other nutrient cycling. Combined, these proxies
indicate strong terrestrial-marine connections during the mid-Pliocene when sea ice in the Ross Sea was
significantly reduced, and serve as a potential analog for future warming and sea ice/ice-sheet retreat.

2072
Fri_111_EN-7_2666
Mass Budgets of Methylmercury in Kongfjorden, Svalbard

Seunghee Han1 (shan@gist.ac.kr), Jihee Kim1

1
Gwangju Institute of Science and Technology (GIST), School of Earth Sciences and Environmental Engineering,
Gwangju, Korea, Republic of

Methylmercury (MeHg) is a neurotoxin that bioaccumulates in marine food webs and human can be exposed to
MeHg through seafood consumption. While MeHg concentrations in Arctic food webs are relatively higher than
lower latitudes, major sources of MeHg in Arctic organisms and seawater remain uncertain. In the current
study, we observed the concentrations of total Hg and MeHg using a CVAFS, and the
methylation/demethylation rate constants using enriched stable isotope methods combined with MeHg
measurement by GC-ICP-MS. Furthermore, the compositions of dissolved organic matter (DOM) in seawater
were determined by excitation-emission matrix fluorescence spectroscopy. The average MeHg concentration in
seawater was 0.11±0.03 pM (0.053-0.17 pM), and the highest concentration was found to be 0.17 pM at the
surface of the inner fjord. The largest source of MeHg was in-situ methylation in the water column and input
from stream and glacier discharge was the second largest source, based on the MeHg mass budget estimated
using the field observation and incubation data. The result of mass budget agreed well to the spatial
distribution pattern of MeHg and DOM components in this region, showing higher concentrations of MeHg and
soil humic-like DOM in the surface layer. Overall, an increase of terrestrial organic input, in relation to future
climate change, is likely to amplify methylation rates of Hg(II) in Arctic fjord.

2073
Fri_112_GG-1_96
Geological Structure of the Lambert Glacier Area (East Antarctica)

Evgenii Mikhalsky1 (emikhalsky@mail.ru)

1
VNII Okeangeologia, Antarctic, St Petersburg, Russian Federation

The Lambert Glacier area (Mac.Robertson Land−Princess Elizabeth Land) is underlain by a wide range of
geological bodies in terms of their age, lithology and tectonic setting. Various models to explain the complex
geological composition and protracted tectonic evolution have been proposed but nevertheless it remains the
subject of continuing discussion and investigation.
The study region consists of three major crustal provinces, defined by their geological histories and Sm-Nd TDM
model ages: the Ruker Province (2.8-3.6 Ga), the Vestfold Province (2.7-3.0 Ga), and the Rayner Province (1.6-
2.4 Ga). The Ruker Province comprises the Mawson−Stinear Zone composed of an early Precambrian basement
and overlying Proterozoic supracrustal sequences, and accreted the PP Lambert Zone. The Rayner Province
comprises: (1) Fisher Inlier composed of mid-MP juvenile arc-related mafic and felsic rocks, (2) Beaver−Prydz
(BEAP) Zone comprising late-MP arc(?) felsic rocks with rare mid-MP inheritance, and (3) South Princess
Elizabeth (SPEL) Zone comprising late-MP − early NP felsic rocks of either juvenile or within crust origin. The
Fisher Inlier and BEAP Zone include recently discovered PP rocks (India edge? Mawson Continent?)
subsequently reworked. Tectonothermal events in the Rayner Province are concentrated in three age intervals:
ca 1200−1100 Ma (Fisher Phase), ca 1000−950 Ma (Beaver Phase), and ca 800 Ma (Bolingen Phase). Cambrian
reworking affected much of the SPEL and eastern BEAP zone.

2074
Fri_113_GG-1_118
Upper Mantle P-wave Velocity Structure Beneath the Terra Nova Bay, Antarctica

Yongcheol Park1 (ypark@kopri.re.kr), Won Sang Lee2, Choon-Ki Lee2, Samantha Hansen3
1
Korea Polar Research Institute (KOPRI), Division of Earth-System Sciences, Incheon, Korea, Republic of, 2Korea
Polar Research Institute (KOPRI), Unit of Ice Sheet and Sea Level Changes, Incheon, Korea, Republic of,
3
University of Alabama, Geological Sciences, Tuscaloosa, United States

The Extreme Geophysics Group (EGG) at Korea Polar Research Intititue (KOPRI) have installed four broadband
seismic stations around Mt. Melbourne during the Antarctic summer in 2010-2011 to monitor the activities of
Mt. Melbourne. Next summer season, seven broadband seismic stations were installed around the end of
David Glacier which is the biggest glacier outlet in the Terra Nova Bay area. The number of seismic station is
increasing year by year, and the Korea Polar Seismic Network (KPSN) consists of seventeen broadband stations
and one infrasound array. The division of Polar Earth-system Science is focused on the research titled
“Characterizing mantle domain beneath West Antarctic Rift System and Antarctic mid-ocean ridges”, and trying
to install OBSs (Ocean Bottom Seismometers) in Terra Nova Bay in order to optimize the data usage combining
with the data set from the landbased seismic network.
The P-wave upper mantle velocity structure was modeled with the teleseismic events observed on the KPSN
and the Transantarcic Moutains Northern Network (TAMNNET) to extend the spatial coverage of the rays. The
preliminary results show two separate low velocity anomalies located beneath Terra Rift and the inland area
from Mt. Melbourne to the north, respectively in 100 km depth.

2075
Fri_114_GG-1_146
1:1000 000 Geological Map of the Lambert Glacier Area (East Antarctica)

Evgeny Mikhalsky1 (emikhalsky@mail.ru), German Leitchenkov1

1
VNII Okeangeologia, Antarctic, St Petersburg, Russian Federation

The Lambert Glacier area (Mac.Robertson Land−Princess Elizabeth Land) including the Prydz Bay shelf has been
subject of long-term multinational and multidisciplinary geological and geophysical research.
A huge amount of geological mapping work in the study area has been done and numerous papers published
elsewhere, while U−Pb zircon ages were obtained for >350 samples. We present a specific zonal legend which
describes the geology of map region. The tectonic grid is dominated by three pre-Cambrian provinces variously
overprinted within the Cambrian orogen. Prydz Bay shelf is generally covered by Late Paleozoic to Mesozoic
deposits and different stratigraphic units crop out in the sea bottom due to differentiated crustal
uplift/subsidence tectonic history and recent ice-sheet erosion.
The basic map units are assigned to two categories: stratigraphic (sedimentary and volcanic including their
metamorphosed counterparts) and non-stratigraphic (intrusive bodies, metamorphic or plutonic-metamorphic
complexes). High-grade metamorphic and plutonic-metamorphic complexes predominate. They are shown
with stripe color patterns, with separate colors indicating protolith age and metamorphic/structural age. We
invent a complex format of indices which includes two age components. The first symbol stands for protolith
age and the second indicates the age of the main-stage metamorphism and pervasive deformation. Thus at the
same time both geological and tectonic features are indicated.

2076
Fri_115_GG-1_150
Study of Ice-caves on Melbourne and Rittmann: Results from ICE-VOLC Project

Gaetano Giudice1 (gaetano.giudice@ingv.it), Giovanni Giuffrida1, Marco Liuzzo1, Andrea Cannata2,3

1
Istituto Nazionale di Geofisica e Vulcanologia, Palermo, Palermo, Italy, 2Università degli Studi di Perugia,
Dipartimento di Fisica e Geologia, Perugia, Italy, 3Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio
Etneo, Catania, Italy

Thanks to the interaction between permanent thick ice layers and fumarolic hot gases, Antarctic volcanoes host
very peculiar features called ice-caves. These are networks of passages melted into the base of the snowpack
where geothermal heat and warm gases are supplied to the ice‐rock interface. Recently, Antarctica ice caves
have attracted the attention of scientists working on both geology and biology fields, since they can provide
precious insights into degassing and heat release from volcanoes, as well as into organisms that thrive in
physically extreme conditions inside the caves.
In the framework of the ICEVOLC project (www.icevolc-project.com) funded by the Italian PNRA, several
activities focused on the investigation of ice-caves in both Melbourne and Rittmann volcanoes (Victoria Land)
were carried out such as:
i) identification of pinnacles and ice-towers, chimney-like ice formations indicating the entrance of the ice-
caves;
ii) identification and mapping of unexplored ice-caves on both volcanoes;
iii) sampling of gases released by fumaroles within the ice-caves to get insights into volcano dynamics and its
state of health;
iv) thermal survey to investigate ice-cave microclimate and evaluate energy exchanges.

2077
Fri_116_GG-1_162
Cenozoic Tectonic Characteristics of the Adare Basin, West Ross Sea

Qiao Zhang1 (zhangqiao0317@163.com), Jinyao Gao1, Fei Ji1,2, Zhongyan Shen1

1
Second Institute of Oceanography, State Oceanic Administration, Hangzhou, China, 2Wuhan University, Chinese
Antarctic Center of Surveying and Mapping, Wuhan, China

Based on the geophysical data from the Adare Basin, we employed the F-K filtering method to recover the
newly processed dataset with high signal noise ratio and complete seismic event which highly contributes to
reveal more detailed geological structures. Combined with glaciation, the associated sedimentary facies were
summarized. Our analysis revealed that, at 16 Ma, due to the thermal effect caused by residual magmatism
and asymmetric spreading of Adare Basin, surrounding areas of two flanks of the Adare trough were
characterized by uplift folds and tilted uplift zone, respectively. The small-scale uplift fold zone was
characterized by nearly upright faults and folds and was located in the southern part of the eastern flank,
whereas the tilted uplift zone dominated in the corresponding district of western flank that reached the
continental margin. By utilizing the contact relationship between igneous rocks and surrounding rocks, igneous
rocks can be divided into two periods: early-stage and late Cenozoic igneous rocks. The early-stage rocks are
generally located dispersedly in the tilted uplift zone and the age is poorly known. It is suggested that they
were related to the residual magmatism. On the other hand, the spatial distribution of Late Cenozoic igneous
rocks, formed not earlier 5.5 Ma, almost covered the whole study area, which indicates that they might be
affected by decompression melting of the mantle because of the large-scale deglaciation since Pliocene.

2078
Fri_117_GG-1_193
Geochemical Analyses of Marine Sediments to Infer sub-ice Geology of Antarctica

Mayuri Pandey1 (mayuri1414@gmail.com), Naresh C. Pant2

1
Banaras Hindu University, Department of Geology, Varanasi, India, 2University of Delhi, Department of
Geology, New Delhi, India

Drilling of the Wilkes Land margin of East Antarctica during expedition 318 was designed to provide a long-term
record of the sed¬imentary archives along an inshore to offshore transect of Cenozoic Antarctic glacia¬tion. To
develop an understanding of sourcing of these sedimentary archives, geochemical characterization was carried
out on the sediments of site U1359 of Miocene age. The prime objectives of this study are to delineate source
rock characteristics, degree of chemical weathering, sorting processes and the geochemical behaviour of
sediments during transportation and deposition.
The Chemical Index of Alteration shows a variability from ~55% to 65% indicating a moderate alteration index.
The chondrtite normalized, UCC and shale normalize graphs conclusively show that the sediments depict
variable behaviour hence cannot be supplied from single source. The significance of grain size and its role in
this particular site was also supported by the La/Th plot and ternary plot of La-Sc-Th.
The sediments source from basic, felsic and metasedimentary provenance interpreted from the heavy mineral
population and mineral chemistry is also supported by various ratio plots and ternary diagram (La-Sc-Th). A
continental island arc tectonic setting along with few samples from active/passive continental margin is
interpreted from the geochemical behaviour of the sediments.

2079
Fri_118_GG-1_230
Geological Mapping in the Convoy Range, Victoria Land, Antarctica

Giovanni Capponi1 (capponi@dipteris.unige.it), Stefano Casale2, Chiara Montomoli2, Rodolfo Carosi3, Simon
Cox4, Laura Crispini1, Laura Federico1, Salvatore Iaccarino2, Andreas Laufer5, Giovanni Musumeci2, Maria
Cristina Salvatore2, Marco Scarsi1
1
University of Genova, DISTAV, Genova, Italy, 2University of Pisa, Dipartimento di Scienze della Terra, Pisa, Italy,
3
University of Torino, Dipartimento di Scienze della Terra, Torino, Italy, 4GNS Science, Dunedin, New Zealand,
5
BGR - Bundesanstalt fur Geowissenschaften und Rohstoffe, Polar Geology Unit, Hannover, Germany

In the austral summer 2017/18, a three person team performed geological and geological-glacial field mapping
in the Convoy Range, at the scale 1/250000. Activity was heli-supported, starting from the Italian Mario
Zucchelli Station, with two principal targets: 1) to complete geological mapping for the area between 76° and
76°30´ S, filling a gap existing between the GIGAMAP maps (Pertusati et al., 2016) to the north and the
geological maps by GNS Science - New Zealand to the south (Gunn & Warren, 1962; Pocknall et al., 1994); 2) to
collect new data (stratigraphic, structural, sedimentological, petrographic and geochronological data) to better
characterize the lithotectonic units cropping out in the investigated area.
In more detail, in Antarctica the activity included:
- geological and geological-glacial field mapping.
- photogeological analyses, to support the field work;
- rock sampling.
On return from Antarctica the activity comprised:
- digitisation of the new cartographic data and their integration in the Geomap dataset;
- elaboration of structural data;
- microstructural analyses;
- minero-petrographic analyses of rocks and glacial deposits.
Gunn B.M., Warren G. - 1962 - New Zealand Geological Survey bulletin 71, 156 p.
Pertusati P.C., Ricci C.A., Tessensohn F. - 2016 - Terra Antartica Reports, 15, 1 - 15.
Pocknall D.T., Chinn T.J., Skyes R., Skinner D.N.B. - 1994 - GNS Science Geological Map 11, 36 p. + 1 map.

2080
Fri_119_GG-1_325
High-resolution Aeromagnetic Imaging of the Lanterman Range, North Victoria Land

Antonia Ruppel1 (antonia.ruppel@bgr.de), Andreas Läufer1, Laura Crispini2, Giovanni Capponi2, Frank Lisker3
1
BGR - Federal Institute for Geosciences and Natural Resources, Hannover, Germany, 2University of Genova,
Genova, Italy, 3University of Bremen, Bremen, Germany

The Lanterman Range covers the boundary between the Wilson Terrane and Bowers Terrane, i.e. the two
western tectonometamorphic units of the Ross-orogenic basement of North Victoria Land, Antarctica. This
boundary is formed by a distinct belt of highly deformed mafic and ultramafic rocks with UHP relicts. It is
interpreted as the trace of a former suture zone that formed during continuous accretion at the Palaeo-Pacific
active continental margin of East Gondwana in the Early Paleozoic.
We report on high-resolution magnetic anomaly data over the Lanterman Range. Preliminary results show two
distinct and nearly parallel magnetic lineaments. These magnetic lineaments follow the main strike of the
Wilson-Bowers terrane boundary. The western of these lineaments correlates with the boundary zone itself.
The eastern lineament cannot be attributed to any exposed rocks so far, which show only rather low magnetic
susceptibility values. Similar paralleling magnetic structures occur further to the southeast, where they are
apparently offset by a possibly post-Jurassic WNW-ESE oriented left-lateral strike-slip zone.
We tentatively propose that the origin of the eastern lineament is due to remnants of the Palaeo-Pacific
subducted slab hidden under the boundary zone of the Bowers Terrane and the easterly dominantly turbiditic
Robertson Bay Terrane. The western may represent remnants of a closed back-arc basin intermittent between
the Wilson and Bowers terranes.

2081
Fri_120_GG-1_327
Geodynamic Modelling of the West Antarctic Mantle - Rift or Plume Dominated?

Eva Bredow1 (eva.bredow@gfz-potsdam.de), Jörg Ebbing1, Folker Pappa1, Valentina Roberta Barletta2, Fausto
Ferraccioli3, Wouter van der Wal4, Johannes Bouman5, Bernhard Steinberger6,7
1
Christian-Albrechts-Universität zu Kiel, Department of Geosciences, Kiel, Germany, 2Technical University of
Denmark, DTU SPACE, National Space Institute, Copenhagen, Denmark, 3British Antarctic Survey, Cambridge,
United Kingdom, 4Delft University of Technology, Delft, Netherlands, 5Federal Agency for Cartography and
Geodesy, Frankfurt, Germany, 6Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences,
Potsdam, Germany, 7University of Oslo, Centre for Earth Evolution and Dynamics (CEED), Oslo, Norway

The observed gravity change and GPS uplift rates beneath the Amundsen Sea Embayment in western
Antarctica can only be explained by glacial isostatic adjustment (GIA) in the presence of a thin elastic
lithosphere and low upper mantle viscosity. Different geological concepts exist to explain the upper mantle
structure. The low viscosity might relate to a warm upper mantle, which might in turn relate to the West
Antarctic Rift Zone or the previously proposed West Antarctic mantle plume.
To address which of the suggested processes is responsible for the low upper mantle viscosity, we combine a
3D lithospheric scale model with geodynamic modelling of the large-scale mantle structures underneath
Antarctica. The 3D lithospheric model is established for the Antarctic continent by combing satellite gravity
gradients and seismological data. The geodynamic models are calculated with the mantle convection code
ASPECT, an open-source code based on finite elements. It features an adaptive mesh refinement that
considerably improves the resolution at regions of interest. Our models focus on West Antarctica and explore
how to reconcile a possible plume with the lithospheric structure. Another aspect that is investigated is the
importance of the sublithospheric composition and temperature on the upper mantle viscosity structure.

2082
Fri_121_GG-1_338
Axial Transport and Sources of Fluvial Gravel in Munindalen, Svalbard

Lenka Ondrackova1, Martin Hanacek1,2, Daniel Nyvlt1 (daniel.nyvlt@seznam.cz)

1
Masaryk University, Faculty of Science, Department of Geography, Brno, Czech Republic, 2Masaryk University,
Faculty of Science, Department of Geological Sciences, Brno, Czech Republic

In order to study the effect of axial transport and lateral inputs on sediment characteristics in High Arctic
proglacial streams we focused on the sediments of Munindalen in central Svalbard. Muninelva River is ~6 km
long; its channel belt is 50-250 m wide and has a valley-train character, which changes into a braided outwash
fan at the mouth. The river is dominantly pebble-cobble gravely along the entire stream with predominant
sandstone and limestone clasts from two main sources according to their position in respect to the main
stream: I) axial head source - Muninbreen Glacier and its terminal moraine-mound complexes; II) lateral
sources - colluvial and alluvial fans, terminoglacial outwash fan from a lateral glacier and bedrock in the
channel belt banks. Our results show that the axial head source is crucial for the origin of cobble fraction,
whereas lateral sources contribute by large amount of pebble material and overwhelms thus the downstream
trend in pebble clasts' roundness. On the contrary, the amount of cobbles transported from the lateral sources
is smaller; therefore the downstream trend of cobble clasts roundness is not masked by lateral inputs. Pebbles
are highly mobile both in river transport and on lateral fans; therefore lateral inputs hides the downstream
roundness trend in Muninelva River sediments, which was not found for cobbles. This study emphasized the
importance of material sources on sedimentary characteristics in proglacial streams.

2083
Fri_122_GG-1_340
Structure and Extent of the Tonian Oceanic Arc Super Terrane, Dronning Maud Land

Antonia Ruppel1 (antonia.ruppel@bgr.de), Joachim Jacobs2,3, Graeme Eagles4, Andreas Läufer1, Wilfried Jokat4
1
BGR - Federal Institute for Geosciences and Natural Resources, Hannover, Germany, 2University of Bergen,
Department of Earth Science, Bergen, Norway, 3Norwegian Polar Institute, Tromsø, Norway, 4Alfred-Wegener-
Institute Helmholtz-Center for Polar and Marine Research, Bremerhaven, Germany

Sør Rondane and adjacent regions in eastern Dronning Maud Land are of major interest regarding our
understanding of the architecture of crustal fragments that were involved in the amalgamation and breakup
history of Rodinia and Gondwana.
Approximately 40.000 line kilometre of new magnetic anomaly data were collected to the east and south of Sør
Rondane with 10 km line spacing. These data are integrated with exposure information from Sør Rondane, the
Belgica Mountains, and the Yamato Mountains. Main emphasis was placed on estimating the spatial extent of
the recently discovered Tonian Oceanic Arc Super Terrane (TOAST), which is interpreted as early
Neoproterozoic juvenile crustal additions within the East African-Antarctic Orogen (EAAO).
The FMA is interpreted as western extent of the TOAST, whereas evidence for its prolongation is provided by
SE-striking parallel positive magnetic anomalies that can be correlated with ca. 1000-900 Ma juvenile rocks in
Sør Rondane. New data constrain the southern and eastern minimum extent of the TOAST, which corresponds
in size with ca. 500000 square kilometres to at least 5% of East Antarctica. The juvenile Tonian rocks developed
outside Rodinia and represent major remnants of the Mozambique Ocean. They resemble rocks of the Arabian-
Nubian shield, but are slightly older. Thus, the EAAO is characterised by major Neoproterozoic crustal additions
on either ends.

2084
Fri_123_GG-1_341
Seismicity of the Eurasian Basin Based on the Data of Polar Seismic Stations

Galina Antonovskaya1 (galina.antonovskaya@gmail.com), Yana Konechnaya1, Natalya Vaganova1, Alexey

Morozov1, Irina Basakina1
1
N. Laverov Federal Center for Integrated Arctic Research, Russian Academy of Sciences, Arkhangelsk, Russian
Federation

On the basis of the N. Laverov Federal Center for Integrated Arctic Research there is an Arkhangelsk seismic
network (ASN). Some of seismic stations of the ASN were installed at the Arctic region. There are on the Franz
Josef Land and Severnaya Zemlya archipelago and on the coast of the Kara Sea. Main goal is seismic monitoring
of the Eurasian Basin.
Seismic information of the Arctic region is not quite complete. For the Eurasian Basin by combining seismic
data bases of the NORSAR (Norway), Kola Department Geophysical Survey of RAS (Russian Federation) and ASN
a General Seismic Catalog above 70°N was created for 1998-2015 for magnitude above 2.0. We compiled the
map of main tectonic elements of the Eurasian Basin and applied on it the seismic information.
Results about the latest seismicity shows tectonic activation in the Arctic Basin caused by rifting, stretching
lithosphere blocks and volcanic activity. Areas of the Mid-Arctic Ridge, transition continent-ocean zone and
graben sides are the most seismic active regions. The weak seismicity of the Barents-Kara shelf can be
explained by ultra-slow speeds of the processes occurring in the lithosphere.
Polar stations record many icequakers associated with formation of icebergs, cracking of glaciers and their
movements. First results correlations of icequakers number with meteorological data were obtained, a
database was created.

2085
Fri_124_GG-1_347
ADMAP-2: The Second Generation Antarctic Crustal Magnetic Anomaly Map

Alexander V. Golynsky1 (sasha@vniio.nw.ru), Dmitry A. Golynsky1, Fausto Ferraccioli2, Tom A. Jordan2, Duncan
A. Young3, Donanld D. Blankenship3, John W. Holt3, Wilfried Jokat4, Alexander V. Kiselev5, Sergey V. Ivanov5,
Valery N. Masolov5, Detlef Damaske6, Carol Finn7, Robin E. Bell8, Karsten Gohl4, Graeme Eagles4, Egidio
Armadillo9, Giorgio Caneva9, Emmanuelle Bozzo9, Rene Forsberg10, Alan Aitken11, Ralph R.B. Frese12, Marta
Ghidella13, Yoshifumi Nogi14, Fernando Bohoyo15, Jesus Galindo-Zaldivar15, Yasmina Martos15, Enrica Quartini3,
Hyung-Rae Kim16, Jongkuk Hong17
1
VNII Okeangeologia, Antarctic Geology, St. Petersburg, Russian Federation, 2BAS, Cambridge, United Kingdom,
3
University of Texas Institute for Geophysics, Austin, United States, 4AWI, Bremerhaven, Germany, 5Polar
Marine Geosurvey Expedition, Lomonosov, Russian Federation, 6BGR - Bundesanstalt fur Geowissenschaften
und Rohstoffe, Hannover, Germany, 7USGS, Denver, United States, 8Lamont-Doherty Earth Observatory of
Columbia University, Palisades, United States, 9Università di Genova, Genova, Italy, 10Technical University of
Denmark, Copenhagen, Denmark, 11The University of Western Australia, Perth, Australia, 12Ohio State
University, Columbus, United States, 13Instituto Antártico Argentino, Buenos Aires, Argentina, 14National
Institute of Polar Research, Tokyo, Japan, 15Universidad de Granada, Instituto Andaluz de Ciencias de la Tierra,
Granada, Spain, 16Kongju National University, Kongju, Korea, Republic of, 17Korea Polar Research Institute
(KOPRI), Incheon, Korea, Republic of

ADMAP-2 is the second generation crustal magnetic anomaly compilation for the Antarctic region south of
60°S. It was produced from more than 3.5 million line-km of airborne and marine magnetic observations
collected since the International Geophysical Year 1957/58 through 2013. The data were edited, IGRF
corrected, profile levelled and gridded on a polar stereographic projection at an interval of 1.5 km.
Microlevelling was also performed on some of the grids from more recent detailed surveys. Data quality was
maintained by statistical analysis of the crossover errors.
Given the ubiquitous polar cover of snow, ice and sea water, the magnetic anomaly compilation offers
important constraints on the global tectonic processes and crustal properties of the Antarctic. It also links
widely separated areas of outcrop to help unify disparate geologic studies, and provides insights on the
lithospheric transition between Antarctica and adjacent oceans, as well as the geodynamic evolution of the
Antarctic lithosphere in the assembly and break-up of the Gondwana, Rodinia, and Columbia supercontinents
and key piercing points for reconstructing linkages between the protocontinents. The magnetic data together
with ice-probing radar and gravity information greatly facilitate understanding the evolution of fundamental
large-scale geological processes such as continental rifting, intraplate mountain building, subduction and
terrane accretion processes, and intraplate basin formation.

2086
Fri_125_GG-1_351
Extent of Princess Elizabeth Land Stenian Accretional Belt Based on Magnetics

Alexander V. Golynsky1 (sasha@vniio.nw.ru), Dmitry A. Golynsky1

1
VNII Okeangeologia, Antarctic Geology, St. Petersburg, Russian Federation

Aeromagnetic surveys over Princess Elizabeth Land have revealed extent of continuous accretional orogen
characterized by low amplitude, linear NE-trending magnetic anomalies that is extremely unique relative to
other regions of the East Antarctic. It can be traced from Clemence Massif to the southern margin of the
Vestfold Hills crustal block and further east to 88° E. Positive anomalies associated with the predominantly
orthogneiss Pickering Series (Laiba, Kudriavtsev, 2006; Mikhalsky et al., 2013) and negative anomalies with the
paragneiss Manning Series. Mafic granulites from the Manning Nunataks show typical characteristics of island
arc basalts; whereas felsic orthogneisses have the characteristics of volcanic arc granites (Liu et al., 2014).
Geochronological data give protolith ages ranging from 1347 to 1020 Ma for these arc-related rocks, indicating
a long-lived magmatic accretion in the Rayner continental arc. The most prominent Robertson anomaly is
reflected by amphibolite-facies rocks only occur in Robertson Nunatak where mafic schists and subordinate
orthogneiss crop out. Isotopically juvenile rocks from the Fisher Terrane and Robertson Nunatak may represent
a small-scale oceanic arc extending eastward across the Lambert Rift. Two fragments of this oceanic arc,
displaced for a distance of about 50-60 km along dextral strike-slip system of faults, are most likely related to
Cretaceous transtensional tectonics associated with break-up of India and Antarctica.

2087
Fri_126_GG-1_354
Vanderford-Totten Rift Structure, East Antarctica

Dmitry A. Golynsky1 (dmitry.a.golynsky@gmail.com), Alexander V. Golynsky1, Alexander V. Kiselev2

1
VNII Okeangeologia, Antarctic Geology, St. Petersburg, Russian Federation, 2Polar Marine Geosurvey
Expedition, Lomonosov, Russian Federation

The new aerogeophysical data collected within the international ICECAP and IceBridge projects (Aitken et al.,
2013) allowed us to distinguish spatial characteristics of the Vanderford-Totten (VT) rift over Wilkes Land in
East Antarctica. Its length exceeds 400 km and width varies from 50 to 100 km. The VT Glaciers are underlain by
distinctive continuous depression with depth up to 2525 m below sea level, their shoulders are extremely
steep, suggesting the tectonic origin of the riftogenic structure. In accordance with the results of the local Airy
isostatic Moho depth estimations, the axial part of the rift is characterized by an essential thinning of the Earth
crust thickness (up to 24-27 km) and it is elevated along entire length of this structure. The potential field
modeling indicates more than 3 km of sedimentary infill within the suggested rift. Additional argument for the
riftogenic crust beneath the VT Glaciers is significant level of seismicity registered here, more than 30 intraplate
earthquakes have occurred to date. Earthquakes magnitude varied from 3.9 to 5.8 and their sources
concentrated in upper part of earth crust in a depth range of 8-10 km, although some of them were registered
at 33 km depth. By analogy with intracratonic basins of southern Australia, it is suggested Permian age of the
rift formation. The VT rift may inherit pre-existing tectonically weak zone between the Albany Fraser orogen's
counterpart in Antarctica and the West Mawson craton.

2088
Fri_127_GG-1_550
Toward a Seismic-based 3D Thermo-mechanical Model of the Greenland Lithosphere

Aurelien Mordret1 (mordret@mit.edu)

1
Massachusetts Institute of Technology, Earth, Atmospheric and Planetary Sciences, Cambridge, United States

During the past 120 million years, the Greenland craton drifted over the Iceland hotspot; however,
uncertainties in geodynamic modeling and a lack of geophysical evidence prevent an accurate reconstruction of
the hotspot track. I image the Greenland lithosphere down to 200 km depth with seismic noise tomography.
The 3D shear-wave velocity model obtained using 4-5 years of continuous records from the GLISN seismic
network is well resolved for most of the Greenland main island. The crustal part of the model clearly shows
different tectonic units. The hotspot track is observed as a linear high-velocity anomaly in the middle and lower
crust, most probably associated with magmatic intrusions. In the upper mantle, a pronounced low-velocity
anomaly below the East coast might be due to the remnant effect of the Iceland hotspot when it was at its
maximum intensity. Thermo-mechanical modeling suggests that this area has higher temperature and lower
viscosity than the surrounding cratonic areas and experiences a higher than average surface heat flow. This
new detailed picture of the Greenland lithosphere will drive more accurate geodynamic reconstructions of
tectonic plate motions and help to better understand the North Atlantic tectonic history. Models of Greenland
glacial isostatic adjustment will benefit from the 3D upper mantle viscosity model, which in turn will enable
more precise estimations of the Greenland ice-sheet mass balance.

2089
Fri_128_GG-1_629
Inferring a Rift-thinned Lithosphere in Princess Elizabeth Land, Antarctica

Devsamridhi Arora1 (devsamridhiarora@yahoo.com), Naresh Pant1, Jamin Greenbaum2, Martin Siegert3, Sun
Bo4, Anupam Chattopadhyay1, Mayuri Pandey5, Donald Blankenship2
1
University of Delhi, Department of Geology, Delhi, India, 2University of Texas Institute for Geophysics, Austin,
United States, 3Imperial College London, London, United Kingdom, 4Polar Research Institute of China, Shanghai,
China, 5Banaras Hindu University, Varanasi, India

Geophysical surveys including radar sounding, laser altimetry, gravity, and magnetics under ICECAP-2
(International Collaborative Exploration of Central East Antarctica through Airborne geophysical Profiling)
program reveal that PEL hosts an assortment of previously unidentified subglacial lakes and complex
geomorphology. Presence of a 1,100 km-long system of canyons and two large lakes connecting south of the
Lambert Rift to the West Ice Shelf has been confirmed.
Ice free exposures of East Antarctic Shield are available along the ~250 km long coastal fringe of East Prydz Bay.
The major outcrop in the east is Archean granulite terrain of the Vestfold hills. The adjacent Rauer Group
contains both Archean and Proterozoic components. Further ~70 km west, Brattstand bluff, Larsemann Hills
and Bollingen Islands constitute the mid-Proterozoic block with a strong Pan African overprint. ~140 km
westwards, Landing Bluff exposes the undeformed granites of Pan African age. A westward younging sequence
is evident and the large time gap of >2000 Ma suggests presence of complex geological history and interleaved
distinct terrains.
We propose presence of a thinned lithosphere (probably a failed rift) in sub-ice East Antarctic terrain along the
detected canyon. Analog modelling related to the Lambert rift is used to demonstrate influence of pervasive
mechanical anisotropy of the basement in defining orientation of this rift system and its connection to the
Lambert Graben.

2090
Fri_129_GG-1_653
Magma-poor Margin off Wilkes Land, Antarctica: Comparison with other Analogs

Vanda Sergeeva1,2 (wanda@list.ru), German Leitchenkov1,2

1
VNII Okeangeologia, St. Petersburg, Russian Federation, 2St. Petersburg State University, St. Petersburg,
Russian Federation

The parts of eastern Indian Ocean off Wilkes Land (Antarctica) and Australia include good examples of
conjugated hyperextended magma-poor margins. In this research we compare crustal characteristics of Wilkes
Land continental margin with those in northern Atlantic (well-studied Newfoundland-Iberia margins) and Indian
Ocean (still poorly-studied Enderby Land - Eastern India margins). According to data from the studied pairs of
passive margins there are few notable differences which include 1) character and duration of crustal stretching;
1) width of rifted regions and zone of exhumed mantle (ZEM)
2) pattern of potential fields above ZEM;
3) morphology of and deformations of ZEM;
4) resolution of Moho boundary beneath ZEM by seismic data;
5) the style/regime/geometry of sea-floor spreading followed rifting and mantle exhumation;
6) crustal (tectonic) prehistory of rifting.
Revealed differences can be explained by rheological conditions of lithosphere, global plate motion, mantle
convection, serpentinization process etc.

2091
Fri_130_GG-1_689
Ammonites from the Byers Peninsula, Livingston Island, Antarctica

Docho Dochev1 (dochev@gea.uni-sofia.bg), Vyara Idakieva1, Marin Ivanov1, Stefan Velev2, Kamen Bonev2
1
Sofia University 'St. Kliment Ohridski', Geology, Paleontology and Fossil Fuels, Sofia, Bulgaria, 2Bulgarian
Antarctic Institute, Sofia, Bulgaria

During the field season in 2016, Bulgarian geological team collected ammonite fauna in the southwestern part
of the Byers Peninsula, Livingston Island. The cephalopod fauna was obtained at the vicinity of the Devils Point
and southern part of the President Beaches areas. The ammonites from this area have already been subject of
studies, mainly by Chilean paleontologists (Tavera, 1970; Covachevich, 1976).
From the Devils Point the ammonites come from dark-grey mudstones, intercalated between coarse-grained
sandstone beds. From this locality we recognize Haplophylloceras strigile and Protancyloceras sp. indet. The
first one is characteristic species for the Uppermost Tithonian and/or for the base of the Berriasian (Thomson,
1979; Yin and Enay, 2004).
The sedimentary rocks cropping out in the southern part of the President Beaches are mudstone-dominated
with small sand-bodies. The ammonites from this area were obtained from the coarse-grained sandstones.
From this locality we identify Spiticeras (S.) spitiensis, S. bilobatum, ?Spiticeras tripartitum lovaldesensis and
Argentiniceras lonchochense. Based on this ammonite assemblage we assume Late Berriasian age for the
sandstone beds exposed in southern part of the President Beaches area.
The biostratigraphic interpretation allowed us to consider late Tithonian-early Berriasian age for the
sedimentary sequence of the Devils Point area and late Berriasian age for the sand-bodies of the President
Beaches area.

2092
Fri_131_GG-1_692
Hydrothermal Breccias from Hurd Peninsula, Livingston Island, Antarctica

Stefan Velev1 (velev@gea.uni-sofia.bg), Docho Dochev2, Kamen Bonev1

1
Bulgarian Antarctic Institute, Sofia, Bulgaria, 2Sofia University 'St. Kliment Ohridski', Sofia, Bulgaria

Based on field data we proposed classification of hydrothermal breccias from Hurd Peninsula. They are
intruded among sedimentary rocks (medium- to coarse grained sandstones, alternating with mudstones and
fine-grained sandstones).
Hydrothermal breccias are classified as magmatic hydrothermal injection breccias (Corbett and Leach, 1998).
These kinds of breccias are related to hydraulic breccias and form by injection of mineralized magmatic fluids.
Magmatic hydrothermal injection beccias in studied area comprise host rock fragment, set in a hydrothermal
matrix, composed of quartz, carbonates and ore minerals (pyrite, chalcopyrite, galena and malachite).
These breccias are classified as rotational, mosaic (jigsaw) and fluidized breccias. Rotational breccias are
characterized by substantial fragment rotation or transport in association with fluid injection. Mosaic or jigsaw
breccias are distinguished by fragments which are separated, but have not undergone substantial transport.
Rock fragments in these breccias may be joined back together by removal of the matrix. Fluidized breccias
contain milled fragments in a transported matrix, to form dike-like bodies.
The formation of the magmatic hydrothermal breccias is an integrated element of the formation and the
evolution of the magmatic hydrothermal system. They are formed by the explosive release of overpressured
magmatic fluids from the fluid saturated magma.

2093
Fri_132_GG-1_714
TRACERS Project: Tephrochronology Study of the Ross Sea, Antarctica

Alessio Di Roberto1 (alessio.diroberto@ingv.it), Ester Colizza2, Paola Del Carlo1, Andrea Gallerani3, Federico
Giglio3
1
Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Pisa, Pisa, Italy, 2Università degli Studi di Trieste,
Dipartimento di Matematica e Geoscienze, Trieste, Italy, 3CNR-ISMAR, Bologna, Italy

Marine sediment sequences from the polar regions are crucial archives for paleoclimatic and
paleoenvironmental studies. Often, they contain tephra layers produced during large explosive volcanic
eruptions. The study of tephra provides significant data and constraints for volcanological reconstructions e.g.
the age of eruptions, their recurrence, dynamics, as well as the spatial and temporal evolution of volcanic
activity. If geochemically fingerprinted and tied to a known, dated eruption tephra layers became isochronous
marker horizons that provide high-resolution time-stratigraphic information. ROSSTEPHRA project, carried out
within the Italian PNRA (2010/A2.12), demonstrated that marine sediment of the Ross Sea, Antarctica, contain
a number of primary tephra layers (Del Carlo et al. 2015). This project laid down the groundwork for the new
multidisciplinary research project TRACERS aimed at the tephrochronology-tephrostratigraphy study of
selected sediment cores sampled in Ross Sea, downwind the principal volcanic edifices. Here we present the
preliminary results of TRACERS project. The projects have proven the validity of the multidisciplinary approach
in polar region to contribute substantially to the improvement of the chronological framework of the area. In
addition, their results contribute to gain new knowledge about eruptive history of the Antarctic volcanoes (age,
frequency, intensity of eruptions, volume of the material erupted).

2094
Fri_133_GG-1_750
Petrology of Charnockite-enderbite Algae Lake Pluton, East Antarctica

Nikita Borovkov1 (nikita.borovkov812@yandex.ru)

1
All-Russia Scientific Research Institute for Geology and Mineral Resources of the Ocean, Geology and Mineral
Resources of Antarctica, St. Petersburg, Russian Federation

Algae Lake Pluton is located in SW part of Banger Hills and its area is around 15 km2. This intrusion is formed by
different rock types and can be applied to anorthosite-mangerite-charnockite association. However, opx-
bearing granites here are enderbites (Pl 70-50%, Afsp 10-15%, Qz 20-15%). Accordingly, rock composition
varies from gabbro-diorite to monzonite and monzodiorite on QAPF diagram. Gabbroic and anorthosite-like
rocks are concentrated at the edge of Pluton. Central part of Pluton is composed by enderbites. Thanks to their
specific geochemistry enderbites and charnockites are essential for reconstruction of geodynamic
circumstances of their formation time. Intrusion of enderbite-charnockite magma is supposed to be syn-
orogenic event. Geochronology data (U-Pb, zircon) provides that intrusion event happened after the maximum
of granulite metamorphism. Obtained geochemical and isotopic data (Sheraton et al., 1991; Tucker et al., 2016,
2017 and our preliminary data) reveal that studied rocks have sufficient crust influence. On tectonic diagrams
(Pearce et al., 1984; Whalen et al., 1987) they are within syn-orogenic fields and A-type granites. The source of
enderbite-charnockite magma is still under discussion. Data on zircon geochemistry, Sm-Nd system,
geochemistry of inclusions in minerals are coming up.

2095
Fri_134_GG-1_762
Seismic/Thermal Structures of the Crust and Uppermost Mantle Beneath Antarctica

Weisen Shen1,2 (weisen.shen@stonybrook.edu), Douglas Wiens1, Terry Wilson3, Sridhar Anandakrishnan4,

Richard Aster5, Samantha Hansen6, Ian Dalziel7, Andrew Nyblade4, Paul Winberry8, Ralph Stephen9, Audrey
Huerta8, Peter Gerstoft10, Peter Bromirski11
1
Washington University in St Louis, St Louis, United States, 2Stony Brook University, Stony Brook, United States,
3
Ohio State University, Columbus, United States, 4Pennsylvania State University, University Park, United States,
5
Colorado State University, Fort Collins, United States, 6University of Alabama, Tuscaloosa, United States,
7
University of Texas at Austin, Austin, United States, 8Central Washington University, Ellensburg, United States,
9
Woods Hole Oceanographic Institution (WHO), Woods Hole, United States, 10Scripps Institution of
Oceanography, University of California, San Diego, United States, 11Scripps Institution of Oceanography, UC San
Diego, San Diego, United States

Since the 1990s, over 200 broadband seismic stations have been deployed across Antarctica. In this
presentation, we discuss our recent efforts to build reference crustal and uppermost mantle shear velocity (Vs)
and thermal models for continental Antarctica with those seismic stations. First, by combining the Rayleigh
wave dispersion maps with P receiver functions, we develop a 3-D Vs model for the crust and uppermost
mantle beneath central and West Antarctica to a depth of ~200 km. Second, using this 3-D seismic model to
constrain the crustal structure, we re-invert for the upper mantle thermal structure using the surface wave
data within a thermodynamic framework. The final product, a high-resolution thermal model together with
associated uncertainty estimates from the Monte Carlo inversion, allows us to derive lithospheric thickness and
surface heat flux maps for the continent. A variety of tectonic features, including a slower/hotter but highly
heterogeneous West Antarctica and a much faster/colder East Antarctic craton, are present in the 3-D
seismic/thermal models. Notably, a seismic signature of lithospheric foundering is observed beneath the
southern TAMs, and an uppermost mantle compositional anomaly is found beneath the Gamburtsev
Mountains. These features from the 3-D models help further investigate the dynamics of Antarctica's
lithosphere and asthenosphere, and provide key constraints on the interaction between the solid Earth and the
West Antarctic Ice Sheet.

2096
Fri_136_GG-1_913
Middle Cambrian Slope Deposits in Northern Victoria Land, Antarctica

Jongsun Hong1 (jhong@kangwon.ac.kr), Jusun Woo2

1
Kangwon National University, Department of Geology, Chuncheon, Korea, Republic of, 2Korea Polar Research
Institute (KOPRI), Incheon, Korea, Republic of

Carbonate-bearing slope deposits are reported from the upper Cambrian Series 3 Spurs Formation in northern
Victoria Land, Antarctica, deposited during the Ross Orogeny. The formation consists of shales interbedded
with conglomerates and thin- to thick-bedded sandstone, which overlies the middle Cambrian Series 3 Glasgow
Volcanics and coeval volcaniclastic Molar Formation and is overlain by the Furongian sandstone-dominated
Eureka Formation. The Spurs conglomerates are composed of granule- to boulder-sized polymictic clasts of
shales, sandstones and limestones. Various limestone clasts include thrombolites, dendrolites, oolitic-peloidal
packstone to grainstone, and minor lime mudstone. These are collectively interpreted as downslope deposits,
in which limestone clasts may have been derived from missing platform margin carbonates, analogous to
Cambrian to Lower Ordovician slope successions elsewhere. On the other hand, devoid of thinly bedded lime
mudstone in the Spurs slope successions is markedly different, possibly due to subdued lime muds behind the
platform edge. It is suggested that the Spurs carbonate platform may have developed within narrow shelf
margin area in the volcanic quiescent time until regression with clastic influx. Such small-scale carbonate
platform dominated by microbial reefs and coarse-grained carbonates would hint how syn-orogenic carbonates
developed in arc-related sedimentary basins along the pacific margin of Gondwana.

2097
Fri_137_GG-1_967
Historic Hydrovolcanism at Deception Island (Antarctica): Hazards Implication

Dario Pedrazzi1 (dpedrazzi@ictja.csic.es), Karoly Németh2, Adelina Geyer3, Antonio Álvarez-Valero4, Gerardo
Aguirre-Díaz5, Stefania Bartolini3
1
Consejo Superior de Investigaciones Científicas, ICTJA, Barcelona, Spain, 2Massey University, Palmerston North,
New Zealand, 3Consejo Superior de Investigaciones Científicas, Barcelona, Spain, 4Universidad de Salamanca,
Salamanca, Spain, 5Universidad Nacional Autónoma de México, Querétaro, Mexico

Deception Island (DI), the southernmost island of the South Shetlands Archipelago (Antarctica), is characterised
by a Quaternary caldera system and a post-caldera succession due to a dispersed (monogenetic), volcanic field.
Volcanic activity since the 18th century involved monogenetic small volume eruptions such as scoria cones and
hydrovolcanic edifices with estimated VEI magnitude of 2-3. The latest volcanic unrest episodes in the 20th and
21st centuries, demonstrates that the volcanic system is still active and that future eruptions are likely.
Magma-water interaction represents a major issue on DI as shown by the 1967, 1969 and 1970 explosive
episodes, where the scientific stations on the island were destroyed, or severely damaged. Nowadays, DI is an
important touristic destination during the austral summer hosting two temporary military bases as well.
A detailed revision of the historical hydrovolcanic post-caldera eruptions of DI was carried out, to understand
the dynamics of magma-water interaction, and to characterise the most likely eruptive scenarios from future
eruptions. Crimson Hill (estimated age 1825-1829), Kroner Lake (estimated age 1829-1912) eruptions and 1967,
1969 and 1970 events were characterised by describing the eruption mechanisms related to the island's
hydrovolcanic activity.
The project was partially funded by the POSVOLDEC project (CTM2016-79617-P)(AEI/FEDER-UE). D.P. is grateful
for his Beatriu de Pinós contract (2016 BP 00086).

2098
Fri_138_GG-1_969
Peculiarities of Ultramafic Alkaline Magmatism in the Lambert Rift Area

Nadezda Suschevskaya1, Daria Tkacheva2 (shunya2004@bk.ru), German Leitchenkov2,3

1
Vernadsky Institute of Geochemistry and Analytical Chemistry of Russian Academу of Sciences, Moscow,
Russian Federation, 2VNII Okeangeologia, St. Petersburg, Russian Federation, 3St. Petersburg State University,
St. Petersburg, Russian Federation

This research is focused on the study of Mesozoic ultramafic alkaline rocks developed in the north-western
flank of Lambert Rift in East Antarctica. The rocks are represented by high- and low-magnesian associations
which are akin by lithophils and Nd-Pb ratio. High-magnesian association was resulted from melting of
metasomatized continental mantle at T~1270о and at depths ~130-140 km. Increased Ni/Co ratios in magmatic
rocks are close to mantle values and demonstrate the mantle source of magma. Analysis of olivine grains in
rock samples shows that liquidus high-magnesian olivines (Fo90-91) from lavas are similar to those of mantle
inclusion. The mantle is distinguished by presence of carbonate, minerals of biotite-phlogopite group and
volatiles. The ultramafic alkaline magmatism is associated with the melting of the ancient metamorphosed
mantle, which is similar with the mantle of the southern Kerguelen Plateau. The plume thermal effect on the
continental blocks margins of India and East Antarctica 117-110 Ma led to the melting of the deep parts of
mantle enriched with volatile components.

2099
Fri_139_GG-1_975
Lateral Variations of Seismic Anisotropy in Grove Mountains

Heng Zhang1 (zhangheng415@itpcas.ac.cn), Junmeng Zhao1, Hongbing Liu1, Changhui Ju1

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

We estimate the azimuthal anisotropy in the upper mantle of the Grove Mountains, East Antarctica. The shear-
wave splitting technique has been applied to the teleseismic data recorded from the 3-component seismic
stations in that region, which were deployed by the Institute of Tibetan Plateau Research (ITPCAS). The
patterns of the azimuthal anisotropy, for the stations a little far from the Lambert rift, show that the fast S-
wave orientation is nearly parallel to the Lambert rift and their amplitudes are relatively small. However, the
orientations and amplitudes of the shear-wave splitting are much more complicated in and around the Lambert
rift. The formation of anisotropy beneath the stations away from the rift is possibly related to the breakup of
Gondwana, and we attribute the complex results near the Lambert rift to the existence of ancient lithospheric
mantle.

2100
Fri_140_GG-1_1013
Crustal Structures and Heat Flux from Curie Depth Estimates in West Antarctica

Ricarda Dziadek1 (ricarda.dziadek@awi.de), Fausto Ferraccioli2, Karsten Gohl1, Cornelia Spiegel3

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, 2British
Antarctic Survey, Cambridge, United Kingdom, 3University of Bremen, Bremen, Germany

The West Antarctic Rift System is one of the least understood rift systems on earth, but displays a unique
coupled relationship between tectonic processes and ice sheet dynamics. Geothermal heat flux (GHF) is a
poorly constrained parameter in Antarctica and suspected to affect basal conditions of ice sheets, i.e., basal
melting and subglacial hydrology. Thermomechanical models demonstrate the influential boundary condition
of geothermal heat flux for (paleo) ice sheet stability. Young, continental rift systems are regions with
significantly elevated geothermal heat flux (GHF), because the transient thermal perturbation to the
lithosphere caused by rifting requires ~100 Ma to reach long-term thermal equilibrium. We discuss airborne,
high-resolution magnetic anomaly data from the Amundsen Sea Sector, to provide additional insight into
deeper crustal structures related to the West Antarctic Rift System in the Amundsen/Bellingshausen sector.
With the depth-to-the-bottom of the magnetic source (DBMS) estimates we reveal spatial changes at the
bottom of the igneous crust and the thickness of the magnetic layer, which can be further incorporated into
tectonic interpretations.

2101
Fri_141_GG-1_1133
Precambrian Crustal Architecture in the Gamburtsev Province of East Antarctica

Fausto Ferraccioli1 (ffe@bas.ac.uk), Wu Guochao2, Carol Finn3, Robin Bell4

1
NERC/ British Antarctic Survey, Geology and Geophysics, Cambridge, United Kingdom, 2Zhejiang University,
School of Earth Sciences, Hangzhou, China, 3US Geological Survey, Denver, United States, 4Lamont-Doherty
Earth Observatory Columbia University, Palisades, NY, United States

The Gamburtsev Subglacial Mountains are underlain by 50-60 km thick crust and over 200 km thick lithosphere
formed during the assembly of a mosaic of distinct geophysical provinces that make up interior East Antarctica.
Enhanced magnetic and gravity images, depth to magnetic and gravity sources and 2D models help unveil the
crustal architecture of the Gamburtsev Province (GP). Potential field imaging enables us to trace major fault
systems that segment the GP into the Northern, Central and Southern domains. Apparent offsets within the
Central Domain are interpreted as revealing a transpressional fault system parallel to the previously proposed
Gamburtsev Suture. Magnetic and gravity modelling, combined with independent sediment provenance
constraints, are interpreted here as revealing arc and back arc terranes of inferred Grenvillian age (1.3-1.0 Ga)
in the Northern and Central domains of the GP. Anomalously dense lower crust beneath these domains may
reflect widespread magmatic underplating. Distinct magnetic anomalies correspond to older Paleoproterozoic
crust of the Lambert Terrane, north of the Gamburtsev Suture. The Southern Domain may represent an
extension of the South Pole Province, an inferred Mesoproterozoic (1.6-1.4 Ga?) igneous province.
The Precambrian crustal architecture of the GP is remarkably well-preserved, in spite of proposed reactivation
of interior East Antarctica during Pan-African age collision responsible for final Gondwana assembly.

2102
Fri_142_GG-1_1415
Stratigraphy of the Basal Beacon Supergroup, Northern Victoria Land, Antarctica

Jusun Woo1 (jusunwoo@kopri.re.kr), Changhwan Oh1, Moon Young Choe1, Jong Ik Lee1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

Regional reconnaissance field works and reviewing previous works on the sedimentary strata of the Beacon
Supergroup (BS) in northern Victoria Land (NVL) have showed a new perspective of the initial post-Ross
sedimentation in NVL. BS in NVL formed on top of an unconformity developed on the basement of the early
Paleozoic in age and the upper boundary of the supergroup is mostly demarcated by Ferrar Dolerite intrusion
or Kirkpatrick Basalt, Jurassic in age. The late Paleozoic glacial deposits herald initiation of post-Ross
sedimentation; Permian Takrouna (TF), Triassic-Jurassic Section Peak, and Jurassic Shafer Peak formations
follow. An outcrop section showing transitional change from the basal glacial deposit into the TF occurs in the
Lanterman Range, northern part of NVL. Morozumi Range and Helliwell Hills, west of the Lanterman Range,
expose the TF which needs to be tested for the geological age based on new plant fossils. BS at the southern
part of the Freyberg Mountains in the north of the Evans Névé, is characterized by basal glacial tillite and
overlying TF. Low-relief hills in the west of the Mesa Range expose thin BS on the basement. The Section Peak
and Shafer Peak formations near Priestly Glacier occur on topographic highs, directly overlying the
unconformity with thin discontinuous diamictite of unknown origin. Difference in the lithology and probable
age of the basal part of the BS in NVL might be resulted from tectonically controlled geometry of the basin.

2103
Fri_143_GG-1_1630
Someting about “CROSS” Program

Junmeng Zhao1 (zhaojm@itpcas.ac.cn), Xiaohan Liu1, Hongbing Liu1, Shichang Kang1, Heng Zhang1, Shuze Chen1
1
Institute of Tibet Plateau Research, Chinese Academy of Sciences, Beijing, China

CROSS Program, a detection and research project, will complete the "CROSS" formed transects which cross the
South Pole through the Antarctic continent to take comprehensive detection research, which will be lasted by
10 to 15 years. Along the perpendicular two transects such scientific surveys as geology, geophysics,
geochemistry, ecology, environment and the atmosphere will be carried out, and the structure and geodynamic
processes of the crust, mantle and the core of Antarctic will be revealed systematically and comprehensively.
Such problems of the global level as splitting of the Gondwana land, the evolution of Tethys tectonic domain,
the hyperplasia of Eurasia continent, the drive mechanism of plates and the asymmetric structure between
northern and southern hemispheres will be discussed. This program will study the resources, environment,
ecological and atmospheric processes of the Antarctic and its impact on global climate change; this program
will also study the genetic relationship between the South Pole and the third pole (Tibetan Plateau), and
establish the northern boundary of Gondwana continent, and develop the theoretical system of earth science
in the Antarctic continent. At the beginning of the Program, we have installed 30 seismic stations in the eastern
part of the Antarctic and the first-term (two years) seismic data have been obtained. By data processing and
interpretation, some results have been obtained.

2104
Fri_144_GG-1_1689
Synsedimentary Deformation in the Permian Takrouna Fm (North Victoria Land)

Laura Crispini1 (laura.crispini@unige.it), Benjamin Bomfleur2, Thomas Mörs3, Andreas Läufer4, Frank Lisker5
1
University of Genova, DISTAV, Genova, Italy, 2Westfälische Wilhelms-Universität Münster, Forschungsstelle für
Paläobotanik, Münster, Germany, 3Swedish Museum of Natural History, Stockholm, Department of
Palaeobiology, Stockholm, Sweden, 4BGR - Federal Institute for Geosciences and Natural Resources, Federal
Institute for Geosciences and Natural Resources, Hannover, Germany, 5University of Bremen, Bremen, Germany

We report on synsedimentary deformation structures in upper Permian deposits of the Takrouna Formation
(Beacon Supergroup) exposed at an unnamed spur east of Mt Remington north of Boggs Valley, central Rennick
Glacier area, North Victoria Land. In the lower part of this section, the formation consists of fluvio-lacustrine
successions of pebbly sandstone, climbing-ripple-laminated sand- and siltstone, and carbonaceous silt- and
mudstone rich in plant debris (Glossopteris leaves and Vertebraria roots). Sand- and siltstone beds in particular
are characterized by prominent synsedimentary brittle-ductile deformation structures at the outcrop scale,
e.g., sedimentary dikes, thrust, growth microfaults, shear folds, normal faults, laminated convolute beds, and
intense slumping. This succession is overlain by about 10 m of barren sand- and siltstone deposits that lack
such evidence for synsedimentary deformation, and are instead folded and tilted by post-sedimentary
deformations. Our synsedimentary tectonic structures may testify to an active tectonism during the late
Permian in northern Victoria Land and give constraints for the changes in paleoclimatic and tectonic conditions
of Gondwana during late Paleozoic-Mesozoic transition.

2105
Fri_145_GG-1_1697
Fault-controlled Ancient Hydrothermal Systems in North Victoria Land, Antarctica

Laura Crispini1 (laura.crispini@unige.it), Giovanni Capponi1, Andreas Läufer2, Frank Lisker3

1
University of Genova, DISTAV, Genova, Italy, 2BGR - Federal Institute for Geosciences and Natural Resources,
Federal Institute for Geosciences and Natural Resources, Hannover, Germany, 3University of Bremen, Bremen,
Germany

Northern Victoria Land (NVL) at the Pacific end of the Transantarctic Mountains is a key region for
understanding the geodynamics of East Antarctica and provides a window to its crustal architecture. The
structural frame of NVL derives from polyphase tectonics and is mainly characterised by NW-SE striking
lineaments, which transect the NVL crust and the Cenozoic rift basins of the Ross Sea and which are responsible
for the reactivation of inherited Paleozoic - Mesozoic discontinuities.
We present preliminary data on regional scale metasomatic and hydrothermal alterations linked to different
exhumed fault systems in NVL. Main hydrothermal alterations are: (i) Mg-Ca- carbonation and silicification of
mafic and ultramafic rocks along faults and brittle-ductile shear zones at the boundary between the Wilson and
Bowers terranes; (ii) Mg-Ca-Fe carbonation of metavolcanic rocks accompanied by syntectonic carbonate
coatings on fault planes, hydraulic brecciation, and quartz-carbonate veining in the Bowers Terrane and at the
Bowers-Robertson Bay terranes boundary; (iii) epidote and chlorite indurated gouge and cataclasite in fault
cores in granitoid rocks and epidotization of metabasalt in the Lanterman Range and in the Bowers Terrane and
in Ferrar Dolerite.
We discuss the fluid-rock interaction during faulting and the relevance of these hydrothermal systems in
reconstructing the tectonic history of this sector of the Transantartic Mountains.

2106
Fri_146_GG-1_1701
Study of a Syntectonic Au-transporting Fluid in North Victoria Land (Antarctica)

Paolo Stefano Garofalo1 (paolo.garofalo@unibo.it), Alexander Gundlach Graham2, Detlef Günther2, Laura
Crispini3, Giovanni Capponi3
1
University of Bologna, Bi.Ge.A. Department Geological & Environmental Sciences Section, Bologna, Italy, 2ETH
Zürich, Department of Chemistry and Applied Biosciences, Zürich, Switzerland, 3University of Genova, DISTAV,
Genova, Italy

We constrain the physical-chemical properties of a hydrothermal fluid linked to the Dorn Glacier shear zone
(Crispini et al., 2011) that crosscuts the metabasalts and metasandstone of Sledger Group (Bowers Terrane,
North Victoria Land, Antarctica). Fluid constraints derive from the analysis of syntectonic quartz vein and
provided by a combination of LA-ICP-TOFMS of fluid inclusions, microthermometric determinations, spindle
stage measurements of fluid inclusions, and panchromatic cathodoluminescence imaging of quartz.
The geological framework for these veins is: close occurrence to regional tectonic lineaments; location within a
greenschist to low-greenschist metamorphic sequence; mineralogic assemblage made mostly by quartz and
carbonates, and low modal abundance of sulphides; carbonate-sericite-albite-sulphide hydrothermal alteration
well developed adjacent to the vein and postdating the regional metamorphism. Moreover there is a poorly
developed mineral and metal zoning within the veins and is gold mineralized. Our dataset provides
informations on the composition and origin of the vein fluid, which formed massive and euhedral quartz
crystals. Assuming P correction of 100-200 MPa, entrapment of massive vein fluid is estimated at 330-400 °C
and at 260-320 °C for druse fluid. The very high Sb concentrations in vein fluid could be explained by
fractionation of Sb into vapour phase of an orogenic fluid.
Crispini L. et al. 2011. Gondwana Res., 19, 128-140.

2107
Fri_148_GG-1_1791
New Permian-Jurassic Deposits in the Far North of Victoria Land, East Antarctica

Benjamin Bomfleur1 (bbomfleur@uni-muenster.de), Thomas Mörs2, Changhwan Oh3, Tae-Yoon Park3, Jusun
Woo3, Laura Crispini4, Andreas Läufer5
1
Westfälische Wilhelms-Universität Münster, Institut für Geologie und Paläontologie, Münster, Germany,
2
Swedish Museum of Natural History, Stockholm, Sweden, 3Korea Polar Research Institute (KOPRI), Incheon,
Korea, Republic of, 4Università di Genova, Genoa, Italy, 5Bundesanstalt für Geowissenschaften und Rohstoffe
(BGR), Hannover, Germany

The geology of the Transantarctic Basin in the far north of Victoria Land is still poorly known. Joint Korean-
Italian-German field work in the central Rennick Glacier area during the 2015-2016 season has yielded exciting
new results. Based on lithology and fossil content, we recognize four distinct terrestrial sedimentary units in
the area; in ascending order,
(1) the Permian Takrouna Formation (thickness ~300 m) with common glossopterid remains;
(2) a previously unknown unit (thickness 75+ m) mainly of reddish-weathering, commonly tabular-cross-bedded
pebbly sandstone with intercalated siltstone and palaeosols, barren of body fossils but rich in trace fossils;
(3) another previously unknown unit (thickness 250+ m) of olive-weathering fine-grained sandstone and thick
overbank mudstone with palaeosols and thin coal seams, containing abundant silicified wood (Kykloxylon,
Agathoxylon), silicified peat, and plant compressions (e.g., Heidiphyllum, Lepacyclotes) indicating a Triassic age;
and
(4) about 15 m of mainly conglomeratic trough-cross-bedded, medium- to coarse-grained quartzose sandstone
similar to the Section Peak Formation (Rhaetian to Early Jurassic) further south. Our results reveal a much more
complete Permian to Jurassic basin fill in that area than was previously thought; on-going palynological
analyses should help clarify the precise stratigraphic relationships to better-known sections elsewhere in the
Transantarctic Mountains and in Tasmania.

2108
Fri_149_GG-1_1830
Satellite Gravity Gradient Imaging of the Antarctic Lithosphere

Fausto Ferraccioli1 (ffe@bas.ac.uk), Joerg Ebbing2, Folker Pappa2, Michael Kern3, Rene Forsberg4
1
NERC/ British Antarctic Survey, Geology and Geophysics, Cambridge, United Kingdom, 2University of Kiel, Kiel,
Germany, 3European Space Agency/ESTEC, Noordwijk, Netherlands, 4Danish Technical University, Lyngby,
Denmark

Satellite gravity gradient data from GOCE provide a new tool to investigate the structure and geodynamic
evolution of the Antarctic lithosphere. Here we analyse satellite gravity gradient images and superimpose them
on a new estimate of crustal thickness derived from inversion of satellite gravity data, combined with
independent seismic estimates. The gradient data clearly image the thinner crust and lithosphere beneath the
Cretaceous to Cenozoic West Antarctic Rift System and the Jurassic Weddell Sea Rift System with respect to the
thicker Precambrian lithosphere of East Antarctica. Within East Antarctica, the satellite gravity data provide
significantly more detail than seen in current passive seismic imaging, including new views into the extent of
the Archean to Mesoproterozoic Terre Adelie Craton and the adjacent crust and lithosphere beneath the
Wilkes and Aurora subglacial basins.
Thick crust underlies the Transantarctic Mountains, the Terre Adelie Craton, the Gamburtsev Subglacial
Mountains and also Eastern Dronning Maud Land, in particular beneath the recently proposed Tonian Oceanic
Arc Superterrane sector.
One of the most prominent lithospheric-scale features recognised from satellite gravity gradient data is the
Trans East Antarctic Shear Zone, which separates the Gamburtsev Province from the Tonian Oceanic Arc
Superterrane. We propose that it represents a major previously unknown Pan-African age suture and/or shear
zone related to Gondwana assembly.

2109
Fri_151_GG-1_1933
Crustal Deformation Derived from GPS Measurement Data around Lützow-Holmbukta

Akihisa Hattori1 (hattori.akihisa@nipr.ac.jp), Yuichi Aoyama1,2, Jun'ichi Okuno1,2, Koichiro Doi1,2

1
SOKENDAI (The Graduate University for Advanced Studies), Department of Polar Science, Tachikawa, Tokyo,
Japan, 2National Institute for Polar Research, Tachikawa, Tokyo, Japan

With objective to monitor crustal deformation due to Glacial Isostatic Adjustment (GIA), Japanese Antarctic
Research Expedition (JARE) have conducted campaign GPS measurements at nine sites on the outcrop rocks
around the Lützow-Holmbukta and in the Riiser-Larsen Mountains areas, Dronning Maud Land (DML), East
Antarctica for a maximum of eighteen years.
In this study, we analyzed the data observed at seven sites, Tottsuki Misaki, Langhovde, Skarvsnes, Skallen,
Rundvågshetta, Padda and Syowa Station during 2004-2017, with precise point positioning (PPP) procedure.
Consequently, subsidence in the range of 2 to 4 mm/year are found at six sites.
We consider that the subsidence is caused by recent increase of surface ice mass loading on DML.

2110
Fri_152_GG-1_1993
U-Pb Zircon Age Constraints from Prydz Bay Evidence of Late Neoproterozoic Basin

Sandip Kumar Roy1 (sroy845@gmail.com), Joy Gopal Ghosh2, Mohd Sadiq2

1
Geological Survey of India, Polar Studies Division, Faridabad, India, 2Geological Survey of India, Faridabad,
India

Prydz Bay area rock broadly classified into basement Sostrene Orthogneiss and overlying metasediments
Brattstrand Paragneiss. These rocks bear evidence of two granulite facies, Late Mesoproterozoic-Early
Neoproterozoic and Late Neoproterozoic-Early Cambrian. These two granulite events have been likened to
collisional tectonics related to Rodinia and Gondwana. The rocks of Prydz bay holds the key towards Rodinia vs
Gondwana. New U-Pb Zircon ages (LAICPMS Multicollector) supports presence of a Late Neoproterozoic basin.
Samples were from Storness, Wilcock and from Mcleaod Island. Analysis shows large concordant cluster around
810Ma. Considering the array of ages it is opined that the maximum depositional age of this rock is around
550Ma or younger. The bedded sillimanite schist rock from Wilcock is also a part of Brattstrand Paragneiss. A
large concordant cluster of zircon from the samples is around 1.1Ga and some prominent smaller clusters are
around 550-2550Ma. It is opined that the maximum depositional age of this rock is around 550Ma. Zircons
from the meta-arkosic rock rock show a large concordant cluster around 550Ma. This rock is interpreted to be a
tuffite and signifies the age of deposition of the basin. The work indicates at least parts Brattstrand Paragneiss
in the Stornes Island and in the northern part of McLeod Island formed during 550 Ma. Thus, Pan-African
suturing in the Prydz Bay area is thus supported even though its orientation and extent remains conjectural.

2111
Fri_153_GG-1_2023
Magmatism and Paleomagnetism of the Quaternary Volcanism in Bransfield Strait

Jeronimo Lopez-Martinez1 (jeronimo.lopez@uam.es), Belen Oliva-Urcia1, Adolfo Maestro2, Andres Gil-Imaz3,

Marceliano Lago3, Carlos Galé3, Teresa Ubide4
1
University Autonoma of Madrid, Faculty of Sciences, Geology and Geochemistry, Madrid, Spain, 2Geological
Survey of CanadaSurvey of Spain, Madrid, Spain, 3University of Zaragoza, Earth Sciences, Zaragoza, Spain,
4
University of Queensland, School of Earth Sciences, Brisbane, Australia

The Quaternary volcanism in the Bransfield Basin, northern Antarctic Peninsula region is related to the
extension of the back-arc basin and the former Phoenix Plate subduction and roll-back under the South
Shetlands Block, combined with the eastward motion of the Scotia Plate along the South Scotia Ridge. The main
and more active volcanic edifices are located parallel to the NE-SW basin axe in blocks differentiated by NW-SE
strike-slip faults. This work shows new results of recent petrologic, mineralogic, geochemical and
paleomagnetic studies in the three most relevant Quaternary volcanic edifices in the region: Deception,
Penguin and Bridgeman islands. The evolution of the magma and the paleomagnetic and magnetic fabric
signals of these volcanoes are interpreted in the framework of the tectonic and geodynamic evolution of the
Bransfield Strait region. Different episodes in the evolution of the mentioned volcanoes are pointed out,
including the caldera formation in Deception Island. Signatures related to the magma source, depth of
crystallization and crustal influence have been identified, showing differences between the main units in the
case of Deception Island.

2112
Fri_154_GG-1_2121
Rittmann Volcano, Northern Victoria Land, a Source of Englacial Tephra

Philip Kyle1 (philipkyle1@gmail.com), Mi Jung Lee2, Jong Ik Lee2, Yeongcheol Han2

1
New Mexico Institute of Mining and Technology, Earth & Environmental Science, Socorro, United States, 2Korea
Polar Research Institute, Incheon, Korea, Republic of

Northern Victoria Land (NVL) is the home to the “active” volcanoes: The Pleiades, Mt Melbourne and Rittmann
volcano. All 3 volcanoes have evidence of recent activity which have deposited tephra in ice cores, blue
ice/snow areas and as surficial tephra layers. Although there is a significant area of geothermal activity at
Rittmann until now there has been no evidence of any recent eruptive activity. We propose that a tephra layer
erupted in 1254 CE and found in ice cores from East and West Antarctica was erupted from Rittmann. We
report a new occurrence of the tephra in an ice core from the Styx Glacier in NVL. Ignimbrite samples formed
by explosive pyroclastic eruptions from Rittmann have glassy fiamme and electron microprobe analyses of the
fiamme have trachytic and phonolitic compositions. Some of the fiamme are identical in composition to glass
tephra shards from the 1254 tephra and suggest Rittmann was the source of the eruption. The 1254 tephra is
found over 2000 km from Rittmann and is the most significant tephrochronological marker in Antarctic ice
cores. The eruption of the 1254 tephra is the largest known of any Quaternary volcano in Antarctica and
probably resulted in the formation of the current 2 km wide caldera which defines Rittmann volcano. This new
discovery and the occurrence of numerous Holocene eruptions from Melbourne volcano show that there is a
significant volcanic hazard from these volcanoes especially to aircraft operations.

2113
Fri_155_GG-1_2149
The Canyon and Isostatic State in PEL

Lin Li1 (lilin@pric.org.cn), Jingxue Guo1, Bo Sun1, Xiangbin Cui1, Jamin Greenbaum2
1
Polar Research Institute of China, Shanghai, China, 2University of Texas, Austin, United States

Princess Elizabeth Land in East Antarctic has only several ice radar profiles currently. The aerogeophysical
exploration project team of CHINARE 32 carries out the aerogeophysical survey by Chinese snow eagle 601
fixed-wing aircraft in PEL. To maximize the accurate ice/rock interface conditions, the result of two-dimensional
gravity interface inversion under radar constraints reveals the formation of the canyon in the study area. It
proved a big canyon under the ice sheet of PEL, quantitative characterization of the canyon features and
analysis the detailed structure. The isostatic gravity anomaly is closely related to the vertical gravity balance
compensation movement of the crustal, and the stability of the regional crust can be understood through the
isostatic state. PEL is widely distributed in subglacial mountains, which is up to 3000km above sea level. With
the area's huge overlying ice sheet, the isostatic state of the crust has a great impact. We calculated the
isostatic gravity anomaly of PEL by the Erie isostatic model and analyzed the crustal isostatic state of this area,
the result shows that the region is negative isostatic anomalies, the southern inland negative anomalies are
very large, which is most likely due to the ablation of ice sheet produced a strong imbalance force, to promote
the crust rising and thicken to supplement the ice loss.

2114
Fri_156_GG-1_2153
The Snow Eagle 601 Scientific Briefing and Preliminary Subglacial Lake Result

Jingxue Guo1 (guojingxue@pric.org.cn), Lin Li1, Bo Sun1, Jamin Greenbaum2, Xiangbin Cui1
1
Polar Research Institute of China, Shanghai, China, 2University of Texas -- Institute for Geophysics, Austin,
United States

The aero-geophysical survey over Princess Elizabeth Land (PEL) was carried out during the Chinese 32th and
33th National Antarctic Research Expedition based on Chinese first fixed-wing aircraft “Snow Eagle 601”, one
purpose of the studies is to reveal the ice sheet processes and glacial history. The platform of “Snow Eagle
601”was equipped with advanced deep ice penetrating radar system (HiCARs radar), it has the advantages of
strong ice-penetrating ability, high resolution and rich data information, based on electromagnetic theory and
radio-echo sounding technique, will allow studies of internal structure of ice sheet, subglacial environments, as
well as ice-sheet dynamics and evolution; The intent of GT -2A airborne gravimeter is also to study the
characteristics of the ice sheet, and the geological structure of the earth under the ice sheet. Preliminary
findings was on the basis of the data of 29 aerogeophysical lines proved the geophysical characteristics of the
ice sheet and bedrock under the PEL. Through the three-dimensional gravity interface inversion method under
radar constraints, we invert the subglacial lake and obtain its structural characteristics. The results show that
this lake is only part of the narrow subglacial lake, and it is likely to become the second large subglacial lake in
Antarctica, which is just after the largest one - Lake Vostok.

2115
Fri_157_GG-1_2210
Constraints on the Evolution of the Marie Byrd Land Dome Topography

Duncan A Young1 (duncan@ig.utexas.edu), Enrica Quartini1,2, Tom G. Richter1, Donald D Blankenship1

1
University of Texas at Austin, University of Texas Institute for Geophysics, Austin, United States, 2University of
Texas at Austin, Department of Geological Sciences, Austin, United States

The elevated subglacial topography underlying the Marie Byrd Land dome likely has played a crucial role in the
inception and evolution of the West Antarctic ice sheet through time. The Marie Byrd Land ice dome hosts a
number of subaerial Miocene to recent propagating volcanic chains, but the crust underlying these volcanoes
was poorly understood. The volcanic centers, a nearby abundance of high amplitude magnetic centers, and
occasional exposures of a ~23 Ma elevated erosion surface have been used to argue for a distinct Cenozoic
hotspot underlying this region and lifting topography over time. Other interpretations include that this region
represents the collapsed remnant of an ancestral West Antarctic orogeny, or represents a broad region uplifted
by subduction driven mantle flow.
In this presentation we review
1) constraints on the the evolution of the Marie Byrd Land Dome from subglacial geomorphology;
2) present the results of airborne gravity for the compensation and rigidity of the MBL crust; and
3) integrate these results with observations of basal melt and additional potential fields data.

2116
Fri_158_GG-1_2219
Eoarchean Crust and 2.7/2.5Ga Orogens in Labrador and East Antarctica - A Link?

Daniel J. Dunkley1,2,3 (kwaidanother@gmail.com), Monika A. Kuisak2, Simon A. Wilde3, Martin J. Whitehouse4,

Anna Sałacinska2, Ross Kielman5, Patrik Konečný6, Aleksandra Gawęda1
1
University of Silesia, Faculty of Earth Sciences, Sosnowiec, Poland, 2Institute of Geological Sciences, Polish
Academy of Sciences, Warsaw, Poland, 3Curtin University, Department of Applied Geology, Perth, Australia,
4
Swedish Museum of Natural History, Stockholm, Sweden, 5Swedish Museum of Natural History, Stockholm,
Stockholm, Sweden, 6Dionýz Štúr State Institute of Geology, Bratislava, Slovakia

The record of continent formation in the first half of the Earth's history is obscured by the advent of plate
tectonic processes that repeatedly ruptured and reassembled Archean crust into new continents. By the end of
the Archean Eon, 2.5 billion years ago (Ga), such processes were already in operation, and continents
worldwide contain late Archean orogens produced by the collision of older crustal remnants. The Nain Province
of coastal Labrador, on the western margin of the North Atlantic Craton (NAC), was assembled from early
Archean and mid-Archean components around 2.7Ga, as indicated by widespread high-T metamorphism and
ductile deformation (Kusiak et al., 2018, Chem. Geol.). New evidence from dating of zircon and monazite in
high-T metamorphic assemblages and in ductile-deformed granitoids indicate widespread orogenic re-working
of the margin of the NAC at ca. 2.5Ga. Similar orogenic ages, recently identified in the conjugate part of the
NAC on the western Greenland coast, also indicate dual timing in the late Archean assembly of the craton. Dual
metamorphism associated with orogenesis in the late Archean is also known from the Napier Complex of East
Antarctica, which also contains early Archean crust (Kelly & Harley, 2005, Contrib. Min. Pet.). These similarities
increase the likelihood that both polar terranes were components of a lost supercontinent, which also may
have included the North China Craton and the Yilgarn Craton of Western Australia.

2117
Fri_159_GG-1_2299
One Period Magma Intrusion or More of Landing Bluff Adamellite

Yingchun cui1,2 (cuiyingchun@fio.org.cn), Xiaochun liu3, Chenguang liu1,2, Jianhui Liu4

1
First Institute of Oceanography,SOA, Qingdao, China, 2Qingdao National Laboratory for Marine Science and
Technology, Qingdao, China, 3Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing,
China, 4Beijing SHRIMP Centre, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China

Landing Bluff Adamellite was common considered as one magma intrusion happened at ca. 500Ma based on
the results of granites from Landing Bluff (Tingey, 1981; Sheraton & Black,1988). Sansom Island located in
Sandefjord Bay, one of marginal gulf of Prydz Bay, east Antarctica and are composed of two kinds of
undeformed biotite granites, which is part of Landing Bluff Adamellite. these granites were firstly conducted
the Ion-microprobe U-Pb zircon dating. The zircons of two samples yield two SHRIMP zircon U-Pb concordant
ages of 516±5 Ma and 496.5±4.7 Ma, respectively. The results indicate that these granites emplaced at two
pulses in Cambrian, and further demonstrated the Pan-African event overprinted this area. These ages reveals
that Landing Bluff Granite has the complex magmatism.
The research was funded by the National Natural Science Foundation of China (No. 41530209) and the Chinese
Polar Environment Comprehensive investigation & Assessment Programmes (CHINARE2015-02-5;
CHINARE2017-04-3).
References:
Tingey R J. 1981. Geological investigations in Antarctica 1968-1969: the Prydz Bay-Amery Ice Shelf-Prince
Charles Mountains area, record 1981/34. Bureau of Mineral Resources, Australia, Canberra, 1-72
Sheraton J W, Black L P. 1988. Chemical evolution of granitic rocks in the East Antarctic Shield, with particular
reference to postorogenic granites. Lithos, 21:37-52

2118
Fri_160_GG-1_2387
Precambrian Evolution of the Ruker Granite-greenstone Terrane of East Antarctica

Vsevolod Maslov1 (massev@gmail.com)

1
VNIIOkeangeologia, Geology and Mineral Resources of the Antarctica, Saint Petersburg, Russian Federation

The area under study belongs to the Ruker granite-greenstone Terrane of the Archaean stabilization. The
studied mountain massifs of Rymill and Bloomfield are located in the southern part of the Prince Charles
Mountains, in the northern part of the archean Ruker Terrane in the area of its connection with the Reiner
province. In the course of isotope-geochronological studies, new data were obtained on the age of protoliths of
the ortho- and para-rocks. The zircons of samples of orthogneisses of the Mawson series and of the primary
sedimentary rocks of the Menzies series were studied. The southern part of the Mt Rymill is composed of
Mesoarchean orthogneisses of the Mawson series whose age of crystallization of magmatic protolith is 3164.2
± 9.2 Ma and 3163.2 ± 7.8 Ma. The maximum time of deposition of the sedimentary protolith of the Menzies
series is estimated at 3.1-3.0 Ga. The rocks of the series form a folded, granite-gneissic, domed structure. A
significant degree of recrystallization most ancient rocks of the Mawson series is associated with high-grade
metamorphism, whose time is compared with the formation of Meso-Neoarchean granite gneisses with an age
of about 2800 Ma. The distribution of the values of the age of detrital zircon in metasedimentary rocks makes it
possible to consider the Mawson series as the foundation for the primary sedimentary rocks of the Menzies
series, the formation of which is associated with the rifting of the Paleoarchean continental crust.

2119
Fri_161_GG-1_2421
Brief Introduction of Natural Earthquake Observation in the East Antarctica

Liu Hongbing1 (hbliu@itpcas.ac.cn), Zhao Junmeng1, Deng Gong1, Li Yawei1

1
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

During the 30th Chinese Antarctic scientific expedition, the Grove Mountains earthquake investigation project
completed 10 seismic stations set-up, 5 stations in the Grove Mountains and 5 stations around the Zhongshan
Station. The installation of the station has been carefully researched, and the station is powered by 200w solar
panels and 6 100ah Gel batteries. The seismometer and recorder were installed in a special Heat insulation box
and heated by 4 pieces 3w silica gel heating plate, heated for 30 minutes every 4 hours. After two years of field
observation, a total of 48GB of seismic data has been obtained, which achieves the desired observation effect.
Especially in the Grove Mountains during the polar night and under low temperature conditions, we obtained
19GB data for the first time. The temperature in the Grove Mountains is as low as 60 degree Celsius below
Zero, and under such conditions our seismic instruments record data continuously for up to 572 days, which
provided valuable experience for future improvement earthquake observation.
The distribution of seismic stations are located in Pu Liz orogenic belt and extending southward in the Grove
Mountains. We can get preliminary crustal structure characteristics for the tectonic evolution of this region, by
analyzing the recorded seismic data from stations using anisotropy and receiver function method.
Keywords: East Antarctica; Earthquake observation; Seismic data; Crustal structure

2120
Fri_162_GG-1_2478
The Franklin Ocean - Evidence for Oceanic Crust in Northern Ellesmere Island?

Nikola Koglin1 (nikola.koglin@bgr.de), Karsten Piepjohn1

1
Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany

The origin and emplacement of the Precambrian/early Palaeozoic Pearya terrane, northern Ellesmere Island,
Canada, is still a matter of debate. A suture zone between Pearya and the passive margin of the Franklinian
basin is assumed within the Petersen Bay Fault Zone [1]. Within this fault zone, amphibolitic rocks of the
Kulutingwak Formation crop out, for which some authors [2, 3] assume an island-arc affinity. During the
CASE19 expedition in 2017, amphibolite and metasedimentary rocks of the Kulutingwak Formation were
collected within the Petersen Bay Fault Zone west of Kulutingwak Fiord. Preliminary data of selected samples
show that the volcanic rocks can be classified as subalkaline andesitic basalt to andesite with tholeiitic to calc-
alkaline geochemical signature. Both, amphibolite and metasedimentary rocks indicate an island-arc setting.
These first geochemical results in combination with a 450-Ma zircon U-Pb age for the amphibolitic rocks [2]
might be an indicator for the existence of an oceanic island arc during Ordovician times and, therefore, an
oceanic basin between Pearya and the passive margin of Laurentia, which might be represented by the
Kulutingwak Formation. However, further investigation is necessary to constrain these preliminary results and
to consider a new assignment of the Kulutingwak Formation.
[1] Piepjohn & von Gosen (2017) GSSP 460, SP460-5.
[2] Trettin (1998) Geol Surv Canada Bull 425:401.
[3] Beranek et al. (2015) J Geol Soc London 172:201-212.

2121
Fri_163_GG-1_2537
Neotectonic Deformation in the Southwestern Ross Sea

Terry Wilson1 (wilson.43@osu.edu), Will Blocher1, Jie Chen1, Tricia Hall1, Jerome Hall1, William Magee1
1
Ohio State University, SES/BPCRC, Columbus, United States

Seismic mapping combined with revised age constraints document the structural evolution of the Terror Rift
and superposed Erebus flexural basin in the southwestern Ross Sea. Terror Rift fault-related subsidence was
underway in the early Miocene (by at least 18 Ma) and syntectonic stratal growth signatures show that most
extension occurred between ~15-5 Ma, but faulting continued through the Pliocene. Ubiquitous normal-sense
fault displacement, the strong case for rollover origin of regional folds within the rift, and the absence of flower
structures, all support an orthogonal rift model with regional extension in the ENE-WSW direction. Total
extensional strain is on the order of < 10%. The eastern margin of Terror Rift is defined by a zone of west-
dipping faults projecting to depth with a listric ramp-flat geometry. This border fault zone projects beneath
Ross Island and the Erebus Basin formed by flexural loading by Plio-Pleistocene volcanoes. Seismic mapping
within western Erebus Basin shows evidence of two discrete sub-basins formed by Mt. Bird loading since 3.8-
4.6 Ma and Mt. Erebus loading since ~1.31 Ma. A 3D thin elastic plate model, using the dip angle of seismically
mapped reflector surfaces as constraints, simulates flexural basin evolution with a best fit lithospheric effective
elastic thickness of 4-5 km.

2122
Fri_164_GG-1_2548
Terminal Deformation and Granitoid Ages of the Kuunga Orogeny, WDML. Antarctica

Geoffrey H. Grantham1 (ghgrantham@uj.ac.za), Erasmus Petrus Burger2, Kenji Horie3, R. James Roberts2
1
University of Johannesburg, Geology, Johannesburg, South Africa, 2University of Pretoria, Geology, Pretoria,
South Africa, 3National Institute of Polar Research, Geoscience, Tachikawa, Japan

Two widely distributed granitic vein types are seen in Sverdrupfjella, W. Dronning Maud Land (WDML),
Antarctica. The younger generation (P2) comprise 2-mica granites and pink 2 feldspar pegmatites. The older
(P1) generation comprises white biotite plagioclase rich pegmatites.
The P2 veins dip mostly shallowly (~45-50o ) to N and NW and displace the older veins along planes with
extensional and compressional top to the south geometries. In contrast, the older P1´s dip mostly ~60 o toward
the S and SW with no displacements. Similarly oriented local shears show normal displacements to the S and
SW. The structures are consistent with late extension toward the S and SW followed by top to the S and SE
compression.
SHRIMP zircon ages on the P1´s yield ages of ~520Ma whereas data from the P2´s yield ages of ~490Ma.
Radiogenic Sr and Nd data from the two types indicate relatively juvenile sources for the P1´s, in contrast to the
P1 granites which were sourced in older crust, similar to Mesoproterozoic TTG gneisses in W Sverdrupfjella.
Radiogenic Sr/Nd data from basement gneisses hosting the veins in E and W Sverdrupfjella show differences
with W Sverdrupfjella characterised by older evolved crust in contrast to the juvenile basement rocks in E.
Sverdrupfjella. The two areas are separated by major thrust faulting coincidant with strong magnetic
anomalies.
The data are inferred to reflect the emplacement of a Kuunga Orogeny mega nappe complex with top to the S
geometry.

2123
Fri_165_ME-2_30
Arctic Explorers in Their Own Words: Interviews, Mental Health and Cognition

Anna G. M. Temp1,2 (atemp@ed.ac.uk), Billy Lee1, Thomas H. Bak1

1
The University of Edinburgh, Psychology, Edinburgh, United Kingdom, 2Polish Academy of Sciences, Institute of
Geophysics, Warsaw, Poland

Palinkas (1990) notes that research into humans in isolated and confined conditions has more frequently taken
place in Antarctica, which Suedfeld (1991) explains by the fact that Arctic teams are somewhat more accessible
and thus easier to evacuate. This is true but neglects an essential characteristic of Arctic team safety: polar
bears. Bears pose a significant threat to human survival in Arctic regions; this means that Arctic teams have to
handle large-calibre fire arms on a regular basis (Norwegian Polar Institute, 2005). Levesque (1991, p. 16)
describes that an Antarctic team spent some of their wintering time plotting an unpopular crew member's
death. In the Arctic, such behaviour would be even more worrying than in this Antarctic team because the
means to murder are ever-present. My research investigates the eleven members of the 38th expedition to the
isolated Polish Polar Station, Hornsund, Svalbard (77° N). This study illuminates their lives via mental health
questionnaires, cognitive testing as well as interviews. Each participant was interviewed before, during and
after polar night. The interviews are a unique approach to understanding how isolated teams feel and why they
feel this way. My results show what makes individuals feel poorly or well, and also what makes a good polar
explorer in the eyes of other polar explorers. Conclusions about preparation and selection techniques are
possible.

2124
Fri_166_ME-2_31
Psychiatric Survival in Arctic Isolation: A Case Study using EFT

Anna G. M. Temp1,2 (atemp@ed.ac.uk), Billy Lee1, Thomas H. Bak1

1
The University of Edinburgh, Psychology, Edinburgh, United Kingdom, 2Polish Academy of Sciences, Institute of
Geophysics, Warsaw, Poland

Historical reports of different psychiatric afflictions during polar night have always been common, for example
Sidney Buddington from the Arctic Polaris expedition (1871) or Sidney Jeffryes from Mawson's Australasian
Antarctic Expedition (1911-1914). Through the past six decades, research has indicated that there are
individuals who have required medical evacuations on psychiatric grounds from Antarctica (e.g. Pattarini et al.,
2016). During my research with the 38th expedition to the Polish Polar Station, Hornsund, Svalbard (77° N), a
participant - Albert - developed severe psychiatric complications in the polar night which eventually resulted in
his evacuation. Albert has allowed me to present his case study. The quantitative results will show how his
mental health differs from the rest of his team at the station but also from an age-/gender-matched control
group in a normal environment (Symptom Checklist-90-Revised and the Profile of Mood States). Albert's
interviews from before and during the polar night illuminate his personal experience. Most important however,
is the successful application of Emotional Freedom Techniques (EFT) in order to alleviate Albert's depression,
anxiety and suicidal ideation. EFT helped Albert feel better and should be considered as a preventative
technique that can be taught to isolated teams pre-deployment to avoid psychiatric afflictions and possibly,
evacuation.

2125
Fri_167_ME-2_112
Disease and Injury Statistics of Japanese Antarctic Research Expedition

Atsushi Ikeda1 (scrapsike716@ybb.ne.jp), Giichiro Ohno2, Kentaro Watanabe3, Satoshi Imura3

1
University of Tsukuba, Department of Urology, Faculty of Medicine, Tsukuba, Japan, 2Tokatsu Hospital,
Department of Surgery, Nagareyama, Japan, 3National Institute of Polar Research, Tachikawa, Japan

In observation activities in the Antarctic region, evaluation of the injury and disease trends in party members
during wintering is indispensable to advance the medical system and research.
A total of 4,233 injury or disease cases in the 1st -39th Japanese Antarctic Research Expeditions were analyzed
and reported in Nankyoku Shiryo (Antarctic Record) (2000).
We obtained disease and injury statistics based on the wintering reports by the 40th-56th wintering party
members who performed activities from February 1999 to January 2016.
Among a total of 578 members (27 females), 2,604 disease or injury cases (4.5 per member) were observed.
The 2,604 cases included cases in the Surgical and Orthopedic (45.1%), Internal Medicine (19.9%),
Dermatological (10.2%), Dental (9.8%), Otological (7.8%), and Ophthalmological (5.6%). The period from
February, when wintering was initiated, to January of the following year was divided into quarters, and changes
in the incidence of diseases and injuries were analyzed. Although results differed among parties, the incidence
was low irrespective of the department in the 3rd quarter (August-October) in each party.
Neither severe cases requiring transportation nor deaths were observed. There was no surgery performed
under general anesthesia. In the 44th party, peritoneal lavage and appendectomy were performed under
lumbar spine anesthesia due to localized peritonitis associated with diverticulitis in 1 case.

2126
Fri_168_ME-2_225
The Adaptation of Chinese Expeditioners under the Antarctic Dome A

Chengli Xu1 (xuchengli0425@sina.com), Yanlei Xiong1, Chengyu Jiang1

1
Institute of Basic Medical Sciences Chinese Academy of Medical Sciences，School of Basic Medicine Peking
Union Medical College, Beijing, China

Dome A (80°22′S, 77°22′E) has the highest ice peak in Antarctica, with an elevation of 4093m. The average
temperature of -54℃ with a barometric pressure of 560-590 hpa (January-April). It is among the most
challenging environments on Earth, due to poor oxygen availability, harsh weather conditions, dangers related
to glaciers and difficult accessibility for transportation. Chinese Kunlun Station was established at Dome A in
2009. We focuses on the adaptation patterns of expeditioners under the hypoxic and cold environment. We
firstly identified the association between psychophysical phenotypes and genome-wide gene expression
changes in human adaptation at Dome A. A group of genes were found to be strongly related to significant
phenotypes. We found 28 genes were potentially involved in the psychological disturbance. A reliable method
was developed to search novel genes and mechanisms related to phenotypes. At Kunlun Station, more than
half of expeditioners experienced AMS symptoms, among which sleep disturbances were prevalent. Our
polysomnography (PSG) study at Dome A suggested that sleep architecture changed and slow wave sleep
reduced. Apneas were prevalent, with almost exclusively of periodic breathing. The nocturnal oxygen
saturation decreased. The strict physical screening examination and pre-acclimatization training before
departure heading Antarctica is necessary.

2127
Fri_169_ME-2_467
The Psychological Safety of Workers in Oil and Diamond Productions in the Arctic

Yana Korneeva1 (amazonkca@mail.ru), Natalia Simonova1, Tamara Tyulyubaeva1

1
Northern (Arctic) Federal University, Psychology Department, Arkhangelsk, Russian Federation

The Arctic is very rich in oil, gas and other minerals. An important role in the development of the Arctic is
played by attracting and retaining a relatively small number of able-bodied people in these remote regions. For
the possibility of prospecting and mining in these hard-to-reach regions with extreme climatic conditions, the
shift method of labor organization is used. Despite the development of the problem in this direction, there
remain a number of poorly understood questions. What are the psychological features of the employee making
mistakes in the workplace, the employees, what position in the oil producing and diamond mining industries
has the greatest risk of accidents, what are the components of the psychological safety of these workers in the
Far East North and the Arctic. The goal is to identify differences in the psychological safety of workers in oil
producing and diamond mining industries under shift work organization in the Far North and the Arctic.
As the research result, the models of psychological safety of oil producers and diamond mining companies
under the shift work organization in the Far North and the Arctic (including psychological properties, functional
states, behavioral characteristics and attitudes to dangerous and extreme factors and conditions of the
professional environment) are refined. The role of production factors in the formation of psychological safety
and safe behavior of the personnel of extractive companies was determined.

2128
Fri_170_ME-2_521
Physiological Stress in Brazilian Antarctic Program (PROANTAR) Participants

Michele Moraes1 (michelemacedo.moraes@gmail.com), Ygor Martins2, Tiago Mendes3, Cristian Espinosa4,

Chams Maluf5, Rosa Arantes1
1
Universidade Federal de Minas Gerais, Laboratório de Neuro-Imuno Patologia Experimental, Instituto de
Ciências Biológicas, Belo Horizonte, Brazil, 2Universidade Federal de Minas Gerais, Laboratório de Fisiologia do
Exercício, Escola de Educação Física, Fisioterapia e Terapia Ocupacional, Belo Horizonte, Brazil, 3Universidade
Federal do Maranhão, Escola de Educação Física, Pinheiro, Brazil, 4Universidad de Magallanes, Laboratorio de
Fisiología, Escuela de Medicina, Universidad de Magallanes, Punta Arenas, Chile, 5Universidade Federal de
Minas Gerais, Departamento de Propedêutica Complementar da Faculdade de Medicina, Belo Horizonte, Brazil

From a physiological perspective Antarctica has a very challenging environment since the cold; the wind and
the sensory monotony are considered stressful stimuli for the human body. However, acclimatization can
attenuate stress responses consequent to sympathetic activation caused by this extreme environment. In
addition, the voyage to Antarctica is commonly carried out by ship, which lasts for a long period and represents
a confinement stress. The aim of this study is to investigate biological variables (autonomic activity, endocrine
and metabolic markers) and humor parameters of progressive adaptation during an Antarctic expedition,
including a period of ship confinement and a period in a camp. Ten volunteers from Brazilian Antarctic Program
were evaluated during 3 weeks in a ship and 3 weeks in an extreme camp, during Brazilian Antarctic Operation
in 2017 summer. Initially, the volunteers performed a maximal progressive exercise and basal data were
collected at 3 moments in the ship. After 1 month of ship confinement, the group camped in Antarctic. There
were evaluated autonomic balance, by measuring the heart rate variability, mood, by Brunel Mood Scale
(BRUMS), and hormonal parameters - samples of blood, saliva and urine were collected to measure TSH and
T4, catabolic state (cortisol/testosterone) and catecholamine's concentration. We will also test the hypothesis
that biological parameters of adaptation and humor relates with VO2MAX along Antarctic field stay.

2129
Fri_171_ME-2_527
Pre-Antarctic Training Mood State in Brazilian Researchers and Military

Michele Macedo Moraes1, Ygor Antonio Tinoco Martins2, Rosa Maria Esteves Arantes1 (rosa@icb.ufmg.br)
1
Universidade Federal de Minas Gerais, Pathology Departament, Neuro-Immunopathology Laboratorory, Belo
Horizonte, Brazil, 2Universidade Federal de Minas Gerais, Exercise Physiology Laboratory, School of Physical
Education, Physiotherapy and Occupational Therapy, Belo Horizonte, Brazil

Every year Brazilian researchers and military personnel are sent to the inhospitable Antarctic environment.
Expeditions to Antarctica include hiking and staying in camps or research stations, with durations ranging from
one season to a year (for a group of wintering military). Considering that participants perform functions in
which they need to maintain attention and focus, changes in their mood and cognitive ability may result in
errors that compromise their functions and even security in an extreme environment such as Antarctica. In
order to prepare the participants of the Antarctic Operations for the conditions faced in the expeditions, the
Brazilian Antarctic Program (PROANTAR) promotes Pre-Antarctic Training (TPA) in which researchers and the
military participate in activities that simulate the stress experienced in the expeditions, such as the pressure of
time for the accomplishment of tasks, the coexistence in restricted groups and strenuous daily physical
activities. Thus, it is possible that the mood responses of the participants to a week of TPA predict the expected
mood changes in the Antarctic field. We used one validate questionnaire - the Brunel Humor Scale (BRUMS) to
compare the mood of researchers and military of PROANTAR at the beginning and at the end of a Week of TPA.
We believe that by understanding these responses we can seek strategies to minimize the risks of the Antarctic
environment on the physical and mental health of the PROANTAR participants.

2130
Fri_172_ME-2_998
Medical and Physiological Studies at the Ukrainian Antarctic Station

Yevgen Moiseyenko1, Stefan-Arpad Madjar1, Olena Kovalevska1, Anna Berezkina1 (anna.berezkina@i.ua)

1
National Antarctic Scientific Center of Ukraine, Kyiv, Ukraine

Since the very beginning of the scientific presence of Ukraine in the Antarctic biomedical research direction has
been developed for the monitoring of individual biomarkers of Antarctic winterers and medical
accompaniment Antarctic expeditions. Constant medical supervision (including the possibility of telemedicine)
the state of health of Antarctic experts and new technology for monitoring the individual parameters of the
functional state of the organism, despite the extreme conditions, allowed to maintain the health and
performance of all the participants of 20 Ukrainian Antarctic expedition (over 200). The main success of the
Antarctic medicine is to preserve the health of all members of 20 expeditions, the creation of an effective
system of medical and psychological selection of candidates, the development of health monitoring methods
for winterers at the Antarctic station, using telemedicine, the introduction of innovative technologies for
prevention, treatment and rehabilitation. The main achievements of scientific developments in the field of
medicine and physiology are to receive new information about human adaptation features to the extreme
conditions of Antarctica, clarifying mechanisms of disadaptative, desynchronosis, "Antarctic syndrome"
symptoms determine the causes of stress, problems of interpersonal relations in a small team, as well as a
significant expansion of knowledge in the field of environmental physiology, extreme and preventive medicine.

2131
Fri_173_ME-2_1117
The Relationship between the Third-quarter Phenomenon and Medical Statistics

Tetsuya Kawabe1 (kawabe@hs.osakafu-u.ac.jp), Atsushi Ikeda2, Nobuo Naruiwa3, Tomo Shigeta4, Reiji Sasaki5,
Nanako Kato6, Asako Sasaki7, Tomoko Kuwabara8, Giichiro Ohno9,10, Kentaro Watanabe10, Satoshi Imura10
1
Osaka Prefecture University, Graduate School of Humanities and Sustainable System Sciences, Osaka, Japan,
2
University of Tsukuba, Department of Urology, Faculty of Medicine, Tsukuba, Japan, 3Kyoto Koka Women's
University, Faculty of Health Science, Kyoto, Japan, 4Osaka Syoin Women's University, Osaka, Japan, 5Kyushu
University, Graduate School of Human-Environment Studies, Fukuoka, Japan, 6Nara Women's University,
Graduate School of Humanities and Sciences, Nara, Japan, 7Ritsumeikan University, Kyoto, Japan, 8Kyoto
University, Graduate School of Education, Kyoto, Japan, 9Tokatsu Hospital, Department of Surgery, Chiba,
Japan, 10National Institute of Polar Research, Tokyo, Japan

Psychological states and health conditions are known to change as a result of long periods of stay in Antarctica.
The “third-quarter phenomenon” hypothesis suggests that these changes in condition occur in the latter half of
long stays. The aim of this research is to analyze the relationship between the third-quarter phenomenon and
statistics of disease and injury during ten wintering periods of ten years in Japanese Antarctic Research
Expeditions (JARE). An analysis of mood scales (the Positive and Negative Affect Schedule [PANAS] and the
Profile of Mood States [POMS]) indicated that seven of ten wintering parties experienced the third-quarter
phenomenon (we name these parties the third-quarter (TQ) parties), and the other three parties did not (two
parties of three had flat mood scores, and one party had unclear results). We name the three parties the non-
third-quarter (NTQ) parties. Subjective complaints of disease and injury were measured by the Subjective
Health Complains Inventory [SHC]. The following findings became clear as a result of the investigation. First, the
number of consultations with a doctor decreased in the third-quarter for all NTQ parties. Second, the number
of consultations regarding surgery and orthopedics decreased by half in the fourth-quarter for only one of the
NTQ parties. Third, the members of both the TQ and NTQ parties had almost the same complaints, but the
members of the NTQ parties did not consult a doctor very much in the third-quarter.

2132
Fri_174_ME-2_1188
Stress Assessment of Performance by Japanese Antarctic Research Expeditions

Nanako Kato1 (n-kato@cc.nara-wu.ac.jp), Sachiko Nishiyama2, Tetsuya Kawabe3, Nobuo Naruiwa4, Asako
Sasaki5, Reiji Sasaki6, Tomo Shigeta7, Tomoko Kuwabara8, Kentaro Watanabe9, Satoshi Imura10, Giichiro Ono11
1
Nara Women's University, Nara, Japan, 2St.Marianna University School of Medicine, Kawasaki, Japan, 3Osaka
Prefecture University, Osaka, Japan, 4Kyoto Koka Women's University, Kyoto, Japan, 5Ritsumeikan University,
Kyoto, Japan, 6Kyushu University, Fukuoka, Japan, 7Osaka Syoin Women's University, Osaka, Japan, 8Kyoto
University, Kyoto, Japan, 9National Institute of Polar Research, Tokyo, Japan, 10National Institute for Polar
Research, Tokyo, Japan, 11Tokatsu Hospital, Chiba, Japan

Japanese wintering members were kept enclosed and isolated in Antarctica. In our post-mission interview,
although they underwent considerable stress, they maintained themselves. In Antarctica, it was not easy for
them to narrate their psychological problems. We could not determine their maladjustment using standard
methods like asking their self-assessment. The main purpose of this research was to investigate their stress by
their performance. We used the Uchida-Kraepelin psychodiagnostic (U-K) test as a performance measure. Data
have been collected for 30 members of one wintering party at 6 periods during mission. Furthermore, using the
Profile of Mood States (POMS), we investigated the relationship between performance by physiological
responses and subjective assessment.
The following became clear as a result of the investigation.
1) In U-K test, the score of PF (which shifted from standard value) changed continuously . Especially, many
members' score on PF was worse at polar daybreak.
2) In POMS, the score on Tension-Anxiety (T-A) was higher at midnight sun. The result did not correlate much
with U-K.
3) Some members rejected this survey.
Most of their scores on PF before rejecting were the worst. Their rejection was also interpreted as performance
suggestive of their coping.
These results indicated that their performance was the clue that helped to assess members under stress.
Therefore, we need various stress assessment methods for providing mental support in Antarctica.

2133
Fri_175_ME-2_1411
Mental Health Management by Leaders of Wintering Parties in Antarctica

Nobuo Naruiwa1 (naruiwa@mail.koka.ac.jp), Tetsuya Kawabe2, Nanako Kato3, Asako Sasaki4, Reiji Sasaki5, Tomo
Shigeta6, Tomoko Kuwabara7, Satoshi Imura8, Giichiro Ohno8,9, Kentaro Watanabe8
1
Kyoto Koka Women's University, Kyoto, Japan, 2Osaka Prefecture University, Osaka, Japan, 3Nara Women's
University, Nara, Japan, 4Ritsumeikan University, Kyoto, Japan, 5Kyushu University, Hukuoka, Japan, 6Osaka
Syoin Women's University, Osaka, Japan, 7Kyoto University, Kyoto, Japan, 8National Institute of Polar Research,
Tokyo, Japan, 9Tokatsu Hospital, Chiba, Japan

Successive Japanese wintering parties were placed in an isolated environment in Antarctica for durations of
about one year. They received few visitors because there were no other permanent research stations nearby.
The environment was very stressful. However, all members completed their tasks with very few injuries and
few big accidents.
We interviewed the wintering members after they returned to Japan from their expeditions. In our interviews,
we hypothesized that the leaders' management of the party played an important part in their party members'
mental health. The main purpose of our research was thus to investigate what the leaders of wintering parties
did to prevent their party members from suffering mental distress and what the leaders considered most
important for managing their parties.
We did semi-structured interviews of ten former leaders of Japanese wintering parties. We focused on their
regard for their parties and their party members in the period of preparation in Japan and of wintering in
Antarctica.
We found that the leaders put careful consideration into selecting a suitable head of each section of the party,
respected the specialties of each member, and maintained a sense of distance between themselves and their
party members so as to remain unbiased.

2134
Fri_176_ME-2_1553
The History of Human Fight against Infectious Disease in Antarctica

Hirohisa Morikawa1 (morikawa.hirohisa@gmail.com)

1
Oshima Hospital of Kagoshima Prefecture, General Internal Medicine, Amami, Japan

In the history of each station in Antarctica, many report were published about infectious disease. You may
think there is no pathogen ,like bacteria and virus but it´s not true. This is a review of the pathogens we human
being fight against. We hope this article will help you to protect from them in Antarctica in the future.

2135
Fri_178_ME-2_2347
An Introduction to the Korean Society of Polar Medicine (KSPM)

Eojin Yi1,2 (eojinkorea@gmail.com), Han Kyeom Kim1,3, Jong Won Hong1,4, Min Goo Lee1,3
1
Korean Society of Polar Medicine, Seoul, Korea, Republic of, 2Yeosu Immigration Office, Yeosu, Korea, Republic
of, 3Korea University College of Medicine, Seoul, Korea, Republic of, 4Yonsei University College of Medicine,
Seoul, Korea, Republic of

The Korean Society of Polar Medicine (KSPM) is an academic and social organization for Antarctic health care,
emergency response, and medical research. Founded on 21st June 2014, it gathered three existing groups
about polar medicine: the Korean Society of Antarctic Practitioners, the Korea University Research Group for
Polar Medicine, and Korea Polar Research Institute. The day of founding KSPM was a day of Antarctic winter
solstice so it has an alias "Antarctic Dong-ji Association". ('Dong-ji' is pronounced same as that of Korean
character 'winter solstice' and 'the companion')
The purpose of the KSPM is not only to provide health care for diseases control, but also to investigate and
characterize the features of medical specificity occurring in the polar region. So the main contents dealt with by
KSPM are
(1) Antarctic Stations,
(2) icebreaker Araon,
(3) medical evacuation,
(4) telemedicine,
(5) psychological and physiological research,
(6) extreme medicine and its medical resource,
(7) medical microbiology,
(8) international cooperation in medicine,
(9) humanities and science: combined research on convergence and integration.
As an well-organized platform, KSPM is an attempt in Korea which is going to be a good 'Agora' for collecting
the experiences and opinions of people who were in Antarctica. The outcomes will be valuable for not only the
Antarctic field but also the development of various research, and ultimately give benefit to humanity and
future generation.

2136
Fri_179_ME-2_2529
Cosmic Ray Measurements in Antarctica and their Impacts on Human Activities

Guillaume Hubert1 (guillaume.hubert@onera.fr)

1
ONERA, the French Aerospace Lab., DPhIEE, Toulouse, France

The primary and the secondary radiation produced in the atmosphere can be a serious issue for the reliability
of microelectronics devices embedded in aircraft and this is of a major concern for aircrew member´s dose
assessment. Moreover, Polar Region development induces an important issue related to space weather.
In the framework of the CHINSTRAP project supported by the French Polar Institute (IPEV), a new cosmic ray
induced neutron spectrometer has been installed in December 2015 in the inner Antarctic Plateau, at
Concordia station. Atmospheric shower modelling associated to a primary cosmic ray model allows for
deducing the proton, muon and electron fields from cascade neutron measurements.
Using the fluence to human dose conversions coefficients, the complementarity of measurement and
modelling makes it possible to calculate the human dose, but also to extrapolate it for other localization. In the
same way, Single Event Effect risk can be determined from electronic devices, which is particularly critical for
nanoscale technologies whose sensitivities are increasing with the technological integration. This paper
proposes to analyze two-year measurements from December 2015 to 2017, and to investigate the Cosmic Ray
impacts on Antarctica activities, in the point of view of human dose and electronic systems. Discussions of this
work will be extended to contributions of the cosmic ray knowledge improvement to the space weather and
the cosmogenic nuclide dating activities.

2137
Fri_180_ME-1_178
Extreme Environment Effects on Human Health in High Altitude in Antarctica

Shinji Otani1 (otanis@alrc.tottori-u.ac.jp), Yoichi Miyaoka2,3, Giichiro Ohno3,4, Kentaro Watanebe3

1
Tottori University, International Platform for Dryland Research and Education, Tottori, Japan, 2Hokkaido
University, Department of Gastroenterological Surgery I, Sapporo, Japan, 3National Institute of Polar Research,
Tachikawa, Japan, 4Tokatsu Hospital, Nagareyama, Japan

Introduction: The Antarctic inland, with average altitude of 2450 m above sea level (a.s.l.), is an extremely cold
and dry place with rarefied air. Many inland parties, from various countries, conduct research activities in
Antarctica: however, obtaining clinical data is challenging. To improving the safety of members during Antarctic
expeditions, we evaluated the impact of extreme environmental conditions of the Antarctic inland on health.
Methods: In total, 33 members of 4 inland parties from the Japanese Antarctic Research Expeditions (JARE) 40,
43, 44, and 46 were included in the study. Dome Fuji Station (Dome F), located 3810 m a.s.l., was the
destination of all the parties. We evaluated the impact of the extreme environmental conditions on subjective
symptoms, percutaneous arterial blood oxygen saturation (PaO2), and hematological findings.
Results: The correlation coefficients of SpO2 levels and headache/sleep disturbance scores were −0.181 (p <
0.001) and −0.101 (p = 0.007), respectively; both headache and sleep disturbance scores exhibited significant
negative correlations with SpO2 levels. Serum erythropoietin concentration increased promptly, and the
number of erythrocytes peaked within 6 weeks.
Conclusion: Thus, as is widely alleged, hematological adaptation occurs over several weeks. SpO2 monitoring
might be useful for the early detection of acute mountain sickness, prior to adaptation.

2138
Fri_183_ME-1_1692
Effects of Environmental Conditions from Antarctica on the Human RBCs Viability

Iris Tusa1 (iris.tusa@gmail.com), Corina Itcus2, Manuela Sidoroff1, Daniela Bratosin3

1
National Institute of Research and Development for Biological Sciences, Bioinformatics, Bucharest, Romania,
2
National Institute of Research and Development for Biological Sciences, Arctic and Antarctic Research,
Bucharest, Romania, 3National Institute of Research and Development for Biological Sciences, Cellular Dynamics
and Flow Cytometry, Bucharest, Romania

Our research analysed human erythrocytes viability in relation to environmental conditions from Antarctica
and was conducted two years on three Romanian researchers that participated in two expeditions in West
Antarctica, King George Island. We chose to study the RBCs adaptation because under these conditions it is
expected that the adaptation of an organism to extreme conditions will be determined by cellular adaptations,
especially at the level of RBCs involved in oxygen transport. The methods to investigate cellular changes at
erythrocyte level was flow cytometry for morphological changes (FSC/SSC analysis) correlated with scanning
microscopy, erythrocytes viability determined with Calcein-AM and the analysis of RBCs apoptosis with
Annexin-V- FITC. We also investigated the number of reticulocytes in the circulation. The results were obtained
by comparing the data gathered from the explorers before and after three weeks spent in Antarctica. Our
investigations have shown a clear decrease of erythrocytes viability in the absence of significant morphological
changes and an increasing of reticulocytes number as a result of a greater elimination of RBCs by apoptosis, as
a compensatory mechanism. It is difficult to say at the moment what climatic factors have led to the change in
the viability of RBCs. Further more we will correlate the results with the climate parameters variations.

2139
Fri_184_ME-1_1982
Health Problems in a Long Term Stay in Antarctic High Land

Giichiro Ohno1,2 (oonog@mb.infoweb.ne.jp), Shinji Otani3, Nobuhito Shimoeda4, Satoshi Imura2, Kentaro
Watanabe2
1
Tokatsu Hospital, Department of Surgery, Nagareyama, Japan, 2National Institute of Polar Research,
Tachikawa, Japan, 3Tottori University, International Platform for Dryland Research and Education, Tottori,
Japan, 4TMC Tochigi Medical Center, Department of Neurosurgery, Tochigi, Japan

Purpose: There is need to study both acute mountain sickness and chronic response during a long term stay in
Antarctic high land. We examined medical cases of wintering-over teams at Dome Fuji ( S77, E39, 3810 m a.s.l.)
and compared them with Syowa station(S69, E39, 29 m a.s.l.).
Methods: Dome Fuji summer operations started in 1995. Wintering-over operations were carried during the
1995-1998 period. The number of wintering-over participants was 9 per year and 27 in total with 243 medical
consultations.
Result: Medical consultations occurred frequently at the beginning of wintering-over and polar night. The
proportion of medical consultations showed that the largest group were surgery and Orthopedic (82 cases)
followed by internal medicine (80 cases), teeth problems (23 cases). The forth is psychiatric problems that
totaled 23 cases. Comparing with Syowa station, internal medical and mental problems were dominant with
less injury cases. Dome Fuji had more cases of headache, gout, alcohol related disorder, frost bite and
insomnia.
We had no fatal case nor major operation in high land. There was one severe case of bradycardia with AV block
that occurred in summer. The patient could be airlifted to Japan.
Discussion: During the long term stay at Dome Fuji, we detected some difference of health problems compared
with Syowa station. To solve these problems, we need to further study hypoxia, coldness, daylight change,
smaller group isolation and work patterns.

2140
Fri_186_OC-3_216
Building the International Guide for Online Arctic Ethnographic Collections

Igor Krupnik1 (krupniki@si.edu), Nicholas Parlato2, Chelsi Slotten1

1
Smithsonian National Museum of Natural History, Anthropology, Washington, United States, 2University of
Northern British Columbia, Geography, Prince George, Canada

The museum practices of collecting objects from indigenous peoples has created a vast and diverse landscape
of museum holdings across the world. Through acquisition, trade, scientific expeditions, and government
policies, the ethnographic collections held in many museums worldwide have achieved a distinct character in
terms of their history, scope, depth of catalog record, and accessibility. Scholarly researchers, indigenous
communities, educators, and the public face many challenges in navigating this uneven and uncharted territory
of world's ethnographic museum collections for northern regions. The paper introduces an effort launched at
the Smithsonian National Museum of Natural History to produce an international “guide” for Arctic
ethnographic collections using individual museum websites and other mostly web-based resources. As of late
2017, the guide covers 15 states, including all polar nations, and over 100 individual museums, with more than
250,000 ethnographic objects total. The paper discusses the rationale and purpose underlying the project, and
explains why accessibility is a critical issue for northern ethnographic collections to address the main question:
To what degree are museum materials available online to outside researchers, students, and indigenous users?

2141
Fri_187_OC-3_623
Promoting the Antarctic Heritage of South Africa with a Digital Museum

Ria Olivier1 (riaolivier@sun.ac.za)

1
Stellenbosch University, Botany and Zoology, Stellenbosch, South Africa

A museum is devoted to the procurement, care, study, and display of objects of lasting interest or value for a
specific subject. The internet and virtual environment create a possibility of digital museums that is a digital
footprint of the physical. Physical museums are essential; humans want to relive the experiences of others. This
is however not always a possibility for everyone. Therefore, the digitised era of objects is more accessible to a
wider audience. A digital museum need to communicate research and exploration to the public, and provide
access to their specimens. It involves a location for the collection and a set of digital objects, on a permanent
base. Therefore, it is necessary to investigate new ways where museums can work together in a global context
to advance research and collections, and engage, inspire and educate the future generations of all countries
and especially South Africa. Antartic Legacy of South Africa's (ALSA) main aim is to preserve our legacy in the
Antarctic region by maintaining a digital archive. It is to be a resource for research in history and humanities,
and secondary to promote this legacy. ALSA investigate the possibilities of utilizing the digitised material in the
archive. This poster will outline the process of creating a digital museum with the digitsed material in the
archive and highlight the open accessibility of such a museum. A copy in CD Format of the ALSA digital museum
will be available during the poster session.

2142
Fri_188_OC-3_1260
Arctic Evidence Eight: An Alliance of Global Arctic Natural History Museums

Jeffery M. Saarela1 (jsaarela@mus-nature.ca)

1
Canadian Museum of Nature, Centre for Arctic Knowledge & Exploration, Ottawa, Canada

Natural history museums hold the record of nature over time, including millions of specimens from the Arctic,
yet museums have been largely on the periphery of Arctic science and Arctic data discussions. The "Arctic
Evidence Eight" is an alliance of eight national Natural History Museums in the eight Arctic Council countries:
Canadian Museum of Nature; Finnish Museum of Natural History; Icelandic Institute of Natural History;
National Museum of Natural History, Smithsonian Institution; Natural History Museum of Denmark; Natural
History Museum, University of Oslo; Swedish Museum of Natural History; and Zoological Institute of the
Russian Academy of Sciences. The Arctic Evidence Eight aspire to play a vital role in saving the world with
evidence, knowledge and inspiration. Each institution holds substantive collections of Arctic flora and fauna, as
well as cultural artefacts and genetic resources, which provide a foundation for creating new knowledge. The
Arctic Evidence Eight are engaged in Arctic exploration and discovery, and have research expertise in diverse
Arctic disciplines, such as taxonomy and systematics, Arctic ecology, environmental monitoring, climate change
monitoring, and Arctic culture, human history and exploration. The Arctic Evidence Eight are engaged in finding
ways to better work together and with the broader scientific community to advance Arctic research and
collections, and engage, inspire and educate citizens about the global Arctic.

2143
Fri_189_OC-3_1485
Canada C3: A Natural History Museum´s Role on a Ship-based Mission Around Canada

Mark Graham1, Jeffrey Saarela2 (jsaarela@nature.ca)

1
Canadian Museum of Nature, Research and Collections, Ottawa, Canada, 2Canadian Museum of Nature, Centre
for Arctic Knowledge and Exploration, Ottawa, Canada

All credible museums conduct research. Natural history museums assemble collections as part of the research
done by their staff of experts and in association with a broad network of collaborators. Work in the Arctic
occurs as part of regular programs of work to explore the vast polar reaches of our planet. It can also happen
opportunistically as part of events that mark significant milestones, for example the International Polar Years,
or in this case the 150th anniversary of the Confederation of Canada, a year of celebrations known as Canada
150. One of the feature projects of Canada 150 was entitled Canada C3, a 150-day icebreaker exploration of the
entire coastal region of Canada, from Toronto, Ontario to Victoria, British Columbia via the northwest passage.
The complex program of activities during the voyage addressed the four themes of Canada 150, the
environment, youth engagement, diversity and inclusion, and reconciliation. Canada C3 developed a scientific
research program as part of the environment theme that explored marine and terrestrial habitats as the ship
moved along its 25,000 kilometer transect around the country. This poster describes how the Canadian
Museum of Nature, Canada's national museum of natural history, participated and lead the program of
research.

2144
Fri_190_OC-3_1523
20th Century Italian Antarctic Exploration: The Ajmone-Cat Collection

Ester Colizza1,2 (colizae@units.it), Ioanna Protopsalti2, Gianguido Salvi1,2, Stefano Cirilli1

1
University of Trieste, Mathematics and Geosciences, Trieste, Italy, 2Museo Nazionale dell'Antartide 'Felice
Ippolito', Trieste, Italy

The Antarctic National Museum - Trieste Section (University of Trieste) collects and preserves marine geological
findings, and preserves archives regarding the history of exploration to present them to the public on a
permanent basis. The Museum is divided into two sectors: the Permanent Exhibition and the Sorting Center.
Since the end of the 1800s many Italian explorers have organized or taken part in various expeditions to the
Southern Seas and by the early 1970s some private expeditions were also being carried out, which are also
included in the Permanent Exhibition.
Here we present the collection of Naval officer Giovanni Ajmone-Cat who made two Antarctic expeditions
(1969-1971 and 1973-1974) on board the steam motorsailer San Giuseppe Due which had been specially built
for the expeditions. He explored Deception Island (South Shetlands), Wiencke and Anvers Islands, and visited
Argentine and American Stations in the Antarctic Peninsula. Recently the Italian Navy, in accordance with the
wishes of the Ajmone-Cat family, has lent the Captain's entire collection to the MNA - Trieste Section. The
collection consists of photographs, slides, movies, maps, papers and information about these two autonomous
trips. These materials are catalogued and we are currently digitizing part of the collection using a laser scanner
with photographic overlay to create a 3D model appropriate for long distance access in order to communicate
these two Antarctic explorations to the public.

2145
Fri_191_OC-3_1651
The Italian Museo Nazionale dell'Antartide

Carlo Alberto Ricci1, Giorgio Bavestrello2, Alessio Casagli3, Ester Colizza4, Michele Fernetti4, Cristiano Landucci4,
Jacqueline Müller3 (jacqueline.muller@unisi.it), Silvia Olmastroni3, Rosaria Palmeri3, Ioanna Protopsalti4,
Gianguido Salvi4, Sonia Sandroni3, Stefano Schiaparelli2, Franco Maria Talarico3, Guido Travaglia4
1
Museo Nazionale dell'Antartide 'Felice Ippolito', Siena, Italy, 2Museo Nazionale dell'Antartide 'Felice Ippolito',
Sede di Genova, Università di Genova, Genova, Italy, 3Museo Nazionale dell'Antartide 'Felice Ippolito', Sede di
Siena, Università di Siena, Siena, Italy, 4Museo Nazionale dell'Antartide 'Felice Ippolito', Sede di Trieste,
Università di Trieste, Trieste, Italy

The Italian Museo Nazionale dell'Antartide (www.mna.it) was established as a consortium of three universities
(Genova, Siena, Trieste) in 1996 with the aim to preserve, study, and increase the value of all material collected
during the Italian Antarctic expeditions, as well as to promote public understanding of Antarctic science.
The specimen repositories host rocks, meteorites, sediment and ice cores and marine and terrestrial flora and
fauna, collected by the Italian Antarctic expeditions since 1985. All the material stored in the repositories is
described in specific data bases. The museum operates as an infrastructure of the Italian Antarctic programme
(PNRA) in support of the national and international scientific community. The storing, classification and
distribution of Antarctic scientific material is a peculiar aspect of the Italian Antarctic museum that marks a
clear difference to other polar museums.
The museum contribues to education, outreach and training by promoting polar knowledge to schools through
lectures, guided visits and didactic experiments to all-level students, from kindergarten to PhD level and to the
general public through permanent exhibitions in Genova, Siena and Trieste.
The museum publishes scientific journals, volumes, and multimedia and is also partner of international
initiatives devoted to the dissemination of information of the specimen collections and results obtained by
PNRA.

2146
Fri_192_OC-3_1785
The History of German Polar Research goes Theatre - The Project “Staging Files”

Christian Salewski1 (christian.salewski@awi.de)

1
Alfred Wegener Institute, Library and Archive, Bremerhaven, Germany

How can a Polar Research Institute convey its history and the historical heritage of its discipline to the public?
What kind of role can archives of these institutions play in this matter? How can these archives use records and
other materials kept by them for the best effect on the public sphere? How can they combine historical
research with the focus on polar research with public relation activities of Polar Research institutes? These
questions will be answered during this talk by having a close look on a staged reading on the history of German
Polar Research, a result of a collaboration between the Alfred-Wegener-Institute´s own Archive for German
Polar Research (AGPR) and the project “Aus den Akten auf die Bühne” (AdA) (“Staging Files”), a cooperation
between the institute of history at Bremen University and the “bremer shakespeare company”.
To fulfill this task, the talk will initially present both AGPR and AdA with the regard to their history, their task or
aims and their work approaches and ways of working. Next, the cooperation between the AGPR and AdA on
the history of German Polar Research will be described with respect to its emergence and its work modus.
Afterwards an overview of the project product, the stage reading, will be given with regard to its contents,
structure and theatrical means. Finally, since the staged reading started in May 2018, a first evaluation of the
project will be presented.

2147
Fri_193_OC-3_1818
Ardently Glacial - Social Issue

Jessica Litman1 (jessica.litman@unine.ch)

1
Natural History Museum Neuchâtel, Neuchâtel, Switzerland

Climate change is no longer a theory to be debated but rather an indisputable reality that requires immediate
global engagement. Given this reality, what role does a museum play in encouraging public awareness and
activism? The Museum of Natural History of Neuchâtel, in presenting an exhibition (2 june 18 - 30 june 2019)
on the polar regions and climate change, is hoping to stimulate a discussion about one of the most pressing
issues of our time. By presenting our natural history collections in the context of the Poles and global warming,
and by presenting pertinent research carried out in polar and alpine regions, the Museum encourages the
visitor to enter an exhibition characterized by paradox. This polarized world is one both up and down, both
water and ice, hostile yet teeming with life, plunged in crisis but with solutions in sight. In the context of the
exhibition, participants have been invited to send us their personal reactions to a brief text written by Claude
Lorius, the French glaciologist who first discovered that gases trapped in polar ice held the key to unraveling
the history of earth´s climate. These reactions, whether in the form of text, video..., will be incorporated into
our exhibition, allowing the public to manifest their opinions in the museum. We thus hope to create a synergic
space where scientific, cultural and personal information is transmitted in two directions, both from the
museum to its visitors and from the visitors to the museum.

2148
Fri_195_OC-3_2300
Archive of Polar Fish Chromosomes, a New Biological Resource for Polar Science

Eva Pisano1,2 (eva.pisano@ge.ismar.cnr.it), Laura Ghigliotti1, Erica Carlig1, Davide Di Blasi1, Marino Vacchi1,
Stefano Schiaparelli3,4, Marco Faimali1
1
National Research Council, Institute of Marine Sciences (ISMAR), Genoa, Italy, 2University of Genoa,
Department of Educational Sciences, Genoa, Italy, 3University of Genoa, Department of Earth, Environmental
and Life Sciences (DISTAV), Genoa, Italy, 4University of Genoa, Italian National Antarctic Museum (MNA),
Section of Genoa, Genoa, Italy

Climate change is expected to impact on marine polar fish leading to local extinctions, invasions and
modifications in the structure of the ecosystems. In the last decade, polar bodies and polar scientists have
spent great effort in establishing monitoring activities in order to gather baseline data on both Arctic and
Antarctic fish, and to interpret future reassessments in the communities. Over time, the potential for accessing
and exchanging scientific information has greatly improved, but the need of specimen and tissue repositories
(not only focusing on DNA) remains of high priority for polar research, representing an invaluable basis for
monitoring plans and a legacy for the future.
Aiming at contributing to this issue, a polar fish chromosomes archive has been established in the framework of
the PNRA Project “Polar Fish Cytogenetic Diversity” (POLICY) carried out at Institute of Marine Sciences, Genoa.
The archive is hosted and curated by the Italian National Antarctic Museum (MNA), Section of Genoa which will
guarantee the link with other biological databases. The archive is organized as a repository of cytogenetic
samples (frozen mitotic cells and slide chromosome preparations) with an associated database including
karyotypic and cytogenomic data and DNA barcodes. Such an overall organization aims at providing the polar
community with a useful biological resource for a wide range of applications, from species characterization and
identification to genome adaptation.

2149
Fri_196_OS-4_117
SIPN South: Coordinating Seasonal Predictions of Sea Ice in the Southern Ocean

Francois Massonnet1,2, Phil Reid3, Jan Lieser4 (jan.lieser@utas.edu.au), Cecilia Bitz5, John Fyfe6, Will Hobbs7,
Kazuya Kusahara4
1
UCL, Louvain-la-Neuve, Belgium, 2Barcelona Supercomputing Center, Barcelona, Spain, 3Bureau of
Meteorology, Hobart, Australia, 4Antarctic Climate & Ecosystems CRC, Hobart, Australia, 5University of
Washington, Seattle, United States, 6Environment and Climate Change Canada, Victoria, Canada, 7University of
Tasmania, Hobart, Australia

Like many regions of our planet, the Antarctic is currently undergoing profound environmental changes. Sea ice
is a prominent element of this environment: it controls the heat, gas, mass and momentum exchanges
between the atmosphere and the ocean. Sea ice has been steadily expanding in the Southern Ocean since the
late 1970s but has displayed significant negative anomalies in recent years. Understanding and predicting how
the sea-ice cover develops over time scales as short as a season is important not only for scientists but also for
stakeholders or teams organizing field campaigns. Despite all potential applications, there has been to date no
overall assessment of the capabilities of current prediction systems to forecast sea ice conditions at time scales
of a season. This is the goal of SIPN South. SIPN South is a 2-yr project endorsed by the Year of Polar Prediction
(YOPP) project. SIPN South aims at evaluating the skill of various forecast systems (statistical, dynamical) in
predicting the regional summer conditions around the Antarctic continent. In this poster, we are presenting the
very first coordinated austral sea ice prediction that will take place in February 2018 (summer sea ice
minimum).

2150
Fri_197_OS-4_345
Operational Polar Sea Ice Forecast and Service in China

Chunhua Li1 (lichunhua0214@hotmail.com), Qinghua Yang1, Lin Zhang1, Ming Li1, Jiechen Zhao1, Zhongxiang
Tian1, Longjiang Mu1, Xiaoyu Sun1, Xingren Wu2, Xi Liang1, Guanghua Hao1, Shang Meng1
1
National Marine Environmental Forecasting Center, Beijing, China, 2Environmental Modeling Center (EMC),
NCEP,NOAA, Washington, United States

The polar sea ice forecast and service is needed urgently with the development of polar research expeditions
and Chinese cargo ship navigations through polar regions in recent years. The operational polar sea ice forecast
and service system is developing at National Marine Environmental Forecasting Center of China (NMEFC). The
synoptic scale sea ice forecasting system is based on a coupled ice-ocean model with multiple parameter data
assimilation and is operational running. The subseasonal and seasonal sea ice prediction are based on the NCEP
Climate Forecast System version 2 (CFSv2) and statistic forecasting method. Moreover, due to the importance
of in-situ sea ice observation data for the sea ice forecast, the sea ice and snow thickness, albedo observations
have been sustained for more than 5 years based on the Zhongshan station in the Antarctic, and ice buoys
were placed on the floe ice in the Arctic ocean to monitor ice drift and ice thickness in recent several years.
Synthesizing the forecast, satellite and site observation data, sea ice service are provided to users such as
Xuelong icebreaker and Chinese merchant ship.

2151
Fri_198_OS-4_408
Sea Ice and Ocean Model Development for CMIP6 at Tsinghua University

Shiming Xu1 (xusm@tsinghua.edu.cn)

1
Tsinghua University, Beijing, China

We summarize the model development for sea ice and ocean component and the initial evaluation for the
CMIP6. A nominal resolution of 0.5 degree is adopted for grid of the ocean and sea ice components, with much
improvement of spatial resolution in the Arctic region. A diagnostic floe-size parameterization and lateral melt
scheme is integrated in the sea ice model, with observational data specific to both Arctic and Antarctic.
Through initial evaluation based on OMIP, pre-industrial and historical runs in CMIP6, we show that the ocean-
ice coupled model and the fully coupled model reproduces reasonable Arctic climatology and changes, and the
positive bias in the Antarctic sea ice extent is greatly reduced. The improvements in the sea ice model and
ocean model serve as an integral part of the coupled model development for CMIP6 at Tsinghua University.

2152
Fri_199_OS-4_451
Arctic Ice Ocean Prediction System (ArcIOPS): An Evaluation of Sea Ice Forecasts

Qinghua Yang1 (yqh@nmefc.gov.cn), Longjiang Mu1, Xi Liang1, Chunhua Li1, Lin Zhang1
1
National Marine Environmental Forecasting Center, Beijing, China

The Arctic sea ice decline in summer opens new shipping routes and increases the marine operations in the
Arctic Ocean. To well manage the opportunities and possible risks, accurate sea ice predictions are strongly
required. In an effort towards reliable Arctic sea ice numerical prediction, the Arctic Ice Ocean Prediction
System (ArcIOPS) was developed at National Marine Environmental Forecasting Center of China (NMEFC). This
system is based on a regional Arctic configuration of the Massachusetts Institute of Technology general
circulation model (MITgcm) and a localized error subspace transform ensemble Kalman filter (LESTKF) to
assimilate weekly CryoSat-2 sea ice thickness data together with daily SMOS sea ice thickness and daily AMSR2
sea ice concentration data. The NCEP GFS numerical weather prediction is used as the atmospheric forcing. The
real-time ensemble based sea ice forecasting experiments were carried out to facilitate the Chinese National
Arctic Research Expedition in summer 2018 (CHINARE2018). The forecasts were evaluated against SSMIS sea
ice concentration data and the in situ sea ice concentration and thickness data. Both sea-ice concentration and
thickness forecasts show reasonable agreement with the independent observations, which proves the
forecasting system has a good potential for the Arctic sea ice predictions.

2153
Fri_200_OS-4_608
Assimilating Copernicus SST into a Arctic Ice-ocean Model with a LSEIK Filter

Xi Liang1 (liangxi700@126.com), Qinghua Yang1, Lars Nerger2, Svetlana Losa2

1
National Marine Environmental Forecasting Center, Beijing, China, 2Alfred Wegener Institute Helmholtz Center
for Polar and Marine Research, Bremerhaven, Germany

Sea surface temperature (SST) data from the Copernicus Marine Service are assimilated into a pan-Arctic ice-
ocean coupled model using the ensemble-based Local Singular Evolutive Interpolated Kalman (LSEIK) filter. It is
found that the SST deviation between model hindcasts and independent SST observations is reduced by the
assimilation. Compared with model results without data assimilation, the deviation between the model
hindcasts and independent SST observations has decreased by up to 0.2 ºC at the end of summer. The
strongest SST improvements are located in the Greenland Sea, the Beaufort Sea and the Canadian Arctic
Archipelago. The SST assimilation also changes the sea ice concentration (SIC). Improvements of the ice
concentrations are found in the Canadian Arctic Archipelago, the Beaufort Sea and the central Arctic basin,
while negative effects occur in the west area of the Eastern Siberian Sea and the Laptev Sea. Also sea ice
thickness (SIT) benefits from ensemble SST assimilation. A comparison with upward-looking sonar observations
reveals that hindcasts of SIT are improved in the Beaufort Sea by assimilating reliable SST observations into
light ice areas. The study illustrates the advantages of assimilating SST observations into an ice-ocean coupled
model system and suggests that SST assimilation can improve SIT hindcasts regionally during the melting
season.

2154
Fri_201_OS-4_630
Daily Arctic Sea Ice Thickness Estimates in Cold Seasons

Longjiang Mu1 (mulj@nmefc.gov.cn), Martin Losch2, Qinghua Yang1, Svetlana N. Losa2,3, Robert Ricker2, Lars
Nerger2
1
National Marine Environmental Forecasting Center, Beijing, China, 2Alfred Wegener Institute, Helmholtz Center
for Polar and Marine Research, Bremerhaven, Germany, 3P.P. Shirshov Institute of Oceanology, St. Petersburg,
Russian Federation

The Arctic multi-year sea ice thickness has undertaken substantial thinning in recent decades. However, direct
observations are inadequate because of the limited in situ expeditions and immature satellite retrievals. The
complementary of CryoSat-2 launched in 2010 and SMOS sea ice thickness allows it possible to combine these
two datasets to get a purely statistical dataset CS2SMOS in cold seasons.
A new daily sea ice thickness dataset in cold seasons from 2010 to 2016 is generated by the Massachusetts
Institute of Technology general circulation model (MITgcm) with the assimilation performed by a localized error
subspace transform ensemble Kalman filter (LESTKF) filter coded in the Parallel Data Assimilation Framework
(PDAF). The atmospheric ensemble forecasts of the UK Met Office Unified Model (UKMO) available in the
TIGGE archive are used to force the model. The available weekly CryoSat-2 sea ice thickness data together with
daily SMOS sea ice thickness and daily SSMIS sea ice concentration data are then assimilated into the model
during analysis process. In situ sea ice thickness observations from Beaufort Gyre Exploration Project and Ice
Mass Balances data are used to evaluate the sea ice thickness estimates. Statistic results show that the sea ice
thickness data have comparable performance to CS2SMOS data in cold seasons, and further provide daily
evolution for future studies.

2155
Fri_202_OS-4_671
Seasonal Prediction of the Antarctic Sea Ice using NEMO3.6-LIM3

Sylvain Marchi1 (sylvain.marchi@uclouvain.be), Hugues Goosse1, Thierry Fichefet1

1
Université catholique de Louvain (UCL), Georges Lemaître Centre for Earth and Climate Research, Louvain-la-
Neuve, Belgium

The Southern Hemisphere sea ice extent has followed an overall positive trend over the last 30 years. In this
context, the last two years appear unusual with a lower than normal sea ice extent for almost all the months.
This drop in sea ice extent after a record high in 2014 highlights the importance of the Antarctic sea ice
variability at the seasonal and interannual timescales. Multiple mechanisms have been proposed to explain this
variability. Although there is evidence that recent changes in the Antarctic sea ice are triggered by atmospheric
conditions, the persistence or re-emergence of the sea ice anomalies has been partly attributed to sea ice-
ocean interactions. In this study, we explore the critical influence of the state of the Southern Ocean on the
seasonal predictability of the sea ice. A simulation covering the period 1979-2016 using the ocean-sea ice
model NEMO3.6-LIM3 driven by atmospheric fields derived from atmospheric reanalyses is first performed and
compared to observations. In a second step, the state of the ocean is perturbed to evaluate the implications of
a warmer or colder than usual ocean on the evolution of the sea ice. In practice, this is achieved by replacing
the ocean conditions at specific times by those simulated at the same season but for a different year, while
keeping the same atmospheric forcing. The impact of such changes on sea ice conditions over the following
months is then assessed.

2156
Fri_203_OS-4_677
Seasonal Sea Ice Forecast Skills and Predictability of the KMA's GloSea5 System

Byoung Woong An1 (byoung.woongan.an@gmail.com), Phi-Hun Chang1, Kiryong Kang1, Hyun-Suk Kang1
1
National Institute of Meteorological Sciences, Earth System Research Division, Seogwipo-si, Korea, Republic of

Ensemble sea ice forecasts of the Arctic Ocean is conducted with the KMA's GloSea5 seasonal prediction
system. We assess the temporal and spatial characteristics of the monthly projection of Arctic sea ice extent
and thickness in terms of forecasts accuracy and variability. The forecast skills are significant for all lead
months, but anomalous around Siberian shelf, Chukchi Sea and Beaufort Sea during summer months. This
study shows the summer sea ice prediction depends strongly on the previous winter sea ice thickness
interacting with the accuracy of the snow depth. In spite of the uncertainties in atmospheric conditions, this
system provides skillful Arctic seasonal sea ice cover predictions up to six months.

2157
Fri_204_OS-4_691
Assimilation of Sea Ice Concentration in a Fully Coupled Earth System Model

Madlen Kimmritz1,2 (madlen.kimmritz@nersc.no), Francois Counillon1,2, Cecilia M. Bitz3, Francois Massonnet4,5,

Yiguo Wang1,2, Ingo Bethke6, Noel Keenlyside2,7, Yongqi Gao1,2
1
NERSC, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen, Norway, 3University of Washington,
Seattle, United States, 4UCL, Louvain-la-Neuve, Belgium, 5Barcelona Supercomputing Center, Barcelona, Spain,
6
Uni Research Climate, Bergen, Norway, 7University of Bergen, Bergen, Norway

A data assimilation method capable of constraining the sea ice of an Earth system model in a dynamically
consistent manner has the potential to enhance the accuracy of climate reconstructions and predictions. The
difficulty in finding such a method lies in the strong nonlinearity of sea ice as well as in the sea ice variables,
that are strongly non-Gaussian distributed and tightly coupled to the rest of the Earth system - particularly
thermodynamically with the ocean.
We assess key practical implementations for assimilating sea ice concentration - the predominant source of
observations in polar regions - with the Norwegian Climate Prediction Model that combines the Norwegian
Earth system Model with the Ensemble Kalman Filter. For our study we conducted ten-year reanalyses in a
perfect model framework. We discuss the benefits of weakly coupled (sea ice only) assimilation, as well as the
impact of strongly coupled ocean-sea ice assimilation. Focusing on the ice variables, we investigate the
performance of solving the analysis for the aggregated and for the multicategory ice states. The case of
updating the ice volumes during the assimilation, thus necessitating the post-processing of unphysical
thicknesses, will also be discussed. The robustness and reliability of the optimal setting is demonstrated for a
20-year reanalysis.
Finally, leaving the perfect model framework, we demonstrate the added value of sea ice assimilation in a
realistic framework.

2158
Fri_205_OS-4_734
Re-interpreting Thermodynamic Arctic Sea Ice Feedbacks

François Massonnet1 (francois.massonnet@uclouvain.be), Martin Vancoppenolle2, Hugues Goosse1, David

Docquier1, Thierry Fichefet1, Edward Blanchard-Wrigglesworth3
1
Université catholique de Louvain (UCL), Louvain-la-Neuve, Belgium, 2LOCEAN Laboratory, Paris, France,
3
University of Washington, Seattle, United States

One of the clearest manifestations of ongoing global climate change is the dramatic retreat and thinning of the
Arctic sea-ice cover. All state-of-the-art climate models reproduce consistently the sign of these changes but
largely disagree on their magnitude. The very deep causes remain contentious and consensual methods to
reduce uncertainty in projections are lacking. Here we propose a process-oriented approach to revisit this
question. We show that inter-model differences in sea-ice loss and, more generally in simulated sea-ice
variability at all time scales, can be traced back to differences in the simulation of two competing
thermodynamic sea-ice feedbacks. In turn, we show that both feedbacks are closely tied to the average ice
thickness simulated by each model, regardless of the complexity of its sea-ice component. The results prompt
modelling groups to focus their priorities on the reduction of sea-ice thickness biases, as we provide physical
evidence that Arctic sea-ice projections from models with unrealistic current thickness can robustly be
distrusted. We finally show that because of the enhancement of the feedbacks as sea ice thins, the recent and
future changes in sea-ice thickness induce a transition of the Arctic towards a state with increased seasonal-to-
interannual variability and less persistence, in other words less predictability.

2159
Fri_206_OS-4_804
A TEOS-10-based Sea Ice Thermodynamic Formulation

Martin Vancoppenolle1 (martin.vancoppenolle@locean-ipsl.upmc.fr), Gurvan Madec1, Trevor McDougall2,

Dupont Frédéric3
1
Sorbonne Universités (Université Pierre et Marie Curie Paris 6), LOCEAN-IPSL, CNRS/IRD/MNHN, Paris, France,
2
University of New South Wales, The School of Mathematics and Statistics, Sidney, Australia, 3Environment
Canada, Dorval, Canada

Sea ice thermodynamics in Earth System Models have a well established physical basis, yet formulations are
generally not fully consistent with the thermodynamics of the other components of the Earth System, in
particular the ocean and continental ice sheets. The ocean components have recently adopted the
International Thermodynamic Equation of Seawater 2010 (TEOS-10), which includes formulations for both
seawater and pure ice.
Since sea ice is at typical temperatures composed of pure ice and concentrated seawater in brine inclusions, it
seems natural to base sea ice thermodynamics on a combination of TEOS-10 standards for sea water and pure
ice. Feistel and Hagen (1998) have proposed such an approach that can readily be used but should be updated
following the recent TEOS-10 developments.
With derive a TEOS-10 thermodynamic formulation for sea ice and question: (i) how consistent the TEOS-10
based sea ice thermal properties are consistent with observations; (ii) how different a TEOS-10 sea ice
formulation is from standard sea ice formulations in current Earth System Models; (iii) how this can be
implemented in climate models.

2160
Fri_207_OS-4_900
Impacts on Sea Ice of Increased Ice Shelf Meltwater over Centennial Timescales

Inga J. Smith1 (inga.smith@otago.ac.nz), Cecilia M. Bitz2, Andrew G. Pauling1,2, Katherine Lilly1, Patricia J.
Langhorne1, Christina L. Hulbe3
1
University of Otago / Te Whare Wananga o Otago, Department of Physics, Dunedin, New Zealand, 2University
of Washington, Atmospheric Sciences, Seattle, United States, 3University of Otago / Te Whare Wananga o
Otago, National School of Surveying, Dunedin, New Zealand

The West Antarctic Ice Sheet may already be undergoing an irreversible mass loss that would result in near
complete melt within the next millennium. The sea ice and climate response to increased Antarctic meltwater
over centennial timescales is investigated with simulations in the Community Earth System Model version 1,
with the Community Atmosphere Model version 4 (CESM1-CAM4). To investigate the response to meltwater
released at the base of ice shelves in a higher CO2 warming world, meltwater was injected at the depth of the
front of the ice shelves, while simultaneously cooling the ocean by an amount required to melt the ice. The
amount of freshwater added increased linearly over time, to represent gradually increased basal melting of ice
shelves. To isolate the effects of ice shelf meltwater from greenhouse gas forcings, a pre-industrial (1850s) run
was subjected to the increased freshwater for 150 years, consistent with published literature on the timescales
of future ice shelf melting. This was then compared with the trends in the response to 20th and 21st century
climate change.

2161
Fri_208_OS-4_904
Research on the Impacts of Freshwater in the New Zealand Earth System Model

Shona Mackie1 (shonalmackie@gmail.com), Inga J. Smith1, Jeffrey K. Ridley2, David P. Stevens3, Cecilia M. Bitz4,
Patricia J. Langhorne1
1
University of Otago / Te Whare Wananga o Otago, Department of Physics, Dunedin, New Zealand, 2MetOffice,
Exeter, United Kingdom, 3University of East Anglia, School of Mathematics, Norwich, United Kingdom,
4
University of Washington, Atmospheric Sciences, Seattle, United States

The New Zealand Earth System Model (NZESM) is being developed and used through the Deep South National
Science Challenge. NZESM is based on the UKESM1 physical model HadGEM3-GC3.1, which is a fully coupled
atmosphere, land, ocean and sea ice model. In our research, we will use the NZESM to investigate the coupled
response of the sea ice module (CICE) and the ocean module (NEMO) to freshwater forcings, including
accounting for the meltwater latent heat. Freshwater flux runs have not been run for the NZESM and its
predecessors in coupled (atmosphere-ice-ocean) mode. Runs with the NZESM will therefore fill a critical
knowledge gap in terms of coupled model behaviour. We will initially run icebergs only (surface freshwater)
runs, using state-of-the-art parameterisations for 1 degree models with and without their associated latent
heat fluxes, to allow direct comparison with standardised control runs and the results from other models. Next,
we will perform simulations with freshwater injection at depth to see if this makes any difference to the
results.

2162
Fri_209_OS-4_1556
Robustness of Arctic Sea-ice Predictability in GCMs

Ed Blanchard-Wrigglesworth1, Mitch Bushuk2 (mitchell.bushuk@noaa.gov)

1
University of Washington, Seattle, United States, 2Geophysical Fluid Dynamics Laboratory, Princeton, United
States

General circulation models have been amply used to quantify Arctic sea-ice predictability. While models show
commonalities in the general tendency of predictability loss, there is significant disagreement in its magnitude
and timing. Here we show that inter-model differences in predictability are linked to inter-model differences in
the persistence timescales of sea-ice anomalies that are unique to each model. Given this result, and previous
work showing that within a single model simulation the magnitude of persistence fluctuates between periods
of high and low persistence that may last several years, we assess whether initial-value predictability is
dependent on the persistence state of the initial conditions. We find that forecast spread predictability is not
significantly different across high/low persistence periods, suggesting that predictability may be robust within
an unchanging climate mean state. Our results also imply that annual periods of high/low persistence are not
predictable and are mainly forced by the atmosphere rather than the ice-ocean system.

2163
Fri_210_OS-4_1800
Combining Information from Models and Automatic Classifications for Ice Charting

Jürgen Holfort1 (juergen.holfort@bsh.de), Sandra Schwegmann1

1
Bundesamt für Seeschifffahrt und Hydrographie, M12 Eisdienst, Rostock, Germany

Sea ice concentration and thickness from numerical models as well as from automatic sea ice classification
algorithms using satellite data are still not suitable for direct use in the production of operational sea ice charts.
However, the usability depends strongly on time and location. For areas with high concentrations both
products are very usable in winter but at low concentrations and/or if the ice is rotten the quality deteriorates.
In addition numerical models have also problems with the fast ice edge. Nevertheless, models and satellite
data can deliver parameters which are not yet, or only in rare cases, depicted in operational ice charts. These
range from directly usable parameters like floe size and ridges to more generalized parameters like roughness
and orientation of linear features. In order to explore the possibilities and challenges a method was
incorporated into the ice analyst routine, which gives the analyst the ice parameter values from models and
automated classifications within the drawn ice polygon to help him setting the appropriate parameters in the
ice chart. This method will be used in the Baltic winter season of 2017/18 and we will give some first insights
gained.

2164
Fri_211_OS-4_1805
Improvement of Sea Ice Movement Information for Ship Route Optimization

Sandra Schwegmann1 (sandra.schwegmann@bsh.de), Jürgen Holfort1

1
Bundesamt für Seeschifffahrt und Hydrographie, M12 Eisdienst, Rostock, Germany

Beyond sea ice concentration and thickness, ice drift and deformation are the most important parameters for
ships passing through sea ice covered regions. However, knowledge on drift and deformation is sparse due to
the lag of suitable and sufficient satellite data. Therefore, the only regular information is based on models.
Models do not only show the actual state of ice drift and deformation but also provide the opportunity to
display near real time ice development, which is essential for ship route planning. By the optimization of
models with respect of sea ice drift both a better representation of the ice situation in total and a decision
support for ship route planning considering ice deformation processes and near future ice development can be
realized in future. As a first step towards this future, we analyze the accuracy of the BSH ice model by
comparing the model ice drift with an operational ice drift product based on satellite data in the sea ice
covered regions of the Baltic Sea. This small region is covered frequently by diverse satellites so that the ice
drift can be calculated generally with a high temporal resolution. Meteorological and oceanographic conditions
are investigated in order to detect drivers for differences between both products and to eliminate weaknesses
in the model. Once the development of the models and S411 has moved on sufficiently, ice drift may become
worldwide additional information transferred to the ships in sea ice covered regions.

2165
Fri_212_OS-4_1813
The Sea Ice Drift Forecast Experiment

Helge F. Goessling1 (helge.goessling@awi.de), Axel Schweiger2, Ed Blanchard-Wrigglesworth3, Thomas

Krumpen1, Marcel Nicolaus1, Ignatius Rigor2, Robert Grumbine4, Frank Kauker1, Rüdiger Gerdes1
1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, 2Polar
Science Center, Applied Physics Laboratory, University of Washington, Seattle, United States, 3Department of
Atmospheric Sciences, University of Washington, Seattle, United States, 4NOAA-NCEP/EMC Marine Modeling
and Analysis Branch, College Park, MD, United States

The Sea Ice Drift Forecast Experiment (SIDFEx) was launched in summer 2017. SIDFEx is a community effort to
solicit, collect, and analyze sea ice drift forecasts, based on arbitrary methods, for a number of IABP sea-ice
buoys on a regular basis. The YOPP initiative is inspired by increasing research and operational needs to
forecast future positions of assets drifting in Arctic sea ice. An example is the need to determine an optimal
start position for the MOSAiC drift. Specifically, it is unclear whether forecast systems that account for initial
conditions can provide additional skill over drift forecasts made using historical sea ice velocity fields. The
MOSAiC drift provides a template for assessing the capabilities to forecast sea-ice drift for a range of
applications, ranging from logistics support for future field experiments to potential search and rescue
operations. The examination of sea ice drift forecasts provides an integrated assessment of many aspects of
the coupled atmosphere-ice-ocean system and will motivate in depth investigations into how key variables are
measured, modeled, and forecast. We expect that a systematic assessment of real drift forecasting capabilities
will improve our physical understanding of sea ice and enable us to identify and resolve model shortcomings.
We will present the current design of SIDFEx, discuss results obtained from one year of SIDFEx submissions, and
present future plans in association with the MOSAiC drift.

2166
Fri_213_OS-4_1871
The Arctic Marine Forecasting Centre of the Copernicus Marine Services

Laurent Bertino1 (laurent.bertino@nersc.no), Malte Müller2, Annette Samuelsen1, Arne Melsom2, Jiping Xie1,
Graigory Sutherland2, Tsuyoshi Wakamatsu1, Øyvind Sætra2, Vidar Lien3
1
Nansen Environmental and Remote Sensing Center, Bergen, Norway, 2MET Norway, Oslo, Norway, 3Institute of
Marine Research, Bergen, Norway

The Arctic Marine Forecasting Center (ARC MFC) provides 10-days forecasts of the ocean currents, sea ice,
marine biogeochemistry and waves on a daily basis and a 25-year reanalysis of the Arctic Ocean updated every
year. The ARC MFC is powered by the Topaz configuration of the HYCOM model, coupled to the sea ice model
CICE, the ecosystem model ECOSMO, and assimilates the following data with the Ensemble Kalman Filter:
along-track sea level anomalies, sea surface temperatures, sea ice concentrations, sea ice drift, sea ice
thickness, in situ temperature and salinity profiles and (only in reanalysis mode) ocean colour data. Waves are
forecasted using an Arctic configuration of the WAM model. We review the main achievements of the ARC MFC
during the first 3 years of the services, the participation to model intercomparison exercises and the plans for
its future developments.

2167
Fri_214_OS-4_1872
Iceberg Meltwater Estimates for the Southern Ocean Including Giant Icebergs

Thomas Rackow1 (thomas.rackow@awi.de), Christine Wesche2, Ralph Timmermann3, Hartmut H. Hellmer3,

Stephan Juricke4, Thomas Jung1,5
1
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Climate Dynamics,
Bremerhaven, Germany, 2Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI),
Operations and Research Platforms, Bremerhaven, Germany, 3Alfred Wegener Institute, Helmholtz Centre for
Polar and Marine Research (AWI), Physical Oceanography of the Polar Seas, Bremerhaven, Germany, 4Jacobs
University Bremen gGmbH, Mathematics & Logistics, Bremen, Germany, 5University of Bremen, Department of
Physics and Electrical Engineering, Bremen, Germany

Iceberg calving is an important component of the mass balance of the Antarctic Ice Sheet, with recent
estimates of ∼1300 Gt/year being on the same level as ice shelf basal melting. The iceberg mass is usually
assumed to be evenly divided between giant icebergs (length >10km) and smaller ones, with some estimates
even preferring giant icebergs (as high as 89%). However, it is still unclear what the best way is to include giant
icebergs into model estimates of the Southern Ocean freshwater cycle.
Here, we estimate the iceberg meltwater input from a simulation of present-day Antarctic icebergs and
compare it to the balance between precipitation and evaporation (P-E) and sea-ice production rates. For the
first time, an iceberg model is initialized with a set of nearly 7000 satellite-observed iceberg positions and sizes.
It reproduces typical drift patterns for a large spectrum of size classes, including typical routes taken by giant
icebergs.
The associated meltwater input is generally on the order of 5-20% of the P-E balance in large areas of the
Southern Ocean, especially around the coast, with local maxima even exceeding P-E. Furthermore, the
freshwater flux from melting icebergs is on the order of 5-20% of coastal sea ice production rates and, thus,
partly compensates the effect of brine rejection in the annual mean. Iceberg melting is also the largest vector
of freshwater input from frozen ice along (and northward of) the sea-ice edge.

2168
Fri_215_OS-4_1916
Improved Sea Ice Drift Estimates in Lagrangian Methods for Sea Ice Forecasting

Charles Brunette1 (charles.brunette@mail.mcgill.ca), Bruno Tremblay1, Robert Newton2

1
McGill University, Atmospheric & Oceanic Sciences, Montreal, Canada, 2Lamont-Doherty Earth Observatory
Columbia University, Palisades, United States

We have recently developed a Lagrangian Ice Tracking System (LITS) for the Arctic Ocean. The LITS tracks
motion of sea ice in a Lagrangian framework using sea ice drifts. It has been used to develop a seasonal
forecasting model of the minimum sea ice extent (Williams et al. 2016) based on observational drifts. In
continuity, we are working on the seasonal predictability of the sea ice system on a regional scale. The current
version of the LITS uses the Polar Pathfinder sea ice motion vectors (V3, Tschudi et al. 2016). However, the raw
drift vectors used to construct Polar Pathfinder contain biases. The satellite-derived velocities (from SMMR,
SSM/I, AMSRE, AVHRR) and free drift estimates present a low bias when compared to the buoy drift
observations, taken to be essentially true. Biases are larger in the summer, when fewer satellite-derived drifts
are available and the composite sea ice drift relies more heavily on the free drift estimates. While being useful
for climatic studies and model validation (Sumata et al. 2015), the issues found in Polar Pathfinder become
more apparent when building a regional forecasting model. To this end, we recompile a new optimally
interpolated sea ice drift dataset, using bias-corrected and error-weighted raw drift vectors from Polar
Pathfinder, buoy data, free drift estimates derived from reanalyses, and other available satellite-derived drifts.

2169
Fri_216_OS-4_2173
Forecasts of 2017 Arctic Sea Ice States Using the Regional Arctic System Model

Samy Kamal1 (smkamal@nps.edu), Wieslaw Maslowski1, Andrew Roberts1, Robert Osiński2, Younjoo Lee3, John
Cassano4, Mark Seefeldt4, Marina Frants3, Meibing Jin5
1
Naval Postgraduate School, Monetery, United States, 2Institute of Oceanology, Polish Academy of Sciences,
Sopot, Poland, 3Naval Postgraduate School, Monterey, United States, 4Univ of Colorado, Boulder, United States,
5
University of Alaska - Fairbanks, Fairbanks, United States

The rate of Arctic climate warming has been at least twice as fast as the global mean. Increasing surface air
temperatures and declining sea ice have been some of the main attributes of that change. Wide-ranging sub-
seasonal to seasonal (S2S) year-around forecasts of sea ice and climate states are becoming increasingly vital to
surging human operations in the area, however the advancement of their skill remains challenging. This
presentation summarizes our approach and results on 2017 Arctic sea ice thickness and concentration S2S
forecasts using the Regional Arctic System Model (RASM).
RASM is a fully coupled regional climate system model, including atmospheric, ocean, sea ice, and land-
hydrology components and a flux coupler to connect them. RASM is used to dynamically downscale the Climate
Forecasting System Reanalysis (CFSR) for 1979-2017 and to create consistent initial conditions for all model
components for S2S ensemble forecasts for each month of 2017. After the initialization, forecasts are forced at
the model boundaries with output from 9-month CFSv2 global forecasts. Their skill is assessed against available
observations. In particular, the effects of lead time, initial conditions, and sea ice rheology on the skill of
forecasts are investigated. Based on these findings, an approach for future forecasts, including increased
resolution of the RASM atmospheric model, marine biogeochemistry predictions and larger ensemble will be
also outlined.

2170
Fri_217_OS-4_2273
Effect of Assimilating SST, SIC and SIT on Seasonal Prediction of Arctic Sea Ice

Keguang Wang1 (keguang.wang@met.no), Jens Boldingh Debernard2, Nils Kristensen2, Caixin Wang1, Yvonne
Gusdal2
1
Norwegian Meteorological Institute, Research and Development, Tromso, Norway, 2Norwegian Meteorological
Institute, Research and Development, Oslo, Norway

The rapid changes in the Arctic sea ice raises increasing demands for seasonal sea ice prediction. However,
there were large biases in the predicted sea ice extent and thickness due partly to the poorly-known initial sea
ice conditions. In this study, a coupled regional ocean-sea ice model ROMS-CICE is applied to investigate the
effect of assimilating sea surface temperature (SST), sea ice concentration (SIC) and sea ice thickness (SIT) on
the seasonal prediction of September Arctic sea ice from April. The years 2011-2016 are chosen as the study
period when all the observations of SST, SIC and SIT are available (although SIT is only available during winter
period). The model is initialized with monthly mean ocean and sea ice state from the UK Met Office's
Forecasting Ocean Assimilation Model (FOAM). A nudging scheme is employed to assimilate the SST, SIC and
SIT, respectively. Both ERA-Interim and ERA5 atmospheric reanalysis are used to assess the effect of
atmospheric impact.

2171
Fri_218_OS-4_2297
Superimposed Ice Contribution to Arctic Sea-ice Mass in an Excessive Snow Region

Caixin Wang1 (wang_caixin@126.com), Anja Rösel2, Keguang Wang1, Robert Graham2, Mats Granskog2,
Sebastian Gerland2
1
Norwegian Meteorological Institute, Tromso, Norway, 2Norwegian Polar Institute, Fram Centre, Tromso,
Norway

Snow on sea ice may delay or slow down the growth and melt of sea ice due to its strong insulative properties
and high albedo. It also can directly contribute to sea-ice mass balance through superimposed ice.
Superimposed ice is a layer of ice formed at the snow-ice interface from freezing water (e.g. melted snow,
liquid precipitation) on contact with underlying cold sea ice. Its contribution to sea-ice mass is substantial in the
Antarctic and sub-Arctic seas . It also forms in the Arctic, but has not attracted much attention. With the
thinning of the Arctic sea ice, the warming of Arctic and possible increase in precipitation, superimposed ice
may become more important. During the Norwegian young ICE expedition N-ICE2015, excessive amount of
snow were found on sea ice north of Svalbard and the contribution of snow to sea-ice mass was up to 15%.
Studies indicate that this might be typical for this region where frequent storms bring precipitation into the ice
pack. During the N-ICE2015, an Ice Mass Balance buoy (IMB) was deployed at 82.2° N in late May 2015 and
then drifted towards Fram Strait. The IMB recorded the evolution of snow and ice thickness until 6 July 2015
when it reached 78.9° N. Ice cores from Fram Strait in summer 2015 indicated that superimposed ice had been
formed. Using 1-D sea ice models, we examine how snow depth, date of melt onset and other factors affects
the formation and role of superimposed ice in Arctic sea-ice mass balance.

2172
Fri_219_OS-4_2307
A Probabilistic Verification Score for Contours Applied to the Arctic Ice Edge

Helge Goessling1 (helge.goessling@awi.de), Thomas Jung1

1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany

We introduce a verification score for probabilistic forecasts of contours—the Spatial Probability Score (SPS).
Defined as the spatial integral of local (Half) Brier Scores, the SPS can be considered the spatial analog of the
Continuous Ranked Probability Score (CRPS). Applying the SPS to idealised ensemble forecasts of the Arctic sea-
ice edge in a global coupled climate model, we demonstrate that the metric responds properly to ensemble
size, spread, and bias. When applied to individual forecasts or ensemble means (or quantiles), the SPS is
reduced to the 'volume' of mismatch, in case of the ice edge corresponding to the Integrated Ice Edge Error
(IIEE). By comparing initialised forecasts with climatological and persistence forecasts, we confirm earlier
findings on the potential predictability of the Arctic sea-ice edge from a probabilistic viewpoint. We conclude
that the SPS is a promising probabilistic verification metric, for contour forecasts in general and for ice-edge
forecasts in particular.

2173
Fri_220_OS-4_2323
A Dataset of Linear Kinematic Features (LKFs) to Evaluate Sea Ice Deformation

Nils Hutter1 (nils.hutter@awi.de), Lorenzo Zampieri1, Martin Losch1

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany

The Arctic sea ice deforms continuously due to stresses imposed by winds, ocean currents and interaction with
coastlines. The most dominant features produced by this deformation in the ice cover are leads and pressure
ridges that are often referred to as Linear Kinematic Features (LKFs). With increasing resolution of classical
(viscous-plastic) sea ice models, or using new rheological frameworks (e.g. Maxwell elasto-brittle), sea-ice
models start to resolve this small-scale deformation. Typical measures for evaluating the modelled LKFs include
scaling properties of sea-ice deformation or lead area density. These metrics avoid the problem of detecting
individual LKFs by applying statistics over continuous fields such as sea ice deformation or concentration. In this
way, these statistical metrics can provide specific information, but lack a comprehensive description of LKFs.
We detect individual LKFs in sea ice deformation fields from satellite observations with an object detection
algorithm. Combining this information with the sea ice drift fields used to derive the deformation fields, the
LKFs are tracked in time. In doing so, the spatial characteristics (density, length, orientation, intersection angle,
curvature) and the temporal evolution can be extracted from the same data-set. Our algorithm can be applied
to both observed and modelled sea-ice deformation and drift making possible a consistent comparison and
thorough evaluation.

2174
Fri_221_OS-4_2512
Improved Sea Ice Edge Prediction Based on Ice Chart Uncertainty Metrics

Penelope Wagner1 (penelopew@met.no), Sean Helfrich2, Nick Hughes1, Antti Kangas3

1
Norwegian Meteorological Institute, Norwegian Ice Service, Tromsø, Norway, 2NOAA, Center for Satellite
Applications and Research (STAR), Washington D.C., United States, 3Finnish Meteorological Institute, Finnish Ice
Service, Helsinki, Finland

Ice charts include a composite of near-real time sea ice information to provide consistent, reliable, and timely
information for ship operators. With the onset of satellite sea ice record from 1979, data from ice charts have
shown potential to improve the climatology record. There is the assumption that the methodology and data
sources, and the resulting bias in the charts, has remained consistent. However, there have been significant
improvements to sources going into ice charts. Information integrated into manual and automated operational
ice products is often misunderstood because it is dependent on operational needs and these vary from those of
the science community. The scientific community requires operational ice information that includes
uncertainties. Uncertainties with human bias in ice charts are difficult to quantify, but can be accounted for by
the data sources, “smearing” of the imagery into polygons, interpreter bias, and time difference between
charting and data sources. A test algorithm has been developed to account for these uncertainty metrics.
Imagery interpretation bias was prioritized due the potentially large contribution and little knowledge of this
error source. A study was developed and tested with a training manual given to ice analysts to gauge their
competency in evaluating ice information from various sources. The training results demonstrate the capability
of the ice chart uncertainty metric to quantify the human bias and other uncertainties.

2175
Fri_222_OS-4_2557
Multi-model Long-range Forecasting of Sea Ice through WMO's Arctic PRCC

Arlan Dirkson1 (arlan.dirkson@gmail.com), Bill Merryfield2, Bertand Denis3

1
University of Victoria, Victoria, Canada, 2Environment and Climate Change Canada, Canadian Centre for
Climate Modelling and Analysis, Victoria, Canada, 3Environment and Climate Change Canada, Dorval, Canada

The World Meteorological Organization (WMO) is establishing a multi-node Arctic Polar Regional Climate
Centre (PRCC) whose functions include long-range forecasting of Arctic sea ice. Through the YOPP-endorsed
project “Forecasting Regional Arctic Sea Ice from a Month to Seasons” (FRAMS), capacity is being developed to
produce multi-model, user-relevant sea ice forecast products. This presentation will describe developments
that have occurred thus far under FRAMS and the anticipated next steps. Included in these initial developments
is the extension of a procedure for producing probabilistic seasonal forecasts of local sea ice coverage to a
multi-model forecasting framework. Such probabilistic forecasts that represent uncertainty can be essential for
end-users who want to quantify risk and make decisions taking forecast uncertainty into account. This
methodology consists of fitting single-model ensemble forecasts of local sea ice concentration to a well-suited
probability distribution, and then calibrating these distributions using trend-adjusted quantile mapping. Here
we report on the utility of this approach in the context of multi-model probabilistic forecasting by combining
calibrated outputs from different models and comparing these forecasts against reference probabilistic
forecasts based on simpler techniques.

2176
Fri_223_OS-4_2567
The Statistical Seasonal Forecast Model of the Norwegian Ice Service

Nicholas Hughes1 (nick.hughes@met.no)

1
Norwegian Meteorological Institute, Norwegian Ice Service, Tromsø, Norway

The Norwegian Ice Service has developed and run since 2013 a statistical seasonal forecast model to predict
the future sea ice area in waters around the Svalbard archipelago. The objective is to provide an indication to
the ice service, and its users, of the likely severity of the next ice season in the area. This take as inputs sea ice
data from the operational ice charts, and uses a combination of environmental input data including sea level
pressure (SLP) data from the NCEP/NCAR Reanalysis 1 and sea surface temperature (SST) from the NOAA
Extended Reconstructed Sea Surface Temperature V3b. This data has been run through the data mining
software Weka to assess the utility of a number of machine learning techniques to seasonal prediction.
Recently, the forecasts have also been forced up to 6 months in advance using SLP and SST ensemble
predictions from the ECMWF Seasonal Forecast System to provide a spread of possible outcomes. We report
here on the techniques used, and evaluate the effectiveness of the model forecasts.

2177
Fri_224_OS-4_2573
A Network Model for Characterizing Brine Channels in Arctic Sea Ice

Rachel Obbard1 (rachel.w.obbard@dartmouth.edu), Scott Pauls2, Sahaj Shah1, Ross Lieb-Lappen1

1
Dartmouth College, Thayer School of Engineering, Hanover, United States, 2Dartmouth College, Department of
Mathematics, Hanover, United States

The permeability of sea ice is a fundamental characteristic with implications in atmospheric chemistry, polar
biology and oceanography. Permeability is controlled by a complex network of brine channels that develops as
the ice forms and whose nature depends upon ice type, depth, and temperature.
Recent advances in three-dimensional imaging using x-ray micro-computed tomography have enabled the
quantification of the brine network morphology and variability. Using imaging of first-year sea ice samples
collected near Utqiaġvik, Alaska, we have collected statistics on brine channel geometry that have allowed us
to parameterize the pore networks based on the variables mentioned above. This enables us to create a
mathematical network model to characterize the topology and connectivity of brine channels. An initial set of
nodes at the top of the sea ice column is selected, where the nodes have throat sizes consistent with the
probability distribution found in natural sea ice. Branches can grow or shrink, split into multiple branches, join
with other branches, remain constant, or stop, all with probabilities dependent upon the given node throat
size, depth/temperature, and proximity to other nodes. The model produced can help address questions such
as how fluid flow varies with depth and temperature and to what extent it is microstructure and path
dependent.

2178
Fri_225_OS-4_2665
Past, Present and Future of Arctic Based on Global Coupled Climate Models

Fernanda Casagrande1,2 (fe.casagrande2@gmail.com), Ronald Souza1, Paulo Nobre2

1
National Institute for Space Research, Antarctic Program, Santa Maria, Brazil, 2National Institute for Space
Research, Cachoeira Paulista, Brazil

The response of Arctic region to an increase in atmospheric GHG concentrations simulated by climate models is
investigated here using the Brazilian Earth System Model (BESM) and compared with CMIP5 models dataset.
We evaluated the ability of climate models to represent the Arctic sea ice changes and climate sensitivity to the
atmospheric Carbon dioxide (CO2) forcing. To do this, we used decadal simulations (1980- 2012), Future
scenarios with Representative Concentration Pathway RCP 4.5 and RCP 8.5 (2006-2100) and quadrupling of the
atmospheric CO2 concentration (2006-2300). We validated our results with satellite observations. BESM results
for the Arctic sea ice seasonal cycle are consistent with CMIP5 models and observations. However, almost all
models tend to overestimate Sea Ice Extent (SIE) in March compared to observations. Future scenarios show
dramatic decrease in SIE as response to an increase in radiative forcing. The projected future sea ice loss is
explained by the combined effects of both: the amplified warming in northern hemisphere and climate
feedbacks. The quadrupling of CO2 concentration numerical experiment shows the amplified warming as
response to CO2 forcing with strongest warming in winter and Autumn season. The interdisciplinar effects of
Anthropogenic forcing in Arctic region still are considering a hot topic and lack conclusive answers.

2179
Fri_226_OS-5_151
Impact of Snow Salinity on CryoSat-2 Arctic Sea Ice Freeboard Measurements

Vishnu Nandan1 (vishnunandan.nandaku@ucalgary.ca), John Yackel1, Torsten Geldsetzer1, Mallik Mahmud1

1
University of Calgary, Geography, Calgary, Canada

The European Space Agency's CryoSat-2 satellite radar altimeter mission provides sea ice freeboard data that
are used to derive estimates of sea ice thickness and volume. These data are crucial to understanding recent
variability and changes in Arctic sea ice. Sea ice thickness retrievals at the CryoSat-2 frequency require accurate
measurements of sea ice freeboard, assumed to be attainable when the main radar scattering horizon
originates at the snow/sea ice interface. Using an extensive snow thermophysical property dataset from late
winter conditions in the Canadian Arctic, we examine the role of saline snow on first-year sea ice (FYI), with
respect to its impact on the location of the main radar scattering horizon, its potential ability to decrease radar
penetration depth, and its subsequent impact on FYI thickness estimates. Based on the dielectric properties of
saline snow commonly found on FYI, we quantify the vertical shift in the CryoSat-2 main scattering horizon.
This is found to be approximately 0.07 m. We propose a thickness-dependent snow salinity correction factor
for FYI freeboard estimates. This significantly reduces CryoSat-2 FYI thickness retrieval error. Relative error
reductions of ~ 11% are found for an ice thickness of 0.95 m and ~ 25% for 0.7 m. Our method also helps to
close the uncertainty gap between SMOS and CryoSat-2 thin ice thickness retrievals. Our results demonstrate
that snow salinity should be considered for FYI freeboard estimates.

2180
Fri_227_OS-5_172
Retrieving Sea Ice Surface Elevation and Total Freeboard from MABEL Data

Xiaoyan Wang1 (wangxiaoy@lzu.edu.cn), Hongjie Xie2, Alberto M. Mestas-Nuñez2, Stephen F. Ackley2

1
Lanzhou University, Lanzhou, China, 2University of Texas at San Antonio, San Antonio, United States

Multiple Altimeter Beam Experimental Lidar (MABEL), the simulator of NASA's Ice, Cloud and land Elevation
Satellite-2 (ICESat-2) to be launched in 2018, is the first of its kind to use a photon-counting technique for
mapping ice surface elevation. In this paper, we will present the MABEL dataset collected over sea ice off
Greenland (northwest, north, and northeast), describe its data processing, and discuss an application to the
retrieval of sea ice elevation and sea ice total freeboard. The signal photons are first separated from noise
photons using a histogram-based surface-finding algorithm provided by NASA. The resulting signal photons are
then low-pass filtered with three different methods (Gaussian, Wavelet, and LOESS) to estimate the ice surface
elevation. The Wavelet method seems to give better results than the other two. The open water/lead along the
track are discriminated solely on the different photon numbers of signal and background, with open water/lead
usually having much smaller number of signal and background photons than other surfaces. The total
freeboard values of ice floe are then retrieved as the difference of surface elevation and water/lead elevation,
after the correction of mean sea surface height is applied. It is expected that the data analysis procedures
developed for MABEL data will serve as a guide for data processing and applications of ICESat-2 data.

2181
Fri_228_OS-5_254
Snowmelt Processes on Antarctic Sea Ice Observed by Satellite Scatterometers

Stefanie Arndt1 (stefanie.arndt@awi.de), Christian Haas1,2

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Sea Ice Physics, Bremerhaven,
Germany, 2University of Bremen, Institute of Environmental Physics, Bremen, Germany

Snowmelt processes on sea ice are the key drivers determining the seasonal sea-ice energy and mass budgets.
While there is strong surface melt on Arctic sea ice, snowmelt on Antarctic sea ice is weak with most snow
surviving the summer. Here, we compile time series of snowmelt onset dates on perennial Antarctic sea ice
from 1992 to 2014 using active microwave observations from European Remote Sensing Satellite (ERS-1/2),
Quick Scatterometer (QSCAT) and Advanced Scatterometer (ASCAT) radar scatterometers. Describing snow
melt processes, we define two transition stages: A weak backscatter rise indicating the initial warming and
metamorphosis of the snowpack (pre-melt), followed by a rapid rise indicating the onset of thaw-freeze cycles
(snowmelt). Results show large interannual variability with average pre-melt and snowmelt onset dates of 29
November and 10 December, respectively, without any significant trends over the study period. Related to
different signal frequencies, we show that QSCAT Ku-band (13.4 GHz signal frequency) derived pre-melt and
snowmelt onset dates are earlier by 25 and 11 days, respectively, than ERS and ASCAT C-band (5.6 GHz) derived
dates. This offset has been considered when constructing the time series. As different signal frequencies result
in different penetration depths, we hypothesize that the different sensors respond to typical snowmelt
processes in different depths within the snow cover.

2182
Fri_229_OS-5_265
PIPERS: SAR backscatter parameters and co-located LiDAR scans in the Ross Sea

Blake Weissling1 (blake.weissling@utsa.edu), Stephen Ackley1, Julie Parno2

1
University of Texas at san antonio, San Antonio, United States, 2Cold Regions Research and Engineering Lab,
Hanover, United States

The austral autumn sea ice cruise to the Ross Sea and Terra Nova Bay under the research project PIPERS
(Polynyas, Ice Production and Seasonal Evolution in the Ross Sea) presented extraordinary opportunities to
acquire co-located SARS imagery and terrestrial laser (LiDAR) scans of the sea ice surface during autumn freeze-
up conditions. Numerous sites, representing mixed first-year ice types (nilas, consolidated pancakes, and ridged
first year) were laser scanned at sub-centimeter scale using a Riegl VZ-1000 LiDAR scanner in both on-the-ice
surveys from multiple scan positions and single-position scans from the high vantage point of the ship's (N.B.
Palmer) bridge wing. Scans generally encompassed areas of at least 100m x 100m with sufficient point cloud
returns to generate surface topography rasters at better than 5 cm resolution. SAR data from two high-
resolution polar orbiting satellites (TerraSAR-X and Sentinal 1) were co-spatial and co-temporally acquired of
the LiDAR survey sites. We present comparisons of raw backscatter, entropy, and roughness parameters from
the polarimetric SAR data for direct comparison to sea ice topography and elevation-derived surface roughness
parameters. Very thin or non-existent snow cover during the cruise period will negate some of the problematic
volume scattering seen in other SAR imagery, and allow better interpretation of the backscatter signal from this
imagery in terms of ice type.

2183
Fri_230_OS-5_343
Snow Cover Observations on Antarctic Sea Ice from in-situ and Model Studies

Leonard Rossmann1 (leonard.rossmann@awi.de), Marcel Nicolaus1, Michael Lehning2,3, Stefani Arndt1, Nina
Maaß4, Lars Kaleschke4, Nander Wever2, Christian Haas1
1
Alfred Wegener Institute, Bremerhaven, Germany, 2WSL Institute for Snow and Avalanche Research SLF, Davos,
Switzerland, 3École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Universität Hamburg, ZMAW,
Hamburg, Germany

The snow cover on Antarctic sea ice impacts the energy, mass, and momentum balance of the sea ice cover.
This strongly influences fluxes between ocean, sea ice, and atmosphere. The snow depth is qualified as an
Essential Climate Variable, whereas the knowledge of the snow cover distribution and properties is still mostly
vague and no large-scale snow depth data product is available. The Snow cover is characterized through a high
spatial and temporal variability, and shows a highly heterogeneous internal stratification. This poses a
challenge to air or space borne snow depth retrieval algorithms. Similarly, sea ice models are not yet able to
resolve snow processes with enough accuracy.
Here we present measurements of snow depth and physical snow properties along drift trajectories of
autonomous Snow Buoys, which were deployed in the Weddell Sea since 2014. Resulting time series of snow
depth show an event driven snow accumulation even during austral summer, whereas melting and a significant
decrease of snow depth is only observed along the marginal sea ice zone. Additional analysis with the 1D multi-
layer thermodynamic snow model SNOWPACK provides insights into internal processes such as snow to ice
development. For these studies the previous land-based snow model SNOWPACK has been extended with a sea
ice module and is forced with re-analysis data. Comparisons between model and in-situ measurements show
the capability of the model to reproduce the prevalent snow stratigraphy.

2184
Fri_231_OS-5_407
Snow Depth Efficacy on the Retrieval of Arctic Sea Ice Thickness and Volume

Lu Zhou1 (zhou-l15@mails.tsinghua.edu.cn), Shiming Xu1, Jiping Liu2

1
Tsinghua University, Beijing, China, 2State University of New York at Albany, Albany, United States

Accurate understanding of snow loading and snow depth is crucial to sea ice thickness and volume retrieval
from satellite altimetry. This study accesses the efficacy of snow depth data in both radar and laser altimetry
using high resolution airborne OIB observation for 2010-2016. In addition, three reanalysis datasets (ERA-
Interim, JRA-55 and MERRA-2) are adopted to investigate long term changes in the snow loading and
accumulation speed. We also review inter-annual variability of snow loading both from climatology and
observations in the recent decade. Although there is potential for the retrieval of sea ice thickness distribution
(ITD) with current satellite data due to their high spatial resolution, the retrieval in state of the art methods are
compromised due to the lack of fine-scale snow depth and the covariability between snow depth and
freeboard, which has profound influence on the thickest part of basin-scale ITD. The effects are more
prominent in laser altimetry (ICESat). These results show that there exists lack of efficacy of existing snow
loading and snow depth data for satellite altimetry, and small-scale variability plays an important role in
retrieval for both types of altimetry.

2185
Fri_232_OS-5_458
Snow Metamorphism at the Interface between Ice and Snow

Mareike Wiese1 (mareike.wiese@slf.ch), Martin Schneebeli1

1
WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland

Temperature gradient snow metamorphism at the interface between ice and overlying snow shows a strongly
different evolution compared to the structural evolution in the bulk snowpack under the same mean
temperature gradient. We demonstrate that a positive temperature gradients leads to the formation of a new
interfacial snow layer caused by the sublimation of the ice. We measured these processeses by time-lapes
micro-tomography. Numerical simulations show a strong horizontal variability of the temperature gradient at
the sub-millimeter scale. This explains the macroscopically observed "enhanced" temperature gradient at such
interfaces. We conclude that this process is relevant for the evolution of the energy balance of a snowpack on
ice, but also for the chemical properties of the snowpack.

2186
Fri_233_OS-5_541
Retrieval of Snow Depth on Sea Ice from FY3B MWRI in the Arctic

Lele Li1 (lilele@ouc.edu.cn), Haihua Chen1, Lei Guan1

1
Ocean University of China, Qingdao, China

Given the high albedo and low thermal conductivity, Snow on sea ice is regarded as one of the key reasons for
the amplification of the warming in polar regions. This study focused on the retrieval of snow depth on sea ice
from brightness temperatures of the Microwave Radiation Imager (MWRI) on board the FengYun (FY)-3B
satellite during the period from December 1, 2010 to April 30, 2011. After cross calibrated to the Advanced
Microwave Scanning Radiometer-EOS (AMSR-E) Level 2A data, the MWRI brightness temperatures were
applied to calculate the sea ice concentrations based on the Arctic Radiation and Turbulence Interaction Study
Sea Ice (ASI) algorithm. The snow depths were derived according to the proportional relationship between the
snow depth and the surface scattering in 18.7 and 36.5 GHz. In order to eliminate the influence of uncertainties
in grain sizes of snow as well as sporadic weather effects, the seven-day averaged snow depths were
calculated. Then the results were compared with the snow depths from two data sets: IceBridge ICDIS4 data
set and the AMSR-E Level 3 Sea Ice products. The bias and standard deviation of differences between the
MWRI snow depth and the IceBridge data are 3.34 cm and 2.79 cm for a total of 52 matchups, respectively.
And the biases between the MWRI and the AMSR-E Level 3 products are ranged between -1.09 and -0.32 cm. It
is proved that the method taken in this study is feasible and the results are reasonable.

2187
Fri_234_OS-5_674
Snow Depth on Arctic Sea Ice from Passive Microwave Radiometers

Philip Rostosky1 (prostosky@iup.physik.uni-bremen.de), Gunnar Spreen1, Marcus Huntemann1, Torben Frost1,2,

Georg Heygster1, Christian Melsheimer1
1
University of Bremen, Institute of Environmental Physics, Bremen, Germany, 2Fudan University, Department of
Physics, Shanghai, China

Snow depth on Arctic sea ice is one of the key parameters to describe and understand changes in the Arctic
climate. Due to its low thermal conductivity, snow strongly influences the growth and melt of Arctic sea ice.
Snow has a high albedo and is therefore important for the Arctic energy budged. Sea ice thickness retrievals
from altimetry rely on accurate snow depth and density estimations.
Observations from satellite radiometers provide a great tool to monitor the Arctic region on a daily and Arctic-
wide scale. The first retrieval for snow depth on sea ice was developed by Marcus and Cavalieri and is based on
passive microwave satellite observations at 19 and 37 GHz. However, in the Arctic, the retrieval is limited to
seasonal ice and snow depths below 50 cm. In addition, rough ice and snow metamorphism can strongly
influence the retrieval.
In this study, a new retrieval for snow on Arctic sea ice is derived using multiple AMSR-E/2 frequency
combinations. The retrieval is trained with airborne snow depth measurements obtained from the NASA
Operation IceBridge campaigns. First results indicate a good performance of the retrieval over seasonal ice and
a reasonable performance over multiyear ice. In a study with the Microwave Emission Model MEMLS, the
theoretical influences of different snow and ice properties on the retrieval are investigated using in situ
measurements from the N-ICE2015 campaign. Additionally, the effects of salty snow and snow metamorphism
are analyzed.

2188
Fri_235_OS-5_706
Snow Depth on Arctic Sea Ice from Historical in Situ Data

Elena Shalina1, Stein Sandven2 (stein.sandven@nersc.no)

1
NIERSC, St. Petersburg, Russian Federation, 2NERSC, Bergen, Norway

The snow layer on top of the sea ice plays an important in the retrieval of ice freeboard and thickness from
satellite altimeter data. In situ observations of the snow layer is needed as input to the retrieval algorithms and
for validation of the resulting thickness estimates. In this study snow data from the Soviet airborne expeditions
Sever have been analyzed for the period 1959-1986, combined with data from the North Pole Drifting stations,
in order to estimate the snow depth climatology for March, April, and May. The data covers the essential parts
of the Arctic sea ice areas, with most data in the Eurasian seas. The following snow parameters have been
analyzed: average snow depth on the level ice, height, and area of sastrugi, depth of snow dunes attached to
ice ridges and depth of snow on hummocks. The research resulted in a new snow depth climatology for the
winter months, showing lower values compared to the Warren climatology in the central Arctic and more
detailed estimates for the Eurasian seas. The analysis of the Sever data showed that the average depth of
undisturbed snow on the level ice varied from 9.8 cm in the Laptev Sea to 15.3 cm in the East Siberian Sea. The
highest values in the East Siberian Sea are explained by the larger proportion of multiyear ice which generally
has thicker snow layer than first-year ice. The new climatology of snow depth will be a useful reference data
against which new observations can be compared.

2189
Fri_236_OS-5_835
Deformed ice and Level Ice Distinction from Dual-polarized Sentinel-1

Tingting Zhu1, Fei Li1,2 (fli@whu.edu.cn), Yu Zhang3, Shengkai Zhang3, Gunnar Spreen4, Georg Heygster4,
Wolfgang Dierking5
1
Wuhan University, Collaborative Innovation Center for Territorial Sovereignty and Maritime Rights, Wuhan,
China, 2Wuhan University, The State Key Laboratory for Information Engineering in Surveying, Mapping and
Remote Sensing, Wuhan, China, 3Wuhan University, Chinese Antarctic Center of Surveying and Mapping,
Wuhan, China, 4University of Bremen, Institute of Environmental Physics, Bremen, Germany, 5AWI,
Bremerhaven, Germany

SAR is the most promising technique for observing sea ice conditions in polar regions due to its all-weather and
all-day availability. Sea ice consists of level and deformed ice floes covering the polar sea zone. It is significant
to understand the relationships between deformed ice and thickness redistribution when Arctic sea ice
thinning since deformed ice including ridges and brash ice over first year and multiyear ice dominates Arctic
surface topography, which alludes to importance of ice deformation distribution in the total ice volume.
Although different scattering mechanisms of deformed ice and level ice provide the proxy for sea ice type
distinction, level ice and deformed ice distinction can only rely on SAR backscatter intensity from Sentinel-1. An
operational algorithm is developed in combination with rich features to capture texture pattern of deformed
ice and level ice. The rich features to depict the deformation ice pattern including ridges, brash ice and rubble
surface field include ridging density, deformation pattern geometry characteristic, GLCM texture and surface
roughness. We focus on Fram Strait, where is a faster export of sea ice allowing larger drifting speed and
deformation using Sentinel-1 dual polarization data from October, 2014 to October, 2017 for ice deformation
identification based on the SVM by feeding rich features. The deformation distribution will be used to retrieve
snow depth over sea ice with different roughness surface.

2190
Fri_237_OS-5_970
Impact of Melting Snow and Melt Ponds on AMSR-E Sea-ice Concentrations

Stefan Kern1 (stefan.kern@uni-hamburg.de), Louisa Bell2, Leif T. Pedersen3

1
University of Hamburg, Center for Climate System Research and Sustainability (CEN), Hamburg, Germany,
2
University of Hamburg, Hamburg, Germany, 3Danish Technical University, Lyngby, Denmark

Brightness temperatures (TB) observed by satellite microwave radiometers allow us to retrieve the sea-ice area
fraction (sea-ice concentration or SIC) with an accuracy of ~ 2% during winter. The accuracy during the melting
season is unknown. Once melting of the snow cover on sea ice commences, TBs change - first due to the snow
wetness and/or an elevated snow grain size due to melt-refreeze cycles, later due to the formation of melt
ponds, i.e. puddles of melt water on the snow or ice surface. Because the penetration depth of microwave
radiation into liquid water is about a few millimeters, melt ponds have the same radiometric signature as open
water in leads and openings between ice floes. Consequently, SIC retrieved over sea ice covered with melt
ponds should represent the net ice surface fraction (ISF). Here we show results of our analysis of the joint
EUMETSAT OSISAF - ESA CCI SIC data products. Time-series of SIC suggest an increase in fractions of SIC near
100% during early melt (May/June) indicative of the impact of wet snow. Inter-comparison with melt-pond
fraction (MPF), 1 minus open-water fraction from leads and openings (SIC_M), and ISF derived from MODIS
optical data reveals an overall negative bias between SIC and SIC_M of only ~1%. However, from a more
detailed analysis we find regional biases between SIC and SIC_M ranging from -20% to +10%. We also find that
SIC exceeds ISF by up to 35%; this over-estimation often but not always equals the MPF.

2191
Fri_238_OS-5_1267
Studying a Full Year of Snow on Arctic Sea Ice - Plans for MOSAiC 2019/20

Marcel Nicolaus1 (marcel.nicolaus@awi.de), Sebastian Gerland2, Donald K. Perovich3

1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany,
2
Norwegian Polar Institute, Fram Centre, Tromso, Norway, 3Dartmouth College, Hanover, United States

The snow cover on sea ice dominates many exchange processes and properties of the ice covered polar oceans.
While it is known for its extraordinarily large spatial and temporal variability, snow properties and even snow
depth distributions are among the least known and most difficult to observe climate variables. Starting in
autumn 2019 and ending in autumn 2020, the international MOSAiC drift experiment will allow to observe the
evolution of a snow pack on Arctic sea ice over a full annual cycle. During the drift with one ice floe along the
transpolar drift, we will be able to perform most comprehensive studies on seasonal sea ice and relate them to
previous expeditions and parallel observations at different locations. Here we present the current status of our
planning of the MOSAiC snow program. The field program will include regular manual observations and
sampling on the main floe of the central observatory, autonomous recordings in a distributed network,
airborne observations in the surrounding, and retrievals of satellite remote sensing products. Along with the
field program, numerical simulations of the MOSAiC snow cover will be performed on different scales, including
large-scale interaction with the atmosphere and the sea ice. The snow studies will also bridge between the
different disciplines, including physical, chemical, biological, and biogeochemical measurements, samples, and
fluxes.

2192
Fri_239_OS-5_1286
Impact of Sea Ice Thickness and Freeboard Products on Forecast Performance

Thomas Kaminski1 (thomas.kaminski@inversion-lab.com), Frank Kauker2,3, Leif Toudal Pedersen4,5, Michael

Vossbeck6, Helmuth Haak7, Laura Niederdrenk7, Stefan Hendricks3, Robert Ricker3, Michael Karcher2,3, Haijo
Eicken8, Ola Grabak9
1
The Inversion Lab, Hamburg, Germany, 2Ocean Atmosphere Systems, Hamburg, Germany, 3Alfred Wegener
Institute for Polar and Marine Research, Bremerhaven, Germany, 4eolab.dk, Copenhagen S, Denmark, 5DTU
Space - National Space Institute, Lyngby, Denmark, 6Inversion Lab, Hamburg, Germany, 7Max Planck Institute
for Meteorology, Hamburg, Germany, 8Geophysical Institute, University of Alaska, Fairbanks, United States,
9
European Space Agency ESRIN, Frascati, Italy

The A+5 project of ESA's Arctic+ initiative has constructed a flexible system for Arctic Mission Benefit Analysis
(ArcMBA) that evaluates in a mathematically rigorous fashion the observational constraints imposed by
individual and groups of EO data products in using the quantitative network design (QND) approach.
The assessment of the observation impact (added value) is performed in terms of the uncertainty reduction in
a four-week forecast of sea ice and snow volumes for three regions along the Northern Sea Route.
The assessments covered seven EO products, three real products and four hypothetical products.
The real products are monthly sea ice thickness (SIT), sea ice freeboard (SIFB), and radar freeboard (RFB), all
derived from CryoSat-2 by AWI. These are complemented by two hypothetical laser freeboard products and
two hypothetical snow depth products.
On the basis of the per-pixel uncertainty ranges that are provided with the CryoSat-2 products, the SIT achieves
the best performance for SIV forecasts. For SNV, the performance of RFB is better. A hypothetical laser
freeboard (LFB) product with low accuracy has a similar impact as RFB on both SIV and SNV. A reduction in the
uncertainty of the LFB product yields a significant increase in performance.
Combining with a hypothetical snow depth product achieves a significant performance.

2193
Fri_240_OS-5_1287
Snow on Sea Ice from Models and Measurements

Leif Pedersen1 (ltp@space.dtu.dk), Till Rasmussen2, Kasper Holst Lund2, Rasmus Tonboe2
1
DTU Space - National Space Institute, Lyngby, Denmark, 2Danish Meteorological Institute, Copenhagen Ø,
Denmark

Variability in thickness, density and emissivity of snow on sea ice is a major limiting factor for the accuracy of
sea ice thickness retrievals from laser and radar altimetry as well as for ice concentration retrievals from
microwave radiometer measurements.
In addition, snow plays a significant role in sea ice thermodynamics by limiting sea ice growth rates due to its
strong insulating effect.
In this study, we have compared a number of datasets for snow on sea ice obtained from operational ice/ocean
models, climate models and remote sensing observations. We have compared the snow thicknesses obtained
by the different methods to radar snow depth measurements from NASAs Operation Ice Bridge (OIB) and we
find significant differences between models as well as between observation datasets.

2194
Fri_241_OS-5_1806
Sea Ice Concentration Observed Low Microwave Frequency Radiometers

Carolina Gabarro1 (cgabarro@icm.csic.es), Mukesh Gupta1, Justino Martinez1, Antonio Turiel1

1
Institute of Marine Research ICM-CSIC, BEC, Barcelona, Spain

The launch of the Soil Moisture and Ocean Salinity (SMOS) mission, in 2009, marked the dawn of a new type of
space-based microwave observations. Although the mission was originally conceived for hydrological and
oceanographic studies, SMOS is also making inroads in the cryospheric sciences by measuring the thin ice
thickness. SMOS carries an L-band (1.4 GHz), passive interferometric radiometer (the so-called MIRAS) that
measures the electromagnetic radiation emitted by the Earth's surface, at about 50 km spatial resolution,
continuous multi-angle viewing, large wide swath (1200-km), and with a 3-day revisit time at the equator, but
more frequently at the poles. AMSR-2 instrument is on JAXA´s GCOM-W1 spacecraft, and was launched on
2012. AMSR-2 have radiometers working at several bands: 6.9, 7.3, 10.65, 18.7, 23.8, 36.5, and 89.0 GHz.
An assessment on the differences on the sea ice concentration (SIC) maps obtained from low microwave
frequencies radiometers, 6.9GHz (from AMSR-2) and SMOS, versus higher frequency (19Ghz and 37GHz)
radiometers are presented. Despite its lower spatial resolution relative higher frequencies, SMOS-derived SIC
products are little affected by the atmosphere and the snow (almost transparent at L-band). Moreover L-band
measurements are more robust in front of the accelerated metamorphosis and melt processes during summer
affecting the ice surface fraction measurements.

2195
Fri_242_OS-5_1828
Potential of Snow-ice Formation in the Arctic

Anja Rösel1 (anja.rosel@npolar.no), Robert M. Graham1, Mats A. Granskog1, Ioanna Merkouriadi1, Glen E.
Liston2, Bin Cheng3, Polona Itkin1, Sebastian Gerland1
1
Norwegian Polar Institute, Research Department, Tromsø, Norway, 2Colorado State University, Cooperative
Institute for Research in the Atmosphere (CIRA), Fort Collins, United States, 3Finnish Meteorological Institute,
Helsinki, Finland

As a consequence of a general thinning of Arctic sea ice the snow depth to sea-ice thickness ratio is increasing.
At some point, this will result in more widespread negative freeboard in parts of the Arctic, where the snow
depth at a given time in a season stays constant or increases. These areas could potentially be flooded in case
of mechanical breaking of ice due to deformation or when sea ice becomes permeable. Flooding of sea ice can
create new habitats for snow infiltrating phytoplankton communities. Flooding also effects remote sensing
applications, like radar based sea-ice thickness retrievals from CryoSat-2, by biasing the retrieved sea ice
thickness towards higher values. In colder months this flooded layer will freeze, creating snow-ice. Snow-ice
formation will release additional heat from the ocean to the atmosphere and contribute to the sea-ice mass
balance. These processes are widespread on seasonal sea ice in Antarctica. However, recent studies show a
significant occurrence of snow-ice in the Arctic Ocean north of Svalbard in 2015, due to the high precipitation in
this region compared with other parts of the Arctic. In this study we examine the potential of flooding and
subsequent snow-ice formation in different regions of the Arctic Ocean with respect to inter-annual variability
of snow precipitation and sea-ice thickness, by using a 1D-snow/ice thermodynamic model forced with sea ice
drift and reanalysis data.

2196
Fri_243_OS-5_1925
Construction of Snow Depth Statistical Model Based on IMB Data on Arctic Sea Ice

Qing Ji1 (jiqing@whu.edu.cn), Xiaoping Pang1, Xi Zhao1, Qingquan Liu1, Ruibo Lei2
1
Chinese Antarctic Center of Surveying and Mapping, Wuhan University, Wuhan, China, 2Key Laboratory for
Polar Science of the State Oceanic Administration, Polar Research Institute of China, Shanghai, China

Snow cover on Arctic sea ice is crucial to the global climate system through snow-ice albedo feedback
mechanism. In order to solve the issue of lacking of snow depth information on Arctic sea ice at a large spatial
scale, we constructed the snow depth model using the Ice Mass Balance buoys measurements in the Arctic,
compared with previous snow depth model, and analyzed the variation of monthly average snow depth on the
Arctic sea ice. The results show that the snow depth model built up in this paper efficiently reflects the
distribution of snow depth on Arctic sea ice, with the bias varies from -0.3 to 1.0cm, and -5% to 12% for mean
relative error. Monthly average snow depth calculated from the model indicates that the snow depth on the
Arctic sea ice rose gently from January to March, and stabilized in April and May, continued to decrease from
June to July and fell to the minimum in August. In September and October, the snow depth increased rapidly in
the Canadian Arctic Archipelago and Northern Greenland. The snow depth model constructed in this paper can
provide basic information and reference for the study of sea ice and global climate change.

2197
Fri_244_OS-5_2072
White Snow Is Not White noise (Unfortunately)

Thomas Lavergne1 (thomas.lavergne@met.no), Rasmus Tonboe2, Signe Aaboe3, Leif Toudal Pedersen4
1
Norwegian Meteorological Institute, Oslo, Norway, 2Danish Meteorological Institute, Copenhagen, Denmark,
3
Norwegian Meteorological Institute, Tromsø, Norway, 4Danish Technical University, Lyngby, Denmark

In this contribution, the authors consider snow not as a (suite of) parameter(s) to be measured, but as an
impediment to the accurate retrieval of Sea Ice Concentration (SIC) and Type (SIType) from space-borne
Passive Microwave Radiometers (PMR). In the Arctic winter the accuracy of SIC and SIType retrieval algorithms
is at present limited by the lack of knowledge of snow characteristics such as depth, grain size, wetness,
density, layering and emissivity. State-of-the-art SIC algorithms allow retrieval uncertainties in the order of 3-
5% (1-sigma), but should aim to 0.5-1% to really be useful for constraining the heat fluxes through cracks and
leads.
We investigate the patterns of the noise observed in the recent EUMETSAT OSI SAF and ESA CCI SIC data
records, and link these to snow and upper sea ice properties. We also use emission models to illustrate how
snow contributes to the inaccuracies of SIC algorithms, and how the impact differs between the algorithms.
Inaccurate first-year/multi-year sea ice classification due to snow is also investigated in the Copernicus Climate
Change (C3S) sea ice type data record. We show how lack of knowledge of the snow parameters propagates as
non-white noise for the retrieval of SIC and SIType.
Finally, we show results from early attempts to either mitigate the influence of snow in the SIC algorithms, or
to jointly retrieve concentration, type, and snow parameters from multi-channels PMR such as the JAXA's
AMSR2.

2198
Fri_245_OS-5_2399
About a Way to Improve Snow-depth Retrieval for Antarctic Sea Ice

Burcu Ozsoy1 (ozsoybu@gmail.com), Stefan Kern2

1
Istanbul Technical University, Polar Research Center, Istanbul, Turkey, 2University of Hamburg, Integrated
Climate Data Center - ICDC, Hamburg, Germany

Snow on Antarctic sea ice is known for its large spatiotemporal variability. High cyclone activity causes a deeper
snow cover in the Antarctica. Physical properties like density, grain size, liquid water content, and salinity are
more diverse comparing to Arctic. This provides big challenges for the retrieval of sea ice concentration and sea
ice thickness from satellite observations. Particularly there is still an accurate data set of snow depth on sea ice
needed.
Satellite microwave radiometry (MWR) permits to retrieve snow depth on sea ice on hemispheric scale. Several
studies demonstrated, however, that these snow depth estimates are biased depending on various snow and
sea-ice properties. One of these is surface roughness. Combination of satellite MWR with surface roughness
information from altimetry was shown to mitigate this bias. We elaborated on this approach and combine the
along-track variability of total (sea ice and snow) freeboard estimates from ICESat laser altimeter observations
with the classic approach to compute snow depth because such surface roughness data is not available for the
entire satellite MWR. Therefore, we analyze a unique data set of ICESat roughness, satellite scatterometer
data, satellite microwave brightness temperatures (other than those used in the classic retrieval),
meteorological data from reanalysis, and ship-based observations of sea ice and snow properties to find a
proxy for the surface roughness.

2199
Fri_246_OS-5_2501
Physical and Optical Properties of Snow over Melting Arctic Sea Ice

Gauthier Verin1,2 (gauthier.verin@takuvik.ulaval.ca), Ghislain Picard1, Marcel Babin2, Laurent Arnaud1, Florent
Dominé2, Marie-Hélène Forget2, Joannie Ferland2
1
IGE, Université Grenoble Alpes, CNRS, IRD, St Martin d'Hères, France, 2Takuvik (CNRS & U Laval) and Québec-
Océan, Université Laval, Québec, Canada

Snow cover is a common and important feature in polar regions. It strongly affects the radiative transfer of
Arctic sea ice by increasing its reflectance and drastically reducing the amount of light reaching the water
column. As a consequence, the snow layer plays a crucial role with ocean primary production which is mainly
light limited before the onset of melt. Observing snow properties and sea ice optics is thus a fundamental key
to a better understanding of the links between snow and ocean biology.
Intensive snow samplings, covering the entire melt season, were conducted during GreenEdge campaigns in
2015 and 2016 over landfast sea ice near Qikiqtarjuaq community in Baffin Island. Optical properties such as
albedo, vertical profile of irradiance in snow and transmittance through the ice were measured as well as
physical properties including stratigraphy observations and vertical profiles of snow density and snow specific
surface area.
Based on these observations, the melt season can be divided in four main phases with very different signatures
in albedo spectra as a consequence of snow metamorphism. Among all parameters, snow height was the main
factor controlling transmittance. An ice algae bloom was observed in 2015, and its intensity depended on the
snow history which was derived from the vertical profile of snow physical properties. The onset of melting
marked the end of this bloom.

2200
Fri_247_OS-5_2622
Improving Observations and Understanding of Snow on Arctic Sea Ice: ESA Arctic+

Michel Tsamados1 (m.tsamados@ucl.ac.uk)

1
University College London, London, United Kingdom

Only satellite remote sensing can provide the pan-Arctic view required to fully understand changes to the
Earth's sea ice fields but important observational gaps remain which limit both our interpretation of remote-
sensing data and our understanding of the Arctic climate system. In that regard, snow on sea ice represents
both a major source of uncertainty in sea ice concentration and thickness retrievals from satellite data, and a
poorly resolved quantity of climatic importance. The overarching objective of this proposal is to address these
issues and to produce a state of the art now on sea ice thickness and density product. To achieve this goal we
will use data from the most advanced and recent EO missions.
We will utilize a comprehensive array of airborne and in-situ snow measurements to develop and validate two
independent approaches to snow thickness retrieval on Arctic sea ice. In the Dual-altimeter Snow Thickness
(DuST) product, we will utilize data from multiple contemporary satellite altimeters to derive information about
the snow layer. In the SNOw on Drifting Sea Ice (SnoDSI) product we will utilize satellite-derived sea ice drift
and precipitation from atmospheric reanalysis to build a package that accumulates, redistributes and melts
snow on individually tracked ice parcels at daily resolution. Because of the impact of the snow thickness and
density estimates for sea ice thickness retrievals this proposal will feed in the Arctic+ Theme 2: Sea Ice Mass
project.

2201
Fri_248_OS-5_1230
Snow Depth on Antarctic Sea Ice from Satellite: Time Series and Trends 2002 - 2017

Torben Frost1,2, Georg Heygster1 (heygster@uni-bremen.de), Stefan Kern3

1
University of Bremen, Institute of Environmental Physics, Bremen, Germany, 2Fudan University, Shanghai,
China, 3Universität Hamburg, Integrated Climate Data Center - ICDC, Hamburg, Germany

The high albedo and low heat conductivity of snow on sea ice strongly influence polar radiative processes and
heat transfer, needed for climate and numerical weather prediction models. Furthermore, accurate snow
depth data are required to retrieve sea ice thickness from altimeter freeboard measurements. Only passive
microwave sensors on satellites offer the possibility to continuously retrieve snow depth on Antarctic scale
independent of daylight and cloud cover. However, in the Antarctic specific processes (flooding, melting and
refreezing) together with sea ice ridges and leads cause highly variable snow properties so that often the
accuracy of the retrieved snow depth is not known.
Here the empirical snow-depth retrieval algorithm by Markus and Cavalieri (1998), later adapted to AMSR-E
(Advanced Microwave Scanning Radiometer for EOS) data by conversion of AMSR-E brightness temperatures to
SSM/I equivalent brightness temperatures (Comiso et al., 2003, Brucker and Markus, 2013) is re-calibrated
using visual ship-based observations from an extended ASPeCt data set (Worby and Allison, 1999, Worby et al.,
2008) on a monthly basis and by Antarctic sectors so that the resulting algorithm is directly applicable. A data
set for the years 2002-2017 will be presented together with a physical analysis of monthly average snow
depths sea ice concentration and air temperature, as well as their trends and correlations.

2202
Fri_249_OS-7_79
Vertical Ocean Heat Redistribution Sustaining Sea-Ice Trends in the Ross Sea

Olivier Lecomte1, Hugues Goosse1 (hugues.goosse@uclouvain.be), Thierry Fichefet1, Casimir de Lavergne2,3,4,

Antoine Barthélemy1, Violette Zunz5
1
Université catholique de Louvain (UCL), Earth and Life Institute, Georges Lemaître Centre for Earth and Climate
Research (ELI/TECLIM), Louvain-la-Neuve, Belgium, 2Sorbonne Universités (Université Pierre et Marie Curie Paris
6), Paris, France, 3CNRS-IRD-MNHN, Paris, France, 4LOCEAN Laboratory, Paris, France, 5Vrije Universiteit Brussel
(VUB), Earth System Science & Department of Geography, Brussels, Belgium

Several processes have been hypothesized to explain the slight overall expansion of Antarctic sea ice over the
satellite observation era, including externally forced changes in local winds or in the Southern Ocean's
hydrological cycle, as well as internal climate variability. Here, we show the critical influence of an ocean-sea-
ice feedback. Once initiated by an external perturbation, it may be sufficient to sustain the observed sea-ice
expansion in the Ross Sea, the region with the largest and most significant expansion. We quantify the heat
trapped at the base of the ocean mixed layer and demonstrate that it is of the same order of magnitude as the
latent heat storage due to the long-term changes in sea-ice volume. The evidence thus suggests that the recent
ice coverage increase in the Ross Sea could have been achieved through a reorganization of energy within the
near-surface ice-ocean system.

2203
Fri_250_OS-7_131
Holocene Sea Ice Variability Driven by Wind and Polynya Efficency in Ross Sea

Karin Mezgec1, Barbara Stenni2, Xavier Crosta3, Valerie Masson-Delmotte4, Carlo Baroni5, Martina Braida6,
Virginia Ciardini7, Ester Colizza6, Romana Melis6, Maria Cristina Salvatore5, Mirko Severi8, Claudio Scarchilli7,
Rita Traversi8, Roberto Udisti8, Massimo Frezzotti7 (massimo.frezzotti@enea.it)
1
University of Siena, Department of Physical Sciences, Earth and Environment, Siena, Italy, 2Ca' Foscari
University of Venice, Department of Environmental Sciences, Informatics e Statistics, Venice, Italy, 3Université de
Bordeaux, UMR-CNRS 5805 EP, Pessac cédex, France, 4Université Paris Saclay, LSCE (CEA-CNRS-UVSQ/IPSL),
Paris, France, 5University of Pisa, Department of Earth Sciences, Pisa, Italy, 6University of Trieste, Department of
Mathematics and Geosciences, Trieste, Italy, 7ENEA, Roma, Italy, 8University of Florence, Department of
Chemistry “Ugo Schiff”, Florence, Italy

The causes of the recent increase in Antarctic sea ice extent, characterised by large regional contrasts and
decadal variations, remain unclear. In the Ross Sea, where such a sea ice increase is reported, 50% of the sea
ice is produced within wind-sustained latent-heat polynyas. Combining information from marine diatom
records and sea-salt sodium and water isotope ice core records, we here document contrasting patterns in sea
ice variations between coastal and open sea areas in Western Ross Sea over the current interglacial period.
Since about 3600 years Before Present, an increase in the efficiency of regional latent-heat polynyas resulted in
more coastal sea ice, while sea ice extent decreased overall. These past changes coincide with remarkable
optima or minima in the abundances of penguins, silverfish and seal remains, confirming the high sensitivity of
marine ecosystems to environmental and especially coastal sea ice conditions.

2204
Fri_251_OS-7_300
Sea-ice Production in Arctic Polynyas between 2002 and 2017

Andreas Preußer1 (preusser@uni-trier.de), Sascha Willmes1, Kay I. Ohshima2, Günther Heinemann1

1
University of Trier, Environmental Meteorology, Trier, Germany, 2Institute of Low Temperature Science,
Hokkaido University, Ocean and Sea Ice Dynamics, Sapporo, Japan

In this study, a high-resolution (2 km) MODIS thermal infrared satellite data set featuring spatial and temporal
characteristics of 17 Arctic polynya regions is presented for winter seasons 2002/2003 to 2016/2017. The data
set features the most recent updates of the employed MOD/MYD29 sea ice product (Col. 6) which includes
improvements to the cloud masking and land/ocean separation. Thin-ice thickness distributions are calculated
from MODIS ice-surface temperatures, combined with ECMWF ERA-Interim atmospheric reanalysis data in an
energy balance model. Daily thin-ice thickness composites are subsequently computed. A gap-filling approach
is applied to account for clouds and missing data in the thermal infrared imagery. The most recent winter
season in the data set (2016/17) features the so far highest annual sea-ice production with a volume of 2258
km³, presumably originating from highly active polynyas throughout the eastern Arctic and/or a particularly
thin and less extensive wintertime sea-ice coverage that season. Thin-ice thicknesses from an AMSR-E passive
microwave data set are used to evaluate and quantify sensor-specific capabilities and error sources for a large-
scale pan-Arctic polynya monitoring. Despite obvious differences, such as the acquired signal at the sensor,
varying spatial resolutions or the individual sensitivity for cloud cover, both data sets are coherent in terms of
capturing the general properties of Arctic polynyas for an overlapping 9-yr period.

2205
Fri_252_OS-7_321
The Impact of Snowmelt on the Arctic Ocean Heat Budget

George Duffy1 (george.a.duffy@vanderbilt.edu), Ralf Bennartz1

1
Vanderbilt University, Earth and Environmental Sciences, Nashville, United States

The ocean surface heat flux is typically calculated from the sum of longwave radiation, shortwave radiation,
sensible heat flux, and evaporative heat flux. In polar oceans, an additional heat sink may also arise through the
melting of snowfall. In this study, we use Cloudsat measurements and ECMWF-ERA interim reanalysis to
quantify the impacts of snowmelt in the Arctic Ocean. Focusing on the freeze-up season, we find that the
cooling from snowmelt can provide a cooling in the order of 1-10% of the net ocean heat flux on month-long
time scales. During heavy snowstorms, the cooling from snowmelt may represent the dominating factor in
oceanic heat flux.

2206
Fri_253_OS-7_356
Water Isotopes Signature in Surface Antarctica (COMBINISO Project)

Amaelle Landais1 (amaelle.landais@lsce.ipsl.fr), Camille Bréant1, Mathieu Casado1, Alexandre Cauquoin1, Elise
Fourre1, Frederic Prie1, Alexandra Touzeau1
1
LSCE/IPSL, Gif sur Yvette, France

The aim of the COMBINISO project is to disentangle the different influences on the water isotope composition
on the East Antarctic plateau to provide more faithful reconstruction of climate and water source origin from
the snow cores over the last decades. A wealth of isotopic measurements have been acquired at the
continuum between surface snow, subsurface snow and atmosphere mainly at the Dome C station showing
how precipitation, temperature and metamorphism influences the snow surface isotopic composition. In
parallel, a huge modeling effort have been deployed both at the global scale and at the local scale by (1)
implementing tritium in the atmospheric model equipped with stable water isotopes LMDZ-iso and (2)
implementing water vapor transport and water stable isotopes in the snowpack model CROCUS. Finally, an
array of snow cores analyzed at different Antarctic stations are interpreted together with modeling outputs to
provide insight on the recent evolution of climate and moisture source, including stratospheric input in very dry
regions of the East Antarctic plateau.

2207
Fri_254_OS-7_399
Circumpolar Deep Water Upwelling and Suppressed Sea Ice Production in Prydz Bay

Guijun Guo1 (guoguijun@fio.org.cn), Jiuxin Shi2, Libao Gao1

1
First Institute of Oceanography, Qingdao, China, 2Ocean University of China, Qingdao, China

Strengthened Circumpolar Deep Water (CDW) intrusion into shelf region around Antarctic can increase oceanic
heat supply on the shelf, enhancing ice shelf basal melt and suppressing sea ice production synchronously. In
Prydz Bay, highly modified CDW (mCDW) upwells to subsurface in the southeastern embayment, where
relative warm mCDW inflow encounters with extremely cold denser shelf water. Strengthened convection
during ice freezing season extends to as deep as 300 m, bringing the upwelled warm water to surface.
Accumulated upward heat supply through convection from intermediate mCDW to surface during March-
August is estimated at 3.9×1015 kJ, which can reduce sea ice production by 12.7 km3, approximate half of the
ice production volume in Davis Polynya. This study highlights the potential reversal of sea ice increasing trend
in the southern ocean and further hindering of dense shelf water formation around Antarctic due to
strengthened intrusion of CDW.

2208
Fri_255_OS-7_473
How Much Submarine Melt Water from Greenland is in the Labrador Sea?

Monika Rhein1 (mrhein@physik.uni-bremen.de), Steinfeldt Reiner1, Oliver Huhn1, Jürgen Sültenfuss1

1
Institute for Environmental Physics, University of Bremen, Bremen, Germany

Submarine melt of the Greenland Ice sheet (GrIS) is significantly contributing to the accelerating mass loss of
GrIS. When this additional freshwater flows into the central Labrador Sea, the vertical density stratification
could increase and weaken deep convection, and thus the meridional overturning circulation. How much
submarine melt water (SMW) reaches the convection region and where it leaves the Greenland Boundary
Current is up to now uncertain. Helium and Neon isotopes are unique tools to identify and quantify the fraction
of SMW in the ocean down to fractions of 0.05%. Here we present SMW distributions from hydrographic and
noble gas measurements in the Greenland Boundary Current and the Labrador Sea form historical data and
samples taken in summer 2015.

2209
Fri_256_OS-7_480
Frazil Ice Streaks on PIPERS: the Role of Sea Ice-Ocean Interactions

Agnieszka Herman1 (oceagah@ug.edu.pl), Stephen Ackley2, Ted Maksym3, Sharon Stammerjohn4

1
University of Gdansk, Institute of Oceanography, Gdynia, Poland, 2University of Texas San Antonio, Snow and
Ice Geophysics Laboratory, San Antonio, United States, 3Woods Hole Oceanographic Institution (WHOI), Woods
Hole, United States, 4University of Colorado, Boulder, United States

In polar regions, open water areas (e.g., polynyas) are regions of high production rates of new sea ice. If the
wind is sufficiently strong, streaks of frazil ice tend to form on the sea surface. Observations show that the
streaks have several remarkable features: their spacing is irregular; there are sharp boundaries between
regions with high and low frazil concentration; neighboring streaks tend to merge into larger ones, but they
never split. These features make the Langmuir circulation an unlikely explanation for the formation of frazil
streaks. In this paper, we propose a model reproducing the overall behavior and evolution of frazil streaks, and
we make an attempt to answer a question whether their formation is solely a result of upper-ocean turbulence,
with ice crystals behaving as a passive tracer that accumulates in convergence zones, or, alternatively, whether
the presence of ice itself affects the turbulence patterns in a way that further reinforces streak formation. Our
results suggest that the second scenario is consistent with observations, and that growth rates of frazil clusters
on the sea surface are enhanced by turbulence suppression within those clusters - which in turn is a
consequence of enhanced viscosity in areas of high frazil concentration and lowered effective restitution
coefficient between colliding crystals. This last property speeds up transition of frazil/grease ice into pancake
ice, thus substantially influencing the evolution of the ice cover.

2210
Fri_257_OS-7_491
Linking Precipitation Deuterium Excess and the Occurrence of Cyclones

Franziska Aemisegger1 (franziska.aemisegger@env.ethz.ch)

1
ETH Zurich, Institute for Atmospheric and Climate Science, Zürich, Switzerland

Deuterium excess is an important second order isotope parameter that has been widely used for paleoclimate
reconstructions mainly of sea surface temperature but also of relative humidity. Deuterium excess is a
particularly powerful tracer for moisture source properties, because it is intrinsically sensitive to non-
equilibrium conditions occurring in unsaturated (i.e. strongly evaporative) environments and thus allows to
quantify the deviation from thermodynamic equilibrium during phase changes. To first order, the deuterium
excess of water vapour is conserved during transport and moderate rain out along an air parcel's trajectory. On
this poster, a robust process-based link is established between cold advection induced by the occurrence of
cyclones and the interannual variability of precipitation deuterium excess at four stations of the Global
Network of Isotopes in Precipitation (GNIP) in the North Atlantic. Positive anomalies of annual precipitation
deuterium excess are found to be linked with positive anomalies of strong ocean evaporation in the moisture
source region of the respective station's precipitation. Furthermore, a strong signal is also detected in the
occurrence frequencies of cyclones located to the northwest of the moisture source region. The possible
implications of these results for the use of precipitation deuterium excess as a proxy for the location of the
storm track are discussed.

2211
Fri_258_OS-7_544
Changes in Sea Ice Deformation and Impact of the Wind Forcing

Alexandra Kazlova1 (kazlova@uni-bremen.de), Gunnar Spreen1

1
University of Bremen, Bremen, Germany

An increase in Arctic sea ice speed during recent decades by 10-15% per decade has been observed from buoy
and satellite observations.Higher resolution Synthetic Aperture Radar(SAR) observations are best suited for sea
ice deformation retrieval,but they were not yet fully analysed for long-term ice deformation changes.How
much the different components in the sea ice force balance have contributed to the observed changes in sea
ice dynamics is not fully understood.
Sea ice motion fields from SAR observations can be used to obtain sea ice strain rates i.e. sea ice deformation
fields.Currently,there is no SAR satellite sea ice deformation datasets covering the complete Arctic Basin
available.The RGPS data mainly covers the Canadian Arctic region(1996-2008) and the ENVISAT dataset covers
the European Arctic region(2007-2012).Since 2015 Sentinel-1 offers a better coverage of the Arctic
basin.Available SAR datasets are analysed for the changes in space and time.Findings will contribute to better
quantify the changes in Arctic sea ice dynamics and evaluate sea-ice models.
Observed sea ice deformation changes are compared to Atmospheric reanalysis to gain understanding of
causes.On short time scale wind is the main driver of sea ice drift.Studies show that for most of the Arctic Basin
changes in wind speed cannot explain the increase in sea ice drift speed.In this study we compare sea ice
deformation fields from satellites to wind forcing from reanalysis to quantify their relation.

2212
Fri_259_OS-7_567
The Platelet-affected under-Ice Boundary Layer

Natalie Robinson1 (natalie.robinson@niwa.co.nz), Brett Grant1, Craig Stevens1,2, Ben Galton-Fenzi3

1
National Institute for Water and Atmospheric Research, Marine Physics, Wellington, New Zealand, 2University
of Auckland, Physics, Auckland, New Zealand, 3Antarctic Climate & Ecosystems CRC, Hobart, Australia

The influence of the ice shelf cavities on sea ice processes has not been quantified at any scale. Here we focus
on processes in the upper ocean boundary layer in a region of Ice Shelf Water (ISW) outflow. Accumulations of
platelet ice, up to several metres thick, form the physical boundary structure through most of the year in
Western McMurdo Sound in the Ross Sea. Recent observations have revealed an amplified ocean response to
the modified boundary in excess of 30 m deep. We interpret these observations as multiple modes contributing
to effective drag of up to two orders of magnitude greater than is presently used in regional ocean models.
Here we suggest quantifiable relationships between the upstream and ambient conditions; the thickness of the
platelet layer; and the longevity of supercooled ISW front the calving front; which are intended to inform
under-ice boundary layer parameterisations.

2213
Fri_260_OS-7_817
Albedo and Energy Balance of Melt Pond During Late Summer in the Central Arctic

Tao Li1 (litaoocean@163.com), Jialiang Zhu1

1
Ocean University of China, College of Oceanic and Atmospheric Sciences, Qingdao, China

In order to understand the thermodynamical process on the melt pond surface in the Arctic, in situ
observations of the melt pond radiation have been carried out in the Central Arctic during the Chinese Arctic
Surveys in 2012, 2014 and 2016. Based on the surface state of melt pond, we categorize the melt pond into five
types: original melt pond (ORMP), water-ice covered melt pond (WIMP), thin snow covered melt pond (TSMP,
snow depth is less than 1cm), moderate snow covered melt pond (MSMP, snow depth is between 1 to 2cm)
and deep snow covered melt pond (DSMP, snow depth is more than 2cm). The albedos of the five types of melt
pond are 0.1-0.2 for the ORMP, 0.2-0.35 for the WIMP, 0.35-0.55 for the TSMP, 0.55-0.8 for the MSMP and 0.8-
0.95 for the DSMP. Moreover, the albedos of ORMP and WIMP decrease gradually with the increased depth of
melt pond. On the contrary, the albedos of TSMP, MSMP and DSMP are not affected by the depth of melt pond
but the covered ice thickness that increase the albedo with ice growing. During the late summer, solar
shortwave radiation is still the main energy resource for the melt pond developing. The partitioning of solar
radiation into the melt pond system has been calculated based on previous theory and in situ measurements.
The covered ice cap has absorbed less then 5% of the solar radiation, while about 60% of them has been
absorbed by the melt water and 35% by the underlying ice and ocean.

2214
Fri_262_OS-7_895
Mercury and Organic Aerosols Cycling Response to Sea Ice Change in the Polar Sea

Zhouqing Xie1 (zqixe@ustc.edu.cn), Hui Kang1, Jiancehng Wang1, Xiawei Yu1

1
University of Science and Technology of China, Hefei, China

Sea ice change in the Southern Ocean and the Arctic Ocean influences the pollutant, gases and particles across
the air/sea/ice interface and ultimately interactions and feedbacks with the climate and ecological system. One
of the discoveries response to dynamic of sea ice in these regions is the mercury cycling. Atmospheric
chemistry occurring on and above sea ice is found to destroy mercury in the marine boundary layer in the
austral summertime, and increase or retreat of sea ice influences the air-sea exchange of mercury. A lot of
saturated mercury in the seawater below the ice, and will be released with the ice melts. Such kinds of
chemical and physical processes are important to understand and evaluate the risk of ecosystem exposed to
this toxic element. Sea ice will also influence on the biological activities, which will contribute a substantial
organic fraction of the atmospheric aerosol. The concentration of bacterium over the floating sea ice region
was higher than found over the open sea areas. Temporal and spatial change in biological particles including
primary organic aerosol, secondary organic aerosol and associated biogenic volatile compounds (e.g. isoprene,
halocarbon, and DMS) for atmospheric processes and air/sea/ice interfaces are thus urgent to fully investigate.
These results will provide constraint for model simulation of climate change in the regional scale.

2215
Fri_263_OS-7_931
Linking Water Isotopes and Air-sea Interactions: Two Southern Ocean Case Studies

Iris Thurnherr1 (iris.thurnherr@env.ethz.ch), Franziska Aemisegger1, Pascal Graf1, Stephan Pfahl1, Maxi
Böttcher1, Yongbiao Weng2, Harald Sodemann2, Josué Gehring3, Alexis Berne3, Irina Gorodetskaya4, Heini
Wernli1
1
ETH Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland, 2University of Bergen,
Geophysical Institute & Bjerknes Centre for Climate Research, Bergen, Norway, 3EPFL, ENAC-LTE, Lausanne,
Switzerland, 4University of Aveiro, Centre for Environmental and Marine Studies, Aveiro, Portugal

Stable water isotopes (SWI) have been used as climate proxies for several decades. At the synoptic time-scale,
SWI serve as tracers to investigate moist processes associated with weather systems. In this presentation, we
link hourly signals of boundary layer vapour SWI with air-sea fluxes induced by the synoptic-scale flow. For this
the measurements performed in the framework of the Antarctic Circumnavigation Expedition (ACE) are used.
During this international campaign in the austral summer 2016/2017, SWI in atmospheric water vapour,
precipitation and ocean surface waters were measured on board the Russian research vessel Akademik
Tryoshnikov. Together with radio sonde profiles, radar observations and high-resolution humidity
measurements a comprehensive data set is available to study the Southern Ocean fresh water cycle. In order to
put the measurements in a spatial context, the SWI measurements are combined with operational analysis
data of the European Centre for Medium-Range Weather Forecasts and simulations from the isotope-enabled
regional numerical model COSMOiso.
Here we present two cases studies of one cold and one warm advection event, in which we highlight the
relevant processes that influence the strongly contrasting SWI signatures associated with these events. A
composite analysis of ~20 temperature advection events shows that cold, respectively warm advection, is
associated with distinct SWI signatures of the near-surface water vapour.

2216
Fri_264_OS-7_989
Surface Drag over Arctic Sea Ice: Direct Observations from an Icebreaker

John Prytherch1 (john.prytherch@misu.su.se), Ian Brooks2, Margaret Yelland3, Dom Salisbury4, Ben Moat3,
Michael Tjernström1
1
Stockholm University, Department of Meteorology, Stockholm, Sweden, 2University of Leeds, ICAS, Leeds,
United Kingdom, 3National Oceanography Centre Southampton, Southampton, United Kingdom, 4ECMWF,
Reading, United Kingdom

The surface drag, or roughness, over sea ice is prescribed in numerical weather prediction, climate and Earth
system models in order to determine atmosphere-ice/ocean momentum exchange. There are few direct
observations of surface drag available to develop drag parameterisations from. This is particularly the case for
both the Marginal Ice Zone (MIZ), and for modern Arctic conditions.
Here we present direct eddy covariance and inertial dissipation estimates of surface momentum exchange
obtained in the Arctic Ocean from the icebreaker Oden during two expeditions; the Arctic Clouds in Summer
Experiment (ACSE) in 2014 and Arctic Ocean 2016. The extensive data set spans a range of surface conditions
during the Arctic summer and autumn, with both melting and freezing periods, ice-free to ice-covered ocean
with a large fraction of measurements within the MIZ, and 10-minute average winds up to 22 m/s.
The wind measurements are corrected for platform motion and for flow distortion using computational fluid
dynamic modelling of the airflow over Oden. Surface conditions are characterised using ship-based digital
imagery and infrared temperature sensors, as well as satellite-based estimates of sea ice concentration. The
dependence of the measured drag on surface conditions is analysed and compared to published
parameterisations.

2217
Fri_265_OS-7_991
Sea-air Flux and Transfer Velocity of CH4 / CO2 Measured on the Siberian Shelf

John Prytherch1 (john.prytherch@misu.su.se), Brett F Thornton2, Ian Brooks3, Kristian Andersson2, Marc
Geibel4, Dom Salisbury5, Patrick Crill2, Michael Tjernström1, Christoph Humborg2
1
Stockholm University, Department of Meteorology, Stockholm, Sweden, 2Stockholm University, Department of
Geological Sciences, Stockholm, Sweden, 3University of Leeds, ICAS, Leeds, United Kingdom, 4Stockholm
University, Baltic Sea Centre, Stockholm, Sweden, 5ECMWF, Reading, United Kingdom

The East Siberian Arctic Shelf (ESAS) seas have been proposed as a substantial source of methane (CH4) to the
atmosphere, and are an important sink for atmospheric CO2. We report extensive direct eddy covariance
observations of CO2 and CH4 fluxes between the sea and the atmosphere, from a ship in the ESAS seas during
July-August 2014.
Our results show that that sea emissions of CH4 leading to atmospheric enhancements of CH4 above the ESAS
are regionally explainable by wind-driven diffusive fluxes. Based on our measurements, we estimate an annual
sea-air flux of 1.49 Tg yr−1 for the entire ESAS. Areas of enhanced flux from seafloor-released bubbles
transferring CH4 directly into the atmosphere were observed but had limited spatial extent. For example in one
location in the East Siberian Sea, we observed sea-air CH4 fluxes exceeding 600 mg m−2 d−1, over an area of
~100 m2. Although locally impressively large, such fluxes make a negligible contribution to total ESAS CH4
emissions.
We also present direct determination of the CO2 and CH4 air-sea gas transfer velocity in a wide range of Arctic
sea ice conditions. We show that the gas transfer velocity increases near linearly with decreasing sea ice
concentration and that previous modeling approaches may overestimate gas transfer rates in sea ice regions.

2218
Fri_266_OS-7_993
Multi-annual Observations of Tropospheric BrO at Two Antarctic Stations

Udo Frieß1 (udo.friess@iup.uni-heidelberg.de), Richard Querel2, Karin Kreher3, Jan-Marcus Nasse1, Ulrich Platt1
1
University of Heidelberg, Im Neunheimer Feld 229, Heidelberg, Germany, 2National Institute for Water and
Atmospheric Research, Lauder, New Zealand, 3BK Scientific GmbH, Mainz, Germany

The presence of high amounts of bromine monoxide (BrO) each spring in Polar Regions has a substantial impact
on the oxidative capacity of the polar boundary layer. Released by autocatalytic processes on saline surfaces,
such as sea ice, snow and aerosols, BrO frequently leads to a virtually complete destruction of near-surface
ozone. Furthermore, the oxidation of DMS by BrO can have a potential impact on climate. The oxidation of
elemental mercury by BrO leads to an enhanced influx of this toxic compound into the polar biosphere.
Here we present multi-decadal observations of the vertical distribution of tropospheric BrO and aerosols using
Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements performed at the New
Zealand Antarctic Observatory Arrival Heights (78°S) since 1998 and at the German Antarctic Station Neumayer
(70°S) since 2003. By detection of absorption structures of atmospheric constituents in scattered sunlight from
different directions, this technique allows for the reconstruction of vertical profiles of trace gases and aerosols
in the armospheric boundary layer. We present a detailed statistical analysis of the amount, frequency, and
vertical distribution of BrO in the Antarctic boundary layer, enabling the identification of possible source
regions and the impact of blowing snow and aerosols on the release of BrO, as well as transport processes,
such as an influx of reactive bromine from the boundary layer into the free troposphere.

2219
Fri_267_OS-7_1016
Observed Greenland Ice Sheet Run-off Distribution in the Greenland Sea

Tilia Breckenfelder1,2 (t.breckenfelder@uni-bremen.de), Oliver Huhn2, Monika Rhein1,2, Jürgen Sültenfuß2,

Torsten Kanzow3, Janin Schaffer3
1
University of Bremen, MARUM - Center for Marine Environmental Sciences, Bremen, Germany, 2University of
Bremen, Institute of Environmental Physics, Bremen, Germany, 3Alfred-Wegener-Institute, Helmholtz Centre for
Polar and Marine Research, Bremerhaven, Germany

The mass loss from the Greenland Ice Sheet (GrIS) is one of the main sources for the global sea level rise and
almost quadrupled from 1992-2000 to 2000-2011. The additional freshwater could influence the formation of
components of the North Atlantic Deep Water and thereby might alter the strength of the climate relevant
Atlantic Meridional Overturning Circulation. The accelerated run-off is influenced by an intrusion of warm
water onto the shelf near the outlet glaciers and an increased atmospheric warming impacting surface melt.
The drainage basin of the Northeast Greenland Ice Stream covers 16% of the GrIS. Main outlets of this ice
stream are the Nioghalvfjerdsfjorden Glacier with a calving front of around 30 km and the Zachariae Isstrøm,
both are located near the Fram Strait and the Greenland Sea. We identify and quantify the submarine and
surface melt water distribution in the near- and far-field of these glaciers by analyzing the low soluble noble
gases helium and neon. They are used in an Optimum Multiparameter analysis in combination with
hydrographic data to calculate the submarine and surface melt water fractions. Early results show strong glacial
melt water outflow from the cavity below the marine-terminated Nioghalvfjerdsfjorden Glacier into the upper
200 m, indicated by high noble gas concentrations in front of the glacier.

2220
Fri_268_OS-7_1023
Importance of Deformed Ice in the Polar Regions for the Climate Models

Jean Sterlin1 (jean.sterlin@uclouvain.be), François Massonnet1, Thierry Fichefet1

1
Université catholique de Louvain / Earth and Life Institute, ELIC, Louvain-la-Neuve, Belgium

Sea ice comes in a variety of sizes and shapes depending on the mechanical and thermodynamical events it has
undergone. New ice offers little resistance to the winds and currents, while deformed ice contains hummocks
and ridges that influence how heat and momentum are transferred at the atmosphere-ice-ocean interfaces. In
most climate models, the surface fluxes are determined from "bulk formulas" with constant drag coefficients
based on roughness length estimates. Therefore, these formulations do not account for the space-time
variability of transfer coefficients due to variations in ice roughness. However, the ice roughness can be
estimated from the models by quantifying the amount of deformed ice (Tsamados et al, 2013). To study the
effect of ice deformation on the surface fluxes and the associated impact on the sea ice, we implement a tracer
of deformed ice into the ocean-ice model NEMO-LIM3 v3.6 and modify the drag coefficients accordingly. From
a run of NEMO-LIM3 between 1958 and 2015 at 1 degree resolution, we examine the spatial and temporal
evolution of the drag coefficients in the Arctic and Antarctic regions. We investigate the effects on the surface
fluxes and impacts on the sea ice state. This study allows us to formulate an initial assessment on the
importance of deformed ice variability for the current climate models.

2221
Fri_269_OS-7_1100
Hydrodynamics between Prydz Bay and India Bay (Antarctica) during 2012 - 2017

Alvarinho J. Luis1 (alvluis1@gmail.com), Vinit Ravindra Lotliker1, Shridhar D. Jawak1

1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Polar Remote Sensing Division, Polar
Sciences Group, Vasco da Gama, India

Under India's project “Monitoring of hydrodynamics of coastal Antarctica between Prydz Bay (69S, 76oE) and
India Bay (66oS, 9oE),” vertical profiles of density were recorded at every 1o longitude apart using Expendable
CTD probes during austral summer of 2012-2017 onboard cargo ships chartered for Indian Antarctic Expedition.
The thermohaline structure showed mixed layer thickness of about 50 m on average which deepened to 80 m
due to anomalous environmental forcing such as storms in 2017. High salinity winter water (>34.5 psu)
dominantly occupied the water column all along the Prydz Bay -India Bay. It is inferred that bottom topographic
features and coastal geometry influenced the thermohaline structure. The depth integrated heat content
revealed high values (>840 x 109 Jm2) at 42oE, while low value were encountered at India Bay and Prydz Bay
due to large influx of melt water. T-S diagrams revealed freshening signatures of water masses at most
hydrographic stations. The distribution of different water masses is as follows: Antarctic Surface Water was
confined to the upper 25 m, Ice Shelf Water was detected between 350 and 500 m, Continental Shelf Water
was identified between 350 and 700 m, while Circumpolar Deep Water was confined to below 900m. We
address the role of air-sea heat fluxes and winds on the evolution of thermohaline structure and its inter-
annual changes. The observational program will continue to generate a long time series for unraveling climate
signals.

2222
Fri_270_OS-7_1105
Atmospheric Drivers of Antarctic Regional Sea Ice Extent Variability

Cristina M. Surdu1 (cristina.surdu@nyu.edu), David M. Holland1,2

1
New York University, Center for Global Sea-Level Change, Abu Dhabi, United Arab Emirates, 2New York
University, Courant Institute of Mathematical Sciences, New York, United States

Polar sea ice plays a major role in Earth's climate system. Sea ice growth and decay is governed by complex
feedbacks between sea ice, the atmosphere, and the ocean. Sea ice is, however, more responsive to
atmospheric forcing, seasonal changes in air temperature being the main driver. Moreover, a high correlation
exists between anomalies in sea ice extent and mean sea level pressure as shown by previous studies.
Polar lows are intense maritime mesocyclones forming at high latitudes, extending over hundreds of
kilometers, and are associated with high surface wind speeds and large heat fluxes out of the ocean. As a result
of strong air-sea fluxes, sea ice conditions are impacted. The extent to which polar storms impact sea ice
conditions has been, however, hardly investigated previously.
This study proposes a long term (1996-2017), monthly analysis of major polar lows as derived from ERA-Interim
reanalysis data. The reanalysis will be evaluated against the monthly sea ice extent obtained from spaceborne
observations. The overall aim is to assess the impact of storms on regional sea ice extent and identify regions
that are prone to a greater change as a result of atmospheric forcing. During the 2016 spring, the Antarctic sea
ice extent was at its lowest since the late 1970s, with pronounced regional sea ice extent anomalies.
Investigations will be carried out to determine the possibility of anomalous sea ice extent during different
seasons being impacted by polar storms.

2223
Fri_271_OS-7_1154
Seasonal Impact of the Southern Annular Mode on Antarctic Sea Ice Extent

Edward Doddridge1 (ewd@mit.edu), John Marshall1

1
Massachusetts Institute of Technology, Earth, Atmospheric, and Planetary Sciences, Cambridge, United States

Through analysis of remotely-sensed sea surface temperature (SST) and sea ice concentration data we
investigate the impact of winds related to the Southern Annular Mode (SAM) on sea ice extent around
Antarctica. We show that positive SAM anomalies in the austral summer are associated with anomalously cold
SSTs that persist and lead to anomalous ice growth in the following autumn, while negative SAM anomalies
precede warm SSTs and a reduction in sea ice extent during autumn. The largest effect occurs in April, when a
unit change in the detrended summertime SAM is followed by a 1.8±0.6 ×105 km2 change in detrended sea ice
extent. We find no evidence that sea ice extent anomalies related to the summertime SAM affect the
wintertime sea ice extent maximum. Our analysis shows that the wind anomalies related to the negative SAM
during the 2016/17 austral summer contributed to the record minimum Antarctic sea ice extent observed in
March 2017.

2224
Fri_272_OS-7_1227
Seasonality of Antarctic Microseisms: A Window on Sea Ice Variability

Dimitri Zigone1 (zigone@unistra.fr), Alessia Maggi1

1
Institut de Physique du Globe de Strasbourg, Ecole et Observatoire de Science de la Terre de Strasbourg,
Strasbourg, France

When ocean waves interact with the solid Earth, they generate seismic signals called microseisms that peak in
two different period bands between 1 and 20 seconds. These peaks are visible on most station noise spectra
worldwide; they tend to amplify during winter due to stronger storm activity in the oceans. Using data
recorded between 2001 and 2009, Grob et al. (2011) showed that Antarctic noise spectra behave differently:
they tend to attenuate during winter due to the presence of sea ice. They also proved that Antarctic
microseisms exhibit seasonal behavior that correlates directly with the local sea-ice conditions near the
recording station. We aim to monitor sea-ice formation and its variability at key locations along the Antarctic
coast, such as the Dumont d'Urville station, by extending the Grob et al. (2011) study to data recorded
between 2010 and 2017.

2225
Fri_273_OS-7_1249
Carbon Dynamics during the Formation of Sea Ice at Different Growth Rates

Daniela König1 (daniela_koenigd@bluewin.ch), Lisa Miller2, Svein Vagle2, Kyle Simpson2

1
ETH Zurich, Zürich, Switzerland, 2Institute of Ocean Sciences, Sidney, Canada

Given the potentially important contribution of sea ice to sequestration of inorganic carbon (TIC) in deep
waters, relatively little is known about the distribution of TIC during the formation of sea ice or how different
ice growth rates might affect the allocation of carbon to ice, water, or air. To illuminate these carbon dynamics,
we grew ice in an experimental seawater tank (1 m3) under abiotic conditions up to a thickness of 20 cm at
three different air temperatures (-40 °C, -25 °C, -15°C). Carbonate system parameters were determined by
discrete sampling of ice cores and water, as well as continuous measurements by multiple sensors deployed
mainly in the water phase. A budgetary approach revealed that of the initial TIC content of the water, only 5 %
was located in the ice phase by the end of the experiment at the slowest growth rate (1 cm/d), while for the
fastest growth rate (12 cm/d), this value increased to over 10 %. Exchange with air appeared to be negligible,
with the majority of the TIC remaining in the under-ice water (90-95 %). Along with a good correlation between
salinity and TIC in the ice and water samples, these observations highlight the importance of brine drainage to
TIC redistribution during ice formation. For experiments without mixing of the under-ice water, the sensor data
further suggested a stronger stratification, and thus potentially larger carbon sequestration for ice grown at a
colder temperature and faster growth rate.

2226
Fri_274_OS-7_1269
Unexpected Halogen Activation during Fall at Neumayer III/Antarctica

Jan-Marcus Nasse1 (jan.nasse@iup.uni-heidelberg.de), Udo Frieß1, Denis Pöhler1, Stefan Schmitt1, Holger
Sihler1,2, Rolf Weller3, Thomas Schaefer3,4, Zsófia Jurányi3, Ulrich Platt1
1
Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany, 2Max-Planck Institute for
Chemistry, Mainz, Germany, 3Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany,
4
Leibniz Institute for Tropospheric Research, Leipzig, Germany

The influence of Reactive Halogen Species (IO, BrO, ClO, etc.) on the lower polar troposphere has been subject
of intense research for over three decades. Ozone Depletion Events or the oxidation of gaseous elemental
mercury are well observed phenomena that occur during the respective springtime in both Arctic and
Antarctic. While an autocatalytic release mechanism from salty surfaces (sea ice or aerosols), the so-called
bromine explosion, has been identified as the likely cause of the rapid increase of inorganic bromine mixing
ratios, many other aspects of the atmospheric halogen chemistry, like chlorine release, remain unclear.
Since January 2016, we are operating a fully automated Long-Path DOAS instrument at Neumayer III in coastal
Antarctica. It can detect a wide range of trace gases including ClO, BrO, OClO, IO, and NO2 at a temporal
resolution of 5-30 minutes.
The analysis of two years of observations shows several surprising findings which give new insights into polar
halogen chemistry. For instance, we detect unexpectedly strong bromine activity in late summer and autumn
(in addition to springtime events) with BrO mixing ratios frequently exceeding 20 ppt and peaks up to
unprecedented 110 ppt. Furthermore, ClO mixing ratios up to 90 ppt and OClO up to 10 ppt could be detected -
the source mechanism for reactive chlorine, however, remains unclear. We will give an overview of the time
series and discuss interesting case studies with regard to chemistry and meteorology.

2227
Fri_275_OS-7_1296
A Scaling Law for the Floe Size Distribution of Pancake Ice

Alberto Alberello1 (alberto.alberello@outlook.com), Luke Bennetts2, Miguel Onorato3, Marcello Vichi4,

Alessandro Toffoli1
1
The University of Melbourne, Parkville, Australia, 2University of Adelaide, Adelaide, Australia, 3Università degli
Studi di Torino, Torino, Italy, 4University of Cape Town, Cape Town, South Africa

In the pancake ice region of the marginal ice zone (MIZ), the sea ice cover begins to affect the momentum
exchange between atmosphere and ocean. Moreover, the ice cover begins dissipating energy of surface waves
travelling through it. However, remote sensing techniques often fail to provide accurate informations on the
geometrical properties of the small floes (i.e. diameter less than 10 meters). In this context, bridge based
observations are necessary to improve and calibrate all other techniques. The Antarctic Sea Ice Processes and
Climate (ASPeCt) protocol provides a streamlined methodology to classify sea ice, however, there is a certain
degree of subjectivity on the data quality that relies on the ability of the trained observer. The S.A. Agulhas II
sailed the Southern Ocean in the austral winter of 2017. During the cruise, the icebreaker encountered a large
patch of pancake ice that extended for more than 150 km from the edge of the MIZ. The sea-ice was digitally
recorded with a camera installed on the monkey bridge. A MATLAB algorithm has been developed to analyse
the digital images and extract the ice concentration and the floe size distribution. It was found that the pancake
size exceedance probability follows two distinct power laws, with the exponent changing for pancake
diameters roughly equal to 3 meters.

2228
Fri_276_OS-7_1299
Modeling Modified Circumpolar Deep Water Intrusions onto Prydz Bay

Chengyan Liu1 (chengyan-liu@qq.com), Zhaomin Wang2, Chen Cheng1, Ruibin Xia1, Bingrui Li3
1
Nanjing University of Information Science & Technology, School of Marine Sciences, Nanjing, China, 2Hohai
University, College of Oceanography, Nanjing, China, 3Polar Research Institute of China, Nanjing, China

An eddy-resolving coupled regional ocean-sea ice-ice shelf model is employed to locate the hot spots where
modified Circumpolar Deep Water (mCDW) intrudes onto the continental shelf within Prydz Bay, and locate the
paths through which mCDW is transported to the Amery Ice Shelf (AIS) calving front. Evaluation of the model
output is with satellite, hydrographic and borehole data. Two critical windows responsible for mCDW intrusions
are identified. The first is the eastern branch of the cyclonic Prydz Bay gyre (PBG) that carries mCDW to the ice
front line, accounting for an annual mean heat transport of ~8.7 ×1011 J s-1. The second is located to the east of
the Four Ladies Bank (FLB) where mCDW is channeled through submarine troughs, accounting for an annual
mean heat transport of ~16.2 ×1011 J s-1. The eddy-induced heat transport accounts for ~23% in the path of the
PBG and ~52% in the path of the eastern coastal current, with respect to their total onshore heat transport.
The seasonal pulsing of mCDW intrusions is greatly dependent on the seasonal cycle of the Antarctic Slope
Current (ASC) that peaks with a maximum of ~29.3 Sv at 75°E in June. In austral winter, mCDW is allowed to
access the eastern flank of the AIS calving front with potential consequences for the basal mass balance of the
AIS. The dynamic effects of small-scale troughs on the longshore ASC play an important role in the onshore
mCDW transport.

2229
Fri_277_OS-7_1320
Seasonality of Antarctic Sea-ice and Snow Properties from Autonomous Systems

Stefanie Arndt1 (stefanie.arndt@awi.de), Leonard Rossmann1, Louisa Tiemann1, Mario Hoppmann2, Marcel
Nicolaus1
1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Sea Ice Physics, Bremerhaven,
Germany, 2Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Physical Oceanography
of the Polar Seas, Bremerhaven, Germany

Studying seasonally varying snow and sea-ice properties in the ice-covered oceans is a key element for
investigations of processes between atmosphere, sea ice, and ocean. A dominant characteristic of Antarctic sea
ice is the year-round snow cover, which substantially impacts the sea-ice energy and mass budgets by, e.g.,
preventing surface melt in summer, and amplifying sea-ice growth through extensive snow-ice formation.
However, substantial observational gaps in the description of year-round Antarctic pack ice and its snow cover
lead to a limited understanding of important processes between atmosphere, sea ice and ocean.
Here, we introduce a unique observational dataset comprised of a number of critical parameters relevant to
the snow/ice and ice/ocean interface, recorded by a suite of snow and ice-mass balance buoys (IMBs) deployed
in the Weddell Sea between 2013 and 2018.
From these data we infer seasonal snow accumulation rates, which allow to describe the spatial distribution
and temporal evolution of the Antarctic snowpack. Vertical temperature profiles from co-deployed IMBs are
used to validate these findings, and to calculate energy budgets across the atmosphere-ocean boundary.
Our results highlight that data from autonomous, ice-based platforms are a key element in better
understanding sea-ice and snow properties, processes and their seasonal evolution.

2230
Fri_278_OS-7_1325
Dissolved Gas Properties and Water Formation in a Coastal Polynya during PIPERS
Brice Loose1 (bloose@uri.edu), Samuel Gartzman1, Sharon Stammerjohn2, Sarah Searson3
1
University of Rhode Island, Narragansett, United States, 2University of Colorado Boulder, Boulder, United
States, 3National Institute of Water and Atmospheric Research (NIWA), Auckland, New Zealand

Antarctic sea ice production is thought to be fundamental to determining the strength of the southern
hemisphere meridional overturning circulation and the solubility pump, through its control of air-sea exchange,
and through brine rejection. The unbuffered gases (He, Ne, N2,O2, N2,Ar, Kr, and Xe), dissolved in seawater,
contain a fingerprint of sea ice and other bio-physical processes that ultimately determine gas content in the
deep ocean. We collected discrete noble gas samples and in-situ gas measurements using an Underwater Mass
Spectrometer (UMS) attached to the CTD rosette, during the the PIPERS cruise between April 11 to June 14
2017 in the Ross Sea. The UMS is an early prototype of instrumentation that has the potential to expand the
spatial and temporal coverage of in-situ dissolved gases such as N2 and Ar. These measurements reveal glacial
meltwater effluents that are incorporated into subsurface waters before those waters exit the continental shelf
along the abyssal troughs in the Ross Sea. Within the mixed layer, persistent under-saturation in all the
dissolved gases reflects heat loss that fast exceeds the rate of air-sea and air-ice gas exchange, leading to shelf
waters that do not convey their entire gas burden into the deep sea during their transformation into deep
water. We use the gases and hydrography to reflect on the competing effects between secular freshening in
the Ross Sea and the salination process of shelf water during polynya ice production.

2231
Fri_279_OS-7_1329
Mapping Antarctic Peninsula Iceberg Melt Variability with Satellite Imagery

Mariama C Dryak1 (mariama.dryak@maine.edu), Ellyn M Enderlin1

1
University of Maine, Earth and Climate Sciences, Climate Change Institute, Orono, United States

Warming air and ocean temperatures have led to a global increase in glacier and ice sheet melt, impacting the
amount of freshwater being added to the oceans. Along the Antarctic Peninsula climate warming is responsible
for the break-up of ice shelves that formerly buttressed the flow of ice from marine-terminating glaciers to the
ocean. Both ice shelf collapse and subsequent acceleration of glaciers that previously fed the shelves has
resulted in increased iceberg discharge to neighboring ocean basins. In order to fully understand the impacts of
increased iceberg discharge on local-to-global ocean properties, iceberg freshwater fluxes must be quantified.
Patterns in Antarctic iceberg melt can be mapped through the differencing of repeat high-resolution digital
elevation models (DEMs), as has been recently demonstrated around Greenland. Specifically, here we use
repeat very high-resolution WorldView satellite images to create iceberg DEMs, then difference the iceberg
elevations in time to construct estimates of iceberg melting from 2011 to 2018. Spatial and temporal variations
in iceberg melting are analyzed in order to determine whether iceberg meltwater fluxes have varied
considerably in the past decade.

2232
Fri_280_OS-7_1333
Evidence of Polynya Frazil Ice Growth over Tens of Vertical Meters during PIPERS

Lisa De Pace1 (lisamdepace@gmail.com), Brice Loose1, Madison Smith2, Samuel Gartzman1, Sharon
Stammerjohn3
1
University of Rhode Island, Narragansett, United States, 2University of Washington, Seattle, United States,
3
University of Colorado Boulder, Boulder, United States

Strong katabatic winds and subzero air temperatures drive extreme oceanic heat loss in coastal polynyas,
during the polar night. We observed repeated katabatic wind events in the Terra Nova Bay polynya of the Ross
Sea, during the PIPERS cruise, which occurred between April 11 and June 14, 2017. During these conditions,
mixed layer depth extended to 600 m and mixed layer temperatures were driven to or below the freezing
point. Yet, temperature and salinity profiles were not perfectly homogenous throughout the mixed layer.
Instead, we observed an apparent source of heat and salt in the top tens of meters, evident as a warmer saltier
bulge in the CTD profiles. Considering both the colder air above and water below, we surmise that the increase
in temperature and salinity reflects latent heat and salt release during unconsolidated ice production
throughout the upper water column. We use the thermodynamic state equations and models of frazil ice
production to test whether frazil ice production could lead to the observed thermohaline anomalies.
Conversely, we use simple heat and salt budgets to put bounds on the amount of frazil ice production that is
implied by these observations. These and related measurements provide insight to the boundary conditions for
the dense water that is produced in coastal polynyas, and eventually incorporated into Antarctic Bottom
Water.

2233
Fri_281_OS-7_1378
Southern Ocean Polar Mesocyclones Dynamics from WRF High Resolution Hindcast

Polina Verezemskaya1,2 (verezem@sail.msk.ru), Victor Stepanenko2, Sergey Gulev1

1
P.P. Shirshov Institute of Oceanology, Sea-Air Interaction Laboratory, Moscow, Russian Federation, 2Moscow
State University, Research Computing Center, Moscow, Russian Federation

Mesocyclones (MC) in high latitudes are important maritime atmospheric phenomena, characterized by strong
wind speeds and surface heat fluxes. The lack of assimilated observational data in Southern Hemisphere (SH) in
the global ocean and atmospheric models and also the rough resolution of the latter does not allow realistic
representation of MCin these datasets. Most of modern studies of the MC activity in SH are using tracking
algorithms based on reanalyses data, significantly underestimating number of MC and their intensity (Irving et
al., 2010; Pezza et al., 2015). Thus, dynamical characterization of MC, developed in these studies covers only a
fraction of mesocyclone population.
In this study, we present thermodynamical and lifecycle characteristics of polar MC in SH, basing on the high-
resolution (10 km) Weather Research and Forecasting model regional hindcast for winter 2004. The hindcast is
validated involving different observational data: satellite-derived integral water vapor content (AMSR-E),
surface winds (QuikSCAT), AMRC AAWSP weather stations data. The WRF reproduced 95% of polar MC of
satellite-based dataset of the Southern Ocean MC tracks (Verezemskaya et al., 2017).
Dynamical characteristics of polar MCs from satellite database such as surface fluxes, CAPE/CIN, existence of
cold/warm core, Eady rate, potential vorticity anomalies are calculated for different types of MCs according to
their cloudiness pattern type and large-scale background conditions.

2234
Fri_282_OS-7_1418
PIPERS: Fall-winter Observations of Dissolved Iron in the Ross Sea Polynyas

Peter Sedwick1 (psedwick@odu.edu), Stephen Ackley2, Michael Dinniman3, Brice Loose4, Casey O'Hara1, Bettina
Sohst1, Sharon Stammerjohn5
1
Old Dominion University, OEAS, Norfolk, United States, 2University of Texas San Antonio, Geosciences, San
Antonio, United States, 3Old Dominion University, CCPO, Norfolk, United States, 4University of Rhode
IslandIsland, GSO, Kingston, United States, 5University of Colorado Boulder, INSTAAR, Boulder, United States

Primary production on the Ross Sea continental shelf is thought to be limited by the supply of dissolved iron
(DFe), which is derived from melting of sea ice and glacial ice, intrusion and upwelling of Circumpolar Deep
Water, and vertical resupply from the benthos. The latter will be most important during winter, when katabatic
winds drive sea ice formation and convective overturn in coastal polynyas, although the impact of these
processes on the water-column distribution of DFe has not been previously documented. As part of the project
Polynyas and Ice Production Evolution in the Ross Sea (PIPERS), we collected hydrographic data and water-
column samples for DFe analysis in the Terra Nova Bay (TNB) and Ross Ice Shelf (RIS) polynyas during April-June
2017 (fall-early winter). We observed several intense katabatic wind events in the TNB polynya, where the
surface mixed layer varied from ~250 m to ~600 m depth over lateral distances of ~10 km. Stations occupied in
the RIS polynya, where weather conditions were less extreme, revealed surface mixed layer depths < 300 m.
These observations and our preliminary DFe data suggest that convective overturn progresses slowly and
episodically over winter, perhaps earlier in the TNB polynya, where there is also evidence of substantial DFe
inputs associated with Ice Shelf Water.

2235
Fri_283_OS-7_1530
High Heat Flux Events and the Role of Sea Ice in the Iceland Greenland Seas

James Pope1 (japope@bas.ac.uk), Tom Bracegirdle1, Ian Renfrew2, Andy Elvidge2

1
British Antarctic Survey, Cambridge, United Kingdom, 2University of East Anglia, Norwich, United Kingdom

The Iceland Greenland seas Project (IGP) represents a coordinated meteorological and oceanographic study of
the Iceland and southern Greenland Seas. The aim being to characterise the atmospheric forcing and the ocean
response of coupled atmosphere-ocean processes; in particular cold-air outbreaks in the vicinity of the
marginal-ice-zone and their triggering of oceanic heat loss and the generation of dense water masses. Within
the project a climatological assessment using regional climate modelling tools of changes in the distribution
late winter/early spring (January-February-March-April) sea ice concentration will be undertaken. The
modelling will focus on how changes in the location of the sea ice front over the duration of the satellite record
have impacted on location, magnitude and frequency of cold air outbreaks and high heat flux events. Here we
present the initial analysis of these modelling studies, using three fixed sea ice conditions representative of the
maximum (1986), minimum (2016) and median (2004) sea ice concentrations. Our results will focus on the
changes in the distribution and frequency of high heat flux events and an initial assessment of how these will
change into the future.

2236
Fri_284_OS-7_1542
Contrasting Carbon Monoxide Cycles in the North Pacific and the Amundsen Sea

Young Shin Kwon1,2 (kwonys@kopri.re.kr), Tae Siek Rhee1, Doshik Hahm3, Hyun-Chul Kim1, Hyoun-Woo Kang4
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2University of Science and Technology-
Korea, Daejeon, Korea, Republic of, 3Pusan National University, Pusan, Korea, Republic of, 4Korea Institute of
Ocean Science and Technology, Pusan, Korea, Republic of

To investigate how the CO budget in the mixed layer governs the CO emission from sea to air, we measured air-
sea gas exchange, microbial consumption rate, and CDOM on-board during two expeditions in the Amundsen
Sea and the North Pacific in summer season of 2012. Dark incubation experiments revealed that microbial
consumption rate in the North Pacific was 4.5 nM d-1 whilst 0.8 nM d-1 in the Amundsen Sea. Also CO
production rate was about 3.5-times higher in the North Pacific (2.4 nM d-1) due mainly to inefficient dilution by
shallow mixed layer in the region. It seems that this different CO budget between the two regions causes
different amplitude of diurnal variation of dissolved CO. That is, compared to the Amundsen Sea, CO is
produced faster in daytime and removed faster throughout the day in the North Pacific where the amplitude of
CO cycle is larger. In both regions, sea-to-air flux density was insignificant (about 0.1 nM d-1 for the both
regions) compared to microbial consumption which covers above over 95% of CO. Our observations indicate
that the source strength of the ocean was evenly weak regardless of the scale of CO budget in the ocean. That
is, marine biota can be thought as a main control of CO in the atmosphere, the important trace gas for the
global climate change.

2237
Fri_285_OS-7_1563
Impact of Winter Storms in a Thinner Arctic Sea-ice Regime

Polona Itkin1 (polona.itkin@npolar.no), Robert Graham1, Mats Granskog1, N-Ice Team1

1
Norwegian Polar Institute, Fram Centre, Tromsø, Norway

The integrative effects of increased winter storm activity in the Arctic's Atlantic sector were studied using a
collection of field observations and analyses. In early 2015, during the six-month N-ICE2015 expedition in the
pack ice north of Svalbard, we observed a chain of events in the atmosphere-ice-ocean system that was
triggered by several powerful winter storms. Our unique, interdisciplinary observations show that these winter
storms entail significant effects that last much longer than the short-lived storm events themselves. The rapid
warm and moist air advection associated with the storms contributed to a deep snow-pack and ice surface
warming that inhibited thermodynamic sea-ice growth. Instead, the heavy snow-load promoted flooding and
formation of snow-ice. The strong winds deformed the sea ice, opening up leads, increased air-to-sea CO2
fluxes by a factor of 20 and increased the concentration of sea-salt aerosols. The storms also enhanced ocean
mixing, with ocean-to-ice heat fluxes that were 17 times larger than background values when warm Atlantic
Water was near the surface. This resulted in mid-winter bottom-ice melt rates of 5-25 cm/day. In spring, the
aggregate effect of winter storms promoted algal growth at the flooded snow-ice interface, produced ice algal
hotspots in pressure ridges, and the light transmission through leads set off an extensive under-ice
phytoplankton bloom. Frequent winter storms have profound impacts in a thinner Arctic sea-ice regime.

2238
Fri_286_OS-7_1585
Global Research Challenges and CATCH - The Cryosphere and ATmospheric CHemistry

Markus Frey1 (maey@bas.ac.uk), Jennie Thomas2, Thorsten Bartels-Rausch3

1
Natural Environment Research Council / British Antarctic Survey, Cambridge, United Kingdom, 2CNRS /
Laboratoire Atmosphères, Milieux et Observations Spatiales (LATMOS), Paris, France, 3Paul Scherrer Institute
(PSI), Villigen, Switzerland

The cold regions on Earth are undergoing significant climate change. Yet many underlying chemical, biological,
and physical processes and feedbacks are still poorly understood strongly motivating continued research in
cold regions. Such research inherently requires cooperation among researchers and programs across national
boundaries to achieve science objectives. CATCH is an emerging activity of the IGAC (International Global
Atmospheric Chemistry) project and is endorsed by SOLAS (Surface Ocean-Lower Atmosphere Study). CATCH
facilitates interdisciplinary and international research with a focus on interactions between snow, ice, ocean,
aerosols, and clouds in cold regions. CATCH science addresses cold region research challenges to help reduce
model uncertainties and improve climate predictions. Here we give an overview of scientific aims and strategy
to develop collaborative research teams and projects. Particular areas of interest include: sea ice changes,
atmosphere-ice-ocean interactions and their impacts on atmospheric chemistry; feedbacks between climate
change and atmospheric chemistry mediated by changes in the cryosphere; the production, processing and
climate impacts of aerosols and cloud precursors; ice cores as archives of past environmental change, and the
influence of background atmospheric chemistry on the fate of pollution. CATCH seeks to link research on a
fundamental, molecular level with larger scales targeted by field and satellite observations.

On behalf of the CATCH Implementation Team, IGAC, http://www.igacproject.org/activities/CATCH, Boulder,

United States

2239
Fri_287_OS-7_1623
Evaporation at 2 Poles: Moisture & Sensible Heat Flux in the Arctic & Antarctic

Linette Boisvert1 (linette.n.boisvert@nasa.gov), Chung-Lin Shie1

1
NASA Goddard Space Flight Center, Greenbelt, United States

The process of evaporation provides water vapor from the surface to the atmosphere, where it becomes the
most radiatively important and abundant greenhouse gas altering the Earth's energy balance and water cycle.
However, it is often poorly captured because surface in-situ measurements of evaporation are scarce,
especially over the Polar Regions.
The sea ice at both poles acts as a barrier between the ocean and atmosphere inhibiting the exchange of heat,
momentum, and moisture. However, variations in the sea ice cover could lead to changes in the amount of
heat and moisture supplied to the atmosphere. Since the Arctic and Antarctic sea ice have been behaving very
differently over the satellite record, it is crucial to study these changes on the moisture and sensible heat
fluxes. These variations could affect surface energy budgets, larger occurrences of low-level clouds, and higher
near-surface humidity and temperatures.
Little research has been done looking at the moisture and sensible heat flux from the Arctic and Antarctic sea
ice pack. This work will use data from NASA's AIRS and the scheme from Boisvert et al., 2013, which utilizes the
Monin-Obukhov Similarity Theory. Changes have been made to the boundary layer parameterizations
specifically for sea ice in order to produce a 2003-2016 moisture and sensible heat flux product. Regional and
seasonal differences will be addressed along with any trends and interannual variability.

2240
Fri_288_OS-7_1711
Surface Heat Budgets in the Ross and Weddell Seas and Global Climate Variability

Giannetta Fusco1 (giannetta.fusco@uniparthenope.it), Yuri Cotroneo1, Giuseppe Aulicino2, Dario Cerrone1

1
Parthenope University, Napoli, Italy, 2Università Politecnica delle Marche, Ancona, Italy

The monthly mean surface heat budgets, over last fifty years, in the Ross and Weddell Seas have been
estimated using meteorological parameters provided by the ECMWF and sea ice information from SSM/I data
and SIT (sea ice thickness) algorithm.
The areas show opposite variations before 1998 and synchronous behaviour after 1999. This may be explained
by the global climate variability expressed by ENSO, SAM and wavenumber-3 pattern or by combination among
them. Also ACW could be involved. The interaction among these signals can imply a different behaviour of
surface heat budgets in the two areas.
Our results show that circumpolar SLP and SST signals exhibit coherent components on interannual whereas
covarying significant energy between SAM and ENSO variability is observed. This implies that SAM and ENSO
modes play a superimposed role interfering constructively or destructively on interannual scale. Furthermore,
the hovmoller diagrams for interannual SLP anomalies exhibits two stronger ACW cycles around 1982-1991.
Before 1982 and after 1991 the absence of ACW seems to be related to the dominant signature of SAM in
modulating circumpolar variability.
Also CEOF analysis show that the SAM has assumed a leading role between 1972-81 and 1991-2000
determining no ACW events. Starting from 2003 until present a wavenumber-3 pattern could have played a
role in continuing the phase relationship between heat fluxes in the two Antarctic sectors.

2241
Fri_289_OS-7_1748
Terra Nova Bay Polynya Evolution by MODIS Imagery during Winter 2003 - 2016

Manuela Sansiviero1 (manuela.sansiviero@uniparthenope.it), Giuseppe Aulicino2, Stephan Paul3, Cinzia

Cesarano4, Giannetta Fusco1, Giorgio Budillon1
1
Parthenope University, Napoli, Italy, 2Università Politecnica delle Marche, Ancona, Italy, 3Alfred Wegener
Institute, Bremerhaven, Germany, 4Progetto Terra, Napoli, Italy

Remote sensing is essential for monitoring polynyas dynamics. On regional scales, passive microwave (PM)
radiometers provide useful information about their extent. Their coarse resolution often limits an accurate
separation of open water from ice cover. Despite their sensitivity to the presence of clouds, thermal infrared
(TIR) Moderate Resolution Imaging Spectroradiometers (MODIS) provide high resolution information (typically
1 Km) at large swath widths, several times per day.
In this study we apply a new methodology that combines a sequence of MODIS swath-based scenes to examine
the TNB evolution in the winter season during the last 14 years (2003-2016). Results have been validated
through the comparison with a huge set of SAR images acquired by ENVISAT, SENTINEL and COSMO-SkyMed
satellites. The good agreement with most of the analyzed SAR images demonstrated the potential of this tool
for the continuous monitoring of the polynya extent and the consequent estimation of ice production rates. A
comparison with TNB polynya extent estimations retrieved by other MODIS and PM based tools has also been
carried out and differences discussed. Furthermore, the polynya events identified through our technique have
been compared to the katabatic events captured by the automatic weather stations located along the TNB
coast, and their interannual variability analyzed.

2242
Fri_290_OS-7_1766
Biogenic Aerosol in Central Antarctica: The Ocean-atmosphere Interaction

Silvia Becagli1 (silvia.becagli@unifi.it), Rita Traversi1, Mirko Severi1, Laura Caiazzo1, Luigi Lazzara2, Giovanna
Mori2, Christian Marchese3, Claudio Scarchilli4, Virginia Ciardini4
1
University of Florence, Department of Chemistry 'Ugo Schiff', Sesto Fiorentino, Italy, 2University of Florence,
Department of Biology, Florence, Italy, 3Université du Quebec a Rimouski, Dep.de Biologie, Chimie et
Geographie, Rimouski, Canada, 4ENEA, Laboratorio di Osservazione e Analisi della Terra e del Clima, Rome, Italy

Ten years data of atmospheric oxidised sulphur compounds (methanesulphonic acid (MSA) and non-sea salt
sulphate, nssSO4) from the east Antarctic Plateau at Dome C (75° 06' S, 123° 20' E, 3220 m a.s.l. and 1100 km
away from the nearest coast) are here presented. Biogenic sulphur aerosol is produced by the oxidation of the
dimethylsulphyde produced by phytoplankton. The two sulphur-derived species exhibit a seasonal cycle
characterised by maxima in the summer from October to March. In particular MSA presents two summer
maxima the first one in November and the second in February, the latter with MSA concentrations higher than
the first-one. The two maxima are characterized by different size distribution and seem to be related to
different source area of DMS characterized by different timing of primary production. The two maxima of MSA
are analysed also as function of sea ice extent and area of ice free in the marginal ice zone in the two different
source areas. Sea ice is an important parameter affecting polar primary production. It regulates primary
production in the shelves by:
(i) providing a substrate for algal growth on the underside of the ice;
(ii) limiting the photosynthetic radiation available to primary producers;
(iii) limiting the development of thermal or fresh water stratification in the freezing season; and
(iv) enhancing water stratification during the melting season, therefore regulating the amount of available
nutrients in the euphotic layer.

2243
Fri_291_OS-7_1767
Ross Sea Shelf Water Variability and Interactions with the Atmospheric Forcing

Pasquale Castagno1 (pasquale.castagno@uniparthenope.it), Giannetta Fusco1, Daniela D'Amore1, Pierpaolo

Falco1, Giorgio Budillon1
1
Parthenope University, Napoli, Italy

The Antarctic Bottom Water (AABW), the densest and coldest water that occupies the bottom layer of the
world ocean, is formed in few areas around Antarctica. The production of the AABW plays a major role in
determining the strength of the Meridional Overturning Circulation.
Observations within the Southern Ocean's Pacific sector indicate a decadal trend of reduced salinity of both the
AABW and shelf waters.
CTD data and moored time-series collected in the Ross Sea from 1995 to 2017 in the framework of the Italian
National Antarctic Research Program (PNRA) show strong changes in the thermohaline characteristics of the
dense shelf water (SW), a precursor of the AABW.
We observe a freshening of about 0.05 per decade in the western Ross Sea both at the SW formation area
(Terra Nova Bay polynya - TNBp) and at the Ross Sea shelf break near Cape Adare (CA) where the AABW is
formed and exits the Ross Sea. Besides the negative salinity trend, we note a periodical variability of the salinity
time series of about 6-7 years in the TNBp and of 4-5 years at CA.
The physical processes driving the SW interannual variability in the Ross Sea are poorly understood, here we
investigate the relationship of the complex interaction among the atmospheric forcing, sea ice production, and
ocean thermohaline variability.

2244
Fri_292_OS-7_1815
Shelf and Slope Dynamics Offshore the West Svalbard Continental Margin

Manuel Bensi1 (mbensi@inogs.it), Leonardo Langone2, Vedrana Kovacevic1, Laura Ursella1, Ilona Goszczko3,
Stefano Aliani4, Michele Rebesco1, Cinzia De Vittor1, Federica Relitti1, Matteo Bazzaro1, Davide Deponte1,
Roberto Laterza1, Paolo Mansutti1, Renata G. Lucchi1, Anna Wåhlin5, Thomas Soltwedel6, Ragnheid Skogseth7,
Frank Nilsen7, Matthias Forwick8, Agnieszka Beszczynska-Möller3, Roberta Ivaldi9, Maurizio Demarte9, Stefano
Miserocchi2, Angelo Viola10
1
OGS - National Institute of Oceanography and Experimental Geophysics, Trieste, Italy, 2CNR - ISMAR - National
Research Council, Italy, Bologna, Italy, 3IOPAN -Institute of Oceanology - Polish Academy of Sciences, Sopot,
Poland, 4CNR - ISMAR - National Research Council, Italy, La Spezia, Italy, 5UGOT - University of Gothenburg,
Gothenburg, Sweden, 6AWI - Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany,
7
UNIS - University Centre in Svalbard, Longyearbyen, Norway, 8UiT The Arctic University of Norway in Tromsø,
Tromsø, Norway, 9Italian Navy, Hydrographic Institute, Genova, Italy, 10CNR - ISAC - National Research Council,
Italy, Roma, Italy

The large-scale circulation and dense water formation (DWF) in the Svalbard archipelago influence the
thermohaline circulation in the whole Arctic. DWF depends on the rate of cooling and homogenisation of the
Atlantic water along its northward pathway, brine rejection, boundary convection on shelves and slopes, and
open-ocean convection. This study focuses on the shelf and slope dynamics and the entrainment processes,
which occur along the west Spitsbergen margin. Two short (~140m) moorings (S1 and ID2), deployed at a depth
of ~1040 m over the slope, collected multiannual (2014-2017) time-series in an area of interaction between the
West Spitsbergen Current and the descending shelf plumes. Time-series revealed a large thermohaline and
current variability between October and April. Data highlight the presence of Norwegian Sea Deep Water (θ = -
0.90°C, S = 34.90, σθ = 28.07 kg m-3) influenced by occasional intrusions of warmer (up to +2°C), saltier (up to
~35), less dense (down to 27.98 kg m-3), and more oxygenated water during fall-winter periods. The result is
the injection of heat into the deep sea. Notably, such intrusions occur simultaneously at both sites 170km
apart, suggesting that strong winds could trigger the formation of gravity plumes but is the particulate matter
that renders them more energetic and heavier than pure TS plumes. Here we discuss the origin, timing, and
role of such plumes in a period characterized by a general warming and ice reduction of the Arctic.

2245
Fri_293_OS-7_1823
The Seesaw between Oceanic and Atmospheric Heat Fluxes in the Barents Sea Region

Igor Bashmachnikov1,2 (igorb1969@mail.ru), A.Yu. Yurova1,3, L.P. Bobylev2,4, A.V. Vesman2,5

1
St. Petersburg State University, St. Petersburg, Russian Federation, 2NIERSC, St.Petersburg, Russian Federation,
3
NIERSC, St. Petersburg, Russian Federation, 4NERSC, Bergen, Norway, 5Arctic & Antarctic Research Institute,
St.Petersburg, Russian Federation

Observations and model results suggest existence of a negative feedback between the intensity of the oceanic
and the atmospheric heat fluxes at scales of 30-year and longer time scale,- the so called Bjerknes
compensation. The link between the oceanic and atmospheric fluxes is maintained through ocean-atmosphere
heat exchange, mostly over the north Greenland Sea and the Barents Sea. A local positive feedback in the
ocean-ice-atmosphere system makes the latter to strongly amplify the intensity of the forced fluctuations.
In this work, variations of convergence of advective heat fluxes in the ocean (dQoc) and in the atmosphere
(dQatm) in the regions were investigated for time scales of 1-10 years, using model results and observations. In
both, dQoc and dQatm data, the 2-4-year and 5-8 year cycles were detected. Cross-wavelet analysis of dQoc and
dQatm showed nearly out-of-phase variations of dQoc and dQatm in the Barents Sea region at 5-8 year scales. This
was not the case for dQoc and dQatm for the north Greenland Sea region. The results suggest a significance of
ocean-atmosphere exchange over the Barents Sea in maintenance of the Bjerknes compensation mechanism in
the Arctic.
The research was supported by RSF project 17-17-01151

2246
Fri_294_OS-7_1849
Antarctic Sea Ice Region as a Source of Biogenic Organic Nitrogen in Aerosols

Manuel Dall´Osto1 (dallosto@icm.csic.es), R Simo1

1
ICM CSIC, Barcelona, Spain

Climate warming affects the development and distribution of sea ice, but at present the evidence of polar
ecosystem feedbacks on climate through changes in the atmosphere is sparse. By means of synergistic
atmospheric and oceanic measurements in the Southern Ocean near Antarctica, we present evidence that the
microbiota of sea ice and sea ice-influenced ocean are a previously unknown significant source of atmospheric
organic nitrogen, including low molecular weight alkyl-amines. Given the keystone role of nitrogen compounds
in aerosol formation, growth and neutralization, our findings call for greater chemical and source diversity in
the modelling efforts linking the marine ecosystem to aerosol-mediated climate effects in the Southern Ocean.

On behalf of the PEGASO Team

2247
Fri_295_OS-7_1883
Long-term Measurements of CO2 Flux over Sea Ice in the Canadian Arctic

Brian Butterworth1 (brian.butterworth@ucalgary.ca), Brent Else1, Shawn Marriott1

1
University of Calgary, Geography, Calgary, Canada

The Arctic marine environment plays and important role in the global carbon cycle. However there remain
large uncertainties in how sea ice, in particular spring melt and autumn freeze-up, affect air-sea fluxes of
carbon dioxide (CO2). To test the impact of these ice regimes measurements of CO2 flux (as well as momentum,
sensible and latent heat) were collected from a 10 m eddy covariance tower installed on Qikirtaarjuk Island (a
small rock outcrop in the Dease Strait located roughly 35 km southwest of Cambridge Bay, Nunavut in the
Canadian Arctic). The study area exhibited open water in the summer and full sea ice cover in the winter
months, making it possible to study the transitional ice periods in the spring and autumn. The system
incorporated recent developments in the field of air-sea gas exchange by measuring CO2 mixing ratio using a
closed-path infrared gas analyzer system with a dried airstream, thus avoiding the known water vapor issues
associated with using open-path gas analyzers in low flux environments. The results from one year of
continuous flux measurements will be shown, highlighting the seasonal trends in gas exchange and comparing
flux magnitudes during melt and freeze-up to those found in laboratory experiments and previous field studies.

2248
Fri_296_OS-7_1902
Changes in Heat Content and Melt-water at Maxwell Bay, King George Island

Pedro J. Llanillo1 (pedro.llanillo@usach.cl), Christopher M. Aiken2, Raul R. Cordero1, Alessandro Damiani3,

Edgardo Sepulveda1, Kyu-Cheul Yoo4, Hoil Yoon4
1
Universidad de Santiago de Chile, Santiago, Chile, 2Pontificia Universidad Católica, Santiago, Chile, 3Chiba
University, Chiba, Japan, 4Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

Ocean processes controlling the oceanic heat flux to the ice face of Antarctic tidewater glaciers are crucial to
understand the reduction of the Antarctic ice-shelves. With the support of Instituto Antártico Chileno (INACH),
we carried out a field campaign in Maxwell Bay, King George Island, in February 2016. These measurements
provided a valuable dataset of current oceanographic conditions, which we compared with the oceanographic
conditions measured in a previous campaign carried out by the Korea Polar Research Institute (KOPRI) in
December 2000. From that comparison, we found warming and freshening of the upper part of the water
column in Maxwell Bay. These hydrographic changes might be explained by the intra-seasonal cycle (February
versus December) or might be due to interdecadal changes (i.e. an increased penetration of warmer subsurface
waters into the Maxwell Bay area and an increased freshwater input from the surrounding tidewater glaciers).
The origin of these changes will be discussed in the light of the new measurements to be obtained during our
next field campaign in December 2017.

2249
Fri_297_OS-7_1997
Interannual to Decadal Labrador Sea Ice Variability due to Local-scale Processes

Sally Close1 (sally.close@univ-grenoble-alpes.fr), Christophe Herbaut2, Marie-Noelle Houssais2, Anne-Cécile

Blaizot2
1
Institut des Géosciences de l'Environnement, Grenoble, France, 2UPMC/LOCEAN, Paris, France

Processes affecting the surface state of the Labrador Sea are of wider interest due to its role as a site of water
mass formation. Sea ice can modify the surface state; however, the processes by which its variability is forced
are unclear in this region. Motivated by this, the mechanisms responsible for the interannual- to decadal-scale
variability of the Labrador Sea ice in winter are analysed, drawing on observations, an ice-ocean model, and a
fully-coupled simulation from the CMIP5 archive. A coherent series of mechanisms is found in all cases. The
highest values of sea ice area occur when the northern Labrador Sea is ice covered. The sea ice in this region is
found to be primarily thermodynamically forced, with growth occurring in response to anomalously fresh
surface conditions. Positive freshwater anomalies propagate rapidly to the region from a source area off the
southeast Greenland coast and originate from sea ice melt, associated with the enhanced offshore transport of
sea ice here. The sea ice transport is in turn driven by local atmospheric wind conditions, which are strongly
correlated with Greenland blocking. A further link is found both with the sea ice transport through the
Denmark Strait in the preceding autumn, representing a dependence on the availability of sea ice to be melted,
and also, at longer time scales, with the Atlantic Multidecadal Oscillation, suggesting a multidecadal-scale link
to wider sea surface temperature conditions.

2250
Fri_298_OS-7_2183
Heat Loss Variability and Subantarctic Mode Water at Southern Ocean OOI Mooring

Sarah Ogle1, Veronica Tamsitt2, Simon Josey3, Sarah Gille2, Ivana Cerovecki2, Lynne Talley2 (ltalley@ucsd.edu)
1
Carleton College, Northfield, United States, 2University of California San Diego, Scripps Institution of
Oceanography, La Jolla, United States, 3National Oceanography Centre, Southampton, United Kingdom

The Ocean Observatories (OOI) air-sea flux mooring, deployed in February 2015 at 54S, 90W, in the southeast
Pacific sector of the Southern Ocean, is the furthest south open ocean mooring ever deployed. Observations
analyzed here (Feb 2015-Aug 2017) provide the first accurate quantification of the annual cycle of net air-sea
heat exchange and the wind stress from one of the prime Subantarctic Mode Water (SAMW) formation
regions. We find that extreme turbulent heat loss events reaching a daily mean of -290 W m-2 promote the
formation of deep winter mixed layers up to 600 m deep. Extreme heat loss events are associated with winds
from the southwest bringing relatively cold, dry air to the mooring location leading to large air-sea temperature
and humidity differences. There is large interannual variability in the frequency of wintertime extreme heat
loss events and associated mixed layer deepening, with strong heat loss in winter 2015 and weak heat loss in
2016. These results have important implications for the role of turbulent heat loss in Subantarctic Mode Water
(SAMW) formation.

2251
Fri_299_OS-7_2192
Observations of Significant CO2 Uptake in Antarctic Polynyas

Tae Siek Rhee1 (rhee@kopri.re.kr), Christopher J Zappa2, Young Shin Kwon1, Taejin Choi1, Eun-Jin Yang1, Ji Hee
Kim1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Lamont-Doherty Earth Observatory of
Columbia University, Ocean and Climate Physics, Palisades, United States

We present the first direct observations of ocean and atmospheric pCO2 measured at the Korean Antarctic
base, Jang Bogo, locating near the Terra Nova Bay (TNB) polynya in the Ross Sea since February, 2015. The TNB
polynya opens a small area (~1000 km2) in the winter. In contrast, the area exposed to the atmosphere in the
summer is greater than 8 times the winter polynya, therefore, significantly enhancing air-sea gas exchange. The
pCO2 in seawater swung from ~120 matm in February to ~425 matm in early October. In November, the pCO2
suddenly dropped as much as ~100 matm in a week. This decrease of pCO2 continued until late February when
the sea-ice concentration was minimal. With growing sea ice, the pCO2 increased in parallel catching the
atmospheric concentration in June/July, depending on the year, and continued to increase until October. Daily
mean of air-sea CO2 flux in the TNB polynya widely varied from ~-70 mmol m-2 d-1 to ~20 mmol m-2 d-1. Based
on these observations of pCO2 in the TNB polynya, the annual uptake of CO2 came up with ~9 g C m-2, which
takes into account the fraction of sea-ice concentrations estimated from AMSR2 microwave emission imagery.
Extrapolating to all polynyas surrounding Antarctica, we expect the annual uptake of ~ 9.5 Tg C of CO2 from the
atmosphere. This is comparable to the amount of CO2 degassed into the atmosphere south of the Antarctic
Polar Front (62°S).

2252
Fri_300_OS-7_2201
Monitoring Subsurface Meltwaters from Surface Observation in Nares Strait

Lovisa Waldrop Bergman1 (lovisawaldropbergman@gmail.com), Céline Heuzé1

1
University of Gothenburg, Department of Marine Sciences, Gothenburg, Sweden

Petermann Glacier, one of the largest marine-terminating glaciers of Greenland, loses the majority of its mass
through basal melt by the comparatively warm ocean. The fate of this meltwater is virtually unknown, for it
circulates more than 100 m below the surface and cannot easily be monitored. Ocean surface currents and sea
ice drift in contrast can be retrieved continuously through satellite remote sensing. We here investigate
whether remote sensing monitoring of the meltwater layer could be possible.
Using an MITgcm simulation validated by a unique new dataset of surface drifters and hydrographic profiles
from the I/B Oden Petermann2015 expedition, we quantify the relationship between the surface currents and
the circulation of the meltwater in Petermann Fjord and surrounding Nares Strait. A series of sensitivity
experiments determines whether this relationship is most pronounced in specific wind and/or sea ice
conditions.
Year-round monitoring of glacial meltwater flows around Greenland, and ultimately into the North Atlantic, is a
prerequisite to understand the particular role of meltwaters on the global ocean circulation.

2253
Fri_301_OS-7_2206
Connecting the Spring Atmospheric Pacific-arctic Mode to Summer Beaufort Ice

Minghong Zhang1 (honghong19850409@gmail.com), Will Perrie1, Zhenxia Long1

1
Bedford Institute of Oceanography, Dartmouth, Canada

We identify a spring atmospheric Pacific-Arctic mode (PAM) and investigate its connections to summer
Beaufort Sea ice. PAM is the second EOF mode of seasonal sea level pressure poleward of 20oN with a variance
of 12%. A positive PAM has a negative anomaly in the subpolar Pacific and positive anomalies in the Beaufort-
Chukchi region of the Arctic and the midlatitude Pacific, exhibiting an intensified Aleutian Low and North Pacific
High, and a northward displaced Beaufort Sea High. PAM is associated with the distribution of cyclone activity
and tracks and warm (polar) air advection due to modulation of the tropospheric circulation anomalies
associated with the East Asian trough and the Pacific side of the polar vortex. PAM accounts for 16% of the
internal variability of the following September Beaufort sea ice coverage. A positive PAD leads to increased
open water days in the Beaufort Sea during spring and summer. During positive PAM, strong easterly winds in
the Beaufort Sea enhance ice advection and reduce ice thickness, due to the associated intensified and
northward extended Aleutian Low. Moreover, the increased solar radiation further accelerates ice melt, due to
reduced cloud cover and water content associated with fewer cyclones in the Beaufort Seas. Thinner ice and
increased open water foster a stronger summer ice-albedo feedback resulting in accelerated early-summer ice
melt. PAM is a potential predictor for Beaufort Sea ice melting.

2254
Fri_302_OS-7_2394
Evaluation of Wind Products with Wave Glider Observations in the Southern Ocean

Sebastiaan Swart1 (sebastiaan.swart@marine.gu.se), Kevin Schmidt2, Chris Reason2, Sarah Nicholson3

1
University of Gothenburg, Marine Sciences Department, Gothenburg, Sweden, 2University of Cape Town, Cape
Town, South Africa, 3CSIR, Cape Town, South Africa

Surface ocean wind datasets are required to be of high spatial-temporal resolution and precision to accurately
force or be assimilated into coupled numerical models and to understand ocean-atmospheric processes. In situ
observed surface winds from the Southern Ocean are scarce and, consequently, the validity of models is often
questioned. Multiple wind products were compared to the first high-resolution in situ measurements of wind
speed from Wave Glider (WG) deployments in the Southern Ocean to determine which blended product best
represents the magnitude and variability of the observed wind field. Results show that the ECMWF product is
the most accurate in representing the temporal variability of winds, exhibiting consistently higher correlation
coefficients with in situ data across all wind speed categories. However, NCEP-II Reanalysis matches in situ
trends of deviation from the mean and performs best in depicting the mean wind state, especially at high
winds. ECMWF also leads to smaller differences in wind speeds from the in situ data, while CFSv2 showed
higher biases and a greater RMSE. The SeaWinds (SW) product performed poorly at representing the mean or
wind stress variability compared to WG observations. Overall, the study shows autonomous surface vehicles
provide valuable observations by which to validate, understand, and potentially assist in correcting
satellite/reanalysis products, particularly in remote regions, where few in situ estimates exist.

2255
Fri_303_OS-7_2475
Factors Controlling Water Mass Variations over the Chukchi Borderland, Arctic

Kyoung-Ho Cho1 (kcho@kopri.re.kr), Young-Seok Choi1, Eri Yoshizawa1, Sung-Ho Kang1

1
Korea Polar Research Institute, Incheon, Korea, Republic of

We have carried out hydrographic surveys since 2010 to monitor the Pacific-orign waters over the Chukchi
Borderland (CBL) in the western Arctic Ocean. Based on CTD data analysis, the heat content from the Pacific
Summer Water (PSW) is highly correlated with sea ice extent reduction over the region. Yearlong mooring and
numerical simulation data are analyzed to verify what factors lead the PSW variation. We found two factors
controlling the variation of PSW over the region: variation of summer waters incoming through the Bering
Strait (BS) and variation of local winds over the East Siberian Sea (ESS) shelf. Temporal variation of PSW
temperature over CBL is in-phase with that of the Alaskan Coastal Water (ACW) temperature even if there is a
time lag. Relatively cold water over the ESS shelf is transported to the CBL by local winds and subducted into
the PSW layer by the thermohaline intrusion.

2256
Fri_304_OS-7_2558
Remote in situ Measurements of Sea Ice Evolution

Rachel Obbard1 (rachel.w.obbard@dartmouth.edu), Alice Bradley1, Ignatius Rigor2, Jim Johnson2

1
Dartmouth College, Thayer School of Engineering, Hanover, United States, 2University of Washington, Applied
Physics Laboratory, Seattle, United States

We present the results of field experiments in Elson Lagoon (Utqiaġvik, Alaska), designed to test our ability to
remotely monitor the onset of freezing, freezing rate and ice type in natural sea ice in real time. Two
Microstructure in situ Salinity and Temperature (MIST) buoys were launched in open water in October 2017
and allowed to freeze into the developing sea ice. Each buoy carried two vertical arrays of wire harps (Notz,
Wettlaufer and Worster, 2005), developed to make in situ measurements of salinity and solid fraction profiles
in growing sea ice. The technique measures temperature and impedance as sea ice grows downward across
regularly spaced wire pairs, and is based on the principle that pure solid ice is a good insulator whereas
interstitial saltwater brine is a good conductor. Impedance and temperature data, along with air temperature,
GPS location, and buoy tilt was transmitted hourly via iridium. Salinity of the interstitial brine was inferred from
the liquidus relationship (Cox and Weeks, 1986) and combined with the measured solid mass fraction to give
the time resolved bulk salinity profile of the growing sea ice.
We examined the sea ice growth process and the effect of changes in surface temperature and salinity on
growth rate and microstructure. To interpret the data, we also conducted laboratory experiments on heat
transfer in sea ice using the ICE-MITT, a purpose built refrigeration system that holds ice cores at user-defined
temperature gradients.

2257
Fri_305_OS-7_2585
Modeling the Formation and Persistence of an Open Ocean Polynya

Gustavo Marques1 (gmarques@ucar.edu)

1
National Center for Atmospheric Research (NCAR), Climate & Global Dynamics, Boulder, United States

The recent appearance of the Weddell Polynya has motivated the need for a better understanding of this
phenomenon. Climate models must be able to represent this phenomenon correctly, since it has the potential
to affect bottom water formation and, therefore, impact the large-scale ocean circulation. The initial
development of the Weddell Polynya has been explained by interactions between the large-scale oceanic flow
and a seamount (Maud Rise). However, the environmental conditions necessary for the persistence of the
polynya remain elusive. Here, we use numerical simulations in idealized geometric configurations to investigate
how changes in atmospheric forcing and model parameters (e.g., grid resolution, boundary layer scheme and
vertical coordinate) impact the formation, propagation and persistence of an open ocean polynya. The
experiments are conducted using an ocean model (MOM6) coupled with a sea ice model (SIS2). We show that
the formation and persistence of the polynya is strongly influenced by surface buoyancy fluxes. The threshold
in buoyancy gain above which the polynya does not form varies depending on model parameters. Our results
provide insights into the model parameters necessary to correctly represent an open ocean polynya in climate
models.

2258
Fri_306_OS-7_2597
Arctic Layer Salinity Controls Vertical Mixing with Deep Atlantic Layer

Sigrid Lind1,2 (sigridl@imr.no), Randi B. Ingvaldsen3, Tore Furevik2

1
Insitute of Marine Research, Tromsø, Norway, 2University of Bergen, Geophysical Institute & Bjerknes Centre
for Climate Research, Bergen, Norway, 3Institute of Marine Research, Bergen, Norway

The Arctic Ocean is cold, stratified and sea ice covered due to the presence of a cold and relatively fresh upper
layer, here called the Arctic layer, which suppresses direct influence from the subsurface layer of warm and
saline Atlantic Water below (the Atlantic layer). It is largely unknown if, how and to what extent heat and salt is
transferred up from the deep Atlantic layer.
Based on an extensive observational hydrographic data set covering the northern Barents Sea from 1970-2016,
we find that there is considerable vertical mixing of heat and salt between the Arctic and Atlantic layers,
causing year-to-year variations in the Atlantic layer temperature. We show that the Arctic layer salinity largely
controls the stratification, vertical mixing and upward heat and salt fluxes from the Atlantic layer.
Our findings demonstrate that vertical mixing between the Arctic and Atlantic layers is key to the Arctic
environment, as it controls the rate of heat transfer from the deep Atlantic layer towards the surface, where it
can influence sea ice concentration and lower troposphere temperatures.
The corresponding upward salt flux constitutes a positive feedback, as increased salinity in the Arctic layer will
weaken the stratification and enhance the mixing. This positive feedback mechanism is likely operating in
larger parts of the Arctic Ocean, emphasizing the need for monitoring the changes in the water column to
understand and predict the rapid climate transition in the Arctic.

2259
Fri_307_OS-7_2683
Oceanic Emissions of Aerosol-forming Substances in Antarctica and Subantarctic

Rafel Simó1 (rsimo@icm.csic.es), Manuel Dall'Osto1, Pau Cortés1, Marina Zamanillo1, Charlotte Cree2, Pablo
Rodríguez-Ros1, Sdena Nunes1, Daffne López-Sandoval3, Gonzalo L. Pérez4, Eva Ortega-Retuerta5, Mikhail
Emelianov1, Dolors Vaqué1, Cèlia Marrasé1, Marta Estrada1, M. Montserrat Sala1, Mark F. Fitzsimmons2, Rachael
Beale6, Ruth Airs6, Jurgita Ovadnevaite7, Marco Paglione8, David C.S.. Beddows9, Darius Ceburnis7, Matteo
Rinaldi8, Stefano Decesari8, Maria Cristina Facchini8, Roy M. Harrison9, Colin O'Dowd7
1
Institut de Ciències del Mar-CSIC, Barcelona, Spain, 2Plymouth University, Plymouth, United Kingdom, 3King
Abdullah University of Science and Technology, Thuwal, Saudi Arabia, 4INIBIOMA, SC de Bariloche, Argentina,
5
CNRS, Banyuls, France, 6Plymouth Marine Laboratory, Plymouth, United Kingdom, 7National University of
Ireland Galway, Galway, Ireland, 8Institute of Atmospheric Sciences and Climate, NRC, Bologna, Italy, 9University
of Birmigham, Birmingham, United Kingdom

Climate warming affects the development and distribution of sea ice around Antarctica and its associated
ecosystems, but at present the evidence of feedbacks on climate through ecosystem-derived changes in the
atmosphere is sparse. The PEGASO cruise visited the Antarctic region of the South Orkney Islands at the
northern edge of the Weddell Sea, and the Subantarctic region of the South Georgia Island, in summer 2015.
Each region was studied intensively in lagrangian mode over a few days and diel cycles. Oceanic measurements
of plankton abundance, diversity, activity and physiology, plus organic matter characteristics, aerosol-forming
organic volatile compounds (dimethylsulfide, methylamines, isoprene, halomethanes) and nutrient
concentrations, were compared with simultaneous atmospheric measurements of aerosol numbers, size and
composition. Samples of surface seawater and melted sea ice were bubbled in an aerosol-generation tank and
the characteristics of the sprayed aerosol were monitored. This integrated study allowed to link phytoplankton
bloom stages and the emission of aerosol-forming particulate and gaseous substances. Our findings call for
greater chemical and source diversity in the modeling efforts linking the marine ecosystem to aerosol-mediated
climate effects in the Southern Ocean.

2260
Fri_308_SH-8_211
Lake Bonney Narrows: 114 Years of Observations Started by Scott Himself

Peter Doran1 (pdoran@lsu.edu), Ian Hawes2, Macij Obryck1, Krista Myers1

1
Louisiana State University, Baton Rouge, United States, 2University of Canterbury, Christchurch, New Zealand

Lake Bonney, in Taylor Valley, has two distinct lobes separated by a relatively shallow sill in a narrow channel
referred to as the Bonny Narrows. Robert Falcon Scott passed through the Bonney Narrows in 1903 on his first
expedition in the area, and made a measurement of the channel's width that has been used to estimate lake
level at the time in order to extend our lake level record for Lake Bonney to well over 100 years now. Lake level
has risen between December 1903 and January 2017 by ~16 m, on average 0.14 m/yr. The sill depth was at
most a meter deep during Scott's visit and the two lobes had only joined in the years prior to Scott's visit.
Photographs taken by Griffith Taylor's party on Scott's second expedition show that there was a dramatic lake
level rise between 1903 and 1911 of almost 3 m. The sill is now an important physical control of the
geochemistry and ecology of the two lobes. West Lake Bonney (WLB) has a hypersaline brine bottom water
which is held back from East Lake Bonney (ELB) by the sill. The brine is displaced over the sill, by a mechanism
referred to as “chemocline leakage”. The brine sinks on the ELB side following a former river channel until if
finds it´s neutral buoyancy in ELB, about 4 to 5 m below the sill depth. In this presentation, I will review the
history of the connectivity between the two lobes of Lake Bonney as indicated by geochemical proxies and
physical evidence collected from the lake surface and through recent diving operations.

2261
Fri_309_SH-8_450
Air Temperature in Franz Josef Land Archipelago from 1899 to 1940

Przemysław Wyszyński1 (przemyslaw.wyszynski@umk.pl), Rajmund Przybylak1

1
Nicolaus Copernicus University, Department of Meteorology and Climatology, Toruń, Poland

The results of an investigation into the air temperature conditions in Franz Josef Land Archipelago (FJL) from
1899 to 1940, on the basis of all available early instrumental data gathered during exploratory and scientific
expeditions, are presented. Traditional analysis based on mean monthly data was supplemented by an
approach less popular in the scientific literature, i.e. the additional use of daily data (MAX, MEAN, MIN, DTR).
Such rich sets of data allowed for more comprehensive and precise recognition of air temperature conditions in
the FJL. Based on these kinds of daily data, it was also possible to calculate the number of so-called
'characteristic days' (i.e. the number of days with temperatures exceeding specified thresholds) and day-to-day
temperature variability and, for the first time, to determine different characteristics of thermal seasons
(duration, onset and end dates). The results were compared with contemporary temperature conditions
(climate normals 1961-1990 and 1981-2010) to estimate the range of their changes between historical and
present times.
The research work was supported by a grant entitled 'Causes of the early 20th century Arctic warming', funded
by the National Science Centre, Poland (Grant No. 2015/19/B/ST10/02933) and a grant entitled 'Variability of
the Russian Arctic and Subarctic Climate in the Last Three Hundred Years', funded by the National Science
Centre, Poland (Decision No.DEC-2012/07/B/ST10/04002).

2262
Fri_310_SH-8_1349
Mapping the Dispersion of Airborne Microorganisms in Byers Peninsula, Antarctica

Ana Justel1 (ana.justel@uam.es), Lucas Fernández Piana2,3, Julio Rodríguez4, Marcela Svarc2,3, Sergi González5,
Francisco Vasallo6, Pablo Sanz7, Antonio Quesada8
1
Universidad Autonoma de Madrid, Department of Mathematics, Madrid, Spain, 2Universidad de San Andres,
Department of Mathematics and Science, Buenos Aires, Argentina, 3CONICET, Buenos Aires, Argentina,
4
Universidad Autonoma de Madrid, Department of Economical Analysis, Madrid, Spain, 5Spanish Meteorological
Agency (AEMET), Barcelona, Spain, 6Spanish Meteorological Agency (AEMET), Cádiz, Spain, 7Universidad
Autonoma de Madrid, Scientific Computing Center, Madrid, Spain, 8Universidad Autonoma de Madrid,
Department of Biology, Madrid, Spain

A new unsupervised classification method is proposed for exploring dispersal and colonization capacity of
microorganisms in Antarctica with a large multivariate functional data set, which includes more than 88M
observations from a combination of geographic positioning and meteorological variables. Definitions of the
appropriate distance and standardization are crucial and is done taking into account the nature of the data as
functions. The method is applied to clustering back-trajectories arriving to Byers Peninsula (Livingston Is,
Antarctica) to establish the dispersal capability of microorganisms susceptible of colonizing newly exposed
locations in a climate change scenario. Twelve years of 5-day back trajectories every six hours, computed with
the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, are clustered in groups that
circulate in nearby regions, regardless of the moment they pass, and with similar environmental conditions
(temperature, humidity, etc.). Main air transport patterns capture seasonal differences and rare events that
influence in the microorganism viability, but do not take into account the speed at which propagules move.
Another set of trajectories passing over Byers Peninsula and with origin in some of the terrestrial regions near
Antarctica, are considered. The two clusters combination provides a map of airborne microorganism dispersion
to be associated to in-situ captured propagules.

2263
Fri_311_SH-8_1355
Data Mining Cloud Regimes for the Purpose of Model Validation

Alex Schuddeboom1 (alex.schuddeboom@pg.canterbury.ac.nz), Adrian McDonald1, Olaf Morgenstern2, Mike

Harvey2, Simon Parsons1
1
University of Canterbury, Christchurch, New Zealand, 2National Institute for Water and Atmospheric Research,
Wellington, New Zealand

Modern climate models have long standing problems with the representation of cloud that result in large
radiative biases over many regions of the globe, such as the Southern Ocean. To investigate these issues, cloud
regimes are derived from satellite data and then compared to model output. In particular, cloud top pressure -
cloud optical thickness joint histograms from the Moderate Resolution Imaging Spectroradiometer (MODIS)
satellite are clustered using the self organizing maps (SOMs) clustering methodology. This results in the
identification of 12 distinct cloud regimes from the MODIS data.
These regimes were then used to cluster output from the HadGem3 GA7 atmosphere only model. This allowed
for comparisons between the behaviour of the regimes in observational data and in model output to be
undertaken. These comparisons initially focused on the rate at which a given regime occurs and how that
occurrence rate changes between different regions. Further analysis investigated the mean cloud properties
associated with a given regime. One of these properties was the cloud radiative effect (CRE) derived from
CERES satellite observations, these are then compared with model output for each of the identified regimes.
The overall CRE bias within the model was then attributed to each of the regimes, clearly identifying which
regimes caused the largest problems in the model. This approach was also extended to other variables such as
cloud phase and aerosol optical depth.

2264
Fri_312_SH-8_1538
FAIR Data Management in the Polar Regions

Taco De Bruin1,2 (taco.de.bruin@nioz.nl), Marten Tacoma2,3

1
NIOZ Royal Netherlands Institute for Sea Research, National Marine Facilities, Den Burg, Netherlands, 2Utrecht
University, Utrecht, Netherlands, 3NIOZ Royal Netherlands Institute for Sea Research, Netherlands Polar Data
Center, Den Burg, Netherlands

According to the description, this session aims at bringing together different communities of data users and
emphasizes the integration of data and information from various sources and disciplines.
However, before these goals of data integration across disciplines can be achieved, the data should be made
available. The data from polar research should be easily Findable for all users, should be Accessible without
impeding barriers, should be Interoperable to allow data to be used in different applications and should be Re-
usable to enable new, interdisciplinary science. In short, the data should be FAIR.
Fortunately, since about two decades, international groups of data managers have been building global data
access infrastructures, which implement these FAIR-principles and cover most data types and all disciplines in
the polar regions. A few examples are the systems built by SCAR's Standing Committee on Antarctic Data
Management (SCADM), by the Sustainable Arctic Observing Network (SAON) and by the Southern Ocean
Observing System (SOOS).
This presentation will provide a comprehensive overview of the existing data access infrastructures in all
disciplines. It will also address the current, joint effort by SCADM, SOOS and the Arctic Data Committee (ADC)
to develop a federated search mechanism across existing infrastructures, linking these infrastructures to one
point of entry and allowing users to re-use data which are easily findable, accessible and interoperable.

2265
Fri_313_SH-8_1608
A Comparison of ISCCP D and ISCCP H Clouds over the Southern Ocean using SOMs

Simon Parsons1, Adrian Mcdonald1 (adrian.mcdonald@canterbury.ac.nz), Alex Schuddeboom1

1
University of Canterbury, School of Physical & Chemical Sciences, Christchurch, New Zealand

Clouds play an important role in the global energy budget, with strong regional variations in cloud cover
evident. One region of concern is the Southern Ocean, due to a short wave (SW) bias in the cloud radiative
effect (CRE) from climate models when compared to satellite observations. This long standing problem is
compounded by a sparse observational record in that region, other than satellite observations, which makes
identification of the specific drivers of these biases difficult to determine. We use satellite data to compare
with model output and test new methodologies for classifying the data to gain quantitative metrics which can
help to identify particular model issues.
The International Cloud Climatology Project (ISCCP) was established to improve the understanding of clouds
and their role in the climate system. Cloud top pressure and optical depth joint histograms from the ISCCP D1
dataset have been used with the Self-Organising Map (SOM) data mining methodology to determine 15 cloud
regimes. The ISCCP D1 data set ended in 2009 and has been recently superseded by ISCCP H.
This study presents a comparison between the ISCCP D1 and ISCCP H datasets which is undertaken using SOMs.
The relative frequency of Occurrence (RFO) and total cloud fraction (TCF) of these cloud regimes are
determined, with regards to the Southern Ocean. We also compare these two satellite datasets against results
from the COSP satellite simulator applied to output from the HadGem3 GA7 model.

2266
Fri_314_SH-8_1739
Arctic and Southern Ocean Mean States in Ten Reanalyses

Petteri Uotila1 (petteri.uotila@helsinki.fi), Hugues Goosse2, Keith Haines3, Matthieu Chevallier4, Antoine
Barthélemy5, Clément Bricaud6, Jim Carton7, Neven Fučkar8, Gilles Garric6, Doroteaciro Iovino9, Frank Kauker10,
Meri Korhonen11, Vidar S. Lien12, Marika Marnela13, François Massonnet14,15, Davi Mignac3, K Andrew
Peterson16, Remon Sadikni17, Li Shi18, Steffen Tietsche19, Takahiro Toyoda20, Jiping Xie21, Zhaoru Zhang22
1
University of Helsinki, Institute for Atmospheric and Earth System Research, Helsinki, Finland, 2Université
catholique de Louvain, Earth and Life Institute, Louvain-la-Neuve, Belgium, 3University of Reading, Reading,
United Kingdom, 4Centre National de Recherches Météorologiques, Météo France/CNRS UMR 3589, Toulouse,
France, 5Formerly at Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium,
6
Mercator Océan, Toulouse, France, 7University of Maryland, Maryland, United States, 8Barcelona
Supercomputing Centre, Barcelona, Spain, 9Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici,
Bologna, Italy, 10Alfred Wegener Institute, Bremerhaven, Germany, 11Finnish Meteorological Institute, Helsinki,
Finland, 12Institute of Marine Research, Bergen, Norway, 13Formerly at Finnish Meteorological Institute, Helsinki,
Finland, 14Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium, 15Barcelona
Supercomputing Center, Barcelona, Spain, 16Met Office, Exeter, United Kingdom, 17University of Hamburg,
Hamburg, Germany, 18Bureau of Meteorology, Melbourne, Australia, 19European Centre for Medium-Range
Weather Forecasts, Reading, United Kingdom, 20Meteorological Research Institute, Japan Meteorological
Agency, Tsukuba, Japan, 21Nansen Environmental and Remote Sensing Center, Bergen, Norway, 22Shanghai Jiao
Tong University, Shanghai, China

Even after a number of targeted field expeditions and improved satellite coverage, the polar ocean
observations remain sparse and time series short. Given these circumstances, one could argue that reanalysis
descriptions of polar oceans are the most complete ones. Therefore global and regional ocean reanalysis
products (ORAs) are increasingly used in polar research, but their quality remains to be systematically assessed.
To address this, the Polar ORA Intercomparison Project (Polar ORA-IP) has been established following on from
the ORA-IP project. Several aspects of ten selected ORAs in the Arctic and Antarctic were addressed by
concentrating on comparing their mean states in terms of snow, sea ice, ocean transports and hydrography.
Most polar diagnostics were carried out for the first time for a such an extensive set of ORAs. In this
presentation we focus on liquid ocean diagnostics, while Iovino and co-authors present sea-ice diagnostics. For
the multi-ORA mean state, we found that deviations from observations were typically smaller than individual
ORA anomalies, often attributed to offsetting biases of individual ORAs. The ORA ensemble mean therefore
appears to be a useful product and, while knowing its main anomalies and recognising its restrictions, it can be
used to gain useful information on the physical state of the polar marine environment.

2267
Fri_315_SH-8_1792
Scientific Archives in Polar Data Science: The Archive for German Polar Research

Christian Salewski1 (christian.salewski@awi.de)

1
Alfred Wegener Institute, Library and Archive, Bremerhaven, Germany

Inside archives of polar research institutions records are preserved with historical scientific data. Taking the
example of the Archive for German Polar Research (AGPR) of the Alfred-Wegener-Institute this talk will show

• what kind of records from polar research contexts contains scientific data,
• how the these holdings found their way into the AGPR,
• how they are there conserved, preserved and described for a future use by scientists,
• what kind of efforts are made to provide the accessibility of these data for the scientific community
and
• how far the cooperation between archives and data repositories is developed.

All these questions are discussed in the context of the history of archiving German polar Research and the
AGPR's tasks, resources and contents. Even the legal frame, the tradition of archival work and the archival
organization and networks in Germany are considered.

2268
Fri_316_SH-8_1946
A Comparison of Surface Winds over the Ross Sea Region Using Cluster Analysis

Adrian Mcdonald1 (adrian.mcdonald@canterbury.ac.nz), Simon Parsons2

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand, 2University of Canterbury, School of
Physical & Chemical Sciences, Christchurch, New Zealand

We compare the statistics of surface wind regimes in reanalyses, general circulation models and remotely
sensed observations using cluster analysis. In particular, we use the Self Organizing Map and k-means clustering
approaches to identify representative wind regimes over the Ross Sea. These regimes are derived from
reanalysis output from the ERA-20CM ensemble and the 20th Century Reanalysis version 2 ensemble. We then
compare these patterns with the Coggins types which are derived from ERA-Interim reanalyses using a k-means
scheme. The frequency of occurrence of specific patterns for the different ensemble members and the two
different reanalyses are used to identify uncertainties in these occurrence rates, also comparing to the Coggins
types. Variations in the frequencies derived as a function of time are also examined to identify trends in the
surface winds over the Ross Sea. We then validate the representativeness of the various regimes relative to
observations of surface wind velocity from the WindSat dataset and surface weather stations over a subset of
the reanalysis period. We also examine whether frequencies derived from CMIP5 model output over the
historical period compares with the reanalyses derived frequencies. Finally, we decompose the differences
observed between the reanalyses derived patterns and the model output derived patterns into pattern
variations and frequency changes to gain a greater understanding of the reasons for the observed differences.

2269
Fri_317_SH-8_2217
Digitization and Analysis of the SPRI-NSF-TUD Radar Data Archive

Emma J. MacKie1 (mackie3@stanford.edu), Dustin M. Schroeder1,2, Julian A. Dowdeswell3, Katherine I. Vega1,

Matthew R. Siegfried1, Winnie Chu1, Robert G. Bingham4
1
Stanford University, Department of Geophysics, Stanford, United States, 2Stanford University, Department of
Electrical Engineering, Stanford, United States, 3University of Cambridge, Scott Polar Research Institute,
Cambridge, United Kingdom, 4University of Edinburgh, School of Geosciences, Edinburgh, United Kingdom

Between 1967 and 1979, airborne RES surveys were taken of Antarctica in a collaboration between the Scott
Polar Research Institute (SPRI), the National Science Foundation (NSF), and the Technical University of Denmark
(TUD), known as the SPRI-NSF-TUD surveys. These 400,000 km of surveys are the oldest observations of
internal and subglacial features in Antarctica and provide the opportunity for comparison with modern RES
campaigns in order to study temporal changes in the ice sheet over the last 50 years. However, the SPRI-NSF-
TUD survey was recorded on 35 mm film and the resolution of existing prints makes it difficult for such
comparisons to be made. We used Hollywood film scanning equipment to digitize this collection and obtain
over two million high resolution images. We elaborate on the methods used to digitize and position this data
and present our observations of features including internal layers, volcanic ash layers, subglacial channels,
accretion plumes, grounding lines, and subglacial lakes. These are interpreted in the context of glaciological
and geological processes.

2270
Fri_319_SH-8_2408
Training a Machine Learning Model to Find Polar Data on the Web

Siri Jodha Khalsa1 (sjsk@nsidc.org), Ruth Duerr2, Chris Mattmann3, Karanjeet Singh4, Simin Ahmadi Karvigh5,
Omid Davtalab5
1
University of Colorado Boulder, CIRES/National Snow and Ice Data Center, Boulder, United States, 2Ronin
Institute, Boulder, United States, 3NASA, JPL, Pasadena, United States, 4University of Southern California, IRDS,
Los Angeles, United States, 5University of Southern California, Los Angeles, United States

Increasing amounts of data about the polar environment are being made available on the Web. This includes
the huge volumes of data coming from Earth observing sensor systems but also smaller, unique data sets from
individual investigations, modeling experiments and data rescue operations. While finding these data in well-
curated major repositories is straightforward, finding data that is published in journal papers, posted to
investigators' websites or appearing in blogs is much more challenging. The “Polar Deep Insights” project,
funded by the United States (US) National Science Foundation (NSF), is developing polar-specific indexing and
search paradigms for improved content discovery, information extraction and exploration, while extending
search capabilities to the deep web and nontraditional (e.g. multimedia) content. These next-generation search
technologies are making it possible to understand people, places, things and the connections between them
through analysis of unstructured text as well as online images, videos, web pop-ups, online forms, web scripts
and other ways information is presented on the web. Interactive tools make it possible for domain experts to
construct machine-learning (ML) models used by the crawler to identify web content of potential interest. In
this presentation we give an overview of the project and provide example applications whereby historical
information about the polar regions is made findable.

2271
Fri_320_SH-8_2625
Historic Antarctic Peninsula Maps and Diary Accounts Linked to GIS Data Bases

Wolfgang Rack1 (wolfgang.rack@canterbury.ac.nz), Ursula Rack1

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand

The north-eastern side of the Antarctic Peninsula was scientifically explored from 1901-03 by the Swedish
Antarctic expedition under Otto Nordenskjoeld. From this expedition originate a number of maps which show
and illustrate in combination with diary accounts the state of the environment at the turn form the 19th to the
20th century. We relate the maps and described locations to present day satellite data and observations. This is
achieved by a semi-automatic process identifying features in the drawings, diaries, and images. We interpret
the expedition accounts based on our comparison, and we try to better identify features based on diary
entries. Our result gives new insight in the outstanding observational achievements of the time, and in
environmental change in space and time since then. We focus on changes in the cryosphere by confining past
snow and ice areas as a baseline for climate change studies.

2272
Fri_321_SH-9_11
Viewing Ice: Cognitive Frames and the Construction of the Polar Regions

Mathias Albert1 (mathias.albert@uni-bielefeld.de)

1
University of Bielefeld, Bielefeld, Germany

Both polar regions in themselves and taken together are characterized by the existence of a set of closely
intertwined epistemic communities with a strong natural science core interacting with political, economic, and
legal actors and systems (and, to a lesser degree, the social sciences). These epistemic communities do not
participate in one, but in a range of partly overlapping but distinct discourses, contributing to providing
sometimes overlapping, sometimes diverging cognitive frames that allow different kinds of actors to address
the Artic and/or the Antarctic as relevant objects within their respective discursive settings. Recursively, these
discourses frame research priorities, political agendas, as well as the evolution and density of research
communities).
The proposed paper will at first elaborate on the relation between epistemic communities and the evolution of
cognitive frames conceptually. In a second step it will provide some illustrations particularly pertaining to the
Arctic, demonstrating how various cycles of cognitive framing are connected to shifting (geo-)political
representations. A final section will sketch a research project that aims at studying natural science research
communities as core contributors to epistemic communities.

2273
Fri_322_SH-9_36
Stable Isotopes Meet Shakespeare: Antarctic Science in Literature

Johanna Grabow1,2 (johanna.grabow@gmx.de)

1
Leipzig University, Institute of British Studies, Leipzig, Germany, 2Scott Polar Research Institute, University of
Cambridge, Cambridge, United Kingdom

Antarctica has undergone a shift from Terra Australis Incognita to the continent for science and a global
laboratory. Yet it has also encouraged authors to fill the icy wastes with their own ideas, stories, dreams and
visions. Literature and the science dealing with Antarctica, however, do not have to exist in mutually exclusive
worlds; they can co-operate and benefit from each other.
This paper aims to discern how Antarctic science has inspired and been depicted in the literary output from the
seventh continent - and how literature can in turn inspire science.
From underwater lakes to remote sensing and ice core drilling, scientific projects populate the written page.
Dystopian scenarios of climate change and highly spectacular findings are just as well fictionally played out as
well-researched and detailed descriptions of scientific processes. These texts can be produced by literary
inclined scientists, but most often they stem from authors interested in the subject matter and consequently
wanting to engage their readership in the discourse.
I will look at the forms and functions these excursions into the world of science have in literature. Antarctic
literature can bring both the science and the continent it is conducted on closer to the rest of the world. In
short, science and literature should work together to promote Antarctica, its values, fragility and importance to
a wider audience.

2274
Fri_324_SH-9_218
Valuing Antarctic Visual Arts: An Examination of their Impact

Adele Jackson1 (adele.jackson@pg.canterbury.ac.nz)

1
University of Canterbury, Gateway Antarctica, Christchurch, New Zealand

The creation of objects and imagery is a fundamental aspect of human intellect and expression. Though the
cultural diversity of artistic expression is vast, a common thread is the compulsion to create and communicate.
In Antarctica where there is no indigenous population and no indigenous cultural production is there value in
importing cultural expression and representation? And if so, what is the value of artists' presence?
Since the earliest days of Antarctic exploration visual artists were essential members of expedition teams. They
had a valuable role in documenting topography, flora, fauna, expedition activities and environmental
conditions for purposes specific to science, navigation, sovereignty claims and fundraising. With the
development of photography, visual arts have evolved and diversified to offer ways of viewing and
understanding Antarctica beyond documentary representation.
Visual artists from many countries continue to secure passage to Antarctica. Several national Antarctic
programmes support artist residencies. The diversity of Antarctic arts production is wide having evolved out of
different socio-cultural and political histories over hundreds, even thousands, of years. This paper will discuss
methods to assess the value of artists working in Antarctica. Preliminary findings show that diverse cultural and
artistic responses to Antarctica advance human understanding of and relationships with the continent and the
wider world.

2275
Fri_325_SH-9_236
Methodological Challenges of Participant-produced Video Diaries in Antarctica

Meredith Nash1 (meredith.nash@utas.edu.au), Robyn Moore1

1
University of Tasmania, Sociology, Hobart, Australia

Although participant-produced videos provide many methodological benefits, this critical reflection provides
fellow researchers with insights into the challenges faced when using such methods in a remote polar
environment. To do so, we draw on our study of a leadership program for women in STEMM conducted on a
ship in Antarctica. The remote location of this study raised methodological beyond the routine issues
associated with video diaries. For instance, we discuss methodological challenges that arose throughout the
research period including managing the burden of research participation in Antarctica, underestimating
participant technological skills, lack of privacy and time to make videos, and data loss. To conclude, we
highlight implications for using participatory video methods in other remote settings.

2276
Fri_327_SH-9_525
Helplessness in Antarctica: A Psychanalytic Approach on the Social Bonding

Michele Moraes1, Rosa Arantes1 (rosa@icb.ufmg.br)

1
Universidade Federal de Minas Gerais, Neuro-Immunopathology Laboratory, Belo Horizonte, Brazil

Here we reflect on the feeling of solitude and helplessness that silently permeates the sense of union among
people in the Antarctic expeditions, based on our own experiences in Antarctica field and in interviews with
other participants of diverse nationalities. It is our interest to discuss the individual's experiences in Antarctica
focusing in helplessness, under the view of psychanalysis. One aspect is related to the features of Antarctica
living condition and the singular socialization processes to deal with the threatening environment, the
confinement and precarious condition of life. Helplessness, according to its theoretical development in
psychoanalytic theory emphasizes its origin in the human newborn immaturity and impotence to deal bodily
and psychically with the life demands. This helplessness emerges in Antarctic context as a sense of profound
solitude, impotence against the nature and dependence on the others. Our civilization was built as a strategy to
diminish our impotency against nature forces, life enigmas and our own death. We propose that in isolated and
threatening situation such as experienced in Antarctica, the reduction of narcissistic defenses exposes the
subject to a profound feeling of solitude and helplessness, as well as to a prominent anguish by depending on
the others. The helplessness inaugurates the need of the other, the ability to desire, and the construction of
social bondage that affects so many antarcticians and their discourses.

2277
Fri_328_SH-9_605
Human and Social Capacity of the Arctic Region of Neo-industrial Development

Marina Belonozhko1 (mlb@inbox.ru), Svetlana Siteva1, Alexander Gyurjinyan1

1
Industrial University of Tyumen, Department of Marketing and Public Administration, Tyumen, Russian
Federation

The beginning оf the new stage of industrial development of the Russian Arctic, the implementation of a large-
scale investment projects (oil and gas development, the construction of plants for the production of liquefied
natural gas) actualized the problem of the demand of human resources with the required qualification and
absence of social infrastructure.
The authors, on the basis of many years studying of the social situation in the Tyumen North, conducted a
complex study of the human capacity required for the successful implementation of the planned investment
projects.
Human capacity was considered not only as a recruitment opportunity to develop the Arctic region, but also as
the formed actual capabilities of the personnel, demanded and necessary for the practical solving of specific
tasks. First of all, these are the following interrelated indicators: socio-demographic characteristics of the
quantity and quality of people who intend to live and (or) work in the Arctic; their professional competences;
their physical, mental and social health, which are taken in the scales of the sociological dimension.
The results of the mass surveys of northerners and in-depth interviews of experts on polar issues are presented
differentially in the context of four social groups of neo-industrial development: old residents of the Northern
region, with the exception of the indigenous peoples of the North; representatives of indigenous ethnic groups;
new residents; shift workers.

2278
Fri_329_SH-9_628
Antarctic Legacy of South Africa (ALSA): Past Decade, Approaches and Challenges

Ria Olivier1 (riaolivier@sun.ac.za)

1
Stellenbosch University, Botany and Zoology, Stellenbosch, South Africa

Is there a place for an entity as ALSA within a South Africa National Antarctic Programme(SANAP) as well as the
global Antarctic environment? This presentation will look at the activities of ALSA for the past decade and how
it evolved to be an essential part of SANAP. The project has faced many challenges on different levels to
maintain sustainability. The role that the ALSA has played in the past decade within the research community
will be outlined. The importance of keeping record of human activity in the Antarctic region will be emphasised
and how the project is preserving these records of human contribution and engagement. The evolving of the
project in itself is not merely as a research medium and digital archive, but is of utmost importance for the
contributions by the human involvement and interaction in the Antarctic region and their valuable contribution
towards this region. The insights gained from the human interactions led to a much more comprehensive
project in the last few years. The project started out as a novel approach in the history, humanities and social
sciences, but developed into a project that can span collaboration on an international level. The management,
including approach and challenges of the digital archive especially regarding collection and storage of data will
form an essential part of the presentation. South Africa can contribute the knowledge and experience of an
open accessed platform with its challenges to the wider polar community.

2279
Fri_330_SH-9_912
Internationalization of National Polar Policy through Policy Integration Theory

Rohani Mohd Shah1 (rohanimohdshah@salam.uitm.edu.my), Hamisah Abd. Rahman2

1
Universiti Teknologi MARA, Faculty of Law, Shah Alam, Malaysia, 2Universiti Teknologi MARA, Faculty of
Business Management, Puncak Alam, Malaysia

The internalization of environmental protection policy into the core of economic development strategies and
policies of a state will be best applied through the Policy Integration Theory. The Policy Integration Theory
enhanced the role plays by Antarctica in stabilizing the planetary raising temperature due to global warming
from the negative impact of urbanization activities through The Antarctic Treaty 1959 and the Environmental
Protocol of 1991. Today, this theory becomes a compromise used to reinforcing State standard on
environmental protection policy which previously governed by the economic actors. This Theory adopted the
international environmental protection policy initiated through AntarcticaTreaty and its Environmental
Protocol to be practiced and activated voluntarily by State in their quest for better quality of life from the
aspects of environmental concerns and its economy. It is often suggested, there is an inherent conflict of
interest between protecting the environment and promoting economic growth. Thus, Theory on Policy
Integration may be the possible suggestion in pursuing the compromise. The paper will discuss, the
effectiveness of Antarctica science diplomacy in National Polar Policy, The Policy Integration Theory in
enhancing states economic sectors. Lastly, the key factors restraining the full potential of Antarctica science
and its diplomacy in igniting an economic burst of the state member.

2280
Fri_331_SH-9_1252
Impacts of Cryosphere Change in the Hindu Kush Himalaya on Humans and Society

Rodney Garrard1,2 (garrard.rodney@gmail.com)

1
University of Bern, Department of Geography, Bern, Switzerland, 2Heidelberg University, Department of
Geography, Heidelberg, Germany

There is increasing concern on how the change in the cryosphere in the Hindu Kush Himalaya (HKH) will impact
downstream populations and society. The majority of studies refer to retreat in glaciated areas and reduction
of glacial mass, although there are unique exceptions in the Karakoram region where glaciers are stagnant or
increasing in mass. Most studies refer in very general terms to “downstream populations” without specific
information on how and to which extent the population would be impacted. Neither is there a comprehensive
analysis on the number of people affected, or the socio-economic impact at stake. This presentation
synthesises the existing body of literature on the human impacts of changing meltwater regimes from
transborder glacier-fed and snow-fed river systems in the HKH. The presentation relies mostly on a recently
peer-reviewed publication of the same name and distinguishes five main strands of existing research of
cryosphere change in the HKH: socioeconomic impacts; hydropower; agriculture, irrigation and food security,
and; cultural impacts. The review also reviews acute glacier-related hazards considering research in the field of
glacier lake outburst floods (GLOFs) has gained attention. Each research stream is discussed and key case
studies described, highlighting important methodologies and results found. Finally, an outline of topics
requiring further research is offered.

2281
Fri_332_SH-9_1578
Innovative Methods for Unpacking Team Process Dynamics

Steven Kozlowski1 (stevekoz@msu.edu), Chu-Hsiang Chang1, Subir Biswas2

1
Michigan State University, Psychology, East Lansing, United States, 2Michigan State University, Electrical and
Computer Engineering, East Lansing, United States

Psychologists have studied small group and team effectiveness for decades and, although there has been
considerable progress, there remain significant challenges. Meta-analyses and systematic research provide
solid evidence for team psycho-social processes (cognitive, motivational, affective, and behavioral) that
contribute to team effectiveness and empirical support for interventions that enhance team processes (team
design, composition, training, and leadership). Yet, there are also concerns that team processes, which are
inherently dynamic, have primarily been assessed as static constructs. Team-level processes and outcomes are
multilevel phenomena that emerge, bottom-up from the interactions among team members over time, under
the shifting demands of a work context. Thus, research to understand the emergence and evolution of team
processes must capture their dynamics over time and over long durations. Our research, funded by NASA, is
using several innovative methods to study individual and team psycho-social functioning in the Antarctic and in
NASA mission simulations. The methods employed include daily ratings (experience sampling methods [ESM])
to assess team psycho-social functioning, linguistic analyses of daily journals to augment ESM ratings, and
electronic sensors to capture team interaction networks and reactions (physiological, psychological). The
presentation will highlight the intersection of these innovative methods and challenges for unpacking team
dynamics.

2282
Fri_333_SH-9_1945
In from the Cold? Interdisciplinary Perspectives on the Case of Sidney Jeffryes

Kimberley Norris1 (kimberley.norris@utas.edu.au), Gary Steel2, Elizabeth Leane3,4

1
University of Tasmania, Psychology, Hobart, Australia, 2Lincoln University, Lincoln, New Zealand, 3University of
Tasmania, English, Hobart, Australia, 4Institute of Marine and Antarctic Studies, University of Tasmania, Hobart,
Australia

Bringing together the expertise of researchers from Psychology, English, and History, this paper takes an
interdisciplinary approach to examining the account of Sidney Jeffryes - an Australian Antarctic expedition
member who demonstrated significant mental decline during his tenure 'on the ice', and following his return to
Australia. Based on historical documents, hypotheses are proposed for the psychological diagnosis of Jeffryes'
condition and factors (both interpersonal and intrapersonal) that precipitated it. Analysis of texts written by
Jeffryes and those associated with him are examined to provide more context in understanding Jeffryes'
experience during and after the expedition, shedding light on why this has remained a largely 'untold' piece of
Antarctic history.

2283
Fri_334_SH-9_2405
Anthropological Study of Cultural Heritage in French Subantarctic Places

Elisa Dupuis1 (dupuis.elisa0@gmail.com), Emmanuelle Sultan2

1
Université Paris-Sorbonne, Histoire de l'Art et Archéologie, Paris, France, 2Muséum National d'Histoire
Naturelle, Paris, France

Since its discovery, a large number of experiences took place in have been the theater of a diversity of
experiences the Antarctic sector and sub Antarctic territory administered by France (Terres Australes et
Antarctiques Françaises, TAAF). Their manifestations, past and contemporary, illustrate the determination of
man to appropriate that area. Keeping a memory of its origin is a sociological mechanism that structures the
relationship between human being and their history. In the Southern, such a mechanism takes on particular
significance since the place is apriori suitable for nobody. In the TAAF, remoteness and isolation have always
constrained human settlement. Nevertheless, the associated activity subsists and daily life unfolds. Material
and immaterial production, past and present, illustrates the ability of human to always transcend the
constraints imposed due to the environment. It is this legacy specific to the heritage that constitutes the
scientific object of this study. We question this issue from the anthropological point of view and from the point
of view of the management of material associated with Sub-Antarctic and Antarctic cultural heritage.

2284
Fri_335_SH-9_2433
Climate Awareness in Popular Culture

Astrid Surmatz1 (a.m.surmatz@uva.nl)

1
University of Amsterdam, Humanities, Amsterdam, Netherlands

Climate change and climate awareness have been rising during the last decades. Earlier popular culture
representations of arctic or antarctic areas e.g. in the 1950ies were often still centered around Science fiction
scenario´s that emphasized the foreignness and often hostility of those areas. From the 1990ies onward, there
are several reflections of the climate change discourse both in film, comics, thrillers, even picturebooks or
digital representations in the wider sense, which shape a more diversified and open image of the polar areas.
Some of them rely heavily on emotional appeals, e.g. the cuteness factor of penguins, or the tragic situation for
polar bear cubs. Others translate climate change threats into various plots of human interference with what is
perceived as unspoiled nature or pristine surroundings. The way in which popular culture and multimedial
approaches represent scientific developments, and the way they reflect on for instance climate change
awareness are at the core of this paper, which combines cultural studies, multimedia studies, gender and
postcolonial theory. The paper will conclude with a look at the Disney film Frozen and its allusions to polar
discovery, (sub)arctic milieu and the influence of humans on climate developments. The medial and popular
culture images of the polar areas including climate change then again trigger a broader discourse on the
anthropocene, and may reflect back on how scientific approaches to climate change are viewed.

2285
Fri_336_SH-9_2439
Cryosalide - A New Generation of Human-environment Observatory

Emmanuelle Sultan1 (emmanuelle.sultan@mnhn.fr), Daphné Buiron2, Ann-Isabell Guyomard3, Elisa Dupuis4

1
MNHN, DGD REVE, Dinard, France, 2Collectif CryoSalide, Paris, France, 3Oijha - Art and Ethics from Antarctica,
Paris, France, 4Sorbonne Universités (Université 4), Paris, France

This new generation Observatory has the mission to collect, archive and promote Antarctic related elements in
the broader sense : the Antarctic Treaty area including the Southern ocean and the Southern islands. Extending
this concept, the Observatory will also consider other oecumene areas which share a system of common
values, transcending national and academic frontiers.
It is a new generation Observatory considering its missions in the fields of academy, education, knowledge and
arts dedicated to question the notions of committment and empowerment. Because of the diversity of actors
related to Antarctica, this Observatory will gather different perceptions which will sometimes confront each
other, bring value or transcend each other, making a link with the paradox of this continent as pristine and void
from Antarctic people. Exploring the idea of « Antarctic people » will question about the relation, the standing
and the place of Humanity in the circle of life.
This observatory is based on numerous corpus:
1) existing but scattered
2) being collected
3) to be imagined ...that will be presented in the framework of POLAR 2018.

2286
Fri_337_SY-1_24
A Free Service for Precise Positioning in Polar Regions (CSRS-PPP)

Calvin Klatt1, Thomas James2, Monic Buettner2 (monic.buettner@canada.ca), Peter Johnson3

1
Natural Resources Canada, Canadian Geodetic Survey, Ottawa, Canada, 2Natural Resources Canada,
Geological Survey of Canada, Sidney, Canada, 3EngineNorth, Ottawa, Canada

Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) services enable geoscientists to
obtain high quality position information in regions where no local surveying infrastructure exists. The Canadian
government provides one such service, known as the Canadian Spatial Reference System Precise Point
Positioning (CSRS-PPP) Service which works at any location on Earth and is free to the user.
For management purposes CSRS-PPP log files containing information about the location of surveys, and some
technical parameters are retained. Utilizing these files we see very substantial usage in polar regions, where
such services would appear to be an excellent tool for geoscience. Prior to October 2015, over 64,000 GNSS
files had been processed in the North Atlantic region (including Greenland), and 144,000 files had been
processed in Antarctica. In general these observations were conducted with high quality dual-frequency
equipment, with long observation times for cm-level positioning. Gridded maps of these observations are
presented, showing continental-scale experiments, coastal studies, etc.
The CSRS-PPP service currently process over 1400 files each day on average, with the majority of these files for
geoscience purposes, and the majority of the data obtained in a location outside Canada. Intended for the
surveying community in Canada, the CSRS-PPP now also serves a global, geoscientific, clientele.

2287
Fri_338_SY-1_190
A New Bathymetry Compilation for the Cape Darnley Region, East Antarctica

Jodie Smith1 (jodie.smith@ga.gov.au), Yoshifumi Nogi2, Hideki Miura2

1
Geoscience Australia, Canberra, Australia, 2National Institute of Polar Research, Tokyo, Japan

We present the first detailed bathymetry compilation for the Cape Darnley region in East Antarctica. This
region is of broad scientific interest as it is a key location for understanding the Cretaceous breakup of central
Gondwana, basins on the continental shelf contain valuable paleoenvironmental records, the shelf is an
important marine habitat, and the Cape Darnley polynya is one of only four sites of Antarctic Bottom Water
production - a cold, dense, nutrient-rich water mass that forms on the continental shelf and sinks to abyssal
depths, driving ocean currents around the world. However, oceanographic and ecosystem models in this region
are poorly constrained by lack of detailed bathymetry.
Single beam and multibeam bathymetry datasets were compiled from multiple marine science voyages
undertaken over several decades. The data were held by several institutes and were of varying resolution and
quality. The new dataset improves previous regional bathymetric representations and enables visualization of
shelf and slope morphology in unprecedented detail. The compilation provides important baseline information
underpinning a range of scientific applications. In particular, the bathymetry provides the first detailed insights
into potential bottom water transport pathways from the Cape Darnley polynya into the global deep ocean
circulation system. Geomorphic interpretation of the bathymetry data provides insights into past glacial
dynamics and contemporary seafloor processes.

2288
Fri_339_SY-1_192
Real-time Imaging Flow of High-resolution Ice-sounding Radar

Shinan Lang1 (langshinan@bjut.edu.cn), Qiang Wu1, Xiaojun Liu2, Bo Zhao2

1
Beijing University of Technology, Faculty of Information Technology, School of Information and
Communications Engineering, Beijing, China, 2Institute of Electronics, Chinese Academy of Sciences, the Key
Laboratory of Electromagnetic Radiation and Sensing Technology, Beijing, China

Ice-sounding radar is an established technique for probing ice masses and remotely sensing the basal
conditions with sufficient resolution over a large area in a comparatively short period. Regarding the signal
processing of ice-sounding radar, focused synthetic aperture radar (SAR) imaging techniques have been applied
to ice-sounding data to improve the gain and resolution for many years. However, direct implementation of the
imaging algorithms are still computationally expensive. At the moment, we are developing a real-time
processor by using a modern commercial DSP chip named TMS320C6678. Therefore, it is essential to develop
an appropriate real-time imaging algorithm which is adapted to the real-time processor based on DSP. Based
on the comparison of the previous imaging algorithms, a range-Doppler algorithm (RDA) integrated with shift-
and-correlate (SAC) algorithm is proposed for the real-time implementation of high-resolution ice-sounding
radar imaging on the designed real-time processor. To clarify the practical feasibility of the RDA integrated with
SAC algorithm, theoretical analysis is carried out in detail. In addition, the hardware architecture of the
designed real-time processor, and the implementation of the proposed algorithm on the processor are
demonstrated. The real-time imaging is carried on the data collected during the 33th Chinese National Antarctic
Research Expedition (CHINARE 33) over Princess Elizabeth Land (PEL) via ice-sounding radar called HiCARS.

2289
Fri_340_SY-1_318
Understanding Outgoing Long-wave Radiation from the Antarctic Atmosphere

Jordis Tradowsky1, Greg Bodeker1, Jono Conway1, Laura Revell1 (laura@bodekerscientific.com)

1
Bodeker Scientific, Alexandra, New Zealand

Antarctica´s heat budget defines how it will respond to climate change. Antarctica cools itself mainly by
emitting longwave infrared radiation. Approximately 50% of the emission happens at wavelengths beyond 15
µm. Because measurements made at these long wavelengths are scarce, it is not possible to model with
confidence the response of Antarctica to changes in climate. This presentation outlines a process for
developing site atmospheric state best estimates of temperature and water vapour to constrain a state-of-the-
art radiative transfer model. The sensitivity to changes in the surface emissivity can then be tested using the
radiative transfer model. Such a robust analysis of the problem is an essential first step before attempting to
mitigate the knowledge gap through a measurement campaign. The presentation will outline our collaboration
with international partners to design a campaign to measure the far-infrared emissivity above Antarctica.

2290
Fri_341_SY-1_359
iCUPE - Integrative and Comprehensive Understanding on Polar Environments

Tuukka Petäjä1, Ella-Maria Duplissy1 (ella-maria.duplissy@helsinki.fi), Pauli Paasonen1, Hanna K. Lappalainen1

1
University of Helsinki, Helsinki, Finland

iCUPE (Integrative and Comprehensive Understanding on Polar Environments) is a 3-year project that answers
to ERA-PLANET (European network for observing our changing planet) thematic strand 4 (Polar areas and
natural resources).
The vision of iCUPE is to establish and maintain long-term, coherent and coordinated observations and
research activities on environmental quality and natural resources in polar areas. The core idea of iCUPE is the
development of novel, integrated, quality-controlled and harmonized in-situ observations and satellite data in
the polar areas, as well as data products to the end users. iCUPE combines the integrated in-situ and satellite
Earth Observation with a modelling platform. It
1) synthesizes data from comprehensive long-term measurements, intensive campaigns and satellites,
collected during the project or provided by on-going international initiatives,
2) relates the observed parameters to impacts, and
3) delivers novel data products, metrics and indicators to the stakeholders concerning the environmental
status, availability and extraction of natural resources in the polar areas.
The project will improve our understanding of the pollution sources and sinks, environmental and
anthropogenic changes and elements of the cryosphere in polar areas by conducting high-level and high impact
research by analyzing these integrated data together with the modelling frameworks.

On behalf of the iCUPE Consortium, Helsinki, Finland.

2291
Fri_342_SY-1_383
Pacific Central Arctic Ocean (CAO) Observing System (K-AOOS)

Sung-Ho Kang1 (shkang@kopri.re.kr)

1
Korea Polar Research Institute (KOPRI), Division of Polar Ocean Sciences, Incheon, Korea, Republic of

Sea ice-covered area in Pacific Central Arctic Ocean (CAO) is a major study site of the Korean Arctic program,
regularly visited by its flagship and an icebreaker, Araon. Annually conducted ocean-going expeditions occupy a
number of oceanographic stations and place a few moorings, focusing on baseline oceanography, sea ice
dynamics and lower trophic level. Mid trophic level and fish, however, are yet to be the principal targets of the
project. But fisheries potential in the Central Arctic Ocean and the basis for its sound management are of
interest to Korea, as a party to the recent negotiation of the proposed fisheries agreement in the CAO. Korea-
Arctic Ocean Observing System (K-AOOS) program has developed as a platform of international cooperation,
welcoming numerous foreign scientists on board and providing instrument deployment opportunities.
Currently K-AOOS Araon's field program is designed for ecosystem and climate change focused researches.
Efforts to engage more scientists from the national and international research communities are being made
and especially collaborations between Korea Polar Research Institute and others are going well at individual
and institutional scientist levels. K-AOOS advocates a data policy that promotes a wide sharing of validated and
calibrated data. K-AOOS takes a view that a dedicated scientific leadership in the CAO is warranted that can
coordinate multi-national and multi-partner field expeditions and maximize the scientific output.

2292
Fri_343_SY-1_563
Persys-WebGIS-based Permafrost Data Visualisation System for ESA GlobPermafrost

Antonie Haas1 (antonie.haas@awi.de), Guido Grosse2, Birgit Heim3, Andreas Walter4, Antonia Immerz4,
Christian Schäfer-Neth4, Annett Bartsch5, Frank Martin Seifert6
1
Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Computing and Data Center,
Bremerhaven, Germany, 2Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Periglacial
Research, Potsdam, Germany, 3Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research,
Periglacial, Potsdam, Germany, 4Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research,
Computing and Data Center, Bremerhaven, Germany, 5Zentralanstalt für Meteorologie und Geodynamik ZAMG,
Vienna, Austria, 6European Space Agency ESRIN, Frascati, Italy

ESA GlobPermafrost (www.globpermafrost.info) provides a remote sensing data service for permafrost
research and applications. This service comprises data product generation for various regions and spatial scales
as well as specific infrastructures for visualisation and access to datasets.
PerSys is the open access geospatial information system for dissemination and visualisation of remote sensing
data derived within the ESA GlobPermafrost project. The data products are visualised in the PerSys WebGIS and
are described and searchable in the PerSys Data Catalogue. The PerSys Data Catalogue is a core component of
the Arctic Permafrost Geospatial Centre (APGC), set up within ERC PETA-CARB at AWI1.
The visualisation employs the AWI WebGIS infrastructure maps@awi (http://maps.awi.de), relying on OGC-
standardized Web Mapping/Feature Services (WMS, WFS).
The WebGIS supports the project specific visualisation of raster and vector data products such as land cover,
Landsat multispectral index trends, InSAR-based land surface deformations, rock glacier velocities, and
permafrost model outputs.
The WebGIS projects are adapted to the products specific spatial scales, e.g. the Arctic WebGIS visualizes
Circum-Artic products as well as other large-scale data products. Rock-glacier data products of higher spatial
resolution are visualised on regional scale in the WebGIS projects Alps, Andes and Central Asia.
PerSys is accessible via the GlobPermafrost project webpage.

2293
Fri_345_SY-1_1126
Mapping Surface Facies of Midtre Lovénbreen, Svalbard using WorldView-3 Imagery

Shridhar Jawak1 (shridhar.jawak@gmail.com), Alvarinho Luis1, Manoj Patley2, Timothy Warjri3, Sagar
Wankhede4
1
National Centre for Antarctic and Ocean Research (ESSO-NCAOR), Ministry of Earth Sciences, Vasco da Gama,
India, 2Bharathidasan University, Department of Geography, Chennai, India, 3Savitribai Phule Pune University,
Department of Geography, Ganeshkhind, India, 4Mangalore University, Department of Geoinformatics,
Mangalore, India

Monitoring the spatial variability in snow and ice surface facies on ice sheets can improve our understanding of
surface albedo variations and mass balance feedback mechanisms. Using high-resolution multispectral (MS)
and shortwave infrared (SWIR) imageries captured by WorldView-3 and stereo digital elevation model (DEM)
data, we map glacier surfaces of Midtre Lovénbreen, Ny-Ålesund, Svalbard. The objective of this study is to
implement MS image for characterization of the glacier surfaces in Arctic region. We used geographical object-
based image analysis (GEOBIA) methods by designing four spectral band ratios for glacier facies mapping: (a)
Near Infra-Red (NIR) Ratio (NIRR) using NIR-1 and NIR-2, (b) traditional Normalized Difference Snow Index
(NDSI) using green band and SWIR, (c) Normalized Difference Snow/Ice Index NDSII) using red band and SWIR,
and (d) Normalized Difference Glacier Index (NDGI) using traditional green and red bands. Seven glacier facies
were identified, viz., fresh snow, wet snow glacier ice, melting ice, dirty ice, debris and shadowed ice.
Accuracies of derived glacier facies maps were assessed using ground truth data collected during the 9th Indian
Arctic Expedition. Results indicate that the object-oriented classification scheme yields 93% accuracy for
mapping surface facies of Midtre Lovénbreen. Our future research would focus on spatiotemporal glacier
surface change detection studies in the Arctic.

2294
Fri_346_SY-1_1223
Evolution of the Concordia Seismological Observatory Station

Dimitri Zigone1 (zigone@unistra.fr), Peter Danecek2, Maxime Bès de Berc1, Alessia Maggi1, Jean-Yves Thoré1,
Jean-Jacques Leveque1, Armelle Bernard1, Andrea Morelli3, Alberto Delladio2, Jérôme Chappellaz4, Olivier
Alemany4, Philippe Possenti4
1
Institut de Physique du Globe de Strasbourg, Ecole et Observatoire de Science de la Terre de Strasbourg,
Strasbourg, France, 2Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy, 3Istituto Nazionale di Geofisica e
Vulcanologia, Bologna, Italy, 4Institut des Géosciences de l'Environnement, Grenoble University, Grenoble,
France

Concordia (75°S 123°E) is a scientific base located at Dome C, on the East Antarctica ice sheet. It is run by the
French polar institute and the Italian Antarctic Program, and hosts a seismological observatory that is jointly
operated by EOST (Strasbourg) and INGV (Roma). Concordia's seismometers have provided ten years of
observatory-quality data from this remote and strategic location. The station was integrated into the
GEOSCOPE network in 2008; its data are streamed in real time to the GEOSCOPE and IRIS datacenters under
the station code CCD.
Concordia's seismometers - a Trillium T240 and a Streckeisen STS2 - currently operate in an artificial vault at
~12 m depth. The vault was constructed from shipping containers buried in snow, it is thermally stable, but it
deforms due to the hydrostatic pressure of the snow. Its proximity to the base causes strong diurnal noise (~40
dB) at frequencies above 1 Hz, especially during the summer season; the ~100 m thick firn (snow) layer forms a
waveguide that traps anthropic noise from the base and transmits it to the seismometers.
We are planning to upgrade the station by placing a posthole sensor at a depth of approximately 130 meters,
i.e. below the firn layer waveguide and the ice pinch-out depth. This installation should minimize noise from
thermal effects, from tilting, and from anthropogenic activity. Drilling is scheduled to start in January 2018. We
shall present updates from the drilling and from in-situ instrument tests.

2295
Fri_348_SY-1_1410
West Antarctica Digital Geological Dataset for Cross-discipline Use

Christine S Siddoway1 (csiddoway@coloradocollege.edu), Simon C. Cox2, Alex Burton-Johnson3, Alexie Millikin1,

Belinda Smith Lyttle2, Samuel Elkind1, A.G. Geomap4
1
Colorado College, Geology, Colorado Springs, United States, 2GNS Science, Dunedin, New Zealand, 3British
Antarctic Survey, Cambridge, United Kingdom, 4SCAR, GeoMAP Action Group, Dunedin, New Zealand

The SCAR GeoMAP Project has produced a digital geological dataset of West Antarctica, a tectonically active
region of thin crust that is undergoing rapid glaciological change. Suitable for reproduction at 1:250 000 scale
or more detailed, the dataset covers the on-continent coastal area bordering the southern Pacific Ocean.
Supraglacial features and glacial till, seasonal water and blue ice are mapped using DigitalGlobe high resolution
satellite imagery. These provide a baseline for past and future icesheet fluctuation. Sparse bedrock exposures
are classified using data from published geological maps and literature, ground-based geological data, and
firsthand observations. The bedrock data aid in evaluation of potential geological influences upon the
cryosphere, such as bedrock roughness, subglacial volcanism and/or geothermal flux which may affect icesheet
stability and the position and velocity of outlet glaciers. The database features links to bibliographic source files
for primary literature and published maps. International GeoSciML data protocols are used for feature
classification, making the database attribute-rich, queriable, and compatible with national/international
geoinformatics and BigData programmes. The development of the resource is timely in respect to several
international scientific research programmes, including IODP 379 in the Amundsen Sea, the Thwaites Glacier
Project, and ongoing oceanographic surveys along the southern Pacific margin.

2296
Fri_349_SY-1_1504
Estimation of Velocity of Polar Record Glacier, Antarctica using InSAR Technique

Prashant H Pandit1 (prashant.pandit@outlook.com), Shridhar D. Jawak2, Alvarinho J. Luis2

1
TERI University, Department of Natural Resources, New Delhi, India, 2National Centre for Antarctic & Ocean
Research (ESSO-NCAOR), Polar Remote Sensing Division, Vasco- Da- Gama, India

The ice flow velocity is a critical variable in understanding the glacier dynamics. The Synthetic Aperture Radar
Interferometry (InSAR) is a robust technique to monitor Earth´s surface mainly to measure its topography and
deformation. The phase information from two or more interferogram further helps to extract information
about height and displacement of the surface. We used this technique to derive glacier velocity for Polar
Record Glacier (PRG), East Antarctica using Sentinel-1 Single Look Complex images captured in Interferometric
Wide mode. The PRG is located in the Prydz Bay area on the eastern side of the Amery Ice Shelf. It is the largest
outlet glacier along the Ingrid Christensen Coast, bounded by Meknattane Nunataks and Dodd Island. For
velocity estimation, Persistent Scatterer interferometry (PS-InSAR) method has been applied. This method uses
time coherent of permanent pixel of master images and correlates to same pixel of the slave image to get
displacement by tracking the intensity of that pixels. C-band sensor of European Space Agency, Sentinel-1A and
1B data were used in this study. Estimated average velocity of the PRG is approximated to be ≈400 m/year
which varies from ≈100 to ≈700 m/year. This study found that PRG moves with a velocity of ≈700 m/year in
lower part whereas the upper inland area flowing with ≈200 m/year. The western part of the glacier is moving
faster in comparison with the eastern part of the glacier.

2297
Fri_350_SY-1_1743
Low-cost Autonomous Stations for Measuring Impacts of Climate Change on Glaciers

Guilherme Netto1 (guilherme.netto@inf.ufpel.edu.br), Jorge Arogony-Neto2, Ricrado Jaña3, Christoph

Schneider4, Inti Gonzalez5
1
Universidade de Rio Grande, IO, Rio Grande, Brazil, 2Universidade de Federal do Rio Grande / INCT da Criosfera,
IO, Rio Grande, Brazil, 3Instituto Antárctico Chileno, Punta Arenas, Chile, 4Humboldt-Universität zu Berlin,
Geography Department, Berlin, Germany, 5CEQUA, Punta Arenas, Chile

The project aims at proposing new methods for monitoring glaciers by means of a network of sensors based on
a situational awareness model. Glaciers have a very important role in the planet's climate, and changes in their
behavior can trigger extreme weather events, change the climate and affect the level of the oceans and their
ecosystems. Therefore, efforts to monitor the planet's ice behavior have been increasingly necessary in order
to better understand how glaciers interact with the atmosphere and oceans.
The idea is to implement a set of sensors, with a good spatial distribution, to collect data remotely, verifying
the changes that occur throughout the ice masses. This approach would allow assessment of the melting rate
of glaciers and their relation to climatic events.
Based on these characteristics, this project created two prototype network sensors to monitor glacier
parameters and meteorological data on glacier surfaces in an integrated way. The edge sensor set consists of
an Automatic Weather Station (AWS) and two ablation electronics (eAS) stations, both using the Arduino
prototyping platform.
AWS were built to withstand extreme weather conditions, combining materials such as carbon fiber and
stainless steel, being extremely portable and maintaining a low assembly cost. The eAS are an evolution of
traditional ice stakes and use RFID technology to improve space-temporal resolution of ablation
measurements.

2298
Fri_351_SY-1_1881
Lessons Learned from Interdisciplinary Snow Research in Svalbard

Catherine Larose1 (catherine.larose@ec-lyon.fr), Elena Barbaro2, Adrien Boniface1, Mats Bjorkman3, Jean-
Charles Gallet4, Jack Kohler4, Krystyna Kozioł5, Bartek Luks6, Tonu Martma7, Andrea Spolaor2, Thomas Vikhamar
Schuler4, Christian Zdanowicz8
1
University of Lyon, Ecully Cedex, France, 2University Ca' Foscari of Venice, Venice, Italy, 3University of
Gothenberg, Gothenberg, Sweden, 4Norwegian Polar Institute, Tromso, Norway, 5Pedagogical University of
Cracow, Krakow, Poland, 6Instytut Geofizyki Polskiej Akademii Nauk, Warsaw, Poland, 7Tallinn University of
Technology, Tallinn, Estonia, 8Uppsala University, Uppsala, Sweden

For decades, the Svalbard archipelago has been an area of interest for
physical, chemical and biological investigations of snow and ice, due to its vulnerable location for climatic
interactions and air-mass transport pathways. However, despite the many and demanding field campaigns
carried out during the last decades, it has been difficult to link the findings from different projects to obtain the
larger picture of snow research in Svalbard, and therefore its importance to the Arctic system is likely
underestimated. This is in part related to the heterogeneity of sampling locations and sampling times, which
does not promote direct comparisons between the different projects and also to the often mono-disciplinary
nature of the research being carried out. Here, we present some of the lessons learned during SnowNet, a
collaborative research initiative, developed to foster interdisciplinary Arctic field research. We will discuss key
aspects to ensure that the collected data are consistent and comparable, ranging from protocol development,
sample collection strategies and data processing and formatting, as well as some of the difficulties
encountered. By coordinating our efforts in the field, we can optimize the use of logistics and financial
resources, while minimizing our environmental footprint.

2299
Fri_352_SY-1_1890
Understanding Variability of Arctic Methane Fluxes and Addressing Knowledge Gaps

Kassandra Reuss-Schmidt1, Donatella Zona1 (d.zona@sheffield.ac.uk)

1
University of Sheffield, Sheffield, United Kingdom

Methane emissions from Arctic permafrost soils could result in substantial global warming, as permafrost soils
store 1300-1370 Pg of organic carbon, two times the current atmospheric stock. The Arctic is warming at twice
the rate of the global mean, causing the southernmost border of permafrost to steadily recedes northwards.
The main difficulties hindering an accurate baseline estimate are the high spatiotemporal variability in methane
emissions, and the poor data available from these systems. Arctic wetlands are in fact extremely
heterogeneous and methane fluxes can differ significantly between sites only meters apart.
Here we evaluate the effect of footprint variability on the methane fluxes from two eddy covariance sites
located on the large wetland area in the North Slope of Alaska. The local domain of each of these sites contains
well developed polygonal tundra, as well as, other thermorkarst features such as drained lake basins and their
drainage channels. We found that the footprint variability, has a significantly influence on the observed
methane fluxes, contributing to about 10% of the unexplained variability in CH4 fluxes. We present and discuss
the sources of this spatial variability and the remote sensing data required to assess the influence of this spatial
variability on the CH4 fluxes across the Arctic. This study highlights the data gaps and needs to be able to refine
our understanding of the controls on the greenhouse gas fluxes across the Arctic.

2300
Fri_353_SY-1_1994
Acoustic Networks - The Key to Observing the Ocean under the Arctic Sea Ice

Hanne Sagen1 (hanne.sagen@nersc.no), Marcel Babin2, Agnieszka Beszczynska-Möller3, Bruce Cornuelle4, Brian
Dushaw1, Matthew Dzieciuch4, Lee Freitag5, Patrick Gorringe6, Claire Gourcuff7, Bruce Howe8, Birgit Klein9, Yann
Le Page10, Peter N. Mikhalevsky11, Andrey Morozov12, Walter Munk4, Glenn Nolan6, Eric Rehm13, Michel Rixen14,
Stein Sandven1, Henrik Søiland15, Dag Tollefsen16, Peter Worcester4
1
Nansen Environmental and Remote Sensing Center, Bergen, Norway, 2Université Laval, Département de
Biologie/Pavillon Alexandre-Vachon, Québec, Canada, 3Institute of Oceanology PAS, Sopot, Poland, 4University
of California San Diego, Scripps Institution of Oceanography, La Jolla, United States, 5Woods Hole
Oceanographic Institution, Woods Hole, United States, 6EuroGOOS - European Global Ocean Observing System,
Brussels, Belgium, 7Euro-Argo ERIC, Plouzane, France, 8University of Hawaii at Manoa, Honolulu, United States,
9
Bundesamt fuer Seeschifffahrt und Hydrographie, Hamburg, Germany, 10ALSEAMAR, Meyreuil, France,
11
Leidos, Maritime Systems Division, Arlington, United States, 12Teledyne Marine Systems, Falmouth, United
States, 13Unité Mixte Internationale Takuvik, CERC sur la Télédétection de la Nouvelle Frontière Arctique du
Canada, Quebec, Canada, 14World Climate Research Programme, Geneva, Switzerland, 15Institute of Marine
Research, Bergen, Norway, 16Forsvarets Forskningsinstitutt, Maritime Systemer, Horten, Norway

The weakest component of the overall Arctic observing system is the in situ ocean observing system. Advanced
drifting ice-ocean observatories provide multi-disciplinary data in near real time, but they require stable ice
conditions. Profiling floats and gliders, frequently used in open ocean, have to surface to transmit data, update
their clocks, and geo-position via satellite. In ice covered regions floats may not be able to surface for many
months. During this time the sensors will collect data, but the positions where the data are taken will be
unknown and the clocks will not be accurate.
Multipurpose acoustic networks will be an important contribution to the development of a sustainable Arctic
Ocean Observing System. A network of fixed mooring systems with acoustic transceivers in the Arctic Ocean
will provide an underwater geo-positioning system for all users in direct analogy with GPS positioning. The
same system will provide ocean observation through acoustic thermometry, passive acoustic monitoring, and
oceanographic point measurements. Moored multipurpose acoustic networks have been implemented in a
sequence of year-long research experiments in the Fram Strait and in the Beaufort Sea. New initiatives for
establishing acoustic networks in the interior of the Arctic have begun. These initiatives are timely given the
several Arctic projects recently funded by the EU's research program HORIZON 2020 and a number of national
programs.

2301
Fri_354_SY-1_2080
Enhancement of in situ Observing systems in the Arctic under the INTAROS Project

Agnieszka Beszczynska-Moeller1 (abesz@iopan.gda.pl), Peter Voss2, Stein Sandven3, Hanne Sagen3, Andreas
Ahlstroem2, Truls Johannessen4, Thomas Soltwedel5, Mathias Goeckede6
1
Institute of Oceanology PAS, Sopot, Poland, 2Geological Survey of Denmark and Greenland, Copenhagen,
Denmark, 3Nansen Environmental and Remote Sensing Center, Bergen, Norway, 4University of Bergen,
Geophysical Institute, Bergen, Norway, 5Alfred Wegener Institute Helmholtz Center for Polar and Marine
Research, Bremerhaven, Germany, 6Max Planck Institute for Biogeochemistry, Jena, Germany

The H2020 project Integrated Arctic Observation System (INTAROS) aspires to increase the temporal and
geographic coverage of in situ observations and add new key geophysical and biogeochemical variables in
selected regions of the Arctic. Using a combination of mature and new instruments and sensors to be
integrated with existing observatories, INTAROS aims to fill selected gaps in the present-day system and build
additional capacity of pan-Arctic monitoring networks.
Three reference sites have been selected as key locations for monitoring ongoing Arctic changes: Costal
Greenland, paramount for freshwater output from the Greenland ice sheet; North of Svalbard (shelf to deep
basin) - the hot-spot for ocean-air-sea ice interactions, and heat and biological energy input to the European
Arctic; and Fram Strait - the critical gateway for exchanges between the Arctic and the World oceans. Two
distributed observatories: for ocean and sea ice and for terrestrial and atmospheric measurements will be
extended with multidisciplinary observations, still missing from the central Arctic and remote coastal areas.
New sensors, integrated platforms and experimental set-ups will be implemented during a two-year long
deployment phase (2018-2020) with an aim for sustained use in a future iAOS. New observations will be used
for integration of new data products, demonstration studies and stakeholder consultations and contribute to
ongoing and future long-term initiatives (e.g. OSPAR, SAON, YOPP).

2302
Fri_355_SY-1_2383
Best Practices for a New Network to Monitor the Cryosphere

Charles Fierz1 (fierz@slf.ch), Thorsteinn Thorsteinsson2, Aldís Elfarsdóttir3,4, Anna Haberkorn1, Petra Heil5,
Rodica Nitu6, Craig Smith7, Penelope M. Wagner8
1
WSL Institute for Snow and and Avalanche Research SLF, Davos Dorf, Switzerland, 2Icelandic Meteorological
Office, Reykjavik, Iceland, 3Harvard University, Cambridge, United States, 4Icelandic Meteorological Office,
Reikjavik, Iceland, 5Australian Antarctic Division and ACE CRC, University of Tasmania, Hobart, Australia, 6World
Meteorological Organization, Geneva, Switzerland, 7Environment and Climate Change Canada, Saskatoon,
Canada, 8Norwegian Meteorological Institute, Tromsø, Norway

Global Cryosphere Watch, a cross cutting WMO initiative, aims at bringing together operational and scientific
networks to monitor all components of the cryosphere and make this data available to all interested
communities in near real time. CryoNet stations forming the core of this network are required to comply with
best practices developed in common by the operational and scientific community. These best practices are
based on existing guidelines. They will help homogenise measurement procedures and reporting to ensure that
high quality data is collected worldwide on selected variables of each cryospheric component. This is the basis
for a global exchange of cryospheric data that will lead to a better understanding of cryospheric processes but
also contribute to deliver improved services to society. In this contribution we will present the status of our
compilation of best practices and describe how we have integrated input and feedback from various scientific
and operational communities to develop these documents. The future vision is to have an ongoing open but
controlled update mechanism for these best practices, reflecting continuously new developments in
measurement techniques and technologies.

2303
Fri_356_SY-1_2507
Common Metadata Scheme for Translating between Metadata Dialects

Alexander Smirnov1 (alexander@arcticportal.org), Pip Bricher2, Taco de Bruin3, Anton Van de Putte4, Halldór
Jóhannsson1, Peter Pulsifer5, Stein Tronstad6
1
Arctic Portal, Akureyri, Iceland, 2Southern Ocean Observing System, Hobart, Australia, 3Royal Netherlands
Institute for Sea Research, Texel, Netherlands, 4Royal Belgian Institute of Natural Sciences, Brussels, Belgium,
5
National Snow and Ice Data Center (NSIDC), Boulder, United States, 6Norwegian Polar Institute, Tromsø,
Norway

There is a demand to share metadata across polar data centers. However, a variety of metadata catalogues and
standards makes this task challengeable. Presently the ISO 19115 is a key standard for sharing metadata.
Unfortunately, due to its complexity it is not widely used among the community.
A common set of metadata elements relevant across polar sciences has been developed to facilitate
interoperability and sharing between polar data repositories and online portals. We analyzed the metadata
schemas for a set of catalogues (GCMD, Polar Data Catalogue, IPY, NSIDC, etc.) and found existing metadata
elements common to all or many of the schemas. This set is proposed as a preliminary community
recommendation for catalogue publishers to improve interoperability across catalogues.

2304
Fri_357_SY-1_2623
The National Polar Metadata Infrastructure

Simona Longo1 (simona.longo@cnr.it), Angelo Pietro Viola2, Cosimo Elefante2, Vito Vitale2, Mauro Mazzola2
1
CNR, DTA, Rome, Italy, 2CNR - ISAC - National Research Council, DTA, Rome, Italy

In the Arctic complex interactions between atmosphere, ocean, cryosphere and biosphere on a broad spectrum
of temporal and spatial scales, are largely responsible for "arctic amplification".Measurements are fundamental
to answer relevant questions on climate system variability.The CNR is in charge to managing and disseminate
scientific results of Italian activities carried out either in the Arctic and in the frame of PNRA. In this contest,
CNR is establishing the National Polar Metadata Infrastructure, using technologies based on brokering
approach, to provide to the polar scientific community, instruments through which easily manage historical and
real-time data and metadata. The infrastructure will ensure data discovery through the interconnection of the
system with the most common ones, integration with the global environmental observation network of GEOSS,
and will contribute to increase the entire GEO community.In this approach, different servers (called “nodes”)
are connected to “brokering nodes”, hosting metadata and data. Every node communicates with the brokering
system that allows data integration and interoperability between different kinds of servers.The Italian research
activity in the arctic region has increased in the recent years and the CNR developed the infrastructure IADC a
system to easily manage real-time data and metadata.

2305
Fri_358_TE-2_155
Development of Antarctic Seismo-acoustic Station: Results from ICE-VOLC Project

Danilo Contrafatto1, Rosario Fasone2, Angelo Ferro1, Graziano Larocca1, Giuseppe Laudani1, Salvatore
Rapisarda1, Luciano Scuderi1, Luciano Zuccarello1, Andrea Cannata1,3 (andrea.cannata@unipg.it)
1
Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Catania, Italy, 2FASEL elettronica s.r.l.,
Mascalucia, Italy, 3Università degli Studi di Perugia, Dipartimento di Fisica e Geologia, Perugia, Italy

Scientific instrumentations installed in Antarctic regions will face the most extreme climate on the planet, so
they have to be tolerant of very low temperatures and robust enough to survive extreme wind speeds.
Furthermore, one of the most challenging task is powering a remote system year round at polar latitudes
because of following factors: i) solar radiation varies through time from 24 hours during the Antarctic summers
to no light during winters;
ii) the high winds are often unpredictable in duration and in strength;
iii) cold temperatures of the polar nights reduce the capacity of batteries.
In the framework of the ICEVOLC project (www.icevolc-project.com), a permanent seismo-acoustic station was
developed able to face the aforementioned issues. Sensors and digital acquisition system were chosen to be
rugged and operative at very low temperature. Hybrid powering system, integrating solar panel and wind
generator, to guarantee continuous batteries charging in every weather conditions and Antarctic seasons, was
chosen. Energy produced is managed by two controllers operating in synergy. In particular FASEL controller
specifically designed for the project and another commercial controller carry out the following tasks:
i) ensure correct charging batteries,
ii) maintain temperature inside the battery case making use of heaters powered by extra energy,
iii) switches off the instruments in case of measured low battery package voltage to preserve batteries to deep
discharges.

2306
Fri_359_TE-2_161
Low-temperature Tests of Ice Friction

Jialin Hong1, Pavel Talalay1 (ptalalay@yahoo.com)

1
Jilin University, Changchun, China

Ice friction is one of the major technological issue in almost every application that involves moving parts one of
which is ice, such as glacier movements, design of offshore structures, different ice sports, drilling in the ice,
ice/snow vehicles, icebreakers, aircraft on icy runway, etc. High friction on ice is desired for vehicles in winter
road conditions and shoes on ice, while low friction is desired in ice sports and some parts of the ice breaker or
drills. The main parameters influenced on the ice friction are temperature, sliding velocity, applied normal
force, contact area, humidity, thermal conductivity and surface roughness, structure and hydrophobicity of
slider and ice. Even numerous ice friction studies were focused on effect of temperature, most of them were
done at temperatures above -25 °C which is not low enough to apply for some extreme environment as cold as
polar regions. Thus, we investigated promising materials that can be used to decrease or increase friction in the
wide temperature range from -60 °C to 0 °C using a linear friction tester by varying several impact factors.

2307
Fri_360_TE-2_219
Multi-Functional Ice Drills Testing Facility

Rusheng Wang1 (wangrs@jlu.edu.cn), Pavel Talalay1, Youhong Sun2, Xiaopeng Fan1, An Liu1
1
Jilin University, Polar Research Center, Changchun, China, 2Jilin University, College of Construction Engineering,
Changchun, China

The first stages of drilling equipment development is most sensibly tested in a laboratory facility prior to using
it out in the field. A multi-functional Ice Drill Testing Facility (IDTF) allows to test all kinds of mechanical and
thermal ice drills throughout the year including electromechanical cable-suspended drills, hot-water drills,
rapid air drills, thermal sondes for subglacial lake exploration, and others. The IDTF consists of several systems:
(1) ice well and freezing system;
(2) heat-insulated building and cooling system;
(3) rotary drilling platform.
The liner of ice well made of steel cylinder (Ø1 m) is sunk into the shaft (Ø2.6 m) to a depth of 12.5 m below
the ground. According to different operating mode, the different sub-glacial conditions can be imitated in the
ice well by freezing system. A two-room, heat-insulated building, containing a tall hall (6×6×15.2 m) with air-
cooling system and an entrance hall (3×6×4.5 m), was constructed above the ice well. A rotary drilling platform
on the second level of the tall hall allows for the drilling of at least nine holes with a diameter of 130-150 mm
around the perimeter of the ice well. The refrigerators were chosen by freezing the ice well within 72 hours.
The temperature of artificial ice can be adjusted from -5 to -30 °C and the lowest temperature of ambient air in
the IDTF can be controlled to -20 °C. The first tests performed in the IDTF illustrated the facility's convenient
performance for ice drill testing.

2308
Fri_361_TE-2_228
Environment Monitoring Demonstration Networks on Prydz Bay

Wenfang Cheng1, Jiangang Zhu1, Lizong Wu1 (wulizong@pric.org.cn)

1
Polar Research Institute of China, Shanghai, China

China promoted and implemented environmental monitoring programs and arrayed multi-discipline
monitoring sensors on Prydz Bay since early 1990s. Multi-discipline data was collected including hydrological,
meteorological, geophysical and biological data. A rapid data transmission network was framed connecting R/V
Xuelong, polar Stations and domestic berth. For forecasting and prediction based on long-term monitoring,
China designed a long-term environmental monitoring network on Prydz Bay based on the existing work. All
the conventional monitoring works in China were covered in the design objectives in this network. We also
expanded the monitoring works according to new international developments and long-term plans. This design
has been proved performable and exemplary especially in the ice-breaking navigation work on Prydz Bay.

2309
Fri_362_TE-2_432
Small-diameter Vibrocorer for Sediment Coring Beneath Antarctic Ice Shelves

Xiaopeng Fan1, Bing Li1 (bing@jlu.edu.cn), Da Gong1, Yunchen Liu1, Yazhou Li1, Pavel Talalay1
1
Jilin University, Changchun, China

Sediments beneath the Antarctic ice shelves contain important paleo-climatic and paleo-environmental
records, which will offer a long-term perspective on Antarctic ice sheet retreat history and sub-ice shelf ocean
circulation patterns. We designed a vibrocorer which could collect sediments from beneath Antarctic ice
shelves through an access hole formed with the hot-water drill. This vibrocorer includes four units: water-proof
pressure chamber, vibrator, core-barrel unit and spring buffer. For the vibrator, we utilize the self-synchronous
theory of dual-mass vibrating machine which allows to compress radial size of the vibrocorer. Actuating
motors, whose power are supplied by 36V DC lithium battery, rotating in opposite directions can generate
vertical, horizontal, or alternative vibrations. The configuration of vibrocorer is 270 mm in maximal radial size,
7.5m in total length and 300kg in total weight, which aims to get the sediment core with max 6m in length and
108mm in diameter. The vibrocorer has been proved to work functionally during laboratory testing and is
prepared for field testing in the season 2017-2018 at the Ekströmisen, Dronning Maud Land, Antarctica.

2310
Fri_363_TE-2_438
A Shallow Hot-water Drill

Gang Liu1,2 (gangliu16@mails.jlu.edu.cn), Pavel Talalay1,2, Rusheng Wang1,2, Xiaopeng Fan1,2, Jialin Hong1,2,
Bowen Liu1,2, An Liu1,2, Sysoev Mikhail1,2
1
Jilin University, Polar Research Center, Changchun, China, 2Jilin University, College of Construction Engineering,
Changchun, China

To get shallow access holes in high mountain glaciers and polar ice caps and sheets, the hot-water drilling is a
meaningful method for temperature observation, ice dynamics study, etc. Hot-water drill is considered as one
of the most effective non-core drilling methods in ice because of the high rate of penetration and low
environment impact. However, there is no complete theoretical base for designing of hot-water drilling
systems and for choosing of optimal drilling parameters. Thus, the drilling process is mainly controlled by the
experience of drillers. Theoretical estimations were done to predict hot-water temperature at the bottom of
the borehole, diameter of the borehole, rate of penetration, required power for ice melting and the total
pressure loss in water circulation system. The shallow drill system, designed and produced in Polar Research
Center, includes a high-pressure washer, a winch with 100 m high-pressure hose, mast, dead weight, nozzle
and sensors ( temperature sensors, load cells, encoder, flowmeter, and pressure gauge). Experiments with
shallow hot-water drill were taken at the low temperature test drilling facility with the main aim to find
relationship between rate of penetration and borehole diameter from diameter and type of nozzle, water
temperature and flow rate. Theoretically, the drill is capable to produce access borehole with diameter near
100 mm at rate of 30 m/h. These parameters have been proved during testing in 10 m deep ice-well.

2311
Fri_364_TE-2_501
Hot-Water Coring System with PDM Motor

Yang Yang1 (yangyang2014@jlu.edu.cn), Xiaopeng Fan1, Pinlu Cao1, Rusheng Wang1, Nan Zhang1, Pavel Talalay1
1
Jilin University, Changchun, China

Subglacial rocks and ice-rock interface plays a key role in the dynamics of the overlying ice sheet. Samples of
basal and subglacial material can give unique information for paleo-climatic and paleo-environmental records,
microbiological study, geology and tectonics. Hot water drilling system is considered to be the fastest way to
reach the target depth. To get core sample, the drill nozzle will be changed to the coring part combination,
positive displacement motor (PDM) with core barrel and drill bit. PDM motor is used to transform hydraulic
pressure of hot water flow to the rotation and torque, and also balanced by anti-torque system. Core barrel is
used to protect the core samples from the hot temperature environment and mechanical erosion. The type of
drill bits will be chosen according to the material being drilled. Gravity chips chamber will be included into
downhole assembly while coring the ice with rock or soil. If only ice coring, the system can work without chips
chamber, because the hot water circulation will melt all ice chips. It is planned to test the temperature and
flow rate distribution in the system on the testing stand. The detailed concept of ice and subglacial bedrock
PDM corer is being worked out.

2312
Fri_372_BE-5_1696
Algal Biomass Production in Central European Non-summer and Arctic Conditions

Josef Elster1,2 (josef.elster@ibot.cas.cz), Jana Kvíderová2, Pavel Přibyl1, Linda Nedbalová1, Marie Šabacká2,
Jaromír Lukavský1, Miloš Barták3, Peter Váczi3, Josef Hájek3, Tomáš Branyik4, Petr Kaštánek4, Irena Branyiková4
1
Institute of Botany, Academy of Sciences of the Czech Republic, Třeboň, Czech Republic, 2University of South
Bohemia, České Budějovice, Czech Republic, 3Masaryk University, Brno, Czech Republic, 4University of Chemistry
and Technology, Prague, Czech Republic

Arctic under present climatic changes brings new opportunities for industrial developments (oil and gas
resources, fish and fisheries management, shipping in the Arctic ocean, etc.). Urbanisation and development all
technological support for humen life is one of the most glabolly urgent tast for future. Low temperature
biotechnology and explore the biotechnological potential of polar and other low temperature adapted
cyanobacteria and microalgae (micro-algae), which can produce valuable metabolites in Central European non-
summer and Arctic conditions is great challenge for Czech Science. Microalgae and cyanobacteria are a rich
source of bioactive molecules with many potential uses such as components in human/animal nutrition,
pharmaceuticals, nutraceuticals, cosmetics, biopesticides, phytohormones, etc. Many of metabolites from
microalgae have been shown to possess varied bioactivities. Microalgal bioactive molecules thus hold a bright
and promising future in scientific research including a great opportunity for drug discovery. In proposed
lecture, the non-marine environmental conditions in Arctic environments and microalgal adaptations will be
introduced with respect to possible biotechnological applications. The presentation also provides a survey of
the possible compounds to be exploited from Arctic microalgae. Possible constructions of photobioreactors for
mass cultivation of microalgae are proposed for operations in the Arctic.

2313
Fri_365_TE-2_595
Hydraulic Fracturing in Ice Drilling Borehole: Theory and Tests

Chen Chen1, Han Zhang1,2 (hanz16@mails.jlu.edu.cn), Yong Chen1, Pavel Talalay1,2

1
Jilin University, College of Construction Engineering, Changchun, China, 2Jilin University, Polar Research Center,
Changchun, China

Hydraulic fracturing initiated by increasing the fluid pressure in the borehole to the point where the smallest
principal stress at the borehole becomes tensile has been used commercially as a stimulation technique in the
petroleum industry since the early fifties. The same situations potentially can happen under condition when
drilling fluid pressure exceeds ice pressure at certain depth while drilling in ice sheets and glaciers. We propose
an estimation of overpressure that causes the hydraulic fracture in ice on the base of theory of rocks fracturing.
This estimation reveals the critical relationship between the drilling depth and density of the drilling fluid at
which hydraulic fracturing occurs and provides the theoretical basis of adjusting the density of drilling fluid.
Several hydraulic fracturing tests were carried out to simulate ice fracturing on the borehole wall with artificial
ice samples under a special three-axis hydraulic fracturing test system. Based on combining with theory
consideration and experimental results, this study supports the hypothesis that hydraulic fracture is a plausible
mechanism for the possible phenomenon in ice drilling borehole.

2314
Fri_366_TE-2_654
Experimental Research of Hot-water Ice Coring Drill

An Liu1,2 (liuan15@mails.jlu.edu.cn), Rusheng Wang1,2, Pavel Talalay1,2

1
Jilin University, College of Construction Engineering, Changchun, China, 2Jilin University, Polar Research Center,
Changchun, China

How to acquire ice cores efficiently is becoming an increasingly key problem due to abundant information of
climatic variation in intact ice cores. Compared with the traditional coring drill by armor cable, hot water
drilling has its unique advantages: drill rapidly and environmental friendly. This paper proposed a hot-water ice
coring drill, which is used in combination with the hot-water drilling system and can get ice cores at any depth.
The hot water is supplied by the same hydraulic hose that is used for the hot-water drilling. 3.25m long drill
includes core barrel, guiding tubes, core catchers and drill head with 36 nozzles 1mm in diameter. The core
barrel (96 mm inner diameter) is 3m long. The hot water passes through 4 guiding tubes (4mm inner diameter)
fixed along outside of the core barrel to the drill head. The prototype of the drill is produced and experiments
in ice drill testing facility are carried out. The ice cores are obtained successfully with a special optimal drilling
parameter.

2315
Fri_367_TE-2_847
IBED Drill Testing in Ice and Bedrock

Xingchen Li1,2 (lixc17@mails.jlu.edu.cn), Pavel Talalay1,2, Pinlu Cao1,2, Xiaopeng Fan1,2, Nan Zhang1,2, Yang
Yang1,2, Han Zhang1,2, Xiao Li1,2, Yunwang Chen1,2, An Liu1,2, Yazhou Li1,2
1
Jilin University, College of Construction Engineering, Changchun, China, 2Jilin University, Polar Research Center,
Changchun, China

To drill through ice and bedrock in Antarctic, a new, modified version of the cable-suspended Ice and Bedrock
Electromechanical Drill (IBED) was designed and tested in Polar Research Center, Jilin University. The IBED can
drill in ice, debris-rich ice and rock by changing different module that permits the accomplishment of two
different tasks: (1) an ice-core drill; and (2) a bedrock core drill. The upper part is almost the same and includes
four sections: cable termination; a slip-rings section; an antitorque system; and an electronic pressure
chamber. The ice drill could penetrate successfully 800 mm of artificial ice with nearly 100% recovery rate. The
cutting load was about 400 N, and the average ROP - 12.7 m/h. Testing of bedrock drill on drilling of granite
samples showed that the toothed diamond drill bit could penetrate 1m and at a rate of 1-1.5 m h−1 at low load
(< 2 kN) and torque (< 30 N m). In addition, tests of the double drill pipe was questionable as the drill was stuck
after penetration of 300-400 mm. The reason of stucking was not clear, and additional tests are planning in the
near future.

2316
Fri_368_TE-2_902
An Introduction to a New Inland Traverse Project (2017 - 2026) by KOPRI

Jong Ik Lee1 (jilee@kopri.re.kr), Ji Woong Chung1, Seong Joon Jun1, Won Sang Lee1, Joohan Lee1, Yeadong Kim1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of

Korea Polar Research Institute (KOPRI) opened the second Antarctic research station, Jang Bogo Station, at
Terra Nova Bay, Ross Sea area in 2014, and many scientific expeditions are currently operated including
geology (KAGEX), geophysics (EGG), meteorite searching (KOREAMET), ecosystem monitoring (CEMP) and
shallow ice coring. From 2017, KOPRI started a new inland traverse project during ten years with
multidisciplinary purpose. The project includes 1) finding a safe and reliable traverse route, 2) developing a
2,000m hot water drilling co-project with British Antarctic Survey for subglacial lake expedition and 3)
developing a 3,000m deep ice core drilling technology. Using previous results by satellite altimetry and
airborne radar surveys, the existence of subglacial lakes at the upstream of David Glacier is getting clear. During
2017 austral summer season, a traverse team will approach the possible candidate lake site and conduct a
ground radar survey. The results of 2017 season expedition and long-term project plan will be presented at the
meeting.

2317
Fri_369_TE-2_1953
Experiments on Electric-heated Hotpoints for Boring in Ice

Yazhou Li1 (jluyazhouli@163.com), Xiaopeng Fan1, Mikhail Sysoev1, Pavel Talalay1

1
Jilin University, Polar Research Center, Changchun, China

The electric-heated hotpoints are used for boring in ice to install ablation sticks, to determine ice thickness, to
locate englacial and subglacial streams, to deploy sensors and tools under ice shelves, to measure
temperatures, closure rates and other internals of glaciers like variation with depth of ice flow velocity,
identification of dust layers, video observation and so on. Recently, interest in hotpoint using was rekindled in
connection with proposed projects for subglacial environment exploration at the Earth and other planets.
Hotpoint melting rate depends on the following variables:
(1) input power;
(2) cross-sectional area of the thermal tip;
(3) axial load (in the limited range);
(4) temperature of the drilled ice and
(5) design features like material and shape of the tip, properties of thermal element, etc.
To study relationship between input power, axial load and shape of the thermal tip, a 0.8-m long hotpoint with
changeable thermal tips and computer-controlled testing stand were designed. Series of tests were carried out
in artificial ice with temperature of -20 °C. Totally, 14 copper melting tips with different shapes and the same
outer diameter of 55 mm were tested. The heat was provided by five diametrically installed cartridge heaters
with total rated power of 2.4 kW. The results of the presented experiments provide the prominent reference
for hotpoint optimization.

2318
Morning Plenary IV
23.06.2018 07:50-09:00, A Davos

Keynote Lecture VII

The need for coordinated observations to inform responses to rapid Arctic change

Hajo Eicken (heicken@alaska.edu)


International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, AK, USA

Rapid Arctic change poses challenges from the local to the global scale, whether it involves Arctic residents and
ecosystems adapting to changing land-, sea-, and icescapes or the development of global policy frameworks to
mitigate drivers of change such as greenhouse gas forcing. Informed responses to Arctic change require
sustained, coordinated observations of essential variables that describe the present state of the system, inform
predictions of future states, and serve as indicators of major transitions or changes in state, and support policy
and decision-makers.
Over the past decade or so, a rich diversity of different implementation approaches, networks, and platforms
has emerged, covering a range of observational scales from the local to the regional to the pan-Arctic. A key
question – central to the Arctic Observing Summit 2018 – is how to foster structured coordination of these
efforts, whether driven by bottom-up aggregation of, e.g., community-based monitoring or top-down
organization through, e.g., global observing system frameworks.
This presentation illustrates how such structured coordination may be brought about by (i) drawing on toolkits
developed for the design of regional or global observing systems, (ii) translating to the local scale the broader
concept of societal benefits derived from services provided by the Arctic system, and (iii) focusing on the aim of
informed response as a way to encourage convergence of different activities and approaches.

2319
Morning Plenary IV
23.06.2018 07:50-09:00, A Davos

Keynote Lecture VIII

The Southern Ocean – globally important, surprisingly unknown

Anna Wåhlin (anna.wahlin@marine.gu.se)


Department of Marine Sciences, University of Gothenburg, Sweden

The Southern Ocean is fundamental to global climate, marine biomass, and sea-level change. Its storage of heat
and carbon and its redistribution of physical and biogeochemical properties affects all oceans. It is also one of
the least known sectors of planet Earth with large unexplored areas. The fate of the West Antarctic Ice Sheet is
considered the greatest remaining unsolved problem when predicting future global sea level. This giant ice
sheet is drained by glaciers that terminate in the ocean, where they form floating ice shelves overlying vast
sub-ice cavities. Physical processes in these cavities are key for the melting and break-up of the ice sheet.
However, due to the lack of data for boundary conditions, forcing, and validation of theories and models, these
environments are still very poorly understood. Another main knowledge gap is the seasonally sea-ice covered
parts of the Southern Ocean, an area larger than the South American continent. The Southern Ocean accounts
for about 50% of the oceans uptake of CO2. Observations of the ice-covered regions remain mostly non-
existent because of its remoteness and harsh environment. The ice prevents satellite-based remote sensing of
the sea, available in other regions. Data is obtained at great logistical cost and elevated risk, and it is vital that
the international community work together to create sustainable and efficient observing systems in this area.
Without a clear understanding and long-term observations of the air-sea-ice fluxes, we are unable to supply
climate models with correct process descriptions and validation. As a result, we currently hold a poor
understanding of the key ocean processes. This presentation will outline major knowledge gaps existing in the
Southern Ocean and recent advances addressing them within the Southern Ocean Observing System (SOOS).

2320
BE-9g - Life distribution and responses to environmental changes in Polar ecosystems
23.06.2018 09:00-10:30, C Aspen

121
Long-term Dietary Trends and Resiliency of Pacific Walruses to Climate Change

Alexander Thornton1 (alexander.e.thornton@gmail.com), Lara Horstmann1, Nicole Misarti2

1
University of Alaska Fairbanks, College of Fisheries & Ocean Sciences, Fairbanks, United States, 2University of
Alaska Fairbanks, Water & Environmental Research Center, Fairbanks, United States

Sea ice loss threatens Arctic species, such as Pacific walruses (Odobenus rosmarus divergens). Long-term
dietary studies are useful in assessing impacts of climate change. We obtained stable isotope data (δ15N, δ13C)
from cementum growth layers in walrus teeth to assess diet variability. By documenting changes over
individual lifetimes and population-wide trends, we investigate resiliency and vulnerability of walruses to
environmental change. Partnering with museums and subsistence users, we chose teeth collected from 1880-
2016. A generalized additive model shows δ15N and δ13C decrease over time, while expressing cyclical, but
inverse patterns. Walrus trophic level reached a low in the 1960s and peaked in the 1990s, followed by a recent
decline; this may correlate with population size. When sexes were analyzed separately, this pattern was
different for females, who reached a δ15N peak in the 1980s. Declines in δ13C through time may link with large-
scale environmental trends and mirror observations in marine species in other biogeographic regions, including
Antarctica. Autocorrelation functions show short- and long-term oscillations of δ15N and short-term oscillations
of δ13C through time, suggesting biotic influences on diet (e.g., mollusk depletion and repopulation). High
variability in δ13C and δ15N indicates walruses are generalist predators consuming varying proportions of
pelagic and benthic prey. Walruses may thus have potential resiliency in the face of climate change.

2321
496
Genetic Selection in Antarctic fur Seals - Effects of Prey and Sealing

Alison Cleary1 (alison.cleary@npolar.no), Marthan Bester2, Carolina Bonin3, Jaume Forcada4, Michael Goebel5,
Simon Goldsworthy6, Christophe Guinet7, Joe Hoffman8, Kit Kovacs1, Christian Lydersen1, Andrew Lowther1
1
Norwegian Polar Institute, Tromsø, Norway, 2University of Pretoria, Hatfield, South Africa, 3Hampton
University, Hampton, United States, 4British Antarctic Survey, Cambridge, United Kingdom, 5National Oceanic
and Atmospheric Administration, La Jolla, United States, 6South Australian Research and Development Institute,
Urrbrae, Australia, 7Centre d'Etudes Biologiques de Chizé (CEBC), Chizé, France, 8University of Bielefeld,
Bielefeld, Germany

Antarctic fur seals, Arctocephalus gazella, breed on sub-Antarctic islands around the continent. This discrete,
yet circumpolar, distribution is an ideal natural laboratory for exploring genetic selection. All of the islands
inhabited by A. gazella are near the polar front, but they differ in key parameters, notably in the composition
of available prey and in the degree of commercial harvesting each colony experienced. In terms of prey, krill
form the majority of A. gazella's diet in West Antarctica, whereas further east myctophid fish form the bulk of
the diet. In terms of harvest pressure, more readily accessible islands, such as South Georgia, suffered high
rates of exploitation during sealing, while more remote and inaccessible islands, such as Bouvetøya, were
harvested at much lower levels. How then have these disparate pressures driven genetic selection in A.
gazella? To address this question, we sequenced 100,000 loci across the genomes of 97 individuals from 8
major colonies across the circumpolar breeding distribution. By comparing the frequencies of genetic changes,
and mapping changes back onto annotated genomes, we can begin to unravel the effects of these natural and
anthropogenic selective forces on A. gazella at a molecular level. Understanding the evolutionary
consequences of sealing, and the ongoing selective pressure of different prey regimes may provide insight to
guide management of this species within a rapidly changing Southern Ocean.

2322
1033
Post-weaning Dispersal of Antarctic Fur Seal young of the Year

Michael E. Goebel1 (mike.goebel@noaa.gov), Jeremy T. Sterling2, Noel A. Pelland2, Daniel P. Costa3, Birgitte I.
McDonald4, Douglas J Krause1, Jefferson T. Hinke1
1
NOAA, Antarctic Ecosystem Research Division, La Jolla, United States, 2NOAA, National Marine Mammal
Laboratory, Seattle, United States, 3University of California Santa Cruz, Santa Cruz, United States, 4Moss
Landing Marine Labs, Moss Landing, United States

First-year survival (FYS) is a critical parameter driving trends in abundance and recruitment in vertebrate
populations and can be a substantial driver of life-time reproductive success. FYS of Antarctic fur seals (AFS) in
the South Shetland Islands is highly variable and declining. Newly-weaned AFS are shallow divers that likely
depend upon highly productive areas with high-density prey to survive an abrupt transition to nutritional
independence. This critical time in pinniped life history is under-studied. Our objective was to investigate
habitat use and dispersal patterns for AFS young-of-the-year using satellite-linked telemetry. We instrumented
39 AFS pups over three years. Pups were tracked from their natal colony on average 64 d (±67.0). Over 21,000
ARGOS locations were processed with a continuous-time correlated random walk model. One pup which was
recaptured the following year spent 93.2% of its winter migration (251d) south of the Polar Front. Some pups
spent their post-weaning months in the Bransfield Strait, the location of an extensive and growing winter
fishery for Antarctic krill. The overlap between this critical period in AFS life history and the winter krill fishery
is a concern for the conservation of this and other krill-dependent species. More studies of distribution and
foraging ecology of young of the year are necessary to understand the full extent of the impact of the fishery.

2323
1243
Acoustic Monitoring of Top Predators in the Ross Sea Marine Protected Area (MPA)

Alexa Hasselman1 (alexa.hasselman@pg.canterbury.ac.nz), Regina Eisert1, Michael Hayes2, Andrew Wright3,4

1
Gateway Antarctica, University of Canterbury, Christchurch, New Zealand, 2College of Engineering, University
of Canterbury, Christchurch, New Zealand, 3University of Canterbury, Gateway Antarctica, Christchurch, New
Zealand, 4Bedford Institute of Oceanography, Fisheries and Oceans, Dartmouth, Canada

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is expected to officially
declare the Ross Sea region Marine Protected Area (MPA), located in a pristine and ecologically important area
of the Southern Ocean, in December 2017. CCAMLR requires ongoing monitoring of the MPA to ensure
objectives are met, specifically prevention of ecosystem effects as a result of fishing for Antarctic toothfish. The
focus of proposed research and monitoring for the MPA is on toothfish predators, including Weddell seals and
Type-C killer whales. These and other top predators are valuable indicators of ecosystem status, since their
presence, diversity, and abundance integrate multiple external drivers acting on the ecosystem.
The aim of our study was to establish the methodology for comprehensive passive acoustic monitoring of
marine mammals in the MPA. During January 2018, we deployed a series of 'sound traps' with a 288KHz sample
rate in an area used by killer whales and other marine mammals to generate presence/absence data, diel
activity patterns, and abundance information. Concurrent video was also obtained using underwater 'camera
traps' to correlate various calls to observed behaviors, individual identity, and group structure. The findings
obtained will inform the design of passive acoustic monitoring networks in the Ross Sea region MPA and greatly
contribute to our understanding of the ecology of key top predators in that ecosystem.

2324
2047
Assessing Global Change Influences on the Distribution of Antarctic fur Seals

Mary-Anne Lea1,2 (maryanne.lea@utas.edu.au), Ben Arthur1,3, Marthan Bester4, PJ de Bruyn4, W. Chris

Oosthuizen4, Michael Sumner2,5, Simon Wotherspoon1,5, Mia Wege4, Mark Hindell1,2
1
Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia, 2Antarctic Climate &
Ecosystems Cooperative Research Centre, Hobart, Australia, 3CSIRO Oceans & Atmosphere, Hobart, Australia,
4
University of Pretoria, Zoology & Entomology, Pretoria, South Africa, 5Australian Antarctic Division, Hobart,
Australia

Antarctic fur seals are a numerous, adaptable and far-ranging circumpolar species. While krill forms a
significant component of their diet in the South Atlantic, individuals in the southern Pacific and Indian Oceans
rely on mesopelagic fish and squid. Over the last ten years, we have studied the winter habitat requirements of
Antarctic fur seals at Marion Island. One of the primary aims has been to assess how the predicted southwards
movement of Southern Ocean fronts and the intensification of westerly winds (positive Southern Annular
Mode) may influence the distribution and foraging success of pelagic Southern Ocean marine predators. Since
2008, the post-breeding movements of over three hundred female Antarctic fur seals from Marion Island have
been studied using flipper-tag geolocation tags. Movement analysis of this unique and extensive time series
has been conducted using freely available, customised software (bsam and SGAT R packages). This approach
has enabled the detection of key individual and aggregated annual foraging areas during this ten-year period
(2008-2017). Predicted inter-annual southwards shifts in prime foraging areas were assessed in relation to
mean and annual frontal positioning and sea-ice extent. Understanding how changes in the foraging behaviour
and success of higher trophic level species relate to signals of global change, will enable better predictions of
ecosystem change and population level response in the Southern Ocean into the future.

2325
2187
Life in the Fast Lane: Fur Seal Foraging at the Edge of their Distribution

Renato Borras-Chavez1, Michael E Goebel2 (mike.goebel@noaa.gov), Stella Villegas-Amtmann3, Luis Huckstadt3,

Daniel P Costa3, Carla N Rivera1, Jose M Fariña1, Francisco Bozinovic1
1
Catholic University of Chile, Center of Applied Ecology and Sustainability-CAPES, Santiago, Chile, 2National
Oceanic and Atmospheric Administration, Antarctic Ecosystem Research Division, San Diego, United States,
3
University of California Santa Cruz, Department of Ecology and Evolutionary Biology, Santa Cruz, United States

At its most southerly breeding range, the Antarctic fur seal (AFS) operates at its highest field metabolic rate in
an environment challenging the physiological limits for energy acquisition. Currently, we have little
understanding on how edge colonies, already coping with high environmental variability, may deal with
additional variation contributed by specific atmospheric events. By using a combination of diet estimates and
biologging we evaluated how additional environmental variability (2014/15 EL NINO year against regular years)
may affect the behavior of these colonies. Foraging behavior was compared between all years using 18
variables that represent five categories: trip duration, recovery time (time ashore and surface time), diving
effort, habitat use and diet. Differences were found in trip duration (longer trips), recovery time (shorter time
ashore) and habitat use between 2014/15 and normal years. No differences were found in diving effort since
colonies are already operating at their physiological maximum. Diet was no different between years. This
suggest that, in critical years, individuals will not take decisions that may risk the success of capturing prey
(longer but close to shore trips and shorter time ashore) differing from other AFS colonies under critical
conditions. Adaptive mechanisms may be shaping the behavior of these colonies highlighting the importance of
research on evolutionary patterns in colonies living constantly in the fast lane of life.

2326
EN-6a - Reconstructing past environmental change in the Polar Regions
23.06.2018 09:00-10:30, A Studio

1572
Reconstructing Holocene Climate and Deglaciation from Antarctic Lake Sediments

Stephen Roberts1 (sjro@bas.ac.uk), Louise Foster1,2, Emma Pearson2, Steve Juggins2, Dominic Hodgson1,
Krystyna Saunders3, Erin McClymont4, David Naafs5, Elie Verleyen6
1
British Antarctic Survey, Cambridge, United Kingdom, 2Newcastle University, School of Geography, Politics and
Sociology, Newcastle, United Kingdom, 3Australian Nuclear Science and Technology Organisation, Sydney,
Australia, 4University of Durham, Dept. of Geography, Durham, United Kingdom, 5Bristol University, Dept. of
Chemistry, Bristol, United Kingdom, 6Ghent University, Dept. of Protisology, Ghent, Belgium

We present quantitative reconstructions of past temperature change from Antarctic and sub-Antarctic lake
sediments using temperature-sensitive membrane-spanning glycerol dialkyl glycerol tetraether (GDGT) lipids of
Archaea/Bacteria, and examine Holocene palaeoclimate change and the deglaciation of ice-free areas on the
Antarctic Peninsula (AP) and South Georgia (SG). Global GDGT calibrations do not perform well for low
temperature/high latitude lake sediments because GDGT presence, type and provenance is largely unstudied.
To address this, we quantified modern-day environmental controls on GDGT compositional abundance in
surface sediments of 38 (sub-)Antarctic lakes. GDGT compounds were found in 37 lakes, with branched GDGT
(brGDGT) compounds dominant. Mean summer air temperature (MSAT) explained most variance in the
brGDGT data allowing development of a new brGDGT-summer temperature calibration for (sub-)Antarctic lakes
with significantly improved statistical performance at low temperatures. Reconstructed summer temperatures
from three strategically-located palaeolimnological records reveal that deglaciation near to present limits was
likely completed by or during a late Holocene temperature maxima, centred on c. 4-3 ka, with a significant
cooling trend into, and minor glacial readvances during, the C16-19th Southern Hemisphere (SH) 'Little Ice Age'.
We link Holocene temperature shifts and regional lags to variations in SH insolation and Westerly wind
strength.

2327
1797
A 43 ka Multi-proxy Record of Paleoenvironments from an East Antarctic Lake

Anish Kumar Warrier1 (akwarrier@gmail.com), Siddaiah Mahesh Badanal2, Rahul Mohan2, Rajasekhariah
Shankar3, Rasik Ravindra4, Rajesh Asthana5
1
Manipal University, Manipal, India, 2National Centre for Antarctic & Ocean Research (ESSO-NCAOR), Antarctic
Science Division, Vasco da Gama, India, 3Mangalore University, Marine Geology, Mangalore, India, 4Ministry of
Earth Sciences, New Delhi, India, 5Geological Survey of India, Kolkata, India

Lakes situated in polar regions are quite sensitive to slight variations in the climate, and therefore can be
effectively used to reconstruct past variations in the environmental conditions arising due to climate change.
Schirmacher Oasis (SO) is one of the ice-free regions in East Antarctica and is bestowed with several freshwater
lakes. In this work, we present a multi-proxy work carried out on a 79-cm sediment core from L-49 Lake. The
core has an age-span of ~43 cal ka B.P. which is constrained by five AMS radiocarbon dates. A range of
environmental magnetic measurements were made in addition to estimation of the total organic matter
content for the samples. The iron-bearing minerals are mainly derived from the catchment as there is no
obliteration of the magnetic signal due to magnetic dissolution, bacterial magnetite and authigenic greigite.
The magnetic properties are high during the last glacial period indicating a fairly high concentration of coarse-
grained magnetite. Such high values are indicative of extremely cold climatic conditions in the SO. During the
Holocene, the values are quite low, suggesting relatively warmer climatic conditions. This is also supported by
the high values of organic matter content indicating an increase in productivity in the lake system. Deglaciation
in the SO began at around 20 cal ka B.P. which is fairly consistent with other paleoclimatic records from the
region as well as other ice-free regions in East Antarctica.

2328
1186
Groundwater and Thaw Legacy of a Large Paleolake in Taylor Valley, Antarctica

Krista Myers1 (kmyer19@lsu.edu), Peter Doran1, Neil Foley2, Slawek Tulaczyk2, Hilary Dugan3, Esben Auken4, Jill
Mikucki5, Ross Virginia6
1
Louisiana State University, Geology and Geophysics, Baton Rouge, United States, 2University of California,
Santa Cruz, Earth and Planetary Sciences, Santa Cruz, United States, 3University of Wisconsin - Madison, Center
for Limnology, Madison, United States, 4Aarhus University, Department of Geoscience, Aarhus, Denmark,
5
University of Tennessee, Knoxville, Department of Microbiology, Knoxville, United States, 6Dartmouth College,
Institute of Arctic Studies, Hanover, United States

The McMurdo Dry Valleys (MDVs) in East Antarctica contain a number of perennial ice-covered lakes fed by
ephemeral meltwater streams. Paleodeltas and paleoshorelines throughout Fryxell Basin in Taylor Valley
provide evidence of significant lake level change occurring since the Last Glacial Maximum (LGM). During the
LGM, grounded ice in the Ross Sea extended into the eastern portion of Taylor Valley, creating a large ice
dammed paleolake referred to as Glacial Lake Washburn (GLW). Airborne resistivity data collected by SkyTEM,
a time-domain airborne electromagnetic sensor system, was used to map groundwater systems in the lake
basin. A large low resistivity region indicative of liquid water extends hundreds of meters away from the
modern lake extent which is consistent with the presence of a degrading thaw bulb from GLW. As lake level in
Fryxell Basin fell to modern levels, the newly exposed saturated sediment surrounding the lake began to freeze.
We hypothesize that this process is ongoing and will continue until equilibrium is reached between the
geothermal gradient and atmospheric temperatures.
Though groundwater systems were previously thought to be minimal or nonexistent in the MDVs, regional
resistivity data now show that extensive reservoirs exist beneath these lakes. The presence of deep
groundwater systems beneath MDV lakes has important implications for hydrologic and ecosystem
connectivity in an environment largely driven by the availability of liquid water.

2329
1034
Assessing the Impacts of Antarctic Bases on Fildes Peninsula Aquatic Ecosystems

Santiago Giralt1 (sgiralt@ictja.csic.es), Dermot Antoniades2, Roberto Urrutia3

1
Institute of Earth Sciences Jaume Almera (ICTJA-CSIC), Barcelona, Spain, 2Centre d'Études Nordiques, Université
Laval, Québec, Canada, 3University of Concepción, Concepción, Chile

The Fildes Peninsula (King George Island, South Shetland Islands) has been the site of year-round human
presence since the construction of Bellingshausen Station in 1968. The peninsula is now home to six permanent
bases, creating one of Antarctica's densest human concentrations. Substantial infrastructure supports these
bases, including an airport, roads, pipelines, and diesel generators. The construction and operation of these
facilities has caused considerable disturbances, although the precise nature of the effects on most ecosystems
is still poorly understood.
In 2016 and 2017, eight lakes were sampled to determine nutrient and metal concentrations as well as basic
water column properties. Short sediment cores were also retrieved to determine lake conditions prior to
human presence on the peninsula, and to develop records of how anthropogenic pollutants have affected the
lakes since bases were established. XRF core scanner, x-ray diffraction, and CT-Scan images have been used to
determine how the deposition of pollutants to the lakes has changed in the past. Biological indicators, including
diatoms and fossil pigments, will be employed to determine how aquatic communities have changed over time
and if they been affected by local human activities. By comparing our study lakes situated near and distant
from bases, we will determine what observed changes can be attributed to natural changes and thus quantify
anthropogenic effects on Fildes Peninsula aquatic ecosystems.

2330
2614
Reconstructing Westerly Wind Variability Using Sub-Antarctic Lake Sediments

Krystyna Saunders1,2 (krystyna.saunders@ansto.gov.au), Stephen Roberts3, Bianca Perren3, Christoph Butz2,

Christoph Dätwyler2, Raphael Neukom2, Louise Sime3, Martin Grosjean2, Hodgson Dominic3
1
Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia, 2University of Bern, Institute
of Geography, Bern, Switzerland, 3British Antarctic Survey, Cambridge, United Kingdom

The position and strength of the Southern Hemisphere westerly winds (SHW) is important for temperature and
rainfall variability from the mid- to high-latitudes of the Southern Hemisphere. The SHW also influence
Southern Ocean circulation, regulate ocean-atmosphere CO2 degassing, and influence sea ice extent around
Antarctica. While observations since the 1950s show the winds have strengthened and shifted southwards, this
period is too short to understand their natural variability, especially as stratospheric ozone depletion and rising
greenhouse gases from anthropogenic activities are considered to be driving these changes. Here, we present
SHW strength reconstructions spanning the last 12,000 years from sub-Antarctic Macquarie Island (54°S, 158°E)
based on independent proxies that track the changing inputs of sea salt aerosols and minerogenic particles into
lake sediments. Our reconstructions show close agreement with temperature, sea ice and atmospheric CO2
records from Antarctic ice cores for the last 12,000 years, and southern South American temperature for much
of the last Millennium.

2331
1029
Sub-antarctic Peats as Recorders of Westerly Wind Changes. Preliminary Results

Francois De Vleeschouwer1 (francois.devleeschouwer@ensat.fr), Dominic Hodgson2, Stephen Roberts2, Chuxian

Li3, Nathalie van der Putten4, Angela Gallego-Sala5, Alex Whittle2,5, Sarah Davies6, Bianca Perren2
1
EcoLab, Université de Toulouse, CNRS, INPT, UPS, Castanet-Tolosan, France, 2British Antarctic Survey,
Cambridge, United Kingdom, 3CNRS/EcoLab, Castanet-Tolosan, France, 4Vrije Universiteit Amsterdam, Faculty of
Science, Cluster Earth and Climate, Amsterdam, Netherlands, 5University of Exeter, Geography Department,
Exeter, United Kingdom, 6Aberystwyth University, Aberystwyth, United Kingdom

Peatlands are important terrestrial archives of past environmental change and human impact. Some peatlands
are only fed by atmospheric inputs and therefore have the potential to record a more global or hemispheric
signature than other continental deposits. Easily datable, they can produce high-resolution, precisely dated
records covering the Holocene and beyond. Peatlands located on high-latitude sub-Antarctic Islands are heavily
influenced by the prevailing Southern Hemisphere Westerly winds (SHW) and provide excellent archives in
areas of the Southern Ocean where terrestrial palaeorecords are otherwise scarce. In particular, they are
excellent traps for particulate material (dust) transported in the atmosphere and provide information about
past changes in the SHW. Changes in the relative strength and latitudinal position of the SHW are thought to be
both spatially- and temporally- variable, influencing the Southern Ocean circulation and controlling how much
carbon-rich deep water reaches the ocean surface. To better understand changes in the SHW and its impact on
carbon exchange between the ocean-atmosphere over millennial-centennial timescales, we sampled peatlands
from several islands located within the SHW core belt. Here, we reconstruct past (decadal to millennial)
changes in the SHW position and strength from proxy records of wind-driven particulates and develop a more
complete understanding of how the SHW modulate the oceanic uptake of CO2.

2332
BE-12a - Functional ecology of polar microbial communities in a changing world
23.06.2018 09:00-10:30, A Forum

440
Functional Succession from Ice to Developed Soils in the Arctic

Alexandre Anesio1 (a.m.anesio@bristol.ac.uk), Maisie Nash1, Gilda Varliero2, Gary Barker2, Martyn Tranter1,
Liane G. Benning3,4,5
1
University of Bristol, School of Geographical Sciences, Bristol, United Kingdom, 2University of Bristol, School of
Life Sciences, Bristol, United Kingdom, 3German Research Centre for Geosciences, Potsdam, Germany,
4
University of AberdeenLeeds, School of Earth & Environment, Leeds, United Kingdom, 5Free University of Berlin,
Department of Earth Sciences, Berlin, Germany

Glaciers in the Northern Hemisphere are retreating and their forefields present a unique opportunity to
investigate the initial phases of soil weathering/formation and microbial succession in terrestrial cold habitats.
In Arctic environments, the relative importance of primary autotrophic microbial colonisers (e.g. cyanobacteria
and chemolithotrophs), input of allochthonous sources and recycling of ancient organic carbon during the
initial phase of soil establishment is still debated. In this study, the functional microbial diversity of four Arctic
glacier forefields was investigated using metagenomic analysis. In total, 72 soil samples were collected and
sequenced using the Illumina Next-Seq 500. The annotated assembled metagenomes were used in a newly
developed pipeline to provide a quantitative approach to investigate selected ecologically relevant genes. Our
study shows a succession of processes with age, whereby communities in soils previously overridden ice,
strongly represented by a C-fixation metabolism, are gradually replaced by a metabolism involved in the
degradation of complex organic carbon. Genes associated with N-fixation were significantly high only in
forefields where total nitrogen content was low. The metabolic diversity observed in our chronosequence gives
insights into feedback mechanisms between geochemistry and microbial colonisation during soil development
after glacial retreat.

2333
330
Temperature Sensitivity of the High Alpine Soil icrobiome

Johanna Donhauser1 (johanna.donhauser@wsl.ch), Pascal Niklaus2, Beat Frey1

1
Swiss Federal Research Institute WSL, Birmensdorf, Switzerland, 2University of Zurich, Department of
Evolutionary Biology and Environmental Studies, Zurich, Switzerland

Climate change leads to rapid warming of arctic and alpine environments with strong impacts on the soil
microbiome. However, the effects of elevated temperature on soil microbial diversity and functions and the
link between them are still poorly understood.
To assess the temperature adaptation, we incubated eight high-alpine soils adapted to different altitudes and
aspects at five temperatures between 4 - 35 °C for one month. Sequencing of the bacterial 16S rRNA gene at
the DNA and RNA level as well as 3H-leucine incorporation as a measure for bacterial growth were used to
investigate shifts of abundance, activity and optimal growth temperature.
All soils intrinsically exhibited an optimal temperature for bacterial growth of 25 - 30 °C. Only incubation above
25 °C led to a shift of the growth optimum towards the incubation temperature. Conversely, preliminary results
indicate a gradual shift of the bacterial community structures in response to temperature over all incubation
temperatures. Changes at the DNA level might indicate enrichment of taxa adapted to the respective
treatment temperature in the community as they may gain a selective advantage leading to enhanced turnover
relative to less well adapted taxa. On the contrary, shifts in abundance at the RNA level only suggest increase
and decrease of activity without concurrent turnover as an important mechanism of temperature adaptation.

2334
431
Greenhouse Gas Fluxes and Microbial Activities in Dry and Wet High-arctic Soils

Aline Frossard1 (aline.frossard@wsl.ch), Vivien Hotter2, Ramona Kern2, Bjorn Tytgat3, Christophe Seppey4, David
Velazquez5, Pascal Niklaus6, Antonio Quesada5, Ulf Karsten2, Mette Svenning4, Elie Verleyen3, Beat Frey1
1
Swiss Federal Research Institute WSL, Birmensdorf, Switzerland, 2University of Rostock, Rostock, Germany,
3
Ghent University, Ghent, Belgium, 4The Arctic University of Norway, Tromso, Norway, 5Autonomous University
of Madrid, Madrid, Spain, 6University of Zurich, Zurich, Switzerland

High-arctic tundra-soil ecosystems are particularly sensible to global changes due to their proximity to freezing,
snow cover, light availability and scarcity of vegetation. Hydrological fluctuations in these soils are also
important, where drier soils are expected to be less buffered to temperature, directly impacting the soil
biological activity. Yet, little is known on the effects of soil moisture in the regulation of microbial activities in
high-arctic soils and their impact on greenhouses gas exchanges with the atmosphere. In a study part of the
CLIMARCTIC consortium, the fluxes of greenhouse gases (CO2, CH4 and N2O) were assessed along a moisture
gradient (30 - 70 %) in high-arctic tundra soils near Ny-Ålesund (Svalbard) and linked to microbial activities and
community structures. Fluxes of CO2 were highest in dry soils, indicating higher respiration compared to wetter
soils in which CO2 fixation was more important than respiration. Methane (CH4) was mostly consumed except
for the wettest soils where CH4 was emitted. Comparing these results with microbial functional diversity such
as abundance of functional genes or extracellular enzymes activities involved in C and N-cycling will allow to
highlight the importance of soil moisture in tundra soils for microbial activities and their impact on greenhouse
gases fluxes.

2335
504
The Microbiome of the High-alpine Permafrost and its Response to Warming

Carla Pérez Mon1 (carla.perezmon@wsl.ch), Aline Frossard1, Beat Stierli1, Beat Frey1
1
WSL Swiss Federal Institute for Forest Snow and Landscape Research, Zurich, Switzerland

The microbiome of temperate mountain permafrost is still poorly understood. Here we present the results of a
pioneering metagenomic study on the permafrost microbial communities from the Swiss Alps. Samples taken in
the ridge of “Muot-da-Barba-Peider” (N 46.49634 E 9.93145, 2979 m. a. s. l) revealed a unique, highly diverse
microbial community enriched in bacterial members of the novel Patescibacteria superphylum and with a
significant proportion (14%) of poorly characterized fungi. Based on these results, we established an in situ
experiment in which permafrost soils at a depth of 1.6m were placed into the surface active layer in order to
simulate thawing of permafrost as a consequence of warming. After one year, DNA content as a proxy for
microbial biomass in the transferred permafrost soil increased. This may imply changes in the microbial
community structures and functions with potential impacts on the C- and N- cycles in these soils. All together
our results contribute to a better understanding of the future status of the permafrost microbiome subjected
to warming and its implications for the high mountain ecosystem functioning.

2336
1631
Biostimulation of Antarctic Soil on a Freeze-thaw Regime: A Promising Approach

Hugo Emiliano de Jesus1 (hugoemil@gmail.com), Charles K. Lee1, S. Craig Cary1, Raquel S. Peixoto2, Alexandre S.
Rosado2
1
University of Waikato, Faculty of Science and Engineering, Hamilton, New Zealand, 2Federal University of Rio
de Janeiro, Institute of Microbiology, Rio de Janeiro, Brazil

Several studies have applied and evaluated bioremediation treatments on Antarctic soils; however, most of
them take place during the summer to take advantage of higher temperatures. The Antarctic continent is
constantly subject to temperature fluctuations, and summer periods are short and not enough to achieve the
biodegradation goals. Recently, a few studies have shown the possibility of developing a bioremediation
treatment over freezing periods with significant hydrocarbon degradation ratios. However, none of those
studies compared a conventional summer bioremediation treatment against a freeze-thaw cycle (FTC) with
temperatures varying between negative and positive, which frequently occur in Antarctica. A 75-day
experiment was performed aiming to evaluate the differences in bacterial communities in a nutrient-amended
treatment (BS) at 4°C against a FTC nutrient-amended treatment (FBS) (temperatures from -20 to 4°C) in
contaminated soil by diesel oil. Our results revealed that 35.9% of OTUs found in FTC samples were shared
between control and nutrient-amended treatments, relative to 4.3% of OTUs for the same treatments in
unfrozen soils. Predicted functional pathways analysis showed that 12 out of 16 related xenobiotic
biodegradation pathways were at least twice higher in FTC nutrient-amended soil compared to all other
treatments. Based on the results, FBS treatment might represent a new effective, fast, and conservative
strategy for bioremediation in Antarctica.

2337
1213
Methane Producing Archaea in Siberian Permafrost and their Response to Thaw

Stine Holm1 (stine.holm@gfz-potsdam.de), Susanne Liebner1, Fabian Horn2, Christian Knoblauch3, Dirk Wagner1
1
Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences, Section 5.3. Geomicrobiology,
Potsdam, Germany, 2Helmholtz-Zentrum Potsdam, Section 5.3. Geomicrobiology, Potsdam, Germany,
3
Universität Hamburg, Department of Earth Sciences, Hamburg, Germany

Methane production in thawing permafrost can be substantial but often evolves after long lag phases or is
lacking, potentially a result of low or absent methanogenic community or limited substrate. We investigated
samples of a permafrost core of Kurungnakh Island, Siberia, seeking an explanation on the contrasting
evolution of methane production after permafrost thaw. Subsamples were incubated anaerobically at 4°C for 7
years. The enumeration of methanogenic mcrA gene copies was performed by quantitative PCR (qPCR), and the
community composition was determined by amplicon based sequencing. The initial community of the upper
layer of the core, formed during cold and dry conditions was dominated by Thaumarchaota. These samples did
not show methane production by the end of the incubation experiment. In contrast, the layers below 9m
deposited under warm and wet conditions established methane production and were dominated by
Euryarchaeota, with a high abundance of methanogens (47-78%). During the incubation the diversity of these
samples decreased to a dominance of Methanomicrobiales. Based on methane production, community analysis
and qPCR results, we conclude that thaw stimulated methanogenesis in permafrost environments where an
initial active methanogenic community was present. The response of the methanogenic community appears to
depend on the conditions, under which the soil was formed, with warmer and wetter conditions enhancing the
activity of methanogens after thaw.

2338
ME-1_ME-2a - Human Adaptation to High Altitude & Human Science from the Extreme
Poles
23.06.2018 09:00-10:30, A Schwarzhorn

111
Human Hemoglobin and Hematocrit Values at Varying Altitude

Max Gassmann1 (maxg@access.uzh.ch)

1
University of Zurich, Physiology, Zurich, Switzerland

Living at and travelling to high altitude including Antartica is a physiological challenge. While lowlanders have
to acclimatize to reduced oxygen supply (and cold) by increasing red blood cell production, highlanders living in
different regions of the world have developed various adaptive mechanisms to cope with these harsh
conditions. Indeed, in contrast to South American Highlanders (Quechua and Aymaras), Tibetans only
moderately elevate their hematocrit and hemoglobin at high altitude. We recently asked the question if an
elevation lower than 1500 m above sea level shows an impact on Hb levels in men. To answer this question, we
analyzed blood from 70,000 Swiss men aged 18-22 years and observed a significant increase of Hb values for
every 300 meters of augmented altitude. Our data provides convincing evidence that even altitudes below
1500 m must be considered when defining normal hemoglobin and hematocrit values.

2339
113
Regulating Iron and Hemoglobin Levels at High Altitude

Martina Muckenthaler1 (martina.muckenthaler@med.uni-heidelberg.de)

1
University of Heidelberg, Heidelberg, Germany

At high altitude erythropoiesis is increased to allow for the elevated demand of oxygen. In red blood cells
oxygen is bound to iron within the hemoglobin molecule to circulate in the human body. Thus, iron levels have
to be sufficient to maintain adequate tissue oxygenation at high altitude. Iron metabolism is controlled by
hypoxia at various levels that will be discussed in my presentation. The level of hemoglobin defines anemia that
adversely affects various aspects of human health including cognitive performance, work productivity as well as
complications during pregnancy affecting mother and fetus. We analyzed 'high altitude' as a well-established
modifier of Hb concentration and show that Hb values in South American inhabitants increase more
dramatically with altitude compared to all other regions of the world. By contrast, individuals of Tibetan origin
show a significantly lower Hb concentration at all altitudes. All other ethnicities studied showed a comparable
increase of Hb in response to altitude. We provide a multiple meta-regression-model revealing the change in
hemoglobin concentration with increasing altitude in dependence of sex and ethnicity in adults.

2340
344
Lactate Metabolism in Tibetans

Mauro Marzorati1 (mauro.marzorati@ibfm.cnr.it)

1
Consiglio Nazionale delle Ricerche, Istituto di Bioimmagini e Fisiologia Molecolare, Segrate, Italy

Upon acclimatization to severe hypoxia, Caucasian lowlanders undergo an apparent blunting of anaerobic
glycolysis, the so-called “lactate paradox” (LP) (the finding that at the same fraction of the maximum work rate,
blood lactate increases at high altitude to a lesser extent than at sea level attaining lower peak levels ([Lab]peak)
at voluntary exhaustion. With regard to high-altitude natives, [Lab]peak at altitude has been reported to be lower
in Sherpas and in Quechuas and in the same range of that of acclimatized lowlanders. Moreover, the
persistence of low [Lab]peaks 6 weeks after descent from altitude to sea level, has induced to hypothesize that in
Quechuas the LP may have become a fixed metabolic feature.
In order to gain a better insight into the glycolytic capacity of altitude natives, we have assessed blood lactate
concentration at exhaustion in Tibetans with different altitude exposure history: a) in a group of native
Tibetans living at Shegar (4,300 m); b) in a group of Tibetan highlander migrants born and living between 3,500
and 4,500 m until 2-32 days prior to the descent to Kathmandu (Nepal, 1,300 m); c) in a group of Tibetan
lowlanders, born and living in Kathmandu.
In all investigated groups, [Lab]peak values were of the same order of magnitude as those observed in Caucasians
at sea level (10 to 13 mM). The present results seem to indicate that the LP might not be a constant feature of
high altitude acclimatization.

2341
549
The Effect of Normobaric and Hypobaric Hypoxia on Peripheral Perfusion

Adam C. McDonnell1 (adam.mcdonnell@ijs.si), Ola Eiken2, Pietro E. di Prampero3, Igor B. Mekjavic1,4

1
Jozef Stefan Institute, Department of Automation, Biocybernetics and Robotics, Ljubljana, Slovenia, 2KTH Royal
Institute of Technology, Department of Environmental Physiology, Swedish Aerospace Physiology Centre,
Stockholm, Sweden, 3University of Udine, Department of Medical and Biological Sciences, Udine, Italy, 4Simon
Fraser University, Department of Biomedical Physiology and Kinesiology, Burnaby, Canada

According to the equivalent air altitude (EAA) theory, the physiological responses observed
during exposure to normobaric and hypobaric hypoxia are similar. This study evaluated the EAA theory on the
basis of the circadian rhythm of proximal-distal skin temperature gradient. Specifically, we assessed the effect
of hypoxia on daytime and nocturnal peripheral perfusion and whether the effect was modified by the ambient
pressure. Data from three separate experimental trials were analysed:
1) Acute trial: 10-day (N = 14 males) confinement in a normobaric hypoxia (simulated altitude = 4170m;
2) Adaptation trial: 21-day (N = 11 males) confinement to a normobaric hypoxia (simulated altitude = 4,000m,
and
3) Chronic trial: 12-month assignment (N=16 males and 2 females) at the Antarctic research base Concordia.
We monitored the proximal-distal skin temperature gradient (ΔTc-t), an index of peripheral perfusion, during
the day and night. Nocturnal ΔTc-t was not different between the groups and was below the vasoconstriction
threshold, thus reflecting a tendency for nocturnal cutaneous vasodilatation. Sleep onset is highly dependent
on peripheral skin temperature, and as there was no difference in ΔTc-t between the groups, there appears to
be no effect of ambient pressure on nocturnal peripheral perfusion.

2342
1507
Cerebral Deoxygenation and Cognitive Performance in Different Hypoxic Conditions

Mathias Aebi1,2 (mathias.aebi@gmail.com), Nicolas Bourdillon2, Philip Noser1, Denis Bron1, Grégoire Millet2
1
Aeromedical Center, Dübendorf, Switzerland, 2University of Lausanne, Institute of Sport Sciences, Lausanne,
Switzerland

Introduction: Mountaineers and pilots are regularly exposed to hypobaric hypoxia (HH) conditions. For safety
reasons, it is paramount to investigate how concentration and cognition may be affected and the influence of
cerebral deoxygenation. The aim of this study was to investigate how cognitive performance was altered and
its relation with cerebral oxygenation in different normobaric and hypobaric hypoxic conditions.
Methods: Sixteen pilots trainees (26 ± 4 years old) performed a concentration test (KLT) in five randomized
conditions [Normobaric Normoxia, NN; HH at 3000m and 5500m; Normobaric Hypoxia NH and Hypobaric
Normoxia HN at 5500m]. During each KLT, tissue oxygenation index (TOI) was measured by near-infrared
spectroscopy. Cerebral oxygen delivery (cDO2) was calculated with measured cerebral middle artery velocity by
transcranial Doppler, hemoglobin concentration and earlobe oxygen saturation.
Results: Percentage of error (%Err) on KLT was higher at 5500m in HH (16.3 ± 13.3%, P=0.002) and NH (14.2 ±
9.2%, P=0.025) but not in HN (6.8 ± 6.0%) and 3000m HH (10.4 ± 11.1%), compared to NN (7.2 ± 3.9%). TOI was
impaired at 5500m in HH (68.2 ± 7.1, P< 0.001) and in NH (72.2 ± 6.3) but was similar between all other
conditions (NN: 80.8 ± 6.5; 3000m HH: 77.2 ± 6.1 and 5500 HN: 79.7 ± 6.6). cDO2 was similar in all conditions.
No significant relationships between percent change from NN to any condition in cDo2 or TOI and %Err was
observed, suggesting a complex regulation.

2343
1747
Sleep and Perfomance in Humans Exposed to Extreme Photoperiods at High Altitude

Olivier Mairesse1,2,3 (olivier.mairesse@vub.be), Helio Fernandez-Tellez1,2, Eoin McDonald-Nethercott4, Daniel

Neu3,5, Martine Van Puyvelde1,2, Xavier Neyt2, Romain Meeusen1, Nathalie Pattyn1,2
1
Vrije Universiteit Brussel (VUB), Brussel, Belgium, 2Royal Military Academy, Brussel, Belgium, 3Brugmann
University Hospital, Brussels, Belgium, 4Cambridge University, Cambridge, United Kingdom, 5Université Libre de
Bruxelles, Brussels, Belgium

Crewmembers of polar expeditions often face difficulties initiating and maintaining sleep and show decreased
rapid eye movement (REMS) and slow-wave sleep, as well as circadian phase delays, poor sleep quality and
increased sleep fragmentation. 13 males took part in a winter-over campaign at Dome C and completed 8
measurement cycles every 6 weeks including a.o. polysomnography (PSG), actigraphy, subjective sleep,
sleepiness and fatigue assessments and psychomotor vigilance testing. A control group (n=13; 2 females)
performed a single measurement cycle in normobaric normoxia. Overall, results indicate that Hivernauts
present with increased sleep onset latencies and reduced sleep efficiency. Latencies to REMS appear to be
shorter, REMS duration increase and light sleep decreases. Hivernauts all show periodic breathing, significantly
impacting sleep fragmentation. Cognitive speed is reduced in Hivernauts and associated to higher sleep
fragmentation. Phase-delays are observed in crewmembers subjected to fixed bedtimes, while the remainder
show free-running sleep-wake activity. Situational sleepiness is moderate in Hivernauts, but higher than in
controls. Except increased obstructive respiratory events towards the end of the campaign, sleep, sleepiness
and psychomotor performance variables, show to be fairly robust and stable over time. Results from the largest
PSG dataset to date in Antarctica suggest that the sleep-related individual differences are phenotypic in nature.

2344
CR-5a - Interactions between ice mass balance, the solid Earth, and sea-level changes
23.06.2018 09:00-10:30, A Seehorn

2546
What Is Important to Get Right When Modelling the Greenland Ice Sheet?

Ruth Mottram1 (rum@dmi.dk), Peter Langen1, Christian Rodehacke1,2, Fredrik Boberg1, Jens Hesselbjerg
Christensen3
1
Danish Meteorological Institute, Copenhagen, Denmark, 2Alfred Wegener Institute, Bremerhaven, Germany,
3
University of Copenhagen, Nielse Bohr Institute, Center for Ice and Climate, Copenhagen, Denmark

Ice sheet and glacier models need accurate surface mass balance inputs to reproduce ice sheet extent and
likely evolution. Different regional climate models (RCMs) produce subtly different estimates of ice sheet
surface mass balance (SMB) for the Greenland ice sheet. While the total ice sheet SMB number is similar, there
can be substantial differences spatially and in terms of the components of surface mass balance: precipitation,
melt, runoff, retention and sublimation with potentially large knock-on effects for ice sheet dynamical models.
Similarly, SMB generated from coarser resolution GCMs is often used (for example in ISMIP6) to force ice sheet
models using simplified SMB schemes.
We use the Devon Ice Cap as a model glacier to show that ice sheet dynamical models are strongly sensitive to
choices made in producing SMB forcing when using the same climate model.
Similarly, using carefully designed sensitivity experiments we explore the importance of albedo, orography and
retention parameter choices in calculating SMB using output from a GCM, EC-Earth and an RCM, HIRHAM5, run
at 5km resolution over Greenland. The experiments emphasise that albedo remains a significant source of
uncertainty in estimates of rates of melt and runoff and sea level rise but also that accounting for topographic
changes on centennial to millennial timescales is likely to be important in estimating the rate of ice sheet mass
loss.

2345
1528
Interest of a Regional Climate Model for Doing future Projections over Greenland

Xavier Fettweis1 (xavier.fettweis@ulg.ac.be), Alison Delhasse1, Cecile Agosta1, Charles Amory1, Christoph
Kittel1, Charlotte Lang1
1
University of Liège, Geography, Liège, Belgium

With the aim of evaluating the added value of a regional climate model in downscaled future projections over
the Greenland Ice Sheet, we have compared the surface fields (snowfall and summer near-surface
temperature) coming from the “best” CMIP5 and CMIP6 global models (GCMs) with these fields simulated by
the MAR model forced by the same GCMs.
These "best" GCMS were selected according to their ability to simulate the summer temperature at 700 hPa
and the general circulation at 500 hPa over Greenland with respect to ERA-Interim over 1980-1999. However,
despite their ability to correctly represent the free atmosphere, the selected GCMs present significant biases at
the surface of the ice sheet. The comparison shows that MAR is however able to strongly reduce these GCM
surface biases. We then forced the lateral boundaries of MAR with ERA-Interim to which we applied
temperature corrections of +1°C and +2°C. The outputs were compared to MAR forced by GCM future
projections corresponding to a climate about 1 and 2°C warmer than the current climate. The results of the
different GCM-forced runs and sensitivity experiments are very similar to each other as the GCMs do not
project general circulation changes. Moreover, the sensitivity experiments forced by modified ERA-Interim
reveal that the projected SMB decrease is exponentially amplified if the increased occurrence of blocking
events over Greenland in summer that has been observed since the 2000´s continues in the future.

2346
1987
Reduced Firn Refreezing Capacity Endangers Arctic Glaciers and Ice Caps

Brice Noël1 (b.p.y.noel@uu.nl), Willem Jan van de Berg1, Stef Lhermitte2, Horst Machguth3,4, Bert Wouters1,
Nicole Schaffer5, Michiel R. van den Broeke1
1
IMAU/UU, Utrecht, Netherlands, 2TU Delft, Department of Geoscience and Remote Sensing, Delft, Netherlands,
3
University of Zurich, Department of Geography, Zurich, Switzerland, 4University of Fribourg, Department of
Geosciences, Fribourg, Switzerland, 5Universidad de La Serena, Centro de Estudios Avanzados en Zonas Áridas
(CEAZA), La Serena, Chile

Melting of the Greenland ice sheet (GrIS) and its peripheral glaciers and ice caps (GICs) significantly contributes
to ongoing sea level rise. Exploiting a novel, 1 km surface mass balance product, statistically downscaled from
the output of the regional climate model RACMO2.3 and evaluated against in-situ and remote sensing data, we
identify 1997 as a tipping point for GICs mass balance. That year marks the onset of a rapid deterioration in the
GICs firn capacity to refreeze meltwater. Consequently, GICs runoff increases faster than meltwater
production, tripling the pre-1997 mass loss.
Similar processes are at play in the neighbouring Canadian Arctic Archipelago (CAA). During the last two
decades, ice masses in northern and southern CAA have experienced warmer conditions resulting in enhanced
surface melt, tripling and doubling the pre-1996 mass loss, respectively. While the interior of the northern ice
caps can still buffer most of the additional melt in extensive accumulation zones, the lack of a perennial firn
area over the low-lying southern glaciers caused uninterrupted mass loss since the 1980s.
In the absence of significant refreezing, this indicates inevitable disappearance of these highly sensitive Arctic
glaciers and ice caps in the near future.

2347
2375
Separating Cryospheric and Oceanic Mass Changes in GRACE Monthly Solutions

Andreas Groh1 (andreas.groh@tu-dresden.de), Martin Horwath1, Benjamin D. Gutknecht1

1
Technische Universität Dresden, Dresden, Germany

For the period 2002 - 2017, mass changes in the Earth´s subsystems can be derived from time-variable gravity
field solutions provided by the GRACE mission. We present a regional integration approach based on directly
tailored sensitivity kernels, derived by a formal optimization procedure that minimizes the sum of propagated
GRACE solution errors and leakage errors. This approach ensures consistency between mass change estimates
for individual regions (e.g. ice sheet drainage basins) and the corresponding estimates for their aggregations.
The proposed approach has been successfully applied within ESA´s Climate Change Initiative (CCI) projects on
the Antarctic Ice Sheet and the Greenland Ice Sheet for the mass change products for both ice sheets. The CCI
products comprise mass change time series for individual drainage basins and aggregations (basin products). In
addition, time series of mass change grids with a formal resolution of 50x50km² (gridded product) are derived.
The algorithm has been adapted for oceanic applications in the frame of the CCI Sea Level Budget Closure
project. Special emphasis is placed on the separation of mass signals at the ice-ocean interface. Therefore, a-
priori information on the spatial mass change patterns to be expected in both sub-systems is introduced into
kernel tailoring algorithm. First results of the ocean mass change time series and grids, which are consistent
with the latest CCI ice sheet products, are presented and discussed.

2348
1755
Ice Sheet - Solid Earth - Climate Interactions during the Last Deglaciation

Florian Ziemen1 (florian.ziemen@mpimet.mpg.de), Marie Kapsch1, Virna Meccia1, Thomas Riddick1, Meike
Bagge2, Volker Klemann2, Uwe Mikolajewicz1
1
Max Planck Institute for Meteorology, Hamburg, Germany, 2GFZ German Research Centre for Geosciences,
Potsdam, Germany

We study the last deglaciation in a new modeling system that encompasses a wide range of interactions
between ice sheets, their mass balance, the solid Earth and the climate. The system consists of the modified
Parallel Ice Sheet Model (mPISM), the Viscoelastic Lithosphere and Mantle model (VILMA), and the Max Planck
Institute Earth System Model (MPI-ESM). The surface mass balance of the ice sheets is computed with an
energy balance model, shelf basal melt from temperature and salinity of the adjacent ocean. By applying
VILMA, sea-level change due to ice loads is calculated considering surface deformation, eustasy and geoid
change. In MPI-ESM, glaciers, topography, rivers, coastlines and bathymetry adapt to changes in ice sheets and
topography. The model system is forced only with transient orbital parameters and greenhouse gas
concentrations.
In our experiments, the retreating ice sheets leave behind vast periglacial lakes and marginal seas. Gigantic ice
sheet surges into these basins lead to the formation of large ice shelves with low surface elevations causing
strong melt. Where the basins are connected to the open ocean, basal melt and calving increase the ice loss at
the shelves. Over time, the retarded sea-level response shrinks the periglacial basins again. This study presents
first experiments that include the full range of interactions between ice sheets, solid Earth, atmosphere and
ocean circulation.

2349
1331
The Land-ice Contribution to SLR Since 1992

Jonathan Bamber1 (j.bamber@bristol.ac.uk), Stephen Chuter1, Richard Westaway1, Bert Wouters2, Ben
Marzeion3
1
University of Bristol, Bristol, United Kingdom, 2Utrecht University, Utrecht, Netherlands, 3Bremen University,
Bremen, Germany

Within several projects aimed at constraining the mass balance of glaciers, ice caps (GIC) and the ice sheets, we
have developed consistent, rigorous estimates of land ice mass trends over the satellite era from the early
1990s to the present day. Our results combine satellite laser and radar altimetry including ERS, ENVISat, ICESat
and CryoSat, along with GRACE data from 2003 onward. We have separate time series for Greenland,
Antarctica and North Atlantic GIC. The latter represents about half the GIC contribution to SLR over the period
of interest. For GIC outside of this region, we utilise existing analyses of ICESat and GRACE data combined with
terrestrial geodetic methods and modelled surface mass balance to extend the time series backwards.
For 2003-2015, we obtain mean rates of 84±22 Gt/yr, 269±18 Gt/yr and 135±15 Gt/yr for Antarctica, Greenland
and Arctic GIC respectively. Our preliminary estimate for other GIC contributions is 140 Gt/yr giving a total land
ice contribution of 623 Gt/yr, which has a sea level equivalent of 1.73 mm/yr. This is, however, not necessarily
the same as the contribution to sea level rise, nor the ocean mass trend measured by GRACE, for example land-
locked GIC may or may not contribute to SLR. We note that the trend in mass exchange with the ocean is not
linear in time. Finally, we present the trends from the early 1990s, which have larger uncertainties and assess
these estimates in relation to the sea level budget for the same time period.

2350
SH-8 - Data science for polar environments – discovery, rescue, and mining
23.06.2018 09:00-10:30, A Wisshorn

483
Technical and Social Systems for Data Reuse on Human Ecodynamics in the Arctic

Colleen Strawhacker1 (colleen.strawhacker@colorado.edu), Rachel Opitz2, Adam Brin3

1
National Snow and Ice Data Center, University of Colorado, Boulder, United States, 2University of Glasgow,
Glasgow, United Kingdom, 3Digital Antiquity, Tempe, United States

An inherent challenge of interdisciplinary work is that it requires us to engage with data and information
collected and analyzed by other researchers who specialize in different types of data analysis. Doing so can be
laborious, requiring extended explanation and discussion of each domain's assumptions, resulting in barriers to
large-scale, temporally deep analysis. dataARC is attempting to support interdisciplinary work by developing a
data discovery tool that provides intentionally interdisciplinary search result sets and contextualizes the results
from each domain - including archaeology, paleoecology, and the humanities - within a shared conceptual
model. In practice, the project is creating a data discovery tool that provides results directly related to a search
and connected results, and provides explanations for the links between them. The creation of structured and
contextualized, intentionally interdisciplinary result sets requires that we define the levels of granularity at
which data elements operate, connections among data elements to form basic ideas, and connections among
specific ideas and broader, overarching concepts. This paper presents the data structure and knowledge model
developed within the dataARC project and discusses the challenges encountered in operationalizing these
structures to produce useful, intelligible search results that can enable interdisciplinary teams to share their
data and understandings of that data with more confidence and clarity.

2351
520
Atmospheric River Impacts on Greenland: A Self-organizing Map Analysis

Kyle Mattingly1 (kmatt842@uga.edu), Thomas Mote1

1
University of Georgia, Geography, Athens, United States

The Greenland Ice Sheet (GrIS) has been losing mass during the past few decades in part due to negative
surface mass balance (SMB). Several recent episodes of rapid GrIS mass loss have coincided with anomalous
poleward moisture transport by atmospheric rivers (ARs). ARs likely contribute to GrIS melt through the
greenhouse effect of water vapor, radiative effects of clouds, latent heat release within upstream air masses,
and energy from liquid precipitation. ARs may also provide positive inputs to SMB through snow accumulation.
We compile a long-term record of moisture transport events affecting Greenland by applying a self-organizing
map (SOM) classification as well as a conventional object-based AR identification algorithm to integrated water
vapor transport (IVT) data from multiple atmospheric reanalyses. We then analyze AR effects on GrIS melt and
SMB using passive microwave melt data and the Modèle Atmosphérique Régional (MAR) regional climate
model.
The SOM and object-based AR results closely agree on the temporal and spatial variability of moisture
transport affecting Greenland. AR events result in widespread anomalous GrIS melt during the warm season,
and there is a robust relationship between annually accumulated IVT and melt. Moisture transport impacts on
SMB are more complex, as ARs induce strong negative SMB anomalies in the warm season ablation zone but
enhance accumulation in higher elevations during the warm season and everywhere during the cold season.

2352
624
Antarctic Legacy of South Africa (ALSA) Preserve Human Data, what is the Value?

Ria Olivier1 (riaolivier@sun.ac.za)

1
Stellenbosch University, Botany and Zoology, Stellenbosch, South Africa

ALSA's main aim is to preserve information/data of the human involvement from South Africa by maintaining a
digital data repository. This presentation will show the criteria for assessment and selection of historical data of
personal and official nature for the digital repository. The following questions will be answered; do human
personal experiences add any value and significant meaning to environmental research? Is digital material such
as narratives, images, maps and diaries easy accessible? Will the material add to the visualization and
interpretation of information? In order to answer these questions, the presentation will look at a few examples
to illustrate the value of human experiences. It will emphasise the importance to ensure that personal
experiences are documented and preserved for the legacy of a country, but also to preserve it for the
substantial amount of scientific deductions and analysis that can be gained from preserving the information.
Therefore, the personal data has to be discovered, retained and be made accessible for mining of information.
An in depth look into the preserving through a digital repository will be done and to demonstrate that new
possibilities and additions can be added on as needs change and differ in the future. The contributions of
human involvement therefore is much more than just a few pictures and diaries left behind, their work and life
can enhance our perceptions of the environment in the polar regions to preserve the future.

2353
985
Creation of a Historical Southern Ocean Climate Dataset from Ships' Logbooks

Praveen Teleti1 (prt31@cam.ac.uk), W. G. Rees1, J. A. Dowdeswell1

1
Scott Polar Research Institute, University of Cambridge, Dept of Geography, Cambridge, United Kingdom

Historical ship's logbooks can provide meteorological observations in the Southern Ocean (SO), one of the
largest climate data-deficient regions on Earth. In this study, we capture data from logbooks of whaling ships
operating in the Weddell Sea and Indian Ocean sector of the SO, from the 1930s to the 1960s. We attempt to
extract meteorological information and create a gridded climate dataset. We discuss the effectiveness of
various data extraction techniques used to deal with historical climate documents, and develop new and
improve existing methods for working with historical data. Meteorological variables such as wind strength and
direction, air and sea temperatures are standardised and converted into consistent modern units of
measurement. Extensive quality checks are made for completeness and accuracy, and to eliminate known
measurement bias from the observations. Cross-validation of the data is possible when independent
observations were found for ships in close proximity. Finally, the dataset is structured according to the
internationally accepted International Maritime Meteorological Archive format, which includes the most
commonly reported meteorological variables, including the time, location, and ship related metadata. Further
analysis of resulting meteorological dataset is useful to understand long-term changes in SO climate. Dataset
can be fed as forcing and boundary conditions to global climate models to improve parametrisations, hence
simulated results.

2354
1048
Documentary Evidence of 19th c. Sea Ice Extent in the Davis Strait & Baffin Bay

Matthew Ayre1 (matthew.ayre@ucalgary.ca), Patricia Wells1, Ravi Sankar1, Maribeth Murray1

1
University of Calgary, Arctic Institute of North America, Calgary, Canada

Historical observations obtained from British Arctic whaling logbooks kept during voyages in the Arctic waters
of the Davis Strait & Baffin Bay constitute a rare subset of environmental data that provide a unique view of the
regions past climate. Approximately 6000 voyages left British ports to engage in Arctic whaling over the 300
years it was practiced. The latter part of this enduring endeavour, executed throughout the 19th and into the
early 20th c. was focussed in in this locality; less than 150 documents from this period are known to exist. British
whalers circumnavigated this region annually between April and October, actively seeking out the sea ice edge;
for it was here they pursued their prize - the bowhead whale (Balaena mysticetus). These surviving documents
contain detailed, daily observations of meteorological conditions (wind direction/speed, precipitation), sea ice,
icebergs and fauna encountered. This research has made near exhaustive use of the known surviving collection
with 117 documents (1809-1911) from British whaling in the region being identified and digitally imaged.
Digitization of the ~25000 days of observations has been completed with the assistance of citizen science
volunteers. Preliminary results illustrate that ice observations can be used to reconstruct average monthly sea
ice edge positions for the entire summer melt season, extending the current known seasonal sea ice
climatology for the region back to the early 19th century.

2355
2308
Arctic and Antarctic Sea Ice in Ten Ocean Reanalyses

Doroteaciro Iovino1 (dorotea.iovino@cmcc.it), Petteri Uotila2, Hugues Goosee3, Keith Haines4, Matthieu
Chavallier5, Antoine Barthelemy3, Clement Bricaud6, Jim Carton7, Neven Fuckar8, Gilles Garric6, Frank Kauker9,
Meri Korhonen10, Vidar Lien11, Marika Marnela10, Francois Massonnet3, Davi Mignac4, Andrew Peterson12,
Remon Sadikni13, Li Shi14, Steffen Tietsche15, Takahiro Toyoda16, Jiping Xie17, Zhaoru Zhang18
1
Euro-Mediterranean Center on Climate Change, Ocean Modelling and Data Assimilation, Bologna, Italy,
2
University of Helsinki, Helsinki, Finland, 3Earth and Life Institute, Universite Catholique de Louvain, Louvain-la-
Neuve, Belgium, 4University of Reading, Reading, United Kingdom, 5Centre National de Recherches
Meteorologiques, Meteo France/CNRS, Toulouse, France, 6Mercator Ocean, Toulouse, France, 7University of
Maryland, College Park, United States, 8Barcelona Supercomputing Centre, Barcelona, Spain, 9Alfred Wegener
Institute, Bremerhaven, Germany, 10Finnish Meteorological Institute, Helsinki, Finland, 11Institute of Marine
Research, Bergen, Norway, 12Met Office, Exeter, United Kingdom, 13University of Hamburg, Hamburg, Germany,
14
Bureau of Meteorology, Melbourne, Australia, 15European Centre for Medium-Range Weather Forecasts,
Reading, United Kingdom, 16Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Japan,
17
Nansen Environmental and Remote Sensing Center, Bergen, Norway, 18Shanghai Jiao Tong University,
Shanghai, China

Polar regions are key components of the climate system whose understanding can largely benefit from merging
observation-based estimates with advanced numerical models. Global and regional Ocean Reanalyses (ORA)
products are increasingly used in polar research. To assess the quality of ORA products in representing the sea
ice-ocean state over recent decades, the Polar ORA Intercomparison Project has been established, following on
from the ORA-IP project.
Ten selected ORAs (among which 7 include sea ice data assimilation) are considered,
extensively analysed and evaluated in the Arctic and Antarctic regions by comparing snow, sea ice, ocean
transports and hydrography with available data sets. This is the first time that most sea ice diagnostics are
performed for such a large set of ORAs. This presentation presents sea-ice diagnostics, while the presentation
by Uotila and co-authors focuses on liquid ocean diagnostics. ORA product biases against observed data and
their mutual spread are quantified, and possible reasons for discrepancies investigated. Particular attention is
given to the comparison of the MultiModel ensemble Mean (MMM) with individual products and the
identifications of outliers, aiming to identify physical mechanisms causing common and individual ORA sea-ice
biases. Monthly data for the 1993-2010 period are considered. The importance of the atmospheric forcing, air-
ocean coupling protocol and sea-ice data assimilation for the sea-ice performance is also discussed.

2356
SY-1a - Earth Observation: Solutions for data collection, compilation and dissemination
23.06.2018 09:00-10:30, B Pischa

2586
Integrated Arctic Observation System Development under Horizon 2020

Stein Sandven1 (stein.sandven@nersc.no), Hanne Sagen1

1
Nansen Environmental and Remote Sensing Center, Bergen, Norway

INTAROS is a research and innovation action under the H2020-BG-09 aiming to develop an integrated Arctic
Observation System (iAOS). INTAROS will extend, improve and unify existing systems in the different regions of
the Arctic. The project has focus on integration of data from atmosphere, ocean, cryosphere and terrestrial
sciences, provided by institutions in Europe, North America and Asia. Satellite earth observation (EO) data plays
an increasingly important role in such observing systems, because the amount of EO data for observing the
global climate and environment grows year by year. EO data will therefore be integrated into iAOS based on
existing products and databases. In situ observing systems are much more limited due to logistical and
technological constraints. The sparseness of in situ data is therefore the largest gap in the overall observing
system. INTAROS is currently assessing strengths and weaknesses of existing observing systems and contributes
with more sensors and platforms to enhance the in situ network. Building sustainable Arctic observing systems
requires coordination, mobilization and cooperation between available infrastructures, modeling communities
and relevant stakeholder groups. INTAROS also includes development of community-based observing systems,
which are combined with scientific data. Thereby, INTAROS will contribute to better-informed decisions related
to economic activities, environmental regulations and development in local communities.

2357
1495
Exploitation of the Existing Arctic Observing Systems under the INTAROS Project

Roberta Pirazzini1 (roberta.pirazzini@fmi.fi), David Gustafsson2, Michael Tjernström3, Andreas Ahlstroem4, Ingo
Schewe5, Hanne Sagen6, Stein Sandven6
1
Finnish Meteorological Institute, Meteorological Research, Helsinki, Finland, 2Swedish Meteorological and
Hydrological Institute, Norrköping, Sweden, 3Stockholm University, Department of Meteorology, Stockholm,
Sweden, 4Geological Survey of Denmark and Greenland, Copenhagen, Denmark, 5Alfred Wegener Institute,
Bremerhaven, Germany, 6Nansen Environmental and Remote Sensing Centre, Bergen, Norway

In the framework of the H2020 project "Integrated Arctic Observation System" (INTAROS), the existing Arctic
observing systems and selected in situ and satellite data products are assessed, exploited, and standardized to
enable their delivery to a multidisciplinary, integrated Arctic Observing System (iAOS) through established
databases. The assessment and exploitation addressed observations of the ocean, atmosphere, cryosphere and
land including physical, chemical, and biological parameters.
Strengths, weaknesses, gaps in spatial/temporal coverage, missing monitoring parameters, sustainability, and
data management of the existing in situ observation networks are analyzed. Moreover, coverage, resolution,
timeliness, uncertainty, format, and metadata of selected in situ and satellite data collections are assessed with
respect to the requirements needed for applications within weather prediction and sea ice services, hazard risk
assessment and prevention, climate, environmental protection. The quality and the processing of selected
datasets are improved to meet the highest standards set by the European and international organizations. New
products resulting from the exploitation of available data are provided, and sparse data are made accessible
through the existing repositories.
The main result is the enhanced quality, quantity, accessibility and documentation of existing Arctic
observations, which are then ready to be ingested into the iAOS.

2358
1714
Sea-ice Observations: Recommended Protocols for Data Collection & Dissemination

Petra Heil1 (petra.heil@utas.edu.au), Penelope Mae Wagener2

1
Australian Antarctic Division and ACE CRC, Hobart, Australia, 2Norwegian Ice Service, Tromso, Norway

CryoNet forms the core of the Global Cryosphere Watch [GCW]'s surface network, leveraging on existing
cryospheric observatories and promoting the upgrade of other suitable facilities. The aim is to build a sustained
network of environmental observing stations, that will yield routine high-quality data and are committed to
comply in its methods, quality control and data dissemination with agreed GCW practices. To ensure consistent
quality data within CryoNet, the GCW is currently developing best practices for its observatories, including
those for sea ice. These Best Practices will form the official recommendations on necessary sea ice variables
required for the science and operational sea ice community and WMO sampling requirements. For the Sea-Ice
Best Practices a set of required and desired variables has been compiled, acknowledging that remotely-sensed
products are the only effective means to provide information on some of the sea-ice variables. Here we
present observational rules for key sea-ice parameters and how to obtain consistent long-term data while
reducing measurement uncertainties. We also discuss challenges of observing sea ice, which seasonally and
regionally is highly variable and covers large expanses. Using the example of the ASPeCt and ASSIST underway
sea-ice observations we demonstrate the virtue of accepting Lagrangian observatories into CryoNet as well as
how digital data recording reduces recording errors while enabling near-real time data distribution.

2359
2452
Connecting CryoNet Stations with WMO Systems, an Interoperability Effort of GCW

Joel Fiddes1,2 (joelfiddes@gmail.com), Matthias Bavay3, Charles Fierz3, Rodica Nitu4, Øystein Godøy5
1
University of Oslo, Oslo, Norway, 2World Meteorological Organization, Geneva, Switzerland, 3WSL Institute for
Snow and Avalanche Research SLF, Davos, Switzerland, 4World Meteorological Organization (WMO), Geneva,
Switzerland, 5Norwegian Meteorological Institute, Oslo, Norway

The WMO Global Cryosphere Watch (GCW) is an international mechanism for supporting all key cryospheric in-
situ and remote sensing observations. To meet the needs of WMO Members and partners in delivering services
to users a global network of “CryoNet” stations is being established. These stations monitor the state of the
cryosphere and report to the GCW dataportal. Data are identified through discovery metadata which includes
access mechanisms for data. The GCW data management is decentralised in the sense that the data centres of
the CryoNet stations host the data, but expose discovery metadata to central catalogue which makes these
searchable. The GCW Data Portal will also serve real-time data from the stations into WMO Information System
(WIS/GTS) if required by the user community.
To date 120 stations have been approved as CryoNet and Contributing stations of the GCW surface observing
network; more than 50% of these are operated by universities and research organizations, which are not
familiar with the WMO metadata and data exchange mechanisms and do not have the resources to adopt
them. These are often significant barriers to entry.
Here we present a data interoperability tool that enables GCW to add value by being the “blackbox” whereby
research scientists are not exposed to operational details (and costs) of WMO while WMO receives a
standardised product and is not exposed to the true diversity of formats, standards etc. at the individual station
level.

2360
1923
The International Arctic Systems for Observing the Atmosphere (IASOA) Framework

Taneil Uttal1 (taneil.uttal@noaa.gov), Sara Morris2

1
NOAA Earth System Research Laboratory, Physical Science Division, Boulder, United States, 2Cooperative
Institute for Research in Environmental Sciences, NOAA/ESRL/PSD, Boulder, United States

The International Arctic Systems for Observing the Atmosphere (www.iasoa.org) was launched during the
International Polar Year and is a consortium that combines the observing assets and expertise from multiple
Arctic Observatories distributed around the Arctic Ocean Three significant facilitating tools developed by IASOA
include a data portal that has informed and been coordinated with the data portal developed by Global
Cryosphere Watch, development of graphical datagrams that substantially extend the information about the
end-to-end collection/processing of in-situ instruments and support of thematic science working groups that
produce concrete outcomes such as processed, calibrated, interoperable datasets and collaborative cross
observatory research results. The IASOA framework is described and proposed as a template for new
international coordination programs such as T-MOSAiC (land-based studies during the MOSAiC Arctic Ocean
Campaign). The general theme discussed is the task of creating effective, high yield, networked observing
systems in the Arctic - requirements and challenges.

2361
1547
The National Polar Data Centers as Linking Pins between Data Providers and Users

Taco F de Bruin1, Marten A Tacoma1 (marten.tacoma@nioz.nl)

1
NIOZ Royal Netherlands Institute for Sea Research & Utrecht University, Den Hoorn Texel, Netherlands

Nowadays, many countries with a National Polar Research Program require all data collected within that
program to be submitted to a National Polar Data Centre (NPDC). These NPDCs carry out different roles. For
data originating from the domain of the data centre, the NPDC will manage the data. For data from other
domains for which a national domain specific data centre exists, the NPDC will play a coordinating role, while
for data without a domain-specific host the NPDC will perform basic data management tasks. As a result, the
NPDC will have a complete overview of all polar data within a national Polar program.
The NPDC is also the gateway to various international data access infrastructures, offering the user access to a
wealth of integrated data from all disciplines. NPDCs from around the world cooperate in SCAR's Standing
Committee on Antarctic Data Management (SCADM) and IASC-SAON's Arctic Data Committee (ADC). These two
committees manage and maintain data access infrastructures for the Antarctic resp. Arctic regions.
This presentation will describe the work done by SCADM and ADC and will specifically address how data are
distributed using portals such as the Antarctic Master Directory (AMD). Current initiatives for further data
integration will be highlighted.

2362
EN-2a - Contamination in Polar and High Altitude Environments
23.06.2018 09:00-10:30, B Parsenn

2372
Microplastic Pollution in the Greenland Sea and Selective Intake by a Seabird

Françoise Amélineau1,2 (francoise.amelineau@gmail.com), Delphine Bonnet3, Olivier Heitz4, Valentine

Mortreux3, Ann Harding5, Nina Karnovsky6, Wojciech Walkusz7, Jérôme Fort1, David Grémillet2
1
Université de La Rochelle, Laboratoire Littoral, Evironnement et Sociétés, La Rochelle, France, 2CEFE, CNRS -
Université Montpellier, Montpellier, France, 3Université de Montpellier, Laboratoire MARBEC, Montpellier,
France, 4Université de Montpellier, Institut Universitaire de Technologie de Montpellier-Sète, Sète, France,
5
Alaska Pacific University, Environmental Science Department, Anchorage, United States, 6Pomona College,
Department of Biology, Claremont, United States, 7Fisheries and Oceans Canada, Winnipeg, Canada

Microplastics (MPs) are found everywhere on earth. Despite Arctic remoteness from major sources of plastics,
recent studies suggest that Arctic sea-ice is a sink for MPs, and several Arctic seabirds are already
contaminated. However, very few data exist for this area. Our aims were to quantify MPs in little auk (Alle alle)
foraging area and diet. Little auks are zooplanktivorous and dive between 0-50m. They are expected to be less
contaminated than filter or surface feeders. Our study was conducted in East Greenland where data on MP
were inexistent, for two breeding seasons with different sea-ice concentrations (SIC): 2005 (high SIC) and 2014
(low SIC). Despite the Arctic origins of the water masses in our study area, MP abundances were similar to
those of other oceans, with 0.99 ± 0.62m-3 in 2005 (high SIC), and 2.38 ± 1.11m-3 in 2014 (very low SIC). MP rise
between 2005 and 2014 might be linked to a global increase in plastic pollution or to lower SIC in 2014, if MPs
are released to the water column once sea-ice melts. All chick meals contained plastic filaments, with 9.99 and
8.99 pieces per meal in 2005 and 2014 respectively. Importantly, little auks ate more light colored MPs than
darker ones, strongly suggesting an active contamination with birds mistaking MPs for their prey. Overall, we
stress the great vulnerability of Arctic marine ecosystems to MP pollution in a warming Arctic, where sea-ice
melting could release high amounts of trapped debris.

2363
2659
Microplastic Contamination in Sea Ice from the Arctic Ocean

La Daana Kanhai1 (ladaana.kanhai@research.gmit.ie), Katarina Gardfeldt2, Richard Thompson3, Ian O'Connor1

1
Galway Mayo Institute of Technology, Marine and Freshwater Research Centre (MFRC), Galway, Ireland,
2
Chalmers University of Technology, Department of Chemistry and Chemical Engineering, Gotenburg, Sweden,
3
Plymouth University, Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences,
Plymouth, United Kingdom

Sea ice in polar oceans has been identified as a potential sink for microplastics. In the context of a changing
climate, these sea ice sinks can possibly function as microplastic sources when the ice melts. Assessments
regarding microplastics in sea ice are particularly important as they provide an understanding of the
microplastics that polar organisms may be exposed to in the future. The present study, investigated the
abundance, distribution and composition of microplastics in sea ice and water beneath ice in the Arctic Central
Basin. During the Arctic Ocean 2016 expedition onboard Swedish icebreaker Oden, there were twenty-five
stations at which sea ice cores were retrieved and water pumped from beneath the ice was filtered. Cores were
sectioned, melted and filtered. Potential microplastics from samples are in the process of being isolated and
analyzed using Fourier Transform Infrared Spectroscopy (FT-IR).

2364
1860
Microplastics in the Surface Ocean of the Canadian Arctic Archipelago

Kirstie Jones-Williams1,2 (kirnes79@bas.ac.uk), Victoria Peck1, Tamara Galloway2, Matthew Cole3, Clara Manno1
1
British Antarctic Survey, Cambridge, United Kingdom, 2Exeter University, Exeter, United Kingdom, 3Plymouth
Marine Laboratory, Plymouth, United Kingdom

The Arctic is already one of the most environmentally stressed regions in the world owing to the rate of ocean
warming, acidification and sea ice melt. This makes the Arctic marine ecosystem particularly vulnerable to the
additional threat posed by plastic pollution. Approximately 12.7 million tonnes of plastic litter enter the
World's oceans each year. Whilst data on the spatial and temporal spread of plastics in the Canadian Arctic
Archipelago is limited, recent studies have shown plastics present in surface waters at both a visible and
microscopic scale. Microplastics (< 5mm) have been shown to be bioavailable and entering the ecosystem by
ingestion from small zooplankton. On CCGS Amundsen Expedition 2017 Leg 2B, surface waters were
opportunistically sampled to collect microplastics from seven stations using a HydroBios Neuston net (300 µm
aperture mesh) within Baffin Bay and the Canadian Archipelago. This study aims to provide insight into the
concentration of plastics and properties of different polymer types in the region. Secondly, based upon counts
of amphipods versus microplastics found in each sample, we will present a ratio of zooplankton: microplastics,
providing environmental context for microplastics occurrence. These findings come at a time of vital
importance for developing a baseline for monitoring the extent of plastic pollution in the Arctic.

2365
2422
The 'Mother-ships' of Microplastics on Sub-Antarctic beaches

Juliana Assunção Ivar do Sul1,2 (juliana.ivardosul@io-warnemuende.de), Renata Portis1

1
Federal University of Rio Grande, Rio Grande, Brazil, 2Leibniz Institute for Baltic Sea Research Warnemünde
(IOW), Rostock, Germany

Beaches in King George and Elephant Islands, South Shetland Islands, were opportunistically sampled for
macroplastics (>0.5 cm) during expeditions from the Brazilian Antarctic Program in 2014 (OPERANTAR XXXII,
Project Penguins & Skuas) and 2016 (OPERANTAR XXXV, Project INTERBIOTA). 608 items were counted,
measured and analysed in relation to the type of material, degradation and biofouling. Ordinary plastics (PET,
PP; 60%), expanded polystyrene (27%) and rubber (11%) were mostly sampled. All are synthetic materials that
slowly break down and accumulate in the environment. 73 items were whole objects measuring 32±101 cm
and included PET bottles and packaging, but also nautical ropes and buoys. Few are labelled indicating their
origins; others accumulated organisms in their surfaces, suggesting long-rage transport in the sea. However,
88% were fragments from larger objects, measuring 5±8 cm. Polystyrene pieces were recurrent on beaches, as
also observed in other sub-Antarctic islands. Potential sources are nautical buoys and protective packaging
from electronic equipment. On beaches, these fragments will eventually become microplastics (< 5 mm) with
rounded shapes, small enough to be ingested by organisms in marine food chains. As source identification is
one of the major challenges on microplastic pollution research, the positive recognition of their 'mother-ships'
allow the implementation of effective measures to minimize microplastic releases into the Antarctic
environment.

2366
710
Microplastic Pollution in the Southern Ocean

Catherine Waller1 (c.l.waller@hull.ac.uk), Huw Griffiths2, Claire Waluda2, Sally Thorpe2, Iván Loaiza3, Bernabé
Moreno3, Cesar Pacherres3, Kevin Hughes2
1
University of Hull, SES, Hull, United Kingdom, 2British Antarctic Survey, Cambridge, United Kingdom,
3
Científicadel Sur University, Carrerade Biología Marina, Vila el Salvador, Peru

It is estimated that there are up to 5 trillion pieces of plastic in the oceans (Erikssen et al., 2014). Microplastic
pollution (particles < 5mm) is recognised as a major problem in the world ocean, with much of it accumulating
in oceanic gyres (Cozar et al., 2014). Antarctica is generally thought of as a pristine and isolated wilderness, free
of most of the anthropogenic stressors found in populated regions of the world. However, recent studies in the
Southern Ocean have reported microplastics in deep-sea sediments (Van Cauwenberg et al., 2013) and surface
waters (Cincinelli et al., 2017). We present our predictions of microplastic contamination in the Southern
Ocean, based on quantifiable data from research stations, cruise ships and fishing effort. Our findings suggest
that at an Ocean basin level concentrations should be insignificant, but that at point sources the contamination
may be high. We report the detection of the first microplastics in shallow benthic sediments close to a number
of research stations on King George Island. Worryingly, our predictions of primary microplastic concentrations
from local sources are five orders of magnitude lower than levels reported in published sampling surveys, some
of which were comparable to levels found in highly populated areas of the world (Erikssen et al., 2014;
Adventurescience, 2016). We speculate that plastic contamination originating outside the Southern Ocean is
crossing the Polar Front and contributing to the problem.

2367
91
Plastic Pollution Around Antarctica: Preliminary Results from the ACE Expedition

Giuseppe Suaria1 (giuseppe.suaria@sp.ismar.cnr.it), Jasmine Lee2, Vonica Perold3, Tommy Bornman4, Stefano
Aliani1, Peter Ryan3
1
CNR-ISMAR, Institute of Marine Sciences - Italian Research Council, Lerici, Italy, 2University of Queensland,
Centre for Biodiversity Conservation Science, St Lucia, Australia, 3University of Cape Town, Percy FitzPatrick
Institute of African Ornithology, Rondebosch, South Africa, 4South African Environmental Observation Network,
Elwandle Coastal Node, Port Elizabeth, South Africa

The Antarctic Circumnavigation Expedition (ACE) sampled micro, meso and macroplastic litter around
Antarctica from December 2016 to March 2017. No mesoplastic items were found in plankton samples
collected with a 200 µm Neuston net and only 22 macrolitter items were observed floating south of the
Subtropical Front in almost 15,000 km of transect counts, confirming that the Southern Ocean is the ocean
least polluted by plastics globally. Nevertheless, anthropogenic debris was found in two seabed Agassiz trawls
and macroplastic items were recovered from most beach landings, though quantity varied with location. Small
numbers of fibers were found in beach sediments from Antarctic and sub-Antarctic sites and synthetic
microfibres were detected in virtually all bulk water samples collected around Antarctica. Surprisingly, there
was no marked gradient in these fibres as we approached continental source areas. Confirmation of the
identity of these fibres is still pending, but if they prove to be synthetic, they suggest that all the world's surface
waters apparently carry low concentrations of microfibre pollutants, at a density of ~0.1-1 fibres per litre.

2368
OS-5a - The role of snow on sea ice for sea-ice parameter retrieval and variability
23.06.2018 09:00-10:30, B Jakobshorn

781
Towards Producing a Daily Snow-on-Sea Ice Data Set

Julienne Stroeve1 (j.stroeve@ucl.ac.uk), Glen Liston2, Andrew Barrett3

1
University College London, Earth Sciences, London, United Kingdom, 2Glen.Liston@colostate.edu, Cooperative
Institute for Research in the Atmosphere, Fort Coling, United States, 3University of Colorado, National Snow and
Ice Data Center, Boulder, United States

Estimates of ice thickness across the Arctic Ocean have become available over the past 20 years based on data
from ERS-1/2, Envisat, ICESat, CryoSat-2 satellites and Operation IceBridge aircraft campaigns. However, the
different measurement approaches, sensor technologies and spatial coverage present formidable challenges in
producing a comprehensive view of long-term sea ice thickness changes. Key among these is that measurement
techniques do not measure ice thickness directly - retrievals also require snow depth and density.
A sophisticated snow accumulation model is tested in a Lagrangian framework to map daily snow depths across
the Arctic sea ice cover using different atmospheric reanalysis data as input. Accuracy of the snow
accumulation is assessed through comparison with Operation IceBridge data and ice mass balance buoys
(IMBs).

2369
1850
Assessing Precipitation and Snow Accumulation in the Arctic and Southern Oceans

Linette Boisvert1 (linette.n.boisvert@nasa.gov), Melinda Webster1, Alek Petty1, Thorsten Markus1

1
NASA Goddard Space Flight Center, Greenbelt, United States

Precipitation over the Arctic and Southern Oceans is a key component of the ocean fresh water budget, while
the magnitude of snow accumulation over sea ice controls the strength of the snows insulative properties.
However, precipitation from reanalysis over the polar regions show large uncertainties in both frequency and
magnitude, due to the lack of in situ data for validation in these regions and differing model schemes
representing cloud physics. Introducing problems for those modeling snow accumulation on sea ice, specifically
for use in estimating sea ice thickness from laser altimetry data.
In recent years, the Arctic has become warmer and wetter, which leads to the questions: Is more precipitation
falling and more of this as rain in the Arctic, is more precipitation or rainfall also occurring in the Antarctic?
What are the implications of more frequent rainfall on modeling snow depth on sea ice? For example, rain
events will modify the existing snow pack by causing large changes in the insulating properties and surface
albedo.
In this work we compare precipitation from 8 different reanalysis: MERRA, MERRA2, NCEP-R1, NCEP-R2, ERA-
Interim, CFSR, ASR and JRA-55 over the Arctic and Southern Oceans. We assess the annual, seasonal, and
regional differences and compare results with Ice Mass Balance Buoy data to explore sources of discrepancies
between products during observed snowfall and rainfall events in the Arctic and Southern Oceans.

2370
2668
A New Snow on Sea Ice Budget Model and Snow Depth Dataset over the Polar Oceans

Alek Petty1,2 (alek.a.petty@nasa.gov), Melinda Webster1, Linette Boisvert1,2, Thorsten Markus1

1
NASA Goddard Space Flight Center, Greenbelt, United States, 2University of Maryland, ESSIC, College Park,
United States

Poor knowledge of snow on sea ice over the polar oceans provides a key source of uncertainty in our
understanding of freshwater budgets and the estimation of sea ice thickness from satellite altimetry. Here we
present a new, open-source, two-layer Eulerian snow budget model developed to improve the representation
of snow on sea ice across both poles. The model includes several parameterizations to represent various
sources and sinks of snow on sea ice through the accumulation season (September through April), e.g. wind
compaction and blowing snow lost to leads. The model is forced with daily reanalysis-derived snowfall and
winds, and satellite-derived ice concentration and drifts. We explore the sensitivity of the modelled snow
depths to the input forcing data and model parameters, and compare the results with observations where
possible (e.g. field data from 1979-1991, 1997-1998, buoy data from 2000-present and NASA´s Operation
IceBridge data from 2009 to present). We demonstrate the utility of the new snow depth product (available
daily) to produce updated sea ice thickness estimates from ESA´s CryoSat-2 mission (2008 onwards) and look
ahead to the upcoming launch of ICESat-2 (summer 2018). It is our hope that the open source framework will
encourage community involvement in possible improvements and additions to the model physics (e.g. rain-on-
snow, snow ice formation, snow melt processes), especially as new forcing/validation datasets are made
available.

2371
260
A Dynamic Snow Load Model for Satellite Altimeter Sea Ice Thickness Retrievals

Rachel Tilling1 (r.tilling@leeds.ac.uk), Andy Ridout2, Isobel Lawrence2, Michel Tsamados2, Sammie Buzzard2,
Julienne Stroeve2, Andrew Shepherd1
1
University of Leeds, Leeds, United Kingdom, 2University College London, London, United Kingdom

Satellite radar altimeter data are now widely used to produce estimates of sea ice thickness across the Arctic
Ocean. However, these estimates rely to varying degrees on the use of a snow climatology in the conversion of
sea ice freeboard to thickness. The application of a climatological snow load is currently the largest source of
uncertainty in the ice thickness estimates that we produce at the UK Centre for Polar Observation and
Modelling (CPOM) from CryoSat-2 data. To reduce this uncertainty, we have developed a dynamic snow load
for application with our sea ice processor that enables us to account for inter-annual and spatial variations in
the snow cover. The dynamic snow load model is initialised using precipitation and evaporation data from
reanalysis, and developed with a dependence on sea ice concentration, drift, and atmospheric temperature.
The When applied to CryoSat-2 sea ice observations, the dynamic snow load results in a decrease in ice
thickness compared with climatological estimates by up to 70 cm in regions of seasonal ice cover such as Baffin
Bay and the Siberian Shelf Seas. This demonstrates the ability of CryoSat-2 to measure ice thickness over
thinner (< 0.5 m) ice regimes than previously thought. Here we summarise the development of our dynamic
snow load, and evaluate using in situ campaign data. We then assess its impact on spatial and inter-annual
variations in Arctic-wide sea ice thickness and volume estimates compared with a snow climatology.

2372
76
The Role of Snow Distribution on the Antarctic Sea Ice Mass and Energy Balance

Nander Wever1 (nwever@gmail.com), Katherine Leonard2,3,4, Ted Maksym5, Kevin Manning6, Jordan Powers6,
Seth White4, Jan Lenaerts1
1
University of Colorado, Department of Atmospheric and Oceanic Sciences (ATOC), Boulder, United States,
2
École Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering,
Lausanne, Switzerland, 3WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland,
4
University of Colorado, Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, United
States, 5Woods Hole Oceanographic Institution (WHOI), Woods Hole, United States, 6National Center for
Atmospheric Research (NCAR), Mesoscale and Microscale Meteorology (MMM) Laboratory, Boulder, United
States

Snow on sea ice is increasingly recognized as a key component of the sea ice system. The snow cover
substantially impacts the mass and energy balance of sea ice, but exhibits high variability in space and time. As
in-situ measurements are scarce and many remote sensing products show large uncertainties, the use of
physics-based snow and sea ice models is attractive. Here, we present spatially explicit simulations of the
snow-sea ice system using the recently developed sea ice module for the physics based SNOWPACK model for
three floes of different age, that were visited in July and August 2013 in the Weddell Sea. Terrestrial laser scans
of the snow surface, combined with highly spatially resolved ice thickness and snow depth measurements, are
used to initialize the model. The simulations are then forced by meteorological observations provided by
weather station buoys left on the ice, augmented by AMPS Polar WRF reanalysis data. The resulting simulated
sea ice energy and mass balance is verified by Ice Mass Balance (IMB) buoys installed on the floes. Results show
that the snowpack provides a strong control on the energy and mass balance and that taking into account the
snow cover distribution enables an accurate simulation of the total sea ice mass balance. Simulated ice growth
rates correspond well with the IMB buoy data. These results illustrate that physics based models of the snow-
sea ice system provide accurate assessments of the spatial and temporal evolution of sea ice.

2373
397
Satellite Remote Sensing of Large-scale Arctic Sea Ice Thickness and Snow Depth

Lu Zhou1 (zhou-l15@mails.tsinghua.edu.cn), Shiming Xu1, Jiping Liu2

1
Tsinghua University, Beijing, China, 2State University of New York at Albany, Albany, United States

Large-scale retrieval is carried out for sea ice thickness (Hi) and snow depth over sea ice (Hs), based on
concurrent radar altimetry of CryoSat-2 satellite and L-band (1.4 GHz) passive radiometry based on SMOS
satellite. Two physical models, the L-band radiation model for the sea ice cover, and the hydrostatic
relationship based on buoyancy model, are adopted. Verification for the retrieval is carried out with CryoVEx
airborne data, which co-registers with CryoSat-2 tracks. Results also show reduced uncertainties for both Hi
and Hs. Especially, the uncertainty involving the climatological snow loading and the potential lack of efficacy
for radar altimetry in current era is addressed, with much lower and spatially uncorrelated uncertainty and
better estimation of ice volume. The retrieved large-scale Hi and Hs fields provide new perspective for
investigating Arctic climate change.

2374
CR-8e - Latest highlights from high altitude and polar ice cores
23.06.2018 09:00-10:30, C Sanada I

2442
Basal Ice Properties in Two-million-Year-old Allan Hills Cores

Yuzhen Yan1 (yuzheny@princeton.edu), John Higgins1, James Menking2, Aron Buffen2, Ed Brook2, Heather
Clifford3, Andrei Kurbatov3, Paul Mayewski3, Jessica Ng4, Jeffrey Severinghaus4, Michael Bender1
1
Princeton University, Princeton, NJ, United States, 2Oregon State University, Corvallis, OR, United States,
3
University of Maine, Orono, ME, United States, 4University of California San Diego, La Jolla, CA, United States

Currently the longest continuous ice core record, capped at 800 thousand years (kyr) old, comes from the
EPICA Dome C. Concerted efforts in the ice core community are underway to find and retrieve stratigraphically
continuous deep ice cores older than 800
 kyr. A complimentary approach to deep coring is shallow drilling in
Blue Ice Areas (BIAs), where ancient ice is brought to the surface by a combination of glacial flow and subglacial
topography. Discontinuous ice as old as two million years has been found in two adjacent drill holes in the Allan
Hills BIA. Here we report the elemental and isotopic composition of the trapped gases (N2, O2, Ar, and CO2),
along with high-resolution stable water isotopes, in > 2 million year old basal ice from the two cores. Our data
indicate that the ice is deformed and that mixing takes place at sub-meter length scales. In addition, although
much of the ice older than 800 kyr appears to contain pristine greenhouse gases, the oldest basal ice contains
both elevated CH4 and CO2 as high as 1200 ppm. High CO2 samples are associated with depleted (< -10 ‰) δ13C
of CO2, consistent with contributions from the respiration of organic carbon (δ13C ~-25‰). Alternative
approaches for determining paleo-atmospheric CO2 (e.g. Δ17O of O2) will be discussed.

2375
789
Is there 1.5 Million-year Old Ice Near Dome C, Antarctica?

Frédéric Parrenin1 (frederic.parrenin@univ-grenoble-alpes.fr), Marie G. P. Cavitte2,3, Donald D. Blankenship2,

Jérôme Chappellaz1, Hubertus Fischer4, Olivier Gagliardini1, Valérie Masson-Delmotte5, Olivier Passalacqua1,
Catherine Ritz1, Jason Roberts6,7, Martin J. Siegert8, Duncan A. Young2
1
CNRS/IRD/UGA, Institut des Géosciences de l'Environnement, St Martin d'Hères, France, 2University of Texas at
Austin, Jackson School of Geosciences, Institute for Geophysics, Austin, United States, 3University of Texas at
Austin, Jackson School of Geosciences, Department of Geological Sciences, Austin, United States, 4University of
Bern, Physics Institute & Oeschger Centre for Climate Change Research, Climate and Environmental Physics,
Bern, Switzerland, 5CEA-CNRS-UVSQ/IPSL, Laboratoire des Sciences du Climat et de l'Environnement, Gif-sur-
Yvette, France, 6Australian Antarctic Division, Kingston, Australia, 7University of Tasmania, Antarctic Climate &
Ecosystems Cooperative Research Centre, Hobart, Australia, 8mperial College London, Grantham Institute and
Department of Earth Science and Engineering, London, United Kingdom

Ice sheets provide exceptional archives of past changes in polar climate, regional environment and global
atmospheric composition. The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA
Dome C (EDC), reaching ~800,000 years. Obtaining an older paleoclimatic record from Antarctica is one of the
greatest challenges of the ice core community. Here, we use internal isochrones, identified from airborne radar
coupled to ice-flow modelling to estimate the age of basal ice along transects in the Dome C area. Three
glaciological properties are inferred from isochrones: surface accumulation rate; geothermal flux; and the
exponent of the Lliboutry velocity profile. We find that old ice (>1.5 Myr, 1.5 million years) likely exists in two
regions: one ~40km south-west of Dome C along the ice divide to Vostok, close to a secondary dome that we
name “Little Dome C” (LDC); and a second region named “North Patch” (NP) located 10-30 km north-east of
Dome C, in a region where the geothermal flux is apparently relatively low. Our work demonstrates the value
of combining radar observations with ice flow modelling to accurately represent the true nature of ice flow,
and understand the formation of ice-sheet architecture, in the centre of large ice sheets.

2376
1672
An Essay to Reconstruct MIS-11 Climate from 4 Water Isotopologues in Vostok Ice

Alexey Ekaykin1,2 (ekaykin@aari.ru), Arina Veres1,2, Anna Kozachek1, Vladimir Lipenkov1, Aleksandra Skakun1,
Diana Vladimirova1,2
1
Arctic and Antarctic Research Institute, Saint Petersburg, Russian Federation, 2Saint Petersburg State
University, Institute of Earth Sciences, Saint Petersburg, Russian Federation

A strong limitation of the stable water isotope method to reconstruct past temperature changes is related to
the fact that the isotopic composition of a polar ice core depends both on local conditions and conditions in the
moisture source. There have been attempts to use a second-order parameter, dxs = dD - 8*d18O, in parallel to
the isotopic composition itself (dD or d18O), in order to discriminate between both factors. It has been shown
that the results strongly depend on the sensitivity of dxs to the condensation temperature, which is poorly
known. Recently a new parameter, 17O-excess = ln(d17O)-0.528*ln(d18O), has been developed, that was
initially thought to depend only on the air humidity in the moisture source. However it was soon demonstrated
that the variability of 17O-excess in deep Antarctic ice cores would imply unrealistically strong humidity
oscillations in the past, which means that other factors (primarily, local conditions during condensation in ice
clouds) play a role, too. Here we present a new, detailed isotopic record for the MIS-11 epoch (370-440 ka BP)
reconstructed from the Vostok ice core, and for the first time attempt a climatic paleo-reconstruction based on
3 independent parameters (dD, dxs and 17O-excess). Our results (including the past variability of air humidity
in the moisture source) are consistent with the published data, and demonstrate that this approach has the
potential to improve the ice core-based paleo-reconstructions.

2377
1285
Temperature and Circulation Changes in the Ross Sea over the Last 1000 Years

Anais Orsi1, Barbara Stenni2 (barbara.stenni@unive.it), Amaelle Landais1, Martin Werner3, Nancy Bertler4,5
1
LSCE (UMR 8212 CEA-CNRS-UVSQ/IPSL), Université Paris Saclay, Gif Sur Yvette, France, 2Ca' Foscari University
of Venice, Department of Environmental Sciences, Informatics and Statistics, Venice, Italy, 3Alfred Wegener
Institute for Polar and Marine Research, Bremerhaven, Germany, 4Victoria University of Wellington, Antarctic
Research Centre, Wellington, New Zealand, 5GNS Science, Lower Hutt, New Zealand

The Antarctic has an unusual climate history compared to other continents for the past 2000 years : unlike
other regions, the last 50 years are not unusually warm, and the period around 1850 is not unusually cold. All
of Antarctic 2000-year climate records are derived from water isotopes from ice cores. Could it be that water
isotopes are not a faithful temperature recorder, or is it that Antarctica has a distinct climate variability over
this time period?
Here we compare a temperature reconstruction derived from the analysis of inert gas isotopes
(δ15N and δ40Ar) with water isotopes to provide multiple constraints on the climate history of the past 1000
years at Talos Dome, Antarctica. Talos Dome is a peripheral dome located in the South Pacific/Ross Sea sector
of the East Antarctic Plateau. It receives air masses mainly from the Indian and secondarily from Pacific sectors
of the Southern Ocean. As a result, its climate presents similarities both to West Antarctica and to the East
Antarctic plateau sites of Dome C and Vostok.
We find that inert gas isotopes indicate a long term cooling trend at the site, which is not recorded in the δD
signal. We use the climate model ECHAM5-wiso to link the d-excess to change in the atmospheric circulation
over the Ross Sea, which can explain the discrepancy between δD and temperature. These results provide new
constraints on the changes in the circulation associated with the Little Ice Age cooling in West Antarctica.

2378
888
Characterisation of AIM Events in the Ross Sea Region from the RICE Ice Core

Abhijith Ulayottil Venugopal1 (abhijith.uv@vuw.ac.nz), Nancy Bertler1, James Lee2, Giuseppe Cortese3, Rebecca
Pyne3
1
Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand, 2Oregon State
University, Corvallis, United States, 3GNS Science - Institute of Geological and Nuclear Sciences Ltd., Wellington,
New Zealand

The last glacial in Antarctica is punctuated by several episodes of warm events, when air temperature rose
between 1-3°C, which are referred to as 'Antarctic Isotope Maxima' (AIM) events.The comparison of Antarctica
and Greenland ice core records shows an out of phase relationship between AIM events and their northern
counterparts- Dansgaard/Oeschger events, referred to as the 'Bipolar Seesaw'. Possible explanations include
oceanic teleconnections via a shift in strength of the Atlantic Meridional Overturning Circulation and Antarctic
Bottom Water formation.
Roosevelt Island is a local ice rise at the northern edge of the Ross Ice Shelf. A 764m deep Roosevelt Island
Climate Evolution (RICE) ice core was obtained between 2011-2013. Due to its proximity to Ross Sea, the RICE
records have the potential to provide new insights into the drivers and consequences during the evolution of
AIM events.
Here, we present the highly resolved major ion record of the RICE core spanning the time period between
83,000 to 25,000 years B.P., presented on the RICE17 age scale.The major ion record, including sodium, methyl
sulphonic acid, and calcium provide useful indicators of past environmental conditions such as changes in sea
ice extent, primary productivity and latitudinal shifts in circumpolar westerlies.The record will also be
correlated with existing Antarctic ice cores to gain insights into the regional heterogeneity in the environmental
conditions during the evolution of AIM events.

2379
444
Sequences of Events over Terminations II and III in the Dome C Ice Core

Thomas Extier1 (thomas.extier@lsce.ipsl.fr), Camille Bréant1, Lucie Bazin1, Frédéric Prié1, Anaïs Orsi1, Patricia
Martinerie2, Barbara Stenni3, Jean Jouzel1, Valérie Masson-Delmotte1, Markus Leuenberger4, Didier Roche1,5,
Amaelle Landais1
1
LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France, 2Université Grenoble-Alpes, CNRS,
IRD, IGE, UMR 5001, Grenoble, France, 3University Ca' Foscari of Venice, Department of Environmental Sciences,
Informatics and Statistics, Venice, Italy, 4University of Bern, Climate and Environmental Physics, Physics Institute
and Oeschger Center for Climate Research, Bern, Switzerland, 5Vrije Universiteit Amsterdam, Earth and Climate
Cluster, Faculty of Earth and Life Sciences, Amsterdam, Netherlands

Glacial-interglacial transitions are recorded in various climatic archives over the Quaternary. The EPICA Dome C
(EDC) ice core provides high latitude climate reconstructions based on water isotopes as well as global proxy
records such as greenhouse gases concentrations, and low latitudes tracers δ18Oatm
(i.e. δ18O of atmospheric O2) or d-excess over the last 800 ka. These high-resolution records illustrate the
variety of glacial-interglacial transitions observed under different orbital and sea level contexts.
We present here new detailed measurements of δ18Oatm, δ15N and d-excess on the EDC ice core over
Terminations II and III. First, we analyze the millennial variability superimposed to the orbital signal in the
different isotopic records, and describe the different sequences of events for these two deglaciations.
Termination III is associated with several millennial-scale events while Termination II is depicted by only one
major Heinrich event. Second, we compare our new high-resolution δ18Oatm profile to East Asian δ18Ocalcite,
which presents similar orbital and millennial variations related to the monsoon activity or shifts in the
InterTropical Convergence Zone position to propose an improved way of using δ18Oatm to constrain ice core
chronologies. Finally, we present such an application refining the ice core dating of MIS5.

2380
OS-7g - Atmosphere-Ice-Ocean interactions in the Polar Regions
23.06.2018 09:00-10:30, C Sanada II

70
Role of Polar Anticyclones for Arctic Sea Ice Melting in Summer

Heini Wernli1 (heini.wernli@env.ethz.ch), Lukas Papritz2,3

1
ETH Zurich, Zürich, Switzerland, 2University of Bergen, Geophysical Institute, Bergen, Norway, 3Bjerknes Centre
for Climate Research, Bergen, Norway

Annual minima in Arctic sea ice extent and volume are decreasing rapidly since the late 1970ies, with
substantial interannual variability. It was shown that summers with a particularly strong reduction of Arctic sea
ice extent are characterized by anticyclonic flow anomalies from the surface to the upper troposphere. Here
we adopt a weather-system perspective to investigate the origin of these seasonal circulation anomalies and
show that they are caused by an increased occurrence of episodic upper-level induced Arctic anticyclones. Sea
ice reduction is systematically enhanced during these transient episodes with Arctic anticyclones and the
seasonal reduction of sea ice volume correlates with the area averaged frequency of Arctic anticyclones
poleward of 70°N (correlation coefficient of 0.57). A trajectory analysis reveals that these anticyclones result
from extratropical cyclones injecting extratropical air masses with low potential vorticity into the Arctic upper
troposphere. Our results emphasize the fundamental role of extratropical cyclones and associated diabatic
processes in establishing Arctic anticyclones and in turn seasonal circulation anomalies, which are of key
importance for understanding the variability of summertime Arctic sea ice melting.

2381
476
Airmass Transport and Dynamical Drivers of an Extreme Arctic Winter Warm Event

Hanin Binder1,2 (binder@lmd.ens.fr), Maxi Boettcher2, Christian M. Grams2,3, Hanna Joos2, Stephan Pfahl2, Heini
Wernli2
1
Laboratoire de Météorologie Dynamique/IPSL, École Normale Supérieure, Paris, France, 2Institute for
Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland, 3Institute of Meteorology and Climate
Research (IMK-TRO), Karlsruhe Institute of Technology, Karlsruhe, Germany

During a one-week episode at the turn of the years 2015/2016, maximum surface air temperature in the Arctic
reached record high values of more than 0°C, which led to pronounced, widespread sea-ice melting in the
middle of the cold season. In this study, we adopt a Lagrangian perspective to investigate the origin of the
warm air masses and the meteorological processes that allowed them to reach the North Pole. We show that
(i) the extreme event resulted from a complex chain of extraordinary dynamical and physical processes, (ii)
three fundamentally different airstreams contributed to the high Arctic temperatures, of which two airstreams
were initially extremely cold and located either in the Arctic lower troposphere and subsequently heated by
intense surface fluxes, or in the midlatitude upper troposphere and subsequently heated by adiabatic
compression, (iii) the poleward transport of these warm airstreams occurred along an exceptionally intense
low-level jet that established between a sequence of Icelandic lows and a strong Scandinavian anticyclone, and
(iv) the setup and persistence of this dipolar pattern was supported by continuous warm conveyor belt ascent
into the upper part of the anticyclone. The findings emphasise the combined role of multiple transport
processes and transient synoptic-scale dynamics for establishing an extreme Arctic heat and melt event.

2382
1601
Turbulent Fluxes Near an Advancing Sea-ice Edge

Ola Persson1 (ola.persson@colorado.edu), Christopher Fairall2, Byron Blomquist1, Andrey Grachev1

1
University of Colorado/CIRES/NOAA/ESRL/PSD, Boulder, United States, 2NOAA/Earth System Research
Laboratory/PSD, Boulder, United States

In the marginal ice zone (MIZ), it is expected that the turbulent fluxes of momentum and sensible heat are
dependent on a number of surface characteristics and processes that impact the surface roughness and the
stability in the atmospheric surface layer. These include ice concentration, ice thickness, ice freeboard, floe
sizes, and ocean wave characteristics (height and period). The range of length scales over which these
parameters vary in the MIZ is large. The relationship between some of these characteristics and the turbulent
fluxes are represented by recent bulk flux parameterization schemes (e.g., Andreas et al, 2010; Lüpkes et al
2012; Lüpkes and Gryanik 2015). During the Sea State field program in the Beaufort and Chukchi Seas from Oct
3 to Nov 5, 2015, direct covariance and inertial dissipation measurements of the turbulent fluxes were made
from the bow of the icebreaker R/V Siquliak, while many of the surface characteristics were also measured
from various platforms on board. Hence, this data set provides a good opportunity to explore the relationships
between surface characteristics and the turbulent fluxes in the advancing marginal ice zone.
This presentation will show the complex surface environment encountered during Sea State, and demonstrate
the extent to which existing bulk flux parameterizations can represent the directly measured turbulent fluxes of
sensible heat and momentum in this environment.

2383
81
Cold air Outbreaks in the Nordic Seas: Climatology and Link to Large-scale Flow

Lukas Papritz1,2 (lukas.papritz@uib.no), Thomas Spengler1,2, Christian M. Grams3,4

1
Geophysical Institute, University of Bergen, Bergen, Norway, 2Bjerknes Centre for Climate Research, Bergen,
Norway, 3Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland, 4Institute for
Meteorology and Climate Research (IMK-TRO), Karlsruhe Institute of Technology, Karlsruhe, Germany

Marine cold air outbreaks (CAOs) at high latitudes are harbingers of severe weather such as polar lows and
they lead to intense air-sea heat fluxes. We first present a 35-year long Lagrangian climatology of wintertime
CAO air masses in the Nordic Seas including the Irminger and the Barents Seas. Based on this climatology we
study
(1) the origin and pathways of CAO airmasses,
(2) their thermodynamic evolution, and
(3) their contribution to winter mean air-sea heat fluxes.
Specifically, we show that CAOs in the Nordic Seas originate largely in the interior Arctic, entering the Nordic
Seas via Fram Strait. In addition, also flows across southern Greenland and katabatic drainage contribute. As we
show further, the spatio-temporal variability of CAO air masses is essentially dictated by the frequency of CAOs.
Second, we investigate the linkage of CAO formation with the low-frequency variability of the large-scale flow
using a weather regime classification. We show that each regime is characterised by a typical CAO frequency
anomaly pattern and a corresponding imprint in CAO airmass pathways and air-sea heat fluxes. Thereby, the
strength and location of the storm tracks in each regime are found to be decisive for the pathways of CAO air
masses and, thus, for CAO occurrence. The mechanistic linkage between CAOs and weather regimes may help
to better understand variability in open ocean convections, as well as forecasting the occurrence of polar lows.

2384
585
Formation of Convergence Zones in Cold Air Outbreaks

Shun-Ichi Watanabe1 (watanabe-s@aori.u-tokyo.ac.jp), Hiroshi Niino1, Thomas Spengler2

1
Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan, 2University of Bergen, Bergen,
Norway

During cold air outbreaks, low-level atmospheric convergence zones often emerge over relatively warmer seas
downstream of coastlines, sea ice edges, and mountains. We investigate the formation mechanism of such
convergence zones using idealized numerical experiments and analytic theory. In the numerical experiments, a
cold air outbreak is simulated in a simplified setup including a coastline and a mountain, where the former has
a kink. The numerical simulations show that varying the angle of the kink in the coastline as well as changing
the height of the mountain, or removing it, cause a difference in the fetch (traveling distance over sea) of the
cold airmass. A warm wedge is formed due to the difference of the fetch, because the longer fetch causes more
warming by the sensible heat flux. Hydrostatically, this results in a low pressure trough, which induces a
pressure gradient force towards the warmest area. The turbulent momentum transport in the convectively
mixed layer is important for the formation of the convergence zone, because it enhances frictional
convergence into the pressure trough. The moisture enhances the convergence by intensifying vertical motion
due to diabatic heating. We also present an analytic model for the setup with the kink in the coastline using the
basic state flow and the bulk formula for the surface sensible heat flux. The theoretical estimates of the
pressure trough and convergence agree well with the results of the numerical experiments.

2385
1001
Influence of Surface Fluxes on Polar Low Development: Idealised Simulations

Annick Terpstra1,2 (annick.terpstra@uib.no), Thomas Spengler2

1
University of East Anglia, Norwich, United Kingdom, 2Geophysical Institute, University of Bergen and Bjerknes
Centre for Climate Research, Bergen, Norway

Excursions of cold air masses from the ice-covered high-latitude area into oceanic regions are frequently
accompanied by the development of intense mesoscale cyclones. This particular ocean-atmosphere
configuration exhibits favorable conditions for relative large surface turbulence exchange of momentum,
moisture, and heat. In this study, we examine the impact of this air-sea-exchange on the development of polar
lows.
We utilise an idealised numerical channel model to gain insight into the role of surface heat and moisture
fluxes on the dynamical evolution of polar lows. The initial setup consists of a baroclinic jet in thermal wind
balance. To mimic cold air outbreaks we prescribe sea surface temperatures that are higher than the low-level
air temperature. This setup enables a systematic investigation of the relative contributions from surface
sensible and latent heat fluxes on polar low development by varying the intensity of the initial baroclinicity,
moisture, and air-sea temperature difference. In addition we investigate the relative role of sensible and latent
heat fluxes by gradually changing the intensity of surface exchange in a set of sensitivity experiments.
Identification of moisture sources and sinks further illustrates the role of surface heat and moisture exchange
on the intensification of polar lows.

2386
BE-9h - Life distribution and responses to environmental changes in Polar ecosystems
23.06.2018 11:00-12:30, C Aspen

1382
Habitat Suitability and Conservation of McMurdo Dry Valley Soil Biodiversity

E. Ashley Shaw1 (elizabeth.shaw@colostate.edu), Jasmine R. Lee2, Aleks Terauds3, Diana H. Wall1

1
Colorado State University, Department of Biology, Fort Collins, United States, 2University of Queensland, Centre
for Biodiversity and Conservation Science, Brisbane, Australia, 3Australian Antarctic Division, Kingston, Australia

Antarctica's McMurdo Dry Valleys (MDV) are the continent's largest ice-free area, containing soil biodiversity
that has not been considered in conservation planning. This biodiversity consists of soil-inhabiting microbes,
nematodes, rotifers, tardigrades, springtails and mites. While specific habitat requirements vary by species,
abiotic factors (e.g., water and carbon availability, temperature, and soil geochemistry) are known to drive
distributions. Yet, soils are highly heterogeneous and these abiotic factors vary greatly landscape-wide.
Furthermore, climate-driven changes in lake and stream hydrology are already occurring, producing immediate
impacts on surrounding soil environment and communities. Given their vulnerability to such changes, including
soils and dependant biodiversity in conservation planning is critical.
We obtained an Antarctic Science International Bursary to undertake a collaborative project to examine the
drivers of soil biota in the MDV and build habitat suitability models to predict current and future distributions.
Soil biodiversity and chemistry data were gathered from the MDV Long Term Ecological Research Project (US
NSF) and compiled into a spatially explicit dataset. With this dataset, we modelled habitat suitability by taxon,
confirming that environmental drivers of species distributions vary. We used the models to spatially predict
species distributions and then combined them to identify sites of conservation priority across the MDV.

2387
2037
Soil Changes in 10 Years of Environmental Change in Victoria Land (Antarctica)

Nicoletta Cannone1 (nicoletta.cannone@uninsubria.it), Mauro Guglielmin2, Dirk Wagner3

1
Università degli Studi dell'Insubria, Scienc eand High Technology, Como, Italy, 2Università degli Studi
dell'Insubria, Varese, Italy, 3GFZ German Research Centre for Geosciences, Potsdam, Germany

In Victoria Land, continental Antarctica, across a latitudinal gradient between Apostrophe Island (73°) and
Finger Point (77°S) in the period 2002-2013 were detected significant environmental changes involving climate,
active layer thickness, vegetation abundance and composition and soil chemistry. In particular, despite air
temperature did not change, there was an increase of incoming radiation and active layer thickness. In
response to these environmental change, soils exhibited a large decrease of water content (more pronounced
at deeper depths), and a general pH increase associated to an increase of conductivity (more pronounced in
ornithogenic soils). Opposite trends were observed for most inorganic compounds comparing ornithogenic and
not-ornithogenic soils. The changes in soil chemistry reflect concomitant changes in climate and active layer
and vegetation cover, with a decrease of mosses and a concomitant increase of lichens in most sites. These
changes may be due to soil evolution processes or to different dynamics of the active layer. The observed
changes in soil chemistry did not appear to be strictly related to the aeolian dust deposition or to the Southern
Oscillation Index.

2388
418
Polar Soil Fungi in a Changing Climate

Marta Misiak1,2 (marak34@bas.ac.uk), Lynne Boddy2, Peter Convey1, Will Goodall-Copestake1, Kevin K
Newsham1
1
British Antarctic Survey, Cambridge, United Kingdom, 2Cardiff University, Cardiff School of Biosciences, Cardiff,
United Kingdom

Climate change in polar regions has negatively affected top predator species such as the polar bear and has
caused the expansion of higher plant communities, but the effects of altered temperature and water
availability on microbes at the bases of polar food webs, such as the fungi, which drive vital ecosystem
processes, have largely been ignored. Here, 16 fungi, including the widespread Pseudogymnoascus pannorum,
were isolated from soil collected from the Arctic and Antarctic and screened for the production of enzymes.
The effects of altered water availability and temperature on the growth and enzyme activities of the isolates
were then measured in laboratory experiments. All 16 isolates produced cellulase, chitinase, phosphatases and
esterase. The data obtained from the growth rate experiments suggested that increased temperature and
reduced water availability have differing effects on the growth and enzyme production of the fungal species
tested.

2389
2111
Penguins as Drivers of Microbial Diversity in Maritime Antarctic Soils

Mafalda Baptista1,2 (mafaldasbaptista@gmail.com), Maria Monteiro2, Charles Lee2, Catarina Magalhães1, Craig
Cary2
1
University of Porto, Interdisciplinary Centre of Marine and Environmental Research, Porto, Portugal, 2University
of Waikato, International Centre for Terrestrial Antarctic Research, Hamilton, New Zealand

Penguin activity affects microbial communities in Antarctica soils. Previous studies have shown distinct
microbial communities in penguin-colonized ornithogenic soils, in relic ornithogenic soils, and in mineral soils.
At Cape Adare, northern Victoria Land, we conducted a survey across Ridley beach (the site of the largest
Adélie penguin rookery in Antarctica) to test the hypothesis that within a penguin colony distinct patterns of
microbial communities could be seen. Analysis of prokaryotic community composition were based on
sequencing of 16S rRNA gene PCR amplicons, and analysis of soil geochemistry were based on ammonium,
phosphate, C and N content, electrical conductivity (EC), and pH in a total of 26 sites. The highest
concentrations of phosphate, EC, C, and N were seen at the beach´s central sites, radially decreasing towards
the Adare Peninsula and the ocean. These parameters were strongly positively correlated and were significant
environmental drivers of community composition. Ordination of the sampling sites showed they could be
separated into two groups: those for which the most abundant OTU had a relative abundance higher than 20%
and the ones for which it was lower. Up to six different OTUs were present at a given site with an abundance
>20%, highlighting a high level of plasticity in a geographically confined place with homogeneous soil
geochemistry, and suggesting a differentiating penguin influence across the sites of a rookery.

2390
120
Long-term Ecological Research on King George Island, Antarctica

Hong Kum Lee1 (hklee@kopri.re.kr), Seok Cheol Kim2, Chang Uk Hyun1, Hyun-Ju No1, Marc Oliva3, Ji Hee Kim1,
Kyu Song Lee2, Hyun-Cheol Kim1, Ok-Sun Kim1, Sang Hee Kim1, Hyoungseok Lee1, Soon Gyu Hong1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Gangneung-Wonju National University,
Gangneung, Korea, Republic of, 3Universidade de Lisboa, Lisbon, Portugal

Baton Peninsula, King George Island (KGI) is the focus of a Korean-lead study on the effects of environmental
changes on the terrestrial ecosystem since 2009. It harbors diverse organisms and micro-ecosystems including
representative local ecosystems: wet coastal environments with diverse mosses and lichens; dry inland
environments with only a few lichen species; and patterned ground with exposed mineral soil and limited
vegetation on rocks. In 2015, a vegetation base map was developed for Barton Peninsula using satellite images,
UAV images, and field surveys. As well as diversity of microorganisms and invertebrates, our long-term
monitoring includes microclimate, light intensity, soil temperature and moisture. Different micro-environments
act on different genotypes of the same lichen species. While water availability is the most important factor for
all organisms, photosynthetic lichens and mosses are also affected by snow cover due to its protection from
sunlight and light availability. Lake sediment core records of during last 3,000 years revealed the variation of
abundant fungi, microalgae and invertebrate depending on the depth. It implies KGI in the Antarctic Peninsula
is one of the most vulnerable ecosystems in a changing climate. As a hotspot of ANTOS and LAPES, the map and
database of KGI long-term monitoring as well as biological responses in molecular level will allow a
comprehensive understanding of ecosystem in space and time in environmental changes.

2391
1901
Survivors or Colonizers? Case Study of the Freshwater Copepod Boeckella poppei

Claudia Maturana1, Jennifer Jackson2, Peter Convey2, Elie Poulin1 (epoulin@uchile.cl)

1
Institute of Ecology and Biodiversity, University of Chile, Santiago, Chile, 2British Antarctic Survey, Natural
Environment Research Council, Cambridge, United Kingdom

The Quaternary brought numerous cycles of ice sheet extension and contraction across the Antarctic continent,
resulting in major disruption of terrestrial habitats and the extinction of diverse taxa. Currently there are two
main hypotheses to explain the present-day occurrence of freshwater biota in Antarctica
(1) recent colonization from lower latitudes during inter-glacial periods;
(2) persistence in refugia within Antarctica.
The genus Boeckella has a Gondwanan distribution, and B. poppei is unique as the only terrestrial or freshwater
invertebrate that occurs in all three of the generally recognized Antarctic biogeographic regions. We describe
population structuring and divergence times across the maritime Antarctic, sub-Antarctic South Georgia and
Patagonia. We used a combination of molecular approaches targeting one mitochondrial fast-evolving (cox1)
and two nuclear slow-evolving markers (28S and ITS), and traditional morphological taxonomy. Our data clearly
support the refugial hypothesis, with two independent regional recolonization events from putative refugia in
the southern Antarctic Peninsula and the South Orkney Islands. Molecular phylogenetic reconstruction showed
two distinct clades,
(1) Patagonian and
(2) Antarctica, separating 3 Mya.
Within Antarctica two haplogroups were present,
(1) sub-Antarctic + southern Antarctic Peninsula and
(2) northern Antarctic Peninsula, separating 1 Mya.

2392
EN-6b - Reconstructing past environmental change in the Polar Regions
23.06.2018 11:00-12:30, A Studio

189
Miniature Old-growth Moss Forests as Proxies for Microclimates in Antarctica

Melinda Waterman1 (melindaw@uow.edu.au), Ayako Egawa1, Jessica Bramley-Alves1, Angélica Casanova-

Katny2, Gustavo Zuniga3, Quan Hua4, Sharon Robinson1
1
University of Wollongong, School of Biological Sciences, Wollongong, Australia, 2Catholic University of Temuco,
Program in Environmental Studies (NEA), Temuco, Chile, 3Universidad de Santiago de Chile, Laboratorio de
Fisiología y Biotecnología Vegetal, Santiago, Chile, 4Australian Nuclear Science and Technology Organisation,
Institute for Environmental Research, Lucas Heights, Australia

Terrestrial flora of Antarctica's frozen continent is dominated by bryophytes (mosses, liverworts) restricted to
the limited ice-free areas. These plants constantly battle against sub-zero temperatures, extreme winds,
reduced water availability and high levels of damaging ultraviolet radiation due to reduced stratospheric ozone;
all impacting the ability of Antarctic species to survive and grow. Thus, it is imperative that we monitor
Antarctic flora in response to changes in climate, in particular to ozone depletion. Furthermore, there is a
substantial need for regional climate proxies given the sparse distribution, limitations and short record of
Antarctic meteorological stations. As resilient plants with simple structures, mosses are suitable candidates for
proxy development as they can preserve long-term records of their immediate microclimate in their chemical
signatures; for example, sunscreen compounds preserved in their cell walls. We aim to develop and use
Antarctic mosses as biological proxies for climate around the Antarctic coast. This includes analysing sunscreens
and stable isotopes of a range of Continental and Maritime mosses that have been dated using the radiocarbon
bomb-pulse method. Long-term regional climate records, such as moss water availability and ozone levels,
could be locked away as chemical signatures within old-growth moss shoots of up to 420 years old.

2393
208
The Circumpolar Shrub Cassiope tetragona: an Archive of High Arctic Climate

Stef Weijers1 (weijers@uni-bonn.de)

1
University of Bonn, Department of Geogrpahy, Bonn, Germany

High Arctic instrumental meteorological data are often discontinuous and represent only a few decades, which
limits interpolation and upscaling of climatic data in this part of the Arctic and reconstructions based on reliable
climate proxies are needed to fill in observational gaps.
Annual growth of the evergreen circumpolar dwarf shrub species Cassiope tetragona represents such a climate
proxy. Annual shoot length growth of this species can be accurately measured through the presence of so-
called wintermarksepta (WMS), dark bands of meristem tissue in the white pith that demarcate the end of a
growing season. WMS-distances offer an alternative to ring widths in the High Arctic, where trees and tall
shrubs are absent. The growth chronologies developed for this long-lived (>150 years) species are the longest
developed for the High Arctic so far. Intact subfossil specimens have been found, and small stem fragments
found in soil cores may offer the possibility for longer-term reconstructions.
Annual growth of C. tetragona was found to be strongly limited by growing season temperatures at many High
Arctic sites in experimental warming and dendroecological studies. Annual growth parameters of the species
thus form a reliable proxy for past temperatures. Several examples of studies on C. tetragona as climate proxy
will be presented, including from High Arctic sites such as the world's northernmost polar desert in North
Greenland and sites in Svalbard.

2394
1150
The Siberian Margin in the Context of Holocene Sea Level Rise and Climate

Henning A. Bauch1 (hbauch@geomar.de)

1
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, c/o GEOMAR, Kiel, Germany

After the Holocene sea-level highstand some 5-6 ka ago, a time of sedimentary stabilization commenced on the
Siberian shelves. Drastic decreases in sedimentation rates in the Laptev Sea occurred at water depths >30
meters whereas in the inner shelf region deposition continued due to input from rivers and coastal erosion.
Compared with that latter process, the Lena Delta should comprise a region of sediment catchment where
aggradation wins over erosion. However, little is known about the detailed history of this delta during the
second half of the Holocene. To gain more insight into this issue several islands within the Lena Delta were
studied. All of these are comprised of massive peat of several meters in thickness. Using discrete specimens of
water mosses, detailed radiocarbon-based chronologies of these peat sections were established. These show
that the islands' history above the present-day delta sea level is c. 4000 yrs. old. Moreover, a major change in
peat growth occurred after 2500 yrs BP in both, accumulation and species composition. Because these changes
also correlate well in time with major shifts in ocean circulation and sea ice drift patterns elsewhere the
environmental developments at the Siberian margin reflect the overall climate development witnessed around
the Arctic during the late Holocene.

2395
1481
The Potential for Using Arctic Carbonate Microfossils as Paleo-pH Proxies

Emily Osborne1 (emily.osborne@noaa.gov), Thomas Cronin2, Laura Gemery2, Catherine Davis3, Jeremy Mathis1,
Robert Thunell3
1
National Oceanographic and Atmospheric Administration, Oceanic and Atmospheric Research/Arctic Research
Program, Silver Spring, United States, 2United States Geological Survey, Eastern Geology and Paleoclimate
Science Center, Reston, United States, 3University of South Carolina, School of the Earth, Ocean, and
Environment, Columbia, United States

Modern ocean time-series indicate the Arctic Ocean is experiencing ocean acidification at an accelerated rate,
and it is expected to experience the largest net decline in seawater pH globally during the coming century.
Modern pH observations are especially limited in the Arctic Ocean, highlighting the importance of paleo-pH
reconstructions from sediment records. Recent developments in boron-based paleo-pH proxies provide
opportunities to reconstruct past carbonate chemistry of seawater but have yet to be applied to the Arctic
sedimentary record. This work evaluates the pH proxy potential of boron to calcium (B/Ca) ratios in Arctic
foraminifera and ostracodes preserved in Pacific Arctic surface sediments. B/Ca results are compared to in situ
bottom water pH and saturation state (Ω) to develop modern species-specific calibrations that can be applied
to paleo-pH reconstructions. The calibration sample set includes nearly 80 sediment core-tops distributed
along a latitudinal gradient (62°N to 73°N) in the Bering and Chukchi Seas. The sampling locations represent a
range of bottom water temperature (-1.5 to 4.9 °C) and pH (7.7 to 8.1) conditions, ideal for calibrating relations
between various oceanographic parameters and shell chemistry. Results include trace element data for
multiple species of benthic foraminifera (Elphidium incertum and Nonion labradorica) and ostracodes
(Sarsicytheridea bradii and Krithe spp.) that are broadly distributed across the Arctic environment.

2396
1862
Seafloor Methane Seepage at NW Svalbard Since the Last Glacial Maximum

Andrea Schneider1 (andrea.schneider@uit.no), Giuliana Panieri1, Aivo Lepland2, Chiara Consolaro3, Antoine
Crémière2, Matthias Forwick1, Joel E. Johnson4, Andreia A. Plaza-Faverola1, Simone Sauer5, Jochen Knies2
1
UiT The Arctic University of Norway, Tromsø, Norway, 2Geological Survey of Norway, Trondheim, Norway,
3
Plymouth University, Plymouth, United Kingdom, 4University of New Hampshire, New Hampshire, United
States, 5Ifremer, Plouzané, France

The amplification of global warming in the Arctic raises concern about the role of methane, a powerful
greenhouse gas. A large amount of methane is present in continental margin sediments worldwide that may be
released into the water column and atmosphere during future climate warming. Therefore, it is important to
evaluate the character, timing, and triggers of past seafloor methane seepage to better understand future
seepage dynamics.
Vestnesa Ridge, located at 79°N in 1200 m water depth offshore NW Svalbard, is one of the northernmost
known active methane seep sites and is characterised by a subseafloor fluid flow system, numerous seafloor
pockmarks, and gas flares in the water column.
Our study applies multiple proxies in the geological record to reconstruct past methane seepage variability on
Vestnesa Ridge:
i) geochemical data from diagenetically altered fossil foraminiferal tests,
ii) mineralogical and stable isotope composition of methane-derived authigenic carbonate, and
iii) sediment geochemistry of multiple sediment cores.
We observe several seepage events that coincide with the Last Glacial Maximum extent of the Svalbard Barents
Sea Ice Sheet, with the Heinrich Event 1 (ca. 18.5 cal ka BP), and multiple events in the early Holocene.
Geological evidences for enhanced methane flux and seafloor methane seepage imply that glacio-isostatic
adjustments during ice sheet advance and retreat may have triggered methane seepage at Vestnesa Ridge.

2397
1184
Paleodynamics in Thaw Lakes: Accumulation of Aquatic vs Permafrost Carbon

Josefine Lenz1,2 (josefine.lenz@awi.de), Katey M. Walter Anthony2, Christopher V. Maio3, Guido Grosse1,4
1
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Periglacial Research Section,
Potsdam, Germany, 2University of Alaska - Fairbanks, Water and Environmental Research Center, Fairbanks,
United States, 3University of Alaska - Fairbanks, Department of Geosciences, Fairbanks, United States,
4
University of Potsdam, Institute of Earth and Environmental Science, Potsdam, Germany

Permafrost deposits preserve organic matter which is decomposed and potentially released as greenhouse
gases (CO2 and CH4) during thermokarst processes and in particular thaw lake development. Younger near-
surface and older organic matter from slumping and expanding lake shores are deposited in the lake basin and
contribute to the lacustrine carbon cycle. Bioproductivity within the lakes complements carbon accumulation in
lacustrine deposits and provides an additional source of young carbon and greenhouse gases.
A set of lake sediment cores from Goldstream Valley in the discontinuous permafrost zone of Interior Alaska
was studied for their origin of organic matter during the Holocene. With the aim to distinguish the provenance
(terrestrial or aquatic) of carbon contributions to sediments over time, core samples were analyzed for their
total organic carbon/total nitrogen ratio (C/N) as well as stable carbon isotopes.
The case study of Goldstream Valley Lake located in yedoma permafrost, indicates a dominance of aquatic
plant material in the littoral zone with a mean C/N ratio as low as 8.7. Although a similar signal is found for
sediments in the lake's central basin, a clear shift to a terrestrial carbon signal (C/N of 22) is presumably
indicating the trash layer of the initial lake phase. Further, ongoing organic matter decomposition in talik
sediments proves to be crucial to assess the contribution of thaw lakes to future climate change by mobilizing
Pleistocene soil carbon.

2398
BE-12b - Functional ecology of polar microbial communities in a changing world
23.06.2018 11:00-12:30, A Forum

257
High Alpine Lake Ecosystems in a Post-glacial Era

Julia Kleinteich1 (julia.kleinteich@ifg.uni-tuebingen.de), Ana Lucia1, Sven Seidensticker1, Kurt Hanselmann2,

Andreas Kappler1, Elif Koeksoy1, Kartrin Wunsch1, Maria-De-Lourdes Prieto-Espinoza1, Leonard Kurtz1, Florian
Möllmann1, Christiane Zarfl1
1
University of Tuebingen, Center for Applied Geosciences, Tübingen, Germany, 2ETH Zurich, Microbial Ecology,
Zürich, Switzerland

The increased melt of ice in areas of retreating glaciers in High Mountain and polar environments creates new
ecosystems and changes existing ones. Particles and attached compounds such as nutrients are released from
the glacier and enter the fluvial system including glacier-fed lakes, which become impacted in their physical and
chemical habitat properties. The disappearance of glaciers may fundamentally change these systems with
unknown consequences on organismic diversity, nutrient cycling and resilience towards further changes. To
understand the importance of glaciers for alpine lake ecosystems, we compared glacier-fed and permafrost-
influenced lakes at three locations in the Swiss Alps in two field campaigns in 2016 / 2017. We analyzed
microbial diversity as well as physical and chemical properties in lakes and in glacier forefields. Glacier-fed lakes
had a higher turbidity, suspended sediment concentration, and conductivity than permafrost-influenced lakes.
In contrast, nutrients (nitrate and phosphate) did not differ between the two. Microbial mats were found in
both lake types, but microbial community compositions differed markedly. In glacier-fed streams they were
similar to each other independent of the source glacier. In contrast, permafrost lakes showed high variability in
microbial community compositions. Future work aims to better understand changes in the fluvial properties
and project responses of High Mountain aquatic ecosystems in a possible post-glacial era.

2399
258
Geochemical and Microbiological Co-succession in an Arctic Glacier Forefield

Robin Wojcik1 (robin.wojcik@gfz-potsdam.de), Beat Frey2, Johanna Donhauser2, Anja Schleicher3, Liane G.
Benning1,4
1
GFZ German Research Centre for Geosciences, Interface Geochemistry, Potsdam, Germany, 2WSL Institute for
Snow and Avalanche Research SLF, Forest Soils and Biogeochemistry Rhizosphere Processes, Birmensdorf,
Switzerland, 3GFZ German Research Centre for Geosciences, Inorganic and Isotope Geochemistry, Potsdam,
Germany, 4Free Unversity of Berlin, Geochemistry, Berlin, Germany

The link between carbon cycling and weathering in recently deglaciated areas may result in important
feedbacks on global warming and biogeochemical element cycles, particularly since glaciers are predicted to
retreat at increasing rates in the future. In addition, recently deglaciated areas are unique environments to
study the initial development soils and their associated terrestrial microbial ecosystems.
In newly formed proglacial soils, the scarcity of carbon and nutrients is thought to be the dominant limiting
factor for microbial colonization and development. However, the processes controlling carbon and nutrient
cycling in such settings remain poorly understood. To address this gap, we studied the functional linkages
between soil mineralogy, weathering parameters carbon and nutrient distributions and microbial communities
along a 150 years chronosequence in the glacier forefield of Fláajökull, south-east Iceland.
Our results show a clear decrease in pH, conductivity and soil grain size along the chronosequence which is
accompanied by an increase in clay size contents. In this contribution, we will discuss the links between
changes in weathering parameters and microbial community development along the chronosequence with the
aim to better quantify the development of new soils upon glacier retreat.

2400
110
Microbial Communities and Ecological Function in Dry Valley Lakes, Antarctica

Ok-Sun Kim1 (oskim@kopri.re.kr), Miye Kwon1, Jaejin Lee1, John Priscu2, Jongik Lee1, Soon Gyu Hong1
1
Korea Polar Research Institute (KOPRI), Incheon, Korea, Republic of, 2Montana State University, Montana,
United States

Permanently ice-covered lakes in the McMurdo Dry Valleys of Antarctica are physicochemically stratified along
depth and have significant biological gradients. Despite the long-term ecological researches on these extreme
environments, there remains a paucity of studies on microbial community structure and its ecological function.
We conducted the comprehensive analysis of bacterial communities and additional biogeochemistry with
depth profiles in five ice-covered lakes. Specific assemblages were confined exclusively to a certain
environment. In Lake Bonney, 30 m depth of the East and West Lobe was dominated by two distinct Firmicutes
classes. Candidate division WM88 occurred at 15 m depth of Lake Fryxell, whereas lineages of Chlorobi are
detected only at the depth of 18 m in Lake Miers. Furthermore, Lake Fryxell was dominated by various
uncultured bacterial lineages belonging to Bacteroidetes, Actinobacteria, Planctomycetes and candidate
divisions JS1, WM88, and SAR 406. To study their ecological roles, shotgun metagenomics was carried out in all
depths sampled and here we present significant results in order to implicate the microbial ecological function
in this hypersaline ecosystem, Antarctica.

2401
1540
Arctic 'Omics: Role of Molecular Ecology in Deciphering Arctic Ecosystems

Timothy M. Vogel1 (vogel@univ-lyon1.fr), Rose Layton1, Adrien Boniface1, Benoit Bergk Pinto1, Catherine
Larose1
1
University of Lyon, Environmental Microbial Genomics, Ecully, France

Climate change is rapidly altering the arctic sea and landscape to forms and functions not previously observed
while our understanding of the importance of arctic microbial communities is just beginning. Molecular
methods (i.e. through the use of extracted DNA, RNA and proteins) are playing a critical role in deciphering the
current and changing function of these microbial communities by identifying members of the communities and
their potential and expressed functions. The heterogeneity of the microbial community structure and the
homogeneity of certain functions define an ecosystem with specific interactions that are currently being
modified under selective pressure of the changing environment. The difficulties and rewards of exploring arctic
microbial communities through molecular methods will be described with examples evaluating the role of
atmospheric microorganisms in the snow and ice, the dynamics of the snow microbial communities, and the
spatial heterogeneity of these arctic microbial communities. The functional future of these microbial
communities will have a direct impact on the role of the Arctic in global geochemical cycling and arctic
foodwebs.

2402
1733
Monitoring Climate Change: Lichens do it Well in Antarctica

Leopoldo Sancho1 (sancholg@farm.ucm.es), Ana Pintado1, Theodore Gannutz2, Steven Frishman3, Allan
Green1,4, Catherine Beard5, Ian Hogg4,6, Mercedes Vivas1, Craig Cary4
1
Universidad Complutense, Departamento de Biologia Vegetal II, Madrid, Spain, 2Private, Loysville, United
States, 3Private, Yerington, United States, 4Waikato University, Hamilton, New Zealand, 5Department of
Conservation, Hamilton, New Zealand, 6Polar Knowledge Canada, Canadian High Arctic Research Station
(CHARS), Cambridge Bay, New Zealand

Lichens grow on snow free sites throughout Antarctica from the Maritime to 85°S in the Ross Sea region, a span
of round 22 degrees latitude. Lichens show two orders of magnitude difference in growth rate from the slowest
yet known, 0.36 mm/century in the Dry Valleys (77.5°S) to around the fastest, 87 mm/century at Livingston
Island (62.4°S). As a result, lichen growth rate appears to be possibly the best biological indicator of climate in
Antarctica. Temperatures have been changing rapidly in the maritime Antarctic, increasing until 1998 and now
declining. Lichen growth has tracked these changes and results from growth measurement over 38 years shows
that they respond strongly to warming (26% increase over a 0.58° temperature rise for Usnea antarctica, 45%
per 1°C increase). However, falling temperatures cause almost catastrophic declines not just from lower growth
rates but with loss of complete thalli of some species due to snow kill. The latter follows loss in productivity
when lichens remain covered in snow for long periods. Evidence suggests that snow kill may be an important
factor forcing lichen community change throughout the continent. We also present a new data set from Cape
Hallett that spans 51 years, one of the longest in Antarctica, and which is an important intermediate site
between the two extremes. Whilst longer active periods from increasing precipitation probably drive
productivity, actual growth rate is likely to be a response to temperature.

2403
1855
Aerobiology over Antarctica

David Pearce1 (david.pearce@northumbria.ac.uk)

1
Northumbria University, Applied Sciences, Newcastle-upon-Tyne, United Kingdom

The rate of dispersal to an ecosystem can significantly influence ecosystem dynamics. Aerial transport has also
been identified as an important source of biological input to remote locations. However, the contribution of
aerial dispersal in shaping patterns of biodiversity and ecosystem function remains poorly understood, mainly
due to the lack of coordinated efforts in gathering data at appropriate temporal and spatial scales. In this study,
circum-Antarctic samples were collected during the ACE cruise, to map aerobiological diversity around
Antarctica, to identify the main input routes and sources, potential biodiversity hotspots and areas of special
concern for biological conservation. This unique sample set has enabled the investigation of Antarctic
atmospheric ecology from regional to continental scales.

2404
ME-1_ME-2b - Human Adaptation to High Altitude & Human Science from the Extreme
Poles
23.06.2018 11:00-12:30, A Schwarzhorn

119
Person-Environment Fit: Needs and Challenges in Antarctica

Cyril Jaksic1 (cyriljaksic@hotmail.com), Gary Steel1, Emma Stewart1, Kevin Moore1

1
Lincoln University, Christchurch, New Zealand

Working in an isolated and confined environment (ICE), such as the Antarctic, presents a range of challenges for
those who work there. While everyone copes differently with isolation and confinement, some key indicators
might allow identification, prior to the deployment, of those better equipped to adjust well. In the present
research, a Person-Environment fit theory, drawn from organisational psychology, has been used to investigate
the interaction between the individuals' deployed to work at various Antarctic stations and the environment's
characteristics, and how this interaction relates to measures of adjustment. The research included two studies.
The first study (n=14) used a series of self-report questionnaires to gather data from winter-overs throughout
their stay. The second study (n=59) employed a single, self-report questionnaire to record former winter-overs'
recollection of their experience. Analysis of these data revealed the important role of needs for affiliation,
intimacy and privacy, and their relationships to social adjustment within the station. Results also supported the
hypothesis that such adjustment is negatively related to winter-over syndrome and positively related to job
satisfaction. Overall, the results suggest that theoretical approaches that consider interactions between
personal characteristics and defining environmental features lead to better understanding of human
adaptation to extreme environments.

2405
1941
Expeditioner Adjustment to Antarctic Employment: Does One Size Fit All?

Clare Hawkes1, Kimberley Norris1 (kimberley.norris@utas.edu.au), Jeff Ayton2, Douglas Paton3

1
University of Tasmania, Psychology, Hobart, Australia, 2Australian Antarctic Division, Polar Medicine, Kingston,
Australia, 3Charles Darwin University, Darwin, Australia

Limited research has been conducted outside the theoretical paradigm of the third-quarter phenomenon to
examine patterns of expeditioner adjustment to Antarctic employment, and whether this is a primarily
homogeneous experience. As such, an exploratory paradigm adopting latent growth curve analysis was utilised
within the current research to determine whether such patterns could be quantitatively identified. 423
expeditioners within the Australian Antarctic Program provided data regarding mood prior to departure for
Antarctica, each month they were 'on the ice', and upon return to Australia. The findings supported the long-
standing postulated notion that the psychological adjustment in Antarctic expeditioners is primarily
homogeneous. These finding can be utilised to guide the development of a new theoretical model to help
explain the pattern of psychological adjustment in Antarctic expeditioners, as well as assist in development and
implementation of intervention and prevention programs for Antarctic expeditioners.

2406
22
Drugs in Antarctica; the Use of Expired Drugs at Extremes of Temperature

Emma Browne1 (blackrock46@yahoo.co.uk), Others TBC1

1
BASMU, Plymouth, United Kingdom

Background: Medical provisions for BAS bases are ordered on an annual basis from the UK, and transported to
the bases by non-refrigerated ship spending 1-2 months in the tropics enroute (approx 25-30C, RH 80-90%).
Due to supply chain and expiry dating, products are often approaching expiry by the time of arrival on base and
many expire prior to the following year's resupply. The lowest average temp is at Halley Station (-10°C in the
summer, down to -55°C in the extreme).
Aim: To consider the use of expired drugs in a remote environment.
Methods:
1) Two separate literature reviews to establish current evidence on A) stability of expired drugs and B) stability
of drugs stored outside recommended conditions.
2) Results of testing of stability of expired drugs returned from Antarctica by HPLC or RP-HPLC.
Five expired agents, returned from Antarctica, were analysed using stability indicating methods. These drugs
may have been exposed to sub-zero temperatures on transporting from ship to base and back, and on the
occasional periods when building temperature may drop below freezing, for example during power cuts. They
were transported by sea through the tropics twice and were 15-51 months post expiry date.
Stability indicating HPLC or RP-HPLC analysis was used for each agent.
Results: There are several studies providing evidence that many drugs are stable post expiry. Heat tends to lead
to more drug degradation than cold. All tested drugs were stable 15-51 months post expiry.

2407
982
Personality Characteristics, Perception and Copy Patterns in Extreme Environment

Denise Giuliana Ferravante1 (denise.ferravante@enea.it)

1
ENEA, Technical Antarctic Unit, Rome, Italy

This paper concerns the results of the quantitative and qualitative analysis of the interviews and tests
administered to the crews that took part, from 2004 to 2016, at the winter expeditions to Antarctica, at
Concordia Station. The winterers are multicultural groups because they include Italian and French people. They
are selected and trained by Italian and French specialists through specific psychological tests and training
methods. Particularly there will be presented the results of some psychological tests used for the aptitude
evaluation of Italian subjects who have participated in the last thirteen winter Expeditions to Antarctica and
who have remained in a confined environment for one year at Concordia Station. Also there will be presented
the results of the debriefing with the crewmembers of the last expeditions to Concordia Station. The debriefing
was made using questionnaires, tests and interviews to assess the winterer's perception of psychological
adaptation, coping strategies, feelings and mood. They were asked about what they found different from their
expectations, what they preferred and what they didn't like, the quality of the interpersonal relationship, the
existence of sub-groups, their evolution with time, the relationship with the leader and the outside
environment (research's investigators, logistic support, etc.) The objective was to identify what is useful to do
to improve future missions.

2408
1575
“Ice-tronauts:” Antarctica as a Space Exploration Analog for Team Functioning

Steven Kozlowski1 (stevekoz@msu.edu), Chu-Hsiang Chang1, Jessica Webb1, Jeffery Olenick1, Jeff Ayton2
1
Michigan State University, Psychology, East Lansing, United States, 2Australian Antarctic Division, Polar
Medicine, Kingston, Australia

The isolated, confined, and extreme (ICE) conditions that characterize polar exploration and research are
excellent analogs for studying the effects of ICE stressors that will affect individual and team psycho-social
functioning during long duration space exploration missions to the moon and Mars. This is critical because,
although team effectiveness has been studied for well over 60 years, most of the research is static. While much
is known regarding the psycho-social factors that contribute to team effectiveness (i.e., team cohesion, affect,
conflict), relatively little is known about how they vary or fluctuate over time, trends that characterize long
term changes, and factors that account for variance in psycho-social functioning. Our research, funded by
NASA, is investigating ICE team functioning in winter-over and summer scientific missions in Antarctica (in
collaboration with the Australian Antarctic Division and others), as well as in two NASA mission simulations.
Mission durations range from a matter of a few weeks to upwards of one year, depending on the analog. The
protocol across all analogs captures daily ratings on psycho-social factors which are analyzed to identify within
person and within team variability, long term trends, and factors that account for changes. The presentation
will discuss findings across these research locations, focusing on polar settings as an excellent analog for
understanding space team functioning for long duration exploration missions.

2409
1664
IMAgE: Interdisciplinary (bio)monitoring at Princess Elisabeth Station

Bjorn Baselet1, Randy Vermeesen1, Sarah Baatout1, Marjan Moreels1 (marjan.moreels@sckcen.be)

1
SCK-CEN, Radiobiology Unit, Mol, Belgium

It is beyond doubt that a stay in space affects human physiology and health. Besides increased radiation levels
and reduced gravity, health problems can be caused by other stress factors e.g. isolation and confinement and
disturbed sleep. So far, the mechanisms of human adaptation to these environments are unknown. Since the
number of space experiments is limited, ground-based platforms are useful to recreate aspects of the extreme
space environment. Within IMAgE, the impact of extreme conditions on human physiology will be investigated
at the Belgian Princess Elisabeth Station at Antarctica (PEA). The environmental part will specifically monitor
ionizing radiation doses and ozone concentrations present in- and outside PEA. In addition, immune changes,
stress-related hormones and oxidative stress will be measured in blood, saliva and urine from volunteers.
Furthermore, heart and oxygen saturation will be monitored. In parallel, a study assessing the microbiome
with/without Spirulina supplementation will be conducted. Besides experimental research, a considerable
amount of time will be devoted to dissemination and education activities. In conclusion, the IMAgE project is a
unique pilot study to perform multidisciplinary bio-monitoring. Obtained data can be compared with previous
Antarctic studies, and will bring more insight into physiological changes in humans exposed to the PEA
environment.

2410
CR-5b - Interactions between ice mass balance, the solid Earth, and sea-level changes
23.06.2018 11:00-12:30, A Seehorn

104
Antarctic Snow Accumulation over the past 200 Years

Elizabeth Thomas1 (lith@bas.ac.uk), Jan Melchior van Wessem2, Jason Roberts3, Elisabeth Isaksson4, Elisabeth
Sclosser5, TJ Fudge6, Paul Vallelonga7, Brooke Medley8, Jan Lenaerts2, Nancy Bertler9, Michiel R. van den
Broeke2, Daniel Dixon10, Massimo Frezzotti11, Barbara Stenni12, Mark Curran3, Alexey Ekaykin13
1
British Antarctic Survey, IDP, Cambridge, United Kingdom, 2Institute for Marine and Atmospheric research,
Utrecht, Netherlands, 3Australian Antarctic Division, Hobart, Australia, 4Norwegian Polar Institute, Tromso,
Norway, 5Univ. of Innsbruck, Innsbruck, Austria, 6University of Washington, Seattle, United States, 7Centre for
Ice and Climate, Copenhagen, Denmark, 8NASA Goddard Space Flight Center, Maryland, United States,
9
National Ice Core Research Laboratory, Wellington, New Caledonia, 10University of Maine, Maine, United
States, 11ENEA, Rome, Italy, 12University of Venice, Venice, Italy, 13Arctic and Antarctic Research Institute, St
Petersburg, Russian Federation

The Antarctic Ice Sheet (AIS) is the largest reservoir of fresh water on the planet, even small changes in its
volume could have significant impacts on global mean sea level. Here we present Antarctic snow accumulation
variability, at the regional scale, over the past 200 years based 79 ice core snow accumulation records. The
records were evaluated against precipitation from ERA-interim reanalysis and converted to regional surface
mass balance (SMB) by regressing onto the modelled SMB from RACMO2.3p2. Our results show that SMB for
the total Antarctic ice sheet (including ice shelves) has increased at a rate of 7 +/- 0.13 Gt dec-1 since 1800 AD,
representing a net reduction in sea level of ~ 0.02 mm dec-1 since 1800 and ~0.04 mm dec-1 since 1900 AD. The
largest contribution is from the Antarctic Peninsula, where the annual average SMB during the most recent
decade (2001-2010) is 123 +/- 44 Gt yr-1 higher than the annual average during the first decade of the 19th
century.

2411
857
Antarctic Ice Flow Line Map

Yan Liu1 (lyxixi_2003@163.com), Liyun Zhao1, John Moore1, Xiao Cheng1

1
Beijing Normal University, College of Global Change and Earth System Science, Beijing, China

We generate a complete, accurate, high-resolution, digital mosaic flow line map for the whole Antarctica by a
novel automatically tracking method based on surface ice flow velocity dataset. Multi-level and up to 10200-
neighborhood (101 by 101) search windows are used to track directions along flow lines with high precision,
and adapt to the spatial inconsistency of the original flow directions. A set of restrictions based on physical
principle of ice flow are also taken in account. The flow lines obtained are highly consistent with the ice flow
features revealed by the remote sensing images. This detailed flow line map give a clear divide of the ice sheet-
ice shelf systems of the whole Antarctica. This view of ice sheet motion redefines our understanding of spatial
distribution pattern and characteristics of Antarctic ice streams, and has far-reaching implications and
application for the reconstruction and prediction of ice sheet evolution, ice mass supply and migration.

2412
650
Mechanical Modelling of Iceberg Capsize Constrained by Seismic Inversion

Pauline Bonnet1,2,3 (pbonnet@ipgp.fr), Amandine Sergeant4, Vladislav Yastrebov5, Anne Mangeney1,2,6, Olivier
Castelnau3, Jean-Paul Montagner1, Eleonore Stutzmann1
1
Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Seismology Group, CNRS UMR 7154, Paris, France,
2
Université Paris-Diderot 7, Sorbonne Paris Cité, UFR STEP, Paris, France, 3ENSAM, CNAM, Laboratoire Procédés
et Ingénierie en Mécanique et Matériaux, CNRS, Paris, France, 4ETH Zurich, Laboratoire of Hydraulics, Hydrology
and Glaciology (VAW), Zurich, Switzerland, 5MINES ParisTech, PSL Research University, Centre des Matériaux,
CNRS UMR 7633, BP 87, Evry, France, 6Inria, LAboratoire J.-L. Lions, ANGE team, CEREMA, CNRS, Paris, France

Iceberg calving is responsible for most of the mass loss occuring at the front of marine-terminating glaciers in
Greenland. Capsizes of calved icebergs generate long-period seismic signals that are recorded by local and
global stations. The emitted seismicity contains precious informations about the source mechanisms involved
during the calving process. A versatile mechanical modelling of iceberg capsize has been developed by A.
Sergeant et al. [2016]. Inversion of seismic signals provides constraints to the model and enables calculation of
the iceberg volume and source dynamics. This model has been first tested on two particular events at the
Helheim glacier, Greenland (25 July 2013 at 03:13 UTC and 31 July 2013 at 19:31 UTC) and the results are
consistent with the iceberg volume measured separately using optical images. A difficulty of the capsize
modelling lies in accurate models used for the strongly coupled iceberg-water interaction, as the iceberg
dynamics strongly depends on the water flow initiated during the capsize. The models with and without drag
force, with and without added mass will be considered, as well as models including immobile and deformable
terminus. In this presentation, we will analyze how these different iceberg-ocean interaction models affect the
resulting seismic signals. By comparing synthetic seismograms with data, the most adequate models will be
selected.

2413
1118
What is the Viscosity of the Mantle Beneath Antarctica, and why Do we Care?

Pippa Whitehouse1 (pippa.whitehouse@durham.ac.uk), Grace Nield1, Wouter van der Wal2, Douglas Wiens3,
Andrew Lloyd3, Matt King4
1
Durham University, Durham, United Kingdom, 2Delft University of Technology, Delft, Netherlands, 3Washington
University in St Louis, St Louis, United States, 4University of Tasmania, Hobart, Australia

In traditional studies of glacial isostatic adjustment, mantle viscosity is inferred from observations of relative
sea-level change or present-day uplift that reflect the solid Earth response to past (known) changes in ice and
ocean loading. In Antarctica, we lack robust constraints on the surface loading history in many regions, and
therefore recent studies have sought to use independent evidence to constrain the viscosity beneath
Antarctica. In this presentation we review the different methods and data sets used to determine mantle
viscosities across Antarctica, and we outline the range of values that are deduced under different rheological
assumptions. Finally, we discuss the implications of the emerging viscosity distribution for past and future ice
sheet dynamics, and highlight areas that we recommend should be the focus of future research.

2414
1450
Ice Dynamic Model with Laterally Varying Relaxation Time

Wouter van der Wal1 (w.vanderwal@tudelft.nl), Dirk Oude Egbrink1, Pablo Vizcaino Rubio1, Bas de Boer2,
Roderik van de Wal2
1
Delft University of Technology, Delft, Netherlands, 2Utrecht University, Utrecht, Netherlands

The elevation of an ice sheet controls its mass balance, either through the influence on temperature or because
local sea level changes. Elevation depends on the ice thickness and the relaxation of the bedrock, which in ice
sheet models is often modelled by assuming a constant relaxation time. However, it is known that mantle
viscosity varies with location, hence also bedrock relaxation times will vary across the Earth's surface. The goal
of this study is to include variations in relaxation time in an ice sheet model and study the effect on the
equilibrium state in areas where large variations in relaxation time are expected, such as Antarctica.
We use the ANICE ice-sheet model with a bedrock relaxation module adapted to compute bedrock
deformation for a location specific relaxation time. The reference case is constant relaxation time with a value
of 3000 years. For a realistic ice dynamic simulation a 3D map of relaxation times should be used. However, we
only have estimates of viscosity that are derived from a global seismic model in combination with parameters
for olivine rheology. Relaxation time maps are obtained by varying relaxation time to obtain the same bedrock
deformation as predicted with the viscosity map in a GIA model. Results for a dynamic ice sheet based on the
relaxation time maps show that the small relaxation times in West Antarctica result in a 2.5% smaller LGM ice
sheet and 10% variation in ice volume that melted between LGM and present.

2415
2468
Reconciled Model Projections for the Antarctic Contribution to Sea Level Rise

Tamsin Edwards1 (tamsin.edwards@kcl.ac.uk), Andreas Wernecke2, Mark Brandon2, Gaël Durand3, Neil R
Edwards2, Philip B Holden2, Isabel Nias4, Antony Payne4, Catherine Ritz3
1
King's College London, Department of Geography, London, United Kingdom, 2Open University, Milton Keynes,
United Kingdom, 3CNRS, Grenoble, France, 4University of Bristol, Bristol, United Kingdom

Recent estimates for sea level rise from Antarctica in coming centuries span near-zero to several metres, with
the huge range arising largely from possible socio-economic pathways. But within any particular pathway, high
rates of mass loss are driven by the controversial marine ice cliff instability (MICI) mechanism. We find MICI is
not required to reproduce past Antarctic sea level rise (1992-2011; Last Interglacial, 130,000-115,000 years
ago; Mid-Pliocene, 3 million years ago). With MICI, Antarctica is most likely to produce 40 cm sea level rise by
2100; without, it is unlikely to exceed this. We cannot, however, firmly rule MICI out.

2416
SH-9a - Polar research in the humanities and social sciences: approaches and challenges
23.06.2018 11:00-12:30, A Wisshorn

2688
The Arctic Science Agreement Propels Science Diplomacy

Paul Arthur Berkman1 (paul.berkman@tufts.edu), Lars Kullerud2, Allen Pope3, Alexander Vylegzhanin4, Oran
Young5
1
Tufts University, Fletcher School of Law and Diplomacy, Medford, United States, 2University of the Arctic,
Arendal, Norway, 3International Arctic Science Committee, Akureyri, Iceland, 4MGIMO, Moscow, Russian
Federation, 5University of California Santa Barbara, Santa Barbara, United States

The presentation will share perspectives reported in Science magazine on 3 November 2017 (Volume 358: 596-
598). The Agreement on Enhancing International Arctic Scientific Cooperation, signed on 11 May 2017 by
foreign ministers of the eight Arctic States, including the United States and Russia, as well as Greenland and the
Faroe Islands, is a strong signal reaffirming the global relevance of science as a tool of diplomacy, reflecting a
common interest to promote scientific cooperation even when diplomatic channels among nations are
unstable. Although the Arctic States are the signatories, the "Arctic Science Agreement" emphasizes that these
States "may continue to enhance and facilitate cooperation with non-Parties with regard to Arctic science."
This holistic (international, interdisciplinary, and inclusive) science cooperation broadens the scope of the
Arctic Science Agreement beyond its defined area to address "common Arctic issues," in particular,
"sustainable development and environmental protection" as established by the Arctic Council, balancing
economic prosperity, environmental protection and societal well-being with the "best available knowledge for
decision-making." With science defined broadly as the study of change to include natural and social sciences as
well as indigenous knowledge, such science diplomacy helps to balance national interests and common
interests for the lasting benefit of all on Earth with hope and inspiration across generations.

2417
1360
Impact before Madrid: Cultures of Antarctic Environmental Protection pre-1991

Alessandro Antonello1 (aantonello@unimelb.edu.au)

1
University of Melbourne, School of Historical and Philosophical Studies, Melbourne, Australia

Environmental impact assessment is a central regulatory process in contemporary Antarctic governance as

determined by the Madrid Protocol of 1991. The centrality of the EIA process in Antarctic affairs mirrors a
broader development in which EIA has come to be the central regulatory tool in environmental policy
worldwide, since its first introduction in the United States in 1969. This paper investigates the place of ideas
and policies relating to 'environmental impact' in the Antarctic Treaty System before the signing of the Madrid
Protocol in 1991. It will look at three case studies. First, the EIA process of the United States National Science
Foundation in the McMurdo Dry Valleys in the 1970s. Secondly, the discussions about 'impact' in the CRAMRA
negotiations between 1982 and 1988. And thirdly, the rhetoric and practices of impact in the Greenpeace
World Park Base of the 1980s. Each of these cases will build into a larger picture of the contours and limits of
the idea of 'impact', especially as it related to potential or actual bureaucratic processes in that period. This
paper contributes not only to polar history, but to the broader discipline of environmental history to
understand one of the fundamental structures of modern environmental protection that has hitherto remained
under-studied.

2418
2667
Changing Ice at the Poles: Ramifications for Legal and Social Boundaries

Hayley Brazier1 (hbrazier@uoregon.edu)

1
University of Oregon, History, Eugene, United States

The problem of changing ice in the Arctic and Antarctic is central to the research of polar scientists. Yet
scientists are not the only scholars who can bring critical perspectives to polar ice. Social scientists and
humanities scholars, like environmental historians, can also contribute to the debate about ice and our
understanding of the ice-ocean interface. This paper draws on a developing field of literature to argue that ice
in the Southern and Arctic Oceans muddles the borders that legal and diplomatic institutions attempt to create.
International regulatory regimes like the United Nations Convention on the Law of the Sea and the Antarctic
Treaty have attempted to construct legal boundaries that do not necessarily acknowledge or adapt to the
complexities of the polar environments. Ice shelves, icebergs, and sea ice undermine human-imposed
boundaries when they obscure the shoreline in Antarctica, move between national jurisdictions in the North
Atlantic, or melt to reveal new borders of untapped oil resources in the Arctic. When ice changes, nations are
left to negotiate in terms of realpolitik the circumstances under which they may share oceanic resources. As
scientists continue to study changing trends of ice at the poles, the humanities and social sciences are well
positioned to determine the social and legal ramifications of such environmental change.

2419
381
Defining Values: In a Word, who we Are

Gary Steel1 (gary.steel@lincoln.ac.nz), Sira Engelbertz2

1
Lincoln University, Department of Tourism, Sport, and Society, Lincoln, New Zealand, 2University of Canterbury,
Gateway Antarctica, Christchurch, New Zealand

The concept of values has been one of significant interest to polar social scientists in the last decade, yet there
has been a puzzling lack of a clear and explicit definition of the concept in many of the publications and other
academic output from this research. In the rare instance where a definition of “value” is offered by a
researcher - explicitly or, more usually, implicitly - it can deviate markedly from those used by researchers in
other disciplines. The lack of consensus for such a critical, theoretical term hinders collaborative,
interdisciplinary work, and hampers direct comparison of research findings. This leads to a pervasive and
regrettable inefficiency in the study of this important area. This paper presents common themes and key
differences in several definitions of 'values' drawn from the general, social science literature and, where they
can be found, more specific definitions from studies of 'polar values'. The paper then proposes a working
definition as a starting point for discussion amongst polar researchers.

2420
1294
Framing Antarctica as Fragile

Hanne Nielsen1,2 (hanne.nielsen@utas.edu.au)

1
University of Tasmania / Institute for Marine and Antarctic Studies, Hobart, Australia, 2Association of Polar
Early Career Scientists, Alfred-Wegener Institute, Helmholtz Center for Polar and Marine Research, Potsdam,
Germany

Antarctica has been framed in many ways over the course of its human history: as a place for profit; a place for
heroes; the ultimate testing ground; a place of purity, or a place of transformation. In recent times Antarctica
has come to be cast as a fragile place. Although dominant in modern Western discourse, the view of Antarctica
as a place that requires protection is not inevitable. This paper examines how the idea of Antarctic “fragility”
manifests not only in a policy setting, but also the realm of cultural production. It asks how the “fragility”
theme has appeared at different times, for various audiences, and uses media and advertising to trace links
between public opinion, policy, publicity, and protection over the past century. By analysing representations of
Antarctica in the media and contextualising these temporally and nationally, it traces how popular attitudes
towards the continent have evolved over time. Gaining a comprehensive understanding of how framing of
Antarctica has shifted - from a place of danger to be conquered to a place requiring protection - also reveals
why we care about the place. Most people will never visit Antarctica, so their imagined versions of the far
south are far more vivid than the ice itself. In the context of climate change, it is more important than ever to
gain an understanding of human interactions with and conceptions of the far south. Analysis of media texts
helps illuminate the discourse behind framing Antarctica as fragile.

2421
310
New Critical Realities: Indigenous Film in the Time of Climate Change

Lisa Bloom1 (lbloom2@mindspring.com)

1
University of California, Gender and Women's Studies, Berkeley, United States

This paper draws on writing done for my book project Polar Art and the Climate Crisis: Witnessing the
Anthropocene. The book addresses polar art and film not just as an illustration of planetary demise and a call
for action. But as a challenge to our imagination. Much of this work brings into being new forms of seeing,
feeling, and sociality, that are connected to living through this kind of slow-moving disaster inflicted by
environmental and climate breakdown. How very different these emotions of precariousness are from the old
flag-planting heroism of explorations to “the ends of the earth” of an earlier epoch.
This presentation focuses on indigenous filmmakers to shift our view of the polar regions from the heroic to the
climatic, from the white, male explorer's perspective of remote wildernesses to the Inuit/Indigenous
perspective that frames the land and the people of the land as a mix of human and non-human forces. It
focuses on the experimental film, “Qapirangajuq: Inuit Knowledge and Climate Change,” (2010) by Nunavut-
based director Zacharias Kunuk and Ian Munroe, the first documentary in the Igloolik-based language that
explores how a northern indigenous community is affected by climate change from an indigenous perspective.
My analysis calls attention to how this film replaces the sublime aesthetic of the polar heroic age with an
alternative aesthetic - one that is a counter aesthetic (anti-heroic), focuses on the everyday (quotidian), and is
indigenous (Inuit).

2422
SY-1b - Earth Observation: Solutions for data collection, compilation and dissemination
23.06.2018 11:00-12:30, B Pischa

2333
Establishing a Data Stewardship Model for Arctic Observing through Collaboration

Peter L. Pulsifer1 (peter.pulsifer@colorado.edu), Marten Tacoma2, Stein Tronstad3

1
University of Colorado, National Snow and Ice Data Center, Boulder, United States, 2Royal Netherlands Institute
for Sea Research, Texel, Netherlands, 3Norwegian Polar Institute, Tromsø, Norway

In November of 2014 the International Arctic Science Committee (IASC) and the Sustaining Arctic Observing
Networks (SAON) established the Arctic Data Committee (ADC). The ADC comprises national and other
organizational members who participate in working groups on a variety of different topics including federated
search, vocabularies and semantics, eduction and others. In addition to actively engaging in working groups
that directly support practice, the ADC works to ensure a better understanding of the Arctic data system as a
whole and the policies, funding and societal drivers that underpin Arctic and polar data management and
stewardship.
Most recently, the ADC took a leadership role in bringing together more than ten active polar data programs,
initiatives and actors to focus on work planning and coordination of effort. This meeting complemented past
workshops and fora (e.g. IPY, Polar Data Forums etc.) that have been effective in defining important
community challenges and technical issues. The focus of the meeting was to generate detailed plans on how
best to mobilise existing and pending funded activities to develop a particular international data sharing case
study.
Collaboratively engaging with the diverse actors, projects and programs in the Arctic and elsewhere is the
priority of the ADC moving forward.

2423
1794
Putting Antarctica on the Map: 25 Years of the Antarctic Digital Database

Peter Fretwell1 (ptf@bas.ac.uk), Adrian Fox1

1
British Antarctic Survey, Mapping And Geographic Information Centre, Cambridge, United Kingdom

The SCAR Antarctic Digital Database is a seamless compilation of international topographic data covering
Antarctica south of 60°S. It is the primary source of map data for coastlines, rock-outcrop and contours, and
has been used extensively for cartography, science and logistics since its launch in 1993.
Over the last 25 years it has documented both the evolution of knowledge about the topography of Antarctica
and major changes in the physical landscape.
Here we summarise key changes captured in the ADD over the last quarter century, and current developments
to ensure its relevance in the digital landscape of the next decade.
The initial baseline data came from 200+ regional scale maps from 11 national mapping agencies, later
supplemented by newer vector data. Recently significant sources of new information are continent-wide,
automatically-generated datasets from remote sensing.
Delivery has changed from release on CD in 1993 to a web application which allows selection and download of
data in a range of formats and resolutions, and provides web services for other systems.
The availability of more remote sensing data has driven demand for more up-to-date information. We now
intend to provide more frequent updates to capture the dynamic nature of Antarctic topography. Including
continent-wide datasets from new sources has required updating metadata attributes, improving quality
control procedures and more automated ways to generalize the lower-resolution datasets.

2424
1720
Polar Thematic Exploitation Platform

Andrew Fleming1, Andreas Cziferszky1 (ancz@bas.ac.uk), Till Rasmussen2, Thomas Puestow3, David Arthurs4,
Alexander Boresch5, Doris Baum5, Robin Skahjem-Eriksen6, Michael Hicks7, Tom Carrieres8, Andy Jeffrey9,
Henriette Skorup10
1
British Antarctic Survey, Cambridge, United Kingdom, 2Danish Meteorological Institute, Copenhagen, Denmark,
3
C-CORE, St Johns, Canada, 4Polar View, Ottawa, Canada, 5AWST, Vienna, Austria, 6S&T, Oslo, Norway,
7
International Ice Patrol, New London, CT, United States, 8Canadian Ice Service, Ottawa, Canada, 9Satellite
Applications Catapult, Harwel, United Kingdom, 10DTU Space - National Space Institute, Copenhagen, Denmark

The volume and variety of Earth Observation (EO) data available for the polar regions is growing rapidly,
providing opportunities for more complex investigations by the polar research community. With this increase in
data and plans for new polar observing satellites, there are challenges to fully process, analyse, disseminate
and exploit these new EO data.
The European Space Agency has established the Polar Thematic Exploitation Platform (PTEP) which provides
the necessary collaborative computing environment for polar researchers. The PTEP projects address present
challenges and opportunities in scientific data exploitation by collocating data, processing capabilities and ICT
infrastructure, providing a complete cloud based work-environment.
This presentation will describe the Polar TEP concept and the range of potential uses it will support. We will
present details of the platform where users can bring their algorithms and applications directly to the data. It
will also cover the rich set of polar EO datasets, toolboxes and processing capabilities, plus functionality to
allow deployment of user defined workflows and processing environments.
We will also outline a pilot project which demonstrates the use of Polar TEP to investigate current and future
iceberg risk in Baffin Bay. The pilot project integrates a diverse set of data, processors and models, allowing
investigation of linkages between iceberg trajectories, changes in ice sheet velocity and glacier calving rates.

2425
637
Quantarctica 3: A Cross-platform, Full-featured Open GIS for Antarctic Research

Kenichi Matsuoka1 (kenichi.matsuoka@npolar.no), George Roth1, Anders Skoglund1, Stein Tronstad1, Yngve
Melvær1, Michiel R. van den Broeke2, Huw Griffiths3, Robert Headland4, Brad Herried5, Katsuro Katsumata6,
Anne Le Brocq7, Kathy Licht8, Fraser Morgan9, Peter Neff10, Jean de Pomereu4, Anton P. Van de Putte11,
Catherine Ritz12, Mirko Scheinert13, Takeshi Tamura14
1
Norwegian Polar Institute, Tromsø, Norway, 2Universiteit Utrecht, Institute for Marine and Atmospheric
Research, Utrecht, Netherlands, 3British Antarctic Survey, Cambridge, United Kingdom, 4Scott Polar Research
Institute, University of Cambridge, Cambridge, United Kingdom, 5Polar Geospatial Center, University of
Minnesota, St. Paul, United States, 6Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan,
7
University of Exeter, College of Life and Environmental Sciences, Exeter, United Kingdom, 8Indiana University
Purdue University Indianapolis, Department of Earth Sciences, Indianapolis, United States, 9Landcare Research,
Auckland, New Zealand, 10University of Rochester, Earth and Environmental Sciences, Rochester, United States,
11
Royal Belgian Institute of Natural Sciences, Brussels, Belgium, 12Université Grenoble Alpes, L'Institut des
Géosciences de l'Environnement, Grenoble, France, 13Technische Universität Dresden, Institute of Planetary
Geodesy, Dresden, Germany, 14National Institute of Polar Research, Tachikawa, Japan

Version 3 of the open GIS package “Quantarctica” was released in early 2018 (http://quantarctica.npolar.no).
This geospatial data package is built on the free, open-source, cross-platform QGIS software, is capable of
operating entirely offline, and includes a wide range of cartographic basemap layers, scientific datasets, and
satellite imagery. Version 1 Quantarctica was first released in 2013, and it became a SCAR product in 2014.
For this latest version, the Quantarctica Editorial Board selected peer-reviewed datasets for a wide range of
Antarctic users, adding over 130 new basemap and scientific data layers and widening the thematic coverage
from Glaciology and Geophysics to other themes such as Atmospheric Science, Biology, Oceanography, Social
Sciences, and more. We also expanded the project's extent and data coverage to 40°S, including sub-Antarctic
islands.
Here, we briefly revisit the development process and accomplishments of the Quantarctica project, before
showcasing Quantarctica 3's expanded and deepened data coverage, new features, and practical applications
in Antarctic research, logistics, education, and outreach. We also present our ongoing efforts and experiences
with the Antarctic science community, including workshops, data solicitation and open data sharing, and direct
engagement with Antarctic researchers in the field, in the office, and on social media.

2426
510
A MODIS and Machine Learning Based Daily air Temperature Dataset for Antarctica

Hanna Meyer1 (hanna.meyer@geo.uni-marburg.de), Marwan Katurji2, Thomas Nauß1, Pierre Roudier3, Peyman
Zawar-Reza2
1
Philipps-Universität Marburg, Geography, Marburg, Germany, 2University of Canterbury, Center for
Atmospheric Research, Christchurch, New Zealand, 3Landcare Research, Soils & Landscapes, Palmerston North,
New Zealand

Air temperature is an important baseline parameter for a range of scientific studies in Antarctica, e.g.
climatology, hydrology or ecology. Climate stations provide sub-daily measurements, however, their low spatial
density does not allow for comprehensive spatio-temporal analysis. While climate models can be used to fill
these gaps, their coarse spatial resolution only allows capturing broad scale patterns. The application of remote
sensing technology, on the other hand, provides fine resolution proxies for air temperature that make it
possible to assess small-scale dynamics. The application of remote sensing data and methods is therefore
inevitable.
This study uses time series of the MODIS Terra and Aqua sensors to estimate daily air temperature at 1 km
spatial resolution. Machine learning algorithms are used to relate MODIS as well as process specific auxiliary
predictors to measured air temperature recorded by 70 climate stations distributed over Antarctica. In this
context, new modelling strategies are applied that account for the spatio-temporal autocorrelation in the data
hence allowing for an adequate training of the model.
The resulting data set is unique as it provides daily air temperature at 1km spatial resolution for the entire
continent. The new product therefore presents a baseline for temperature pattern and trend analysis at an
adequate resolution to study both, regional and local scale climate variability.

2427
607
The GeoMAP Dataset of Antarctic Rock Exposures

Simon Christopher Cox1 (s.cox@gns.cri.nz), Belinda Smith-Lyttle1, Christine Siddoway2, Gianni Capponi3,
Synnøve Elvevold4, Alex Burton-Johnson5, Jacqueline Halpin6, Paul Morin7, David Elliot8, Geomap Action Group9
1
GNS Science, Dunedin, New Zealand, 2Colorado College, Department of Geology, Colorado Springs, United
States, 3DISTAV, Genova, Italy, 4Norwegian Polar Institute, Tromsø, Norway, 5British Antarctic Survey,
Cambridge, United Kingdom, 6University of Tasmania/Institute for Marine and Antarctic Studies, Hobart,
Australia, 7University of Minnesota, Polar Geospatial Center, Saint Paul, United States, 8Ohio State University,
Columbus, United States, 9SCAR, Cambridge, United Kingdom

The SCAR GeoMap action group has been building a detailed digital geological dataset of Antarctica. We have
been capturing existing geological map data, refining its spatial reliability, improving representation of glacial
sequences and geomorphology. The initiative is aimed towards continent-wide perspectives and for cross-
discipline use, our international team is collaboratively classifying and describing around 72,000 distinct areas
that cover 51,000 km2. The dataset will describe 'known geology' of rock exposures rather than 'interpreted'
sub-ice features. Glacial deposits are an important focus for their potential to contain records of ice
fluctuations of relevance to climate change. Here we present background on:
(1) Completion, or very near-completion, of the first version of a continent-wide dataset. All rock outcrops will
have geological attributes assigned to them in GeoSciML suitable for use at 1:250,000 (or more-regional) scale.
(2) The large number of hard-copy geological maps and data sources, which range in scale and quality.
(3) Development of local legends, which highlight geological variation across the region.
(4) Progress towards a unified classification scheme.
(5) Bibliographic links referencing authors of key original work.
(6) Potential for the dataset to provide fresh perspectives, for example, through combined geological legends
and interrogation of continent-wide time-space plots.

2428
EN-2b - Contamination in Polar and High Altitude Environments
23.06.2018 11:00-12:30, B Parsenn

2099
Arctic Sea Ice: A Transport Vehicle and Temporal Sink for Microplastic!

Ilka Peeken1 (ilka.peeken@awi.de), Sebastian Primpke2, Birte Beyer2, Julia Gütermann2, Thomas Krumpen1,
Melanie Bergmann1, Laura Hehemann1, Gunnar Gerdts2
1
Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI), Bremerhaven, Germany,
2
Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI), Helgoland, Germany

Microplastics (MP) are a problem of growing environmental concern and have been acknowledged in polar
oceans with particularly high concentrations in Arctic sea ice. Sea ice has long been recognised as a transport
vehicle for contaminants from both distant and local sources. The Fram Strait represents a major gateway for
both the inflow of warm Atlantic water with anthropogenic imprints, and the outflow of sea ice originating
from the Siberian shelves and carried south via the Transpolar Drift. The MP content and composition from sea
ice cores collected by RV Polarstern in 2014 and 2015 at five different locations along the Transpolar Drift allow
for studying the various imprints of MP pollution. Through focal plane array detector-based micro-fourier-
transform infrared imaging we recorded MP concentrations of up to 1.2 × 107 m-3. Most particles were smaller
than 50µm. Separate analyses of the various ice core horizons showed a strong shift in polymer distribution,
depending on the source area and drifting paths of the sea ice, highlighting the transport capacities of sea ice
for MP. The quantities found exceed previous reports by several orders of magnitude underlining the
importance of sea ice as a temporary sink for MP. The role of focal sources versus long-range transport of MP
particles will be discussed in the context of upcoming exploration of the Arctic Ocean due to climate change.

2429
1340
Assessment of Pollution from Two Ice Cores from Col du Dome, French Alps

Monica Arienzo1 (marienzo@dri.edu), Susanne Preunkert2, Joe McConnell1, Nathan Chellman1, Kelly Gleason1,
Michel Legrand2
1
Desert Research Institute, Reno, United States, 2Université Grenoble Alpes, CNRS, Institut des Géosciences de
l'Environnement (IGE), Grenoble, France

Ice cores extracted from high altitude glaciers have proven to be important archives of human impacts on the
free troposphere over continents. Measurements of heavy metals, sulfur, nitrate, ammonium, and black
carbon in ice cores have previously been used to quantify pollution sources including coal, oil, and mining and
to determine the relative contributions of pollutants with time.
Here we present recent results from two ice cores extracted at the Col du Dome site (4250 m above sea level)
located in the French Alps: the C10 core (126 m long) drilled in 1994 and the CDM core (140 m long) drilled in
2012. Nearly 30 trace elements and chemical species were analyzed at the Desert Research Institute via the
continuous flow analysis system allowing for sub-annual resolution of many of the pollutants of interest. Based
on the ammonium record that exhibits a well-marked seasonal cycle with a winter minima, seasonally resolved
trends of various pollutants were determined for the 1890-2000 C.E. time period. Primary Matrix Factorization
(PMF) was used to assess the apportionment of trace elements and chemical species to specific pollution
sources. The PMF results are compared to available pollution emission estimates and to other ice core records
to determine the influence of transport and deposition processes of pollutants to the Alps over the past.

2430
1803
Photochemical Reactions in Freshwater: Mountain vs. Polar Environments

Davide Vione1 (davide.vione@unito.it)

1
University of Torino, Torino, Italy

Sunlight illumination of surface waters induces photochemical reactions with transformation of naturally
occurring compounds and xenobiotics, inactivation of pathogens, and effects on biogeochemical cycles. These
reactions consist of direct photolysis of sunlight-absorbing molecules, and of indirect phototransformation. In
the latter case, sunlight is absorbed by naturally-occurring photosensitisers (e.g. chromophoric dissolved
organic matter or CDOM, nitrate and nitrite) to produce several reactive transient species that trigger
transformation reactions. The transients include, among others, the hydroxyl (·OH) and carbonate (CO3-·)
radicals, singlet oxygen (1O2) and CDOM triplet states (3CDOM*). Their occurrence in surface waters depends
on sunlight irradiance and on key water parameters such as chemistry and depth. In mountain environments,
the nature and photoreactivity of CDOM is strongly affected by the vegetation surrounding the water body
(forests, alpine meadows or bare rocks). Moreover, the duration of the ice-cover period could strongly affect
photochemistry. As we recently demonstrated, the latter phenomenon is thought to play a key role in Antarctic
lakes, also because ice protects CDOM from sunlight-induced photobleaching and ensures the occurrence of
very photoreactive CDOM in lake water soon after the ice melt. Therefore, Antarctic lakes are very efficient
photoreactors towards xenobiotics contained in the ice, which could reach lake water as the ice melts.

2431
2202
New Forensic Methods to Quantify Unseen Human Impact on Terrestrial Antarctica

Georgia Wakerley1, Charles Lee1 (charles.lee@waikato.ac.nz), Ian McDonald1, Craig Cary1

1
University of Waikato, International Centre for Terrestrial Antarctic Research, Hamilton, New Zealand

Under the Antarctic Treaty System of 1959, National Antarctic Programs and individuals have an obligation to
keep the Antarctic continent in a 'pristine' state. The current definition of 'pristine' focuses on visible physical
and chemical impacts without regard to the unseen remnants of human activities. The McMurdo Dry Valleys
(MDV) is a microorganism-dominated ecosystem, where the effects and risks of releasing DNA from human and
human-associated microbiota as part of routine activities are unknown. Using forensics-grade techniques and
newly developed ultra-sensitive methodologies based on digital PCR, human trace DNA has been detected in
field camps after habitation. We will present assessments of impact from human and human-associated
microbial genetic materials for a range of sites, from highly impacted to previously unvisited locations. We will
elucidate the relationship between the degree of detectable impact with the level of documented activities,
and these results can potentially be developed as tools to detect undocumented activities and impact across
the Antarctic continent. This research is part of the Dry Valley Ecosystem Resilience (DryVER) programme,
funded by the New Zealand Ministry of Business, Innovation and Employment, that aims to provide evidence-
based risk management of the McMurdo Dry Valleys. The data generated from these tools will be used to
produce an “impact index” to inform the review of current environmental management guidelines.

2432
213
Anthropogenic Trace Elements (Bi, Cd, Cr, Pb) Emissions in the West Antarctica

Franciele Schwanck1 (franschwanck@gmail.com), Jefferson Simoes1, Michael Handley2, Paul Mayewski2,

Ronaldo Bernardo1
1
Centro Polar e Climatico, Porto Alegre, Brazil, 2Climate Change Institute, Orono, United States

Atmospheric concentrations of trace elements are influenced by natural and anthropogenic processes. Most
anthropogenic sources (fossil fuel combustion, smelting, industry, agriculture, and large-scale land use) have
increased since the late 19th century becoming a worldwide issue for humans and the environment. Here, we
present long-term Bi, Cd, Cr, Pb records in West Antarctica during the period 1882-2015 based on ice-core
concentration analyses from Pine Island Glacier ice divide. Two Mount Johns ice cores (79°55´28" S, 94°23´18"
W, 2100 m a.s.l) were recovered in the austral summer of 2008/2009 (91.20 m depth) and 2015 (19.12 m
depth). Trace element concentrations were determined using inductively coupled plasma mass spectrometry
(CCI/UMaine). The results of enrichment factor and principal component analysis revealed that anthropogenic
activities were likely important contributors to those trace element records. We find that Bi, Cd, Cr, and Pb
emissions increased after 1884 reaching a maximum by 1900. Concentrations remained high until the late
1920s, with a temporary low during the Great Depression (1931) and again at the end of World War II (1948)
when concentrations dropped to background levels. Concentrations increased after 1960 and remained high
until the present. Concentrations during the early 21th century were lower than the peak of the 20th century
concentrations but well above background levels.

2433
2132
Mercury in the Southern Ocean: Pathway from Primary Producers to Top Predators

José Seco1,2 (jseco@ua.pt), João Pedro Coelho1, José Carlos Xavier3,4, Geraint Tarling4, Miguel Pardal5, Paco
Bustamante6, Gabriele Stowasser4, Ryan A Saunders4, Sue Gregory4, Richard A Philips4, Andrew S Brierley2,
Maria Eduarda Pereira1
1
University of Aveiro, Centre for Environmental and Marine Studies, Aveiro, Portugal, 2University of St Andrews,
Pelagic Ecology Research Group, St. Andrews, United Kingdom, 3University of Coimbra, Marine and
Environmental Sciences Centre (MARE-UC), Coimbra, Portugal, 4British Antarctic Survey, Cambridge, United
Kingdom, 5University of Coimbra, Center for Functional Ecology (CFE-UC), Coimbra, Portugal, 6Université La
Rochelle, Centre de Recherche sur les Ecosystèmes Littoraux Anthropisés, La Rochelle Cedex, France

Although Antarctica is seen as the remote and pristine continent, the levels of contaminants in the Southern
Ocean have increased significantly. Mercury is one of the pollutants that it's found in higher concentration than
expected in Antarctic waters. With this study, we aim to better understand the concentration of mercury and
its pathway along the Southern Ocean marine trophic web.
Samples were collected along several taxonomic groups from microalgae, crustacean, fish, cephalopods and
top predators, between 2015 to 2017 on the Scotia Sea, one of the most productive areas of the Southern
Ocean. Plankton and nekton were collected around South Georgia and South Orkneys. Predator samples were
collected by colleagues in the islands.
This presentation will be focused in the path that mercury since it gets absorbed in the micro algae to the levels
that it reaches in the long living top predators, using stable isotopes analyses as proxy for trophic level.
Establishing the base levels of mercury in the Southern Ocean food web is crucial to better understand how this
pollutant will may affect the Antarctic ecosystems.

2434
OS-5b - The role of snow on sea ice for sea-ice parameter retrieval and variability
23.06.2018 11:00-12:30, B Jakobshorn

2106
Snow Depth and Sea Ice Thickness in the Antarctic

Ted Maksym1 (tmaksym@whoi.edu), Ron Kwok2, Katherine Leonard3,4, Jeffrey Mei1,5, Hanumant Singh6, Ernesto
Trujillo3, Jeremy Wilkinson7, Guy Williams8
1
Woods Hole Oceanographic Institution, Woods Hole, United States, 2Jet Propulsion Laboratory, California
Institute of Technology, Pasadena, United States, 3Swiss Federal Institute for Forest Snow and Landscape
Research WSL, Lausanne, Switzerland, 4Univ of Colorado, Boulder, United States, 5Massachusetts Institute of
Technology, Cambridge, United States, 6Northeastern University, Boston, United States, 7British Antarctic
Survey, Cambridge, United Kingdom, 8University of Tasmania, Tasmania, Australia

Determining ice thickness distribution from satellites in the Antarctic is difficult in large part because of
challenges with estimating the snow depth distribution. At present, current satellite ice thickness products
cover a wide range of thickness estimates due to differences in how snow cover is treated. We present a
comparison of NASA IceBridge snow depths and surface topography with in situ measurements of three-
dimensional “layer-cakes” of surface topography, snow depth, and ice thickness for Antarctic sea ice in late
spring. First, we present a method to extend sparse radar retrievals of snow depth across sea ice floes. Next,
using relationships between snow freeboard, snow depth and ice thickness from the field data, we calculate ice
thickness for IceBridge data in the Antarctic, with an estimate of the error. These results are compared to other
methods for estimating these relationships. Consistent with prior analysis, these data suggest a significantly
thicker sea ice cover in near coastal Antarctica than has been suggested from shipboard estimates of the
broader pack.

2435
2083
Exploiting Digital Imagery for Snow Surface Retrieval on Sea Ice

Adam Steer1,2 (adam@synth3d.co), Petra Heil2,3, Jan Lieser1

1
University of Tasmania, Hobart, Australia, 2Antarctic Climate & Ecosystems Cooperative Research Centre,
Hobart, Australia, 3Australian Antarctic Division, Hobart, Australia

We show how imagery from uncalibrated airborne cameras can be used to reconstruct the snow/air interface
on Antarctic sea ice, using data collected on the SIPEX-II research voyage during austral spring 2012. Imagery
collected by an airborne surveying package was used to develop a 3D surface model using a structure-from-
motion approach. This model was validated using coincident airborne LiDAR and in situ observation of total
freeboard. Our study demonstrates that equivalent surveys may be obtained using unmanned vehicles (drones)
carrying only a camera and basic navigation equipment. Using this method, detailed floe-to-multifloe scale
models of snow topography may be derived without logistically intensive airborne surveying programs. In turn,
this allows for quick repeat surveys - simplifying the capture of a surface topography time series at any given
field research site. It also allows for highly detailed analysis of relationships between surface features and how
the evolve over time. Finally, we show how different surveying scenarios affect data quality and the ability to
easily co-register surface models with other coincident datasets. We discuss how future surveys should be
planned, which data need to be collected alongside the imagery used to generate 3D models, and where future
development should be aimed at in terms of uncertainty computations and data quality assessment.

2436
65
GPR for Rapid and Accurate Snow-thickness Measurements on Antarctic Sea Ice

Jan Lieser1,2 (jan.lieser@utas.edu.au), Andreas Pfaffhuber3, Christian Haas4,5

1
University of Tasmania, Antarctic Climate & Ecosystems CRC, Hobart, Australia, 2University of Tasmania,
Institute for Marine and Antarctic Studies, Hobart, Australia, 3NGI, Oslo, Norway, 4York University, Toronto,
Canada, 5Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany

Snow thickness on sea ice is not known on the regional scales and to the accuracy required for climate analysis
and to assess its significant role in the Earth's cryosphere mass balance. The thickness of snow on sea ice is a
largely under-sampled, but crucially important parameter when estimating sea-ice thickness from space-borne
sensors. Traditional sampling methods comprise meter-stick measurements or snow probes, which yield highly
accurate data but are sparse in space and time, whereas remote sensing data have the potential to cover large
areas but exhibit large uncertainties. To increase the local data volume and to apply as an intermediate level
for remote-sensing data validation, we present non-destructive ground-penetrating radar (GPR) snow-thickness
data of remarkable accuracy (millimetre to centimetre) when compared to in-situ data. The semi-regional data
collected during two Antarctic campaigns in late winter/early spring confirm the underestimation of snow
thickness on sea ice using remote-sensing methods by roughly 30%. The radar wave propagation was found to
be rather constant in snow (+/- 6%), supporting the applicability of GPR for regional snow thickness surveys of
snow thicker than 10cm, which was the detection limit of the off-the-shelf GPR setup used in this study.

2437
252
Vertical Snow Structures from Local to Regional Scale

Stefanie Arndt1 (stefanie.arndt@awi.de), Nicolas Stoll1,2, Stephan Paul1

1
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Sea Ice Physics, Bremerhaven,
Germany, 2University of Bremen, Institute of Geosciences, Bremen, Germany

Snow on sea ice alters the properties of the underlying ice cover as well as associated exchange processes at
the interfaces between atmosphere, sea ice and ocean. As Antarctic snow cover persists during most of the
year, it contributes significantly to the sea-ice mass budget due to comprehensive physical (seasonal) transition
processes within the snowpack. It is therefore necessary to locate and quantify internal snowmelt, snow
metamorphism, and snow-ice formation in the Antarctic snowpack on different spatial scales. Doing so, we
present here in-situ observations of physical snow properties from point measurements and transect lines
during recent expeditions in the Weddell Sea from 2013 to 2018, covering summer and winter conditions.
Analysis of snow pit measurements on both small (< 100m) and floe-size (< 2km) scales reveal significant
variations in the horizontal snowpack structure. In order to describe internal snow processes on regional scales,
we grouped the observed snow conditions, differentiating for snow conditions between eastern (seasonal sea
ice) and western Weddell Sea (perennial sea ice). While the thick perennial snowpack is highly metamorphous
with a large number of internal layers, the seasonal snowpack is less stratified. Results of the study will improve
our understanding on processes and interactions in the snowpack as well as at the snow/ice interface
associated with seasonal and inter-annual variations in the sea-ice mass budget of the Southern Ocean.

2438
1770
Comparison of Winter Field Data to Ice Thickness from ALS, ASIRAS and CryoSat-2

Anja Rösel1 (anja.rosel@npolar.no), Jennifer A. King1, Henriette Skourup2, Sine Munk Hvidegaard2, Sebastian
Gerland1, Gunnar Spreen3, Chris Polashenski4, Veit Helm5, Glen E. Liston6
1
Norwegian Polar Institute, Research Department, Tromsø, Norway, 2DTU Space - National Space Institute,
Lyngby, Denmark, 3University of Bremen, Inst. of Environmental Physics, Bremen, Germany, 4U.S. Army Cold
Regions and Engineering Laboratory, Hanover, United States, 5Alfred Wegener Institute - Helmholtz Center for
Polar and Marine Research, Bremerhaven, Germany, 6Colorado State University, Cooperative Institute for
Research in the Atmosphere (CIRA), Fort Collins, United States

Current freeboard and associated sea-ice thickness retrievals from the SIRAL radar altimeter on the CryoSat-2
satellite rely on the premise that the return signal measured is from the ice surface. However, it has been
indicated that where a thick, layered, wet, or saline snow cover is present this return may arise from
somewhere within the snowpack rather than from the snow-ice interface. We present a case study for winter
conditions in which co-located freeboard measurements from airborne laser scanner (ALS), the Airborne
Synthetic Aperture and Interferometric Radar Altimeter System (ASIRAS) and CryoSat-2 are compared to ice
thickness measurements from both helicopter-borne and ground based electromagnetic-sounding, and to
point measurements of ice and snow properties. This case study was performed in the Arctic Ocean in April
2015 in the region north of Svalbard. This study adds to a body of evidence that documents the complexity of
sea-ice freeboard retrievals from radar altimetry. It particularly highlights that radar penetration of the snow
on sea ice can be low and variable even at temperatures as low as -15°C. While this knowledge can have far-
reaching consequences for radar based sea-ice thickness and consequently total Arctic sea ice volume
estimates, we can use this information to improve altimetry processing routines, reduce uncertainty
assessments for freeboard retrievals, and thus increase the accuracy of derived ice thickness information.

2439
2642
Dual Frequency Airborne Radar Measurement for Potential Estimates of Snow Depth

Henriette Skourup1 (hsk@space.dtu.dk), Alessandro Di Bella1, Sine Munk Hvidegaard1, Nicolaj Hansen1, Arne
Vestergaard Olesen1, Alex Coccia2, Rene Forsberg1, Tânia Casal3, Malcolm Davidson3
1
Technical University of Denmark, National Space Institute, Kongens Lyngby, Denmark, 2MetaSensing,
Noordwijk, Netherlands, 3European Space Agency/ESTEC, Noordwijk, Netherlands

Snow on sea ice is difficult to measure from space. As snow introduces one of the largest uncertainties in the
error budget of the sea ice freeboard to thickness conversion, it is important to find a solution to obtain
reliable Arctic wide snow depths. The ESA CryoSat-2 validation experiment (CryoVEx) 2016 airborne fall
campaign was the first to fly combined Ka- and Ku-band radars on the same platform. Where the CryoVEx 2016
fall campaign was dedicated to the Greenland Ice Sheet a campaign in the spring 2017 was covering sea ice in
different regions representing different sea ice types. The airborne instruments are the ESA Ku-band radar
altimeter (ASIRAS), MetaSensing Ka-band radar altimeter (KAREN), together near-infrared Airborne Laser
Scanner (ALS). Even though some studies has indicated that ASIRAS reflects from the air-snow surface and do
not penetrate down to the snow-ice surface, as typically assumed by Ku-band radars in dry cold snow
conditions, the waveform turns out to be more complex, and often show dual peaked waveforms, potentially
reflecting from the air-snow and snow-ice surface. The Ka-band radar is expected to reflect from the air-snow
surface. Both radars are tied together with the ALS observations of the air-snow surface. Here we present an
analysis of waveforms from the Ka/Ku-band airborne radars in different sea ice regions, to investigate the
potential for estimating snow depths in support of future dual-frequency satellite missions.

2440
AC-6_AC-7a - Across the Southern Ocean: Atmospheric and ice mass changes & Seeing the
Future: Predicting Variability and Change of the Polar Climate and Environment
23.06.2018 11:00-12:30, C Sanada I

556
Significant Mass Loss Recorded for Bahía del Diablo Glacier, Antarctic Peninsula

Sebastián Marinsek1,2 (smarinsek@dna.gov.ar), José Luis Seco1, Evgeniy Ermolin1, Alfredo J Costa3
1
Instituto Antártico Argentino, Departamento de Glaciología, Gral. San Martín, Argentina, 2Universidad
Tecnológica Nacional, Facultad Regional Buenos Aires, C.A.B.A., Argentina, 3Instituto Antártico Argentino,
Departamento de Ciencias de la Atmósfera, Gral. San Martín, Argentina

During 2015 and 2016 austral winters a lack of precipitation was observed in the north-eastern Antarctic
Peninsula compared to previous years. This condition led to very negative mass balances in both glaciological
years for Bahía del Diablo glacier.
After 6 years of positive or near zero mass balances, -380 mm w. eq. (2016/17) and -605 mm w. eq. (2015/16)
were determined, being the latter the highest loss registered for the whole series. Annual precipitation of ~100
mm water equivalent at sea level and ~300 mm water equivalent at 650 m a.s.l. were recorded for this both
periods, which are both less than the mean for the previous 12 years of ~290 mm and ~510 mm respectively.
The mass balance for Bahía del Diablo glacier has a very high negative correlation with the mean summer air
temperature (MSAT) recorded by an automatic weather station nearby the glacier. During 2016 and 2017
summers the recorded values for MSAT were not between the warmest of the series and were not warm
enough to be the main driver for the negative mass balances. Only the lack of precipitation was the main factor
that led to the very low mass balance recorded.

2441
667
Geodetic Mass Balances from InSAR-remote Sensing for Fuego-patagonia

Philipp Malz1, David Farias1, Christian Sommer1, Roman Guliaev2, Wolfgang Meier1, Thorsten Seehaus1, Ricardo
Jana3, Gino Casassa4,5, Matthias Braun1 (matthias.h.braun@fau.de)
1
Friedrich-Alexander-Universität Erlangen-Nürnberg, Geography, Erlangen, Germany, 2Friedrich-Alexander-
Universität Erlangen-Nürnberg, Physics, Erlangen, Germany, 3Instituto Antárctico Chileno, Punta Arenas, Chile,
4
Universidad de Magallanes, Punta Arenas, Chile, 5Geoestudios, San José de Maipo, Chile

We provide an overview of the development of glaciated area in the region from 45° to 56°S in South America
over the last decade. With Cordillera Darwin, Gran Campo Nevado and the two Patagonia Ice Fields the region
includes the major ice masses of the southern hemisphere outside the large polar ice sheets. Many of its
glaciers are reported to retreat by large rates and contribute to sea level rise, however, mass balance
measurements are sparse. We provide geodetic glacier mass balance measurements using InSAR products from
the missions TanDEM-X and SRTM. Our database comprises digital elevation models from 2000 and 2011-2016
from which we derive surface elevation changes and convert results to mass changes. Our analysis provides
glacier specific changes and hence leads to a better interpretation of on-going processes evoking the observed
changes. Consistent methods also enable comparability of specific mass loss rates of the different sub-regions.

2442
843
Sediment Records of Climate Variability from the Subantarctic Auckland Islands

Greer Gilmer1 (greer.gilmer@otago.ac.nz), Christopher M. Moy1, Jonathan E. Nichols2, Imogen M. Browne3,

Lorelei Curtin4, Marcus J. Vandergoes5, Christopher H. F. Aebig1, Gary S. Wilson1
1
University of Otago, Dunedin, New Zealand, 2Lamont-Doherty Earth Observatory of Columbia University, New
York, United States, 3University of South Florida, Tampa, United States, 4Columbia University, New York, United
States, 5GNS Science, Wellington, New Zealand

The Southern Hemisphere westerly winds (SHWW) are a fundamental component of global oceanic and
atmospheric circulation, and play a primary role in regulating CO2 flux in the mid to high southern latitudes.
Situated within the core of the SHWW, and with multiple protected fjord sub-basins, deep lakes, and peatlands,
the New Zealand subantarctic Auckland Islands (50°S) are uniquely positioned for the development of high-
resolution records of ocean and atmospheric change. We will present a record of SHWW variability using fjord
sediment cores, supported by records from peatlands and lake cores, to create a multi-proxy and multi-site
reconstruction of past climate change associated with the SHWW. Modern process and paleoclimate studies
suggest that in lacustrine and fjord settings, mixing of the water column, and precipitation-driven erosion
within catchments is linked to an increase in SHWW strength over the Auckland Islands. Between 13 and 9 ka,
an overall increase in redox-sensitive elements in the fjord sediment cores and elevated n-alkane δD values
from peatlands signal a combination of reduced SHWW strength and warmer atmospheric temperatures. Since
5.5 ka, we interpret declining n-alkane δD values to indicate enhanced SHWW flow. We will discuss these
results within the context of other SHWW paleoclimate records including terrestrial records developed from
southern South America and the South Island of New Zealand in order to evaluate SHWW change across the
Pacfic basin.

2443
1253
Multi Temporal Mass Balance of the NPI (1975-2016) & Links with Regional Climate

Ines Dussaillant1,2 (ines.dussaillant@legos.obs-mip.fr), Etienne Berthier1, Mariano Masiokas3, Vincent Favier2,

Fanny Brun2
1
LEGOS/OMP, Université de Toulouse, CNES, CNRS, IRD, Toulouse, France, 2IGE, Université Grenoble Alpes,
CNRS, IRD, Grenoble, France, 3IANIGLA, CONICET, Mendoza, Argentina

The northern Patagonian Icefield (NPI) is the second largest ice mass in Patagonia (3740 km²). Several estimates
of recent volume changes confirm an acceleration of ice loss in the last decades compared to the long term loss
since the Little Ice Age. However, glacier-climate relationships are still poorly understood and the drivers of the
accelerated mass wastage are still unclear. We will compare five digital elevation models of the Northern
Patagonian Icefield (NPI) generated from the Shuttle Radar Topography Mission in 2000, SPOT5-HRS sensor for
2005 and 2012, SPOT6 and SPOT7 stereo-imagery for 2016, and earlier Chilean cartography for 1975, to assess
multi-temporal mass balance changes of the 38 largest NPI glaciers. We will then analyze the glacier volume
changes over these sub-periods together with climate trends observed from nearby stations and downscaled
regional climate models. We will also compare the observed glacier changes with recent variations in the
Antarctic Oscillation (AO) and the Pacific Decadal Oscillation (IPO), known to have an important role in
modulating climate in Patagonia. Our study will improve our understanding of the climatic causes behind the
recent glacier wastage in this region using up-to-date estimates of ice mass loss at the NPI.

2444
1330
Patagonian Surface Mass Balance Sensitivity to Regional Climatic Changes

Gabriela Collao-Barrios1 (gabriela.collao@univ-grenoble-alpes.fr), Vincent Favier1,2, Fabien Gillet-Chaulet1,2,

Hubert Gallée1,2, Xavier Fettweis3
1
Université Grenoble Alpes, IGE Institut des Géosciences de l'Environnement, Grenoble, France, 2CNRS, IGE
Institut des Géosciences de l'Environnement, Grenoble, France, 3Université de Liège, Département de
Géographie, Liège, Belgium

Patagonian icefields are the largest ice-covered regions in the Southern Hemisphere after Antarctica. They are
under the influence of the westerlies coming from the southern Pacific Ocean. Estimations of total mass
balance from different sources show the acceleration of mass losses over the last decades compared to the
mean value since the Little Ice Age. In the global climate changes context, the causes of this accelerated waste
are generally related to regional warming although there is still uncertainty in temperature and precipitation
trends in Patagonia. Indeed, in this zone, the equilibrium line altitude (ELA) is located at an altitude that
correspond to vast and flat plateaus. This characteristic makes the icefields surface mass balance (SMB)
particularly sensitive to small shifts in the ELA. Here, we estimate the Patagonian Icefields SMB using the
regional circulation model MAR forced with the Era-Interim reanalysis for the period 1979-2012. MAR is
coupled with the surface model SISVAT that includes a snow surface module. We analyze the sensitivity of the
SMB to atmospheric variables to assess the causes of glacier wastage. Particularly, we analyze the impact of
temperature and moisture changes on the final SMB.

2445
1707
The Signature of Atmospheric Circulation Patterns in Antarctic Precipitation

Gareth Marshall1 (gjma@bas.ac.uk), David Thompson2, Michiel R. van den Broeke3

1
British Antarctic Survey, Cambridge, United Kingdom, 2Colorado State University, Fort Collins, United States,
3
Institute for Marine and Atmospheric Research, Utrecht, Netherlands

We analyse the relationships between large-scale patterns of Southern Hemisphere climate variability and the
detailed spatial structure of Antarctic precipitation. Linkages between the high spatial resolution (27 km) daily
precipitation from the RACMO2 regional atmospheric model and four patterns of large-scale Southern
Hemisphere climate variability are examined: these are the southern baroclinic annular mode (BAM), the
southern annular mode (SAM), and the two Pacific-South American (PSA) teleconnection patterns. We find that
variations in all four patterns influence the spatial configuration of precipitation across Antarctica, consistent
with their signatures in high-latitude meridional moisture fluxes. They impact not only the mean but also the
incidence of extreme precipitation events. In addition, seasonal trends in some of the circulation patterns have
contributed significantly to precipitation trends in areas of the continent: for example, the SAM on the
opposing wetting and drying trends on the western and eastern sides of the Antarctic Peninsula. Although
current coupled-climate models are able to reproduce all four patterns of atmospheric variability, they often
struggle to correctly replicate their regional impacts on Antarctic climate. Thus, linking these patterns directly
to Antarctic precipitation variability may allow a better estimate of future changes in precipitation than using
model output alone.

2446
OS-7h - Atmosphere-Ice-Ocean interactions in the Polar Regions
23.06.2018 11:00-12:30, C Sanada II

983
Atmospheric Response to Marginal-ice-Zone Drag Parameterisation

Ian Renfrew1 (i.renfrew@uea.ac.uk), Andy Elvidge2,3, John Edwards3

1
University of East Anglia, School of Environmental Sciences, Norwich, United Kingdom, 2University of East
Anglia, Norwich, United Kingdom, 3Met Office, Exeter, United Kingdom

A physically-based parameterization of atmospheric surface drag over the marginal-ice-zone (MIZ) has recently
been validated and tuned based on a large set of observations of surface stress from the Barents Sea and Fram
Strait. This parameterization has now been implemented in the Met Office Unified Model (MetUM) and is
available for both weather and climate applications. Here we present model simulations of a collection of cold-
air outbreak cases in the vicinity of the MIZ from the 'ACCACIA' field campaign, and for a standard global model
test suite of cases. Our focus is on the response of the atmosphere to changes in surface drag. The new
parameterization has a significant impact on simulated boundary layer conditions; for example changing
temperatures by 2-3 K. Comparisons with aircraft observations over and downwind of the MIZ show that
simulations with the new sea-ice drag scheme generally have the lowest bias and lowest root-mean-square
errors. Notably the wind speed and temperature biases are reduced to less than 0.1 m s-1 and 0.1 K
respectively. The atmospheric response is relatively widespread - impacting most of the Arctic and Antarctic
sea-ice areas - with the largest changes in the vicinity of the MIZ and affecting the entire atmospheric boundary
layer.

2447
1736
Wind Stress Forcing in the Arctic and North Atlantic Oceans

Tamas Kovacs1,2 (tamas.kovacs@awi.de), Rüdiger Gerdes1,2

1
Alfred Wegener Institute, Bremerhaven, Germany, 2Jacobs University, Bremen, Germany

One of the key processes responsible for driving the circulation of ocean waters is the wind stress. This
important air-sea interaction stands for the imparting of atmospheric momentum to the ocean. The prevailing
wind patterns largely influence the velocity in the top Ekman layer in the ocean, sustaining the observed
system of surface currents. Given the internal variability of the wind climate, these surface currents are subject
to anomalies in space and time that can have large scale effects on oceanic processes.
This is particularly true in the Arctic and the subpolar North Atlantic oceans that play a key role in the global
ocean circulation, and are influenced by variations of wind stress forcing associated with large scale
atmospheric modes in these regions.
In this study we examine the sensitivity of surface currents, ice cover, freshwater and heat content in these
ocean basins to wind stress forcing through numerical experiments. The tool for this is the Modini-system, a
partial coupling technique that allows flexible experiments with prescribed wind stress fields for the ocean in
the otherwise fully coupled Earth System Model of the Max Planck Institute. In this work we present our results
investigating the role of wind stress forcing in shaping the distribution and exchanges of state variables in and
between the Arctic and North Atlantic oceans by comparing our model results using external wind stress
forcing with the Modini-system, and fully coupled runs.

2448
299
The Potential Impact of Polar Lows on the North Atlantic Ocean

Helene Bresson1 (h.m.e.bresson@pgr.reading.ac.uk), Kevin Hodges1, Len Shaffrey1, Giuseppe Zappa1

1
University of Reading, Department of Meteorology, Reading, United Kingdom

Polar lows (PLs) are intense mesoscale cyclones (diameter of 200-600 km) that form at high latitudes during
winter. Their wind speeds (above 15 m.s-1) can substantially impact on and offshore activities. A previous ocean
model study, where 238 PLs/month were parameterized in the surface forcing over the north-east Atlantic
Ocean, indicated that the wind speeds and heat fluxes associated with PLs may have a strong impact on deep-
water formation in the Nordic Seas and increase the Atlantic Meridional Overturning Circulation. To explicitly
investigate this possible link, we use the 98-year high-resolution simulations (present day forcings) from the
MetOffice HadGEM3-GC2 coupled climate model (horizontal resolution of 25 km in the atmosphere and 0.25°
in the ocean). We first track and identify PLs in the model over the Nordic Seas. HadGEM-GC2 shows a similar
representation of PLs compared to observations and reanalyses, with a mean of 2.75 PLs/month compared to
2.25 PLs/month from the CFSR reanalysis and with no obvious inter-annual or seasonal pattern or trend. A clear
link is found between PLs and surface heat fluxes: the higher the PL numbers the higher the heat fluxes.
However, this relationship is too weak (mean increase of +15 W.m-2 for high PL numbers years) to impact the
ocean circulation. Subsequently, almost no correlation occurs between PL numbers and the ocean density,
suggesting that the previously hypothesized mechanism is not found in HadGEM3-GC2.

2449
1190
Recent Regional Variabilities Reflected in Kongsfjorden: An IndARC Perspective

Divya David T1 (divyadavidt@gmail.com), Subeesh M. P2, Renjith V. R3, Ravichandran M2, Anil Kumar N2
1
ESSO-National Centre for Antarctic and Ocean Research, Goa, India, 2ESSO-National Centre for Antarctic &
Ocean Research, Goa, India, 3Indian Institute of Technology Mumbai, Mumbai, India

The time series IndARC multisensor subsurface mooring data from July 2014 to July 2017 and the summer-fall
CTD profiles collected in a biweekly interval at Kongsfjorden (an open fjord on the north-west coast of
Spitsbergen in the Svalbard archipelago with its mouth located at 79 oN and 11 oE exhibiting a sub Arctic
nature) had been analyzed along with the atmospheric observations, reanalysis, model and remote sensing
datasets to delineate the regional variabilities captured and to understand the dynamics. The temperature,
salinity, dissolved oxygen; photosynthetically active radiation, fluorescence; turbidity and nitrate were
recorded at an hourly interval while the currents at half an hour interval at defined depths below 20 meters in
the mooring line. The interannual as well as intraseasonal atmospheric-fjord processes, Atlantic water
intrusions, glacial melt and the interactions during the observational period had been studied in detail. Besides
the prominent intraseasonal variability on a biweekly scale that was found driven by the local winds, the
physical and biochemical processes showed a strong coupling even at higher frequencies as evident from the
high resolution data. The present study could be considered as substantiation that showed that the regional
variabilities were quite well captured in the fjord system which makes it a hotspot to conduct the climate scale
regional studies.

2450
 2670
Drivers of Atmospheric Warming and Melt in Larsen C Ice Shelf Inlets

Andrew Elvidge1 (a.elvidge@uea.ac.uk), Ian Renfrew1, Peter Kuipers Munneke2

1
University of East Anglia, Environmental Sciences, Norwich, United Kingdom, 2Utrecht University, Science,
Utrecht, Netherlands

Foehn winds generated by westerly flow across the Antarctic Peninsula have a dominant influence on the
climate and surface energy balance over Larsen C Ice Shelf. Satellite observations have shown that the greatest
annual ice shelf melt is found in inlets prone to the strongest foehn winds (foehn jets). However, this pattern is
not reproduced in single-case numerical model experiments.
High resolution Met Office Unified Model experiments have been conducted covering two recent 6-month
periods; the melt seasons of 2014-15 and 15-16. The model output is validated against new observations from
an automatic weather station located in one of the major inlets. The combination of ideally-located surface
observations and the extended-period simulations afford the first comprehensive characterisation of air-ice
interactions in Larsen inlets.
The range of conditions - both foehn and non-foehn - responsible for leeside warming and inlet ice melt are
evaluated. The variability in surface fluxes in the immediate lee of the Peninsula is examined, with links drawn
to the orographically forced flow dynamics; in particular the jet/wake foehn structure. The net energy available
for melt is revealed to be governed by the two large and opposite-signed surface turbulent heat fluxes
(downward sensible and upward latent), the balance of which varies diurnally and spatially. Successful
prediction of leeside melt is contingent on the model's ability to correctly reproduce this delicate balance.

2451
 1440
Surprising Atmosphere-ice-Ocean Feedback Response to Drake Passage Closure

Matthew England1 (m.england@unsw.edu.au)

1
ARC Centre of Excellence for Climate Systems Science, Sydney, Australia

The response of the climate system to Drake Passage (DP) closure is examined using a coupled ocean-
atmosphere-ice model. Upon DP closure the initial response is consistent with previous ocean-only studies,
with an invigoration of Antarctic overturning and a collapse of North Atlantic Deep Water (NADW) production.
This results in a dominance of southward heat transport and Antarctic sinking when DP is closed. However,
within just a decade, the increased southward heat transport has melted back much of Antarctic sea-ice and
weakened the subpolar westerlies. These effects, not captured in models without ice-atmosphere feedbacks,
combine to force Antarctic Bottom Water to warm and freshen, to the point that this water mass becomes less
dense than NADW. This leads to a contraction of Antarctic overturning, allowing NADW to ventilate the deep
ocean once more. Poleward heat transport also settles back to values very similar to the unperturbed DP open
case. Yet remarkably the equilibrium climate retains a strong Southern Hemisphere warming. Here it is ocean-
atmosphere-ice feedbacks, particularly the sea-ice albedo feedback, not southern sinking, that maintain the
warm polar oceans when DP is closed. We further find that DP closure leads to warming that is sufficient to
inhibit ice sheet growth over West Antarctica. This highlights the importance of the DP gap, Antarctic sea-ice
and the associated ice-albedo feedback in maintaining the present-day glacial state over Antarctica.

2452
 GG-1e - Magmatic, tectonic, and geodynamic investigations of the Polar Regions
23.06.2018 14:00-15:30, C Aspen

1934
The Magmatic Evolution of the Antarctic Peninsula Crustal Block

Joaquin Bastias1 (j.bastias.silva@gmail.com), Richard Spikings1, Alexey Ulianov2, Anne Grunow3, Teal Riley4, Alex
Burton-Johnson4, Urs Schaltegger1, Francisco Hervé5
1
University of Geneva, Earth Science Department, Genève, Switzerland, 2University of Lausanne, Institute of
Earth Sciences, Lausanne, Switzerland, 3Ohio State University, Byrd Polar and Climate Research Center,
Columbus, United States, 4British Antarctic Survey, Cambridge, United Kingdom, 5Universidad de Chile,
Departamento de Geología, Santiago, Chile

The interpretation of the Eastern Palmer Land Shear Zone as a suture between an autochthonous gondwanan
block with an allochthonous arc that collided at ca. 105 Ma, (Vaughan and Storey, 2000) contradicts the former
interpretation that the arc products of the Antarctic Peninsula were an in-situ record of the 'Andean'
subduction during the Mesozoic and part of the Cenozoic (Suarez, 1976). In the last two decades it has been
published new dataset that have argued against the consistency of the 'accretionary model' (e.g. Burton-
Johnson and Riley, 2015). However, a dense framework of data is required to tackle such a regional-scale
problematic.
We present a new dataset of geochronology, isotopic tracing and geochemical studies of the Antarctic
Peninsula Batholith and the Antarctic Peninsula Volcanic Group; in localities that are spread over 1000 km. We
have collected over 100 U-Pb zircon ages, 40 Ar/Ar ages in groundmass and biotite, which are combined with
isotopic tracing of Sr-Nd-Pb in whole-rock and Hf in zircons. These results are also compared with the previous
works conducted in the region.
Burton-Johnson and Riley. Journal of the Geological Society. 172 (6), 822-835.
Suarez. 1976. Geology. 4, 211-214.
Vaughan and Storey. 2000. Journal of the Geological Society. 157, 1243-1256.

2453
 2016
South Georgia Island Current Tectonic Setting from GPS and Marine Seismic Data

Robert Smalley, Jr.1, Peter Matheny1, Ian W. Dalziel2 (ian@ig.utexas.edu), Lawrence A. Lawver3, Demián
Gómez4, Felix Norman Teferle5, Addisu Hunegnaw5, Kibrom Ebuy Abraha5, Conrad C. Suen6
1
University of Memphis, Center for Earthquake Research and Information, Memphis, United States, 2University
of Texas at Austin, Department of Geological Sciences, University of Texas Institute for Geophysics, Jackson
School of Geosciences, Austin, United States, 3University of Texas at Austin, University of Texas Institute for
Geophysics, Jackson School of Geosciences, Austin, United States, 4The Ohio State University, School of Earth
Sciences, Columbus, United States, 5Université du Luxembourg, Faculté des Sciences, de la Technologie et de la
Communication, Esch-sur-Alzette, Luxembourg, 6University of Texas at Austin, Department of Geological
Sciences, Jackson School of Geosciences, Austin, United States

The South Georgia microcontinent (SGM) is an allochthonous block from south-east Tierra del Fuego that has
been transported over the past 80-100 My as part of Scotia Plate (SP) development. While its trajectory is
poorly constrained, SGM is now located on the east end of the North Scotia Ridge (NSR) approximately 1600
km east of its original position. West of SGM, NSR forms the South America plate (SAP) - SP boundary. Based on
Scotia Arc bathymetric morphology and geological history, SGM has been considered part of the SP, with the
plate boundary along its northern side. SGM seismic activity, while very low, is concentrated along its southern
border and interpreted, based on a few small thrust mechanisms, to represent underthrusting and uplift of
South Georgia Island on an NSR restraining bend on the north-eastern margin of SGM. More recently, also
based on this seismicity, the plate boundary has been placed on SGM's south side, suggesting SGM has, or is
being, transferred to SAP. We report on marine seismic reflection surveys north and south of the island, and
results from a 4 station continuous GPS network on the island, to determine the block's current tectonic affinity
with respect to the SAP and SP, and examine SGM for internal deformation. We will present preliminary
geodetic results, based on 3 years of continuous GPS data indicating SGM motion and deformation, and multi-
channel seismic reflection profiles across the margins of SGM showing indications of compression.

2454
 2369
Mantle Anisotropy in Tierra del Fuego from MT Data: Scotia Arc Development

Lourdes González-Castillo1, Fernando Bohoyo2, Andreas Junge3, Jesus Galindo-Zaldivar4 (jgalindo@ugr.es),

Marcel Cembrowski3, Pablo Torres-Carbonell5, Ana Ruiz-Constán6, Pedro Ibarra2, Adolfo Maestro2, Antonio
Pedrera2, Patricia Ruano1
1
Universidad de Granada, Departamento de Geodinámica, Granada, Spain, 2Instituto Geológico y Minero de
España, Madrid, Spain, 3Goethe-Universität, Frankfurt am Main, Germany, 4IACT (CSIC-Universidad de
Granada), IACT / Geodinamica, Granada, Spain, 5Centro Austral de Investigaciones Científicas (CONICET),
Ushuaia, Argentina, 6Instituto Geológico y Minero de España, Granada, Spain

The Scotia Arc was formed by the eastwards migration and dispersion of the continental fragments that
connected South America and the Antarctic Peninsula. In this process the Drake Passage constituted a narrow
gateway that facilitates the eastward flow of the mantle from the Pacific towards the Atlantic. Tierra del Fuego,
northwards of Drake Passage, is a key area to study the effect in the upper mantle of this major tectonic event.
18 long period magnetotelluric sites were recorded along 2 profiles using LEMI-417 stations the 3 magnetic and
2 telluric field components in the frequency range of 4 Hz to investigate the deep crustal and upper mantle
conductivity. Standard robust processing was performed yielding high quality transfer functions. The
interpretation of phase tensor invariants and tipper vectors was undertaken by 3D anisotropic modeling using
the Frankfurt group software based on Comsol Multiphysics 5.2™. GEBCO database was considered to take into
account the effect of surrounding seawater. A main NW-SE oriented anisotropy is determined in the upper
mantle. This anisotropy may be consequence of former mantle anisotropies parallel to the Andes Cordillera
rotated during the development of the northern branch of the Scotia Arc. However, the most suitable
interpretation suggests that this remarkable anisotropy may be related to the eastwards mantle flow across
the Drake Passage during the development of the Scotia Arc.

2455
 2379
Magnetic Anomalies in Ona Basin: Early Seafloor Spreading in Drake Passage

Jesus Galindo-Zaldivar1 (jgalindo@ugr.es), Anatoly Schreyder2, Fernando Bohoyo3, Yasmina M. Martos4, Andres
Maldonado5
1
IACT (CSIC-UGR), Dpto. Geodinamica, Universidad de Granada, Granada, Spain, 2Russian Academy of Sciences/
P.P. Shirshov Institute of Oceanology/, Moscow, Russian Federation, 3Instituto Geológico y Minero de España,
Madrid, Spain, 4NASA Goddard Space Flight Center, Planetary Magnetospheres Laboratory, Greenbelt, United
States, 5IACT (CSIC- Universidad de Granada), Granada, Spain

Opening of the Drake Passage and Scotia Sea since the Eocene/Early Oligocene constitutes one of the most
relevant tectonic events that determined the instauration of the Antartic Circumpolar Current. Ona Basin, in
the southwestern Scotia Sea, included two sectors of NW-SE linear magnetic anomalies that evidence the early
stages of oceanic spreading. The western sector, near the corner of Shackleton Fracture Zone, included 3
sequences of N1200E trending linear anomalies characterized by amplitudes from 80 to 170 nT and 15-30 km
wavelengths. They are interrupted by two orthogonal fractures zones. The best fitting of measured and
theoretical profiles suggest a correspondence with A9-A16. Spreading process started near the time of chron
C16n.1r (35.892-36.051 my) and ceased in time of chron C9r (27.439-27.859 my). Average spreading velocity is
about 0.8 cm/ yr. Moreover, in the eastern Ona Basin, bounded by the Terror Rise, N1300E linear magnetic
anomalies of 50-100 nT amplitudes and 20-50 km wavelength, affected by one transform fault, are possible
related to anomalies A18-A20. Spreading process started near the time of chron C20n (42.301-43.432 my) and
ceased in time of chron C18n.1r (39.627-39.698 my). Average spreading velocity is no more than 1.7 cm/ yr.
These sets of anomalies are oblique to more recent NE-SW linear anomalies related to the younger spreading
of the West Scotia Ridge.

2456
 892
The Characteristic of Geophysical Fields around the Prydz Bay, Antarctica

Liu Chenguang1, Zheng Yanpeng1, Gao Jinyao2 (jygao@mail.hz.zj.cn)

1
The First Insititude of Oceanography, SOA, Qingdao, China, 2The Second Insititude of Oceanography, SOA,
Hangzhou, China

During 2011~2017, geophysical survey was curried out around Prydz Bay under the project of Chinese National
Antarctica Research Expedition. More than 30000km marine gravity data, as well as magnetic data, has been
collected by R/V XUELONG. In addition, 5 sites of OBS data has been obtained. The characteristic of gravity and
magnetic fields, the thickness and anisotropy of crust can be discussed.

2457
 448
Seafloor Spreading Process in the Cosmonauts Sea, off East Antarctica

Tomoko Hanyu1 (hanyuu.tomoko@nipr.ac.jp), Yoshifumi Nogi1,2, Masakazu Fujii1,2

1
Graduate University for Advanced Studies, Department of Polar Science, Tokyo, Japan, 2National Institute of
Polar Research, Geoscience Group, Tokyo, Japan

The Cosmonauts Sea in the western Enderby Basin, off East Antarctica, had been formed as a result of opening
between Antarctica and Sri Lanka/India/Madagascar. The seafloor spreading history of this region is still poorly
understood because of sparse marine geophysical data. No obvious magnetic anomaly lineations are observed
in a Japanese/German aero geophysical survey of the N-S observation lines, and this area is considered to be
created by seafloor spreading during the Cretaceous Normal Superchron. We carried out systematic vector
geomagnetic survey including the SE-NW oriented four track lines in the Cosmonauts Sea using the Japanese
icebreaker Shirase during the 54th Japanese Antarctic Research Expedition (JARE). We analyzed these data
combined with previous data obtained in other JARE cruises.
The isochrons M10N-M3n with the almost NW-SE spreading direction were newly identified with several small
segments in the south of the Cosmonauts Sea. The wide-spreading continental ocean transition zone was
inferred by the magnetic boundary strikes, as well as satellite gravity data. The transition of seafloor spreading
direction was observed at 65°S seafloor, which likely formed during chron M3n-M0r. It suggests that NNE-SSW
oriented seafloor spreading started since the chron M0 in the north of the Cosmonauts Sea. We will show clear
magnetic anomalies related seafloor spreading in the Cosmonaut Sea and present initial breakup process
between Sri Lanka/India and Antarctica.

2458
 EN-5 - Big data, small data, your data. What does good data management mean to you?
23.06.2018 14:00-15:30, A Studio

1173
What Polar Data Do you Need, and how Would you Like to Access and Use Them?

Julie Friddell1, Gabrielle Alix1 (gabrielle.alix@uwaterloo.ca), David Friddell1, Chantel Ridsdale1, Kishor
Sudarshanakumar1
1
Polar Data Catalogue, University of Waterloo, Canadian Cryospheric Information Network, Dept. of Geography
and Environmental Management, Waterloo, Canada

Using examples from Canada's polar research and data community and the Polar Data Catalogue, this
presentation will highlight a selection of users' evolving expectations regarding polar data and some of the
challenges to making curated data collections truly accessible and usable. We will describe issues with
providing efficient access to datasets resulting from disparate collection and recording methods, designing a
friendly user interface for both novice and advanced users, providing streamlined access to complex datasets
containing Terabytes of files, protecting sensitive data, and other examples. We will provide an opportunity for
direct feedback from the audience on functions and interfaces which serve the needs of the polar research
community and other targeted users.
The Polar Data Catalogue (PDC, https://polardata.ca) is one of Canada's primary online sources for data and
information about the Arctic and Antarctica. With over 2,500 metadata descriptions of projects and datasets
and almost 3 million data files, the PDC contains data on physical, social, and health science and other research
in Canada and globally, including significant collections from the ArcticNet Network of Centres of Excellence,
the International Polar Year, satellite imagery from the RADARSAT-1 and RADARSAT-2 missions, and hundreds
of metadata from the Circumpolar Biodiversity Monitoring Programme. The PDC is a member of the World
Data System and is Canada's National Antarctic Data Centre.

2459
 1344
Mapping Information Landscape in the Context of Disaster Diplomacy in the Arctic

Yekaterina Kontar1,2 (yekaterina.kontar@tufts.edu), Peter Pulsifer3, Paul Berkman1,2

1
Tufts University, The Fletcher School of Law and Diplomacy, Medford, United States, 2Tufts University, Science
Diplomacy Center, Medford, United States, 3National Snow and Ice Data Center (NSIDC), Boulder, United States

Disaster resilience is a common interest and goal throughout the Arctic region. Building resilience foremost
requires a thorough understanding of the physical and social processes behind the key components of disasters
- hazards, risks, and vulnerability. This requires collaborations among disaster experts, including practitioners,
natural and social scientists, and local knowledge holders. Expert collaborations across the Arctic nations
significantly expand the data and knowledge pools. Disaster diplomacy encourages and facilitates such
collaborations. To inform decision-making, produced data needs to be readily available to the policymakers in a
useable to them format. By developing a disaster-relevant information e-cosystem model we were able to map
relevant information flow and identify gaps in it. The ecosystem metaphor allowed us to identify key data
sources (e.g. scientific projects and data centers) and information users (e.g. policymakers, emergency
managers, and communities at risk) in the field of Arctic disasters, and map the flow of information between
them. The corpus analyzed as a foundation for the model included assessments and reports published by the
working groups of the Arctic Council - an intergovernmental forum that promotes cooperation among the
Arctic States and indigenous communities on issues of sustainable development. Lessons learned from this
analysis will be beneficial to other pan-Arctic collaborations that depended on data sharing.

2460
 1240
Data Management for Model Output: What Are the Issues?

Stuart Corney1, Jess Melbourne-Thomas1,2, Rowan Trebilco1 (rowan.trebilco@utas.edu.au), Michael Sumner1,2,

Andrew Constable1,2
1
Antarctic Climate & Ecosystems Cooperative Research Centre, Hobart, Australia, 2Australian Antarctic Division,
Hobart, Australia

Procedures around data deposition and access for observational data that relate to marine and Antarctic
environments are now fairly well established. However, despite an increasing expectation that model output
will be generally available as part of publication of scientific research, the corresponding procedures relating to
model output are yet to be clearly defined. Data repositories allow for permanent storage and curation of
data/model output while also encouraging increased re-use by the general community. This is beneficial for
observations, which are bound to a fixed time and place, but how well does this system work for model
output?
In this presentation, we will discuss a number of scenarios involving the cataloguing of model output. Specific
issues raised include
· Ensuring model currency: what happens to my output when I update my model?
· Does model output have a half-life?
· My model is global, but my study is regional. Should model output outside of the original study region be
archived?
· Models are a representation of a system, based on certain assumptions, defined to answer specific questions.
What are my responsibilities to ensure future users understand these restrictions upon the output?
· Model output or modelling environment? When should I archive just the output, and when is a code
repository or virtual machine the better choice?

2461
 2230
Developing an Environmental Data Portal: Characteristics and Design Principles

Ionut Iosifescu Enescu1 (ionut.iosifescu@wsl.ch), Gian-Kasper Plattner1, Lucia Espona Pernas1, Michael
Lehning2,3, Konrad Steffen1,3,4
1
Swiss Federal Research Institute WSL, Birmensdorf, Switzerland, 2WSL Institute for Snow and Avalanche
Research SLF, Davos, Switzerland, 3EPFL, Lausanne, Switzerland, 4ETH Zurich, Zurich, Switzerland

The Swiss Federal Research Institute WSL is developing EnviDat, an overarching environmental data portal for
facilitating the management, search and access to its rich data reservoir. EnviDat is designed to publish,
connect and search existing data, while data curation and quality control remain with the experts. The current
EnviDat Beta version provides access to several polar data sets such as the high resolution sea ice surface
topography from the SIPEX-2 expedition, East Antarctica, 2012 (www.envidat.ch/dataset/10-16904-9). More
polar and high-altitude research data will be incorporated into EnviDat, including the Greenland Climate
Network (GC-Net).
The EnviDat design principles focus on usability and user-friendliness, with easy search and find, availability of
relevant data filters, and ideally one click access to the data source. The portal´s functional requirements
include metadata and map search, the publishing of datasets with DOIs, and the provision of a data repository.
Non-functional requirements such as reliability, security and maintainability are taken into account through a
multi-server architecture. Moreover, the interoperability with the wider data management community is
achieved by leveraging community software such as CKAN and by adopting best practices in data sharing.
Based on the above characteristics and design principles, EnviDat represents an important WSL initiative
dedicated to addressing the challenges related to data sharing with the community.

2462
 1143
CASEarth Poles: A Big Earth Data Platform for Three Poles

Xin Li1,2 (lixin@lzb.ac.cn), Tao Che1, Xinwu Li3, Lei Wang2,4, Anmin Duan5, Donghui Shangguan1, Xiaoduo Pan1,
Miao Fang1
1
Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,
Lanzhou, China, 2CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences,
Beijing, China, 3Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China,
4
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China, 5Institute of Atmospheric
Physics, Chinese Academy of Sciences, Beijing, China, Beijing, China

Unprecedented changes on climate and environment have been observed in the three poles, including Arctica,
Antarctica and the Tibetan plateau (the so-called Third Pole). The three poles are relatively data-scarce regions
due to the data accessibility and hard living environment though numerous earth observation data have been
collected. And consequences of these changes on global environment and human being remain poorly known.
To address these challenges, there is an urgent need for better data acquisition, integration, curation, and
service, and use these data to better support fundamental scientific research and sustainable development for
the three poles.
The CASEarth Poles, a project within the framework of “Big Earth Data Science and Engineering” program of
Chinese Academy of Sciences, aims to construct a comprehensive big data platform of the three poles. This
project will devote to: (1) breaking the bottleneck of polar data integration, curation, and sharing, (2)
developing high resolution remote sensing products over the three poles, (3) generating atmospheric reanalysis
datasets for polar regions, (4) exploring synchronization, asynchronization, and teleconnection of
environmental changes in the three poles, (5) investigating the dynamics of climate, water cycle, and
ecosystem, and interactions among multi-spheres in polar regions and their effects globally, (6) supporting the
decision-making on sea ice forecast, polar development and governance.

2463
 1625
Southern Ocean Data Sharing Tools in a Global Data Management Community

Pip Bricher1 (data@soos.aq), Steve Diggs2, Joana Beja3, Alicia Aleman4, Mathieu Belbeoch5, Taco de Bruin6,
Kenneth Casey7, James Cusick8, Bruno Danis9, Florence Fetterer10, Alexander Kozyr11, Wu Lizong12, Benjamin
Pfeil13, Roger Proctor14, Petra Ten Hoopen15, Anton P. Van de Putte9
1
Southern Ocean Observing System, University of Tasmania, Battery Point, Australia, 2Scripps Institution of
Oceanography, San Diego, United States, 3British Oceanographic Data Centre, Liverpool, United Kingdom,
4
NASA HQ, Baltimore, United States, 5JCOMMOPS, Brest, France, 6Taco.De.Bruin@nioz.nl, Texel, Netherlands,
7
National Centers for Environmental Information, Baltimore, United States, 8Australian Antarctic Division,
Kingston, Australia, 9Royal Belgian Institute for Natural Sciences, Brussels, Belgium, 10National Snow and Ice
Data Center, Boulder, United States, 11National Centers for Environmental Information, Knoxville, United States,
12
Polar Research Institute of China, Hangzhou, China, 13Bjerknes Centre for Climate Research, Bergen, Norway,
14
Integrated Marine Observing System, Hobart, Australia, 15British Antarctic Survey, Cambridge, United
Kingdom

The Southern Ocean Observing System (SOOS) bridges many divides - among communities, scientific
disciplines, National Antarctic Programs, logistics personnel, and scientists. Each of these groups has a history
of data sharing through online systems that have been built up to meet their needs through decades of
negotiation and effort. Data management for this disparate community must build on the existing data sharing
infrastructure and behavioral norms of its constituent groups.
To support the SOOS 20-year vision, the SOOS Data Management Sub-Committee is tasked with developing an
integrated data management system to collect the marine observing datasets from around Antarctica,
document them, make them discoverable, accessible,and compile them into composite datasets that can be
fed into circumpolar models. This is a task that is well beyond the capacity of any small group of data managers
to implement and one that can only be fulfilled by working within a global ecosystem of data integration
efforts.
In this presentation, we will describe the new tools that SOOS has developed to date and the community
relationships through which we hope to accomplish this vision.

2464
 BE-8 - Polar wildlife - Ecology, health and disease
23.06.2018 14:00-15:30, A Forum

39
Diseases Threatening Polar Seabirds: From Immuno-ecology to Conservation

Amandine Gamble1 (amandine.gamble@cefe.cnrs.fr), Romain Garnier2, Jérémy Tornos1, Raül Ramos3, Thierry
Boulinier1
1
CEFE, CNRS - Université Montpellier, Montpellier, France, 2University of Cambridge, Department of Veterinary
Medicine, Cambridge, United Kingdom, 3Universitat de Barcelona, Departament de Biologia Evolutiva,
Barcelona, Spain

Infectious diseases are a relatively neglected but potentially important threat to wild populations, especially in
polar areas where global changes may facilitate the introduction of new parasites. In addition, the life histories
of seabirds, combining long lifespan and high site fidelity, raises the possibility that their immune system may
have evolved special features to protect them against potential recurrent exposure to parasites at the breeding
site. This is notably the case for species breeding in dense aggregations which can be subject to recurrent
epizootics, as observed in Arctic and Subantarctic populations of seabirds hit by avian cholera. In this context,
we combined observational and experimental data to undertake basic immune-ecological investigations that
led us to some original findings with potential implications for conservation. Our results, obtained in
collaboration with several groups of biologists in Arctic and Subantarctic, particularly highlight the dynamics of
Lyme disease Borrelia in Arctic and Antarctic seabird colonies and of avian cholera in an albatross colony. They
also stress that the persistence of maternally inherited immunity varies between seabird species, being
especially long in Procellariiforms. These results thus open some promising venue for the use of vaccination in
the wild in some critical situations.

2465
 2154
From “-omics” to Behavior of Reproduction in a Top Antarctic Predator

Michelle Shero1 (mrshero@alaska.edu), Gregg Adams2, Robert McCorkell3, Amy Kirkham1, Kimberly Goetz4,
Daniel Costa5, Jennifer Burns1
1
University of Alaska Anchorage, Biological Sciences, Anchorage, United States, 2University of Saskatchewan,
Western College of Veterinary Medicine, Saskatoon, Canada, 3University of Calgary, Faculty of Veterinary
Medicine, Calgary, Canada, 4National Institute of Water and Atmospheric Research (NIWA), Wellington, New
Zealand, 5University of California Santa Cruz, Ecology & Evolutionary Biology, Santa Cruz, United States

From 2010-2017, we used a suite of molecular, physiological, and behavioral tools to study factors influencing
reproduction in adult female Weddell seals (Leptonychotes weddellii; n=291) in Erebus Bay, Antarctica.
Metabolomics approaches were used to determine biochemical pathways critical to establishing a successful
pregnancy, and were paired with early pregnancy diagnosis via ultrasound (embryos ≥3mm diameter).
Pregnancy rates were high (82%), yet Weddell seals are known to have low birth rates (65%) relative to other
pinnipeds. Energy balance in late gestation is likely important to carrying the embryo to term. Indeed,
constructed embryo growth curves revealed that Weddell seals have a protracted placental gestation (~10.5
months), which would spread the energetic costs of pregnancy over a longer timeframe. Remarkably, neither
mass nor body condition influenced the probability of embryo loss or pupping. However, increased foraging
effort (dive duration, depth, exceeding aerobic capacities) across gestation influenced the probability of
pupping the next year. Despite intense foraging, Weddell seals exhibited low rates of energy acquisition,
gaining only 15% of the mass and lipid stores typically acquired by other phocid seal species during gestation. In
combination, this integrative approach suggests that the Weddell seal's life history has been shaped by
energetic constraints, and may also make this top predator particularly vulnerable to environmental
perturbations.

2466
 2049
Detecting and Mitigating Health Threats to Muskoxen in a Changing Arctic

Susan Kutz1 (skutz@ucalgary.ca), Sylvia Checkley1, Chimone Dalton1, Tracy Davison2, Juliette DiFrancesco1, Taya
Forde3, Craig Gerlach1, Wendy Hutchins1, Pratap Kafle1, Lisa-Marie Leclerc4, Fabien Mavrot1, Matilde Tomaselli1,
Frank van der Meer1, Katherine Wynne-Edwards1
1
University of Calgary, Calgary, Canada, 2Government of Northwest Territories, Inuvik, Canada, 3University of
Glasgow, Glasgow, United Kingdom, 4Government of Nunavut, Kugluktuk, Canada

Rapid climate change in the arctic is posing increasing threats to wildlife health and sustainability, and by
extension, the health and socio-economic well-being of northern communities. During the past decade,
muskoxen, which are integral to the culture, food system and economy of communities in many parts of the
Arctic, are experiencing widespread disease, mortality, and regional population declines. This has resulted in
significant concerns about muskox health and sustainability as well as the food safety and security for local
people. We are using a combination of scientific, traditional, and local knowledge to evaluate and monitor the
health and vulnerability of muskoxen in a rapidly changing Arctic. Specifically, we are
(i) determining the current health status of muskoxen in parts of the Inuvialuit and Kitikmeot regions, Canada,
(ii) investigating the ecology and drivers of three emerging parasitic, bacterial, and viral diseases,
(iii) developing indicators of health to incorporate into muskox monitoring programs.
Our goal is to establish and implement an integrative and responsive muskox health surveillance system that
can pro-actively inform wildlife management, public health, and land-use policy. Tools, techniques, and
programs developed will lead to improved technical and human resources for health monitoring not only of
muskoxen, but other arctic wildlife, and will contribute to conservation and improved food safety and security
across the North.

2467
 52
Plasticity of Female Humpback Whale Fertility to Variable Nutritional Condition

Greta Dalle Luche1 (greta.dalleluche@griffithuni.edu.au), Ashley Boggs2, John Kucklick2, Susan Bengtson Nash1
1
Griffith University, Environmental Future Research Institute (EFRI), Brisbane, Australia, 2National Institute of
Standards and Technology (NIST), Hollings Marine Laboratory, Charleston, United States

The southern hemisphere humpback whale (HW), Megaptera novaenangliae, have evolved to optimise energy
intake and expenditure by breeding at equatorial latitudes in winter, and feeding on Antarctic krill in summer.
During their migration journey, pregnant HW give birth and nurse a single calf, only relying on their previously
accumulated fat. The recording of HW vocalisation in Antarctica, and an observation of a 2.4 male to female
gender ratio among migrating individuals has led to the hypothesis that not all females engage in the migration
annually. As the mating also takes place during the migration, it is plausible that a number of females would
not participate back out of the migration and incorporate one or more years of rest between pregnancies to
replenish their energy reserves. Accordingly, the female inter-calving period may vary as a function of summer
feeding conditions.
This work combines blubber steroid hormonal profiles with histological measurements of the adipocytes of 36
free-roaming, migrating female HW to test the expectation that the individual's reproductive state and
nutritional condition correlate. Reproductive state is assessed by liquid chromatography tandem mass
spectrometry (LC-MS/MS) measurement of testosterone, androstenedione and progesterone from remotely
collected biopsies. This work contributes new knowledge regarding HW reproductive habits, and provides
insight into the resilience of female fertility to years of variable krill availability.

2468
 2046
Factors Determining the Gastrointestinal Microbiota in Chinstrap Penguin Chicks

Andres Barbosa1 (barbosa@mncn.csic.es), Vanessa Balague2, Francisco Valera3, Ana Martinez4, Jesus Benzal3,
Miguel Motas5, Julia I. Diaz6, Carlos Pedros-Alio7
1
Museo Nacional de Ciencias Naturales, CSIC, Ecologia Evolutiva, Madrid, Spain, 2Insititut de Ciencies del Mar,
CSIC, Barcelona, Spain, 3Estacion Experimental de Zonas Aridas, CSIC, Almeria, Spain, 4Instituto Investigaciones
en Materiales, UNAM, Mexico DF, Mexico, 5Facultad de Veterinaria, Universidad de Murcia, Murcia, Spain,
6
Centro de Estudios Parasitologicos y de Vectores, CONICET, La Plata, Argentina, 7Centro Nacional de
Biotecnología CNB-CSIC, Madrid, Spain

The gastrointestinal microbiota is composed by a complex community which depends of different factors,
external/ internal and environmental/genetics. We carried out a cross-fostering experiment in nesting
chinstrap penguins. In experimental nests one of the chicks was exchanged at seven days old with a chick from
another nest with the same hatching date. In control nests, chicks were briefly removed and put back in the
nest again. After twenty days we collected cloacal samples of adults and chicks and carried out sequencing of
the V1-V3 region of the 16S rDNA by Illumina. We did not find any effect of chick manipulation in bacteria
diversity as no differences were found between experimental and control chicks. We found differences in
bacteria diversity between adults and biological chicks but not with adopted chicks. We did not find significant
relationships of bacteria diversity between chicks reared in the same nest but from different parents and either
between siblings reared in different nests. Moreover, we did not find significant relationships between parents
and the biological chicks or the adopted chicks. This suggests that chick bacteria diversity is not dependent of
the parents or external factors and should be dependent of chick intrinsic factors.

2469
 485
Range Expansion of Protostrongylid Nematodes in Response to Arctic Warming

Pratap Kafle1 (pkafle@ucalgary.ca), Lisa-Marie Leclerc2, Peter Peller1, Tracy Davison3, Marsha Branigan4,
Morgan Anderson5, Shane Black6, Heather Sayine-Crawford7, Stephanie Behrens7, Mike Suitor8, Matilde
Tomaselli1, Fabien Mavrot1, Susan Kutz1
1
University of Calgary, Calgary, Canada, 2Government of Nunavut, Kugluktuk, Canada, 3Government of
Northwest Territories, Yellowknife, Canada, 4Government of Northwest Territories, Inuvik, Canada, 5British
Columbia Government, Fish and Wildlife, Prince George, Canada, 6Canada North Outfitting, Edmonton, Canada,
7
Government of Northwest Territories, Norman Wells, Canada, 8Government of Yukon, Whitehorse, Canada

Protostrongylids, Umingmakstrongylus pallikuukensis (UP) and Varestrongylus eleguneniensis (VE), are

pathogenic parasites of northern ungulates. These parasites are of interest not only because of their possible
impacts on their hosts but also because their recent and rapid northern range expansion associated with Arctic
warming provides a model system for understanding the impacts of climate change on parasitic nematodes in
general. We aimed to
i). determine the diversity and distribution of protostrongylids in muskoxen and caribou in the Canadian Arctic,
and
ii). assess climate warming as a potential driver for their range expansion.
We performed widespread fecal surveys across the Canadian Arctic from 2013-2017; conducted lab
experiments on the thermal sensitivities of UP and VE, and modelled the suitable habitat for these parasites
using the field, laboratory data, with satellite-derived climate data from historical to future period. We found
that protostrongylid diversity in muskoxen and caribou varies geographically. On Victoria Island, UP and VE are
expanding rapidly northwards, but at differential rates. UP is expanding faster over a broader geographical
range. Predictive habitat modelling using the parasite's physiological data and the Arctic climate data shows a
significant expansion of suitable habitat for both the lungworms, but greater for UP. Similarly, models predict
the possibility of a future invasion of other Arctic islands currently free of lungworms.

2470
 ME-1_ME-2c - Human Adaptation to High Altitude & Human Science from the Extreme
Poles
23.06.2018 14:00-15:30, A Schwarzhorn

2254
Monitoring Genetic Adaptation in Humans Using Ingenuity Pathway Analyses (IPA®)

Alexander Choukèr1 (achouker@med.uni-muenchen.de), Jean-Noël Billaud2, Judith-Irina Buchheim1, Matthias

Feuerecker1, Claudia Strewe1, Roel Quintens3, Marjan Moreels4, Igor Mekjavic5, Brian Crucian6, Clarence Sams6,
Satish Mehta6, Sarah Baatout4, Gustav Schelling7
1
Hospital of the University of Munich, LMU, Dept of Anesthesiology, Laboratory of Translational Research,
München, Germany, 2QIAGEN, Inc. Department of Bioinformatics, Redwood City, CA, United States,
3
3Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium, 4Radiobiology Unit, Belgian
Nuclear Research Centre (SCK•CEN), Mol, Belgium, 5Department of Automation, Biocybernetics and Robotics,
Jozef Stefan Institute, Ljubljana, Slovenia, Ljubljana, Slovenia, 6NASA-Johnson Space Center, Houston, TX, United
States, 7Hospital of the University of Munich, LMU, Dept of Anesthesiology, München, Germany

Adaptation to changing environments has been critical to survive. A hallmark of adaptive responses to
environmental pressure is genetic regulation. Antarctica is providing a unique, space-analogue environment to
investigate such adaption. The CHOICE study took place in 2 overwintering crews at the Antarctic station
Concordia (3200m) and was complemented by a simulated microgravity study in Slovenia. Here a similar sized
group was exposed for 21d to 3 conditions of hypoxia and bedrest (PlanHab). Transcriptomics were performed
in blood (Affymetrix Human Gene2.0ST) and analyzed through “Array Studio” (OmicSoft,NC,USA) and IPA.
Comparisons of the earlier time point (3-4 wks upon arrival) to baseline revealed in both Concordia seasons
prominent changes of ~790-850 genes (FC2,FDR< 0.01). The exposition to a comparable condition in an
experimental setup in PLanHab under hypoxia resulted in 360 gene alterations, while combination of
hypoxia+immobilization showed a much higher number of significant gene changes (~2500). Between both
Concordia seasons and the PlanHab hypoxic ambulatory condition 1072 or 1182 common genes were detected.
Several top canonical pathways were identified by IPA® and included immune and metabolic related pathways.
Grants & support from ESA ELIPS 3/4 programs, NASA HRP, IPEV, PNRA, AWI, BelSPO, DLR and the European
Union Programme FP7 and all the wintering over Crews and volunteers (PlanHab) who supported with
outstanding professionalism.

2471
 2684
Sleep during an Antarctic Winter: Summer Is the Answer

Nathalie Pattyn1,2 (nathalie.pattyn@gmail.com), Olivier Mairesse1,2, Emilie Dessy1,2, Martine Van Puyvelde1,
Xavier Neyt1, Peter Marquis3, Anne Hicks3, Romain Meeusen2
1
Royal Military Academy, VIPER, Brussels, Belgium, 2Vrije Universiteit Brussel (VUB), Brussels, Belgium, 3British
Antarctic Survey Medical Unit, Plymouth, United Kingdom

According to the literature, sleep disturbances are worse in the Antarctic winter, the period of isolation and
constant darkness (latitude dependent). This is confirmed by results on much larger samples from Arctic
regions. However, there is still no consensus on the causal mechanisms, and there is a lack of investigations
during the period of constant illumination.
The current project investigated sleep and its circadian regulation at the height of summer and at the height of
winter in two winterover crews. To disentangle the effect of time on station and the effect of seasonality, 1
crew had the summer measurements during their second summer on station, whereas the other was measured
during the first summer on station.
The results show the same sleep disturbances for both summer and winter when it was measured after 6
months on site. When summer measurements were recorded after 1 month on site, the results paint a slightly
different picture: sleep onset latency is similarly disturbed, but the amount of slow wave sleep and sleep
efficiency are less affected. A melatonin phase delay was present at all seasons in both groups. These results
underscore that there is more to sleep in Antarctica than a disturbed photoperiodicity: the duration of time-on-
station has a major effect on the psychophysiological adaptation. Overall, the present results show the need for
a specific support to personnel from both summer and winter campaigns in terms of sleep and fatigue
management.

2472
 2160
Extreme Epidemiology & Innovation: Australian Antarctic Health Register-1986-2018

Jeff Ayton1 (jeff.ayton@aad.gov.au), Roland Watzl1, Clive Strauss1

Australian Antarctic Division, Polar Medicine Unit, Kingston, Australia
1

Antarctica is an isolated, confined and extreme environment. Australia has conducted expeditions to Antarctica
since 1911, and the Australian Antarctic Division (AAD) has maintained a permanent presence in Australia´s
Antarctic Territory since 1948, with three continental stations and one subantarctic station. Medical support
for expeditions was initially informed with access to paper based medical logs and research reports. In 1986,
the AAD developed a unique and innovative electronic health register, now called the Australian Antarctic
Health Register (AAHR), to capture longitudinal epidemiology including expeditioner medical history, medical
fitness, all health events and treatment, and importantly, person-years of exposure to the extreme expedition
environments. This unique evidence base informs Australia´s Antarctic expedition medical and safety policy
development. It is integral to medical screening, research and support. Online access from Antarctic stations via
satellite enabled confidential data entry utilising ICD9 and specific Antarctic coding. In 2009, the AAHR was
integrated with a program wide electronic health record for all clinical and telemedicine support. This paper
highlights 30 years of experience with the AAHR and the importance of epidemiology and electronic health
records in ensuring the safety and wellbeing of those travelling and living in polar and extreme environments
such as Antarctica, the Arctic and those contemplating long term space missions.

2473
 1891
POWER - Physiological AdaptatiOns in Women during a North PolE exploRation

Susan Gallon1 (susan.gallon@googlemail.com), Jessica Devitt2, Caroline Gilbert3, Andrew Lange2, Alexandre
Zahariev4, Sophie Bourgeon5, Chantal Simon6, Audrey Bergouignan2,4
1
University of Glasgow, Glasgow, United Kingdom, 2University of Colorado, Aurora, United States, 3Ecole
Nationale Veterinaire d'Alfort, Maison-Alfort, France, 4CNRS, Strasbourg, France, 5Arctic University of Norway,
Tromso, Norway, 6University of Lyon, Lyon, France

The earth's Polar Regions offer a unique set of challenges and hazards including extreme temperatures,
blizzards, difficult and changing terrain due to the shifting icepack, and disrupted circadian patterns due to the
extended hours of day light. Due to the geography and remoteness of the Arctic, deep access is restricted to
walking or cross-country skiing. These modes of locomotion impose a very high energy expenditure which,
coupled with the extreme conditions, pose a challenge to health. The extent to which this extreme
environment impacts the human body is poorly understood. Few men have been studied during Arctic
explorations but no data exist for women.
The objective of this research project was to take advantage of an all-female polar expedition to examine the
metabolic and physiological adaptations to extreme conditions in women skiing to the North Pole
(http://www.euroarabianexpedition.com/, April 2018). Specifically, we examined changes in
1) energy needs (free-living total energy expenditure, metabolic rates and body composition),
2) biological rhythms (pattern of physical activity, sleep, body temperature and melanocortin) and
3) physiological stress (saliva cortisol).
This study shows how collaboration between scientists and explorers provides an exceptional opportunity to
better understand the physiological flexibility of humans when facing extreme environmental conditions.
Energetics data will be analyzed prior to the congress.

2474
 1584
Antarctic Research Enabling Space Exploration

Marc Shepanek1 (marc.a.shepanek@nasa.gov)

1
NASA HQ, Office of the Chief Health and Medical Officer, Washington, United States

This presentation will address some of the most currently pressing research questions, countermeasures and
training that make Antarctica an excellent space mission analog.

2475
 2390
A 30-year Analysis of Medical Evacuation Case in Korean Antarctic Station

Eojin Yi1,2 (eojinkorea@gmail.com)

1
Korean Society of Polar Medicine, Seoul, Korea, Republic of, 2Yeosu Immigration Office, Yeosu, Korea, Republic
of

One of the biggest challenges facing the antarctic station is medical evacuation (Medevac) in case of
unpredictable emergency. Since its establishment in 1988, Korea Antarctic King Sejong Station (62°13´S,
58°47´W) is operated by winter-over team consisting of about 17 people each year. In case of Medevac, it is
transferred initially to Chilean Frei base in King George Island using a helicopter or Zodiac, and subsequently
transported to the flight to Punta Arenas.
In this study, we collected 22 Medevac cases (24 people) in the past 30 years (1988-2017). It is compared with
other previous studies, and also seasonal difference to Antarctic winter and summer. Orthopedic problems due
to trauma had the highest proportion of the entire Medevac cases, else there were distress and frostbite,
burns, tooth problems, head trauma, gastritis, tuberculosis, eye problem, decompression sickness, and
malignancy work-up, etc.
Since the Medevac system in Antarctica is directly related to the member's safety issue, it is essential to
prepare for specified emergencies. It could be done by case-specific scenario, guidelines, and regular training
considered each Medevac steps: first aid, waiting Medevac, rapid transfer, proper treatment. Additionally, it
needs to be considered along with the efforts of such pre-screening, safety education to prevent these
Medevac situations in advance.
(This article is revised and updated version of the 2016 COMNAP symposium proceeding.)

2476
 CR-5c - Interactions between ice mass balance, the solid Earth, and sea-level changes
23.06.2018 14:00-15:30, A Seehorn

1336
A Programme to Understand Thwaites Glacier and its Contribution to Sea Level

David Vaughan1 (dgv@bas.ac.uk), Ted Scambos2

1
British Antarctic Survey, Cambridge, United Kingdom, 2University of Colorado, Denver, United States

Since the 1990s, satellites have shown accelerating ice loss in the glaciers draining central West Antarctica into
the Amundsen Sea. The rate of ice loss now accounts for about 10 percent of global sea-level rise. Pine Island
Glacier, which has the highest rate of ice loss, was the focus of the UK-NERC iSTAR Programme and US-NSF
funded projects during the past decade. Recent studies indicate that the greatest uncertainty and risk for
future rapid sea-level rise now arises from Thwaites Glacier. Rapid changes are already underway and there is
concern that ice sheet loss from the Thwaites Glacier basin will become irreversible, if it is not already.
The need to characterize the potential range and uncertainty in Antarctic contributions to sea-level rise on
decadal to multi-century timescales was underscored by the SCAR in its "Horizon Scan 2020", and by U.S.
National Academy of Sciences, Engineering, and Medicine. Building on this priority, and recognizing the high
logistic and scientific demands call for an international endeavour, the US-NSF and the UK-NERC have begun a
joint initiative focusing on Thwaites Glacier and the adjacent Amundsen Sea, involving ~30 UK and US
institutes, and international partners. The program will improve understanding of the stability of marine ice
sheets, the processes of thinning, retreat, and acceleration, and the role of oceans in driving change. It will
require shipborne, aircraft, and over-snow research in the austral summers of 2018-2021.

2477
 572
A New Heat Flux Model Incorporating Variable Crustal Radiogenic Heat Production

Alex Burton-Johnson1 (alerto@bas.ac.uk), Jacqueline Halpin2, Joanne Whittaker2, Felicity Graham2, Sally
Watson2
1
British Antarctic Survey, Geology & Geophysics Team, Cambridge, United Kingdom, 2Institute for Marine and
Antarctic Studies, University of Tasmania, Hobart, Australia

We present findings recently published in GRL (Burton-Johnson et al., 2017) on the variability of Antarctic sub-
glacial heat flux and the impact from upper crustal geology.
Our new method reveals that the upper crust contributes up to 70% of the Antarctic Peninsula's subglacial heat
flux, and that heat flux values are more variable at smaller spatial resolutions than geophysical methods can
resolve. Results indicate a higher heat flux on the east and south of the Peninsula (mean 81 mWm-2) where
silicic rocks predominate, than on the west and north (mean 67 mWm-2) where volcanic arc and quartzose
sediments are dominant. Whilst the data supports the contribution of HPE-enriched granitic rocks to high heat
flux values, sedimentary rocks can be comparable dependent on their provenance and petrography. Models of
subglacial heat flux must utilize a heterogeneous upper crust with variable radioactive heat production if they
are to accurately predict basal conditions of the ice sheet. Our new methodology and dataset facilitate
improved numerical model simulations of ice sheet dynamics.
The most significant challenge faced remains accurate determination of crustal structure, particularly the
depths of the HPE-enriched sedimentary basins and the sub-glacial geology away from exposed outcrops.
Continuing research (particularly detailed geophysical interpretation) will better constrain these unknowns and
the effect of upper crustal geology on the Antarctic ice sheet.

2478
 850
Combining Upper Crust and Lithosphere Contributions to Heat Flow Models

Anya Reading1,2 (anya.reading@utas.edu.au), Tobias Staal2,3, Jacqueline Halpin2, Joanne Whittaker2

University of Tasmania, Mathematics and Physics, Hobart, Australia, 2University of Tasmania / Institute for
1

Marine and Antarctic Studies, Hobart, Australia, 3University of Tasmania, Earth Sciences, Hobart, Australia

Geothermal heat supplied to the base of Antarctic ice sheets, and the spatial variation of supplied heat, is an
important input model parameter in ice sheet models. Continental models of heat flow (usually referred to in
the cryosphere research community as heat flux density, abbreviated to heat flux) may be generated using
seismic wavespeed tomography maps or by inference from other geophysical observables. Upper crustal
models, however, are generated directly from measuring the heat production of dominant or particularly
radiogenic lithologies.
In this contribution, we combine upper crust and lithosphere contributions to heat flow models with a focus on
East Antarctica, including the continental interior which is covered by ice of several kilometres thickness. We
review alternative approaches to combining low resolution information on the deeper lithosphere with broad
spatial coverage, and high resolution information with very limited spatial coverage relating to the upper
crustal. Providing effective estimates of the heat supplied by the upper crust is an important research goal due
to the significance of small pockets of elevated heat flow on ice sheet models. Our model for East Antarctica
represents a step towards future probabilistic approaches to solid Earth constraints for ice sheet models.

2479
 1390
The Sensitivity of GIA in West Antarctica to a Laterally Varying Earth Structure

Grace Nield1, Pippa Whitehouse1 (pippa.whitehouse@durham.ac.uk), Wouter van der Wal2, Bas Blank2, Andrew
Lloyd3, Douglas Wiens3, JP O'Donnell4, Graham Stuart4, Alex Brisbourne5
1
Durham University, Department of Geography, Durham, United Kingdom, 2Delft University of Technology,
Faculty of Aerospace Engineering, Delft, Netherlands, 3Washington University in St Louis, Department of Earth
and Planetary Sciences, St. Louis, United States, 4University of Leeds, School of Earth and Environment, Leeds,
United Kingdom, 5British Antarctic Survey, Cambridge, United Kingdom

The one-dimensional Earth structure adopted in many glacial isostatic adjustment (GIA) models leads to bias in
model predictions in regions where rheological parameters differ significantly from the 1D structure used. The
advancement of 3D GIA modelling techniques in recent years has led to improvements in the representation of
the Earth through the incorporation of laterally varying structure. This study investigates the influence of 3D
Earth structure on deformation rates in West Antarctica using a finite element GIA model with power-law
rheology, where the effective mantle viscosity depends on stress. We use a high resolution model of seismic
velocity to infer temperatures and derive creep parameters from a flow law for the crust and upper mantle
with the aim of determining a data-driven model of Earth rheology across Antarctica. We investigate the range
of plausible mantle viscosities this model predicts, given uncertainties in the input parameters to the flow law.
Furthermore, we consider the differences in model-predicted vertical deformation rates when compared to an
equivalent 1D Earth structure.

2480
 1885
Utilizing GPS to Investigate Ice History and Earth Model Inputs to GIA Models

Stephanie Konfal1 (skonfal@hotmail.com), Pippa Whitehouse2, Tim Hermans3, Wouter van der Wal3, Terry
Wilson1, Michael Bevis1, Eric Kendrick1, Ian Dalziel4, Robert Smalley5
1
Ohio State University, Columbus, United States, 2Durham University, Durham, United Kingdom, 3Delft
University of Technology, Delft, Netherlands, 4University of Texas -- Institute for Geophysics, Austin, United
States, 5Center for Earthquake Research and Information, Memphis, United States

ANET (Antarctic Network) GPS observations from the Polar Earth Observing Network (POLENET) record solid
earth deformation in response to ice mass change. In the Transantarctic Mountains (TAM) region, observed
horizontal motions are towards modelled West Antarctic centers of ice mass loss, opposite to the radially
outward pattern expected. We investigate alternative ice history and earth structure inputs to GIA models in an
attempt to reproduce observed motions in the region. The W12 ice history model is altered to include
unloading in the Wilkes Subglacial Basin based on glaciological records indicating LGM ice thicknesses greater
than present. These scenarios, along with the unmodified W12 ice history, are coupled with 60 radially varying
(1D) earth model combinations. Additionally, the influence of laterally heterogeneous earth structure is
investigated by coupling loading scenarios with earth models that permit two different viscosity profiles on
either side of a longitudinal boundary bisecting East and West Antarctica. For both the 1D and laterally
heterogeneous case, resulting model-predicted motions fit ANET GPS-derived crustal motions in the northern
and central TAM region for a suite of earth model combinations. Further south, observed and predicted
motions do not agree. Best fitting ice history and earth models are presented, including preferred upper
mantle viscosity values.

2481
 687
A New Global GPS Dataset for Testing and Improving Modelled GIA Uplift Rates

Maike Schumacher1 (maike.schumacher@bristol.ac.uk), Matt King2, Jonathan Rougier1, Zhe Sha1, Shfaqat
Abbas Khan3, Jonathan Bamber1
1
University of Bristol, Bristol, United Kingdom, 2University of Tasmania, Hobart, Australia, 3Technical University
of Denmark, Lyngby, Denmark

Permanent GPS stations provide a globally distributed record of long-term signatures of glacial isostatic
adjustment (GIA). In this study, we use about 4000 GPS vertical velocities as an observational estimate of global
GIA uplift rates, after correcting for major elastic deformation effects. A novel fully automatic strategy is
developed to post-process the GPS time series and to correct for non-GIA artifacts. Before estimating vertical
velocities and uncertainties, we detected outliers and jumps, and corrected for atmospheric mass loading
displacements. We corrected the resulting velocities for the elastic response of the solid Earth to global
changes in ice sheets and glaciers, as well as for changes in the Earth's rotational pole relative to the 20th
Century average. We applied a spatial median filter to remove sites reflecting local effects and to arrive at the
~4000 GPS site velocities.
The novel global GPS dataset shows a clean GIA signal at all post-processed stations and is therefore suitable to
investigate the behaviour of global GIA forward models. The dataset is compared with 13 global GIA solutions
considering differences in reference frame origins. Furthermore, we use the novel dataset to update global
forward model solutions within a Bayesian Hierarchical Modelling framework to identify statistically significant
deviations between the observations and the models, which may be due to either uncertain mantle rheology
and/or ice loading history or GPS errors.

2482
 SH-9b - Polar research in the humanities and social sciences: approaches and challenges
23.06.2018 14:00-15:30, A Wisshorn

1438
Creative Antarctica: Towards a Critical Evaluation of Residency Programs

Elizabeth Leane1 (elizabeth.leane@utas.edu.au), Carolyn Philpott2, Annalise Rees3

1
University of Tasmania, Institute for Marine and Antarctic Studies / School of Humanities, Hobart, Australia,
2
University of Tasmania, Conservatorium of Music, School of Creative Arts, Hobart, Australia, 3University of
Tasmania, Institute for Marine and Antarctic Studies, Hobart, Australia

Interdisciplinary collaboration is crucial to addressing threats to the Antarctic region, including global warming,
growing tourist numbers and marine harvesting. Currently, creative artists and non-scientific researchers can
visit Antarctic bases primarily through national residency programs. Such residencies have long existed, but
began to be consolidated into formal state-sponsored schemes in the late twentieth century. The structure and
format of residency programs vary considerably with national context, with each emphasizing a different (and
often uneasy) combination of artistic merit, promotion, communication, education and public accessibility.
Given the financial investment that many states make in these residencies, it is worth critically evaluating their
purpose and effectiveness. In preparation for a larger research project, this paper explores ways in which such
an evaluation might be undertaken. We briefly compare several residency programs, before posing a series of
questions. How does access to Antarctica impact on creative artists and the scientists they work alongside?
What innovations arise from the residencies? What can we learn from other residency models, such as those in
scientific institutions or wilderness environments? What do several decades of residencies teach us about the
most productive options for the future? We conclude by outlining some methods we plan to use to address
these questions and expected benefits for key stakeholders.

2483
 2526
Feminist Institutional Research: Challenges, Opportunities for Antarctic Science

Morgan Seag1 (mcs89@cam.ac.uk)

1
University of Cambridge, Scott Polar Research Institute, Cambridge, United Kingdom

Scholars in Antarctic humanities and social sciences are increasingly turning to gendered histories. Thanks to
scholarship in a range of disciplines, it is well understood that Antarctic activity has always been deeply
gendered (eg Glasberg, Lewander, Dodds). Still, much remains to be done. In particular, we have a limited
understanding of the processes through which women gained access to Antarctic field opportunities after
being categorically excluded through much of the twentieth century, and we insufficiently understand how
national contexts contributed to sometimes dramatic variation in women's access to the continent.
Drawing on archival work and interviews dealing with the British Antarctic Survey and the US Antarctic
Program, as well as existing literature on several other national Antarctic programs, this paper examines the
potential of a feminist institutional framework to address current gaps. It asks: how can the tools of feminist
institutionalism help us unpack the historical exclusion of women from Antarctica and the factors that
contributed to progress? What trends, connections, and contingencies are revealed? What weaknesses are
identified, and what lessons can be learned? It is argued that this approach offers valuable insights into several
dimensions of Antarctic activity, from scientific and sociocultural to geopolitical. Inspired by Traweek and
others, this paper issues a call for international discourse on Antarctica's gendered institutional histories.

2484
 2295
Collaborators, Competitors or Window Shoppers

Jihoon Jeong1 (jj@kopri.re.kr), Sunhwi Kim1, Chaerin Jung1, Hyoung Chul Shin1
1
Korea Polar Research Institute (KOPRI), International Cooperation Team, Incheon, Korea, Republic of

Collaborators, competitors or window shoppers: perception of Asian Arctic observers determined by media
coverage and public commentaries
The emergence of Asian actors in the Arctic affairs is attracting attention from many stakeholders in the Arctic,
ever since the 2013 Kiruna Ministerial Meeting.
As most of the region in the Arctic Circle is under sovereignty or sovereign right of the eight Arctic states, non-
Arctic players generally look for invitations from the Arctic, which in turn renders their overall perception by
the Arctic community a matter of significance.
This study aims to provide empirical answers to the following questions:
(a) What activities of Asian observer states, and at what time draw the attention of the eight Arctic states and
become featured in Arctic media and commented by key Arctic figures?
(b) What is the attitude toward the activity in each case - positive, negative, or neutral?
(c) Can the background of the respective attitudes be determined?
From selected Arctic media, we collected and analyzed articles that cover Arctic activities of these Asian Arctic
observers, since May 2013. The articles were classified by issue areas (i.e. research/education; environmental
conservation; regional development; shipping/routes; resources; and strategy/military), and then sorted by the
nature of the stances expressed therein. The perception conveyed by these articles did not always correspond
with the public statements of the observers in question.

2485
 163
A Gap in the Antarctic humanities, and why it Should Be Filled

Alejandra Mancilla1 (alejandra.mancilla@ifikk.uio.no)

1
University of Oslo, Philosophy, Oslo, Norway

Most analyses of Antarctic politics and geopolitics so far have taken a descriptive approach and presented
matter-of-factly what actors there are, what goals they have, and what tensions and challenges this will bring
to the Antarctic Treaty System. In this presentation, I suggest that such a descriptive approach should be
complemented by a normative one, where assessments are made concerning—among other topics—the status
of territorial claims and the external legitimacy of the Antarctic Treaty System. Starting from the assumption
that politics is not just a matter of force and rhetoric, but also a matter of following certain basic moral
principles, such a normative assessment is urgently needed in a time where global pressure over living and
non-living natural resources in Antarctica will keep mounting. Its practical purpose, ultimately, should be to
foster peaceful knowledge-based management and policy-making in the White Continent.

2486
 1892
Antarctica and Space as Environmental Analogues

Peter Suedfeld1 (psuedfeld@psych.ubc.ca)

1
The University of British Columbia, Department of Psychology, Vancouver, Canada

Antarctic stations have for decades been used as research analogues of spacecraft, especially space stations
such as Skylab, Mir, and the International Space Station. The two environments share isolation, confinement,
novelty, discomfort, danger, and remoteness. They are attractive analogues because research in space is
expensive, complex, and limited in research time, facilities, and subjects. It is time to review this practice.
Analogues should not merely look similar, they should have similar effects. Is this true of Antarctica and space?
Data, some of them unpublished, from multi-year studies conducted in the two environments are reviewed to
compare the stressful and adverse (pathogenic) and healthful, positive (salutogenic) effects of the two
environments on human physiology and psychology in order to evaluate this question.

2487
 1911
Arctic Horizons and IASSA: The State and the Future of Arctic Social Sciences

Andrey Petrov1 (andrey.petrov@uni.edu)

1
University of Northern Iowa/IASSA, Cedar Falls, United States

This presentation will offer an overview of the Arctic Horizons report that outlines major milestones, trends
and priorities in Arctic social sciences research. The report resulted from a series of workshops with primarily
US researchers devoted to identifying strengths, weaknesses, emerging science questions and funding priorities
for social sciences in the Arctic. These findings are placed in the broader international context from the
positions of the International Arctic Social Sciences Association (IASSA).

2488
 SY-1c - Earth Observation: Solutions for data collection, compilation and dissemination
23.06.2018 14:00-15:30, B Pischa

2401
Towards Cross-weaving of Knowledge for Better Decisions

Finn Danielsen1, PâviâraK Jakobsen2, Nette Levermann3, Bjarne Lyberth4, Michael Køie Poulsen1, Hajo Eicken5,
Martin Enghoff1, Peter Pulsifer6 (peter.pulsifer@colorado.edu), Julia Collins6, Betsy Sheffield6
1
Nordic Foundation for Development and Ecology, Copenhagen, Denmark, 2Qaasuisup Municipality, Aasiaat
Area Office, Aasiaat, Greenland, 3Greenland Ministry of Fisheries and Hunting, Nuuk, Greenland, 4Greenland
Association of Fishermen and Hunters (KNAPK), Nuuk, Greenland, 5University of Alaska Fairbanks, International
Arctic Research Center, Fairbanks, United States, 6Exchange for Local Observations and Knowledge of the Arctic,
National Snow and Ice Data Center, University of Colorado at Boulder, Boulder, United States

Arctic people observe the environment all year round. Their knowledge is critical for effective resource
management. Yet, while approaches to data collection with community members have been well described,
means of disseminating and using local knowledge for decision-making have received less attention. Here, we
discuss lessons learned and tools developed from Greenland. Our case is the Piniakkanik Sumiiffinni
Nalunaarsuineq (PISUNA) approach in Greenland. Here, in communities where there is interest, the village
residents establish a Natural Resource Council comprising hunters and fishers. They decide which species and
resource uses should be observed. Together, they compile data on species and resource uses during their
hunting and fishing activities. Every three months, data are summarised and analysed, and possible
management interventions discussed. The proposed management interventions and supporting data are
forwarded to the government. The Council uses matrices that encourage self-interpretation and validation and,
at the same time, they promote discussion of resource management actions. With 2-3 keystrokes, decision-
makers can access trend-information and management proposals at PISUNA-net, a searchable icon-based
database developed with SIZO-net and ELOKA projects. This approach combines local knowledge with digital
technology, providing an opportunity for the community members' insights and knowledge to be used and
their voices heard.

2489
 2177
Community-based Monitoring Networks, Data Sharing, and Earth Observation

Noor Johnson1,2 (noor.johnson@colorado.edu), Maryann Fidel3, Lisbeth Iversen4, Rodion Sulyandziga5, Hajo
Eicken6, Martin Enghoff7, Olivia Lee6, Peter Pulsifer1, Ania Albin7, Michael Køie Poulsen7, Colleen Strawhacker1,
Finn Danielsen7
1
University of Colorado Boulder, National Snow and Ice Data Center, Boulder, United States, 2Tufts University,
Fletcher School of Law and Diplomacy, Medford, United States, 3Yukon River Inter-Tribal Watershed Council,
Anchorage, United States, 4Nansen Environmental and Remote Sensing Center, Bergen, Norway, 5Center for
Support of Indigenous Peoples of the North, Moscow, Russian Federation, 6University of Alaska Fairbanks,
International Arctic Research Center, Fairbanks, United States, 7Nordic Foundation for Development and
Ecology, Copenhagen, Denmark

Community-based monitoring and observing programs exist around the Arctic, drawing on both Indigenous
methods of observation, protocols developed by scientists, and combinations of the two. These programs use a
variety of data collection methods, ranging from interviews to field diaries to handheld computers and digital
devices. In this paper, we examine challenges and opportunities related to data collection, compilation, and
dissemination for community-based monitoring programs. Community-based monitoring offers unique, in situ
observational data that can contribute to management of natural resources as well to large scale observing
systems. Management of CBM data requires an understanding of the context in which community members
engage in both formal and informal observing, with implications for design of infrastructures and networks for
data sharing. We draw on information gathered through workshops with community-based monitoring
practitioners held in Alaska, Canada, and Russia, organized under the INTAROS project, and a student field trip
to Svalbard, organized by INTAROS and REGIMES. Practitioners gathered at the workshops identified good
practices and specific needs for establishing and sustaining CBM programs and connecting them to natural
resource management and decision-making. Participants also discussed CBM in relation to broader themes
such as access to resources, health of subsistence species, and unusual events.

2490
 1116
The Earth Radiation Budget Explorer (EAGER) Mission Concept

Benjamin Walter1 (benjamin.walter@pmodwrc.ch), Margit Haberreiter1, Wolfgang Finsterle1, Werner Schmutz1

1
Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf, Switzerland

It is widely accepted that a significant net-influx of radiative energy of about 1 Wm-2 to the Earth's atmosphere
is mainly responsible for global warming. However, instruments and methods used to determine the global
radiative energy budget at the top of the atmosphere (TOA) are so far not able to accurately resolve this small
difference between the incoming and outgoing radiation. The relevant radiative components include the Total
Solar Irradiance (TSI), the Spectral Solar Irradiance (SSI), the Reflected Solar Radiation (RSR) and the Earth's
Infrared Emission (EIE).
The Earth Radiation Budget Explorer (EAGER) mission concept planned by PMOD/WRC together with the
University of Leipzig, the Fraunhofer Institute for Physical Measurement Techniques and the Royal Observatory
of Belgium aims for providing direct measurements of all four components required for detecting the energy
budget imbalance with unpreceded accuracy. We present the instrumental approach and technical challenges
of the EAGER mission concept consisting of two Sun and four Earth oriented instruments on an Airbus satellite
platform: i) A Digital Absolute Radiometer (DARA) for measuring TSI, ii) an Extreme-UV and Infrared (EUV/IR)
Spectrometer (SolACER) for measuring SSI, iii) three Bolometric Oscillation Sensors (BOS) for measuring RSR
and EIE, and iv) a DARA Albedo Earth Sensor (DARA-AES) for periodically recalibrating the BOS instruments.

2491
 1617
An International Observing System for the Southern Ocean

Louise Newman1 (louise.newman@utas.edu.au), Andrew Constable2, Sebastiaan Swart3, Oscar Schofield4, Mike
Williams5, Phillippa Bricher6
1
Southern Ocean Observing System, Institute for Marine and Antarctic Studies, Hobart, Australia, 2Australian
Antarctic Division, Hobart, Australia, 3University of Gothenberg, Gothenburg, Sweden, 4Rutgers University, New
Jersey, United States, 5National Institute for Water and Atmospheric Research, Wellington, New Zealand,
6
Southern Ocean Observing System, Hobart, Australia

The Southern Ocean and its related atmo-, cryo-, geo- and bio-sphere, has a profound influence on the global
Earth system. Although geographically remote, it directly impacts global societies through, for example, its role
in maintaining Earth's heat and carbon budgets and storage, provision of food, and in providing intrinsic value
for conservation and tourism. Moreover, the ocean-ice-atmosphere interactions will have far-reaching
consequences for the globe through sea-level rise. Yet, the Southern Ocean remains one of the most under-
observed regions in the world. The IPCC has identified uncertainties in estimations of future state of Southern
Ocean processes, and highlighted that a sustained system for observing trends in physics, chemistry and
biology is urgent for this region, to reduce those uncertainties. The Southern Ocean Observing System (SOOS)
developed over the last decade to fill this urgent need. SOOS has established regional and capability working
groups to coordinate the contributions of Antarctic nations in delivering a system for observing essential
variables, and to provide data streams to the scientific community, stakeholders and policy-makers. SOOS also
provides a hub for accessing data repositories, linking data from satellites, remote in-situ observations, and in-
field activities. In this paper, we outline the vision for SOOS and, in particular, highlight new products that
facilitate fieldwork planning and coordination, and data discovery and sharing.

2492
 1232
ICEBERG: Imagery Cyberinfrastructure to Enhance Research in Geosciences

Shantenu Jha1, Heather Lynch2 (heather.lynch@stonybrook.edu), Vena Chu3, Mike Salvatore4, Mike Willis5
1
Rutgers University, Piscataway, United States, 2Stony Brook University, Stony Brook, United States, 3University
of California Santa Barbara, Santa Barbara, United States, 4Northern Arizona University, Flagstaff, United
States, 5University Colorado, Boulder, United States

ICEBERG: Imagery Cyberinfrastructure and Extensible Building Blocks to Enhance Research in the Geosciences
Satellite imagery is rapidly transforming the way we see the planet, including our ability to study the most
remote parts of the Arctic and Antarctic. Satellite imagery can help us map networks of rivers, study changes in
the flow and thickness of glaciers, identify rock and soil types, and even find animals like penguins and seals.
Because the availability of imagery in polar areas has increased rapidly over the last decade, we are now faced
with a challenge: How do we scale-up the scientific discoveries that have been enabled by satellite imagery to
larger spatial scales? Moving from small pilot-studies to pan-Arctic or pan-Antarctic analyses of geological and
biological processes requires new infrastructure to link scientists, satellite imagery, and high-performance
computers. This new imagery-computing superhighway will make it easier for scientists to study processes at
much larger spatial scales than has been previously possible. Our project, called ICEBERG — Imagery
Cyberinfrastructure and Extensible Building-Blocks to Enhance Research in the Geosciences, aims to build the
cyberinfrastructure required to make the most of satellite imagery for geosciences, starting with researcher
working in polar areas, where much of this science is already underway, and then branching out to the entire
EarthCube community.
ICEBERG is supported by the NSF EarthCube program

2493
 1683
Geoinformation System for Environmental Monitoring of the Arctic Ocean

Vladimir Volkov1, Eduard Kazakov1 (ekazakov@niersc.spb.ru), Denis Demchev1,2

1
Nansen International Environmental and Remote Sensing Centre, Saint Petersburg, Russian Federation, 2Arctic
and Antarctic Research Institute, Saint Petersburg, Russian Federation

Continuous collection of environmental data about the Arctic ocean, involving algorithms and models for the
analysis of its characteristics is essential not only for operational monitoring and enforcing economic activities,
but also to explore different-scale natural processes in the atmosphere and ocean, their dynamics.
The presentation discusses the establishment of a comprehensive geographic information system based on
open source satellite data, combining the processes of assessment of ice conditions and primary productivity of
the ocean. The core algorithms are developed and implemented methods for automated classification of types
of sea ice, ice drift fields retrieving, ice deformations retrieving, iceberg detection and calculations of various
characteristics of biological productivity.
Collecting and processing of data consolidated in a integrated information system that is accessed via standard
protocols with two types of interfaces - web portal NIERSC Data Center and desktop application NIERSC QGIS
ToolBox implemented as an extension to the open source desktop GIS QGIS. Deployment of desktop solution is
automated with the virtual machines hypervisor Oracle VirtualBox and Vagrant software with storing the
source codes of the algorithms on GitHub.
Development of data processing methods and access interfaces allows to explore natural environment of the
Arctic ocean more deeply with every step.

2494
 EN-2c - Contamination in Polar and High Altitude Environments
23.06.2018 14:00-15:30, B Parsenn

1837
Temporal Trends of PCBs and OCPs in Landlocked Char from High Arctic Lakes

Ana Cabrerizo1 (anacabrerizopastor@hotmail.com), Derek Muir1, Günter Köck2, Debbie Iqaluk3, Xiaowa Wang1,
Scott Lamoureux4, Melissa Lafraeniere4
1
Environment & Climate Change Canada, Burlington, Canada, 2Institute for Interdisciplinary Mountain Studies,
Insbruck, Austria, 3Resolute Bay, Resolute, Canada, 4Queen's University, Kingston, Canada

Temporal trends and climate related parameters affecting the fate of legacy persistent organic pollutants
(POPs) such as polychlorinated biphenyls (PCBs), organochlorine pesticides (HCHs, DDTs and HCB) and
toxaphene were examined in landlocked Arctic char from six lakes in the Canadian Arctic located on Cornwallis
Island (Resolute, Char, Amituk Lakes), Ellesmere Island (Lake Hazen) and two paired lakes in Melville Island
(West and East Lakes). Research performed over the past 10 years in the study area has revealed ongoing
permafrost disturbances, which are of significant magnitude and importance on the West Lake watershed and
lake (Melville Island). Adult char were collected in late July from almost every year from 2001 to 2016, by gill
netting or by jigging through the ice at a rate of 7 to 25 adult fish per lake and year. All fish were dissected in
situ and subsamples of muscle+skin, liver, otoliths and GI tract were kept frozen for transport and storage in an
ultra clean freezer (-30ºC). In total, more than 500 samples from muscle+skin arctic char were collected and
analyzed for POPs in this study with the aim of i) examining the trends of legacy POPs such as PCBs and OCPs
(DDTs, HCHs and HCB) and toxaphene, ii) study which parameters are affecting the occurrence of POPs in Arctic
char and iii) investigate whether or not climatic parameters and climatic oscillation patterns may affect the
temporal trends of POPs in Arctic Char.

2495
 1541
Emerging and Legacy POPs in Norwegian Marine Sediments: The MAREANO Program

Stepan Boitsov1 (stepan@imr.no), Jarle Klungsøyr1, Henning K.B. Jensen2

1
Institute of Marine Research, Bergen, Norway, 2Geological Survey of Norway, Trondheim, Norway

The Norwegian national program of seabed mapping, MAREANO, has been carried out on a yearly basis for
over a decade in remote open-sea areas of the Norwegian Arctic. Several groups of organic contaminants in
surface and subsurface sediments from shelf areas of the Barents and the Norwegian Seas have been mapped.
The hydrocarbons are the most abundant among all the studied types of contaminants due to natural presence
in the marine environment. Analyses of 48 separate PAH compounds in dated sediment cores, together with
grain size and total organic carbon contents, allow to distinguish the natural background from anthropogenic
inputs and discuss possible sources. While pyrogenic PAHs dominate the PAH composition of most samples,
petrogenic and biogenic PAHs are sometimes also found in significant amounts. The geographical distribution
of manmade legacy POPs (PCBs, five types of chlorinated pesticides, PBDEs) in surface sediments shows some
variations at low levels throughout the area. The first results of analyses of several groups of emerging
contaminants (PFAS, PFR, siloxanes), as well as alkylphenols, alkylphenol ethoxylates and bisphenol A, indicate
trace amounts of some of these compounds in surface sediments. A pilot study of microplastics in a small
selection of samples from the same areas have revealed the presence of different quantities of several types of
plastics in the µm range in all the analysed samples. However, several methodological challenges remain.

2496
 1444
Anthropogenic Effects on the Marine Environment at Palmer Station, Antarctica

Terence Palmer1 (terry.palmer@tamucc.edu), Stephen Sweet2, Andrew Klein3, Larry Hyde1, Paul Montagna1,
Jose Sericano2, Terry Wade2
1
Texas A&M University-Corpus Christi, Harte Research Institute, Corpus Christi, United States, 2Texas A&M
University, Geochemical and Environmental Research Group, College Station, United States, 3Texas A&M
University, Department of Geography, College Station, United States

Palmer Station is a small US research base (15-40 people) north of the Antarctic Circle (64.8°S). In 1989, the
Argentine supply vessel Bahia Paraiso ran aground and eventually sunk, leaking an estimated half a million
liters of diesel and other hydrocarbons. Subsequent impact monitoring from 1989 to 1992 determined that
some marine sediments were contaminated, along with bioaccumulation in, and mortality of, intertidal limpets
(Nacella concinna). However, an assessment of local anthropogenic effects on the marine environment had not
been conducted since 1992. In 2014 and 2015, marine sediments were collected to quantify the extent and
effects of any potential contamination on deep (18 to 24 m), soft-sediment benthic macrofauna from both the
Bahia Paraiso, and from Palmer Station itself. Intertidal and subtidal limpet tissues were also sampled to
determine any potential contamination effects in shallow areas (< 10 m) where hard substrate dominates.
Preliminary results show that Polycyclic Aromatic Hydrocarbon (PAH) concentrations in the sediment have
decreased since 1991, however high concentrations exist at three sites within the vicinity of Palmer Station.
PAH concentrations in limpet tissues have also decreased over time, however concentrations are still high in
limpet tissues at the Bahia Paraiso and at some sites close to Palmer Station. The status of human impacts on
the marine benthos, and comparisons with the 1989 to 1992 assessments will be presented.

2497
 95
First Detection of SCCPs in Humpback Whales Foraging in Antarctic Waters

Valeria Casà1,2 (valeria.casa@griffithuni.edu.au), Louise van Mourik3, Liesbeth Weijs4, Susan Bengtson Nash2
1
Environmental Futures Research Institute, Nathan, Australia, 2Griffith University, Nathan, Australia, 3VU
University Amsterdam, Amsterdam, Netherlands, 4Griffith University, Gold Coast, Australia

Chlorinated paraffins are industrial mixtures of polychlorinated-n-alkanes. Their synthesis started in the 1900s
when they were used in the preparation of an antiseptic solution during World War I. They can be released
through production, storage, transportation, usage and disposal of, plastics, adhesives, rubber, sealants, liquor
leathering and metal cutting fluids. Short chain chlorinated paraffins (SCCPs; C10-13) are of particular interest
because they have been detected in remote environments, such as the poles of the earth, demonstrating their
capacity for long range transport. Further, their persistence, capacity for bioaccumulation in lipids and long-
range transport, led to their inclusion in the persistent organic pollutants (POPs) list, under the Stockholm
Convention, in May 2017. Here we report for the first time, the detection of SCCPs in the blubber of humpback
whales (n=10), belonging to the southern hemisphere E1 population known to feed on Antarctic krill
(Euphausia superba) in Antarctic waters. The blubber samples were collected from humpback whales stranded
along Australian coasts between 2008-2012 and approximately 2g of blubber from each specimen was
dedicated to the analysis. As long-lived cetaceans with a large proportion of body lipid mass, humpback whales
represent suitable bioindicators of Antarctic lipophilic chemical pollution. The study serves as a further proof of
the ubiquity and bioaccumulation potential of these newly listed POPs.

2498
 419
Persistent Pollutants in Arctic and Antarctic Krill and in Commercial Krill Oil

Simonetta Corsolini1 (simonetta.corsolini@unisi.it), Nicole Camicetti2, Tania Martellini2, Alessandra Cincinelli2

1
University of Siena, Department of Physics, Earth and Environmental Sciences, Siena, Italy, 2University of
Florence, Department of Chemistry 'Ugo Schiff', Florence, Italy

Krill are considered key-species of marine ecosystems of the Polar Regions, being main food source for fish,
marine mammals and birds in the Southern Ocean and in Arctic seawaters. Through ingestion, persistent
organic pollutants accumulated in their body could be transferred to their predators due to biomagnification
process and may cause effects in the entire trophic web. We studied krill from the Arctic and Antarctic
seawaters in order to assess the toxic risk for their predators. Recently, the krill oil has been used in
commercial preparation of pills for supplying unsaturated fatty acids, hence including humans in the list of krill
predators. In order to assess the contaminant level and toxic risk for predators, the presence of some
persistent organic pollutants was determined by gaschromatography-mass spectrometry in Antarctic and Arctic
krill samples and commercial pills. The sum of 4 congeners of mono- and 8 congeners of non-ortho
polychlorinated biphenyls was < 0.001-0.471 and < 0.001-0.499 ng/g wet wt in the Antarctic and Arctic krill,
respectively. HCHs and DDTs were more abundant in the Arctic krill (0.856±0.315 ng/g wet wt) while the sum of
23 congeners of polybrominated diphenyl ether predominated in the Antarctic krill (0.121±0.074 ng/g wet wt),
with BDE47 making up most of the residue. The same contaminants were detected in the krill oil pills; the
assessed TDI was below the limit suggested by the World Health Organization.

2499
 2244
Adelie Penguins as Indicators of Persistent Organic Pollutants (POPs)

Phoebe Lewis1 (phoebe.lewis@rmit.edu.au), Thomas McGrath1, Louise Emmerson2, Jeff Shimeta1, Bradley
Clarke1
1
RMIT University, Centre for Environmental Sustainability and Remediation (ENSURE), Melbourne, Australia,
2
Australian Antarctic Division, Kingston, Australia

Persistent organic pollutant (POP) exposure in Adelie penguins (Pygoscelis adeliae) may reflect local or regional
conditions better than other seabird groups as they are highly constrained within their foraging habitat and
remain south of 60oS during winter. While POP contamination within Antarctica is largely caused by long-range
atmospheric transport, Antarctic research bases have been shown to be local sources of emerging POPs such as
polybrominated diphenyl ethers (PBDEs). In addition, Antarctic soil concentrations near Adelie penguin
colonies have shown elevated concentrations of legacy POPs such as organochlorine pesticides (OCPs) and
polycholorinated biphenyls (PCBs), suggesting guano and bird remains may contribute substantially to local
contamination levels. This study aims to evaluate Adelie penguin colonies as indicators of local contamination
of POPs within east Antarctica. Soil samples (n=68) were collected from Adelie colonies within close proximity
to Australian research stations Mawson and Davis as well as further afield during the 2016/17 austral summer.
Samples are being analysed for OCPs, PCBs, PBDEs and novel flame retardants using selective pressurised liquid
extraction (S-PLE) and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Results will
provide baseline data for regional POP contamination with Adelie species local to east Antarctica, as well as
provide an assessment of potential station-derived impacts.

2500
AC-6_AC-7b - Across the Southern Ocean: Atmospheric and ice mass changes & Seeing the
Future: Predicting Variability and Change of the Polar Climate and Environment
23.06.2018 14:00-15:30, C Sanada I

2293
Understanding Diversity in CMIP5 Projections of Winds over the Southern Ocean

Tom Bracegirdle1 (tjbra@bas.ac.uk), Patrick Hyder2, Caroline Holmes1

1
British Antarctic Survey, Cambridge, United Kingdom, 2Met Office Hadley Centre, Exeter, United Kingdom

The CMIP5 climate models simulate a robust poleward shift and strengthening of the main eddy-driven belt of
Southern Hemisphere (SH) mid-latitude near-surface westerly winds ('westerly jet' or 'jet') as part of the
climate change response to increasing greenhouse gases. Such changes have wide-reaching implications both
regionally and globally relating to impacts on, for example, uptake of heat and CO2 in the Southern Ocean and
ice-ocean interactions around Antarctica. However, there is a large inter-model spread in the magnitude of jet
responses.
The focus of this presentation will on linkages between diversity in simulated CMIP5 sea ice area (SIA),
Antarctic amplification and diversity in projected 21st century changes in the westerly jet. Broadly it is found
that model diversity in projected 21st century jet strengthening is much more highly correlated with sea ice
area (SIA) (and associated Antarctic amplification) than diversity in jet shift. Specifically, CMIP5 models with
larger simulated present-day SIA broadly exhibit more sea-ice retreat and less jet strengthening in future
projections. To help disentangle cause and effect in the coupled model analysis, output from uncoupled
atmosphere-only fixed sea-surface experiments from CMIP5 was also evaluated. This analysis points to a
coupled link between simulated present-day jet strength biases and projected future jet strengthening.

2501
 2400
Increasing the Predictability of Arctic land Surface Energy Fluxes

Gabriela Schaepman-Strub1 (gabriela.schaepman@ieu.uzh.ch)

1
University of Zurich, Dept. Evol. Biology and Environmental Studies, Zürich, Switzerland

The energy budget of Arctic land surfaces is expected to change significantly under future climate warming. All
components of the energy budget might undergo shifts under increasing air temperature and precipitation.
Examples include changes of irradiance due to alterations in cloud cover; of albedo as a response to changing
snow cover, water surface extent, plant composition and structure; and of ground heat fluxes in response to
changing thermal conductivity related to increasing or decreasing soil moisture. However, predictions of most
of these changes are still highly uncertain, as well as their combined effect onto the energy budget.
Based on our recent observational and modelling studies of land surface energy budget components in the
northeastern Siberian Arctic tundra and recent literature, I will synthesize the status and needs to improve the
predictability of land surface energy fluxes in the Arctic. Discussed aspects include observations, experiments,
and modelling from local to regional scale. A special emphasis will be on how we can predict the effects of
vegetation change on shortwave energy fluxes through experimental evidence, linking plant traits to
vegetation-light interaction, from leaf to landscape scale.

2502
 1858
Observational Evidence for Predictive Skill from Arctic Summer Sea-ice Extent

Erlend Moster Knudsen1, Shengping He2 (shengping.he@uib.no), David W.J. Thompson3, Tore Furevik2
University of Cologne/Institute for Geophysics and Meteorology, Köln, Germany, 2Geophysical Institute,
1

University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway, 3Colorado State University,
Department of Atmospheric Science, Fort Collins, United States

We investigate the lead/lag linkages between summertime Arctic sea ice extent (SIE) and high-latitude climate.
Arctic SIE anomalies exhibit notable persistence from midsummer (~July) through autumn (~October). The
persistence of summertime Arctic SIE anomalies extends to Arctic temperature, geopotential height, and mid-
tropospheric zonal flow. Hence, summertime SIE anomalies are significantly linked to Arctic climate variability
up to three months in advance. The inferred skill that derives from summertime SIE is robust over the Arctic
basin, but does not appear to extend to midlatitudes. It is theorized that the lagged relationships between
summertime SIE and autumn Arctic climate derive from a combination of
1) the persistence of SIE anomalies from summer to autumn and
2) the anomalous surface fluxes of heat and moisture that accompany the persistent SIE anomalies.

2503
 454
Modulation of Arctic Climate Change by Atlantic Multidecadal Variability

Rym Msadek1 (msadek@cerfacs.fr), Christophe Cassou1

1
CNRS / Cerfacs, Toulouse Cedex, France

Arctic sea ice has undergone a substantial decline since the beginning of satellite observations (Stroeve et al.
2014), a negative trend that is modulated by internal variability on decadal time scales, which complicates
near-term predictions of Arctic climate (Swart et al. 2015). We focus here on the modulation of Arctic sea ice
response to CO2 by Atlantic Multidecadal Variability (AMV) using the following sensitivity experiments done
with the CNRM-CM5 climate model:
1-Control (CTL): Twin ensemble experiments (13 members of 30 years) started from a strong (AMV+) and weak
(AMV-) AMV state, respectively, with fixed external forcing.
2-Abrupt CO2: Same as CTL except that CO2 is instantaneously doubled at the beginning of the simulation and
then hold fixed.
3-Transient CO2: Same as CTL except that CO2 is increased by 2% per year.
We present climate differences in terms of air temperature, surface heat fluxes, winds and sea ice in the AMV+
and AMV- ensembles and analyze the variability of oceanic heat transport through the main Arctic gateways.
Previous studies suggested an increased ocean heat transport into the Arctic in response to climate change
because of an enhanced heat flux into the Barents Sea (Koenigk et al. 2013). We show that such transport can
be modulated by the AMV in agreement with previous studies (Zhang 2015, Arthun and Eldevik 2016). We
highlight the importance of better understanding ocean decadal variability for improved predictions of Arctic
climate.

2504
 2358
Sub-seasonal Predictability of Cold Air Outbreaks

Mikhail Dobrynin1 (mikhail.dobrynin@uni-hamburg.de), Erik Kolstad2, Daniela Domeisen3, Johanna Baehr1

1
Institute of Oceanography, Universität Hamburg, CEN - Center for Earth System Research and Sustainability,
Hamburg, Germany, 2Uni Research Climate, Bjerknes Centre for Climate Research, Bergen, Norway, 3ETH Zürich,
Zürich, Switzerland

Rapid propagation of cold polar air masses into middle or lower latitudes known as cold air outbreaks (CAOs)
leads to the formation of extreme negative anomalies of air temperature over large areas. The most persistent
CAOs may have a period of a few weeks, which is in the sub-seasonal forecasting range. Here, we investigate
the potential of a seasonal prediction system to provide a skilful prediction of long-term CAOs on sub-seasonal
scales. We use the seasonal prediction system based on the mixed resolution CMIP5 version of the Max Planck
Institute for Meteorology Earth System Model (MPI-ESM-MR). In our analysis of 30-members ensemble
hindcasts we focus on strong and most persistent CAOs in the period from 1982 to 2017. Prediction skill of sub-
seasonal CAOs as well as background parameters such as surface and 850 hPa air temperature will be
presented.

2505
 POLAR 2018
AUTHOR INDEX
A
Aaboe, Signe Fri_244_OS-5_2072
Aalstad, Kristoffer 2485
Aalto, Pasi 2499
Aanderud, Zachary Thu_197_BE-12_2223, Tue_150_BE-3_2653
Aarbakke, Ole N.S. Tue_355_OS-8_795
Abbatt, Jon 495
Abbatt, Jonathan P.D. Tue_45_AC-1_1139
Abbott, Benjamin Thu_197_BE-12_2223
Abbott, Tirzah Fri_110_EN-7_2657
Abd. Rahman, Hamisah Fri_330_SH-9_912
Abdul Mutalib, Firdaus Tue_198_BE-4_1996
Abdul Rahim, Rashidah Tue_151_BE-3_1888
Abdul Rahman, Nur Fadzliana 2419
Abe, Lyu 1272, 1376
Abel, Steven 1796
Abele, Doris 1343
Abeli, Thomas 1051
Abermann, Jakob Thu_241_CR-4_2410
Abernathey, Ryan 2171
ABN, Dating Team Wed_184_CR-8_2290
Abollino, Ornella Fri_79_EN-7_754, Tue_63_AC-1_1703
Abraha, Kibrom Ebuy 2016
Abraham, Luke 1521
Abrahamsen, Povl 1292, 1433, Wed_258_OS-6_1555
Abrahamsson, K. Wed_215_OS-2_1279
Abram, Nerilie J. Fri_55_EN-6_917
Abreu, José Thu_142_BE-9_1615, Tue_192_BE-4_1611, Tue_193_BE-4_1613
Abu Samah, Azizan Wed_30_AC-2_1998
Accettella, Daniela Tue_247_GG-2_200, Tue_279_GG-2_1478
Achaz, Guillaume Thu_146_BE-9_1807
Acinas, Silvia G 2065
Ackley, Stephen 1605, 2021, 2156, 2503, 2524, 263, 264, Fri_229_OS-5_265,
Fri_256_OS-7_480, Fri_282_OS-7_1418, Thu_339_OS-3_479, Wed_205_OS-2_358, Wed_315_TE-
1_553
Ackley, Stephen F. 945, Fri_227_OS-5_172
Ackley, Steve 1181, 744, Wed_206_OS-2_378
Acosta Hospitaleche, Carolina Fri_54_EN-6_798
Acosta Navarro, Juan Camilo 660
Action Group, Geomap 607
Acuña, Francisco Ferrando Thu_278_CR-6_309
Adams, Byron 307, Tue_150_BE-3_2653, Wed_89_BE-7_2697
Adams, Byron J. Fri_39_EN-5_879
Adams, Gregg 2154
Adams, Jenni 1476
Adams, Merrin Fri_34_EN-2_2691
Adhikari, Bishwa Wed_89_BE-7_2697
Adhikari, Dilip Tue_305_GG-2_2602
Adhikari, Surendra Thu_257_CR-5_1064
Adie, Euan Tue_318_OC-1_1718
Adie, Susan 380
Adlard, Stacey Thu_105_BE-8_2236
Adnan, Nur Hidayu Syuhada Tue_146_BE-3_2310
2506
Adolfo Ferron, Francisco Fri_7_EN-2_372
Adriaenssens, Evelien 2488
Adusumilli, Susheel 1347
Aebi, Mathias 1507
Aebig, Christopher H. F. 843
Aemisegger, Caroline 1802
Aemisegger, Franziska 1041, 2643, Fri_257_OS-7_491, Fri_263_OS-7_931, Thu_23_AC-
8_489, Wed_12_AC-2_915, Wed_5_AC-2_492
Aerts, Rien 60
Afanasyeva, Victoria Thu_210_CR-4_702
Agabi, Abdelkrim 1272
Agabi, Karim 1376
Agersted, Mette Dalgaard Fri_10_EN-2_555, Thu_88_BE-5_1225
Agnan, Yannick Fri_74_EN-7_277
Agosta, Cecile 1528, Thu_248_CR-5_297
Agosta, Cécile 1988, Thu_303_CR-6_2306, Thu_308_CR-6_2640
Agrios, Liana 1889, 2580
Aguayo, Yessenia Tue_169_BE-4_712
Aguera, Antonio 1864, Wed_86_BE-7_1866
Agüera, Antonio Tue_167_BE-4_662
Agüera Garcia, Antonio Tue_159_BE-4_430
Aguiar-Gonzalez, Borja Wed_270_OS-6_2186
Aguilar Muñoz, Polette Thu_199_BE-12_2444
Aguilar-Islas, Ana Wed_219_OS-2_1594
Aguirre-Díaz, Gerardo Fri_137_GG-1_967
Agusti, Susana 1345, Tue_358_OS-8_940
Ahlert, Abigail 1178
Ahlstroem, Andreas 1495, Fri_354_SY-1_2080
Ahn, In-Young 324, Thu_96_BE-5_2413, Wed_84_BE-7_1505
Ahn, S.H. Tue_73_AC-1_2020
Ahn, So Hyun Thu_52_BE-2_234
Ahonen, Heidi 1311
Ai, Likun Wed_107_CR-3_863, Wed_108_CR-3_864
Ai, Songtao Thu_274_CR-6_170
Aiken, Christopher M. Fri_296_OS-7_1902
Ainley, David 1179, 478, Thu_181_BE-11_1180
Airs, Ruth Fri_307_OS-7_2683
Aitken, Alan Fri_124_GG-1_347
Akçar, Naki Tue_300_GG-2_2339
Akhoudas, Camille Wed_243_OS-6_1007
Akperov, Mirseid Wed_24_AC-2_1727
Aksenov, Yevgeny 1396, 2471
Al Samarai, Imen Tue_19_AA-1_2319
Alarcón, Emilio Thu_53_BE-2_314
Alba, Marco Wed_260_OS-6_1628
Albani, Samuel Wed_160_CR-8_818
Alberello, Alberto 1298, 239, Fri_275_OS-7_1296, Wed_227_OS-6_247
Albert, Mary 1072, 730, Wed_322_TE-1_1066
Albert, Mathias Fri_321_SH-9_11
Albin, Ania 2177
Albin, Anna Thu_385_SH-6_1666
Albot, Anya Tue_262_GG-2_833
Albot, Olga Tue_276_GG-2_1354
Albot, Olya Tue_298_GG-2_2261
Albrecht, Torsten 1076
Albretsen, Jon 1112
Aldenhoff, Wiebke Thu_355_OS-3_1824
Alderman, Rachael 1896
Alekseev, Genrikh Tue_101_AC-5_534, Tue_93_AC-5_532
Aleman, Alicia 1625
Alemany, Olivier Fri_346_SY-1_1223
2507
Alessandro Ciro, Rappazzo Fri_81_EN-7_1015
Alexander, Patrick Thu_283_CR-6_794, Wed_131_CR-3_2658
Alexander, Simon 1077
Alfons, Schwarzenboeck Tue_59_AC-1_1546
Alfonsi, Lucilla 1650, 1676, 1693, Wed_47_AC-4_1772
Alfonso, Davila 215
Al-Handal, Adil Yousif Thu_79_BE-5_144
Ali, Syed Mubashshir Thu_3_AC-3_508
Aliabadi, Amir A. Tue_45_AC-1_1139
Aliani, Stefano 91, Fri_109_EN-7_2635, Fri_292_OS-7_1815, Fri_97_EN-7_2076,
Thu_78_BE-2_2639
Alias, Antoinette Wed_4_AC-2_475
Alias, Siti 1922, Tue_197_BE-4_1932
Alias, Siti Aisah Fri_28_EN-2_2190
Alias, Siti Aisyah Thu_162_BE-9_2309
Alias, Zazali Thu_162_BE-9_2309
Alix, Gabrielle 1173
Allcock, Louise 290, Thu_122_BE-9_839
Allen, Andrew 2151
Allen, Andrew E. Thu_55_BE-2_559
Allen, Claire 1577, 1710, 279, Thu_356_OS-3_2058, Wed_188_CR-8_2517
Allen, Stephanie Thu_71_BE-2_2031
Alley, Richard 828, Wed_161_CR-8_819
Almeida, Lucas Tue_317_OC-1_1681
Almeida, Pedro Henrique Araujo Wed_387_TE-3_2431
Almela, Pablo Tue_115_BE-1_1368, Wed_55_AC-7_1380
Aloisi, Giovanni Wed_243_OS-6_1007
Alsos, Inger G. 1014
Altenbernd, Tabea 780
Altimira, Iris Tue_200_BE-4_2075
Altstädter, Barbara 1113, Wed_313_TE-1_472, Wed_324_TE-1_1115, Wed_329_TE-
1_1391
Álvarez-Valero, Antonio Fri_137_GG-1_967
Alvaro, Maria Chiara 2107, Tue_323_OC-1_2117
Alves, Gilmar 1693
Amalfitano, Stefano Thu_126_BE-9_1020, Tue_184_BE-4_1367
Ambrizzi, Tércio Tue_105_AC-5_2432
Ambrožová, Klára Thu_1_AC-3_283
Amélineau, Françoise 1842, 2372
Amice, Erwan Tue_351_OS-1_2032
Amini Tehrani, Nasrin 133
Amory, Charles 1528, 1988, Thu_248_CR-5_297, Thu_303_CR-6_2306,
Thu_308_CR-6_2640
Amsler, M.O. 2102
An, Byoung W. Wed_203_OS-2_233
An, Byoung Woong Fri_203_OS-4_677
An, Chunlei 891, Wed_132_CR-7_94
An, Jiachun Thu_247_CR-5_238, Thu_274_CR-6_170
Anandakrishnan, Sridhar 2566, 828, Fri_134_GG-1_762
Ananicheva, Maria Thu_275_CR-6_266
Andersen, Dale 215
Andersen, Dale T. Thu_198_BE-12_2267
Andersen, Helén J. 1159
Anderson, Jacob 1374, Tue_277_GG-2_1373
Anderson, Jeffrey 785
Anderson, John Thu_139_BE-9_1441, Tue_279_GG-2_1478
Anderson, Morgan 485
Anderson, N. John Fri_102_EN-7_2336
Anderson, Philip 1134
Andersson, Andreas J. Thu_55_BE-2_559
Andersson, Kristian Fri_265_OS-7_991
2508
Andersson, Per 2255, 2391
Andò, Sergio 126
Andrade, André Wed_340_TE-3_184
André, Vânia Tue_233_CR-1_452
André, Welti Tue_27_AC-1_244
Andreassen, Liss M. 910
Andreassen, Liss Marie 1312, Wed_366_TE-3_1310
Andrée, Elin Wed_271_OS-6_2231
Andreoni, Igor 503
Andresen, Katrine J. 1200
Andrew, Klein Fri_23_EN-2_1834
Añel, Juan Wed_19_AC-2_1348
Anenberg, Susan Wed_297_SH-5_1044
Anesio, Alex 470
Anesio, Alexandre 440
Anesio, Alexandre M Tue_147_BE-3_2461
Angelier, Frédéric Thu_106_BE-8_2366
Angelina, Lo Giudice Fri_81_EN-7_1015
Angliss, Robyn 2491
Angulo-Preckler, Carlos Wed_87_BE-7_2085
Ani, Lona Tue_329_OC-1_2599
Anilkumar, N Thu_72_BE-2_2367, Wed_251_OS-6_1335
Anilkumar, N. Thu_49_BE-2_55
Anker, Paul Thu_211_CR-4_749
Anna Thomas, Femi Tue_110_BE-1_664
Annett, Amber Wed_210_OS-2_708
Ansorge, Isabelle Wed_255_OS-6_1463
Ansorge, Isabelle J Wed_311_TE-1_934
Ansorge, Isabelle J. Thu_124_BE-9_978, Wed_320_TE-1_923
Ansorge, Isabelle Jane Wed_273_OS-6_2411
Antonello, Alessandro 1360
Antoniades, Dermot 1034, Fri_57_EN-6_1032, Thu_307_CR-6_2590
Antonovskaya, Galina Fri_123_GG-1_341
Antony, Runa Fri_77_EN-7_613, Fri_95_EN-7_2013, Thu_188_BE-12_599
Anwar, Muhammad Zohaib Thu_193_BE-12_1011
Aoki, Shigeru 697, Wed_237_OS-6_944
Aoki, Teruo 537, Wed_143_CR-7_1496
Aoyama, Yuichi Fri_151_GG-1_1933, Thu_249_CR-5_404, Thu_265_CR-5_2284
Appel, Igor 2227, Thu_389_SH-6_2225
Apponi, Umberto Wed_44_AC-4_772
Aquino, Francisco 2194, Tue_104_AC-5_2179
Aquino, Francisco Eliseu 2091, Tue_100_AC-5_474
Aquino, Luca Fri_101_EN-7_2286
Aragon, Pedro 1014
Aragón, Pedro 1321, Thu_125_BE-9_1018
Arantes, Rosa Fri_170_ME-2_521, Fri_327_SH-9_525
Arantes, Rosa Maria Esteves Fri_171_ME-2_527
Aravena, Marcelo Gonzalez Thu_162_BE-9_2309
Arbugaeva, Evgenia 1690
Archambault, Philippe 1082, 524
Archer, Olivier Wed_280_OS-6_2648
Arcone, Steven 730
Ardilouze, Constantin 2496
Ardini, Francisco 1614, Fri_19_EN-2_1422, Fri_85_EN-7_1385, Tue_63_AC-1_1703
Ardyna,, Mathieu 2060
Arena, Giuseppe Tue_134_BE-3_1284
Arendt, Kristin 413
Areso, Omar 511
Arianna Collaboration, The 481
Arienzo, Monica 1340, Tue_96_AC-5_1149
Arigony Neto, Jorge Wed_357_TE-3_792
2509
Arigony-Neto, Jorge 1465, Wed_372_TE-3_1469, Wed_373_TE-3_1570
Aristidi, Eric 1272
Armadillo, Egidio 745, Fri_124_GG-1_347
Armand, Leanne 140, 626, Thu_217_CR-4_899, Tue_250_GG-2_363, Tue_251_GG-
2_364, Tue_254_GG-2_669, Tue_285_GG-2_1669
Armitage, Thomas 1857, 1861
Armitage, Tom Wed_249_OS-6_1291
Armour, Kyle 1341, 2518, 2565
Armstrong, Betsy Wed_121_CR-3_2073
Armstrong, Richard Fri_94_EN-7_1869
Armstrong, RIchard Wed_121_CR-3_2073
Armstrong, Richard L. 1602
Arnaud, Laurent 1318, 1513, Fri_246_OS-5_2501, Wed_140_CR-7_1323,
Wed_144_CR-7_1515, Wed_149_CR-7_2423, Wed_348_TE-3_317
Arndt, Jan Erik 1656, Thu_226_CR-4_1458
Arndt, Janina Wed_85_BE-7_1637
Arndt, Stefani Fri_230_OS-5_343
Arndt, Stefanie 252, 699, Fri_228_OS-5_254, Fri_277_OS-7_1320
Arnold, Stephen Wed_297_SH-5_1044
Arnold, Steve Tue_83_AC-1_2541
Arogony-Neto, Jorge Fri_350_SY-1_1743
Arola, Antti Tue_66_AC-1_1752
Aronson, R.B. 2102
Arora, Devsamridhi 641, Fri_128_GG-1_629
Arora, Manoj Kumar Thu_203_CR-4_50
Aroviita, Jukka 1854
Arpagaus, Phillipe Fri_75_EN-7_313
Arreak, Andrew 1981
Arrigo, Kevin 823
Arslan, Ali Nadir Wed_141_CR-7_1372
Artamonova, Anastasya Wed_282_OS-6_2679
Arthern, Robert J. 729
Arthur, Ben 2047
Arthurs, David 1720
Arz, Helge Fri_59_EN-6_1428
Arzhanov, Maxim Tue_239_CR-1_1732
Asay-Davis, Xylar 250, Thu_207_CR-4_547
Ascaso, Carmen 2256
Ash, Jeanine 1950, 812, Tue_267_GG-2_1005
Ashcroft, Michael 185, Wed_83_BE-7_1301
Ashcroft, Michael B Thu_112_BE-9_186
Ashley, Michael 1403, 1939, 849, Tue_8_AA-1_1088
Ashley, Michael C. B. 2204, 503, Tue_16_AA-1_2218
Ashton, Gail V Tue_153_BE-4_145
Asmi, Eija 1561, 1924, Wed_14_AC-2_976, Wed_35_AC-2_2434
Asmus, Ashley 2686
Asorey, Hernán 511
Aspholm, Paul 2019
Assmann, Karen 854
Assmann, Karen M. Wed_239_OS-6_957
Assmy, Philipp 1093, 1309, 1699, Fri_99_EN-7_2082, Thu_74_BE-2_2483,
Tue_117_BE-1_1948, Wed_212_OS-2_814
Assmy, Phillip Thu_356_OS-3_2058
Assmy,, Philipp 2060
Aster, Richard 1274, Fri_134_GG-1_762
Asthana, Rajesh 1797
Astorga España, Maria Soledad Thu_199_BE-12_2444
Astorga-España, María Soledad Fri_100_EN-7_2138
Atadzhanova, Oksana Wed_282_OS-6_2679
Atkins, Cliff 1244, 2050, 881, Fri_83_EN-7_1246
Atkinson, Angus 1047, 1165
2510
Atkinson, Ian Thu_80_BE-5_191
Audy, Ondřej Fri_18_EN-2_1401
Auel, Holger 2045
Auken, Esben 1186, 2152
Aulicino, Giuseppe 424, Fri_288_OS-7_1711, Fri_289_OS-7_1748, Thu_337_OS-3_428
Aumack, Craig Tue_362_OS-8_2543
Aun, Margit Wed_14_AC-2_976
Autio, Riitta Wed_216_OS-2_1531
Avak, Sven Erik 237
Avango, Dag 2645, 2663
Avendaño, Ruben Fri_12_EN-2_742
Avery, Julie Thu_101_BE-8_1593
Avila, Conxita Thu_151_BE-9_2015, Thu_158_BE-9_2234, Wed_87_BE-7_2085
Avila, Malu Tue_322_OC-1_2025
Ayala, Alvaro 1956, 920, Wed_125_CR-3_2298
Ayala, Álvaro 1055, 1452
Ayre, Matthew 1048
Ayton, Jeff 1575, 1941, 2160
Azaro, Maurizio Tue_114_BE-1_1366
Azinhaga, Patricia Tue_307_OC-1_294
Azzaro, Filippo Fri_81_EN-7_1015, Fri_87_EN-7_1460, Fri_90_EN-7_1532,
Thu_133_BE-9_1266, Tue_134_BE-3_1284, Tue_138_BE-3_1694, Tue_139_BE-3_1708
Azzaro, Maurizio Fri_81_EN-7_1015, Fri_85_EN-7_1385, Fri_86_EN-7_1389,
Fri_87_EN-7_1460, Fri_90_EN-7_1532, Thu_126_BE-9_1020, Thu_133_BE-9_1266, Tue_134_BE-
3_1284, Tue_138_BE-3_1694, Tue_139_BE-3_1708, Tue_184_BE-4_1367, Wed_328_TE-1_1371,
Wed_332_TE-1_1529, Wed_96_CR-2_1525, Wed_97_CR-2_1527

B
Błaszczyk, Małgorzata 2409
Bačkor, Martin Tue_235_CR-1_715
Bałazy, Piotr 1534
Baas, Peter 9
Baatout, Sarah 1664, 2254
Babcock, Esther Wed_98_CR-2_2018
Babin, Marcel 1699, 2060, 2302, Fri_246_OS-5_2501, Fri_353_SY-1_1994,
Thu_91_BE-5_1590, Thu_94_BE-5_2078, Tue_356_OS-8_810
Baca, Mateusz Thu_139_BE-9_1441
Baccarini, Andrea 1041, Tue_27_AC-1_244, Tue_56_AC-1_1467, Tue_77_AC-1_2134
Baccolo, Giovanni 126, 826, Wed_160_CR-8_818, Wed_166_CR-8_1030
Backhaus, Norman Wed_302_SH-5_1215
Backman, John 1924, 2499
Backman, Leif Wed_35_AC-2_2434
Bacon, Sheldon 1857, Wed_249_OS-6_1291, Wed_281_OS-6_2649
Badaluta, Carmen Tue_112_BE-1_949
Badanal, Mahesh Fri_52_EN-6_618
Badhe, Renuka 1636
Baehr, Johanna 2358, 760
Baer, Kristina Charlotte 331
Bagaglia, Marco Tue_12_AA-1_1564
Bageston, Jose Valentin 2184, Wed_40_AC-4_385
Bagge, Meike 1755
Baggenstos, Daniel 1749, 1763, 518
Bagshaw, Elizabeth 1306
Bagshaw, Elizabeth A Tue_147_BE-3_2461
Bagshaw, Liz 2560
Baguet, Jo 1577
Bahr, Frank 808
Bai, Lesheng 1599
Bai, Youcheng Thu_56_BE-2_642
Bai, Yuqi Thu_30_AC-8_1273
Bailey, Ian Fri_56_EN-6_938
2511
Bailleul, Pia Tue_376_SH-2_926
Baisden, W. Troy 826
Bak, Thomas H. Fri_165_ME-2_30, Fri_166_ME-2_31
Bak, Young-Suk 1056, 1618
Baker, Chelsey Tue_322_OC-1_2025
Baker, Kirralee 2182
Baklanov, Alexander Wed_32_AC-2_2163
Baladima, Foteini Wed_128_CR-3_2436
Balague, Vanessa 2046
Balks, Megan 2094
Ball, Becky 2189, Wed_89_BE-7_2697
Ballinger, Thomas Thu_24_AC-8_560
Baltensperger, Urs 1041, Fri_21_EN-2_1609, Tue_37_AC-1_767, Tue_56_AC-1_1467
Bamber, Jonathan 1331, 687
Banasiak, Dariusz Wed_341_TE-3_217
Banerjee, Argha 953
Bange, Jens 670, Wed_318_TE-1_815, Wed_324_TE-1_1115
Bannister, Daniel 1140
Banwell, Alison 379
Baptista, Mafalda 2111
Baqué, Mickael Tue_130_BE-3_1130
Barandun, Martina 951
Barbakov, Oleg Wed_286_SH-4_611
Barbante, Carlo 1634, 646, Tue_65_AC-1_1731, Wed_176_CR-8_1721,
Wed_183_CR-8_2007, Wed_185_CR-8_2304
Barbaro, Elena Fri_351_SY-1_1881, Tue_65_AC-1_1731
Barbeau, Katherine A. Thu_55_BE-2_559
Barber, David 1706
Barbieri Ferreira Mendonça, Claudia Tue_70_AC-1_1895
Barbolini, Massimiliano Wed_147_CR-7_2144
Barbosa, Andres 2046
Barbosa, Andrés Thu_103_BE-8_2084, Thu_104_BE-8_2101
Barbraud, Christophe 735, 921, Thu_113_BE-9_205
Bärfuss, Konrad Wed_313_TE-1_472, Wed_324_TE-1_1115, Wed_329_TE-1_1391
Barker, Gary 440, 470
Barker, Joel Wed_165_CR-8_1024
Barlasina, Maria Elena 1561
Barletta, Valentina Thu_267_CR-5_2349
Barletta, Valentina R. Wed_385_TE-3_2382
Barletta, Valentina Roberta Fri_120_GG-1_327
Barnard, Christine Fri_47_EN-5_2661
Barnes, David Tue_186_BE-4_1419
Barnes, David K A 2
Barnes, David K. A. Tue_189_BE-4_1558
Barnes, David KA Tue_153_BE-4_145
Baroni, Carlo Fri_250_OS-7_131
Baroni, Davide Fri_8_EN-2_411
Baroni, Mélanie 126
Barraza, Francisco Wed_153_CR-8_183
Barreira, Sandra 2155
Barrell, Chris 963
Barrera Oro, Esteban 1451, Thu_321_EN-4_1328
Barrera-Oro, Esteban Tue_220_BE-10_1776, Tue_222_BE-10_2128, Tue_223_BE-10_2331
Barret, Maialen 2325, Fri_100_EN-7_2138, Fri_46_EN-5_2435, Thu_199_BE-12_2444
Barrett, Andrew 781, Wed_121_CR-3_2073
Barrett, J. E. Thu_148_BE-9_1832
Barrett, Jeb 307, Wed_89_BE-7_2697
Barrett, John E. Fri_39_EN-5_879
Barrett, Peter 2389
Barrett, Tate 433
Barroso, A. Tue_74_AC-1_2048
2512
Bart, Phil Tue_279_GG-2_1478
Bart, Philip Tue_252_GG-2_370
Barták, Miloš Fri_372_BE-5_1696, Thu_172_BE-9_335, Thu_187_BE-12_471,
Thu_191_BE-12_873, Tue_157_BE-4_334, Tue_162_BE-4_453, Tue_235_CR-1_715
Bartels-Rausch, Thorsten 237, Fri_286_OS-7_1585
Barthelemy, Antoine 2308
Barthélemy, Antoine Fri_249_OS-7_79, Fri_314_SH-8_1739
Bartholow, Sarah Tue_307_OC-1_294
Barticevic, Elias 1277
Bartlett, Jesamine Thu_125_BE-9_1018, Tue_154_BE-4_149
Bartolini, Stefania Fri_137_GG-1_967
Barton, Kerry Thu_161_BE-9_2281
Bartsch, Annett 2627, Fri_343_SY-1_563
Barzycka, Barbara 2409
Basakina, Irina Fri_123_GG-1_341
Basberg, Bjørn L. 12
Baselet, Bjorn 1664
Båserud, Line 670
Bashmachnikov, Igor Fri_293_OS-7_1823, Thu_359_OS-3_2226, Wed_266_OS-6_1972
Bassi Marinho Pires, Luciana Thu_45_AC-8_2487
Bassis, Jeremy 1483
Bastias, Joaquin 1934
Batalha Roque, Mariane Tue_243_CR-1_1995
Bates, Amanda 259
Batta-Lona, Paola 716
Batté, Lauriane 2496
Baturina, Maria 1854
Bauch, Dorothea Tue_361_OS-8_2287, Wed_272_OS-6_2282
Bauch, Henning A. 1150
Bauer, Robert Fri_38_EN-5_853
Baum, Doris 1720
Bauman, Katherine Thu_194_BE-12_1242
Baurain, Denis 1567, Thu_326_EN-4_1588, Tue_124_BE-3_956
Bauska, Thomas Wed_171_CR-8_1591
Bavay, Matthias 2452
Bavestrello, Giorgio Fri_191_OC-3_1651
Bax, Narissa 2, Tue_186_BE-4_1419, Wed_306_SH-5_1462
Bay, Ryan Thu_224_CR-4_1275
Bayer Mayer, Eder Tue_99_AC-5_306
Bayliss, Daniel 1272
Bazile, Eric 9
Bazin, Lucie 444, Wed_187_CR-8_2490
Bazzano, Andrea Fri_19_EN-2_1422
Bazzaro, Matteo Fri_292_OS-7_1815
Beaird, Nick Thu_301_CR-6_2067
Beale, Rachael Fri_307_OS-7_2683
Beamish, Alison 2428
Beard, Catherine 1733
Beaudette, Ross 834
Beaulieu, Marieke 1699
Beaumet, Julien 1436, Thu_248_CR-5_297, Wed_4_AC-2_475
Becagli, S 1846
Becagli, Silvia 1771, 2110, 2499, Fri_290_OS-7_1766, Fri_63_EN-6_1645,
Tue_63_AC-1_1703, Tue_64_AC-1_1704, Tue_76_AC-1_2119
Beck, Alexander 7
Beck, Jonas 427, 834, Wed_177_CR-8_1744, Wed_180_CR-8_1764
Beck, Lisa 2274
Beddows, D 1846
Beddows, David C.S.. Fri_307_OS-7_2683
Beem, Lucas 1856
Beem, Lucas H. Thu_238_CR-4_2213
2513
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Begeman, Carolyn Branecky Thu_264_CR-5_2142
Bégin, Paschale N. Wed_70_BE-6_558
Behe, Carolina 1108
Behrendt, John C 1569
Behrens, Erik 1080
Behrens, Stephanie 485
Beilman, David 365
Beiranvand Pour, Amin 13, Wed_337_TE-3_14
Beja, Joana 1625
Bekker, Anriette 239
Belair, Stephane 222
Bélanger, Simon Fri_108_EN-7_2583
Belart, Joaquin M. C. 1312
Belbeoch, Mathieu 1625
Belinco, Matías Germán Wed_301_SH-5_1212
Bell, Louisa 968, Fri_237_OS-5_970, Thu_345_OS-3_939, Thu_346_OS-3_972
Bell, Robin 379, Fri_141_GG-1_1133
Bell, Robin E. 1412, Fri_124_GG-1_347
Bell, Trevor 1716, 1981
Bellaire, Sascha Thu_294_CR-6_1510
Bellerby, Richard 683
Belnap, Jayne 564, Thu_312_EN-3_566, Wed_305_SH-5_1434
Belonovskaya, Elena Tue_180_BE-4_1207
Belonozhko, Lidiia Wed_286_SH-4_611
Belonozhko, Marina Fri_328_SH-9_605
Belt, Simon 1257, Thu_348_OS-3_1247, Thu_351_OS-3_1327, Thu_356_OS-
3_2058, Thu_363_OS-3_1576, Wed_217_OS-2_1580
Belter, H. Jakob 1573, 699
Beltran, Roxanne Thu_101_BE-8_1593, Thu_102_BE-8_1839, Thu_98_BE-8_38
Benabdelmoumene, Hassane 2001
Bender, Michael 2442
Benetti, Marion Wed_243_OS-6_1007
Bengtson Nash, Susan 52, 95
Bennartz, Ralf Fri_252_OS-7_321
Benner, Ronald 89
Bennetts, Luke 1298, Fri_275_OS-7_1296
Bennie, Jon Wed_83_BE-7_1301
Benning, Liane G 470
Benning, Liane G. 122, 2473, 258, 440
Benny, Taylor Thu_112_BE-9_186
Benoit, Lionel 1544, Thu_302_CR-6_2115
Bensi, Manuel Fri_292_OS-7_1815, Thu_78_BE-2_2639, Tue_247_GG-2_200,
Tue_279_GG-2_1478, Wed_238_OS-6_955, Wed_241_OS-6_974
Bentley, Michael Tue_278_GG-2_1455, Tue_301_GG-2_2440
Bentley, Mike 1577, 1958, 745, Thu_295_CR-6_1539, Tue_257_GG-2_747
Beny, François 1950, 812, Tue_267_GG-2_1005
Benzal, Jesus 2046
Berben, Sarah Thu_362_OS-3_2555
Berchenko, Igor 2562
Berchok, Catherine Tue_346_OS-1_1621
Bereiter, Bernhard 1749, Wed_178_CR-8_1750, Wed_181_CR-8_1775
Berezkina, Anna Fri_172_ME-2_998
Berg, Sonja 2014
Bergamasco, Andrea 175, Tue_247_GG-2_200, Tue_275_GG-2_1300, Tue_279_GG-
2_1478, Wed_238_OS-6_955, Wed_241_OS-6_974
Bergami, Elisa Fri_12_EN-2_742, Fri_14_EN-2_984, Fri_32_EN-2_434
Berge, Jorgen Thu_93_BE-5_2029
Berge, Jørgen 1093, 1835, 2562, Thu_76_BE-2_2582, Thu_89_BE-5_1268
Bergeot, Nicolas Wed_42_AC-4_640
Berger, Jonathan Tue_337_OC-4_1919, Tue_348_OS-1_1918
2514
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Bergmann, Melanie 2099, 2100, Fri_3_EN-2_174
Bergouignan, Audrey 1891
Bergstrom, Anna 157, Wed_115_CR-3_1189
Bergstrom, Dana 2699, Thu_318_EN-4_592
Bergström, Martin 288
Berini, Francesca Thu_133_BE-9_1266
Berkman, Paul 1344, Thu_381_SH-6_1238
Berkman, Paul Arthur 2688
Bernado, Ronaldo Torma Wed_133_CR-7_168
Bernales, Jorge 1397, 1668, Thu_253_CR-5_837, Tue_284_GG-2_1643,
Wed_375_TE-3_1675
Bernard, Armelle Fri_346_SY-1_1223
Bernard, Kim Thu_143_BE-9_1724, Tue_158_BE-4_389, Tue_190_BE-4_1559,
Wed_264_OS-6_1788
Bernard-Grand'Maison, Claire Thu_289_CR-6_1262
Bernardo, Ronaldo 213, 2194
Bernardo, Ronaldo Torma Tue_100_AC-5_474, Wed_123_CR-3_2148
Bernardová, Alexandra Thu_387_SH-6_1852
Bernasconi, Matteo 123
Bernasconi, Pietro Tue_15_AA-1_2209
Berne, Alexis 1661, 449, 739, 959, Fri_263_OS-7_931, Thu_48_AC-8_2689,
Tue_36_AC-1_738, Wed_12_AC-2_915, Wed_127_CR-3_2305, Wed_5_AC-2_492, Wed_8_AC-
2_746
Bernhard, Germar Wed_14_AC-2_976
Berte, Johan Wed_384_TE-3_2326
Berthier, Etienne 1253, 1678, Wed_353_TE-3_507
Bertini, Laura Thu_140_BE-9_1550, Thu_141_BE-9_1552
Bertino, Laurent Fri_213_OS-4_1871, Wed_226_OS-6_152
Bertler, Nancy 104, 1285, 1404, 1592, 875, 888, Wed_161_CR-8_819, Wed_162_CR-
8_868
Bertler, Nancy A. Tue_262_GG-2_833
Bertler, Nancy A.N. 826
Bertò, Michele Tue_65_AC-1_1731, Wed_176_CR-8_1721, Wed_183_CR-8_2007
Bertram, Rachel 1826
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Besic, Nikola 959, Wed_127_CR-3_2305, Wed_31_AC-2_2064
Bester, Marthan 2047, 496
Bester, Marthán N. Thu_82_BE-5_455, Wed_311_TE-1_934
Bestley, Sophie 1632, Thu_134_BE-9_1357, Thu_190_BE-12_830
Bestmann, Ulf Wed_313_TE-1_472
Beszczynska-Moeller, Agnieszka Fri_354_SY-1_2080,
Wed_274_OS-6_2497
Beszczynska-Möller, Agnieszka 1604, 2001, Fri_292_OS-
7_1815, Fri_353_SY-1_1994
Beszteri, Sara 1386
Bethke, Ingo 1790, Fri_204_OS-4_691
Bevis, Michael 1885
Beyer, Birte 2099
Bhat, Shripathi 2612, 2613
Bhatt, Uma 1345, 1882, Tue_358_OS-8_940
Bi, Dave 869
Bianchi, Federico 1447, 2274, Tue_37_AC-1_767, Tue_54_AC-1_1448
Bianchi Fasani, Gianluca Thu_270_CR-6_82
Biasatti, Dana 1587
Bickert, Torsten 281
Biddle, Jennifer Tue_337_OC-4_1919, Tue_348_OS-1_1918
Biddle, Louise 1446, 2246
Biddle, Louise C. Wed_239_OS-6_957
Bieber, John Tue_11_AA-1_1377
Biebow, Nicole 331, Thu_376_SH-6_643
2515
Bierkens, Marc F.P. 1503
Biersma, Elisabeth M. Thu_114_BE-9_374
Biersma, Elise Thu_322_EN-4_1421
Bigot, Lionel 1376
Bijl, Peter Tue_274_GG-2_1202
Bijl, Peter K. 1740, Tue_287_GG-2_1734, Tue_292_GG-2_1968
Bilker-Koivula, Mirjam Thu_245_CR-5_115
Billaud, Jean-Noël 2254
Billingsley, Brendan Fri_45_EN-5_2357
Bin Ahmad Mazuki, Muhammad Yunus Wed_30_AC-2_1998
Binder, Hanin 476
Binder, Tobias Thu_304_CR-6_2425
Bingham, Robert G. 1229, 729, Fri_317_SH-8_2217
Bintanja, Richard 1655
Birnbaum, Gerit 1464, Wed_3_AC-2_337
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Bischof, Jens Tue_261_GG-2_783
Bischof, Kai 1386, 273, Thu_377_SH-6_962
Biskaborn, Boris 2678
Bissett, Andrew 1106, Thu_190_BE-12_830, Tue_129_BE-3_1107
Biswas, Subir Fri_332_SH-9_1578
Bitz, Cecilia 1341, 142, 2536, Fri_196_OS-4_117
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Bjørk, Anders Anker Wed_361_TE-3_948
Bjorkman, Anne 965
Bjorkman, Mats Fri_351_SY-1_1881
Björnsson, Halldor 2328
Blachowiak-Samolyk, Katarzyna 2562, Thu_76_BE-2_2582
Black, Caitlin Thu_183_BE-11_2631
Black, Shane 485
Blacker, Joshua 470
Blackport, Russell 661, 668
Blain, Stephane Thu_62_BE-2_914
Blain, Stéphane 1281, 594
Blair, Berill 2248
Blais, Marie Amelie Thu_94_BE-5_2078
Blaizot, Anne-Cécile Fri_297_OS-7_1997, Wed_245_OS-6_1040
Blake, James 1128, Wed_365_TE-3_1131
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Blanchard-Wrigglesworth, Ed Fri_209_OS-4_1556, Fri_212_OS-4_1813
Blanchard-Wrigglesworth, Edward Fri_205_OS-4_734
Blanchet, Jean-Pierre 589, Tue_82_AC-1_2527
Blanco-Ameijeiras, Sonia Thu_60_BE-2_778
Blanco-Bercial, Leocadio Tue_355_OS-8_795
Blank, Bas 1390, 704
Blankenship, Don 1856, 2424
Blankenship, Donald 28, Fri_128_GG-1_629
Blankenship, Donald D 2403, Fri_157_GG-1_2210, Thu_238_CR-4_2213
Blankenship, Donald D. 789, 854, Thu_236_CR-4_2150
Blankenship, Donanld D. Fri_124_GG-1_347
Blaxell, Marcello 1958
Blazit, Alain 1272
Blicher, Martin 290, Wed_81_BE-7_529
Blindow, Norbert Wed_65_AC-6_770
Blinova, Ilona 198
Bliven, Francis L. Wed_22_AC-2_1654
Blocher, Will Fri_163_GG-1_2537
Block, Donald Wed_269_OS-6_2181
Blok, Daan 1514, Fri_49_EN-6_429
Blom, Izak 713
Blomdin, Robin Wed_375_TE-3_1675
2516
Blomquist, Byron 1601, 1605
Blomster, Jaanika Wed_216_OS-2_1531
Bloom, Lisa 310, 311
Bluhm, Bodil 1835, 2100, Thu_95_BE-5_2270, Tue_363_OS-8_2616
Bluhm, Bodil A Tue_357_OS-8_840
Blunier, Thomas 826
Blusztajn, Jurek 2056
Bo, Sun 1856, Fri_128_GG-1_629
Boberg, Fredrik 2546
Bobrik, Anna Fri_71_EN-7_33
Bobylev, L.P. Fri_293_OS-7_1823
Bobylev, Leonid Thu_344_OS-3_919, Thu_39_AC-8_2002
Bochkarev, Nikita Thu_390_SH-6_2245
Bock, Christian Tue_226_BE-10_2469
Bock, Michael Fri_58_EN-6_1224, Wed_180_CR-8_1764
Boda, Kenneth 80
Boddy, Lynne 418
Bodeker, Greg Fri_340_SY-1_318
Bodeker, Gregory Elton Wed_33_AC-2_2259
Bodrossy, Levente 1106, Tue_129_BE-3_1107
Boebel, Olaf 2604, Tue_347_OS-1_1717, Tue_350_OS-1_1978, Wed_278_OS-
6_2634
Boeckmann, Christine 2110
Boeckmann, Grant 1233
Boehme, Lars 123, Wed_258_OS-6_1555
Boehnke, Rafal Thu_76_BE-2_2582
Boeke, Robyn Tue_48_AC-1_1182
Boetius, Antje 2100
Boettcher, Maxi 476, Wed_5_AC-2_492
Bogan, Daniel 1854, 352, Wed_75_BE-6_1843
Bogan, Samuel Tue_219_BE-10_392
Boggs, Ashley 52
Boghosian, Alexandra 379
Bogner, Christina Wed_90_BE-7_1579
Bohanon, Luke Thu_378_SH-6_1085
Bohaty, Steve 281
Bohaty, Steven Tue_259_GG-2_765
Bohoyo, Fernando 2369, 2379, Fri_124_GG-1_347, Tue_291_GG-2_1963, Tue_292_GG-
2_1968
Boiaski, Nathalie Tue_105_AC-5_2432
Boike, Julia 1522
Boisier, Juan Pablo Wed_11_AC-2_859
Boissonot, Lauris Tue_164_BE-4_466
Boisvert, Linette 1850, 2668, Fri_287_OS-7_1623
Boisvert, Linette N. 531
Boitsov, Stepan 1541
Bojkov, Bojan Wed_380_TE-3_2108
Bojovic, Dragana 2011
Bolas, Conor 1041, Tue_56_AC-1_1467
Boles, Bruce 2214
Bolinesi, Francesco Tue_139_BE-3_1708, Tue_170_BE-4_723
Bollen, Michael Tue_276_GG-2_1354, Tue_298_GG-2_2261
Bolshunov, Alexey 2317
Bolton, William Robert Wed_76_BE-6_1906
Bombosch, Annette 380
Bomfleur, Benjamin Fri_144_GG-1_1689, Fri_148_GG-1_1791
Bonamano, Simone Fri_81_EN-7_1015, Wed_328_TE-1_1371
Bonci, Maria Cristina Tue_285_GG-2_1669
Bondoux, Erick 1272
Bondzio, Johannes H. Thu_256_CR-5_1057
Bonev, Kamen Fri_130_GG-1_689, Fri_131_GG-1_692
2517
Bonhomme, Serge 1272
Boniface, Adrien 1540, 1886, Fri_351_SY-1_1881
Bonilla-Neira, Jesús Tue_17_AA-1_2221
Bonin, Carolina 496, Thu_118_BE-9_707
Bonnet, Delphine 2372
Bonnet, Pauline 650
Borenstein, Steven Wed_312_TE-1_376
Boresch, Alexander 1720
Borges Mendes, Carlos Rafael Tue_152_BE-4_46
Borm, Jan 2019
Bornemann, Horst Thu_82_BE-5_455
Bornman, Thomas G 1172
Bornman, Tommy 91, Thu_50_BE-2_57
Borovkov, Nikita Fri_133_GG-1_750
Borowicz, Alex Thu_179_BE-11_1151
Borras-Chavez, Renato 2187
Borrmann, Stephan 495, Tue_35_AC-1_719, Tue_45_AC-1_1139
Bortoli, Daniele Wed_29_AC-2_1977
Bossi, Rossana 433
Bost, Charles A. 921
Bost, Charles-André Thu_156_BE-9_2169
Boterblom, Wilrieke Tue_274_GG-2_1202
Botta, Silvina Tue_152_BE-4_46
Böttcher, Maxi Fri_263_OS-7_931, Wed_12_AC-2_915
Bouchard, Caroline 1082
Bouchez, Guillaume 1272
Bouckoms, Sarah Tue_313_OC-1_1282
Boudevillain, Brice 1661, Tue_36_AC-1_738
Boulinier, Thierry 39
Bouman, Johannes Fri_120_GG-1_327
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Bourgeon, Sophie 1891
Bourne, Duncan 222
Boutin, Jacqueline Thu_62_BE-2_914
Boutle, Ian 1796
Boutoute, Marc Tue_224_BE-10_2373
Bovio Winkler, Patricia Thu_199_BE-12_2444
Bowden, David Thu_138_BE-9_1414
Bowden, Joseph 1443
Bowen, Andrew Wed_330_TE-1_1480
Bowen, Melissa Thu_138_BE-9_1414
Bower, K. N. Tue_52_AC-1_1221
Bower, Keith 1796
Bowie, Andrew 1103, 594
Bowie, Andy 1281
Bowman, J. Wed_215_OS-2_1279
Bowman, Jeff 1037, Tue_113_BE-1_1038, Wed_224_OS-2_2193, Wed_269_OS-
6_2181
Bown, Francisca 1691, Thu_230_CR-4_1673
Box, Jason 2415
Boy, Jean-Paul Thu_266_CR-5_2311
Boyd, Phil 2265
Boyd, Philip Thu_164_BE-9_2363
Boyd, Philip W. 1497
Boyd, Phillip W. 1106, Tue_129_BE-3_1107
Boysen, Angela K. Tue_144_BE-3_2272
Bozem, Heiko 1163, 246, 495, Tue_35_AC-1_719, Tue_45_AC-1_1139
Bozinovic, Francisco 2187
Bozzato, Deborah Thu_58_BE-2_741
Bozzo, Emmanuelle Fri_124_GG-1_347
Bracegirdle, Thomas 1404, 1817, 349, Thu_149_BE-9_1875
2518
Bracegirdle, Tom 1537, 2293, 963, Fri_283_OS-7_1530
Bracher, Astrid Thu_60_BE-2_778
Brachfeld, Stefanie 2580
Brad, Traian 1132
Bradley, Alice 1991, 2146, Fri_304_OS-7_2558, Thu_393_SH-6_2318,
Tue_324_OC-1_2247, Tue_338_OC-4_2135
Bradley, James Thu_202_BE-12_2698
Brady, Anne-Marie 64
Brady, Michael 134
Braeckman, Ulrike Thu_79_BE-5_144
Brækkan, Ragnar Wed_128_CR-3_2436
Braga, Juliana Tue_311_OC-1_577
Braida, Martina Fri_250_OS-7_131
Bramley-Alves, Jessica 185, 189, Thu_112_BE-9_186
Brandão, Simone-N Thu_322_EN-4_1421
Brandon, Mark 2468
Brandt, Angelika 497
Branigan, Marsha 485
Bransome, Nicole Thu_323_EN-4_1477, Thu_327_EN-4_1814
Branyik, Tomáš Fri_372_BE-5_1696
Branyiková, Irena Fri_372_BE-5_1696
Bratosin, Daniela Fri_183_ME-1_1692
Brauchli, Tristan 2510
Braun, Christina Fri_103_EN-7_2352, Thu_150_BE-9_2004, Thu_328_EN-4_2009
Braun, Matthias 667, 953, Tue_30_AC-1_377, Wed_62_AC-6_339, Wed_65_AC-
6_770
Braun, Matthias H. Wed_63_AC-6_350
Braun, Matthias Holger Wed_58_AC-7_1799
Bravo, Leon Thu_140_BE-9_1550, Thu_141_BE-9_1552
Bravo, Leon A. Tue_169_BE-4_712, Tue_206_BE-4_2463
Bravo Gallart, Silvia 2158, Tue_332_OC-2_2162
Bray, Stephen G. 108
Brayshaw, David Thu_36_AC-8_1821
Brayton, Casey 2112
Brazier, Hayley 2667
Bréant, Camille 444, Fri_253_OS-7_356, Wed_23_AC-2_1671
Brearley, Alex Wed_258_OS-6_1555
Brearley, Alexander 416, Wed_321_TE-1_997
Brearley, J. Alexander Wed_242_OS-6_996
Breckenfelder, Tilia Fri_267_OS-7_1016
Bredow, Eva Fri_120_GG-1_327
Breed, Greg Thu_98_BE-8_38
Brell, Maximilian 2428
Bremer, Ulisses Wed_340_TE-3_184
Bremer, Ulisses Franz Wed_369_TE-3_1356, Wed_370_TE-3_1358
Brennan, Paul 1306, 1433
Brenneis, Tina Thu_60_BE-2_778
Bressac, Matthieu 2265
Bresson, Helene 299, Wed_53_AC-7_301
Bretschneider, Lutz Wed_313_TE-1_472
Brett, Gemma 526
Brewer, Michael 2285
Brey, Thomas 487, Thu_320_EN-4_1208
Bricaud, Clement 2308
Bricaud, Clément Fri_314_SH-8_1739
Bricher, Phillippa 1617, Fri_44_EN-5_2321
Bricher, Pip 1625, Fri_356_SY-1_2507, Wed_259_OS-6_1627, Wed_260_OS-
6_1628
Brierley, Andrew 123
Brierley, Andrew S 2132
Brigham, Lawson 619
2519
Brigham-Grette, Julie 2607
Brin, Adam 483
Brinker, Regina 1917
Brinkerhoff, Douglas 2239
Brinkhuis, Henk Tue_287_GG-2_1734
Brisbourne, Alex 1390, 165, Thu_229_CR-4_1649, Thu_230_CR-4_1673
Brisbourne, Alex M. 729
Bristol, Emily M. Fri_72_EN-7_41
Brittain, John 1854
Brix Zinglersen, Karl Wed_198_EN-1_1844
Broady, Paul 2294, Thu_163_BE-9_2329, Tue_146_BE-3_2310
Brock, Ben 1956
Brodzik, Mary J. 1602
Brodzik, Mary Jo Wed_121_CR-3_2073
Brogioni, Marco 1370, 316, Wed_348_TE-3_317
Brombacher, Anieke Fri_56_EN-6_938
Bromirski, Peter Fri_134_GG-1_762
Bromwich, David 1595, 1599, 465, Thu_228_CR-4_1597, Wed_66_AC-6_1596,
Wed_67_AC-6_1600
Bromwich, David H.
Bron, Denis 1507
Brongo, Andrea Fri_33_EN-2_2509
Brook, Ed 2442, Wed_171_CR-8_1591
Brook, Edward 826, 834
Brook, Edward J. Wed_168_CR-8_1053, Wed_177_CR-8_1744
Brook, Edward Jeremy Wed_180_CR-8_1764
Brooks, Cassandra 790, 791, Thu_319_EN-4_788
Brooks, Ian 1134, 963, Fri_264_OS-7_989, Fri_265_OS-7_991
Brooks, Shaun Thu_317_EN-4_188, Thu_318_EN-4_592
Brough, Neil Tue_51_AC-1_1220
Brown, Joel Thu_223_CR-4_1248
Brown, Kristina 1119, 1345, Thu_382_SH-6_1308, Tue_357_OS-8_840, Tue_358_OS-
8_940
Brown, Mark V. 1106, Tue_129_BE-3_1107
Brown, Mark Vincent 2188
Brown, Phil 1796
Brown, Renée F. Fri_39_EN-5_879
Brown, Ross 223
Brown, Scott 2559
Brown, Thomas Wed_217_OS-2_1580
Browne, Emma 22
Browne, Imogen M. 1950, 812, 843, Tue_267_GG-2_1005
Brua, Bob Wed_75_BE-6_1843
Brua, Robert 352
Brucker, Ludovic Wed_338_TE-3_15
Brückmann, Jens Fri_5_EN-2_253
Brückner, Marlen 1636
Brügger, Sandra 1125, 425, Tue_176_BE-4_1121
Bruls, Anja 1740
Brumsack, Hans-Jürgen 1577
Brun, Fanny 1253, Wed_353_TE-3_507
Brunette, Charles Fri_215_OS-4_1916
Brus, David Wed_336_TE-1_2356
Brussaard, Corina P.D. 1682
Bruyant, Flavienne 1699
Bruyant,, Flavienne 2060
Bruzzone, Gabriele 1008, Fri_81_EN-7_1015, Fri_90_EN-7_1532, Wed_328_TE-1_1371,
Wed_331_TE-1_1511, Wed_332_TE-1_1529
Buatier de Mongeot, Francesco 1381
Buchan, Susannah Tue_352_OS-1_2249
Buchheim, Judith-Irina 2254
2520
Buchhorn, Marcel 2428
Buckingham, Christian 1292
Buckley, Bradley Tue_221_BE-10_2087
Bucklin, Ann 716, Tue_355_OS-8_795
Büdel, Burkhard 924
Budillon, Giorgio 2185, Fri_289_OS-7_1748, Fri_291_OS-7_1767, Wed_263_OS-
6_1754, Wed_265_OS-6_1947
Budzik, Tomasz Thu_309_CR-6_2687, Wed_341_TE-3_217
Buen, Helge Tue_349_OS-1_1940
Buettner, Monic Fri_337_SY-1_24
Buettner, Stefan Fri_82_EN-7_1201
Buffen, Aron 2442, Wed_171_CR-8_1591
Buhr, Marty Thu_13_AC-3_2074
Buiron, Daphné Fri_336_SH-9_2439, Thu_373_SH-3_2556, Wed_291_SH-4_2454
Buizert, Christo 826, Wed_156_CR-8_554, Wed_168_CR-8_1053, Wed_192_CR-
8_2589
Bulat, Sergey 1589
Bull, Roger D. Tue_182_BE-4_1265
Bullard, Joanna 2050
Bullard, Joanna E. Fri_102_EN-7_2336
Bullett, Terry 578
Bulygina, Olga Tue_78_AC-1_2250
Buma, Anita 1424, 1427
Buma, Anita G. J. 1682
Bunch, Pete 279
Buoso, Sandro Fri_79_EN-7_754
Burada, Girija Kalyani Thu_27_AC-8_933
Buras, Allan Tue_161_BE-4_446
Burbidge, Geoff 222
Burgard, Clara 1270
Burgay, Francois 646
Burger, Erasmus Petrus Fri_164_GG-1_2548
Burger, Flavia 1956
Burgess, David 2677, Thu_289_CR-6_1262
Burgess, Henry Thu_396_SH-6_2531, Wed_60_AC-7_2438
Buri, Pascal 2385
Burini, Alessandro Wed_380_TE-3_2108
Burkart, Julia 495, Tue_45_AC-1_1139
Burke, Andrea Wed_169_CR-8_1261
Burkhardt, Elke Tue_350_OS-1_1978
Burkhardt-Holm, Patricia Tue_218_BE-10_67
Burns, Jennifer 2154, Thu_101_BE-8_1593, Thu_102_BE-8_1839, Thu_154_BE-
9_2143, Thu_98_BE-8_38
Burns, Victoria 1726
Burrow, Stephen 1306
Burrows, William Thu_8_AC-3_1393
Burton, Michael 1403
Burton, Michael G. 2204
Burton-Johnson, Alex 1934, 572, 607, Fri_348_SY-1_1410
Burzyński, Artur Tue_212_BE-4_2632
Busack, Michael 1687
Buschbaum, Christian Tue_196_BE-4_1737
Busetto, Maurizio 1771, 2499
Bushinsky, Seth 2171
Bushueva, Irina 2381
Bushuk, Mitch 1554, Fri_209_OS-4_1556
Busso, Maurizio M. Tue_12_AA-1_1564
Bustamante, Paco 2132
Butterworth, Brian Fri_295_OS-7_1883
Butz, Christoph 2614
Buyuksagnak, Y. Barbaros Thu_400_SH-7_648
2521
Buzzard, Samantha Tue_322_OC-1_2025
Buzzard, Sammie 260

C
Caballero, Marta Tue_30_AC-1_377
Cabanas, Mariana Wed_294_SH-5_4
Cabanes, Damien 89, Fri_75_EN-7_313, Thu_60_BE-2_778
Cabedo-Sanz, Patricia 1257
Cable, Rachel Thu_192_BE-12_927
Cabral, A.S Wed_96_CR-2_1525, Wed_97_CR-2_1527
Cabral, Anderson S. Fri_90_EN-7_1532
Cabrerizo, Ana 1837
Cabrol, Lea Fri_100_EN-7_2138, Fri_46_EN-5_2435
Cabrol, Léa 2325, Thu_199_BE-12_2444
Caburlotto, Andrea 626, Tue_247_GG-2_200, Tue_254_GG-2_669, Tue_285_GG-2_1669
Caccavo, Jilda 1848
Caccavo, Jilda Alicia Thu_106_BE-8_2366, Thu_393_SH-6_2318, Tue_224_BE-10_2373
Caccia, Massimo 1008, Fri_81_EN-7_1015, Fri_90_EN-7_1532, Wed_328_TE-1_1371,
Wed_331_TE-1_1511, Wed_332_TE-1_1529
Cacciani, Marco Thu_5_AC-3_775, Tue_61_AC-1_1639, Wed_6_AC-2_666,
Wed_7_AC-2_680
Cachorro, V. Tue_74_AC-1_2048
Cachorro, V. E. Tue_75_AC-1_2054
Caduff, Rafael Tue_240_CR-1_1840
Cafarella, Lili Wed_48_AC-4_1887
Caffau, Mauro Tue_272_GG-2_1160
Caffee, Marc 1397, Tue_284_GG-2_1643
Cahill, Catherine Wed_200_EN-1_2137
Cai, Yue 1889
Caiazzo, Laura 1771, Fri_290_OS-7_1766, Tue_64_AC-1_1704
Cairo, Francesco 1077, Tue_53_AC-1_1313
Calisto Ulloa, Nancy Fri_15_EN-2_1073
Calisto-Ulloa, Nancy Fri_16_EN-2_1258
Callaghan, Terry 1642, Thu_387_SH-6_1852, Wed_60_AC-7_2438
Calle, A. Tue_75_AC-1_2054
Calle, Natalia Thu_199_BE-12_2444
Calonne, Neige Wed_148_CR-7_2335
Calvert, Doug 2198
Calzolai, Giulia Tue_63_AC-1_1703, Tue_64_AC-1_1704
Calzolari, Francesco 1771
Camara, Paulo Wed_83_BE-7_1301
Camara, Roberto 1693
Câmara, Paulo Tue_128_BE-3_1138
Camelbeeck, Thierry Thu_302_CR-6_2115
Cameron, Chris Wed_33_AC-2_2259
Camicetti, Nicole 419
Campana, Gabriela Laura Tue_189_BE-4_1558
Campbell, Adam Thu_222_CR-4_1078
Campbell, Ethan 2112
Campbell, Karley 2066
Campeau, Stephane 352
Campeau, Stéphane Wed_75_BE-6_1843
Campen, Richard 2214
Campin, Jean-Michel Wed_248_OS-6_1176
Camporeale, Giuseppe 114
Campos, Camila 2646
Canario, Joao Thu_19_AC-8_171
Canário, João 2681, Fri_26_EN-2_2022, Tue_233_CR-1_452
Cancouet, Romain Wed_335_TE-1_2354
Canese, Simonepietro 930, Thu_131_BE-9_1204
Caneva, Giorgio Fri_124_GG-1_347
2522
Canini, Fabiana Thu_140_BE-9_1550, Thu_141_BE-9_1552, Tue_111_BE-1_695,
Tue_160_BE-4_443
Cannata, Andrea 156, Fri_115_GG-1_150, Fri_358_TE-2_155, Thu_246_CR-5_153
Cannavò, Flavio Thu_246_CR-5_153
Cannone, Nicoletta 2037, Thu_233_CR-4_1870, Tue_237_CR-1_1256
Cao, Pinlu 128, Fri_364_TE-2_501, Fri_367_TE-2_847, Wed_310_TE-1_107
Cape, Mattias 2540
Capek, Petr Tue_148_BE-3_2513
Capello, Marco Thu_69_BE-2_1859, Thu_78_BE-2_2639
Capone, Doug Thu_166_BE-9_2380, Thu_196_BE-12_2191
Capotondi, Antonietta 214
Capotondi, Lucilla Thu_351_OS-3_1327
Cappelletti, D. Tue_81_AC-1_2374
Cappelletti, David 2110, 2274, Fri_19_EN-2_1422, Tue_63_AC-1_1703, Tue_65_AC-
1_1731, Tue_76_AC-1_2119
Cappello, Simone Fri_14_EN-2_984
Capponi, Gianni 607
Capponi, Giovanni Fri_118_GG-1_230, Fri_119_GG-1_325, Fri_145_GG-1_1697,
Fri_146_GG-1_1701
Capra, Alessandro Thu_255_CR-5_1000
Capron, Emilie 2415
Capurro, Andrea Thu_321_EN-4_1328
Caramello, Nubia Tue_310_OC-1_494
Carbognani, Albino Tue_12_AA-1_1564
Carbotte, Suzanne Fri_38_EN-5_853
Carcavilla, Luis 2034
Cardenas, Cesar Tue_204_BE-4_2348, Tue_207_BE-4_2493
Cardenas, M. Bayani 1543
Cárdenas, César Thu_321_EN-4_1328
Cardia Simoes, Jefferson Thu_273_CR-6_154
Cardia Simões, Jefferson Fri_7_EN-2_372, Tue_295_GG-2_2040, Tue_99_AC-5_306,
Wed_158_CR-8_684
Cardona, Luis Thu_151_BE-9_2015, Thu_158_BE-9_2234
Cardone, Ignacio Thu_397_SH-7_61
Caricchi, Chiara Tue_266_GG-2_988, Tue_272_GG-2_1160
Carlig, Erica 930, Fri_195_OC-3_2300, Thu_131_BE-9_1204, Tue_175_BE-4_999
Carlson, David 1636
Carlson, Laura T. Tue_144_BE-3_2272
Carlstrom, John 2637
Carmack, Eddy 1119, 1345, 2100, 384, Tue_357_OS-8_840, Tue_358_OS-8_940
Carnat, Gauthier 414, 744, Wed_205_OS-2_358, Wed_206_OS-2_378, Wed_208_OS-
2_464, Wed_221_OS-2_2027
Carneiro, Ulisses Tue_71_AC-1_1913
Caroppo, Carmela Thu_133_BE-9_1266
Carosi, Rodolfo Fri_118_GG-1_230
Carotenuto, Federico Wed_331_TE-1_1511, Wed_332_TE-1_1529
Carpenedo, Camila Tue_105_AC-5_2432
Carpenter, Edward Thu_166_BE-9_2380, Thu_196_BE-12_2191
Carrasco, Jorge Wed_67_AC-6_1600
Carrera, Vania Thu_53_BE-2_314
Carrieres, Tom 1720
Carrion, Daniela 1691
Carslaw, Ken 1041, Tue_56_AC-1_1467
Carter, Jeremy Thu_194_BE-12_1242
Carter, Lionel 826
Cartigny, Matthieu 1710
Carton, Jim 2308, Fri_314_SH-8_1739
Carturan, Luca Wed_183_CR-8_2007
Caruso, Carla Thu_140_BE-9_1550, Thu_141_BE-9_1552
Caruso, G. Wed_96_CR-2_1525, Wed_97_CR-2_1527
Caruso, Gabriella Fri_81_EN-7_1015, Fri_86_EN-7_1389, Fri_90_EN-7_1532,
2523
Thu_126_BE-9_1020, Thu_133_BE-9_1266, Tue_114_BE-1_1366, Tue_184_BE-4_1367,
Wed_332_TE-1_1529
Carvalho, Filipa Thu_143_BE-9_1724
Carvalho, Pedro Wed_138_CR-7_806
Carvalho-Silva, Micheline Tue_128_BE-3_1138
Cary, Craig 1733, 2111, 2198, 2202, Thu_117_BE-9_688, Thu_166_BE-9_2380,
Thu_174_BE-11_838, Thu_195_BE-12_2116, Thu_196_BE-12_2191, Tue_277_GG-2_1373
Cary, S. Craig 1631
Cary, Stephen 564, Thu_312_EN-3_566
Cary, Stephen Craig 2140, Wed_305_SH-5_1434
Casà, Valeria 95
Casado, Mathieu 1513, Fri_253_OS-7_356, Wed_144_CR-7_1515
Casagli, Alessio Fri_191_OC-3_1651
Casagrande, Fernanda Fri_225_OS-4_2665
Casal, Tania 1168, Tue_257_GG-2_747
Casal, Tânia 2642
Casale, Stefano Fri_118_GG-1_230
Casallas Moreno, Edwin Alexander Tue_17_AA-1_2221
Casanova-Katny, Angelica 1985
Casanova-Katny, Angélica 189
Casassa, Gino 1678, 667, Thu_282_CR-6_774, Wed_63_AC-6_350
Casati, Barbara Thu_8_AC-3_1393
Casey, Kenneth 1625
Casey, Kimberly A Tue_68_AC-1_1789
Casillo, Angela 1548, Tue_137_BE-3_1551
Cassano, John 136, 2418, 2503, 263, Fri_216_OS-4_2173, Wed_327_TE-1_1363
Cassar, Nicolas
Cassou, Christophe 454
Castagno, Pasquale Fri_291_OS-7_1767, Fri_85_EN-7_1385, Fri_86_EN-7_1389,
Fri_87_EN-7_1460, Wed_255_OS-6_1463, Wed_265_OS-6_1947
Castelino, Jude Tue_259_GG-2_765
Castellani, Giulia 1777, Wed_220_OS-2_1787
Castelnau, Olivier 650
Caswell, Hal 735
Catala, Philipe 594
Cattadori, Matteo Tue_307_OC-1_294
Cauquoin, Alexandre Fri_253_OS-7_356
Cavanagh, Rachel Thu_149_BE-9_1875
Cavieres, Lohengrin Tue_169_BE-4_712, Tue_206_BE-4_2463
Cavitte, Marie G. P. 789
Ceballos Romero, Elena 2079
Ceburnis, Darius Fri_307_OS-7_2683
Ceccarini, Alessio Fri_33_EN-2_2509
Cecchetto, Matteo 2107, Tue_323_OC-1_2117
Cefarelli, Adrian O. 1912
Ceia, Filipe Wed_81_BE-7_529
Celeste, Antonio Wed_255_OS-6_1463
Cembrowski, Marcel 2369
Cere, Milena 1051
Ceroni, Constanza Tue_214_BE-4_2680
Cerovecki, Ivana 1290, Fri_298_OS-7_2183
Cerro, Elena Fri_12_EN-2_742
Cerrone, Dario Fri_288_OS-7_1711
Cesarano, Cinzia Fri_289_OS-7_1748
Cesaroni, Claudio 1650, 1676, Wed_47_AC-4_1772
Chaboureau, Jean-Pierre Tue_39_AC-1_887
Chabrillat, Sabine 2428
Chacko, Racheal Wed_251_OS-6_1335
Chadid, Merieme Tue_1_AA-1_74
Chakraborty, Elora Thu_284_CR-6_883
Challita, Zalpha 1272
2524
Champenois, Willy 414
Chang, Chae-Won Fri_63_EN-6_1645
Chang, Chu-Hsiang 1575, Fri_332_SH-9_1578
Chang, Phi-Hun Fri_203_OS-4_677
Chapellier, Eric 1272, 1376
Chapman, Christopher 1006
Chappellaz, Jerome Wed_182_CR-8_1874
Chappellaz, Jérôme 1423, 789, Fri_346_SY-1_1223
Chapron, Bertrand Wed_280_OS-6_2648
Chapuis, Jean-Louis Thu_182_TE-3_1780
Charlier, Karine Tue_274_GG-2_1202
Chase, Andrew 2158
Chase, Zanna 1103, Thu_254_CR-5_862, Tue_289_GG-2_1937
Chatterjee, Sourav Wed_226_OS-6_152, Wed_251_OS-6_1335
Chattopadhyay, Anupam Fri_128_GG-1_629
Chattová, Barbora Tue_249_GG-2_328
Chauvaud, Laurent Tue_351_OS-1_2032
Chauvaud, Sylvain Tue_351_OS-1_2032
Chavallier, Matthieu 2308
Che, Tao 1143
Cheah, Wee Tue_198_BE-4_1996
Che-Castaldo, Christian 1914, Thu_153_BE-9_2126
Chechin, Dmitry 1967, 2504, Wed_3_AC-2_337
Checkley, Sylvia 2049
Cheeseman, Ted 380
Chellman, Nathan 1340, Tue_96_AC-5_1149
Chen, Chen Fri_365_TE-2_595, Tue_137_BE-3_1551
Chen, Gao Thu_13_AC-3_2074
Chen, Haihua Fri_233_OS-5_541
Chen, Huizi Thu_358_OS-3_2161
Chen, Jian Wed_196_EN-1_1626
Chen, Jianfang Thu_56_BE-2_642
Chen, Jie Fri_163_GG-1_2537
Chen, Jun 2280
Chen, Linling 2328, 721
Chen, Liqi Thu_68_BE-2_1494
Chen, Meilian 401
Chen, Nan Tue_23_AC-1_71
Chen, Shuze Fri_143_GG-1_1630
Chen, Xianyao 703
Chen, Yanji Wed_310_TE-1_107
Chen, Yong Fri_365_TE-2_595
Chen, Yunwang Fri_367_TE-2_847
Chen, Zhihua 973
Chen, Zhuoqi Wed_358_TE-3_856
Cheng, Bin 289, Fri_242_OS-5_1828, Thu_385_SH-6_1666, Wed_354_TE-3_533
Cheng, Chen Fri_276_OS-7_1299
Cheng, Chi-Hing Christina 2613
Cheng, Xiao 857, Wed_354_TE-3_533, Wed_358_TE-3_856
Cheng, Yuan Thu_218_CR-4_1021
Cheng, Zian 725
Chenguang, Liu 892
Cherchi, Annalisa Tue_87_AC-5_176
Cherel, Yves 290, 906, Thu_156_BE-9_2169
Chernokulsky, Alexander Tue_78_AC-1_2250
Chernov, Robert Thu_306_CR-6_2542
Chernova, Ludmila 1667
Cheung, Ho Nam Thu_22_AC-8_445
Chevalier, Jean-Marie Wed_42_AC-4_640
Chevalley, Yvan Wed_127_CR-3_2305
Chevallier, Matthieu 2496, Fri_314_SH-8_1739
2525
Chiantore, Mariachiara Thu_133_BE-9_1266
Chiari, Massimo Tue_64_AC-1_1704
Chierci, Melissa Fri_99_EN-7_2082
Chierici, Melissa Fri_98_EN-7_2081, Wed_225_OS-2_2458
Chikkamadaiah, Krishnaiah Fri_1_EN-2_48
Chin, Krista 1854, Wed_75_BE-6_1843
China, Swarup Tue_42_AC-1_1039, Tue_43_AC-1_1052, Tue_77_AC-1_2134
Chládová, Zuzana Thu_9_AC-3_1709
Cho, Hana 2448
Cho, Kyoung-Ho Fri_303_OS-7_2475
Choe, Moon Young Fri_142_GG-1_1415
Choi, Han-Gu Tue_116_BE-1_1633
Choi, Hyun Deok Tue_68_AC-1_1789
Choi, Taejin Fri_299_OS-7_2192
Choi, Young-Seok Fri_303_OS-7_2475
Choquet, Rémi 1842
Chorley, Hannah 303
Choudhary, Shabnam Fri_48_EN-6_34
Choudhry, Iqra 1779
Choukèr, Alexander 2254
Choularton, T. W. Tue_50_AC-1_1218, Tue_52_AC-1_1221
Choularton, Thomas 1796
Chowdhry Beeman, Jai Wed_168_CR-8_1053, Wed_186_CR-8_2479, Wed_187_CR-8_2490
Chown, Steven , 2168
Chown, Steven L 1490
Chown, Steven L. 37, 713
Choy, Emily Thu_382_SH-6_1308
Chripko, Svenya 435
Christel, Isadora 2011
Christensen, Jens Hesselbjerg 1646, Tue_283_GG-2_1640
Christian, Claire 1474, Thu_323_EN-4_1477
Christiansen, Casper T. 1514
Christiansen, Henrik 1746, Thu_144_BE-9_1757, Thu_152_BE-9_2114, Tue_159_BE-
4_430, Tue_220_BE-10_1776
Christiansen, Jorgen S. Tue_175_BE-4_999
Christianson, Knut 2560, 2566
Christie, Frazer 1341
Christille, Jean Marc Tue_12_AA-1_1564
Christl, Marcus Tue_300_GG-2_2339
Christner, Brent 796
Christoffersen, Kirsten 1326, 352
Christophersen, Annemarie 1592
Chu, Vena 1232, 1926
Chu, Winnie Fri_317_SH-8_2217, Thu_288_CR-6_1185
Chung, Hosung Tue_116_BE-1_1633
Chung, Ji Woong Fri_368_TE-2_902
Chuter, Stephen 1331
Cianfarra, Paola Thu_255_CR-5_1000
Ciardini, Virginia Fri_250_OS-7_131, Fri_290_OS-7_1766
Cibin, Giannantonio Wed_166_CR-8_1030
Cicone, Antonio Wed_47_AC-4_1772
Cid, Critina Wed_87_BE-7_2085
Cilenti, Lucrezia Fri_86_EN-7_1389
Cilliers, Pierre 1650, Wed_47_AC-4_1772
Cimino, Megan Thu_143_BE-9_1724, Tue_190_BE-4_1559
Cincinelli, Alessandra 419, Fri_8_EN-2_411
Cires, Samuel Wed_55_AC-7_1380
Cirilli, Stefano Fri_190_OC-3_1523
Cisewski, Boris Tue_350_OS-1_1978
Cisternas, Sebastian 1691
Čížková, Klára Wed_15_AC-2_992
2526
Claesson Liljedahl, Lillemor 1129
Claeys, Philippe Tue_260_GG-2_769
Clare, Lindsay 1306
Clark, Chris Tue_302_GG-2_2480
Clark, Christopher Tue_281_GG-2_1533
Clark, Douglas A. 1893
Clark, Graeme 2118
Clark, Malcolm Thu_138_BE-9_1414
Clark, Melody S Tue_153_BE-4_145
Clark, Peter U. 2588, 2664
Clark, Sydney Wed_219_OS-2_1594
Clarke, Andrew Thu_322_EN-4_1421
Clarke, Bradley 2244
Clarke, Laurence Thu_159_BE-9_2242, Thu_190_BE-12_830
Clarke, Laurence J. Tue_129_BE-3_1107
Classen, Lew Tue_14_AA-1_2086
Claud, Chantal 739, 952, Wed_27_AC-2_1936, Wed_8_AC-2_746
Claudio, Cesaroni 1786
Clausen, Lasse Boy Novock 1650
Claustre, Herve Thu_62_BE-2_914
Cleary, Alison 496
Cleary, Kathleen 365
Clem, John Tue_11_AA-1_1377
Clemen, Hans-Christian Tue_35_AC-1_719
Clementson, Lesley 1081
Clemenza, Massimiliano Wed_166_CR-8_1030
Clemmensen, Karina E 1979
Clewlow, Harriet 75
Clifford, Heather 2442
Close, Sally Fri_297_OS-7_1997
Clotten, Caroline 2063
Clucas, Gemma Thu_179_BE-11_1151
Cobbing, Nick 1506
Coccia, Alex 2642
Coch, Caroline Tue_316_OC-1_1574
Codd, Geoffrey A. 2376
Codiglia, Riccardo Tue_247_GG-2_200, Tue_279_GG-2_1478
Codilean, Alexandru 1958
Codron, Francis 1436
Coelho, João Pedro 2132
Coenen, Jason 1076
Cohen, Denis 2036
Cohen, Jon Thu_89_BE-5_1268
Cohen, Lana 1506, 531
Cokelet, Edward 1619
Colao, Francesco Tue_53_AC-1_1313
Cole, Matthew 1860
Coleine, Claudia 462, 694, Tue_111_BE-1_695, Tue_160_BE-4_443
Coleman, Lucy Tue_321_OC-1_1915
Coleman, Morgan Thu_117_BE-9_688
Coleman, Richard 44, Wed_360_TE-3_874
Colesie, Claudia 924
Colgrove, Dominique Fri_74_EN-7_277
Colizza, Ester Fri_132_GG-1_714, Fri_190_OC-3_1523, Fri_191_OC-3_1651,
Fri_250_OS-7_131, Thu_351_OS-3_1327, Tue_247_GG-2_200, Tue_275_GG-2_1300
Collaboration, ARA Tue_6_AA-1_1059
Collao-Barrios, Gabriela 1330, 1678
Collares Gonçalves, Bento 447
Colleoni, Florence 175, Tue_247_GG-2_200, Tue_279_GG-2_1478, Tue_87_AC-5_176,
Wed_238_OS-6_955, Wed_241_OS-6_974
Collins, Julia 2401
2527
Collins, R. Eric Tue_348_OS-1_1918
Colman, Daniel Tue_142_BE-3_2165
Colombo, Andrea , , , 852
Colwell, Steve 1140
Colwell, Steve R. Tue_51_AC-1_1220
Colwell, Steven Wed_1_AC-2_62
Coman, Cristian 1132, Thu_157_BE-9_2222
Comeau, Darin 250
Comeau, Darin S. Thu_207_CR-4_547
Comola, Francesco 2332, 2451, 2609
Compo, Gilbert P. Thu_12_AC-3_2071
Comstock, Jennifer Tue_84_AC-1_2650
Conca, Eleonora Fri_79_EN-7_754
Conceição, E. Tue_74_AC-1_2048
Connolly, P. J. Tue_50_AC-1_1218
Consolaro, Chiara 1862
Consortium, Tara Oceans 2065, 633, 793
Constable, Andrew 1239, 1240, 1352, 1617, 1632, 2346, 267, Thu_134_BE-9_1357,
Thu_149_BE-9_1875, Thu_164_BE-9_2363
Constantine, Rochelle Thu_138_BE-9_1414
Contador Mejías, Tamara A. Tue_181_BE-4_1234
Conte, A Wed_96_CR-2_1525, Wed_97_CR-2_1527
Conte, Antonella Tue_114_BE-1_1366, Tue_184_BE-4_1367
Contrafatto, Danilo 156, Fri_358_TE-2_155
Convey, Pete Thu_125_BE-9_1018
Convey, Peter 1128, 1321, 1901, 1922, 2294, 2419, 418, Fri_28_EN-2_2190,
Thu_114_BE-9_374, Thu_119_BE-9_727, Thu_162_BE-9_2309, Thu_163_BE-9_2329,
Thu_322_EN-4_1421, Tue_145_BE-3_2289, Tue_146_BE-3_2310, Tue_154_BE-4_149,
Tue_181_BE-4_1234, Wed_365_TE-3_1131, Wed_79_BE-6_2251
Conway, Howard 826
Conway, Jono Fri_340_SY-1_318, Wed_33_AC-2_2259
Conway, Tim Fri_75_EN-7_313
Conway, Tim M. 1657
Cook, Alison Thu_295_CR-6_1539, Wed_62_AC-6_339
Cook, Sue 44, Wed_360_TE-3_874
Cooke, Jeff 503
Cooper, Alan 1095
Cooper, Jennifer Tue_6_AA-1_1059
Cooper, Lee 1587, Thu_87_BE-5_1065
Cooper, Zachary Tue_348_OS-1_1918
Copes, Gustavo 1561
Copjakova, Renata 2077
Copland, Luke 2124, Thu_289_CR-6_1262, Thu_295_CR-6_1539
Coppola, Daniela 1175
Corbin, Joel Fri_21_EN-2_1609
Corbin, Joel C. 1381
Cordeiro de Sousa, Isabela M. 1950, 812, Tue_267_GG-2_1005
Cordero, Raul 2587, Thu_46_AC-8_2581, Wed_11_AC-2_859
Cordero, Raul R. Fri_296_OS-7_1902
Cordone, Angelina Fri_85_EN-7_1385
Corkill, Matthew 591, Wed_213_OS-2_861
Corley, Alison 1889
Cormier, Marc-Andre Wed_217_OS-2_1580
Cornet, Luc Thu_326_EN-4_1588
Corney, Stuart 1239, 1240, 1352, Thu_149_BE-9_1875, Tue_183_BE-4_1364
Cornford, Stephen L. 729
Cornuelle, Bruce Fri_353_SY-1_1994
Corr, Hugh 1264, 1306, 1756, 28, Thu_260_CR-5_1784, Wed_118_CR-3_1762
Corr, Hugh F J 2360
Corradi, Nicola Tue_285_GG-2_1669
Corre, Erwan Tue_204_BE-4_2348
2528
Correia, Emilia 1693
Corsaro, Maria Michela 1548, Tue_137_BE-3_1551
Corsi, Ilaria Fri_14_EN-2_984, Fri_32_EN-2_434
Corsolini, Simonetta 419, Fri_12_EN-2_742, Fri_17_EN-2_1399, Fri_18_EN-2_1401,
Fri_8_EN-2_411
Cortés, Gonzalo Wed_112_CR-3_1026
Cortés, Pau Fri_307_OS-7_2683
Cortese, Giuseppe 1950, 812, 888, Tue_267_GG-2_1005
Corti, Giovanni Wed_134_CR-7_312
Cory, Rose 2477
Cosenza, Alessandro Fri_81_EN-7_1015
Cosme, Emmanuel 17
Cossio, Anthony Tue_158_BE-4_389
Costa, Alfredo J 556
Costa, Daniel 2154, 2603, Thu_154_BE-9_2143
Costa, Daniel P 2187
Costa, Daniel P. 1033
Costa, Lívia Tue_132_BE-3_1145
Costa, Maria Joao Wed_29_AC-2_1977
Costa, Rafaela Mattos Wed_376_TE-3_1836, Wed_58_AC-7_1799
Costa, Vanessa Tue_295_GG-2_2040
Costi, Juliana Wed_357_TE-3_792, Wed_373_TE-3_1570
Cotronei, Salvatore Fri_17_EN-2_1399, Fri_18_EN-2_1401
Cotroneo, Yuri Fri_288_OS-7_1711, Wed_255_OS-6_1463, Wed_263_OS-6_1754
Cotté, Cedric Thu_156_BE-9_2169
Cottier, Finlo 1093, 1114, Thu_93_BE-5_2029
Cottlerle, Diego Tue_275_GG-2_1300
Cotton, Richard 1796
Coulombe, Stephanie Tue_165_BE-4_513
Coulson, Stephen Fri_28_EN-2_2190
Coulson, Stephen J. Wed_79_BE-6_2251
Counillon, Francois Fri_204_OS-4_691
Coupel, Pierre Fri_108_EN-7_2583
Coursol, Laurence 589
Couto, Nicole Wed_264_OS-6_1788
Covi, Federico Wed_134_CR-7_312
Cowan, Alex 380
Cowan, Don 2488
Coward, Andrew 2471
Cox, Christopher 1924, 821, Thu_11_AC-3_2010, Thu_37_AC-8_1829, Wed_26_AC-
2_1927
Cox, Martin Thu_134_BE-9_1357
Cox, Simon Fri_118_GG-1_230
Cox, Simon C. Fri_348_SY-1_1410
Cox, Simon Christopher 607, Wed_71_BE-6_612
Coyne, Kathryn Thu_166_BE-9_2380, Thu_196_BE-12_2191
Crampton, James 813
Crawford, Christopher Wed_388_TE-3_2437
Crawford, David W. 1912
Crawford, James Thu_13_AC-3_2074
Crazzolara, Claudio Wed_324_TE-1_1115
Creamean, Jessie 1473
Cree, Charlotte Fri_307_OS-7_2683
Crémière, Antoine 1862
Cremonesi, Llorenç Wed_160_CR-8_818
Crevier, Yves 222, 2552
Crewell, Susanne 1661, Tue_69_AC-1_1820, Wed_3_AC-2_337, Wed_9_AC-2_782
Crews, Laura 1112
Crill, Patrick 2021, Fri_265_OS-7_991
Crisafi, E. Wed_96_CR-2_1525, Wed_97_CR-2_1527
Crisafi, Ermanno Fri_90_EN-7_1532, Thu_126_BE-9_1020, Tue_138_BE-3_1694,
2529
Tue_139_BE-3_1708
Crispini, Laura 1715, Fri_118_GG-1_230, Fri_119_GG-1_325, Fri_144_GG-1_1689,
Fri_145_GG-1_1697, Fri_146_GG-1_1701, Fri_148_GG-1_1791
Cristini, Luisa 1636, 2011
Cristofanelli, Paolo 1771
Crocker, Daniel 2603
Crocket, Kirsty 245
Cronin, Thomas 1481
Croser, Jonathan 1796
Cross, Jessica 1473, 1619
Crosta, Xavier Fri_250_OS-7_131, Thu_352_OS-3_1362, Tue_246_GG-2_187
Crouzet, Nicolas 1272, 1376
Crucian, Brian 2254
Crucifix, Michel Tue_303_GG-2_2505
Cruz, Maria Jimena Wed_288_SH-4_880
Cuesta, Juan Tue_39_AC-1_887
Cuffaro, Marco Tue_279_GG-2_1478
Cuffey, Kurt 490
Cui, Qifeng Wed_310_TE-1_107
Cui, Xiangbin Fri_155_GG-1_2149, Fri_156_GG-1_2153
Cui, Xiangqun 503
Cui, Yingchun Fri_159_GG-1_2299
Cullum, Michael Thu_242_CR-4_2530
Culp, Joseph 1854, 352, Wed_75_BE-6_1843, Wed_77_BE-6_1992
Cummings, Vonda 2198, Thu_117_BE-9_688, Thu_138_BE-9_1414
Cuo, Lan Wed_105_CR-3_686
Curran, Mark 104, Wed_184_CR-8_2290
Curran, Mark A.J. Fri_55_EN-6_917
Curtin, Lorelei 843
Curtius, Joachim Tue_37_AC-1_767
Cusick, James 1625
Cutroneo, Laura Thu_69_BE-2_1859, Thu_78_BE-2_2639
Czech, Hendryk 1381, Fri_21_EN-2_1609
Cziferszky, Andreas 1720

D
D’Amore, Daniela Fri_291_OS-7_1767
Da Matta Agostini, Kamila Tue_70_AC-1_1895
Da Rosa, Kátia Kellem Wed_58_AC-7_1799
Daase, Malin 1835, 2562, Thu_89_BE-5_1268
Daban, Jean-Baptiste 1272
Dabboor, Mohammed 134
Dach, Rolf Thu_261_CR-5_1812
Dachs, Jordi Fri_12_EN-2_742
Daczko, Nathan 855
Dadaglio, Laetitia 2098
Dadic, Ruzica 826, Wed_161_CR-8_819
Dagsson Waldhauserova, Pavla Wed_141_CR-7_1372
Daher, Mayara P Fri_104_EN-7_2355
Dahl-Jensen, Dorthe 1306, 826, 885
Dahlke, Sandro Wed_3_AC-2_337
Dai, Zigao 503
Dalaiden, Quentin Thu_219_CR-4_1031
Dall´Osto, Manuel 1846, Fri_294_OS-7_1849
Dalla Rosa, José Mauro Tue_100_AC-5_474
Dalla Rosa, Luciano Tue_152_BE-4_46
Dallafior, Tanja N. 1199
Dalle Fratte, M. Wed_96_CR-2_1525, Wed_97_CR-2_1527
Dalle Luche, Greta 52
Dallimore, Scott Tue_242_CR-1_1969
Dallmayr, Remi 537
2530
Dall'Osto, Manuel Fri_307_OS-7_2683
Dalman, Laura 2066
Dalton, Chimone 2049
Dalziel, Ian 1819, 1885, Fri_134_GG-1_762
Dalziel, Ian W. 2016
Damaske, Detlef Fri_124_GG-1_347
Damiani, Alessandro 2587, Fri_296_OS-7_1902, Thu_46_AC-8_2581, Wed_11_AC-2_859
Damm, Ellen Wed_329_TE-1_1391
D'Andrilli, Juliana 796
Danecek, Peter Fri_346_SY-1_1223, Thu_246_CR-5_153
Danesi, Stefania Thu_258_CR-5_1226, Thu_271_CR-6_100
D'Angelo, Alessandra Fri_109_EN-7_2635, Fri_97_EN-7_2076, Thu_78_BE-2_2639
D'Angelo, Giulia 1650
Daniels, Megan 959
Danielsen, Finn 2177, 2401, Thu_385_SH-6_1666
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Danza, Francesco Thu_192_BE-12_927
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Das, Suresh Thu_279_CR-6_603
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Davey, Matthew 1128, Wed_365_TE-3_1131
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Davies, Diana M. 108
Davies, Sarah 1029, 1577
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Dayal, Archana Thu_165_BE-9_2370, Tue_120_BE-1_2362, Tue_322_OC-1_2025
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De Bernardis, Paolo 2450
De Boer, Bas 1450
2531
De Boer, Gijs Wed_312_TE-1_376
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Wed_241_OS-6_974
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Debeljak, Pavla 1281
Debernard, Jens Thu_380_SH-6_1214
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Decima, Moira Thu_138_BE-9_1414
Decker, Julie 1838
2532
Deconto, Rob 2578
DeConto, Rob 303, Tue_302_GG-2_2480
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Dehairs, Frank 414, Wed_204_OS-2_291, Wed_206_OS-2_378
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Delaforge, Aurélie 2302
Delanoe, Julien Tue_59_AC-1_1546
Delanoë, Julien 987
Delcloo, Andy 1009, Wed_22_AC-2_1654
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Dell'Acqua, Fabio Wed_147_CR-7_2144
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Delladio, Alberto Fri_346_SY-1_1223, Thu_246_CR-5_153
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8_1030
Delord, Karine Thu_113_BE-9_205
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DelSontro, Tonya 645
Deman, Florian 414, Wed_204_OS-2_291, Wed_206_OS-2_378
Demarte, Maurizio Fri_292_OS-7_1815
Demchenko, Pavel 907
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Demchev, Denis M. 1526
Demianiuk, Ewa Thu_139_BE-9_1441
Deming, Jody Tue_337_OC-4_1919, Tue_348_OS-1_1918
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Denis, Bertand Fri_222_OS-4_2557
Deponte, Davide Fri_292_OS-7_1815
Déqué, Michel 2496, Wed_4_AC-2_475
Deregibus, Dolores 1343, Thu_79_BE-5_144, Tue_189_BE-4_1558, Wed_86_BE-7_1866
Derksen, Chris 222, 223, Wed_377_TE-3_1897, Wed_380_TE-3_2108
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Descy, Jean-Pierre Wed_206_OS-2_378
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Deshler, Terry 1077
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Devasthale, Abhay 502, Thu_2_AC-3_505
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2533
Dexheimer, Dari Thu_7_AC-3_1346
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Wed_7_AC-2_680
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Díaz Aguirre, María José Tue_196_BE-4_1737
Díaz-Puente, Javier 2094
Dibb, Jack E. Tue_68_AC-1_1789
Dichek, Daniel Wed_269_OS-6_2181
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Dieckmann, Gerhard S. Wed_214_OS-2_1278
Diedrich, Erhard Wed_350_TE-3_420
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Dietrich, Reinhard 1761
Dietrich, Ulrike 1722
Diez, Anja 1756, Wed_118_CR-3_1762
DiFrancesco, Juliette 2049
Diggs, Steve 1625
DiGirolamo, Nicolo Wed_379_TE-3_2052
Dijkstra, Henk A. Wed_255_OS-6_1463
Dillon, Megan Tue_321_OC-1_1915
Dinasquet, Julie 2098
Ding, Baohong Wed_125_CR-3_2298
Ding, Minghu Thu_338_OS-3_459, Thu_44_AC-8_2277
Dinniman, Michael 823, Fri_282_OS-7_1418, Wed_321_TE-1_997
Dinniman, Mike Wed_270_OS-6_2186
Dirkson, Arlan Fri_222_OS-4_2557
Divito, Kate 716
Dixon, Daniel 104
Dmitriev, Andrei 2317
Dmoch, Kasia 2562
Doblas-Reyes, Francisco 2011
Dobricic, Srdan 731
Dobricic, Srdjan 2276
Dobrynin, Mikhail 2358, 760, Thu_75_BE-2_2484
Dochen, Kerrie 1394
Docherty, Catherine 1854
Dochev, Docho Fri_130_GG-1_689, Fri_131_GG-1_692
Docquier, David 500, Fri_205_OS-4_734
Dodd, Justin Fri_110_EN-7_2657
Dodd, Justin P. 1950, 812, Tue_267_GG-2_1005
Dodd, Paul 1183, Fri_98_EN-7_2081
Dodd, Paul A. 1506
Doddridge, Edward 1157, Fri_271_OS-7_1154, Wed_248_OS-6_1176
Dohaney, Jacqueline 1244
Doi, Koichiro Fri_151_GG-1_1933, Thu_249_CR-5_404, Thu_265_CR-5_2284
Dokken, Trond Thu_362_OS-3_2555
Dolant, Caroline Wed_338_TE-3_15
2534
Domack, Eugene 1056, 2540, Thu_211_CR-4_749
Domeisen, Daniela 2358, 760
Dominé, Florent Fri_246_OS-5_2501
Dominic, Hodgson 2614
Dommen, Josef 1041, Tue_37_AC-1_767, Tue_56_AC-1_1467
Dommergue, Aurélien 1886
Donda, Federica Tue_254_GG-2_669, Tue_285_GG-2_1669
Doney, Scott 1037
Donhauser, Johanna 258, 330
Donoso, Alfonso Tue_370_SH-1_1409
Dooley, Julia Tue_307_OC-1_294, Tue_329_OC-1_2599, Tue_341_OC-4_2574
Dorador, Cristina Tue_112_BE-1_949
Doran, Peter 1186, 2152, 307, Fri_308_SH-8_211, Thu_111_BE-9_159,
Wed_115_CR-3_1189, Wed_69_BE-6_212
Doran, Peter T. Fri_39_EN-5_879
Doronin, Maxim 1589
Dorrington, Rosmary A 1172
Dorschel, Boris 1656, Thu_82_BE-5_455, Tue_286_GG-2_1730
Dorval, Emmanis Thu_155_BE-9_2157
Dos Reis, Pedro Amaral 2091
Dotta, Silvia 355, Tue_310_OC-1_494, Tue_311_OC-1_577
Dotta, Sílvia Tue_317_OC-1_1681
Dotto, Tiago Wed_236_OS-6_768, Wed_249_OS-6_1291
Dotto, Tiago S. Wed_281_OS-6_2649
Dou, Tingfeng Thu_44_AC-8_2277
Double, Michael Tue_352_OS-1_2249
Doubt, Jennifer C. Fri_40_EN-5_1263
Dougherty, Phil 2158
Douglas, David Thu_37_AC-8_1829
Doulgeris, Konstantinos Wed_336_TE-1_2356
Dove, Dayton Tue_281_GG-2_1533
Dove, Isabel Tue_250_GG-2_363
D'Ovidio, Francesco Thu_156_BE-9_2169
Dovis, Fabio 1693, Wed_47_AC-4_1772
Dow, Christine 2424
Dowdeswell, J. A. 985
Dowdeswell, Julian 28
Dowdeswell, Julian A. Fri_317_SH-8_2217
Downey, Rachel 2, Thu_322_EN-4_1421, Tue_186_BE-4_1419
Downie, Rod 1798, 75
Doyle, Santiago Raúl 1343
Dozier, Melissa Thu_181_BE-11_1180
Drabek, Ondrej Tue_249_GG-2_328
Drake, Henri 2171
Drange, Helge Wed_233_OS-6_627
Dreossi, Giuliano 1513, Wed_164_CR-8_979, Wed_176_CR-8_1721, Wed_183_CR-
8_2007
Drews, Reinhard 736
Dreyer, Jan Wed_272_OS-6_2282
Driemel, Amelie Fri_35_EN-5_361
Drivdal, Magnus 1835
Drost, Helen 384
Drüe, Clemens 369
Drummond, James 1831, 2028
Drummond, James R. 1217
Druzhkova, Elena 2562
Dryak, Mariama C Fri_279_OS-7_1329
Du, Fujia 503
Du Plessis, Marcel Wed_273_OS-6_2411, Wed_311_TE-1_934
Du Preez, Byron Thu_183_BE-11_2631
Duan, Anmin 1143
2535
Duan, Keqin 903
Duarte, Carlos 1345, Tue_358_OS-8_940
Duarte, Emmanuel Tue_317_OC-1_1681
Duarte, Pedro 1309, Thu_74_BE-2_2483, Tue_117_BE-1_1948, Wed_212_OS-
2_814
Duarte, Teresa Tue_233_CR-1_452
Dubbini, Marco Thu_255_CR-5_1000
Dubois, Clotilde 2496
Ducklow, Hugh 1037, 1237, 1841
Duda, Patrizia Thu_381_SH-6_1238
Dudykina, Inna Tue_343_OS-1_896
Duerr, Ruth Fri_319_SH-8_2408
Duffy, George Fri_252_OS-7_321
Duffy, Grant 37, Thu_125_BE-9_1018
Duffy, Meghan Thu_217_CR-4_899, Tue_250_GG-2_363, Tue_251_GG-2_364,
Tue_285_GG-2_1669
Duformentelle, Pierrette 2001
Dufour, Ambroise Thu_42_AC-8_2092
Dufour, Anne Wed_139_CR-7_1228
Dufour, Carolina 2171, Wed_246_OS-6_1099
Dufour, Carolina O. 386, Wed_228_OS-6_387
Dugan, Hilary 1186, 2152
Duguay, Claude 2638
Duhaime, Melissa Thu_192_BE-12_927
Duke, Grace Fri_61_EN-6_1603
Duke, Patrick Fri_73_EN-7_261
Dumais, Simon Tue_316_OC-1_1574
Dumont, Marie Wed_139_CR-7_1228
Dunbar, Gavin 1877, Fri_83_EN-7_1246
Dunbar, Robert Thu_78_BE-2_2639
Dunkley, Daniel J. 2233, Fri_158_GG-1_2219
Dunn, Michael Thu_105_BE-8_2236
Dunn-Sigouin, Etienne 2105
Dunse, Thorben 1957
Dunstan, Piers 596
Duplissy, Ella-Maria 2274, 360, Fri_341_SY-1_359
Duprat, Luis 591, Wed_213_OS-2_861
Dupuis, Elisa Fri_334_SH-9_2405, Fri_336_SH-9_2439, Thu_373_SH-3_2556,
Wed_291_SH-4_2454
Dupuy, Regis 1163, Tue_35_AC-1_719
Dupuy, Régis Tue_59_AC-1_1546
Durak, Onur Sabri Tue_373_SH-1_2605
Duran, Claudio Thu_48_AC-8_2689
Duran, Juan Jose 2034
Duran-Alarcon, Claudio 1661, 739, Tue_103_AC-5_2129, Tue_36_AC-1_738, Wed_8_AC-
2_746
Durand, Gael Wed_275_OS-6_2534
Durand, Gaël 2468
Duran-Valsero, Juan José Wed_120_CR-3_2038
Durham, Elizabeth 1991
Durieu, Benoit 1567, Thu_326_EN-4_1588, Tue_124_BE-3_956
Dushaw, Brian Fri_353_SY-1_1994
Dussaillant, Ines 1253, 1678
Dutrieux, Pierre 1433
DuVernois, Michael Tue_20_AA-1_2511
Dvornikov, Yuri 2627
Dvornikov, Yuriy Wed_119_CR-3_2030
Dwyer, John Wed_388_TE-3_2437
Dybwad, Christien 1699
Dybwad, Christine Thu_91_BE-5_1590, Thu_94_BE-5_2078
Dykyy, Ihor Tue_174_BE-4_950
2536
Dymova, Taisiya Wed_375_TE-3_1675
Dyonisius, Michael 834, Wed_171_CR-8_1591
Dziadek, Ricarda Fri_140_GG-1_1013, Tue_268_GG-2_1022
Dziak, Robert 2424
Dzieciuch, Matthew Fri_353_SY-1_1994

E
E, Dongchen Wed_46_AC-4_1624
Eagles, Graeme 1168, 1315, 780, Fri_122_GG-1_340, Fri_124_GG-1_347,
Thu_304_CR-6_2425, Tue_255_GG-2_705
Eastman, Joseph T. Tue_222_BE-10_2128
Eayrs, Clare 239, Tue_39_AC-1_887, Wed_227_OS-6_247
Ebbing, Joerg Fri_149_GG-1_1830
Ebbing, Jörg Fri_120_GG-1_327
Eberlein, Lutz Thu_263_CR-5_2024
Ebermann, Benjamin 2042, Thu_263_CR-5_2024
Ebrahimi, Saloomeh Tue_149_BE-3_2647
Eckhardt, Sabine 477
Edel, Léo 952
Edmundson, Stephen Tue_51_AC-1_1220
Edwards, Arwyn Thu_165_BE-9_2370, Thu_202_BE-12_2698, Tue_120_BE-1_2362
Edwards, Collin R. Tue_121_BE-3_573
Edwards, John 983
Edwards, Jon 834
Edwards, Jon S. Wed_177_CR-8_1744
Edwards, Neil R 2468
Edwards, Ross 826
Edwards, Stuart 140
Edwards, Tamsin 2468, Tue_340_OC-4_2523
Egawa, Ayako 189
Egerer, Ulrike 493, Tue_28_AC-1_249
Egli, Pascal Emanuel 1111
Eglinton, Timothy Ian 2056, Fri_96_EN-7_2069
Ehlers, Todd 736
Ehn, Jens 1706
Ehrlich, Andre 1967
Ehrlich, André 1163, 493, 495, Wed_3_AC-2_337
Ehrlich, Julia 497, Wed_209_OS-2_506
Ehrmann, Werner 1710, 1889, Thu_211_CR-4_749
Eichler, Anja 237, 402, Wed_179_CR-8_1760
Eicken, Haijo Fri_239_OS-5_1286
Eicken, Hajo 2177, 2401
Eiken, Ola 549
Einarsson, Arni 1854
Einarsson, Árni 352
Einarsson, Bergur Thu_305_CR-6_2467
Eirund, Gesa 1222
Eisen, Olaf 1264, 1306, 1638, 736, Thu_235_CR-4_2005, Thu_304_CR-6_2425,
Wed_142_CR-7_1471, Wed_375_TE-3_1675
Eisert, Regina 1243, Thu_178_BE-11_1110
Ejiri, Mitsumu K. 1964, Wed_28_AC-2_1974
Ekaykin, Alexey 104, 1513, 1672, Wed_126_CR-3_2301, Wed_68_AC-6_1725
Ekern, Lindsey 1187
Ekman, Annica M. L. 1199, 1288
El Haddad, Imad 1381, Fri_21_EN-2_1609
Elagina, Nelly Thu_306_CR-6_2542
Elberling, Bo 1514
Elburg, Marlina A. 1315
Eldevik, Tor 148, 1778
Eléaume, Marc Thu_145_BE-9_1801, Thu_146_BE-9_1807, Thu_147_BE-9_1809
Elefante, Cosimo Fri_357_SY-1_2623
2537
Elfarsdóttir, Aldís Fri_355_SY-1_2383
Elger, Judith Tue_305_GG-2_2602
Elias-Piera, Francyne Tue_188_BE-4_1501, Tue_310_OC-1_494, Wed_84_BE-7_1505
Eling, Lukas 826, Wed_162_CR-8_868
Elipot, Shane Wed_256_OS-6_1508
Elkind, Samuel Fri_348_SY-1_1410
Ellingsen, Ingrid 2100
Elliot, David 607
Elliot, Joshua 730
Elliott, Ashley 1309
Elliott, Joshua Wed_322_TE-1_1066
Ellwood, Michael , 1657, 2265, Fri_75_EN-7_313
Els, Nora Thu_110_BE-9_158
Else, B E 2066
Else, B. Wed_215_OS-2_1279
Else, Brent Fri_295_OS-7_1883, Fri_73_EN-7_261
Elster, Josef 1684, Fri_372_BE-5_1696, Thu_387_SH-6_1852, Thu_9_AC-3_1709,
Tue_133_BE-3_1197, Tue_194_BE-4_1652, Wed_197_EN-1_1686
Elvehøy, Hallgeir 1312
Elverum, Shelly 1981
Elvevold, Synnøve 1315, 607
Elvidge, Andrew 2670
Elvidge, Andy 963, 983, Fri_283_OS-7_1530
Elwood, Micheal Fri_89_EN-7_1502
Ely, Jeremy Tue_281_GG-2_1533
Emami-Khoyi, Arsalan Tue_163_BE-4_457
Emelianov, Mikhail Fri_307_OS-7_2683
Emiliano de Jesus, Hugo 1631
Emilie, Beaudon Wed_165_CR-8_1024
Emmenegger, Lukas Wed_178_CR-8_1750, Wed_181_CR-8_1775
Emmerson, Louise 2244, Thu_105_BE-8_2236
Emmons, Louisa K. Tue_68_AC-1_1789
Enberg, Sara Wed_216_OS-2_1531
Enderlin, Ellyn M Fri_279_OS-7_1329
Engel, Zbyněk Thu_287_CR-6_1161
Engel, Zbynek Tue_232_CR-1_284
Engelbertz, Sira 381
Enghoff, Martin 2177, 2401
England, Mark 1046, Wed_56_AC-7_1482
England, Matthew 1440
Eppers, Oliver 246, 495, Tue_35_AC-1_719
Epstein, Howard 1882
Epstein, Howard E. 2428
Erazo, Natalia Tue_113_BE-1_1038
Erbe, Christine 2547
Ercan, Fabian E Z Fri_49_EN-6_429
Erhardt, Tobias 834
Erickson, Zachary 2212
Ericson, Jessica Thu_173_BE-11_582, Wed_82_BE-7_580
Eriksen, Ruth 108
Erikson, Anders 1272
Eriksson, Leif E.B. Thu_355_OS-3_1824
Ermokhina, Ksenia 2627
Ermolin, Evgeniy 556
Ershova, Elizavert A. Tue_355_OS-8_795
Ershova, Elizaveta Tue_363_OS-8_2616
Esau, Igor Tue_78_AC-1_2250
Escalera, Laura Tue_170_BE-4_723
Escutia, Carlota 1740, Tue_274_GG-2_1202, Tue_290_GG-2_1959, Tue_291_GG-
2_1963, Tue_292_GG-2_1968, Tue_294_GG-2_2035, Tue_296_GG-2_2044
Esefeld, Jan 1054, Thu_328_EN-4_2009
2538
Eskerod Borgstrøm, Rasmus Wed_198_EN-1_1844
Esper, Oliver Thu_333_OS-3_53, Thu_349_OS-3_1251, Thu_354_OS-3_1653
Esper, Oliver M. 1950, 812, Tue_267_GG-2_1005
Espin-Lopez, Pedro Fidel Wed_147_CR-7_2144
Espinosa, Cristian Fri_170_ME-2_521
Espona Pernas, Lucia 2230
Essery, Richard 1938
Essl, Franz 713
Estrada, Claudia 1277
Estrada, Marta Fri_307_OS-7_2683
Estrada Goic, Claudia Wed_294_SH-5_4
Etchebehere, Claudia Thu_199_BE-12_2444
Etourneau, Johan Thu_348_OS-3_1247, Tue_274_GG-2_1202, Tue_292_GG-2_1968,
Tue_294_GG-2_2035, Tue_296_GG-2_2044
Etzelmuller, Bernd 752
Eugster, Werner 645
Euskirchen, Eugénie Wed_76_BE-6_1906
Evangelinos, Dimitrios Tue_274_GG-2_1202
Evangelinos, Dimitris Tue_290_GG-2_1959, Tue_291_GG-2_1963, Tue_292_GG-2_1968,
Tue_294_GG-2_2035, Tue_296_GG-2_2044
Evangelista, Heitor Fri_60_EN-6_1453, Tue_187_BE-4_1457, Tue_42_AC-1_1039,
Tue_43_AC-1_1052, Tue_57_AC-1_1492, Tue_70_AC-1_1895, Tue_71_AC-1_1913
Evans, Clive Tue_314_OC-1_1337
Evans, Eleri 44, Wed_360_TE-3_874
Evenson, Paul Tue_11_AA-1_1377, Tue_13_AA-1_1782
Everson, Inigo 123
Evgrafova, Alevtina Tue_316_OC-1_1574, Wed_297_SH-5_1044, Wed_90_BE-7_1579
Evtushevsky, Oleksandr 942, Wed_13_AC-2_928
Expedition Members, ACE 1490
Extier, Thomas 444, Wed_187_CR-8_2490

F
F. Boutron, Claude 1634
Fabel, Derek 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Faber, Anne-Katrine 2415
Fabri-Ruiz, Salomé Thu_116_BE-9_658, Tue_167_BE-4_662
Facchini, Maria Cristina Fri_307_OS-7_2683
Fahl, Kirsten 1685, 2063, Thu_362_OS-3_2555
Faimali, Marco Fri_195_OC-3_2300
Fairall, Christopher 1601, 1605
Falco, Pierpaolo Fri_291_OS-7_1767, Fri_85_EN-7_1385, Wed_255_OS-6_1463,
Wed_263_OS-6_1754, Wed_265_OS-6_1947
Fan, Gaojing Thu_59_BE-2_756
Fan, Ke 961
Fan, Xiaopeng 128, 891, Fri_360_TE-2_219, Fri_362_TE-2_432, Fri_363_TE-2_438,
Fri_364_TE-2_501, Fri_367_TE-2_847, Fri_369_TE-2_1953, Wed_310_TE-1_107
Fang, Aimin Tue_282_GG-2_1557
Fang, Ling Wed_193_CR-8_1670
Fang, Miao 1143
Fang, Yu 945
Fanteï-Caujolle, Yan 1272
Farias, David 667, 920
Farías, David Wed_63_AC-6_350
Fariña, Jose M 2187
Farinotti, Daniel 910, 920, Thu_285_CR-6_652, Thu_286_CR-6_932
Farmer, Lauren 380
Farooq, Usama Wed_231_OS-6_570
Farrell, Tony 384
Fasone, Rosario Fri_358_TE-2_155
Fast, Jerome Tue_68_AC-1_1789
Faucher, Benoit 215
2539
Faust, Johan 1120, 463
Favier, Vincent 1253, 1330, 1436, 1678, Thu_248_CR-5_297
Fawcett, Sarah Thu_50_BE-2_57
Fawcett, Sarah E 1172
Fazi, Stefano Thu_133_BE-9_1266
Fèbvre, Guy Tue_59_AC-1_1546
Federico, Laura Fri_118_GG-1_230
Fedorov, Aleksandr Wed_266_OS-6_1972
Feeser, Kelli 2189
Feltham, Daniel 1396
Feltham, Daniel Lee 2641
Feltham, Danny 2053
Feng, Tiantian Thu_358_OS-3_2161
Fenton, Mairi 2090, Wed_210_OS-2_708, Wed_211_OS-2_811
Fenty, Ian 1171, Wed_325_TE-1_1170
Fer, Ilker Wed_256_OS-6_1508
Ferguson, Megan 2491
Ferland, Joannie 2302, Fri_246_OS-5_2501
Fernandes, Paul 123
Fernandes, Richard Wed_380_TE-3_2108
Fernandes Filho, Elpidio InacioFri_104_EN-7_2355
Fernandes Filho, Elpidio InácioFri_31_EN-2_2343, Wed_387_TE-3_2431
Fernandez, Linda Thu_325_EN-4_1566
Fernández, Lucas Wed_20_AC-2_1383, Wed_55_AC-7_1380
Fernández, Susana Thu_233_CR-4_1870
Fernández Piana, Lucas Fri_310_SH-8_1349
Fernandez-Méndez, M. Wed_215_OS-2_1279
Fernandéz-Méndez, Mar Thu_74_BE-2_2483
Fernández-Méndez, Mar 1309, Wed_212_OS-2_814
Fernandez-Tellez, Helio 1747
Fernandoy, Francisco 1452, Tue_97_AC-5_2495, Wed_153_CR-8_183, Wed_189_CR-
8_2538
Fernetti, Michele Fri_191_OC-3_1651
Feron, Sarah 2587, Thu_46_AC-8_2581, Tue_97_AC-5_2495, Wed_11_AC-2_859
Ferraccioli, Fausto 1168, 1756, 704, 745, Fri_120_GG-1_327, Fri_124_GG-1_347,
Fri_140_GG-1_1013, Fri_141_GG-1_1133, Fri_149_GG-1_1830, Thu_260_CR-5_1784,
Tue_257_GG-2_747, Wed_118_CR-3_1762
Ferracioli, Fausto 2360
Ferrada, Luis Valentin 2429, Tue_367_SH-1_251
Ferrando, Sara 930
Ferrara, Grace Wed_299_SH-5_1070
Ferrari, Flávia Fri_101_EN-7_2286
Ferrari, Flávia Ramos Tue_178_BE-4_1158, Tue_205_BE-4_2404
Ferrari, Raffaele 2536
Ferravante, Denise Giuliana 982
Ferreira, Mariana Tue_128_BE-3_1138
Ferrero, Luca 2110
Ferretti, Roberta 1008, Fri_81_EN-7_1015, Fri_90_EN-7_1532, Wed_328_TE-1_1371,
Wed_331_TE-1_1511, Wed_332_TE-1_1529
Ferro, Angelo 156, Fri_358_TE-2_155
Fetterer, Florence 1625, Wed_121_CR-3_2073, Wed_259_OS-6_1627
Fettweis, Xavier 1330, 1528, 1988, 2506, Thu_283_CR-6_794, Thu_303_CR-6_2306,
Thu_308_CR-6_2640, Wed_131_CR-3_2658, Wed_268_OS-6_2122
Feuerecker, Matthias 2254
Fialho, Paulo Tue_77_AC-1_2134
Fialho Azinhaga, Patricia Tue_310_OC-1_494
Fichefet, Thierry 500, Fri_202_OS-4_671, Fri_205_OS-4_734, Fri_249_OS-7_79,
Fri_268_OS-7_1023, Wed_268_OS-6_2122
Fiddes, Joel 2452, 2485
Fidel, Maryann 2177
Fielding, Sophie 2133, 711
2540
Fierli, Federico Tue_53_AC-1_1313
Fierz, Charles 2452, Fri_355_SY-1_2383, Wed_136_CR-7_552, Wed_137_CR-
7_728, Wed_141_CR-7_1372, Wed_143_CR-7_1496
Fietz, Susanne 676, 693, Tue_136_BE-3_1442
Figueiredo, Cosme Alexandre O.B. 2184
Figueras i Ventura, Jordi Wed_127_CR-3_2305
Filipova, Ludmila 1793
Filippova, Viktoriia 2368, Tue_379_SH-2_2652
Findlay, Helen Tue_360_OS-8_1960
Findlay, Ken Tue_352_OS-1_2249
Finger, David Wed_141_CR-7_1372
Fink, David 1374, 1958, Tue_277_GG-2_1373
Finn, Carol Fri_124_GG-1_347, Fri_141_GG-1_1133
Finocchiaro, Furio Thu_351_OS-3_1327
Finsterle, Wolfgang 1116
Firing, Yvonne Wed_258_OS-6_1555
Firla, Max 1054
Fischer, Elizabeth Thu_283_CR-6_794
Fischer, Hubertus 1423, 1638, 1763, 427, 518, 789, 834, Fri_58_EN-6_1224,
Wed_174_CR-8_1641, Wed_177_CR-8_1744, Wed_178_CR-8_1750, Wed_180_CR-8_1764,
Wed_181_CR-8_1775
Fischer, Matthias 2547
Fish, Meredith 2643
Fisher, Andrew Thu_264_CR-5_2142
Fisher, David 215, Wed_91_CR-2_210
Fishwick, James Thu_356_OS-3_2058
Fitzsimmons, Mark F. Fri_307_OS-7_2683
Fitzsimons, Ian 855
Flamant, Cyrille Tue_39_AC-1_887
Flamm, Patrick Thu_404_SH-7_2243
Flandez, Eduardo Thu_282_CR-6_774
Flanner, Mark Tue_68_AC-1_1789
Fleming, Andrew 1720, Wed_365_TE-3_1131
Fleming, Zoë L. 2598, Tue_51_AC-1_1220
Flesher, Christopher Wed_319_TE-1_846
Flexas, Mar 2212
Flin, Frédéric Wed_139_CR-7_1228
Flinkman, Juha Thu_383_SH-6_1536
Flocco, Daniela 2053
Flores, Hauke 1777, 2060, 497, 906, Thu_152_BE-9_2114, Thu_322_EN-4_1421,
Thu_91_BE-5_1590, Thu_94_BE-5_2078, Tue_224_BE-10_2373, Wed_209_OS-2_506,
Wed_220_OS-2_1787
Flores, José-Abel Tue_294_GG-2_2035
Floricioiu, Dana Thu_212_CR-4_860
Florindo, Fabio Tue_87_AC-5_176
Florindo Lopez, Cristian Wed_238_OS-6_955
Florindo-Lopez, Cristian Tue_247_GG-2_200, Wed_241_OS-6_974
Flouttard, Alexandre Thu_48_AC-8_2689
Fluharty, David Wed_299_SH-5_1070
Fluhrer, Anke Wed_355_TE-3_655
Focaracci, Francesca Thu_140_BE-9_1550, Thu_141_BE-9_1552
Fogal, Pierre F. 1217
Fogt, Ryan 465
Fogwill, Christopher J. 2588
Fogwill, Germán Pérez 1561
Foley, Catherine Thu_177_BE-11_1094
Foley, Neil 1186
Fondahl, Gail 2368, Tue_379_SH-2_2652
Fong, Allison 2260, Tue_360_OS-8_1960
Fonseca, Duilio Thu_282_CR-6_774
Font, Alejandro Tue_204_BE-4_2348, Tue_207_BE-4_2493
2541
Fontana, Pablo Gabriel Wed_290_SH-4_2359
Fontaneto, Diego 2107
Forbelská, Marie Tue_162_BE-4_453
Forbes, Bruce Wed_88_BE-7_2673
Forbes, Martin 606, Thu_208_CR-4_615
Forbes, Richard 298, 449
Forcada, Jaume 496
Ford, Elaina Thu_394_SH-6_2377
Forde, Taya 2049
Foresti, Loris Wed_127_CR-3_2305
Forget, Marie-Hélène Fri_246_OS-5_2501
Førland, Eirik Wed_128_CR-3_2436
Forlin, Edy Tue_279_GG-2_1478
Forrer, Heather Thu_50_BE-2_57
Forrer, Heather J 1172
Forrest, Alex 2424
Forrest, Steven Thu_179_BE-11_1151
Forsberg, Rene 1168, 2360, 2642, 807, Fri_124_GG-1_347, Fri_149_GG-1_1830,
Thu_267_CR-5_2349, Tue_257_GG-2_747
Forsberg, René 1756, Thu_260_CR-5_1784, Wed_118_CR-3_1762, Wed_385_TE-
3_2382
Forsmo, Vidar Tue_349_OS-1_1940
Förster, Simon 2392
Fort, Jérôme 1842, 2372
Forte, E. Wed_96_CR-2_1525, Wed_97_CR-2_1527
Forte, Emanuele 1524, Wed_95_CR-2_1520
Fortier, Louis 1082
Forwick, Matthias 1656, 1862, Fri_292_OS-7_1815
Forwick, Mattias 1120
Foster, Louise 1572, 1577
Foster, Scott 596
Fountain, Andrew 2189, 2257, 229
Fourcy, Damien Thu_182_TE-3_1780
Fourquez, Marion 2265, Thu_192_BE-12_927, Tue_143_BE-3_2271
Fourre, Elise Fri_253_OS-7_356
Fox, Adrian 1794
Fox, Stuart 1796
Frajka-Williams, Eleanor 1292
France, J. Wed_215_OS-2_1279
France, James 2283
Francelino, Marcio Rocha Fri_104_EN-7_2355, Fri_31_EN-2_2343
Francelino, Márcio Rocha Wed_387_TE-3_2431
Franceschini, Chiara Wed_164_CR-8_979
Francesconi, Sandro Fri_70_EN-6_2486, Wed_130_CR-3_2500
Francia, Patrizia 755
Francis, Diana Tue_39_AC-1_887
Francis, Jane Tue_278_GG-2_1455
Francis, Jennifer 2328, 721
Francois, Roger Fri_75_EN-7_313
Frank, Martin Wed_272_OS-6_2282
Franke, Dieter 736
Fransson, A. Wed_215_OS-2_1279
Fransson, Agneta Fri_98_EN-7_2081, Fri_99_EN-7_2082, Wed_225_OS-2_2458
Frants, Marina Fri_216_OS-4_2173
Franz, Daniela Wed_119_CR-3_2030
Franziska, Aemisegger Tue_56_AC-1_1467
Frappier, Roxanne Tue_238_CR-1_1562
Fraser, Alexander 44, Wed_360_TE-3_874
Fraser, Ceridwen 597
Fraser, William 1841, 2196, Thu_143_BE-9_1724, Tue_190_BE-4_1559,
Wed_264_OS-6_1788
2542
Frazer, Eamon 526
Frédéric, Dupont Fri_206_OS-4_804
Frédéric, Szczap Tue_59_AC-1_1546
Frederichs, Thomas 281, Thu_210_CR-4_702, Thu_211_CR-4_749
Fredin, Ola 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Fredj, Erick Thu_143_BE-9_1724, Wed_264_OS-6_1788
Frei, Esther R. Tue_208_BE-4_2515
Freitag, Lee 2235, Fri_353_SY-1_1994
Freitas, Marcos Wed_373_TE-3_1570
Freitas, Pedro 2681
French, Hugh Wed_95_CR-2_1520
French, Nadia 545
Frenger, Ivy 386
Frese, Ralph R.B. Fri_124_GG-1_347
Fressin, François 1272
Fretwell, Peter 1128, 1577, 1794, 1798, 286, Wed_365_TE-3_1131
Frey, Beat 258, 330, 431, 504, Thu_189_BE-12_700
Frey, Markus 1134, 2113, Fri_286_OS-7_1585, Wed_154_CR-8_201
Frezzotti, Massimo 104, Fri_250_OS-7_131, Fri_69_EN-6_2364, Wed_164_CR-8_979
Friberg, Nikolai 1854
Fricker, Helen 1347
Friddell, David 1173
Friddell, Julie 1173, Fri_47_EN-5_2661
Friedl, Peter Thu_226_CR-4_1458, Wed_355_TE-3_655
Friedlaender, Ari 594
Friedl-Vallon, Felix Tue_40_AC-1_971
Friedrich, Ronny 1334
Frieß, Udo Fri_266_OS-7_993, Fri_274_OS-7_1269
Fripiat, F Wed_215_OS-2_1279
Fripiat, François 414, Wed_204_OS-2_291
Frishman, Steven 1733
Fritts, David C. 2184
Fritz, Michael 109, Tue_360_OS-8_1960
Frolov, Denis Tue_316_OC-1_1574
Frolov, Ivan Thu_385_SH-6_1666
Fromm, Tanja Thu_216_CR-4_894
Frossard, Aline 431, 504
Frost, Torben Fri_234_OS-5_674, Fri_248_OS-5_1230
Fruth, Thomas 1272
Fu, Xinshu Thu_34_AC-8_1811
Fučkar, Neven Fri_314_SH-8_1739
Fuckar, Neven 2308, 660
Fuda, Jean-Luc 2001
Fudge, T. J. 826
Fudge, TJ 104
Fudge, Tyler J. Wed_168_CR-8_1053
Fuentes, Ivan 1452
Fugmann, Gerlis 1848, 2011, 2146, Thu_392_SH-6_2252, Thu_393_SH-6_2318,
Tue_307_OC-1_294, Tue_324_OC-1_2247, Tue_338_OC-4_2135
Fujii, Masakazu 448, 780
Fujioka, Toshiyuki 1374, Tue_277_GG-2_1373
Fujita, Koji 1297, Wed_172_CR-8_1610
Fujita, Shuji 1235, Wed_169_CR-8_1261
Fujitake, Nobuhide Fri_84_EN-7_1293, Tue_126_BE-3_1092, Wed_72_BE-6_977
Fukamachi, Yasushi Wed_117_CR-3_1280
Fukuda, Yoichi Thu_265_CR-5_2284
Fukui, Koaro 1235
Fuller, Richard 2168
Funck, Thomas 1200
Funk, Martin 1303, 1648, Thu_297_CR-6_1674
Fuoco, Roger Fri_33_EN-2_2509, Fri_70_EN-6_2486
2543
Furevik, Tore 1858, Fri_306_OS-7_2597, Thu_47_AC-8_2596
Fusco, Giannetta Fri_288_OS-7_1711, Fri_289_OS-7_1748, Fri_291_OS-7_1767,
Tue_139_BE-3_1708, Wed_255_OS-6_1463
Fyfe, John 27, Fri_196_OS-4_117
Fyke, Jeremy 250, 2674, 787
Fyke, Jeremy G. Thu_207_CR-4_547

G
Głuchowska, Marta 2554
Gabarro, Carolina Fri_241_OS-5_1806
Gabella, Marco 959, Wed_127_CR-3_2305
Gabric, Albert 2398
Gabrieli, Jacopo Wed_176_CR-8_1721, Wed_183_CR-8_2007
Gabrielli, Paolo 1634, Wed_165_CR-8_1024, Wed_176_CR-8_1721, Wed_183_CR-
8_2007
Gabrielsen, Tove 1114, Tue_211_BE-4_2621
Gabrielsen, Tove M. 2562, Thu_76_BE-2_2582
Gad, Ulrik Pram 199
Gaddam, Vinay Wed_109_CR-3_884
Gaddam, Vinay K Thu_280_CR-6_610
Gaedicke, Christoph 736, Thu_235_CR-4_2005
Gagliardini, Olivier 789
Gagnon, Christian Thu_19_AC-8_171
Gagnon, David 2158
Gaisser, Tom Tue_11_AA-1_1377
Gajbhiye, Deepak Y Tue_271_GG-2_1124
Gal, Jong-Ku Thu_348_OS-3_1247
Galbán-Malagón, Cristóbal Fri_12_EN-2_742
Galé, Carlos Fri_153_GG-1_2023
Galeandro, Angelo Thu_255_CR-5_1000
Gales, Jenny Tue_247_GG-2_200, Tue_279_GG-2_1478, Wed_238_OS-6_955,
Wed_241_OS-6_974
Gales, Jenny A. 1950, 812, Tue_267_GG-2_1005
Galí, Marti 2098
Galindo, Virginie 2302
Galindo-Zaldivar, Jesus 2369, 2379, Fri_124_GG-1_347
Gallagher, Martin 1796
Gallee, Hubert Thu_308_CR-6_2640
Gallée, Hubert 1330, 1436, 1988, 298, 449, 9, Thu_248_CR-5_297, Thu_303_CR-
6_2306, Tue_79_AC-1_2292
Gallego-Sala, Angela 1029
Galleguillos, Carolina Tue_215_BE-4_2685
Gallerani, Andrea Fri_132_GG-1_714, Thu_351_OS-3_1327
Gallet, Jean-Charles Fri_351_SY-1_1881, Tue_65_AC-1_1731
Galley, R 2066
Gallon, Susan 1891
Galloway, Tamara 1860
Gallus, Lorenzo 930
Galmes, Jeroni Tue_169_BE-4_712, Tue_206_BE-4_2463
Galton-Fenzi, Ben Fri_259_OS-7_567, Wed_230_OS-6_562
Galton-Fenzi, Benjamin K. 576, Thu_236_CR-4_2150
Gambino, Salvatore 156, Thu_246_CR-5_153
Gamble, Amandine 39
Gamble, John 1095
Gamboa Sojo, Viviana Fri_65_EN-6_1986
Gandois, Laure 2325
Gandolfi, Antonella Thu_351_OS-3_1327
Gandy, Niall Tue_281_GG-2_1533
Gandyukhin, Viktor 639
Ganesan, Latha Tue_345_OS-1_1429
Ganeshan, Manisha Thu_15_AC-3_2662
2544
Gannutz, Theodore 1733
Gao, Jing Wed_104_CR-3_681
Gao, Jinyao Fri_116_GG-1_162
Gao, Libao Fri_254_OS-7_399, Wed_229_OS-6_393
Gao, Tengfei Thu_218_CR-4_1021
Gao, Yongqi Fri_204_OS-4_691
Gao, Zhongyong Thu_68_BE-2_1494
Garabato, Alberto G. Wed_281_OS-6_2649
García, Marga Tue_291_GG-2_1963, Tue_294_GG-2_2035, Tue_296_GG-2_2044
García-Hernández, Cristina Thu_233_CR-4_1870
Gardfeldt, Katarina 2659
Gariboldi, Karen Thu_351_OS-3_1327
Garmash, Olga 2274
Garnaud, Camille 222
Garnett, Mark H 1979
Garnier, Jimmy 735
Garnier, Romain 39
Garofalo, Paolo Stefano Fri_146_GG-1_1701
Garrard, Rodney Fri_331_SH-9_1252
Garric, Gilles 1659, 2308, Fri_314_SH-8_1739
Garrido-Benavent, Isaac 2256, 90
Gärtner-Roer, Isabelle Tue_308_OC-1_346
Gartzman, Sam 2021, 2524
Gartzman, Samuel Fri_278_OS-7_1325, Fri_280_OS-7_1333
Gascard, Jean-Claude 1659, 2017
Gascoin, Simon 1055, 1449
Gascon, Gabrielle Thu_8_AC-3_1393
Gašparová, Romana Thu_172_BE-9_335
Gassiy, Violetta 368
Gassmann, Max 111
Gasson, Ed 813
Gasson, Edward 303, Tue_302_GG-2_2480
Gasteur, Sven Thu_134_BE-9_1357
Gattacceca, Jerome Tue_260_GG-2_769
Gaudie Ley Lindau, Filipe Wed_158_CR-8_684
Gaume, Johan 2332
Gautam, Alok Tue_29_AC-1_348
Gauthier, Pierre 589
Gavrilo, Maria 2100
Gavrilov, Alexander 2547
Gavrilyeva, Tuyara Thu_381_SH-6_1238, Thu_390_SH-6_2245
Gawęda, Aleksandra Fri_158_GG-1_2219
Gayen, Bishakhdatta 576, Wed_232_OS-6_574
Gazi, Sahina Thu_115_BE-9_657
Gázquez-Sanchez, Fernando 1699
Ge, Shulan 973, Tue_264_GG-2_889
Gebhardt, Andrea Catalina Tue_305_GG-2_2602
Gebhardt, Catalina 281
Gedamke, Jason Tue_352_OS-1_2249
Gehring, Josué Fri_263_OS-7_931, Wed_12_AC-2_915, Wed_31_AC-2_2064,
Wed_5_AC-2_492
Geibel, Marc Fri_265_OS-7_991
Geiger, Alain Wed_137_CR-7_728
Geissler, Wolfram 780
Geissler, Wolfram H. Tue_305_GG-2_2602
Geldsetzer, Torsten 1271, 134, Fri_226_OS-5_151, Wed_347_TE-3_308
Geletti, Riccardo Tue_254_GG-2_669, Tue_275_GG-2_1300
Gelfius, Nicolas-Xavier 2066
Gelfo, Javier N. Fri_53_EN-6_786
Gemery, Laura 1481
Genet, Helene 1847, Wed_76_BE-6_1906
2545
Geng, Hong Thu_247_CR-5_238
Genovese, Cristina 1614, 591, Wed_213_OS-2_861
Genthon, Christophe 114, 1513, 1661, 298, 449, 739, 9, 952, Tue_36_AC-1_738,
Wed_31_AC-2_2064, Wed_8_AC-2_746
Gentile, Vittorio Wed_255_OS-6_1463
Geoffroy, Maxime 1082, Thu_89_BE-5_1268
Geomap, A.G. Fri_348_SY-1_1410
Gerakis, Jérôme 1272
Gerard, Karin Tue_214_BE-4_2680, Tue_217_BE-4_2692, Tue_228_BE-10_2695
Gerber, Franziska 959, Wed_127_CR-3_2305
Gerdes, Axel 1715
Gerdes, Dieter Thu_82_BE-5_455
Gerdes, Rüdiger 1736, Fri_212_OS-4_1813, Thu_107_BE-8_2338, Thu_341_OS-
3_724, Wed_278_OS-6_2634
Gerdts, Gunnar 2099
Gerhard, Nicoli Pozzebon Wed_133_CR-7_168
Gerlach, Craig 2049
Gerland, Sebastian 1506, 1770, 1778, Fri_218_OS-4_2297, Fri_238_OS-5_1267,
Fri_242_OS-5_1828
German, Christopher Wed_330_TE-1_1480
Germann, Urs 959, Wed_127_CR-3_2305
Gerrish, Laura 1165
Gerstoft, Peter Fri_134_GG-1_762
Gest, Léa Wed_168_CR-8_1053
Geyer, Adelina Fri_137_GG-1_967
Ghaffari, Peygham 1114
Ghidella, Marta Fri_124_GG-1_347
Ghiglione, Claudio 2107, Tue_323_OC-1_2117
Ghigliotti, Laura 930, Fri_195_OC-3_2300, Thu_131_BE-9_1204, Tue_175_BE-4_999,
Tue_314_OC-1_1337
Ghil, Michael Wed_255_OS-6_1463
Ghosh, Joy Gopal Fri_152_GG-1_1993
Giacomino, Agnese Fri_79_EN-7_754
Giannarelli, Stefania Fri_33_EN-2_2509, Fri_70_EN-6_2486, Thu_126_BE-9_1020,
Wed_130_CR-3_2500
Giardi, Fabio Tue_64_AC-1_1704
Giblin, Anne 2141
Gibson, Chris 1072, 1233
Giddings, Lesley-Ann Thu_194_BE-12_1242
Gier, Jessica Thu_374_SH-6_105
Giesbrecht, Karina E. 1912
Giese, Jörg 1955
Giesecke, Ricardo Thu_53_BE-2_314
Giginyak, Yuri Fri_78_EN-7_740
Giglio, Federico 2133, Fri_109_EN-7_2635, Fri_132_GG-1_714, Fri_97_EN-7_2076,
Thu_351_OS-3_1327, Thu_78_BE-2_2639
Gilbert, Caroline 1891
Gilbert, Ella 1475
Gilbert, Lin 1759
Gilbert, Neil 2275, 636
Gil-Imaz, Andres Fri_153_GG-1_2023
Gille, Sarah 1290, 2536, Fri_298_OS-7_2183
Gilles, Mary K. Tue_42_AC-1_1039, Tue_43_AC-1_1052
Gillespie, Lynn J. Tue_182_BE-4_1265
Gillet-Chaulet, Fabien 1330, 1678
Gillon, Michaël 1272
Gilmer, Greer 843, Thu_347_OS-3_1109
Gilmore, Robert W. 380
Gil-Pelegrin, Eustaquio Tue_169_BE-4_712
Gim, Y.T. Tue_73_AC-1_2020
Gimpel, Carla Thu_169_BE-9_2465
2546
Giongo, Gabriel Augusto 2184
Giordanengo, Giorgio Wed_44_AC-4_772
Giordano, Daniela 1175
Giordano, Patrizia Thu_351_OS-3_1327
Giorgetti, Giovanna Tue_266_GG-2_988, Tue_272_GG-2_1160
Giorio, Chiara Wed_152_CR-8_92
Giovanelli, Giorgio Wed_29_AC-2_1977
Giralt, Santi Thu_307_CR-6_2590
Giralt, Santiago 1034, Fri_57_EN-6_1032
Girard, Ralph 222
Girard-Ardhuin, Fanny 2055
Girst, Simone 2681
Gislason, Astthor 413
Giudice, Gaetano 156, Fri_115_GG-1_150, Thu_246_CR-5_153
Giuffrida, Giovanni 156, Fri_115_GG-1_150, Thu_246_CR-5_153
Gjelten, Herdis M. Wed_128_CR-3_2436
Gjorup, Davi Tue_243_CR-1_1995
Gkritzalis, Thanos 2021
Glass, Jennifer Wed_224_OS-2_2193, Wed_269_OS-6_2181
Glasser, Neil 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Glazovsky, Andrey 2381, Wed_345_TE-3_276
Gleason, Kelly 1340, Tue_96_AC-5_1149
Glessmer, Mirjam 1002
Glok, Nanalia Tue_101_AC-5_534
Glok, Natalia Tue_93_AC-5_532
Glover, Adrian 711
Glowacki, Piotr 1831, Thu_380_SH-6_1214
Gnatiuk, Natalia Thu_39_AC-8_2002
Goździk, Agata 2019
Gobat, Jason 2235, 2238
Gobel, Christian 1465, Wed_372_TE-3_1469
Gobet, Erika 1125, Tue_176_BE-4_1121
Godbold, Jasmin 468
Goddard, Paul B. Wed_228_OS-6_387
Goderis, Steven Tue_260_GG-2_769
Godø, Olav Rune Thu_123_BE-9_964
Godoi, Ana Flávia L. Tue_42_AC-1_1039, Tue_43_AC-1_1052
Godoi, Ricardo Tue_57_AC-1_1492
Godoi, Ricardo H. M. Tue_42_AC-1_1039, Tue_43_AC-1_1052
Godøy, Øystein 2452, Thu_380_SH-6_1214
Goebel, Michael 496, Thu_118_BE-9_707, Thu_135_BE-9_1405, Thu_155_BE-9_2157
Goebel, Michael E 2187
Goebel, Michael E. 1033
Goeckede, Mathias Fri_354_SY-1_2080
Goedkoop, Willem 1435, 1854
Goel, Vikram Thu_223_CR-4_1248
Goergens, Chad 465
Goerlandt, Floris 288
Goessling, Helge 2350, Fri_219_OS-4_2307, Thu_384_SH-6_1644
Goessling, Helge F. Fri_212_OS-4_1813
Goethel, Christina Thu_87_BE-5_1065
Goetz, Josh 1233
Goetz, Kimberly 2154, Thu_154_BE-9_2143
Gohl, Karsten 1135, 281, 780, Fri_124_GG-1_347, Fri_140_GG-1_1013,
Thu_226_CR-4_1458, Tue_268_GG-2_1022
Goksøyr, Anders Tue_218_BE-10_67
Goldberg, Dan 2628
Goldsmith, Paul Tue_15_AA-1_2209
Goldstein, Michael 5
Goldsworthy, Simon 496
Golikov, Alexey 290, Wed_81_BE-7_529
2547
Golledge, Nicholas 1592, 315, 813, 826, 831, 875, Thu_253_CR-5_837, Tue_87_AC-
5_176
Golledge, Nicholas R. 2588
Golynsky, Alexander 639
Golynsky, Alexander V. Fri_124_GG-1_347, Fri_125_GG-1_351, Fri_126_GG-1_354
Golynsky, Dmitry A. Fri_124_GG-1_347, Fri_125_GG-1_351, Fri_126_GG-1_354
Gomez, Natalya 2588, 2664, Thu_253_CR-5_837, Thu_29_AC-8_1083
Gomez, Rodrigo Wed_372_TE-3_1469
Gómez, Demián 2016
Gómez Fuentes, Claudio Fri_15_EN-2_1073
Gómez-Fuentes, Claudio Fri_16_EN-2_1258
Gomez-Heras, Miguel Wed_99_CR-2_2033
Gommershtadt, Olga Tue_209_BE-4_2528
Gonçalves, Ivan 1272
Gonçalves, Manoela Araújo Thu_277_CR-6_305
Gonçalves, Vívian Tue_128_BE-3_1138
Gonçalves Esteves, Vania Tue_70_AC-1_1895
Gonçalves Jr., Sérgio J. Tue_42_AC-1_1039, Tue_43_AC-1_1052
Goncharova, Olga Fri_71_EN-7_33
Gong, Da Fri_362_TE-2_432
Gong, Deng Fri_161_GG-1_2421
Gong, Xianda 425
Gong, Xuefei 503, Tue_18_AA-1_2263, Tue_5_AA-1_981
Gonzalez, Claudio Tue_214_BE-4_2680
Gonzalez, Inti Fri_350_SY-1_1743
Gonzalez, Javier 2414
Gonzalez, Marcelo Tue_204_BE-4_2348, Tue_207_BE-4_2493
Gonzalez, Sergi Tue_115_BE-1_1368, Wed_20_AC-2_1383, Wed_55_AC-7_1380
González, Humberto E. Thu_53_BE-2_314
González, R. Tue_75_AC-1_2054
González, Sergi Fri_310_SH-8_1349
González-Castillo, Lourdes 2369
Gonzalez-Wevar, Claudio Tue_217_BE-4_2692
Goodall-Copestake, Will 418
Goodall-Copestake, William Thu_171_BE-9_2615
Goodman, Paul 2536
Goodrich, Cordielyn Thu_143_BE-9_1724
Goodsell, Becky 828
Goodwin, Ian 2167
Goosee, Hugues 2308
Gooseff, Michael 157, 2189, 2257, 307, Wed_73_BE-6_1582
Gooseff, Michael N. Fri_39_EN-5_879
Goosse, Hugues Fri_202_OS-4_671, Fri_205_OS-4_734, Fri_249_OS-7_79,
Fri_314_SH-8_1739, Fri_55_EN-6_917, Thu_219_CR-4_1031, Thu_272_CR-6_143, Wed_275_OS-
6_2534
Gordini, Emiliano Tue_279_GG-2_1478
Gordon, Arnold L 2185
Gorman, Kristen 2196
Gorodestkaya, Irina V. 2598
Gorodetskaya, Irina 1004, 1041, 1802, Fri_263_OS-7_931, Tue_336_OC-4_1768,
Wed_12_AC-2_915, Wed_5_AC-2_492
Gorodetskaya, Irina V. 1661, 1951, 1954, 2643, Thu_48_AC-8_2689, Wed_22_AC-2_1654
Gorringe, Patrick Fri_353_SY-1_1994, Wed_260_OS-6_1628
Goss, Gryphen 1668
Gossart, Alexandra 1009, 1661, 1951, 1954, Wed_22_AC-2_1654
Gosselin, Michel Fri_108_EN-7_2583
Goszczko, Ilona Fri_292_OS-7_1815
Goto-Azuma, Kumiko 537
Gottlieb, Jens Tue_240_CR-1_1840
Gottschalk, Matthias 493, Tue_28_AC-1_249
Gough, Laura 2686
2548
Gourbeyre, Christophe Tue_59_AC-1_1546
Gourcuff, Claire Fri_353_SY-1_1994
Gourdon, Aurelie 1544
Gourmelen, Noel 1833, 2628
Goursaud, Sentia Fri_55_EN-6_917, Wed_23_AC-2_1671
Gouttevin, Isabelle 1522
Gouvret, Carole 1272
Grabak, Ola Fri_239_OS-5_1286
Grabiec, Mariusz 2041, 2409, Thu_309_CR-6_2687
Grabow, Johanna Fri_322_SH-9_36
Grachev, Andrey 1601, 1924
Gradinger, Rolf 1722, 1835
Gradone, Joseph Thu_67_BE-2_1470
Graeve, Martin 497, Tue_164_BE-4_466
Graf, Pascal 1041, 2643, Fri_263_OS-7_931, Wed_5_AC-2_492
Graham, Alastair G.C. 729
Graham, Alexander Gundlach Fri_146_GG-1_1701
Graham, Felicity 572
Graham, Jennifer Wed_270_OS-6_2186
Graham, Mark Fri_189_OC-3_1485
Graham, Robert Fri_218_OS-4_2297, Fri_285_OS-7_1563, Wed_9_AC-2_782
Graham, Robert M. 531, Fri_242_OS-5_1828
Grajewski, Tomasz 1868
Gramlich, Gabriela 402
Grams, Christian M. 476, 81
Granados, Ignacio Fri_57_EN-6_1032, Thu_307_CR-6_2590
Grange, Laura 259, 468
Granger, Julie Wed_219_OS-2_1594
Grannas, Amanda M. Fri_95_EN-7_2013
Granskog, Mats Fri_218_OS-4_2297, Fri_285_OS-7_1563, Fri_98_EN-7_2081,
Wed_225_OS-2_2458
Granskog, Mats A. 1506, 531, Fri_242_OS-5_1828, Thu_74_BE-2_2483
Granskog, Mats. A 1309
Grant, Brett 526, Fri_259_OS-7_567, Wed_316_TE-1_569
Grant, Cindy 1082
Grant, Georgia 1877
Grant, Susie Thu_149_BE-9_1875
Grantham, Geoffrey H. Fri_164_GG-1_2548
Grattacaso, Martina Fri_32_EN-2_434
Graversen, Rune 2328
Gray, Alison 2171
Gray, Andrew Wed_365_TE-3_1131
Gray, Laurence 1957
Gray, Stephen 1289
Graybill, Jessica 1952
Grayson, Stuart Thu_178_BE-11_1110
Graziano, Marco Tue_114_BE-1_1366, Tue_184_BE-4_1367
Grazioli, Jacopo 1661, 449, Wed_31_AC-2_2064
Greń, Katarzyna Fri_64_EN-6_1867
Grebmeier, Jackie 2100, Tue_363_OS-8_2616
Grebmeier, Jacqueline 1587, 2520, Thu_87_BE-5_1065
Green, Allan 1733, 924
Green, J.A. Mattias Thu_29_AC-8_1083
Green, Mattias 2676
Greenbaum, Jamin 1856, Fri_128_GG-1_629, Fri_155_GG-1_2149, Fri_156_GG-1_2153
Greenbaum, Jamin S. 854, Thu_236_CR-4_2150, Thu_238_CR-4_2213
Greene, Chad A. Thu_236_CR-4_2150
Gregoire, Lauren Tue_281_GG-2_1533
Gregory, Sue 2132
Greku, Rudolf 1042
Greku, Tatyana 1042
2549
Grémillet, David 1842, 2372
Gremion, Gwenaelle Thu_392_SH-6_2252
Grenier, Melanie 601
Greve, Michelle 713
Greve, Ralf Thu_237_CR-4_2200
Griebler Junior, José Celso 2194
Griessinger, Nena Wed_148_CR-7_2335
Griffies, Stephen 1292, 2171
Griffies, Stephen M. 386, Wed_228_OS-6_387, Wed_246_OS-6_1099
Griffin, Natasha Thu_197_BE-12_2223
Griffiths, Howard Thu_114_BE-9_374
Griffiths, Huw 2346, 349, 637, 710, 711, Thu_329_EN-4_2095, Wed_258_OS-
6_1555
Griffiths, Ross W. Wed_232_OS-6_574
Grigioni, Paolo 114, Thu_246_CR-5_153
Grilli, Roberto 1423
Grist, Jeremy P. 500
Grobe, Hannes 1656, Fri_35_EN-5_361
Groebner, Julian Tue_26_AC-1_242
Groh, Andreas 2375, Thu_263_CR-5_2024, Wed_385_TE-3_2382
Grondin, Pierre-Luc 2060
Grooß, Jens-Uwe 1077
Grooss, Jesn-Uwe 2412
Groot Zwaaftink, Christine Tue_31_AC-1_405
Groppi, Christopher E. Tue_15_AA-1_2209
Grosbois, Guillaume Wed_77_BE-6_1992
Grosfeld, Klaus 1638
Grosjean, Martin 2614
Gross, Felix Tue_305_GG-2_2602
Grosse, Guido 1184, Fri_343_SY-1_563
Grotti, Marco 1614, Fri_19_EN-2_1422, Tue_63_AC-1_1703
Gruber, Nicolas 1167, 678
Grumbine, Robert Fri_212_OS-4_1813
Grünewald, Thomas 1210
Grunow, Anne 1934, Thu_313_EN-3_1144, Tue_312_OC-1_925
Gryanik, Vladimir M. Thu_10_AC-3_1742
Grynczel, Agata Wed_274_OS-6_2497
Grythe, Henrik 2499
Grytsai, Asen 942, Wed_13_AC-2_928
Grzelak, Katarzyna Thu_97_BE-5_2651
Grzymski, Joe Thu_160_BE-9_2258
Gu, Bozhong 503
Guajardo, Mariela Thu_201_BE-12_2553, Thu_77_BE-2_2592, Tue_140_BE-3_2003
Gualtieri, Lisa C. Fri_40_EN-5_1263
Guan, Lei Fri_233_OS-5_541
Gudgel, Rich 1554
Gudmundsson, G Hilmar 1758
Gudmundsson, Hilmar 2392
Gudra, Tadeusz Wed_341_TE-3_217
Guedes, Leonardo Tue_71_AC-1_1913
Guemas, Virginie 660
Guest, Peter 136, 2021, 2503, 263
Gugerli, Rebecca 901
Guggenberger, Georg Wed_90_BE-7_1579
Gugliandolo, Concetta Thu_126_BE-9_1020
Guglielmin, Mauro 1524, 2037, Thu_233_CR-4_1870, Tue_237_CR-1_1256,
Wed_95_CR-2_1520, Wed_96_CR-2_1525, Wed_97_CR-2_1527
Guillaso, Stéphane 2103
Guillaumot, Charlene 1864
Guillaumot, Charlène Thu_147_BE-9_1809, Tue_159_BE-4_430, Wed_86_BE-7_1866
Guillong, Marcel 237
2550
Guillot, Tristan 1272, 1376
Guinet, Christophe 496, Thu_156_BE-9_2169
Gulev, Sergey Fri_281_OS-7_1378
Guliaev, Roman 667
Gulisano, Adriana Maria 509, 511
Gunderson, Troy Thu_166_BE-9_2380, Thu_196_BE-12_2191
Gunther, Allison 371
Günther, Detlef Fri_146_GG-1_1701
Guo, Guijun Fri_254_OS-7_399
Guo, Huadong Wed_111_CR-3_1010
Guo, Jingxue Fri_155_GG-1_2149, Fri_156_GG-1_2153
Guo, Song Thu_218_CR-4_1021
Guo, Wenkai 437
Guochao, Wu Fri_141_GG-1_1133
Gupta, Mukesh Fri_241_OS-5_1806
Gurses, Özgür Thu_232_CR-4_1698
Gusain, H.S Thu_203_CR-4_50
Gusdal, Yvonne Fri_217_OS-4_2273
Guseva, Yulia 639
Gustafsson, David 1495
Gustavson, Kim Fri_10_EN-2_555
Gütermann, Julia 2099
Gutierrez Rodriguez, Andres Thu_138_BE-9_1414
Gutknecht, Benjamin D. 2375
Gutow, Lars Fri_3_EN-2_174
Gutt, Julian 2346, Thu_82_BE-5_455, Wed_85_BE-7_1637
Guyomard, Ann-Isabell Fri_336_SH-9_2439, Wed_291_SH-4_2454
Guzzi, Alice 2107, Tue_323_OC-1_2117
Gwyther, David E. Thu_236_CR-4_2150
Gyeong, Hye-Ryeon Thu_200_BE-12_2492
Gypens, Nathalie Wed_208_OS-2_464
Gysel, Martin 1041, 1381, Tue_56_AC-1_1467
Gyurjinyan, Alexander Fri_328_SH-9_605

H
Ha, Ho Kyung 1002
Ha, Sangbeom Thu_334_OS-3_78
Ha, Sun-Yong Wed_84_BE-7_1505
Haak, Helmuth Fri_239_OS-5_1286
Haapala, Jari 1206, Wed_203_OS-2_233, Wed_335_TE-1_2354
Haas, Antonie Fri_343_SY-1_563
Haas, Christian 1254, 1573, 526, 65, Fri_228_OS-5_254, Fri_230_OS-5_343,
Thu_333_OS-3_53
Haase, Ina Wed_90_BE-7_1579
Haberkorn, Anna Fri_355_SY-1_2383
Häberli, Marcel 1763
Haberreiter, Margit 1116
Haeberli, Marcel 518
Haenel, Florian Tue_40_AC-1_971
Hagedorn, Birgit 2506
Hagemann, Jonas 1687
Hagen, Wilhelm 2045, Tue_164_BE-4_466
Hagenmuller, Pascal Wed_139_CR-7_1228
Haggstrom, Ingemar 2228
Haghipour, Negar Fri_96_EN-7_2069
Hahm, Doshik Fri_284_OS-7_1542
Hahn-Woernle, Lisa 1489, Thu_86_BE-5_918
Haid, Verena Thu_360_OS-3_2291
Haidr, Nadia Fri_54_EN-6_798
Haigh, Joanna Wed_154_CR-8_201
Haines, Keith 2308, Fri_314_SH-8_1739
2551
Hájek, Josef Fri_372_BE-5_1696, Tue_162_BE-4_453, Tue_235_CR-1_715
Hakala, Simo 360
Halberstadt, Anna Ruth 303
Halici, Gokhan Tue_235_CR-1_715
Hall, Chris 2228
Hall, David M. 1394
Hall, Dorothy Wed_379_TE-3_2052
Hall, Ian 1257
Hall, Jerome Fri_163_GG-1_2537
Hall, Richard 2328
Hall, Tricia Fri_163_GG-1_2537, Tue_304_GG-2_2572
Hallberg, Robert 2536
Hallet, Bernard 2482
Hallgren, Allan Tue_11_AA-1_1377
Hallmann, Christian Tue_125_BE-3_1019
Halpin, Jacqueline 572, 607, 850, 855, Thu_254_CR-5_862, Tue_289_GG-2_1937
Halpin, Jacquline 690
Halsband, Claudia Tue_355_OS-8_795
Hamari, Britta Wed_14_AC-2_976
Hamidi, Azmir Tue_145_BE-3_2289
Hamilton, Lawrence 173
Hammann, Arno 1449, Tue_97_AC-5_2495
Hampai, Dariush Wed_166_CR-8_1030
Han, Chang Hee Wed_185_CR-8_2304
Han, Changhee 1634
Han, Hyangsun 197, Wed_342_TE-3_268
Han, Seunghee Fri_111_EN-7_2666
Han, Xibin Fri_67_EN-6_2166
Han, Yeongcheo Fri_63_EN-6_1645
Han, Yeongcheol 1634, Fri_154_GG-1_2121, Fri_68_EN-6_2240, Fri_69_EN-6_2364,
Wed_191_CR-8_2579
Han, Zhengbing Thu_59_BE-2_756
Hanacek, Martin Fri_121_GG-1_338, Fri_66_EN-6_2057
Hancock, Alyce 2182
Handcock, Mark Thu_353_OS-3_1408
Handley, Michael 213
Handorf, Dörthe 2328
Hanea, Anca 1592
Hanlon, Regina 1473
Hanna, Edward 2328, 721, Thu_24_AC-8_560
Hannigan, James 2682
Hannula, Henna-Reetta Wed_143_CR-7_1496
Hanselmann, Kurt 257, Fri_5_EN-2_253
Hansen, Christel Tue_229_CR-1_138, Tue_230_CR-1_139
Hansen, Georg H. Tue_25_AC-1_241, Tue_26_AC-1_242
Hansen, Jasmine Siena Sarling Thu_262_CR-5_1863
Hansen, Miriam 287
Hansen, Nicolaj 2642
Hansen, Oskar 1443
Hansen, Rikke 1443
Hansen, Samantha 1274, Fri_113_GG-1_118, Fri_134_GG-1_762
Hansson, Hans-Christen 1199
Hanyu, Tomoko 448
Hao, Guanghua Fri_197_OS-4_345
Hao, Weifeng Wed_46_AC-4_1624
Harada, Naomi Thu_399_SH-7_539
Harbor, Jon 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Harder, Tristan H. Tue_42_AC-1_1039, Tue_43_AC-1_1052
Hardesty, Jasper 1586, Wed_200_EN-1_2137
Hardesty, Joe Tue_72_AC-1_1920
Hardge, Kristin 497, Wed_209_OS-2_506
2552
Harding, Ann 1842, 2372
Hardman, Molly A. 1602
Harman, John 514
Harris, Danielle Tue_352_OS-1_2249
Harris, Neil 1041
Harris, Ursula Thu_80_BE-5_191
Harrison, Roy 1846
Harrison, Roy M. Fri_307_OS-7_2683
Hart, Tom Thu_137_BE-9_1413, Thu_176_BE-11_1087, Thu_177_BE-11_1094,
Thu_179_BE-11_1151, Thu_183_BE-11_2631
Harth, Christina 834
Hartikainen, Juha 1129, 2036
Hartley, Iain P 1979
Hartman, Julian D. 1740
Hartmann, Markus 1041, 425, 433, Tue_27_AC-1_244, Tue_44_AC-1_1122, Tue_56_AC-
1_1467
Harvey, Brandon 380
Harvey, H. Rodger 2056
Harvey, Mike Fri_311_SH-8_1355, Thu_138_BE-9_1414, Tue_49_AC-1_272
Harwood, David 813
Harwood, David M. 1950, 812, Tue_267_GG-2_1005
Hashimoto, Taishi Wed_49_AC-4_2316
Hasholt, Bent 2506
Haskell, Tim 1081, 414
Hasler, Christel Fri_89_EN-7_1502
Hasselman, Alexa 1243
Hassett, Brandon 1722
Hassler, Christel , 2265, 89, Fri_75_EN-7_313, Thu_192_BE-12_927, Tue_143_BE-
3_2271
Hassler, Christel S. 2340
Hastings, Meredith Wed_219_OS-2_1594
Hatcher, Patrick G. Fri_95_EN-7_2013
Hattermann, Tore 1112, 1136, Wed_247_OS-6_1137
Hattori, Akihisa Fri_151_GG-1_1933, Thu_249_CR-5_404, Thu_265_CR-5_2284
Hauck, Christian 274
Haucke, Max Wed_326_TE-1_1231
Haumann, Alexander 304
Haumann, F. Alexander 1167
Hausmann, Ute Wed_244_OS-6_1012
Havenhand, J.N. 2102
Havermans, Charlotte 2045
Håvik, Lisbeth 718
Hawes, Ian 2376, Fri_308_SH-8_211, Thu_117_BE-9_688, Thu_195_BE-
12_2116, Wed_305_SH-5_1434
Hawkes, Clare 1941
Haworth, Anna 1577
Hayashi, Kentaro Fri_84_EN-7_1293, Tue_126_BE-3_1092, Wed_72_BE-6_977
Hayashida, Hakase 2195
Hayatsu, Masahito Tue_126_BE-3_1092
Hayden, Anna Thu_29_AC-8_1083
Hayes, Michael 1243
Haynes, Peter 1537
Hayward, Scott Thu_125_BE-9_1018, Tue_154_BE-4_149
Hayward, Scott A. L. Tue_181_BE-4_1234
He, Shengping 1858
Headland, Robert 637
Heal, Katherine R. Tue_144_BE-3_2272
Hebbeln, Dierk Tue_299_GG-2_2327
Hechenleitner, Kimberly Wed_294_SH-5_4
Hefter, Jens Thu_333_OS-3_53, Thu_349_OS-3_1251
Hehemann, Laura 2099
2553
Heiden, Jasmin P Thu_60_BE-2_778
Heiden, Jasmin P. 2340
Heiðmarsson, Starri 2256
Heijmans, Monique M.P.D. Tue_195_BE-4_1688
Heikkinen, Pauli Wed_35_AC-2_2434
Heil, Petra 1081, 1714, 2083, 609, Fri_355_SY-1_2383
Heilig, Achim Wed_142_CR-7_1471
Heim, Birgit 2428, Fri_343_SY-1_563
Heimbach, Patrick Thu_237_CR-4_2200
Hein, Andrew S. 1229
Heindler, Franz Tue_159_BE-4_430
Heindler, Franz M. Thu_144_BE-9_1757, Tue_220_BE-10_1776
Heindler, Franz Maximilian 1746
Heinemann, Günther 1468, 369, 644, Fri_251_OS-7_300, Thu_336_OS-3_410
Heinesch, Bernard 414
Heino, Jani 1854
Heinold, Bernd Tue_67_AC-1_1781, Wed_3_AC-2_337
Heitz, Olivier 2372
Hejduková, Eva Tue_133_BE-3_1197
Held, Andreas Tue_32_AC-1_561
Held, Christoph 2, 2045, Thu_82_BE-5_455, Tue_186_BE-4_1419
Helfrich, Sean Fri_221_OS-4_2512
Helland, Alexander Tue_240_CR-1_1840
Helleis, Frank Tue_45_AC-1_1139
Hellemans, Bart 1746, Thu_144_BE-9_1757, Tue_220_BE-10_1776
Hellessey, Nicole Thu_173_BE-11_582, Wed_82_BE-7_580
Hellmer, Hartmut 1136, Wed_236_OS-6_768
Hellmer, Hartmut H. Fri_214_OS-4_1872
Helm, Veit 1761, 1770, 2042, Thu_304_CR-6_2425
Helmig, Detlev Fri_74_EN-7_277
Helsel, Fred Wed_200_EN-1_2137
Hemming, Sidney 2580
Hemming, Sidney R. 1889, 2521
Hendrick, Francois 1009
Hendricks, Stefan 1573, 2051, 968, Fri_239_OS-5_1286
Hendry, Katharine 416, Fri_105_EN-7_2397
Henley, Sian Wed_242_OS-6_996
Henneberg, Olga 7
Henneberger, Jan 7
Henning, Silvia 1041, Tue_27_AC-1_244, Tue_56_AC-1_1467
Henriksen, Thøger 1443
Henry, Greg Tue_208_BE-4_2515
Herbaut, Christophe 2001, Fri_297_OS-7_1997, Wed_245_OS-6_1040
Herber, Andreas 1163, 246, 495, Thu_107_BE-8_2338, Tue_35_AC-1_719
Herber, Andreas B. Tue_45_AC-1_1139
Herbold, Craig 2140
Hereme-Ruedlinger, Rasme Tue_201_BE-4_2097
Hereñú, Ubaldo 511
Herenz, Paul 1009, 2598
Herman, Agnieszka 35, 482, Fri_256_OS-7_480
Herman, Frederic 1379, 1544
Herman, Krzysztof Wed_341_TE-3_217
Herman, Rachael Thu_179_BE-11_1151
Hermann, Markus Wed_324_TE-1_1115
Hermanns, Reginald 752
Hermans, Christian 1009, Wed_16_AC-2_1017
Hermans, Tim 1885
Hermanson, Mark Fri_24_EN-2_1930
Hermichen, Wolf-Dieter 2014
Hernandez, Jorge 1691, Thu_230_CR-4_1673
Hernández-Molina, F. Javier Tue_291_GG-2_1963
2554
Herraiz-Borruguero, Laura 1002
Herreid, Sam 99
Herreras, M. Tue_75_AC-1_2054
Herried, Brad , 637
Herrmann, Hartmut 425, Tue_44_AC-1_1122
Hersko, Judit Thu_367_SH-3_1350, Tue_335_OC-4_1351
Hervé, Francisco 1934
Herzschuh, Ulrike 2428
Hesselbjerg Christensen, Jens 2546
Hetzenecker, Marcus Thu_267_CR-5_2349
Hetzenecker, Markus 1741
Heuzé, Céline Fri_300_OS-7_2201, Thu_355_OS-3_1824, Wed_235_OS-6_737
Héuzé, Celiné 1002
Hewitt, Helene Wed_258_OS-6_1555
Hewitt, Rebecca 1847
Heygster, Georg Fri_234_OS-5_674, Fri_236_OS-5_835, Fri_248_OS-5_1230,
Thu_345_OS-3_939, Wed_363_TE-3_1063, Wed_383_TE-3_2314
Heywood, Karen 1060, 1433, 2246
Heywood, Karen J. Wed_239_OS-6_957
Hezel, Paul 2341
Hicks, Anne 2684
Hicks, Michael 1720
Higgins, John 2442
Hilger, Andrew 28
Hilger, Paula 752
Hill, Alice Wed_121_CR-3_2073
Hill, Nicole 596
Hill, Simeon 1047, 1165
Hillebrand, Helmut Tue_353_OS-1_2600
Hillebrand-Voiculescu, Alexandra 1132, Tue_112_BE-1_949
Hillenbrand, Claus-Dieter 1656, 1710, 1889, 279, 281, Thu_206_CR-4_394, Thu_210_CR-
4_702, Thu_211_CR-4_749, Tue_259_GG-2_765
Hillman, Ben Thu_7_AC-3_1346
Hillman, Benjamin 1586
Hilsheimer, Philipp 670
Hilton, Robert G. Fri_96_EN-7_2069
Hinckley, Eve-Lyn Wed_73_BE-6_1582
Hindell, Mark 2047, 2346
Hindell, Mark A Thu_156_BE-9_2169
Hindell, Mark A. 1632
Hindmarsh, Richard C. A. 826
Hindshaw, Ruth 1719, Thu_393_SH-6_2318
Hinke, Jefferson Thu_135_BE-9_1405
Hinke, Jefferson T. 1033
Hirabayashi, Motohiro 1235, 537
Hirano, Daisuke Wed_237_OS-6_944
Hirawake, Toru Wed_117_CR-3_1280
Hiroi, Yoshikuni 2233
Hirshberg, Diane 1908
Hirst, Catherine 2255, 2391
Hitchcock, Peter 760
Hitziger, Thomas Thu_252_CR-5_820
Hmiel, Benjamin 834
Hobbie, John 2141
Hobbs, Will 391, 697, Fri_196_OS-4_117
Hochmuth, Katharina 1135, 281, Tue_269_GG-2_1086
Hock, Regine 649, Wed_134_CR-7_312
Hocking, Emma 1577
Hodges, Kevin 299, Wed_53_AC-7_301
Hodgson, David Tue_281_GG-2_1533
Hodgson, Dominic 1029, 1572, 1577, Fri_59_EN-6_1428
2555
Hodson, Andrew J. Thu_165_BE-9_2370, Tue_120_BE-1_2362
Høegh Bojesen, Mikkel Tue_240_CR-1_1840, Wed_198_EN-1_1844
Hoek, Wim Z Fri_49_EN-6_429
Hoekstra, Marie 2638
Hoelemann, Jens Fri_82_EN-7_1201
Hoelzle, Martin 771, 951
Hoem, Nils Thu_173_BE-11_582, Wed_82_BE-7_580
Hoeppner, Kathrin 1181
Hoerhold, Maria 2415
Höfer, Juan Thu_53_BE-2_314
Hoffman, Joe 496
Hoffman, Joseph Thu_118_BE-9_707
Hoffman, Matthew 250
Hoffman, Matthew J. Thu_207_CR-4_547
Hoffmann, Lars 2412
Hoffmann, Ralf Thu_79_BE-5_144
Hofmann, Eileen 2346, 823
Hofstede, Coen 1264, 736
Hogan, Bartholomew 514
Hogan, Kelly 1710, Tue_259_GG-2_765
Hogg, Anna 1759, Wed_258_OS-6_1555
Hogg, Ian 1733, Thu_322_EN-4_1421, Tue_165_BE-4_513
Hogg, Oliver Thu_329_EN-4_2095
Hokada, Tomokazu 2233
Hoke, Winfried Thu_384_SH-6_1644
Holden, Philip B 2468
Holder, Liam Thu_217_CR-4_899
Holding, Johnna 1119, 1345, 943, Tue_358_OS-8_940
Hole, Georgia 29
Hole, Lars Robert Thu_4_AC-3_698
Hölemann, Jens Tue_361_OS-8_2287, Wed_261_OS-6_1729
Holfort, Jürgen Fri_210_OS-4_1800, Fri_211_OS-4_1805
Holko, Ladislav Wed_141_CR-7_1372
Holland, David 239, Tue_39_AC-1_887, Wed_227_OS-6_247
Holland, David M. 614, Fri_270_OS-7_1105
Holland, Marika 735
Holland, Paul 1549, 1817, Wed_281_OS-6_2649
Hollands, Thomas 1774
Hollenbach, David Tue_15_AA-1_2209
Hollmann, Hannes Wed_145_CR-7_1921
Hollmen, Tuula Wed_201_EN-1_2253
Holloway, Jean 1848, 2146, 302, Thu_393_SH-6_2318, Tue_338_OC-4_2135
Holloway, Max 279
Holm, Stine 1213
Holman, Amy 1289
Holmén, Kim Thu_380_SH-6_1214
Holmes, Caroline 1817, 2293, Thu_36_AC-8_1821
Holmes, Thomas 1103, 1281, 594
Holschuh, Nicholas 2560, 2566
Holstein, Jan 487
Holt, John W. Fri_124_GG-1_347
Honda, Meiji 2303
Hong, Jialin Fri_359_TE-2_161, Fri_363_TE-2_438
Hong, Jong Kuk 13, Tue_242_CR-1_1969, Tue_275_GG-2_1300, Wed_337_TE-3_14
Hong, Jong Won Fri_178_ME-2_2347
Hong, Jongkuk Fri_124_GG-1_347
Hong, Jongsun Fri_136_GG-1_913
Hong, Sang Bum Wed_191_CR-8_2579
Hong, Sangbum Fri_63_EN-6_1645, Fri_69_EN-6_2364
Hong, Sang-Bum 401
Hong, Soon Gyu 110, 1132, 120, Thu_117_BE-9_688, Thu_157_BE-9_2222
2556
Hong, Sungmin 1634, Fri_68_EN-6_2240, Wed_185_CR-8_2304
Hong, Yang 945, Wed_362_TE-3_966
Hongbing, Liu Fri_161_GG-1_2421
Hooley, Jack Wed_249_OS-6_1291
Hoor, Peter 495, Tue_35_AC-1_719, Tue_45_AC-1_1139
Hoose, Corinna 1288
Hop, Haakon 1835, Thu_74_BE-2_2483
Hopcroft, Russ Tue_363_OS-8_2616
Hopcroft, Russell 2100, 413
Hopcroft, Russell R. Tue_355_OS-8_795
Höpfner, Michael 1077, 2412, Tue_40_AC-1_971
Hoppe, Clara 2274
Hoppe, Clara Jule Marie 1114, 1745
Hoppmann, Mario 1254, Fri_277_OS-7_1320, Wed_261_OS-6_1729
Höppner, Kathrin 1774, Thu_226_CR-4_1458, Wed_350_TE-3_420
Horák, Aleš Thu_55_BE-2_559
Horgan, Huw , 315, 828
Hörhold, Maria 1560
Horie, Kenji Fri_164_GG-1_2548
Horikawa, Keiji Tue_293_GG-2_2130
Horn, Fabian 1213
Horn, Jen Tue_312_OC-1_925
Horn, Myriel Wed_261_OS-6_1729, Wed_279_OS-6_2644
Horvat, Christopher 142, Tue_360_OS-8_1960
Horvath, Alexander Wed_385_TE-3_2382
Horwath, Martin 1761, 2042, 2375, Thu_263_CR-5_2024, Wed_385_TE-3_2382
Hosale, Mark-David Tue_339_OC-4_2139
Hošek, Jiří Thu_9_AC-3_1709
Hosekova, Lucia 2053, 2471
Hoshi, Kazuhiro 2303
Hosking, Scott 1140
Hotter, Vivien 431
Hou, Shugui 1297
Houben, Alexander Tue_287_GG-2_1734
Houghton, Melissa 1896
Hourdin, Frédéric 298, 739, 9
Houska, Jakub Tue_249_GG-2_328
Houssais, Marie-Noelle 2001, Fri_297_OS-7_1997
Houssais, Marie-Noëlle Wed_245_OS-6_1040
Howe, Bruce Fri_353_SY-1_1994
Howell, Stephen 134, 2552, Wed_347_TE-3_308
Howkins, Adrian 229, 307
Howkins, Adrian J. Fri_39_EN-5_879
Høye, Toke 1443
Hrafnsdottir, Þóra Katrín 1854
Hrbáček, Filip Thu_1_AC-3_283, Thu_233_CR-4_1870, Tue_235_CR-1_715
Hrbacek, Filip 2077, Fri_103_EN-7_2352, Tue_232_CR-1_284, Tue_237_CR-
1_1256, Wed_92_CR-2_282
Hsieh, Hsun-Yi Thu_322_EN-4_1421
Hu, Chuanyu Thu_59_BE-2_756
Hu, Hongqiao Wed_51_AC-4_2624
Hu, Keliang 1939, Tue_4_AA-1_679
Hu, Lei 503
Hu, Yi 1939, 503, 849, Tue_4_AA-1_679
Hu, Zhengyi 891, Thu_204_CR-4_164
Hua, Quan 185, 189, 834
Huang, Lin 433
Huang, Mengxue Tue_263_GG-2_848
Huang, Wei 1447
Huang, Xiaoxuan Tue_261_GG-2_783
Huang, Yong Thu_218_CR-4_1021
2557
Huang, Yuanhui 973
Hubbard, Alun 2506
Huber, Jacqueline 421, Tue_308_OC-1_346
Huber, Jaques Fri_74_EN-7_277
Hubert, Guillaume Fri_179_ME-2_2529
Huckstadt, Luis 2187, 2603
Huckstat, Luis Thu_154_BE-9_2143
Hudak, David Thu_8_AC-3_1393
Hudson, K P C Wed_194_EN-1_47
Hudson, Stephen 1506
Hudson, Stephen R. 1309, 531
Hudson, Thomas S. 165
Huerta, Audrey Fri_134_GG-1_762
Huerta, Marlene Wed_113_CR-3_1035
Huffman, Louise 584, Tue_307_OC-1_294
Hugentobler, Michael 1648
Hughes, Kelli Tue_142_BE-3_2165
Hughes, Kevin 2034, 710, Thu_125_BE-9_1018, Thu_403_SH-7_1983
Hughes, Kevin A. 1321
Hughes, Nicholas Fri_223_OS-4_2567, Wed_346_TE-3_280
Hughes, Nick 2494, Fri_221_OS-4_2512
Huhn, Oliver Fri_255_OS-7_473, Fri_267_OS-7_1016
Hui, Fengming 289, Wed_354_TE-3_533
Hulbe, Christina , 606, 828, Thu_208_CR-4_615, Thu_222_CR-4_1078
Hulbe, Christina L. Fri_207_OS-4_900
Humbert, Angelika 1264
Humborg, Christoph Fri_265_OS-7_991
Humphreys, Grant Thu_183_BE-11_2631
Humphries, Grant Thu_137_BE-9_1413
Hundhausen, Marie 670
Hunegnaw, Addisu 2016
Huneke, Wilma Wed_230_OS-6_562
Hung, Hayley 433
Hunstad, Ingrid 1650, 1676, 1693, Wed_44_AC-4_772
Huntemann, Marcus 1254, Fri_234_OS-5_674
Hunter, Alasdair 660
Huntington, Henry 1345, 1903, 1907, 2520, Tue_358_OS-8_940
Huot, Pierre-Vincent Wed_268_OS-6_2122
Huot, Yannick 2060, Thu_94_BE-5_2078
Hur, Jin 401
Hur, Soon Do 1634, Fri_68_EN-6_2240, Fri_69_EN-6_2364, Wed_185_CR-8_2304,
Wed_191_CR-8_2579
Hur, Soondo Fri_63_EN-6_1645
Hurry, Vaughan 924
Hurwitz, Benjamin Wed_269_OS-6_2181
Huss, Matthias 2392, 649, 901, 951, Thu_285_CR-6_652, Thu_297_CR-6_1674
Husum, Katrine 1257, Thu_356_OS-3_2058, Thu_363_OS-3_1576, Tue_272_GG-
2_1160
Hutchins, Wendy 2049
Huth, Alex Thu_239_CR-4_2216
Hutter, Nils Fri_220_OS-4_2323
Huvenne, Veerle Thu_329_EN-4_2095
Huwald, Hendrik 2510, 2609
Huybrechts, Philippe Tue_260_GG-2_769, Tue_303_GG-2_2505
Hvidegaard, Sine Wed_346_TE-3_280
Hvidegaard, Sine Munk 2642
Hvitfeld Iversen, Morten 2079
Hwang, Hee Jin Wed_185_CR-8_2304
Hwang, Heejin Fri_69_EN-6_2364
Hyde, Larry 1444
Hyder, Patrick 2293, Wed_258_OS-6_1555
2558
Hyland, Glenn 609
Hyun, Chang Uk 120
Hyun, Chang-Uk Wed_343_TE-3_270

I
Iaccarino, Antonio Thu_5_AC-3_775
Iaccarino, Salvatore Fri_118_GG-1_230
Iakovenko, Nataliia Thu_130_BE-9_1155, Tue_177_BE-4_1146
Ibarra, Pedro 2369
Ichikawa, Takashi Tue_2_AA-1_398
Ickes, Luisa 1288
Idakieva, Vyara Fri_130_GG-1_689
Idalino, Filipe Daros Thu_278_CR-6_309
Iermano, Ilaria Wed_255_OS-6_1463
Ignatiev, Sergei 2317
Ignatiuk, Dariusz 2409, Thu_309_CR-6_2687
Iisla, Enrique Fri_92_EN-7_1825
Iizuka, Yoshinori 1235, Wed_172_CR-8_1610
Ikeda, Atsushi Fri_167_ME-2_112, Fri_173_ME-2_1117
Ikeda, Hiroshi Thu_265_CR-5_2284
Ikehara, Minoru Tue_246_GG-2_187, Tue_293_GG-2_2130
Iken, Katrin 2100, Thu_95_BE-5_2270, Tue_363_OS-8_2616
Ilicak, Mehmet Wed_233_OS-6_627
Ilyina, Tatiana Thu_75_BE-2_2484
Immerz, Antonia Fri_343_SY-1_563
Immerzeel, Walter Wed_353_TE-3_507
Immerzeel, Walter W. 1503
Imura, Satoshi Fri_167_ME-2_112, Fri_173_ME-2_1117, Fri_174_ME-2_1188,
Fri_175_ME-2_1411, Fri_184_ME-1_1982
Inall, Mark Wed_242_OS-6_996
Ingalls, Anitra E. Tue_144_BE-3_2272
Ingeman-Nielsen, Thomas Tue_240_CR-1_1840
Ingvaldsen, Randi 1604, 958, Thu_47_AC-8_2596
Ingvaldsen, Randi B. Fri_306_OS-7_2597
Intrieri, Janet 214, 255, Wed_312_TE-1_376
Introne, Douglas Wed_123_CR-3_2148
Iosifescu Enescu, Ionut 2230
Iovino, Doroteaciro 2308, Fri_314_SH-8_1739, Thu_360_OS-3_2291
Iqaluk, Debbie 1837
Irarrazaval, Inigo 1379
Irarrazaval Bustos, Inigo 1544
Ireland, Louise 1577
Iriarte, Jose Luis Thu_53_BE-2_314
Iribarren, Pablo Thu_282_CR-6_774
Irving, James 1111
Isaksen, Ketil 752
Isaksson, Elisabeth 104, Fri_24_EN-2_1930
Ishino, Saki 1950, 812, Tue_267_GG-2_1005
Ishiwa, Takeshige Thu_249_CR-5_404, Thu_251_CR-5_590
Isiler, Dogac B. Tue_326_OC-1_2402, Tue_327_OC-1_2445
Ismail-Zadeh, Alik Thu_381_SH-6_1238
Ita, Yoshifusa Tue_2_AA-1_398
Itaki, Takuya Tue_293_GG-2_2130
Itcus, Corina 1132, Fri_183_ME-1_1692, Thu_157_BE-9_2222, Tue_112_BE-
1_949
Itkin, Polona 1206, 1506, Fri_242_OS-5_1828, Fri_285_OS-7_1563
Itoh, Motoyo 1119
Iturrate-Garcia, Maitane Tue_195_BE-4_1688
Ivaldi, Roberta Fri_292_OS-7_1815
Ivanescu, Liviu 589
Ivanov, Boris Wed_314_TE-1_536
2559
Ivanov, Marin Fri_130_GG-1_689
Ivanov, Nikolai Tue_101_AC-5_534
Ivanov, Nikolay Wed_26_AC-2_1927
Ivanov, Sergey V. Fri_124_GG-1_347
Ivanov, Vladimir Thu_385_SH-6_1666
Ivar do Sul, Juliana Assunção 2422
Iversen, Lisbeth 2177
Ivey, Mark 1586, Tue_72_AC-1_1920, Wed_200_EN-1_2137
Ivins, Erik Thu_257_CR-5_1064

J
J. Burn-Nunes, Laurie 1634
Jabour, Julia Thu_318_EN-4_592
Jaccard, Samuel Fri_75_EN-7_313
Jaccard, Samuel L. Fri_89_EN-7_1502
Jackson, Adele Fri_324_SH-9_218, Thu_375_SH-6_571
Jackson, Jennifer 1901
Jackson, Jennifer A. Thu_114_BE-9_374
Jacobi, Hans-Werner Wed_128_CR-3_2436
Jacobs, Joachim 1315, Fri_122_GG-1_340
Jacobs, Stanley S. Wed_239_OS-6_957
Jacobsen, Carsten Suhr Thu_193_BE-12_1011
Jacobsen, Dean 1854
Jacobsen, Marc 199
Jacques, Caroline 2021, Wed_221_OS-2_2027
Jafar, Syed Thu_115_BE-9_657
Jaffe, Rudolf Fri_94_EN-7_1869
Jaggi, Janessa Tue_312_OC-1_925
Jaggi, Matthias Wed_149_CR-7_2423
Jäggi, Adrian Thu_261_CR-5_1812
Jahn, Alexandra 1178, 1392, 1394, Wed_252_OS-6_1395, Wed_56_AC-7_1482
Jain, Anand Tue_110_BE-1_664
Jakob, Torsten Thu_58_BE-2_741
Jakobi, Gert 1381
Jakobs, Stan Thu_231_CR-4_1680
Jakobsen, PâviâraK 2401
Jakobsson, Martin 1200
Jaksic, Cyril 119
Jakuba, Michael Wed_330_TE-1_1480
Jalil, Camila Wed_294_SH-5_4
James, Paul 1277
James, Thomas Fri_337_SY-1_24
Jamieson, Stewart 1430, 745, Tue_257_GG-2_747, Tue_265_GG-2_909, Tue_278_GG-
2_1455, Tue_301_GG-2_2440
Jana, Ricardo 667
Jaña, Ricardo 1465, Wed_372_TE-3_1469
Jaña, Ricrado Fri_350_SY-1_1743
Janches, Diego 2184
Jania, Jacek 2041, 2409
Janko, Karel 1684, Thu_130_BE-9_1155, Tue_177_BE-4_1146
Janout, Markus 1573, 1604, 2060, 2100, Fri_82_EN-7_1201, Thu_94_BE-5_2078,
Tue_361_OS-8_2287, Wed_261_OS-6_1729
Jansen, Daniela Thu_304_CR-6_2425
Jansen, Eystein Thu_362_OS-3_2555
Jansen, Peter 108
Janssen, David J. Fri_89_EN-7_1502
Janssens, Julie 1614, 591, 844, Fri_75_EN-7_313, Fri_88_EN-7_1498, Wed_213_OS-
2_861
Järvinen, Emma 1163, 246, Tue_35_AC-1_719
Jaskólski, Marek 1976
Jaskólski, Marek W. Wed_202_EN-1_2345
2560
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Jawak, Shridhar D. Fri_269_OS-7_1100, Fri_349_SY-1_1504, Wed_240_OS-6_960
Jee, Geonhwa 1944, 578
Jeffrey, Andy 1720
Jehin, Emmanuel 1272
Jena, Babula Thu_244_CR-4_88, Thu_26_AC-8_878
Jena, Babulal Thu_72_BE-2_2367
Jendersie, Stefan 2285
Jeni Victor, N Tue_62_AC-1_1679
Jenk, Theo Wed_153_CR-8_183, Wed_193_CR-8_1670
Jenk, Theo M. Wed_179_CR-8_1760
Jenk, Theo Manuel 1297
Jenkins, Adrian 1002, 1060, 1433
Jenkins, Richard 1619
Jenouvrier, Stephanie 488, 735, Thu_153_BE-9_2126, Thu_179_BE-11_1151
Jenouvrier, Stéphanie 921
Jensen, Henning K.B. 1541
Jensen, Mari 2415
Jenson, George V Wed_262_OS-6_1738
Jenssen, David Fri_75_EN-7_313
Jeofry, Hafeez 293
Jeong, Jihoon 2295
Jeong, Jin Young Thu_52_BE-2_234
Jepsen, Nis Thu_5_AC-3_775
Jerez, Silvia Thu_103_BE-8_2084, Thu_104_BE-8_2101
Jeromson, Matt 1958
Jersabek, Christian D. Thu_322_EN-4_1421
Jeyaratnam, Jeyavinoth Wed_131_CR-3_2658
Jha, Shantenu 1232
Ji, Fei Fri_116_GG-1_162
Ji, Qing Fri_243_OS-5_1925, Wed_356_TE-3_733
Jiang, Chengyu Fri_168_ME-2_225
Jiang, Peng 503
Jiang, Su Wed_132_CR-7_94
Jiang, Xiaoben Tue_142_BE-3_2165
Jiao, Liping 401
Jiao, Yutian Wed_277_OS-6_2626
Jimenez, Julissa 2156
Jiménez, Begoña Fri_12_EN-2_742
Jiménez-Espejo, Francisco J. Tue_262_GG-2_833
Jin, Haiyan Thu_56_BE-2_642
Jin, Meibing Fri_216_OS-4_2173
Jin, Young Keun Tue_242_CR-1_1969, Tue_275_GG-2_1300
Jindal, Tanu Fri_20_EN-2_1437
Jingxue, Guo 1856
Jinyao, Gao 892
Jiskra, Martin Fri_74_EN-7_277
Joe, Paul Thu_8_AC-3_1393
Johannessen, Ola Thu_64_BE-2_929
Johannessen, Ola M Wed_226_OS-6_152
Johannessen, Truls Fri_354_SY-1_2080
Jóhannesson, Tómas Thu_305_CR-6_2467
Johannsson, Halldor 2011, 2019
Jóhannsson, Halldór Fri_356_SY-1_2507
Johansson, Erik 502
Johansson, Malin Wed_346_TE-3_280
Johansson, Margareta 1642
John, Timm 1955
Johnsen, Geir 1309, Thu_89_BE-5_1268
Johnson, Craig 596
Johnson, David 1979
2561
Johnson, Helen 1375
Johnson, Jay 1233
Johnson, Jim Fri_304_OS-7_2558
Johnson, Joel E. 1862
Johnson, Katelyn 826
Johnson, Katelyn M. Tue_262_GG-2_833
Johnson, Ken 2536
Johnson, Kenneth 2171
Johnson, Noor 2174, 2177, 484, Fri_45_EN-5_2357
Johnson, Peter Fri_337_SY-1_24
Johnson, Robert Thu_173_BE-11_582
Johnston, Nadine Thu_149_BE-9_1875
Jokat, Wilfried 1315, 780, Fri_122_GG-1_340, Fri_124_GG-1_347, Tue_248_GG-
2_206
Jolivet, Aurelie Tue_351_OS-1_2032
Jolley, Dianne Fri_34_EN-2_2691
Jolly, Ben Tue_236_CR-1_858
Jonas, Tobias Wed_148_CR-7_2335
Jonassen, Marius 670
Jones, Anna 1134
Jones, Anna E. Tue_51_AC-1_1220
Jones, Elizabeth 2090
Jones, Fiona Thu_137_BE-9_1413, Thu_176_BE-11_1087, Thu_183_BE-11_2631
Jones, Julie 465
Jones, Martin Wed_217_OS-2_1580
Jones, Megan Wed_67_AC-6_1600
Jones, Richard 1374, 881
Jones, Richard Selwyn Tue_265_GG-2_909
Jones, Tyler 2288, 490
Jones-Williams, Kirstie 1860, Thu_69_BE-2_1859
Jong, Lenneke Thu_254_CR-5_862
Joo, Houng-Min Thu_52_BE-2_234
Joos, Hanna 476
Jordan, Madeleine 730
Jordan, Tom 1168, 1756, 2360, Tue_257_GG-2_747, Wed_118_CR-3_1762
Jordan, Tom A. Fri_124_GG-1_347, Thu_260_CR-5_1784
Jörg, Ebbing 704
Josey, Simon 986, Fri_298_OS-7_2183
Joshi, Manoj 1537
Jossart, Quentin Thu_144_BE-9_1757, Thu_145_BE-9_1801, Thu_146_BE-9_1807,
Thu_147_BE-9_1809, Tue_185_BE-4_1369
Joubert, Warren 239, Wed_227_OS-6_247
Joughin, Ian 44
Jourdain, Nicolas 1436, Wed_244_OS-6_1012, Wed_275_OS-6_2534
Jourdan, Olivier 1163, 246, Tue_59_AC-1_1546
Jouvet, Guillaume 1648, Thu_286_CR-6_932
Joux, Fabien 2098
Jouzel, Jean 1513, 444
Joy, Kurt 2198, 564, Thu_174_BE-11_838, Thu_312_EN-3_566, Wed_305_SH-
5_1434
Joyce, Rachel 796
Ju, Changhui Fri_139_GG-1_975
Ju, Hyeon Tae 197
Ju, Mengshan 973
Juńczyk, Tomasz 2019
Judge, Miller Thu_194_BE-12_1242
Judy, Logan 1668
Juggins, Steve 1572, 1577
Juhl, Andrew 2066, Tue_362_OS-8_2543
Juhls, Bennet Tue_361_OS-8_2287
Jumelet, Julien Tue_36_AC-1_738
2562
Jun, Hye Lim 2448
Jun, Sang-Yoon 207
Jun, Seong Joon Fri_368_TE-2_902
Jun, Seong-Joon Fri_63_EN-6_1645
Jung, Chaerin 2295
Jung, Chang Hoon Tue_73_AC-1_2020
Jung, Ji Hoon 2426
Jung, Ji Young Thu_200_BE-12_2492
Jung, Jinyoung 401, Tue_360_OS-8_1960
Jung, Thomas 1769, 2350, 2646, Fri_214_OS-4_1872, Fri_219_OS-4_2307,
Thu_384_SH-6_1644, Wed_54_AC-7_1211
Jungblut, Anne D. 2376
Junge, Andreas 2369
Juniper, Kim Fri_73_EN-7_261
Junmeng, Zhao Fri_161_GG-1_2421
Junninen, Heikki 2274, Tue_37_AC-1_767
Jurányi, Zsófia Fri_274_OS-7_1269
Juricke, Stephan Fri_214_OS-4_1872
Justel, Ana Fri_310_SH-8_1349, Tue_115_BE-1_1368, Wed_20_AC-2_1383,
Wed_55_AC-7_1380

K
Kędra, Monika 1587, Thu_91_BE-5_1590, Thu_97_BE-5_2651
K. Lee, Charles 1631
Kääb, Andreas Wed_366_TE-3_1310
Kaartokallio, Hermanni Wed_203_OS-2_233
Kaas, Eigil 1646, Tue_283_GG-2_1640
Kacprzak, Paula Thu_93_BE-5_2029
Kadota, Moe 537
Kafle, Pratap 2049, 485
Kahlert, Maria 352
Kahn, Ralph 477
Kaikkonen, Laura Wed_216_OS-2_1531
Kaiser, Brooks Thu_325_EN-4_1566
Kakareka, Sergey Fri_6_EN-2_323, Fri_78_EN-7_740
Kalas, Paul 1376
Kalberer, Markus Wed_152_CR-8_92
Kaleschke, Lars 2051, Fri_230_OS-5_343
Kalmbach, Andrew Thu_166_BE-9_2380, Thu_196_BE-12_2191
Kaluzienski, Lynn 730
Kam, Hosik 2184
Kamal, Samy Fri_216_OS-4_2173
Kamasaka, Kohei Tue_137_BE-3_1551
Kameda, Takao Wed_134_CR-7_312
Kamenkovich, Igor 2536
Kaminski, Thomas Fri_239_OS-5_1286
Kamp, Peter 1877
Kämpfer, Niklaus 1209
Kampova, Barbora Tue_232_CR-1_284
Kanawade, Vijay Tue_29_AC-1_348
Kane, Douglas 2145
Kang, H.J. Tue_73_AC-1_2020
Kang, Hui Fri_262_OS-7_895
Kang, Hyoun-Woo Fri_284_OS-7_1542
Kang, Hyun-Suk Fri_203_OS-4_677
Kang, Jungho Fri_69_EN-6_2364
Kang, Jung-Ho Fri_63_EN-6_1645
Kang, Kiryong Fri_203_OS-4_677
Kang, Mingu 2448
Kang, Seung-Goo Tue_242_CR-1_1969, Tue_275_GG-2_1300
Kang, Shichang Fri_143_GG-1_1630
2563
Kang, Sung-Ho 2426, Fri_303_OS-7_2475, Fri_342_SY-1_383, Thu_52_BE-2_234,
Thu_96_BE-5_2413, Tue_275_GG-2_1300
Kangas, Antti Fri_221_OS-4_2512
Kanhai, La Daana 2659
Kankaanpää, Paula Thu_383_SH-6_1536
Kanna, Naoya Wed_117_CR-3_1280
Kanzow, Torsten 1183, Fri_267_OS-7_1016, Wed_278_OS-6_2634
Kao-Kniffin, Jenny 2361
Kaplin, Nikita 1908, Tue_374_SH-2_204
Kappler, Andreas 257, Fri_5_EN-2_253, Tue_125_BE-3_1019
Kapsch, Marie 1755
Kapsch, Marie-Luise Wed_146_CR-7_1929
Karahalil, Meric Thu_332_EN-4_2396, Tue_325_OC-1_2393
Karam Francis, Diana Wed_227_OS-6_247
Karas, Bogumil J. Thu_55_BE-2_559
Karcher, Michael Fri_239_OS-5_1286
Karentz, Deneb Thu_160_BE-9_2258
Karjalainen, Satu-Maaria 352
Karle, Albrecht 2481
Karlsen, Odd André Tue_218_BE-10_67
Karlsen, Stein Rune Wed_88_BE-7_2673
Karlsson, Karl-Göran 502, Wed_349_TE-3_406
Karlsson, Nanna Thu_304_CR-6_2425
Karlsson, Nanna B. 1638
Karlsson, Nanna Bjørnholt 1306
Karnovsky, Nina 2372
Karp-Boss, Lee 793
Karpechko, Alexey 2328
Karppinen, Tomi Wed_14_AC-2_976
Karsten, Ulf 431
Karvigh, Simin Ahmadi Fri_319_SH-8_2408
Kashin, Sergey Wed_314_TE-1_536
Kašparová, Eva Thu_130_BE-9_1155
Kasprzak, Marek 1976
Kassab, Christine M. 2521
Kassabian, Lara Wed_269_OS-6_2181
Kaštánek, Petr Fri_372_BE-5_1696
Kästner, Udo 246
Katchinoff, Joachim 2391
Käthner, Ralf Wed_324_TE-1_1115
Katlein, Christian 1699, 2060, 699, Thu_94_BE-5_2078
Kato, Nanako Fri_173_ME-2_1117, Fri_174_ME-2_1188, Fri_175_ME-2_1411
Katsumata, Katsuro 637
Katurji, Marwan 1361, 510, Thu_117_BE-9_688, Wed_305_SH-5_1434, Wed_327_TE-
1_1363
Kaufmann, Ronald Thu_155_BE-9_2157
Kauker, Frank 2308, Fri_212_OS-4_1813, Fri_239_OS-5_1286, Fri_314_SH-8_1739
Kauko, Hanna M 2060
Kauko, Hanna M. 1309, Thu_74_BE-2_2483
Kaul, Norbert Tue_268_GG-2_1022
Kavan, Jan Thu_1_AC-3_283, Thu_21_AC-8_278, Thu_287_CR-6_1161,
Wed_93_CR-2_332
Kavanaugh, Maria 1037
Kawabe, Tetsuya Fri_173_ME-2_1117, Fri_174_ME-2_1188, Fri_175_ME-2_1411
Kawaguchi, So 682, Thu_164_BE-9_2363, Thu_173_BE-11_582, Wed_82_BE-7_580
Kawamoto, Jun Tue_137_BE-3_1551
Kawamura, Kenji 1749, 516, 537
Kazadzis, Stelios Tue_25_AC-1_241, Tue_26_AC-1_242
Kazakov, Eduard 1683, 2324, Wed_374_TE-3_1658
Kazankov, Andrey 639
Kazlova, Alexandra Fri_258_OS-7_544
2564
Ke, Changqing 2280
Keck, Francois 352
Kecorius, Simonas 1163, Tue_32_AC-1_561
Kedra, Monika Thu_94_BE-5_2078
Keenlyside, Noel Fri_204_OS-4_691, Thu_22_AC-8_445
Keil, Kathrin Tue_360_OS-8_1960
Keisling, Benjamin A. 1950, 812, Tue_267_GG-2_1005
Keith, David 2118
Keleshis, Christos Wed_336_TE-1_2356
Kellem da Rosa, Kátia Thu_273_CR-6_154
Keller, Elizabeth 826, Thu_253_CR-5_837
Keller, Elizabeth D 1592, 831
Kellerhals, Thomas 402, 518
Kelley, Lisa 1474
Kelley, Maxwell Thu_283_CR-6_794
Kelman, Ilan Thu_381_SH-6_1238
Kempf, Nicolas Tue_372_SH-1_2532
Kempf, Scott D Thu_238_CR-4_2213
Kender, Sev 1257
Kendrick, Eric 1885
Kennicutt II, Mahlon Chuck
Kenny, Nathan Tue_207_BE-4_2493
Kent, Elizabeth Wed_258_OS-6_1555
Kepski, Daniel 1
Kerminen, Veli-Matti 2274, 360
Kern, Michael Fri_149_GG-1_1830, Wed_380_TE-3_2108
Kern, Ramona 431
Kern, Stefan 945, 968, Fri_237_OS-5_970, Fri_245_OS-5_2399, Fri_248_OS-
5_1230, Thu_345_OS-3_939, Thu_346_OS-3_972
Kerr, Rodrigo Tue_166_BE-4_581, Wed_236_OS-6_768
Kerr, Ross C. Wed_232_OS-6_574
Kerr, Yann H 316, Wed_348_TE-3_317
Keslinka, Liliana Fri_11_EN-2_726
Key, Jeffrey Wed_349_TE-3_406
Keyser, Margrete N. S. 1159
Khairedinova, Alexandra Wed_167_CR-8_1043
Khalsa, Siri Jodha Fri_319_SH-8_2408, Wed_121_CR-3_2073
Khan, Alia 1402, 1404, Fri_94_EN-7_1869, Wed_121_CR-3_2073
Khan, Shfaqat Abbas 687, Thu_250_CR-5_456, Wed_361_TE-3_948
Khan, Zoya Tue_145_BE-3_2289
Khare, N. Fri_48_EN-6_34
Kharyutkina, Elena Thu_38_AC-8_1928
Khazmutdinova, Karina 2536
Kheyrollah Pour, Homa 2638
Khim, Boo-Keun Thu_334_OS-3_78
Khmeleva, Victoria Wed_374_TE-3_1658
Khomutov, Artem 2627
Khomyak, Alexey Wed_167_CR-8_1043
Khosrawi, Farah Tue_55_AC-1_1461
Khosrawi, Farahnaz Tue_40_AC-1_971
Khromova, Tatiana 1667
Khvorostovsky, Kirill 968
Kida, Morimaru Fri_84_EN-7_1293, Tue_126_BE-3_1092, Wed_72_BE-6_977
Kielman, Ross Fri_158_GG-1_2219
Kiesel, Joshua 524, Wed_80_BE-7_523
Kihm, Ji-Hoon Thu_167_BE-9_2417, Thu_314_GG-1_2170
Kilian, Rolf Fri_59_EN-6_1428
Kilic, Dogushan Fri_21_EN-2_1609
Kim, Baek-Min 207, 2569
Kim, Han Kyeom Fri_178_ME-2_2347
Kim, Hyeong Jeek Thu_334_OS-3_78
2565
Kim, Hyosun Wed_300_SH-5_1089
Kim, Hyoung Jun Tue_275_GG-2_1300
Kim, Hyun Cheol Thu_334_OS-3_78
Kim, Hyun-Cheol 120, Wed_342_TE-3_268, Wed_343_TE-3_270, Wed_344_TE-3_271
Kim, Hyun-Chul Fri_284_OS-7_1542
Kim, Hyung-Rae Fri_124_GG-1_347
Kim, Jeong-Han 1944, Wed_40_AC-4_385
Kim, Ji Hee 120, Fri_299_OS-7_2192, Tue_116_BE-1_1633
Kim, Jihee Fri_111_EN-7_2666
Kim, Jinseok 2424
Kim, Jin-Soo Thu_31_AC-8_1316
Kim, Jong-Min Wed_367_TE-3_1314
Kim, Joo-Hong Fri_63_EN-6_1645
Kim, Jung-Hyun Thu_348_OS-3_1247
Kim, Khan Thu_194_BE-12_1242
Kim, Kwanwoo Thu_52_BE-2_234, Thu_54_BE-2_320
Kim, Mincheol Thu_200_BE-12_2492
Kim, Ok-Sun 110, 120
Kim, Sang Hee 120
Kim, Sanghee Thu_167_BE-9_2417
Kim, Seok Cheol 120
Kim, Seong-Joong 207, Fri_63_EN-6_1645
Kim, Songyi Wed_191_CR-8_2579
Kim, Sookwan 1950, 812, Tue_242_CR-1_1969, Tue_247_GG-2_200, Tue_267_GG-
2_1005, Tue_275_GG-2_1300, Tue_279_GG-2_1478
Kim, Suhwan Tue_275_GG-2_1300
Kim, Sunghan 1618, 1950, 812, Thu_334_OS-3_78, Tue_267_GG-2_1005,
Tue_276_GG-2_1354, Tue_298_GG-2_2261
Kim, Sunhwi 2295
Kim, Sun-Mi Tue_116_BE-1_1633
Kim, Tae Wan 1002, 1433, Thu_96_BE-5_2413, Wed_239_OS-6_957
Kim, Yeadong , Fri_368_TE-2_902
Kim, Yong-Ha 2184
Kim, Young-Gyun Tue_275_GG-2_1300
Kimmritz, Madlen Fri_204_OS-4_691
Kimoto, Katsunori Tue_246_GG-2_187
Kimura, Hajime Thu_399_SH-7_539
Kindeberg, Theodor Thu_55_BE-2_559
King, Amy 103, Wed_152_CR-8_92
King, Catherine Fri_34_EN-2_2691
King, Diana 185
King, Diana H Thu_112_BE-9_186
King, Edward C. 729
King, Jennifer 1506
King, Jennifer A. 1770
King, John 1140
King, John C 1475
King, Josh Wed_377_TE-3_1897
King, Joshua 222
King, Martin 2068, Thu_34_AC-8_1811, Thu_40_AC-8_2012
King, Matt 1118, 1958, 687, Thu_254_CR-5_862, Thu_266_CR-5_2311,
Wed_306_SH-5_1462
King, Rob 682
King, Tyler 1543, 2145, 2477
Kingslake, Jonathan 379, 826
Kingslake, Jonny 1076, Wed_134_CR-7_312
Kinnard, Christophe 1449
Kinner, Ida 1668
Kinsey, James Wed_330_TE-1_1480
Kinsman, Nicole 1289
Kipfstuhl, Sepp 1560, 2415, 826, Tue_96_AC-5_1149
2566
Kirchhoff, Katharina Thu_384_SH-6_1644
Kirchner, Nina Tue_344_OS-1_1219
Kirkevåg, Alf 995
Kirkham, Amy 2154, Thu_101_BE-8_1593, Thu_102_BE-8_1839, Thu_98_BE-8_38
Kirner, Ole Tue_55_AC-1_1461
Kirner, Oliver Tue_40_AC-1_971
Kirpes, Rachel 1473
Kirpotin, Sergey Wed_60_AC-7_2438
Kiselev, Alexander V. Fri_124_GG-1_347, Fri_126_GG-1_354
Kitamura, Kyotaro 516, 537
Kitchener, John Thu_159_BE-9_2242
Kittel, Christoph 1528, 1988, Thu_303_CR-6_2306, Thu_308_CR-6_2640,
Wed_268_OS-6_2122
Kivi, Rigel Tue_66_AC-1_1752, Wed_14_AC-2_976, Wed_35_AC-2_2434
Kjær, Helle A. 826
Kjeldsen, Kristian Thu_250_CR-5_456
Kjeldsen, Kristian K. Wed_361_TE-3_948
Kjøllmoen, Bjarne 1312
Klages, Johann 281
Klages, Johann Philipp Thu_210_CR-4_702
Klarenberg, Ingeborg Thu_185_BE-12_169
Klatt, Calvin Fri_337_SY-1_24
Klein, Andrew 1444, Fri_27_EN-2_2043
Klein, Birgit Fri_353_SY-1_1994, Wed_335_TE-1_2354
Klein, Felix Fri_21_EN-2_1609
Klein, François Fri_55_EN-6_917, Thu_219_CR-4_1031, Thu_272_CR-6_143
Klein, Vincent Tue_274_GG-2_1202
Kleindienst, Sara Tue_125_BE-3_1019
Kleiner, Thomas 1638, Thu_232_CR-4_1698
Kleinert, Anne Tue_40_AC-1_971
Kleinteich, Julia 257, Fri_5_EN-2_253
Klekociuk, Andrew Wed_13_AC-2_928
Klemann, Volker 1755
Klemmedson, Angela Thu_155_BE-9_2157
Klene, Anna 1486
Klene, Anna E. Tue_244_CR-1_2539
Klevjer, Thor Thu_123_BE-9_964
Klimach, Thomas Tue_45_AC-1_1139
Klimont, Zbigniew 731
Klinck, John 823, Wed_270_OS-6_2186
Kling, George 1543, 2141, 2477
Kling, George W. 645
Klingenberg, Torgeir Ferdinand Wed_366_TE-3_1310
Klinger, Marin 1598
Klocker, Andreas 2125, 499, Wed_230_OS-6_562
Kloss, Paul 487
Klungsøyr, Jarle 1541
Knapp, Angela N 1172
Knazkova, Michaela Tue_232_CR-1_284, Wed_92_CR-2_282
Kneifel, Stefan Wed_22_AC-2_1654
Knetsch, Stefan Wed_326_TE-1_1231, Wed_364_TE-3_1069
Knies, Jochen 1862, 463, Thu_363_OS-3_1576
Knoblauch, Christian 1213
Knöfel, Christoph 2042, Thu_263_CR-5_2024
Knopp, Jennie Wed_75_BE-6_1843
Knudsen, Erlend Wed_9_AC-2_782
Knudsen, Erlend Moster 1858
Knust, Rainer Thu_82_BE-5_455
Ko, Eunho Thu_81_BE-5_400
Koch, Daleen Wed_307_SH-5_1612
Koch, Florian 2340
2567
Koch, Franziska Wed_137_CR-7_728
Koch, Joshua Wed_115_CR-3_1189
Koch, Magaly 2103
Koch, Paul 2603
Kochzius, Marc Thu_144_BE-9_1757
Köck, Günter 1837
Koebcke, Marcos Tue_71_AC-1_1913
Koeksoy, Elif 257, Fri_5_EN-2_253
Koenig, Lora 2506
Koenig, Zoe 2060
Koenig, Zoé 1659
Koenig-Langlo, Gert 1464
Koffman, Tobias N. 1334
Koglin, Nikola Fri_162_GG-1_2478, Thu_235_CR-4_2005
Kogure, Masaru 1964, Wed_28_AC-2_1974
Kohlbach, Doreen 497, Tue_224_BE-10_2373, Wed_209_OS-2_506
Kohler, Jack 1756, Fri_351_SY-1_1881, Thu_377_SH-6_962, Wed_118_CR-
3_1762
Kohler, Tyler Tue_199_BE-4_2008
Kohma, Masashi Wed_49_AC-4_2316
Kohn, Rachel 796
Kohout, Alison Wed_227_OS-6_247
Kohoutek, Jiří Fri_17_EN-2_1399, Fri_18_EN-2_1401
Kohut, Josh 1841, Thu_143_BE-9_1724, Wed_264_OS-6_1788
Kohut, Joshua Tue_190_BE-4_1559
Koike, Makoto 537
Koivula, Hannu Thu_245_CR-5_115, Thu_269_CR-5_2550
Kojima, Taichi Fri_84_EN-7_1293
Kokubun, Nobuo Wed_72_BE-6_977
Koldtoft, Iben 2415
Koldunov, Aleksey Wed_266_OS-6_1972
Kolisoja, Pauli 1129
Köllner, Franziska 495, Tue_35_AC-1_719, Tue_45_AC-1_1139
Kolstad, Erik 2358, 963
Koltz, Amanda 2686, Tue_216_BE-4_2690
Komárek, Jiří Tue_194_BE-4_1652
Komarov, Alexander 134
Kominz, Michelle 1877
Komuro, Yuki 537
Kondo, Yutaka 537
Kondrik, Dmitry Thu_63_BE-2_922, Thu_64_BE-2_929
Konečný, Patrik Fri_158_GG-1_2219
Konechnaya, Yana Fri_123_GG-1_341
Konfal, Stephanie 1885
Kong, Janet 1910
König, Daniela Fri_273_OS-7_1249
König-Langlo, Gert Thu_231_CR-4_1680
Konstantinov, Pavel Wed_32_AC-2_2163, Wed_37_AC-2_2636
Kontar, Katia Thu_381_SH-6_1238
Kontar, Yekaterina 1344
Kontula, Anne 1129
Konya, Keiko Thu_259_CR-5_1616
Koons, Peter 730
Koppel, Darren Fri_34_EN-2_2691
Körgesaar, Mihkel 288
Korhonen, Meri 2308, Fri_314_SH-8_1739, Wed_261_OS-6_1729
Korkina, Varvara 1908
Korneeva, Yana Fri_169_ME-2_467
Korneykova, Maria Thu_184_BE-12_40
Korokikth, Elena 826
Korost, Dmitry Wed_167_CR-8_1043
2568
Korth, Wilfried Thu_252_CR-5_820
Koschnick, Nils Tue_225_BE-10_2416
Koseoglu, Deniz Can Thu_363_OS-3_1576
Kosobokova, Ksenia 2100, 2562, 413, Tue_363_OS-8_2616
Kosobokova, Ksenia N. Tue_355_OS-8_795
Kotovitch, Marie 414, Wed_206_OS-2_378
Kotta, Jonne 683
Koubbi, Philippe 2346, Thu_322_EN-4_1421
Kouhia, Reijo 1129
Kouraev, Alexei 2638
Kourantidou, Melina Thu_325_EN-4_1566
Kouremeti, Natalia Tue_25_AC-1_241, Tue_26_AC-1_242
Kourzeneva, Ekaterina Wed_119_CR-3_2030
Koushik, N Wed_10_AC-2_805
Kouznetsov, Rostislav 670
Kovac, John Tue_22_AA-1_2669
Kovacevic, Vedrana Fri_292_OS-7_1815, Thu_78_BE-2_2639, Tue_247_GG-2_200,
Tue_279_GG-2_1478, Wed_238_OS-6_955, Wed_241_OS-6_974
Kovacs, Kit 1311, 496
Kovacs, Tamas 1736
Kovalevska, Olena Fri_172_ME-2_998
Kovalonok, Svitlana Tue_174_BE-4_950
Kowalczuk, Piotr 2060, Thu_91_BE-5_1590, Thu_94_BE-5_2078
Kowalewski, Douglas 303
Kozachek, Anna 1672, Wed_126_CR-3_2301, Wed_68_AC-6_1725
Kozioł, Krystyna Fri_351_SY-1_1881
Kozlov, Igor 2676, Wed_282_OS-6_2679
Kozlowski, Natalie Tue_250_GG-2_363
Kozlowski, Steven 1575, Fri_332_SH-9_1578
Kozlowsky, Daniela Tue_57_AC-1_1492
Kozyr, Alexander 1625
Kraaijenbrink, Philip Wed_353_TE-3_507
Kraaijenbrink, Philip D.A. 1503
Kraan, Casper 287, 487, Wed_85_BE-7_1637
Kraev, Gleb 1952
Kral, Stephan 670, Wed_318_TE-1_815
Kramer, Daniel Wed_339_TE-3_83
Kramer, Rolf 2488
Krastel, Sebastian Tue_305_GG-2_2602
Krause, Detmar Wed_350_TE-3_420
Krause, Douglas Thu_118_BE-9_707, Thu_135_BE-9_1405, Thu_136_BE-9_1406
Krause, Douglas J 1033
Kravchenko, Volodymyr 942
Kreft, Holger 713
Kreher, Karin Fri_266_OS-7_993
Kreissig, Katharina Tue_294_GG-2_2035
Krejci, R 1846
Kremer, Anne 1685
Kremser, Stefanie Tue_49_AC-1_272
Krijgsman, Wout Tue_264_GG-2_889
Krinner, Gerhard 1436, 449, 739, Thu_248_CR-5_297, Wed_4_AC-2_475, Wed_8_AC-
2_746
Krishnan, Abiramy Thu_162_BE-9_2309
Krishnan, K. P. Thu_57_BE-2_647
Krishnan, K.P. 604, Tue_106_BE-1_93
Krishnan, Srinath 1199
Kristensen, Nils Fri_217_OS-4_2273
Kristiansen, Svein Fri_98_EN-7_2081, Wed_225_OS-2_2458
Kristiansen, Trond 1665
Krizsan, Levente Tue_23_AC-1_71
Kromkamp, Jacco 1424
2569
Kronenberg, Marlene 771
Krueger, Konstantin 1464
Krüger, Thomas Wed_329_TE-1_1391
Krumpen, Thomas 1573, 2055, 2099, 497, Fri_212_OS-4_1813, Thu_341_OS-3_724,
Thu_94_BE-5_2078
Krupnik, Igor Fri_186_OC-3_216
Ksenofontov, Stanislav Wed_302_SH-5_1215
Kuchař, Aleš Wed_19_AC-2_1348
Kucklick, John 52
Kudikov, Arseniy Thu_306_CR-6_2542
Kudoh, Sakae Fri_84_EN-7_1293, Tue_126_BE-3_1092, Tue_177_BE-4_1146,
Wed_72_BE-6_977
Kudriavtsev, Vladimir Wed_280_OS-6_2648
Kudrjashov, Vladimir Thu_315_EN-4_43
Kudryavtsev, Vladimir 2676
Kuehne, Sandra 2330
Kuerten, Andreas Tue_37_AC-1_767
Kug, Jong-Seong Thu_31_AC-8_1316
Kuhl, Tanner 1072, 1233
Kuhn, Carey 1619
Kuhn, Gerhard 1656, 1710, 1889, 2014, 736, Thu_206_CR-4_394, Thu_210_CR-
4_702, Thu_235_CR-4_2005, Thu_349_OS-3_1251, Thu_354_OS-3_1653
Kühnel, Anna Wed_90_BE-7_1579
Kuipers Munneke, Peter 2670
Kuisak, Monika A. 2233, Fri_158_GG-1_2219
Kujala, Pentti 288
Kukharchyk, Tamara Fri_78_EN-7_740
Kukko, Antero Thu_269_CR-5_2550
Kukla, Daniel 2330
Kukliński, Piotr 1534
Kuklinski, Piotr 683
Kulesa, Craig 2204, Tue_15_AA-1_2209, Tue_16_AA-1_2218
Kulhanek, Denise K. 1950, 812, Tue_267_GG-2_1005
Kulk, Gemma 1424, 1427, 1682
Kullerud, Lars 2688, Tue_318_OC-1_1718
Kulmala, Markku 2274, 2499, 360, Thu_385_SH-6_1666, Tue_37_AC-1_767
Kuma, Peter Tue_58_AC-1_1493
Kumar, Avinash Thu_244_CR-4_88, Thu_26_AC-8_878
Kumar, Karanam Kishore Tue_88_AC-5_797, Wed_10_AC-2_805
Kumar, Vikash 87
Kumar Sinha, Rupesh Tue_110_BE-1_664
Kumpis, Michael Thu_80_BE-5_191
Kumpula, Timo 2627
Kunisch, Erin 1835
Kunkel, Daniel 495, Tue_45_AC-1_1139
Kuo, Chao-Lin Tue_7_AA-1_1084
Kuprikov, Mikhail Wed_314_TE-1_536
Kuprikov, Nikita Wed_314_TE-1_536
Kurbatov, Andrei 2442, 826
Kurihara, Tatsuo Tue_137_BE-3_1551
Kurle, Carolyn Thu_136_BE-9_1406
Kurtz, Leonard 257
Kusahara, Kazuya Fri_196_OS-4_117
Kushner, Paul 661
Kusk, Anders Wed_361_TE-3_948
Kustka, Adam B. Thu_55_BE-2_559
Kustov, Vasily 1924
Kutnetzowa, Elena Thu_382_SH-6_1308
Kutscher, Liselott 2255
Kutschner, Liselott 2391
Kutuzov, Stanislav Thu_306_CR-6_2542, Wed_167_CR-8_1043
2570
Kutz, Susan 2049, 485
Kuwabara, Tomoko Fri_173_ME-2_1117, Fri_174_ME-2_1188, Fri_175_ME-2_1411
Kuzmina, Svetlana Tue_93_AC-5_532
Kvernvik, Ane Cecilie 1114
Kvíderová, Jana Fri_372_BE-5_1696, Wed_197_EN-1_1686
Kwasniewski, Slawomir Thu_76_BE-2_2582
Kwok, Ron 1853, 1857, 1861, 2106
Kwon, Hataek Wed_36_AC-2_2551
Kwon, Miye 110
Kwon, Young Shin Fri_284_OS-7_1542, Fri_299_OS-7_2192
Kyle, Philip 1095, Fri_154_GG-1_2121
Kyle, Philip R 598
Kylling, Arve Tue_31_AC-1_405

L
La, Hyoung Sul Thu_96_BE-5_2413
La Ferla, Rosa Bruna Wed_96_CR-2_1525, Wed_97_CR-2_1527
La Ferla, Rosabruna Fri_81_EN-7_1015, Fri_85_EN-7_1385, Fri_87_EN-7_1460,
Fri_90_EN-7_1532, Thu_126_BE-9_1020, Thu_133_BE-9_1266, Tue_114_BE-1_1366,
Tue_134_BE-3_1284, Tue_138_BE-3_1694, Tue_139_BE-3_1708, Tue_184_BE-4_1367
La Gioia, Carmela Fri_79_EN-7_754
La Spina, Alessandro 156
Laberg, Jan Sverre 1950, 812, Tue_267_GG-2_1005, Tue_272_GG-2_1160
Labrousse, Sara 735, 921
Lacelle, Denis 215, Tue_238_CR-1_1562, Wed_91_CR-2_210
Lacher, Larissa 7
Lachlan-Cope, T. Tue_52_AC-1_1221
Lachlan-Cope, Tom 1475, 963, 987, Tue_51_AC-1_1220
Ladkin, Russ 963
Laepple, Thomas 1513
Laffineur, Quentin 1009, 2598, Wed_16_AC-2_1017, Wed_22_AC-2_1654
Laffite, Amandine Tue_143_BE-3_2271
Lafraeniere, Melissa 1837
Lafreniere, Melissa 2633
Lagana', Pasqualina Thu_133_BE-9_1266
Laganà, Pasqualina Fri_86_EN-7_1389
Lago, Marceliano Fri_153_GG-1_2023
Lagrange, Anne-Marie 1376
Laidre, Kristin Wed_299_SH-5_1070
Laiho, Rory Wed_252_OS-6_1395
Lajus, Julia Thu_366_SH-3_295
Lakkala, Kaisa Wed_14_AC-2_976
Lalande, Catherine 1082, 1093
Lalung, Japareng 2294
Laluraj, C.M. Wed_157_CR-8_602
Lamarre, Jean-François Tue_165_BE-4_513
Lamban, Luis Javier Wed_99_CR-2_2033
Lambert, Alyn 1077
Lambert, Fabrice Wed_153_CR-8_183
Lambert, Rémi Wed_245_OS-6_1040
Lambion, Alexandre 1567
Lambrecht, Astrid 736
Lamers, Machiel 2248
Lamoureux, Scott 1837, 2633
Lampert, Astrid 1113, Wed_313_TE-1_472, Wed_324_TE-1_1115, Wed_329_TE-
1_1391
Lamping, Nele Thu_349_OS-3_1251
Lamy, Frank Fri_59_EN-6_1428, Thu_333_OS-3_53, Thu_354_OS-3_1653
Lanckman, Jean-Pierre F. 2678
Landais, Amaelle 1285, 1513, 444, Fri_253_OS-7_356, Wed_144_CR-7_1515,
Wed_149_CR-7_2423, Wed_186_CR-8_2479, Wed_187_CR-8_2490, Wed_23_AC-2_1671,
2571
Wed_68_AC-6_1725
Landucci, Cristiano Fri_191_OC-3_1651
Landy, Jack 1706
Lane, Stuart Nicholas 1111
Lang, Charlotte 1528
Lang, Shinan Fri_339_SY-1_192
Lange, , Benjamin 2060
Lange, Andrew 1891
Lange, Benjamin 497, Wed_209_OS-2_506
Lange, Benjamin A. 1777, Wed_220_OS-2_1787
Lange, R 1846
Langen, Peter 2546
Langen, Peter Lang Tue_283_GG-2_1640
Langer, Moritz 1522
Langhorne, Pat 1081, 526
Langhorne, Patricia J. 898, Fri_207_OS-4_900, Fri_208_OS-4_904
Langley, Kirsty Tue_240_CR-1_1840, Wed_198_EN-1_1844
Langlois, Alexandre 17, Wed_338_TE-3_15, Wed_339_TE-3_83
Langohr, Carsten 670
Langone, Leonardo Fri_109_EN-7_2635, Fri_292_OS-7_1815, Fri_97_EN-7_2076,
Thu_351_OS-3_1327, Thu_78_BE-2_2639
Lannuzel, D. Wed_215_OS-2_1279
Lannuzel, Delphine 1497, 1614, 591, 594, 844, Fri_88_EN-7_1498, Wed_213_OS-2_861
Lantuit, Hugues 2678
Lanzetta, Rosa 1548
Lapalus, Philippe Wed_139_CR-7_1228
Lapazaran, Javier Thu_291_CR-6_1283
Lapointe, Melanie 222
Lappalainen, Hanna Thu_385_SH-6_1666
Lappalainen, Hanna K. Fri_341_SY-1_359
Laprise, René Tue_82_AC-1_2527
Lara, Mark Wed_76_BE-6_1906
Lara, Yannick 1567, Thu_326_EN-4_1588, Tue_124_BE-3_956
Larocca, Graziano 156, Fri_358_TE-2_155, Thu_246_CR-5_153
Larose, Catherine 1540, 1886, 2283, Fri_351_SY-1_1881, Thu_193_BE-12_1011
Larour, Eric Thu_257_CR-5_1064
Larsen, Aud 2264
Larter, Robert 1710, 281, Tue_259_GG-2_765
Larter, Robert D. 1656, Thu_226_CR-4_1458
Larue, Fanny 17
LaRue, Michelle 1179, 478, Thu_181_BE-11_1180
Laruelle, Marlene Wed_298_SH-5_1045
Laska, Kamil Tue_232_CR-1_284
Laska, Michał Thu_309_CR-6_2687
Láska, Kamil Thu_1_AC-3_283, Thu_21_AC-8_278, Thu_287_CR-6_1161,
Thu_9_AC-3_1709, Tue_235_CR-1_715, Wed_15_AC-2_992
Laske, Sarah Wed_75_BE-6_1843
Laskin, Alexander Tue_42_AC-1_1039, Tue_43_AC-1_1052
Latarius, Katrin Wed_335_TE-1_2354
Laterza, Roberto Fri_292_OS-7_1815
Latola, Kirsi 331
Latorre, Ana Wed_294_SH-5_4
Lau, Danny 1435
Lau, Danny C.P. 1854
Lau, Maggie Tue_121_BE-3_573
Laudani, Giuseppe Fri_358_TE-2_155
Lauermann, Felix 493
Laufer, Andreas Fri_118_GG-1_230
Läufer, Andreas 1315, 1715, 1955, Fri_119_GG-1_325, Fri_122_GG-1_340,
Fri_144_GG-1_1689, Fri_145_GG-1_1697, Fri_148_GG-1_1791, Thu_235_CR-4_2005
Laughinghouse, H Dail Thu_326_EN-4_1588
2572
Laukert, Georgi Tue_361_OS-8_2287, Wed_272_OS-6_2282
Laurent, Oscar 237
Laurila, Tuomas 1924
LaValley, Meredith 1108
Lavergne, Celine Fri_100_EN-7_2138
Lavergne, Céline Thu_199_BE-12_2444
Lavergne, Thomas Fri_244_OS-5_2072, Thu_345_OS-3_939, Thu_346_OS-3_972
Lavin, Paris 1132, Thu_157_BE-9_2222, Tue_112_BE-1_949
Lavoie, Isabelle 352, Wed_75_BE-6_1843
Lavrentiev, Ivan Thu_306_CR-6_2542, Wed_345_TE-3_276
Law, Kathy Tue_83_AC-1_2541, Wed_297_SH-5_1044
Lawrence, Dale Wed_312_TE-1_376
Lawrence, Isobel 260
Lawrence, Jade Wed_269_OS-6_2181
Lawrence, John 1403
Lawrence, Joshua 123
Lawrence, Justin Wed_224_OS-2_2193, Wed_269_OS-6_2181
Lawrence-Slavis, Noah 1619
Lawver, Lawrence A. 2016
Layton, Kara K.S. Tue_156_BE-4_269
Layton, Rose 1540, 1886
Layton, Rose Emma 2283
Lazzara, Luigi Fri_290_OS-7_1766
Le Bel, Deborah A 2185
Le Brocq, Anne 293, 637
Le Dantec, Théo 1719
Le Guen, Camille 123
Le Page, Yann Fri_353_SY-1_1994
Le Roux, Gael Fri_29_EN-2_2337
Le Roux, Peter C. 713
Le Sommer, Julien Wed_275_OS-6_2534
Lea, Mary-Anne 1632, 2047, 906, Tue_320_OC-1_1898, Wed_306_SH-5_1462
Leaitch, Richard 495
Leaitch, W. Richard Tue_45_AC-1_1139
Leal, José Pereira Wed_212_OS-2_814
Leander, Carina 1159
Leane, Elizabeth 1277, 1438, Fri_333_SH-9_1945
Lear, Caroline 1257
Lebedeva, Liudmila Wed_124_CR-3_2232
Leblanc, Mathieu 1082
Lebouvier, Marc Thu_182_TE-3_1780
Lebreton, Benoit 497
Lebrun, Marion 801, Tue_356_OS-8_810
Leckie, Mark R. 1950
Leckie, R. Mark 812, Tue_267_GG-2_1005
Leclerc, Lisa-Marie 2049, 485
Lecomte, Olivier Fri_249_OS-7_79
L'Ecuyer, Tristan 870, Wed_8_AC-2_746
Leduc-Leballeur, Marion 1370, 316, Wed_144_CR-7_1515, Wed_348_TE-3_317
Lee, Allison 866
Lee, B.Y. Tue_73_AC-1_2020
Lee, Billy Fri_165_ME-2_30, Fri_166_ME-2_31
Lee, Changsup 1944, 578
Lee, Charles 2111, 2140, 2198, 2202, 564, Thu_174_BE-11_838, Thu_195_BE-
12_2116, Thu_196_BE-12_2191, Thu_312_EN-3_566, Wed_305_SH-5_1434
Lee, Choon-Ki 197, 2424, Fri_113_GG-1_118
Lee, Craig 2199, Wed_334_TE-1_2203
Lee, Craig M. 2235, 2238
Lee, Dabin Thu_51_BE-2_226
Lee, Hanna 1514
Lee, Hong Kum 120
2573
Lee, Hyoungseok 120
Lee, Jae Hyung Thu_52_BE-2_234
Lee, Jae Il 1056, 1618, Thu_347_OS-3_1109, Tue_276_GG-2_1354,
Tue_280_GG-2_1479, Tue_298_GG-2_2261
Lee, Jae N. Tue_38_AC-1_784
Lee, Jaejin 110
Lee, James 834, 888, Wed_162_CR-8_868, Wed_190_CR-8_2575
Lee, James E. 826, Wed_177_CR-8_1744
Lee, James Edward Wed_180_CR-8_1764
Lee, Jasmine 2168, 91, Thu_330_EN-4_2164
Lee, Jasmine R. 1382
Lee, Ji Young 2448
Lee, Jiyeon 2424
Lee, Jong Ik 598, Fri_142_GG-1_1415, Fri_154_GG-1_2121, Fri_368_TE-2_902
Lee, Jongik 110
Lee, Joohan 197, Fri_368_TE-2_902
Lee, Khanghyun Fri_68_EN-6_2240, Fri_69_EN-6_2364
Lee, Kyu Song 120
Lee, Mi Jung 197, 598, Fri_154_GG-1_2121
Lee, Min Goo Fri_178_ME-2_2347
Lee, Min Kyung 1056, 1618, Thu_347_OS-3_1109, Tue_276_GG-2_1354,
Tue_298_GG-2_2261
Lee, Olivia 2177
Lee, Peter 2214
Lee, Sang Heon Thu_51_BE-2_226, Thu_52_BE-2_234, Thu_54_BE-2_320
Lee, Sang Hoon 1433, Thu_51_BE-2_226, Wed_239_OS-6_957
Lee, SangHoon 401
Lee, Sanghoon 854, Thu_81_BE-5_400
Lee, Sang-Moo Wed_367_TE-3_1314
Lee, Seung Hyun 197, 2424
Lee, Seung Mi Fri_68_EN-6_2240
Lee, Won Sang 197, 2424, Fri_113_GG-1_118, Fri_368_TE-2_902
Lee, Wongsang 854
Lee, Yoo Kyung Thu_200_BE-12_2492
Lee, Younjoo 2418, Fri_216_OS-4_2173
Lefebvre, Eric 1318, Wed_140_CR-7_1323
Le'Gallais, Bridie Thu_268_CR-5_2446
Legg, Sonya 1292
Legrand, Michel 1340, Wed_179_CR-8_1760, Wed_23_AC-2_1671
LeGrande, Allegra N. Thu_283_CR-6_794
Lehejček, Jiří Tue_161_BE-4_446, Tue_249_GG-2_328
Lehmann, Prisca Wed_174_CR-8_1641
Lehmenhecker, Sascha 1687
Lehner, Susanne 1298
Lehning, Michael 1210, 2230, 2332, 2451, 2510, 2609, 959, Fri_230_OS-5_343,
Tue_336_OC-4_1768, Wed_127_CR-3_2305, Wed_136_CR-7_552
Lehtipalo, Katrianne 1041, Tue_56_AC-1_1467
Lei, Jintao Wed_46_AC-4_1624
Lei, Ruibo Fri_243_OS-5_1925
Leibman, Marina 2627
Leidman, Sasha Wed_134_CR-7_312
Leihy, Rachel 37
Leitchenkov, German 1135, 639, 745, 780, Fri_114_GG-1_146, Fri_129_GG-1_653,
Fri_138_GG-1_969, Thu_210_CR-4_702, Thu_235_CR-4_2005
Leite, Ricardo Wed_212_OS-2_814
Lelchat, Florian Thu_60_BE-2_778
Leliaert, Frederik Thu_144_BE-9_1757
Lemaitre, Nolwenn Fri_75_EN-7_313
Lembke-Jene, Lester 973
Lembrechts, Jonas 333
Lemmetyinen, Juha 222
2574
Lemonnier, Florentin 298, 739, Wed_8_AC-2_746
Lenaerts, Jan 104, 2674, 76, Thu_219_CR-4_1031
Lenaerts, Jan T. M. 787
Lenaerts, Jan T.M. 1951, 1954
Leng, Melanie 1257, 416, Wed_258_OS-6_1555
Lenoir, Jonathan 333
Lento, Jen 1854
Lento, Jennifer 1435, 352, Wed_75_BE-6_1843
Lenz, Josefine 1184, Thu_382_SH-6_1308
Leon, Rosa Thu_196_BE-12_2191
Leonard, Greg 1081, 526
Leonard, Katherine 1167, 2106, 76, Thu_48_AC-8_2689
Leonard, Katherine C. 1802, Tue_336_OC-4_1768
Lepidi, Stefania Wed_48_AC-4_1887
Lepland, Aivo 1862
Leppänen, Leena Wed_135_CR-7_412, Wed_141_CR-7_1372, Wed_143_CR-7_1496
Leppäranta, Matti Thu_341_OS-3_724
LeRoi, Donald Thu_135_BE-9_1405
Lesins, Glen 2028
Lesser, David 2204, Tue_16_AA-1_2218
Leu, Eva 1114
Leuenberger, Markus 444
Levasseur, Maurice Thu_374_SH-6_105
Leventer, Amy 2540, 626, Thu_217_CR-4_899, Tue_250_GG-2_363, Tue_251_GG-
2_364, Tue_285_GG-2_1669
Leveque, Jean-Jacques Fri_346_SY-1_1223
Lever, James 730
Levermann, Anders 1758
Levermann, Nette 2401
Levy, Joseph 2189, 2257, Thu_174_BE-11_838, Wed_94_CR-2_829
Levy, Richard , 1592, 1826, 303, 813, 831, Tue_276_GG-2_1354, Tue_280_GG-
2_1479, Tue_298_GG-2_2261
Lewallen, Eric Thu_118_BE-9_707
Lewinschal, Anna 1199
Lewis, Jared Wed_33_AC-2_2259
Lewis, McKenna 1187, Tue_200_BE-4_2075
Lewis, Phoebe 2244
Lewis Williams, Elizabeth Tue_342_OC-4_2620
Lewkowicz, Antoni 302
Leysinger Vieli, Gwendolyn J.-M. C. Thu_300_CR-6_2059
Lhermitte, Stef 1661, 1954, 1987, Thu_209_CR-4_632, Wed_22_AC-2_1654
Li, Bin Thu_395_SH-6_2525
Li, Bing Fri_362_TE-2_432, Wed_310_TE-1_107
Li, Bingrui Fri_276_OS-7_1299, Wed_234_OS-6_635
Li, Camille 135, 1790, 2068, 2341, Thu_34_AC-8_1811, Thu_40_AC-8_2012
Li, Chaolun Tue_155_BE-4_180
Li, Chuanjin 891, Wed_163_CR-8_876
Li, Chunhua Fri_197_OS-4_345, Fri_199_OS-4_451
Li, Chuxian 1029
Li, Cuihua 1607
Li, Dong Thu_59_BE-2_756
Li, Dongyi Wed_196_EN-1_1626
Li, Fei Fri_236_OS-5_835, Thu_33_AC-8_1702, Thu_343_OS-3_851,
Wed_116_CR-3_1192, Wed_46_AC-4_1624
Li, Guoping Wed_310_TE-1_107
Li, Haiyan 2211
Li, Hongliang Thu_56_BE-2_642
Li, Hongmei Thu_75_BE-2_2484
Li, Huan 945, Wed_362_TE-3_966
Li, Huilin 910
Li, Huirong Thu_83_BE-5_583
2575
Li, Huiru 273
Li, Jing Thu_339_OS-3_479
Li, King-Fai 703, 717
Li, Lele Fri_233_OS-5_541
Li, Li Wed_132_CR-7_94
Li, Lin Fri_155_GG-1_2149, Fri_156_GG-1_2153
Li, Manchun Wed_352_TE-3_498
Li, Ming Fri_197_OS-4_345
Li, Qianyu Tue_264_GG-2_889
Li, Ren Wed_102_CR-3_182
Li, Rongxing 1191, 1196, Thu_218_CR-4_1021, Wed_116_CR-3_1192
Li, Sha Thu_30_AC-8_1273
Li, Shuo 530
Li, Tao Fri_260_OS-7_817
Li, Wei Tue_23_AC-1_71
Li, Xiao Fri_367_TE-2_847
Li, Xiaoyan 503
Li, Xin 1143, Tue_234_CR-1_600
Li, Xingchen Fri_367_TE-2_847
Li, Xinwu 1143, Wed_111_CR-3_1010
Li, Xuewei Thu_218_CR-4_1021
Li, Yazhou Fri_362_TE-2_432, Fri_367_TE-2_847, Fri_369_TE-2_1953
Li, Yiping 530
Li, Yuan Wed_196_EN-1_1626
Li, Yuansheng 891, Thu_204_CR-4_164, Wed_132_CR-7_94, Wed_310_TE-1_107
Li, Yuhong Tue_33_AC-1_579
Li, Zhengyang 503, Tue_5_AA-1_981
Liang, Ensi 503
Liang, Lei Wed_111_CR-3_1010
Liang, Xi Fri_197_OS-4_345, Fri_199_OS-4_451, Fri_200_OS-4_608
Libois, Quentin 1318, 589
Licht, Kathy 1889, 2580, 637
Licht, Kathy J. 2521
Lidström, Sven 1636
Lieb-Lappen, Ross Fri_224_OS-4_2573
Liebner, Susanne 1213
Lien, Vidar 2308, Fri_213_OS-4_1871
Lien, Vidar S. Fri_314_SH-8_1739
Lieser, Jan 2083, 65, 744, Fri_196_OS-4_117
Lifton, Nathaniel 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Liggett, Daniela 1277, 1962, 2275, 636, Thu_403_SH-7_1983
Ligtenberg, Stefan 696
Lihavainen, Heikki Wed_336_TE-1_2356
Lilien, David 2560
Lille-Langøy, Roger Tue_218_BE-10_67
Lilly, Katherine Fri_207_OS-4_900
Lim, Chang-Kyu Fri_63_EN-6_1645
Lim, Michael 1976
Lim, Yu Jeong Thu_51_BE-2_226
Lima Correia, Alexandre Fri_7_EN-2_372
Lin, Heshan Thu_85_BE-5_893
Lin, Longshan Wed_196_EN-1_1626
Linares, Melissa Wed_131_CR-3_2658
Linck Rosenhaim, Ingrid Thu_107_BE-8_2338
Lincoln, Benjamin 2676
Lind, Sigrid Fri_306_OS-7_2597, Thu_47_AC-8_2596
Lindahl, Björn D 1979
Lindau, Filipe Gaudie Ley Wed_133_CR-7_168
Lindbäck, Katrin Thu_221_CR-4_1074
Lindenberg, Christian 670
Linders, Torsten Wed_271_OS-6_2231
2576
Lindzey, Laura Wed_319_TE-1_846
Lines, Austin 730, Wed_322_TE-1_1066
Link, Heike 524, Wed_80_BE-7_523
Linse, Katrin 711, Thu_114_BE-9_374, Thu_329_EN-4_2095
Lintott, Bryan 130
Linty, Nicola 1693, Wed_47_AC-4_1772
Lipenkov, Vladimir 1672, Wed_126_CR-3_2301, Wed_161_CR-8_819, Wed_182_CR-
8_1874, Wed_68_AC-6_1725
Lipenkov, Vladimir Ya. Wed_187_CR-8_2490
Lipovsky, Bradley 2175
Lippl, Stefan Wed_65_AC-6_770
Lique, Camille 1375, 2055
Lishman, Ben 1306
Lisker, Frank 1715, Fri_119_GG-1_325, Fri_144_GG-1_1689, Fri_145_GG-1_1697
Lisok, Justyna 2110, Tue_76_AC-1_2119, Tue_81_AC-1_2374
Liston, Glen 781
Liston, Glen E. 1770, Fri_242_OS-5_1828
Listowski, C. Tue_52_AC-1_1221
Listowski, Constantino 987
Liszka, Cecilia Thu_66_BE-2_1319
Litman, Jessica Fri_193_OC-3_1818
Littell, Jeremy 1289
Litvinov, Alexander 1042
Liu, An Fri_360_TE-2_219, Fri_363_TE-2_438, Fri_366_TE-2_654,
Fri_367_TE-2_847
Liu, Bowen Fri_363_TE-2_438
Liu, Chenguang Fri_159_GG-1_2299
Liu, Chengyan Fri_276_OS-7_1299, Wed_267_OS-6_1990
Liu, Emma Fri_57_EN-6_1032
Liu, Fengshan 1381
Liu, Gang Fri_363_TE-2_438
Liu, Geng Fri_67_EN-6_2166
Liu, Hongbing Fri_139_GG-1_975, Fri_143_GG-1_1630
Liu, Jian Tue_34_AC-1_621
Liu, Jianhui Fri_159_GG-1_2299
Liu, Jianjun Wed_51_AC-4_2624
Liu, Jingbiao Wed_310_TE-1_107
Liu, Jiping 397, Fri_231_OS-5_407, Thu_30_AC-8_1273
Liu, Kun Thu_85_BE-5_893
Liu, Liangduan 503
Liu, Qingquan Fri_243_OS-5_1925
Liu, Shijie 1191, 1196, Thu_218_CR-4_1021
Liu, Tingting Wed_381_TE-3_2159
Liu, Wenqing Thu_6_AC-3_1245
Liu, Xiaochun Fri_159_GG-1_2299
Liu, Xiaohan Fri_143_GG-1_1630, Tue_282_GG-2_1557
Liu, Xiaojun Fri_339_SY-1_192
Liu, Xiaomin Thu_358_OS-3_2161
Liu, Yan 857
Liu, Yanguang 1973, Tue_247_GG-2_200, Tue_279_GG-2_1478
Liu, Yi Thu_6_AC-3_1245
Liu, Yina Fri_23_EN-2_1834
Liu, Yinghui 512
Liu, Yongwen Wed_310_TE-1_107
Liu, Yunchen Fri_362_TE-2_432, Wed_310_TE-1_107
Liu, Yuncheng 128
Liu, Zhiquan 1599
Liuzzo, Marco 156, Fri_115_GG-1_150, Thu_246_CR-5_153
Lizieri, Claudineia Tue_310_OC-1_494
Lizong, Wu 1625, Wed_260_OS-6_1628
Llanillo, Pedro Wed_11_AC-2_859
2577
Llanillo, Pedro J. Fri_296_OS-7_1902
Llauca, Harold Wed_112_CR-3_1026
Lloret, Elena Thu_151_BE-9_2015
Lloyd, Andrew 1118, 1274, 1390
Lloyd, Gary 1796
Lloyd, James Tue_136_BE-3_1442
Lo, Mandy 384
Lo Giudice, A. Wed_96_CR-2_1525, Wed_97_CR-2_1527
Lo Giudice, Angelina Thu_126_BE-9_1020, Thu_133_BE-9_1266, Tue_114_BE-1_1366,
Tue_184_BE-4_1367
Loaiza, Iván 710
Lobo, Francisco Tue_294_GG-2_2035, Tue_296_GG-2_2044
Lobo, Francisco J. Tue_291_GG-2_1963, Tue_292_GG-2_1968
Lobo, Prem 1381
Loeb, Valerie 1165
Loewemark, Ludvig Thu_94_BE-5_2078
Löffler, Mareike Tue_27_AC-1_244
Loftfield, Julia 1577
Logan, Liz C Thu_237_CR-4_2200
Loginov, Sergey Thu_38_AC-8_1928
Lohmann, Ulrike 1222, 7
Loisel, Julie 365
Lok, Lai Bun 1306
Lombardi, Denis Thu_302_CR-6_2115
Long, David G. 1602
Long, Jennifer E. 1912
Long, Panpan Fri_67_EN-6_2166
Long, Zhenxia Fri_301_OS-7_2206, Thu_35_AC-8_1816
Longo, Simona Fri_357_SY-1_2623
Lønne, Ole Jørgen Thu_380_SH-6_1214
Loonen, Maarten J. J. E. Thu_377_SH-6_962
Loose, B. Wed_215_OS-2_1279
Loose, Bernd 1464
Loose, Brice 2021, 2246, 2503, 2524, Fri_278_OS-7_1325, Fri_280_OS-7_1333,
Fri_282_OS-7_1418
Lopes, Paulo Tue_317_OC-1_1681
Lopes de Faria, André Luiz Tue_243_CR-1_1995
Lopez, Alberto 514
Lopez, Christian Tue_279_GG-2_1478
Lopez, Constanza Wed_294_SH-5_4
Lopez, Zambra Tue_214_BE-4_2680, Tue_228_BE-10_2695
López, Viviana Elisa 509, 511
López Moreno, Juan Ignacio Wed_141_CR-7_1372
Lopez-Martinez, Jeronimo 2034, Fri_153_GG-1_2023, Wed_99_CR-2_2033
López-Martínez, Jerónimo 2094, 2103, Thu_233_CR-4_1870, Wed_120_CR-3_2038
López-Quirós, Adrian Tue_274_GG-2_1202
López-Quirós, Adrián Tue_290_GG-2_1959, Tue_291_GG-2_1963, Tue_292_GG-2_1968,
Tue_294_GG-2_2035, Tue_296_GG-2_2044
López-Sandoval, Daffne Fri_307_OS-7_2683
Lorek, Andreas Tue_130_BE-3_1130
Lorenz Simoes, Carolina Thu_273_CR-6_154
Lorenz Simões, Felipe Tue_181_BE-4_1234
Lorenzo, Cristian Tue_369_SH-1_867
Losa, Svetlana Fri_200_OS-4_608
Losch, Martin 1822, Fri_201_OS-4_630, Fri_220_OS-4_2323
Loskutova, Olga 1854
Lotliker, Vinit Ravindra Fri_269_OS-7_1100, Wed_240_OS-6_960
Louw, Anche 622, 625, 713
Love, Peter Wed_39_AC-4_382
Lovejoy, Connie 413
Löwe, Henning 1522, Wed_149_CR-7_2423
2578
Lowry, Dan 826
Lowry, Daniel 875
Lowther, Andrew 496
Lozano, Maria Fernanda Thu_121_BE-9_832
Lu, Haiping 503
Lubośny, Marek Tue_212_BE-4_2632
Lucarelli, Franco Tue_63_AC-1_1703, Tue_64_AC-1_1704
Lucassen, Magnus Thu_152_BE-9_2114
Lucchi, Renata G. Fri_292_OS-7_1815, Fri_65_EN-6_1986
Lucchi, Renata Giulia Tue_247_GG-2_200, Tue_266_GG-2_988, Tue_272_GG-2_1160
Lucia, Ana 257
Lucieer, Vanessa Wed_360_TE-3_874
Lüdecke, Cornelia Thu_364_SH-3_84
Ludvigsen, Martin Thu_89_BE-5_1268
Luepkes, Christof 1464
Luethi, Martin Thu_225_CR-4_1400, Thu_301_CR-6_2067
Luhtanen, Anne-Mari Wed_216_OS-2_1531
Luis, Alvarinho 32, Fri_345_SY-1_1126, Wed_368_TE-3_1324
Luis, Alvarinho J Thu_26_AC-8_878, Thu_27_AC-8_933
Luis, Alvarinho J. Fri_269_OS-7_1100, Fri_349_SY-1_1504, Wed_240_OS-6_960
Lukavský, Jaromír Fri_372_BE-5_1696
Luks, Bartłomiej Wed_141_CR-7_1372
Luks, Bartek 1, Fri_351_SY-1_1881
Lulak, Martin Fri_66_EN-6_2057
Lulakova, Petra Thu_189_BE-12_700, Tue_148_BE-3_2513
Luláková, Petra Tue_249_GG-2_328
Luna, Alberto Wed_20_AC-2_1383, Wed_55_AC-7_1380
Lund, Kasper Holst Fri_240_OS-5_1287
Lundesgaard, Oyvind 1489
Lunz, Susanne Thu_263_CR-5_2024
Luo, Wei Thu_83_BE-5_583
Luo, Yuhan Thu_6_AC-3_1245
Luojus, Kari Wed_380_TE-3_2108
Lupi, Angelo 2110, 2499
Lüpkes, Christof 1113, 1967, 2504, Thu_10_AC-3_1742, Wed_3_AC-2_337
Lussana, Cristian 752
Lüthi, Martin 1303, 1949
Lüthi, Martin P. Thu_220_CR-4_1036, Thu_300_CR-6_2059
Lutsenko, Dmytro Tue_174_BE-4_950
Lutton, Anthony 816
Lutz, Arthur F. 1503
Lutz, Birgit Fri_3_EN-2_174
Lutz, Joshua Wed_269_OS-6_2181
Lutz, Stefanie 122
Lutz, Steffi 2473
Luyendyk, Bruce 813
Lyberth, Bjarne 2401
Lydersen, Christian 1311, 496
Lydholm Rasmussen, Mikkel Wed_198_EN-1_1844
Lygre, Kjetil 2562
Lynch, Amanda 5, 6
Lynch, Heather 1232, 447, Thu_177_BE-11_1094, Thu_179_BE-11_1151,
Thu_180_BE-11_1152, Thu_183_BE-11_2631
Lynch, Heather J. 1914, 488, Thu_137_BE-9_1413, Thu_153_BE-9_2126
Lynnes, Amanda 1474
Lyons, William 1402
Lyons, Wm Berry 816
Lytvynov, Valery Tue_174_BE-4_950
Lyver, Phil Thu_161_BE-9_2281

M
2579
M, Ravichandran 1190, Tue_60_AC-1_1635
M. P, Subeesh 1190
M.C, Manoj Thu_352_OS-3_1362
Ma, Bin 1939, 503, 849, Tue_4_AA-1_679
Ma, Chao Wed_46_AC-4_1624
Ma, Hongmei Wed_132_CR-7_94
Ma, Tianming Wed_132_CR-7_94
Ma, Xuwen Thu_218_CR-4_1021
Mańko, Maciej 2554, Tue_362_OS-8_2543
Maahn, Maximilian Wed_22_AC-2_1654
Maaß, Nina Fri_230_OS-5_343
Maccario, Lorrie 1886
Macchi, Gustavo 1451
Macdonald, Robie W. 2056
MacDonell, Shelley 1449, 1452, 1956, Thu_293_CR-6_1466, Tue_97_AC-5_2495
Macelloni, Giovanni 1370, 316, Wed_348_TE-3_317
MacFerrin, Michael Wed_142_CR-7_1471
Machguth, Horst 1987, 421, 771
Mächler, Lars Wed_178_CR-8_1750, Wed_181_CR-8_1775
MacHutchon, Keith 1298, Wed_227_OS-6_247
Machutchon, Keith 239
Macias-Fauria, Marc 2672, 29, Wed_88_BE-7_2673
Mack, Michelle 1847
Macke, Andreas 460, Wed_3_AC-2_337
Mackie, Emma 28
MacKie, Emma J. Fri_317_SH-8_2217
Mackie, Shona Fri_208_OS-4_904
Mackintosh, Andrew 881, Tue_265_GG-2_909
Maclean, Ilya Wed_83_BE-7_1301
Macrì, Patrizia Tue_266_GG-2_988, Tue_272_GG-2_1160
Madec, Gurvan 1396, 801, Fri_206_OS-4_804, Wed_244_OS-6_1012, Wed_275_OS-
6_2534
Madeleine, Jean-Baptiste 114, 298, 449, 739, 9, Wed_8_AC-2_746
Madice, Project Team 1127
Madjar, Stefan-Arpad Fri_172_ME-2_998
Madonia, Alice Fri_81_EN-7_1015, Wed_328_TE-1_1371, Wed_332_TE-1_1529
Madonna, Erica 135
Madsen, James 2158, Tue_11_AA-1_1377, Tue_332_OC-2_2162, Tue_339_OC-
4_2139
Madsen, Martin 2415
Maercker, Jakob Wed_326_TE-1_1231
Maerz, Christian 1120
Maes, Gregory E. 1746
Maes, Sarah Thu_152_BE-9_2114
Maestro, Adolfo 2369, Fri_153_GG-1_2023
Maffezzoli, Niccolò 646
Magaeva, Anastasia Thu_361_OS-3_2353
Magalhaes, Catarina Tue_117_BE-1_1948
Magalhães, Catarina 2111, Fri_26_EN-2_2022, Wed_212_OS-2_814
Magalhaes Mata, Mauricio Wed_253_OS-6_1439
Magee, Liam 1277
Magee, William Fri_163_GG-1_2537
Maggi, Alessia Fri_272_OS-7_1227, Fri_346_SY-1_1223
Maggi, Valter Wed_160_CR-8_818, Wed_166_CR-8_1030
Magnin, Florence 752, Tue_316_OC-1_1574
Mah, Christopher Thu_146_BE-9_1807
Mahadevan, Amala Wed_273_OS-6_2411
Mahesh Badanal, Siddaiah 1797
Mahmud, Mallik 134, Fri_226_OS-5_151, Wed_347_TE-3_308
Mahony, Sue Wed_169_CR-8_1261
Maie, Nagamitsu Fri_84_EN-7_1293
2580
Maimone, G Wed_96_CR-2_1525, Wed_97_CR-2_1527
Maimone, Giovanna Fri_81_EN-7_1015, Fri_90_EN-7_1532, Thu_133_BE-9_1266,
Tue_114_BE-1_1366, Tue_134_BE-3_1284, Tue_138_BE-3_1694, Tue_184_BE-4_1367
Main, Christopher R. Thu_166_BE-9_2380
Maio, Christopher V. 1184
Mairesse, Olivier 1747, 2684
Majaneva, Sanna Thu_93_BE-5_2029, Tue_360_OS-8_1960
Majewski, Wojciech Thu_139_BE-9_1441
Makarevich, Pavel 2562
Makarieva, Olga Wed_124_CR-3_2232
Makhalanyane, Thulani 2488
Makhotina, Irina 2504
Mäkinen, Jaakko Thu_245_CR-5_115, Thu_269_CR-5_2550, Wed_151_CR-7_2464
Makinson, Keith Thu_211_CR-4_749
Makkonen, Risto 995
Makshtas, Alexander 1924, Thu_385_SH-6_1666, Wed_26_AC-2_1927
Maksym, Ted 1181, 1802, 2106, 2503, 2524, 263, 264, 744, 76, 785, Fri_256_OS-
7_480, Wed_315_TE-1_553
Makuch, P. Tue_81_AC-1_2374
Malandrino, Mery Fri_19_EN-2_1422, Fri_79_EN-7_754, Tue_63_AC-1_1703
Malard, Lucie 1148
Maldonado, Andres 2379
Malin, Michael C. 2482
Mallet, Paul-Etienne Wed_27_AC-2_1936
Maluf, Chams Fri_170_ME-2_521
Malyarenko, Alena 2285, 526
Malz, Philipp 667, Wed_63_AC-6_350
Manandhar, Sujata 1893
Mancilla, Alejandra 163, 59
Mancini, Francesco Thu_255_CR-5_1000
Mancuso, Monique Tue_134_BE-3_1284
Manganini, Steven 2056
Mangeard, Pierre-Simon Tue_11_AA-1_1377
Mangeney, Anne 650
Mangold, Alexander 1009, 2598, Wed_16_AC-2_1017, Wed_22_AC-2_1654
Mangoni, Olga Fri_85_EN-7_1385, Tue_138_BE-3_1694, Tue_139_BE-3_1708,
Tue_170_BE-4_723
Mankoff, Kenneth 2041
Mann, Paul James Fri_72_EN-7_41
Manna, Ishita Thu_284_CR-6_883
Manning, Kevin 76
Manno, Clara 1860, 2133, Fri_14_EN-2_984, Thu_66_BE-2_1319, Thu_69_BE-
2_1859, Thu_78_BE-2_2639
Mano, Marie-José Tue_118_BE-1_1999
Manoj, M.C. Tue_246_GG-2_187
Mansutti, Paolo Fri_292_OS-7_1815, Tue_279_GG-2_1478
Mantel, Thomas 1648
Manucharyan, Georgy 2208
Mao, Jingqiu Tue_83_AC-1_2541
Mao, Jingqui Wed_297_SH-5_1044
Marcelli, Augusto Wed_166_CR-8_1030
Marcelli, Marco Fri_81_EN-7_1015, Wed_328_TE-1_1371, Wed_332_TE-1_1529
Marchese, Christian Fri_290_OS-7_1766
Marchi, Sylvain Fri_202_OS-4_671
Marcone, Giorgia Letizia Thu_133_BE-9_1266
Marečková, Michaela Tue_157_BE-4_334
Marelle, Louis Tue_68_AC-1_1789
Margiotta, Francesca Tue_170_BE-4_723
Margulis, Steve Wed_131_CR-3_2658
Maria, Papale Fri_81_EN-7_1015
Mariani, Zen Thu_8_AC-3_1393
2581
Mariash, Heather 1326, Wed_75_BE-6_1843
Marie, Dominique 1589
Mariethoz, Gregoire 1379, 1544
Marin, Constantin 1132, Thu_157_BE-9_2222, Tue_112_BE-1_949
Marina, Tomás Ignacio 1343
Marinelli, Flavia Thu_133_BE-9_1266
Marinov, Irina 2536
Marinsek, Sebastian Wed_62_AC-6_339
Marinsek, Sebastián 556, Wed_65_AC-6_770
Maritati, Alessandro Thu_254_CR-5_862
Mark, Felix C. Thu_152_BE-9_2114
Mark, Felix Christopher Tue_225_BE-10_2416
Markle, Bradley 103, 490
Markov, Alexey Thu_310_CR-6_85, Wed_310_TE-1_107
Markowicz, K.M. Tue_81_AC-1_2374
Markowicz, Kris 2110, Tue_76_AC-1_2119
Markowicz, Krzysztof Tue_65_AC-1_1731
Markus, Thorsten 1850, 2668
Marnela, Marika 2308, Fri_314_SH-8_1739
Marques, Diego Tue_310_OC-1_494, Tue_317_OC-1_1681
Marques, Gustavo Fri_305_OS-7_2585
Marquez, Jose 222
Marquis, Peter 2684
Marrasé, Cèlia Fri_307_OS-7_2683
Marri, Alice Fri_8_EN-2_411
Marriott, Shawn Fri_295_OS-7_1883
Marschoff, Enrique Thu_321_EN-4_1328
Marsh, Dan 1873
Marsh, Oliver J. 729, Thu_212_CR-4_860
Marshall, Gareth 1521, 1549, 1707, 198
Marshall, John 1157, 1174, Fri_271_OS-7_1154, Wed_248_OS-6_1176
Marshall, Lucianne M. 1912
Marshall, Shawn Tue_288_GG-2_1894
Martelli, Leonardo Thu_255_CR-5_1000
Martellini, Tania 419, Fri_8_EN-2_411
Martellucci, Riccardo Wed_328_TE-1_1371
Martin, Adam 1095, Tue_270_GG-2_1097
Martin, Bruce 2516
Martin, Carlos Thu_223_CR-4_1248, Thu_260_CR-5_1784
Martin, Olivier Thu_302_CR-6_2115
Martín-Algarra, Agustín Tue_290_GG-2_1959
Martinerie, Patricia 444
Martinez, Ana 2046
Martinez, Justino Fri_241_OS-5_1806
Martinez, Karla 2325
Martinez, Philippe Tue_274_GG-2_1202
Martinez Cruz, Karla Thu_199_BE-12_2444
Martínez-Cruz, Karla Fri_100_EN-7_2138
Martinov, Fedor Tue_361_OS-8_2287
Martins, Ygor Fri_170_ME-2_521
Martins, Ygor Antonio Tinoco Fri_171_ME-2_527
Martins Dellagnezze, Bruna Thu_199_BE-12_2444
Martma, Tonu Fri_351_SY-1_1881, Wed_225_OS-2_2458
Martos, Yasmina Fri_124_GG-1_347
Martos, Yasmina M. 2379
Marty, Christoph Wed_137_CR-7_728, Wed_141_CR-7_1372
Martynova, Yuliya Thu_38_AC-8_1928
Marzeion, Ben 1331, 543, Thu_272_CR-6_143
Marzorati, Mauro 344
Mas e Braga, Martim Wed_253_OS-6_1439
Masi, Silvia 2476
2582
Masina, Simona Thu_360_OS-3_2291, Tue_87_AC-5_176
Masiokas, Mariano 1253
Maslov, Mikhail Thu_186_BE-12_417
Maslov, Vsevolod Fri_160_GG-1_2387
Maslova, Olga Thu_186_BE-12_417
Maslowski, Wieslaw 2418, Fri_216_OS-4_2173
Masolov, Valery N. Fri_124_GG-1_347
Massa, Charly 365
Massabo, Dario 1381
Massafferri, André Tue_71_AC-1_1913
Massicotte, Philippe 2060
Massning, A 1846
Massom, Rob 1081, 941
Masson Delmotte, Valérie Wed_23_AC-2_1671
Masson-Delmotte, Valerie Fri_250_OS-7_131, Wed_164_CR-8_979
Masson-Delmotte, Valérie 1513, 444, 789, Fri_55_EN-6_917
Massonnet, Francois 2308, Fri_196_OS-4_117, Fri_204_OS-4_691
Massonnet, François 500, 801, Fri_205_OS-4_734, Fri_268_OS-7_1023, Fri_314_SH-
8_1739
Mastorakis, Andrea Wed_219_OS-2_1594
Matějka, Michael Thu_287_CR-6_1161
Mata, Mauricio Wed_236_OS-6_768
Mateos, D. Tue_74_AC-1_2048, Tue_75_AC-1_2054
Mathakutha, Rabia 713
Matheny, Peter 2016
Mather, James Tue_84_AC-1_2650
Mathias, Delphine Tue_351_OS-1_2032
Mathiot, Pierre Wed_244_OS-6_1012, Wed_275_OS-6_2534
Mathis, Jeremy 1481
Matoba, Sumito 1235, 537, Wed_172_CR-8_1610
Matsuoka, Kenichi 1168, 1756, 2360, 637, Thu_221_CR-4_1074, Thu_223_CR-4_1248,
Thu_260_CR-5_1784, Tue_257_GG-2_747, Wed_118_CR-3_1762
Matsuoka, Kenny 1127
Mattar, Cristian Tue_103_AC-5_2129
Matthes, Heidrun Wed_24_AC-2_1727
Matthiessen, Jens 1120, 1699, Thu_94_BE-5_2078, Tue_305_GG-2_2602
Mattila, Oli-Pekka Wed_380_TE-3_2108
Mattingly, Kyle 520
Mattmann, Chris Fri_319_SH-8_2408
Mattmueller, Ramona Tue_350_OS-1_1978
Mattos Costa, Rafaela Thu_273_CR-6_154
Maturana, Claudia 1901
Maturilli, Marion 2110, Wed_3_AC-2_337
Matyshak, George Tue_191_BE-4_1581
Matyshak, Georgy Fri_71_EN-7_33
Mätzler, Eva Tue_240_CR-1_1840, Wed_198_EN-1_1844
Mauritsen, Thorsten 1459
Mauser, Wolfram Wed_137_CR-7_728
Maussion, Fabien Thu_272_CR-6_143
Mavlyudov, Bulat Thu_306_CR-6_2542
Mavrot, Fabien 2049, 485
Max Wrasse, Cristiano 2184
Maximiano, Tiago Tue_166_BE-4_581
Maximov, Trofim 2255, 2391
Maximov, Trofim C. Tue_195_BE-4_1688
Mayer, Christoph 1183, 736
Mayers, Kyle Thu_71_BE-2_2031, Tue_322_OC-1_2025
Mayewski, Paul 213, 2442
Mayewski, Paul A. 826
Mayzaud, Patrick Tue_224_BE-10_2373
Mazloff, Matthew 1290, 2112, 2171, 2536
2583
Mazzanti, Paolo Thu_270_CR-6_82
Mazzola, M. Tue_81_AC-1_2374
Mazzola, Mauro 2110, 2274, Fri_109_EN-7_2635, Fri_357_SY-1_2623, Tue_26_AC-
1_242, Tue_64_AC-1_1704, Tue_65_AC-1_1731, Tue_76_AC-1_2119
Mazzoleni, Claudio Tue_77_AC-1_2134
Mazzoleni, Lynn R. Tue_77_AC-1_2134
Mazzoli, Claudio Tue_323_OC-1_2117
McCaffrey, Anthony Wed_45_AC-4_779
McCammon, Molly 1289
McCarthy, Forrest 2239
McCarthy, Matt 2603
McClintock, J. 2102
McClymont, Erin 1572
McConnell, Joe 1340, Tue_96_AC-5_1149, Wed_171_CR-8_1591
McConnell, Joseph 796
McCorkell, Robert 2154
McCormack, Stacey A. 267
McCrow, John P. Thu_55_BE-2_559
McCusker, Kelly 661
McCutcheon, Jenine 122, 2473
McDonagh, Elaine Wed_258_OS-6_1555
McDonald, Adrian Fri_311_SH-8_1355, Tue_58_AC-1_1493, Wed_231_OS-6_570
Mcdonald, Adrian Fri_313_SH-8_1608, Fri_316_SH-8_1946
McDonald, Birgitte 2603
McDonald, Birgitte I. 1033
McDonald, Ian 2140, 2202, Thu_195_BE-12_2116
McDonald-Nethercott, Eoin 1747
McDonnell, Adam C. 549
McDougall, Trevor Fri_206_OS-4_804
McDowall, Philip Thu_179_BE-11_1151
McFadzean, Stuart Wed_364_TE-3_1069
McGowan, Suzanne Fri_102_EN-7_2336
McGrath, Maddie 1668
McGrath, Thomas 2244
McGuire, Anthony David Wed_76_BE-6_1906
McGuire, Dave 1847
McInnes, Julie Thu_105_BE-8_2236
McInnes, Sandra Thu_119_BE-9_727
McIntyre, Cameron 2056
McIvor, Ewan 1198
McKay, Christopher Wed_91_CR-2_210
McKay, Rob 1826, Tue_262_GG-2_833
McKay, Rob M. 1950, Tue_267_GG-2_1005
McKay, Robert 1592, 812, 813, 826, Tue_275_GG-2_1300, Tue_276_GG-2_1354,
Tue_280_GG-2_1479, Tue_298_GG-2_2261, Tue_87_AC-5_176, Wed_162_CR-8_868
McKay, Robert M. Thu_347_OS-3_1109
McKenna, Christine 1537
McKinlay, John 596
McKnight, Diane 1402, 307, Fri_94_EN-7_1869, Tue_199_BE-4_2008
McKnight, Diane M. Fri_39_EN-5_879
McLean, Lauren Thu_194_BE-12_1242
McLennan, Donald Tue_165_BE-4_513, Wed_339_TE-3_83
McLennan, Stephanie Wed_195_EN-1_568
McLeod, Rebecca Thu_161_BE-9_2281
McLinden, Chris Wed_382_TE-3_2224
Mclnnes, Sandra Thu_322_EN-4_1421
McMeeking, Gavin 1402
McMullin, R. Troy Tue_182_BE-4_1265
McNabb, Robert 951
McNeil, Christopher Wed_115_CR-3_1189
McPhee, James 1055, 1452, 1956, 2178, 920, Wed_112_CR-3_1026, Wed_113_CR-
2584
3_1035
McQuaid, James B. 122
McQuaid, Jeff Thu_55_BE-2_559
McRaven, Leah 808
Meccia, Virna 1755, Wed_146_CR-7_1929
Mech, Mario 1661, Tue_69_AC-1_1820, Wed_3_AC-2_337
Medley, Brooke 104, 787
Meeusen, Romain 1747, 2684
Mehlmann, Carolin 2269, Thu_335_OS-3_248
Mehta, Satish 2254
Mei, Fan 1586
Mei, Jeffrey 2106
Mei, M. Jeffrey 785
Mei, Miguel 1561
Meier, Lars Arne Fri_103_EN-7_2352
Meier, Martin Fri_31_EN-2_2343
Meier, Wolfgang 667
Meijers, Andrew 1290, 349, Wed_258_OS-6_1555
Meiklejohn, Ian Tue_163_BE-4_457, Tue_230_CR-1_139, Tue_231_CR-1_202
Meinander, Outi Wed_14_AC-2_976
Meiners, K. Wed_215_OS-2_1279
Meiners, Klaus 1081, 1239, 844, Thu_164_BE-9_2363
Meiners, Klaus M 203
Meinig, Christian 1619
Meire, Lorenz 551
Meirink, Jan Fokke Wed_349_TE-3_406
Meissner, Katrin J 831
Meister, Marlene Tue_350_OS-1_1978
Meister, Matthew Wed_224_OS-2_2193, Wed_269_OS-6_2181
Meister, Rakia Wed_385_TE-3_2382
Mékarnia, Djamel 1272, 1376
Mekjavic, Igor 2254
Mekjavic, Igor B. 549
Melbourne-Thomas, Jess 1239, 1240, 1352, 1632, Thu_134_BE-9_1357
Melbourne-Thomas, Jessica 2346, 267, Thu_164_BE-9_2363, Tue_183_BE-4_1364
Melis, Romana Fri_250_OS-7_131
Melkonian, Jeanne 2001
Melles, Martin 2014
Melling, Humfrey Tue_346_OS-1_1621
Melnick, Gary Tue_15_AA-1_2209
Melnikov, Igor 1835
Melo, Stella Thu_8_AC-3_1393
Meloni, Daniela Thu_5_AC-3_775, Tue_61_AC-1_1639, Wed_6_AC-2_666,
Wed_7_AC-2_680
Meloth, Thamban 1127, Thu_221_CR-4_1074, Thu_281_CR-6_617, Thu_352_OS-
3_1362, Wed_157_CR-8_602
Melsheimer, Christian 2519, Fri_234_OS-5_674, Wed_363_TE-3_1063, Wed_383_TE-
3_2314
Melsom, Arne Fri_213_OS-4_1871
Melton, Joe Tue_241_CR-1_1904
Melvær, Yngve 637
Melzer, Amir 1648
Mémin, Anthony Thu_266_CR-5_2311
Mendes, Carlos Rafael Tue_166_BE-4_581
Mendes, Tiago Fri_170_ME-2_521
Mendes Jr., Cláudio Wed_373_TE-3_1570
Mendes Junior, Claudio Wilson Wed_357_TE-3_792
Mendonca, Joseph Wed_382_TE-3_2224
Meneghello, Gianluca 1174, Wed_248_OS-6_1176
Menemenlis, Dimitris 2125, 486
Meng, Shang Fri_197_OS-4_345
2585
Menking, James 2442
Menking, James Andrew Wed_171_CR-8_1591
Menna, Milena Wed_255_OS-6_1463, Wed_263_OS-6_1754
Menneken, Martina 1955
Mennucci, Claudio 1381
Mensah, Amewu 1381
Mensah, Darlington Thu_291_CR-6_1283
Menviel, Laurie 826
Menze, Sebastian 946, 958
Mercenier, Remy Thu_225_CR-4_1400, Thu_301_CR-6_2067
Mercenier, Rémy 1949, Thu_220_CR-4_1036
Mercer, Jennifer 1831
Merchel, Malgorzata Wed_274_OS-6_2497
Mered, Mikaa 2147
Meredith, Michael 1167, 1292, Wed_258_OS-6_1555, Wed_321_TE-1_997
Meredith, Mike 1424
Mergelov, Nikita 2371
Merican, Faradiana Tue_145_BE-3_2289
Merican, Faradina 2294, Thu_163_BE-9_2329, Thu_322_EN-4_1421, Tue_146_BE-
3_2310
Merino, Nacho Wed_275_OS-6_2534
Merkouriadi, Ioanna Fri_242_OS-5_1828
Merl, Maximilian Thu_216_CR-4_894
Merlivat, Liliane Thu_62_BE-2_914
Mernild, Sebastian Thu_380_SH-6_1214
Merrifield, Mark 1489
Merryfield, Bill Fri_222_OS-4_2557
Mertes, Stephan 1163, 246, Tue_35_AC-1_719
Meseguer, Ana Thu_103_BE-8_2084, Thu_104_BE-8_2101
Messerli, Alexandra Wed_366_TE-3_1310
Mestas-Nuñez, Alberto M. Fri_227_OS-5_172
Mestre, Gelys Thu_121_BE-9_832
Metcalf, James S. 2376
Metelka, Ladislav Wed_15_AC-2_992
Metfies, Katja 2060, 497, Wed_209_OS-2_506
Metsämäki, Sari Wed_380_TE-3_2108
Metzdorff, América Fri_12_EN-2_742
Metzig, Robert Wed_350_TE-3_420
Meulemans, Zachary 1233
Mevi, Gabriele Thu_5_AC-3_775, Tue_61_AC-1_1639, Wed_6_AC-2_666,
Wed_7_AC-2_680
Meyer, Amelie 1309, 1506, 2060, Wed_256_OS-6_1508
Meyer, Amélie 1659
Meyer, Bettina 196, 682, Tue_168_BE-4_675
Meyer, Hanna 1361, 510
Meyer, Maybritt Thu_346_OS-3_972
Meyer, Ulrich Thu_261_CR-5_1812
Meyers, Stephen 813
Mezgec, Karin Fri_250_OS-7_131
Mialon, Arnaud 316, Wed_348_TE-3_317
Michael, Katharina 682, Tue_168_BE-4_675
Michaud, Emma Thu_97_BE-5_2651
Michel, Christine 2060, 2066, Thu_91_BE-5_1590, Thu_94_BE-5_2078
Michel, Clio 135, 1790, Wed_25_AC-2_1804
Michel, Roberto Fri_101_EN-7_2286, Wed_340_TE-3_184
Michele, Furnari Fri_81_EN-7_1015
Michelsen, Anders 1514
Miege, Clement Wed_134_CR-7_312
Miettinen, Arto Thu_352_OS-3_1362
Miettunen, Elina Wed_203_OS-2_233
Migała, Krzysztof 1
2586
Mignac, Davi 2308, Fri_314_SH-8_1739
Migoń, Piotr 1976
Mikhail, Sysoev Fri_363_TE-2_438
Mikhalevsky, Peter N. Fri_353_SY-1_1994
Mikhalsky, Evgenii Fri_112_GG-1_96
Mikhalsky, Evgeny Fri_114_GG-1_146
Mikkelsen, Andreas 2506
Mikkelsen, Mikkel Tue_240_CR-1_1840
Mikkonen, Anu Tue_114_BE-1_1366
Mikolajewicz, Uwe 1755, Wed_146_CR-7_1929
Mikucki, Jill 1186, 2152, 2214, Thu_194_BE-12_1242
Milbau, Ann 333
Miles, Evan S. 2385
Milinevsky, Gennadi 942, Tue_174_BE-4_950, Wed_13_AC-2_928
Millán, Rocio 2094
Miller, Brian S. Tue_352_OS-1_2249
Miller, Elanor Tue_352_OS-1_2249
Miller, Jeffrey Thu_24_AC-8_560
Miller, Julie 696
Miller, L.A. Wed_215_OS-2_1279
Miller, Lisa Fri_273_OS-7_1249, Fri_73_EN-7_261
Miller, Lisa A. Thu_374_SH-6_105
Miller, Nathaniel 821
Miller, Rebecca 2118
Miller, Rebecca E Thu_112_BE-9_186
Millet, Grégoire 1507
Millikin, Alexie Fri_348_SY-1_1410
Milner, Alexander 1854
Milton, Isaiah Thu_118_BE-9_707
Minakowski, Piotr Thu_335_OS-3_248
Ming, Yi Tue_46_AC-1_1156
Mink, Sandra 2103
Mintenbeck, Katja Tue_226_BE-10_2469
Mioche, Guillaume Tue_59_AC-1_1546
Miranda, Nuno 2552
Miserocchi, Stefano Fri_109_EN-7_2635, Fri_292_OS-7_1815, Fri_81_EN-7_1015,
Fri_97_EN-7_2076, Thu_78_BE-2_2639
Mishra, R K Thu_72_BE-2_2367
Mishra, R.K. Thu_49_BE-2_55
Misiak, Marta 418
Mitchell, B. Greg Thu_169_BE-9_2465
Mitrovica, Jerry 2167
Miura, Hideki Fri_338_SY-1_190, Fri_51_EN-6_548
Miyamoto, Atsushi 1235
Miyamoto, Tomoharu 2233
Miyaoka, Yoichi Fri_180_ME-1_178
Moat, Ben Fri_264_OS-7_989
Mock, Thomas Wed_217_OS-2_1580
Moffat, Carlos Wed_270_OS-6_2186, Wed_321_TE-1_997
Moffat-Griffin, Tracy Wed_40_AC-4_385
Moffett, Claire 433
Mogo, S. Tue_75_AC-1_2054
Mogo, Sandra Tue_74_AC-1_2048
Mohamad Radzi, Ranina Alya Thu_163_BE-9_2329
Mohamad-Fauzi, Nuradilla 1922, Tue_197_BE-4_1932
Mohammad, Mahadi Tue_198_BE-4_1996
Mohan, Rahul 1317, 1797, Fri_52_EN-6_618, Thu_115_BE-9_657, Thu_244_CR-
4_88, Thu_352_OS-3_1362, Thu_379_SH-6_1123
Mohd Shah, Rohani Fri_330_SH-9_912
Moholdt, Geir 1957, Thu_221_CR-4_1074, Wed_366_TE-3_1310
Mohr, Claudia 1447, Tue_54_AC-1_1448
2587
Moiseev, Denis 2562
Moiseyenko, Yevgen Fri_172_ME-2_998
Moissl-Eichinger, Christine Thu_198_BE-12_2267
Mojica, Jhon Wed_227_OS-6_247
Mojica Moncada, Jhon 239
Mokhov, Igor Tue_239_CR-1_1732, Tue_78_AC-1_2250, Wed_24_AC-2_1727
Moksnes, O. 2102
Mölg, Nico Tue_308_OC-1_346
Mölg, Thomas Tue_30_AC-1_377
Molina, Marco Tue_215_BE-4_2685
Molina-Montenegro, Marco Tue_201_BE-4_2097
Molis, Markus Tue_196_BE-4_1737
Molleker, Sergej 1077
Mollenhauer, Gesine Thu_333_OS-3_53, Thu_349_OS-3_1251, Thu_354_OS-3_1653
Møller, Eva Friis 748, Fri_10_EN-2_555, Thu_88_BE-5_1225
Möllmann, Florian 257
Moloney, Coleen L. Thu_124_BE-9_978
Molotch, Noah Wed_113_CR-3_1035
Molteni, Ugo Tue_37_AC-1_767
Momo, Fernando Roberto 1343, Thu_109_BE-9_42
Monahan, Adam 2195
Mondal, Mainak Wed_232_OS-6_574
Mondini, Antonio Thu_193_BE-12_1011, Tue_112_BE-1_949
Monforti-Ferrario, Fabio 2276
Monien, Patrick 1577
Monier, Marie Tue_59_AC-1_1546
Monroe, Emily Tue_47_AC-1_1169
Monsanto, Daniela Tue_163_BE-4_457
Montagna, Paul 1444
Montagner, Jean-Paul 650
Monteiro, Maria 2111, Thu_195_BE-12_2116
Monteiro, R. Tue_74_AC-1_2048
Montoli, Enea 175, Tue_87_AC-5_176
Montomoli, Chiara Fri_118_GG-1_230
Montomoli, Francesco 1370
Montpetit, Benoit 134, Wed_338_TE-3_15
Moon, Heung Soo 1056
Moon, Jangil Fri_63_EN-6_1645, Fri_68_EN-6_2240
Moore, Anna 1403, Tue_3_AA-1_403
Moore, Christopher Fri_74_EN-7_277
Moore, GWK 718, 963
Moore, John 857
Moore, John C. 2686
Moore, Kent 2112, 2120, 808
Moore, Kevin 119
Moore, Robyn Fri_325_SH-9_236
Moore, Sue Tue_346_OS-1_1621
Moorman, Brian 371
Mora, Carla 2681
Moraes, Michele Fri_170_ME-2_521, Fri_327_SH-9_525
Moraes, Michele Macedo Fri_171_ME-2_527
Morales Guerrero, Andrés Felipe Tue_17_AA-1_2221
Morata, Nathalie Thu_91_BE-5_1590, Thu_94_BE-5_2078, Thu_97_BE-5_2651,
Tue_360_OS-8_1960
Mordret, Aurelien Fri_127_GG-1_550
Mordy, Calvin 1619
Moreau, Camille 2, Thu_145_BE-9_1801, Thu_146_BE-9_1807, Thu_147_BE-9_1809,
Tue_186_BE-4_1419
Moreau, Luc Thu_301_CR-6_2067
Moreau, Sebastien 1497, 1614, 591, 844, Fri_88_EN-7_1498, Wed_213_OS-2_861
Moreau, Sébastien 414
2588
Moreels, Marjan 1664, 2254
Moreira, Eugenia 1451, Tue_222_BE-10_2128, Tue_223_BE-10_2331
Morelli, Andrea Fri_346_SY-1_1223, Thu_258_CR-5_1226
Moreno, Bernabe 2, Tue_186_BE-4_1419
Moreno, Bernabé 710
Moreno, Mario Thu_77_BE-2_2592, Tue_140_BE-3_2003
Moreno-Merino, Luis Wed_120_CR-3_2038
Moreno-Pino, Mario Thu_201_BE-12_2553
Moreton, Steve 1577
Morgan, Fraser 2275, 636, 637, Thu_324_EN-4_1500, Tue_236_CR-1_858,
Wed_71_BE-6_612
Morgan-Kiss, Rachael 307
Morgan-Kiss, Rachael M. Fri_39_EN-5_879
Morgenstern, Olaf Fri_311_SH-8_1355, Tue_49_AC-1_272, Tue_58_AC-1_1493
Mori, Giovanna Fri_290_OS-7_1766
Mori, Tatsuhiro 537
Morigi, Caterina Fri_65_EN-6_1986, Thu_351_OS-3_1327, Tue_272_GG-2_1160
Morikawa, Hirohisa Fri_176_ME-2_1553
Morin, Pascal Thu_380_SH-6_1214
Morin, Paul 607
Mork, Kjell Arne Wed_335_TE-1_2354
Mørk, Finn 1200
Morkusová, Jana Tue_162_BE-4_453
Morley, Simon A Tue_153_BE-4_145
Morlighem, Mathieu Thu_256_CR-5_1057
Moroni, Beatrice 2110, Tue_63_AC-1_1703, Tue_76_AC-1_2119
Morozov, Alexey Fri_123_GG-1_341
Morozov, Andrey Fri_353_SY-1_1994
Morozova, Polina 2061
Morris, Richard Ashley 1957
Morris, Sara 1923, 1924
Morrison, Adele 2171
Morrison, Adele K. 386
Mörs, Thomas Fri_144_GG-1_1689, Fri_148_GG-1_1791
Mortensen, John 551
Mortensen, Lis 2019
Mortenson, Eric 2195
Mörth, Carl-Magnus 2255
Mortier, Laurent 2001
Mortreux, Valentine 2372
Mosbech, Anders 748, Thu_88_BE-5_1225
Moser, Gleyci Fri_60_EN-6_1453, Tue_187_BE-4_1457
Moster Knudsen, Erlend Tue_69_AC-1_1820, Wed_3_AC-2_337
Motas, Miguel 2046, Thu_103_BE-8_2084, Thu_104_BE-8_2101
Mote, Thomas 2506, 520, Thu_24_AC-8_560
Moteki, Nobuhiro 537
Motoyama, Hideaki 1235, 537
Motoyoshi, Yoichi 2233
Mott, Rebecca 959
Mott-Grünewald, Rebecca 1210
Mottram, Ruth 2546
Mouginot, Jeremie 1678, Thu_256_CR-5_1057
Mould, Jeremy 1403
Mourtazin, Albert Wed_280_OS-6_2648
Moussavi, Mahsa 1931, Thu_240_CR-4_2378
Moustafa, Samiah 2506
Moy, Christopher M. 843
Msadek, Rym 1554, 2496, 435, 454
Mu, Longjiang Fri_197_OS-4_345, Fri_199_OS-4_451, Fri_201_OS-4_630,
Wed_277_OS-6_2626
Mucciarone, David Thu_78_BE-2_2639
2589
Muckenthaler, Martina 113
Mudryk, Lawrence 223
Mueller, Carsten W. 2361, Fri_103_EN-7_2352
Muhamad Darif, Nur Aqilah Tue_198_BE-4_1996
Muilwijk, Morven Wed_233_OS-6_627
Muir, Alan 1759
Muir, Derek 1837, 2633, Fri_24_EN-2_1930
Mulder, Jacob 855
Muldoon, Gail 1856
Muldoon, Gail R. Thu_238_CR-4_2213
Müller, Jacqueline Fri_191_OC-3_1651
Müller, Juliane 1950, 812, Thu_333_OS-3_53, Thu_349_OS-3_1251, Thu_354_OS-
3_1653, Tue_267_GG-2_1005
Müller, Kim Janka Wed_220_OS-2_1787
Müller, Malte Fri_213_OS-4_1871
Müller, Martin 670
Müller, Rolf 2412, Tue_55_AC-1_1461
Müller, Simon Tue_42_AC-1_1039, Tue_43_AC-1_1052
Müller, Wolfgang A. 760
Mulvaney, Robert Wed_154_CR-8_201
Munch, Thomas 1513
Münchow, Andreas 1183
Mundy, C. J. 1309
Mundy, C.J. 2066, 2302, Tue_357_OS-8_840, Wed_215_OS-2_1279
Munk, Walter Fri_353_SY-1_1994
Munk Hvidegaard, Sine 1770
Münnich, Matthias 678
Munoz, Yuribia 1910
Muñoz, Ariel Wed_153_CR-8_183
Munsell, Steve Wed_134_CR-7_312
Muppidi, Ravi Kumar 436
Muraviev, Anton 1667
Murphy, Damian 1964, Wed_39_AC-4_382, Wed_40_AC-4_385
Murphy, Eugene 2346, Thu_123_BE-9_964, Thu_149_BE-9_1875
Murphy, Karen 1289
Murphy, Mel 2391, Fri_106_EN-7_2447
Murphy, Melissa 1606
Murray, Alison Fri_46_EN-5_2435
Murray, Alison E. Thu_169_BE-9_2465
Murray, Maribeth 1048, Fri_44_EN-5_2321
Murukkesh, Nuncio 604
Muscari, Giovanni Thu_5_AC-3_775, Tue_61_AC-1_1639, Wed_6_AC-2_666,
Wed_7_AC-2_680
Muscatello, Beatrice Wed_130_CR-3_2500
Muschitiello, Francesco Thu_362_OS-3_2555
Musco, Maria Elena Tue_266_GG-2_988, Tue_272_GG-2_1160
Mushta, Aleksandra 1526, 2324, Thu_359_OS-3_2226
Musicò, Elvira 1786
Mustafa, Emienour Muzalina Fri_28_EN-2_2190
Mustafa, Osama 1054, Wed_323_TE-1_1071, Wed_326_TE-1_1231, Wed_364_TE-
3_1069
Musumeci, Giovanni Fri_118_GG-1_230
Muthuraj, Ashokan Tue_345_OS-1_1429
Myamin, Vladislav Fri_78_EN-7_740
Myers, Krista 1186, 2152, Fri_308_SH-8_211, Thu_111_BE-9_159, Wed_115_CR-
3_1189
Myers, Madeline Thu_111_BE-9_159
Mykrä, Heikki 1854

N
N, Anil Kumar 1190
2590
N, Jeni Victor Tue_60_AC-1_1635
N, Koushik Tue_88_AC-5_797
Němeček, Karel Tue_249_GG-2_328
N. Losa, Svetlana Fri_201_OS-4_630
Naafs, David 1572
Nachtsheim, Dominik Thu_82_BE-5_455
Nadal Junqueira Villela, Franco Tue_70_AC-1_1895
Naegeli, Kathrin 951
Nagar, Swati Thu_379_SH-6_1123
Nagatsuka, Naoko 537
Nagler, Thomas 1741, Thu_267_CR-5_2349, Wed_380_TE-3_2108
Naik, Aditya 641
Naik, Ravi Wed_262_OS-6_1738
Naik, Ravidas Krishna Thu_72_BE-2_2367
Nainwal, Harish Chandra 953
Nair, Abhilash Fri_52_EN-6_618, Thu_352_OS-3_1362
Naish, Tim 1877
Naish, Timothy , 303, 813, 826
Nakamura, Takuji 1964, Wed_28_AC-2_1974, Wed_40_AC-4_385, Wed_49_AC-4_2316
Nakamura, Tetsu 2303
Nakao, Nazuna Tue_375_SH-2_322
Nakayama, Yoshihiro 486
Nam, Seung-Il Thu_348_OS-3_1247
Namsarev, Zorigto Tue_118_BE-1_1999
Nandan, Vishnu 134, Fri_226_OS-5_151, Wed_347_TE-3_308
Napoleoni, Felipe 1691, Thu_230_CR-4_1673
Napolioni, Felipe Thu_229_CR-4_1649
Näränen, Jyri Thu_245_CR-5_115, Thu_269_CR-5_2550
Narayana Pillai, Anilkumar Wed_262_OS-6_1738
Narayanan, Sri Hari Krishna Thu_237_CR-4_2200
Narcisi, Biancamaria 126, Fri_69_EN-6_2364
Naruiwa, Nobuo Fri_173_ME-2_1117, Fri_174_ME-2_1188, Fri_175_ME-2_1411
Nash, Maisie 440, 470
Nash, Meredith Fri_325_SH-9_236, Wed_306_SH-5_1462
Näslund, Jens-Ove 1129
Nassar, Ray Wed_382_TE-3_2224
Nasse, Jan-Marcus 2113, Fri_266_OS-7_993, Fri_274_OS-7_1269
Nastasi, Massimiliano Wed_166_CR-8_1030
Nati, Federico 528
Naughten, Kaitlin Thu_253_CR-5_837
Nauss, Thomas 1361
Nauß, Thomas 510
Nava, Silvia Fri_19_EN-2_1422, Tue_63_AC-1_1703, Tue_64_AC-1_1704
Navarro, Francisco 2256, Thu_291_CR-6_1283
Naveen, Ron Thu_137_BE-9_1413, Thu_183_BE-11_2631
Naveira Garabato, Alberto 1292, Wed_249_OS-6_1291
Nayak, G. N. Fri_48_EN-6_34
Nedbalová, Linda Fri_372_BE-5_1696, Tue_133_BE-3_1197, Tue_194_BE-4_1652
Needham, Jay 2591
Neff, Peter 637, 826
Neff, William Thu_11_AC-3_2010, Thu_12_AC-3_2071, Thu_13_AC-3_2074
Negrel, Jean 1506
Negrete, Javier Tue_152_BE-4_46
Negusini, Monia 1003, Thu_255_CR-5_1000, Wed_363_TE-3_1063
Nehrbass-Ahles, Christoph 1423, Fri_58_EN-6_1224
Nehrke, Gernot 1699, Wed_225_OS-2_2458
Nehyba, Slavomir Fri_66_EN-6_2057
Neil, Harris Tue_56_AC-1_1467
Neilson, Beth 2477
Neilson, Bethany 1543, 2145
Neitola, Kimmo 1561, Wed_336_TE-1_2356
2591
Nel, Werner Thu_32_AC-8_1700
Nelles, Anna 481
Nelson, C. Hans Tue_294_GG-2_2035, Tue_296_GG-2_2044
Nelson, Frederick 1486
Németh, Karoly Fri_137_GG-1_967
Nerger, Lars Fri_200_OS-4_608, Fri_201_OS-4_630
Nerini, Daniele Wed_127_CR-3_2305
Netto, Guilherme Fri_350_SY-1_1743
Neu, Daniel 1747
Neuber, R. Tue_75_AC-1_2054
Neuber, Roland Thu_377_SH-6_962, Thu_380_SH-6_1214
Neudecker, Mariele 2220
Neufeld, David Tue_15_AA-1_2209
Neukom, Raphael 2614, Fri_55_EN-6_917
Newall, Jennifer 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Newman, Louise 1617, 2346
Newsham, Kevin K 418
Newton, Robert 1334, Fri_215_OS-4_1916
Neyt, Xavier 1747, 2684
Ng, Hong Chin 416, Fri_105_EN-7_2397
Ng, Jessica 2442, Thu_224_CR-4_1275
Nghiem, Son Thu_17_AC-8_8
Nias, Isabel 2468
Nicholls, Keith 1292, 1306, 1433, Thu_211_CR-4_749
Nicholls, Keith W. 1136
Nichols, Jonathan E. 843
Nichols, Peter Thu_84_BE-5_882
Nichols, Peter D Thu_173_BE-11_582, Wed_82_BE-7_580
Nicholson, Emily 2118
Nicholson, Sarah Fri_302_OS-7_2394
Nicol, Stephen Thu_173_BE-11_582, Wed_82_BE-7_580
Nicolas, Julien 1595, 465, Thu_228_CR-4_1597, Wed_66_AC-6_1596, Wed_67_AC-
6_1600
Nicolaus, Marcel 1254, 531, 699, Fri_212_OS-4_1813, Fri_230_OS-5_343,
Fri_238_OS-5_1267, Fri_277_OS-7_1320
Nicovich, John Thu_13_AC-3_2074
Niebuhr, Andreas 1443
Niederdrenk, Laura 1426, Fri_239_OS-5_1286
Niehoff, Barbara 497, Tue_164_BE-4_466, Wed_209_OS-2_506
Nield, Grace 1118, 1390
Nielsen, Arne T. Thu_314_GG-1_2170
Nielsen, Daniel Aagren 2182, 2188
Nielsen, Hanne 1277, 1294, 1848, Tue_338_OC-4_2135, Wed_306_SH-5_1462
Nielsen, Julius Fri_17_EN-2_1399, Fri_18_EN-2_1401
Nielsen, Torkel Gissel 748
Nielsen, Tove 1200
Niemann, Helge Wed_221_OS-2_2027
Niessen, Frank 1685
Nieto, Ana 2103
Nieto, Fernando Tue_290_GG-2_1959
Niino, Hiroshi 585
Nijs, Ivan 333
Nikiema, Oumarou Tue_82_AC-1_2527
Nikitin, Stanislav 1667, Thu_296_CR-6_1647
Niklaus, Pascal 330, 431
Niklaus, Pascal A. Tue_195_BE-4_1688
Nikolopoulos, Anna 1699, 2060, Thu_94_BE-5_2078, Wed_261_OS-6_1729,
Wed_271_OS-6_2231
Nilsen, Frank Fri_292_OS-7_1815
Nine, Cara Tue_365_SH-1_132
Nisancioglu, Kerim 2415
2592
Nishijima, Jun Thu_265_CR-5_2284
Nishimura, Koji Wed_49_AC-4_2316
Nishimura, Kouichi 1134
Nishioka, Jun Thu_374_SH-6_105
Nishiyama, Sachiko Fri_174_ME-2_1188
Nishiyama, Takanori 1964, Wed_28_AC-2_1974
Nissen, Cara 678
Nitsche, Frank O. Fri_38_EN-5_853
Nitschke, Kim Tue_84_AC-1_2650
Nitu, Rodica 2452, Fri_355_SY-1_2383
Niwano, Masashi Thu_294_CR-6_1510
Nixdorf, Uwe
Njaastad, Birgit 1198
No, Hyun-Ju 120
Noble, Taryn Thu_254_CR-5_862, Tue_289_GG-2_1937
Nobre, Paulo Fri_225_OS-4_2665
Noel, Brice Thu_295_CR-6_1539
Noël, Brice 1987
Noer, Gunnar Wed_27_AC-2_1936
Noetzli, Jeannette 1880, 2678
Nogi, Yoshifumi 448, Fri_124_GG-1_347, Fri_338_SY-1_190
Noguchi, Tomohide Wed_237_OS-6_944
Noh, Younho Fri_62_EN-6_1620
Nolan, Glenn Fri_353_SY-1_1994
Nomura, Daiki Wed_117_CR-3_1280, Wed_206_OS-2_378, Wed_214_OS-2_1278,
Wed_215_OS-2_1279, Wed_225_OS-2_2458
Noone, David 2674
Normand, Signe 965
Noro dos Santos, Marina Wed_254_OS-6_1445
Norrbin, Fredrika Tue_355_OS-8_795
Norris, Kimberley 1941, Fri_333_SH-9_1945
Norris, Sara 1134
Norton, Kevin 881, Tue_265_GG-2_909
Nosenko, Gennady 1667, 2381, Thu_296_CR-6_1647
Noser, Philip 1507
Nöthig, Eva Maria 2060
Nöthig, Eva-Maria 1699, Wed_209_OS-2_506
Notz, Dirk 1270, 1426, 1459
Novellino, Antonio Wed_260_OS-6_1628
Novey, Katherine Thu_194_BE-12_1242
Novichkova, Anna 1854
Novikhin, Andrey Tue_361_OS-8_2287
Novillo, Manuel 1451, Tue_222_BE-10_2128
Nowak, Marcin 1868
Nowak, Stefan Wed_313_TE-1_472, Wed_329_TE-1_1391
Nowicki, Sophie M. J. Thu_283_CR-6_794
Nozawa, Satonori 2228
Nucciarelli, Giuliano Tue_12_AA-1_1564
Nummelin, Aleksi 2341
Nuncio, M. Wed_262_OS-6_1738
Nunes, Sdena Fri_307_OS-7_2683
Nuñez, Martin 333
Núñez, Luis Alberto Tue_17_AA-1_2221
Nunnally, Clifton 1187, Tue_200_BE-4_2075
Nuntiyakul, Waraporn Tue_11_AA-1_1377
Nur, Nadav 1179
Nurser, George 1396, Wed_258_OS-6_1555
Nuruzzama, Mohammad 1317
Nusbaumer, Jesse 2674
Nussbaumer, Samuel U. Tue_308_OC-1_346
Nyblade, Andrew 1274, Fri_134_GG-1_762
2593
Nyeki, Stephan Tue_25_AC-1_241
Nylen, Tom 2198
Nymand Larsen, Joan 1908
Nys, Kevin Wed_16_AC-2_1017
Nyvlt, Daniel 2077, Fri_103_EN-7_2352, Fri_121_GG-1_338, Fri_66_EN-6_2057,
Tue_232_CR-1_284, Tue_249_GG-2_328, Wed_92_CR-2_282, Wed_93_CR-2_332
Nývlt, Daniel Thu_21_AC-8_278, Thu_233_CR-4_1870, Thu_287_CR-6_1161

O
O’Neale, Dion Wed_327_TE-1_1363
Oaquim, Anna Fri_60_EN-6_1453, Tue_187_BE-4_1457
Obbard, Rachel 1991, Fri_224_OS-4_2573, Fri_304_OS-7_2558
Obernosterer, Ingrid 1281, 2098, 2265, 594
Oberreuter, Jonathan 1691, Thu_230_CR-4_1673
Obornik, Miroslav Thu_55_BE-2_559
O'Brien, Phil 140, 626, Tue_285_GG-2_1669
O'Brien, Philip Thu_217_CR-4_899, Thu_80_BE-5_191, Tue_250_GG-2_363,
Tue_251_GG-2_364, Tue_254_GG-2_669
Obrist, Daniel Fri_74_EN-7_277
Obrochta, Stephen Fri_56_EN-6_938
Obryck, Macij Fri_308_SH-8_211
Obryk, Maciej 2189, 2257, Wed_69_BE-6_212
O'Byrne, Amanda Fri_102_EN-7_2336
Ochoa, Hector Wed_14_AC-2_976
Ochoa, Héctor 511
Ochyra, Ryszard 1577
O'Connor, Ewan 1561, 670
O'Connor, Ian 2659
O'Connor, Michael 1543
Odetti, Angelo 1008, Fri_81_EN-7_1015, Fri_90_EN-7_1532, Wed_328_TE-1_1371,
Wed_331_TE-1_1511, Wed_332_TE-1_1529
O'Donnell, JP 1390
O'Dowd, Colin Fri_307_OS-7_2683
O'Driscoll, Richard Thu_138_BE-9_1414
Oettershagen, Philipp 1648
O'Farrell, Siobhan 869
O'Flaherty, Nicholas 2180
Ogata, Jun 537
Ogawa, Fumiaki Thu_22_AC-8_445
Ogawa, Yasunobu 2228
Ogawa-Tsukagawa, Yoshimi 537
Ogle, Sarah Fri_298_OS-7_2183
Ogneva, Olga Tue_191_BE-4_1581
Ogren, John 2499
Oh, Changhwan Fri_142_GG-1_1415, Fri_148_GG-1_1791
O'Hara, Casey Fri_282_OS-7_1418
Ohata, Sho 537
Ohneiser, Christian , Tue_276_GG-2_1354, Tue_298_GG-2_2261
Ohno, Giichiro Fri_167_ME-2_112, Fri_173_ME-2_1117, Fri_175_ME-2_1411,
Fri_180_ME-1_178, Fri_184_ME-1_1982
Ohshima, Kay I. Fri_251_OS-7_300, Wed_237_OS-6_944
Oikkonen, Annu 1206
Okie, Jordan 2189, Tue_142_BE-3_2165
Oktar, Ozgun Thu_331_EN-4_2351, Tue_325_OC-1_2393, Tue_326_OC-1_2402,
Tue_327_OC-1_2445, Tue_328_OC-1_2498
Okuno, Jun’ichi Thu_265_CR-5_2284
Okuno, Jun'ichi Fri_151_GG-1_1933, Thu_249_CR-5_404, Thu_251_CR-5_590
Ólafsson, Jón 1854
Olalla Tárraga, Miguel Ángel 37
Olalla-Tarraga, Miguel Angel Thu_125_BE-9_1018
Olalla-Tárraga, Miguel Á. 1321
2594
Ólason, Einar 2096
O'Leary, Mick 2167
Olenick, Jeffery 1575
Olesen, Arne 1168, 1756, Thu_260_CR-5_1784, Tue_257_GG-2_747,
Wed_118_CR-3_1762
Olesen, Arne V 2360
Olesen, Arne Vestergaard 2642
Oleszczuk, Barbara Thu_91_BE-5_1590, Thu_97_BE-5_2651
Oliva, Marc 120, Fri_57_EN-6_1032, Thu_233_CR-4_1870, Thu_307_CR-6_2590
Olivares, Sebastian Thu_199_BE-12_2444
Oliva-Urcia, Belen Fri_153_GG-1_2023, Wed_99_CR-2_2033
Oliver, Matthew Thu_143_BE-9_1724, Thu_67_BE-2_1470, Tue_190_BE-4_1559,
Wed_264_OS-6_1788
Olivier, Frédéric Tue_351_OS-1_2032
Olivier, Ria 624, Fri_187_OC-3_623, Fri_329_SH-9_628
Olivio, Elisabetta 1135
Olivo, Elisabetta 175, Tue_247_GG-2_200, Tue_279_GG-2_1478, Wed_238_OS-
6_955
Olmastroni, Silvia Fri_191_OC-3_1651, Fri_32_EN-2_434
Olofsson, Jan-Ola 1668
Olonscheck, Dirk 1459
Olsen, Are Fri_99_EN-7_2082
Olsen, Lasse M. 1309, Thu_74_BE-2_2483
Olson, Christine Fri_74_EN-7_277
Olson, Lasse Mork 2060
Olund, Sydney 816
Onarheim, Ingrid 148
Ondrackova, Lenka Fri_121_GG-1_338
Ondruch, Jakub Thu_1_AC-3_283, Thu_21_AC-8_278
O'Neel, Shad Wed_115_CR-3_1189
O'Neill, Rachel J. 716
O'Neill, Tanya 2094, Wed_195_EN-1_568
Ono, Giichiro Fri_174_ME-2_1188
Ono, Kazuya Wed_237_OS-6_944
Onofri, Silvano 442, 462, 694, Tue_111_BE-1_695, Tue_160_BE-4_443
Onorato, Miguel 239, Fri_275_OS-7_1296, Wed_227_OS-6_247
Onstott, Tullis C. Tue_121_BE-3_573
Oosthuizen, W. Chris 2047, Thu_82_BE-5_455
Opała-Owczarek, Magdalena 1
Opdyke, Brad Thu_217_CR-4_899
Opdyke, Bradley 626
Opfergelt, Sophie 362
Opher, Jacob 416
Opielinski, Krzysztof Wed_341_TE-3_217
Opitz, Rachel 483
Orasche, Juergen 1381
Orasche, Jürgen Fri_21_EN-2_1609
O'Regan, Matt 1120
Orekhova, Alla Thu_172_BE-9_335
Orgeret, Florian 921
Orquera, Federico 2155
Orr, Andrew 1475, 1521, 1549, 2412, Thu_228_CR-4_1597
Orsenigo, Simone 1051
Orsi, Anais 1285
Orsi, Anaïs 444, Fri_55_EN-6_917
Orsolini, Yvan 1873, Thu_18_AC-8_16, Thu_33_AC-8_1702
Ortega-Becerril, Jose A. Wed_99_CR-2_2033
Ortega-Retuerta, Eva Fri_307_OS-7_2683
Orthe, Nils Kristian Wed_366_TE-3_1310
Ortiz-Alvarez, Rüdiger 2256
Orttung, Robert Wed_293_SH-5_3, Wed_298_SH-5_1045
2595
Osadchiev, Alexander 2268
Osborne, Emily 1481, Tue_315_OC-1_1571
O'Shea, S. Tue_52_AC-1_1221
O'Shea, Sebastian 1796
Osiński, Robert Fri_216_OS-4_2173
Osinski, Robert 2418
Osipov, Igor Tue_318_OC-1_1718
Osmont, Dimitri 1125, 709, Tue_176_BE-4_1121
Osorio, Magdalena Tue_204_BE-4_2348, Tue_207_BE-4_2493
Ossebaar, Sharyn 2090
Ostafin, Krzysztof 1388
Østerhus, Svein 1136
Otani, Shinji Fri_180_ME-1_178, Fri_184_ME-1_1982
Otero, Jaime Thu_291_CR-6_1283
O'Toole, Malcolm Thu_156_BE-9_2169
Oudar, Thomas 661
Oude Egbrink, Dirk 1450
Oulkar, Sunil Thu_280_CR-6_610, Wed_109_CR-3_884
Ouyang, Lunxi Wed_354_TE-3_533
Ovadnevaite, Jurgita Fri_307_OS-7_2683
Overbeck, Jacquelyn 1289
Overeem, Irina 2506
Overland, James 799
Overland, James E 2328
Owczarek, Piotr 1
Owsianowski, Nils Thu_82_BE-5_455
Oyabu, Ikumi 516
Ozsoy, Burcu Fri_245_OS-5_2399, Thu_331_EN-4_2351, Thu_332_EN-4_2396,
Thu_400_SH-7_648, Tue_325_OC-1_2393, Tue_326_OC-1_2402, Tue_327_OC-1_2445,
Tue_328_OC-1_2498
Ozsoy-Cicek, Burcu 945

P
Přibyl, Pavel Fri_372_BE-5_1696
Přibylová, Petra Fri_12_EN-2_742, Fri_17_EN-2_1399, Fri_18_EN-2_1401
Paasonen, Pauli Fri_341_SY-1_359
Pacciaroni, Massimo Wed_255_OS-6_1463
Pace, Giandomenico Thu_5_AC-3_775, Tue_61_AC-1_1639, Wed_6_AC-2_666,
Wed_7_AC-2_680
Pacelli, Claudia 442, Tue_160_BE-4_443
Pacherres, Cesar 710
Pacoureau, Nathan Thu_113_BE-9_205
Padeiro, Ana Fri_26_EN-2_2022
Paden, John 2566, 28
Padinchati Krishnan, Kottekkatu Tue_110_BE-1_664
Padrtova, Barbora 2608
Paglia, Eric 2663
Paglione, Marco Fri_307_OS-7_2683
Paiella, Alessandro 2619
Paiva, Vitor H. Thu_142_BE-9_1615
Pakhomov, Evgeny 1047, 1165
Pakhomov, Evgeny A. Thu_124_BE-9_978
Palacios, David Thu_307_CR-6_2590
Paleari, Chiara Ileana 126
Palerme, Cyril Wed_8_AC-2_746
Pallentin, Arne Thu_138_BE-9_1414
Palm, Stephen P. 1954
Palmer, Terence 1444, Fri_27_EN-2_2043
Palmer, Terry Fri_23_EN-2_1834
Palmeri, Rosaria Fri_191_OC-3_1651
Pan, B. Jack Thu_90_BE-5_1484
2596
Pan, Jianming Thu_59_BE-2_756
Pan, Xiaoduo 1143
Panagi, Marios 2598
Pandey, Mayuri Fri_117_GG-1_193, Fri_128_GG-1_629
Pandit, Prashant H Fri_349_SY-1_1504
Paneerselvam, C Tue_62_AC-1_1679
Pang, Hongxi 1297
Pang, Xiaoping 725, Fri_243_OS-5_1925, Wed_356_TE-3_733
Panieri, Giuliana 1862
Pant, Naresh 641, Fri_128_GG-1_629
Pant, Naresh C. Fri_117_GG-1_193
Pant, Ramesh Raj Wed_106_CR-3_701
Papale, M Wed_96_CR-2_1525, Wed_97_CR-2_1527
Papale, Maria Tue_114_BE-1_1366, Tue_184_BE-4_1367
Papina, Tatjana Tue_176_BE-4_1121
Pappa, Folker 704, Fri_120_GG-1_327, Fri_149_GG-1_1830
Papritz, Lukas 135, 70, 718, 81, 86, 963, Thu_23_AC-8_489, Wed_17_AC-2_1058
Paramasivan, Elango Tue_62_AC-1_1679
Paranhos, R Wed_96_CR-2_1525, Wed_97_CR-2_1527
Paranhos, Rodolfo Fri_90_EN-7_1532
Pardal, Miguel 2132
Paredes, Pablo 1691, Thu_230_CR-4_1673
Park, Hotaek 1935
Park, Jisoo Thu_51_BE-2_226, Thu_81_BE-5_400
Park, Taewook Thu_81_BE-5_400
Park, Tae-Yoon 13, Fri_148_GG-1_1791, Thu_314_GG-1_2170, Wed_337_TE-3_14
Park, Tae-Yoon S. Thu_167_BE-9_2417
Park, Yong Cheol 197
Park, Yongcheol 13, 2424, Fri_113_GG-1_118, Wed_337_TE-3_14
Parker, Alex Thu_196_BE-12_2191
Parker, Rebecca Fri_56_EN-6_938, Tue_280_GG-2_1479
Parker, Steve 930
Parker, Steven J. Thu_131_BE-9_1204
Parker, Thomas C 1979
Parkes, David 543
Parlato, Nicholas Fri_186_OC-3_216
Parli, Bhaskar 604
Parmiggiani, Flavio 424, Thu_337_OS-3_428
Parnikoza, Ivan Tue_174_BE-4_950
Parno, Julie Fri_229_OS-5_265
Parno, Matthew 785
Parrenin, Frédéric 789, Wed_168_CR-8_1053, Wed_169_CR-8_1261, Wed_186_CR-
8_2479, Wed_187_CR-8_2490
Parrilli, Ermenegilda 1548
Parsons, Simon Fri_311_SH-8_1355, Fri_313_SH-8_1608, Fri_316_SH-8_1946,
Tue_58_AC-1_1493
Pascal, Graf Wed_12_AC-2_915
Pascu, Denisa 1132
Pashkevich, Albina 2663
Pasian, Marco Wed_147_CR-7_2144
Pasotti, Francesca Thu_144_BE-9_1757, Tue_159_BE-4_430
Pasquale, David Wed_259_OS-6_1627
Pasqualini, Angelica 1334
Passalacqua, Olivier 789
Passos, Heber Tue_71_AC-1_1913
Patel, Lavkush Thu_280_CR-6_610, Wed_109_CR-3_884
Patel, Lavkush Kumar Thu_281_CR-6_617
Patel, Tasnim Thu_144_BE-9_1757
Patil, Shramik 1317, Thu_115_BE-9_657
Patley, Manoj Fri_345_SY-1_1126
Paton, Douglas 1941
2597
Patra, Sivaji Thu_49_BE-2_55
Patterson, Molly O. 1950, 812, Tue_267_GG-2_1005
Patterson-Fraser, Donna Thu_143_BE-9_1724, Tue_190_BE-4_1559
Pattyn, Frank 1638
Pattyn, Nathalie 1747, 2684
Pätzold, Falk 1113, Wed_313_TE-1_472, Wed_324_TE-1_1115, Wed_329_TE-
1_1391
Pauchard, Aníbal 333
Paul, Frank Thu_298_CR-6_1795
Paul, Stephan 1468, 1573, 2051, 252, 968, Fri_289_OS-7_1748
Paul-Bhaskar, Jane Theophline 604
Pauling, Andrew G. 898, Fri_207_OS-4_900
Pauls, Scott Fri_224_OS-4_2573
Paulsen, Maria 2, Tue_186_BE-4_1419
Paun, Victoria I. 1132
Paun, Victoria Ioana Tue_112_BE-1_949
Pausch, Franziska 2340
Pautet, P.-Dominique 1964, Wed_39_AC-4_382
Pavlov, Alexey 1506, Tue_360_OS-8_1960
Pavlov, Alexey K. 1309, 1636
Pawlowski, Lukasz 1976
Paxman, Guy 745, Tue_257_GG-2_747, Tue_301_GG-2_2440
Payne, Antony 2468
Pearce, David 1148, 1855, Wed_55_AC-7_1380
Pearce, John 1108
Pearson, Emma 1572, 1577
Pearson, Gareth Tue_212_BE-4_2632
Pearson, Michael 20, Wed_288_SH-4_880
Peck, Lloyd 1128, 259, 286, Wed_365_TE-3_1131
Peck, Lloyd Samuel 56, Tue_153_BE-4_145
Peck, Victoria 1860, Thu_69_BE-2_1859
Pecknold, Sean 2516
Pedentchouk, Nikolai Wed_217_OS-2_1580
Peder, Roberts Thu_366_SH-3_295
Pedersen, Christina A. Thu_377_SH-6_962
Pedersen, Leif Fri_240_OS-5_1287
Pedersen, Leif T. Fri_237_OS-5_970, Thu_345_OS-3_939
Pedersen, Leif Toudal 1270, Fri_239_OS-5_1286
Pedrazzi, Dario Fri_137_GG-1_967
Pedrera, Antonio 2369
Pedro, Joel 103
Pedros-Alio, Carlos 2046
Pedrós-Alió, Carlos 2065
Peeken, I Wed_215_OS-2_1279
Peeken, Ilka 1309, 1699, 1777, 2060, 2099, 497, Thu_91_BE-5_1590, Thu_94_BE-
5_2078, Wed_209_OS-2_506
Peguero-Pina, José Tue_169_BE-4_712
Pehlke, Hendrik Thu_320_EN-4_1208
Peinke, Isabel Wed_139_CR-7_1228
Peixoto, Raquel S. 1631
Pelayo, Marta 2094
Pelland, Noel A. 1033
Peller, Peter 485
Pelletier, Ludovick 589
Pellicciotti, Francesca 1055, 1452, 1956, 2385, 920, 99, Wed_125_CR-3_2298
Pelon, Jacques Tue_68_AC-1_1789
Pelucchi, Paolo Thu_272_CR-6_143
Pelyasov, Alexander Thu_385_SH-6_1666
Pena-Molino, Beatriz 697
Peña-Rodríguez, Jesús Tue_17_AA-1_2221
Penduff, Thierry Wed_255_OS-6_1463
2598
Peng, Shilin Wed_310_TE-1_107
Pennycook, Jean Thu_181_BE-11_1180
Pereira, Antônio Fri_101_EN-7_2286
Pereira, Antonio Batista Tue_178_BE-4_1158, Tue_205_BE-4_2404
Pereira, Jorge M. Thu_142_BE-9_1615
Pereira, Jorge Miguel Tue_192_BE-4_1611
Pereira, Jose Edson Wed_254_OS-6_1445
Pereira, Maria Eduarda 2132
Pereira, Matias 511
Pereira, Nuno 1793
Perera, Rushi Thu_217_CR-4_899
Pérez, Gonzalo L. Fri_307_OS-7_2683
Pérez, Lara F. 1200, Tue_291_GG-2_1963
Pérez Díaz, Lucía Tue_255_GG-2_705
Pérez Mon, Carla 504
Perez-Mon, Carla Thu_189_BE-12_700
Pérez-Ortega, Sergio 2256, 90
Pergl, Jan 713
Perold, Vonica 91
Perondi, Cleiva Thu_277_CR-6_305
Perovich, Donald K. Fri_238_OS-5_1267
Perras, Alexandra Thu_198_BE-12_2267
Perren, Bianca 1029, 2614, Fri_59_EN-6_1428
Perrie, Will 2211, Fri_301_OS-7_2206
Perry, Aaron 2214
Perry, Frances 1165
Perryman, Wayne Thu_135_BE-9_1405
Persoiu, Aurel 1132, Tue_112_BE-1_949
Persson, Ola 1601, 1605, 214, 821
Pertierra, Luis 1321
Pertierra, Luis R. Thu_125_BE-9_1018
Pesjak, Lea Thu_254_CR-5_862
Petajä, Tuukka Thu_385_SH-6_1666
Petäjä, Tuukka 2499, 360, Fri_341_SY-1_359
Peter, Darcy L. Fri_72_EN-7_41
Peter, Hans-Ulrich 1054, Thu_150_BE-9_2004, Thu_328_EN-4_2009, Wed_323_TE-
1_1071, Wed_326_TE-1_1231
Peter, Thomas 1077
Peters, Leo Wed_145_CR-7_1921
Peterse, Francien 1740
Petersen, Mark 250
Petersen, Mark R. Thu_207_CR-4_547
Petersen, Nina 963
Peterson, Algot K Fri_99_EN-7_2082
Peterson, Algot Kristoffer Wed_256_OS-6_1508
Peterson, Andrew 2308
Peterson, K Andrew Fri_314_SH-8_1739
Petkov, Boyan 1771
Petkov, Boyan H. 1003, Wed_363_TE-3_1063
Petrenko, Larisa Wed_282_OS-6_2679
Petrenko, Vasilii 834, Wed_171_CR-8_1591
Petronio, Lorenzo Tue_275_GG-2_1300
Petroselli, Chiara 2110, Tue_63_AC-1_1703
Petrou, Katherina 2182, 2188
Petrov, Andrey 1908, 1911, 1952
Petrov, Dmitry Fri_71_EN-7_33
Petsch, Carina Thu_277_CR-6_305, Wed_376_TE-3_1836, Wed_386_TE-3_2384,
Wed_58_AC-7_1799
Pettersson, Lasse Thu_63_BE-2_922
Pettersson, Rickard 2257
Pettit, Erin 2540
2599
Petty, Alek 1850, 1857, 2668
Petty, Alek A. 531
Peuker, Alexander Wed_313_TE-1_472
Pézard, Laurent Wed_139_CR-7_1228
Pfaffhuber, Andreas 65
Pfahl, Stephan 476, Fri_263_OS-7_931, Wed_12_AC-2_915, Wed_5_AC-2_492
Pfeifer, Christian 1054, Wed_323_TE-1_1071, Wed_326_TE-1_1231, Wed_364_TE-
3_1069
Pfeiffer, Madlene Thu_232_CR-4_1698
Pfeil, Benjamin 1625
Phang, Siew Moi Fri_28_EN-2_2190
Philips, Richard A 2132
Philleo, Margaret Wed_269_OS-6_2181
Phillips, Richard A. Thu_142_BE-9_1615
Phillips, Tony 1549
Phillips, Vaughan 1473
Philpott, Carolyn 1438
Phipps, Steven 1958, Thu_254_CR-5_862
Phiri, Ethel Tue_136_BE-3_1442
Piacentino, Gabriela Tue_223_BE-10_2331
Piard, Luc 114, 298
Piazza, Paola 2107, Tue_323_OC-1_2117
Piazzolla, Daniele Fri_81_EN-7_1015
Picard, Ghislain 1318, 1370, 1513, 17, 316, Fri_246_OS-5_2501, Wed_140_CR-
7_1323, Wed_141_CR-7_1372, Wed_144_CR-7_1515, Wed_149_CR-7_2423, Wed_348_TE-3_317
Picard, Kim Thu_80_BE-5_191
Pichon, Gérard Thu_133_BE-9_1266
Pickart, Bob 963
Pickart, Robert 1473, 808
Pickering, Rebecca 416
Pieber, Simone 1381, Fri_21_EN-2_1609
Pienkowski, Anna 2633
Piepenburg, Dieter 287, 487, 524, 711, Tue_361_OS-8_2287, Wed_85_BE-7_1637
Piepjohn, Karsten Fri_162_GG-1_2478
Pierini, Stefano Wed_255_OS-6_1463
Piermattei, Viviana Fri_81_EN-7_1015, Wed_328_TE-1_1371, Wed_332_TE-1_1529
Piersanti, Mirko 1650, Wed_47_AC-4_1772
Pieterse, Jodi Tue_136_BE-3_1442
Pilar, Helen 2415
Pilosu, Luca Wed_44_AC-4_772
Pilote, Martin Thu_19_AC-8_171, Tue_233_CR-1_452
Pimentel, Edson Tue_311_OC-1_577
Pina Estany, Carles Fri_36_EN-5_665
Pinchuk, Alexei 1079
Pinkerton, Matt Thu_138_BE-9_1414, Tue_183_BE-4_1364
Pintado, Ana 1733
Pirazzini, Roberta 1495, Thu_385_SH-6_1666, Wed_141_CR-7_1372, Wed_143_CR-
7_1496
Pisani, Davide Thu_119_BE-9_727
Pisano, Eva 930, Fri_195_OC-3_2300, Thu_131_BE-9_1204, Tue_175_BE-4_999,
Tue_314_OC-1_1337
Pisarev, Sergey Wed_261_OS-6_1729
Pišoft, Petr Wed_19_AC-2_1348
Pitcher, Lincoln 2506
Pithan, Felix Thu_3_AC-3_508
Pittaluga, Jessica 1614
Pitts, Michael 1077, 2412, Tue_53_AC-1_1313
Place, Sean 390, Tue_219_BE-10_392
Plancherel, Yves 1375
Plante, Mathieu 1822
Pla-Rabes, Sergi Fri_57_EN-6_1032, Thu_307_CR-6_2590
2600
Platis, Andreas Wed_324_TE-1_1115
Platonov, Vladimir Wed_2_AC-2_292
Platt, Ulrich Fri_266_OS-7_993, Fri_274_OS-7_1269
Plattner, Gian-Kasper 2230
Plaza-Faverola, Andreia A. 1862
Pletnikoff, Karen 1289
Plötz, Joachim Thu_82_BE-5_455
Poblete, Matias Fri_12_EN-2_742
Podoliak, Aleksei 2317
Poe, Aaron 1289
Pogge von Strandmann, Philip 2391
Pogge von Strandmann, Phillip1606
Pogojeva, Maria Fri_107_EN-7_2544
Pöhler, Denis Fri_274_OS-7_1269
Pokrovsky, Oleg 2391
Polanowski, Andrea Thu_105_BE-8_2236, Thu_159_BE-9_2242
Polashenski, Chris 1770
Polashenski, Christopher M. Tue_68_AC-1_1789
Polcari, Marco 1786
Poli, Annarita Thu_126_BE-9_1020
Polito, Michael Thu_179_BE-11_1151
Pollard, David 2578, Tue_256_GG-2_743, Tue_302_GG-2_2480
Pollard, Wayne 215, Wed_91_CR-2_210
Polukhin, Alexander 2268
Polvani, Lorenzo 1046, Wed_56_AC-7_1482
Polyak, Leonid Tue_261_GG-2_783
Polyakov, Igor 2100
Polzin, Kurt 1292
Poniecka, Ewa A Tue_147_BE-3_2461
Ponti, Stefano 1524
Ponto, Kevin 2158
Poole, Lamont 1077
Popa, Elena 2021
Pope, Allen 1636, 1931, 2688, Thu_240_CR-4_2378
Pope, James 1521, 1549, 963, Fri_283_OS-7_1530
Popović, Danijela Thu_139_BE-9_1441
Popovnin, Victor 2061
Porcelli, Don 2255, 2391
Portella Sampaio, Daniela 722
Portis, Renata 2422
Porto, Bárbara Tue_131_BE-3_1141
Possenti, Philippe Fri_346_SY-1_1223
Possingham, Hugh 1896
Possner, Anna 1222
Post, Alix 140, 626
Post, Eric 2672
Postigo, Mariana Wed_87_BE-7_2085
Potenza, Marco A.C. Wed_160_CR-8_818
Potocki, Mariusz 103
Potoki, Mariusz Wed_138_CR-7_806
Poulain, Pierre Marie Wed_255_OS-6_1463, Wed_263_OS-6_1754
Poulain, Pierre-Marie Wed_241_OS-6_974
Poulin, Elie 1901, Tue_214_BE-4_2680, Tue_217_BE-4_2692, Tue_228_BE-
10_2695
Poulin, Michel 413
Poulsen, Michael Køie 2177, 2401
Poulton, Alex Thu_71_BE-2_2031
Poupart, Timothée Thu_106_BE-8_2366
Pouzenc, Cyprien 1272
Povashny, Vasily Tue_361_OS-8_2287
Powell, Brian 1489, Thu_86_BE-5_918
2601
Powell, Ross 1076
Power, Michael Wed_75_BE-6_1843, Wed_77_BE-6_1992
Powers, Heath Tue_84_AC-1_2650
Powers, Jordan 76
Pozdnyakov, Dmitry Thu_385_SH-6_1666, Thu_63_BE-2_922, Thu_64_BE-2_929
Pozo, Karla Fri_12_EN-2_742, Fri_17_EN-2_1399, Fri_18_EN-2_1401
Pozzebon Gerhard, Nicoli Fri_7_EN-2_372
Pozzoli, Luca 2276, 731
Prabhakaran, Ramya Bala Fri_29_EN-2_2337
Præbel, Kim 2612, 2613, Fri_8_EN-2_411
Prakash, Prince Wed_250_OS-6_1307
Prakash, Satya Wed_250_OS-6_1307
Pratap, Bhanu Thu_221_CR-4_1074, Thu_280_CR-6_610, Wed_109_CR-3_884
Prater, Clay Fri_102_EN-7_2336
Prater, Isabel 2361, Fri_103_EN-7_2352
Pratt, Kerri 1473, Tue_83_AC-1_2541, Wed_297_SH-5_1044
Praz, Christophe Wed_31_AC-2_2064
Prehn, Brandon Thu_180_BE-11_1152
Pressler, Yamina 2686
Preunkert, Susanne 1340, Wed_179_CR-8_1760
Preußer, Andreas 1468, Fri_251_OS-7_300
Previtali, Ezio Wed_166_CR-8_1030
Prevot, Andre 1381
Prévôt, André Fri_21_EN-2_1609
Priamikov, Sergey 1831
Price, Richard 1095
Price, Stephen 250
Price, Stephen F. Thu_207_CR-4_547
Prie, Frederic Fri_253_OS-7_356
Prié, Frédéric 444
Priestley, Rebecca 1244
Prieto-Espinoza, Maria-De-Lourdes 257, Fri_5_EN-2_253
Primpke, Sebastian 2099
Princivalle, Francesco Tue_266_GG-2_988, Tue_272_GG-2_1160
Prinz, Rainer Thu_241_CR-4_2410
Priscu, John 110, 307, Wed_69_BE-6_212
Priscu, John C. Fri_39_EN-5_879
Privitera, Eugenio Thu_246_CR-5_153
Proctor, Roger 1625
Proietti, Silvia Thu_140_BE-9_1550, Thu_141_BE-9_1552
Proksch, Martin 1522
Prokushkin, Anatoly 2391
Proshutinsky, Andrey 2676
Prothro, Lindsay Thu_139_BE-9_1441
Protopsalti, Ioanna Fri_190_OC-3_1523, Fri_191_OC-3_1651
Protsenko, Elizaveta 1665
Proud, Roland 123
Provost, Christine 1659
Prowse, Terry 1119
Pruvost, Patrice Tue_183_BE-4_1364
Prytherch, John Fri_264_OS-7_989, Fri_265_OS-7_991
Przyłucka, Aleksandra Tue_212_BE-4_2632
Przybylak, Rajmund 439, Fri_309_SH-8_450
Pshenichnov, Leonid Tue_174_BE-4_950
Puestow, Thomas 1720
Puigcorbe, Viena Wed_213_OS-2_861
Puigcorbé, Viena 591
Pulgar, Sebastian 1691
Pulsifer, Peter 1344, 2174, 2177, 2401, 484, Fri_356_SY-1_2507, Fri_44_EN-5_2321
Pulsifer, Peter L. 2333, Fri_45_EN-5_2357
Purcarea, Cristina 1132, Thu_157_BE-9_2222, Thu_193_BE-12_1011, Tue_112_BE-
2602
1_949
Purcell, Jennifer Tue_362_OS-8_2543
Putzke, Jair Thu_120_BE-9_800
Pyle, John Wed_154_CR-8_201
Pyle, Roger Tue_11_AA-1_1377
Pyne, Alex
Pyne, Rebecca 888, Wed_162_CR-8_868
Pyne, Rebecca E. 826
Pyšek, Petr 713

Q
Qi, Di 19, Thu_68_BE-2_1494
Qi, Yangjun Wed_122_CR-3_2093
Qiao, Gang Thu_218_CR-4_1021
Qu, Bo 2398
Qu, Meng Wed_356_TE-3_733
Quaas, Johannes Wed_3_AC-2_337
Quartini, Enrica 2403, Fri_124_GG-1_347, Fri_157_GG-1_2210
Quartino, Maria Liliana Wed_86_BE-7_1866
Quartino, María Liliana Tue_189_BE-4_1558
Queirós, José Pedro Tue_192_BE-4_1611, Tue_193_BE-4_1613
Querel, Richard Fri_266_OS-7_993
Quesada, Antonio 431, Fri_310_SH-8_1349, Tue_115_BE-1_1368, Wed_55_AC-7_1380
Questel, Jennifer M. 716, Tue_355_OS-8_795
Quin, Douglas 2591
Quiñonez, Fernando Tue_17_AA-1_2221
Quintens, Roel 2254
Qvistgaard, Keld 2494

R
R. Pertierra, Luis 1014
Rabe, Bemjamin Wed_261_OS-6_1729
Rabe, Benjamin 497, Wed_272_OS-6_2282, Wed_279_OS-6_2644
Rabert, Claudia Thu_141_BE-9_1552
Rachlewicz, Grzegorz 1976
Rack, Ursula 1417, Fri_320_SH-8_2625, Thu_368_SH-3_1416
Rack, Wolfgang , 526, Fri_320_SH-8_2625, Wed_231_OS-6_570
Rackow, Thomas 1769, Fri_214_OS-4_1872
Raclot, Thierry Thu_106_BE-8_2366
Racoviteanu, Adina Wed_121_CR-3_2073
Radicchi, Gerusa Wed_283_SH-4_25, Wed_284_SH-4_26
Radovan, Ana Tue_69_AC-1_1820
Raes, Eric 2260
Raes, Eric J. 1106, Tue_129_BE-3_1107
Raffi, Rossana Wed_95_CR-2_1520
Ragettli, Silvan 2385
Rahaman, Waliur 1317
Rahimian, Zahra Tue_288_GG-2_1894
Raimbaud, Patrick 2302
Raina, Jean-Baptiste 2188
Rainville, Luc 2199, 2235, 2238, Wed_334_TE-1_2203
Räisänen, Petri 995
Raj, Roshin P Wed_226_OS-6_152
Raja-Halli, Arttu Wed_151_CR-7_2464
Rajan, S 604
Ralph, F. Martin 2643, Thu_48_AC-8_2689
Ralph, Martin Wed_5_AC-2_492
Ramage, Joan M. 1602
Ramage, Justine Tue_316_OC-1_1574
Ramelli, Maximiliano 511
Ramesh, D.S 436
2603
Ramey, Charles Wed_269_OS-6_2181
Ramírez, Constanza Tue_169_BE-4_712, Tue_206_BE-4_2463
Ramirez Buchheister, Gustavo 651
Ramírez Ruíz, Giovanna Estefania Tue_17_AA-1_2221
Ramjan, Saroat 1271
Ramkumar, Geetha Tue_88_AC-5_797, Wed_10_AC-2_805
Ramos, Oscar Thu_121_BE-9_832
Ramos, Raül 39
Rampal, Pierre 2096
Ran, Youhua Tue_234_CR-1_600
Randall, Krystal Wed_83_BE-7_1301
Randelhoff, Achim Wed_261_OS-6_1729
Ranieri, Andrea 1008, Wed_331_TE-1_1511, Wed_332_TE-1_1529
Raphael, Marilyn 1404, 304, Thu_353_OS-3_1408
Rapisarda, Salvatore Fri_358_TE-2_155
Rappazzo, A.C. Wed_96_CR-2_1525, Wed_97_CR-2_1527
Rappazzo, Alessandro C. Tue_138_BE-3_1694
Rappazzo, Alessandro Ciro Tue_114_BE-1_1366, Tue_184_BE-4_1367
Rasch, Morten Thu_392_SH-6_2252
Rasch, Philip 2674, Tue_85_AC-1_2671
Rasmussen, Marianne 2547
Rasmussen, Mitchell 1543
Rasmussen, Till 1720, Fri_240_OS-5_1287
Rastetter, Edward 2141
Rastner, Philipp Thu_298_CR-6_1795, Thu_301_CR-6_2067
Ratcliffe, Norman 75, Thu_88_BE-5_1225
Ratnarajah, Lavenia 591, 594, Fri_88_EN-7_1498
Ratnarajah, Lavy Wed_213_OS-2_861
Rauer, Heike 1272
Raup, Bruce Wed_121_CR-3_2073
Raut, Jean-Christophe Tue_68_AC-1_1789
Rautenberg, Alexander 670, Wed_318_TE-1_815
Rautio, Arja Wed_297_SH-5_1044
Rautio, Milla Wed_77_BE-6_1992
Ravegnani, Fabrizio Wed_29_AC-2_1977
Ravelo, Alexandra 2100
Ravichandran, M Thu_244_CR-4_88, Thu_26_AC-8_878, Tue_62_AC-1_1679,
Wed_226_OS-6_152, Wed_250_OS-6_1307
Ravindra, Rasik 1797
Rawat, Rashmi Wed_50_AC-4_2561
Ray, Deborah Fri_56_EN-6_938
Ray, Jessica Louise 2264
Ray, Laura 730, Wed_322_TE-1_1066
Ray Sarkar, Sneha Fri_93_EN-7_1845
Raymond, Ben 1632, 267, 906, Thu_322_EN-4_1421
Raynaud, Dominique Wed_168_CR-8_1053, Wed_187_CR-8_2490
Raynolds, Martha 1882
Razdan, Alek 785
Reading, Anya 850, Thu_254_CR-5_862, Tue_269_GG-2_1086
Reading, Anya M 690
Reason, Chris Fri_302_OS-7_2394
Rebesco, Michele Fri_292_OS-7_1815, Tue_247_GG-2_200, Tue_272_GG-2_1160,
Tue_279_GG-2_1478, Wed_238_OS-6_955, Wed_241_OS-6_974
Rebolledo, Lorena Thu_321_EN-4_1328
Recio-Blitz, Cayetana Thu_291_CR-6_1283
Redaelli, Gianluca 755
Reddy, C.D 436
Redondas, Alberto Wed_14_AC-2_976
Rees, Annalise 1438
Rees, Gareth 198, 437
Rees, W. G. 985
2604
Reese, Ronja 1076, 1758
Reeve, Krissy Anne Wed_278_OS-6_2634
Regayre, Leighton 1041, Tue_56_AC-1_1467
Regi, Mauro 755
Reguero, Marcelo Fri_53_EN-6_786, Fri_54_EN-6_798
Rehm, Eric Fri_353_SY-1_1994
Rehman, Faizan Ur Wed_106_CR-3_701
Rehren, Thilo 402
Reichert, Konny 1298
Reichle, Leah 1882
Reid, Keith 2346
Reid, Phil Fri_196_OS-4_117
Reid, Philip 941
Reid, William 711
Reigstad, Marit 1114, 1778, Thu_76_BE-2_2582, Thu_91_BE-5_1590
Reijmer, Carleen Thu_231_CR-4_1680
Reiner, Steinfeldt Fri_255_OS-7_473
Reiners, Peter W. 2521
Reis, Pedro 2194, Tue_104_AC-5_2179
Reiser, Fabian 644, Thu_336_OS-3_410
Reiss, Christian 1165, Thu_155_BE-9_2157, Tue_158_BE-4_389
Reiss, Christian S. Thu_169_BE-9_2465
Relitti, Federica Fri_292_OS-7_1815
Relly, Tamsin 2330
Rembauville, Mathieu Thu_62_BE-2_914
Rémy, Frédérique Thu_266_CR-5_2311
Renaud, Paul 683, Thu_76_BE-2_2582
Renaud, Paul E. Thu_97_BE-5_2651
Rendoll Cárcamo, Javier A. Tue_181_BE-4_1234
Renfrew, Ian 2670, 557, 808, 963, 983, Fri_283_OS-7_1530, Wed_17_AC-2_1058
Renfrew, Ian A 1475
Renner, Angelika 1604, Thu_123_BE-9_964
Rennermalm, Asa 2506, Wed_134_CR-7_312
Renwick, James Wed_33_AC-2_2259
Resende Secchi, Eduardo Tue_152_BE-4_46
Retamales-Muñoz, Gabriel Tue_103_AC-5_2129
Rethemeyer, Janet 2014, 2361
Reuder, Joachim 670, 963, Wed_318_TE-1_815
Reusch, David Thu_43_AC-8_2172
Reuss-Schmidt, Kassandra Fri_352_SY-1_1890
Réveillet, Marion 1449, 1452
Revell, Laura Fri_340_SY-1_318, Tue_49_AC-1_272
Reverchon, Camille Wed_353_TE-3_507
Reverdin, Gilles Wed_243_OS-6_1007
Revill, Andy 1632
Rex, Markus , 329, 822
Reygondeau, Gabriel 1047
Rhee, Tae Siek Fri_284_OS-7_1542, Fri_299_OS-7_2192
Rhein, Monika Fri_255_OS-7_473, Fri_267_OS-7_1016
Rhodes, Rachael 1134, Wed_171_CR-8_1591
Ribeiro, Hugo Fri_26_EN-2_2022, Wed_212_OS-2_814
Ricci, Carlo Alberto Fri_191_OC-3_1651
Ricciardelli, Annarita 1548
Rich, Robert 375
Richard, Steve Fri_38_EN-5_853
Richmond, Kristof 514, Wed_319_TE-1_846
Richter, Claudio Thu_82_BE-5_455
Richter, Thomas 2269, Thu_335_OS-3_248
Richter, Tom G. 854, Fri_157_GG-1_2210
Rick, Brianna Tue_244_CR-1_2539
Rickard, Graham 1080
2605
Ricker, Robert 1573, 2051, 2055, Fri_201_OS-4_630, Fri_239_OS-5_1286
Rickli, Joerg Dominik 2056
Rickli, Jörg Fri_89_EN-7_1502
Rico, Eugenio Tue_115_BE-1_1368, Wed_55_AC-7_1380
Riddick, Thomas 1755
Rider, Melissa Thu_179_BE-11_1151
Ridley, Jeffrey K. Fri_208_OS-4_904
Ridout, Andrew 2641, Wed_249_OS-6_1291
Ridout, Andy 260, Wed_281_OS-6_2649
Ridsdale, Chantel 1173
Riedel, Arne Wed_296_SH-5_656
Riedel, Michael Tue_242_CR-1_1969
Riemann-Campe, Kathrin Thu_107_BE-8_2338
Riesgo, Ana Tue_207_BE-4_2493
Riesselman, Christina Fri_61_EN-6_1603, Thu_117_BE-9_688, Thu_347_OS-3_1109,
Tue_276_GG-2_1354, Tue_277_GG-2_1373, Tue_280_GG-2_1479, Tue_297_GG-2_2197,
Tue_298_GG-2_2261
Riggs, George Wed_379_TE-3_2052
Rignot, Eric 1678, 486
Rigor, Ignatius Fri_212_OS-4_1813, Fri_304_OS-7_2558
Riihelä, Aku Wed_349_TE-3_406
Riipinen, Ilona 1199
Riis, Tenna Fri_106_EN-7_2447
Riley, Teal 1934
Rinaldi, Matteo Fri_307_OS-7_2683
Ringgaard, Ida Margrethe 1646, Tue_283_GG-2_1640
Ringler, Todd 250
Ringler, Todd D. Thu_207_CR-4_547
Rinke, Annette 531, Tue_69_AC-1_1820, Wed_24_AC-2_1727, Wed_3_AC-2_337,
Wed_9_AC-2_782
Rintala, Janne-Markus Wed_216_OS-2_1531
Rintala, J-M. Wed_215_OS-2_1279
Rintoul, Stephen 2237, 2241
Rintoul, Steve 697
Rios Reyes, Carlos Alberto Tue_17_AA-1_2221
Ripley, Brad S. 713
Ripper, Elisabeth Wed_380_TE-3_2108
Rippeth, Tomas 2676
Riser, Stephen 2112, 2171, 2536
Rita, Rita Tue_76_AC-1_2119
Rita, Traversi 2110
Ritter, C. Tue_75_AC-1_2054
Ritter, Ch. Tue_81_AC-1_2374
Ritter, Christoph 2110, Tue_76_AC-1_2119
Rittger, Karl Wed_121_CR-3_2073
Ritz, Catherine 1370, 2468, 637, 789, Thu_238_CR-4_2213
Riva, Matthieu 2274
Rivaro, Paola Fri_85_EN-7_1385, Fri_86_EN-7_1389, Fri_87_EN-7_1460
Rivera, Andres 1691, Thu_229_CR-4_1649, Thu_230_CR-4_1673, Tue_301_GG-
2_2440
Rivera, Betsy Tue_169_BE-4_712
Rivera, Carla N 2187
Rivet, Jean-Pierre 1272
Rixen, Christian 353
Rixen, Michel 147, Fri_353_SY-1_1994
Rizman-Idid, Mohammed 1922, Tue_197_BE-4_1932
Rizzo, C Wed_96_CR-2_1525, Wed_97_CR-2_1527
Rizzo, Carmen Tue_114_BE-1_1366, Tue_184_BE-4_1367
Roach, Lettie 142, 77
Robert, Henri Thu_144_BE-9_1757, Tue_159_BE-4_430
Roberts, Andrew 2418, Fri_216_OS-4_2173
2606
Roberts, Jason 104, 1856, 789, Thu_254_CR-5_862, Thu_268_CR-5_2446
Roberts, Jason L. Thu_238_CR-4_2213
Roberts, Kaitlyn 2633
Roberts, R. James Fri_164_GG-1_2548
Roberts, Stephen 1029, 1572, 1577, 2614
Roberts, Steve Fri_59_EN-6_1428
Roberts, Tjarda Thu_4_AC-3_698
Roberts, William 2288, 490
Robertson, Thomas 2275
Robertson, Tommy Tue_236_CR-1_858
Robillard, Cassandra M. Fri_40_EN-5_1263
Robin, Marc Thu_182_TE-3_1780
Robinson, Allen Fri_21_EN-2_1609
Robinson, Carol Thu_66_BE-2_1319
Robinson, David M Tue_150_BE-3_2653
Robinson, Laura Tue_186_BE-4_1419
Robinson, Natalie 2285, 526, Fri_259_OS-7_567, Thu_161_BE-9_2281, Wed_316_TE-
1_569
Robinson, S.A. 2699
Robinson, Sharon 185, 189, Wed_83_BE-7_1301
Robinson, Sharon A Thu_112_BE-9_186
Robson, Ben 1452
Roca-Marti, Montserrat Wed_213_OS-2_861
Roca-Martí, Montserrat 591
Rocha, João 1793
Roche, Didier 444
Röckmann, Thomas 2021, Wed_221_OS-2_2027
Rodehacke, Christian 2546, Thu_232_CR-4_1698
Rodrigues, Camila Tue_128_BE-3_1138, Tue_132_BE-3_1145
Rodrigues Bezerra, Alerson Tue_70_AC-1_1895
Rodrigues da Silva, Eduardo 355
Rodriguez, Edith 1561
Rodriguez, Julio Wed_20_AC-2_1383, Wed_55_AC-7_1380
Rodríguez, Edith Tue_25_AC-1_241, Tue_66_AC-1_1752
Rodríguez, Julio Fri_310_SH-8_1349
Rodríguez, Ricardo 2256
Rodríguez-Ros, Pablo Fri_307_OS-7_2683
Rodríguez-Tovar, Francisco J. Tue_292_GG-2_1968
Roesler, Erika 1586, Thu_7_AC-3_1346, Wed_200_EN-1_2137
Roessler, Sebastian 2428
Rogan-Finnemore, Michelle
Rogozhina, Irina 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Rohardt, Gerd Wed_278_OS-6_2634
Rohde, Jessica Tue_315_OC-1_1571
Rohner, Christoph 1949, 2552, Thu_220_CR-4_1036, Thu_301_CR-6_2067
Rojo, Maxence Wed_27_AC-2_1936
Roldan, Gabriela 1277, 1848, 2571, Thu_372_SH-3_2545, Thu_403_SH-7_1983
Rolland-du-Roscoat, Sabine Wed_139_CR-7_1228
Roman, Matěj Thu_233_CR-4_1870
Roman, Matej Tue_249_GG-2_328
Roman, Miguel Wed_379_TE-3_2052
Roman, Samuele Thu_192_BE-12_927
Romano, Vincenzo 1650, 1676, 1693, Wed_44_AC-4_772
Romanovsky, Vladimir 2141, Wed_76_BE-6_1906
Romanovsky, Vladimir E. 2678
Romans, Brian W. 1950, 812, Tue_267_GG-2_1005
Romão, Marcelo Thu_45_AC-8_2487
Romeo, Roberto Tue_254_GG-2_669, Tue_285_GG-2_1669
Romero, Oscar E. 1950, 812, Tue_267_GG-2_1005
Romualdi, Chiara Tue_168_BE-4_675
Rondo, Linda Tue_37_AC-1_767
2607
Rongen, Martin 1216
Rønn, Regin 1514
Ronowicz, Marta 1534, Tue_211_BE-4_2621
Roop, Heidi 141, Tue_329_OC-1_2599
Ropert-Coudert, Yan 2346, Thu_106_BE-8_2366
Roquet, Fabien Wed_320_TE-1_923
Rosa, Carlos Tue_128_BE-3_1138, Tue_131_BE-3_1141, Tue_132_BE-3_1145
Rosa, Kátia Kellem da Thu_277_CR-6_305, Thu_278_CR-6_309, Wed_376_TE-3_1836
Rosa, Luiz Tue_128_BE-3_1138, Tue_131_BE-3_1141, Tue_132_BE-3_1145
Rosa, Rui 290
Rosado, Alexandre S. 1631
Rosales, Jon 1166
Rosati, Tony 1554
Roscales, José Luis Fri_12_EN-2_742
Rose, Clémence 2274
Rose, Nicholas M. Fri_93_EN-7_1845
Roseby, Zoe 1710
Rösel, Anja 1506, 1770, Fri_218_OS-4_2297, Fri_242_OS-5_1828
Rosenfeld, Daniel 1041
Rosenfeld, Sebastian Tue_217_BE-4_2692
Rosenheim, Brad 1056, 1710, Thu_211_CR-4_749
Rosenthal, Yair Thu_217_CR-4_899
Rosevear, Madelaine 526
Rosevear, Madelaine G. 576
Rosing, Minik T. Fri_93_EN-7_1845
Ross, Ed 1573
Ross, Neil 293, 745, Tue_257_GG-2_747, Tue_278_GG-2_1455, Tue_301_GG-
2_2440
Rossi, Sergio Tue_188_BE-4_1501, Wed_84_BE-7_1505
Rossmann, Leonard 1699, Fri_230_OS-5_343, Fri_277_OS-7_1320
Rosso, Isabella 2171
Rossouw, Marius W. Thu_168_BE-9_2441
Rost, Björn 1745
Rostosky, Philip Fri_234_OS-5_674
Rotermund, Lina M. Tue_357_OS-8_840
Roth, George 637
Rototaeva, Oksana Thu_296_CR-6_1647
Rott, Helmut 1741, Wed_380_TE-3_2108
Roudier, Pierre 1361, 2275, 510, Tue_236_CR-1_858, Wed_71_BE-6_612
Rougier, Jonathan 687
Roukaerts, Arnout Wed_204_OS-2_291
Roulle, Jacques Wed_139_CR-7_1228
Roura, Ricardo Thu_323_EN-4_1477, Wed_287_SH-4_824
Rousset, Clement Wed_244_OS-6_1012
Rowe, Penny Thu_46_AC-8_2581
Roy, Alexandre 17, Wed_338_TE-3_15
Roy, Louis-Philippe Thu_382_SH-6_1308
Roy, Sandip Kumar Fri_152_GG-1_1993, Thu_299_CR-6_2000, Tue_271_GG-2_1124
Roychowdhury, Rajarshi 2607
Royer, Alain 17, Wed_338_TE-3_15, Wed_339_TE-3_83
Royo-Llonch, Marta 2065
Rtiz, Catherine 1856
Ruan, Xiaozhou 2212
Ruano, Patricia 2369
Rubiano Esmeral, María Betsabé Tue_17_AA-1_2221
Rudaya, Elizabeth 1589
Rudaya, Natalia Tue_176_BE-4_1121
Rudeva, Irina Tue_95_AC-5_841
Ruediger, Stein 2063
Ruethi, Joel Thu_189_BE-12_700
Ruffolo, David Tue_11_AA-1_1377
2608
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Rühland, Kathleen Wed_75_BE-6_1843
Rühland, Kathleen M. 352
Ruhnke, Roland Tue_40_AC-1_971, Tue_55_AC-1_1461
Rui, Leonardo Tue_247_GG-2_200
Ruiz-Constán, Ana 2369
Ruiz-Fernández, Jesús Thu_233_CR-4_1870, Thu_307_CR-6_2590
Ruiz-Lara, Simon Tue_201_BE-4_2097
Rümmler, Marie-Charlott Wed_323_TE-1_1071
Ruo Redda, Andrea Fri_79_EN-7_754
Ruotsalainen, Hannu Thu_245_CR-5_115
Ruppel, Antonia 1315, 1715, Fri_119_GG-1_325, Fri_122_GG-1_340
Rush, Melanie 2158
Rusley, Calvin Tue_121_BE-3_573
Russell, Joellen 1404, 2171, 2536
Russo, Simone 731
Rutter, Nick 1938, Wed_377_TE-3_1897
Ruzicka, James J. Thu_124_BE-9_978
Ryan, Peter 91
Ryan, Svenja Thu_82_BE-5_455, Wed_257_OS-6_1512
Ryan-Colton, Ellen 185
Rybak, Elena 2061
Rybak, Oleg 2061
Ryczek, Maciej Tue_84_AC-1_2650
Rynders, Stefanie 1396, 2471
Rysgaard, Soren 2066
Rysgaard, Søren 2302, 551

S
S, Sathish Kumar Tue_60_AC-1_1635
Šabacká, Marie Fri_372_BE-5_1696
Šácha, Petr Wed_19_AC-2_1348
Słomska, Angelika Thu_171_BE-9_2615
Sałacinska, Anna Fri_158_GG-1_2219
Saarela, Jeffery M. 1259, Fri_188_OC-3_1260, Fri_40_EN-5_1263, Tue_182_BE-4_1265
Saarela, Jeffrey Fri_189_OC-3_1485
Sabacka, Marie 1684, Thu_387_SH-6_1852
Sabirov, Rushan 290, Wed_81_BE-7_529
Sabu, P Wed_251_OS-6_1335
Sachs, Torsten 2428
Sadatzki, Henrik 2264, Thu_362_OS-3_2555
Sadikni, Remon 2308, Fri_314_SH-8_1739
Sadiq, Mohd Fri_152_GG-1_1993
Sætra, Øyvind Fri_213_OS-4_1871
Sáez, Patricia L. Tue_169_BE-4_712, Tue_206_BE-4_2463
Sagen, Hanne 1495, 2586, Fri_353_SY-1_1994, Fri_354_SY-1_2080
Saggiomo, Maria Fri_85_EN-7_1385, Tue_170_BE-4_723
Saggiomo, Vincenzo Tue_170_BE-4_723
Sagnotti, Leonardo Tue_266_GG-2_988, Tue_272_GG-2_1160
Sah, Karuna 606
Sailley, Sevrine 1165
Saini, Jaspreet Singh Thu_192_BE-12_927
Saini, Shailendra Wed_50_AC-4_2561
Saints, Jon Thu_181_BE-11_1180
Saito, Akinori Wed_49_AC-4_2316
Saito, Takeshi 1235
Sáiz, Alejandro Tue_11_AA-1_1377
Saiz-Lopez, Alfonso 646
Sakakibara, Daiki Wed_117_CR-3_1280
Sala, M. Montserrat Fri_307_OS-7_2683
2609
Sala, Martino 1111
Salabarnada, Ari Tue_274_GG-2_1202
Salabarnada, Ariadna 1740, Tue_290_GG-2_1959, Tue_291_GG-2_1963, Tue_292_GG-
2_1968, Tue_294_GG-2_2035, Tue_296_GG-2_2044
Salamatin, Andrey Wed_161_CR-8_819, Wed_182_CR-8_1874
Salas, Leo 1179, Thu_181_BE-11_1180
Salas y Mélia, David 2496
Salazar, Guillem 633
Salazar, Juan Francisco 1277
Saldo, Roberto Thu_345_OS-3_939
Salerno, Giuseppe 156
Salerno, Melisa 54
Sales, Gabriele Tue_168_BE-4_675
Salihoğlu, Barış 1075
Salimbeni, Simone Thu_258_CR-5_1226, Thu_271_CR-6_100
Salinas, Vanesa Anabella Thu_109_BE-9_42
Salisbury, Dom Fri_264_OS-7_989, Fri_265_OS-7_991
Salivonchyk, Svetlana Fri_6_EN-2_323
Sallee, Jean Baptiste 1002, 1006
Sallée, Jean-Baptiste Wed_243_OS-6_1007, Wed_244_OS-6_1012, Wed_257_OS-6_1512
Salleh, Sazlina Tue_198_BE-4_1996
Salmon, Rhian 1244, 141, Tue_307_OC-1_294
Salvatore, Maria Cristina Fri_118_GG-1_230, Fri_250_OS-7_131
Salvatore, Mark Thu_148_BE-9_1832, Tue_199_BE-4_2008
Salvatore, Mike 1232
Salvi, Gianguido Fri_190_OC-3_1523, Fri_191_OC-3_1651
Salvini, Francesco Thu_255_CR-5_1000
Salzmann, Nadine 901
Salzmann, Ulrich 281
Samaké, Abdoulaye 2096
Samaran, Flore Tue_352_OS-1_2249
Sampaio, Marcelo Tue_43_AC-1_1052
Sams, Clarence 2254
Sams, Sarah 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Samuelsen, Annette 1075, Fri_213_OS-4_1871
Samui, Gautami Fri_77_EN-7_613
Samy, Sakthivel Tue_60_AC-1_1635, Tue_62_AC-1_1679
Sanabria, Mayerling Thu_121_BE-9_832
Sanchez, Ricardo Wed_14_AC-2_976, Wed_35_AC-2_2434
Sánchez, Pablo 2065
Sánchez, Ricardo 1561
Sanchez Goñi, Maria Fernanda Thu_348_OS-3_1247
Sanchez-Gomez, Emilia 435
Sánchez-Navas, Antonio Tue_290_GG-2_1959
Sanchez-Vidal, Anna Fri_109_EN-7_2635
Sancho, Leopoldo 1733
Sancho-Knapik, Domingo Tue_169_BE-4_712
Sandberg Sørensen, Louise 807
Sandells, Mel Wed_377_TE-3_1897
Sanders, Sylvia 89
Sandhu, Har Amrit Singh Thu_203_CR-4_50
Sandroni, Sonia Fri_191_OC-3_1651
Sands, Chester Thu_145_BE-9_1801, Tue_185_BE-4_1369, Tue_186_BE-4_1419
Sands, Chester J 2
Sandström, Cecilia A. M 1159
Sandven, Stein 1495, 2586, 968, Fri_235_OS-5_706, Fri_353_SY-1_1994,
Fri_354_SY-1_2080, Thu_345_OS-3_939, Thu_385_SH-6_1666
Sangiorgi, Francesca 1740, 1950, 812, Tue_267_GG-2_1005, Tue_87_AC-5_176
Sanguino, Laura 1886
Sanjurjo, Jorge Thu_307_CR-6_2590
Sankar, Ravi 1048
2610
Sankare, Housseyni Tue_82_AC-1_2527
Sansiviero, Manuela Fri_289_OS-7_1748
Santarelli, Lucia Wed_48_AC-4_1887
Santolaria-Otin, Maria Thu_22_AC-8_445
Santora, Jarrod 478
Santos, João Tue_117_BE-1_1948
Santos, João Pereira Fri_26_EN-2_2022
Santos, Margarida C. Tue_233_CR-1_452
Santos, Mercedes Thu_321_EN-4_1328
Santruckova, Hana Tue_148_BE-3_2513
Sanyal, Aritri Thu_188_BE-12_599
Sanz, Pablo Fri_310_SH-8_1349, Wed_20_AC-2_1383, Wed_55_AC-7_1380
Sapart, Celia 744
Sapart, Célia 2021, Wed_205_OS-2_358, Wed_206_OS-2_378
Sapart, Célia Julia Wed_221_OS-2_2027
Sapp, Amanda 796
Saravia, Leonardo A Wed_86_BE-7_1866
Saravia, Leonardo Ariel 1343
Sarkar, A. Thu_49_BE-2_55
Sarmiento, Jorge 1167, 2171, 2536
Sarti, Pierguido 1003
Sartor, Stefano Tue_12_AA-1_1564
Sasaki, Asako Fri_173_ME-2_1117, Fri_174_ME-2_1188, Fri_175_ME-2_1411
Sasaki, Reiji Fri_173_ME-2_1117, Fri_174_ME-2_1188, Fri_175_ME-2_1411
Sass, Henrik Tue_147_BE-3_2461
Sass, Louis Wed_115_CR-3_1189
Sastri, Akash Fri_73_EN-7_261
Satir, Tanzer Thu_331_EN-4_2351
Sato, Kaoru Wed_49_AC-4_2316
Sato, Toru Wed_49_AC-4_2316
Sattler, Birgit Thu_110_BE-9_158, Thu_198_BE-12_2267, Thu_202_BE-12_2698
Saucède, Thomas Thu_116_BE-9_658, Thu_145_BE-9_1801, Thu_146_BE-9_1807,
Thu_147_BE-9_1809, Thu_322_EN-4_1421, Tue_159_BE-4_430, Tue_167_BE-4_662,
Tue_217_BE-4_2692
Sauer, Simone 1862
Sauermilch, Isabel 1135, Thu_254_CR-5_862, Tue_269_GG-2_1086
Sauheitl, Leopold Wed_90_BE-7_1579
Saulnier-Talbot, Emilie 352, Wed_75_BE-6_1843
Saunders, Clinton 239
Saunders, Krystyna 1572, 2614
Saunders, Ryan Thu_70_BE-2_1975
Saunders, Ryan A 2132
Sauvé, Jade Wed_246_OS-6_1099
Savaglia, Valentina Tue_118_BE-1_1999
Savarino, Joel 2113
Savarino, Joël Wed_154_CR-8_201
Savitsky, Oleksandr Tue_174_BE-4_950
Savoca, S. Wed_96_CR-2_1525, Wed_97_CR-2_1527
Savoca, Serena Tue_114_BE-1_1366, Tue_184_BE-4_1367
Savvinova, Antonina 2368, Tue_379_SH-2_2652
Savy, Jean Phillippe Wed_261_OS-6_1729
Sayine-Crawford, Heather 485
Sayre-McCord, Thomas Thu_179_BE-11_1151
Scambos, Ted 1336, 1347, 2424, Fri_38_EN-5_853
Scambos, Theodore 1598
Scarchilli, Claudio 1661, 646, Fri_250_OS-7_131, Fri_290_OS-7_1766
Scarsi, Marco Fri_118_GG-1_230
Schaafsma, Fokje 497
Schaafsma, Fokje L. 906, Wed_220_OS-2_1787
Schacht, Jacob Tue_67_AC-1_1781
Schade, John D. Fri_72_EN-7_41
2611
Schaefer, Carlos Fri_101_EN-7_2286, Wed_340_TE-3_184
Schaefer, Carlos Ernesto Fri_104_EN-7_2355, Fri_31_EN-2_2343, Tue_243_CR-1_1995
Schaefer, Carlos Ernesto Gonçalves Reynaud Thu_120_BE-9_800
Schaefer, Carlos Ernesto Gonçalves Reynauld Tue_178_BE-4_1158,
Tue_205_BE-4_2404, Wed_387_TE-3_2431
Schaefer, Marius 1678, Thu_282_CR-6_774
Schaefer, Michael 1464
Schaefer, Thomas Fri_274_OS-7_1269
Schaepman-Strub, Gabriela 2400, Thu_31_AC-8_1316, Tue_195_BE-4_1688, Wed_302_SH-
5_1215
Schäfer-Neth, Christian Fri_343_SY-1_563
Schaffer, Janin 1183, Fri_267_OS-7_1016
Schaffer, Nicole 1449, 1452, 1987
Schall, Elena Tue_350_OS-1_1978
Schaltegger, Urs 1934
Scharien, Randall 1271
Scharien, Randy 134, 1706
Schartau, Ann Kristin 1326
Schartau, Anna Kristin 1854
Schättler, Birgit Wed_350_TE-3_420
Schauer, Ursula Wed_279_OS-6_2644
Schaufelberger, Gerd Wed_336_TE-1_2356
Scheepstra, Annette 331
Scheiblauer, Stefan 1741
Scheidegger, Philipp Wed_178_CR-8_1750
Scheinert, Mirko 2042, 637, Thu_263_CR-5_2024
Scheiter, Matthias Thu_282_CR-6_774
Schelling, Gustav 2254
Scherer, Reed 1076, Fri_110_EN-7_2657
Scherer, Reed P. 826
Scheschonk, Lydia 273
Scheuffele, Hanna Tue_225_BE-10_2416
Schevers, Amanda 2633
Schewe, Ingo 1495
Schiaparelli, Stefano 2107, Fri_191_OC-3_1651, Fri_195_OC-3_2300, Tue_323_OC-
1_2117
Schick, Kelly 136
Schimnowski, Adrian Tue_357_OS-8_840
Schimnowski, Oksana Fri_73_EN-7_261
Schindler, Johannes Wed_193_CR-8_1670
Schindler, Maria Fri_5_EN-2_253
Schlager, Ursula Thu_216_CR-4_894
Schleicher, Anja 258
Schlichtholz, Konrad Tue_102_AC-5_1712
Schlichtholz, Pawel Thu_20_AC-8_195, Tue_102_AC-5_1712
Schlindwein, Vera Tue_347_OS-1_1717
Schlögl, Sebastian 1210
Schloss, Irene 1343
Schlosser, Elisabeth 304
Schlosser, Peter 1334
Schmale, David 1473
Schmale, Julia , 1041, 425, Fri_37_EN-5_673, Tue_27_AC-1_244, Tue_56_AC-
1_1467, Tue_83_AC-1_2541, Wed_297_SH-5_1044
Schmid, Lino Wed_142_CR-7_1471, Wed_148_CR-7_2335
Schmid, Thomas 2094, 2103, Wed_99_CR-2_2033
Schmidely, Loïc 1423, Fri_58_EN-6_1224
Schmider, François-Xavier 1272, 1376
Schmidt, Britney Wed_224_OS-2_2193, Wed_269_OS-6_2181
Schmidt, Gavin Thu_283_CR-6_794
Schmidt, Henrik 116
Schmidt, Katrin 1165
2612
Schmidt, Kevin Fri_302_OS-7_2394
Schmidt-Aursch, Mechita 2424
Schmied, Julia 2563
Schmitt, Jochen 1423, 1763, 427, 518, Fri_58_EN-6_1224, Wed_174_CR-8_1641,
Wed_177_CR-8_1744, Wed_178_CR-8_1750, Wed_180_CR-8_1764, Wed_181_CR-8_1775
Schmitt, Stefan Fri_274_OS-7_1269
Schmitz, Daniela Fri_101_EN-7_2286, Thu_120_BE-9_800
Schmutz, Werner 1116
Schnaiter, Martin 1041, Tue_35_AC-1_719
Schneebeli, Martin 1522, Fri_232_OS-5_458, Thu_294_CR-6_1510, Wed_148_CR-
7_2335, Wed_149_CR-7_2423, Wed_150_CR-7_2459, Wed_161_CR-8_819
Schneider, Andrea 1862
Schneider, Christoph Fri_350_SY-1_1743
Schneider, David 1177, 465
Schneider, Johannes 1163, 246, 495, Tue_35_AC-1_719, Tue_45_AC-1_1139
Schneider, Susanne 352
Schnetger, Bernhard 1120, 1577
Schodlok, Michael 486
Schoeneich, Philippe 2678
Schofield, Oscar 1617, 1841, Tue_190_BE-4_1559
Scholtz, Andreas 1113
Schön, Isa Thu_144_BE-9_1757
Schossler, Venisse 2091, 2194
Schouten, Stefan Tue_287_GG-2_1734
Schranz, Franziska 1209
Schreyder, Anatoly 2379
Schröder, Ludwig 1761, 2042, Thu_263_CR-5_2024
Schröder, Michael Thu_82_BE-5_455
Schroeder, David 2053, 2641
Schroeder, Dustin 1347, 28, Thu_288_CR-6_1185
Schroeder, Dustin M. Fri_317_SH-8_2217
Schuback, Nina 1745
Schuddeboom, Alex Fri_311_SH-8_1355, Fri_313_SH-8_1608
Schuler, Thomas 1957
Schulz, Alexander 2274
Schulz, Christiane 495
Schulz, Eric 108
Schulz, Hannes 1163, 495
Schulz, Kai 2182
Schum, Simeon Tue_77_AC-1_2134
Schumacher, Maike 687
Schumacher, Stefanie Fri_35_EN-5_361
Schunemann, Adriano Luis Fri_31_EN-2_2343
Schuster, Max 2547
Schutt, David Fri_9_EN-2_522
Schwab, Melissa Sophia 2056, Fri_96_EN-7_2069
Schwaizer, Gabriele Wed_380_TE-3_2108
Schwaller, Mathew Thu_179_BE-11_1151, Thu_180_BE-11_1152
Schwaller, Mathew R. 1914, Thu_153_BE-9_2126
Schwanck, Franciele 213, Wed_123_CR-3_2148
Schwanck Carlos, Franciéle Fri_7_EN-2_372
Schwartz, Egbert Tue_142_BE-3_2165
Schwarz, Egbert 1298, Wed_350_TE-3_420
Schwarz, Joshua 1402
Schwegmann, Sandra Fri_210_OS-4_1800, Fri_211_OS-4_1805
Schweiger, Axel 2120, Fri_212_OS-4_1813
Schweingruber, Fritz H. Tue_195_BE-4_1688
Schwerdhelm, Sonja Thu_304_CR-6_2425
Schwikowski, Margit 1125, 1297, 237, 402, 425, 709, 771, Thu_230_CR-4_1673,
Tue_176_BE-4_1121, Wed_153_CR-8_183, Wed_179_CR-8_1760, Wed_193_CR-8_1670
Sciacca, Virginia Tue_347_OS-1_1717
2613
Sciare, Jean Wed_336_TE-1_2356
Sclosser, Elisabeth 104
Scoccimarro, Enrico 231
Scoccione, Andrea Tue_53_AC-1_1313
Scoto, Federico 646
Scott, Jeffery 1174
Screen, James 661, 668, Tue_94_AC-5_672
Scuderi, Luciano Fri_358_TE-2_155
Seag, Morgan 2526, Thu_392_SH-6_2252
Searson, Sarah 2524, Fri_278_OS-7_1325
Secchi, Eduardo Tue_166_BE-4_581
Seco, José 2132
Seco, José Luis 556
Sedwick, Peter 2503, 2524, Fri_282_OS-7_1418
Seefeldt, Mark Fri_216_OS-4_2173
Seehaus, Thorsten 667, Wed_62_AC-6_339, Wed_63_AC-6_350, Wed_65_AC-6_770
Sefton, Juliet Fri_83_EN-7_1246
Segabinazzi Dotto, Tiago Tue_166_BE-4_581
Segger, Benjamin Wed_9_AC-2_782
Segnana, Michela Wed_176_CR-8_1721
Segner, Helmut Tue_218_BE-10_67
Seidenglanz, Anne Tue_98_AC-5_2611
Seidensticker, Sven 257, Fri_5_EN-2_253
Seifert, Derya M. 524, Wed_80_BE-7_523
Seifert, Frank Martin Fri_343_SY-1_563
Sein, Dmitry 1769
Sejr, Mikael 2100, 551, 748, 943, Tue_351_OS-1_2032
Seki, Osamu 1950, 812, Tue_267_GG-2_1005, Tue_293_GG-2_2130
Selbmann, Laura 442, 462, 694, Tue_111_BE-1_695, Tue_160_BE-4_443
Selyuzhenok, Valeria Thu_341_OS-3_724, Thu_359_OS-3_2226
Semenov, Vladimir 907, Thu_28_AC-8_980, Wed_24_AC-2_1727
Semmler, Tido 1769, 2646, Thu_232_CR-4_1698
Senatore, Maria Ximena 2430, Thu_371_SH-3_2420
Senf, Martin 1054
Sennéchael, Nathalie 1659
Senra, Eduardo O Fri_104_EN-7_2355
Sensoy Sorman, Aynur Wed_141_CR-7_1372
Seo, Hyunkyo 1961
Seo, Tae-Kun Tue_116_BE-1_1633
Seo, Won-Sang 2426
Seppey, Christophe 431
Sepulveda, Armando 2325
Sepulveda, Edgardo Fri_296_OS-7_1902
Sepulveda Jauregui, Armando Thu_199_BE-12_2444
Sepúlveda-Jauregui, Armando Fri_100_EN-7_2138
Serafini, Michelina Thu_270_CR-6_82
Sergeant, Amandine 650
Sergeev, Denis 557, 963
Sergeeva, Vanda Fri_129_GG-1_653
Sericano, Jose 1444, Fri_23_EN-2_1834
Sericano, José Fri_27_EN-2_2043
Seroussi, Helene Thu_256_CR-5_1057
Serra, Elena Wed_375_TE-3_1675
Serrano, Enrique 2103
Serrao, Ester Tue_212_BE-4_2632
Seth, Barbara 427, 834, Wed_174_CR-8_1641, Wed_177_CR-8_1744,
Wed_180_CR-8_1764
Seu, Roberto 1786
Seunarine, Surujhdeo Tue_11_AA-1_1377
Severi, Mirko 1771, Fri_250_OS-7_131, Fri_290_OS-7_1766, Fri_63_EN-6_1645,
Tue_64_AC-1_1704, Wed_169_CR-8_1261
2614
Severinghaus, Jeff 1749
Severinghaus, Jeffrey 2442, 834, Thu_224_CR-4_1275, Wed_156_CR-8_554,
Wed_171_CR-8_1591, Wed_192_CR-8_2589
Severinghaus, Jeffrey P 826
Sewell, Mary A. Tue_185_BE-4_1369
Seyboth, Elisa Tue_152_BE-4_46
Seymour, Justin 2188
Sgubin, Giovanni Wed_255_OS-6_1463
Sha, Zhe 687
Shackleton, Sarah 1749, Wed_171_CR-8_1591, Wed_192_CR-8_2589
Shaffrey, Len 299, Thu_36_AC-8_1821, Wed_53_AC-7_301
Shaftel, Rebecca 1854, 352, Wed_75_BE-6_1843
Shah, Sahaj Fri_224_OS-4_2573
Shakhin, Dmitriy 2324
Shalina, Elena Fri_235_OS-5_706, Thu_344_OS-3_919
Shane, Neville Fri_38_EN-5_853
Shang, Zhaohui 1939, 503, 849, Tue_4_AA-1_679
Shangguan, Donghui 1143
Shanhun, Fiona Thu_117_BE-9_688, Thu_161_BE-9_2281
Shankar, Rajasekhariah 1797
Shankar, Ramachandran 953
Sharma, Milap Chand Thu_279_CR-6_603, Thu_284_CR-6_883
Sharma, Parmanand Thu_280_CR-6_610, Thu_281_CR-6_617, Wed_109_CR-3_884
Sharma, Varun 2451, 959
Sharman, Andy Thu_318_EN-4_592
Sharp, Lyndsey A. Fri_40_EN-5_1263
Sharp, Martin Thu_293_CR-6_1466, Thu_295_CR-6_1539
Shaver, Gaius 2141, 2686
Shaver, Gaius R. 645
Shaw, E. Ashley 1382, Thu_170_BE-9_2508
Shaw, Justine 1896, Tue_320_OC-1_1898, Wed_306_SH-5_1462
Shaw, Thomas 1055, 1956, Wed_125_CR-3_2298
Shea, Joseph Wed_353_TE-3_507
Shean, David E. 729
Sheeba Nettukandy, Chenoli Wed_30_AC-2_1998
Sheesley, Rebecca 433
Sheffield, Betsy 2401
Shen, Hui 289
Shen, Weisen Fri_134_GG-1_762
Shen, Zhongyan Fri_116_GG-1_162
Shepanek, Marc 1584
Shepherd, Andrew 1060, 1759, 260, Wed_385_TE-3_2382
Sheridan, Patrick 2499
Sherley, Richard 123
Shero, Michelle 2154, Thu_101_BE-8_1593, Thu_154_BE-9_2143
Sherrell, Robert 823
Shetti, Rohan Tue_161_BE-4_446
Shetye, Suhas Thu_115_BE-9_657
Shevenell, Amelia E. 1950, 812, Tue_267_GG-2_1005
Shevnina, Elena Wed_119_CR-3_2030, Wed_59_AC-7_2026
Shi, Guitao 891, Thu_204_CR-4_164, Wed_132_CR-7_94
Shi, Jiuxin Fri_254_OS-7_399, Wed_277_OS-6_2626
Shi, Li 2308, Fri_314_SH-8_1739
Shi, Wenbin 945
Shi, Xuefa 1973
Shibata, Akiho 538, Thu_399_SH-7_539
Shibata, Hilary 319
Shibistova, Olga Wed_90_BE-7_1579
Shie, Chung-Lin Fri_287_OS-7_1623
Shigeta, Tomo Fri_173_ME-2_1117, Fri_174_ME-2_1188, Fri_175_ME-2_1411
Shiklomanov, Nikolay 1067, 1486, Wed_298_SH-5_1045
2615
Shimeta, Jeff 2244
Shimoeda, Nobuhito Fri_184_ME-1_1982
Shin, Changsoo Tue_242_CR-1_1969
Shin, Edward Thu_81_BE-5_400
Shin, H.C. Wed_215_OS-2_1279
Shin, Hyoung Chul 1831, 2295, 2426, 2448, Thu_96_BE-5_2413
Shin, Jinhwa 1423
Shin, Kyung-Hoon Thu_348_OS-3_1247
Shipboard Party, All Thu_94_BE-5_2078
Shiraishi, Kazuyuki 2233
Shokr, Mohammed 2519, Wed_354_TE-3_533, Wed_356_TE-3_733, Wed_383_TE-
3_2314
Short, Katherine Thu_119_BE-9_727
Shrivastava, Prakash Kumar Thu_299_CR-6_2000, Tue_271_GG-2_1124
Shuckburgh, Emily 1537, Wed_258_OS-6_1555
Shuman, Christopher Thu_209_CR-4_632
Shupe, Mathew Thu_12_AC-3_2071
Shupe, Matthew 329, 821, 822
Si, Fuqi Thu_6_AC-3_1245
Sicre, Marie-Alexandrine Tue_274_GG-2_1202
Siddoway, Christine 1412, 607
Siddoway, Christine S Fri_348_SY-1_1410
Sidoroff, Manuela 1132, Fri_183_ME-1_1692
Sidoroff, Manuela E. Thu_157_BE-9_2222
Sieber, Matthias 1657, Fri_75_EN-7_313, Thu_60_BE-2_778
Siebert, Holger 493, Tue_28_AC-1_249
Siebert, Ursula 2547
Siegel, Victoria 514, Wed_319_TE-1_846
Siegel, Volker 1047, 1165
Sieger, Rainer Fri_35_EN-5_361, Thu_82_BE-5_455
Siegert, Martin 293, Fri_128_GG-1_629, Thu_260_CR-5_1784, Tue_301_GG-2_2440
Siegert, Martin J Thu_238_CR-4_2213
Siegert, Martin J. 789
Siegfried, Matthew 1347
Siegfried, Matthew R. Fri_317_SH-8_2217
Siegwart, Roland 1648
Sierra, María José 2094
Sierra, Roxana Wed_165_CR-8_1024
Siew, Peter Yu Feng Thu_34_AC-8_1811
Sigl, Michael 1125, 709, Tue_176_BE-4_1121, Wed_179_CR-8_1760
Sigray, Peter Tue_344_OS-1_1219
Sigurðsson, Oddur Thu_305_CR-6_2467
Sihler, Holger Fri_274_OS-7_1269
Sikand, Monika Tue_23_AC-1_71
Silaev, Andrey Wed_59_AC-7_2026
Silin, Anatoly Wed_286_SH-4_611
Silva-Busso, Adrian Wed_120_CR-3_2038
Silvano, Alessandro 697
Sime, Louise 209, 2614, 279, Wed_164_CR-8_979
Simeonov, Valentin Tue_36_AC-1_738
Simizu, Daisuke Wed_237_OS-6_944
Simkins, Lauren Thu_139_BE-9_1441
Simmonds, Ian Tue_95_AC-5_841
Simmons, Breana Wed_89_BE-7_2697
Simo, R 1846, Fri_294_OS-7_1849
Simó, Rafel Fri_307_OS-7_2683
Simoes, Jefferson 213, Wed_138_CR-7_806, Wed_369_TE-3_1356, Wed_370_TE-
3_1358
Simões, Jefferson 2091, 2194, Tue_104_AC-5_2179, Tue_131_BE-3_1141, Tue_92_AC-
5_256, Wed_340_TE-3_184, Wed_373_TE-3_1570, Thu_277_CR-6_305, Thu_278_CR-6_309,
Tue_100_AC-5_474, Wed_123_CR-3_2148, Wed_133_CR-7_168, Wed_357_TE-3_792,
2616
Wed_376_TE-3_1836, Wed_386_TE-3_2384, Wed_58_AC-7_1799
Simon, Andrii Tue_174_BE-4_950
Simon, Chantal 1891
Simon, Heike Thu_60_BE-2_778
Simonova, Natalia Fri_169_ME-2_467
Simons, Veronique Thu_326_EN-4_1588
Simonsen, Marius 826
Simonsen, Sebastian 807, Thu_267_CR-5_2349
Simpson, Kyle Fri_273_OS-7_1249
Simpson, William Tue_83_AC-1_2541, Wed_297_SH-5_1044
Sinclair, Victoria 360
Singh, Ajit Thu_280_CR-6_610, Thu_281_CR-6_617, Wed_109_CR-3_884
Singh, Anand K Wed_50_AC-4_2561
Singh, Archana Thu_57_BE-2_647, Tue_110_BE-1_664
Singh, Bijendra 436
Singh, Hanumant 2106, 785, Thu_179_BE-11_1151, Wed_315_TE-1_553
Singh, Karanjeet Fri_319_SH-8_2408
Singh, Neelu Fri_1_EN-2_48
Singh, Shiv M. 1950, 812, Tue_267_GG-2_1005
Singha, Suman Wed_346_TE-3_280
Singley, Joel Wed_73_BE-6_1582
Sinha, Rupesh Kumar Tue_106_BE-1_93
Sinnhuber, Björn-Martin Tue_40_AC-1_971
Sinyanya, Kolisa Thu_50_BE-2_57
Sioris, Chris Wed_382_TE-3_2224
Sipilä, Mikko 2274
Širović, Ana Tue_352_OS-1_2249
Siteva, Svetlana Fri_328_SH-9_605
Sivaramakrishnan, Rajan Fri_1_EN-2_48
Six, Katharina Thu_75_BE-2_2484
Sjöblom, Anna Wed_79_BE-6_2251
Sjolte, Jesper Fri_55_EN-6_917
Skaar, Katrine Sandnes 2264
Skagseth, Øystein Wed_226_OS-6_152
Skahjem-Eriksen, Robin 1720
Skakun, Aleksandra 1672, Wed_126_CR-3_2301, Wed_187_CR-8_2490
Skatulla, Sebastian 239
Skjelvan, Ingunn Fri_99_EN-7_2082
Skoglund, Anders 637
Skogseth, Ragnheid 2562, Fri_292_OS-7_1815
Skorup, Henriette 1720
Skourup, Henriette 1770, 2642, 968, Wed_346_TE-3_280
Skow, H 1846
Skytte, Mathias 1443
Slabon, Patricia Tue_286_GG-2_1730
Slagstad, Dag 683
Slawny, Kristina 1072, 1233
Sleighter, Rachel L. Fri_95_EN-7_2013
Sletten, Ronald 2506
Sletten, Ronald S. 2482
Slotten, Chelsi Fri_186_OC-3_216
Slowik, Jay Fri_21_EN-2_1609
Sluijs, Appy Tue_287_GG-2_1734
Small, David 1949, 1958, 2552
Smalley, Robert 1885
Smalley, Jr., Robert 2016
Smedsrud, Lars 148
Smedsrud, Lars Henrik Wed_233_OS-6_627
Smellie, John Tue_270_GG-2_1097
Smieszek, Malgorzata (Gosia) 1962, 2278
Smik, Lukas 1257, Thu_348_OS-3_1247, Thu_351_OS-3_1327, Thu_356_OS-
2617
3_2058, Wed_217_OS-2_1580
Smirnov, Alexander Fri_356_SY-1_2507, Tue_101_AC-5_534
Smith, Alison 1128, Wed_365_TE-3_1131
Smith, Andrew 834, Thu_229_CR-4_1649
Smith, Andrew M. 729
Smith, Andy 1060, Thu_230_CR-4_1673, Tue_301_GG-2_2440
Smith, Benjamin 1347, Thu_239_CR-4_2216
Smith, Craig 1489, 2540, 911, Fri_355_SY-1_2383, Thu_86_BE-5_918,
Thu_92_BE-5_1905, Tue_200_BE-4_2075
Smith, Craig R. 1187
Smith, Doug 661
Smith, Emma 1264, Thu_235_CR-4_2005
Smith, Emma C 736
Smith, Inga 1081
Smith, Inga J. 898, Fri_207_OS-4_900, Fri_208_OS-4_904
Smith, James 1710, Thu_211_CR-4_749
Smith, Jodie Fri_338_SY-1_190, Thu_80_BE-5_191
Smith, K.E. 2102
Smith, Laura K.O. Tue_330_OC-2_461
Smith, Laurence 2506, Wed_352_TE-3_498
Smith, Madison 142, 2524, 77, Fri_280_OS-7_1333
Smith, Nefertiti Thu_118_BE-9_707
Smith, Sharon S. 2678
Smith, Steven Tue_85_AC-1_2671
Smith, Walker O. Thu_78_BE-2_2639
Smith Lyttle, Belinda Fri_348_SY-1_1410
Smith-Johnsen, Christine 1873
Smith-Lyttle, Belinda 607
Smol, John Wed_75_BE-6_1843
Smol, John P. 352
Smola, Zofia 1114
Smolikova, Jana Tue_232_CR-1_284
Smoot, Caitlin Tue_363_OS-8_2616
Smykla, Jerzy Thu_130_BE-9_1155
Smyth, Tim Wed_258_OS-6_1555
Snels, Marcel Tue_53_AC-1_1313
Soares, Melena Wed_262_OS-6_1738
Sobolowski, Stefan 2068, Thu_34_AC-8_1811, Thu_40_AC-8_2012
Sobota, Ireneusz 1868, Fri_64_EN-6_1867, Thu_388_SH-6_1876
Sodemann, Harald 1004, 86, 963, Fri_263_OS-7_931, Wed_12_AC-2_915, Wed_5_AC-
2_492
Sohm, Jill Thu_166_BE-9_2380, Thu_196_BE-12_2191
Sohn, Byung-Ju Wed_367_TE-3_1314
Sohst, Bettina Fri_282_OS-7_1418
Søiland, Henrik Fri_353_SY-1_1994
Soja, Amber Tue_68_AC-1_1789
Sokol, Eric Thu_148_BE-9_1832
Sokol, Eric R. Tue_199_BE-4_2008
Sokoloff, Paul C. Fri_40_EN-5_1263, Tue_182_BE-4_1265
Sokolov, Aleksandr Wed_60_AC-7_2438
Solan, Martin 468
Solberg, Rune Wed_380_TE-3_2108
Solgaard, Anne Munck Wed_361_TE-3_948
Solomon, Amy 1473, 214, Wed_312_TE-1_376
Soltwedel, Thomas Fri_292_OS-7_1815, Fri_354_SY-1_2080
Sommer, Christian 667, Wed_136_CR-7_552, Wed_63_AC-6_350
Sommerfeld, Anja 329
Sommeria, Joel 1002, Wed_257_OS-6_1512
Son, Young-Sun Wed_344_TE-3_271
Song, Arnold 785
Song, Ho Jung Thu_52_BE-2_234
2618
Song, Lehui Fri_67_EN-6_2166
Song, Tengfei 1973
Sonke, Jeroen E. Fri_74_EN-7_277
Soon, Maureen Fri_75_EN-7_313
Soonthornthum, Boonrucksar Tue_10_AA-1_1322
Søreide, Janne 1093, 1534, Tue_211_BE-4_2621
Søreide, Janne E. 2562, Thu_76_BE-2_2582
Sørensen, Atle M. Thu_345_OS-3_939
Sørensen, Louise Thu_267_CR-5_2349
Sørli, Simon 1656
Sorman, Ali Arda Wed_141_CR-7_1372
Sosdian, Sindia 1257
Sosedova, Yulia Tue_37_AC-1_767
Sosnica, Krzysztof Thu_261_CR-5_1812
Sotille, Maria Eliza Wed_369_TE-3_1356, Wed_370_TE-3_1358
Sou, Tessa 2195
Souquieres, Claude-Eric Wed_197_EN-1_1686
Sousa, António Tue_117_BE-1_1948
Sousa, António Gaspar Gonçalves Fri_26_EN-2_2022, Wed_212_OS-2_814
Sousa, Leandra 1079
Sousa Lopes, José Norberto Tue_317_OC-1_1681
Souverijns, Niels 1009, 1661, 1951, 1954, Wed_22_AC-2_1654
Souza, Ronald Fri_225_OS-4_2665
Sow, Swan Li San 1106, Tue_129_BE-3_1107
Sowa, Anna 1534
Soyol-Erdene, Tseren-Ochir 1634, Wed_185_CR-8_2304
Spada, Nicholas 1473
Spagnolo, Matteo 729
Spall, Mike 718
Spampinato, Letizia 156
Spang, Reinhold 1077, 2412
Spanò, N. Wed_96_CR-2_1525, Wed_97_CR-2_1527
Sparks, Stephen Wed_169_CR-8_1261
Spears, Anthony Wed_269_OS-6_2181
Specchiulli, Antonietta Fri_86_EN-7_1389
Speer, Kevin 2536
Speller, Nicholas Wed_269_OS-6_2181
Spengler, Thomas 1001, 557, 585, 81, 963, Wed_25_AC-2_1804
Spensberger, Clemens Wed_17_AC-2_1058
Spergel, Julian 379
Spezie, Giancarlo Wed_265_OS-6_1947
Spiegel, Cornelia Fri_140_GG-1_1013
Spielvogel, Sandra Wed_90_BE-7_1579
Spiesecke, Stefanie Tue_350_OS-1_1978
Spigel, Robert Wed_69_BE-6_212
Spikings, Richard 1934
Spina, Laura Thu_246_CR-5_153
Spingys, Carl 1292
Spinolo, Julia 1668
Spogli, Luca 1650, 1676, 1693, 1786, Wed_47_AC-4_1772
Spokas, Kurt Tue_205_BE-4_2404
Spolaor, Andrea 646, Fri_351_SY-1_1881, Tue_65_AC-1_1731, Wed_164_CR-8_979,
Wed_176_CR-8_1721, Wed_183_CR-8_2007
Spreen, Gunnar 1206, 1770, 1853, 2519, Fri_234_OS-5_674, Fri_236_OS-5_835,
Fri_258_OS-7_544, Fri_99_EN-7_2082, Thu_74_BE-2_2483, Wed_363_TE-3_1063, Wed_383_TE-
3_2314
Sprintall, Janet 2212
Staal, Tobias 1958, 690, 850, 855, Thu_254_CR-5_862
Stabeno, Phyllis 1619, 799
Stachoň, Zdeněk Thu_287_CR-6_1161
Stafford, Kathleen 1311, Tue_352_OS-1_2249
2619
Stafford, Kathleen Mary Tue_346_OS-1_1621
Stainthorp, Rose Tue_167_BE-4_662
Stajich, Jason E. 694, Tue_111_BE-1_695
Stamatiou, Kostas Thu_181_BE-11_1180
Stammerjohn, Sharon 1181, 1343, 2021, 2503, 2524, 263, 264, 744, 823, Fri_256_OS-7_480,
Fri_278_OS-7_1325, Fri_280_OS-7_1333, Fri_282_OS-7_1418, Thu_181_BE-11_1180,
Wed_205_OS-2_358, Wed_206_OS-2_378
Stamnes, Knut Tue_23_AC-1_71
Staněk, Martin Wed_15_AC-2_992
Staniland, Iain Tue_192_BE-4_1611
Stanish, Lee Thu_148_BE-9_1832
Stanitski, Diane Thu_37_AC-8_1829
Stansell, Nathan 1076
Stastny, Thomas 1648
Statscewich, Hank Thu_143_BE-9_1724, Thu_92_BE-5_1905, Tue_190_BE-4_1559,
Wed_264_OS-6_1788
Staub, Benno 1880
Stebel, Kerstin Tue_25_AC-1_241, Tue_26_AC-1_242
Stech, Michael Thu_114_BE-9_374
Stedmon, Colin Fri_98_EN-7_2081
Steel, Gary 119, 381, Fri_333_SH-9_1945
Steel, Michael 148
Steele, Michael 2120
Steen, Harald Thu_74_BE-2_2483
Steen-Larsen, H. C. Wed_104_CR-3_681
Steen-Larsen, Hans Christian 1560, 2415, Wed_68_AC-6_1725
Steer, Adam 2083
Stefels, Jacqueline 2090, Thu_374_SH-6_105, Wed_210_OS-2_708, Wed_211_OS-
2_811
Steffel, B.V. 2102
Steffen, Konrad 2230, Thu_294_CR-6_1510, Wed_142_CR-7_1471, Wed_148_CR-
7_2335
Steger, Christian 696
Steig, Eric 1341, 2288, 490
Steig, Eric J. 826
Steiger, Nadine 1002, Wed_257_OS-6_1512
Steiger, Nathan Fri_55_EN-6_917
Stein, Ruediger 1685, Thu_362_OS-3_2555
Steinberg, Deborah 1165, 1841, Tue_190_BE-4_1559
Steinberger, Bernhard Fri_120_GG-1_327
Steiner, Jakob Thu_241_CR-4_2410
Steiner, Jakob F. 2385
Steiner, Ladina Wed_137_CR-7_728
Steiner, Nadja 2195, 384
Steinhage, Daniel 1264, Thu_82_BE-5_455
Stelling, Jonathan 365
Stelmach Pessi, Igor 1567
Stenberg de Serves, Malin 1668
Stengel, Benjamin 1381, Fri_21_EN-2_1609
Stenni, Barbara 104, 1285, 1513, 444, Fri_250_OS-7_131, Fri_55_EN-6_917,
Wed_164_CR-8_979, Wed_183_CR-8_2007
Stenseng, Lars 807
Stepanenko, Victor Fri_281_OS-7_1378
Stephen, Ralph Fri_134_GG-1_762
Sterlin, Jean Fri_268_OS-7_1023
Sterling, Jeremy T. 1033
Sterzai, Paolo Thu_255_CR-5_1000, Tue_279_GG-2_1478
Stevens, Craig , 2285, 2424, Fri_259_OS-7_567, Thu_117_BE-9_688, Wed_316_TE-
1_569
Stevens, Darren Tue_193_BE-4_1613
Stevens, David P. Fri_208_OS-4_904
2620
Stevens, Laura Thu_240_CR-4_2378
Stevenson, Emily 1606, Fri_106_EN-7_2447
Stevenson, Kevin 1376
Stewart, Andrew 2125
Stewart, Craig 2285
Stewart, Emma 119
Stewart, Jamieson Tue_255_GG-2_705
Steyn, Christien 713
Stibal, Marek Tue_148_BE-3_2513
Stierli, Beat 504
Still, Holly Thu_222_CR-4_1078
Stilz, Peter 2547
Stirnimann, Luca Thu_50_BE-2_57
Stival, Leandro Tue_57_AC-1_1492
St-Laurent, Pierre 823
Stocchi, Paolo 1877
Stocker, Thomas 1423, Fri_58_EN-6_1224
Stockton, Amanda Wed_269_OS-6_2181
Stohl, Andreas 477, Tue_31_AC-1_405
Stokes, Chris Thu_295_CR-6_1539, Tue_278_GG-2_1455
Stokke, Øyvind 2606
Stoll, Nicolas 252
Stone, Kane Wed_13_AC-2_928
Stone, Robert Thu_37_AC-8_1829
Stone, William 514, Wed_319_TE-1_846, Wed_69_BE-6_212
Stordal, Frode 1873
Stowasser, Gabriele 2132, 2133, Thu_66_BE-2_1319
Strand, Øivind Tue_351_OS-1_2032
Strandell Erstorp, Elias Tue_344_OS-1_1219
Strass, Volker Wed_278_OS-6_2634
Stratmann, Frank 1041, 2598, 425, 433, Tue_27_AC-1_244, Tue_44_AC-1_1122,
Tue_56_AC-1_1467
Strauss, Clive 2160
Strawhacker, Colleen 2174, 2177, 483, 484, Fri_44_EN-5_2321, Fri_45_EN-5_2357
Street, Lorna E 1979
Streletskiy, Dmitriy 1486
Streletskiy, Dmitry 1067, 2678, Wed_298_SH-5_1045
Strewe, Claudia 2254
Strobel, Anneli Tue_218_BE-10_67
Stroeve, Julienne 1706, 173, 260, 735, 781, Tue_356_OS-8_810
Stroeven, Arjen 1397, 1668, Tue_284_GG-2_1643, Wed_375_TE-3_1675
Strohmeier, Michael 1687
Strom, J 1846
Strong, Kimberly 1217
Strößenreuther, Undine Thu_263_CR-5_2024
Strozzi, Tazio Tue_240_CR-1_1840
Strugnell, Jan 2346, Thu_122_BE-9_839
Strutton, Peter 1497, Fri_88_EN-7_1498
Strzalka, Kazimierz Thu_132_BE-9_1255
Strzelecki, Mateusz 1976, Wed_199_EN-1_1971
Strzelecki, Matt C. Wed_202_EN-1_2345
Stuart, Fin Tue_284_GG-2_1643
Stuart, Graham 1390
Stuart, Stephen Wed_33_AC-2_2259
Stübner, Eike I Thu_76_BE-2_2582
Stulic, Lukrecia 1468
Sturm, Matthew Wed_377_TE-3_1897
Stutz, Jamey 881, Tue_265_GG-2_909, Tue_312_OC-1_925
Stutzmann, Eleonore 650
Suaria, Giuseppe 91
Subke, Jens-Arne 1979
2621
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Subramaniam, Ajit 2559
Subramaniam, Roshni 1239, Tue_183_BE-4_1364
Subt, Cristina 1056, Thu_211_CR-4_749
Sudarshanakumar, Kishor 1173
Suedfeld, Peter 1892
Suen, Conrad C. 2016
Suganuma, Yusuke Thu_206_CR-4_394, Tue_293_GG-2_2130
Sugden, David 1430, Tue_301_GG-2_2440
Sugisaki, Saiko Tue_293_GG-2_2130
Sugisaki, Saiko T. 1950, 812, Tue_267_GG-2_1005
Sugiyama, Shin Wed_117_CR-3_1280
Suitor, Mike 485
Sullivan, Arnold 869
Sultan, Emmanuelle Fri_334_SH-9_2405, Fri_336_SH-9_2439, Thu_373_SH-3_2556,
Wed_291_SH-4_2454
Sültenfuss, Jürgen Fri_255_OS-7_473
Sültenfuß, Jürgen Fri_267_OS-7_1016
Sulyandziga, Rodion 2177
Sumner, Michael 1240, 1352, 2047, Thu_134_BE-9_1357, Thu_164_BE-9_2363
Sun, Bo Fri_155_GG-1_2149, Fri_156_GG-1_2153
Sun, Heng Thu_68_BE-2_1494
Sun, Lantao 1046, 661
Sun, Tianrui 503
Sun, Weiping Thu_59_BE-2_756
Sun, Xiaoyu Fri_197_OS-4_345
Sun, Youhong 128, Fri_360_TE-2_219, Wed_310_TE-1_107
Sunagawa, Shinichi 633
Sundaram, Suchithra 614
Sundet, Jan Thu_325_EN-4_1566
Sundfjord, Arild 1112, 1604, 2676, Wed_256_OS-6_1508
Suntzeff, Nicholas B. 503
Suomi, Irene 1980, 670
Surdu, Cristina M. Fri_270_OS-7_1105
Surkont, Jaroslaw Wed_212_OS-2_814
Surmatz, Astrid Fri_335_SH-9_2433
Suschevskaya, Nadezda Fri_138_GG-1_969
Suter, Luis 1067, Wed_298_SH-5_1045
Sutherland, David Wed_270_OS-6_2186
Sutherland, Graigory Fri_213_OS-4_1871
Sutter, Johannes 1638
Suzuki, Kazuyoshi Thu_259_CR-5_1616
Suzuki, Kenta Tue_293_GG-2_2130
Suzuki, Toshitaka 1235
Svarc, Marcela Fri_310_SH-8_1349, Wed_20_AC-2_1383, Wed_55_AC-7_1380
Svenning, Mette 431
Swadling, Kerrie Thu_164_BE-9_2363, Tue_183_BE-4_1364
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Swanger, Kate Wed_98_CR-2_2018
Swanson, Heidi Wed_75_BE-6_1843
Swart, Sebastiaan , 1446, 1617, 2212, Fri_302_OS-7_2394, Wed_273_OS-6_2411
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Sweetman, Andrew 1187, Tue_200_BE-4_2075
Swiard, Zuzanna 1976
Swoboda, Steffen 1093
Sykora-Bodie, Seth Tue_371_SH-1_2131
Sysoev, Mikhail Fri_369_TE-2_1953
Szczuciński, Witold Thu_210_CR-4_702
Szitpanov, Milos Tue_23_AC-1_71
Sztein, Ester Thu_381_SH-6_1238
Szymanowski, Mariusz 1
2622
Szymanski, Wojciech 1

T
T. Vallelonga, Paul 1634
Tabisola, Heather 1619
Tacoma, Marten 2333, Fri_312_SH-8_1538
Tacoma, Marten A 1547, Fri_41_EN-5_1545
Takacs-Vesbach, Cristina 307, Tue_142_BE-3_2165
Takacs-Vesbach, Cristina D. Fri_39_EN-5_879
Takahashi, Akinori 75
Talalay, Pavel 128, 891, Fri_359_TE-2_161, Fri_360_TE-2_219, Fri_362_TE-2_432,
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Fri_369_TE-2_1953, Wed_310_TE-1_107
Talarico, Franco Maria Fri_191_OC-3_1651
Talley, Lynne 2112, 2171, 2524, 2536, Fri_298_OS-7_2183
Talley, Lynne D.
Talling, Peter 1710
Tamistt, Veronica 1290
Tamsitt, Veronica 2171, Fri_298_OS-7_2183
Tamura, Takeshi 637, 697, Wed_237_OS-6_944
Tan, Elcin Thu_14_AC-3_2584
Tanabe, Yukiko Fri_84_EN-7_1293, Tue_126_BE-3_1092, Wed_70_BE-6_558,
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Tananaev, Nikita 1719, 2325, Wed_90_BE-7_1579
Tandon, Neil F. 500
Tang, Guanjie Thu_218_CR-4_1021
Tang, Jiakui Thu_339_OS-3_479
Tang, Linggang Fri_67_EN-6_2166
Tang, Yuangui 530
Tang, Zheng 973
Tankersley, Matthew 1412
Tanner, Neal Wed_319_TE-1_846
Tao, Charling 503
Tarasenko, Anastasia Wed_280_OS-6_2648
Tarkhov, Matvey Tue_191_BE-4_1581
Tarling, Geraint 1165, 2132, Thu_66_BE-2_1319, Thu_70_BE-2_1975
Tarling, Geraint A. 2133
Tarroux, Arnaud Thu_180_BE-11_1152
Taskjelle, Torbjørn 1309
Tavagnacco, Daniele Tue_12_AA-1_1564
Tavano, Virginia Maria Tue_166_BE-4_581
Tavares, Flavia Alves Wed_133_CR-7_168
Taylor, Ellen 2214
Taylor, Lee 1847
Taylor, Michael Wed_39_AC-4_382, Wed_40_AC-4_385
Taylor, Michael J. 1964
Taylor, Patrick 809, Tue_47_AC-1_1169, Tue_48_AC-1_1182
Taylor-Offord, Sam 828
Taylor-Silva, Briar Fri_61_EN-6_1603, Tue_297_GG-2_2197
TBC, Others 22
Team, ACE-SPACE Tue_27_AC-1_244
Team, N-Ice Fri_285_OS-7_1563
Tedesco, Letizia 231, Wed_203_OS-2_233
Tedesco, Marco 2506, 379, Thu_283_CR-6_794, Wed_131_CR-3_2658,
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Teferle, Felix Norman 2016
Tegen, Ina Tue_67_AC-1_1781
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Teisserenc, Roman 1719, 2325
Teixeira, Camilla Fri_24_EN-2_1930
2623
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Tejsner, Pelle Wed_297_SH-5_1044
Tekman, Mine Fri_3_EN-2_174
Teleti, Praveen 985
Telipska, Marta Tue_174_BE-4_950
Temp, Anna G. M. Fri_165_ME-2_30, Fri_166_ME-2_31
Ten Hoopen, Petra 1625
Terauds, Aleks 1382, 1896, 2168, 827
Termine, Marco Fri_33_EN-2_2509
Terpstra, Annick 1001, 1004, 2643, 963, Thu_48_AC-8_2689, Wed_17_AC-2_1058,
Wed_25_AC-2_1804
Terrado, Marta 2011
Terray, Laurent 435
Terzo, Olivier 1693, Wed_44_AC-4_772
Teschke, Katharina Thu_320_EN-4_1208
Tesi, Tommaso Fri_109_EN-7_2635, Fri_81_EN-7_1015, Fri_97_EN-7_2076,
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Teske, Peter Tue_163_BE-4_457
Tessin, Allyson 1120, Thu_94_BE-5_2078, Tue_360_OS-8_1960
Testa, Ward Thu_98_BE-8_38
Teste, Gregory Wed_182_CR-8_1874
Teste, Grégory 1423
Testor, Pierre 2001
Tetzner, Dieter Wed_188_CR-8_2517, Wed_189_CR-8_2538
Thalasso, Frederic 2325, Fri_100_EN-7_2138, Thu_199_BE-12_2444
Thaler, Mary 413
Tham, Yee Jun 2274
Thamban, Meloth Fri_77_EN-7_613, Fri_95_EN-7_2013, Thu_188_BE-12_599,
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Thatje, S. 2102
Thayer, Abigail 1560
Thayyil, Jayachandran Wed_45_AC-4_779
Thébault, Julien Tue_351_OS-1_2032
Theile, Thiemo Wed_161_CR-8_819
Thoen, Isaías Ullmann Tue_100_AC-5_474, Wed_133_CR-7_168
Thölix, Laura Wed_35_AC-2_2434
Thomas, Elizabeth , 103, 104
Thomas, Giles 288
Thomas, Helmuth Fri_73_EN-7_261
Thomas, Jennie Fri_286_OS-7_1585
Thomas, Jennie L. Tue_68_AC-1_1789
Thomas, Jenny Fri_36_EN-5_665, Fri_37_EN-5_673
Thomas, Liz Wed_152_CR-8_92, Wed_188_CR-8_2517
Thomas, Matthew 1375
Thomas, Rachel K 1172
Thomazini, Andre Fri_104_EN-7_2355
Thomazini, André Tue_178_BE-4_1158, Tue_205_BE-4_2404
Thomisch, Karolin Tue_350_OS-1_1978
Thompson, Andrew 1857, 2208, 2212
Thompson, David 1707
Thompson, David W.J. 1858
Thompson, Lonnie Wed_165_CR-8_1024
Thompson, Richard 2659
Thompson, Jr, Donald Thu_101_BE-8_1593
Thoms, Silke 1386
Thomson, Jim 2199, 77, Wed_334_TE-1_2203
Thomson, Laura 2677
Thomson, Stuart N. 2521
Thoré, Jean-Yves Fri_346_SY-1_1223
Thornton, Alexander 1848, 2136
Thornton, Alexander E. Thu_393_SH-6_2318
2624
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Thornton, Brett F Fri_265_OS-7_991
Thorpe, Sally 710, Thu_123_BE-9_964
Thorsteinsson, Thorsteinn Fri_355_SY-1_2383, Thu_305_CR-6_2467
Thunell, Robert 1481
Thurnherr, Iris 1041, Fri_263_OS-7_931, Tue_56_AC-1_1467, Wed_12_AC-2_915,
Wed_5_AC-2_492
Tian, Liuxi Thu_339_OS-3_479
Tian, Yixiang Thu_218_CR-4_1021
Tian, Zhongxiang Fri_197_OS-4_345
Tian-Kunze, Xiangshan 2051
Tiedamann, Ralf Thu_235_CR-4_2005
Tiedemann, Ralf 736, 973
Tiemann, Louisa 1254, Fri_277_OS-7_1320
Tietsche, Steffen 2308, Fri_314_SH-8_1739
Tignat Perrier, Romie 1886
Tikhomirov, Alexey 2028
Tilav, Serap 2123, Tue_11_AA-1_1377
Tilling, Rachel 260, 2641
Timmermann, Ralph 1468, Fri_214_OS-4_1872
Timmermans, Mary-Louise 1174
Tinner, Willy 1125, Tue_176_BE-4_1121
Tinti, Stefano Thu_258_CR-5_1226
Tinto, Kirsteen 1412
Tinto, Kirsty 379
Tippenhauer, Sandra 1183, 1568, 1687
Tipper, Ed Fri_106_EN-7_2447
Tiribilli, Chiara Fri_70_EN-6_2486
Tishkov, Arkadiy Tue_180_BE-4_1207
Tison, J.-L. Wed_215_OS-2_1279
Tison, Jean-Louis 1181, 2021, 2503, 2524, 414, 744, Wed_204_OS-2_291,
Wed_205_OS-2_358, Wed_206_OS-2_378, Wed_208_OS-2_464, Wed_214_OS-2_1278,
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Titovsky, Alexey Wed_60_AC-7_2438
Tiwari, A.K. Fri_48_EN-6_34
Tiwari, Manish 87
Tiwari, V.M 436
Tjernström, Michael 1495, 502, Fri_264_OS-7_989, Fri_265_OS-7_991, Thu_2_AC-3_505
Tkacheva, Daria Fri_138_GG-1_969
Tobler, Leonhard 402
Todgham, Anne 2601
Toffoli, Alessandro 1298, 239, Fri_275_OS-7_1296, Wed_227_OS-6_247
Toledano, C. Tue_75_AC-1_2054
Tollefsen, Dag Fri_353_SY-1_1994, Tue_349_OS-1_1940
Tolotti, Raffaella Tue_285_GG-2_1669
Tolotti, Raffella Tue_254_GG-2_669
Tomaselli, Matilde 2049, 485
Tomasi, Claudio 1003
Tomasino, Maria Paola Tue_117_BE-1_1948, Wed_212_OS-2_814
Tomikawa, Yoshihiro 1964, Wed_28_AC-2_1974, Wed_49_AC-4_2316
Tominaga, Masako Wed_330_TE-1_1480
Tomini, Isabella Tue_279_GG-2_1478
Tonboe, Rasmus 1270, Fri_240_OS-5_1287, Fri_244_OS-5_2072
Tonboe, Rasmus T. Thu_345_OS-3_939
Tong, Xiaohua 1191, 1196, Thu_218_CR-4_1021, Wed_116_CR-3_1192
Tonnard, Manon 1103, 1281, 594
Tonolla, Mauro Thu_192_BE-12_927
Toose, Peter Wed_377_TE-3_1897
Tooze, Sian Thu_254_CR-5_862, Tue_289_GG-2_1937
Topp-Jørgensen, Elmer Thu_392_SH-6_2252
2625
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Torma Bernardo, Ronaldo Fri_7_EN-2_372
Tornos, Jérémy 39
Toro, Manuel Fri_57_EN-6_1032, Thu_307_CR-6_2590
Torres-Carbonell, Pablo 2369
Tortell, Philippe D. 1745
Toudal Pedersen, Leif Fri_244_OS-5_2072
Toullec, Jean-Yves Tue_204_BE-4_2348
Tournadre, Jean Wed_280_OS-6_2648
Touzeau, Alexandra 1513, Fri_253_OS-7_356
Townsend, Dougal Tue_270_GG-2_1097
Toyoda, Takahiro 2308, Fri_314_SH-8_1739
Trachsel, Jürg Wed_150_CR-7_2459
Tradowsky, Jordis Fri_340_SY-1_318
Tranter, Martyn 440, Tue_147_BE-3_2461
Trathan, Phil 1798, 711
Travaglia, Guido Fri_191_OC-3_1651
Travassos, Jandyr Wed_138_CR-7_806
Traversi, Rita 1771, 433, Fri_19_EN-2_1422, Fri_250_OS-7_131, Fri_290_OS-
7_1766, Fri_63_EN-6_1645, Tue_63_AC-1_1703, Tue_64_AC-1_1704
Treasure, Anne M. Thu_124_BE-9_978, Wed_311_TE-1_934, Wed_320_TE-1_923
Trebilco, Rowan 1239, 1240, 1352, 1632, 2346, 267, Thu_134_BE-9_1357,
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Treblico, Rowan 906
Tredinnick, Ross 2158
Trefault, Nicole Thu_201_BE-12_2553, Thu_77_BE-2_2592, Tue_140_BE-3_2003
Tremblay, Bruno 1822, Fri_215_OS-4_1916
Tremblay, Jean-Eric Fri_108_EN-7_2583
Tremblay, Jean-Éric 2060, Thu_94_BE-5_2078
Treverrow, Adam Thu_268_CR-5_2446
Triana Gomez, Arantxa Wed_363_TE-3_1063
Trimborn, Scarlett 1386, 2340, Thu_60_BE-2_778
Trinh, Rebecca 1237
Tripathi, Binu Thu_200_BE-12_2492
Tripathi, Sachchida Tue_29_AC-1_348
Tripathy, S. C Wed_262_OS-6_1738
Tripathy, Sarat Chandra Thu_49_BE-2_55
Tritscher, Ines 1077, 2412
Trnková, Katerina Thu_187_BE-12_471
Troedsson, Christofer 2264
Tromp, Jeroen 1274
Tronstad, Stein 2333, 637, Fri_356_SY-1_2507
Trotter, Simon
Truax, Olivia Thu_117_BE-9_688, Tue_280_GG-2_1479
Truffer, Martin 2239, 2540, Thu_92_BE-5_1905
Trujillo, Ernesto 2106, 2510
Trull, Thomas W. 1106, Tue_129_BE-3_1107
Trull, Thomas William 601
Trull, Tom 108, 1103, 2265
Trummel, Betty Tue_307_OC-1_294
Trusel, Luke 1931, 379, Thu_240_CR-4_2378
Tsamados, Michel 1706, 260, 2641, Fri_247_OS-5_2622, Wed_249_OS-6_1291,
Wed_281_OS-6_2649, Wed_389_TE-3_2656
Tschanz, Brigitte 1209
Tseng, Gabriel 2664, Thu_253_CR-5_837
Tsukernik, Maria 2643, Tue_336_OC-4_1768
Tsumura, Kohji Tue_2_AA-1_398
Tsushima, Akane 537
Tsutsumi, Masaki 1964, 2228, Wed_28_AC-2_1974, Wed_49_AC-4_2316
Tuckwell, Rebecca Wed_154_CR-8_201
Tulaczyk, Slawek 1076, 1186, 2152, Thu_264_CR-5_2142, Tue_252_GG-2_370
2626
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1_2247, Tue_56_AC-1_1467
Tung, Ka-Kit 703
Tunved, P 1846
Turchetti, Simone Thu_369_SH-3_1660
Turchun, Sasha Fri_106_EN-7_2447
Turetta, Clara 646
Turiel, Antonio Fri_241_OS-5_1806
Turnbull, Johanna 185, Thu_112_BE-9_186
Turner, Adrian 250
Turner, Adrian K. Thu_207_CR-4_547
Turner, Darren Wed_315_TE-1_553
Turner, Dave Wed_312_TE-1_376
Turner, John 1472, 286, Thu_149_BE-9_1875
Turnherr, Iris 2643, Thu_48_AC-8_2689
Tusa, Iris 1132, Fri_183_ME-1_1692, Thu_157_BE-9_2222
Tutino, Maria Luisa 1548
Tuzet, François Wed_139_CR-7_1228
Tuzson, Bela Wed_181_CR-8_1775
Tuzson, Béla Wed_178_CR-8_1750
Tyler, Paul 259
Tyrell, Nicholas 2328
Tytgat, Bjorn 431
Tyulyubaeva, Tamara Fri_169_ME-2_467

U
Ubide, Teresa Fri_153_GG-1_2023
Uchida, Masaki Tue_177_BE-4_1146
Uddin, Syed A. 503
Udisti, R 1846
Udisti, R. Tue_81_AC-1_2374
Udisti, Roberto 2499, Fri_250_OS-7_131, Fri_63_EN-6_1645, Tue_76_AC-1_2119
Uemura, Ryu Wed_172_CR-8_1610
Uenzelmann-Neben, Gabriele 1135, 281, Tue_245_GG-2_124, Tue_259_GG-2_765
Uglietti, Chiara 1297
Ukita, Jinro 2303
Ulayottil Venugopal, Abhijith 826, 888
Ulianov, Alexey 1934
Ultee, Lizz 1483
Uotila, Petteri 2308, 2328, Fri_314_SH-8_1739, Thu_385_SH-6_1666
Upstill-Goddard, Robert Thu_69_BE-2_1859
Urbancic, Gabin 1980, 670
Urbini, Stefano Thu_258_CR-5_1226, Thu_270_CR-6_82, Thu_271_CR-6_100
Uribe, Jose Andres 1691, Thu_230_CR-4_1673
Urrutia, Roberto 1034
Ursella, Laura Fri_292_OS-7_1815, Tue_247_GG-2_200, Tue_279_GG-2_1478,
Wed_238_OS-6_955, Wed_241_OS-6_974
Ushio, Shuki Wed_237_OS-6_944
Uszczyk, Aleksander Thu_309_CR-6_2687
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Uxa, Tomas Tue_232_CR-1_284

V
V. R, Renjith 1190
Väänänen, Riikka 360
Vaccari, Lisa Fri_32_EN-2_434
Vacchi, Marino 930, Fri_195_OC-3_2300, Thu_131_BE-9_1204, Tue_175_BE-4_999,
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Váczi, Peter Fri_372_BE-5_1696, Thu_187_BE-12_471, Thu_191_BE-12_873,
Tue_235_CR-1_715
Vader, Anna 2562
2627
Vaganova, Natalya Fri_123_GG-1_341
Vage, Kjetil 963
Våge, Kjetil 718, 808
Vagle, Svein Fri_273_OS-7_1249
Vairo, Carlos 63
Valbousquet, Franck 1272
Valdes, Paul 2288, 279
Valente, Pedro Tue_104_AC-5_2179
Valera, Francisco 2046
Valero, Luis Tue_294_GG-2_2035, Tue_296_GG-2_2044
Vallat, Raphael 1544
Vallejos, Valentina Tue_169_BE-4_712
Vallelonga, Paul 104, 646
Vallelonga, Paul T. 826
Valletta, Rachel Wed_98_CR-2_2018
Van As, Dirk 1129, 2506
Van Breedam, Jonas Tue_303_GG-2_2505
Van de Berg, Willem Jan 1865, 1987, 696
Van de Flierdt, Tina 1826, 1889, 1950, 812, Tue_267_GG-2_1005, Tue_294_GG-2_2035
Van de Kamp, Jodie 1106, Tue_129_BE-3_1107
Van de Poll, Willem Hendrik 1427, 1682
Van de Putte, Anton P. 1514, 1625, 1746, 637, 906, Fri_356_SY-1_2507, Fri_44_EN-5_2321,
Fri_46_EN-5_2435, Thu_144_BE-9_1757, Thu_152_BE-9_2114, Thu_322_EN-4_1421,
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Van de Wal, Roderik 1450
Van de Wiel, Bas J. H. 9
Van den Broeke, Michiel R. 104, 1707, 1987, 637, 696, Thu_231_CR-4_1680
Van der Goot, Gerrit 1424
Van der Linden, Fanny 414, Wed_205_OS-2_358, Wed_206_OS-2_378
Van der Meer, Frank 2049
Van der Merwe, Pier 1103, 1281, 594
Van der Putten, Nathalie 1029
Van der Veen, Carina 2021, Wed_221_OS-2_2027
Van der Wal, Wouter 1118, 1390, 1450, 1885, 704, Fri_120_GG-1_327
Van der Watt, Lize-Marié Thu_366_SH-3_295, Wed_285_SH-4_296
Van der Wiel, Karin Wed_235_OS-6_737
Van Dingenen, Rita 731
Van Dongen, Eef 1648, Thu_286_CR-6_932
Van Franeker, Jan A. 906, Wed_220_OS-2_1787
Van Franeker, Jan Andries 497
Van Ginneken, Matthias Tue_260_GG-2_769
Van Goethem, Marc 2488
Van Haastrecht, Laurine Nathalie 315
Van Horn, David 2189, 2257, Tue_142_BE-3_2165
Van Kleunen, Mark 713
Van Leeuwe, Maria A. 2090, Wed_210_OS-2_708, Wed_211_OS-2_811, Wed_215_OS-
2_1279
Van Liefferinge, Brice 1638
Van Lipzig, Nicole 1009, 1951
Van Lipzig, Nicole P.M. 1661, 1954, Wed_22_AC-2_1654
Van Malderen, Roeland Wed_16_AC-2_1017
Van Meijgaard, Erik 1865
Van Mourik, Louise 95
Van Ommen, Tas Thu_238_CR-4_2213
Van Opzeeland, Ilse 2604, Tue_350_OS-1_1978, Tue_352_OS-1_2249, Tue_353_OS-
1_2600
Van Peer, Tim E. 1950, 812, Tue_267_GG-2_1005
Van Pinxteren, Manuela 425, Tue_44_AC-1_1122
Van Puyvelde, Martine 1747, 2684
Van Ulft, Bert 1865
Van Vuuren, Bettine Tue_163_BE-4_457
2628
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Van Wijk, Esmee 2237, 697
Van Wyk de Vries, Maximillian 1229
Vance, Derek 1657, 2056, Fri_75_EN-7_313
Vancleave, Samantha 2214
Vancoppenolle, Martin 801, 844, Fri_205_OS-4_734, Fri_206_OS-4_804, Tue_356_OS-
8_810
Vandepitte, Leen Thu_322_EN-4_1421
Vandergoes, Marcus J. 843
Vanderlinden, Fanny 744
Vanhaecke, Frank Fri_19_EN-2_1422
Vanhoorne, Bart Thu_322_EN-4_1421
Vannuccini, Maria Luisa Fri_14_EN-2_984
Vanreusel, Ann Thu_144_BE-9_1757
Vaqué, Dolors Fri_307_OS-7_2683
Varela, Diana E. 1912
Varentsov, Mikhail Thu_28_AC-8_980, Wed_2_AC-2_292, Wed_32_AC-2_2163,
Wed_37_AC-2_2636
Vargel, Céline 17
Varin, Cristiano Tue_65_AC-1_1731, Wed_164_CR-8_979
Varliero, Gilda 440, 470
Varma, Vidya Tue_49_AC-1_272
Varpe, Øystein 1665, 1835
Vasallo, Francisco Fri_310_SH-8_1349, Tue_115_BE-1_1368, Wed_20_AC-2_1383,
Wed_55_AC-7_1380
Vasel, Brian Wed_52_AC-4_2696
Vasilenko, Evgeny Wed_345_TE-3_276
Vasilev, Nikolai 2317
Vasques Freitas, Ana Carolina Thu_45_AC-8_2487
Vaughan, David 1060, 1336
Vaughan, David G. 729
Vaughan, Matthew 828
Vaughn, Bruce 1560
Vecchi, Gabriel 1554
Vedenin, Andrey 2100
Veettil, Bijeesh Tue_92_AC-5_256
Veettil, Bijeesh Kozhikkodan Thu_278_CR-6_309
Vega, Greta 1321
Vega, Greta C. 37, Thu_125_BE-9_1018
Vega, Katherine I. Fri_317_SH-8_2217
Veijo, Aaltonen Tue_25_AC-1_241, Tue_66_AC-1_1752
Veit-Köhler, Gritta 524
Velasco-Merino, C. Tue_75_AC-1_2054
Velazquez, David 431, Tue_115_BE-1_1368, Wed_55_AC-7_1380
Velev, Stefan Fri_130_GG-1_689, Fri_131_GG-1_692
Velho, Luiz Felipe Wed_376_TE-3_1836, Wed_386_TE-3_2384
Venables, Hugh 1424, Wed_321_TE-1_997
Verbruggen, Maarten Wed_16_AC-2_1017
Verde, Cinzia 1175
Verdugo, Josefa Wed_329_TE-1_1391
Verdy, Ariane 2171
Veres, Arina 1672, Wed_126_CR-3_2301
Verezemskaya, Polina Fri_281_OS-7_1378
Verhagen, Erik Wed_384_TE-3_2326
Verheye, Hans Thu_50_BE-2_57
Verheye, Marie Thu_144_BE-9_1757
Verin, Gauthier Fri_246_OS-5_2501
Verleyen, Elie 1567, 1572, 1577, 431
Verma, Abhishek Tue_271_GG-2_1124
Vermeesen, Randy 1664
Vernet, Maria 1187, 2540, 866, Thu_90_BE-5_1484, Thu_92_BE-5_1905,
2629
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Veron, Dana 298, Tue_36_AC-1_738
Vesman, A.V. Fri_293_OS-7_1823
Vesman, Anna 2324, Wed_266_OS-6_1972
Vestergaard, Niels Thu_325_EN-4_1566
Viau, André Tue_238_CR-1_1562
Viboud, Samuel 1002, Wed_257_OS-6_1512
Vichi, M. Wed_215_OS-2_1279
Vichi, Marcello 231, 239, Fri_275_OS-7_1296, Thu_335_OS-3_248, Wed_227_OS-
6_247
Vickers, Chelsea 2140
Vicomte, Marie Wed_27_AC-2_1936
Videla, Yohann 2178
Vieira, Goncalo 2678, 2681
Vieira, Gonçalo Thu_307_CR-6_2590, Tue_233_CR-1_452
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Viglione, Giuliana 2212
Vignati, Elisabetta 731
Vignes, Lucie Wed_257_OS-6_1512
Vignols, Rebecca 198
Vignon, Etienne 114, 9
Vihma, Timo 2328, 670, Thu_385_SH-6_1666, Thu_39_AC-8_2002, Thu_4_AC-
3_698, Wed_59_AC-7_2026
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Vijay, Saurabh 953, Wed_361_TE-3_948, Wed_372_TE-3_1469
Vikhamar Schuler, Thomas Fri_351_SY-1_1881
Vikram, Surendra 2488
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Viljoen, Johannes Jacobus 676
Villa-Alfageme, María 2079
Villacieros, Nico Wed_261_OS-6_1729
Villegas-Amtmann, Stella 2187
Vincent, Christian Wed_353_TE-3_507
Vincent, Warwick F. 2681, 546, Tue_233_CR-1_452, Wed_70_BE-6_558
Vingerhagen, Ruth Thu_392_SH-6_2252
Vinogradova, Anna Tue_24_AC-1_72
Vinsova, Petra Tue_148_BE-3_2513
Vinther, Jakob Thu_314_GG-1_2170
Viola, Angelo 2110, 2274, Fri_109_EN-7_2635, Fri_292_OS-7_1815
Viola, Angelo Pietro Fri_357_SY-1_2623, Wed_331_TE-1_1511, Wed_332_TE-1_1529
Viola, Salvatore Tue_347_OS-1_1717
Vione, Davide 1803
Vionnet, Vincent 17
Virginia, Ross 1186, 2152
Virkkula, Aki 1561, 2499
Virtanen, Heikki Wed_151_CR-7_2464
Virtue, Patti Thu_173_BE-11_582, Thu_84_BE-5_882, Wed_82_BE-7_580
Vishnu Vardhan, K Thu_49_BE-2_55
Visinand, Camille Thu_356_OS-3_2058
Visnovic, Gianpaolo Tue_279_GG-2_1478
Vitale, Vitale 2110
Vitale, Vito 2274, 2499, Fri_357_SY-1_2623, Thu_380_SH-6_1214
Vittuari, Luca Thu_255_CR-5_1000, Thu_270_CR-6_82
Vivas, Mercedes 1733
Vizcaino Rubio, Pablo 1450
Vladimirova, Diana 1672, 2415, Wed_126_CR-3_2301
2630
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Vlug, Anouk Thu_272_CR-6_143
Vockenhbuer, Christof Tue_300_GG-2_2339
Vogel, Alexander 425
Vogel, Timothy 2283
Vogel, Timothy M. 1540, 1886
Vogl, Teresa Tue_32_AC-1_561
Vogt, Meike 678
Vögtli, Marius 2552
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Voss, Paul Thu_4_AC-3_698
Voss, Peter Fri_354_SY-1_2080
Vossbeck, Michael Fri_239_OS-5_1286
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Vouoterakos, Panagiotis Wed_336_TE-1_2356
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Wacker, Lukas 1656
Wada, Tomotake Tue_177_BE-4_1146
Waddington, Edwin D. 826
Wade, Terry 1444, Fri_23_EN-2_1834, Fri_27_EN-2_2043
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Wadhams, Peter 2207, 424, Thu_337_OS-3_428
Wagener, Penelope Mae 1714
Wagner, Dirk 1213, 2037
Wagner, Ioan (Johann) Tue_165_BE-4_513
Wagner, Penelope 2494, Fri_221_OS-4_2512
Wagner, Penelope M. 1309, Fri_355_SY-1_2383
Wagner, Sasha Fri_94_EN-7_1869
Wagner, Till Wed_156_CR-8_554
Wagner-Cremer, F Fri_49_EN-6_429
Wagnon, Patrick Wed_353_TE-3_507
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Wåhlin, Anna K. Wed_239_OS-6_957
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Waite, Anya 2260, Tue_361_OS-8_2287
Wakamatsu, Tsuyoshi Fri_213_OS-4_1871
Wake, Leanne Thu_242_CR-4_2530, Wed_377_TE-3_1897
Wakerley, Georgia 2202
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Walczowski, Waldemar Wed_274_OS-6_2497, Wed_335_TE-1_2354
Walczyńska, Katarzyna 1534, Tue_211_BE-4_2621, Tue_212_BE-4_2632
2631
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Waliur, Rahaman Wed_157_CR-8_602
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Walker, Christopher K. 2204, Tue_15_AA-1_2209
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Walker, Donald 1882
Walker, Kaley A. 1217
Walkington, Matt Wed_316_TE-1_569
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Wallis, Ben Matthew Fri_28_EN-2_2190
Walsh, Jennifer Tue_158_BE-4_389
Walter, Andrea 1303, Thu_300_CR-6_2059, Thu_301_CR-6_2067
Walter, Andreas Fri_343_SY-1_563
Walter, Benjamin 1116
Walter, Silas 771
Walter Anthony, Katey M. 1184
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Wang, Caixin Fri_217_OS-4_2273, Fri_218_OS-4_2297
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Wang, Cunguang Wed_362_TE-3_966
Wang, Dongliang Wed_310_TE-1_107
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Wang, Guanxing Wed_106_CR-3_701
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Wang, Jia Wed_234_OS-6_635
Wang, Jiancehng Fri_262_OS-7_895
Wang, Jianhua Wed_310_TE-1_107
Wang, Jianjun Thu_85_BE-5_893
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Wang, Keguang Fri_217_OS-4_2273, Fri_218_OS-4_2297
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Wang, Shimeng Wed_34_AC-2_2388
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2632
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Wang, Yicheng Wed_34_AC-2_2388
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Weidmann, Yvo 1648
Weigelt, Estella Tue_248_GG-2_206
2633
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Wesche, Gary 2136, Tue_307_OC-1_294
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Westaway, Richard 1331
Westerhold, Thomas Tue_259_GG-2_765
Westermann, Seabastian 752
Westermann, Sebastian 2485
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2634
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Wiedmann, Ingrid 2079
Wiehmann, Sonja Thu_60_BE-2_778
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Wiese, Mareike Fri_232_OS-5_458, Wed_161_CR-8_819
Wiggins, Helen 375
Wiig, Øystein 1311
Wiktor, Jozef 1114
Wilbraham, Jo 2376
Wild, Christian T. Thu_212_CR-4_860
Wilde, Simon A. Fri_158_GG-1_2219
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Wilhelm, Mary Beth 215
Wilhelms, Frank Thu_235_CR-4_2005
Wilhelms-Dick, Dorothee Thu_60_BE-2_778
Wilkinson, Jeremy 2106
Wille, Jonathan 1436
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Williams, Jonny Tue_49_AC-1_272
Williams, Mark Fri_94_EN-7_1869
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Williams, Michael 2285
Williams, Mike 1617, 2524, 526, Thu_138_BE-9_1414, Wed_316_TE-1_569
Williams, Nancy 2171
Williams, Timothy 2096
Williams, Tony 2196
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Williams, William J. 1119
Williamson, Christopher J Tue_147_BE-3_2461
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Willis, Michael John Thu_262_CR-5_1863
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Willoughby, Amanda S. Fri_95_EN-7_2013
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1_1999, Tue_124_BE-3_956
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Wilson, Alana Wed_121_CR-3_2073
Wilson, Cody 1668
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Wilson, Gary S. 843
2635
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Wilson, Katherine 1981
Wilson, Nerida 1751
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2_2572
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Winkelmann, Ricarda 1758
Winogradow, Aleksandra Thu_97_BE-5_2651
Winqvist, Camilla Wed_308_SH-5_2395
Winsor, Kelsey Wed_98_CR-2_2018
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4_1559, Wed_201_EN-1_2253, Wed_264_OS-6_1788
Winstrup, Mai 826
Winsvold, Solveig Havstad Wed_366_TE-3_1310
Winter, Anna Thu_304_CR-6_2425
Winter, Marten 713
Winton, Holly 2113, Wed_154_CR-8_201
Winton, Michael 1554, 386, Wed_228_OS-6_387, Wed_246_OS-6_1099
Wipf, Sonja 353
Witrant, Emmanuel Wed_186_CR-8_2479, Wed_187_CR-8_2490
Witte, Carson 2559
Witte, Ursula 711
Wittek, Boris Wed_205_OS-2_358, Wed_208_OS-2_464
Wittekind, Dietrich 2547
Wlodarska-Kowalczuk, Maria 683
Woelfing, Benno 2547
Woiwode, Wolfgang Tue_40_AC-1_971
Wojcik, Robin 258
Wojtasiewicz, Bozena 601
Wojtun, Bronislaw 1
Wold, Anette Thu_356_OS-3_2058
Wolf, Klara 1114, 1745
Wolfe, Jon 250, Thu_207_CR-4_547
Wolff, Eric 1134, 279, Wed_152_CR-8_92, Wed_169_CR-8_1261, Wed_188_CR-
8_2517
Wolff, Mareile A. Wed_128_CR-3_2436
Wolf-Gladrow, Dieter 1699
Wolfire, Mark 2204, Tue_15_AA-1_2209
Wollenburg, Jutta Thu_94_BE-5_2078
Wollenburg, Jutta Erika 1699
Wong, Hao Jie 1922
Wongpan, Pat 1081
Woo, Jusun 13, Fri_136_GG-1_913, Fri_142_GG-1_1415, Fri_148_GG-1_1791,
Thu_314_GG-1_2170
Wood, Michael Thu_256_CR-5_1057
Wood, Norman Wed_8_AC-2_746
Woodward, John Thu_242_CR-4_2530
Woodward, Malcolm 416
Wookey, Philip Andrew 1979
Woolley, Skipton 596
Woollings, Tim Thu_36_AC-8_1821
Worcester, Peter Fri_353_SY-1_1994
Worsnop, Douglas R. Tue_37_AC-1_767
Wotherspoon, Simon 2047
Wouters, Bert 1331, 1987, Thu_209_CR-4_632
Wrasse, Cristiano Wed_40_AC-4_385
Wrenger, Burkhard 670
Wright, Andrew 1243
Wrohan, Ian A. 1912
2636
Wu, Cheng 1447
Wu, Chengxiang Wed_234_OS-6_635
Wu, Chenxi 1196
Wu, Hui Wed_122_CR-3_2093, Wed_125_CR-3_2298
Wu, Li Tue_264_GG-2_889
Wu, Qian 1944
Wu, Qiang Fri_339_SY-1_192
Wu, Sheng Wed_310_TE-1_107
Wu, Shuangye 1297
Wu, Tonghua Wed_102_CR-3_182
Wu, Xingren Fri_197_OS-4_345
Wu, Xuefeng 503
Wu, Yang Wed_267_OS-6_1990
Wu, Yutian 575
Wuite, Jan 1741
Wulff, Angela Thu_79_BE-5_144
Wulff, Thorben 1568, 1687
Wunsch, Kartrin 257
Wuttig, Kathrin 1103, 1614, 594
Wyatt, Shea N. 1912
Wynne-Edwards, Katherine 2049
Wyszyński, Przemysław 439, Fri_309_SH-8_450

X
Xavier, Jose 286, 290, Tue_307_OC-1_294
Xavier, José Tue_329_OC-1_2599, Wed_81_BE-7_529
Xavier, José C Thu_403_SH-7_1983
Xavier, José C. Thu_142_BE-9_1615
Xavier, José Carlos 2132, Tue_192_BE-4_1611, Tue_193_BE-4_1613
Xia, Ruibin Fri_276_OS-7_1299
Xian, Peng 1402, Fri_94_EN-7_1869
Xiao, Cunde 826, Thu_44_AC-8_2277
Xiao, Di 503
Xiao, Haifeng 1191, 1196
Xiao, Wenshen 1950, 812, Tue_261_GG-2_783, Tue_263_GG-2_848, Tue_264_GG-
2_889, Tue_267_GG-2_1005
Xie, Aihong Wed_34_AC-2_2388
Xie, Changwei Wed_102_CR-3_182
Xie, Hongjie 945, Fri_227_OS-5_172, Thu_339_OS-3_479, Wed_362_TE-3_966
Xie, Jiping 2308, Fri_213_OS-4_1871, Fri_314_SH-8_1739
Xie, Zhouqing Fri_262_OS-7_895
Xiong, Yanlei Fri_168_ME-2_225
Xiong, Zhifang 1950, 812, Tue_267_GG-2_1005
Xu, Baiqing 1365
Xu, Chengli Fri_168_ME-2_225
Xu, Hao 1297
Xu, Jin 503
Xu, Shiming 397, Fri_198_OS-4_408, Fri_231_OS-5_407, Thu_30_AC-8_1273
Xue, Xia Wed_89_BE-7_2697

Y
Yackel, John 1271, 134, Fri_226_OS-5_151, Wed_347_TE-3_308
Yager, Patricia 823
Yaitskaya, Natalia Thu_361_OS-3_2353
Yakubov, Shamil 1665
Yakushev, Evgeniy 1665, Fri_107_EN-7_2544
Yamaguchi, Akira Tue_260_GG-2_769
Yamamoto, Masanobu Tue_293_GG-2_2130
Yamanouchi, Takashi 66
Yamazaki, Koji 2303
Yan, Yuzhen 2442
2637
Yanag, Daqing 1935
Yang, Bin 834
Yang, Eun Jin Thu_52_BE-2_234
Yang, Eun-Jin Fri_299_OS-7_2192
Yang, Guang Tue_155_BE-4_180
Yang, Huigen 503
Yang, Kang 1926, Wed_352_TE-3_498
Yang, Kun Wed_122_CR-3_2093, Wed_125_CR-3_2298
Yang, Qinghua 289, Fri_197_OS-4_345, Fri_199_OS-4_451, Fri_200_OS-4_608,
Fri_201_OS-4_630
Yang, Qiong 799
Yang, Shihai 503
Yang, Shuting 1646, Tue_283_GG-2_1640
Yang, Wei Wed_125_CR-3_2298
Yang, Xiaosong 1554
Yang, Xin 1134, Wed_154_CR-8_201
Yang, Xingxing Wed_111_CR-3_1010
Yang, Xu Tue_4_AA-1_679
Yang, Yang Fri_364_TE-2_501, Fri_367_TE-2_847, Tue_85_AC-1_2671,
Wed_310_TE-1_107
Yang, Yuande Thu_274_CR-6_170
Yang, Yuekui Thu_15_AC-3_2662
Yanpeng, Zheng 892
Yao, Tandong 753, Wed_104_CR-3_681
Yao, Tangdong 903
Yashayev, Igor Fri_108_EN-7_2583
Yastrebov, Vladislav 650
Yawei, Li Fri_161_GG-1_2421
Yde, Jacob Tue_148_BE-3_2513
Ye, Wenkai Thu_218_CR-4_1021
Ye, Yufang 2519, Wed_383_TE-3_2314
Yeşilyurt, Serdar Tue_300_GG-2_2339
Yelland, Margaret Fri_264_OS-7_989, Wed_258_OS-6_1555
Yermakova, Yelena 366
Yi, Chaolu Thu_290_CR-6_1276
Yi, Eojin 2390, Fri_178_ME-2_2347
Yi, Li 703
Yin, Jianjun Wed_228_OS-6_387
Yirmibesoglu, Sinan Tue_325_OC-1_2393, Tue_326_OC-1_2402, Tue_327_OC-1_2445,
Tue_328_OC-1_2498
Yoo, Kyu-Cheul 1056, 1618, Fri_296_OS-7_1902, Thu_334_OS-3_78, Thu_347_OS-
3_1109, Tue_276_GG-2_1354, Tue_280_GG-2_1479, Tue_298_GG-2_2261
Yoon, Hi Il 1618
Yoon, Ho Il Fri_62_EN-6_1620, Thu_334_OS-3_78, Tue_298_GG-2_2261
Yoon, Hoil Fri_296_OS-7_1902
Yoon, Seungtae 2424
Yoon, YJ 1846
Yoon, Young Jun Tue_73_AC-1_2020
Yoshizawa, Eri Fri_303_OS-7_2475
You, Cheng Thu_2_AC-3_505
Young, Abram 2204, Tue_16_AA-1_2218
Young, Duncan 1856, 2403
Young, Duncan A Fri_157_GG-1_2210
Young, Duncan A. 789, 854, Fri_124_GG-1_347, Thu_236_CR-4_2150, Thu_238_CR-
4_2213
Young, Emma Thu_123_BE-9_964
Young, G. Tue_50_AC-1_1218, Tue_52_AC-1_1221
Young, Jodi N. Tue_144_BE-3_2272
Young, Oran 2688
Young, Tun Jan Tue_322_OC-1_2025
Youngflesh, Casey 488, Thu_137_BE-9_1413, Thu_153_BE-9_2126, Thu_179_BE-
2638
11_1151
Yu, Haibin Wed_310_TE-1_107
Yu, Xiawei Fri_262_OS-7_895
Yu, Yong Thu_83_BE-5_583
Yu, Zicheng 365
Yuan, Xiangyan 503, Tue_18_AA-1_2263, Tue_5_AA-1_981
Yuan, Xiaojun 1607
Yumruktepe, Çağlar 1075
Yun, Su Kyung 197
Yun, Sukyoung 2424
Yunoki, Shun Wed_117_CR-3_1280
Yurova, A.Yu. Fri_293_OS-7_1823

Z
Zabłocka, Monika Thu_91_BE-5_1590
Zabotin, Nikolay 578
Zaccone, Renata Fri_87_EN-7_1460, Tue_139_BE-3_1708
Zacher, Katharina Tue_189_BE-4_1558
Zagorodnov, Victor 764, Wed_159_CR-8_766, Wed_317_TE-1_763
Zagórski, Piotr Wed_199_EN-1_1971
Zagovenkova, Anastasia 1665
Zahariev, Alexandre 1891
Zaika, Yulia 1636, 198, 68, Thu_381_SH-6_1238
Zainudin, Hilal Tue_198_BE-4_1996
Zakharov, Denis Wed_81_BE-7_529
Zakharova, Elena 2638
Zakhvatkina, Natalia 2324
Zaldei, Alessandro Wed_331_TE-1_1511, Wed_332_TE-1_1529
Zamanillo, Marina Fri_307_OS-7_2683
Zambardino, Giovanni Wed_265_OS-6_1947
Zambianchi, Enrico Wed_255_OS-6_1463
Zamora, Lauren 477
Zamora, Rodrigo 1691, Thu_229_CR-4_1649, Thu_230_CR-4_1673
Zampieri, Lorenzo 2350, Fri_220_OS-4_2323
Zanatta, Marco 1163, 1381, 246, Tue_35_AC-1_719
Zaniboni, Filippo Thu_258_CR-5_1226
Zanowski, Hannah 1341, 386
Zanutta, Antonio Thu_255_CR-5_1000
Zappa, Chris 2524
Zappa, Christopher 2424
Zappa, Christopher J 2185, 2559, Fri_299_OS-7_2192
Zappa, Giuseppe 299, Wed_53_AC-7_301
Zappalà, Giuseppe Fri_81_EN-7_1015, Fri_90_EN-7_1532, Wed_332_TE-1_1529
Zarankin, Andres 54
Zarankin, Andrés Wed_288_SH-4_880
Zarfl, Christiane 257, Fri_5_EN-2_253
Zaripova, Zarina Wed_81_BE-7_529
Zawar-Reza, Peyman 1361, 510, Wed_327_TE-1_1363
Zawierucha, Krzysztof Zawierucha 1684
Zdanowicz, Christian Fri_351_SY-1_1881
Zdobnov, Evgeny Thu_192_BE-12_927
Zekollari, Harry Tue_260_GG-2_769
Zelano, Isabella Fri_79_EN-7_754
Zemp, Michael 421, Tue_308_OC-1_346
Zeng, Junbao 530
Zeng, Yinxin Thu_83_BE-5_583
Zeng, Yin-Xin Tue_127_BE-3_1101
Zentek, Rolf 1468
Zeppenfeld, Sebastian 425, Tue_44_AC-1_1122
Zgur, Fabrizio Tue_247_GG-2_200, Tue_279_GG-2_1478
Zhan, Liyang Tue_33_AC-1_579
2639
Zhang, Baojun Thu_247_CR-5_238
Zhang, Dongqi 826
Zhang, F. Wed_215_OS-2_1279
Zhang, Fan Wed_106_CR-3_701
Zhang, Guoqing Wed_103_CR-3_659
Zhang, Haifeng Thu_59_BE-2_756
Zhang, Han Fri_365_TE-2_595, Fri_367_TE-2_847
Zhang, Heng Fri_139_GG-1_975, Fri_143_GG-1_1630
Zhang, Hui 503, 761
Zhang, Jiexia Tue_33_AC-1_579
Zhang, Jinlun 2017, 2120
Zhang, Lin 289, Fri_197_OS-4_345, Fri_199_OS-4_451
Zhang, Lu Wed_111_CR-3_1010
Zhang, Mengjie 1587
Zhang, Minghong Fri_301_OS-7_2206
Zhang, Nan 128, 891, Fri_364_TE-2_501, Fri_367_TE-2_847, Wed_310_TE-1_107
Zhang, Pengfei 575
Zhang, Qi Thu_44_AC-8_2277
Zhang, Qianggong Fri_13_EN-2_936
Zhang, Qiao Fri_116_GG-1_162
Zhang, Qingchuan Wed_46_AC-4_1624
Zhang, Renhe Wed_122_CR-3_2093
Zhang, Rudong Tue_85_AC-1_2671
Zhang, Shengkai Fri_236_OS-5_835, Thu_343_OS-3_851, Wed_46_AC-4_1624
Zhang, Taoliang Tue_261_GG-2_783
Zhang, Wangbin 1297
Zhang, Xiangdong 1935, 661
Zhang, Yinsheng Wed_116_CR-3_1192
Zhang, Yongxin Wed_105_CR-3_686
Zhang, Yu Fri_236_OS-5_835, Thu_343_OS-3_851
Zhang, Zhaoru 2308, Fri_314_SH-8_1739
Zhao, Bo Fri_339_SY-1_192
Zhao, Jiechen 289, Fri_197_OS-4_345
Zhao, Jinping Wed_276_OS-6_2577, Wed_277_OS-6_2626
Zhao, Jun Thu_59_BE-2_756
Zhao, Junmeng Fri_139_GG-1_975, Fri_143_GG-1_1630
Zhao, Lin Wed_102_CR-3_182
Zhao, Liyun 857
Zhao, Ming Tue_46_AC-1_1156
Zhao, Renjie 973
Zhao, Xi 725, Fri_243_OS-5_1925, Wed_356_TE-3_733
Zhao, Yucheng 1964
Zhao, Yunliang Fri_21_EN-2_1609
Zheng, Hong Thu_55_BE-2_559
Zhou, George 1272
Zhou, Haijin Thu_6_AC-3_1245
Zhou, Hongyan 503
Zhou, Jiayun Wed_221_OS-2_2027
Zhou, Jilin 503
Zhou, Lu 397, Fri_231_OS-5_407
Zhou, Shenjie 963
Zhu, Hejun 1274
Zhu, Jialiang Fri_260_OS-7_817
Zhu, Lixian Wed_354_TE-3_533
Zhu, Siyu 945, Wed_362_TE-3_966
Zhu, Tingting Fri_236_OS-5_835, Thu_343_OS-3_851
Zhu, Xiaofan Wed_102_CR-3_182
Zhu, Yongtian Tue_18_AA-1_2263
Zhu, Zonghong 503
Zhuang, Yanpei Thu_56_BE-2_642
Zhuravskiy, Danila Wed_314_TE-1_536
2640
Ziaja, Wieslaw 1387, 1388
Ziegler, Amanda 1187, 911, Thu_86_BE-5_918
Ziemen, Florian 1755, Wed_146_CR-7_1929
Zigone, Dimitri Fri_272_OS-7_1227, Fri_346_SY-1_1223
Zimin, Alexei Wed_282_OS-6_2679
Zimmerman, Christian Wed_75_BE-6_1843
Zimmermann, Ralf 1381, Fri_21_EN-2_1609
Zinnecker, Hans Tue_21_AA-1_2655
Ziolkowski, Lori A. 2473
Zitterbart, Daniel P. Tue_347_OS-1_1717
Zocca, R. Tue_74_AC-1_2048
Zolina, Olga Thu_18_AC-8_16, Thu_22_AC-8_445, Thu_42_AC-8_2092
Zona, Donatella Fri_352_SY-1_1890
Zondervan, Albert Thu_206_CR-4_394
Zoor, Lena 2361
Zou, Xun 1595
Zoumplis, Angela 2151
Zsom, Andras 6
Zubkova, Evgenia 2676
Zubrzycki, Sebastian 2361
Zuccarello, Luciano 156, Fri_358_TE-2_155, Thu_246_CR-5_153
Zucconi, Laura 442, 462, 694, Tue_111_BE-1_695, Tue_160_BE-4_443
Zuniga, Gustavo 189, Wed_83_BE-7_1301
Zunz, Violette Fri_249_OS-7_79
Zuo, Fei Wed_234_OS-6_635
Zverina, Ondrej 2077
Zweng, Melissa Wed_259_OS-6_1627
Zwinger, Thomas 1129, 2036
Zwintz, Konstanze 1376

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