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    Sea Ice Modeling

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    korina_kuhar
    This document summarizes the key points of a student paper on sea ice modeling. It first introduces sea ice, describing its characteristics such as forming from frozen ocean water between -1.8 to 0 degrees Celsius. Sea ice is then described as important for regulating climate and supporting Arctic ecosystems. The document outlines the need for sea ice models to understand changes over time and make predictions, as systematic measurements only cover around 40 years. It then describes the basic physics behind a simple sea ice model involving equations for ice thickness, momentum, enthalpy, and heat. Model results are shown for Antarctic sea ice thickness and Arctic predictions for 2030.

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    © All Rights Reserved
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    Sea Ice Modeling

    Uploaded by

    korina_kuhar
    30 views29 pages
    This document summarizes the key points of a student paper on sea ice modeling. It first introduces sea ice, describing its characteristics such as forming from frozen ocean water between -1.8 to 0 degrees Celsius. Sea ice is then described as important for regulating climate and supporting Arctic ecosystems. The document outlines the need for sea ice models to understand changes over time and make predictions, as systematic measurements only cover around 40 years. It then describes the basic physics behind a simple sea ice model involving equations for ice thickness, momentum, enthalpy, and heat. Model results are shown for Antarctic sea ice thickness and Arctic predictions for 2030.

    Original Description:

    Presentation: How physicists model the behavior of sea ice.

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    This document summarizes the key points of a student paper on sea ice modeling. It first introduces sea ice, describing its characteristics such as forming from frozen ocean water between -1.8 to 0 degrees Celsius. Sea ice is then described as important for regulating climate and supporting Arctic ecosystems. The document outlines the need for sea ice models to understand changes over time and make predictions, as systematic measurements only cover around 40 years. It then describes the basic physics behind a simple sea ice model involving equations for ice thickness, momentum, enthalpy, and heat. Model results are shown for Antarctic sea ice thickness and Arctic predictions for 2030.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    30 views29 pages

    Sea Ice Modeling

    Uploaded by

    korina_kuhar
    This document summarizes the key points of a student paper on sea ice modeling. It first introduces sea ice, describing its characteristics such as forming from frozen ocean water between -1.8 to 0 degrees Celsius. Sea ice is then described as important for regulating climate and supporting Arctic ecosystems. The document outlines the need for sea ice models to understand changes over time and make predictions, as systematic measurements only cover around 40 years. It then describes the basic physics behind a simple sea ice model involving equations for ice thickness, momentum, enthalpy, and heat. Model results are shown for Antarctic sea ice thickness and Arctic predictions for 2030.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 29

    Sea ice modeling

    Korina Kuhar
    Modern physics
    04/20/16

    Content:

    SEA ICE:
    - introduction
    - characteristics
    - importance

    Content:

    SEA ICE:
    - introduction
    - characteristics
    - importance

    Content:

    POLAR REGIONS

    SEA ICE:
    - introduction
    - characteristics
    - importance

    Content:

    POLAR REGIONS

    WHY THE NEED FOR


    MODELS

    SEA ICE:
    - introduction
    - characteristics
    - importance

    Content:

    POLAR REGIONS

    WHY THE NEED FOR


    MODELS
    MODELING:
    - physics behind the
    models
    - simple model

    SEA ICE:
    - introduction
    - characteristics
    - importance

    Content:

    WHY THE NEED FOR


    MODELS
    MODELING:
    - physics behind the
    models
    - simple model

    RESULTS
    CONCLUSION
    POLAR REGIONS

    Introduction

    frozen ocean water, grows and melts


    in the ocean

    Introduction

    frozen ocean water, grows and melts


    in the ocean

    - found in remote polar oceans


    - covers about 25 million km2 of the Earth (2.5 x area of Canada
    or 15% of world's oceans)
    - up to 3m thick

    Characteristics
    Sweet water freezes at 0C Ocean water freezes at around -1.8 C

    Characteristics
    Sweet water freezes at 0C Ocean water freezes at around -1.8 C

    In deep ocean top 100-150 m needs to reach


    freezing point for the ice to form

    Salty,
    dense,
    cooler

    Less salty,
    less dense,
    warmer

    Importance

    Source:
    http://worldoceanreview.com/en/wor-1/climate-system/g
    reat-ocean-currents/
    (16/04/2016)

    Source:
    http://www.realclimate.org/index.php/archives/2015/03/whats-going-onin-the-north-atlantic/
    (16/04/2016)

    Structure

    BRINE pockets between ice crystals saline


    and liquid (ice around it is NOT salty!)
    -over the time brine can dry out
    - the older the ice, less
    salty it is
    - brine concentration affects
    thickness

    Brine
    Source: All about sea ice
    (16/04/2016)

    POLAR REGIONS
    Arctic

    Antarctic

    Geography

    Semi enclosed ocean

    Mainly land mass


    surrounded by sea

    Ice thickness

    2-3 m (5m max)

    1-2 m

    Ice area

    15 milion km2

    18 milion km2

    Ice are during warm


    period

    7 milion km2

    3 milion km2

    Trend, 1979-2008

    decrease of 4.1%

    increase of 0.9%

    Arctic and Antarctic ice coverage

    Source:
    http://nsidc.org/cryosphere/seaice/ch
    aracteristics/difference.html
    (16/04/2016)

    NEED FOR SEA ICE MODELS

    Systematic measurements: only last ~40 years

    Limited number of sensors

    Lack of satellite coverage, bad weather

    Predictions
    Models for climate studies:
    how sea ice evolves and how it will be affected by
    changing climate

    Model
    (x,y)

    (h)

    Sea ice in cells (10 km2)


    No variation in properties
    within a cell

    Group of cells: domain


    Values of properties in
    each cell change as the
    time evolves

    A cell is a stacked pile of


    layers (12)
    Properties do not vary
    within a layer
    Values of properties in
    each cell change as the
    time evolves

    Time step: 1 day

    Physics of sea ice

    Source:
    http://karelnovosti.ru/incidents/dvoe-zhitelej-karelii-provalili
    s-v-avtomobile-pod-led/
    (16/04/2016)

    Atmosphere above and ocean below


    BOUNDARY CONDITIONS
    Processes: thermodynamics and dynamics

    Physics of sea ice


    4 GOVERNING EQUATIONS
    DESCRIBING 4 PHYSICAL
    PROPERTIES

    Source:
    http://karelnovosti.ru/incidents/dvoe-zhitelej-karelii-provalili
    s-v-avtomobile-pod-led/
    (16/04/2016)

    Ice thickness distribution

    Conservation of momentum

    Conservation of enthalpy

    Heat equation

    Atmosphere above and ocean below


    BOUNDARY CONDITIONS
    Processes: thermodynamics and dynamics

    THICKNESS:

    Ice thickness distribution (ITD)

    Internal stress(ridging)

    (thermodynamic growth,f)

    Reduction due to
    lateral melting, L

    g(x ,h , t)

    THERMODYNAMICS:

    Specific heat c
    Density
    Thermal conductivity k

    Rate of change
    from TD

    Heat equation

    Mechanical
    redistribution
    Conservation of enthalpy

    DYNAMICS:

    Wind

    u
    Stress tensor

    Ocean
    currents

    Conservation of motion

    Coriolis force
    Sea surface
    tilt

    Simple algorithm flow


    1) Solve sea ice momentum equation to
    obtain velocity
    2) Solve the heat equation for each layer
    separately
    3) Solve ITD equation, obtain updated g( x ,h , t )
    4) Results obtained in 2 insert into enthalpy
    distribution
    5) Update the temperatures

    Results

    Simulated Antarctic sea ice thickness

    Results, Arctic

    Predictions, 2030

    Source: http://www.atmos.washington.edu/~bitz/BitzCongressionalBrief_20Mar2013.pdf (19/04/2016)

    Conclusion

    Sea ice and ocean


    (atmosphere): 2 way
    street
    Models: a long term
    climate study
    Model the past to
    'predict' the future

    Issues:
    - anomalies
    - missing parameters
    - relevant/irrelevant
    factors

    THANKS FOR YOUR


    ATTENTION!

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