Monsoon

Population dynamics of Noctiluca scintillans (Macartney) Kof. et Swezy containing the photosynthetic endosymbiont Pedinomonas noctilucae (Subrahman.) Sweeney was investigated in relation to environmental conditions in the upper Gulf of Thailand. A clear association was observed between the abundance of N. scintillans and the monsoon cycle, with its blooms occurring during the southwest (SW) monsoon from May to September, and low abundance during the northeast (NE) monsoon from November to February. Nutrient concentrations were higher during the SW monsoon than during the NE monsoon due to the combined effect of increased river discharge into the northern upper gulf and the transport of the riverine inputs by the prevailing clockwise circulation of the water. These nutrient conditions favored the growth of both phytoplankton and the endosymbiont. Correlation analysis revealed that the higher abundance of N. scintillans in the SW monsoon was manifested primarily by higher growth throu...

AUSMI merupakan singkatan dari Australia Monsun Index, didefinisikan sebagai nilai rata-rata angin zonal pada level ketinggian 850 milibar dalam area antara 5–15LS dan 110–130BT. Indeks monsun Australia tersebut merepresentasikan dengan sangat baik curah hujan monsunal di sebagian BMI dan di Australia bagian utara pada skala musiman, antarmusiman, tahunan, antartahunan, hingga skala 10-tahunan (Yulihastin 2011).

Stratigraphic exposures, fluvial archives and borehole data have been allowed to reconstruct the alluvial history of Late Pleistocene to Late Holocene and climate changes in the monsoonal wet – dry region of lower Damodar Basin (West Bengal, India). The facies architectures and climate proxies suggest that five to six climate changes occurred in between ~ 14 ka and 6 ka. Supporting evidence from the floodplain of Damodar River demonstrates that the successive phases of aggradation and incision were linked to the south-west monsoonal variability of Late Quaternary period. The onset of semi-arid climate was associated with caliches, pond and backswamp deposits of wanning low energy floods. The relatively warm-humid climate was associated with sandy bedforms, valley fills, slack water deposits and ferruginous nodules. This paper presents a synthesis of the available palaeoclimatic records from the lower Ganga Basin and the rivers of western and central India for the palaeoenvironmental significance of Late Quaternary deposits and discusses the influence of palaeoclimatic controls on the fluvial architectures and archives that developed below the floodplain of Damodar River. We have taken some representative studies from the region to reveal the spatial variability in fluvial successions in response to climate changes during this period.

Graphical abstract Abstract In December 2014, Kelantan was hit by the worst flood ever recorded. Did the rainfall exceed historical records, how rare are they and what causes them? This paper answers these questions. Estimation of the return periods uses the GEV distribution model and stations with more than 25 years records. Spatial distribution plots of the cumulated rainfall depths were constructed using IDW interpolation method. Four major outcomes are: 1) Spatial rainfall patterns show high amounts of rainfall accumulated by phases (Phase 1-daily rainfall up to 300 mm; Phase 2-daily rainfall up to 500 mm); 2) record breaking rainfall events occurred at 9 stations significantly at Gunung Gagau (1598.9 mm compared to 976.5 mm 7-day cumulated rainfall). Many stations upstream of the river basin experienced ARIs near and over 100 years and several experienced more than 200 years; and 4) Enhanced rainfall were experienced due to the combined effect of the monsoon season, Madden Julian Oscillation and temperature below anomalies at the Siberian High.

The study of the water quality of surface water bodies in Greater Hyderabad Municipal Corporation (GHMC) has carried out to assess the risk to ecology. A Qualitative study has also been done in pre-monsoon and post-monsoon seasons considering the change in various parameters and its concentrations. It had been found that concentration of parameters in pre-monsoon period is higher than post-monsoon which is natural phenomenon. This study is main consideration to assess the quality of water for its best utilization like drinking and to maintain sustainable environment. Water bodies facing degradation due to anthropogenic activities such as directing human waste and changes in land use pattern etc. thus leading to the deterioration of environmental quality as well as a decrease in the surface area and depth of water bodies. Present study is to assess the quality of the water bodies in GHMC by developing a water quality index (WQI) and to predict the future pollution levels. For this purpose, 29 surface water bodies had been selected in GHMC for the study. Only two sample sites named Osman Sagar and Himayat Sagar are found fit for in all studied water quality parameters on comparison with standards.

Question:
What is the information and evidence on the seasonal vulnerability and risk calendar in Nepal at a national and sub-national level?

Summary
Nepal faces many seasonal disasters, including floods, landslides, fires, droughts and diseases. Findings of this rapid review indicates that:
◾Most people are killed and injured during July–September which is in the monsoon period.
◾Preparedness activities could take place in anticipation of seasonal disasters.
◾The Tarai is vulnerable to floods, lightening, epidemics and drought in the monsoon period; and fires, windstorms, and drought in the dry season.
◾The Hills are vulnerable to floods, landslides, drought, epidemics, lightening, and hailstorms in the monsoon period; and fires, windstorms, and drought in the dry season.
◾The Mountains are vulnerable to landslides, glacial lake outburst floods, drought, lightening, and epidemics in the lower parts of the mountain region in the monsoon period; windstorms in the dry season; and avalanches in the winter period.
◾The monsoon season (June-September) often experiences landslides, flooding, thunderstorms, disease (cholera, gastroenteritis, diarrhoea, encephalitis, meningitis, typhoid, jaundice, malaria, Japanese encephalitis) and drought (when the monsoon rains fail).
◾The dry season (March-June) often experiences household and wildfires, drought, heatwaves, and windstorms.
◾The winter season (November-February) often experiences avalanches, avian influenza, and crop damage.
◾Nepal is very vulnerable to climate change which is expected to lead to more extreme weather and changing seasons.
◾Summer cropping season (June-September) involves rice, maize and millet, while the winter cropping season (October-May) involves wheat, barley and potatoes.
◾Seasonal food shortages are quite common in many parts of Nepal. July-August and January-March are traditionally agricultural lean seasons, leading to increased risks of food insecurity.
◾Water-borne diseases are common between June-August. Water sources may be seasonal.
◾Seasonal migration is related to the agricultural cycle, with young men leaving to find work, leaving those behind more vulnerable to disasters.

Other seasonal events which may increase vulnerability include:
◾The main festival season, which is in October/November. Festivals can see mass gatherings of people.
◾Autumn and spring, which are the main tourist trekking and hiking seasons in Nepal.

The Indonesian Throughflow (ITF) is a critical part of the global thermohaline conveyor. It plays a key role in transporting heat from the equatorial Pacific (the Indo-Pacific Warm Pool) to the Indian Ocean and exerts a major control on global climate. The complex tectonic history of the Indonesian Archipelago, a result of continued northward motion and impingement of the Australasian Plate into the Southeast Asian part of the Eurasian Plate, makes it difficult to reconstruct long-term (i.e., million year) ITF history from sites within the archipelago. The best areas to investigate ITF history are downstream in the Indian Ocean, either in the deep ocean away from strong tectonic deformation or along proximal passive margins that are directly under the influence of the ITF. Although previous Ocean Drilling Program and Deep Sea Drilling Project deepwater cores recovered in the Indian Ocean have been used to chart Indo-Pacific Warm Pool influence and, by proxy, ITF variability, these sections lack direct biogeographic and sedimentological evidence of the ITF. International Ocean Discovery Program Expedition 356 will drill a transect of cores over 10° latitude on the northwest shelf (NWS) of Australia to obtain a 5 m.y. record of ITF, Indo-Pacific Warm Pool, and climate evolution that has the potential to match orbital-scale deep-sea records in its resolution. Coring the NWS will reveal a detailed shallow-water history of ITF variability and its relationship to climate. It will allow us to understand the history of the Australian monsoon and its variability, a system whose genesis is thought to be related to the initiation of the East Asian monsoon and is hypothesized to have been in place since the Pliocene or earlier. It also will lead to a better understanding of the nature and timing of the development of aridity on the Australian continent.
Detailed paleobathymetric and stratigraphic data from the transect will also allow subsidence curves to be constructed to constrain the spatial and temporal patterns of vertical motions caused by the interaction between plate motion and convection within the Earth’s mantle, known as dynamic topography. The NWS is an ideal location to study this phenomenon because it is positioned on the fastest moving continent since the Eocene, on the edge of the degree two geoid anomaly. Accurate subsidence analyses over 10° of latitude can resolve whether northern Australia is moving with/over a time-transient or long-term stationary downwelling within the mantle, thereby vastly improving our understanding of deep-Earth dynamics and their impact on surficial processes

A dramatic increase in regional summer rainfall amount has been proposed for the Arabian Peninsula during the middle Holocene (ca. 9-5 ka BP) based on lacustrine sediments, inferred lake levels, speleothems, and pollen. This rainfall increase is considered primarily the result of an intensified Indian summer monsoon as part of the insolation-driven, northward shift of the boreal summer position of the Inter-Tropical Convergence Zone (ITCZ) to over the deserts of North Africa, Arabia, and northwest India. We examine the basis for the proposed drastic climate change in Arabia and the shifts in the summer monsoon rains, by reviewing paleohydrologic lacustrine records from Arabia. We evaluate and reinterpret individual lake-basin status regarding their lacustrine-like deposits, physiography, shorelines, fauna and flora, and conclude that these basins were not occupied by lakes, but by shallow marsh environments. Rainfall increase required to support such restricted wetlands is much smaller than needed to form and maintain highly evaporating lakes and we suggest that rainfall changes occurred primarily at the elevated edges of southwestern , southern, and southeastern Arabian Peninsula. These relatively small changes in rainfall amounts and local are also supported by pollen and speleothems from the region. The changes do not require a northward shift of the Northern Hemisphere summer ITCZ and intensification of the Indian monsoon rainfall. We propose that (a) latitudinal and slight inland expansion of the North African summer monsoon rains across the Red Sea, and (b) uplifted moist air of this monsoon to southwestern Arabia highlands, rather than rains associated with intensification of Indian summer monsoon, as proposed before, increased rains in that region; these African monsoon rains produced the modest paleo-wetlands in downstream hyperarid basins. Furthermore, we postulate that as in present-day, the ITCZ in the Indian Ocean remained at or near the equator all year round, and the Indian summer monsoon, through dynamically induced air subsidence, can reduce rather than enhance summer rainfall in the Levant and neighboring deserts, including Arabia. Our summary suggests a widening to the north of the latitudinal range of the rainfall associated with the North African summer monsoon moisture crossing the Red Sea to the east. We discuss other mechanisms that could have potentially contributed to the formation and maintaining of the modest paleo-wetlands.

Reconstructing the Plio-Pleistocene sedimentary history of the Yellow Sea, is important for understanding the long-term influence of the Yellow River (Huanghe) and/or Yangtze River (Changjiang) on the Asian marginal seas and to further constrain any links between river development, regional paleo-environmental change, tectonic deformation and/or global climate change. Here we present the first high-resolution clay mineral record combined with Sr-Nd isotopic compositions from a 300-m long sediment core recovered in the western South Yellow Sea. Our study suggests that large-scale transgression in the Yellow Sea occurred after ~0.8 Ma, possibly related to tectonic subsidence of eastern China coast and the Min-Zhe Uplift. In contrast, the sedimentary environment of Bohai and Yellow Seas was mainly dominated by fluvial/lacustrine deposits at 3.5e0.8 Ma. Provenance analysis suggests a major change in sediment provenance from the Yangtze River to the Yellow River at ~0.8 Ma, which corresponds to the timing of the final integration of the Yellow River in its present form. At the same time the major channels of the Yangtze River migrated from the South Yellow Sea to the modern Yangtze River delta due to the subsidence of east China coast. The consistence in timing of the provenance transition and large-scale regional marine transgression suggests that tectonic deformation, rather than climate change, is the first-order control on the evolution of the Yellow and Yangtze Rivers and sedimentary environmental change in the Bohai and Yellow Seas.

The Western Ghats is a contentious landscape described in the familiar language of disciplines and boundaries, a language that has influenced the way in which development and environmental projects have been designed. It is possible the contentions arise from a particular ontology, created by a way of seeing the Ghats that divides nature from culture, relying on a view from above that distances one from place, an outsider's view. This way of seeing differs from an understanding that emerges when engaging in the Ghats on foot. This paper grapples with this difference through a literary engagement with one of Kuvempu's epic novels, Malegalalli Madumagalu. The novel reveals two different ontologies through an unraveling of text and imaging: one that privileges the colonial eye requiring skies and eyes to be clear, and another that privileges a local experience structured by the everyday practice of walking in a monsoon terrain.

Evaluation of the applicability and utility of watershed hydrologic models in different hydro-geologic and soil conditions is necessary for a range of spatial scales and to assess the utility of these models as watershed water resources management tools. This study presents the application of the hydrological model TOPNET to the Big Darby Creek watershed, Ohio, United States. It focuses on the simulation modeling of stream flow in the watershed based on meteorological data for the eight year period of 1992–1999. Visual comparison of time series plots and statistical measures namely, Nash-Sutcliffe efficiency (NS), coefficient of correlation (R2), and the percent bias (PBIAS) were used to assess the model performance. The statistical model evaluation results indicated that the model has a relatively high confidence and can give a good representation of the flow hydrographs for the watershed. For the calibration period simulations of annual stream flow were accurate with a mean R2 and NS of 86% and 85% for the Big Darby at Darbyville gaging station. For the little Darby at West Jefferson gaging station a mean R2 of 81% was obtained while the NS averaged 78%. Further analysis based on the aggregation of the water years into wet seasons and dry seasons, the model was also able to adequately simulate stream flow for both gaging stations and for both low flow periods and high flow periods. Statistical analysis for the validation period also yielded high R2 values of 88% and 83% for the Darby at Big Darby at Darbyville gaging station and Little Darby at West Jefferson gaging station respectively. The worst PBIAS obtained for both calibration and validation period was 18% and this is better than recommended values for satisfactory daily simulations of ±25% for PBIAS. The encouraging simulation results obtained in this study shows the utility and usefulness of the TOPNET model in hydrological modeling and ultimately as a water resources management tool.

In 1691, the Mughal biographer Sher Khan Lodi wrote that “it is impossible to capture the essence of music in pen and ink on the surface of a page.” This is true of all music: writing about music is famously like dancing about architecture. But the Hindustani classical tradition to which he was referring is, in addition, not based on fixed pieces of music written down on paper. In the performance of a Hindustani raga, music is only ever brought into being in the moment of its sounding, improvised by the creative artist in response to that particular audience. Once the last note has died away, the music is lost forever, taking the visceral, emotional, human experience of being there, listening, with it into silence. Leaving behind… what, exactly? What residue remains of the moment of musical experience, when everything else has gone? And why have so many writers across the ages tried so very hard to recapture those lost moments on paper, including myself, when we know it can’t be done?

Draft version.  Published version here: https://doi.org/10.18732/hssa89

Most notions of the seasons in works of ancient Indian medicine list frost, spring, summer, rainy season, autumn and winter as the particular times of the year. However , in some contexts, the hibernal season frost (śiśira) is left out and replaced by a second rainy season, called beginning of the rain (prāvṛṣ) and placed between summer and the actual rainy season. In this paper, I firstly introduce the concept of the seasons and the division of the year into two halves. Secondly, I examine the di-chotomy of two seasonal schemes inside one scientific corpus, which varies regarding the included seasons. Concerning this matter, I follow the investigations of Francis Zimmermann 1 in order to prove that the two schemes are utilized both intentionally and systematically in specific contexts. The two seasonal schemes serve diverse cases, being of use for the physician in different aspects of his work.

Yamuna river pollution has been extensively studied with regard to some selected parameters in five locations at Palla, Nizamuddin Midstream, Nizamuddin Quarter Stream, Agra Canal Midstream, and Agra Canal Quarter Stream in Delhi, India. Seasonal and location-wise variation of pollutants namely dissolve oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), ammonia (AMM), total coliform and fecal coliform were studied for 6 years during the period of 2000–2005. The study results revealed the lowest level of pollution during monsoon. The statistical analysis revealed a positive correlation between DO, BOD, COD, TKN, and AMM.

Zooplankton were collected from Lake Taal between January and December 2008 in order to test for differences in species composition and abundance between a lake basin with intensive fish cage (FC) aquaculture and an open water area without FCs. Most species showed similar patterns of occurrence in both basins while having differences in abundance. Several rotifer species were more abundant in FC sites most of the year, while for microcrustaceans higher abundances in FC sites only happened during the first 2 months. Their distribution is attributed to the presence of higher nutrient levels in FC sites as well as wind-induced basin-wide water movements during the different monsoon seasons which disperse plankton and nutrients from FC sites to other parts of the lake. Zooplanktonic indicators, such as the Brachionus–Trichocerca quotient (Q B/T) and the ratio of calanoids to cladocerans and cyclopoids, clearly demonstrate the eutrophic state of the lake. A comparison with previous studies suggests that the lake was already eutrophic prior to the introduction of aquaculture in the 1970s. The trophic conditions in Lake Taal may be attributed to the lakes’ tropical and volcanic nature, with productivity further enhanced by increased nutrient input from aquaculture.

Intensive agricultural practices implemented to secure increased crop yields have potentially negative environmental effects due to the generation of sediment and nutrients from agricultural fields. The monsoon climate and current agricultural practices on mountainous landscapes of the Haean catchment in South Korea have significantly affected water quality by transporting sediment and nutrients to downstream water bodies. The aim of this study is to suggest strategies for a permanent reduction of sediment and nitrate from this catchment through an efficient application of best management practices (BMPs). We applied three BMPs; split fertilizer application (SF), winter cover crop cultivation (CC), and a combination of the two (SFCC) to major dryland crops (cabbage, potato, radish and soybean) in order to investigate their effectiveness at the catchment scale through the Soil and Water Assessment Tool (SWAT) model. We found that the SF scenario reduced nitrate pollution while sediment and crop yield did not change relative to the baseline (BL) scenario. The application of the CC scenario reduces both sediment and nitrate load while crop yields increased. The combination of split fertilization and cover cropping (SFCC) showed the highest positive effect on reducing sediment and nitrate and increasing crop yields compared to a single application. We estimated the variability in the effectiveness of BMPs for major crop types and could demonstrate that specific sites and crop types, such as soybean, were less influential in reducing sediment and nitrate loads. Those sites and crops could be considered for additional BMP measures to mitigate water deterioration by target pollutants. Recommendations for BMP applications should also consider minor crops and other land use types in order to reduce overall water pollution and efficiently improve crop yields in this catchment.