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Showing 1 to 20 of 25 for “"Weddell Sea"”.
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Growth and motion at the Weddell Sea ice edge
The formation of sea ice in the presence of turbulence was studied using data from drifting buoy<br/>deployments and ice sampling in the Weddell Sea during April 2000. The study sought to<br/>improve understanding of pancake ice in terms of dynamics, heat fluxes, ice growth rates …
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The Evolution and Impact of Weddell Sea Deep Water
… Sheet is largely marine based and grounded below sea level, which makes it especially vulnerable for sea-level forcing and ocean warming. In turn, the Southern Ocean overturning circulation is partially driven by deep water formation along the Antarctic continent, which is strongly modulated by …
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The Study of Weddell Sea Ice using passive microwave and buoy data
The growth of the Weddell Sea ice cover in 1980 is examined, using Nimbus-7 satellite Scanning Multi-channel Microwave Radiometer (SMMR) data in combination with data (positional, air temperature and atmospheric pressure) from 4 Nimbus-tracked drifting buoys. Ice concentrations are retrieved from …
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Satellite Remote Sensing Investigations into Changing Ice-shelf Extents in the Eastern Weddell Sea Sector of Antarctica
… change. Therefore, contemporary glaciological research is increasingly focussed on the long-term future stability of the vast West and East Antarctic Ice Sheets under different climate change scenarios, where similar changes to atmospheric and oceanic processes to those found in the Antarctic …
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Antarctic Bottom Water in CMIP5 models : characteristics, formation, evolution
… (AABW) are changing, causing significant steric sea level rise. Understanding the causes of these changes is critical for projections of future sea level, yet previous generations of climate models failed to represent AABW accurately. Present-day biases in AABW potential temperature, salinity and …
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Concentration and isotopic composition of marine nitrous oxide, in particular the oxygen-17 isotope excess
… and tropical Atlantic Ocean, the Scotia Sea and the Weddell Sea. This indicates a biological source for oxygen isotope excess in N2O, as oceanic N2O was not in equilibrium with the atmosphere (0.9 ‰). δ(15N) values ranged from 2.3 to 25.1 ‰ (relative to Air-N2). δ(18O) measured in the …
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Iceberg-keel ploughmarks on the seafloor of Antarctic continental shelves and the North Falkland Basin: implications for palaeo-glaciology
… the mid-shelf Pine Island Trough and outermost Weddell Sea shelf regions of Antarctica, detailed analysis of >13,000 iceberg-keel ploughmarks was undertaken. By considering the draft of icebergs calved from Antarctica today, calculated from detailed satellite altimetric datasets by this work, …
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Seismic-stratigraphic analysis of shelf-margin delta/slope fan and basin floor fan on high-latitude and middle-latitude margins (Ross Sea, Weddell Sea and Alabama/West Florida shelf): Paleoclimatic and eustatic implications
… first chapter discusses the northwestern Ross Sea, the second discusses the southeastern Weddell Sea and the third discusses the Alabama/west Florida margin. The purpose was to investigate stratigraphic relationships between deposition during glacial periods (i.e., eustatic lowstands) and …
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Antarctic sea ice trends and its response to the Southern annular mode
Sea ice covers vast regions of the Southern Ocean and impacts on the climate as well as the plant and animal life of the region. The variability of sea ice in the Southern Ocean affects the entire food web of the region, from phytoplankton to Antarctic krill through to the apex predators such as …
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Modeling Studies of Antarctic Krill (<i>Euphausia superba</i>) Survival During Transport Across the Scotia Sea and Environs
… at South Georgia, which is in the eastern Scotia Sea, are hypothesized to be sustained by import of individuals from upstream regions, such as the western Antarctic Peninsula. To test this hypothesis a modeling framework consisting of the Harvard Ocean Prediction System (HOPS) and a …
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Quantitative ecology reveals scale-dependent structural processes of the Antarctic benthos through time
… scales. Depth, temperature, salinity, and sea ice impact community structure at large spatial scales (e.g., > 60 km). Far less is known about the interactions between taxa and environment at smaller scales, particularly due to the difficulties in collecting polar data. The study of …
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Marine cycling of neodymium in the South Atlantic and the Southern Oceans
… area of the South Atlantic, the Bellingshausen Sea, and the Antarctic sub-ice shelf cavities, respectively. Measurements on seawater neodymium isotopic composition (ƐNd) and carbon isotopic composition (δ13C) of 40°S transect in the South Atlantic are made to examine the cycling of Nd in this …
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Reconstruction of the historical climate of the Southern Ocean from whaling ships’ logbooks
… observations from the whaling logbooks. The mean sea-level pressure (MSLP) changes across the Southern Ocean diverge: for example, in the northern reaches (55°S latitudinal band) MSLP in the historical period (the 1930s and 1950s) is found to be lower than modern climatology (1981-2010). It is in …
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Topographic preconditioning of open ocean deep convection
… oceanic convection over Maud Rise in the Weddell Sea indicates that bottom topography may play a role in selecting the location and scale of deep convecting oceanic chimneys below large scale atmospheric negative buoyancy forcing. Topographic preconditioning of open ocean deep convection …
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Quaternary grounding-line fluctuations in Antarctica
… line, where the ice sheet goes afloat over seawater. However, there is to-date no conclusive evidence that the ice sheet has gone away in last few million years. Thus, characterizing and understanding the transitions between the glacial and interglacial states of the ice sheet is a …
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Iodine in sea ice and the polar atmosphere.
… been studied. Laboratory experiments involving sea ice- and ice associated- diatoms have shown how the extreme conditions experienced in sea ice brine channels may lead to an increase in production of organic forms of iodine. Trends were observed in production by different classes of enzymes, …
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Phytoplankton's role in the biological pump during the growth season across the Atlantic Southern Ocean
Southern Ocean phytoplankton growth is seasonally co-limited by light and iron availability. In winter, iron and macronutrients such as nitrate are supplied to surface waters during deep mixing events. Sea ice melt and increased solar radiation in spring drive rapid stratification of surface …
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The dynamics of mean circulation on the continental shelf
… e.g. in the Middle Atlantic Bight and in the Weddell Sea. A theoretical model is developed to explore the driving mechanism of this mean circulation. In the model, the velocity field is decomposed into a depth-independent bottom geostrophic component and a thermohaline component relative to …
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Evolution of tectonic and stratigraphic geometries in the Southern Outeniqua Basin
… margin during the incipient formation of the Weddell Sea (147Ma) between Antarctica and West Gondwana. Later mid-Jurassic (150-130Ma) extension along the North-Falkland rift zone lead to the oblique extension along the southern margin and the development of normal faults orientated NE-SW. …
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