scholarly journals Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica

2021 ◽  
pp. 101901
Author(s):  
Pierre-Vincent Huot ◽  
Christoph Kittel ◽  
Thierry Fichefet ◽  
Nicolas C. Jourdain ◽  
Jean Sterlin ◽  
...  
Keyword(s):  
Sea Ice ◽  
East Antarctica ◽  
Atmospheric Forcing

scholarly journals Methanesulphonic acid movement in solid ice cores

2004 ◽  
Vol 39 ◽  
pp. 540-544 ◽  
Author(s):  
Barbara T. Smith ◽  
Tas D. Van Ommen ◽  
Mark A. J. Curran
Keyword(s):  
Diffusion Coefficient ◽  
Biological Activity ◽  
Sea Ice ◽  
Diffusion Mechanism ◽  
Ice Core ◽  
Ice Cores ◽  
East Antarctica ◽  
The Core ◽  
Central Value

AbstractMethanesulphonic acid (MSA) is an important trace-ion constituent in ice cores, with connections to biological activity and sea-ice distribution. Post-depositional movement of MSA has been documented in firn, and this study investigates movement in solid ice by measuring variations in MSA distribution across several horizontal sections from an ice core after 14.5 years storage. The core used is from below the bubble close-off depth at Dome Summit South, Law Dome, East Antarctica. MSA concentration was studied at 3 and 0.5 cm resolution across the core widths. Its distribution was uniform through the core centres, but the outer 3 cm showed gradients in concentrations down to less than half of the central value at the core edge. This effect is consistent with diffusion to the surrounding air during its 14.5 year storage. The diffusion coefficient is calculated to be 2 ×10–13 m2 s–1, and the implications for the diffusion mechanism are discussed.

Emperor penguins and the First German South Polar Expedition, 1901–1903: The elusive colony in Posadowsky Bay

Polar Record ◽  
2021 ◽  
Vol 57 ◽  
Author(s):  
Barbara Wienecke
Keyword(s):  
Sea Ice ◽  
Satellite Imagery ◽  
East Antarctica ◽  
Scientific Interest ◽  
Breeding Colony ◽  
Emperor Penguins ◽  
Aptenodytes Forsteri ◽  
South Polar

Abstract Members of the First German South Polar Expedition (1901–1903) encountered emperor penguins (Aptenodytes forsteri) near their wintering station in the sea ice of Posadowsky Bay, East Antarctica. The penguins appeared to be generally less of scientific interest, but more of a useful resource. Despite the presence of chicks, the men were uncertain about the existence of a breeding colony, and did not record the position of the penguin aggregation they encountered. In later years, only a few sightings confirmed the existence of a colony, and the last ground visit took place in 1960. Based on satellite imagery, a colony appears to exist even now. This paper examines what impact the expedition may have had on this colony, and whether it still exists.

scholarly journals Major factors controlling Holocene δ13Corgchanges in a seasonal sea-ice environment, Adélie Land, East Antarctica

2005 ◽  
Vol 19 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
X. Crosta ◽  
J. Crespin ◽  
I. Billy ◽  
O. Ther
Keyword(s):  
Sea Ice ◽  
East Antarctica ◽  
Major Factors

scholarly journals Characteristics of Sea-ice thickness and Snow-depth distributions of the Summer landfast ice in Lützow-Holm Bay, East Antarctica

2006 ◽  
Vol 44 ◽  
pp. 281-287 ◽  
Author(s):  
Shotaro Uto ◽  
Haruhito Shimoda ◽  
Shuki Ushio
Keyword(s):  
Sea Ice ◽  
Interannual Variability ◽  
Snow Depth ◽  
East Antarctica ◽  
Ice Thickness ◽  
First Year ◽  
Total Thickness ◽  
Sea Ice Thickness ◽  
Landfast Ice ◽  
Northeasterly Wind

AbstractSea-ice observations have been conducted on board icebreaker shirase as a part of the Scientific programs of the Japanese Antarctic Research Expedition. We Summarize these to investigate Spatial and interannual variability of ice thickness and Snow depth of the Summer landfast ice in Lützow-Holm Bay, East Antarctica. Electromagnetic–inductive observations, which have been conducted Since 2000, provide total thickness distributions with high Spatial resolution. A clear discontinuity, which Separates thin first-year ice from thick multi-year ice, was observed in the total thickness distributions in two voyages. Comparison with Satellite images revealed that Such phenomena reflected the past breakup of the landfast ice. Within 20–30km from the Shore, total thickness as well as Snow depth decrease toward the Shore. This is due to the Snowdrift by the Strong northeasterly wind. Video observations of Sea-ice thickness and Snow depth were conducted on 11 voyages Since December 1987. Probability density functions derived from total thickness distributions in each year are categorized into three types: a thin-ice, thick-ice and intermediate type. Such interannual variability primarily depends on the extent and duration of the Successive break-up events.

Arctic sea ice variability and trends in the last four decades: role of ocean-atmospheric forcing

2021 ◽  
pp. 301-324
Author(s):  
Avinash Kumar ◽  
Juhi Yadav ◽  
Rohit Srivastava ◽  
Rahul Mohan
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Atmospheric Forcing ◽  
Arctic Sea

Atmospheric forcing of coastal polynyas in the south-western Weddell Sea

2015 ◽  
Vol 27 (4) ◽  
pp. 388-402 ◽  
Author(s):  
Verena Haid ◽  
Ralph Timmermann ◽  
Lars Ebner ◽  
Günther Heinemann
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Reanalysis Data ◽  
Ocean Model ◽  
Weddell Sea ◽  
Small Scale ◽  
Atmospheric Conditions ◽  
Atmospheric Forcing ◽  
The South ◽  
Ice Production

AbstractThe development of coastal polynyas, areas of enhanced heat flux and sea ice production strongly depend on atmospheric conditions. In Antarctica, measurements are scarce and models are essential for the investigation of polynyas. A robust quantification of polynya exchange processes in simulations relies on a realistic representation of atmospheric conditions in the forcing dataset. The sensitivity of simulated coastal polynyas in the south-western Weddell Sea to the atmospheric forcing is investigated with the Finite-Element Sea ice-Ocean Model (FESOM) using daily NCEP/NCAR reanalysis data (NCEP), 6 hourly Global Model Europe (GME) data and two different hourly datasets from the high-resolution Consortium for Small-Scale Modelling (COSMO) model. Results are compared for April to August in 2007–09. The two coarse-scale datasets often produce the extremes of the data range, while the finer-scale forcings yield results closer to the median. The GME experiment features the strongest winds and, therefore, the greatest polynya activity, especially over the eastern continental shelf. This results in higher volume and export of High Salinity Shelf Water than in the NCEP and COSMO runs. The largest discrepancies between simulations occur for 2008, probably due to differing representations of the ENSO pattern at high southern latitudes. The results suggest that the large-scale wind field is of primary importance for polynya development.

scholarly journals A Numerical Investigation of Formation and Variability of Antarctic Bottom Water off Cape Darnley, East Antarctica

2014 ◽  
Vol 44 (11) ◽  
pp. 2921-2937 ◽  
Author(s):  
Yoshihiro Nakayama ◽  
Kay I. Ohshima ◽  
Yoshimasa Matsumura ◽  
Yasushi Fukamachi ◽  
Hiroyasu Hasumi
Keyword(s):  
Sea Ice ◽  
Continental Slope ◽  
Bottom Water ◽  
Heat Budget ◽  
East Antarctica ◽  
Salt Flux ◽  
Ice Formation ◽  
Minor Importance ◽  
Antarctic Bottom Water ◽  
Dense Water

Abstract At several locations around Antarctica, dense water is formed as a result of intense sea ice formation. When this dense water becomes sufficiently denser than the surrounding water, it descends the continental slope and forms Antarctic Bottom Water (AABW). This study presents the AABW formation off the coast of Cape Darnley [Cape Darnley Bottom Water (CDBW)] in East Antarctica, using a nonhydrostatic model. The model is forced for 8 months by a temporally uniform surface salt flux (because of sea ice formation) estimated from Advanced Microwave Scanning Radiometer for Earth Observing System (EOS; AMSR-E) data and a heat budget calculation. The authors reproduce AABW formation and associated periodic downslope flows of dense water. Descending pathways of dense water are largely determined by the topography; most dense water flows into depressions on the continental shelf, advects onto the continental slope, and is steered downslope to greater depths by the canyons. Intense sea ice formation is the most important factor in the formation of AABW off Cape Darnley, and the existence of depressions is of only minor importance for the flux of CDBW. The mechanism responsible for the periodic downslope flow of dense water is further analyzed using an idealized model setup. The period of dense water outflow is regulated primarily by the topographic beta effect.

scholarly journals Increased sea ice cover alters food web structure in East Antarctica

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Loïc N. Michel ◽  
Bruno Danis ◽  
Philippe Dubois ◽  
Marc Eleaume ◽  
Jérôme Fournier ◽  
...  
Keyword(s):  
Sea Ice ◽  
Food Web ◽  
Ice Cover ◽  
East Antarctica ◽  
Food Web Structure ◽  
Web Structure

scholarly journals Fast Ice Prediction System (FIPS) for land-fast sea ice at Prydz Bay, East Antarctica: an operational service for CHINARE

2020 ◽  
pp. 1-13
Author(s):  
Jiechen Zhao ◽  
Bin Cheng ◽  
Timo Vihma ◽  
Petra Heil ◽  
Fengming Hui ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Thickness ◽  
Cold Bias ◽  
Prediction System ◽  
Atmospheric Forcing ◽  
Ice Melt ◽  
Fast Ice ◽  
Sar Imagery ◽  
Operational Service ◽  
Snow And Ice

Abstract A Fast Ice Prediction System (FIPS) was constructed and is the first regional land-fast sea-ice forecasting system for the Antarctic. FIPS had two components: (1) near-real-time information on the ice-covered area from MODIS and SAR imagery that revealed, tidal cracks, ridged and rafted ice regions; (2) a high-resolution 1-D thermodynamic snow and ice model (HIGHTSI) that was extended to perform a 2-D simulation on snow and ice evolution using atmospheric forcing from ECMWF: either using ERA-Interim reanalysis (in hindcast mode) or HERS operational 10-day predictions (in forecast mode). A hindcast experiment for the 2015 season was in good agreement with field observations, with a mean bias of 0.14 ± 0.07 m and a correlation coefficient of 0.98 for modeled ice thickness. The errors are largely caused by a cold bias in the atmospheric forcing. The thick snow cover during the 2015 season led to modeled formation of extensive snow ice and superimposed ice. The first FIPS operational service was performed during the 2017/18 season. The system predicted a realistic ice thickness and onset of snow surface melt as well as the area of internal ice melt. The model results on the snow and ice properties were considered by the captain of R/V Xuelong when optimizing a low-risk route for on-ice transportation through fast ice to the coastal Zhongshan Station.

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