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Record Details

Record 1 of 296
Surface winds over West Antarctica
Author and Affiliation:
Bromwich, David(Ohio State Univ., Columbus, OH, United States)
Abstract: Five winter months (April-August 1988) of thermal infrared satellite images were examined to investigate the occurrence of dark (warm) signatures across the Ross Ice Shelf in the Antarctic continent. These features are inferred to be generated by katabatic winds that descend from southern Marie Byrd Land and then blow horizontally across the ice shelf. Significant mass is added to this airstream by katabatic winds blowing from the major glaciers that flow through the Transantarctic Mountains from East Antarctica. These negatively buoyant katabatic winds can reach the northwestern edge of the shelf - a horizontal propagation distance of up to 1,000 km - 14 percent of the time. Where the airstream crosses from the ice shelf to the ice-covered Ross Sea, a prominent coastal polynya is formed. Because the downslope buoyancy force is near zero over the Ross Ice Shelf, the northwestward propagation of the katabatic air mass requires pressure gradient support. The study shows that the extended horizontal propagation of this atmospheric density current occurred in conjunction with the passage of synoptic cyclones over the southern Amundsen Sea. These cyclones can strengthen the pressure gradient in the interior of West Antarctica and make the pressure field favorable for northwestward movement of the katabatic winds from West Antarctica across the ice shelf in a geostrophic direction. The glacier winds from East Antarctica are further accelerated by the synoptic pressure gradient, usually undergo abrupt adjustment beyond the exit to the glacier valley, and merge into the mountain-parallel katabatic air mass.
Publication Date: Jul 01, 1993
Document ID:
19930022714
(Acquired Dec 28, 1995)
Accession Number: 93N31903
Subject Category: GEOPHYSICS
Coverage: Abstract Only
Document Type: Conference Paper
Publication Information: NASA. Goddard Space Flight Center, The First Annual West Antarctic Ice Sheet (WAIS) Science Workshop; p 44
Publisher Information: United States
Financial Sponsor: NASA; United States
Organization Source: Ohio State Univ.; Polar Research Center.; Columbus, OH, United States
Description: 1p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: ANTARCTIC REGIONS; GLACIERS; GROUND WIND; INFRARED IMAGERY; ROSS ICE SHELF; SATELLITE IMAGERY; AIR MASSES; ATMOSPHERIC DENSITY; CYCLONES; LAND ICE; MOUNTAINS; PRESSURE GRADIENTS; SEA ICE; WINTER
Imprint And Other Notes: In NASA. Goddard Space Flight Center, The First Annual West Antarctic Ice Sheet (WAIS) Science Workshop p 44 (SEE N93-31878 12-46)
Availability Source: Other Sources
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