Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica
The glaciers draining into the Amundsen Sea Embayment are rapidly losing mass, making a significant contribution to current sea level rise. Studies of Pine Island Glacier (PIG) in this region indicate that the mass loss is associated with rapid melting of its floating ice shelf driven by warm Circum...
Published in: | Journal of Geophysical Research: Oceans |
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American Geophysical Union
2013
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Online Access: | http://nora.nerc.ac.uk/id/eprint/21345/ https://nora.nerc.ac.uk/id/eprint/21345/1/jgrc20212.pdf |
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ftnerc:oai:nora.nerc.ac.uk:21345 2023-05-15T13:23:34+02:00 Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica Walker, Dziga P. Jenkins, Adrian Assmann, Karen M. Shoosmith, Deborah R. Brandon, Mark A. 2013-06-13 text http://nora.nerc.ac.uk/id/eprint/21345/ https://nora.nerc.ac.uk/id/eprint/21345/1/jgrc20212.pdf en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/21345/1/jgrc20212.pdf Walker, Dziga P.; Jenkins, Adrian orcid:0000-0002-9117-0616 Assmann, Karen M.; Shoosmith, Deborah R.; Brandon, Mark A. 2013 Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica. Journal of Geophysical Research: Oceans, 118 (6). 2906-2918. https://doi.org/10.1002/jgrc.20212 <https://doi.org/10.1002/jgrc.20212> Publication - Article PeerReviewed 2013 ftnerc https://doi.org/10.1002/jgrc.20212 2023-02-04T19:33:25Z The glaciers draining into the Amundsen Sea Embayment are rapidly losing mass, making a significant contribution to current sea level rise. Studies of Pine Island Glacier (PIG) in this region indicate that the mass loss is associated with rapid melting of its floating ice shelf driven by warm Circumpolar Deep Water (CDW) that is able to penetrate all the way to its grounding line, and that recent intensification of the mass loss is associated with higher melt rates and stronger subice-shelf circulation. CDW is sourced from within the Antarctic Circumpolar Current (ACC) situated well north of the glacial ice fronts. To be able to access the Amundsen Sea glaciers, CDW must first cross the continental shelf break where the deep ocean meets the shallower waters of the continental shelf. Here, we present data that shows how CDW moves along the continental slope and across the shelf break into the Amundsen Sea. On-shelf flow of CDW is enhanced where a subsea trough bisects the shelf edge. A previously unreported undercurrent is observed flowing eastward along the shelf edge and when this current encounters the trough mouth it circulates southward into the trough and toward the glaciers. Upwelling associated with this trough circulation appears to allow Lower CDW onto the shelf that would otherwise be blocked by the topography. These observations concur with the results of a theoretical modeling study of circulation in a similar topographic setting and also with the results of a regional ocean/ice modeling study of the Amundsen Sea specifically. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Antarctica Journal Ice Shelf Pine Island Pine Island Glacier Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Amundsen Sea Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Journal of Geophysical Research: Oceans 118 6 2906 2918 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The glaciers draining into the Amundsen Sea Embayment are rapidly losing mass, making a significant contribution to current sea level rise. Studies of Pine Island Glacier (PIG) in this region indicate that the mass loss is associated with rapid melting of its floating ice shelf driven by warm Circumpolar Deep Water (CDW) that is able to penetrate all the way to its grounding line, and that recent intensification of the mass loss is associated with higher melt rates and stronger subice-shelf circulation. CDW is sourced from within the Antarctic Circumpolar Current (ACC) situated well north of the glacial ice fronts. To be able to access the Amundsen Sea glaciers, CDW must first cross the continental shelf break where the deep ocean meets the shallower waters of the continental shelf. Here, we present data that shows how CDW moves along the continental slope and across the shelf break into the Amundsen Sea. On-shelf flow of CDW is enhanced where a subsea trough bisects the shelf edge. A previously unreported undercurrent is observed flowing eastward along the shelf edge and when this current encounters the trough mouth it circulates southward into the trough and toward the glaciers. Upwelling associated with this trough circulation appears to allow Lower CDW onto the shelf that would otherwise be blocked by the topography. These observations concur with the results of a theoretical modeling study of circulation in a similar topographic setting and also with the results of a regional ocean/ice modeling study of the Amundsen Sea specifically. |
format |
Article in Journal/Newspaper |
author |
Walker, Dziga P. Jenkins, Adrian Assmann, Karen M. Shoosmith, Deborah R. Brandon, Mark A. |
spellingShingle |
Walker, Dziga P. Jenkins, Adrian Assmann, Karen M. Shoosmith, Deborah R. Brandon, Mark A. Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica |
author_facet |
Walker, Dziga P. Jenkins, Adrian Assmann, Karen M. Shoosmith, Deborah R. Brandon, Mark A. |
author_sort |
Walker, Dziga P. |
title |
Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica |
title_short |
Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica |
title_full |
Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica |
title_fullStr |
Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica |
title_full_unstemmed |
Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica |
title_sort |
oceanographic observations at the shelf break of the amundsen sea, antarctica |
publisher |
American Geophysical Union |
publishDate |
2013 |
url |
http://nora.nerc.ac.uk/id/eprint/21345/ https://nora.nerc.ac.uk/id/eprint/21345/1/jgrc20212.pdf |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) |
geographic |
Antarctic The Antarctic Amundsen Sea Pine Island Glacier |
geographic_facet |
Antarctic The Antarctic Amundsen Sea Pine Island Glacier |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Antarctica Journal Ice Shelf Pine Island Pine Island Glacier |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Antarctica Journal Ice Shelf Pine Island Pine Island Glacier |
op_relation |
https://nora.nerc.ac.uk/id/eprint/21345/1/jgrc20212.pdf Walker, Dziga P.; Jenkins, Adrian orcid:0000-0002-9117-0616 Assmann, Karen M.; Shoosmith, Deborah R.; Brandon, Mark A. 2013 Oceanographic observations at the shelf break of the Amundsen Sea, Antarctica. Journal of Geophysical Research: Oceans, 118 (6). 2906-2918. https://doi.org/10.1002/jgrc.20212 <https://doi.org/10.1002/jgrc.20212> |
op_doi |
https://doi.org/10.1002/jgrc.20212 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
118 |
container_issue |
6 |
container_start_page |
2906 |
op_container_end_page |
2918 |
_version_ |
1766373194443259904 |