The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf
Oceanic heat strongly influences the glaciers and ice shelves along West Antarctica. Prior studies show that the subsurface onshore heat flux from the Southern Ocean on the shelf occurs through deep, glacially carved channels. The mechanisms enabling the export of colder shelf waters to the open oce...
Published in: | Journal of Geophysical Research: Oceans |
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Language: | English |
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American Geophysical Union
2019
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Online Access: | http://nora.nerc.ac.uk/id/eprint/525558/ https://nora.nerc.ac.uk/id/eprint/525558/1/Brearley_et_al-2019-Journal_of_Geophysical_Research__Oceans.pdf https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JC014679 |
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ftnerc:oai:nora.nerc.ac.uk:525558 2023-05-15T13:41:44+02:00 The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf Brearley, J.A. Moffat, C. Venables, H.J. Meredith, M.P. Dinniman, D.S. 2019-11 text http://nora.nerc.ac.uk/id/eprint/525558/ https://nora.nerc.ac.uk/id/eprint/525558/1/Brearley_et_al-2019-Journal_of_Geophysical_Research__Oceans.pdf https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JC014679 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/525558/1/Brearley_et_al-2019-Journal_of_Geophysical_Research__Oceans.pdf Brearley, J.A. orcid:0000-0003-3700-8017 Moffat, C.; Venables, H.J.; Meredith, M.P. orcid:0000-0002-7342-7756 Dinniman, D.S. 2019 The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf. Journal of Geophysical Research: Oceans, 124 (11). 7718-7743. https://doi.org/10.1029/2018JC014679 <https://doi.org/10.1029/2018JC014679> cc_by_4 CC-BY Publication - Article PeerReviewed 2019 ftnerc https://doi.org/10.1029/2018JC014679 2023-02-04T19:49:28Z Oceanic heat strongly influences the glaciers and ice shelves along West Antarctica. Prior studies show that the subsurface onshore heat flux from the Southern Ocean on the shelf occurs through deep, glacially carved channels. The mechanisms enabling the export of colder shelf waters to the open ocean, however, have not been determined. Here, we use ocean glider measurements collected near the mouth of Marguerite Trough (MT), west Antarctic Peninsula, to reveal shelf‐modified cold waters on the slope over a deep (2,700 m) offshore topographic bank. The shelf hydrographic sections show subsurface cold features (θ <=1.5 °C), and associated potential vorticity fields suggest a significant instability‐driven eddy field. Output from a high‐resolution numerical model reveals offshore export modulated by small (6 km), cold‐cored, cyclonic eddies preferentially generated along the slope and at the mouth of MT. While baroclinic and barotropic instabilities appear active in the surrounding open ocean, the former is suppressed along the steep shelf slopes, while the latter appears enhanced. Altimetry and model output reveal the mean slope flow splitting to form an offshore branch over the bank, which eventually forms a large (116 km wide) persistent lee eddy, and an onshore branch in MT. The offshore flow forms a pathway for the small cold‐cored eddies to move offshore, where they contribute significantly to cooling over the bank, including the large lee eddy. These results suggest eddy fluxes, and topographically modulated flows are key mechanisms for shelf water export along this shelf, just as they are for the shoreward warm water transport. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Ice Shelves Southern Ocean West Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic Southern Ocean Antarctic Peninsula West Antarctica Marguerite ENVELOPE(141.378,141.378,-66.787,-66.787) Journal of Geophysical Research: Oceans 124 11 7718 7742 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Oceanic heat strongly influences the glaciers and ice shelves along West Antarctica. Prior studies show that the subsurface onshore heat flux from the Southern Ocean on the shelf occurs through deep, glacially carved channels. The mechanisms enabling the export of colder shelf waters to the open ocean, however, have not been determined. Here, we use ocean glider measurements collected near the mouth of Marguerite Trough (MT), west Antarctic Peninsula, to reveal shelf‐modified cold waters on the slope over a deep (2,700 m) offshore topographic bank. The shelf hydrographic sections show subsurface cold features (θ <=1.5 °C), and associated potential vorticity fields suggest a significant instability‐driven eddy field. Output from a high‐resolution numerical model reveals offshore export modulated by small (6 km), cold‐cored, cyclonic eddies preferentially generated along the slope and at the mouth of MT. While baroclinic and barotropic instabilities appear active in the surrounding open ocean, the former is suppressed along the steep shelf slopes, while the latter appears enhanced. Altimetry and model output reveal the mean slope flow splitting to form an offshore branch over the bank, which eventually forms a large (116 km wide) persistent lee eddy, and an onshore branch in MT. The offshore flow forms a pathway for the small cold‐cored eddies to move offshore, where they contribute significantly to cooling over the bank, including the large lee eddy. These results suggest eddy fluxes, and topographically modulated flows are key mechanisms for shelf water export along this shelf, just as they are for the shoreward warm water transport. |
format |
Article in Journal/Newspaper |
author |
Brearley, J.A. Moffat, C. Venables, H.J. Meredith, M.P. Dinniman, D.S. |
spellingShingle |
Brearley, J.A. Moffat, C. Venables, H.J. Meredith, M.P. Dinniman, D.S. The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf |
author_facet |
Brearley, J.A. Moffat, C. Venables, H.J. Meredith, M.P. Dinniman, D.S. |
author_sort |
Brearley, J.A. |
title |
The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf |
title_short |
The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf |
title_full |
The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf |
title_fullStr |
The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf |
title_full_unstemmed |
The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf |
title_sort |
role of eddies and topography in the export of shelf waters from the west antarctic peninsula shelf |
publisher |
American Geophysical Union |
publishDate |
2019 |
url |
http://nora.nerc.ac.uk/id/eprint/525558/ https://nora.nerc.ac.uk/id/eprint/525558/1/Brearley_et_al-2019-Journal_of_Geophysical_Research__Oceans.pdf https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JC014679 |
long_lat |
ENVELOPE(141.378,141.378,-66.787,-66.787) |
geographic |
Antarctic Southern Ocean Antarctic Peninsula West Antarctica Marguerite |
geographic_facet |
Antarctic Southern Ocean Antarctic Peninsula West Antarctica Marguerite |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Ice Shelves Southern Ocean West Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Ice Shelves Southern Ocean West Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/525558/1/Brearley_et_al-2019-Journal_of_Geophysical_Research__Oceans.pdf Brearley, J.A. orcid:0000-0003-3700-8017 Moffat, C.; Venables, H.J.; Meredith, M.P. orcid:0000-0002-7342-7756 Dinniman, D.S. 2019 The role of eddies and topography in the export of shelf waters from the West Antarctic Peninsula shelf. Journal of Geophysical Research: Oceans, 124 (11). 7718-7743. https://doi.org/10.1029/2018JC014679 <https://doi.org/10.1029/2018JC014679> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2018JC014679 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
124 |
container_issue |
11 |
container_start_page |
7718 |
op_container_end_page |
7742 |
_version_ |
1766156088358469632 |