The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current
The date of inception of the Antarctic Circumpolar Current is debated due to uncertainty in the relative opening times of Drake Passage and the Tasman Seaway. Using an idealized eddy-resolving numerical ocean model, we investigate whether both ocean gateways have to be open to allow for a substantia...
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ftnerc:oai:nora.nerc.ac.uk:510890 2023-05-15T13:49:32+02:00 The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current Munday, D. R. Johnson, H. L. Marshall, D. P. 2015-03 text http://nora.nerc.ac.uk/id/eprint/510890/ https://nora.nerc.ac.uk/id/eprint/510890/1/Munday_et_al-2015-Paleoceanography.pdf https://doi.org/10.1002/2014PA002675 en eng Wiley https://nora.nerc.ac.uk/id/eprint/510890/1/Munday_et_al-2015-Paleoceanography.pdf Munday, D. R. orcid:0000-0003-1920-708X Johnson, H. L.; Marshall, D. P. 2015 The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current. Paleoceanography, 30 (3). 284-302. https://doi.org/10.1002/2014PA002675 <https://doi.org/10.1002/2014PA002675> cc_by_4 CC-BY Publication - Article PeerReviewed 2015 ftnerc https://doi.org/10.1002/2014PA002675 2023-02-04T19:41:38Z The date of inception of the Antarctic Circumpolar Current is debated due to uncertainty in the relative opening times of Drake Passage and the Tasman Seaway. Using an idealized eddy-resolving numerical ocean model, we investigate whether both ocean gateways have to be open to allow for a substantial circumpolar current. We find that overlapping continental barriers do not impede a circumpolar transport in excess of 50Sv, as long as a circumpolar path can be traced around the barriers. However, the presence of overlapping barriers does lead to an increased sensitivity of the current's volume transport to changes in wind stress. This change in sensitivity is interpreted in terms of the role of pressure drops across continental barriers and submerged bathymetry in balancing the momentum input by the surface wind stress. Specifically, when the pressure drop across continents is the main balancing sink of momentum, the zonal volume transport is sensitive to changes in wind stress. Changes in zonal volume transport take place via altering the depth-independent part of the circumpolar transport rather than that arising from thermal wind shear. In such a scenario, isopycnals continue to slope steeply across the model Southern Ocean, implying a strong connection between the deep and surface oceans. This may have consequences for the meridional overturning circulation and its sensitivity to wind stress. Article in Journal/Newspaper Antarc* Antarctic Drake Passage Southern Ocean Natural Environment Research Council: NERC Open Research Archive Antarctic Southern Ocean The Antarctic Drake Passage Paleoceanography 30 3 284 302 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The date of inception of the Antarctic Circumpolar Current is debated due to uncertainty in the relative opening times of Drake Passage and the Tasman Seaway. Using an idealized eddy-resolving numerical ocean model, we investigate whether both ocean gateways have to be open to allow for a substantial circumpolar current. We find that overlapping continental barriers do not impede a circumpolar transport in excess of 50Sv, as long as a circumpolar path can be traced around the barriers. However, the presence of overlapping barriers does lead to an increased sensitivity of the current's volume transport to changes in wind stress. This change in sensitivity is interpreted in terms of the role of pressure drops across continental barriers and submerged bathymetry in balancing the momentum input by the surface wind stress. Specifically, when the pressure drop across continents is the main balancing sink of momentum, the zonal volume transport is sensitive to changes in wind stress. Changes in zonal volume transport take place via altering the depth-independent part of the circumpolar transport rather than that arising from thermal wind shear. In such a scenario, isopycnals continue to slope steeply across the model Southern Ocean, implying a strong connection between the deep and surface oceans. This may have consequences for the meridional overturning circulation and its sensitivity to wind stress. |
format |
Article in Journal/Newspaper |
author |
Munday, D. R. Johnson, H. L. Marshall, D. P. |
spellingShingle |
Munday, D. R. Johnson, H. L. Marshall, D. P. The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current |
author_facet |
Munday, D. R. Johnson, H. L. Marshall, D. P. |
author_sort |
Munday, D. R. |
title |
The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current |
title_short |
The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current |
title_full |
The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current |
title_fullStr |
The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current |
title_full_unstemmed |
The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current |
title_sort |
role of ocean gateways in the dynamics and sensitivity to wind stress of the early antarctic circumpolar current |
publisher |
Wiley |
publishDate |
2015 |
url |
http://nora.nerc.ac.uk/id/eprint/510890/ https://nora.nerc.ac.uk/id/eprint/510890/1/Munday_et_al-2015-Paleoceanography.pdf https://doi.org/10.1002/2014PA002675 |
geographic |
Antarctic Southern Ocean The Antarctic Drake Passage |
geographic_facet |
Antarctic Southern Ocean The Antarctic Drake Passage |
genre |
Antarc* Antarctic Drake Passage Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Southern Ocean |
op_relation |
https://nora.nerc.ac.uk/id/eprint/510890/1/Munday_et_al-2015-Paleoceanography.pdf Munday, D. R. orcid:0000-0003-1920-708X Johnson, H. L.; Marshall, D. P. 2015 The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current. Paleoceanography, 30 (3). 284-302. https://doi.org/10.1002/2014PA002675 <https://doi.org/10.1002/2014PA002675> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1002/2014PA002675 |
container_title |
Paleoceanography |
container_volume |
30 |
container_issue |
3 |
container_start_page |
284 |
op_container_end_page |
302 |
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1766251492767956992 |