Connecting Antarctic Cross-Slope Exchange with Southern Ocean Overturning
Previous idealized investigations of Southern Ocean overturning have omitted its connection with the Antarctic continental shelves, leaving the influence of shelf processes on Antarctic Bottom Water (AABW) export unconsidered. In particular, the contribution of mesoscale eddies to setting the strati...
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ftcaltechauth:oai:authors.library.caltech.edu:j8gs2-azq33 2024-06-23T07:47:50+00:00 Connecting Antarctic Cross-Slope Exchange with Southern Ocean Overturning Stewart, Andrew L. Thompson, Andrew F. 2013-07 https://doi.org/10.1175/JPO-D-12-0205.1 unknown American Meteorological Society https://doi.org/10.1175/JPO-D-12-0205.1 oai:authors.library.caltech.edu:j8gs2-azq33 eprintid:43713 resolverid:CaltechAUTHORS:20140207-083123508 info:eu-repo/semantics/openAccess Other Journal of Physical Oceanography, 43(7), 1453-1471, (2013-07) Antarctica Southern Ocean Eddies Meridional overturning circulation Mesoscale processes Primitive equations model info:eu-repo/semantics/article 2013 ftcaltechauth https://doi.org/10.1175/JPO-D-12-0205.1 2024-06-12T05:56:05Z Previous idealized investigations of Southern Ocean overturning have omitted its connection with the Antarctic continental shelves, leaving the influence of shelf processes on Antarctic Bottom Water (AABW) export unconsidered. In particular, the contribution of mesoscale eddies to setting the stratification and overturning circulation in the Antarctic Circumpolar Current (ACC) is well established, yet their role in cross-shelf exchange of water masses remains unclear. This study proposes a residual-mean theory that elucidates the connection between Antarctic cross-shelf exchange and overturning in the ACC, and the contribution of mesoscale eddies to the export of AABW. The authors motivate and verify this theory using an eddy-resolving process model of a sector of the Southern Ocean. The strength and pattern of the simulated overturning circulation strongly resemble those of the real ocean and are closely captured by the residual-mean theory. Over the continental slope baroclinic instability is suppressed, and so transport by mesoscale eddies is reduced. This suppression of the eddy fluxes also gives rise to the steep "V"-shaped isopycnals that characterize the Antarctic Slope Front in AABW-forming regions of the continental shelf. Furthermore, to produce water on the continental shelf that is dense enough to sink to the deep ocean, the deep overturning cell must be at least comparable in strength to wind-driven mean overturning on the continental slope. This results in a strong sensitivity of the deep overturning strength to changes in the polar easterly winds. © 2013 American Meteorological Society. Manuscript received 14 October 2012, in final form 11 March 2013. A.L.S.'s and A.F.T.'s research was supported by the California Institute of Technology and NSF Award OCE-1235488. The simulations presented herein were conducted using the CITerra computing cluster in the Division of Geological and Planetary Sciences at the California Institute of Technology, and the authors thank the CITerra technicians for ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Southern Ocean Caltech Authors (California Institute of Technology) Antarctic Southern Ocean The Antarctic Journal of Physical Oceanography 43 7 1453 1471 |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
topic |
Antarctica Southern Ocean Eddies Meridional overturning circulation Mesoscale processes Primitive equations model |
spellingShingle |
Antarctica Southern Ocean Eddies Meridional overturning circulation Mesoscale processes Primitive equations model Stewart, Andrew L. Thompson, Andrew F. Connecting Antarctic Cross-Slope Exchange with Southern Ocean Overturning |
topic_facet |
Antarctica Southern Ocean Eddies Meridional overturning circulation Mesoscale processes Primitive equations model |
description |
Previous idealized investigations of Southern Ocean overturning have omitted its connection with the Antarctic continental shelves, leaving the influence of shelf processes on Antarctic Bottom Water (AABW) export unconsidered. In particular, the contribution of mesoscale eddies to setting the stratification and overturning circulation in the Antarctic Circumpolar Current (ACC) is well established, yet their role in cross-shelf exchange of water masses remains unclear. This study proposes a residual-mean theory that elucidates the connection between Antarctic cross-shelf exchange and overturning in the ACC, and the contribution of mesoscale eddies to the export of AABW. The authors motivate and verify this theory using an eddy-resolving process model of a sector of the Southern Ocean. The strength and pattern of the simulated overturning circulation strongly resemble those of the real ocean and are closely captured by the residual-mean theory. Over the continental slope baroclinic instability is suppressed, and so transport by mesoscale eddies is reduced. This suppression of the eddy fluxes also gives rise to the steep "V"-shaped isopycnals that characterize the Antarctic Slope Front in AABW-forming regions of the continental shelf. Furthermore, to produce water on the continental shelf that is dense enough to sink to the deep ocean, the deep overturning cell must be at least comparable in strength to wind-driven mean overturning on the continental slope. This results in a strong sensitivity of the deep overturning strength to changes in the polar easterly winds. © 2013 American Meteorological Society. Manuscript received 14 October 2012, in final form 11 March 2013. A.L.S.'s and A.F.T.'s research was supported by the California Institute of Technology and NSF Award OCE-1235488. The simulations presented herein were conducted using the CITerra computing cluster in the Division of Geological and Planetary Sciences at the California Institute of Technology, and the authors thank the CITerra technicians for ... |
format |
Article in Journal/Newspaper |
author |
Stewart, Andrew L. Thompson, Andrew F. |
author_facet |
Stewart, Andrew L. Thompson, Andrew F. |
author_sort |
Stewart, Andrew L. |
title |
Connecting Antarctic Cross-Slope Exchange with Southern Ocean Overturning |
title_short |
Connecting Antarctic Cross-Slope Exchange with Southern Ocean Overturning |
title_full |
Connecting Antarctic Cross-Slope Exchange with Southern Ocean Overturning |
title_fullStr |
Connecting Antarctic Cross-Slope Exchange with Southern Ocean Overturning |
title_full_unstemmed |
Connecting Antarctic Cross-Slope Exchange with Southern Ocean Overturning |
title_sort |
connecting antarctic cross-slope exchange with southern ocean overturning |
publisher |
American Meteorological Society |
publishDate |
2013 |
url |
https://doi.org/10.1175/JPO-D-12-0205.1 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Southern Ocean |
op_source |
Journal of Physical Oceanography, 43(7), 1453-1471, (2013-07) |
op_relation |
https://doi.org/10.1175/JPO-D-12-0205.1 oai:authors.library.caltech.edu:j8gs2-azq33 eprintid:43713 resolverid:CaltechAUTHORS:20140207-083123508 |
op_rights |
info:eu-repo/semantics/openAccess Other |
op_doi |
https://doi.org/10.1175/JPO-D-12-0205.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
43 |
container_issue |
7 |
container_start_page |
1453 |
op_container_end_page |
1471 |
_version_ |
1802638032106422272 |