A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current
The relative roles of isoneutral stirring by mesoscale eddies and dianeutral stirring by small-scale turbulence in setting the large-scale temperature–salinity relation of the Southern Ocean against the action of the overturning circulation are assessed by analyzing a set of shear and temperature mi...
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ftmit:oai:dspace.mit.edu:1721.1/108339 2023-06-11T04:06:42+02:00 A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current Naveira Garabato, Alberto C. Polzin, Kurt L. Ferrari, Raffaele Zika, Jan D. Forryan, Alexander Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ferrari, Raffaele 2015-02 application/pdf http://hdl.handle.net/1721.1/108339 en_US eng American Meteorological Society http://dx.doi.org/10.1175/jpo-d-15-0025.1 Journal of Physical Oceanography 0022-3670 1520-0485 http://hdl.handle.net/1721.1/108339 Naveira Garabato, Alberto C.; Polzin, Kurt L.; Ferrari, Raffaele; Zika, Jan D. and Forryan, Alexander. “A Microscale View of Mixing and Overturning Across the Antarctic Circumpolar Current.” Journal of Physical Oceanography 46, no. 1 (January 2016): 233–254. © American Meteorological Society orcid:0000-0002-3736-1956 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Meteorological Society Article http://purl.org/eprint/type/JournalArticle 2015 ftmit https://doi.org/10.1175/jpo-d-15-0025.1 2023-05-29T08:31:13Z The relative roles of isoneutral stirring by mesoscale eddies and dianeutral stirring by small-scale turbulence in setting the large-scale temperature–salinity relation of the Southern Ocean against the action of the overturning circulation are assessed by analyzing a set of shear and temperature microstructure measurements across Drake Passage in a “triple decomposition” framework. It is shown that a picture of mixing and overturning across a region of the Antarctic Circumpolar Current (ACC) may be constructed from a relatively modest number of microstructure profiles. The rates of isoneutral and dianeutral stirring are found to exhibit distinct, characteristic, and abrupt variations: most notably, a one to two orders of magnitude suppression of isoneutral stirring in the upper kilometer of the ACC frontal jets and an order of magnitude intensification of dianeutral stirring in the subpycnocline and deepest layers of the ACC. These variations balance an overturning circulation with meridional flows of O(1) mm s⁻¹ across the ACC’s mean thermohaline structure. Isoneutral and dianeutral stirring play complementary roles in balancing the overturning, with isoneutral processes dominating in intermediate waters and the Upper Circumpolar Deep Water and dianeutral processes prevailing in lighter and denser layers. Article in Journal/Newspaper Antarc* Antarctic Drake Passage Southern Ocean DSpace@MIT (Massachusetts Institute of Technology) Antarctic Southern Ocean The Antarctic Drake Passage Journal of Physical Oceanography 46 1 233 254 |
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Open Polar |
collection |
DSpace@MIT (Massachusetts Institute of Technology) |
op_collection_id |
ftmit |
language |
English |
description |
The relative roles of isoneutral stirring by mesoscale eddies and dianeutral stirring by small-scale turbulence in setting the large-scale temperature–salinity relation of the Southern Ocean against the action of the overturning circulation are assessed by analyzing a set of shear and temperature microstructure measurements across Drake Passage in a “triple decomposition” framework. It is shown that a picture of mixing and overturning across a region of the Antarctic Circumpolar Current (ACC) may be constructed from a relatively modest number of microstructure profiles. The rates of isoneutral and dianeutral stirring are found to exhibit distinct, characteristic, and abrupt variations: most notably, a one to two orders of magnitude suppression of isoneutral stirring in the upper kilometer of the ACC frontal jets and an order of magnitude intensification of dianeutral stirring in the subpycnocline and deepest layers of the ACC. These variations balance an overturning circulation with meridional flows of O(1) mm s⁻¹ across the ACC’s mean thermohaline structure. Isoneutral and dianeutral stirring play complementary roles in balancing the overturning, with isoneutral processes dominating in intermediate waters and the Upper Circumpolar Deep Water and dianeutral processes prevailing in lighter and denser layers. |
author2 |
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ferrari, Raffaele |
format |
Article in Journal/Newspaper |
author |
Naveira Garabato, Alberto C. Polzin, Kurt L. Ferrari, Raffaele Zika, Jan D. Forryan, Alexander |
spellingShingle |
Naveira Garabato, Alberto C. Polzin, Kurt L. Ferrari, Raffaele Zika, Jan D. Forryan, Alexander A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
author_facet |
Naveira Garabato, Alberto C. Polzin, Kurt L. Ferrari, Raffaele Zika, Jan D. Forryan, Alexander |
author_sort |
Naveira Garabato, Alberto C. |
title |
A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
title_short |
A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
title_full |
A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
title_fullStr |
A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
title_full_unstemmed |
A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
title_sort |
microscale view of mixing and overturning across the antarctic circumpolar current |
publisher |
American Meteorological Society |
publishDate |
2015 |
url |
http://hdl.handle.net/1721.1/108339 |
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_source |
American Meteorological Society |
op_relation |
http://dx.doi.org/10.1175/jpo-d-15-0025.1 Journal of Physical Oceanography 0022-3670 1520-0485 http://hdl.handle.net/1721.1/108339 Naveira Garabato, Alberto C.; Polzin, Kurt L.; Ferrari, Raffaele; Zika, Jan D. and Forryan, Alexander. “A Microscale View of Mixing and Overturning Across the Antarctic Circumpolar Current.” Journal of Physical Oceanography 46, no. 1 (January 2016): 233–254. © American Meteorological Society orcid:0000-0002-3736-1956 |
op_rights |
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. |
op_doi |
https://doi.org/10.1175/jpo-d-15-0025.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
46 |
container_issue |
1 |
container_start_page |
233 |
op_container_end_page |
254 |
_version_ |
1768378773749628928 |