Eddy stirring in the Southern Ocean
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C09019, doi:10.1029/2010JC006818. There is an ongo...
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/4855 2023-05-15T13:53:14+02:00 Eddy stirring in the Southern Ocean Naveira Garabato, Alberto C. Ferrari, Raffaele Polzin, Kurt L. 2011-09-17 application/pdf https://hdl.handle.net/1912/4855 en_US eng American Geophysical Union https://doi.org/10.1029/2010JC006818 Journal of Geophysical Research 116 (2011): C09019 https://hdl.handle.net/1912/4855 doi:10.1029/2010JC006818 Journal of Geophysical Research 116 (2011): C09019 doi:10.1029/2010JC006818 Antarctic Circumpolar Current Eddy stirring Mixing Article 2011 ftwhoas https://doi.org/10.1029/2010JC006818 2022-05-28T22:58:27Z Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C09019, doi:10.1029/2010JC006818. There is an ongoing debate concerning the distribution of eddy stirring across the Antarctic Circumpolar Current (ACC) and the nature of its controlling processes. The problem is addressed here by estimating the isentropic eddy diffusivity κ from a collection of hydrographic and altimetric observations, analyzed in a mixing length theoretical framework. It is shown that, typically, κ is suppressed by an order of magnitude in the upper kilometer of the ACC frontal jets relative to their surroundings, primarily as a result of a local reduction of the mixing length. This observation is reproduced by a quasi-geostrophic theory of eddy stirring across a broad barotropic jet based on the scaling law derived by Ferrari and Nikurashin (2010). The theory interprets the observed widespread suppression of the mixing length and κ in the upper layers of frontal jets as the kinematic consequence of eddy propagation relative to the mean flow within jet cores. Deviations from the prevalent regime of mixing suppression in the core of upper-ocean jets are encountered in a few special sites. Such ‘leaky jet’ segments appear to be associated with sharp stationary meanders of the mean flow that are generated by the interaction of the ACC with major topographic features. It is contended that the characteristic thermohaline structure of the Southern Ocean, consisting of multiple upper-ocean thermohaline fronts separated and underlaid by regions of homogenized properties, is largely a result of the widespread suppression of eddy stirring by parallel jets. This study was conducted during A.C.N. G.’s stay at MIT, which was supported jointly by MIT and the U.K. Natural Environment Research Council (NERC) through a NERC Advanced Research Fellowship ... Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Antarctic Southern Ocean The Antarctic Journal of Geophysical Research 116 C9 |
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Open Polar |
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Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Antarctic Circumpolar Current Eddy stirring Mixing |
spellingShingle |
Antarctic Circumpolar Current Eddy stirring Mixing Naveira Garabato, Alberto C. Ferrari, Raffaele Polzin, Kurt L. Eddy stirring in the Southern Ocean |
topic_facet |
Antarctic Circumpolar Current Eddy stirring Mixing |
description |
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C09019, doi:10.1029/2010JC006818. There is an ongoing debate concerning the distribution of eddy stirring across the Antarctic Circumpolar Current (ACC) and the nature of its controlling processes. The problem is addressed here by estimating the isentropic eddy diffusivity κ from a collection of hydrographic and altimetric observations, analyzed in a mixing length theoretical framework. It is shown that, typically, κ is suppressed by an order of magnitude in the upper kilometer of the ACC frontal jets relative to their surroundings, primarily as a result of a local reduction of the mixing length. This observation is reproduced by a quasi-geostrophic theory of eddy stirring across a broad barotropic jet based on the scaling law derived by Ferrari and Nikurashin (2010). The theory interprets the observed widespread suppression of the mixing length and κ in the upper layers of frontal jets as the kinematic consequence of eddy propagation relative to the mean flow within jet cores. Deviations from the prevalent regime of mixing suppression in the core of upper-ocean jets are encountered in a few special sites. Such ‘leaky jet’ segments appear to be associated with sharp stationary meanders of the mean flow that are generated by the interaction of the ACC with major topographic features. It is contended that the characteristic thermohaline structure of the Southern Ocean, consisting of multiple upper-ocean thermohaline fronts separated and underlaid by regions of homogenized properties, is largely a result of the widespread suppression of eddy stirring by parallel jets. This study was conducted during A.C.N. G.’s stay at MIT, which was supported jointly by MIT and the U.K. Natural Environment Research Council (NERC) through a NERC Advanced Research Fellowship ... |
format |
Article in Journal/Newspaper |
author |
Naveira Garabato, Alberto C. Ferrari, Raffaele Polzin, Kurt L. |
author_facet |
Naveira Garabato, Alberto C. Ferrari, Raffaele Polzin, Kurt L. |
author_sort |
Naveira Garabato, Alberto C. |
title |
Eddy stirring in the Southern Ocean |
title_short |
Eddy stirring in the Southern Ocean |
title_full |
Eddy stirring in the Southern Ocean |
title_fullStr |
Eddy stirring in the Southern Ocean |
title_full_unstemmed |
Eddy stirring in the Southern Ocean |
title_sort |
eddy stirring in the southern ocean |
publisher |
American Geophysical Union |
publishDate |
2011 |
url |
https://hdl.handle.net/1912/4855 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Journal of Geophysical Research 116 (2011): C09019 doi:10.1029/2010JC006818 |
op_relation |
https://doi.org/10.1029/2010JC006818 Journal of Geophysical Research 116 (2011): C09019 https://hdl.handle.net/1912/4855 doi:10.1029/2010JC006818 |
op_doi |
https://doi.org/10.1029/2010JC006818 |
container_title |
Journal of Geophysical Research |
container_volume |
116 |
container_issue |
C9 |
_version_ |
1766258236071084032 |