Eddy stirring in the Southern Ocean
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 ? from a collection of hydrographic and altimetric observati...
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2011
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ftsouthampton:oai:eprints.soton.ac.uk:153603 2023-08-27T04:06:15+02:00 Eddy stirring in the Southern Ocean Naveira Garabato, A.C. Ferrari, R. Polzin, K.L. 2011 https://eprints.soton.ac.uk/153603/ unknown Naveira Garabato, A.C., Ferrari, R. and Polzin, K.L. (2011) Eddy stirring in the Southern Ocean. Journal of Geophysical Research, 116 (C9), C09019. (doi:10.1029/2010JC006818 <http://dx.doi.org/10.1029/2010JC006818>). Article PeerReviewed 2011 ftsouthampton https://doi.org/10.1029/2010JC006818 2023-08-03T22:19:34Z 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 ? from a collection of hydrographic and altimetric observations, analyzed in a mixing length theoretical framework. It is shown that, typically, ? 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 ? 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. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean University of Southampton: e-Prints Soton Antarctic Southern Ocean The Antarctic Journal of Geophysical Research 116 C9 |
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University of Southampton: e-Prints Soton |
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ftsouthampton |
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description |
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 ? from a collection of hydrographic and altimetric observations, analyzed in a mixing length theoretical framework. It is shown that, typically, ? 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 ? 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. |
format |
Article in Journal/Newspaper |
author |
Naveira Garabato, A.C. Ferrari, R. Polzin, K.L. |
spellingShingle |
Naveira Garabato, A.C. Ferrari, R. Polzin, K.L. Eddy stirring in the Southern Ocean |
author_facet |
Naveira Garabato, A.C. Ferrari, R. Polzin, K.L. |
author_sort |
Naveira Garabato, A.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 |
publishDate |
2011 |
url |
https://eprints.soton.ac.uk/153603/ |
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_relation |
Naveira Garabato, A.C., Ferrari, R. and Polzin, K.L. (2011) Eddy stirring in the Southern Ocean. Journal of Geophysical Research, 116 (C9), C09019. (doi:10.1029/2010JC006818 <http://dx.doi.org/10.1029/2010JC006818>). |
op_doi |
https://doi.org/10.1029/2010JC006818 |
container_title |
Journal of Geophysical Research |
container_volume |
116 |
container_issue |
C9 |
_version_ |
1775347058063966208 |