Overturning cells in the Southern Ocean and subtropical gyres
The circulation of the subtropical gyres can be decomposed into a horizontal recirculation along contours of constant Bernoulli potential and an overturning circulation across these contours. While the geometry and topology of Bernoulli contours is more complicated in the subtropical gyres than in t...
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ftdoajarticles:oai:doaj.org/article:b3d3a4e2229b4fb49d790dd97ca7615c 2023-05-15T18:24:19+02:00 Overturning cells in the Southern Ocean and subtropical gyres J. A. Polton D. P. Marshall 2007-01-01T00:00:00Z https://doaj.org/article/b3d3a4e2229b4fb49d790dd97ca7615c EN eng Copernicus Publications http://www.ocean-sci.net/3/17/2007/os-3-17-2007.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 https://doaj.org/article/b3d3a4e2229b4fb49d790dd97ca7615c Ocean Science, Vol 3, Iss 1, Pp 17-30 (2007) Geography. Anthropology. Recreation G Environmental sciences GE1-350 article 2007 ftdoajarticles 2022-12-31T01:43:37Z The circulation of the subtropical gyres can be decomposed into a horizontal recirculation along contours of constant Bernoulli potential and an overturning circulation across these contours. While the geometry and topology of Bernoulli contours is more complicated in the subtropical gyres than in the Southern Ocean, these subtropical overturning circulations are very much analogous to the overturning cell found in the Southern Ocean. This analogy is formalised through an exact integral constraint, including the rectified effects of transient eddies. The constraint can be interpreted either in terms of vertical fluxes of potential vorticity, or equivalently as an integral buoyancy budget for an imaginary fluid parcel recirculating around a closed Bernoulli contour. Under conditions of vanishing buoyancy and mechanical forcing, the constraint reduces to a generalised non-acceleration condition, under which the Eulerian-mean and eddy-induced overturning circulations exactly compensate. The terms in the integral constraint are diagnosed in an eddy-permitting ocean model in both the North Pacific subtropical gyre and the Southern Ocean. The extent to which the Eulerian-mean and eddy-induced overturning circulations compensate is discussed in each case. Article in Journal/Newspaper Southern Ocean Directory of Open Access Journals: DOAJ Articles Pacific Southern Ocean |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
spellingShingle |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 J. A. Polton D. P. Marshall Overturning cells in the Southern Ocean and subtropical gyres |
topic_facet |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
description |
The circulation of the subtropical gyres can be decomposed into a horizontal recirculation along contours of constant Bernoulli potential and an overturning circulation across these contours. While the geometry and topology of Bernoulli contours is more complicated in the subtropical gyres than in the Southern Ocean, these subtropical overturning circulations are very much analogous to the overturning cell found in the Southern Ocean. This analogy is formalised through an exact integral constraint, including the rectified effects of transient eddies. The constraint can be interpreted either in terms of vertical fluxes of potential vorticity, or equivalently as an integral buoyancy budget for an imaginary fluid parcel recirculating around a closed Bernoulli contour. Under conditions of vanishing buoyancy and mechanical forcing, the constraint reduces to a generalised non-acceleration condition, under which the Eulerian-mean and eddy-induced overturning circulations exactly compensate. The terms in the integral constraint are diagnosed in an eddy-permitting ocean model in both the North Pacific subtropical gyre and the Southern Ocean. The extent to which the Eulerian-mean and eddy-induced overturning circulations compensate is discussed in each case. |
format |
Article in Journal/Newspaper |
author |
J. A. Polton D. P. Marshall |
author_facet |
J. A. Polton D. P. Marshall |
author_sort |
J. A. Polton |
title |
Overturning cells in the Southern Ocean and subtropical gyres |
title_short |
Overturning cells in the Southern Ocean and subtropical gyres |
title_full |
Overturning cells in the Southern Ocean and subtropical gyres |
title_fullStr |
Overturning cells in the Southern Ocean and subtropical gyres |
title_full_unstemmed |
Overturning cells in the Southern Ocean and subtropical gyres |
title_sort |
overturning cells in the southern ocean and subtropical gyres |
publisher |
Copernicus Publications |
publishDate |
2007 |
url |
https://doaj.org/article/b3d3a4e2229b4fb49d790dd97ca7615c |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Ocean Science, Vol 3, Iss 1, Pp 17-30 (2007) |
op_relation |
http://www.ocean-sci.net/3/17/2007/os-3-17-2007.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 https://doaj.org/article/b3d3a4e2229b4fb49d790dd97ca7615c |
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1766204756030652416 |