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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ftnerc:oai:nora.nerc.ac.uk:16033 2023-05-15T18:24:13+02:00 Overturning cells in the Southern Ocean and subtropical gyres Polton, Jeff A. Marshall, David P. 2007 http://nora.nerc.ac.uk/id/eprint/16033/ http://www.ocean-sci.net/3/17/2007/os-3-17-2007.pdf unknown Polton, Jeff A. orcid:0000-0003-0131-5250 Marshall, David P. 2007 Overturning cells in the Southern Ocean and subtropical gyres. Ocean Science, 3 (1). 17-30. https://doi.org/10.5194/os-3-17-2007 <https://doi.org/10.5194/os-3-17-2007> Marine Sciences Earth Sciences Publication - Article PeerReviewed 2007 ftnerc https://doi.org/10.5194/os-3-17-2007 2023-02-04T19:30:17Z 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 Natural Environment Research Council: NERC Open Research Archive Pacific Southern Ocean Ocean Science 3 1 17 30 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Marine Sciences Earth Sciences |
spellingShingle |
Marine Sciences Earth Sciences Polton, Jeff A. Marshall, David P. Overturning cells in the Southern Ocean and subtropical gyres |
topic_facet |
Marine Sciences Earth Sciences |
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 |
Polton, Jeff A. Marshall, David P. |
author_facet |
Polton, Jeff A. Marshall, David P. |
author_sort |
Polton, Jeff A. |
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 |
publishDate |
2007 |
url |
http://nora.nerc.ac.uk/id/eprint/16033/ http://www.ocean-sci.net/3/17/2007/os-3-17-2007.pdf |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Polton, Jeff A. orcid:0000-0003-0131-5250 Marshall, David P. 2007 Overturning cells in the Southern Ocean and subtropical gyres. Ocean Science, 3 (1). 17-30. https://doi.org/10.5194/os-3-17-2007 <https://doi.org/10.5194/os-3-17-2007> |
op_doi |
https://doi.org/10.5194/os-3-17-2007 |
container_title |
Ocean Science |
container_volume |
3 |
container_issue |
1 |
container_start_page |
17 |
op_container_end_page |
30 |
_version_ |
1766204584136540160 |