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Buoyancy forcing and the subpolar Atlantic meridional overturning circulation
The North Atlantic meridional overturning circulation and its variability are examined in terms of the overturning in density space and diapycnal water mass transformation. The magnitude of the mean overturning is similar to the surface water mass transformation, but the density and properties of th...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10590669/ https://www.ncbi.nlm.nih.gov/pubmed/37866380 http://dx.doi.org/10.1098/rsta.2022.0181 |
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author | Buckley, Martha W. Lozier, M. Susan Desbruyères, Damien Evans, Dafydd Gwyn |
author_facet | Buckley, Martha W. Lozier, M. Susan Desbruyères, Damien Evans, Dafydd Gwyn |
author_sort | Buckley, Martha W. |
collection | PubMed |
description | The North Atlantic meridional overturning circulation and its variability are examined in terms of the overturning in density space and diapycnal water mass transformation. The magnitude of the mean overturning is similar to the surface water mass transformation, but the density and properties of these waters are modified by diapycnal mixing. Surface waters are progressively densified while circulating cyclonically around the subpolar gyre, with the densest waters and deepest convection occurring in the Labrador Sea and Nordic Seas. The eddy-driven interaction between the convective interior and boundary currents is a key to the export of dense waters from marginal seas. Due to the multitude of pathways of dense waters within the subpolar gyre, as well as mixing with older waters, waters exiting the subpolar gyre have a wide range of ages, with a mean age on the order of a decade. As a result, interannual changes in water mass transformation are mostly balanced locally and do not result in changes in export to the subtropics. Only persistent changes in water mass transformation result in changes in export to the subtropics. The dilution of signals from upstream water mass transformation suggests that variability in export of dense waters to the subtropics may be controlled by other processes, including interaction of dense waters with the energetic upper ocean. This article is part of a discussion meeting issue ‘Atlantic overturning: new observations and challenges’. |
format | Online Article Text |
id | pubmed-10590669 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | The Royal Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-105906692023-10-23 Buoyancy forcing and the subpolar Atlantic meridional overturning circulation Buckley, Martha W. Lozier, M. Susan Desbruyères, Damien Evans, Dafydd Gwyn Philos Trans A Math Phys Eng Sci Articles The North Atlantic meridional overturning circulation and its variability are examined in terms of the overturning in density space and diapycnal water mass transformation. The magnitude of the mean overturning is similar to the surface water mass transformation, but the density and properties of these waters are modified by diapycnal mixing. Surface waters are progressively densified while circulating cyclonically around the subpolar gyre, with the densest waters and deepest convection occurring in the Labrador Sea and Nordic Seas. The eddy-driven interaction between the convective interior and boundary currents is a key to the export of dense waters from marginal seas. Due to the multitude of pathways of dense waters within the subpolar gyre, as well as mixing with older waters, waters exiting the subpolar gyre have a wide range of ages, with a mean age on the order of a decade. As a result, interannual changes in water mass transformation are mostly balanced locally and do not result in changes in export to the subtropics. Only persistent changes in water mass transformation result in changes in export to the subtropics. The dilution of signals from upstream water mass transformation suggests that variability in export of dense waters to the subtropics may be controlled by other processes, including interaction of dense waters with the energetic upper ocean. This article is part of a discussion meeting issue ‘Atlantic overturning: new observations and challenges’. The Royal Society 2023-12-11 2023-10-23 /pmc/articles/PMC10590669/ /pubmed/37866380 http://dx.doi.org/10.1098/rsta.2022.0181 Text en © 2023 The Authors. https://creativecommons.org/licenses/by/4.0/Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, provided the original author and source are credited. |
spellingShingle | Articles Buckley, Martha W. Lozier, M. Susan Desbruyères, Damien Evans, Dafydd Gwyn Buoyancy forcing and the subpolar Atlantic meridional overturning circulation |
title | Buoyancy forcing and the subpolar Atlantic meridional overturning circulation |
title_full | Buoyancy forcing and the subpolar Atlantic meridional overturning circulation |
title_fullStr | Buoyancy forcing and the subpolar Atlantic meridional overturning circulation |
title_full_unstemmed | Buoyancy forcing and the subpolar Atlantic meridional overturning circulation |
title_short | Buoyancy forcing and the subpolar Atlantic meridional overturning circulation |
title_sort | buoyancy forcing and the subpolar atlantic meridional overturning circulation |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10590669/ https://www.ncbi.nlm.nih.gov/pubmed/37866380 http://dx.doi.org/10.1098/rsta.2022.0181 |
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