The meridional overturning circulation variability and heat content changes in the North Atlantic subpolar gyre
The meridional Overturning Circulation (MOC) of the North Atlantic ocean is a key component of the global climate system, through its role in redistributing heat, freshwater end chemical properties between low and high latitude regions. In mid-high latitude regions, the North Atlantic Current (NAC)...
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ftccsdartic:oai:HAL:tel-01362211v1 2023-05-15T16:30:35+02:00 The meridional overturning circulation variability and heat content changes in the North Atlantic subpolar gyre Variabilité de la circulation méridienne de retournement et du contenu de chaleur dans le gyre subpolaire de l'Atlantique Nord Desbruyères, Damien Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) Université de Bretagne occidentale - Brest Herlé Mercier 2013-01-22 https://tel.archives-ouvertes.fr/tel-01362211 https://tel.archives-ouvertes.fr/tel-01362211/document https://tel.archives-ouvertes.fr/tel-01362211/file/These-2013-EDSM-Oceanographie_physique-DESBRUYERES_Damien.pdf en eng HAL CCSD NNT: 2013BRES0074 tel-01362211 https://tel.archives-ouvertes.fr/tel-01362211 https://tel.archives-ouvertes.fr/tel-01362211/document https://tel.archives-ouvertes.fr/tel-01362211/file/These-2013-EDSM-Oceanographie_physique-DESBRUYERES_Damien.pdf info:eu-repo/semantics/OpenAccess https://tel.archives-ouvertes.fr/tel-01362211 Earth Sciences. Université de Bretagne occidentale - Brest, 2013. English. ⟨NNT : 2013BRES0074⟩ North Atlantic current Meridional Overturning circulation Ovide Subpolar Gyre Subtropical Gyre North Atlantic Variability ORCA025 ARIANE Altimetry Gyre subpolaire Gyre subtropical Atlantique Nord Variabilité Circulation méridienne de retournement Courant Nord Atlantique Altimétrie [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/doctoralThesis Theses 2013 ftccsdartic 2021-10-17T01:14:47Z The meridional Overturning Circulation (MOC) of the North Atlantic ocean is a key component of the global climate system, through its role in redistributing heat, freshwater end chemical properties between low and high latitude regions. In mid-high latitude regions, the North Atlantic Current (NAC) forms the upper limb of the MOC. It flows northeastward at the subtropical/subpolar boundary, and splits into two main branches in the eastern subpolar gyre: a northern branch that recirculates within the subpolar region and a southern branch that feed the Nordic Seas.A realistic eddy-permitting simulation (ORCA025-G70, 1/4°) is combined with a Lagrangian analysis tool (ARIANE) to investigate the MOC variability (1965-2004) across the A25-Ovide line, which joins Greenland to Portugal. Two vertical overturning cells are identified: a subtropical cell connecting low and high latitudes (12Sv) and a cell internal to the subpolar gyre (4Sv). The decadal MOC variability is associated with synchronized transport changes of the subtropical and subpolar inflow within the NAC. The latter undergoes important horizontal restructuring with opposed transport changes of its northern and southern branches. Those horizontal transport changes are largely induced by the horizontal variability of the subtropical inflow.Changes in oceanic heat transport across A25-Ovide are largely responsible for the observed heat content changes in the eastern subpolar gyre (1965-2004). Heat transport variability at A25-Ovide results from an imbalance between opposed changes in its velocity and temperature components. Both temperature and velocity anomalies are partly reflected in large scale heaves of isopycnals, and potentially relate to the varying proportion of warm subtropical waters and cold subpolar waters advected within the northern NAC branch.A 2000’s mean full-depth circulation computed along the merged AR7W/A25-Ovide line from repeated hydrographic profile and altimetry data indicates a minor contribution of the Labrador Sea to the basin ... Doctoral or Postdoctoral Thesis Greenland Labrador Sea north atlantic current North Atlantic Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Greenland |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
North Atlantic current Meridional Overturning circulation Ovide Subpolar Gyre Subtropical Gyre North Atlantic Variability ORCA025 ARIANE Altimetry Gyre subpolaire Gyre subtropical Atlantique Nord Variabilité Circulation méridienne de retournement Courant Nord Atlantique Altimétrie [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
North Atlantic current Meridional Overturning circulation Ovide Subpolar Gyre Subtropical Gyre North Atlantic Variability ORCA025 ARIANE Altimetry Gyre subpolaire Gyre subtropical Atlantique Nord Variabilité Circulation méridienne de retournement Courant Nord Atlantique Altimétrie [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Desbruyères, Damien The meridional overturning circulation variability and heat content changes in the North Atlantic subpolar gyre |
topic_facet |
North Atlantic current Meridional Overturning circulation Ovide Subpolar Gyre Subtropical Gyre North Atlantic Variability ORCA025 ARIANE Altimetry Gyre subpolaire Gyre subtropical Atlantique Nord Variabilité Circulation méridienne de retournement Courant Nord Atlantique Altimétrie [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
The meridional Overturning Circulation (MOC) of the North Atlantic ocean is a key component of the global climate system, through its role in redistributing heat, freshwater end chemical properties between low and high latitude regions. In mid-high latitude regions, the North Atlantic Current (NAC) forms the upper limb of the MOC. It flows northeastward at the subtropical/subpolar boundary, and splits into two main branches in the eastern subpolar gyre: a northern branch that recirculates within the subpolar region and a southern branch that feed the Nordic Seas.A realistic eddy-permitting simulation (ORCA025-G70, 1/4°) is combined with a Lagrangian analysis tool (ARIANE) to investigate the MOC variability (1965-2004) across the A25-Ovide line, which joins Greenland to Portugal. Two vertical overturning cells are identified: a subtropical cell connecting low and high latitudes (12Sv) and a cell internal to the subpolar gyre (4Sv). The decadal MOC variability is associated with synchronized transport changes of the subtropical and subpolar inflow within the NAC. The latter undergoes important horizontal restructuring with opposed transport changes of its northern and southern branches. Those horizontal transport changes are largely induced by the horizontal variability of the subtropical inflow.Changes in oceanic heat transport across A25-Ovide are largely responsible for the observed heat content changes in the eastern subpolar gyre (1965-2004). Heat transport variability at A25-Ovide results from an imbalance between opposed changes in its velocity and temperature components. Both temperature and velocity anomalies are partly reflected in large scale heaves of isopycnals, and potentially relate to the varying proportion of warm subtropical waters and cold subpolar waters advected within the northern NAC branch.A 2000’s mean full-depth circulation computed along the merged AR7W/A25-Ovide line from repeated hydrographic profile and altimetry data indicates a minor contribution of the Labrador Sea to the basin ... |
author2 |
Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) Université de Bretagne occidentale - Brest Herlé Mercier |
format |
Doctoral or Postdoctoral Thesis |
author |
Desbruyères, Damien |
author_facet |
Desbruyères, Damien |
author_sort |
Desbruyères, Damien |
title |
The meridional overturning circulation variability and heat content changes in the North Atlantic subpolar gyre |
title_short |
The meridional overturning circulation variability and heat content changes in the North Atlantic subpolar gyre |
title_full |
The meridional overturning circulation variability and heat content changes in the North Atlantic subpolar gyre |
title_fullStr |
The meridional overturning circulation variability and heat content changes in the North Atlantic subpolar gyre |
title_full_unstemmed |
The meridional overturning circulation variability and heat content changes in the North Atlantic subpolar gyre |
title_sort |
meridional overturning circulation variability and heat content changes in the north atlantic subpolar gyre |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://tel.archives-ouvertes.fr/tel-01362211 https://tel.archives-ouvertes.fr/tel-01362211/document https://tel.archives-ouvertes.fr/tel-01362211/file/These-2013-EDSM-Oceanographie_physique-DESBRUYERES_Damien.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Labrador Sea north atlantic current North Atlantic |
genre_facet |
Greenland Labrador Sea north atlantic current North Atlantic |
op_source |
https://tel.archives-ouvertes.fr/tel-01362211 Earth Sciences. Université de Bretagne occidentale - Brest, 2013. English. ⟨NNT : 2013BRES0074⟩ |
op_relation |
NNT: 2013BRES0074 tel-01362211 https://tel.archives-ouvertes.fr/tel-01362211 https://tel.archives-ouvertes.fr/tel-01362211/document https://tel.archives-ouvertes.fr/tel-01362211/file/These-2013-EDSM-Oceanographie_physique-DESBRUYERES_Damien.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766020318016569344 |