Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification
International audience The cycle of open ocean deep convection in the Labrador Sea is studied in a realistic, high-resolution (4 km) regional model, embedded in a coarser (1⁄3°) North Atlantic setup. This configuration allows the simultaneous generation and evolution of three different eddy types th...
Published in: | Journal of Physical Oceanography |
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Main Authors: | , , , , , , |
Other Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2008
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Online Access: | https://hal.science/hal-00266980 https://hal.science/hal-00266980/document https://hal.science/hal-00266980/file/Chanut2008.pdf https://doi.org/10.1175/2008JPO3485.1 |
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Université de Rennes 1: Publications scientifiques (HAL) |
op_collection_id |
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English |
topic |
Eddies North Atlantic Ocean Boundary currents Ocean dynamics Ocean circulation [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] |
spellingShingle |
Eddies North Atlantic Ocean Boundary currents Ocean dynamics Ocean circulation [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] Chanut, Jérôme Barnier, Bernard Large, William Debreu, Laurent Penduff, Thierry Molines, Jean-Marc Mathiot, Pierre Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification |
topic_facet |
Eddies North Atlantic Ocean Boundary currents Ocean dynamics Ocean circulation [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] |
description |
International audience The cycle of open ocean deep convection in the Labrador Sea is studied in a realistic, high-resolution (4 km) regional model, embedded in a coarser (1⁄3°) North Atlantic setup. This configuration allows the simultaneous generation and evolution of three different eddy types that are distinguished by their source region, generation mechanism, and dynamics. Very energetic Irminger Rings (IRs) are generated by barotropic instability of the West Greenland and Irminger Currents (WGC/IC) off Cape Desolation and are characterized by a warm, salty subsurface core. They densely populate the basin north of 58°N, where their eddy kinetic energy (EKE) matches the signal observed by satellite altimetry. Significant levels of EKE are also found offshore of the West Greenland and Labrador coasts, where boundary current eddies (BCEs) are spawned by weakly energetic instabilities all along the boundary current system (BCS). Baroclinic instability of the steep isopycnal slopes that result from a deep convective overturning event produces convective eddies (CEs) of 20-30 km in diameter, as observed and produced in more idealized models, with a distinct seasonal cycle of EKE peaking in April. Sensitivity experiments show that each of these eddy types plays a distinct role in the heat budget of the central Labrador Sea, hence in the convection cycle. As observed in nature, deep convective mixing is limited to areas where adequate preconditioning can occur, that is, to a small region in the southwestern quadrant of the central basin. To the east, west, and south, BCEs flux heat from the BCS at a rate sufficient to counteract air-sea buoyancy loss. To the north, this eddy flux alone is not enough, but when combined with the effects of Irminger Rings, preconditioning is effectively inhibited here too. Following a deep convective mixing event, the homogeneous convection patch reaches as deep as 2000 m and a horizontal scale on the order of 200 km, as has been observed. Both CEs and BCEs are found to play ... |
author2 |
Laboratoire des Écoulements Géophysiques et Industriels Grenoble (LEGI) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) National Center for Atmospheric Research Boulder (NCAR) Modelling, Observations, Identification for Environmental Sciences (MOISE) Inria Grenoble - Rhône-Alpes Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK) Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Chanut, Jérôme Barnier, Bernard Large, William Debreu, Laurent Penduff, Thierry Molines, Jean-Marc Mathiot, Pierre |
author_facet |
Chanut, Jérôme Barnier, Bernard Large, William Debreu, Laurent Penduff, Thierry Molines, Jean-Marc Mathiot, Pierre |
author_sort |
Chanut, Jérôme |
title |
Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification |
title_short |
Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification |
title_full |
Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification |
title_fullStr |
Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification |
title_full_unstemmed |
Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification |
title_sort |
mesoscale eddies in the labrador sea and their contribution to convection and restratification |
publisher |
HAL CCSD |
publishDate |
2008 |
url |
https://hal.science/hal-00266980 https://hal.science/hal-00266980/document https://hal.science/hal-00266980/file/Chanut2008.pdf https://doi.org/10.1175/2008JPO3485.1 |
long_lat |
ENVELOPE(43.000,43.000,73.500,73.500) |
geographic |
Greenland Central Basin |
geographic_facet |
Greenland Central Basin |
genre |
Greenland Labrador Sea North Atlantic |
genre_facet |
Greenland Labrador Sea North Atlantic |
op_source |
ISSN: 0022-3670 EISSN: 1520-0485 Journal of Physical Oceanography https://hal.science/hal-00266980 Journal of Physical Oceanography, 2008, 38 (8), pp.1617-1643. ⟨10.1175/2008JPO3485.1⟩ |
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op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1175/2008JPO3485.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
38 |
container_issue |
8 |
container_start_page |
1617 |
op_container_end_page |
1643 |
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1798846802483478528 |
spelling |
ftunivrennes1hal:oai:HAL:hal-00266980v1 2024-05-12T08:04:35+00:00 Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification Chanut, Jérôme Barnier, Bernard Large, William Debreu, Laurent Penduff, Thierry Molines, Jean-Marc Mathiot, Pierre Laboratoire des Écoulements Géophysiques et Industriels Grenoble (LEGI) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) National Center for Atmospheric Research Boulder (NCAR) Modelling, Observations, Identification for Environmental Sciences (MOISE) Inria Grenoble - Rhône-Alpes Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK) Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) 2008-08 https://hal.science/hal-00266980 https://hal.science/hal-00266980/document https://hal.science/hal-00266980/file/Chanut2008.pdf https://doi.org/10.1175/2008JPO3485.1 en eng HAL CCSD American Meteorological Society info:eu-repo/semantics/altIdentifier/doi/10.1175/2008JPO3485.1 hal-00266980 https://hal.science/hal-00266980 https://hal.science/hal-00266980/document https://hal.science/hal-00266980/file/Chanut2008.pdf doi:10.1175/2008JPO3485.1 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 0022-3670 EISSN: 1520-0485 Journal of Physical Oceanography https://hal.science/hal-00266980 Journal of Physical Oceanography, 2008, 38 (8), pp.1617-1643. ⟨10.1175/2008JPO3485.1⟩ Eddies North Atlantic Ocean Boundary currents Ocean dynamics Ocean circulation [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] info:eu-repo/semantics/article Journal articles 2008 ftunivrennes1hal https://doi.org/10.1175/2008JPO3485.1 2024-04-18T00:12:29Z International audience The cycle of open ocean deep convection in the Labrador Sea is studied in a realistic, high-resolution (4 km) regional model, embedded in a coarser (1⁄3°) North Atlantic setup. This configuration allows the simultaneous generation and evolution of three different eddy types that are distinguished by their source region, generation mechanism, and dynamics. Very energetic Irminger Rings (IRs) are generated by barotropic instability of the West Greenland and Irminger Currents (WGC/IC) off Cape Desolation and are characterized by a warm, salty subsurface core. They densely populate the basin north of 58°N, where their eddy kinetic energy (EKE) matches the signal observed by satellite altimetry. Significant levels of EKE are also found offshore of the West Greenland and Labrador coasts, where boundary current eddies (BCEs) are spawned by weakly energetic instabilities all along the boundary current system (BCS). Baroclinic instability of the steep isopycnal slopes that result from a deep convective overturning event produces convective eddies (CEs) of 20-30 km in diameter, as observed and produced in more idealized models, with a distinct seasonal cycle of EKE peaking in April. Sensitivity experiments show that each of these eddy types plays a distinct role in the heat budget of the central Labrador Sea, hence in the convection cycle. As observed in nature, deep convective mixing is limited to areas where adequate preconditioning can occur, that is, to a small region in the southwestern quadrant of the central basin. To the east, west, and south, BCEs flux heat from the BCS at a rate sufficient to counteract air-sea buoyancy loss. To the north, this eddy flux alone is not enough, but when combined with the effects of Irminger Rings, preconditioning is effectively inhibited here too. Following a deep convective mixing event, the homogeneous convection patch reaches as deep as 2000 m and a horizontal scale on the order of 200 km, as has been observed. Both CEs and BCEs are found to play ... Article in Journal/Newspaper Greenland Labrador Sea North Atlantic Université de Rennes 1: Publications scientifiques (HAL) Greenland Central Basin ENVELOPE(43.000,43.000,73.500,73.500) Journal of Physical Oceanography 38 8 1617 1643 |