Importance of Boundary Processes for Heat Uptake in the Subpolar North Atlantic
International audience The decadal to multidecadal temperature variability of the intermediate (700-2,000 m) North Atlantic Subpolar Gyre (SPG) significantly imprints the global pattern of ocean heat uptake. Here, the origins and dominant pathways of this variability are investigated with an ocean a...
Published in: | Journal of Geophysical Research: Oceans |
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Format: | Article in Journal/Newspaper |
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2020
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Online Access: | https://insu.hal.science/insu-03683222 https://insu.hal.science/insu-03683222/document https://insu.hal.science/insu-03683222/file/75239.pdf https://doi.org/10.1029/2020JC016366 |
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ftccsdartic:oai:HAL:insu-03683222v1 2023-12-17T10:31:02+01:00 Importance of Boundary Processes for Heat Uptake in the Subpolar North Atlantic Desbruyères, D. G. Sinha, B. Mcdonagh, E. L. Josey, S. A. Holliday, N. P. Smeed, D. A. New, A. L. Megann, A. Moat, B. I. Laboratoire d'Océanographie Physique et Spatiale (LOPS) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) 2020 https://insu.hal.science/insu-03683222 https://insu.hal.science/insu-03683222/document https://insu.hal.science/insu-03683222/file/75239.pdf https://doi.org/10.1029/2020JC016366 en eng HAL CCSD Wiley-Blackwell info:eu-repo/semantics/altIdentifier/doi/10.1029/2020JC016366 insu-03683222 https://insu.hal.science/insu-03683222 https://insu.hal.science/insu-03683222/document https://insu.hal.science/insu-03683222/file/75239.pdf BIBCODE: 2020JGRC.12516366D doi:10.1029/2020JC016366 http://hal.archives-ouvertes.fr/licences/copyright/ info:eu-repo/semantics/OpenAccess ISSN: 2169-9275 EISSN: 2169-9291 Journal of Geophysical Research. Oceans https://insu.hal.science/insu-03683222 Journal of Geophysical Research. Oceans, 2020, 125, ⟨10.1029/2020JC016366⟩ [SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2020 ftccsdartic https://doi.org/10.1029/2020JC016366 2023-11-19T00:09:57Z International audience The decadal to multidecadal temperature variability of the intermediate (700-2,000 m) North Atlantic Subpolar Gyre (SPG) significantly imprints the global pattern of ocean heat uptake. Here, the origins and dominant pathways of this variability are investigated with an ocean analysis product (EN4), an ocean state estimate (ECCOv4), and idealized modeling approaches. Sustained increases and decreases of intermediate temperature in the SPG correlate with long-lasting warm and cold states of the upper ocean with the largest anomalous vertical heat exchanges confined to the vicinity of continental boundaries and strong ocean currents. In particular, vertical diffusive processes along the boundaries of the Labrador, Irminger, and Newfoundland basins are important drivers of the recent intermediate depth warming trend observed during 1996-2014. The overall effect of those processes is captured by a one-dimensional diffusive model with appropriate boundary-like parametrization and demonstrated through the boundary-focused downward propagation of a passive tracer in a 3-D numerical simulation. Our results imply that the slow and quasi-periodic ventilation of intermediate thermohaline properties and associated heat uptake in the SPG are not strictly driven by convection-restratification events in the open seas but also receives a key contribution from boundary sinking and mixing. Increased skill for modeling and predicting intermediate-depth ocean properties in the North Atlantic will hence require the appropriate representation of surface-deep dynamical connections within the boundary currents encircling Greenland and Newfoundland. Article in Journal/Newspaper Greenland Newfoundland North Atlantic Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Greenland Newfoundland Journal of Geophysical Research: Oceans 125 9 |
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 |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Desbruyères, D. G. Sinha, B. Mcdonagh, E. L. Josey, S. A. Holliday, N. P. Smeed, D. A. New, A. L. Megann, A. Moat, B. I. Importance of Boundary Processes for Heat Uptake in the Subpolar North Atlantic |
topic_facet |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience The decadal to multidecadal temperature variability of the intermediate (700-2,000 m) North Atlantic Subpolar Gyre (SPG) significantly imprints the global pattern of ocean heat uptake. Here, the origins and dominant pathways of this variability are investigated with an ocean analysis product (EN4), an ocean state estimate (ECCOv4), and idealized modeling approaches. Sustained increases and decreases of intermediate temperature in the SPG correlate with long-lasting warm and cold states of the upper ocean with the largest anomalous vertical heat exchanges confined to the vicinity of continental boundaries and strong ocean currents. In particular, vertical diffusive processes along the boundaries of the Labrador, Irminger, and Newfoundland basins are important drivers of the recent intermediate depth warming trend observed during 1996-2014. The overall effect of those processes is captured by a one-dimensional diffusive model with appropriate boundary-like parametrization and demonstrated through the boundary-focused downward propagation of a passive tracer in a 3-D numerical simulation. Our results imply that the slow and quasi-periodic ventilation of intermediate thermohaline properties and associated heat uptake in the SPG are not strictly driven by convection-restratification events in the open seas but also receives a key contribution from boundary sinking and mixing. Increased skill for modeling and predicting intermediate-depth ocean properties in the North Atlantic will hence require the appropriate representation of surface-deep dynamical connections within the boundary currents encircling Greenland and Newfoundland. |
author2 |
Laboratoire d'Océanographie Physique et Spatiale (LOPS) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Desbruyères, D. G. Sinha, B. Mcdonagh, E. L. Josey, S. A. Holliday, N. P. Smeed, D. A. New, A. L. Megann, A. Moat, B. I. |
author_facet |
Desbruyères, D. G. Sinha, B. Mcdonagh, E. L. Josey, S. A. Holliday, N. P. Smeed, D. A. New, A. L. Megann, A. Moat, B. I. |
author_sort |
Desbruyères, D. G. |
title |
Importance of Boundary Processes for Heat Uptake in the Subpolar North Atlantic |
title_short |
Importance of Boundary Processes for Heat Uptake in the Subpolar North Atlantic |
title_full |
Importance of Boundary Processes for Heat Uptake in the Subpolar North Atlantic |
title_fullStr |
Importance of Boundary Processes for Heat Uptake in the Subpolar North Atlantic |
title_full_unstemmed |
Importance of Boundary Processes for Heat Uptake in the Subpolar North Atlantic |
title_sort |
importance of boundary processes for heat uptake in the subpolar north atlantic |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://insu.hal.science/insu-03683222 https://insu.hal.science/insu-03683222/document https://insu.hal.science/insu-03683222/file/75239.pdf https://doi.org/10.1029/2020JC016366 |
geographic |
Greenland Newfoundland |
geographic_facet |
Greenland Newfoundland |
genre |
Greenland Newfoundland North Atlantic |
genre_facet |
Greenland Newfoundland North Atlantic |
op_source |
ISSN: 2169-9275 EISSN: 2169-9291 Journal of Geophysical Research. Oceans https://insu.hal.science/insu-03683222 Journal of Geophysical Research. Oceans, 2020, 125, ⟨10.1029/2020JC016366⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2020JC016366 insu-03683222 https://insu.hal.science/insu-03683222 https://insu.hal.science/insu-03683222/document https://insu.hal.science/insu-03683222/file/75239.pdf BIBCODE: 2020JGRC.12516366D doi:10.1029/2020JC016366 |
op_rights |
http://hal.archives-ouvertes.fr/licences/copyright/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2020JC016366 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
125 |
container_issue |
9 |
_version_ |
1785584194072608768 |