Importance of boundary processes for heat uptake in the Subpolar North Atlantic
The decadal to multi‐decadal temperature variability of the intermediate (700 – 2000 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)...
Published in: | Journal of Geophysical Research: Oceans |
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Online Access: | https://doi.org/10.1029/2020JC016366 https://archimer.ifremer.fr/doc/00636/74853/75239.pdf https://archimer.ifremer.fr/doc/00636/74853/75240.nc |
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fttriple:oai:gotriple.eu:10670/1.uiuxo9 2023-05-15T16:29:56+02:00 Importance of boundary processes for heat uptake in the Subpolar North Atlantic Desbruyères, Damien Sinha, B. Mcdonagh, E. L. Josey, S. A. Holliday, N. P. Smeed, D. A. New, A. L. Megann, A. Moat, B. I. 2020-01-01 https://doi.org/10.1029/2020JC016366 https://archimer.ifremer.fr/doc/00636/74853/75239.pdf https://archimer.ifremer.fr/doc/00636/74853/75240.nc en eng American Geophysical Union (AGU) doi:10.1029/2020JC016366 10670/1.uiuxo9 https://archimer.ifremer.fr/doc/00636/74853/75239.pdf https://archimer.ifremer.fr/doc/00636/74853/75240.nc Archimer, archive institutionnelle de l'Ifremer Journal Of Geophysical Research-oceans (2169-9275) (American Geophysical Union (AGU)), 2020-09 , Vol. 125 , N. 9 , P. e2020JC016366 (16p.) envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2020 fttriple https://doi.org/10.1029/2020JC016366 2023-01-22T17:09:15Z The decadal to multi‐decadal temperature variability of the intermediate (700 – 2000 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 1‐dimensional diffusive model with appropriate boundary‐like parametrization and demonstrated through the boundary‐focused downward propagation of a passive tracer in a 3D 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 modelling 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. Plain language summary The subarctic basins of the North Atlantic Ocean play a fundamental role in regulating the climate system. This occurs notably throughout direct connections between the ocean surface (and hence the atmosphere) and deep oceanic layers, which enable the long‐term sequestration and subsequent propagation of physical and biogeochemical anomalies (e.g. heat, carbon). Here, ... Text Greenland Newfoundland North Atlantic Subarctic Unknown Greenland Newfoundland Journal of Geophysical Research: Oceans 125 9 |
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envir geo |
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envir geo Desbruyères, Damien 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 |
envir geo |
description |
The decadal to multi‐decadal temperature variability of the intermediate (700 – 2000 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 1‐dimensional diffusive model with appropriate boundary‐like parametrization and demonstrated through the boundary‐focused downward propagation of a passive tracer in a 3D 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 modelling 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. Plain language summary The subarctic basins of the North Atlantic Ocean play a fundamental role in regulating the climate system. This occurs notably throughout direct connections between the ocean surface (and hence the atmosphere) and deep oceanic layers, which enable the long‐term sequestration and subsequent propagation of physical and biogeochemical anomalies (e.g. heat, carbon). Here, ... |
format |
Text |
author |
Desbruyères, Damien 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, Damien 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, Damien |
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 |
American Geophysical Union (AGU) |
publishDate |
2020 |
url |
https://doi.org/10.1029/2020JC016366 https://archimer.ifremer.fr/doc/00636/74853/75239.pdf https://archimer.ifremer.fr/doc/00636/74853/75240.nc |
geographic |
Greenland Newfoundland |
geographic_facet |
Greenland Newfoundland |
genre |
Greenland Newfoundland North Atlantic Subarctic |
genre_facet |
Greenland Newfoundland North Atlantic Subarctic |
op_source |
Archimer, archive institutionnelle de l'Ifremer Journal Of Geophysical Research-oceans (2169-9275) (American Geophysical Union (AGU)), 2020-09 , Vol. 125 , N. 9 , P. e2020JC016366 (16p.) |
op_relation |
doi:10.1029/2020JC016366 10670/1.uiuxo9 https://archimer.ifremer.fr/doc/00636/74853/75239.pdf https://archimer.ifremer.fr/doc/00636/74853/75240.nc |
op_doi |
https://doi.org/10.1029/2020JC016366 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
125 |
container_issue |
9 |
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1766019645745135616 |