Labrador Sea subsurface density as a precursor of multidecadal variability in the North Atlantic: a multi-model study
The subpolar North Atlantic (SPNA) is a region with prominent decadal variability that has experienced remarkable warming and cooling trends in the last few decades. These observed trends have been preceded by slow-paced increases and decreases in the Labrador Sea density (LSD), which are thought to...
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ftcopernicus:oai:publications.copernicus.org:esd90745 2023-05-15T17:06:03+02:00 Labrador Sea subsurface density as a precursor of multidecadal variability in the North Atlantic: a multi-model study Ortega, Pablo Robson, Jon I. Menary, Matthew Sutton, Rowan T. Blaker, Adam Germe, Agathe Hirschi, Jöel J.-M. Sinha, Bablu Hermanson, Leon Yeager, Stephen 2021-04-26 application/pdf https://doi.org/10.5194/esd-12-419-2021 https://esd.copernicus.org/articles/12/419/2021/ eng eng doi:10.5194/esd-12-419-2021 https://esd.copernicus.org/articles/12/419/2021/ eISSN: 2190-4987 Text 2021 ftcopernicus https://doi.org/10.5194/esd-12-419-2021 2021-05-03T16:22:15Z The subpolar North Atlantic (SPNA) is a region with prominent decadal variability that has experienced remarkable warming and cooling trends in the last few decades. These observed trends have been preceded by slow-paced increases and decreases in the Labrador Sea density (LSD), which are thought to be a precursor of large-scale ocean circulation changes. This article analyses the interrelationships between the LSD and the wider North Atlantic across an ensemble of coupled climate model simulations. In particular, it analyses the link between subsurface density and the deep boundary density, the Atlantic Meridional Overturning Circulation (AMOC), the subpolar gyre (SPG) circulation, and the upper-ocean temperature in the eastern SPNA. All simulations exhibit considerable multidecadal variability in the LSD and the ocean circulation indices, which are found to be interrelated. LSD is strongly linked to the strength of the subpolar AMOC and gyre circulation, and it is also linked to the subtropical AMOC, although the strength of this relationship is model-dependent and affected by the inclusion of the Ekman component. The connectivity of LSD with the subtropics is found to be sensitive to different model features, including the mean density stratification in the Labrador Sea, the strength and depth of the AMOC, and the depth at which the LSD propagates southward along the western boundary. Several of these quantities can also be computed from observations, and comparison with these observation-based quantities suggests that models representing a weaker link to the subtropical AMOC might be more realistic. Text Labrador Sea North Atlantic Copernicus Publications: E-Journals Earth System Dynamics 12 2 419 438 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
The subpolar North Atlantic (SPNA) is a region with prominent decadal variability that has experienced remarkable warming and cooling trends in the last few decades. These observed trends have been preceded by slow-paced increases and decreases in the Labrador Sea density (LSD), which are thought to be a precursor of large-scale ocean circulation changes. This article analyses the interrelationships between the LSD and the wider North Atlantic across an ensemble of coupled climate model simulations. In particular, it analyses the link between subsurface density and the deep boundary density, the Atlantic Meridional Overturning Circulation (AMOC), the subpolar gyre (SPG) circulation, and the upper-ocean temperature in the eastern SPNA. All simulations exhibit considerable multidecadal variability in the LSD and the ocean circulation indices, which are found to be interrelated. LSD is strongly linked to the strength of the subpolar AMOC and gyre circulation, and it is also linked to the subtropical AMOC, although the strength of this relationship is model-dependent and affected by the inclusion of the Ekman component. The connectivity of LSD with the subtropics is found to be sensitive to different model features, including the mean density stratification in the Labrador Sea, the strength and depth of the AMOC, and the depth at which the LSD propagates southward along the western boundary. Several of these quantities can also be computed from observations, and comparison with these observation-based quantities suggests that models representing a weaker link to the subtropical AMOC might be more realistic. |
format |
Text |
author |
Ortega, Pablo Robson, Jon I. Menary, Matthew Sutton, Rowan T. Blaker, Adam Germe, Agathe Hirschi, Jöel J.-M. Sinha, Bablu Hermanson, Leon Yeager, Stephen |
spellingShingle |
Ortega, Pablo Robson, Jon I. Menary, Matthew Sutton, Rowan T. Blaker, Adam Germe, Agathe Hirschi, Jöel J.-M. Sinha, Bablu Hermanson, Leon Yeager, Stephen Labrador Sea subsurface density as a precursor of multidecadal variability in the North Atlantic: a multi-model study |
author_facet |
Ortega, Pablo Robson, Jon I. Menary, Matthew Sutton, Rowan T. Blaker, Adam Germe, Agathe Hirschi, Jöel J.-M. Sinha, Bablu Hermanson, Leon Yeager, Stephen |
author_sort |
Ortega, Pablo |
title |
Labrador Sea subsurface density as a precursor of multidecadal variability in the North Atlantic: a multi-model study |
title_short |
Labrador Sea subsurface density as a precursor of multidecadal variability in the North Atlantic: a multi-model study |
title_full |
Labrador Sea subsurface density as a precursor of multidecadal variability in the North Atlantic: a multi-model study |
title_fullStr |
Labrador Sea subsurface density as a precursor of multidecadal variability in the North Atlantic: a multi-model study |
title_full_unstemmed |
Labrador Sea subsurface density as a precursor of multidecadal variability in the North Atlantic: a multi-model study |
title_sort |
labrador sea subsurface density as a precursor of multidecadal variability in the north atlantic: a multi-model study |
publishDate |
2021 |
url |
https://doi.org/10.5194/esd-12-419-2021 https://esd.copernicus.org/articles/12/419/2021/ |
genre |
Labrador Sea North Atlantic |
genre_facet |
Labrador Sea North Atlantic |
op_source |
eISSN: 2190-4987 |
op_relation |
doi:10.5194/esd-12-419-2021 https://esd.copernicus.org/articles/12/419/2021/ |
op_doi |
https://doi.org/10.5194/esd-12-419-2021 |
container_title |
Earth System Dynamics |
container_volume |
12 |
container_issue |
2 |
container_start_page |
419 |
op_container_end_page |
438 |
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1766060973467107328 |