Surface factors controlling the volume of accumulated Labrador Sea Water
We explore historical variability in the volume of Labrador Sea Water (LSW) using ECCO, an ocean state estimate configuration of the Massachusetts Institute of Technology general circulation model (MITgcm). The model's adjoint, a linearization of the MITgcm, is set up to output the lagged sensi...
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European Geosciences Union
2024
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Online Access: | http://nora.nerc.ac.uk/id/eprint/537289/ https://nora.nerc.ac.uk/id/eprint/537289/1/os-20-521-2024.pdf https://os.copernicus.org/articles/20/521/2024/os-20-521-2024.html https://doi.org/10.5194/os-20-521-2024 |
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ftnerc:oai:nora.nerc.ac.uk:537289 2024-05-12T08:05:59+00:00 Surface factors controlling the volume of accumulated Labrador Sea Water Kostov, Yavor Messias, Marie-José Mercier, Herlé Marshall, David P. Johnson, Helen L. 2024-04-11 text http://nora.nerc.ac.uk/id/eprint/537289/ https://nora.nerc.ac.uk/id/eprint/537289/1/os-20-521-2024.pdf https://os.copernicus.org/articles/20/521/2024/os-20-521-2024.html https://doi.org/10.5194/os-20-521-2024 en eng European Geosciences Union https://nora.nerc.ac.uk/id/eprint/537289/1/os-20-521-2024.pdf Kostov, Yavor; Messias, Marie-José; Mercier, Herlé; Marshall, David P.; Johnson, Helen L. 2024 Surface factors controlling the volume of accumulated Labrador Sea Water. Ocean Science, 20 (2). 521-547. https://doi.org/10.5194/os-20-521-2024 <https://doi.org/10.5194/os-20-521-2024> cc_by_4 Publication - Article PeerReviewed 2024 ftnerc https://doi.org/10.5194/os-20-521-2024 2024-04-17T14:01:54Z We explore historical variability in the volume of Labrador Sea Water (LSW) using ECCO, an ocean state estimate configuration of the Massachusetts Institute of Technology general circulation model (MITgcm). The model's adjoint, a linearization of the MITgcm, is set up to output the lagged sensitivity of the water mass volume to surface boundary conditions. This allows us to reconstruct the evolution of LSW volume over recent decades using historical surface wind stress, heat, and freshwater fluxes. Each of these boundary conditions contributes significantly to the LSW variability that we recover, but these impacts are associated with different geographical fingerprints and arise over a range of time lags. We show that the volume of LSW accumulated in the Labrador Sea exhibits a delayed response to surface wind stress and buoyancy forcing outside the convective interior of the Labrador Sea at important locations in the North Atlantic Ocean. In particular, patterns of wind and surface density anomalies can act as a “traffic controller” and regulate the North Atlantic Current's (NAC's) transport of warm and saline subtropical water masses that are precursors for the formation of LSW. This propensity for a delayed response of LSW to remote forcing allows us to predict a limited yet substantial and significant fraction of LSW variability at least 1 year into the future. Our analysis also enables us to attribute LSW variability to different boundary conditions and to gain insight into the major mechanisms that contribute to volume anomalies in this deep water mass. We point out the important role of key processes that promote the formation of LSW in both the Irminger and Labrador seas: buoyancy loss and preconditioning along the NAC pathway and in the Iceland Basin, the Irminger Sea, and the Nordic Seas Article in Journal/Newspaper Iceland Labrador Sea Nordic Seas North Atlantic Natural Environment Research Council: NERC Open Research Archive Irminger Sea ENVELOPE(-34.041,-34.041,63.054,63.054) Ocean Science 20 2 521 547 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
We explore historical variability in the volume of Labrador Sea Water (LSW) using ECCO, an ocean state estimate configuration of the Massachusetts Institute of Technology general circulation model (MITgcm). The model's adjoint, a linearization of the MITgcm, is set up to output the lagged sensitivity of the water mass volume to surface boundary conditions. This allows us to reconstruct the evolution of LSW volume over recent decades using historical surface wind stress, heat, and freshwater fluxes. Each of these boundary conditions contributes significantly to the LSW variability that we recover, but these impacts are associated with different geographical fingerprints and arise over a range of time lags. We show that the volume of LSW accumulated in the Labrador Sea exhibits a delayed response to surface wind stress and buoyancy forcing outside the convective interior of the Labrador Sea at important locations in the North Atlantic Ocean. In particular, patterns of wind and surface density anomalies can act as a “traffic controller” and regulate the North Atlantic Current's (NAC's) transport of warm and saline subtropical water masses that are precursors for the formation of LSW. This propensity for a delayed response of LSW to remote forcing allows us to predict a limited yet substantial and significant fraction of LSW variability at least 1 year into the future. Our analysis also enables us to attribute LSW variability to different boundary conditions and to gain insight into the major mechanisms that contribute to volume anomalies in this deep water mass. We point out the important role of key processes that promote the formation of LSW in both the Irminger and Labrador seas: buoyancy loss and preconditioning along the NAC pathway and in the Iceland Basin, the Irminger Sea, and the Nordic Seas |
format |
Article in Journal/Newspaper |
author |
Kostov, Yavor Messias, Marie-José Mercier, Herlé Marshall, David P. Johnson, Helen L. |
spellingShingle |
Kostov, Yavor Messias, Marie-José Mercier, Herlé Marshall, David P. Johnson, Helen L. Surface factors controlling the volume of accumulated Labrador Sea Water |
author_facet |
Kostov, Yavor Messias, Marie-José Mercier, Herlé Marshall, David P. Johnson, Helen L. |
author_sort |
Kostov, Yavor |
title |
Surface factors controlling the volume of accumulated Labrador Sea Water |
title_short |
Surface factors controlling the volume of accumulated Labrador Sea Water |
title_full |
Surface factors controlling the volume of accumulated Labrador Sea Water |
title_fullStr |
Surface factors controlling the volume of accumulated Labrador Sea Water |
title_full_unstemmed |
Surface factors controlling the volume of accumulated Labrador Sea Water |
title_sort |
surface factors controlling the volume of accumulated labrador sea water |
publisher |
European Geosciences Union |
publishDate |
2024 |
url |
http://nora.nerc.ac.uk/id/eprint/537289/ https://nora.nerc.ac.uk/id/eprint/537289/1/os-20-521-2024.pdf https://os.copernicus.org/articles/20/521/2024/os-20-521-2024.html https://doi.org/10.5194/os-20-521-2024 |
long_lat |
ENVELOPE(-34.041,-34.041,63.054,63.054) |
geographic |
Irminger Sea |
geographic_facet |
Irminger Sea |
genre |
Iceland Labrador Sea Nordic Seas North Atlantic |
genre_facet |
Iceland Labrador Sea Nordic Seas North Atlantic |
op_relation |
https://nora.nerc.ac.uk/id/eprint/537289/1/os-20-521-2024.pdf Kostov, Yavor; Messias, Marie-José; Mercier, Herlé; Marshall, David P.; Johnson, Helen L. 2024 Surface factors controlling the volume of accumulated Labrador Sea Water. Ocean Science, 20 (2). 521-547. https://doi.org/10.5194/os-20-521-2024 <https://doi.org/10.5194/os-20-521-2024> |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.5194/os-20-521-2024 |
container_title |
Ocean Science |
container_volume |
20 |
container_issue |
2 |
container_start_page |
521 |
op_container_end_page |
547 |
_version_ |
1798848389438242816 |