Reconciling tracer and float observations of the export pathways of Labrador Sea Water
For more than fifty years, it has been generally accepted by oceanographers that the Deep Western Boundary Current (DWBC) is the principal conduit of recently-convected Labrador Sea Water (LSW) exported from the high-latitude North Atlantic to the equator. Supporting this supposition is observationa...
Published in: | Geophysical Research Letters |
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ftoceanrep:oai:oceanrep.geomar.de:19288 2023-05-15T17:05:59+02:00 Reconciling tracer and float observations of the export pathways of Labrador Sea Water Gary, Stefan Francois Lozier, M. Biastoch, Arne Böning, Claus W. 2012 text https://oceanrep.geomar.de/id/eprint/19288/ https://oceanrep.geomar.de/id/eprint/19288/7/grl29837.pdf https://doi.org/10.1029/2012GL053978 en eng AGU (American Geophysical Union) https://oceanrep.geomar.de/id/eprint/19288/7/grl29837.pdf Gary, S. F., Lozier, M., Biastoch, A. and Böning, C. W. (2012) Reconciling tracer and float observations of the export pathways of Labrador Sea Water. Open Access Geophysical Research Letters, 39 (24). L24606. DOI 10.1029/2012GL053978 <https://doi.org/10.1029/2012GL053978>. doi:10.1029/2012GL053978 info:eu-repo/semantics/openAccess Article PeerReviewed 2012 ftoceanrep https://doi.org/10.1029/2012GL053978 2023-04-07T15:06:13Z For more than fifty years, it has been generally accepted by oceanographers that the Deep Western Boundary Current (DWBC) is the principal conduit of recently-convected Labrador Sea Water (LSW) exported from the high-latitude North Atlantic to the equator. Supporting this supposition is observational evidence that the waters of the DWBC have consistently greater equatorward velocities, higher concentrations of passive tracers, and younger ages compared to ocean interior waters. However, recent observations and simulations of floats launched in the DWBC in the Labrador Sea show that most water parcels are quickly ejected from the DWBC and follow instead interior pathways to the subtropics. Here, we show that tracer observations from the last three decades are compatible with the existence of both DWBC and basin-interior export pathways. From analyses of observational data and model output, we find that equatorward transport in the basin interior is consistent with the large-scale vorticity balance at mid-depth. Furthermore, from the modeling analysis we show that despite higher, localized concentrations of tracer and particles in the DWBC, only 5% of particles released in the Labrador Sea are transported from the subpolar to subtropical gyre via a continuous DWBC pathway. Thus, the interior pathway is a significant contributor to LSW export. Highlights: - Lagrangian observations of Labrador Sea Water match Eulerian observations - There is deep equatorward flow in the basin interior - This interior pathway is significant compared to the pathway along the boundary Article in Journal/Newspaper Labrador Sea North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Geophysical Research Letters 39 24 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
For more than fifty years, it has been generally accepted by oceanographers that the Deep Western Boundary Current (DWBC) is the principal conduit of recently-convected Labrador Sea Water (LSW) exported from the high-latitude North Atlantic to the equator. Supporting this supposition is observational evidence that the waters of the DWBC have consistently greater equatorward velocities, higher concentrations of passive tracers, and younger ages compared to ocean interior waters. However, recent observations and simulations of floats launched in the DWBC in the Labrador Sea show that most water parcels are quickly ejected from the DWBC and follow instead interior pathways to the subtropics. Here, we show that tracer observations from the last three decades are compatible with the existence of both DWBC and basin-interior export pathways. From analyses of observational data and model output, we find that equatorward transport in the basin interior is consistent with the large-scale vorticity balance at mid-depth. Furthermore, from the modeling analysis we show that despite higher, localized concentrations of tracer and particles in the DWBC, only 5% of particles released in the Labrador Sea are transported from the subpolar to subtropical gyre via a continuous DWBC pathway. Thus, the interior pathway is a significant contributor to LSW export. Highlights: - Lagrangian observations of Labrador Sea Water match Eulerian observations - There is deep equatorward flow in the basin interior - This interior pathway is significant compared to the pathway along the boundary |
format |
Article in Journal/Newspaper |
author |
Gary, Stefan Francois Lozier, M. Biastoch, Arne Böning, Claus W. |
spellingShingle |
Gary, Stefan Francois Lozier, M. Biastoch, Arne Böning, Claus W. Reconciling tracer and float observations of the export pathways of Labrador Sea Water |
author_facet |
Gary, Stefan Francois Lozier, M. Biastoch, Arne Böning, Claus W. |
author_sort |
Gary, Stefan Francois |
title |
Reconciling tracer and float observations of the export pathways of Labrador Sea Water |
title_short |
Reconciling tracer and float observations of the export pathways of Labrador Sea Water |
title_full |
Reconciling tracer and float observations of the export pathways of Labrador Sea Water |
title_fullStr |
Reconciling tracer and float observations of the export pathways of Labrador Sea Water |
title_full_unstemmed |
Reconciling tracer and float observations of the export pathways of Labrador Sea Water |
title_sort |
reconciling tracer and float observations of the export pathways of labrador sea water |
publisher |
AGU (American Geophysical Union) |
publishDate |
2012 |
url |
https://oceanrep.geomar.de/id/eprint/19288/ https://oceanrep.geomar.de/id/eprint/19288/7/grl29837.pdf https://doi.org/10.1029/2012GL053978 |
genre |
Labrador Sea North Atlantic |
genre_facet |
Labrador Sea North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/19288/7/grl29837.pdf Gary, S. F., Lozier, M., Biastoch, A. and Böning, C. W. (2012) Reconciling tracer and float observations of the export pathways of Labrador Sea Water. Open Access Geophysical Research Letters, 39 (24). L24606. DOI 10.1029/2012GL053978 <https://doi.org/10.1029/2012GL053978>. doi:10.1029/2012GL053978 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2012GL053978 |
container_title |
Geophysical Research Letters |
container_volume |
39 |
container_issue |
24 |
_version_ |
1766060882498945024 |