Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years
The Labrador Sea is important for the modern global thermohaline circulation system through the formation of intermediate Labrador Sea Water (LSW) that has been hypothesized to stabilize the modern mode of North Atlantic deep-water circulation. The rate of LSW formation is controlled by the amount o...
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Copernicus Publications (EGU)
2020
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Online Access: | https://oceanrep.geomar.de/id/eprint/50195/ https://oceanrep.geomar.de/id/eprint/50195/1/cp-16-1127-2020.pdf https://doi.org/10.5194/cp-16-1127-2020 |
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ftoceanrep:oai:oceanrep.geomar.de:50195 2023-05-15T16:30:13+02:00 Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years Lochte, Annalena Schneider, Ralph Kienast, Markus Repschläger, Janne Blanz, Thomas Garbe-Schönberg, Dieter Andersen, Nils 2020-07-03 text https://oceanrep.geomar.de/id/eprint/50195/ https://oceanrep.geomar.de/id/eprint/50195/1/cp-16-1127-2020.pdf https://doi.org/10.5194/cp-16-1127-2020 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/50195/1/cp-16-1127-2020.pdf Lochte, A., Schneider, R., Kienast, M., Repschläger, J., Blanz, T., Garbe-Schönberg, D. and Andersen, N. (2020) Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years. Open Access Climate of the Past, 16 (4). pp. 1127-1143. DOI 10.5194/cp-16-1127-2020 <https://doi.org/10.5194/cp-16-1127-2020>. doi:10.5194/cp-16-1127-2020 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2020 ftoceanrep https://doi.org/10.5194/cp-16-1127-2020 2023-04-07T15:51:17Z The Labrador Sea is important for the modern global thermohaline circulation system through the formation of intermediate Labrador Sea Water (LSW) that has been hypothesized to stabilize the modern mode of North Atlantic deep-water circulation. The rate of LSW formation is controlled by the amount of winter heat loss to the atmosphere, the expanse of freshwater in the convection region and the inflow of saline waters from the Atlantic. The Labrador Sea, today, receives freshwater through the East and West Greenland currents (EGC, WGC) and the Labrador Current (LC). Several studies have suggested the WGC to be the main supplier of freshwater to the Labrador Sea, but the role of the southward flowing LC in Labrador Sea convection is still debated. At the same time, many paleoceanographic reconstructions from the Labrador Shelf focussed on late deglacial to early Holocene meltwater run-off from the Laurentide Ice Sheet (LIS), whereas little information exists about LC variability since the final melting of the LIS about 7000 years ago. In order to enable better assessment of the role of the LC in deep-water formation and its importance for Holocene climate variability in Atlantic Canada, this study presents high-resolution middle to late Holocene records of sea surface and bottom water temperatures, freshening, and sea ice cover on the Labrador Shelf during the last 6000 years. Our records reveal that the LC underwent three major oceanographic phases from the mid- to late Holocene. From 6.2 to 5.6 ka, the LC experienced a cold episode that was followed by warmer conditions between 5.6 and 2.1 ka, possibly associated with the late Holocene thermal maximum. While surface waters on the Labrador Shelf cooled gradually after 3 ka in response to the neoglaciation, Labrador Shelf subsurface or bottom waters show a shift to warmer temperatures after 2.1 ka. Although such an inverse stratification by cooling of surface and warming of subsurface waters on the Labrador Shelf would suggest a diminished convection during the ... Article in Journal/Newspaper Greenland Ice Sheet Labrador Sea North Atlantic Deep Water North Atlantic Sea ice OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Canada Greenland Labrador Shelf ENVELOPE(-58.000,-58.000,56.000,56.000) Climate of the Past 16 4 1127 1143 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The Labrador Sea is important for the modern global thermohaline circulation system through the formation of intermediate Labrador Sea Water (LSW) that has been hypothesized to stabilize the modern mode of North Atlantic deep-water circulation. The rate of LSW formation is controlled by the amount of winter heat loss to the atmosphere, the expanse of freshwater in the convection region and the inflow of saline waters from the Atlantic. The Labrador Sea, today, receives freshwater through the East and West Greenland currents (EGC, WGC) and the Labrador Current (LC). Several studies have suggested the WGC to be the main supplier of freshwater to the Labrador Sea, but the role of the southward flowing LC in Labrador Sea convection is still debated. At the same time, many paleoceanographic reconstructions from the Labrador Shelf focussed on late deglacial to early Holocene meltwater run-off from the Laurentide Ice Sheet (LIS), whereas little information exists about LC variability since the final melting of the LIS about 7000 years ago. In order to enable better assessment of the role of the LC in deep-water formation and its importance for Holocene climate variability in Atlantic Canada, this study presents high-resolution middle to late Holocene records of sea surface and bottom water temperatures, freshening, and sea ice cover on the Labrador Shelf during the last 6000 years. Our records reveal that the LC underwent three major oceanographic phases from the mid- to late Holocene. From 6.2 to 5.6 ka, the LC experienced a cold episode that was followed by warmer conditions between 5.6 and 2.1 ka, possibly associated with the late Holocene thermal maximum. While surface waters on the Labrador Shelf cooled gradually after 3 ka in response to the neoglaciation, Labrador Shelf subsurface or bottom waters show a shift to warmer temperatures after 2.1 ka. Although such an inverse stratification by cooling of surface and warming of subsurface waters on the Labrador Shelf would suggest a diminished convection during the ... |
format |
Article in Journal/Newspaper |
author |
Lochte, Annalena Schneider, Ralph Kienast, Markus Repschläger, Janne Blanz, Thomas Garbe-Schönberg, Dieter Andersen, Nils |
spellingShingle |
Lochte, Annalena Schneider, Ralph Kienast, Markus Repschläger, Janne Blanz, Thomas Garbe-Schönberg, Dieter Andersen, Nils Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years |
author_facet |
Lochte, Annalena Schneider, Ralph Kienast, Markus Repschläger, Janne Blanz, Thomas Garbe-Schönberg, Dieter Andersen, Nils |
author_sort |
Lochte, Annalena |
title |
Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years |
title_short |
Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years |
title_full |
Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years |
title_fullStr |
Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years |
title_full_unstemmed |
Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years |
title_sort |
surface and subsurface labrador shelf water mass conditions during the last 6000 years |
publisher |
Copernicus Publications (EGU) |
publishDate |
2020 |
url |
https://oceanrep.geomar.de/id/eprint/50195/ https://oceanrep.geomar.de/id/eprint/50195/1/cp-16-1127-2020.pdf https://doi.org/10.5194/cp-16-1127-2020 |
long_lat |
ENVELOPE(-58.000,-58.000,56.000,56.000) |
geographic |
Canada Greenland Labrador Shelf |
geographic_facet |
Canada Greenland Labrador Shelf |
genre |
Greenland Ice Sheet Labrador Sea North Atlantic Deep Water North Atlantic Sea ice |
genre_facet |
Greenland Ice Sheet Labrador Sea North Atlantic Deep Water North Atlantic Sea ice |
op_relation |
https://oceanrep.geomar.de/id/eprint/50195/1/cp-16-1127-2020.pdf Lochte, A., Schneider, R., Kienast, M., Repschläger, J., Blanz, T., Garbe-Schönberg, D. and Andersen, N. (2020) Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years. Open Access Climate of the Past, 16 (4). pp. 1127-1143. DOI 10.5194/cp-16-1127-2020 <https://doi.org/10.5194/cp-16-1127-2020>. doi:10.5194/cp-16-1127-2020 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/cp-16-1127-2020 |
container_title |
Climate of the Past |
container_volume |
16 |
container_issue |
4 |
container_start_page |
1127 |
op_container_end_page |
1143 |
_version_ |
1766019942691373056 |