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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ftdoajarticles:oai:doaj.org/article:b68bcd10aa894aa195417e26548e6391 2023-05-15T16:30:28+02:00 Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years A. A. Lochte R. Schneider M. Kienast J. Repschläger T. Blanz D. Garbe-Schönberg N. Andersen 2020-07-01T00:00:00Z https://doi.org/10.5194/cp-16-1127-2020 https://doaj.org/article/b68bcd10aa894aa195417e26548e6391 EN eng Copernicus Publications https://cp.copernicus.org/articles/16/1127/2020/cp-16-1127-2020.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-16-1127-2020 1814-9324 1814-9332 https://doaj.org/article/b68bcd10aa894aa195417e26548e6391 Climate of the Past, Vol 16, Pp 1127-1143 (2020) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2020 ftdoajarticles https://doi.org/10.5194/cp-16-1127-2020 2022-12-31T11:41:19Z 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 Directory of Open Access Journals: DOAJ Articles Canada Greenland Labrador Shelf ENVELOPE(-58.000,-58.000,56.000,56.000) Climate of the Past 16 4 1127 1143 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 A. A. Lochte R. Schneider M. Kienast J. Repschläger T. Blanz D. Garbe-Schönberg N. Andersen Surface and subsurface Labrador Shelf water mass conditions during the last 6000 years |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
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 |
A. A. Lochte R. Schneider M. Kienast J. Repschläger T. Blanz D. Garbe-Schönberg N. Andersen |
author_facet |
A. A. Lochte R. Schneider M. Kienast J. Repschläger T. Blanz D. Garbe-Schönberg N. Andersen |
author_sort |
A. A. Lochte |
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 |
publishDate |
2020 |
url |
https://doi.org/10.5194/cp-16-1127-2020 https://doaj.org/article/b68bcd10aa894aa195417e26548e6391 |
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_source |
Climate of the Past, Vol 16, Pp 1127-1143 (2020) |
op_relation |
https://cp.copernicus.org/articles/16/1127/2020/cp-16-1127-2020.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-16-1127-2020 1814-9324 1814-9332 https://doaj.org/article/b68bcd10aa894aa195417e26548e6391 |
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_ |
1766020198662406144 |