The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event
The so-called " 8.2 ka event" is widely regarded as a major Holocene climate perturbation. It is most readily identifiable in the oxygen-isotope records from Greenland ice cores as an approximately 160-year-long cold interval between 8250 and 8090 years BP. The prevailing view has been tha...
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ftarchimer:oai:archimer.ifremer.fr:40218 2023-05-15T16:28:15+02:00 The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event Tegzes, A. D. Jansen, E. Telford, R. J. 2014-10-24 application/pdf https://archimer.ifremer.fr/doc/00291/40218/38711.pdf https://archimer.ifremer.fr/doc/00291/40218/71311.pdf https://doi.org/10.5194/cp-10-1887-2014 https://archimer.ifremer.fr/doc/00291/40218/ eng eng Copernicus Gesellschaft Mbh https://archimer.ifremer.fr/doc/00291/40218/38711.pdf https://archimer.ifremer.fr/doc/00291/40218/71311.pdf doi:10.5194/cp-10-1887-2014 https://archimer.ifremer.fr/doc/00291/40218/ Author(s) 2014. CC Attribution 3.0 License info:eu-repo/semantics/openAccess restricted use CC-BY Climate Of The Past (1814-9324) (Copernicus Gesellschaft Mbh), 2014-10-24 , Vol. 10 , N. 5 , P. 1887-1904 text Publication info:eu-repo/semantics/article 2014 ftarchimer https://doi.org/10.5194/cp-10-1887-2014 2021-09-23T20:26:50Z The so-called " 8.2 ka event" is widely regarded as a major Holocene climate perturbation. It is most readily identifiable in the oxygen-isotope records from Greenland ice cores as an approximately 160-year-long cold interval between 8250 and 8090 years BP. The prevailing view has been that the cooling over Greenland, and potentially over the northern North Atlantic at least, was triggered by the catastrophic final drainage of the Agassiz-Ojibway proglacial lake as part of the remnant Laurentide Ice Sheet collapsed over Hudson Bay at around 8420 +/- 80 years BP. The consequent freshening of surface waters in the northern North Atlantic Ocean and the Nordic Seas resulted in weaker overturning, and hence reduced northward ocean heat transport. We have reconstructed variations in the strength of the eastern branch of the Atlantic Inflow into the Nordic Seas around the time of the lake outbursts. While the initial freshwater forcing may have been even larger than originally thought, as the lake outbursts may have been accompanied by a major iceberg discharge from Hudson Bay, our proxy records from the mid-Norwegian Margin do not evidence a uniquely large slowdown in the eastern branch of the Atlantic Inflow at the time. Therefore, its main role in the 8.2 ka event may have been the ( rapid) advection of fresh and cold waters to high northern latitudes, initiating rapid sea-ice expansion and an increase in surface albedo. Article in Journal/Newspaper Greenland Greenland ice cores Hudson Bay Ice Sheet Nordic Seas North Atlantic Sea ice Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Greenland Hudson Hudson Bay Climate of the Past 10 5 1887 1904 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
description |
The so-called " 8.2 ka event" is widely regarded as a major Holocene climate perturbation. It is most readily identifiable in the oxygen-isotope records from Greenland ice cores as an approximately 160-year-long cold interval between 8250 and 8090 years BP. The prevailing view has been that the cooling over Greenland, and potentially over the northern North Atlantic at least, was triggered by the catastrophic final drainage of the Agassiz-Ojibway proglacial lake as part of the remnant Laurentide Ice Sheet collapsed over Hudson Bay at around 8420 +/- 80 years BP. The consequent freshening of surface waters in the northern North Atlantic Ocean and the Nordic Seas resulted in weaker overturning, and hence reduced northward ocean heat transport. We have reconstructed variations in the strength of the eastern branch of the Atlantic Inflow into the Nordic Seas around the time of the lake outbursts. While the initial freshwater forcing may have been even larger than originally thought, as the lake outbursts may have been accompanied by a major iceberg discharge from Hudson Bay, our proxy records from the mid-Norwegian Margin do not evidence a uniquely large slowdown in the eastern branch of the Atlantic Inflow at the time. Therefore, its main role in the 8.2 ka event may have been the ( rapid) advection of fresh and cold waters to high northern latitudes, initiating rapid sea-ice expansion and an increase in surface albedo. |
format |
Article in Journal/Newspaper |
author |
Tegzes, A. D. Jansen, E. Telford, R. J. |
spellingShingle |
Tegzes, A. D. Jansen, E. Telford, R. J. The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event |
author_facet |
Tegzes, A. D. Jansen, E. Telford, R. J. |
author_sort |
Tegzes, A. D. |
title |
The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event |
title_short |
The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event |
title_full |
The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event |
title_fullStr |
The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event |
title_full_unstemmed |
The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event |
title_sort |
role of the northward-directed (sub)surface limb of the atlantic meridional overturning circulation during the 8.2 ka event |
publisher |
Copernicus Gesellschaft Mbh |
publishDate |
2014 |
url |
https://archimer.ifremer.fr/doc/00291/40218/38711.pdf https://archimer.ifremer.fr/doc/00291/40218/71311.pdf https://doi.org/10.5194/cp-10-1887-2014 https://archimer.ifremer.fr/doc/00291/40218/ |
geographic |
Greenland Hudson Hudson Bay |
geographic_facet |
Greenland Hudson Hudson Bay |
genre |
Greenland Greenland ice cores Hudson Bay Ice Sheet Nordic Seas North Atlantic Sea ice |
genre_facet |
Greenland Greenland ice cores Hudson Bay Ice Sheet Nordic Seas North Atlantic Sea ice |
op_source |
Climate Of The Past (1814-9324) (Copernicus Gesellschaft Mbh), 2014-10-24 , Vol. 10 , N. 5 , P. 1887-1904 |
op_relation |
https://archimer.ifremer.fr/doc/00291/40218/38711.pdf https://archimer.ifremer.fr/doc/00291/40218/71311.pdf doi:10.5194/cp-10-1887-2014 https://archimer.ifremer.fr/doc/00291/40218/ |
op_rights |
Author(s) 2014. CC Attribution 3.0 License info:eu-repo/semantics/openAccess restricted use |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/cp-10-1887-2014 |
container_title |
Climate of the Past |
container_volume |
10 |
container_issue |
5 |
container_start_page |
1887 |
op_container_end_page |
1904 |
_version_ |
1766017880302813184 |