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 that...
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Online Access: | https://hdl.handle.net/1956/10458 https://doi.org/10.5194/cp-10-1887-2014 |
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ftunivbergen:oai:bora.uib.no:1956/10458 2023-05-15T16:28:22+02:00 The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event Tegzes, Andrea Diana Jansen, Eystein Telford, Richard 2015-07-30T11:23:54Z application/pdf https://hdl.handle.net/1956/10458 https://doi.org/10.5194/cp-10-1887-2014 eng eng Copernicus Publications urn:issn:1814-9332 urn:issn:1814-9324 https://hdl.handle.net/1956/10458 https://doi.org/10.5194/cp-10-1887-2014 cristin:1194522 Attribution CC BY http://creativecommons.org/licenses/by/3.0/ Copyright 2014 The Authors Climate of the Past 10 5 1887-1904 VDP::Matematikk og naturvitenskap: 400::Geofag: 450::Oseanografi: 452 VDP::Mathematics and natural scienses: 400::Geosciences: 450::Oceanography: 452 Peer reviewed Journal article 2015 ftunivbergen https://doi.org/10.5194/cp-10-1887-2014 2023-03-14T17:42:33Z 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. publishedVersion Article in Journal/Newspaper Greenland Greenland ice cores Hudson Bay Ice Sheet Nordic Seas North Atlantic Sea ice University of Bergen: Bergen Open Research Archive (BORA-UiB) Greenland Hudson Hudson Bay Climate of the Past 10 5 1887 1904 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
VDP::Matematikk og naturvitenskap: 400::Geofag: 450::Oseanografi: 452 VDP::Mathematics and natural scienses: 400::Geosciences: 450::Oceanography: 452 |
spellingShingle |
VDP::Matematikk og naturvitenskap: 400::Geofag: 450::Oseanografi: 452 VDP::Mathematics and natural scienses: 400::Geosciences: 450::Oceanography: 452 Tegzes, Andrea Diana Jansen, Eystein Telford, Richard The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event |
topic_facet |
VDP::Matematikk og naturvitenskap: 400::Geofag: 450::Oseanografi: 452 VDP::Mathematics and natural scienses: 400::Geosciences: 450::Oceanography: 452 |
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. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Tegzes, Andrea Diana Jansen, Eystein Telford, Richard |
author_facet |
Tegzes, Andrea Diana Jansen, Eystein Telford, Richard |
author_sort |
Tegzes, Andrea Diana |
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 Publications |
publishDate |
2015 |
url |
https://hdl.handle.net/1956/10458 https://doi.org/10.5194/cp-10-1887-2014 |
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 10 5 1887-1904 |
op_relation |
urn:issn:1814-9332 urn:issn:1814-9324 https://hdl.handle.net/1956/10458 https://doi.org/10.5194/cp-10-1887-2014 cristin:1194522 |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/3.0/ Copyright 2014 The Authors |
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_ |
1766018014604427264 |