Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka BP
There is much uncertainty surrounding the mechanisms that forced the abrupt climate fluctuations found in many palaeoclimate records during Marine Isotope Stage (MIS)-3. One of the processes thought to be involved in these events is the Atlantic Meridional Overturning Circulation ( MOC), which exhib...
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ftucl:oai:eprints.ucl.ac.uk.OAI2:101327 2023-12-24T10:16:10+01:00 Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka BP Dickson, AJ Austin, WEN Hall, IR Maslin, MA Kucera, M 2008-07-15 application/pdf https://discovery.ucl.ac.uk/id/eprint/101327/1/2008PA001595.pdf https://discovery.ucl.ac.uk/id/eprint/101327/ eng eng AMER GEOPHYSICAL UNION https://discovery.ucl.ac.uk/id/eprint/101327/1/2008PA001595.pdf https://discovery.ucl.ac.uk/id/eprint/101327/ open Paleoceanography , 23 (3) , Article PA3206. (2008) Marine isotope stage-3 Abrupt climate-change Last Glacial Period Sea-surface Temperatures Greenland Ice-core Planktonic-foraminifera Thermohaline circulation Iceberg discharges Oxygen-isotope Rapid changes Article 2008 ftucl 2023-11-27T13:07:30Z There is much uncertainty surrounding the mechanisms that forced the abrupt climate fluctuations found in many palaeoclimate records during Marine Isotope Stage (MIS)-3. One of the processes thought to be involved in these events is the Atlantic Meridional Overturning Circulation ( MOC), which exhibited large changes in its dominant mode throughout the last glacial period. Giant piston core MD95- 2006 from the northeast Atlantic Ocean records a suite of palaeoceanographic proxies related to the activity of both surface and deep water masses through a period of MIS- 3 when abrupt climate fluctuations were extremely pronounced. A two- stage progression of surface water warming during interstadial warm events is proposed, with initial warming related to the northward advection of a thin warm surface layer within the North Atlantic Current, which only extended into deeper surface layers as the interstadial progressed. Benthic foraminifera isotope data also show millennialscale oscillations but of a different structure to the abrupt surface water changes. These changes are argued to partly be related to the influence of low- salinity deepwater brines. The influence of deepwater brines over the site of MD95- 2006 reached a maximum at times of rapid warming of surface waters. This observation supports the suggestion that brine formation may have helped to destabilize the accumulation of warm, saline surface waters at low latitudes, helping to force the MOC into a warm mode of operation. The contribution of deepwater brines relative to other mechanisms proposed to alter the state of the MOC needs to be examined further in future studies. Article in Journal/Newspaper Dansgaard-Oeschger events Greenland Greenland ice core ice core north atlantic current North Atlantic Northeast Atlantic Planktonic foraminifera University College London: UCL Discovery Greenland |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
English |
topic |
Marine isotope stage-3 Abrupt climate-change Last Glacial Period Sea-surface Temperatures Greenland Ice-core Planktonic-foraminifera Thermohaline circulation Iceberg discharges Oxygen-isotope Rapid changes |
spellingShingle |
Marine isotope stage-3 Abrupt climate-change Last Glacial Period Sea-surface Temperatures Greenland Ice-core Planktonic-foraminifera Thermohaline circulation Iceberg discharges Oxygen-isotope Rapid changes Dickson, AJ Austin, WEN Hall, IR Maslin, MA Kucera, M Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka BP |
topic_facet |
Marine isotope stage-3 Abrupt climate-change Last Glacial Period Sea-surface Temperatures Greenland Ice-core Planktonic-foraminifera Thermohaline circulation Iceberg discharges Oxygen-isotope Rapid changes |
description |
There is much uncertainty surrounding the mechanisms that forced the abrupt climate fluctuations found in many palaeoclimate records during Marine Isotope Stage (MIS)-3. One of the processes thought to be involved in these events is the Atlantic Meridional Overturning Circulation ( MOC), which exhibited large changes in its dominant mode throughout the last glacial period. Giant piston core MD95- 2006 from the northeast Atlantic Ocean records a suite of palaeoceanographic proxies related to the activity of both surface and deep water masses through a period of MIS- 3 when abrupt climate fluctuations were extremely pronounced. A two- stage progression of surface water warming during interstadial warm events is proposed, with initial warming related to the northward advection of a thin warm surface layer within the North Atlantic Current, which only extended into deeper surface layers as the interstadial progressed. Benthic foraminifera isotope data also show millennialscale oscillations but of a different structure to the abrupt surface water changes. These changes are argued to partly be related to the influence of low- salinity deepwater brines. The influence of deepwater brines over the site of MD95- 2006 reached a maximum at times of rapid warming of surface waters. This observation supports the suggestion that brine formation may have helped to destabilize the accumulation of warm, saline surface waters at low latitudes, helping to force the MOC into a warm mode of operation. The contribution of deepwater brines relative to other mechanisms proposed to alter the state of the MOC needs to be examined further in future studies. |
format |
Article in Journal/Newspaper |
author |
Dickson, AJ Austin, WEN Hall, IR Maslin, MA Kucera, M |
author_facet |
Dickson, AJ Austin, WEN Hall, IR Maslin, MA Kucera, M |
author_sort |
Dickson, AJ |
title |
Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka BP |
title_short |
Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka BP |
title_full |
Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka BP |
title_fullStr |
Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka BP |
title_full_unstemmed |
Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka BP |
title_sort |
centennial-scale evolution of dansgaard-oeschger events in the northeast atlantic ocean between 39.5 and 56.5 ka bp |
publisher |
AMER GEOPHYSICAL UNION |
publishDate |
2008 |
url |
https://discovery.ucl.ac.uk/id/eprint/101327/1/2008PA001595.pdf https://discovery.ucl.ac.uk/id/eprint/101327/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Dansgaard-Oeschger events Greenland Greenland ice core ice core north atlantic current North Atlantic Northeast Atlantic Planktonic foraminifera |
genre_facet |
Dansgaard-Oeschger events Greenland Greenland ice core ice core north atlantic current North Atlantic Northeast Atlantic Planktonic foraminifera |
op_source |
Paleoceanography , 23 (3) , Article PA3206. (2008) |
op_relation |
https://discovery.ucl.ac.uk/id/eprint/101327/1/2008PA001595.pdf https://discovery.ucl.ac.uk/id/eprint/101327/ |
op_rights |
open |
_version_ |
1786203499605786624 |