Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes

Heinrich events, identified as enhanced ice-rafted detritus (IRD) in North Atlantic deep sea sediments (Heinrich, 1988; Hemming, 2004) have classically been attributed to Laurentide ice-sheet (LIS) instabilities (MacAyeal, 1993; Calov et al., 2002; Hulbe et al., 2004) and assumed to lead to importan...

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Main Authors: Álvarez-Solas, J., Montoya, M., Ritz, C., Ramstein, G., Charbit, S., Dumas, C., Nisancioglu, K., Dokken, T., Ganopolski, A.
Format: Article in Journal/Newspaper
Language:English
Published: München : European Geopyhsical Union 2011
Subjects:
550
Online Access:https://doi.org/10.34657/984
https://oa.tib.eu/renate/handle/123456789/623
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spelling ftleibnizopen:oai:oai.leibnizopen.de:GxN3DYsBBwLIz6xGcP-m 2023-11-05T03:42:29+01:00 Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes Álvarez-Solas, J. Montoya, M. Ritz, C. Ramstein, G. Charbit, S. Dumas, C. Nisancioglu, K. Dokken, T. Ganopolski, A. 2011 application/zip application/pdf application/octet-stream https://doi.org/10.34657/984 https://oa.tib.eu/renate/handle/123456789/623 eng eng München : European Geopyhsical Union CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Climate of the Past, Volume 7, Issue 4, Page 1297-1306 data set deep sea deep water global warming Heinrich event ice sheet marine environment marine sediment meridional circulation numerical model paleoclimate sea ice sea level change three-dimensional modeling 550 article Text 2011 ftleibnizopen https://doi.org/10.34657/984 2023-10-08T23:35:10Z Heinrich events, identified as enhanced ice-rafted detritus (IRD) in North Atlantic deep sea sediments (Heinrich, 1988; Hemming, 2004) have classically been attributed to Laurentide ice-sheet (LIS) instabilities (MacAyeal, 1993; Calov et al., 2002; Hulbe et al., 2004) and assumed to lead to important disruptions of the Atlantic meridional overturning circulation (AMOC) and North Atlantic deep water (NADW) formation. However, recent paleoclimate data have revealed that most of these events probably occurred after the AMOC had already slowed down or/and NADW largely collapsed, within about a thousand years (Hall et al., 2006; Hemming, 2004; Jonkers et al., 2010; Roche et al., 2004), implying that the initial AMOC reduction could not have been caused by the Heinrich events themselves. Here we propose an alternative driving mechanism, specifically for Heinrich event 1 (H1; 18 to 15 ka BP), by which North Atlantic ocean circulation changes are found to have strong impacts on LIS dynamics. By combining simulations with a coupled climate model and a three-dimensional ice sheet model, our study illustrates how reduced NADW and AMOC weakening lead to a subsurface warming in the Nordic and Labrador Seas resulting in rapid melting of the Hudson Strait and Labrador ice shelves. Lack of buttressing by the ice shelves implies a substantial ice-stream acceleration, enhanced ice-discharge and sea level rise, with peak values 500–1500 yr after the initial AMOC reduction. Our scenario modifies the previous paradigm of H1 by solving the paradox of its occurrence during a cold surface period, and highlights the importance of taking into account the effects of oceanic circulation on ice-sheets dynamics in order to elucidate the triggering mechanism of Heinrich events. publishedVersion Article in Journal/Newspaper Hudson Strait Ice Sheet Ice Shelves NADW North Atlantic Deep Water North Atlantic Sea ice LeibnizOpen (The Leibniz Association)
institution Open Polar
collection LeibnizOpen (The Leibniz Association)
op_collection_id ftleibnizopen
language English
topic data set
deep sea
deep water
global warming
Heinrich event
ice sheet
marine environment
marine sediment
meridional circulation
numerical model
paleoclimate
sea ice
sea level change
three-dimensional modeling
550
spellingShingle data set
deep sea
deep water
global warming
Heinrich event
ice sheet
marine environment
marine sediment
meridional circulation
numerical model
paleoclimate
sea ice
sea level change
three-dimensional modeling
550
Álvarez-Solas, J.
Montoya, M.
Ritz, C.
Ramstein, G.
Charbit, S.
Dumas, C.
Nisancioglu, K.
Dokken, T.
Ganopolski, A.
Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes
topic_facet data set
deep sea
deep water
global warming
Heinrich event
ice sheet
marine environment
marine sediment
meridional circulation
numerical model
paleoclimate
sea ice
sea level change
three-dimensional modeling
550
description Heinrich events, identified as enhanced ice-rafted detritus (IRD) in North Atlantic deep sea sediments (Heinrich, 1988; Hemming, 2004) have classically been attributed to Laurentide ice-sheet (LIS) instabilities (MacAyeal, 1993; Calov et al., 2002; Hulbe et al., 2004) and assumed to lead to important disruptions of the Atlantic meridional overturning circulation (AMOC) and North Atlantic deep water (NADW) formation. However, recent paleoclimate data have revealed that most of these events probably occurred after the AMOC had already slowed down or/and NADW largely collapsed, within about a thousand years (Hall et al., 2006; Hemming, 2004; Jonkers et al., 2010; Roche et al., 2004), implying that the initial AMOC reduction could not have been caused by the Heinrich events themselves. Here we propose an alternative driving mechanism, specifically for Heinrich event 1 (H1; 18 to 15 ka BP), by which North Atlantic ocean circulation changes are found to have strong impacts on LIS dynamics. By combining simulations with a coupled climate model and a three-dimensional ice sheet model, our study illustrates how reduced NADW and AMOC weakening lead to a subsurface warming in the Nordic and Labrador Seas resulting in rapid melting of the Hudson Strait and Labrador ice shelves. Lack of buttressing by the ice shelves implies a substantial ice-stream acceleration, enhanced ice-discharge and sea level rise, with peak values 500–1500 yr after the initial AMOC reduction. Our scenario modifies the previous paradigm of H1 by solving the paradox of its occurrence during a cold surface period, and highlights the importance of taking into account the effects of oceanic circulation on ice-sheets dynamics in order to elucidate the triggering mechanism of Heinrich events. publishedVersion
format Article in Journal/Newspaper
author Álvarez-Solas, J.
Montoya, M.
Ritz, C.
Ramstein, G.
Charbit, S.
Dumas, C.
Nisancioglu, K.
Dokken, T.
Ganopolski, A.
author_facet Álvarez-Solas, J.
Montoya, M.
Ritz, C.
Ramstein, G.
Charbit, S.
Dumas, C.
Nisancioglu, K.
Dokken, T.
Ganopolski, A.
author_sort Álvarez-Solas, J.
title Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes
title_short Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes
title_full Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes
title_fullStr Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes
title_full_unstemmed Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes
title_sort heinrich event 1: an example of dynamical ice-sheet reaction to oceanic changes
publisher München : European Geopyhsical Union
publishDate 2011
url https://doi.org/10.34657/984
https://oa.tib.eu/renate/handle/123456789/623
genre Hudson Strait
Ice Sheet
Ice Shelves
NADW
North Atlantic Deep Water
North Atlantic
Sea ice
genre_facet Hudson Strait
Ice Sheet
Ice Shelves
NADW
North Atlantic Deep Water
North Atlantic
Sea ice
op_source Climate of the Past, Volume 7, Issue 4, Page 1297-1306
op_rights CC BY 3.0 Unported
https://creativecommons.org/licenses/by/3.0/
op_doi https://doi.org/10.34657/984
_version_ 1781699650859827200