Simulation of ocean-ice sheet interactions during the last deglaciation
[1] The last deglaciation, between 21 thousand years BP (kyr BP) and 8 kyr BP, was punctuated by a series of climatic oscillations, both in the Northern and Southern Hemispheres, often attributed to changes in ocean circulation. These oscillations are explored with an Earth system model of intermedi...
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Online Access: | http://hdl.handle.net/2078.1/41249 https://doi.org/10.1029/2001PA000702 |
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ftunivlouvain:oai:dial.uclouvain.be:boreal:41249 2024-05-12T07:53:20+00:00 Simulation of ocean-ice sheet interactions during the last deglaciation Crucifix, Michel Berger, André UCL - SC/PHYS - Département de physique 2002 http://hdl.handle.net/2078.1/41249 https://doi.org/10.1029/2001PA000702 eng eng Amer Geophysical Union boreal:41249 http://hdl.handle.net/2078.1/41249 doi:10.1029/2001PA000702 urn:ISSN:0883-8305 urn:EISSN:1944-9186 Paleoceanography, Vol. 17, no. 4 (2002) info:eu-repo/semantics/article 2002 ftunivlouvain https://doi.org/10.1029/2001PA000702 2024-04-17T17:32:17Z [1] The last deglaciation, between 21 thousand years BP (kyr BP) and 8 kyr BP, was punctuated by a series of climatic oscillations, both in the Northern and Southern Hemispheres, often attributed to changes in ocean circulation. These oscillations are explored with an Earth system model of intermediate complexity, including a synchronous coupling between atmosphere, ocean, and ice sheet dynamics. We focused more particularly on the impact of Heinrich Event 1 (HE1) on the deglaciation process. Representation for HE1 was achieved by a parameterization of iceberg discharge included in the ice sheet model, based on paleoceanographic evidence. The model simulates the following sequence in response to the HE1: (1) The thermohaline circulation is drastically reduced as soon as HE1 starts, causing a sharp cooling in the North Atlantic and a smooth warming in the Southern Hemisphere. (2) Circulation restarts abruptly at the end of HE1, producing an intense warming in both hemispheres (up to 10degreesC warming in the Greenland-North Atlantic area, with a rapidly decreasing amplitude as one moves southward). (3) Along with this warming, the melting of the North American and Eurasian ice sheets is enhanced, producing a small freshwater discharge to the North Atlantic, but there is no significant impact on Atlantic salinity and thermohaline circulation. (4) A few decades after the post-Heinrich warm event, both the southern Atlantic and Antarctica entered a prolonged cold period caused by the reactivation of the thermohaline circulation. (5) Finally, about 1500 years later, depending on sensitivity experiments, meltwater flowing into the North Atlantic through the Hudson Strait and the Barents Sea causes a gradual vertical stratification of the northern North Atlantic. The presented simulations are compared to paleoarchives by taking into account the limits inherent to the model structure. One of the conclusions is that there is probably no direct link between the meltwater pulse 1A observed in sea level data and the onset ... Article in Journal/Newspaper Antarc* Antarctica Barents Sea Greenland Hudson Strait Ice Sheet North Atlantic DIAL@UCLouvain (Université catholique de Louvain) Barents Sea Greenland Hudson Hudson Strait ENVELOPE(-70.000,-70.000,62.000,62.000) Paleoceanography 17 4 6-1 6-18 |
institution |
Open Polar |
collection |
DIAL@UCLouvain (Université catholique de Louvain) |
op_collection_id |
ftunivlouvain |
language |
English |
description |
[1] The last deglaciation, between 21 thousand years BP (kyr BP) and 8 kyr BP, was punctuated by a series of climatic oscillations, both in the Northern and Southern Hemispheres, often attributed to changes in ocean circulation. These oscillations are explored with an Earth system model of intermediate complexity, including a synchronous coupling between atmosphere, ocean, and ice sheet dynamics. We focused more particularly on the impact of Heinrich Event 1 (HE1) on the deglaciation process. Representation for HE1 was achieved by a parameterization of iceberg discharge included in the ice sheet model, based on paleoceanographic evidence. The model simulates the following sequence in response to the HE1: (1) The thermohaline circulation is drastically reduced as soon as HE1 starts, causing a sharp cooling in the North Atlantic and a smooth warming in the Southern Hemisphere. (2) Circulation restarts abruptly at the end of HE1, producing an intense warming in both hemispheres (up to 10degreesC warming in the Greenland-North Atlantic area, with a rapidly decreasing amplitude as one moves southward). (3) Along with this warming, the melting of the North American and Eurasian ice sheets is enhanced, producing a small freshwater discharge to the North Atlantic, but there is no significant impact on Atlantic salinity and thermohaline circulation. (4) A few decades after the post-Heinrich warm event, both the southern Atlantic and Antarctica entered a prolonged cold period caused by the reactivation of the thermohaline circulation. (5) Finally, about 1500 years later, depending on sensitivity experiments, meltwater flowing into the North Atlantic through the Hudson Strait and the Barents Sea causes a gradual vertical stratification of the northern North Atlantic. The presented simulations are compared to paleoarchives by taking into account the limits inherent to the model structure. One of the conclusions is that there is probably no direct link between the meltwater pulse 1A observed in sea level data and the onset ... |
author2 |
UCL - SC/PHYS - Département de physique |
format |
Article in Journal/Newspaper |
author |
Crucifix, Michel Berger, André |
spellingShingle |
Crucifix, Michel Berger, André Simulation of ocean-ice sheet interactions during the last deglaciation |
author_facet |
Crucifix, Michel Berger, André |
author_sort |
Crucifix, Michel |
title |
Simulation of ocean-ice sheet interactions during the last deglaciation |
title_short |
Simulation of ocean-ice sheet interactions during the last deglaciation |
title_full |
Simulation of ocean-ice sheet interactions during the last deglaciation |
title_fullStr |
Simulation of ocean-ice sheet interactions during the last deglaciation |
title_full_unstemmed |
Simulation of ocean-ice sheet interactions during the last deglaciation |
title_sort |
simulation of ocean-ice sheet interactions during the last deglaciation |
publisher |
Amer Geophysical Union |
publishDate |
2002 |
url |
http://hdl.handle.net/2078.1/41249 https://doi.org/10.1029/2001PA000702 |
long_lat |
ENVELOPE(-70.000,-70.000,62.000,62.000) |
geographic |
Barents Sea Greenland Hudson Hudson Strait |
geographic_facet |
Barents Sea Greenland Hudson Hudson Strait |
genre |
Antarc* Antarctica Barents Sea Greenland Hudson Strait Ice Sheet North Atlantic |
genre_facet |
Antarc* Antarctica Barents Sea Greenland Hudson Strait Ice Sheet North Atlantic |
op_source |
Paleoceanography, Vol. 17, no. 4 (2002) |
op_relation |
boreal:41249 http://hdl.handle.net/2078.1/41249 doi:10.1029/2001PA000702 urn:ISSN:0883-8305 urn:EISSN:1944-9186 |
op_doi |
https://doi.org/10.1029/2001PA000702 |
container_title |
Paleoceanography |
container_volume |
17 |
container_issue |
4 |
container_start_page |
6-1 |
op_container_end_page |
6-18 |
_version_ |
1798842209849573376 |