The modern and glacial overturning circulation in the Atlantic ocean in PMIP coupled model simulations
This study analyses the response of the Atlantic meridional overturning circulation (AMOC) to LGM forcings and boundary conditions in nine PMIP coupled model simulations, including both GCMs and Earth system Models of Intermediate Complexity. Model results differ widely. The AMOC slows down consider...
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Language: | English |
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Copernicus Publications
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Online Access: | http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-962 https://doi.org/10.5194/cp-3-51-2007 |
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ftncar:oai:drupal-site.org:articles_6663 2023-10-01T03:50:55+02:00 The modern and glacial overturning circulation in the Atlantic ocean in PMIP coupled model simulations Weber, S. (author) Drijfhout, S. (author) Abe-Ouchi, A. (author) Crucifix, M. (author) Eby, M. (author) Ganopolski, A. (author) Murakami, S. (author) Otto-Bliesner, Bette (author) Peltier, W. (author) 2007-02-01 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-962 https://doi.org/10.5194/cp-3-51-2007 en eng Copernicus Publications Climate of the Past http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-962 doi:10.5194/cp-3-51-2007 ark:/85065/d7gh9j6c Copyright Author(s) 2007. This work is distributed under the Creative Commons Attribution 3.0 License Text article 2007 ftncar https://doi.org/10.5194/cp-3-51-2007 2023-09-04T18:22:26Z This study analyses the response of the Atlantic meridional overturning circulation (AMOC) to LGM forcings and boundary conditions in nine PMIP coupled model simulations, including both GCMs and Earth system Models of Intermediate Complexity. Model results differ widely. The AMOC slows down considerably (by 20-40%) during the LGM as compared to the modern climate in four models, there is a slight reduction in one model and four models show a substantial increase in AMOC strength (by 10-40%). It is found that a major controlling factor for the AMOC response is the density contrast between Antarctic Bottom Water (AABW) and North Atlantic Deep Water (NADW) at their source regions. Changes in the density contrast are determined by the opposing effects of changes in temperature and salinity, with more saline AABW as compared to NADW consistently found in all models and less cooling of AABW in all models but one. In only two models is the AMOC response during the LGM directly related to the response in net evaporation over the Atlantic basin. Most models show large changes in the ocean freshwater transports into the basin, but this does not seem to affect the AMOC response. Finally, there is some dependence on the accuracy of the control state. Article in Journal/Newspaper Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Antarctic Climate of the Past 3 1 51 64 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
This study analyses the response of the Atlantic meridional overturning circulation (AMOC) to LGM forcings and boundary conditions in nine PMIP coupled model simulations, including both GCMs and Earth system Models of Intermediate Complexity. Model results differ widely. The AMOC slows down considerably (by 20-40%) during the LGM as compared to the modern climate in four models, there is a slight reduction in one model and four models show a substantial increase in AMOC strength (by 10-40%). It is found that a major controlling factor for the AMOC response is the density contrast between Antarctic Bottom Water (AABW) and North Atlantic Deep Water (NADW) at their source regions. Changes in the density contrast are determined by the opposing effects of changes in temperature and salinity, with more saline AABW as compared to NADW consistently found in all models and less cooling of AABW in all models but one. In only two models is the AMOC response during the LGM directly related to the response in net evaporation over the Atlantic basin. Most models show large changes in the ocean freshwater transports into the basin, but this does not seem to affect the AMOC response. Finally, there is some dependence on the accuracy of the control state. |
author2 |
Weber, S. (author) Drijfhout, S. (author) Abe-Ouchi, A. (author) Crucifix, M. (author) Eby, M. (author) Ganopolski, A. (author) Murakami, S. (author) Otto-Bliesner, Bette (author) Peltier, W. (author) |
format |
Article in Journal/Newspaper |
title |
The modern and glacial overturning circulation in the Atlantic ocean in PMIP coupled model simulations |
spellingShingle |
The modern and glacial overturning circulation in the Atlantic ocean in PMIP coupled model simulations |
title_short |
The modern and glacial overturning circulation in the Atlantic ocean in PMIP coupled model simulations |
title_full |
The modern and glacial overturning circulation in the Atlantic ocean in PMIP coupled model simulations |
title_fullStr |
The modern and glacial overturning circulation in the Atlantic ocean in PMIP coupled model simulations |
title_full_unstemmed |
The modern and glacial overturning circulation in the Atlantic ocean in PMIP coupled model simulations |
title_sort |
modern and glacial overturning circulation in the atlantic ocean in pmip coupled model simulations |
publisher |
Copernicus Publications |
publishDate |
2007 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-962 https://doi.org/10.5194/cp-3-51-2007 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic |
op_relation |
Climate of the Past http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-962 doi:10.5194/cp-3-51-2007 ark:/85065/d7gh9j6c |
op_rights |
Copyright Author(s) 2007. This work is distributed under the Creative Commons Attribution 3.0 License |
op_doi |
https://doi.org/10.5194/cp-3-51-2007 |
container_title |
Climate of the Past |
container_volume |
3 |
container_issue |
1 |
container_start_page |
51 |
op_container_end_page |
64 |
_version_ |
1778529296184246272 |