Causes of a fresher, colder northern North Atlantic in late 20th century in a coupled model
Observational evidence indicates that in the northern North Atlantic, especially in the Labrador Sea, almost the whole column of the ocean water is fresher, and colder in late 20th century than in 1950–1960s. Here we analyze a four-member ensemble of the 20th century simulations from a coupled clima...
Published in: | Progress in Oceanography |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Elsevier Ltd.
2007
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Online Access: | http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-213 https://doi.org/10.1016/j.pocean.2006.07.008 |
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ftncar:oai:drupal-site.org:articles_6883 2023-10-01T03:57:14+02:00 Causes of a fresher, colder northern North Atlantic in late 20th century in a coupled model Hu, Aixue (author) Meehl, Gerald (author) Han, Weiqing (author) 2007-05-01 http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-213 https://doi.org/10.1016/j.pocean.2006.07.008 en eng Elsevier Ltd. Progress in Oceanography http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-213 doi:10.1016/j.pocean.2006.07.008 ark:/85065/d72807vm Copyright 2007 Elsevier. Meridional freshwater transport Thermohaline circulation Meridional heat transport Text article 2007 ftncar https://doi.org/10.1016/j.pocean.2006.07.008 2023-09-04T18:22:03Z Observational evidence indicates that in the northern North Atlantic, especially in the Labrador Sea, almost the whole column of the ocean water is fresher, and colder in late 20th century than in 1950–1960s. Here we analyze a four-member ensemble of the 20th century simulations from a coupled climate model to examine the possible causes for these observed changes. The model simulations resemble the observed changes in the northern North Atlantic. The simulated results show that a decreased meridional freshwater divergence and an increased meridional heat divergence associated with a weaker thermohaline circulation in the North Atlantic are the primary causes for the freshening and cooling in the northern North Atlantic. The increased precipitation less evaporation tends to enforce the freshening, but the reduced sea ice flux into this region tends to weaken it. On the other hand, the surface warming induced by a higher atmospheric CO₂ concentration tends to heat up the northern North Atlantic, but is overcome by the cooling from increased meridional heat divergence. Article in Journal/Newspaper Labrador Sea North Atlantic Sea ice OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Progress in Oceanography 73 3-4 384 405 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
topic |
Meridional freshwater transport Thermohaline circulation Meridional heat transport |
spellingShingle |
Meridional freshwater transport Thermohaline circulation Meridional heat transport Causes of a fresher, colder northern North Atlantic in late 20th century in a coupled model |
topic_facet |
Meridional freshwater transport Thermohaline circulation Meridional heat transport |
description |
Observational evidence indicates that in the northern North Atlantic, especially in the Labrador Sea, almost the whole column of the ocean water is fresher, and colder in late 20th century than in 1950–1960s. Here we analyze a four-member ensemble of the 20th century simulations from a coupled climate model to examine the possible causes for these observed changes. The model simulations resemble the observed changes in the northern North Atlantic. The simulated results show that a decreased meridional freshwater divergence and an increased meridional heat divergence associated with a weaker thermohaline circulation in the North Atlantic are the primary causes for the freshening and cooling in the northern North Atlantic. The increased precipitation less evaporation tends to enforce the freshening, but the reduced sea ice flux into this region tends to weaken it. On the other hand, the surface warming induced by a higher atmospheric CO₂ concentration tends to heat up the northern North Atlantic, but is overcome by the cooling from increased meridional heat divergence. |
author2 |
Hu, Aixue (author) Meehl, Gerald (author) Han, Weiqing (author) |
format |
Article in Journal/Newspaper |
title |
Causes of a fresher, colder northern North Atlantic in late 20th century in a coupled model |
title_short |
Causes of a fresher, colder northern North Atlantic in late 20th century in a coupled model |
title_full |
Causes of a fresher, colder northern North Atlantic in late 20th century in a coupled model |
title_fullStr |
Causes of a fresher, colder northern North Atlantic in late 20th century in a coupled model |
title_full_unstemmed |
Causes of a fresher, colder northern North Atlantic in late 20th century in a coupled model |
title_sort |
causes of a fresher, colder northern north atlantic in late 20th century in a coupled model |
publisher |
Elsevier Ltd. |
publishDate |
2007 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-213 https://doi.org/10.1016/j.pocean.2006.07.008 |
genre |
Labrador Sea North Atlantic Sea ice |
genre_facet |
Labrador Sea North Atlantic Sea ice |
op_relation |
Progress in Oceanography http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-213 doi:10.1016/j.pocean.2006.07.008 ark:/85065/d72807vm |
op_rights |
Copyright 2007 Elsevier. |
op_doi |
https://doi.org/10.1016/j.pocean.2006.07.008 |
container_title |
Progress in Oceanography |
container_volume |
73 |
container_issue |
3-4 |
container_start_page |
384 |
op_container_end_page |
405 |
_version_ |
1778528330080845824 |