Investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the North Atlantic
Extratropical SSTs can be influenced by the reemergence mechanism, whereby thermal anomalies in deep winter mixed layer persist at depth through summer and are then reentrained into the mixed layer in the following winter. The impact of reemergence in the North Atlantic Ocean (NAO) upon the climate...
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ftncar:oai:drupal-site.org:articles_6996 2023-10-01T03:57:51+02:00 Investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the North Atlantic Cassou, Christophe (author) Deser, Clara (author) Alexander, Michael (author) 2007-07-15 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-341 https://doi.org/10.1175/JCLI4202.1 en eng Journal of Climate http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-341 doi:10.1175/JCLI4202.1 ark:/85065/d7ft8m8h Copyright 2007 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. Text article 2007 ftncar https://doi.org/10.1175/JCLI4202.1 2023-09-04T18:22:10Z Extratropical SSTs can be influenced by the reemergence mechanism, whereby thermal anomalies in deep winter mixed layer persist at depth through summer and are then reentrained into the mixed layer in the following winter. The impact of reemergence in the North Atlantic Ocean (NAO) upon the climate system is investigated using an atmospheric general circulation model coupled to a mixed layer ocean/ thermodynamic sea ice model.', The dominant pattern of thermal anomalies below the mixed layer in summer in a 150-yr control integration is associated with the North Atlantic SST tripole forced by the NAO in the previous winter as indicated by singular value decomposition (SVD). To isolate the reemerging signal, two additional 60-member ensemble experiments were conducted in which temperature anomalies below 40 m obtained from the SVD analysis are added to or subtracted from the control integration. The reemerging signal, given by the mean difference between the two 60-member ensembles, causes the SST anomaly tripole to recur, beginning in fall, amplifying through January, and persisting through the following spring. The atmospheric response to these SST anomalies resembles the circulation that created them the previous winter but with reduced amplitude (10-20 m at 500 mb per degrees C), modestly enhancing the winter-to-winter persistence of the NAO. Changes in the transient eddies and their interactions with the mean flow contribute to the large-scale equivalent barotropic response throughout the troposphere. The latter can also be attributed to the change in occurrence of intrinsic weather regimes. Article in Journal/Newspaper North Atlantic Sea ice OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Journal of Climate 20 14 3510 3526 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
Extratropical SSTs can be influenced by the reemergence mechanism, whereby thermal anomalies in deep winter mixed layer persist at depth through summer and are then reentrained into the mixed layer in the following winter. The impact of reemergence in the North Atlantic Ocean (NAO) upon the climate system is investigated using an atmospheric general circulation model coupled to a mixed layer ocean/ thermodynamic sea ice model.', The dominant pattern of thermal anomalies below the mixed layer in summer in a 150-yr control integration is associated with the North Atlantic SST tripole forced by the NAO in the previous winter as indicated by singular value decomposition (SVD). To isolate the reemerging signal, two additional 60-member ensemble experiments were conducted in which temperature anomalies below 40 m obtained from the SVD analysis are added to or subtracted from the control integration. The reemerging signal, given by the mean difference between the two 60-member ensembles, causes the SST anomaly tripole to recur, beginning in fall, amplifying through January, and persisting through the following spring. The atmospheric response to these SST anomalies resembles the circulation that created them the previous winter but with reduced amplitude (10-20 m at 500 mb per degrees C), modestly enhancing the winter-to-winter persistence of the NAO. Changes in the transient eddies and their interactions with the mean flow contribute to the large-scale equivalent barotropic response throughout the troposphere. The latter can also be attributed to the change in occurrence of intrinsic weather regimes. |
author2 |
Cassou, Christophe (author) Deser, Clara (author) Alexander, Michael (author) |
format |
Article in Journal/Newspaper |
title |
Investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the North Atlantic |
spellingShingle |
Investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the North Atlantic |
title_short |
Investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the North Atlantic |
title_full |
Investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the North Atlantic |
title_fullStr |
Investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the North Atlantic |
title_full_unstemmed |
Investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the North Atlantic |
title_sort |
investigating the impact of reemerging sea surface temperature anomalies on the winter atmospheric circulation over the north atlantic |
publishDate |
2007 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-341 https://doi.org/10.1175/JCLI4202.1 |
genre |
North Atlantic Sea ice |
genre_facet |
North Atlantic Sea ice |
op_relation |
Journal of Climate http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-341 doi:10.1175/JCLI4202.1 ark:/85065/d7ft8m8h |
op_rights |
Copyright 2007 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. |
op_doi |
https://doi.org/10.1175/JCLI4202.1 |
container_title |
Journal of Climate |
container_volume |
20 |
container_issue |
14 |
container_start_page |
3510 |
op_container_end_page |
3526 |
_version_ |
1778529984688685056 |