The Influence of the AMOC Variability on the Atmosphere in CCSM3
The influence of the Atlantic meridional overturning circulation (AMOC) variability on the atmospheric circulation is investigated in a control simulation of the NCAR Community Climate System Model, version 3 (CCSM3), where the AMOC evolves from an oscillatory regime into a red noise regime. In the...
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ftzenodo:oai:zenodo.org:29218 2023-05-15T17:25:17+02:00 The Influence of the AMOC Variability on the Atmosphere in CCSM3 CLAUDE FRANKIGNOUL GUILLAUME GASTINEAU YOUNG-OH KWON 2013-12-15 https://zenodo.org/record/29218 https://doi.org/10.1175/JCLI-D-12-00862.1 unknown info:eu-repo/grantAgreement/EC/FP7/308299/ https://zenodo.org/communities/ecfunded https://zenodo.org/communities/naclim https://zenodo.org/record/29218 https://doi.org/10.1175/JCLI-D-12-00862.1 oai:zenodo.org:29218 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Atmosphere-ocean interaction North Atlantic Oscillation Thermohaline circulation Decadal variability info:eu-repo/semantics/article publication-article 2013 ftzenodo https://doi.org/10.1175/JCLI-D-12-00862.1 2023-03-11T04:42:51Z The influence of the Atlantic meridional overturning circulation (AMOC) variability on the atmospheric circulation is investigated in a control simulation of the NCAR Community Climate System Model, version 3 (CCSM3), where the AMOC evolves from an oscillatory regime into a red noise regime. In the latter, an AMOC intensification is followed during winter by a positive North Atlantic Oscillation (NAO). The atmospheric response is robust and controlled by AMOC-driven SST anomalies, which shift the heat release to the atmosphere northward near the Gulf Stream/North Atlantic Current. This alters the low-level atmospheric baroclinicity and shifts the maximum eddy growth northward, affecting the storm track and favoring a positive NAO. The AMOC influence is detected in the relation between seasonal upper-ocean heat content or SST anomalies and winter sea level pressure. In the oscillatory regime, no direct AMOC influence is detected in winter. However, an upper-ocean heat content anomaly resembling the AMOC footprint precedes a negative NAO. This opposite NAO polarity seems due to the southward shift of the Gulf Stream during AMOC intensification, displacing the maximum baroclinicity southward near the jet exit. As the mode has somewhat different patterns when using SST, the wintertime impact of the AMOC lacks robustness in this regime. However, none of the signals compares well with the observed influence of North Atlantic SST anomalies on the NAO because SST is dominated in CCSM3 by the meridional shifts of the Gulf Stream/North Atlantic Current that covary with the AMOC. Hence, although there is some potential climate predictability in CCSM3, it is not realistic. Article in Journal/Newspaper north atlantic current North Atlantic North Atlantic oscillation Zenodo Journal of Climate 26 24 9774 9790 |
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Open Polar |
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op_collection_id |
ftzenodo |
language |
unknown |
topic |
Atmosphere-ocean interaction North Atlantic Oscillation Thermohaline circulation Decadal variability |
spellingShingle |
Atmosphere-ocean interaction North Atlantic Oscillation Thermohaline circulation Decadal variability CLAUDE FRANKIGNOUL GUILLAUME GASTINEAU YOUNG-OH KWON The Influence of the AMOC Variability on the Atmosphere in CCSM3 |
topic_facet |
Atmosphere-ocean interaction North Atlantic Oscillation Thermohaline circulation Decadal variability |
description |
The influence of the Atlantic meridional overturning circulation (AMOC) variability on the atmospheric circulation is investigated in a control simulation of the NCAR Community Climate System Model, version 3 (CCSM3), where the AMOC evolves from an oscillatory regime into a red noise regime. In the latter, an AMOC intensification is followed during winter by a positive North Atlantic Oscillation (NAO). The atmospheric response is robust and controlled by AMOC-driven SST anomalies, which shift the heat release to the atmosphere northward near the Gulf Stream/North Atlantic Current. This alters the low-level atmospheric baroclinicity and shifts the maximum eddy growth northward, affecting the storm track and favoring a positive NAO. The AMOC influence is detected in the relation between seasonal upper-ocean heat content or SST anomalies and winter sea level pressure. In the oscillatory regime, no direct AMOC influence is detected in winter. However, an upper-ocean heat content anomaly resembling the AMOC footprint precedes a negative NAO. This opposite NAO polarity seems due to the southward shift of the Gulf Stream during AMOC intensification, displacing the maximum baroclinicity southward near the jet exit. As the mode has somewhat different patterns when using SST, the wintertime impact of the AMOC lacks robustness in this regime. However, none of the signals compares well with the observed influence of North Atlantic SST anomalies on the NAO because SST is dominated in CCSM3 by the meridional shifts of the Gulf Stream/North Atlantic Current that covary with the AMOC. Hence, although there is some potential climate predictability in CCSM3, it is not realistic. |
format |
Article in Journal/Newspaper |
author |
CLAUDE FRANKIGNOUL GUILLAUME GASTINEAU YOUNG-OH KWON |
author_facet |
CLAUDE FRANKIGNOUL GUILLAUME GASTINEAU YOUNG-OH KWON |
author_sort |
CLAUDE FRANKIGNOUL |
title |
The Influence of the AMOC Variability on the Atmosphere in CCSM3 |
title_short |
The Influence of the AMOC Variability on the Atmosphere in CCSM3 |
title_full |
The Influence of the AMOC Variability on the Atmosphere in CCSM3 |
title_fullStr |
The Influence of the AMOC Variability on the Atmosphere in CCSM3 |
title_full_unstemmed |
The Influence of the AMOC Variability on the Atmosphere in CCSM3 |
title_sort |
influence of the amoc variability on the atmosphere in ccsm3 |
publishDate |
2013 |
url |
https://zenodo.org/record/29218 https://doi.org/10.1175/JCLI-D-12-00862.1 |
genre |
north atlantic current North Atlantic North Atlantic oscillation |
genre_facet |
north atlantic current North Atlantic North Atlantic oscillation |
op_relation |
info:eu-repo/grantAgreement/EC/FP7/308299/ https://zenodo.org/communities/ecfunded https://zenodo.org/communities/naclim https://zenodo.org/record/29218 https://doi.org/10.1175/JCLI-D-12-00862.1 oai:zenodo.org:29218 |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode |
op_doi |
https://doi.org/10.1175/JCLI-D-12-00862.1 |
container_title |
Journal of Climate |
container_volume |
26 |
container_issue |
24 |
container_start_page |
9774 |
op_container_end_page |
9790 |
_version_ |
1766116669851172864 |