Mechanisms of Atlantic Meridional Overturning Circulation variability simulated by the NEMO model
We have investigated mechanisms for the Atlantic Meridional Overturning Circulation (AMOC) variability at 26.5° N (other than the Ekman component) that can be related to external forcings, in particular wind variability. Resolution dependence is studied using identical experiments with 1° and 1/4° N...
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Copernicus Publications
2014
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fttriple:oai:gotriple.eu:oai:doaj.org/article:7ac8db010baf453fac5ede2e6d5b42a3 2023-05-15T17:27:49+02:00 Mechanisms of Atlantic Meridional Overturning Circulation variability simulated by the NEMO model V. N. Stepanov K. Haines 2014-07-01 https://doi.org/10.5194/os-10-645-2014 http://www.ocean-sci.net/10/645/2014/os-10-645-2014.pdf https://doaj.org/article/7ac8db010baf453fac5ede2e6d5b42a3 en eng Copernicus Publications 1812-0784 1812-0792 doi:10.5194/os-10-645-2014 http://www.ocean-sci.net/10/645/2014/os-10-645-2014.pdf https://doaj.org/article/7ac8db010baf453fac5ede2e6d5b42a3 undefined Ocean Science, Vol 10, Iss 4, Pp 645-656 (2014) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2014 fttriple https://doi.org/10.5194/os-10-645-2014 2023-01-22T17:49:49Z We have investigated mechanisms for the Atlantic Meridional Overturning Circulation (AMOC) variability at 26.5° N (other than the Ekman component) that can be related to external forcings, in particular wind variability. Resolution dependence is studied using identical experiments with 1° and 1/4° NEMO model runs over 1960–2010. The analysis shows that much of the variability in the AMOC at 26° N can be related to the wind strength over the North Atlantic, through mechanisms lagged on different timescales. At ~ 1-year lag the January–June difference of mean sea level pressure between high and mid-latitudes in the North Atlantic explains 35–50% of the interannual AMOC variability (with negative correlation between wind strength and AMOC). At longer lead timescales ~ 4 years, strong (weak) winds over the northern North Atlantic (specifically linked to the NAO index) are followed by higher (lower) AMOC transport, but this mechanism only works in the 1/4° model. Analysis of the density correlations suggests an increase (decrease) in deep water formation in the North Atlantic subpolar gyre to be the cause. Therefore another 30% of the AMOC variability at 26° N can be related to density changes in the top 1000 m in the Labrador and Irminger seas occurring ~ 4 years earlier. Article in Journal/Newspaper North Atlantic Unknown Ocean Science 10 4 645 656 |
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envir geo V. N. Stepanov K. Haines Mechanisms of Atlantic Meridional Overturning Circulation variability simulated by the NEMO model |
topic_facet |
envir geo |
description |
We have investigated mechanisms for the Atlantic Meridional Overturning Circulation (AMOC) variability at 26.5° N (other than the Ekman component) that can be related to external forcings, in particular wind variability. Resolution dependence is studied using identical experiments with 1° and 1/4° NEMO model runs over 1960–2010. The analysis shows that much of the variability in the AMOC at 26° N can be related to the wind strength over the North Atlantic, through mechanisms lagged on different timescales. At ~ 1-year lag the January–June difference of mean sea level pressure between high and mid-latitudes in the North Atlantic explains 35–50% of the interannual AMOC variability (with negative correlation between wind strength and AMOC). At longer lead timescales ~ 4 years, strong (weak) winds over the northern North Atlantic (specifically linked to the NAO index) are followed by higher (lower) AMOC transport, but this mechanism only works in the 1/4° model. Analysis of the density correlations suggests an increase (decrease) in deep water formation in the North Atlantic subpolar gyre to be the cause. Therefore another 30% of the AMOC variability at 26° N can be related to density changes in the top 1000 m in the Labrador and Irminger seas occurring ~ 4 years earlier. |
format |
Article in Journal/Newspaper |
author |
V. N. Stepanov K. Haines |
author_facet |
V. N. Stepanov K. Haines |
author_sort |
V. N. Stepanov |
title |
Mechanisms of Atlantic Meridional Overturning Circulation variability simulated by the NEMO model |
title_short |
Mechanisms of Atlantic Meridional Overturning Circulation variability simulated by the NEMO model |
title_full |
Mechanisms of Atlantic Meridional Overturning Circulation variability simulated by the NEMO model |
title_fullStr |
Mechanisms of Atlantic Meridional Overturning Circulation variability simulated by the NEMO model |
title_full_unstemmed |
Mechanisms of Atlantic Meridional Overturning Circulation variability simulated by the NEMO model |
title_sort |
mechanisms of atlantic meridional overturning circulation variability simulated by the nemo model |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/os-10-645-2014 http://www.ocean-sci.net/10/645/2014/os-10-645-2014.pdf https://doaj.org/article/7ac8db010baf453fac5ede2e6d5b42a3 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Ocean Science, Vol 10, Iss 4, Pp 645-656 (2014) |
op_relation |
1812-0784 1812-0792 doi:10.5194/os-10-645-2014 http://www.ocean-sci.net/10/645/2014/os-10-645-2014.pdf https://doaj.org/article/7ac8db010baf453fac5ede2e6d5b42a3 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/os-10-645-2014 |
container_title |
Ocean Science |
container_volume |
10 |
container_issue |
4 |
container_start_page |
645 |
op_container_end_page |
656 |
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1766120123294285824 |