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contributor authorde Coëtlogon, Gaëlle
contributor authorFrankignoul, Claude
contributor authorBentsen, Mats
contributor authorDelon, Claire
contributor authorHaak, Helmuth
contributor authorMasina, Simona
contributor authorPardaens, Anne
date accessioned2017-06-09T17:18:22Z
date available2017-06-09T17:18:22Z
date copyright2006/11/01
date issued2006
identifier issn0022-3670
identifier otherams-82839.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4225997
description abstractFive non-eddy-resolving oceanic general circulation models driven by atmospheric fluxes derived from the NCEP reanalysis are used to investigate the link between the Gulf Stream (GS) variability, the atmospheric circulation, and the Atlantic meridional overturning circulation (AMOC). Despite the limited model resolution, the temperature at the 200-m depth along the mean GS axis behaves similarly in most models to that observed, and it is also well correlated with the North Atlantic Oscillation (NAO), indicating that a northward (southward) GS shift lags a positive (negative) NAO phase by 0?2 yr. The northward shift is accompanied by an increase in the GS transport, and conversely the southward shift with a decrease in the GS transport. Two dominant time scales appear in the response of the GS transport to the NAO forcing: a fast time scale (less than 1 month) for the barotropic component, and a slower one (about 2 yr) for the baroclinic component. In addition, the two components are weakly coupled. The GS response seems broadly consistent with a linear adjustment to the changes in the wind stress curl, and evidence for baroclinic Rossby wave propagation is found in the southern part of the subtropical gyre. However, the GS shifts are also affected by basin-scale changes in the oceanic conditions, and they are well correlated in most models with the changes in the AMOC. A larger AMOC is found when the GS is stronger and displaced northward, and a higher correlation is found when the observed changes of the GS position are used in the comparison. The relation between the GS and the AMOC could be explained by the inherent coupling between the thermohaline and the wind-driven circulation, or by the NAO variability driving them on similar time scales in the models.
publisherAmerican Meteorological Society
titleGulf Stream Variability in Five Oceanic General Circulation Models
typeJournal Paper
journal volume36
journal issue11
journal titleJournal of Physical Oceanography
identifier doi10.1175/JPO2963.1
journal fristpage2119
journal lastpage2135
treeJournal of Physical Oceanography:;2006:;Volume( 036 ):;issue: 011
contenttypeFulltext


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