Stability of finite amplitude internal waves in a shear flow
International audience Abstract Five 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 cir...
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ftccsdartic:oai:HAL:hal-03842703v1 2023-05-15T17:36:28+02:00 Stability of finite amplitude internal waves in a shear flow Frankignoul, Claude Sorbonne Université (SU) 1972-11-01 https://hal.archives-ouvertes.fr/hal-03842703 https://doi.org/10.1080/03091927208236091 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.1080/03091927208236091 hal-03842703 https://hal.archives-ouvertes.fr/hal-03842703 doi:10.1080/03091927208236091 ISSN: 0016-7991 Geophysical Fluid Dynamics https://hal.archives-ouvertes.fr/hal-03842703 Geophysical Fluid Dynamics, 1972, 4 (2), pp.91-99. ⟨10.1080/03091927208236091⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 1972 ftccsdartic https://doi.org/10.1080/03091927208236091 2022-11-12T23:50:10Z International audience Abstract Five 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. Article in Journal/Newspaper North Atlantic North Atlantic oscillation Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Geophysical Fluid Dynamics 4 2 91 99 |
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Open Polar |
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Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
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ftccsdartic |
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English |
topic |
[SDE]Environmental Sciences |
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[SDE]Environmental Sciences Frankignoul, Claude Stability of finite amplitude internal waves in a shear flow |
topic_facet |
[SDE]Environmental Sciences |
description |
International audience Abstract Five 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. |
author2 |
Sorbonne Université (SU) |
format |
Article in Journal/Newspaper |
author |
Frankignoul, Claude |
author_facet |
Frankignoul, Claude |
author_sort |
Frankignoul, Claude |
title |
Stability of finite amplitude internal waves in a shear flow |
title_short |
Stability of finite amplitude internal waves in a shear flow |
title_full |
Stability of finite amplitude internal waves in a shear flow |
title_fullStr |
Stability of finite amplitude internal waves in a shear flow |
title_full_unstemmed |
Stability of finite amplitude internal waves in a shear flow |
title_sort |
stability of finite amplitude internal waves in a shear flow |
publisher |
HAL CCSD |
publishDate |
1972 |
url |
https://hal.archives-ouvertes.fr/hal-03842703 https://doi.org/10.1080/03091927208236091 |
long_lat |
ENVELOPE(-63.071,-63.071,-70.797,-70.797) |
geographic |
Curl |
geographic_facet |
Curl |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
ISSN: 0016-7991 Geophysical Fluid Dynamics https://hal.archives-ouvertes.fr/hal-03842703 Geophysical Fluid Dynamics, 1972, 4 (2), pp.91-99. ⟨10.1080/03091927208236091⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1080/03091927208236091 hal-03842703 https://hal.archives-ouvertes.fr/hal-03842703 doi:10.1080/03091927208236091 |
op_doi |
https://doi.org/10.1080/03091927208236091 |
container_title |
Geophysical Fluid Dynamics |
container_volume |
4 |
container_issue |
2 |
container_start_page |
91 |
op_container_end_page |
99 |
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1766135945588899840 |