On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation
International audience The last 810 years of a control integration with the ECHAM1/LSG coupled model are used to clarify the nature of the ocean-atmosphere interactions at low frequencies in the North Atlantic and the North Pacific. To a first approximation, the atmosphere acts as a white noise forc...
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Online Access: | https://hal.science/hal-00772172 https://doi.org/10.1007/S003820050332 |
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ftunivnantes:oai:HAL:hal-00772172v1 2023-05-15T17:32:38+02:00 On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation Frankignoul, Claude Kestenare, Élodie Sennéchael, Nathalie de Coëtlogon, Gaëlle d'Andrea, Fabio Laboratoire d'océanographie dynamique et de climatologie (LODYC) Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL) 2000 https://hal.science/hal-00772172 https://doi.org/10.1007/S003820050332 en eng HAL CCSD Springer Verlag info:eu-repo/semantics/altIdentifier/doi/10.1007/S003820050332 hal-00772172 https://hal.science/hal-00772172 BIBCODE: 2000ClDy.16.333F doi:10.1007/S003820050332 ISSN: 0930-7575 EISSN: 1432-0894 Climate Dynamics https://hal.science/hal-00772172 Climate Dynamics, 2000, 16, pp.333-354. ⟨10.1007/S003820050332⟩ [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2000 ftunivnantes https://doi.org/10.1007/S003820050332 2023-01-17T23:43:51Z International audience The last 810 years of a control integration with the ECHAM1/LSG coupled model are used to clarify the nature of the ocean-atmosphere interactions at low frequencies in the North Atlantic and the North Pacific. To a first approximation, the atmosphere acts as a white noise forcing and the ocean responds as a passive integrator. The sea surface temperature (SST) variability primarily results from short time scale fluctuations in surface heat exchanges and Ekman currents, and the former also damp the SST anomalies after they are generated. The thermocline variability is primarily driven by Ekman pumping. Because the heat, momentum, and vorticity fluxes at the sea surface are correlated in space and time, the SST variability is directly linked to that in the ocean interior. The SST is also modulated by the wind-driven geostrophic fluctuations, resulting in persistent correlation with the thermocline changes and a slight low-frequency redness of the SST spectra. The main dynamics are similar in the two oceans, although in the North Pacific the SST variability is more strongly influenced by advection changes and the oceanic time scales are larger. A maximum covariance analysis based on singular value decomposition in lead and lag conditions indicates that some of the main modes of atmospheric variability in the two oceans are sustained by a very weak positive feedback between the atmosphere, SST, and the strength of the subtropical and subpolar gyres. In addition, in the North Atlantic the main surface pressure mode has a small quasi-oscillatory component at 6-year period, and advective resonance occurs for SST around 10-year period, both periods being also singled out by multichannel singular spectrum analysis. The ocean-atmosphere coupling is however much too weak to redden the tropospheric spectra or create anything more than tiny spectral peaks, so that the atmospheric and oceanic variability is dominated in both ocean sectors by the one-way interactions. Article in Journal/Newspaper North Atlantic Université de Nantes: HAL-UNIV-NANTES Pacific Climate Dynamics 16 5 333 354 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes Frankignoul, Claude Kestenare, Élodie Sennéchael, Nathalie de Coëtlogon, Gaëlle d'Andrea, Fabio On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation |
topic_facet |
[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience The last 810 years of a control integration with the ECHAM1/LSG coupled model are used to clarify the nature of the ocean-atmosphere interactions at low frequencies in the North Atlantic and the North Pacific. To a first approximation, the atmosphere acts as a white noise forcing and the ocean responds as a passive integrator. The sea surface temperature (SST) variability primarily results from short time scale fluctuations in surface heat exchanges and Ekman currents, and the former also damp the SST anomalies after they are generated. The thermocline variability is primarily driven by Ekman pumping. Because the heat, momentum, and vorticity fluxes at the sea surface are correlated in space and time, the SST variability is directly linked to that in the ocean interior. The SST is also modulated by the wind-driven geostrophic fluctuations, resulting in persistent correlation with the thermocline changes and a slight low-frequency redness of the SST spectra. The main dynamics are similar in the two oceans, although in the North Pacific the SST variability is more strongly influenced by advection changes and the oceanic time scales are larger. A maximum covariance analysis based on singular value decomposition in lead and lag conditions indicates that some of the main modes of atmospheric variability in the two oceans are sustained by a very weak positive feedback between the atmosphere, SST, and the strength of the subtropical and subpolar gyres. In addition, in the North Atlantic the main surface pressure mode has a small quasi-oscillatory component at 6-year period, and advective resonance occurs for SST around 10-year period, both periods being also singled out by multichannel singular spectrum analysis. The ocean-atmosphere coupling is however much too weak to redden the tropospheric spectra or create anything more than tiny spectral peaks, so that the atmospheric and oceanic variability is dominated in both ocean sectors by the one-way interactions. |
author2 |
Laboratoire d'océanographie dynamique et de climatologie (LODYC) Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL) |
format |
Article in Journal/Newspaper |
author |
Frankignoul, Claude Kestenare, Élodie Sennéchael, Nathalie de Coëtlogon, Gaëlle d'Andrea, Fabio |
author_facet |
Frankignoul, Claude Kestenare, Élodie Sennéchael, Nathalie de Coëtlogon, Gaëlle d'Andrea, Fabio |
author_sort |
Frankignoul, Claude |
title |
On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation |
title_short |
On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation |
title_full |
On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation |
title_fullStr |
On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation |
title_full_unstemmed |
On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation |
title_sort |
on decadal-scale ocean-atmosphere interactions in the extended echam1/lsg climate simulation |
publisher |
HAL CCSD |
publishDate |
2000 |
url |
https://hal.science/hal-00772172 https://doi.org/10.1007/S003820050332 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0930-7575 EISSN: 1432-0894 Climate Dynamics https://hal.science/hal-00772172 Climate Dynamics, 2000, 16, pp.333-354. ⟨10.1007/S003820050332⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/S003820050332 hal-00772172 https://hal.science/hal-00772172 BIBCODE: 2000ClDy.16.333F doi:10.1007/S003820050332 |
op_doi |
https://doi.org/10.1007/S003820050332 |
container_title |
Climate Dynamics |
container_volume |
16 |
container_issue |
5 |
container_start_page |
333 |
op_container_end_page |
354 |
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1766130853479448576 |