Noise induced multidecadal variability in the North Atlantic: excitation of normal modes
In this paper it is proposed that the stochastic excitation of a multidecadal internal ocean mode is at the origin of the multidecadal sea surface temperature variability in the North Atlantic. The excitation processes of the spatial sea surface temperature pattern associated with this multidecadal...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/42893 2023-12-03T10:26:28+01:00 Noise induced multidecadal variability in the North Atlantic: excitation of normal modes Frankcombe, L.M. Dijkstra, H.A. von der Heydt, A.S. Marine and Atmospheric Research Sub Physical Oceanography 2009 application/pdf https://dspace.library.uu.nl/handle/1874/42893 other unknown 0022-3670 https://dspace.library.uu.nl/handle/1874/42893 info:eu-repo/semantics/OpenAccess International (English) Article 2009 ftunivutrecht 2023-11-08T23:11:08Z In this paper it is proposed that the stochastic excitation of a multidecadal internal ocean mode is at the origin of the multidecadal sea surface temperature variability in the North Atlantic. The excitation processes of the spatial sea surface temperature pattern associated with this multidecadal mode within an idealized three-dimensional model are studied by adding noise to the surface heat flux forcing. In the regime where the internal mode is damped, the amplitude of its sea surface temperature pattern depends on the type of noise forcing applied. While the mode is weakly excited by white noise, only the introduction of spatial and temporal coherence in the forcing, with characteristics of the North Atlantic Oscillation in particular, causes the amplitude of the variability to increase to levels comparable to those observed. Within this idealized model the physical mechanism of the excitation can be determined: the presence of the noise rectifies the background state and consequently changes the growth factor of the internal mode Article in Journal/Newspaper North Atlantic North Atlantic oscillation Utrecht University Repository |
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Utrecht University Repository |
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ftunivutrecht |
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International (English) |
spellingShingle |
International (English) Frankcombe, L.M. Dijkstra, H.A. von der Heydt, A.S. Noise induced multidecadal variability in the North Atlantic: excitation of normal modes |
topic_facet |
International (English) |
description |
In this paper it is proposed that the stochastic excitation of a multidecadal internal ocean mode is at the origin of the multidecadal sea surface temperature variability in the North Atlantic. The excitation processes of the spatial sea surface temperature pattern associated with this multidecadal mode within an idealized three-dimensional model are studied by adding noise to the surface heat flux forcing. In the regime where the internal mode is damped, the amplitude of its sea surface temperature pattern depends on the type of noise forcing applied. While the mode is weakly excited by white noise, only the introduction of spatial and temporal coherence in the forcing, with characteristics of the North Atlantic Oscillation in particular, causes the amplitude of the variability to increase to levels comparable to those observed. Within this idealized model the physical mechanism of the excitation can be determined: the presence of the noise rectifies the background state and consequently changes the growth factor of the internal mode |
author2 |
Marine and Atmospheric Research Sub Physical Oceanography |
format |
Article in Journal/Newspaper |
author |
Frankcombe, L.M. Dijkstra, H.A. von der Heydt, A.S. |
author_facet |
Frankcombe, L.M. Dijkstra, H.A. von der Heydt, A.S. |
author_sort |
Frankcombe, L.M. |
title |
Noise induced multidecadal variability in the North Atlantic: excitation of normal modes |
title_short |
Noise induced multidecadal variability in the North Atlantic: excitation of normal modes |
title_full |
Noise induced multidecadal variability in the North Atlantic: excitation of normal modes |
title_fullStr |
Noise induced multidecadal variability in the North Atlantic: excitation of normal modes |
title_full_unstemmed |
Noise induced multidecadal variability in the North Atlantic: excitation of normal modes |
title_sort |
noise induced multidecadal variability in the north atlantic: excitation of normal modes |
publishDate |
2009 |
url |
https://dspace.library.uu.nl/handle/1874/42893 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
0022-3670 https://dspace.library.uu.nl/handle/1874/42893 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1784275779690954752 |