Intrinsic low-frequency variability of the Gulf Stream
In this paper a process study aimed at analyzing the low-frequency variability of intrinsically oceanic origin of the Gulf Stream (GS) and GS extension (GSE) is presented. An eddy-permitting reduced-gravity nonlinear shallow water model is implemented in an idealized North Atlantic Ocean, with schem...
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ftdoajarticles:oai:doaj.org/article:221d157bc08846d89ea59f87fc44caa5 2023-05-15T17:34:16+02:00 Intrinsic low-frequency variability of the Gulf Stream G. Quattrocchi S. Pierini H. A. Dijkstra 2012-03-01T00:00:00Z https://doi.org/10.5194/npg-19-155-2012 https://doaj.org/article/221d157bc08846d89ea59f87fc44caa5 EN eng Copernicus Publications http://www.nonlin-processes-geophys.net/19/155/2012/npg-19-155-2012.pdf https://doaj.org/toc/1023-5809 https://doaj.org/toc/1607-7946 doi:10.5194/npg-19-155-2012 1023-5809 1607-7946 https://doaj.org/article/221d157bc08846d89ea59f87fc44caa5 Nonlinear Processes in Geophysics, Vol 19, Iss 2, Pp 155-164 (2012) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2012 ftdoajarticles https://doi.org/10.5194/npg-19-155-2012 2022-12-31T14:44:07Z In this paper a process study aimed at analyzing the low-frequency variability of intrinsically oceanic origin of the Gulf Stream (GS) and GS extension (GSE) is presented. An eddy-permitting reduced-gravity nonlinear shallow water model is implemented in an idealized North Atlantic Ocean, with schematic boundaries including the essential geometric features of the coastline and a realistic zonal basin width at all latitudes. The forcing is provided by a time-independent climatological surface wind stress obtained from 41 years of monthly ECMWF fields. The model response yields strong intrinsic low-frequency fluctuations on the interannual to decadal time scales. The modelled time-averaged GS/GSE flows are found to exhibit several features that can also be deduced from satellite altimeter data, such as the Florida Current seaward deflection, the GS separation at Cape Hatteras, and the overall structure of the GSE. The intrinsic low-frequency variability yields two preferred states of the GSE differing in latitudinal location that also have their counterpart in the altimeter data. A preliminary analysis of the variability in terms of dynamical systems theory is carried out by using the lateral eddy viscosity as the control parameter. A complex transition sequence from a steady state to irregular low-frequency variability emerges, in which Hopf and global bifurcations can be identified. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Nonlinear Processes in Geophysics 19 2 155 164 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 G. Quattrocchi S. Pierini H. A. Dijkstra Intrinsic low-frequency variability of the Gulf Stream |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
In this paper a process study aimed at analyzing the low-frequency variability of intrinsically oceanic origin of the Gulf Stream (GS) and GS extension (GSE) is presented. An eddy-permitting reduced-gravity nonlinear shallow water model is implemented in an idealized North Atlantic Ocean, with schematic boundaries including the essential geometric features of the coastline and a realistic zonal basin width at all latitudes. The forcing is provided by a time-independent climatological surface wind stress obtained from 41 years of monthly ECMWF fields. The model response yields strong intrinsic low-frequency fluctuations on the interannual to decadal time scales. The modelled time-averaged GS/GSE flows are found to exhibit several features that can also be deduced from satellite altimeter data, such as the Florida Current seaward deflection, the GS separation at Cape Hatteras, and the overall structure of the GSE. The intrinsic low-frequency variability yields two preferred states of the GSE differing in latitudinal location that also have their counterpart in the altimeter data. A preliminary analysis of the variability in terms of dynamical systems theory is carried out by using the lateral eddy viscosity as the control parameter. A complex transition sequence from a steady state to irregular low-frequency variability emerges, in which Hopf and global bifurcations can be identified. |
format |
Article in Journal/Newspaper |
author |
G. Quattrocchi S. Pierini H. A. Dijkstra |
author_facet |
G. Quattrocchi S. Pierini H. A. Dijkstra |
author_sort |
G. Quattrocchi |
title |
Intrinsic low-frequency variability of the Gulf Stream |
title_short |
Intrinsic low-frequency variability of the Gulf Stream |
title_full |
Intrinsic low-frequency variability of the Gulf Stream |
title_fullStr |
Intrinsic low-frequency variability of the Gulf Stream |
title_full_unstemmed |
Intrinsic low-frequency variability of the Gulf Stream |
title_sort |
intrinsic low-frequency variability of the gulf stream |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/npg-19-155-2012 https://doaj.org/article/221d157bc08846d89ea59f87fc44caa5 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Nonlinear Processes in Geophysics, Vol 19, Iss 2, Pp 155-164 (2012) |
op_relation |
http://www.nonlin-processes-geophys.net/19/155/2012/npg-19-155-2012.pdf https://doaj.org/toc/1023-5809 https://doaj.org/toc/1607-7946 doi:10.5194/npg-19-155-2012 1023-5809 1607-7946 https://doaj.org/article/221d157bc08846d89ea59f87fc44caa5 |
op_doi |
https://doi.org/10.5194/npg-19-155-2012 |
container_title |
Nonlinear Processes in Geophysics |
container_volume |
19 |
container_issue |
2 |
container_start_page |
155 |
op_container_end_page |
164 |
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1766133054388043776 |