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| Titel |
A multi-decadal meridional displacement of the Subpolar Front in the Newfoundland Basin |
| VerfasserIn |
I. Núñez-Riboni, M. Bersch, H. Haak, J. H. Jungclaus, K. Lohmann |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1812-0784
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| Digitales Dokument |
URL |
| Erschienen |
In: Ocean Science ; 8, no. 1 ; Nr. 8, no. 1 (2012-02-15), S.91-102 |
| Datensatznummer |
250005399
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| Publikation (Nr.) |
 copernicus.org/os-8-91-2012.pdf |
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| Zusammenfassung |
| Observations since the 1950s show a multi-decadal cycle of a meridional
displacement of the Subpolar Front (SPF) in the Newfoundland Basin (NFB) in
the North Atlantic. The SPF displacement is associated with corresponding
variations in the path of the North Atlantic Current. We use the ocean
general circulation model MPIOM with enhanced horizontal and vertical
resolutions and forced with NCEP/NCAR reanalysis data to study the relation
of the SPF displacement to atmospheric forcing, intensities of the subpolar
gyre (SPG) and Meridional Overturning Circulation (MOC), and Labrador Sea
Water (LSW) volume. The simulations indicate that the SPF displacement is
associated with a circulation anomaly between the SPG and the subtropical
gyre (STG), an inter-gyre gyre with a multi-decadal time scale. A
sensitivity experiment indicates that both wind stress curl (WSC) and heat
fluxes (which match LSW changes) contribute to the circulation anomalies in
the frontal region and to the SPF displacement. An anticyclonic inter-gyre
gyre is related to negative WSC and LSW anomalies and to a SPF north of its
climatological position, indicating an expanding STG. A cyclonic inter-gyre
gyre is related to positive WSC and LSW anomalies and a SPF south of its
climatological position, indicating an expanding SPG. Therefore, the mean
latitudinal position of the SPF in the NFB (a "SPF index") could be an
indicator of the amount of LSW in the inter-gyre region. Spreading of LSW
anomalies intensifies the MOC, suggesting our SPF index as predictor of the
MOC intensity at multi-decadal time scales. The meridional displacement of
the SPF has a pronounced influence on the meridional heat transport, both on
its gyre and overturning components. |
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