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| Titel |
Assessment of the ocean circulation in the Azores region as predicted by a numerical model assimilating altimeter data from Topex/Poseidon and ERS-1 satellites |
| VerfasserIn |
T. Mailly, E. Blayo, J. Verron |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 15, no. 10 ; Nr. 15, no. 10, S.1354-1368 |
| Datensatznummer |
250012981
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| Publikation (Nr.) |
 copernicus.org/angeo-15-1354-1997.pdf |
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| Zusammenfassung |
| Two years of altimetric data from Topex/Poseidon
(October 1992–September 1994) and ERS-1 (October 1992–December 1993) were
assimilated into a numerical model of the North Atlantic. The results of these
simulations are analysed in the Azores region to assess the performance of our
model in this particular region. Maps of instantaneous dynamic topography and
transports show that the model performs well in reproducing the velocities and
transports of the Azores Front. Drifter data from the Semaphore experiment are
also used to study the correlation between the drifter velocities and the
corresponding model velocities. Some interesting oceanographic results are also
obtained by examining the seasonal and interannual variability of the
circulation and the influence of bathymetry on the variability of the Azores
Front. Thus, on the basis of our two year experiment, it is possible to confirm
the circulation patterns proposed by previous studies regarding the seasonal
variations in the origin of the Azores Current. Moreover, it is shown that the
Azores Current is quite narrow in the first year of assimilation (1992–1993),
but becomes much wider in the second year (1993–1994). The role of the
bathymetry appears important in this area since the mesoscale activity is shown
to be strongly related to the presence of topographic slopes. Finally, spectral
analyses of sea-level changes over time and space are used to identify two types
of wave already noticed in other studies: a wave with (300 km)–1 wave
number and (120 days)–1 frequency, which is characteristic of
mesoscale undulation, and a wave with (600 km)–1 wave number and (250
days)–1 frequency which probably corresponds to a Rossby wave
generated in the east of the basin. |
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