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| Titel |
Surface circulation variability and upwelling phenomenology in the western Sardinia |
| VerfasserIn |
Antonio Olita, Andrea Cucco, Leopoldo Fazioli, Angelo Perilli, Alberto Ribotti, Roberto Sorgente |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074519
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| Zusammenfassung |
| The mean and turbulent surface circulation of the Sardinan Sea (the shelf-slope region west
of Sardinia, western Mediterranean sea) was studied by analyzing an interannual simulation
performed with a hydrodinamic 3D numerical model. The model (an implementation of the
Princeton Ocean Model) was forced with realistic atmospheric and oceanic fields (analyses)
for the quadriennium 2008-2011. The model assimilates along track Sea Level Anomalies by
means of a 3D-variational software. Velocities (meridional and zonal components) were
decomposed in their mean and turbulent part to investigate the mean and fluctuating surface
flow. EOF decomposition was used to get further insight on the simulated dataset
and throw light on the variability of the main circulation features. At surface the
mean circulation is characterized by a southward current field getting closer to the
coast in the southern corner of the Island where if flows over the shelf edge. Eddy
momentum flux field suggests that this southward stream is accelerated by a transfer of
momentum from the eddy to the mean field. The accelerated stream contributes to
precontidition the coastal upwelling in the southern area. The phenomenology of
such a coastal upwelling along the SW Sardinia is described for the first time. The
upwelling in the southern part of Sardinia constitutes the main surface temperature
signal of the modeled SST anomalies, as evidenced by EOF decomposition. A
significant correlation both with wind directions and current intensity was found. This,
jointly with synoptic satellite observations before and during an upwelling event,
suggests that both current and winds participate in creating the upwelling: alongshore
current preconditions the upwelling that is finally triggered by favourable NW winds. |
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