Jeudi 1 decembre - Variability of surface currents and transports of the Central Mediterranean Sea using coastal altimetry
de 11:00 à 12:00
|Où ?||Salle Coriolis|
Fatma JEBRI, Doctorant LEGOS / MIO (Institut Méditerranéen d'Océanologie, Université de Toulon) / INSTM (Institut National des Sciences et Technologies de la Mer, Tunisie)
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Doctorant LEGOS / MIO / INSTM
Title : Variability of surface currents and transports of the Central Mediterranean Sea using coastal altimetry
Along track altimetry data is used to observe and monitor coastal ocean features over the transition area between the Western and Eastern Mediterranean Basins. The relative performances of both the AVISO and the X-TRACK research regional altimetric datasets are compared using in situ observations. Results indicate the good potential of satellite altimetry to retrieve dynamic features over the area.
The seasonal evolution of the surface circulation is then analyzed by conjointly using X-TRACK data and remotely sensed sea surface temperature observations. This combined dataset clearly depicts different current regimes and bifurcations, which allows us to propose a new seasonal circulation scheme for the Central Mediterranean. The analysis shows variations of the path and temporal behavior of the main circulation features: the Atlantic Tunisian Current, the Atlantic Ionian Stream, the Atlantic Libyan Current and the Sidra Gyre. The interannual variations of the latter are also analyzed.
In a second time, the interannual evolution of the Atlantic water volume transport is estimated based on approximate equations model that assimilates altimetry data and is forced by bathymetry constraints. The model parameters are validated with in-situ hydrographic measurements. The mean transport budgets and low errors give highly promising results in the light of values quantified in previous works. The analysis allows us to propose insights on the upper layer transport at the long-term in the wild shelf areas of the Central Mediterranean. This basin variability seems to be mostly dominated by the mesoscale activity.