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| Titel |
Surface circulation in the Eastern Mediterranean using drifters (2005–2007) |
| VerfasserIn |
R. Gerin, P.-M. Poulain, I. Taupier-Letage, C. Millot, S. Ben Ismail, C. Sammari |
| 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 ; 5, no. 4 ; Nr. 5, no. 4 (2009-11-10), S.559-574 |
| Datensatznummer |
250002732
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| Publikation (Nr.) |
 copernicus.org/os-5-559-2009.pdf |
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| Zusammenfassung |
| Within the framework of the EGITTO/EGYPT programs, the spatial structure and
the temporal variability of the surface circulation in the eastern basin of
the Mediterranean Sea was studied with satellite-tracked drifters. A total of
97 drifters drogued to 15-m nominal depth were released between September
2005 and March 2007, regularly along ship-of-opportunity routes in the Sicily
Channel and within specific structures during dedicated campaigns in the
Levantine sub-basin. This study complements previous ones in the former and
in the Ionian, but it is the first one in the latter. After editing and
low-pass filtering, the drifter trajectories were used to estimate
pseudo-Eulerian statistics: mean current, variance ellipses, mean and eddy
kinetic energies. A statistical analysis was also performed dividing the
dataset in two extended seasons (winter and summer). A branching behaviour of
the surface water after passing through the Sicily Channel is evidenced,
together with a seasonal variability inducing a reversal of the circulation
in the southern part of the Ionian. In the Levantine, the surface circulation
describes an eastward flow along the Libyan and Egyptian slopes (the
Libyo-Egyptian Current: LEC) that continues in a cyclonic circuit along the
Middle East and Turkish slopes. This general alongslope circuit can be
perturbed locally and temporally by the numerous anticyclonic eddies that
co-exist in the Levantine, mainly created by the instability of the LEC in
the south (Libyo-Egyptian Eddies: LEEs), but also by the wind (Ierapetra and
Pelops), and by the topography (over the Eratosthenes Seamount and off
Latakia). The most frequent perturbation is the entrainment of part of the
flow seaward: the LEEs close to the slope can interact with the LEC, which
then spreads more or less around them, so that a series of contiguous LEEs
(paddle-wheel effect) can possibly result in an eastward offshore transport
(the so-called Mid Mediterranean Jet). Additionally, when LEEs are close
enough to the slope, most of the surface flow is spread seaward. Along the
slope the current is then induced by the LEEs southern side which results in
a westward current. Locally and temporally the circulation along the slope
can thus be reversed. |
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