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Spreading of Levantine Intermediate Waters by submesoscale coherent vortices in the northwestern M editerranean S ea as observed with gliders
Author(s) -
Bosse Anthony,
Testor Pierre,
Mortier Laurent,
Prieur Louis,
Taillandier Vincent,
d'Ortenzio Fabrizio,
Coppola Laurent
Publication year - 2015
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2014jc010263
Subject(s) - anticyclone , geostrophic wind , oceanography , geology , upwelling , mediterranean climate , mediterranean sea , climatology , geography , archaeology
Abstract Since 2007, gliders have been regularly deployed in the northwestern Mediterranean Sea, a crucial region regarding the thermohaline circulation of the Mediterranean Sea. It revealed for the first time very warm (+0.4∘C) and saline (+0.1) submesoscale anticyclones at intermediate depth characterized by a small radius (∼5 km), high Rossby (∼0.3), and Burger (∼0.7) numbers. They are likely order of 10 to be formed each year, have a life time order a year and certainly contribute significantly to the spreading of the Levantine Intermediate Waters (LIW) toward the whole subbasin, thus potentially impacting wintertime vertical mixing through hydrographical and dynamical preconditioning. They could be mainly formed by the combined action of turbulent mixing and flow detachment of the northward flow of LIW at the northwestern headland of Sardinia. Upwelling conditions along the western coast of Sardinia associated with a southward geostrophic flow within the upper layers seem to play a key role in their formation process.