Modeling the deep eddy field in the southwestern Mediterranean: The life cycle of Sardinian eddies

During the MATER experiment, an eddy characterized by marked Levantine Intermediate Water (LIW) in its core at intermediate depth, and called Sardinian Eddy (SE), has been observed in the Algerian Basin located in the western Mediterranean Sea. Here, results from a numerical simulation allow to investigate thoroughly such structures. The formation of SEs and their life cycle in the model are detailed and compared to in-situ observations. The formation of SEs is associated with the detachment from the continental slope of Sardinia of the large-scale cyclonic gyre found in the Algerian Basin. Once formed, SEs leave the slope westwards. They are strongly barotropic and about 3 to 4 SEs are created each year. At a later stage, SEs develop a baroclinic component as revealed by an emerging surface signature about 1 month after their formation. Coalescence processes and merging of these eddies are documented between Minorca and Sardinia where these eddies accumulate.