Lagrangian eddy tracking reveals the Eratosthenes anticyclonicattractor in the eastern Levantine basin

Abstract

<p>Statistics of anticyclone activity and trajectories in the southeastern Mediterranean sea over the period 2000-2018<br>is created using the DYNED atlas, which links the automated mesoscale eddy detection by the AMEDA algorithm with in<br>situ oceanographic observations. This easternmost region of the Mediterranean sea, delimited by the Levantine coast and<br>Cyprus, has a complex eddying activity, which has not yet been fully characterized. Using Lagrangian tracking<br>to investigate the eddy fluxes and interactions between different subregions in this area, we find that the southeastern Levantine<br>area is isolated, with no anticyclone exchanges with the western part of the basin. Moreover the anticyclonic structure above<br>the Eratosthenes seamount is identified as being an anticyclone attractor, differentiated from other anticyclones and staying<br>around this preferred position up to four years with successive mergings. Colocalized in situ profiles inside eddies provide<br>quantitative information on their subsurface structure and show that similar surface signatures correspond to very different<br>physical properties. Despite interannual variability, the so-called "Eratosthenes attractor" stores a larger amount of heat and<br>salt than neighboring anticyclones, in a deeper subsurface anomaly that usually extend down to 500 m. This suggests that this<br>attractor could concentrate heat and salt from this sub-basin, which will impact the properties of intermediate water masses<br>created there.</p>