Surface connectivity between different areas of the Mediterranean Sea derived from drifter data

The surface connection in the Mediterranean Sea is studied by looking at the statistical properties of 1632 nearsurface Lagrangian trajectories. Based on the key role of the surface dynamics and geographical distribution of the data, this work focused on four study area: Strait of Sicily, Gulf of Lion, Albor´an Sea and Cretan Passage. The strategy used in this work aims at limiting the problem of data coverage by choosing many regions of arrival (defined as target boxes), around each study area, choice based on drifter trajectories, current patterns and regions of interest, and using the bootstrap resampling method to compute Lagrangian statistics. The pseudo– Eulerian analysis obtained from all trajectories passing through each study area shows the main dynamical structures present in the Mediterranean Sea (e.g. Wester Albor´an Gyre, Algerian Current, Northern Current, Lion Gyre, Atlantic Ionian Stream, Pelops Gyre, Western Cretan Gyre, etc.). The data coverage decreases progressively moving away from each study area, following the main surface current flows. Connection percentages computed between each source area and relative target boxes show highest values along the main current patterns. In particular, 70%–50% from Sicily Strait to Sardinia Channel with transit time of about 5–20 days; 40%–30% from Gulf of Lion to Ligurian-North Tyrrhenian Sea with transit time of about 13–37 days; 70% from Albor´an Sea to Algerian coast with transit time of about 17 days; 30% from Cretan Passage to Levantine Basin with transit time of about 20 days.