Dispersion of passive tracers and finite-scale Lyapunov exponents in the Western Mediterranean Sea

A realistic 4-year dataset of the surface velocity field of the western Mediterranean Sea obtained with the Mediterranean Forecasting System and the GFDL-MOM model was used to obtain the finite-scale Lyapunov exponents (FSLE) and finite-size diffusion coefficients. Dispersive properties and Lagrangian parameters in four sub-basins are discussed, and a comparison is made between the FSLE and the Eulerian Okubo–Weiss parameter obtained for the same area with the same dataset. An additional comparison is made with the FSLE calculated from independent datasets obtained from 15 drifters launched in the Algerian basin during October of 1996.