Susanna Zerbini¹, Sara Bruni², Luciana Fenoglio-Marc³, Fabio Raicich⁴ and Maddalena Errico², (1)University of Bologna, Physics and Astronomy (DIFA), Bologna, Italy, (2)University of Bologna, Bologna, Italy, (3)University of Bonn, Bonn, Germany, (4)CNR, Istituto di Scienze Marine, Trieste, Italy