Patrick Marchesiello, IRD Institute for Research and Development, France, Rachid Benshila, CNRS, Paris Cedex 16, France, Francis Auclair, Laboratoire d'Aérologie - Observatoire Midi Pyrénées, Toulouse, France, Rafael Almar, LEGOS, CNES, Toulouse, France and James C McWilliams, UCLA, Los Angeles, CA, United States