%0 Journal Article %T Cluster mission and data analysis for the March 2001 magnetic storm %A F. Frutos Alfaro %A A. Korth %A M. Fr£¿nz %A C. G. Mouikis %J Geof¨ªsica internacional %D 2004 %I Universidad Nacional Aut¨®noma de M¨¦xico %X The Cluster mission is intended for the study of the Earth¡¯s magnetosphere and Sun-Earth relationships. Four satellites fly in a tetrahedral formation sending data that can separate spatial from temporal effects for the first time. This formation will provide a better understanding of microscopic and macroscopic features in the magnetosphere and the solar wind. As an illustration we discuss the CIS data during a large magnetic storm. %K CLUSTER mission %K magnetic storm %K ion spectrometry %U http://www.geofisica.unam.mx/unid_apoyo/editorial/publicaciones/investigacion/geofisica_internacional/anteriores/2004/02/Frutos.pdf