THE JANUARY 10-11, 1997 MAGNETIC CLOUD - MULTIPOINT MEASUREMENTS

The WIND and IMP 8 spacecraft detected a magnetic cloud upstream of Ea rth's bow shock on January 10-11, 1997 while the INTERBALL-1, MAGION-4 , GEOTAIL, and LANL-084 satellites were in the vicinity of the magneto pause and crossed it many times. Based on these multipoint observation s we have determined the velocity of the magnetopause motion induced b y the abrupt changes in the solar wind dynamic pressure during this ev ent, and also the velocity of propagation through the magnetosheath of the structures connected with the magnetic cloud. Using the determine d velocities, we tried to find the spatial orientations and dimensions of the observed disturbances. The estimated orientation of the interp lanetary shock driven by the magnetic cloud is interpreted as a conseq uence of the local deformation of the cloud surface. The timing of mea surements made by the aforementioned satellites suggests that the stro ng density enhancement behind the magnetic cloud is limited in spatial extent. We attribute this enhancement to the interaction of the magne tic cloud with the ambient solar wind plasma.