NUMERICAL-SIMULATION OF INTERPLANETARY PLASMA CLOUDS PROPAGATING ALONG THE HELIOSPHERIC PLASMA SHEET

A two-dimensional, time-dependent, magnetohydrodynamic numerical model is used to investigate a mutual interaction between the interplanetar y plasma cloud (IPC) and the heliospheric plasma sheet (HPS). The incr eased density acts like an obstacle and the lower background solar win d velocity causes slower mass convection. This results in a large dist ortion of the IPC shape and in formation of dimples within shock front s. Large values of the southward interplanetary magnetic field can ori gin when the IPC interacts with the HPS. In addition to generally acce pted scenario of draping around the IPC, we found that this effect occ urs, and is even much more significant, also at a highly distorted par t of the IPC near the HPS.