SOLAR WIND-MAGNETOSPHERE INTERACTION AS SIMULATED BY A 3-D EM PARTICLE CODE

We have studied the solar wind-magnetosphere interaction using a 3-D e lectromagnetic particle code. The results for an unmagnetized solar wi nd plasma streaming past a dipole magnetic field show the formation of a magnetopause and a magnetotail, the penetration of energetic partic les into cusps and radiation belt and dawn-dusk asymmetries. The effec ts of interplanetary magnetic field (IMF) have been investigated in a similar way as done by MHD simulations. The simulation results with a southward IMF show the shrunk magnetosphere with great particle entry into the cusps and nightside magnetosphere. This is a signature of a m agnetic reconnection at the dayside magnetopause. After a quasi-stable state is established with an unmagnetized solar wind we switched on a solar wind with an northward IMF. In this case the significant change s take place in the magnetotail. The waving motion was seen in the mag netotail and its length was shortened. This phenomena are consistent w ith the reconnections which occur at the high latitude magnetopause. I n our simulations kinetic effects will determine the self-consistent a nomalous resistivity in the magnetopause that causes reconnections.