THE GEOMAGNETIC DISTURBANCE OF JUNE, 1991──THE CHARACTERISTICS ON THE GROUND AND AT THE GEOSYNCHRONOUS ALTITUDE

The charaderistics on the ground and at the geosynchronous altitude of the June l99l geomagnetic disturbance were described and the possible sources were analyzed . During this disturbance which lasted nearly 2O days, four geomagnetic storme with different intensity on main phases occurred as well as several strong sudden commencements. Some storms appeared to be the superposition of a few disturbanas and so were complex in shapes. At the geosynchronous altitude, reverse phase occurred many times on Hp component. All these phenomina might have mainly been the responces of the magnetosphere to the multiple high-velcity and high-intensity structures in the interplanetary space, Which at times assodatad with large-scaled strong southward IMF.