HIGH LATITUDE MAGNETOSPHERE DYNAMICS DURING MAGNETIC STORMS: ENERGETIC PARTICLE DATA FROM LOW-ALTITUDE SATELLITES AND GLOBAL MAGNETOSPHERIC MODELING

Experimental data obtained during magnetic storms by low-altitude satellites permit to investigate the high latitude Earth's magnetosphere structure and dynamics. We have studied the variations of the solar energetic particles penetration boundary measured by CORONAS-F and "Universitetskiy-Tatiana" satellites during magnetic storm on 15-17 May 2005 (Dstmin=-263 nT). It was obtained that on 15 May 2005 the penetration boundary was shifted to the low latitudes in the evening sectors of MLT up to 51 degree. Solar energetic particle penetration boundaries have been compared with those calculated by the model of magnetospheric magnetic field. It was shown that during May 2005 event both solar particle penetration boundary obtained from measurements and calculated polar cap boundary are shifted to the lower latitudes in accordance with geomagnetic activity enhancement.