CHANGES OF THE ATMOSPHERIC DENSITY AT SZ-3 ORBIT ALTITUDE

Atmospheric density detector was on board spacecraft SZ-3 launched on March 2002. At SZ-3 orbit altitude (330--410 km) atmospheric density data were collected near half year. The results show that in the rather quiet period of solar and geomagnetic activity, the difference of the atmospheric density between the sunshine and shade area is one of the principal change of thermosphere density, the highest ratio of atmospheric density in the sunshine to the density in the shade reaches about 3.0, and correlate with solar and geomagnetic activity; During 2002-04-17 and 2002-04-19 two strong geomagnetic disturbance events, the globe thermosphere density obviously increases and amplitude of the increase reached about 60%, and shows a positive correlation with a delay of about 6—7 h; The abnormal disturbance of atmospheric density were observed in the 30°N—40°N during these strong geomagnetic disturbance events; The thermospheric density changes with the value of F_10.7 which represents the solar activity level and exhibits a obvious correlation.