The thermospheric neutral density sees a strong variation during equinoxes and solstices due to the solar insolation variation. The long-term continual data from Chinese Atmospheric Density Detector installed on the satellite are used to study this variation, The main results of this study are that the thermospheric density has an obvious symmetry around March equinox and September equinox; the thermosphere density has an obvious asymmetry around June solstice and December solstice; the variations have an obvious hemispheric asymmetry in high latitude (around 80 degrees); the proportion of the atmospheric density is 3~3.6 times at the height of 670 km, 13 times at the height of 560 km; the latitude and the altitude contribute to this asymmetry; the comparison of the measured data and the NRLMSISE00 data shows that the NRLMSISE00 data cannot fully respond to the summer and winter hemisphere atmospheric density variations.

Jure solstic and Devember solstice  /  atmospheric density  /  solar far ultraviolet radiation