Relationship between severe geomagnetic storm, energetic particle storms and thermosphere density strong disturbances

During severe geomagnetic storms, there are strong changes of high energy proton flux and high energy electron flux measured by high energy particle detectors in the geosynchronous orbit. Thermosphere density will follow strong changes in the LEO orbit. Generally, the thermosphere density increased by the enhancement of the solar F_10.7 flux and the energy particle flux, however, which energy particles (e.g. proton or electron) and which particle energies (e.g. E>2MeV relativistic electrons or E<50keV low energies electrons) plays an important role during severe geomagnetic storms. This paper discussed the relationship between severe geomagnetic storm, energy particle storm and thermosphere density from the in-situ measurement data of energy particles from GOES8, GOES11 and GOES12 high energy particle detectors (from 1997 to 2007), and the thermosphere density data from Chinese satellite-borne density detectors (in 2005). The relevant results reveal that during severe geomagnetic storms, high energy proton flux of E>1MeV showed strong enhancement, with the change ratio ≥10³. After one day the thermosphere density strong enhancement follow the variations of the high energy proton flux of E>1MeV and between severe geomagnetic activity, high energy proton flux and thermosphere density exhibits an obvious positive correlation, that is before the severe geomagnetic storm (near 1day), the high energy proton flux showed strong enhancement in the geosynchronous orbit, and after the severe geomagnetic storm (delay 3～6h), the thermosphere density obviously increases.