Effect of solar activity and solar wind parameters on plasma temperature and density in the Earth’s plasmasphere

Measurements from the Interball-1 and Magion-5 satellites of the Interball mission in 1995–2001 have been used to analyze the dependence of the equatorial plasmasphere characteristics on magnetic local time, as well as on solar activity, dynamic pressure, and solar wind density. The proton density at solar minimum is on average higher than at solar maximum, which is probably due to changes in plasma mass composition in the plasmasphere at solar maximum. The daytime and nighttime proton temperatures increase with increasing solar extreme ultraviolet flux, at least in the years of solar maximum. The plasmaspheric plasma density and thermal pressure rise with increasing dynamic pressure and/or density of the undisturbed solar wind, which might be associated with restructuring of the convective electric field in the magnetosphere.