Sunrise Effects on the Latitudinal Variations of Topside Ionospheric Densities and Scale Heights

Abstract

IONOSPHERIC sunrise represents the transition period between quasi-equilibrium conditions attained during the night and those attained during the day. The arrival of sunrise is manifested by a rapid increase in electron temperatures and a less rapid increase in ion temperatures at all altitudes1. In a plasma distribution that tends towards equilibrium, a sharp increase in particle temperature results in a redistribution of the plasma. In the topside ionosphere, this is manifested by a diffusive flux of ions and electrons.