Modelling the ionospheric and plasmaspheric plasma

Abstract
Under magnetically quiet conditions, the outer plasmasphere is the equatorward boundary of the region in which high-latitude processes, such as convection, significantly affect the ionosphere. The low-latitude side of the ionospheric midlatitude trough is located in the plasmasphere. The behaviour of the nightside trough is influenced by field-aligned flows of plasma, as well as by convection drifts, thermospheric winds and particle precipitation. The modelling of field-aligned flow of thermal plasma at high latitudes (the polar wind) still presents problems. The composition of the background neutral atmosphere plays a role in causing the occasional dominance of He$^{+}$ in the topside ionosphere. Penetration of magnetospheric electric fields into the outer plasmasphere can influence the rate of refilling of the upper reaches of the flux tubes.