Abstract

Strong magnetospheric convection electric fields can remove large portions of the outer plasmasphere and transport them the vicinity of the magnetopause. This cold dense thermal plasma of ionospheric origin may have significant effects on processes operating at and near the Earth's magnetopause. In particular, the plume material may reach the magnetopause with densities comparable to those of the magnetosheath and therefore influence reconnection between the interplanetary and terrestrial magnetic fields. Plasmaspheric plasma reaching the magnetopause may therefore escape into the magnetosheath and ultimately into the solar wind or become entrained on reconnected magnetic field lines convecting anti-sunward over the polar cap. Plasmaspheric plasma that fails to reconnect may also enter the low latitude boundary layer and be swept antisunward along the flanks to become part of the plasmasheet. We inspect simulation results for several storm-time events to determine the relative contributions of plasmaspheric plume and magnetosheath plasmas to particle populations in the inner magnetosheath, at the magnetopause, and in the magnetospheric boundary layers. Plume and magnetosheath densities are compared as a function of location and storm phase. The short answer is, “yes”, but not always and not at all locations. The full answer will be presented.