Impulsive Alfven Coupling between the Fully-Ionized Plasmaand the Weakly-Ionized Plasma

Abstract

Basic properties of an impulsive Alfven interaction between the fully-ionized bulk plasma and the weakly-ionized boundary plasma, e.g., between the magnetosphere and the ionosphere, have been studied by means of a three-dimensional self-consistent simulation of the coupled plasma system. It is found that the duration time of an impulsive perturbation given in the fully-ionized bulk plasma, the spatial distribution of the Alfven propagation time, and the ratio between the impedance of the fully-ionized plasma and the resistance of the weakly-ionized plasma are the key factors that determine the propagation dynamics and the weakly-ionized plasma responses for an impulsive MHD perturbation.