The Solar Wind-Magnetosphere-Ionosphere System: An Overview

Abstract

The upper atmosphere at high geomagnetic latitudes is an active component of the solar-terrestrial system. This system, comprising a chain of several distinct plasma regions, features two important characteristics: (1) As one proceeds from the main particle, energy and momentum source on the sun through the solar wind, the magnetosheath, magnetosphere and ionosphere to the sinks in the neutral atmosphere, one observes an increasingly important feedback coupling between adjacent regions; (2) The time scales of response to perturbations originating on the sun are increasingly determined by the properties of the local medium in each region. Being the last link in the solar-terrestrial chain, the upper atmosphere exerts an important feedback effect on the preceding region, the magnetosphere; this in turn influences the form and rate of solar energy delivery to the upper atmosphere. The magnetosphere thus plays an important role as a non-linear transducer of solar energy. For a general review of the solar-terrestrial system see Parker et al. (1979).