The Effects of Energetic Trapped Particles on Magnetospheric Motions and Ionospheric Currents

It is shown that the temporary distortion of a previously stable belt of energetic charged particles, trapped in the earth's magnetic Held, results in a system of ionospheric currents and magnetospheric motions. The currents are caused by the charge separation which occurs in the course of the subsequent adiabatic motion of the energetic particles. The resulting current system closely resembles the well-known Ds current system. The polarization fields, which drive these currents, give rise to magnetospheric motions similar to those of Axford and Hines and the implications of their work then also result. The distortion of the belt could be caused either directly, by the introduction of a new group of trapped particles mainly on the day side of the magnetosphere, or indirectly, through the relatively sudden compression of the earth's field on the day side, caused by the arrival of a neutral stream of charged particles from the sun.