Acceleration and Precipitation of Van Allen Electrons During Magnetospheric Substorms

Abstract

This paper will present a representative portion of data from the more extensive file of the ATS-1 auroral particle correlation experiment. The main purpose is to show that magnetospheric and auroral processes are intimately related and that Van Allen electrons of E> 50 keV are accelerated during Magnetospheric Substorms. In particular, it is shown that (1) intense auroral precipitation does not occur randomly, but only during periods when the outer zone electron fluxes increase (2) electron pitch-angle distribution in the equatorial plane during substorms is peaked toward 90° (3) the pitch-angle distribution changes in time and depends on the flux and (4) life-times of freshly energized Van Allen electrons are considerably shorter than their drift periods. It will be shown that our observations can be explained consistently in terms of energy and pitch-angle diffusion processes accompanying whistler-cyclotron resonance interaction.

This study was conducted while the author was in the School of Physics and Astronomy, University of Minnesota. This manuscript was written in Toulouse, France.