Multipoint measurements of energetic particles in the magnetosphere

Abstract

The benefits of energetic particle measurements in the study of magnetospheric physics lie in the particles' relative ease of detection, their high rectilinear speed, their range of gyroradii, and their immunity to large scale electric fields. With such particles one can observationally separate distinctive plasma regions, one can uniquely assess field line topologies, one can examine connectivity from the magnetospheric equator to the ionosphere, and one can sense the global changes in magnetospheric configuration that, for example, lead immutably to substorm onsets. Multipoint measurements of energetic particles have contributed substantially to our understanding of the Earth's magnetopause, the leakage of particles into the upstream region, the effect of sudden storm compressions, the global nature of substorm dynamics, and the location and character of high-energy acceleration processes in the Earth's magnetotail.