抄録
The terrestrial ring current decays dominantly by charge exchange but Coulomb collisions and wave-particle interactions are also important processes in the overall decay and produce interesting thermal plasma effects. Charge exchange results in energetic neutral atom precipitation over a broad region; Coulomb collisions and wave-particle interactions result in more localized heating of the thermal plasma. All of these processes depend heavily on the composition and energy characteristics of the ring current which has long-term (solar cycle and seasonal) and short-term (geomagnetic storm and substorm) variations. AMPTE/CCE has revolutionized our understanding of ring current composition and energy characteristics and, along with DE-1 and ISEE-1, has contributed new observational information on ring current decay. This review will present recent observational and theoretical results pertaining to ring current decay and the flow of this energy into the thermal populations of the plasmasphere, ionosphere, and neutral atmosphere.
