Upper hybrid waves and energetic electrons in the radiation belt

作者:Yoon Peter H; Kim Sunjung; Hwang Junga; Shin Dae Kyu
来源:JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2017, 122(5): 5365-5376.
DOI:10.1002/2016JA023321

摘要

Van Allen radiation belt is characterized by energetic electrons and ions trapped in the Earth's dipolar magnetic field lines and persisting for long periods. It is also permeated by high-frequency electrostatic fluctuations whose peak intensity occurs near the upper hybrid frequency. Such a phenomenon can be understood in terms of spontaneous emission of electrostatic multiple harmonic electron cyclotron waves by thermal plasmas. In the literature, the upper hybrid fluctuations are used as a proxy for determining the electron number density, but they also contain important information concerning the energetic electrons in the radiation belt and possibly the ring current electrons. The companion paper analyzes sample quiet time events and demonstrates that the upper hybrid fluctuations are predominantly emitted by tenuous population of energetic electrons. The present paper supplements detailed formalism of spontaneous thermal emission of multiple-harmonic cyclotron waves that include upper hybrid fluctuations.

  • 出版日期2017-5