Examining EMIC wave spectral properties using in situ measurements of multi-ion species and hybrid simulations
Thursday, 18 December 2014
Electromagnetic Ion Cyclotron (EMIC) waves are an integral component of the magnetospheric plasma within the Earth's magnetosphere and are suggested, at times, to be the dominant contributor to rapid radiation belt electron loss. This paper presents one EMIC wave event observed by the Van Allen Probes, where strong He-band waves occurred in the high density structure at the edge of the plasmasphere. We extract the simultaneously measured distributions of multi-ion species and examine the wave spectral properties developed under the realistic plasma conditions by carrying out hybrid simulations. The goal is to examine (1) whether the observed waves can be reproduced, (2) how the wave properties are related to the observed plasma parameters, and (3) whether these waves are capable of resonant interacting with geophysically interesting radiation belt electrons. The preliminary result suggests that the observed distribution is indeed unstable and the waves can develop strongest in the He-band.