EMIC Wave Induced Radiation Belt Losses and Proton Aurora

Abstract:

Electromagnetic Ion Cyclotron (EMIC) waves represent an important loss mechanism of ring current ions. Ring current ions scattered into the loss cone have been shown to produce proton aurora at sub-auroral latitudes. Observations of these emissions and their spatial extent provide a unique view of EMIC wave processes and their spatial extent. To this end we use the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) instrument on the DMSP F16, F17 and F18 satellites located in a low Earth polar orbit to study EMIC wave related proton aurora. These data are used to characterize the spatial extent and properties of the proton aurora and associated EMIC waves. Specifically, we use the combination of ultraviolet observations of proton aurora, energetic particle data from DMSP, and EMIC wave data to characterize spatial extent of EMIC waves relative to magnetospheric boundaries; magnetic local time differences in wave characteristics and the spatial/temporal extent of the proton auroras. The two dimensional view made possible by ultraviolet imaging will be used to understand the spatial extent of EMIC wave activity in order to guide their incorporation into ring current wave-particle interaction models.