Observations of EMIC Wave Growth by MMS

Abstract:

Electromagnetic Ion Cyclotron (EMIC) waves are a prevalent wave mode in the Earth's magnetosphere. The active regions responsible for the generation of these waves have been observed using both ground-based and in situ data on a statistical scale. These regions have been shown to persist for time periods on the order of 10s of minutes to several hours, but their initial growth phase is difficult to characterize. The Magnetospheric Multiscale (MMS) mission, comprised of four closely-separated identical spacecraft, have made several observations of the growth phase of these active regions as subsequent spacecraft pass through the same area. The full suite of particle and field instruments on board the MMS spacecraft allow us to characterize the growth conditions which lead to EMIC wave enhancements.