Statistical analysis into the drivers behind relativistic electron precipitation events observed by CALET on the International Space Station

The Calorimetric Electron Telescope (CALET), launched to the International Space Station in 2015, provides more than 7 years of continuous observation of the radiation environment at low earth orbit. Using this dataset, we present a method for the detection and categorization of MeV relativistic electron precipitation (REP) events. From this catalog we identify a subset of a few hundred REP events observed at times where CALET is in magnetic conjunction with the Van Allen probes. These conjugate measurements enable studies of associated plasma wave data from RBSPA/B and potential drivers for MeV electron precipitation. We show that roughly 10 percent of the observed REP events are associated with enhanced electromagnetic ion cyclotron wave activity, suggesting that waves can play a significant role in driving MeV electron precipitation.