  Electromagnetic Ion Cyclotron (EMIC) waves can drive radiation belt depletion
and Low-Earth Orbit (LEO) satellites can detect the resulting electron and
proton precipitation. The ELFIN (Electron Losses and Fields InvestigatioN)
CubeSats provide an excellent opportunity to study the properties of
EMIC-driven electron precipitation with much higher energy and pitch-angle
resolution than previously allowed. We collect EMIC-driven electron
precipitation events from ELFIN observations and use POES (Polar Orbiting
Environmental Satellites) to search for 10s-100s keV proton precipitation
nearby as a proxy of EMIC wave activity. Electron precipitation mainly occurs
on localized radial scales (0.3 L), over 15-24 MLT and 5-8 L shells, stronger
at MeV energies and weaker down to 100-200 keV. Additionally, the observed loss
cone pitch-angle distribution agrees with quasilinear predictions at >250 keV
(more filled loss cone with increasing energy), while additional mechanisms are
needed to explain the observed low-energy precipitation.
