Characteristics of Electron Microburst Precipitation Based on High?Resolution ELFIN Measurements

We present statistical characteristics of electron microburst precipitation using high time-resolution measurements from the low-altitude Electron Losses and Fields InvestigatioN (ELFIN) CubeSats. The radial distribution equatorial projection microbursts as a function geomagnetic activity suggests that they are produced by resonant interaction with quasi-parallel lower-band chorus waves. ELFIN flux provide first models energy spectra 50 keV to 2 MeV. Microbursts energies up 150 have relatively flat pitch-angle spectrum. Estimates scattering rates required produce observed suggest such signatures due near-equatorial wave packets peak amplitudes 0.4–0.9 nT, well above threshold for nonlinear interaction. More rare microbursts, exceeding 500 keV, preferentially near dawn during disturbed periods. interpret them evidence intense ducted waves propagating equator middle latitudes little attenuation.