Lightning-induced Electron Precipitation (LEP) events represent a known loss mechanism for radiation belt electrons. The quantitative role LEP events play in the radiation belt dyanmics, however, is not fully understood. Direct measurements of the D region of the ionosphere, where LEP electrons are deposited, are very limited. However, Very Low Frequency (VLF) remote sensing has for a long time been used to detect perturbations in the D region, in particular using the narrow-frequency signals of VLF transmitting beacons. We present an automated neural-network based search for LEP events using our network of VLF receivers in the continental US detecting, seeded by National Lightning Detection Network (NLDN) lightning strokes. We arrive at a database of nearly 26000 LEP events over a span of 18 months within the continental USA. We find several notable patterns in the occurrence and behavior of events, such as 30.1% of events only containing disturbances in phase, and a substantially greater probability of perturbations in phase and major axis amplitude being negative.
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