Are fast atmospheric pulsations optical signatures of lightning‐induced electron precipitation?

Abstract

Fast Atmospheric Light Pulsations (FAP's) consist of millisecond time‐scale bursts of light which have been observed at L = 1.5–2.2 during searches for atmospheric light emissions associated with supernovae. Their statistics of occurrence resemble those of Lightning‐induced Electron Precipitation (Trimpi events) observed at somewhat higher L‐shells. Here we propose that FAP's are in fact optical signatures of LEP events associated with the ≥ 2 MeV electrons of the inner radiation belt (L ≈ 1.4). These electrons would precipitate at low altitudes and could be modulated with time scales the order of 1 ms. The total loss rate of electrons from the inner belt resulting from these events would be comparable to, but somewhat smaller than, the loss rate due to Coulomb scattering.