A Fermi Gamma‐Ray Burst Monitor Event Observed as a Terrestrial Gamma‐Ray Flash and Terrestrial Electron Beam

Abstract

AbstractWe present an event that was detected by Fermi Gamma‐ray Burst Monitor on 4 February 2014 as the spacecraft was flying over Madagascar. We interpret the three pulses during this event (herein known as 140204581) as the following: the first pulse as a terrestrial gamma‐ray flash, the second as a 2 ms long terrestrial electron beam (TEB) 0.5 ms after the terrestrial gamma‐ray flash, and the last pulse as the TEB mirror pulse 90 ms after the TEB. The nature of these events were confirmed using both the World Wide Lightning Location Network and the Earth Networks Total Lightning Network, which detected the same simultaneous sferic underneath the spacecraft and in the magnetic footprint. Several models were fit to the data, and results show that the vertical narrow beam model was found to be inconsistent with the data.