Fermi Gamma-ray Space Telescope

Over in a Flash: A decade of Terrestrial Gamma-ray Flashes with Fermi-GBM

Oliver Roberts
(G Fitzpatrick, M Stanbro, S McBreen, MS Briggs, RH Holzworth, JE Grove, A Chekhtman, ES Cramer, BG Mailyan)


On the 10th anniversary of continuous monitoring by the Fermi Gamma-ray Space Telescope Gamma-Ray Burst Monitor (Fermi-GBM), we present a summary of scientific findings from the largest catalog of terrestrial gamma ray flashes (TGFs) presently available. Fermi-GBM has been a key player in excelling scientific studies within the TGF community due to its energy range, large effective area and continuous time-tagging of events, enabling sensitive ground-based searches. A combination of this and its low-earth orbit make it the most prolific TGF detector ever. Consequently, population and individual studies of these geophysical phenomena have given great insight into their intrinsic characteristics. Furthermore, triangulating radio pulses from the World‐Wide Lightning Location Network data with a third of these TGFs allow us to probe the storms that produce them, where TGF-genesis may be due to a favorable "recipe" of environmental or meteorological conditions. Such studies will be discussed, along with other recent accomplishments that include the first joint observation of a TGF and a TEB, testing emission models via the spectral fitting of individual observed TGFs and quantifying the concentration of TGFs detected along or near coastlines. Complemented by future campaigns such as the Global Lightning Mapper (GLM), we also explore how Fermi-GBM will continue to play a fundamental role in answering the key outstanding scientific questions on the behavior of TGFs within this active field.