Theoretical investigation of the variability in terrestrial gamma-ray flashes spectra

Terrestrial Gamma-ray Flashes (TGFs) are high-energy photon bursts originating from the Earth´s atmosphere and detected from space. In this work, we show how different electric potentials in TGF-producing lightning lead to an intrinsic variability in TGF spectra. This prediction can be exploited to discriminate which one of the two proposed source mechanisms is truly responsible for the production of TGFs.