Properties of the thundercloud discharges responsible for terrestrial gamma-ray flashes
Article first published online: 8 AUG 2013
©2013. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 40, Issue 15, pages 4067–4073, 16 August 2013
How to Cite
2013), Properties of the thundercloud discharges responsible for terrestrial gamma-ray flashes, Geophys. Res. Lett., 40, 4067–4073, doi:10.1002/grl.50742., , and (
- Issue published online: 28 AUG 2013
- Article first published online: 8 AUG 2013
- Accepted manuscript online: 15 JUL 2013 06:28PM EST
- Manuscript Accepted: 11 JUL 2013
- Manuscript Revised: 10 JUL 2013
- Manuscript Received: 13 JUN 2013
- DARPA. Grant Number: HR0011-1-10-1-0061
- terrestrial gamma-ray flashes
 The source of terrestrial gamma-ray flashes (TGFs) has been an active area of research since their discovery by Compton Gamma-Ray Observatory/Burst and Transient Source Experiment in 1994. These intense bursts of gamma rays originate within thunderclouds via the rapid production of relativistic runaway electrons, accelerated by thundercloud/lightning electric fields to multi-MeV energies. Recent studies have shown that electrical discharges within thunderclouds caused by these runaway electrons can generate currents that rival those of lightning and so could serve as an alternative discharge path for thunderclouds. In particular, the discharges responsible for TGFs produce some of the largest amplitude VLF-LF radio pulses from thunderstorms and, indeed, were previously misidentified as lightning. In this article, we shall provide a brief review of TGFs and present calculations of their electrical properties inside thunderclouds and their gamma-ray and optical emissions. We shall show that the lightning-like events responsible for TGFs emit relatively little visible light and, thus, are inherently dark.