The rarity of terrestrial gamma-ray flashes
Article first published online: 22 APR 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 8, April 2011
How to Cite
2011), The rarity of terrestrial gamma-ray flashes, Geophys. Res. Lett., 38, L08807, doi:10.1029/2011GL046875., et al. (
- Issue published online: 22 APR 2011
- Article first published online: 22 APR 2011
- Manuscript Accepted: 15 MAR 2011
- Manuscript Revised: 11 MAR 2011
- Manuscript Received: 2 FEB 2011
- terrestrial gamma-ray flashes;
- airborne observations;
- atmospheric electricity
 We report on the first search for Terrestrial Gamma-ray Flashes (TGFs) from altitudes where they are thought to be produced. The Airborne Detector for Energetic Lightning Emissions (ADELE), an array of gamma-ray detectors, was flown near the tops of Florida thunderstorms in August/September 2009. The plane passed within 10 km horizontal distance of 1213 lightning discharges and only once detected a TGF. If these discharges had produced TGFs of the same intensity as those seen from space, every one should have been seen by ADELE. Separate and significant nondetections are established for intracloud lightning, negative cloud-to-ground lightning, and narrow bipolar events. We conclude that TGFs are not a primary triggering mechanism for lightning. We estimate the TGF-to-flash ratio to be on the order of 10−2 to 10−3 and show that TGF intensities cannot follow the well-known power-law distribution seen in earthquakes and solar flares, due to our limits on the presence of faint events.