Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Atmospheres
Thunderstorms are known to produce long-lasting gamma-ray glows and powerful terrestrial gamma-ray flashes (TGFs). Since their discovery in 1994, the vast majority of bright TGFs have been observed by spacecraft, and many are associated with lightning. Gamma-ray glows, on the other hand, are long-lasting emissions that occur between lightning flashes and are sometimes terminated by lightning. It is not yet clear how glows might be related to TGFs, nor is it clear whether one mechanism is more important than the other in explaining these highly dynamic energetic emissions.
Dwyer [2024] provides a good explanation for how these energetic emissions may be produced by thunderstorms even without the presence of lightning. Through a relativistic feedback mechanism, thunderstorm electric fields may generate relativistic feedback discharges involving energetic runaway electrons, positrons, and X-rays. Relativistic feedback discharges may develop instabilities, leading to rapid oscillations and large pulses of emitted gamma rays. The transition from gamma-ray glows to multi-pulsed TGFs is a natural consequence of this relativistic feedback mechanism, making the observation of such events strong evidence that relativistic feedback is the dominant mechanism for producing energetic radiation.
The importance of this work lies in its demonstration that intense thunderstorm electrification alone can produce bright gamma-ray glows and highly luminous gamma-ray pulses via the relativistic feedback mechanism. Moreover, the relativistic feedback discharge greatly enhances the field near the start of the avalanche region, potentially initiating lightning and/or narrow bipolar events (NBEs).
Citation: Dwyer, J. R. (2025). Energetic particles produced by thunderstorm electric fields. Journal of Geophysical Research: Atmospheres, 130, e2024JD042193.https://doi.org/10.1029/2024JD042193
—Xiushu Qie, Editor,JGR: Atmospheres
Text © 2025. The authors. CC BY-NC-ND 3.0
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