Detector and lightning locations for two observed events in Kanazawa, Japan
Detector and lightning locations for the observed Event 1 (upper) and Event 2 (lower) in Kanazawa, Japan. The orange circles show the locations of the Terrestrial Gamma-ray Flash (TGF) radiation detectors. The blue circle shows the detectable area of the gamma‐ray glow when it terminated. White triangles show the locations of lightning discharges observed by the Japan Lightning Detection Network (JLDN); cross markers show the locations observed by the Lightning Location System of Hokuriku Electric Power Company (Rikuden LLS), and the white stars show pulse locations estimated by the broadband low frequency (LF) network. Credit: Wada et al. [2020], Figure 2
Source: Journal of Geophysical Research: Atmospheres

Recent ground-based radio-frequency observations have identified a new class of in-cloud lighting discharge called “energetic in-cloud” pulses (EIP). The high peak electric currents of EIP pulses have led to prediction that they might be connected with Terrestrial Gamma-ray Flashes (TGFs). Observations by Wada et al. [2020] confirm this prediction. They move the connection of EIP with TGF from speculation to solid science. This allows for downward TGFs now to be analyzed using radio sensors only, a huge advance since their coverage area is much greater than that of ground-based gamma-ray sensors, hundreds of kilometers versus about two kilometers.

Citation: Wada, Y., Enoto, T., Nakamura, Y., Morimoto, T., Sato, M., Ushio, T., et al. [2020]. High peak‐current lightning discharges associated with downward terrestrial gamma‐ray flashes. Journal of Geophysical Research: Atmospheres, 125, e2019JD031730.

—Minghua Zhang, Editor in Chief, JGR: Atmospheres

Text © 2020. The authors. CC BY-NC-ND 3.0
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