Document Type
Article
Publication Date
7-16-2026
Abstract
We report ground‐based observations of a terrestrial gamma‐ray flash (TGF) associated with a strong negative cloud‐to‐ground lightning strike (‐CG) which occurred near Los Alamos National Laboratory (LANL) in New Mexico, USA. Gamma photons were detected by the Terrestrial High‐energy Observations of Radiation (THOR) instrument, developed at the University of California, Santa Cruz, which has been hosted at LANL since 2022. Simultaneous measurements were also made with the 3‐Dimensional Broadband Interferometric Mapping and Polarization (BIMAP‐3D) system, which includes 3D lightning mapping, two fast antennas, and an additional plastic scintillator. Additional field change waveforms were obtained from the Earth Networks Total Lightning Network (ENTLN). The lightning initiated about 1 km above the ground, leading to a powerful ‐CG with an ENTLN peak current of −237 kA and bipolar field change matching the recently described “energetic compact stroke” (ECS) shape. The TGF was then observed ∼35 µs after the start of the return stroke. We also observe an electric field pulse likely produced by the TGF either in isolation or by coupling to the lightning channel. Based on modeling of the radiated electric field and photon propagation through the atmosphere we infer that the TGF source was on the order of photons. This TGF and associated lightning are extremely similar to some recently reported ECS TGFs in coastal Japan in winter, but we report the first observation of this phenomenon outside of Japan in a different climate, terrain, and season.
Source Publication
Journal of Geophysical Research: Atmospheres
Recommended Citation
Jensen, D. P., Smith, D. M., Shao, X., Lapierre, J. L., & Chaffin, J. M. (2026). Terrestrial Gamma‐Ray Flash Following Intense Negative Return Stroke Observed With BIMAP‐3D. Journal of Geophysical Research: Atmospheres, 131(13), e2026JD046593. https://doi.org/10.1029/2026JD046593
Comments
© 2026 The Authors.
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