TGFs, Gamma‐Ray Glows, and Direct Lightning Strike Radiation Observed During a Single Flight of a Balloon‐Borne Gamma‐Ray Spectrometer

Terrestrial gamma‐ray flashes (TGFs) and other high‐energy radiation phenomena related to thunderstorms remain incompletely understood since their discovery nearly 30 years ago. Space and ground‐based platforms have provided insights, but limitations exist in temporal resolution, signal‐to‐noise ratios, and proximity to events. This study presents findings from a balloon‐borne gamma‐ray spectrometer flown into a thunderstorm over northern Mississippi on 19 June 2023. The instrument detected three distinct millisecond‐duration TGF events correlated with lightning strikes. Sustained gamma‐ray glows lasting up to 2 minutes were measured and tied to thunderstorm electrostatic fields. Notably, radiation was observed during a direct lightning strike to the payload. This complex 800‐millisecond event reveals insights into radiation from leader propagation and return strokes. These findings from a single balloon flight demonstrate the prevalence of energetic processes within thunderstorms. Finally, the balloon platform offered an exceptional combination of temporal resolution and validation capabilities to advance the understanding of thunderstorm radiation motivating future follow‐up studies. Plain Language Summary In this study, a specialized balloon carrying a radiation detector was flown into a thunderstorm to better understand the bursts and glows of high‐energy radiation associated with thunderstorms. The balloon detected several bursts of radiation tied to lightning strikes, as well as more sustained glows of radiation. Key Points A balloon‐borne gamma‐ray spectrometer was flown into a thunderstorm detecting various high‐energy radiation events: terrestrial gamma‐ray flashes and gamma‐ray glow Radiation detected during a direct lightning strike to the payload at 11.9 km altitude revealed insights into high‐energy emissions The variety of radiation spikes and glows observed indicates the prevalence and potential ubiquity of energetic processes in thunderstorms