Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



Committee Chair

James Miller

Committee Member

Don Gregory

Committee Member

Phillip Bitzer

Committee Member

Massimillano Bonamente

Committee Member

Dale Thomas


Pilot balloons, Gamma ray detectors, Lightning


The High Energy Lightning Emission Network (HELEN) campaign involved 8 balloon flights into thunderstorm environments to measure high-energy radiation phenomena like gamma-ray glows and terrestrial gamma-ray flashes (TGFs). Multiple flights detected elevated radiation levels providing evidence for theories on gamma-ray glow generation. Flight 7 measured multiple TGFs coincident spatially and temporally with lightning strikes, supporting theories of TGF origins in lightning leaders and/or return strokes. The same flight also sustained a direct lightning strike, enabling first-of-its-kind energetic radiation measurements during the propagation of the lightning strike. Radiation production was evident in both stepped leaders and return strokes, with higher flux bursts during leader phases. Over the course of its 8 flights, HELEN provided insights into gamma-ray glow source regions, TGF-lightning associations, radiation production in lightning stages, and measurement proximity requirements. These observations advance the understanding of energetic thunderstorm processes and provide motivation for future investigations.



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