Date of Award
2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Physics
Committee Chair
James Miller
Committee Member
Don Gregory
Committee Member
Phillip Bitzer
Committee Member
Massimillano Bonamente
Committee Member
Dale Thomas
Subject(s)
Pilot balloons, Gamma ray detectors, Lightning
Abstract
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.
Recommended Citation
Helmerich, Christopher, "Measurements of terrestrial gamma-ray flashes, gamma-ray glows, and a direct lightning strike from eight flights of the High Energy Lightning Emission Network (HELEN)" (2023). Dissertations. 355.
https://louis.uah.edu/uah-dissertations/355