Toward Large-Scale Aircraft-Based Measurements of Energetic Radiation from Thunderstorms and Lightning

Thunderstorm and lightning related energetic radiation can generally be categorized as (1) leader X-rays, (2) Terrestrial Gamma-ray Flashes (TGFs), or (3) Thunderstorm Ground Enhancements (TGEs). TGFs are usually recorded from satellites, and, on some occasions, they have been recorded from the ground, but only a few attempts have been made to measure TGFs from aircraft. Thunderstorm Ground Enhancements (TGEs) are much longer duration than TGFs, and they are recorded at ground level. Energetic radiation associated with thunderstorms and lightning is a relatively recently recognized hazard. It can have possible adverse effects on commercial and general aviation avionics, thus an experimental understanding of the impulsive and prolonged radiation enhancements onboard aircraft is essential (Eack et al., 1996). In this paper, we present artificial TGFs and TGEs, which were acquired in the lab with a compact CsI scintillator detector, along with commercial and general aviation aircraft-based measurements to assess the feasibility of a large-scale aircraft-based study. Our preliminary results include 180 h of aircraft-based measurements, the longest aircraft-based TGF search to date, and show that the detector hardware, installation protocol, processing software, and search algorithm can be used for a large-scale study of energetic radiation from thunderstorms and lightning.