Within the first week of science flights, the Airborne Lightning Observatory for FEGS and TGFs (ALOFT) campaign has already made startling discoveries about the abundance of gamma-ray glows and terrestrial gamma-ray flashes (TGFs) in tropical thunderstorms. Originally thought to be up to 10,000 times rarer than lightning, TGFs instead have been detected on all three ALOFT science flights to date and appear to be highly correlated with the presence of low-level gamma-ray emissions known as glows. ALOFT is finding glows to be common in the intensifying-to-mature stages of thunderstorm cells, and that glows can last minutes to hours. Observations from ALOFT are thus physically relating the production of high-energy radiation to the lifecycles of tropical thunderstorms.
ALOFT is a collaboration between NASA, the University of Bergen (UIB), and other institutions. ALOFT includes multiple airborne instruments from Marshall and Goddard Space Flight Centers, as well as instruments from UIB, Naval Research Laboratory (NRL), and Sandia National Labs. In addition to detecting gamma-rays, ALOFT is helping validate the International Space Station Lightning Imaging Sensor (ISS LIS) and the Geostationary Lightning Mappers (GLMs), while also testing new techniques for detecting lightning from space and gathering high-resolution observations of tropical convection that are relevant to future NASA missions such as the Atmosphere Observing System (AOS) and the Investigation of Convective Updrafts (INCUS).
FEGS = Fly’s Eye GLM Simulator