Discovery of TGF emission up to very high energies (100 MeV): Discovery of gamma-ray emission up to 100 MeV from terrestrial flashes associated with intense thunderstorms. Evidence for accelerating potentials larger than 100 MV.
Identification of TGF emission up to extremely high energies (100 MeV): Detection of gamma-ray emission up to 100 MeV from terrestrial flashes linked to intense thunderstorms. Evidence for accelerating potentials exceeding 100 MV.