Energetic radiation from thunderclouds: extended particle fluxes directed to Earth’s surface

After introducing spectrometers with the energy threshold of 0.3 MeV the pattern of the thunderstorm ground enhancements (TGEs) observed on Aragats dramatically changed demonstrating multi-hour radiation. In the paper, we analyze comprehensive observations made on different time scales and energy ranges. A new model of TGE is discussed explaining much larger time of particle fluxes from clouds.