Production of Terrestrial Gamma?Ray Flashes During the Early Stages of Lightning Flashes

Terrestrial Gamma-ray Flashes (TGFs) are short emissions of high energy photons associated with thunderstorms. It has been known since the discovery TGFs that they lightning, and several case studies have shown produced at initial phase lightning flash. However, it not tested whether this is true in general. By using largest TGF sample up to date, combined ground-based radio detection data, we perform a statistical study test this. One missions Atmosphere-Space Interactions Monitor (ASIM) consisting innovative combination X- gamma-ray detectors, optical photometers cameras. This allows us investigate temporal relation between gamma-rays by signal discharges. Based on stacking analysis measurements activity, together resolution from ASIM photometers, beginning flashes. In addition, for significant fraction TGFs, activity detected enhanced an interval 150 750 ms following co-located TGFs. The evident randomly selected indicates characteristic property flashes start TGF.