Lightning initiation by simultaneous effect of runaway breakdown and cosmic ray showers

Abstract The combined action of cosmic ray showers (CRS) and runaway breakdown (RB) on thunderstorm atmosphere is studied. The ionization of atmosphere produced by CRS core being strongly amplified in RB conditions is shown to be sufficient to generate a highly ionized plasma region. Electric polarization of this plasma region is manifested in a significant local amplification of a thunderstorm electric field, what could result in a local electric breakdown and lead to initiation of lightning. Experiments which could check the predictions of the theory are proposed.