Generation mechanism of high energy radiation observed during thunderstorm activity

Torii, Tatsuo  

In recent years, increases of -rays seemed to be caused by thunderstorm activities have been observed during winter thunderstorms in Japan. Intense radiation during thunderstorms observed so far can be classified into two types. One is an instantaneous radiation burst lasts for no more than a few milliseconds, it is seemed that the bursts are produced in the process of lightning discharge. The other is the gradual fluctuations, last for a few to several tens of seconds, which are considered to be caused in a region of intense electric field within the thundercloud. In addition to the observed results during winter thunderstorms, the runaway breakdown thought to be triggering by the high energy radiation is outlined.