Long streamers in the upper atmosphere above thundercloud

Abstract

It has been suggested that optical flashes observed in the upper atmosphere above giant thunderstorms (red sprites) are due to streamers. Such streamers are initiated in the lower ionosphere by electron patches caused by electromagnetic radiation from horizontal intracloud lightning and then develop downward in the static electric field due to the thundercloud. The triggering conditions of streamer development are analysed in the paper. Using similarity relations, known characteristics of streamer tips obtained earlier in laboratory conditions are extended to a description of streamers in rare air. Streamer growth in the nonuniform atmosphere is calculated. It is shown that streamers first appear at a height of about 80 km and then grow downward to slightly below 50 km, where they are terminated. This is in agreement with red sprite observations. An altitude distribution of the streamer generated plasma is obtained. The simple models of streamer development presented in this paper could be applied for computations of streamers growing in various other conditions.