Spatial structure of optical emissions in the model of gigantic upward atmospheric discharges with participation of runaway electrons

A spatial distribution and spectra of optical emissions of gigantic upward atmospheric discharges governed by a relativistic runaway electron avalanch e were calculated. High-energy electrons of the avalanche excite emissions accounting for blue jets, which are observed immediately above thundercloud s, and produce a copious amount of secondary low-energy electrons. Some ene rgy obtained by the secondaries from the field, is deposited in optical emi ssions, which was shown to account for red sprites observed at higher altit udes. Calculated distribution of nitrogen molecules over vibration states ( BIIg)-I-3(v) agrees with experimental data. (C) 1999 Published by Elsevier Science B.V.