PRELIMINARY-RESULTS FROM THE SPRITES94 AIRCRAFT CAMPAIGN .1. RED SPRITES

The dual jet aircraft Sprites94 campaign yielded the first color image ry and unambiguously triangulated physical dimensions and heights of u pper atmospheric optical emissions associated with thunderstorm system s. Low light level television images, in both color and in black and w hite (B/M), obtained during the campaign show that there are at least two distinctively different types of optical emissions spanning part o r all of the distance between the anvil tops and the ionosphere. The f irst of these emissions, dubbed ''sprites'' after their elusive nature , are luminous structures of brief (< 16 ms) duration with a red main body that typically spans the altitude range 50-90 km, and possessing lateral dimensions of 5-30 km. Faint bluish tendrils often extend down ward from the main body of sprites, occasionally appearing to reach cl oud tops near 20 km. In this paper the principal characteristics of re d sprites as observed during the Sprites94 campaign are described. The second distinctive type of emissions, ''blue jets,'' are described in a companion paper [Wescott el at, this issue].