Sprite (lightning)

Electrical discharges above thunderstorm clouds

Sprites or red sprites are large-scale electric discharges that occur in the mesosphere, high above thunderstorm clouds, or cumulonimbus, giving rise to a varied range of visual shapes flickering in the night sky. They are usually triggered by the discharges of positive lightning between an underlying thundercloud and the ground.

From Wikipedia, under CC BY-SA. More on occurri.