ELVES, like sprites, are high-altitude manifestations of the electrical fields created by exceptionally intense conventional lightning. They show themselves as glowing, pancake-shaped layers (see illustration: Electromagnetic Pulses). Elves can occur with sprites but form first and do not last as long. The sequence of video images (below) shows the relative timing: just before the conventional lightning strike occurs, the sky is uniformly dark (A). The ensuing flash illuminates the cloud deck and immediately spawns the flattened glow of elves high in the mesosphere (B). Momentarily, sprites erupt throughout this part of the atmosphere, adding their radiance to the faint light from the luminous layer (C). Finally, only the sprites persist (D).



Images: Stephen B. Mende