Natural and artificially initiated lightning.

Recent research on lightning has been motivated, in part, by the desire to prevent spectacular accidents, such as occurred in 1969 during the launch of Apollo 12 and in 1987 during the launch of Atlas-Centaur 67, and by the need to protect advanced ground-based and airborne systems that utilize low voltage, solid-state electronics. The present understanding of both natural and artificially initiated (triggered) lightning is reviewed, and suggestions are given for future research that can improve our understanding both of the physics of lightning and the parameters that are important for protection.