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| Title: |
DEVELOPMENT OF CLOUD-TO-GROUND LIGHTNING |
| Caption: |
(a) Electrical charge separation occurs in a cumulonimbus cloud, most likely by the interaction between rising ice crystals and falling ice pellets. The build-up of negative electrical charge at the base of the cloud locally induces a positive electrical charge below the thunderstorm. (b) A nearly invisible, stepped leader forms a column of electrically charged air that branches downward toward the ground. (c) When the stepped leader gets close to the ground, a spark jumps from a tall object and attaches to the leader; this completes a narrow channel for the rapid flow of electrons. (d) Flowing electrons heat the channel to extremely high temperature and create a return stroke back to the cloud. The process of downward leader followed by upward return stroke repeats itself multiple times in a single lightning flash. |
| Keywords: |
atmosphere, thunderstorms, cumulonimbus clouds, lightning, electricity |
