leader

The streamer which initiates the first phase of each stroke of a lightning discharge; it is a channel of very high ion density which propagates through the air by the continual establishment of an electron avalanche ahead of its tip. Also known as leader streamer.

Related terms:

• streamer
• dart leader
• stepped leader
• leader stroke
• type-p leader
• return streamer
• type-a leader
• pilot streamer
• continuous leader
• lightning stroke