High-Speed Optical Imaging of Lightning and Sparks: Some Recent Results
This review covers selected results of recent observations of natural lightning and laboratory sparks performed using
high-speed video cameras at the Lightning Observatory in Gainesville (LOG), Florida, and at the high-voltage
research facility in Istra, Russia, respectively. The most important results include (a) the first high-speed video images
of bidirectional leader that made contact with the ground and produced a return stroke, (b) the first speed profile of
positive leader that developed in the channel of preceding negative stroke, (c) discovery of unusual plasma formations
that coexist with “normal” discharges inside the artificially-charged cloud, and (d) the first two-frame record of the
connection between negative and positive leaders after the common streamer zone has been formed.