Three types of bidirectional leader development in triggered lightning flashes

The eight cases were contained in six negative triggered lightning flashes, of which one was the altitude-triggered lightning flash and the other five were classical triggered lightning flashes. Except for the triggering type of each flash, Table 1 lists the numbers of return strokes (RSs), the peak value of the studied RSs current, the observation distances of recorded current and electric field signals, and the corresponding relationship between flashes and cases. No relevant current and electric field data were recorded in Flash F. The HSC did not capture the whole process of Flash F,…