CN tower lightning flash components

Based on the records of the new Phantom v5.0 high-speed imaging system (NHSIS) during the past five years (2006- 2010), the cumulative probability distributions of important CN Tower lightning flash parameters flash and ICC durations, flash multiplicity and inter-stroke time (1ST) were determined. During the reporting period, NHSIS recorded 68 CN Tower lightning flashes, of which 56 contained ICCs and 12 contained only return strokes. The flash multiplicity for all flashes (including 21 flashes that contain no return strokes), 35 flashes with ICCs and return strokes, and 12 flashes that contain only return strokes are, respectively, 2.19, 3.43, and 2.42. Therefore, the flash multiplicity of flashes having ICCs and return strokes is the highest. The cumulative probability distribution of ICC duration demonstrates that flashes with only ICCs have considerably larger ICC durations than those of flashes having ICCs and return strokes. Also, generally, flashes that have only return strokes have substantially higher inter-stroke time than that for flashes containing ICCs.