Correlation between the channel-bottom light intensity and channel-base current of a rocket-triggered lightning flash

摘要

The correlations between channel-bottom light intensity and channel-base current of all discharge processes of a rocket-and-wire-triggered lightning flash, including initial continuous current (ICC) pulses, ICC pulse background continuing current (IBCC), return strokes, M components, and M component background continuing currents (MBCC), have been investigated. A rough linear correlation has been found between the current squaredandthe light intensity for ICCpulses (includingpeaks of different ICCpulses), IBCC, the initial rising stage (IRS) of return strokes (including current peaks of different strokes), andMBCC. The slopes of the correlation regression lines for the current squared versus light intensity of ICC pulses and IBCC are similar, but they are about 2–3 times smaller than the slopes of MBCC and 5–7 times smaller than the slopes of the IRS of return strokes. Incontrast,aroughlinearcorrelationhasbeenfoundbetweenthecurrentandthelightintensityfor thelater slow decay stage of return strokes and for theMcomponents. The slopes of the correlation regression lines of the current versus the light intensity for these latter two processes are found to be similar. No simple correlation has been found between the current and the light intensity for the initial fast decay stage (IFDS) of return strokes. The duration of the IFDS of return strokes generally lasts from several microseconds to several tens of microsecondsandismoreor less directly proportional to the corresponding peak return stroke current squared. A time delay ranging from 12 μs to 300 μs has been found between the current and the light intensity of all ICC pulses andM components. The time delay decreases as the corresponding peak current increases.