Lightning discharges accompanied by initial breakdown pulses

Using electric field waveforms of lightning discharges observed in Beijing and Guangzhou, the detectable preliminary breakdown (PB) pulses and the following discharges are analyzed. The results show that, (1) the percentages of detectable PB pulse are 34.5% and 36.9% in Beijing and Guangzhou, respectively. The values are similar, which indicate that the characteristic of storm also play a key role in detectable PB besides the latitude. (2)According to the difference in discharge process of following PB pulse, three discharge types, which exhibits PB pulses followed by inverted IC, hybrid flash (an IC followed by a CG), leader and RS, can be identified. And the fourth type only exhibits a RS waveform without detectable PB pulses. (3)The discharge with undetectable PB pulse is dominant in Beijing and Guangzhou. But the percentage of each discharge type is obvious different in the two regions. The occurrence of different discharge types and different percentage in Beijing and Guangzhou can be contributed to the difference in low positive charge region.