Return strokes measurements of electric field produced by lightning discharges in Malaysia

Abstract

The physics of cloud discharges have not been known completely yet. The cloud to ground discharges is divided by researchers into several stages to make the analyses of lightning flash easier. The first step is preliminary breakdown which is called to pre-starting process prior to leader initiation within the clouds. The leader initiation precedes return strokes in continuing the cloud discharges. The time and amplitude of lightning waveforms differs in each flash with the other ones due to the stochastic characteristics of lightning flashes. This research tries to add more analyses to few previous researches done in tropical regions. On the other hand, observations of this study is compared with those obtained in Sweden to show the differences between statistics of return strokes in Malaysia and Sweden as a temperate region. A broadband antenna and a buffer system for amplifying input signal and also impedance matching is used in this study for capturing electric field of lightning waveforms to carry out statistical analyses on them in Johor, Malaysia. The percentage of single stroke flashes was 18% in Sweden and 12.1% in this study which shows single strokes happens more in temperate regions rather than tropical regions. Total number of 568 subsequent return strokes out of 271 flashes shows a Mean number of 3.4 strokes per flash in Sweden compared with 184 subsequent strokes out of 58 flashes in this study which presents 4.1 strokes per flash in average.