Investigation of preliminary breakdown pulses in lightning waveforms

Abstract

The cloud-to-ground lightning contains one or more sporadic discharges. These cloud discharges usually include a pre-starting process which is called the preliminary breakdown (PB) before a leader initiation. These breakdown processes are not well understood because of the stochastic characteristics of the lightning °ashes. Several models have been introduced to categorise the lightning waveforms. The BIL model is an early model which has been used to investigate the lightning °ashes in di®erent regions from more than 50 years ago till now. This model is closely successful in depicting incipient processes of the cloud-to-ground lightnings. Although the BIL model is useful as a general depiction, the details of the breakdown process di®er from study to study and hence it is not completely standardized. In this paper, the preliminary breakdown pulse (PBP) train is analysed in cloud-to-ground (CG) lightning waveforms recorded in Malaysia using a broadband antenna.