Observation and simulation of dart leader-M component process in rocket-triggered lightning

Three dart leader (DL)-M components in two double-branch lightning flashes were analyzed through high-speed camera and synchronizing current and electric field data. The downward negative DL with a 2-D development speed of 1.2-1.8 x 106 6 m/s from the branch outside the main channel forms the M component after being intercepted by the main channel. The current waveform of DL-M component shows a typical "hook-shaped" waveform, and the electric field waveform can be clearly divided into DL part and M component part. The waveform of the DL part decreases slower than that of the M component part. Using current measured at the channel base as input, three models were used to simulate the corresponding electric field. The DL-M model, which takes the leader process into account, gives better modelling results.