Observation and Modeling of Attempted Leaders in a Multibranched Altitude-Triggered Lightning Flash

A multibranched altitude-triggered lightning flash containing 15 attempted leaders (ALs) was observed. These leaders propagated along three paths with different development processes. The average two-dimensional speed of the ALs ranged from 3.8 × 10 ⁵ m/s to 29.4 × 10 ⁵ m/s, and the terminal height ranged from over 1626 to 505 m above the ground. The progressing characteristics of ALs were investigated in detail based on the high-speed video camera and synchronous electric field data. The electric field waveforms at the termination stage of the AL were divided into two types. Two different termination ways were proposed to describe the process of AL's disappearance. The source charge model was used to simulate the electric field waveform of the ALs, and the results agree well with the measured electric field waveform.