High-speed camera observations of intracloud flashes

This study summarizes the characteristics of 190 intracloud flashes recorded by high-speed video cameras operating at framing rates up to 37,819 frames per second, between 2003 and 2023, in Brazil and the United States of America. The analyzed features include the presence of processes similar to continuing currents and M-components, the behavior of recoil leaders propagating through the intracloud lightning channels, and the possible existence of connecting leaders within intracloud flashes. By analyzing the high-speed videos, we identified several characteristics similar to those observed in cloud-to-ground flashes. Two types of intracloud flashes were identified according to the polarity of the leader propagating along the cloud base. Their duration was estimated by the camera and by an electric field sensor. By comparing these data, the accuracy of high-speed videos in determining intracloud flash durations was evaluated.