A study on progress process of lightning discharge with long lightning channels

Hokuriku region is known to have serious damages to high structures caused by winter thunderstorm. We have been observing winter thunderstorms by LF band receivers since 2016. In the course of observations, lightning discharges with the channel of over 100 km were detected in winter thunderstorm season. Many return strokes were recorded by LLS with these very long lightning channel unlike general lightning discharge in winter thunderstorm season. Moreover, about 60 % of return strokes were positive, and both polarities were detected in 1 flash. This paper reports progress process of lightning discharge with the long channel.