Extremely Long Lightning Channels Observed in Hokuriku During Winter Thunderstorm Season

We have been observing LF electromagnetic waves associated with lightning around Toyama Bay in winter thunderstorm seasons. From received LF signals at 7 stations, their sources are located in 3D using time of arrival method. Lightning flashes with the length of over 100km are detected in the observation results. Unlike general lighting discharges in winter, many return strokes are recorded along LF electromagnetic wave sources.