Characteristics and Aspect of Discharge Progress of Lightning with Widespread and Intermittently by Matching Data of LF-band Observation and LLS

Abstract

In recent years, lightning strokes affects not only industrial facilities but also common households. In order to reduce the damage by lightning strokes, lightning observation have been actively conducted in various places. Japan Sea coast in Hokuriku is known as a rare region in the world where lightning discharges occur in winter season. Winter thunderstorm tends to be different from summer one, with a higher percentage of positive stroke and lower multiplicity of lightning flash. We have installed LF band receiver that can observe electromagnetic wave from the return stroke and the lightning processes of both cloud-to-ground (CG) and cloud-to-cloud (CC) discharge. From the received LF pulses, their radiation source locations are estimated using time of arrival method. As the result, lightning discharge with the length of over 100km are detected in winter thunderstorm season. These discharges are unlike general lightning discharge in winter thunderstorm season.