Abstract
Lightning electric-field waveforms related to power line faults in winter have been identified. Most of those waveforms are inferred to be associated with upward lightning discharges with absolute peak currents over 100kA. They are quite different from common return-stroke waveforms, and lightning discharges which produce these characteristic waveforms are named GC (Ground to Cloud) flashes. These high-current lightning discharges distribute around the coastline in different ways depending on their polarities. Also, spatial distributions of high-current lightning discharges around Japan are investigated. As a result, it is revealed that the region on Honshu Island along the coastline of the Sea of Japan belongs to the area, where the density of high-current lightning flashes is the highest in Japan through the year.
