Thunderstorm days and ground flash density based on LLS (Lightning Location System)

Abstract:
Lightning location systems (LLS) have been implemented in numerous countries and regions. The LLS provides accu-rate estimates of the number of thunderstorm days and ground flash density. According to an international standard, the relationship between ground flash density (NG) and the number of thunderstorm days per year (TD) can be expressed as NG = 0.1 TD. The TD can be estimated from isokeraunic maps to approximate the NG. However, the relationship between thunderstorm days and ground flash density has never been discussed using LLS data. Therefore, we investigated them based on LLS using the Japanese Lightning Detection Network (JLDN) and discussed the validity of NG = 0.1 TD.