LEMP from Lightning Discharges Observed by JLDN

Abstract

Member JLDN (Japanese Lightning Detection Network) is a large-scale lightning location system, which covers from Hokkaido to Southwest Islands of Japan. It observes LEMP (lightning electromagnetic impulse) in the frequency ranges from VLF to LF, and estimates location and current amplitudes of lighting return strokes. The present study evaluates its ability to discriminate LEMP from return-strokes by comparing its output with the observation of a fastantenna network constructed on Fukui Plain. It turns out that about 90% of the sources of LEMP, interpreted by JLDN as positive return strokes in the 10 kA range in summer, are not cloud-to-ground strokes but in-cloud discharges. The number of termination points on ground produced by negative cloud-to-ground strokes in summer is about 1.3 to 1.4 times of the number of negative flashes observed by JLDN.

Flashover rate of medium-voltage line estimated with lightning parameters in Japan

“…In this paper, the authors employ the return-stroke current waveform parameters obtained by Berger et al [11] and those obtained by the JLDN (Japanese Lightning Detection Network) [12]. Table 1 shows the statistics of the peak values and the front duration of the return-stroke current waveform obtained by Berger et al [11].…”

Probability of lightning hits to tall structures taking account of upward lightning

“…Such thunderclouds will be detected by lightning location systems (LLS). In this study, data from LLS named JLDN [6], a single lightning detection network covering all over Japan, are employed.…”

Spatial Distribution of High Current Lightning Discharges in Hokuriku Area in Winter

“…It observes LEMP (lightning electromagnetic impulse) in the frequency range from VLF to LF, and estimates location and current amplitudes of lighting strokes (2) . Records of LEMP over Fukui Plain, captured by JLDN, are compared with records of electric field waveforms observed by the FA network (2) . The observed frequency range by the FA was 0.32 kHz∼1.…”

“…The average estimated peak current of lightning discharges observed simultaneously with transmission line faults in winter in this area was about 200 kA (1) . In this study, spatial distributions of such highcurrent lightning discharges around the coastline of the Sea of Japan in winter are examined with the help of data observed by JLDN (Japanese Lightning Detection Network) and a network of fast antennas (FA) on Fukui Plain (2) . A fast antenna is a device to observe fast electric field change in wide band by using an electrostatic antenna.…”