10:00 AM - 10:15 AM
[HDS07-05] Relation between charge amounts of lightning discharges derived from ELF waveform data and severe weather
In this study, the lightning current waveforms measured by a Rogowski coil installed at Mt. Ogami and ELF waveforms measured at Onagawa observatory are analyzed as a first step. To validate the similarity between current waveforms and ELF waveforms, we investigated the correlation of these two waveforms. Then, the average correlation coefficient and standard deviation are estimated to be r=-0.84 and σ=0.14, respectively. This result indicates that there are high similarities between these two waveforms. From these quantitative analyses, empirical equations that enable us to directly convert from the magnetic field intensities into the charge amounts were obtained.
As a next step, using ELF waveform data obtained at Kuju station in Kyushu and lightning data of the Japan Lightning Detection Network (JLDN), charge amounts for the lightning discharges occurring when down bursts were confirmed in the Kanto Plain are estimated by applying the empirical equations. Then, we newly found a clear characteristics showing that the time variation of charge amounts was drastically changed just before the downburst onset. At the presentation, we will show the results in one down burst event more in detail, and we will also show the statistical results for other downburst events.