TY - JOUR
T1 - Relation between charge amounts of lightning discharges derived from elf waveform data and severe weather
AU - Shimizu, Chihau
AU - Sato, Mitsuteni
AU - Hongo, Yasuji
AU - Tsuchiya, Fiiniiiiori
AU - Takahashi, Yukihiro
N1 - Publisher Copyright:
© 2016 The Institute of Electrical Engineers of Japan.
PY - 2016
Y1 - 2016
N2 - Recently, it was shown that the shape of lightning-generated induction magnetic field waveforms in the ELF frequency range is well comparable to that of lightning current waveforms. Therefore, charge amounts of any lightning discharges occurring within the area where the induction magnetic fields are measured can be easily estimated from ELF waveforms by quantitatively evaluating the relation between ELF waveforms and the current waveforms. In this study, we analyzed lightning current waveforms measured by a Rogowski coil installed at Mt. Ogkami and ELF waveforms measured at Onagawa observatory. Based on the quantitative comparison between the ELF waveforms and the current waveforms, empirical equations that enable us to directly convert from the magnetic field intensities into the current intensities and charge amount were obtained. Furthermore, using ELF waveform data obtained at Kuju station in Kyushu and the Japan Lightning Detection Network (JLDN) lightning data, peak current values and charge amounts for the lightning discharges occurring when severe downbursts occurred in the Kanto Plain were estimated by applying the empirical equations. Then, we newly found a clear feature showing that the time variation of charge amounts drastically changed just before the downburst onset.
AB - Recently, it was shown that the shape of lightning-generated induction magnetic field waveforms in the ELF frequency range is well comparable to that of lightning current waveforms. Therefore, charge amounts of any lightning discharges occurring within the area where the induction magnetic fields are measured can be easily estimated from ELF waveforms by quantitatively evaluating the relation between ELF waveforms and the current waveforms. In this study, we analyzed lightning current waveforms measured by a Rogowski coil installed at Mt. Ogkami and ELF waveforms measured at Onagawa observatory. Based on the quantitative comparison between the ELF waveforms and the current waveforms, empirical equations that enable us to directly convert from the magnetic field intensities into the current intensities and charge amount were obtained. Furthermore, using ELF waveform data obtained at Kuju station in Kyushu and the Japan Lightning Detection Network (JLDN) lightning data, peak current values and charge amounts for the lightning discharges occurring when severe downbursts occurred in the Kanto Plain were estimated by applying the empirical equations. Then, we newly found a clear feature showing that the time variation of charge amounts drastically changed just before the downburst onset.
KW - Charge amounts of lightning discharges
KW - Downburst
KW - Severe weather
UR - http://www.scopus.com/inward/record.url?scp=84971287188&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84971287188&partnerID=8YFLogxK
U2 - 10.1541/ieejfms.136.252
DO - 10.1541/ieejfms.136.252
M3 - Article
AN - SCOPUS:84971287188
VL - 136
SP - 252
EP - 258
JO - IEEJ Transactions on Fundamentals and Materials
JF - IEEJ Transactions on Fundamentals and Materials
SN - 0385-4205
IS - 5
ER -