Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS19] Atmospheric electricity

Tue. May 22, 2018 1:45 PM - 3:15 PM 201A (2F International Conference Hall, Makuhari Messe)

convener:Yasuhide Hobara(Graduate School of Information and Engineering Department of Communication Engineering and Informatics, The University of Electro-Communications), Masashi Kamogawa(Department of Physics, Tokyo Gakugei University), Chairperson:Morimoto Takeshi, KAMOGAWA Masashi(Department of Physics, Tokyo Gakugei University)

2:30 PM - 2:45 PM

[MIS19-04] Accuracy verification of lightning charge moment and lightning charge height remotely estimated by ELF observations using lightning current measurements at wind turbine

*Shun Murai1, Yasuhide Hobara1, Fumito Minoura2, Ryotaro Yoshida2, Hiroaki Mitsuzuka2, Tomomi Narita3, Masaru Ishii4, Mikihisa Saito6, Daisuke Natsuno5 (1.The University of Electro-Communications, 2.TEPCO Power Grid, 3.Shonan Institute of Technology, 4.University of Tokyo, 5.Toyo Sekkei Co.,Ltd, 6.CRIEPI)

Keywords:ELF transients, charge moment, lightning charge, charge height, lightning current, wind turbine

In this paper, estimation accuracy of the lightning charge moment change (Qds) derived from the ELF magnetic field observation is reported. Horizontal magnetic waveforms in the ELF frequency rage (0.1 ~ 1 kHz) are continuously recorded in Moshiri, Hokkaido, and ELF electromagnetic radiations from powerful lightning discharges so-called ELF transients are observed. Qds of these lightning discharges are estimated remotely (till few hundred ~ 1000 km from the lightning source) by an integration of current moment I(t)ds in time also derived by ELF transients. In this paper eight lightning events were studied, and Qds of every lightning stroke was derived. Then estimated Qds from ELF measurement were compared with the lightning charge (Q) based on the electric current waveforms I(t) locally measured in wind turbine facilities by NEDO. As a result, extremely high cross-correlation coefficient was obtained between Qds (I(t)ds)from ELF and Q (I(t)) from wind turbine. We also calculated the height of charge lowered to the ground ds (dividing Qds (ELF) by Q (wind turbine)). Although ds has a considerable variation between lightning discharges, it was revealed that the charge height is located at around -10 ° C to -20 ° C in most events, which agree well with the charge structure of typical thunderstorm cells.