气候变化领域集成服务门户(CCPortal): Long-term observation of electrical discharges during persistent Vulcanian activity

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DOI	10.1016/j.epsl.2021.117084
	Long-term observation of electrical discharges during persistent Vulcanian activity
	Vossen C.E.J.; Cimarelli C.; Bennett A.J.; Geisler A.; Gaudin D.; Miki D.; Iguchi M.; Dingwell D.B.
发表日期	2021
ISSN	0012821X
卷号	570
英文摘要	Very low frequency and wide-band lightning detection networks can detect major volcanic plumes via their intense electrical and lightning activity. However, the high number of non-detected explosive episodes confirmed by direct observations, reveals the limits of these systems in the detection of the more frequent smaller ash-rich explosive events. Here, we use a data-efficient thunderstorm detector to observe electrical discharges generated from July 2018 to January 2020 by the persistent Vulcanian activity of Minamidake crater at Sakurajima volcano in Japan. Two thunderstorm detectors recorded the electrical activity produced by explosions at Minamidake crater from a distance of 3 and 4 km from the active vents. The instruments measured the induced current due to the change in electric field with time within the extremely low frequency range (1-45 Hz). Using a volcanic lightning detection algorithm together with the catalogue of volcanic explosions compiled by the Japan Meteorological Agency (JMA) and Tokyo Volcanic Ash Advisory Center (Tokyo VAAC), the number of electrical discharges, the electrical discharge rate and the total amount of measured voltage were determined for each individual explosive event. In addition, the start of the electrical discharges was compared to the explosion onset as provided by the JMA (with a one-minute time resolution). The sensors detected electrical discharges in 71% of the 724 recorded explosions. Our detection algorithm successfully recognises the presence/absence of electrical discharges with an accuracy of 73%. We find a non-linear positive correlation between the number of discharges and the plume height. Moreover, we find that the maximum electrical discharge rate and the maximum amount of measured voltage by a single discharge also increase with plume height. Fracto- and tribo-electrification appear to be the dominant plume electrification mechanisms. Even for the few explosive events that exceeded the −10 °C isotherm, the timescale of electrical activity seems to be too short for ice nucleation to make a significant contribution to the plume electrification. Finally, for 12% of the electrically-active explosive events, discharges were detected by the sensors more than a minute before the JMA explosion onset. Our results show the capability of our detectors in pinpointing the inception of electrified explosive episodes in real-time and in providing an indication of the magnitude of each explosion, demonstrating their effectiveness as a cost- and data-efficient instrumentation for the monitoring of explosive ash emissions at active volcanoes. © 2021 The Author(s)
关键词	algorithm ash emission electrification mechanisms thunderstorm detector volcanic lightning
英文关键词	Explosions; Explosives; Lightning; Signal detection; Volcanoes; Ash emissions; Detection algorithm; Electrical activities; Electrical discharges; Electrification mechanism; Explosive events; Japan meteorological agencies; Lightning detection; Thunderstorm detector; Volcanic lightning; Electric utilities
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203322
作者单位	Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Theresienstraße 41, Munich, 80333, Germany; Bristol Industrial and Research Associates Ltd (Biral), Unit 8 Harbour Road Trading Estate, Portishead, Bristol, BS20 7BL, United Kingdom; University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom; Institut für Geophysik, Universität Hamburg, Bundesstraße 55, Hamburg, D-20146, Germany; Sakurajima Volcano Research Center, Disaster Prevention Research Institute, Kyoto University, Yokoyama 1722-19, Sakurajima, Kagoshima 891-1419, Japan
推荐引用方式 GB/T 7714	Vossen C.E.J.,Cimarelli C.,Bennett A.J.,et al. Long-term observation of electrical discharges during persistent Vulcanian activity[J],2021,570.
APA	Vossen C.E.J..,Cimarelli C..,Bennett A.J..,Geisler A..,Gaudin D..,...&Dingwell D.B..(2021).Long-term observation of electrical discharges during persistent Vulcanian activity.Earth and Planetary Science Letters,570.
MLA	Vossen C.E.J.,et al."Long-term observation of electrical discharges during persistent Vulcanian activity".Earth and Planetary Science Letters 570(2021).