Long-term observation of electrical discharges during persistent Vulcanian activity
Long-term observation of electrical discharges during persistent Vulcanian activity
复制标题
瓦肯尼亚持续活动期间放电的长期观察
DOI：
10.1016/j.epsl.2021.117084
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发表时间：
2021
影响因子：
5.3
通讯作者：
Donald Bruce Dingwell
中科院分区：
文献类型：
--
作者：
C. Vossen;C. Cimarelli;A. Bennett;A. Geisler;D. Gaudin;D. Miki;M. Iguchi;Donald Bruce Dingwell
甚低频和宽带闪电探测网络可以通过其强烈的电和闪电活动来探测主要的火山羽流。然而，经直接观测证实的大量未探测到的爆炸事件表明，这些系统在探测更频繁的小型富灰爆炸事件方面存在局限性。在这里，我们使用数据高效的雷暴探测器来观测2018年7月至2020年1月日本樱岛火山南岳火山口持续的火山活动产生的放电。两个雷暴探测器记录了南岳火山口距离活动喷口3公里和4公里的爆炸产生的电活动。仪器测量了在极低频范围（1-45 Hz）内电场随时间变化引起的感应电流。使用火山闪电检测算法以及日本气象厅（JMA）和东京火山灰咨询中心（Tokyo VAAC）编制的火山爆炸目录，确定了每个爆炸事件的放电次数，放电率和测量电压总量。此外，还将放电的开始时间与日本气象厅提供的爆炸开始时间进行了比较（时间分辨率为一分钟），在记录的724次爆炸中，传感器检测到71%的放电。我们的检测算法成功地识别了放电的存在/不存在，准确率为73%。我们发现排放的数量和羽流高度之间存在非线性正相关关系。此外，我们发现，最大的放电速率和最大量的测量电压由一个单一的放电也增加羽高度。断裂和摩擦起电似乎是占主导地位的羽流起电机制。即使对于少数超过−10 °C等温线的爆炸事件，电活动的时间尺度似乎太短，冰成核对羽流带电产生重大贡献。最后，对于12%的电活性爆炸事件，传感器在JMA爆炸开始前一分钟以上检测到放电。我们的研究结果表明，我们的检测器能够实时精确定位带电爆炸事件的开始，并提供每次爆炸的强度指示，证明了它们作为监测活火山爆炸性灰排放的具有成本效益和数据效率的仪器的有效性。
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.
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影响因子：
5.2
作者：
K. Nicoll;M. Airey;C. Cimarelli;A. Bennett;G. Harrison;D. Gaudin;K. Aplin;K. Koh;M. Knuever;G. Marlton
通讯作者：
K. Nicoll;M. Airey;C. Cimarelli;A. Bennett;G. Harrison;D. Gaudin;K. Aplin;K. Koh;M. Knuever;G. Marlton
影响因子：
5.2
作者：
Van Eaton, Alexa R.;Amigo, Alvaro;Behnke, Sonja A.
通讯作者：
Behnke, Sonja A.
2016 年至 2017 年阿拉斯加博戈斯洛夫火山喷发期间，充冰是否产生了火山闪电？
影响因子：
3.5
作者：
Van Eaton, Alexa R.;Schneider, David J.;Smith, Cassandra M.;Haney, Matthew M.;Lyons, John J.;Said, Ryan;Fee, David;Holzworth, Robert H.;Mastin, Larry G.
通讯作者：
Mastin, Larry G.
喷发羽流中的火山灰-气体相互作用可以增强或抑制火山灰冰核活动
影响因子：
5.3
作者：
Maters E
通讯作者：
Maters E