First In Situ Observations of Gaseous Volcanic Plume Electrification
First In Situ Observations of Gaseous Volcanic Plume Electrification
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DOI：
10.1029/2019gl082211
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发表时间：
2019-03
影响因子：
5.2
通讯作者：
K. Nicoll;M. Airey;C. Cimarelli;A. Bennett;G. Harrison;D. Gaudin;K. Aplin;K. Koh;M. Knuever;G. Marlton
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文献类型：
--
作者：
K. Nicoll;M. Airey;C. Cimarelli;A. Bennett;G. Harrison;D. Gaudin;K. Aplin;K. Koh;M. Knuever;G. Marlton
火山羽流带电，经常产生壮观的闪电。以前的研究主要集中在了解火山闪电，主要是火山灰粒子充电产生的大电场。在这里，我们报告了以前被忽视的现象，火山羽带电的情况下，可检测的灰。我们提出了第一个原位垂直剖面测量的电荷，热力学和微物理性质内主要是气态羽直接上方的火山爆发。我们的测量表明，大量的电荷（至少±8,000 pC/m3）存在于气态火山云中，而没有可检测到的灰烬。我们认为，羽充电可能会提高氡气体从火山，这会导致电离的排放。这提出了一个迄今尚未认识到的，但可能是常见的，在火山羽流，这是预期调制羽流的特性和寿命的电荷产生机制。这一过程目前在公认的火山柱带电机制中被忽视。
Volcanic plumes become electrically charged, often producing spectacular displays of lightning. Previous research has focused on understanding volcanic lightning, primarily the large electric fields produced by charging of ash particles. Here we report on the previously overlooked phenomenon of volcanic plume electrification in the absence of detectable ash. We present the first in situ vertical profile measurements of charge, thermodynamic, and microphysical properties inside predominantly gaseous plumes directly above an erupting volcano. Our measurements demonstrate that substantial charge (at least ±8,000 pC/m3) is present in gaseous volcanic clouds without detectable ash. We suggest that plume charging may be enhanced by the emission of radon gas from the volcano, which causes ionization. This presents a hitherto unrecognized, but likely to be common, mechanism for charge generation in volcanic plumes, which is expected to modulate plume characteristics and lifetime. This process is currently neglected in recognized mechanisms of volcanic plume electrification.