A review of volcanic electrification of the atmosphere and volcanic lightning

Cimarelli, Corrado und Genareau, Kimberly (2022): A review of volcanic electrification of the atmosphere and volcanic lightning. In: Journal of Volcanology and Geothermal Research, Bd. 422, 107449

Abstract

The electrification of volcanic ash plumes and the occurrence of volcanic lightning are now known to be common phenomena during explosive volcanic eruptions. This knowledge stems from centuries of anecdotal observations, and in recent decades, from improved instrumentation and media attention. Following a summary of previous reviews, this contribution will detail the most recent findings concerning electrification mechanisms of eruption columns/plumes (triboelectrification, fracto-electrification) and how hydrometeor charging contributes to this electrification depending upon the eruption style and abundance of external H2O. Field measurements to determine the charge structure of volcanic ash and gas plumes reveal wide variability both spatially and temporally, indicating the influence of these different charging mechanisms. The charge structure and resulting lightning characteristics have been provided by a suite of both ground-based and satellite-based lightning detection methods and the various characteristics of each are summarized. As these detection methods have revealed, the electrical properties of ash plumes can provide insight into their physical dynamics throughout the course of an eruption. Lightning may therefore provide a means to track changing eruption conditions and the associated hazards, providing another tool for monitoring efforts. Volcanic lightning also leaves physical evidence in associated ashfall deposits. These lightning-induced textures have been documented and are summarized here, in addition to the different experiments that have reproduced such textures. Lightning simulation experiments provide information on changes to ash grain size, size distribution, chemical, and magnetic properties of ash. Lightning discharge and the lightning-induced changes to ash grains potentially impact not only the hazards induced by ashfall, but also changes in atmospheric chemistry relevant to biologic activity, the fluid dynamics of eruption columns/plumes, and ash dispersion. Additionally, shock-tube experiments provide insight on the microphysical dynamics and environmental variables that influence electrification of dusty gas mixtures. Finally, this review summarizes the challenges to volcanic lightning research and the future efforts that can aid in addressing the unanswered questions regarding this phenomenon. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften
• Themengebiete: 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• ISSN: 0377-0273
• Sprache: Englisch