气候变化领域集成服务门户(CCPortal): Wind Entrainment in Jets with Reversing Buoyancy: Implications for Volcanic Plumes

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DOI	10.1029/2020JB020136
	Wind Entrainment in Jets with Reversing Buoyancy: Implications for Volcanic Plumes
	Michaud-Dubuy A.; Carazzo G.; Kaminski E.
发表日期	2020
ISSN	21699313
卷号	125 期号:10
英文摘要	Explosive volcanic eruptions commonly undergo a transition from stable plume to collapsing fountain with associated destructive pyroclastic density currents. A major goal in physical volcanology is to predict quantitatively the limit between the flow regimes as a function of the source and environmental conditions. Atmospheric winds influence the dynamics and stability of the column causing bending and enhancing turbulent air entrainment. However, the predictions made with 1-D models of volcanic plumes accounting for the presence of wind strongly depend on the wind entrainment coefficient β, a parameter whose value varies in the literature. Here we present a new theoretical model to identify an analytical criterion for column collapse in windy conditions. We then present new laboratory experiments on turbulent jets with reversing buoyancy rising in a crossflow in order to better constrain β. Our results show that a single value of (Formula presented.) can be used to describe the behavior of laboratory jets with arbitrary buoyancy. The results allow us to parameterize our 1-D model of volcanic plumes PPM and to show the crucial importance of wind gradient and profile on volcanic column dynamics through the use of the 1991 Mt. Hudson eruption as a case study. Finally, we propose a new transition diagram between the stable plume and collapsing fountain regimes, as a function of wind speed and mass discharge rate only, which can be used for the rapid assessment of major hazards during an explosive eruption. ©2020. The Authors.
英文关键词	atmospheric crosswind; column collapse; eruptive dynamics; laboratory experiments; Plinian eruption; turbulent entrainment
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187567
作者单位	Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
推荐引用方式 GB/T 7714	Michaud-Dubuy A.,Carazzo G.,Kaminski E.. Wind Entrainment in Jets with Reversing Buoyancy: Implications for Volcanic Plumes[J],2020,125(10).
APA	Michaud-Dubuy A.,Carazzo G.,&Kaminski E..(2020).Wind Entrainment in Jets with Reversing Buoyancy: Implications for Volcanic Plumes.Journal of Geophysical Research: Solid Earth,125(10).
MLA	Michaud-Dubuy A.,et al."Wind Entrainment in Jets with Reversing Buoyancy: Implications for Volcanic Plumes".Journal of Geophysical Research: Solid Earth 125.10(2020).