Please use this identifier to cite or link to this item:
Authors: Costa, A.* 
Folch, A.* 
Macedonio, G.* 
Title: Density-driven transport in the umbrella region of volcanic clouds: Implications for tephra dispersion models
Issue Date: 2013
Series/Report no.: /40 (2013)
DOI: 10.1002/grl.50942
Keywords: Large explosive eruptions
Volcanic ash transport
volcanic modeling
tephra transport
Subject Classification05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous 
Abstract: Large explosive volcanic eruptions can generate ash clouds from rising plumes that spread in the atmosphere around a Neutral Buoyancy Level (NBL). These ash clouds spread as inertial intrusions and are advected by atmospheric winds. For low mass flow rates, tephra transport is mainly dictated by wind advection, because ash cloud spreading due to gravity current effects is negligible (passive transport). For large mass flow rates, gravity-driven transport at the NBL can be the dominant transport mechanism. Conditions under which the passive transport assumption is valid have not yet been critically studied. We analyze the conditions when gravity-driven transport is dominant in terms of the cloud Richardson number. Moreover, we couple an analytical model that describes cloud spreading as a gravity current with an advection-diffusion model. This coupled model is used to simulate the evolution of the volcanic cloud during the climatic phase of the 1991 Pinatubo eruption. Citation: Costa, A., A. Folch, and G. Macedonio (2013), Density-driven transport in the umbrella region of volcanic clouds: Implications for tephra dispersion models.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
cosfol2013.pdfarticle894.99 kBAdobe PDFView/Open
Show full item record

Page view(s)

Last Week
Last month
checked on Jun 24, 2018


checked on Jun 24, 2018

Google ScholarTM