气候变化领域集成服务门户(CCPortal): Modelling the size distribution of aggregated volcanic ash and implications for operational atmospheric dispersion modelling

CCPortal

DOI	10.5194/acp-22-3409-2022
	Modelling the size distribution of aggregated volcanic ash and implications for operational atmospheric dispersion modelling
	Beckett, Frances; Rossi, Eduardo; Devenish, Benjamin; Witham, Claire; Bonadonna, Costanza
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	3409
结束页码	3431
卷号	22 期号:5 页码:23
英文摘要	We have developed an aggregation scheme for use with the Lagrangian atmospheric transport and dispersion model NAME (Numerical Atmospheric Dispersion modelling Environment), which is used by the London Volcanic Ash Advisory Centre (VAAC) to provide advice and guidance on the location of volcanic ash clouds to the aviation industry. The aggregation scheme uses the fixed pivot technique to solve the Smoluchowski coagulation equations to simulate aggregation processes in an eruption column. This represents the first attempt at modelling explicitly the change in the grain size distribution (GSD) of the ash due to aggregation in a model which is used for operational response. To understand the sensitivity of the output aggregated GSD to the model parameters, we conducted a simple parametric study and scaling analysis. We find that the modelled aggregated GSD is sensitive to the density distribution and grain size distribution assigned to the non-aggregated particles at the source. Our ability to accurately forecast the long-range transport of volcanic ash clouds is, therefore, still limited by real-time information on the physical characteristics of the ash. We assess the impact of using the aggregated GSD on model simulations of the 2010 Eyjafjallajokull ash cloud and consider the implications for operational forecasting. Using the time-evolving aggregated GSD at the top of the eruption column to initialize dispersion model simulations had little impact on the modelled extent and mass loadings in the distal ash cloud. Our aggregation scheme does not account for the density of the aggregates; however, if we assume that the aggregates have the same density of single grains of equivalent size, the modelled area of the Eyjafjallajokull ash cloud with high concentrations of ash, significant for aviation, is reduced by similar to 2 %, 24 h after the start of the release. If we assume that the aggregates have a lower density (500 kg m(-3)) than the single grains of which they are composed and make up 75 % of the mass in the ash cloud, the extent is 1.1 times larger.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000771353400001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273529
作者单位	Met Office - UK; University of Geneva
推荐引用方式 GB/T 7714	Beckett, Frances,Rossi, Eduardo,Devenish, Benjamin,et al. Modelling the size distribution of aggregated volcanic ash and implications for operational atmospheric dispersion modelling[J],2022,22(5):23.
APA	Beckett, Frances,Rossi, Eduardo,Devenish, Benjamin,Witham, Claire,&Bonadonna, Costanza.(2022).Modelling the size distribution of aggregated volcanic ash and implications for operational atmospheric dispersion modelling.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(5),23.
MLA	Beckett, Frances,et al."Modelling the size distribution of aggregated volcanic ash and implications for operational atmospheric dispersion modelling".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.5(2022):23.