The VOL-CALPUFF model for atmospheric ash dispersal: 1. Approach and physical formulation

摘要: [1] We present a new modeling tool, named VOL-CALPUFF, that is able to simulate the transient and three-dimensional transport deposition of volcanic ash under action realistic meteorological volcanological conditions throughout eruption duration. The model derives from CALPUFF System, software program widely used in environmental applications pollutant dispersion, describes dispersal process both proximal distal regions also presence complex orography. main novel feature its capability coupling Eulerian description plume rise with Lagrangian representation described as series diffusing packets particles or puffs. describe multiparticle nature mixture well tilting effects due wind action. dynamics are by using refined orography-corrected data spatial resolution up 1 km less temporal step h. approach keeps execution time few minutes on common PCs, thus making VOL-CALPUFF possible tool for production forecasts hazard assessment. Besides formulation, this paper presents type outcomes produced shows effect parameters results, anticipates fundamental control atmospheric processes. In companion paper, Barsotti Neri first thorough application simulation weak at Mount Etna (Italy) specific aim comparing predictions independent observations.