Gas ash-particle separation and the role of particle aggregation in volcanic plumes

A complex numerical plume model will be used to characterize and quantify the fate of volcanic gases and particles in volcanic eruption plumes. The overall aim of the project is to improve and extend existing one-dimensional volcanic plume models to better capture the multiphase nature of such plumes by including critical processes such as

sedimentation. Simple integral plume models already play an important role in initialising atmospheric dispersion models

for operational forecasting of volcanic ash clouds, and this project will have clear practical benefits for future volcanic risk

management. This project will make use of a model specifically designed for 3D simulation of volcanic plumes, the Active Tracer High-resolution Atmospheric Model (ATHAM). The first part of the project will involve development of the ash

aggregation module to incorporate the effects of electrically-charged ash particles. This will then enable novel studies of the effects of sedimentation and aggregation. Findings will be used to improve models used at the Met Office for operational ash cloud forecasting.