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.