Abstract:

Simulating the transport and dispersion of a volcanic ash cloud requires accurate representation of the time-varying vertical distribution of mass (VDM) in the plume. By default, operational setup of the NAME atmospheric dispersion and transport model at the London VAAC assumes a simplistic uniform ash VDM from the vent to the plume-top height. This research project assesses the impacts of employing an empirical description of VDM known as the Suzuki Distribution (Suzuki, 1983) when initializing the NAME model. For four past eruption case studies, James uses satellite inversion data of SO2 and ash to determine suitable ‘k’ values which describe the VDM. For each eruption, NAME runs are initialised with both a uniform VDM and distributions described using a Suzuki Distribution. NAME simulation results are compared to satellite and LiDAR data for validation.