3D volcanic aerosol dispersal: a comparison between misr data and numerical simulations

Abstract

The three dimensional reconstruction of volcanic plumes is a central goal to enhance our understanding on dispersal processes. In this paper, we use data from the Multi-angle Imaging SpectroRadiometer (MISR) on board NASA’s Terra spacecraft combined with a stereo matching retrieval procedure. We show the potential of MISR in capturing important features of volcanic plumes like column height, optical depth, type and shape of the finest particles of two highly explosive eruptions occurring on Mt. Etna in 2001 and 2002. This work tests how tephra dispersal models reconstruct the 3D shape of volcanic clouds. We compare MISR data with FALL3D, an Eulerian model for the transport and deposition of volcanic ash and aerosols coupled with the Weather Research and Forecasting (WRF) mesoscale meteorological model. Agreement between simulations and MISR data is good regarding both events, although it could be improved by increasing the accuracy of the meteorological data, a better constraint on volcanological input parameters like the height of the eruptive column and improving our understanding of processes such as aggregation phenomena and volcanic cloud microphysics.