Volcanic ash forecast – application to the May 2008 Chaitén eruption A. Folch1, O. Jorba1, and J. Viramonte2 1Earth Sciences Department, Barcelona Supercomputing Center – Centro Nacional de Suercomputación (BSC-CNS), Jordi Girona 29, 08034 Barcelona, Spain 2Instituto de Geología del Noroeste Argentino (GEONORTE) and CONICET, Universidad Nacional de Salta, Buenos Aires 177, 4400 Salta, Argentina
Abstract. We model the transport and subsequent deposition of ash from Chaitén
volcano, Chile, during the first week of May 2008. The simulation couples the
Weather Research and Forecasting (WRF) meteorological model with the FALL3D
dispersion model. We only use semi-quantitative volcanological inputs based
on the first eruption reports. We consider two different run types based on
forecasted and hindcasted meteorological conditions. The first simulation
type can be regarded as a syn-eruptive operational forecast for the 2–8 May
period. We predict the evolution of the ash cloud position, the concentration
of ash on air, the expected deposit thickness, and the ash accumulation rates
at different localities. The comparison of model results with observed cloud
arrival times and satellite images shows the goodness of the combined
WRF+FALL3D forecast system and points out the feasibility of combining these
two models for short-term forecast of volcanic clouds and ash fallout.
Citation: Folch, A., Jorba, O., and Viramonte, J.: Volcanic ash forecast – application to the May 2008 Chaitén eruption, Nat. Hazards Earth Syst. Sci., 8, 927-940, doi:10.5194/nhess-8-927-2008, 2008.