Volcanic Ash Forecast- Application to the May 2008 Chaitén Eruption

FOLCH, A.; JORBA ,O.; VIRAMONTE J.G.

Natural Hazard and Earth System Sciences

Copernicus Publications on behalf of the European Geosciences Union.

Año: 2008 vol. 8 p. 927 - 940

Abstract. We model the transport and subsequent deposition of ash from Chait´en volcano, Chile, during the first week of May 2008. The simulation couples theWeather 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 shortterm forecast of volcanic clouds and ash fallout.We model the transport and subsequent deposition of ash from Chait´en volcano, Chile, during the first week of May 2008. The simulation couples theWeather 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 shortterm forecast of volcanic clouds and ash fallout.