MAFALDA: An early warning modeling tool to forecast volcanic ash dispersal and deposition

Abstract

Forecasting the dispersal of ash from explosive volcanoes is a scientific challenge to modern volcanology. It also represents a fundamental step in mitigating the potential impact of volcanic ash on urban areas and transport routes near explosive volcanoes. To this end we developed a web-based early-warning modeling tool named MAFALDA (Modeling And Forecasting Ash Loading and Dispersal in the Atmosphere) able to quantitatively forecast ash concentrations in the air and on the ground. The main features of MAFALDA are: the usage of (1) a dispersal model, named VOL-CALPUFF (Barsotti et al. 2008) that couples the column ascent phase with the ash-cloud transport and (2) high-resolution weather forecasting data, the capability to run and merge multiple scenarios, and the web-based structure of the procedure that makes it suitable as an early-warning tool. MAFALDA produces plots for a detailed analysis of ash-cloud dynamics and ground deposition, as well as synthetic 2D maps of areas potentially affected by dangerous concentrations of ash. A first application of MAFALDA to the long-lasting weak plumes produced at Mt. Etna (Italy) is presented. A similar tool can be useful to civil protection authorities and volcanic observatories in reducing the impact of the eruptive events. MAFALDA can be accessed at http://mafalda.pi.ingv.it.