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Abstract

Large volcanic explosions are well known to be capable of exciting a range of atmospheric waves including sound, infrasound, and acoustic-gravity waves (AGW), that can be recorded at very large distances from the source. Understanding their generation and propagation is important to correctly interpret recorded signals and retrieve source parameters, as well as to study atmospheric phenomena of the upper layers of the atmosphere, such as the formation of ionospheric traveling disturbances associated with propagating Lamb waves. Most studies rely on models based on a simplified (linearized) version of the Navier-Stokes equations that do not allow to fully investigate the effects due to the complexity of volcanic sources (presence of gas particle mixtures, shock waves, directivity of the volcanic jet) and to non-linear propagation phenomena. Here, we present preliminary results and efforts to test, within the open-source MagmaFOAM framework, based on the OpenFOAM library, a numerical model that solves the full set of equations for compressible fluids, including the presence of multiple phases (e.g. gas-particles) and components (e.g. air-water vapor). The model is able to consider the relatively large atmospheric computational domains that are required to study AGW. The validated model may provide the opportunity to investigate the generated wavefield for selected eruption source processes and scenarios as well as to test simplified source models.