Monitoring Volcanic ASH with the Chemistry-Transport Model Mocage: Improvements of Source Term and Assimilation of Observations

Volcanic eruptions emit significant amounts of aerosols in the atmosphere and have strong impact on aviation security and air traffic. Our research deals with spatial and temporal improvements of volcanic ash aerosols within the chemistry-transport model MOCAGE [1], [2], the operational air-quality and fast-response model of Météo-France. To better characterize the source term of volcanic eruptions, we implemented the plume rise model FPLUME [3] and compared it to the Mastin [4] empirical parametrization, which confirmed that uncertainties of the volcanic ash modelling are considerable and very sensitive to the source term. For this reason, we explore the potential of assimilating spaceborne, ground-based and in-situ observations. Assimilation of Aerosols Optical Depth (AOD) from MODIS instrument allowed to correct the extent and intensity of the plume of the 2010 Eyjafjallajokull eruption. Further experiments are ongoing to take advantage of LIDAR soundings from EARLINET network and CALIOP instrument, as well as in-situ airborne measurements.