Chapter 5.8 Modelling of mineral dust emissions and transport with the CHIMERE-DUST model: Preliminary analysis of dust events for the AMMA field campaign

The atmospheric transport of mineral dust is difficult to reproduce using global circulation model because their coarse spatial and temporal resolutions limit their ability to represent the small-scale processes that control the generation and the deposition of such particles. The mineral dust transport model CHIMERE-DUST enables to generate concentration fields of mineral dust at high temporal (1h) and spatial (a few kilometres) resolutions for long time periods (several years). The modelled areas include the dust sources of western Africa and the zone of long-range dust transport in the North Atlantic. We present an estimation of the mineral dust concentrations uncertainties as estimated by various model configurations. For selected dust storms that occured over western Africa, the accuracy of the results is discussed in term of sensitivity to the surface emission fluxes (depending on the parameterization employed, the sandblasting process used), to the number and values of dust bins used to account for the particle size distribution and to the dry and wet deposition processes. The modelled results are finally compared to SeaWiFS images and AERONET data. With CHIMERE-DUST used in forecast configuration, some preliminary results will be presented in the framework of the international African Monsoon campaign AMMA.