The spatio-temporal evolution of the Saharan dust and biomass-burning plume during the SAMUM-2 field campaign
in January and February 2008 is simulated at 28 km horizontal resolution with the regional model-system COSMOMUSCAT.
The model performance is thoroughly tested using routine ground-based and space-borne remote sensing
and local field measurements. Good agreement with the observations is found in many cases regarding transport
patterns, aerosol optical thicknesses and the ratio of dust to smoke aerosol. The model also captures major features
of the complex aerosol layering. Nevertheless, discrepancies in the modelled aerosol distribution occur, which are
analysed in detail. The dry synoptic dynamics controlling dust uplift and transport during the dry season are well
described by the model, but surface wind peaks associated with the breakdown of nocturnal low-level jets are not
always reproduced. Thus, a strong dust outbreak is underestimated. While dust emission modelling is a priori more
challenging, since strength and placement of dust sources depend on on-line computed winds, considerable inaccuracies
also arise in observation-based estimates of biomass-burning emissions. They are caused by cloud and spatial errors of
satellite fire products and uncertainties in fire emission parameters, and can lead to unrealistic model results of smoke
transport