Mineral dust transport over West Africa in 2006

The transport of mineral dust over West Africa is quantified using different model runs available through the AMMA-EU project. Aerosol mass fluxes and concentrations are calculated for four north-south transects located along 20°W, 15°W, 10°W, 10°E. Data from the RegCM calculations are used to assess the variability in dust transport on a monthly basis throughout 2006 including the AMMA IOPs. In addition, specific events are chosen to characterise different dust events during 2006. These events occurred during a pre-monsoon cold surge (5-10 March), the monsoon onset (6-14 June), the summer monsoon phase (2-9 July) and the late monsoon (9-14 September). The events were simulated with different models (COSMO-ART, MESO-NH, RegCM) run at different horizontal resolutions. The model results are compared with Aeronet and satellite (CALIPSO, MODIS) data. The study highlights the variability in dust transport under different synoptic conditions as well as the differences in the representation of dust transport in the different models. We present the monthly averages of all months of 2006 and compare individual dust events with results from the regional climate model. Different mechanisms of dust transport (e.g. by the African easterly waves, frontal systems) are highlighted.