Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 6 2 2006 10.5194/acpd-6-1749-2006 http://www.atmos-chem-phys-discuss.net/6/1749/2006/ http://www.atmos-chem-phys-discuss.net/6/1749/2006/acpd-6-1749-2006.html http://www.atmos-chem-phys-discuss.net/6/1749/2006/acpd-6-1749-2006.pdf 1749 1792 2006-03-10 Development and testing of a desert dust module in a regional climate model A. S. Zakey F. Solmon F. Giorgi Department of Chemistry Atmospheric Science, Goteborg University, 41 296 Goteborg, Sweden The Abdus Salam International center for Theoretical Physics, Physics of Weather and climate section, Strada Costiera 11, 34 100 Trieste, Italy We develop a desert dust module and implement it within a regional climate model (RegCM). The dust module includes emission, transport, gravitational settling, wet and dry removal and calculations of dust optical properties. The coupled RegCM-dust model is applied to the simulation of two dust episodes over the Sahara region (a northeastern Africa dust outbreak, and a west Africa-Atlantic dust outbreak observed during the SHADE "Saharan Dust Experiment") as well as a three month simulation over an extended domain covering the Africa-Europe sector. Comparison with satellite and insitu (for SHADE) measurements shows that the model captures the main spatial (both horizontal and vertical) and temporal features of the dust distribution. The main model deficiency occurred in the SHADE case, when the model failed to accurately simulate the development of a mesoscale low associated with an easterly wave that contributed to the generation of the dust outbreak. The model appears suitable to conduct long term simulations of the effects of Saharan dust on African and European climate.