Modeling mineral aerosol production by wind erosion: Emission intensities and aerosol size distributions in source areas

A dust production model (DPM) is obtained by combining preexisting models of saltation and sandblasting, the two processes that lead to mineral aerosol release in arid areas. From a description of the soil characteristics and wind conditions, the DPM allows computation of the amounts of aerosol released and of their size distributions. Semiquantitative comparisons of the model outputs with the few field data available in the litterature validate its main implications. The first one is that the aptitude of a soil to release particles smaller than 20 mum depends on (1) the dry size distribution of aggregates constituting its loose fraction, (2) its roughness length, and (3) the wind velocity. The second implication is that the size distribution of aerosols released in source areas also strongly depends on these parameters.