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 o f saltation and sandblasting, the two processes that lead to mineral aeroso l release in arid areas. From a description of the soil characteristics and wind conditions, the DPM allows computation of the amounts of aerosol rele ased and of their size distributions. Semiquantitative comparisons of the m odel 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 rele ase particles smaller than 20 mum depends on (1) the dry size distribution of aggregates constituting its loose fraction, (2) its roughness length, an d (3) the wind velocity. The second implication is that the size distributi on of aerosols released in source areas also strongly depends on these para meters.