Description of the data and files:


The data sets give parameters that describe the surface features in arid and semi-arid areas of Africa and Asia. The parameters that have been documented are the input data of the dust emission model initially developed by Marticorena and Bergametti (1995) and further modified by Laurent et al. (2006, 2008). A complete description of these parameters can be found in Marticorena et al. (1997).

They typically include (i) the local aerodynamic roughness length Z0, (ii) the roughness length of the erodible fraction of the surface z0s, (iii) the fraction of the considered surface not covered by roughness elements, (iv) the “dry”, or undisturbed soil size-distribution characterized by a combination of lognormal functions defined by their median diameter, standard deviation and mass fraction, (v) the soil texture from which has been estimated the ratio of vertical to horizontal flux, i.e. the sandblasting efficiency and (vi) the residual soil moisture, i.e. the minimum value of soil moisture that must be reach to have an increase of the erosion threshold by soil moisture. These parameters allow estimating the erosion threshold wind friction velocity for different conditions of surface roughness, soil moisture and soil type, to compute a size resolved horizontal flux and then the intensity of the dust flux (Marticorena and Bergametti, 1995; Marticorena et al., 1997).

For a specific region and a given spatial resolution, two data files are given: the “solspe_region_resol.dat” file gives the soil properties (size distribution, sandblasting efficiency, and depending on the region the residual soil moisture) for a given soil type referred to by a name and a numerical label (between 1 and 99). The “surface_region_resol.dat” file gives for each grid cell, its geographical coordinates (X,Y) and the following information for the i different combination of surface features of the grid cell (i=1 to 5 depending on the file):


Depending on the region, the residual soil moisture W0(i) is given in one or the other of the two files.
All files are ascii files with a head line listing the parameters documented in the file.



Region:         Sahara-Sahel-Arabia-Minor Asia            Spatial resolution : 1°×1°

Region:         North EASTERN ASIA                           Spatial resolution : ¼°×¼°

Region:         North of Africa                                         Spatial resolution : ¼°×¼°



REFERENCES


Callot Y., B. Marticorena and G. Bergametti, Geomorphologic approach for modelling the surface features of arid environments in a model of dust emissions: application to the Sahara desert, Geodinamica Acta, 13, 245-270, 2000.

Laurent B., B. Marticorena, G. Bergametti, P. Chazette, F. Maignan and C. Schmechtig, Simulation of the mineral dust emission frequencies from desert areas of China and Mongolia using an aerodynamic roughness length map derived from the POLDER/ADEOS-1 surface products, J. Geophys. Res., Vol.110, D18S04, doi:10.1029/2004JD005013, 2005.

Laurent B., B. Marticorena, G. Bergametti, and F. Mei, Modeling mineral dust emissions from Chinese and Mongolian deserts, Global and Planetary Changes, 52, 121-141, 2006

Laurent, B., B. Marticorena, G. Bergametti, J.-F. Leon, and N. Mahowald, Modeling mineral dust emissions from the Sahara desert using new surface properties and soil database, J. Geophys. Res., doi:10.1029/2007JD009484, 2008.

Marticorena B. and G. Bergametti, Modeling the atmospheric dust cycle: 1-Design of a soil derived dust production scheme, J. Geophys. Res., 100, 16415-16430, 1995.

Marticorena B., G. Bergametti, B. Aumont, Y. Callot, C. N'Doumé and M. Legrand, Modeling the atmospheric dust cycle: 2-Simulations of Saharan dust sources, J. Geophys. Res., 102, 4387-4404, 1997.

Marticorena B. and G. Bergametti Parameterization of the increase of the aeolian erosion threshold wind friction due to soil moisture for semi-arid areas, Annales Geophysicae, 17, 149-157, 1999.

Mei, F., X. Zhang, H. Lu, Z. Shen and Y. Wang, Characterization of MASDs of surface soils in north China and its influence on estimating dust emission, Chinese Science Bulletin, 49, 20 2169-2176, 2004.