A new global three-dimensional transport model of mineral dust aerosols is developed and evaluated. The dust model is embedded in a general circulation model with conservative dynamical core and unique consideration of the polar transportation, which make the model stable in simulations. Comprehensive parameterizations of the emission and deposition processes from Wang et al. [2000] are modified to match the surface conditions and meteorological fields of the climate model. A 20-year simulation from the dust model gives an estimation of dust mobilization of 1974 ± 30 Tg yr-1 and a global dust burden of about 25 Tg for the particles smaller than 10 μm. The vertical distribution, temporal variation on different time scales and surface concentration of the simulated mineral dust aerosols are compared with both observations and simulations from other models. The evaluation results show that the new dust model has the ability to reproduce the principal features of global dust transportation. The main deficiency of the model is the underestimation of the dust activity in East Asia during spring and the overestimation of the concentration in Central Pacific, which have also been reported by other model simulations. The global mean optical thickness of dust at 0.63 μm is 0.028 ± 0.004 in the model, which is comparable to the magnitude of sulphate aerosols. Such result indicates that both anthropogenic and natural sources need to be considered when evaluating the climate feedback of aerosols.
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