Soil/mineral dust particles are highly abundant by mass in the atmosphere, and they play an important role in many atmospheric processes. They change the radiation uxes, are involved in cloud…

Soil/mineral dust particles are highly abundant by mass in the atmosphere, and they play an important role in many atmospheric processes. They change the radiation uxes, are involved in cloud formation, act as carrier of nutrients a ecting biogeochemical cycles. Dust is also an important factor in tropospheric chemistry, since mineral surfaces react with trace gases and adsorb water vapor. The interaction of dust in these processes depends on fundamental dust properties such a the mineralogical composition, morphology of the particle surfaces, and particle size. While most global models only consider one globally uniform dust type, an improved version of the dust module has recently been developed in national aeronautics and space administration (NASA) goddard institute for space studies (giss) earth system model \modele", which distinguishes individual mineral species. Here IT is proposed to improve the representation of the mineral speci c dust aerosols and their physical/chemical interactions with other aerosols in the model as well as to constrain this representation with observations. Following objectives will be speci cally pursuit: 1. Couple dust minerals to the heterogeneous chemistry code, the thermodynamic equilibrium module, and the photolysis code. 2. Calibrate both the default global uniform dust and the mineral speci c dust for the new versions of the model (MODELE2.2 and MODELE3), using a previously developed optimization approach. 3. Evaluate the calibrated model against ground based and satellite retrieved AOD data. 4. Documentation of dust aerosols in the model. Signi cance: the prognostic treatment of DI erent dust minerals in NASA giss modele places the model in a nearly unique position to be used for studying the role of DI erent dust minerals in climate change and variability. Building on this achievement, the proposed project will provide an important contribution to the continuing development of NASA giss modele, which then can be utilized to further our understanding about the involvement in physical processes in the atmosphere of atmospheric soil dust as one of the major aerosols relevant for climate change and variability.