Model study of the impact of heterogeneous reactions on mineral aerosol surfaces on tropospheric chemistry over East Asia
【摘要】：Nine heterogeneous reactions (including uptake of H2O2, HNO3, HO2, N2O5, NO2, NO3, O3, OH and SO2 on mineral aerosol surfaces) are incorporated in a Regional Air Quality Model System (RAQMS) to investigate the impacts of mineral aerosols on tropospheric chemistry in East Asia during the dust storm period in March 2006. The model system shows a good ability in representing the behaviors of gaseous and aerosol species by comparison with observations. Most of the reaction probability γ values used for this study are the best estimation specifically for dust samples from deserts of China, derived from analysis of a number of recent laboratory studies. There are large variations in gas and aerosol concentrations while taking heterogeneous reactions on mineral aerosol surface into account, especially during dust storm events. The domain-averaged monthly mean percentage changes in SO2, NO2, O3, HNO3, NH3, total sulfate, total nitrate and total ammonium concentrations are -6.8%, -5.8%, -2.9%, -29.8%, 24.3%, 9.2%, 22.7%, -19.0%, respectively below 3 km. These changes indicate the considerable perturbation of heterogeneous reactions on mineral aerosol surface to tropospheric chemical system and components. The strength of heterogeneous reactions is determined by both reaction probability and gas precursor concentration. Among the nine reactions, the reactions involving HNO3, SO2, and N2O5 exert relatively large influences on the other chemical components, whereas the reactions regarding H2O2, HO2, and OH have little impacts.