东亚地区沙尘气溶胶影响硫酸盐形成的模式评估

A Modeling Evaluation of the Impact of Mineral Aerosolson the Particulate Sulfate Formation in East Asia

利用ＳＴＥＭ－Ｉ三维区域大气化学模式，耦合沙尘气溶胶表面相过程，研究了１９９４年３月１日至１４日间东亚地区沙尘气溶胶对硫酸盐形成的影响。结果表明，ＳＯ２气体在沙尘气溶胶表面上进行的非均相氧化过程是硫酸盐形成的一条重要途径，由这条途径提供的硫酸盐占其总浓度的２０％～５０％。并发现在模拟时段，沙尘暴过程主要影响沙尘源地下游的中国东部地区硫酸盐的分布，使得那里的硫酸盐浓度增加６０％以上。

The impact of mineral aerosols on the particulate sulfate formation in East Asia during the period of March 1 through March 14, 1994 is studied using a threedimensional regionalscale atmospheric chemistry model (STEMII model) coupled with the mineral dust processes. The results indicate that the heterogeneousphase chemical processes on mineral aerosols account for a significant fraction of the conversion of SO2 to sulfate during this time period, which may contribute from 20% through 50% of the total sulfate production. Comparing with the case of nondust reactions, the reactions on the background aerosol cause an increase in sulfate formation by more than 40% throughout the study domain. These dust events during the simulation period mainly affect the sulfate amounts over the eastern China, closely downwind of dust source regions, where an increase of over 60% in sulfate is caused by mineral dust. 