Abstract: The κ-K?hler theory and a simulation of the aerosol mass concentrations in China for the year 2006 were used to calculate the number concentration of cloud condensation nuclei (CCN) in China and evaluate the contribution of organic aerosol (OA). The number concentrations of CCN in China show a west-to-east gradient, due to the stronger anthropogenic emissions in eastern China. Assuming that all aerosol chemical components are externally mixed, the number concentrations of CCN are 0.9×10³-1.2×10³ cm^-3 seasonally, and OA contributes 30% to the annual mean. Assuming that OA components are internally mixed, while inorganic aerosols are externally mixed, the number concentrations of CCN are 0.9×10³-1.1×10³ cm^-3, and OA contributes 28% to the annual mean. Though the differernce of annual average contribution of OA to CCN number is small when OA is external and internal mixed, there is large different spatially in summer and winter due to more secondary OA in summer and more primary OA in winter. The results show that OA are important sources of CCN in China.

Key words: cloud condensation nuclei number concentration, organic aerosol, mixing state

摘要： 根据κ-K?hler理论, 利用2006年中国境内气溶胶浓度的数值模拟结果, 计算总体气溶胶活化为云凝结核的数浓度, 并评估有机气溶胶对云凝结核数量的贡献。中国境内云凝结核数浓度总体呈东部高西部低的分布, 这与东部受到更多人为源排放影响、气溶胶浓度高有关。假设气溶胶各类化学组分彼此外混合, 则各季节云凝结核数浓度为0.9×10³~1.2×10³ cm^-3, 有机气溶胶对云凝结核数量贡献全年平均为30%。假设气溶胶中有机组分彼此内混合并与其他组分外混合, 则各季节云凝结核数浓度为0.9×10³~1.1×10³cm^-3, 有机气溶胶对云凝结核数量的贡献全年平均28%。尽管有机气溶胶对云凝结核数量的年平均贡献相差不大, 但夏季和冬季的贡献有较大差异, 原因在于夏季有更多的二次有机气溶胶生成, 而冬季更多的是一次有机气溶胶排放。因此, 有机气溶胶是中国云凝结核的重要来源, 并且有机气溶胶的混合状态对云凝结核数量有很大的影响。

关键词: 云凝结核数浓度, 有机气溶胶, 混合状态