利用κ-Köhler理论研究大气气溶胶的吸湿特性

利用κ-K?hler理论对西安、北京两地大气气溶胶体系的吸湿特性进行研究。选取多种代表性无机物（硫酸盐、硝酸盐、氯盐）及有机物（烯烃、芳香烃、羧酸）建立气溶胶体系模型，使研究体系更接近于真实大气成分。结果表明，在空气质量由清洁状态向雾霾发生状态转变的过程中，两种体系中均呈现有机物含量逐渐减少而(NH₄)₂SO₄和NH₄NO₃含量逐渐增多的趋势，这种变化趋势总是促使气溶胶体系整体吸湿能力增强，因此更易吸湿增长形成雾霾。对体系中不同组分对吸湿性的影响进行了定量预测，理论预测的变动趋势与实际观测的变动趋势相同，揭示了雾霾形成过程中各组分的变动趋势及影响程度，为针对性解决雾霾问题提供思路。

Study on hygroscopic properties of atmospheric aerosols using κ-Köhler theory

The κ-K?hler theory was used to study the hygroscopic properties of atmospheric aerosol systems in Xi an and Beijing. The aerosol model was established by choosing several typical inorganic (sulfate, nitrate, chloride) and organic components (cycloene, aromatic hydrocarbon, carboxylic acid) to mimic to the real complex atmospheric composition. The results show that, when air quality changes from clean state to polluted state, the content of organic components gradually decreases whereas the concentration of (NH₄)₂SO₄ and NH₄NO₃ gradually increases in both systems. This trend always promotes the overall hygroscopicity of the aerosol systems, which in turn enhances the adsorption of moisture and thus the formation of haze. The influence of different components on the hygroscopicity of the whole system was also quantitatively predicted. The trend of variation was revealed by the theory and the theoretical prediction was in a good agreement with that observed in practice.