上海PM2.5重污染过程中主要无机盐的来源模拟研究

In recent years, more heavy PM2.5 pollution occurred in the east China, with the features of high pollution level, long sustained period and large polluted areas. Sulfate, nitrate and ammonium are major constituents of PM2.5, which result in low visibility and haze pollution. To control regional complex air pollution in China as well as identify the contributing factors of pollution, it is essential to clarify the emission source of the inorganic aerosols. However, the sensitivity method and the existing source-receptor numerical models cannot trace the sources of secondary pollutants comprehensively. Therefore, based on the framework of air quality model NAQPMS, a new on-line source-tagged model for secondary pollutants is developed (NAQPMS-OSM), which is utilized to investigate the source of secondary aerosol and its precursor in Shanghai. The source-tagged model (NAQPMS-OSM) is compared with other source-traced methods (sensitivity method and CAMx-PSAT model), to assess the uncertainty of the model. In addition, the source-tagged model (NAQPMS-OSM) is used to study the heavy aerosols pollution cases in Shanghai. The major sources (different regions, different timing and different type of emissions) of inorganic aerosols in Shanghai could be identified and quantified, which illustrates the characteristics and formation of PM2.5 pollution in mega city in China.

近年来，我国中东部地区PM2.5重污染事件日益增多，呈现污染程度重、持续时间长、污染面积大等特征。其中，硫酸盐、硝酸盐和铵盐是PM2.5中主要组成部分，能引起能见度恶化，形成霾污染。为推动重污染天气应急减排、区域联防联控，揭示污染成因，亟需阐明无机盐气溶胶的污染来源。然而，传统敏感性方法以及现有的源解析数值模式，无法全面追踪二次污染前体物的时间、空间和排放源类别来源。因此，本研究围绕二次气溶胶污染的源和受体关系，基于区域空气质量模式NAQPMS，发展在线源解析模式，并结合其他主流数值源解析方法，验证模式在不同气象条件下的模拟性能，评估不同方法解析结果的差异及不确定性。基于本项目研发的源解析模式，深入研究上海重污染过程中气溶胶的污染时空特征，分析城市间污染物相互输送的影响，量化地区、类别排放源和时间来源的贡献比率，重点阐明上海PM2.5主要无机盐的污染来源。

近年来，我国中东部地区PM2.5重污染事件日益增多，呈现污染程度重、持续时间长、污染面积大等特征。其中，硫酸盐、硝酸盐和铵盐是PM2.5中主要组成部分，能引起能见度恶化，形成霾污染。为推动重污染天气应急减排、区域联防联控，揭示污染成因，亟需阐明无机盐气溶胶的污染来源。因此，本研究围绕二次气溶胶污染的源和受体关系，基于区域空气质量模式NAQPMS，发展在线源解析模式，并结合其他主流数值源解析方法，验证模式在不同气象条件下的模拟性能，评估不同方法解析结果的差异及不确定性。基于本项目研发的源解析模式，深入研究上海重污染过程中气溶胶的污染时空特征，分析城市间污染物相互输送的影响，量化地区、类别排放源和时间来源的贡献比率，重点阐明上海PM2.5主要无机盐的污染来源。结果发现冬季上海无机盐气溶胶的本地贡献率约为30%，外地贡献较大的地区为江苏和山东地区。时间解析结果表明3天内的排放贡献率可达85%。