离散偶极子法研究雾霾随机团簇粒子的光散射特性

Light Scattering Characteristics of Aerosol Particle Cluster by Discrete-Dipole Approximation Method

分析了硫酸铵、硫酸、硝酸盐、碳和有机碳等组成的雾霾污染物团簇。基于团簇-团簇凝聚(cluster-cluster aggrogation,CCA)模型,模拟构建不同成分,不同形状团簇粒子。在此基础上运用离散偶极子法计算了雾霾团簇粒子的光散射性质,进而仿真计算了不同形状的雾霾团簇粒子的光学散射,分析了雾霾团簇粒子散射场强度随散射角、效率因子与尺度因子变化关系,偏振度随散射角的变化结果。计算结果可用于分析大气雾霾特性和大气光传输特性。

Ammonia sulfate, sulfuric acid, nitrate, carbon and organic carbon aerosol particle cluster are analyzed. Based on the model of cluster-cluster aggregation（CCA）, the aerosol particle clusters with different compounds and shapes are simulated. Optical scattering of aerosol particle clusters is calculated by using discrete dipole approximation method （DDA）. For these particle clusters, the variation of the efficiency factor with size parameters, the variation of scattering field intensity with the scattering angle and the variation of polarization degree with the scattering angle are obtained and analyzed. The calculation can be used for the analysis of the characteristics of fog haze and the light propagation in atmosphere.