离散偶极子方法研究雾霾随机簇团粒子的光散射特性

分析硫酸、硫酸、硝酸盐、碳和有机碳等组成的雾霾污染物簇团，基于团簇 -团簇凝聚模型(CCA)，对簇团粒子的随机三维结构进行了模拟，构建不同成分，不同形状簇团粒子，在此基础上运用离散偶极子近似法计算了雾霾簇团粒子的光散射性质，进而仿真计算了不同形状的雾霾簇团粒子的光学散射，分析了雾霾簇团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。

Calculation of light scattering of aerosol particle cluster by the discrete-dipole approximation method

Ammonia sulfate, sulfuric acid, nitrate, carbon and organic carbon aerosol particle cluster are analyzed. Based on the model of cluster-cluster aggregation(CCA), the three-dimensional fractal structure of the aerosol particle clusters with different compounds and shapes is 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，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.