针对气溶胶折射率在分析大气气溶胶光学特性中的重要性,提出了一种综合利用黑碳仪、浊度计和光学粒子计数器反演大气气溶胶折射率的新方法。该方法根据黑碳仪和浊度计测量的气溶胶吸收系数和散射系数以及光学粒子计数器测量的粒子谱分布,采用球形粒子的米(Mie)散射理论,通过分析吸收系数、散射系数、粒子谱分布和折射率之间的关系来反演大气气溶胶粒子的折射率,并可以同时反演折射率实部和虚部。与其它独立的测量结果对比表明,该方法反演气溶胶折射率是合理的。最后,利用此方法分析了厦门地区的气溶胶折射率。
A new method was proposed for measurement of refractive index of aerosol by using an Aethalometre, an Integrating Nephelometer and an Optical Particle Counter (OPC), because the refractive index is important for studying aerosol. The absorption coefficient and scattering coefficient were measured with the Aethalometre and Integrating Nephelometer, and at the same time, the number density distributions of aerosol particles were measured by the OPC with nominated radii. According to Mie scattering theory, the different distributions could be obtained with different refractive indexes for the same one measured by OPC. Then, the curves of absorption coefficient and scattering coefficient could be calculated with different refractive indexes. Actual value of refractive index could be decided with the real absorption coefficient and scattering coefficient provided by the Aethalometre and Integrating Nephelometer. The comparisons with other instruments show that this method is reasonable. Finally, the refractive characteristics of aerosol particles in Xiamen city area were analyzed.