成都冬季“干”气溶胶等效复折射率变化特征研究

基于成都市2017年12月逐时的"干"气溶胶散射系数和吸收系数观测数据,结合该时段同时次GRIMM180环境颗粒物分析仪的监测资料,利用免疫进化算法一体化反演550nm波长处"干"气溶胶等效复折射率的实部和虚部,并对其冬季变化特征进行了研究,结果表明："干"气溶胶等效复折射率实部和虚部分别为（1.547±0.0552）和（0.0197±0.00604）."干"气溶胶等效复折射率实部和虚部的日变化形态基本一致,主要表现为"单谷型"特征,二者的谷值出现时段位于15：00~18：00.在日时间尺度上而言,"干"气溶胶等效复折射率实部与质量浓度统计上对其散射消光的演化存在协同作用,"干"气溶胶虚部与质量浓度对其吸收消光的演化也存在类似影响."干"气溶胶等效复折射率虚部是单位质量浓度"干"气溶胶吸收消光能力的重要表征.

Characteristics of “dry” aerosol equivalent complex refraction index in winter in Chengdu

By utilizing the hourly observational data of "dry" aerosol scattering coefficient and "dry" aerosol absorption coefficient, as well as the coincidental data obtained from GRIMM180 in Chengdu during December 2017, "dry" aerosol equivalent complex refractive index at 550nm, including both real part and imaginary part as a whole, were integrally retrieved by immune evolutionary algorithm, and then their characteristics in winter were analyzsed. The results showed that:Real part and imaginary part of "dry" aerosol equivalent refractive indices were (1.547±0.0552) and (0.0197±0.00604) respectively. The diurnal variations of real part and imaginary part of "dry" aerosol equivalent complex refractive index generally depicted a consistent pattern, with the feature of "single valley", and the valley occurred between 15:00 and 18:00. To the diurnal time scale, real part of "dry" aerosol equivalent refractive index and mass concentration statistically produced cooperative effect on the evolution of "dry" aerosol scattering extinction, and there existed similar influence of imaginary part of "dry" aerosol equivalent refractive index and mass concentration on the evolution of "dry" aerosol absorption extinction. Imaginary part of "dry" aerosol equivalent refractive index could well symbolize the "dry" aerosol absorption extinction capacity per mass concentration.