基于化学组分参数化的大气气溶胶吸湿性特征

为了探讨大气气溶胶的吸湿性特征,基于观测气溶胶化学组分,计算了吸湿性参数κ.首先,通过PCA分析法,得到了对吸湿性参数κ贡献率较大的化学因子;其次,基于K?hler公式与ZSR混合理论,对各化学组分加权得到各时刻对应的吸湿性参数κchemical;最后,基于κ-K?hler理论,讨论κchemical与其相关性,并通过...

Characteristics of hygroscopicity of atmospheric aerosols based on chemical component parameterization

In order to discuss the hygroscopic characteristics of atmospheric aerosols, the hygroscopic parameters κ were calculated based on the chemical composition of aerosols. The hygroscopic parameters were calculated firstly through PCA analysis, the main influencing chemical factors of hygroscopicity parameters κ were obtained; Secondly, based on the Köhler formula and the ZSR mixing theory, the hygroscopic parameters of each chemical component were weighted to get the corresponding hygroscopic parameters κ_chemical at each time. Finally, based on the κ-Köhler theory, differences between calculated value of hygroscopic characteristics and the theoretical values were discussed by inverting the characteristic parameters of hygroscopicity (optical and particle size hygroscopicity growth factor f(RH), gf). The iterative algorithm and the empirical formula obtained from previous studies were used to calculate the hygroscopic parameters, which was set to verify the accuracy of the chemical method. In addition, the relation between κ_chemical and visibility was also discussed. The results showed that the correlation coefficient between κ_chemical and κ_köhler was 0.78 and the root mean square error of the two was 0.031, which was at a low level. The ratio of the two was basically distributed in the range of 10% of the linear fitting error from the center. The correlation coefficient between the inversion of f(RH) and the instrument measurement f(RH)_measured was as high as 0.99, which further proved a strong linear relationship between them. The gf had a high coincidence degree and correlation with the theoretical value gf_NEP. When the visibility was less than 5km, the κ_NH4NO3 contribution to κ_chemicalwas 74.63%.