A parameterization of low visibilities for hazy days in the North China Plain

作者：Chen, J.; Zhao, C. S.^*; Ma, N.; Liu, P. F.; Goebel, T.; Hallbauer, E.; Deng, Z. Z.; Ran, L.; Xu, W. Y.; Liang, Z.; Liu, H. J.; Yan, P.; Zhou, X. J.; Wiedensohler, A.

来源：Atmospheric Chemistry and Physics, 2012, 12(11): 4935-4950.

DOI：10.5194/acp-12-4935-2012

• AEROSOL OPTICAL-PROPERTIES
• NUMBER SIZE DISTRIBUTIONS
• PEARL RIVER-DELTA
• RELATIVE-HUMIDITY
• HYGROSCOPIC PROPERTIES
• ATMOSPHERIC AEROSOL
• SCATTERING COEFFICIENT
• CHEMICAL-COMPOSITION
• GROWTH MEASUREMENTS
• LIGHT-SCATTERING

Visibility degradation is a pervasive and urgent environmental problem in China. The occurrence of low visibility events is frequent in the North China Plain, where the aerosol loading is quite high and aerosols are strongly hygroscopic. A parameterization of light extinction (K-ex) for low visibilities on hazy days is proposed in this paper, based on visibility, relative humidity (RH), aerosol hygroscopic growth factors and particle number size distributions measured during the Haze in China (HaChi) Project. Observational results show that a high aerosol volume concentration is responsible for low visibility at RH < 90%; while for RH > 90%, decrease of visibility is mainly influenced by the increase of RH. The parameterization of K-ex is developed on the basis of aerosol volume concentrations and RH, taking into accounts the sensitivity of visibility to the two factors and the availability of corresponding data. The extinction coefficients calculated with the parameterization schemes agree well with the directly measured values.

• 出版日期2012
• 单位中国科学院大气物理研究所; 北京大学; 中国气象科学研究院