[Hygroscopic Properties and Closure of Aerosol Chemical Composition in Mt. Huang in Summer].

The hygroscopic properties of aerosol have significant impact on aerosol optical properties, cloud condensation nuclei activity and human health. Aerosol particles growth factor and size-resolved ions chemical compositions were monitored in Mt. Huang. The hygroscopic properties of aerosol particles in Mt. Huang were studied. The results demonstrated that between 70 nm and 230 nm, the mass fractions of (NH4)2SO4, organic matter and other insoluble materials were the highest. The fraction of NH4NO3 standed in the medium. The fraction of NH4HSO4 was the lowest. The fraction of inorganic salts increased with increasing particle diameter. Aerosol particles during daytime had stronger hygroscopicity than that at night and the hygroscopicity of aerosol became stronger when its diameter increased. The calculation hygroscopic parameter κ of aerosol particles showed similar diurnal variation characteristics to the observation κ. Good closure could be achieved when ZSR mixing rule was used based on aerosol chemical composition to calculate aerosol hygroscopic parameter κ and the coefficient of determination was 0.60 for all the diameters.