Advances in photochemical enhancement of photochemical aging of black carbon aerosol in Anguang Institute

[ China Instrument Network Instrument Development ] Recently, the research group of An Guangshang Zhang Weijun has made new progress in the study of light absorption enhancement of atmospheric black carbon aerosol photochemical aging. The related research results are based on The influence of photochemical aging on light absorption of atmospheric black carbon. And aerosol single-scattering albedo was published in Atmospheric Chemistry and Physics (Zone) published by the European Geoscience Association (EGU).

The correlation between Eabs and w at different Ox concentrations, and the shell thickness (Dshell) obtained by algorithm inversion and the complex refractive index imaginary part of the shell (kshell)

Black carbon (BC) in the atmosphere is mainly derived from incomplete combustion of fossil fuels and biomass. BC is the largest light absorber in atmospheric aerosols and has an important impact on the radiation balance of the climate system. BCs discharged into the atmosphere undergo complex aging processes such as collisions with other aerosol particles, condensation of steam on the surface, and atmospheric chemical oxidation. After wrapping, the light absorption is enhanced by the lens effect (the enhancement factor is Eabs, the ratio of light absorption after wrapping to BC after wrapping). The complex atmospheric aging process and variable emission sources make the mechanism of BC light absorption enhancement still controversial.

The research group Zhao Weixiong, Xu Xuezhe, assistant researcher and others used the self-developed broadband cavity enhanced albedo spectrometer combined with thermal diffusion tube to measure the optical properties (Eabs and single scattering albedo (w)) of PM2.5 in Shouxian area. The effect of photochemical aging on Eabs and w was analyzed using Ox (the sum of ozone and nitrogen dioxide) as an indicator of atmospheric photochemical aging. The study found that: (1) The light absorption enhancement of BC depends on the thickness of the shell layer and the light absorption capacity of the shell layer. (2) Under high oxidation conditions, the light absorption of the shell layer is enhanced. This study deepens the understanding of the effects of atmospheric aging on the enhancement of BC light absorption.

The research work was funded by the National Natural Science Foundation of China (No. 41330424), the Anhui Outstanding Youth Science Foundation (No. 1508085J03), the Chinese Academy of Sciences Youth Innovation Promotion Association (2016383) and the Public Welfare Industry (Meteorological) Research Project (No. GYHY201406039). .

(Original title: New progress in the study of light absorption enhancement of atmospheric black carbon aerosol photochemical aging at Anguang)