Observation and analysis of near-surface atmospheric aerosol optical properties in urban Beijing--颗粒学报PARTICUOLOGY

Jing, J., Wu, Y., Tao, J., Che, H., Xia, X., Zhang, X., Yan, P., Zhao, D., & Zhang, L. (2015). Observation and analysis of near-surface atmospheric aerosol optical properties in urban Beijing. Particuology, 18, 144–154. https://doi.org/10.1016/j.partic.2014.03.013

Observation and analysis of near-surface atmospheric aerosol optical properties in urban Beijing

Junshan Jing ^a, Yunfei Wu ^b *, Jun Tao ^c, Huizheng Che ^d, Xiangao Xia ^e, Xiaochun Zhang ^a, Peng Yan ^a, Deming Zhao ^b, Leiming Zhang ^{b f}

a Centre for Atmosphere Watch and Services, Meteorological Observation Centre of China Meteorological Administration, Beijing, China
b Key Laboratory of Regional Climate-Environment for East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
c South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou, China
d Key Laboratory of Atmospheric Chemistry, Centre for Atmosphere Watch and Services, Chinese Academy of Meteorological Sciences, Beijing, China
e Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
f Air Quality Research Division, Science and Technology Branch, Environment Canada, Toronto, Canada

10.1016/j.partic.2014.03.013

Volume 18, February 2015, Pages 144-154

Received 20 December 2013, Revised 27 February 2014, Accepted 5 March 2014, Available online 25 June 2014.

E-mail: Received 20 December 2013, Revised 27 February 2014, Accepted 5 March 2014, Available online 25 June 2014.

Highlights

• Aerosol optical properties from 2009 to 2010 at an urban site in Beijing were investigated.

• Aerosol scattering and absorption were high in autumn and winter while low in summer and spring.

• Regional pollutants from south and southeast and local emissions dominated the aerosol pollution.

• Daily PM_2.5 mass concentration should be controlled to lower than 64 μg/m³.

Abstract

Year-round measurements of the mass concentration and optical properties of fine aerosols (PM_2.5) from June 2009 to May 2010 at an urban site in Beijing were analyzed. The annual mean values of the PM_2.5 mass concentration, absorption coefficient (Ab), scattering coefficient (Sc) and single scattering albedo (SSA) at 525 nm were 67 ± 66 μg/m³, 64 ± 62 Mm⁻¹, 360 ± 405 Mm⁻¹ and 0.82 ± 0.09, respectively. The bulk mass absorption efficiency and scattering efficiency of the PM_2.5 at 525 nm were 0.78 m²/g and 5.55 m²/g, respectively. The Ab and Sc showed a similar diurnal variation with a maximum at night and a minimum in the afternoon, whereas SSA displayed an opposite diurnal pattern. Significant increases in the Ab and Sc were observed in pollution episodes caused by the accumulation of pollutants from both local and regional sources under unfavorable weather conditions. Aerosol loadings in dust events increased by several times in the spring, which had limited effects on the Ab and Sc due to the low absorption and scattering efficiency of dust particles. The frequency of haze days was the highest in autumn because of the high aerosol absorption and scattering under unfavorable weather conditions. The daily PM_2.5 concentration should be controlled to a level lower than 64 μg/m³ to prevent the occurrence of haze days according to its exponentially decreased relationship with visibility.

Graphical abstract

Keywords

PM_2.5; Aerosol optical properties; Haze; Visibility

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