Aerosol surface tension in three Chinese megacities
Description
Surfactants in atmospheric aerosols can reduce the surface tension at the aerosol‒air interface, thereby increasing the activity of cloud condensation nuclei (CCN), and affecting the climate. However, observations of aerosol surface tension in urban atmospheres are limited, and comparative studies at different locations are lacking. Here we share our calculation of surface tension values at the point of activation in three urban/suburban sites located in three Chinese megacities, i.e., Beijing (BJ: 39.97°N, 116.37°E) on the Northern China Plain, Nanjing (NJ: 32.13°N, 118.46°E) in the Yangtze River Delta, and Guangzhou (GZ: 23.00°N, 113.21°E) in the Pearl River Delta.The BJ site is located at the tower branch of the Institute of Atmospheric Physics, Chinese Academy of Sciences (49 m above sea level, asl). This site occurs in downtown Beijing and is surrounded by traffic, gasoline stations, restaurants, businesses, and residences, with an inner city river flowing by, and is influenced mainly by traffic and cooking emissions (Zhang et al., 2017). The Nanjing site is situated on the campus of Nanjing University of Information Science and Technology (40 m asl). The site is influenced by multiple local and regional pollution sources, including residential, industrial, agricultural, traffic, biogenic, and biomass burning emission sources (Song et al., 2023). The GZ site is located at the China Meteorological Administration Atmospheric Watch Network (CAWNET) Panyu station atop Dazhengang Hill (150 m asl). The site is affected by urban pollution from downtown Guangzhou (Cai et al., 2017). The samples collected at these three sites can represent the urban and suburban aerosol properties in the most populated region of eastern China. Also included are the aerosol hygroscopicity measured by hygroscopicity tandem differential mobility analyzer (HTDMA), activation diameters derived from CCN/CN spectrum, wet diameters of the droplets, and organic mass concentration/fraction in the droplets at the point of activation. The method of deriving the surface tension can be found in Fan et al. (2024). Zhang, F., et al., 2017. Uncertainty in Predicting CCN Activity of Aged and Primary Aerosols. J. Geophys. Res. 122. https://doi.org/10.1002/2017JD027058. Song, X. et al., 2023. The Impacts of Dust Storms With Different Transport Pathways on Aerosol Chemical Compositions and Optical Hygroscopicity of Fine Particles in the Yangtze River Delta. J. Geophys. Res. 128, e2023JD039679. https://doi.org/10.1029/2023JD039679. Cai, M. et al., 2017. Comparison of Aerosol Hygroscopcity, Volatility, and Chemical Composition between a Suburban Site in the Pearl River Delta Region and a Marine Site in Okinawa. Aerosol Air Qual. Res. 17, 3194–3208. https://doi.org/10.4209/aaqr.2017.01.0020.
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Steps to reproduce
For reproduction of the data, please refer to Fan, T., Ren, J., Liu, C., Li, Z., Liu, J., Sun, Y., Wang, Y., Jin, X., Zhang, F., 2024. Evidence of Surface-Tension Lowering of Atmospheric Aerosols by Organics from Field Observations in an Urban Atmosphere: Relation to Particle Size and Chemical Composition. Environ. Sci. Technol. 58, 11363–11375. https://doi.org/10.1021/acs.est.4c03141.