Articles | Volume 16, issue 20
Atmos. Chem. Phys., 16, 13271–13289, 2016
https://doi.org/10.5194/acp-16-13271-2016
Atmos. Chem. Phys., 16, 13271–13289, 2016
https://doi.org/10.5194/acp-16-13271-2016

Research article 28 Oct 2016

Research article | 28 Oct 2016

Properties of aerosols and formation mechanisms over southern China during the monsoon season

Weihua Chen1, Xuemei Wang2, Jason Blake Cohen2, Shengzhen Zhou2, Zhisheng Zhang3, Ming Chang1, and Chuen-Yu Chan4 Weihua Chen et al.
  • 1School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China
  • 2School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou, China
  • 3South China Institute of Environmental Sciences, Guangzhou, China
  • 4Key Laboratory of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China

Abstract. Measurements of size-resolved aerosols from 0.25 to 18 µm were conducted at three sites (urban, suburban and background sites) and used in tandem with an atmospheric transport model to study the size distribution and formation of atmospheric aerosols in southern China during the monsoon season (May–June) in 2010. The mass distribution showed the majority of chemical components were found in the smaller size bins (< 2.5 µm). Sulfate was found to be strongly correlated with aerosol water and anticorrelated with atmospheric SO2, hinting at aqueous-phase reactions being the main formation pathway. Nitrate was the only major species that showed a bimodal distribution at the urban site and was dominated by the coarse mode in the other two sites, suggesting that an important component of nitrate formation is chloride depletion of sea salt transported from the South China Sea. In addition to these aqueous-phase reactions and interactions with sea salt aerosols, new particle formation, chemical aging, and long-range transport from upwind urban or biomass burning regions was also found to be important in at least some of the sites on some of the days. This work therefore summarizes the different mechanisms that significantly impact the aerosol chemical composition during the monsoon over southern China.

Download
Short summary
Measurements of size-resolved aerosols (0.25–18 μm) were conducted at three sites (urban, suburban and background sites) in southern China during monsoon season (May–June) in 2010 aqueous-phase reaction was the main formation pathway of droplet mode sulfate. New particle formation, chemical aging, and long-range transport from upwind urban or biomass burning regions were also found to be important in at least some of the sights on some of the sampling days.
Altmetrics
Final-revised paper
Preprint