Volume 16, No. 9, September 2016, Pages 2129-2144 PDF(7.27 MB)
Supplementary MaterialPDF (906 KB)
Process Contributions to Secondary Inorganic Aerosols during Typical Pollution Episodes over the Pearl River Delta Region, China
Zhijiong Huang1, Jiamin Ou1, Junyu Zheng1, Zibing Yuan1, Shasha Yin1, Duohong Chen2, Haobo Tan3
1 School of Environmental and Energy, South China University of Technology, University Town, Guangzhou 510006, China
2 Guangdong Environmental Monitoring Center, State Environmental Protection Key Laboratory of Regional Air Quality Monitoring, Guangzhou, China
3 Key Laboratory of Regional Numerical Weather Prediction, Institute of Tropical and Marine Meteorology, China Meteorological Administration, Guangzhou, China
- Key processes in SIA formation in the PRD were identified using process analysis.
- AERO and advection were two major processes in SIA formation in the PRD.
- PSO4 was dominated by advection, while PNO3 and PNH4 were dominated by AERO.
The Integrated Process Rate (IPR) analysis embedded in CAMx model was used to quantify contributions from different atmospheric processes to the formations and accumulations of ambient PM2.5 and the secondary inorganic aerosol (SIA) during two typical particulate pollution episodes in different seasons in the Pearl River Delta (PRD) region. Process analysis results indicated that primary fine particle emissions were the major sources of high ambient PM2.5 in urban areas with intensive anthropogenic activities. Aerosol process and advection transport were another two major processes contributing to the increasing PM2.5 and SIA over the PRD region. Regarding formation of SIA species, elevations of nitrate and ammonium at Guangzhou (urban), Heshan (rural) and Panyu (suburban) sites were largely associated with aerosol process, while those at Huizhou (urban) site were dominated by advection process, but elevated sulfate concentrations at these four sites were all dominated by advection process. The difference can be attributed to spatial variations of SO2, NOx and NH3 emissions, site locations and meteorological conditions. Advection, aerosol chemistry, deposition and vertical diffusion were important pathways to remove SIA at these four sites. Within the hours with most growing PM2.5 concentrations, aerosol process was the most important contributor to the formation of new SIA throughout the entire planetary boundary layer.
Secondary inorganic aerosol; PM2.5; PRD; CAMx; Process analysis.