Air quality and emissions in the Yangtze River Delta, China
- ISSN: 16807316
- DOI: 10.5194/acp-11-1621-2011
Regional trans-boundary air pollution has become an important issue in the field of air pollution modeling. This paper presents the results of the implementation of the MM5-CMAQ modeling system in the Yangtze River Delta (YRD) for the months of January and July of 2004. The meteorological parameters are obtained by using the MM5 model. A new regional emission inventory with spatial and temporal allocations based on local statistical data has been developed to provide input emissions data to the MM5-CMAQ modeling system. The pollutant concentrations obtained from the MM5-CMAQ modeling system have been compared with observational data from the national air pollution monitoring network. It is found that air quality in winter in the YRD is generally worse than in summer, due mainly to unfavorable meteorological dispersion conditions. In winter, the pollution transport from Northern China to the YRD reinforces the pollution caused by large local emissions. The monthly average concentration of SO sub(2) in the YRD is 0.026 plus or minus 0.011 mg m super(-3) in January and 0.017 plus or minus 0.009 mg m super(-3) in July. Monthly average concentrations of NO sub(2) in the YRD in January and July are 0.021 plus or minus 0.009 mg m super(-3), and 0.014 plus or minus 0.008 mg m super(-3), respectively. The monthly average concentration of PM sub(10) in the YRD is 0.080 plus or minus 0.028 mg m super(-3) in January and 0.025 plus or minus 0.015 mg m super(-3) in July. Visibility is also a problem, with average deciview values of 26.4 plus or minus 2.95 dcv in winter and 17.6 plus or minus 3.3 dcv in summer. The ozone concentration in the downtown area of a city like Zhoushan can be very high, with the highest simulated value reaching 0.24 mg m super(-3). In January, the monthly average concentration of O sub(3) in the YRD is 0.052 plus or minus 0.011 mg m super(-3), and 0.054 plus or minus 0.008 mg m super(-3) in July. Our results show that ozone and haze have become extremely important issues in the regional air quality. Thus, regional air pollution control is urgently needed to improve air quality in the YRD.