Abstract. As the holding city of the 2nd Youth Olympic Games (YOG), Nanjing is highly industrialized and urbanized facing with several air pollution issues. In order to ensure better air quality during the event, the local government took great efforts to control the pollution emissions. However, air quality can still be affected by meteorology. In this paper, the influences of meteorological factors and emission reductions were investigated using observational data and numerical simulations with WRF/CMAQ. During the YOG (August, 2014), the concentration of SO2, NO2, PM10, PM2.5, CO and O3 was 11.6 μg/m3, 34.0 μg/m3, 57.8 μg/m3, 39.4 μg/m3, 0.9 μg/m3, and 38.8 μg/m3, respectively, which were under China National Ambient Air Quality Standard. However, simulation showed that the weather conditions such as weaker winds during the holding time were adverse for better air quality, and raised SO2, NO2, PM10, PM2.5 and CO by 17.5 %, 16.9 %, 19.0 %, 19.5 %, 7.8 % and 0.8 %, respectively. Taking account of local emission abatement only, SO2, NO2, PM10, PM2.5 and CO was decreased by 24.6 %, 12.1 %, 14.5 %, 6.9 % and 7.2 %, respectively. Consequently, stringent emission control measures can reduce the concentrations of air pollutants in short term, and emission reduction is the dominant factor of the air quality improvement during the YOG, which has set up a good example in air protection for important social events.
Impacts of emission reduction and meteorological conditions on air quality improvement during the 2014 Youth Olympic Games in Nanjing, China
