Impacts of emission reduction and meteorological conditions on air quality improvement during the 2014 Youth Olympic Games in Nanjing, China

摘要

As the holding city of the 2nd Youth Olympic Games (YOG), Nanjing is highlyindustrialized and urbanized, and faces several air pollution issues. Inorder to ensure better air quality during the event, the local governmenttook great efforts to control the emissions from pollutant sources. However,air quality can still be affected by synoptic weather, not only emission. Inthis paper, the influences of meteorological factors and emission reductionswere investigated using observational data and numerical simulations withWRF–CMAQ (Weather Research and Forecasting – Community Multiscale Air Quality). During the month in which theYOG were held (August 2014), the observed hourly mean concentrations ofSO, NO, PM, PM, CO and O were11.6 µg m, 34.0 µg m,57.8 µg m, 39.4 µg m, 0.9 mg mand 38.8 µg m, respectively, which were below ChinaNational Ambient Air Quality Standard (level 2). However, model simulationshowed that the weather conditions, such as weaker winds during the YOG, wereadverse for better air quality and could increase SO, NO,PM, PM and CO by 17.5, 16.9, 18.5, 18.8, 7.8 and 0.8 %.Taking account of local emission abatement only, the simulated SO,NO, PM, PM and CO decreased by 24.6, 12.1, 15.1, 8.1 and7.2 %. Consequently, stringent emission control measures can reduce theconcentrations of air pollutants in the short term, and emission reduction isvery important for air quality improvement during the YOG. A good example hasbeen set for air quality protection forimportant social events.