Simulation-based Design of Regional Emission Control Experiments with Simultaneous Pollution of O3 and PM2.5 in Jinan, China

High O-3 and PM2.5 concentrations were frequently observed in Jinan during June 2015 and simultaneously occurred on 8 days, with a maximum 8-hour-averaged 0 3 concentration of 255 mu g m(-3) and a maximum daily averaged PM2.5 concentration of 111 mu g m(-3). In order to investigate simultaneously controlling these two air pollutants, two simulation-based regional emission control experiments were designed using a nested air quality prediction model system (NAQPMS). One emission control scenario ("Conventional Control") implemented the strictest control measures in Jinan and surrounding areas and resulted in a 15.7% reduction of O-3 and a 21.3% reduction of PM2.5 on days polluted by O-3 and PM2.5, respectively. The other emission control scenario ("Source-tagging Control"), by contrast, used online source-tagging modeling results from NAQPMS to select emission reduction regions based on their source contributions to the O-3 and the PM2.5 in Jinan and resulted in a 16.2% reduction of O-3 and a 22.8% reduction of PM2.5 on days polluted by O-3 and PM2.5, respectively. Compared to Conventional Control, this scheme produced smaller reductions in emissions from areas with low contributions to the O-3 and PM2.5 concentrations in Jinan as well as in the total emissions of primary pollutants (the reduced emissions was only 61% of that needed by Conventional Control), and the area and the population affected by these reductions decreased by 12% and 31%, respectively. However, this study demonstrates that Source-tagging Control is more efficient than Conventional Control in reducing simultaneous pollution by O-3 and PM2.5 through regional measures.