A Modeling Study of Impact of Emission Control Strategies on PM2.5 Reductions in Zhongshan, China, Using WRF-CMAQ.

A WRF-CMAQ modeling system is used to assess the impact of emission control strategies and weather conditions on haze pollution in Zhongshan, Guangdong Province, China. One-month simulations for January 2014 are completed and evaluated with the observational data. The simulations show reasonable agreement with the observations. Several sensitivity studies are completed to quantify the percentage contributions of local emissions versus regional emissions to the PM_2.5 concentrations under different weather conditions. The results indicate that the contributions from local emission is higher than those of the emissions from regional transport when there is no intrusion of cold front (i.e., 58% contribution from local emission versus 42% contribution from the regional transport). The contribution of regional transport is increased to 76% when a strong cold front appears. Furthermore, the sensitivity study demonstrates that PM_2.5 concentrations on the first, second, and third days are reduced by 47%, 52%, and 58%, respectively, after the local emissions are turned off when there is no intrusion of cold front. Finally, a case study shows that industrial, residential, and mobile emissions account for 24%, 22%, and 15% of the change of PM_2.5, respectively, during a heavy haze pollution event in Zhongshan. [ABSTRACT FROM AUTHOR]