The "APEC Blue" Phenomenon: Impacts of Regional emission control Meteorology Condition and Regional Transport from a Modeling Perspective

On November 5-11, China hosted the 2014 Asia-Pacific Economic Cooperation (APEC) Economic Leaders' Week in Beijing. To ensure good air quality during the APEC week, a series of strict emission control measures were taken in Beijing and surrounding provinces, which provide us with a great opportunity to examine the effectiveness of regional emission control. As important as emissions, meteorology can also significantly affect air quality in Beijing, so it's meaningful to understand the impact of meteorology conditions in the APEC week. Besides, it's important to study the impact of regional transport as its contribution to Beijing pollution levels is controversial. In this study, we investigate the impacts of emission control, meteorology and regional transport on the air quality during APEC week using a fully online coupled meteorology-chemistry model WRF-Chem. Compared to surface observations, the model has very good performance. The conclusions from this study will provide useful insights for government to control aerosol pollution in Beijing.