How to assess the impacts of China's emission reduction efforts on the East Asia air quality

China and East Asian countries have recently suffered from the air quality problem, especially high concentration of fine particulate matters, due to high demand of fossil fuels for current rapid economic growth. As regards, China and Korea government has tried to make huge efforts both to reduce their primary emissions and to enhance the relevant international research collaboration. Since 2017, the Korea-China Joint Research team has been established at the CRAES (Chinese Research Academy of Environmental Sciences) in Beijing and the Joint Air Quality Study has been performed. One of the purposes of this joint research is to assess the effect of current emission reduction policies/efforts of China on air quality in East Asia by using the air quality monitoring and modeling approach. In this study, the weather and air chemistry modeling with high spatial (e.g. 9km x 9km) and temporal (e.g. hourly) resolution are conducted to quantify the sensitivity of the current emission reduction at the 28 sites in the BTH (Beijing-Tianjin-Hebei) region, and its results are shown.