Numerical Study of the impact of Meteorological and Emission control on the decreasing of PM2.5 concentration in Beijing by WRF-SMOKE-CMAQ model system

In the past years, the PM2.5 concentration in Beijing decreases from 89 ug/m³ in 2013 to 42 ug/m³ in 2019, especially in the recent three years, that the PM2.5 concentration rapidly decreases from 73 ug/m³ in 2016 decreases to 42 ug/m³. An air quality modeling system, based on WRF-SMOKE-CMAQ model, was established before APEC 2014 to forecast daily air quality and assess future air quality improvement plans, which plan expects Beijing’s PM2.5 would reach to 53 ug/m³ in 2020, and reach to 35 ug/m³ in 2030. Actually, the PM2.5 concentration in Beijing has fallen faster than expected, that the annual PM2.5 concentration is 42 ug/m³ in 2019. So how much influence do meteorological factors and emission control have on the annual PM2.5 concentration? The WRF-SMOKE-CMAQ modeling system has been used to re-build the PM2.5 concentration characteristics of Beijing from 2013 to 2019 to distinguish these two factors. Preliminary results show that under the same emission scenarios, the annual average concentration of PM2.5 in Beijing in 2013 was 68.6 ug/m³, and the average annual concentration of PM2.5 in 2017 was 69.4 ug/m³. More detailed model results will be presented.