Impact of Meteorological Conditions on PM2.5 Pollution in China during Winter

Fine particulate matter (PM2.5) poses a risk to human health. In January 2017, the PM2.5 pollution in China was severe, and the average PM2.5 concentration had increased by 14.7% compared to that in January 2016. Meteorological conditions greatly influence PM2.5 pollution. The relationship between PM2.5 and meteorological factors was assessed using monitoring data and the Community Multiscale Air Quality modeling system (CMAQ) was used to quantitatively evaluate the impacts of variations of meteorological conditions on PM2.5 pollution. The results indicate that variations of meteorological conditions between January 2017 and January 2016 caused an increase of 13.6% in the national mean concentration of PM2.5. Unlike the Yangtze River Delta (YRD), where meteorological conditions were favorable, unfavorable meteorological conditions (such as low wind speed, high humidity, low boundary layer height and low rainfall) contributed to PM2.5 concentration worsening by 29.7%, 42.6% and 7.9% in the Beijing-Tianjin-Hebei (JJJ) region, the Pearl River Delta (PRD) region and the Chengdu-Chongqing (CYB) region, respectively. Given the significant influence of local meteorology on PM2.5 concentration, more emphasis should be placed on employing meteorological means to improve local air quality.