Spatial oscillation of the particle pollution in eastern China during winter: Implications for regional air quality and climate

We provided a large-scale observational insight into spatial variations of the particle pollution in eastern China during winter based on recently extended air quality monitoring networks. Severe particle pollution with PM2.5 >150 μg/m3 prevailed in most areas of eastern China during December 2015, when red alert of haze pollution was released in many places. It was found that two distinct pollution processes existed in eastern China during winter. In the fringe areas such as Beijing and Shanghai in eastern China, most of air pollution events were characterized by abrupt peak values and short duration. By comparison, particle pollution in the interior exhibited obvious accumulation and decline processes with much higher PM2.5 concentration. Regional observations in ground networks show notable spatial oscillation of particle pollutants in eastern China, which is the main driver of the abrupt particle pollution in fringe areas. Despite common alternation of northerly and southerly airflows within planetary boundary layer (PBL), particle pollution in central part of eastern China was under the influence of regional accumulated pollutants due to lack of persistent strong winds. In addition, spatial oscillation of particle pollutants weakened with low PBL (<400-600 m). Our results demonstrate that spatial variations of particle pollutants in the central part of northern China play a significant role in regulating air quality in eastern China.