Spatial and Temporal Distributions of Air Pollutants and Size Distribution of Aerosols over Central and Eastern China.

The origins and spatial and temporal distributions of air pollutants (PM, PM, CO, SO, NO and O) during May to June of 2015 were investigated using data from 1490 monitoring sites in China. Aerosol number concentrations and meteorological data from Shijiazhuang, Nanjing, and Suzhou were combined with the MIX Asian emission data and the HYSPLIT model. Furthermore, the diurnal variation, size distribution, and main sources of air pollutants and aerosols were selectively characterized in the North China Plain (NCP) and the Yangtze River Delta (YRD). High values of particulate matter concentrations (PM), including PM and PM, occurred in the northwestern and central regions of eastern China. Elevated PM and PM concentrations represented natural dust sources and anthropogenic resident, power plant, industry, and traffic emissions sources, respectively. The concentrated distributions of SO were similar to those of PM. The CO concentrations were distributed uniformly in China. High O values occurred above the Qinghai province. During the observation period, the air masses mainly originated from the northwest NCP and from the southwest or northeastern ocean in the YRD, resulting in high concentrations of PM, PM, SO, and CO in the NCP, the average values of which were 61.8 ± 40.0, 118.8 ± 66.4, 24.1 ± 24.6 μg m, and 1.2 ± 0.9 mg m, respectively, and were 1.2, 1.4, 1.5, and 1.3 times larger than those in the YRD. NO had higher concentrations in the YRD with an average of 43.7 ± 24.8 μg m, which was 1.2 times larger than that in the NCP. The diurnal variations of PM, NO and CO had bimodal distributions and SO and O had unimodal distributions in the NCP and YRD. The aerosol number concentrations had average values of 12,661 ± 5266, 11,189 ± 5905, and 12,797 ± 5931 cm in Shijiazhuang, Nanjing, and Suzhou. Their diurnal variations displayed trimodal peaks at 18:00-21:00, 11:00-14:00, and 06:00-08:00, and their spectra distributions were all unimodal with peaks at 60-70, 60-70, and 100-110 nm, respectively.