GAO Yue1, SUN Rongguo1,2, CHEN Zhuo1*, ZANG Qingda1
1. School of Chemistry and Material, Guizhou Normal University, Guiyang 550025;
2. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China)
Abstract: Data of PM2.5 from 7 automatic air quality monitoring stations of Nanjing in 2017 were discussed to examine the temporal and spatial characteristic of PM2.5 and it’s sources. The analyzed methods include Kriging spatial interpolation method, Trajectory clustering of air flows, Potential Source Contribution Function (PSCF), and Concentration-Weighted Trajectory (CWT). The results indicated that the highest PM2.5 concentrations ( (PM2.5)) was observed in winter (65.54 μg/m3), followed by spring (41.70 μg/m3), autumn (35.18 μg/m3), and summer (23.56 μg/m3). All the highest (PM2.5) were peaked in Qinhuai district in four seasons. In spring, the atmospheric PM2.5 was easily affected by the coastal and northern continental transport airflow in Nanjing. The contribution of airflow trajectory 2 was up to 51.65% from the Yellow sea, and the (PM2.5) was 50.91μg/m3. In summer, the atmospheric PM2.5 was mainly affected by the transport airflow in Jiangsu province, the Eastern seas and southern coastal cities, in which the contribution of airflow trajectory 1 originated from Jiangsu province was the largest contributor to atmospheric PM2.5 (33.64%) in Nanjing, and the corresponding airflow trajectory (PM2.5) was 35 μg/m3. In autumn, the atmospheric PM2.5 was susceptible to short-distance northerly airflow, and the airflow trajectory 5 corresponding to the south of Shanxi, central in Henan and central in Anhui, which was the highest (PM2.5), with a higher occurrence probability (21.11%) and contribution proportion (27.81%). The atmospheric PM2.5 was mainly affected by the northern continental transport airflow in winter, which was the highest (PM2.5) corresponding to the long-distance airflow trajectory 4 that from Russia, eastern in Mongolia, northern in Hebei, Beijing, Tianjin and central in Shandong province, up to 109.8 μg/m3, with the contribution rate of 26.86%. PSCF and CWT analysis showed that Anhui, Shandong, the Zhejiang province borders Jiangsu province and the Yellow sea coast were the main potential source regions, their affected the air quality in Nanjing, the Hubei province, Beijing, Tianjin and the coasts of the Yellow seas and the Bohai seas also made contributions to the air pollution in Nanjing.
Key words: PM2.5; Spatial-temporal; Trajectory clustering; PSCF; CWT
EARTH AND ENVIRONMENT Vol.47, No.3, Tot No.329, 2019, Page 268-274
