THE CHARACTERISTICS AND POTENTIAL SOURCE AREA ANALYSIS OF PM_2.5 CONCENTRATION FOR ZHENGZHOU DURING 2016

Abstract. This study used the HYSPLIT-4 model combined with cluster analysis, potential source pollution contribution functions and other methods to analyse the ground air pollution monitoring data and meteorological data in Zhengzhou during 2016. The results showed that: 1) the level of PM_2.5 reached the low value in summer. The PM_2.5 concentration reached the highest level in December and reached the lowest level in August. The daily variation characteristics of PM_2.5 concentration in different seasons were roughly the same, and it had an obviously "double-peak" structure. 2) The annual PM_2.5 concentration was positively correlated with atmospheric pressure and relative humidity. The annual PM_2.5 concentration was negatively correlated with temperature, visibility, precipitation, and wind speed. 3) In winter, the air mass trajectory that through the northern Sichuan – Gansu – Shaanxi – Hubei was polluted seriously, and the level of PM_2.5 was the highest which reached to 202.13 μg/m³. In summer, the air mass trajectory that came from Hubei was the lowest level with the value is 40.17 μg/m³. 4) The potential source areas located in northwest of Zhengzhou, Gansu, Hubei and Beijing-Tianjin-Hebei region in spring. The surrounding of Zhengzhou contributed to the pollution of Zhengzhou. The potential source areas appeared in Shaanxi, Sichuan, and Qinghai, the border between Ningxia and Inner Mongolia in autumn. In winter the potential source areas located in Jiangsu, Hubei, Henan, eastern of Shanxi, southern of Shanxi, Ningxia and the area of Yellow Sea, etc.