[Characteristics and Potential Sources of Four Ozone Pollution Processes in Hainan Province in Autumn of 2019].

Based on the air quality and meteorological monitoring data of Hainan province in autumn of 2019, this study analyzed the characteristics and potential sources for the four O polluted processes in Hainan province, using the methods of correlation analysis, HYSPLIT backward trajectory modeling, PSCF (potential source contribution function), and CWT (concentration weighted-trajectory). The results showed that ① the average concentrations of the maximum 8h average (O-8h) for process 1 and process 3, which occurred from September 21 to 30 and November 3 to 11 with the durations of 10 d and 9 d, were 145.52 μg·m and 143.55 μg·m, respectively. Process 2 and process 4 occurred from October 18 to 21 and November 20 to 25, with the durations of 4 d and 6 d, and the average concentrations of O-8h were 130.79 μg·m and 115.46 μg·m, respectively. ② High air pressure, low precipitation and relative humidity, long sunshine duration, and strong solar radiation favored the occurrence of O-polluted weather in Hainan province. Northerly wind was conducive to the increase in O-8h concentration, and wind speeds affected the regional distribution of high-value areas of O-8h concentration in Hainan province. ③ Furthermore, process 1 and process 3 with more serious pollution had a larger air flow divergence, and there were two airflows originating from the inland area and the southeast coastal area, respectively. Air flow of process 2 and process 4 was relatively more concentrated with less O pollution and was classified as southeast coastal air flow. 4 The analysis of potential contribution sources showed that transport from Zhejiang, Jiangxi, Fujian, and Guangdong provinces were the main sources of O pollution in Hainan province in autumn 2019. Among them, the weight potential source contribution function (WPSCF) and weight concentration weighted-trajectory (WCWT) values were larger than 0.36 and 90 μg·m in the PRD (Pearl River Delta) and western Guangdong province regions, respectively.