[Spatiotemporal Variation Characteristics of Ozone and Identification of Key Influencing Factors Based on Random Forest Model： A Case Study of Chuzhou City].

The cause of ozone pollution is a complex scientific problem. Studying the spatiotemporal variation characteristics of O at different time scales and analyzing the key influencing factors of O concentration is of great significance for the precise formulation of urban air pollution control measures and the improvement of urban air quality. Based on the analysis of the spatiotemporal variation characteristics of O concentration in Chuzhou City, we studied the 12 ozone-influencing factors of meteorology and pollutants at multiple time scales using Spearman correlation analysis and a random forest model. The results showed that： ① The O pollution level of Chuzhou City showed an aggravating trend, and the O concentration distribution showed a spatial pattern of "high in the southeast and low in the northwest." ② From February to May, SO concentration had a strong impact on the increase in O concentration. From June to September, PM and PM were significantly positively correlated with ozone and had a greater impact. ③ Relative humidity, temperature, and wind speed had a significant impact on O, whereas barometric pressure and hourly rainfall had a weak impact. ④ The O pollution mechanism in Chuzhou City changed from "pollutant-controlled" to "meteorology-controlled." ⑤ Among meteorological and pollutant factors, the three influencing factors that had the greatest influence on O concentration were temperature, wind speed, and relative humidity, with PM concentration, PM concentration, and SO concentration also contributing. All of the above six influencing factors had a significant nonlinear relationship with the O concentration.