Characteristics of Ozone Pollution and Influencing Factors in Urban and Suburban Areas in Zibo

Abstract

In this study, we obtained monitoring data of O3 and its precursors (NOx, VOCs, and CO), as well as meteorological data (temperature, relative humidity, wind speed, and visibility), in 2019 to analyze the characteristics of O3 pollution and the influencing factors in urban and suburban areas. The results showed that the O3 episodes accounted for 25.8% of the whole observation period, mostly occurring from May to September. The concentration of NOx in urban areas was higher than that in suburban areas, whereas the concentrations of O3 and VOCs were lower. The hourly rate of variation in each pollutant had obvious seasonal characteristics; for example, the time of O3 rise and precursor decline in autumn and winter was approximately 1 h later than that in summer, and the peak period of O3 generation and accumulation was shortened. The increase rate in O3 in urban areas was higher than that in suburban areas. Correlation analysis and partial correlation analysis were used to study the relationship between O3 and its influencing factors. The results showed that O3 was negatively correlated with precursors and relative humidity and positively correlated with visibility, temperature, and wind speed, and these factors interacted with each other. According to the multivariate linear regression analysis, the main controlling factors in urban areas were relative humidity, NOx, visibility, and VOCs, whereas in suburban areas they were relative humidity, temperature, NOx, and VOCs.