Characterizing temporal trends and meteorological influences on ozone pollution in Shenyang region (2018–2021)

Abstract

With the acceleration of industrialization and urbanization, air quality has become a global concern. Ozone (O₃), a significant secondary pollutant in the atmosphere, is increasingly recognized as a major environmental and public health threat. This study focused on Shenyang, a major city in Northeast China, analyzing the temporal variation characteristics of O₃ concentrations at five different functional sites from 2018 to 2021. The study also examined trends and periodicities in O₃ concentrations using the Mann-Kendall test, Theil-Sen slope estimation, and Morlet wavelet analysis. Additionally, stepwise multiple linear regression was employed to assess the correlation between O₃ levels and meteorological factors. The results indicated that, despite variations in annual O₃ levels across different sites, a general downward trend was observed from 2020 to 2021, suggesting a reduction in O₃ pollution. Furthermore, O₃ concentrations were found to peak during the summer, gradually increasing from January and reaching their highest levels in May, June, or July. The Mann-Kendall test results revealed that only O₃ levels at sites D and E exhibited a statistically significant downward trend. All five selected sites showed clear periodic fluctuations in O₃ concentrations. Furthermore, O₃ levels were significantly positively correlated with temperature and wind speed, and significantly negatively correlated with relative humidity.