The annual - inter - annual, seasonal and monthly concentration values of nitrogen dioxide in 346 major cities in China, the values of 15 influencing factors and SHAP values.

This study obtained tropospheric nitrogen dioxide (NO₂) concentration data based on Sentinel-5P and employed statistical analysis and local spatial autocorrelation analysis methods to explore the spatiotemporal distribution and variation characteristics of NO₂ concentrations in 346 major cities in China from 2019 to 2023. Using the Random Forest (RF) model and Shapley Additive Explanations (SHAP) values, the influence of 15 factors on ambient NO₂ concentrations was analyzed.<br><br>The results showed that the NO₂ concentrations in the 346 cities exhibited seasonal variations, with the highest concentrations in winter and the lowest in summer. From 2019 to 2023, NO₂ concentrations showed a fluctuating trend with significant regional differences: the concentrations were relatively higher in provincial capital cities as well as in northern and northeastern China. Temperature-related variables, aerosol optical depth, and leaf area index had significant impacts on NO₂ concentrations. The findings of this study identify key influencing factors and provide a scientific basis for revealing the causes of urban air pollution in China, formulating pollution control strategies, identifying priority areas for remediation, and supporting the development of protection policies.