[Spatiotemporal Distributions and Variations in Summertime Ozone Photochemical Production Regimes over Shanxi].

Satellite-based formaldehyde（HCHO）columns and tropospheric nitrogen dioxide columns were observed using the Ozone Monitoring Instrument（OMI），and groundbased observations of ozone（O）for May-August from 2013 to 2022 were connected to calculate the threshold values of the HCHO to NO ratio（FNR）in Shanxi Province. Then，the spatiotemporal distributions and variations in summertime ozone photochemical production regimes were analyzed. The results showed that：① The volatile organic compound（VOC） -sensitive regime area（FNR < 2.

[Influence of Pollutant Transport from Both Sides of the Taihang Mountains on Cross-Valley Urban Aerosols].

Based on hourly concentration data of PM and PM from 2017 to 2019 and wind speed and direction data at the corresponding times in Yangquan, an urban valley of the Taihang Mountains, the characteristics of air transport in a cross-valley urban area and their influence on aerosols in Yangquan were analyzed using the HYSPLIT model, cluster analysis, and the potential source contribution factor and concentration weight trajectory methods. The pollutant transport characteristics on the east and west sides of the Taihang Mountains were evaluated. The diurnal variation of the aerosols showed a single peak and single valley, with continuous improvements in aerosol concentration from evening to the morning of the next day.