[Analysis of Characteristics and Sensitivity of Photochemical Pollution During High Ozone Season in Shanghai from 2016 to 2020].

The sensitivity analysis of ozone generation in key ozone-polluted regions and cities is an important basis for the prevention and control of near-surface ozone （O₃） pollution. Based on the five-year data of ozone, VOCs, and NO_x from three typical stations in Shanghai, namely Dianshan Lake Station （suburban area）, Pudong Station （urban area）, and Xinlian Station （industrial area） from 2016 to 2020, the nonlinear relationship between ozone and precursors （VOCs and NO_x） during the high-ozone season in the five years was quantitatively analyzed using an observation model. The results showed that the peak months of near-surface ozone in Shanghai were from April to September during 2016 to 2020, with the highest values appearing from June to August. The volume fraction of VOCs and NO₂ concentration had a strong indicative significance for the O₃ concentration at Pudong Station. The O₃ concentration at Dianshan Lake Station was mainly influenced by regional environment, meteorological factors, and cross-regional transmission. The ozone concentration at Xinlian Station was a combination of environmental background concentration and industrial area photochemical pollution. Pudong Station and Dianshan Lake Station were in the VOCs control zone. Xinlian Station was gradually closer to the NO_x control zone from 2016 to 2019, transitioning to the VOCs control zone since 2020. The L_·OH of Pudong Station, Dianshan Lake Station, and Xinlian Station were： NO_x control area>collaborative control area>VOCs control area.