[Ozone Pollution Characteristics and Sensitivity During the Ozone Pollution Days in Summer 2021 of Xinxiang City].

This study was based on the observation of volatile organic compounds (VOCs), conventional gaseous air pollutants, and meteorological parameters observed at the Xinxiang Municipal Party School site from June to August 2021. The ozone (O) characteristics and sensitivity of O pollution days and the control strategy of its precursors were studied using an observation-based model (OBM). It was found that the meteorological conditions were characterized by high temperature, low humidity, and low pressure in O-pollution days. The concentrations of O and its precursors all increased in the O pollution days. Oxygenated volatile organic compounds (OVOCs) and alkanes were the highest-concentration components of VOCs on O pollution days in Xinxiang, and OVOCs had the highest ozone formation potential (OFP) and hydroxyl (·OH) reactivity. According to the relative incremental reactivity (RIR) analysis, during the O pollution days in Xinxiang, Osensitivity was in the VOCs-limited regime in June and in the transitional regime in July and August. Ozone production was more sensitive to alkenes and OVOCs. The RIR values of the precursors in June changed throughout the day, but O sensitivity remained the VOCs-limited regime. In July and August, O sensitivity was the VOCs-limited regime in the morning, transitional regime at noon, transitional and NO-limited regime, respectively in the afternoon. By simulating different precursor-reduction scenarios, the results showed that the reduction of VOCs was always beneficial to the control of O, whereas the reduction of NO had little effect on the control of O and a risk of increasing O.