Analysis on the Ozone Pollution Characteristics and Its Influencing Factors in Chengdu

Based on the conventional ground meteorological observation and data from national environmental monitoring sites from 2015 to 2020 in Chengdu, the annual and monthly variation of ozone pollution and its relationship with meteorological factors were discussed. The results showed that ozone polluted days account for 9.9% of the total monitoring days, accounting for about a third of the total polluted days from 2015 to 2020. The proportion has been increasing year by year. The trend of monthly mean ozone concentration and monthly ozone polluted days is basically consistent, showing an “M” type bimodal distribution feature, reaching its peak in July. The daily average ozone concentration is positively correlated with the daily max temperature and sunshine hours, and negatively correlated with the min relative humidity. Quantitative analysis of meteorological conditions shows that from 2016 to 2019, meteorological conditions were conducive to a decrease in ozone concentration, while in 2020, meteorological conditions were conducive to an increase in ozone concentration.