Impacts of meteorological conditions and precursor emissions on regional ozone pollution in China
In September 2022,China experienced multiple regional ozone pollution processes,and the heavily polluted areas were mainly concentrated in South and North China.Out of 339 cities across the country,a total of 1 844 days/times of ozone exceeding standards occurred,including 3 days/times of severe pollution(all in the Pearl River Delta),123 days/times of moderate pollution,and 1 718 days/times of mild pollution.The downdraft outside the typhoon in September 2022 affected both North and South China for an extended period of time.This downdraft was prone to meteorological conditions that were extremely favorable for the generation and accumulation of ozone,including continuous dryness with little rain,low wind speed and persistently high temperature.It was a significant factor in the ozone pollution process,leading to extended duration,broad impact range,and high pollution level.Cities with a higher number of days experiencing excessive ozone often had higher levels of NO2 and VOCs ozone formation potential(OFP),with OFP of more than 100 μg/m3 and NO2 of roughly 30 μg/m3.Correlation analysis and multiple linear regression results indicated that NO2 emissions were mostly responsible for the regional ozone pollution.These indicated that ozone precursor emissions were still occurring at high levels in North and South China,and that ozone pollution was made worse by the buildup of ozone precursors during unfavorable weather.
NETL
NSTL
万方数据
