呼和浩特市PM2.5和O3浓度特征及其与气象要素的关系OA

To explore the impact of meteorological factors on major atmospheric pollutants in Hohhot,the concentration characteristics of PM2.5 and O3 and their relationship with meteorological factors were analyzed based on the environmental monitoring data and meteorological observing data of Hohhot from 2018 to 2024,using correlation analysis and backward trajectory clustering methods.The results showed that:PM2.5 concentration in Hohhot showed a unimodal trend from 2018 to 2024,with the peak in 2020,and there was no obvious annual variation in O3-8h.Both PM2.5 and O3-8h concentrations showed obvious seasonal variations,and the effects of meteorological factors on PM2.5 and O3-8h varied with seasons and factor value intervals.PM2.5 concentrations were highest in winter,and it had a significant negative correlation with wind speed,ultraviolet intensity and sunshine duration,as well as the positive correlation with relative humidity and temperature.Low wind speed,west-northwest air flow and high humidity were conducive to the formation of PM2.5 pollution,while the increase of north wind and diurnal temperature range were conducive to the decrease ofPM2.5.O3-8h were highest in summer,and it had a significant positive correlation with temperature,ultraviolet intensity and sunshine duration,as well as the negative correlation with relative humidity and precipitation.Low wind speed and southerly air flow were conducive to the rise of O3-8h,and high humidity and precipitation were conducive to the decrease of O3-8h.Higher temperature and daily temperature range were necessary for the occurrence of O3 pollution.The differing impacts of meteorological factors on PM2.5 and O3-8h may be one of the reasons contributing to the rarity of local compound pollution.