庆阳市空气污染及气象因子影响特征分析OA北大核心CSTPCD

Based on air pollution and meteorological data(2015-2021)from Qingyang City,Gansu Province,China,this study employed mathematical statistics and Pearson correlation analysis to examine AQI,primary pol-lutants,and their concentration changes.It aims to explore the influence of meteorological factors on pollution levels and establish response indicators to aid the prevention and control of air pollution in the area.Results indi-cate that Qingyang City predominantly experiences excellent air quality,with distinct seasonal variations in AQI.The best air quality occurs from mid-summer to mid-autumn,followed by spring,and deteriorates significantly in winter.The primary pollutants identified are O3,PM10,and PM2.5,with O3 peaking in summer,and a combination of PM10,O3 and PM2.5 in spring and autumn.Winter and the heating season primarily feature PM10 and PM2.5.A complex interplay between particulate matter and O3 is evident.Annually,concentrations of SO2,NO2,CO,PM2.5,and PM10 demonstrate a declining trend,whereas O3 shows an average increase of 1.5µg·m-3·a-1.Monthly and seasonal concentration fluctuations are significant,with elevated levels of PM10 and PM2.5 in winter and spring,and the highest O3 concentrations in June.Moderate or severe pollution episodes predominantly occur from late autumn to winter and spring,driven by local climate conditions and pollution sources.Temperature significantly enhances O3 concentrations,with high temperatures in early summer and low precipitation serving as primary contributors.External transport and local emissions during the heating season lead to exceedances in PM10 and PM2.5 standards.Daily O3 variations display a unimodal pattern,without significant nighttime decreases.Con-versely,other pollutants exhibit a bimodal daily pattern,with peaks around 04:00 and 15:00,and elevated levels at 20:00 and 09:00.Exceedance days for PM10,PM2.5,and O3 typically coincide with dry conditions or precipita-tion less than 3 mm.Meteorological factors such as air pressure,temperature,humidity,maximum wind speed,and wind direction show marked variations on these days.The periods with the highest frequency of PM10 exceed-ances span from March to April,PM2.5 from December to January of the following year,and O3 from June to July.For PM10,the exceedance thresholds include temperatures of 10-20℃,humidity levels of 20%-50%,air pressure between 850-863 hPa,and maximum wind speeds of 4 m·s-1 or above,predominantly with NW winds.PM2.5 ex-ceedances occur at temperatures of-5-3℃,humidity of 40%-80%,air pressure between 854-867 hPa,and maxi-mum wind speeds of 2-6 m·s-1,with SW and S winds.O3 exceedances are noted at temperatures of 19-26℃,hu-midity of 25%-60%,air pressure between 851-858 hPa,and maximum wind speeds of 3-5 m·s-1,under S and SW winds.