Impact Factors and Source Apportionment of PM2.5 in Gaoyou Suburban Stations
Based on the hourly monitoring data including meteorological elements and PM2.5 mass concentration collected at Gaoyou suburban stations in 2021,PM2.5 mass concentration variations,their influencing factors and source characteristics were studied by the backward trajectory and concentration-weighted trajectory(CWT)method.The results show that the mass concentration of PM2.5 is(33.20±21.99)μg/m3 during the observation period.The mass concentration of PM2.5 has significant seasonal variation characteris-tics,with the highest concentration in the winter,up to(46.74±26.90)μg/m3,and the lowest concentration in the summer,only(22.62±12.54)μg/m3.The pollution occurrence is mainly concentrated in the winter and the spring,counting for 87.6%of the total.The mass concentration of PM2.5 is higher at night than during the day.Meteorological factors has a great influence on the mass con-centration of PM2.5,but the effect fluctuats with the season.Low humidity conditions(<75%)are conducive to the increase of PM2.5 concentration,while high humidity conditions(>75%)are conducive to the removal of PM2.5.Wind speed has a significant effect on PM2.5 concentration,and the PM2.5 concentration decreases by 37.9%when there is precipitation compared with non-precipitation.In Gaoyou,there are significant differences in the corresponding PM2.5 concentrations under different wind direction and wind speed,and the high concentrations of PM2.5 mainly come from the corresponding west and south directions in the urban area.The potential source areas of PM2.5 in Gaoyou were mainly distributed in Anhui and southern Henan to the west of Gaoyou City,and in southern Jiangsu,northern Zhejiang and Shanghai to the south.Affected by the southward transport of pollutants by cold air in the winter,the central part of Shandong also has a great pollution contribution.
GaoyouPM2.5 mass concentrationvariation characteristicmeteorological elementsource apportionment
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NSTL
万方数据
