2020年南昌市大气污染特征与潜在源区

Characteristics and Potential Sources of Atmospheric Pollutionin Nanchang City in 2020

基于南昌市大气环境监测、地面气象观料和GDAS等资料,主要采用后向轨迹聚类分析、潜在源贡献因子和浓度权重轨迹分析方法,分析了2020年南昌市大气污染特征和污染物潜在源区。结果表明:1)南昌市春、夏、秋季以O_(3)污染为主,冬季以PM_(2.5)污染为主。2)大气污染物质量浓度日变化具有明显的季节性特征,PM_(2.5)和PM_(10)在春、秋、冬季呈双峰形分布,NO_(2)在秋、冬季呈弱双峰形分布,春、夏季呈单峰分布,O_(3)呈单峰形分布。南昌市东部大气污染较西部更严重。3)南昌市气流输送季节差异明显,春、秋、冬季主要受偏北气流影响,夏季主要受偏南气流影响。本地源是南昌市大气污染的主要潜在源,安徽省南部、湖北省东部、上饶市西部和九江市的区域输送也有一定贡献。

Atmospheric pollutants and meteorological observation data of 2020 were used to analyze the characteristics and potential sources in Nanchang City.The results showed that the air pollution in Nanchang City was dominated by O 3 in spring,summer and autumn,and dominated by PM 2.5 in winter.The atmospheric pollutants presented obvious seasonal variations.PM 10 and PM 2.5 displayed a“bimodal”pattern in spring,autumn and winter.NO 2 showed a“bimodal”pattern in autumn and winter,and an“unimodal”pattern in spring and summer.O 3 showed an“unimodal”pattern.The air pollution in the east of Nanchang City was more serious than that in the west.There were significant seasonal differences in air flow in Nanchang City.In spring,autumn and winter,the air pollution was mainly affected by northerly air flow;while in summer,it was mainly affected by southerly air flow.The results of potential source contribution factor(PSCF)and concentration weighted trajectory(CWT)showed that local sources were the main potential sources of air pollution in Nanchang City,and and regional transport in southern Anhui Province,eastern Hubei Province,western Shangrao City,and Jiujiang City also contributed to the degradation of air quality in Nanchang City.