郴州市秋冬季PM2.5污染传输路径与潜在源贡献分析

通过应用HYSPLIT、MeteoInfo模型，计算2017—2021年秋冬季抵达郴州地区72 h的后向气流轨迹并进行轨迹聚类、潜在源贡献因子（PSCF）和浓度权重轨迹（CWT）分析，探讨郴州市PM2.5传输特征及污染潜在源分布。结果表明，郴州市秋冬季PM2.5潜在源区主要分布在北偏东方向，以近距离输送为主，频率最高的是从咸宁市通城县经岳阳市平江县、株洲地区的短距离轨迹，其频率为34.17%；WPSCF高值带起源于河南省，经湖北、平江、江西等地区，最终到达郴州。WCWT分析结果得出，PM2.5污染趋势与上述一致，影响范围更宽，影响程度相对较轻。2017—2021年间，郴州地区污染传输通道影响逐年减小，PM2.5浓度平均下降19.7%。

Analysis of PM2.5 Pollution Transport Pathway and Potential Source Contribution in Autumn and Winter in Chenzhou

HYSPLIT and MeteoInfo models were used to calculate the backward airflow trajectory arriving in Chenzhou area for 72 h in autumn and winter from 2017 to 2021， and trajectory cluster， potential source contribution factor (PSCF) and concentration weight trajectory（CWT） analysis were carried out to explore the transport characteristics and potential source distribution of PM2.5. The results showed that the potential source areas of PM2.5 in autumn and winter in Chenzhou were mainly distributed in the northeast direction， short-distance transport dominated. The highest frequency was the short distance trajectory from Tongcheng County， Xianning， to Pingjiang County， Yueyang， and Zhuzhou area， which was 34.17%. The WPSCF high value belt originated in Henan， passed through Hubei， Pingjiang， Jiangxi， and finally reached Chenzhou. The WCWT analysis results showed that the trend of PM2.5 pollution was consistent with the above， affecting a wider area and a relatively light degree. The impact of pollution transport in Chenzhou area decreased year by year， PM2.5 concentration decreased by 19.7% on average.