基于HYSPLIT模型的衡阳市大气PM2.5潜在源分析

Potential Source Analysis of PM2.5 Based on HYSPLIT Model in Hengyang

为查明外来输送对衡阳市大气PM2.5的影响,基于2015年3月至2018年2月衡阳市PM2.5质量浓度数据和GDAS气象数据,利用HYSPLIT模型的后向轨迹模式,结合聚类分析,潜在源分析(PSCF)和浓度权重分析(CWT),对衡阳市不同季节PM2.5外来输送通道及潜在源分布进行分析。研究结果表明:在春、秋、冬三季,途经湘赣交界处、湘东地区输送至衡阳的气团输送路径衡阳PM2.5外来输送的通道方向,且贡献较大,而源自鄂豫交界处,贯穿鄂、经湘东北输送至衡阳的气团输送路径虽然也是衡阳市PM2.5外来输送的通道方向,但贡献较小。来自豫皖交界,途径鄂东,湘东北的气团输送路径为夏季的PM2.5外来输送通道方向。湘东北、湘南、湘东、赣西、鄂中南及豫南地区为春、秋、冬三季衡阳市PM2.5外来输送的主要潜在源区,其中湘东北、湘南、湘东、赣西地区为高浓度贡献潜在源区;而湘东北及鄂中南地区为夏季PM2.5外来输送的主要潜在源区,其中湘东北为高浓度贡献潜在源区。

In order to ascertain the effect of external transportation on PM2.5 in Hengyang City,backward trajectory pattern of HYSPLIT model was used along with PM2.5 concentration data and GDAS meteorological data from March 2015 to February 2018 of Hengyang to analyze the distribution characteristics of the backward trajectory of the external air mass in Hengyang City.In addition,the distribution of PM2.5 external transport channels and potential sources in Hengyang City were analyzed via cluster analysis method,PSCF method and CWT method.The results showed that the air mass transport path from the junction of Hubei and Henan,and then through Hubei and northeastern Hunan to Hengyang is the channel direction of PM2.5 external transport in spring,autumn and winter,with a small contribution rate.In addition,the air mass transport path that passes through the junction of Hunan and Jiangxi and eastern Hunan to Hengyang is the channel direction of PM2.5 with higher contribution rate.In summer,the air mass transport path from the junction of Henan and Anhui,and then through eastern Hubei and northeastern Hunan is the channel direction of PM2.5 external transport.The northeastern and southern and eastern parts of Hunan,western Jiangxi,central and southern Hubei,and southern Henan are the main potential source areas for PM2.5 external transport in Hengyang City in spring,autumn and winter,while the high concentration contribution potential source area of PM2.5 is in northeastern and southern and eastern parts of Hunan,western Jiangxi.In northeastern Hunan,central and southern Hubei are the main potential source areas for PM2.5 external transport in summer,and the contribution rate of northeastern Hunan is higher.