青藏高原阿里地区大气颗粒物质量浓度的季节变化特征  

Seasonal mass concentration variation and potential source regions of atmospheric particulate matter in Ngari area,Tibet Plateau

作　　者：谢会晴 邬光剑[2] 曹泊[1] 于正良 石洪发 张宇轩 黄菊 XIE Huiqing;WU Guangjian;CAO Bo;YU Zhengliang;SHI Hongfa;ZHANG Yuxuan;HUANG Ju(College of Earth and Environmental Sciences,Lanzhou University,Lanzhou,730000,China;State Key Laboratory of Tibetan Plateau Earth System,Resources and Environment,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing,100101,China)

机构地区：[1]兰州大学资源环境学院,兰州730000 [2]中国科学院青藏高原研究所青藏高原地球系统与资源环境全国重点实验室,北京100101

出　　处：《环境化学》2023年第4期1260-1269,共10页Environmental Chemistry

基　　金：国家自然科学基金(41725001);第二次青藏高原科学考察研究(2019QZKK0201)资助。

摘　　要：基于2018-12-01至2019-11-30在中国科学院阿里荒漠环境综合观测研究站颗粒物监测仪的数据,获得了大气颗粒物质量浓度及其季节变化特征.研究结果表明,PM10、PM_(2.5)、PM1在观测期间的日均质量浓度分别为(10.51±8.62)μg·m^(−3)、(4.05±2.36)μg·m^(−3)和(2.47±1.56)μg·m^(−3),低于青藏高原城市地区.PM_(2.5)、PM10远低于国家规定的颗粒物年平均一级浓度限值(GB 3095—2012),表明阿里地区洁净的大气本底特征.阿里地区污染源稀少,气象因子成为影响颗粒物浓度变化的重要因素.尽管阿里地处西风和印度季风的过渡带,西南季风显著影响了阿里站颗粒物浓度变化,季风带来的暖湿气团使季风期颗粒物浓度显著降低;加之边界层高度等气象因素的季节变化,使大气颗粒物浓度呈现明显的季节变化规律,冬季和季风前大于季风期和季风后期.阿里站处于高寒荒漠环境,大气颗粒物以粗颗粒为主,PM_(2.5)/PM10的平均比值为0.39,与其他地点对比,比值偏低.聚类分析表明,阿里站主要受偏西气团影响.潜在源贡献因子分析(PSCF)和浓度权重轨迹分析(CWT)分析结果表明,PM10、PM_(2.5)、PM1主要潜在源区均分布在印度西北部、巴基斯坦北部.由于监测原理的不同和气象因子的影响,MODIS AOD数据与颗粒物浓度数据在12月、7月和8月差异较大,遥感获取的气溶胶参数需要进一步订正提高在高原的适用性.Using a GRIMM Environmental Dust Monitor EDM 365,the temporal variation and PM_(2.5)/PM10 ratio of atmospheric particulate matter concentration at Ngari Station from December 1,2018 to November 30,2019 were analyzed.The results showed that during the monitoring period,the average daily concentrations of PM10,PM_(2.5) and PM1 were(10.51±8.62)μg·m^(−3),(4.05±2.36)μg·m^(−3),(2.47±1.56)μg·m^(−3),respectively,which were lower than those in the urban areas of the Qinghai-Tibet Plateau.PM_(2.5) and PM10 are much lower than the annual average threshold value of classⅠstandard of the ambient air quality standard(GB 3095—2012),indicating the clean atmospheric background characteristics in Ngari.Ngari is located in the transitional zone between westerly winds and Indian monsoon.The southwest monsoon significantly affects the change of particulate matter concentration at Ngari station,and the warm and humid air mass brought by monsoon significantly reduces the particulate matter mass concentration during monsoon.In addition,the seasonal variation of meteorological factors such as boundary layer height makes the mass concentration of PM show obvious seasonal variation,which is higher in winter and premonsoon than in monsoon and post-monsoon.Ngari Station is located in alpine desert environment,and atmospheric particles are mainly coarse particles.The average ratio of PM_(2.5)/PM10 is 0.39,which is lower than other sites.The cluster analysis shows that Ngari station is mainly affected by the westerly winds.The results of potential source contribution function(PSCF)and concentrationweight trajectory(CWT)showed that the main potential source regions of PM10、PM_(2.5)、PM1 were located in north-western India and northern Pakistan.Due to the different monitoring principles and the influence of meteorological factors,the MODIS AOD data and in-situ PM data are quite different in December,July and August,and the aerosol parameters obtained by remote sensing need to be further revised to improve their applicabilit

关 键 词：大气颗粒物 季节变化 潜在源区分析 青藏高原 

分 类 号：X513[环境科学与工程—环境工程]