帕米尔高原东部PM10输送路径及潜在源分析

基于HYSPLIT后向轨迹模式和NCEP的GDAS数据（2019年3月~2020年2月），对抵达帕米尔高原东部的48h后向气团轨迹按季节聚类，其PM₁₀和PM_2.5年均值分别为（29.4±16.4），（9.3±5.1）μg/m³，大气颗粒物以PM₁₀为主，结合同期PM₁₀浓度数据，分析不同路径对帕米尔高原东部PM₁₀聚集的贡献，并利用潜在源贡献因子法（PSCF）和浓度权重轨迹法（CWT），揭示研究期间帕米尔高原东部不同季节PM₁₀的潜在源分布及其贡献水平.结果表明：帕米尔高原东部PM₁₀输送路径的季节特征明显，春季来自中亚的西风气流对应PM₁₀高值，夏季来自中国新疆西部的气流也对应较高PM₁₀值，秋季各轨迹对应PM₁₀值相当，冬季来自南亚方向气流对应PM₁₀高值.PM₁₀春季贡献源区主要位于中国新疆西部、阿富汗东北部、巴基斯坦东北部、塔吉克斯坦中部及东部地区，夏季主要位于中国新疆西部喀什与和田北部地区，秋季主要位于土库曼斯坦东部、乌兹别克斯坦东南部、巴基斯坦北部、阿富汗北部与塔吉克斯坦南部接壤地区，冬季主要位于巴基斯坦东北部、印度北部以及阿富汗北部.

Analysis of transport pathways and potential source regions of PM10 in the eastern Pamirs

Both HYSPLIT backward trajectory model and Global Data Assimilation System (GDAS) meteorological data from the National Centers for Environmental Prediction (NCEP) were used to analyze the 48h backward trajectories of hourly airflow in the eastern Pamirs from March, 2019 to February, 2020. The clustering analysis was used to classify the airflow backward trajectories in different seasons. The annual mean values of surface PM₁₀ and PM_2.5 concentrations were (29.4±16.4) and (9.3±5.1) μg/m³, respectively, indicating that PM₁₀ was the main particulate matters over the eastern Pamirs. Therefore, the hourly observation data of PM₁₀ concentrations were also used to analyze the spatial characteristics of different transport pathways and its contribution to the surface PM₁₀ concentrations in the eastern Pamirs. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) were applied to identify the potential source regions and contribution of PM₁₀ in different seasons to the eastern Pamirs during the study period. Seasonal variations of PM₁₀ transport pathways in the eastern Pamirs were obvious. The westerly airflows from Central Asia carried high concentrations of PM₁₀ in spring, while the airflows from west Xinjiang brought high concentrations of PM₁₀ in summer, and the both airflows made the equal concentration of PM₁₀ in autumn, while the airflows from South Asia took along higher concentrations of PM₁₀ in winter. Furthermore, the potential source regions of PM₁₀ were mainly located in west Xinjiang, northeast Afghanistan, northeast Pakistan, central and east Tajikistan in spring, in Kashgar and north Hotan in west Xinjiang in summer, in east Turkmenistan, southeast Uzbekistan, north Pakistan, and north Afghanistan bordering south Tajikistan areas in autumn, and in northeast Pakistan, north India and north Afghanistan in winter.