【摘要】 采用预浓缩仪-气相色谱/质谱（GC/MS）联用方法测定了2020年夏季青藏高原高海拔背景站点纳木措（海拔4730 m）的卤代烃浓度，结合后向轨迹模型分析了采样点卤代烃传输轨迹及潜在源区域。结果表明：纳木措站大气中主要卤代烃为氯甲烷(3.81×10^-10)、一氟三氯甲烷(CFC-11,2.32×10^-10)、四氯化碳(9.30×10^-11)、三氯三氟乙烷(CFC-113,8.60×10^-11)和二氯甲烷(6.80×10^-11);纳木措站的氟氯烃化合物（CFCs）浓度在全球范围其他背景站点中处于较低水平。采样点CFC-11和CFC-113浓度变化之间呈显著相关（r=0.928,P<0.01）,分析认为是受大气本底传输的影响；而其浓度的变化幅度较大，与现有其他高海拔背景站点特征一致，大于平原地区两者浓度变化幅度。除CFC-11和CFC-113外，其他卤代烃化合物日变化幅度均较小（2%～12%）,无明显昼夜变化特征。后向轨迹模型分析结果显示，四氯化碳浓度可能受印度等周边地区传输的影响，采样期间纳木措站卤代烃浓度主要受亚洲西部影响。更多还原

【Abstract】 In order to study the concentration and variation characteristics of halocarbon in the atmosphere over the Tibetan Plateau, the concentration variation of halocarbon at background site Namco station（4730m a. s. l.） in the summer of 2020 was measured by preconcentrator-GC/MS method. The influence of transport and potential source area on halocarbons was analyzed by using the HYSPLIT model. The results showed that the main halocarbons in the atmosphere of Namco station were methane chloride(3.81×10^-10), CFC-11(2.32×10^-10), CFC-113(8.60×10^-11), tetrachloromethane(9.30×10^-11) and dichloromethane(6.80×10^-11). The concentrations of chlorofluorocarbons（CFCs） at Namco were close to or lower than other global background values. There was no distinct diurnal variation in the concentration of main halocarbon compounds. The concentrations of CFC-11 and CFC-113 were significantly correlated（r=0.928, P<0.01） and might be affected by transfer of atmospheric background. The wide variation range of CFC-11 and CFC-113 in Namco station was consistent with the characteristics of other high-altitude background sites, while it was obviously greater them the results in plain areas. Except for CFC-11 and CFC-13, the diurnal variation amplitude of other halocarbons was small, without obvious diurnal variation characteristics. The results of the HYSPLIT model indicated that the concentration of tetrachloromethane might be influenced by the transport of the surrounding area, the concentration of halocarbon at Namco station was mainly affected by western Asia during the sampling period, and the concentration of chloromethane might be influenced by the surrounding marine natural sources.更多还原