青藏高原玉珠峰冰川和小冬克玛底冰川雪坑中的环境记录

Environmental Records within the Snowpits in the Yuzhufeng Glacier and Xiao Dongkemadi Glacier on the Tibetan Plateau

研究了玉珠峰冰川和小冬克玛底冰川雪坑中离子、正构烷烃和多环芳烃的含量及分布特征,并利用正构烷烃和多环芳烃的相关参数以及离子与这两种有机物之间的相关系数探讨了雪坑中这些化学组分的可能来源.结果表明:虽然同受西风环流的影响,但玉珠峰冰川雪坑中离子、正构烷烃和多环芳烃的含量远高于小冬克玛底冰川,这与它们所处的地理位置有关.∑nC2-1/∑nC2+2和碳优势指数(Car-bon Preference Index,CPI)值表明,这两条冰川中自然来源的正构烷烃主要以陆生高等植物输入为主,低等生物贡献很少,玉珠峰冰川人为来源的正构烷烃要高于小冬克玛底冰川.LPAHs/HPAHs和(Fla+Pyr)/(BghiP+INP)表明两条冰川中的多环芳烃主要来自生物质与煤的低温燃烧,机动车尾气对小冬克玛底冰川也有部分贡献.

The contents and distribution characteristics of ions,n-alkanes and polycyclic aromatic hydrocarbons within the snowpits in the Yuzhufeng Glacier and Xiao Dongkemadi Glacier were studied.Parameters and correlation coefficients between the ions and two organic compounds were used to explore the possible sources of these chemical compositions.The result indicates that they are both influenced by westerly circulation,but the contents of ions,n-alkanes and polycyclic aromatic hydrocarbons in the Yuzhufeng Glacier were higher than those in the Xiao Dongkemadi Glacier,because of the difference in geographical position.The ratios of ∑nC-21/∑nC＋22 and CPI indicate that the n-alkanes from natural sources in these two glaciers mainly come from the higher plants,whereas the contribution from the lower organisms is low,and the n-alkanes from anthropogenic sources in the Yuzhufeng Glacier are higher than that in the Xiao Dongkemadi Glacier.The ratios of LPAHs/HPAHs and（Fly＋Pyr）/（BghiP＋INP） indicate that the polycyclic aromatic hydrocarbons in these two glaciers are mainly derived from low temperature combustion of coal and biomass,and in the Xiao Dongkemadi Glacier partially from the exhaust gas of motor vehicles.