A series of organic compounds in snow and ice were identified from Dasuopu glacier in Xixiabangma in Qinghai-Tibetan Plateau. Organic compounds derived from natural organisms include n-alkanes ranging from C15 to C33,...A series of organic compounds in snow and ice were identified from Dasuopu glacier in Xixiabangma in Qinghai-Tibetan Plateau. Organic compounds derived from natural organisms include n-alkanes ranging from C15 to C33, normal monocarboxylic acids of C6-C18, n-alkan-2-ones of C24-C31 and esters. The unstable compounds widely present in lower troposphere disppear in the middle-upper troposphere. I^ots of other organic compounds from petroleum residues were also unexpectedly identified from the glacier, covering pristane, phytane, extended tricyclic terpanes of C!9-C29 , C24 tetracyclic terpane, αβ hopane compounds of C27-C35 , and cholestanes of C27-C29 . The remote Xixiabangma region is unambiguously polluted from anthropology activities. The petroleum residues were proposed to be mainly from the Mideast and India, not from China. The organic pollutants from oil fires ignited during the well-known Gulf War which broke out in 1991 were also recorded in the glacier. Such organic indexes as nC29/nC!7, nC29/nC27 , nC29/ nC24 , C30-ketone/C30-ester, C24-tetracyclic-/C24-tricyclic-terpane and CPIn (n standing for n-alkanes) exhibit the same strong seasonal variation as δ180, providing information on the atmospheric circulation of the plateau. These ratios decrease in summer half year when the monsoon dominated, and increase in winter half year when the westerly stream jet dominated.展开更多
基金Project supported by the National Scaling Plan (KZ951-A1-204-02-03)the National Natural Science Foundation of China (Grant No. 49671021).
文摘A series of organic compounds in snow and ice were identified from Dasuopu glacier in Xixiabangma in Qinghai-Tibetan Plateau. Organic compounds derived from natural organisms include n-alkanes ranging from C15 to C33, normal monocarboxylic acids of C6-C18, n-alkan-2-ones of C24-C31 and esters. The unstable compounds widely present in lower troposphere disppear in the middle-upper troposphere. I^ots of other organic compounds from petroleum residues were also unexpectedly identified from the glacier, covering pristane, phytane, extended tricyclic terpanes of C!9-C29 , C24 tetracyclic terpane, αβ hopane compounds of C27-C35 , and cholestanes of C27-C29 . The remote Xixiabangma region is unambiguously polluted from anthropology activities. The petroleum residues were proposed to be mainly from the Mideast and India, not from China. The organic pollutants from oil fires ignited during the well-known Gulf War which broke out in 1991 were also recorded in the glacier. Such organic indexes as nC29/nC!7, nC29/nC27 , nC29/ nC24 , C30-ketone/C30-ester, C24-tetracyclic-/C24-tricyclic-terpane and CPIn (n standing for n-alkanes) exhibit the same strong seasonal variation as δ180, providing information on the atmospheric circulation of the plateau. These ratios decrease in summer half year when the monsoon dominated, and increase in winter half year when the westerly stream jet dominated.
