Climatic and environmental implications from organic matter in Dasuopu glacier in Xixiabangma in Qinghai-Tibetan Plateau

A series of organic compounds in snow and ice were identified from Dasuopu glacier in Xixiabangma in Qinghai Tibetan Plateau. Organic compounds derive d from natural organisms include n-alkanes ranging from C-15 to C-33, norma l monocarboxylic acids of C-6-C-18, n-alkan-2-ones of C-24-C-31 and esters. The unstable compounds widely present in lower troposphere disppear in the middle-upper troposphere. Lots of other organic compounds from petroleum r esidues were also unexpectedly identified from the glacier, covering prista ne, phytane, extended tricyclic terpanes of. C-19-C-29, C-24 tetracyclic te rpane, alpha beta hopane compounds of C-27-C-35, and cholestanes of C-27-C- 29. The remote Xixiabangma region is unambiguously polluted from anthropolo gy activities. The petroleum residues were proposed to be mainly from the M ideast and India, not from China. The organic pollutants from oil fires ign ited during the well-known Gulf War which broke out in 1991 were also recor ded in the glacier. Such organic indexes as nC(29)/nC(17),nC(29)/nC(27), nC (29)/nC(24), C-30-ketone/C-30-ester, C-24-tetracyclic-/C-24-tricyclic-terpa ne and CPIn (n standing for n-alkanes) exhibit the same strong seasonal var iation as delta(18)O, 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 do minated.