The relationship of ECM with ice acidity and impurities concentrations are much different between the Qinghai Tibetan Plateau and the polar regions. On the Qinghai Tibetan Plateau, ECM is dependent on the mineral io...The relationship of ECM with ice acidity and impurities concentrations are much different between the Qinghai Tibetan Plateau and the polar regions. On the Qinghai Tibetan Plateau, ECM is dependent on the mineral ions (i.e., Ca 2+ , Mg 2+ , SO 2- 4, etc.) mainly derived from crustal sources, thus displays a positive linear correlation between ECM and these ions. While in polar ice sheets, however, ECM of snow and ice is mainly dependent on the acidic roots such as Cl -, SO 2- 4 and NO - 3 that mostly come from ocean. Therefore, there is good relationship between ECM and concentration of H +. However, the relationship between ECM and major ions has complicated geographical differentiation in the whole Arctic. For instance, there no longer exits the same simple relationship in the central Arctic as that in the Greenland Ice Sheet, probably due to the disturbance of Arctic haze. In general, ECM of snow and ice is a potential indicator of atmospheirc envirmment of cold regions.展开更多
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
The research on extrempholic microorganisms in glacial low-temperature environment receives more attention than ever before. Due to the successive chronological records in ice core, it is important to initiate microbi...The research on extrempholic microorganisms in glacial low-temperature environment receives more attention than ever before. Due to the successive chronological records in ice core, it is important to initiate microbiological studies on ice core samples. 23 samples from one ice core, drilled from central Qinghai-Tibetan Plateau, were analyzed. The number of total microorganisms and culturable microorganisms in different layers showed that it related with the content of dust in ice. It is suggested that the distribution of microorganisms in ice depends on the transportation of materials during glacier development. The bacteria diversity in Malan Glacier was analyzed by 16S rDNA sequencing methods, which showed that many sequences were similar to known psychrophilic bacteria.展开更多
文摘The relationship of ECM with ice acidity and impurities concentrations are much different between the Qinghai Tibetan Plateau and the polar regions. On the Qinghai Tibetan Plateau, ECM is dependent on the mineral ions (i.e., Ca 2+ , Mg 2+ , SO 2- 4, etc.) mainly derived from crustal sources, thus displays a positive linear correlation between ECM and these ions. While in polar ice sheets, however, ECM of snow and ice is mainly dependent on the acidic roots such as Cl -, SO 2- 4 and NO - 3 that mostly come from ocean. Therefore, there is good relationship between ECM and concentration of H +. However, the relationship between ECM and major ions has complicated geographical differentiation in the whole Arctic. For instance, there no longer exits the same simple relationship in the central Arctic as that in the Greenland Ice Sheet, probably due to the disturbance of Arctic haze. In general, ECM of snow and ice is a potential indicator of atmospheirc envirmment of cold regions.
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.
基金This work was supported by the Na-tional Major Development Program(Grant No.G1998040800)the National Science Fund for Distinguished Young Scholars(Grant No.49425101)the Innovation Project of the Chinese Academy of Sci-ences(Grant No.KZCX 1-10-02).
文摘The research on extrempholic microorganisms in glacial low-temperature environment receives more attention than ever before. Due to the successive chronological records in ice core, it is important to initiate microbiological studies on ice core samples. 23 samples from one ice core, drilled from central Qinghai-Tibetan Plateau, were analyzed. The number of total microorganisms and culturable microorganisms in different layers showed that it related with the content of dust in ice. It is suggested that the distribution of microorganisms in ice depends on the transportation of materials during glacier development. The bacteria diversity in Malan Glacier was analyzed by 16S rDNA sequencing methods, which showed that many sequences were similar to known psychrophilic bacteria.
