To assess the seasonality of aerosol deposition and anthropogenic effects on central Himalayas, a 1.85-m deep snow pit was dug on the northern slope of Mt. Qomolangma （Everest）. Based on the morphology and energy di...To assess the seasonality of aerosol deposition and anthropogenic effects on central Himalayas, a 1.85-m deep snow pit was dug on the northern slope of Mt. Qomolangma （Everest）. Based on the morphology and energy dispersive X-ray （EDX） signal, totally 1500 particles were classed into 7 groups： soot; aluminosilicates; fly ash; calcium sulfates; Ca/Mg carbonates; metal oxides; and biological particles and carbon fragments. The size distribution and number fractions of different particle groups exhibited distinct seasonal variations between non-monsoon and monsoon periods, which are clearly related to the differences in air mass pathways. Specifically, the relative abundance of soot in non-monsoon period （25%） was much higher than that in monsoon period （14%）, indicating Mt. Qomolangma region received more anthropogenic influence in non-monsoon than monsoon period.展开更多
High mountains may serve as a condenser for persistent organic pollutants. In the present study, soil and grass samples from Mt. Qomolangma region, China were collected from 4600 to 5620 m a.s.l and were analyzed for ...High mountains may serve as a condenser for persistent organic pollutants. In the present study, soil and grass samples from Mt. Qomolangma region, China were collected from 4600 to 5620 m a.s.l and were analyzed for polycyclic aromatic hydrocarbons (PAHs) to determine if they are concentrated at colder, more elevated sites and to evaluate their possible resources and fractionation. The total PAHs concentration in soil samples was < 600 ng g?1, the critical value to differentiate PAHs levels in remote and urban regions. This implied the PAHs levels at Mt. Qomolangma are relatively low and what one might expect in such a remote region of the world. These low values may represent a soil background for mid-latitude Northern Hemisphere soils away from the direct influence of an anthropogenic source. As for the distribution pattern, the low molecular weight PAHs were prone to accumulate at higher altitude, while the high molecular weight PAHs inversely related or unrelated with elevation. Based on high concentration of phenanthrene at elevated sample site and the ratios of individual PAHs, we deduced that home-heating combustion and vehicle emission may result in the constitution trait of PAHs in this mountain region. Monsoon traveling over India, Pakistan and other countries with dense population may carry contaminant to Mt. Qomolangma region.展开更多
A total of 14 surface snow (0―10 cm) samples were collected along the climbing route (6500―8844 m a.s.l.) on the northern slope of Mt. Qomolangma in May, 2005. Analysis of elemental concentrations in these samples s...A total of 14 surface snow (0―10 cm) samples were collected along the climbing route (6500―8844 m a.s.l.) on the northern slope of Mt. Qomolangma in May, 2005. Analysis of elemental concentrations in these samples showed that there are no clear trends for element variations with elevation due to re- distribution of surface snow by strong winds during spring. In addition, local crustal aerosol inputs also have an influence on elemental composition of surface snow. Comparison between elemental concentration datasets of 2005 and 1997 indicated that data from 2005 were of higher quality. Elemental concentrations (especially for heavy metals) at Mt. Qomolangma are comparable with polar sites, and far lower than large cities. This indicates that anthropogenic activities and heavy metal pollution have little effect on the Mt. Qomolangma atmospheric environment, which can be representative of the background atmospheric environment.展开更多
Thirty samples of total suspended particles were collected at a site in western part of Lhasa,Tibet from August 2006 to July 2007.The 10Be concentrations were determined by Accelerator Mass Spectrometer (AMS).Analysis...Thirty samples of total suspended particles were collected at a site in western part of Lhasa,Tibet from August 2006 to July 2007.The 10Be concentrations were determined by Accelerator Mass Spectrometer (AMS).Analysis of correlation between 10Be concentrations and meteorological factors revealed that the wet scavenging has little effect on 10Be.10Be can be used as a proxy of transport processes of the upper atmosphere over the Tibetan Plateau.Analysis of correlation between 10Be concentrations and NCEP reanalysis data demonstrated that higher 10Be concentrations in spring were probably caused by the atmosphere exchange from stratosphere to troposphere during February to June.Lower 10Be concentrations during August to September were consistent with the synchronous lower O3 values,suggestive of both 10Be and O3 were probably influenced by the atmosphere exchange from troposphere to stratosphere.展开更多
基金supported by the National Natural Science Foundation of China (No. 40605034, 40771087, 40830743)the National Basic Research Program (973) of China (No. 2005CB422004)the State Key Labo- ratory of Cryospheric Sciences (No. SKLCS-ZZ-2008-1)
文摘To assess the seasonality of aerosol deposition and anthropogenic effects on central Himalayas, a 1.85-m deep snow pit was dug on the northern slope of Mt. Qomolangma （Everest）. Based on the morphology and energy dispersive X-ray （EDX） signal, totally 1500 particles were classed into 7 groups： soot; aluminosilicates; fly ash; calcium sulfates; Ca/Mg carbonates; metal oxides; and biological particles and carbon fragments. The size distribution and number fractions of different particle groups exhibited distinct seasonal variations between non-monsoon and monsoon periods, which are clearly related to the differences in air mass pathways. Specifically, the relative abundance of soot in non-monsoon period （25%） was much higher than that in monsoon period （14%）, indicating Mt. Qomolangma region received more anthropogenic influence in non-monsoon than monsoon period.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 40121101, 40501018 and 40401054)the Ministry of Science and Technology of the People's Republic of China (Grant No. 2005CB422004)+2 种基金the"Talent Project"of Chinese Academy of Sciencesthe Social Commonweal Research Project of Ministry of ScienceTechnology of China (Grant No. 2005DIA3J106)
文摘High mountains may serve as a condenser for persistent organic pollutants. In the present study, soil and grass samples from Mt. Qomolangma region, China were collected from 4600 to 5620 m a.s.l and were analyzed for polycyclic aromatic hydrocarbons (PAHs) to determine if they are concentrated at colder, more elevated sites and to evaluate their possible resources and fractionation. The total PAHs concentration in soil samples was < 600 ng g?1, the critical value to differentiate PAHs levels in remote and urban regions. This implied the PAHs levels at Mt. Qomolangma are relatively low and what one might expect in such a remote region of the world. These low values may represent a soil background for mid-latitude Northern Hemisphere soils away from the direct influence of an anthropogenic source. As for the distribution pattern, the low molecular weight PAHs were prone to accumulate at higher altitude, while the high molecular weight PAHs inversely related or unrelated with elevation. Based on high concentration of phenanthrene at elevated sample site and the ratios of individual PAHs, we deduced that home-heating combustion and vehicle emission may result in the constitution trait of PAHs in this mountain region. Monsoon traveling over India, Pakistan and other countries with dense population may carry contaminant to Mt. Qomolangma region.
基金the National Natural Science Foundation of China (Grant Nos. 40401054, 90411003 and 40121101)the National Basic Research Program of China (Grant No.2005CB422004)+1 种基金Social Commonweal Research Project of Ministry of Science and Technology of China (Grant No.2005DIA3J106)the "Talent Project" and Innovation Project (Grant No.KZCX3-SW-334/339) of CAS, and Dean Founda-tion of CAS
文摘A total of 14 surface snow (0―10 cm) samples were collected along the climbing route (6500―8844 m a.s.l.) on the northern slope of Mt. Qomolangma in May, 2005. Analysis of elemental concentrations in these samples showed that there are no clear trends for element variations with elevation due to re- distribution of surface snow by strong winds during spring. In addition, local crustal aerosol inputs also have an influence on elemental composition of surface snow. Comparison between elemental concentration datasets of 2005 and 1997 indicated that data from 2005 were of higher quality. Elemental concentrations (especially for heavy metals) at Mt. Qomolangma are comparable with polar sites, and far lower than large cities. This indicates that anthropogenic activities and heavy metal pollution have little effect on the Mt. Qomolangma atmospheric environment, which can be representative of the background atmospheric environment.
基金supported by the National Basic Research Program of China (2005CB422004)the National Natural Science Foundation of China (40830743,40605034 and 40771187)the Foundation of State Key Laboratory of Cryospheric Science,Chinese Academy of Sciences (SKLCS-ZZ-2008-01)
文摘Thirty samples of total suspended particles were collected at a site in western part of Lhasa,Tibet from August 2006 to July 2007.The 10Be concentrations were determined by Accelerator Mass Spectrometer (AMS).Analysis of correlation between 10Be concentrations and meteorological factors revealed that the wet scavenging has little effect on 10Be.10Be can be used as a proxy of transport processes of the upper atmosphere over the Tibetan Plateau.Analysis of correlation between 10Be concentrations and NCEP reanalysis data demonstrated that higher 10Be concentrations in spring were probably caused by the atmosphere exchange from stratosphere to troposphere during February to June.Lower 10Be concentrations during August to September were consistent with the synchronous lower O3 values,suggestive of both 10Be and O3 were probably influenced by the atmosphere exchange from troposphere to stratosphere.
