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The Indian monsoonal influence on altitude effect of δ^(18)O in surface water on southeast Tibetan Plateau

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Science China Earth Sciences 2012年第3期55卷 438-445页

作者： YANG XiaoXin xu baiqing YANG Wei QU DongMei CAS Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100085China

The altitude effect of δ18O is essential for the study of the paleo-elevation reconstruction and possible to be solved through modern process studies. This study presents new δ18O results from southeast Tibetan Plateau along two transects, the Zayu transect and the Lhasa-Nyang transect, with δ18O data from June to September representative of monsoon period and δ18O data during the rest of the year of non-monsoon period. Altitude effect outweighs the longitude and latitude effects in determining regional δ18O variation spatially. Relevant δ18O data from previous studies in the nearby region have also been combined to comprehensively understand the influence of different moisture sources on δ18O from local scale to regional scale. The δ18O in surface water in the southeast Tibetan Plateau and its nearby regions influenced by the Indian summer monsoon shows that single dominant moisture source or simple moisture sources lead to smaller altitudinal lapse rate, whilst growing contributions from local convection to precipitation enlarge δ18O-altitude rate. It thereupon reveals the significance of the Indian summer monsoon to the altitude effect of δ18O in surface water, and the complicated effect of local convection or westerlies evolution to the variation of altitudinal lapse rate. Paleo-monsoon evolution therefore should be considered when altitude effect is applied to paleo-elevation reconstruction for the Tibetan Plateau.

关键词： δ18O altitude effect Indian monsoon southeast Tibetan Plateau and its nearby regions altitudinal lapse rate

Organochlorine pesticides in fresh-fallen snow on East Rongbuk Glacier of *** (Everest)

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Science China Earth Sciences 2007年第7期50卷 1097-1102页

作者： WANG Feng ZHU Tong xu baiqing KANG ShiChang State Key Joint Laboratory for Environmental Simulation&Pollution Control College of Environmental SciencesPeking UniversityBeijing 100871China Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100085China

During a field campaign in April 2005,fresh-fallen snow samples were collected on the East Rongbuk Glacier of the Mt. Qomolangma at four altitudes (6500 m,6300 m,6100 m and 5900 m),to study the role of Mt. Qomolangma as "cold-traps" for Persistent Organic Pollutants. From these snow samples col-lected at the highest-altitude,organochlorine pesticides (OCPs):HCB,p,p′-DDT and p,p′-DDD were detected,with the concentrations in the ranges of 44―72 pg/L,401―1560 pg/L,and 20―80 pg/L,re-spectively. The concentration of o,p′-DDT was around the method detection limit. Analysis of backward trajectories showed that the detected compounds came from the north of India,suggesting that DDTs detected in the snow were possibly originated from new emissions in this area. Relationships between the concentrations of OCPs in snow samples and the sampling altitudes were discussed. The altitudes had no obvious effect on HCB concentrations in the fresh-fallen snow,while increases in the concen-trations of p,p′-DDT and p,p′-DDD with increasing altitude were found,which was reversed compared to the trends observed in North America. Three factors likely resulted in this trend: (1) the properties of the target compounds; (2) the low temperatures at high altitudes; and (3) the location of the mountain sampling sites relative to their sources.

关键词： Mt. Qomolangma (Everest) Tibet organochlorine pesticides snow long-range transport

Elevational patterns of abundant and rare bacterial diversity and composition in mountain streams in the southeast of the Tibetan Plateau

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Science China Earth Sciences 2019年第5期62卷 853-862页

作者： Keshao LIU TANDong YAO Yongqin LIU baiqing xu Anyi HU Yuying CHEN Key Laboratory of Tibetan Environment Changes and Land Surface Processes Chinese Academy of Sciences University of Chinese Academy of Sciences CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences Key Laboratory of Alpine Ecology and Biodiversity Chinese Academy of Sciences Key Laboratory of Urban Pollutant Conversion Institute of Urban Environment Chinese Academy of Sciences

Elevational gradients are powerful ‘natural laboratory' for testing the responses of microbes to geophysical influences. Microbial communities are normally composed of a few abundant and many rare taxa. Abundant and rare taxa play different ecological roles in kinds of environments, but how their diversity and composition patterns response to elevation gradients is still poorly elucidated. In this study, we investigated the elevational patterns of abundant and rare bacterial diversity and composition in a mountain stream from 712 to 3435 m at Gangrigabu Mountain on the Tibetan Plateau, China. Our results revealed abundant and rare bacteria had similar decreasing elevation trend of alpha diversity, and both of them showed a significant elevational distance-decay relationship. However, the turnover rate of the elevational distance-decay of rare bacteria was higher than that of abundant bacteria. The species-abundance distribution patterns of rare taxonomic composition were associated with the elevational gradient, while most of abundant bacterial clades did not display any relationships with *** results suggested that rare bacteria were more sensitive to changes in elevation gradient.

关键词： Rare bacteria Diversity patterns Elevation gradients Mountain stream

Carbonaceous particles in Muztagh Ata ice core,West Kunlun Mountains,China

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Chinese Science Bulletin 2008年第21期53卷 3379-3386页

作者： LIU XianQin xu baiqing YAO TanDong WANG NingLian WU GuangJian State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Carbonaceous particles concentrations of OC and EC are determined using a two-step gas chroma-tography system in Muztagh Ata ice core covering the time period of 1955―*** the period rep-resented by the core,OC and EC concentrations appear to have changed significantly,varied in the range of 17.7―216.7 and 6.5―124.6,and averaged 61.8,32.9 ng·g-1,*** average concen-tration of EC in Muztagh Ata ice core is much lower than that in an Alpine ice core record(100―300 ng·g-1) during the same period,but it is a factor of 14 in Greenland ice core(2.3 ng·g-1),this may induce a strong impact on the snow albedo in the last 46 years in our study *** indicate two periods with obviously high deposition concentrations(1955―1965 and 1974―1989) and two periods with low concentrations(1966―1973 and 1990―1995),as well as a recent increasing *** com-paring EC and SO42- concentration variations and deciphering OC/EC ratios recorded in the same ice core,we can judge roughly that the carbonaceous particles deposited in Muztagh Ata ice core were attributed to fossil fuel combustion sources.

关键词：冰层磁芯碳微粒物中国昆仑山

Human activity over natural inputs determines the bacterial community in an ice core from the Muztag ata glacier

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Science China Earth Sciences 2024年第5期67卷 1489-1499页

作者： Yongqin LIU Nianzhi JIAO Mukan JI Keshao LIU baiqing xu Bixi GUO Tandong YAO State Key Laboratory of Tibetan Plateau Earth System Resources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Center for Pan-third Pole Environment Lanzhou UniversityLanzhou 730013China University of Chinese Academy of Sciences Beijing 100101China State Key Laboratory for Marine Environmental Science Xiamen UniversityXiamen 361102China

Ice core provides a valuable vertical timeline of past climates and anthropogenic *** proxies have been widely used in these studies,but there are few biological indicators *** address this gap,we investigated the bacterial community from a 74 m ice core of Muztag ata glacier on the Tibetan Plateau to link biological indicators with past climate and anthropogenic *** analyzing the portion of the ice core with environmental proxies available(corresponding to 1907 to 1991),we observed an increase in bacterial richness throughout the ice core,which was associated with higher NH_(4)^(+),an indicator of agricultural *** bacterial community was jointly determined by human activity,natural input,and air temperature,with a strong human influence after the ***,the relative abundance of animal gut-associated bacteria,including Aerococcaceae,Nocardiaceae,Muribaculaceae,and Lachnospiraceae,was associated with livestock number changes in the Central Asian *** with other bacterial lineages,they jointly explained 59.8%of the livestock number *** study provides quantitative evidence of the associations between bacterial indicators and past climate and human activities,highlighting the potential of using bacterial proxies for ice core studies.

关键词： Ice core of Muztag ata glacier Climate change and anthropogenic activity Biological indicator Gut-associated bacteria livestock number in the Central Asian region

Atmospheric Pb variations in Central Asia since 1955 from Muztagata ice core record, eastern Pamirs

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Chinese Science Bulletin 2006年第16期51卷 1996-2000页

作者： LI Zhen YAO Tandong TIAN Lide xu baiqing LI Yuefang Key Laboratory of Cryosphere and Environment Chinese Academy of Sciences Lanzhou 730000 China Laboratory of Environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

A Muztagata ice core recovered at 7010 m altitude in East Pamirs provides a Pb concentration record from 1955 to 2000. The result reveals in- creasing Pb concentrations from 1955 to 1993, with two Pb concentration peaks in 1980 and 1993. After 1993, Pb concentrations in ice core show an obvi- ously declining trend. Analysis shows that the lead in the Muztagata ice core mainly came from anthropo- genic emissions from countries in Central Asia, while the local emission had little contribution.

关键词：冰核慕士塔格山铅大气中亚帕米尔高原

Ammonium record over the last 96 years from the Muztagata glacier in Central Asia

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Chinese Science Bulletin 2008年第8期53卷 1255-1261页

作者： ZHAO HuaBiao YAO TanDong xu baiqing LI Zhen DUAN KeQin State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

As a major alkaline gas in the atmosphere, ammonia (NH3) plays an important role in atmospheric chemistry. However, there is little knowledge about NH3 variations in the Central Asia. Here we ana- lyzed the ammonium (NH+4) history recorded in an ice core from the East Pamir in Central Asia, which was drilled on the Mt. Muztagata at the elevation of 7010 m a.s.l. in 2003. The core was carefully dated and NH4+ concentration history during 1907―2002 was reconstructed. The result shows that NH4+ con- centration remained approximately constant until the 1930s after a sudden decrease at the very begin- ning of the 20th century, followed by a minimum in 1940 before increasing steadily to the peak at the end of 1990s. It is found that the annual mean NH4+ concentration was strongly associated with the Northern Hemisphere temperature, suggesting the impact of temperature on NH3 emissions in the Central Asia. Moreover, an increase of NH+4 concentration after 1940 also reflects the enhancement of NH3 emissions from anthropogenic sources such as fertilizer applications and livestock wastes in the 20th century.

关键词：冰块核心铵含量氨水散发冰川

Characteristics of recent temperate glacier fluctuations in the Parlung Zangbo River basin,southeast Tibetan Plateau

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Chinese Science Bulletin 2010年第20期55卷 2097-2102页

作者： YANG Wei YAO TanDong xu baiqing MA LingLong WANG ZhiHui WAN Ming Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China State Key Laboratory of Cryosphere Chinese Academy of Sciences Lanzhou 730000 China Beibei Meteorological Bureau Chongqing 400700 China

Little is known about recent variation of temperate glaciers on the Tibetan Plateau,although they are of particular theoretical and practical interests in terms of climate change and water *** study of glacier mass balance and terminus variation for six temperate glaciers in the Parlung Zangbo River basin,southeast Tibetan Plateau,shows the facts of the overall negative mass balance and the continued terminus retreat from 2005/2006 to 2007/*** mass balances of smaller glaciers were more negative compared to larger *** the trend of glacier mass balance in the Hengduan Mountains,the Himalayas and glacier shrinkage in southeast Tibetan Plateau,the mass loss and recession of temperate glacier in this region are expected if the current climate condition continues.

关键词：青藏高原东南部冰川波动流域冰川物质平衡特征喜马拉雅山脉水资源供应西藏高原

Seasonal variations of dust record in the Muztagata ice cores

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Chinese Science Bulletin 2008年第16期53卷 2506-2512页

作者： WU GuangJian YAO TanDong xu baiqing TIAN LiDe LI Zhen DUAN KeQin Laboratory of Environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China State Key Laboratory of Cryospheric Science Chinese Academy of Sciences Lanzhou 730000 China

Based on the oxygen isotope ratio and microparticle record in ice cores recovered at Mt. Muztagata, Eastern Pamirs, the seasonal variations of atmospheric dust have been reconstructed for the past four decades. High dust concentrations and coarser particle grains have the similar trend with oxygen iso- tope value. Our statistical results indicate that 50%―60% high dust concentration samples occur dur- ing the season with high oxygen isotope values (summer), while low dust storm frequency during spring and winter. Back-trajectory analysis shows that the air mass hitting Muztagata predominately came from West Asia (such as Iran-Afghanistan Plateau) and Central Asia, which are the main dust source area for Muztagata. Dust storms in those source areas most frequently occur during summer (from May to August), while frequent dust storm events in northern China mainly occur during spring (March to May). Regions in the path of Asian dust transport, such as in Japan, the North Pacific, and Greenland, also show high dust concentrations during spring (from March to May). Our results indicate that dust storms have different seasonality in different regions within Asia.

关键词：灰尘季节变化冰层氧同位素