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Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

Science china Earth sciences 2006年第11期49卷 1156-1169页

作者： WANG Genxu1,3., LI Yuanshou2., WU Qingbai2.& WANG Yibo3.1. {2. of Mountain Hazards and environment, Chinese Academy of sciences, Chengdu 610041,{3. 2. cold and arid regions environmental and engineering research {2., Chinese Academy of sciences, lanzhou 73.000,{3. 3. Resource and environment School, lanzhou University, lanzhou 73.000,{3. 1. institute of Mountain Hazards and environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and environment School Lanzhou University Lanzhou 730000 China 2. cold and arid {2. {3. and engineering research institute Chinese Academy of Sciences Lanzhou 730000 China

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human {3. activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 2..11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

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Vertical quantitative and dominant population distribution of the bacteria isolated from the Muztagata ice core

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Science china Earth sciences 2005年第10期48卷 1728-1739页

作者： XIANG Shurong1, YAO Tandong1, 2, AN Lizhe1, 3. WU Guangjian2, XU Baiqing2, MA Xiaojun 3. LI Zhen1, WANG Junxia1 & YU Wusheng1 1. key laboratory of ice Core and {3. regions environment, {3. and arid regions environmental and engineering research institute, Chinese Academy of {13., lanzhou 73.000, china 2. institute of Tibetan Plateau research, Chinese Academy of {13., Beijing 100085, china 3. College of Life Science, lanzhou University, lanzhou 73.000, china key laboratory of {2. Core and {3. regions environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China institute of Tibetan Plateau research Chinese Academy of {2. Beijing{3. College of Life Science lanzhou University lanzhou{2.

Vertical distribution of the main bacteria isolated from the Muztagata ice core (about 2..4 m) was investigated by means of cultivation and 16S rRNA sequence analysis. The results showed that the amount of culturable bacteria fluctuated with ice core depth, and was more in dirty layer than in clean ice, which suggested the close corresponding relationship between high input of the bacteria deposited by wind and snowflow and dirty layer. Most of the bacteria were psychrophiles and psychrotolerants, including α- and γ-proteobacteria, Cryobacterium psychro-philum, CFB (Cytophaga-Flavobacterium-Bacteroides) group, high-G+C gram-positive bacteria (HGC). Acinetobacter sp. and HGC repeatly occurred in different ice depths, and their quantita-tive distribution was consistent with the change of the total amount of culturable bacteria with depth, which suggested the main bio-indicator; while Flavobacterium, Cryobacterium psychro-philum, and α-proteobacteria, also functioned as a secondary indicator of climatic and environ-mental changes. This study is the first report concerning continuous quantitative variation and pattern of the main culturable bacteria in ice core section.

关键词： Pamirs Plateau, ice core, pattern of bacteria, bio-indicator.

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Decrease trend of dust event frequency over the past 2.0 years recorded in the Malan ice core from the northern Tibetan Plateau

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Chinese Science Bulletin 2005年第24期50卷 2866-2871页

作者： WANG Ninglian key laboratory of Cryosphere and {2., {3. and arid regions environmental and engineering research institute, Chinese Academy of sciences, lanzhou 73.00, china institute of Tibetan Plateau research, Chinese Academy of sciences, Beijing 100085, china key laboratory of Cryosphere and {2. Cold and And Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 73000 China Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

By analyses of the dust layers in the Malan ice core from the northern Tibetan Plateau, it was found that dirty ratio in this core might be a good proxy for dust event frequency. The variations in the dirty ratio displayed a de- crease trend over the past 2.0 years, which implies that dust events became less frequent during the study period. The decrease trend in the variations in dust event frequency might be caused mostly by the natural processes, including increasing precipitation and weakening westerly which might be related with global warming. Furthermore, significant negative correlation was found between the dirty ratio and δ 18O in the Malan ice core. This is highly important for studying the effect of atmospheric dust on climate change.

关键词：青藏高原马伦冰核气候变化扬尘事件发生频率

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Variations in air temperature during the last 100 years revealed by δ^(18)O in the Malan ice core from the Tibetan Plateau

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Chinese Science Bulletin 2003年第19期48卷 2134-2138页

作者： WANG Ninglian, YAO Tandong, PU Jianchen, ZHANG Yongliang, SUN Weizhen & WANG Youqing key laboratory of {2. Core and {3. regions environment, {3. and arid regions environmental and engineering research {12., ChineseAcademy of {13., lanzhou 73.000, china key laboratory of {2. Core and {3. regions environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences China

By comprehensive analyses, it was found that the variations in d 18O recorded in Malan ice core from theKekexili region on the Tibetan Plateau could represent thechanges in air temperature during the summer half year (from May to October) over the Kekexili region and the northern margin of the Tibetan Plateau. The general increase trend in d18O in this ice core during the past century indicated climate warming, and it was estimated that air temperature during the summer half-year rose about 1.2. over there then. However, this ice core record documented that the study area has been cooling while most of the world has been dramatically warming since the late 1970s. A teleconnection was foundbetween the variations in d 18O in the Malan ice core and the North Atlantic Oscillation. Moreover, the variations in d 18O in this ice core were similar to that in the summer half-year air temperature over the southern Tibetan Plateau on thecenturial time scale, but opposite on the multidecadal timescale.

关键词：空气温度 δ^18O 西藏高原全球变暖马伦冰核北大西洋波动气候变化

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Spatial distribution of 10m firn temperature in the Antarctic ice Sheet

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Science china Earth sciences 2011年第5期54卷 655-666页

作者： WANG YeTang1,3.& HOU ShuGui2,3.1 Shandong Marine Fisheries research institute,Yantai 264006,china 2 MOE,{3. laboratory for Coast and Island Development,School of Geographic and Oceanographic sciences,Nanjing University,Nanjing 210093.china 3.tate {3. laboratory of Cryospheric Science,cold and arid regions environmental and {13. research institute,Chinese Academy of sciences,lanzhou 73.000,china 1. Shandong Marine Fisheries research institute Yantai 264006 China3. State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China2. MOE Key Laboratory for Coast and Island Development School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China

A database of Antarctic 10 m firn temperature was constructed using available borehole temperature measurements with data quality control to extend knowledge of Antarctic climate. Slopes from a high-resolution digital elevation model and the main ice divide were used to delineate main drainage sectors across Antarctica. In each drainage sector, a quantitative relationship between temperature and latitude, longitude and altitude was established using available tim temperature data. Quantitative relationships incorporating other factors affecting Antarctic air temperature such as atmospheric circulation and small-scale to- pography were used to derive a 10-km resolution grid map of surface temperature. The resulting temperature patterns presented a reasonable depiction of both large and small-scale variations in Antarctic 10 m firn temperature. This map is useful for many spatial variation studies, Antarctic ice sheet models, and comparison with satellite-derived temperature data and outputs of atmospheric general circulation models.

关键词： Antarctica 10 m firn temperature spatial distribution

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Sea-salt aerosol transport patterns over the Northern Hemisphere inferred from two subarctic ice core records

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Science china Earth sciences 2005年第4期48卷 576-584页

作者： YAN Yuping1,2, KANG Shichang2,3.5, SUN Junying4,5, Paul A. Mayewski2 & QIN Dahe5 1. National Climate Center, china Meteorological Administration, Beijing 100081, china 2. Climate Change institute, University of Maine, Orono, ME 04469, USA 3. institute of Tibetan Plateau research, Chinese Academy of sciences, Beijing 100085, china 4. Chinese Academy of Meteorological sciences, Beijing 100081, china 5. key laboratory of ice Core and cold {13. environment, cold and arid environmental and engineering research institute, Chinese Academy of sciences, lanzhou 73.000, china 1. National Climate Center China Meteorological Administration 100081 Beijing China 2. Climate Change institute University of Maine 04469 Orono ME USA 3. institute of Tibetan Plateau {2. Chinese Academy of Sciences 100085 Beijing China 4. key laboratory of {2. Core and {3. regions environment Cold and Arid Environmental and Engineering Research Institute Chinese Academy of Sciences 730000 Lanzhou China 5. Chinese Academy of Meteorological sciences 100081 Beijing China

Atmospheric circulation reconstruction based on glaciochemical records requires knowledge of chemical concentration controls, such as source, transport pathway and strength. To gain insight into these processes, the relationships between glaciochemical records from two Northern Hemisphere sites (Mt. Logan in Yukon Territory and 2.D in southern Greenland) and instrumental sea level pressure (SLP) series are investigated. Calibrations between Mt. Logan sea-salt sodium (ssNa+) concentration and SLP series show that ssNa+ concentrations are closely correlated with the autumntime (SON) Aleutian Low and the summertime (JJA) North Pacific Subtropical High. Both the deepened Aleutian Low and enhanced North Pacific Sub- tropical High strengthen the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. Calibrations between 2.D ssNa+ concentrations and SLP series indicate that ssNa+ concentrations are closely related to the wintertime (Jan.) icelandic Low. A deepening of the icelandic Low strengthens winter storms and frequent cyclogenesis over the North Atlantic and pushes more sea-salt laden air masses to the Greenland ice sheet. Therefore, ice core ssNa+ records from the Mt. Logan region can be considered as a proxy for reconstructing the au- tumntime Aleutian Low and summertime North Pacific Subtropical High, and the ssNa+ records from Greenland ice core (2.D) may provide a proxy for reconstructing the wintertime icelandic Low.

关键词： sea-salt aerosol, ice core records, sea level pressure, subarctic regions.

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Water transfer characteristics during methane hydrate formation and dissociation processes inside saturated sand

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Journal of Natural Gas Chemistry 2010年第1期19卷 71-76页

作者： Peng Zhang, Qingbai Wu, Yibin Pu, Guanli Jiang, Jing Zhan, Yingmei Wang State key laboratory, {2. and {3. regions environmental and engineering research institute, Chinese Academy of sciences, lanzhou 73.000, Gansu, china [a] State key laboratory Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 Gansu China

Gas hydrates formation and dissociation processes inside porous media are always accompanied by water transfer behavior, which is similar to the water behavior of ice freezing and thawing processes. These processes have been studied by many researchers, but all the studies are so far on the water transfer characteristics outside porous media and the water transfer characteristics inside porous media have been little known. In this study, in order to study the water transfer characteristics inside porous media during methane hydrate formation and dissociation processes, a novel apparatus with three pF-meter sensors which can detect water content changes inside porous media was applied. It was experimentally observed that methane hydrate formation processes were accompanied by water transfer from bottom to top inside porous media, however, the water behavior during hydrate dissociation processes was abnormal, for which more studies are needed to find out the real reason in our future work.

关键词： methane hydrate formation and dissociation processes: water transfer inside porous media saturated

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Turbulent intensity and its similarity function over an Inner Mongolian grassland during spring

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Science china Earth sciences 2010年第5期53卷 773-780页

作者： YUE Ping1,2,3. NIU ShengJie2, HU YinQiao4 & ZHANG Qiang1 1 key laboratory of arid Climate Change and Reducing Disaster of Gansu Province, key laboratory of arid Climate Change and Reducing Disaster of CMA, institute of arid Meteorology, CMA, lanzhou 73.020, china 2 Nanjing University of Information Science and Technology, Nanjing 210044, china 3.Zhangye National Meteorological Observatory, Zhangye 73.000, china 4 {13. and arid regions environmental and engineering research institute, Chinese Academy of Science, lanzhou 73.000, china 1. key laboratory of {2. Climate Change and Reducing Disaster of Gansu Province Key Laboratory of Arid Climate Change and Reducing Disaster of CMA Institute of Arid Meteorology CMA Lanzhou 730020 China2. Nanjing University of Information Science and Technology Nanjing 210044 China3. Zhangye National Meteorological Observatory Zhangye 734000 China4. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Science Lanzhou 730000 China

Macroscopic reason for the development of turbulences in fluid is the conjunction action of velocity and temperature shears. We use the 2.08 spring flux observations in the surface layer over Inner Mongolian grassland, obtain the similarity functions of turbulent intensity under different stratification stability conditions, and calculate the clear day turbulent intensity in the spring, which is then analyzed and compared with the observed values of turbulent intensity. The results show that in the Inner Mongolian grassland, under the condition of spring unstable stratification of the surface layer, dependence of the similarity function of turbulent intensity on stratification stability follows a "2.3.power law". The structural function is a constant under the neutral stratification condition, and complicated under the stable condition. The calculated turbulent intensity has a close correlation with the observed one, which verifies the accuracy of the similarity functions and the suitability of the theorem of turbulent intensity in the grassland region.

关键词： turbulent intensity variance of velocity similarity function grassland

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Vicissitude of Sogo Nur and environmental-climatic change during last 1500 years

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Science china Earth sciences 2004年第z1期47卷 61-70页

作者： JIN Heling, XIAO Honglang, SUN Liangying, ZHANG Hong, SUN Zhong & LI Xiaozekey laboratory of Desert and Desertification, {2. and {3. regions environmental and engineering research institute, Chinese Academy of sciences, lanzhou 73.000, china School of Resources and {12., {13. University, lanzhou 73.000, china 1. key laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences 730000 Lanzhou China2. School of Resources and Environment Lanzhou University 730000 Lanzhou China

Lakes in arid zone are sensitive to climatic changes. The lacustrine sediment sequence in Sogo Nur has well and truly recorded climatic events such as the Sui-Tang Dynasty Warm Period, the Song-Liao Dynasty cold Period, the Medieval Warm Period, the Little {2. Age and the 2.th Century Warm Period. Commonly, the climate in warm Periods was relatively humid,accordingly the lake area extended and water level rose, and v{2. versa. Apart from climatic change, human activity is also an important factor of influencing lake vicissitude, and they played the dominant role alternatively during different periods; the factor of climatic change predominated in historical period, while since the beginning of the 2.th century the utilization of water resources by human has became decisive.

关键词： granularity, soluble salt, lake vicissitude, climatic change, Sogo Nur.

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Climatic and environmental changes over the last millennium recorded in the Malan ice core from the northern Tibetan Plateau

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Science china Earth sciences 2006年第10期49卷 1079-1089页

作者： WANG Ninglian1,2. YAO Tandong2.1, PU Jianchen1, ZHANG Yongliang1 & SUN Weizhen1 1. key laboratory of Cryosphere and {2., {3. and arid regions environmental and engineering research institute, Chinese Academy of sciences, lanzhou 73.000,{12. 2. institute of Tibetan Plateau research, Chinese Academy of sciences, Beijing 100085,{12. 1. key laboratory of Cryosphere and {2. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China 2. institute of Tibetan Plateau research Chinese Academy of Sciences Beijing 100085 China

In this paper, climatic and environmental changes were reconstructed since 112.A.D. based on the Malan ice core from Hol Xil, the northern Tibetan Plateau. The record of δ 18O in the Malan ice core indicated that the warm-season air temperature variations displayed a general increase trend, the 2.th-century warming was within the range of natural climate variability, and the warmest century was the 17th century while the warmest decade was the 1610s, over the entire study period. The “Medieval Warm Epoch” and “Little ice Age” were also reflected by the ice core record. The dust ratio in the Malan ice core is a good proxy for dust event frequency. The 870-year record of the dust ratio showed that dust events occurred much frequently in the 19th century. Comparing the variations of δ 18O and the dust ratio, it is found that there was a strong negative correlation between them on the time scales of 101―102.years. By analyses of all the climatic records of ice cores and tree rings from the northern Tibetan Plateau, it was revealed that dust events were more frequent in the cold and dry periods than in the warm and wet periods.

关键词： the Tibetan Plateau, the Malan ice core, climate changes, dust event frequency.

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