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Chinese Science bulletin 2010年第27期55卷 3205-3214页

作者： HU XlaoFei PAN baoTian KIRbY Eric LI QingYang GENG HaoPeng CHEN JiFeng Key Laboratory of Western China's Environmental Systems (MOE) Lanzhou University Lanzhou 730000 China Department of Geosciences Pennsylvania State University University Park PA16802 USA

The rate and distribution of deformation along the Qilian Mountain,on the northeastern Tibetan Plateau,is needed to understand the evolution of high topography associated with the ***,a number of empirical studies have provided support for the contention,common to most models of fluvial incision,that rock uplift rate exerts a first-order control on the gradient of longitudinal river *** the northern Qilian Mountain,this method is used to extract information about the spatial patterns of differential rock *** of the longitudinal profiles of bedrock channels reveals systematic differences in the channel steepness index along the trend of the frontal *** comparisons of channel steepness reveal that lithology and precipitation have limited influence on channel ***,there is little evidence suggesting that channel steepness is influenced by differences in the sediment *** argue that the distribution of channel steepness in the Qilian Mountain is mostly the result of differential rates of rock ***,channel steepness indices reveal a lower rock uplift rate in the eastern portion of the Qilian Mountain and a higher rate in the middle and *** highest rates appear to occur in the middle-west portions of the range,just to the west of the Yumu Shan.

关键词：青藏高原东北部隆升速率祁连山通道空间差异隆起北缘剖面分析

Difference in Tree Growth Responses to Climate at the Upper Treeline: Qilian Juniper in the Anyemaqen Mountains

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Journal of Integrative Plant biology 2008年第8期50卷 982-990页

作者： Jianfeng Peng Xiaohua Gou Fahu Chen Jinbao Li Puxing Liu Yong Zhang Keyan Fang Center for Arid Environment and Paleoclimate Research (CAEP) Key Laboratory of Westem China's Environment Systems MOE Lanzhou University Lanzhou 730000 China Institute of Resource and Environment Henan University Kaifeng 475004 China Tree-Ring Laboratory Lamont-Doherty Earth Observatory Columbia University NY 10964 USA College of Geography and Environment Sciences Northwest Normal University Lanzhou 730070 China

Three ring-width chronologies were developed from Qilian Juniper （Sabina przewalskii Kom.） at the upper treeline along a west-east gradient in the Anyemaqen Mountains. Most chronological statistics, except for mean sensitivity （MS）, decreased from west to east. The first principal component （PC1） Ioadings indicated that stands in a similar climate condition were most important to the variability of radial growth. PC2 Ioadings decreased from west to east, suggesting the difference of tree-growth between eastern and western Anyemaqen Mountains. Correlations between standard chronologies and climatic factors revealed different climatic influences on radial growth along a west-east gradient in the study area. Temperature of warm season （July-August） was important to the radial growth at the upper treeline in the whole study area. Precipitation of current May was an important limiting factor of tree growth only in the western （drier） upper treeline, whereas precipitation of current September limited tree growth in the eastern （wetter） upper treeline. Response function analysis results showed that there were regional differences between tree growth and climatic factors in various sampling sites of the whole study area. Temperature and precipitation were the important factors influencing tree growth in western （drier） upper treeline. However, tree growth was greatly limited by temperature at the upper treeline in the middle area, and was more limited by precipitation than temperature in the eastern （wetter） upper treeline.

关键词： climate-growth correlations dendrochronology Qilian juniper treeline

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Interannual and interdecadal variations in the North Atlantic Oscillation spatial shift

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Chinese Science bulletin 2011年第24期56卷 2621-2627页

作者： ZHANG XiaoJian JIN LiYa CHEN ChunZhu GUAN DongSheng LI MingZhi Key Laboratory of Western China's Environmental Systems (Ministry of Education) Lanzhou University Lanzhou 730000 China Institute of Geosciences University ofKiel Kiel D-24118 Germany

The spatial shift of the North Atlantic Oscillation (NAO) is analyzed by using the Twentieth Century Reanalysis version 2 dataset and identifying NAO action centers directly on winter mean sealevel pressure (SLP) anomaly maps. The spatial shift of the NAO is characterized by four NAO spatial shift indices: the zonal and meridional shifts of the NAO southern and northern action centers. It is found that the zonal and meridional shift trends of the NAO action centers move along a path of southwest-northwest direction. Spectral analysis shows that the four NAO spatial shift indices have periodicity of 2-6 years and the NAO index has periodicity of 2-3 years in terms of high-frequency variations. On a decadal time scale, the NAO spatial shift indices are closely (positively) related to the NAO index, which is in agreement with previous studies of the relationship between the NAO index and the spatial shift of the NAO pattern. However, there is no relationship between the NAO index and the meridional shift of the northern action center on an interannual time scale. The significant relationship between the NAO index and the interannual variability of NAO spatial shift indices is very likely to be associated with synopticscale Rossby wave breaking, which generates surface pressure anomalies and thus affects the phase and pattern of the NAO. The correlations of winter westerly winds over 90°W-0° and the NAO index and the NAO spatial shift indices have a '+ - + -' structure from the Equator to the North Pole. Although there is close correlation between the NAO spatial shift indices and the strength of the zonal winds in the North Atlantic region, the effect of the zonal winds on the NAO spatial shift differs at different latitudes. Hence, the role of the zonal winds is probably a result of the NAO spatial shifts.

关键词：北大西洋涛动年际时间尺度空间转移年代际变化 Rossby波审计署 NAO 压力异常

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High-resolution climate change in mid-late Holocene on Tianchi Lake,Liupan Mountain in the Loess Plateau in central China and its significance

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Science bulletin 2010年第20期55卷 2118-2121页

作者： ZHOU AiFeng,SUN HuiLing,CHEN FaHu ,ZHAO Yan,AN Chengbang,DONG GuangHui,WANG ZongLi & CHEN JianHui Center for Arid Environment and Paleoclimate Research,Key Laboratory of Western China’s Environmental System(Ministry of Education),Lanzhou 730000,China Center for Arid Environment and Paleoclimate Research Key Laboratory of Western China’s Environmental System (Ministry of Education) Lanzhou China

According to a core from Tianchi Lake,Liupan Mountain in Loess Plateau sediment,fossil pollen assemblages,magnetic susceptibility(MS)and color scale were measured based on reliable Abies leaf macrofossils radiocarbon *** recovered a very good high-resolution mid-late Holocene climate change achieve for the transition area of the East Asia monsoon region and northwest arid *** results show that the basic climate background was in agreement with the records from cave records in monsoon regions in eastern ***,it shows more detailed records in abrupt climate change.

关键词： high resolution mid-late Holocene Tianchi Lake

Asymmetric variability between maximum and minimum temperatures in Northeastern Tibetan Plateau:Evidence from tree rings

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Science China Earth Sciences 2008年第1期51卷 41-55页

作者： Jacoby GORDON Tree-Ring Laboratory Lamont-Doherty Earth Observatory Columbia University NY 10964 USA

Ecological systems in the headwaters of the Yellow River, characterized by hash natural environmental conditions, are very vulnerable to climatic change. In the most recent decades, this area greatly attracted the public's attention for its more and more deteriorating environmental conditions. based on tree-ring samples from the Xiqing Mountain and A'nyêmagên Mountains at the headwaters of the Yellow River in the Northeastern Tibetan Plateau, we reconstructed the minimum temperatures in the winter half year over the last 425 years and the maximum temperatures in the summer half year over the past 700 years in this region. The variation of minimum temperature in the winter half year during the time span of 1578―1940 was a relatively stable trend, which was followed by an abrupt warming trend since 1941. However, there is no significant warming trend for the maximum temperature in the summer half year over the 20th century. The asymmetric variation patterns between the minimum and maximum temperatures were observed in this study over the past 425 years. During the past 425 years, there are similar variation patterns between the minimum and maximum temperatures; however, the minimum temperatures vary about 25 years earlier compared to the maximum temperatures. If such a trend of variation patterns between the minimum and maximum temperatures over the past 425 years continues in the future 30 years, the maximum temperature in this region will increase significantly.

关键词： Tibetan Plateau tree-ring minimum temperature maximum temperature asymmetric variability warming trend

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Spatial differences in rock uplift rates inferred from channel steepness indices along the northern flank of the Qilian Mountain,northeast Tibetan Plateau

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Science bulletin 2010年第Z2期 3205-3214页

作者： KIRbY Eric Department of Geosciences Pennsylvania State UniversityUniversity Park

关键词： Qilian Mountain stream power erosion model channel steepness rock uplift rate river profile