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Comparisons of stable isotopic fractionation in winter and summer at Baishui Glacier No.1,***,China

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Journal of Geographical Sciences 2006年第3期16卷 306-314页

作者： PANG Hongxi HE Yuanqing LU Aigang ZHAO Jingdong NING Baoying YUAN Lingling SONG Bo ZHANG Ningning Key Laboratory of Cryosphere and environment Cold and Arid Regions Enviro~nrnentaland Engineering Research Institute CAS Lanzhou 730000 China Institute of Tibetan Plateau research GAS Beijing 100291 China

Based on the data of δ^18O in surface snow, snow pits, meltwater and the glacier-fed fiver water at Baishui Glacier No. 1, Mt. Yulong, the isotopic fractionation behaviors in the typical monsoonal temperate glacier system in winter and summer were compared. The results indicate that the isotopic fractionation degree in summer is greater than that in winter, suggesting that the snow/ice melting is more intense in summer. Moreover, whenever it is in winter or summer, from surface snow to meltwater, and to glacier-fed fiver water, the gradient of δ^18O with altitude gradually increases. This shows that the degree of isotopic fractionation gradually strengthens when surface snow is being converted into meltwater and finally into glacial fiver water, which suggests that the influence of post-depositional processes on δ^18O gradient in the monsoonal temperate glacier region differs spatially.

关键词： Yulong Mountain monsoonal temperate-glacier δ^18O

Numerical evaluation of the effectiveness of frost heave mitigation strategies for chilled arctic gas pipelines

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research in cold and arid regions 2022年第5期14卷 338-345页

作者： XinZe Li QingBai Wu HuiJun Jin Rui Shi Gang Wu YaPeng Cao State Key Laboratory of Frozen Soils engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China College of Resources and environment University of Chinese Academy of SciencesBeijing 100049China Department of Chemical and Material engineering University of AlbertaEdmontonAB T6G1H9Canada School of Civil engineering/Northeast-China Observatory and research-Station of Permafrost Geo-environment–Ministry of Education/Institute of cold-regions engineering Science and TechnologyNortheast Forestry UniversityHarbinHeilongjiang 150040China Department of Oil&Gas Storage and Transportation engineering School of EngineeringChina University of Petroleum-Beijing at KaramayXinjiang Uygur Autonomous Region 834000China

To prevent the thawing of ice-rich permafrost,it is suggested that gas should be transported in a chilled state(below the freezing temperature)in pipelines buried in ***,frost heave occurs when water migrates towards the chilled pipeline and ice lenses grow underneath the *** might endanger the integrity of the pipeline and the environment as ***,innovative frost heave mitigation measures are required when designing the pipeline,especially those sections in discontinuous permafrost or near the compressor sta*** ground temperature field in response to the operation of a proposed chilled gas pipeline traversing permafrost regions in Alaska was simulated by a pipe-soil thermal interaction geothermal *** heave mitigation measures,including insulation around the pipe,flat slab insulation under the pipe,and heating cables combined with slab insulation,were evaluated for chilled pipeline operation in seasonally varying ambient *** numerical results show that the minimum temperature of the observation point at 2.5 m below the pipe bottom increases by 17%,29%,and 48%when the thermal conductivity of the outer insulation layer is 0.1,0.05,and 0.02 W/(m K),*** flat slab insulation,the thermal field is less sensitive to varying slab thicknesses than to varying thermal conductivity,implying the thermal conductivity,not the thickness,is the crucial ***,the heat flow could be redirected from vertical to horizontal by flat slab *** electrical heating cables could be regarded as a new heat source to balance the heat removal rate of the soil around the chilled *** minimum temperature of the observation point at 1.1 m below the bottom of the pipe increases from-15.2℃to-3.0,1.5,and 7.5℃,corresponding to the heating cable power of 20,30,and 40 W,respectively,with the power of 30 W deemed appropriate for the study *** is concluded that heating cables in combination with insulation

关键词： Permafrost Chilled gas pipeline Temperature field Numerical assessment

Changes and spatial patterns of the differences between ground and air temperature over the Qinghai-Xizang Plateau

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Journal of Geographical Sciences 2007年第1期17卷 20-32页

作者： ZHANG Wengang LI Shuxun WU Tonghua PANG Qiangqiang The National Field Station for Scientific Observation of Cryosphere Special environment and Disaster over the North of Qinghai-Tibet Plateau Golmud 816000 China cold and arid regions environmental and engineering research Institute CAS Lanzhou 730000 China

The difference between ground soil and air temperature （Ts-Ta） was studied by using the data of ground and air temperature of 99 stations over the Qinghai-Xizang （Tibet） Plateau from 1960 to 2000,and its spatial distribution and time changing tendency have been diagnosed by principal component analysis and power spectral analysis methods. The results show that the values of （Ts-Ta） are the maximum in June and the minimum in December. The first three loading eigenvectors, which reflect the main spatially anomalous structure of （Ts-Ta） over the Qinghai-Xizang Plateau, contain the contrary changing pattern between the northwestern and the southeastern regions, the pattern response of the sea level elevation and the geography, and the pattern response of the distribution of the permafrost. There are four patterns of time evolution including the patterns of monotonous increasing or decreasing trends, the basic stability pattern and the parabola pattern with the minimum value. （Ts-Ta） has a periodic variation about 2 years. According to the spatial distribution of the third loading eigenvectors of （Ts-Ta） over the Qinghai-Xizang Plateau in cold season, the permafrost response region and the seasonal frozen ground response region are identified.

关键词： Qinghai-Xizang Plateau difference between ground and air temperature (Ts-Ta) principal component temperature subarea

Seasonal Characteristics of Surface Radiation Fluxes on the East Rongbuk Glacier in the *** region

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Acta meteorologica Sinica 2010年第6期24卷 680-698页

作者：杨兴国秦大河张廷军康世昌秦翔刘宏谊 State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environment and Engineering Research InstituteChinese Academy of Sciences National Snow and Ice Data Center Cooperative Institute for Research in Environmental SciencesUniversity of Colorado Gansu Province Key Laboratory of arid Climatic Change and Disaster Reduction Institute of Arid MeteorologyChina Meteorological Administration

Ground-based measurements are essential for understanding alpine glacier dynamics,especially in remote regions where in-situ measurements are extremely *** 1 May to 22 July 2005（the spring-summer period）,and from 2 October 2007 to 20 January 2008（the autumn-winter period）,surface radiation as well as meteorological variables were measured over the accumulation zone on the East Rongbuk Glacier of Mt. Qomolangma/Everest at an elevation of 6560 m *** using an automatic weather station（AWS）.The results show that surface meteorological and radiative characteristics were controlled by two major synoptic circulation regimes：the southwesterly Indian monsoon regime in summer and the westerlies in *** the AWS site on the East Rongbuk Glacier,north or northwest winds prevailed with high wind speed（up to 35 m s^（-1） in January） in winter while south or southeast winds predominated after the onset of the southwesterly Indian monsoon with relatively low wind speed in *** of incoming shortwave radiation was extremely high due to the high elevation,multiple reflections between the snow/ice surface and clouds,and the high reflective surrounding *** factors also caused the observed 10-min mean solar radiation fluxes around local noon to be frequently higher than the solar constant from May to July *** mean surface albedo ranged from 0.72 during the spring-summer period to 0.69 during the autumn-winter period. The atmospheric incoming longwave radiation was greatly affected by the cloud condition and atmospheric moisture *** overall impact of clouds on the net all-wave radiation balance was negative in the Mt. Qomolangma *** daily mean net all-wave radiation was positive during the entire spring-summer period and mostly positive during the autumn-winter period except for a few overcast *** monthly basis,the net all-wave radiation was always positive.

关键词： Mt.Qomolangma glacier snow surface radiation feature meteorological characteristic

Origin of summer monsoon rainfall identified by δ18O inprecipitation

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Science Bulletin 2005年第23期50卷 2761-2764页

作者： PANG Hongxi1, HE Yuanqing1, 2, ZHANG Zhonglin1, LU Aigang1, GU Juan1 & ZHAO Jingdong1 1. Key Laboratory of Cryosphere and environment, cold and arid Re-gions 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 Key Laboratory of Cryosphere and environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Institute of Tibetan Plateau research Chinese Academy of Sciences Beijing 100085 China

A negative correlation between δ 18O in mon-soon precipitation and f, the ratio of precipitable water in monsoon region to that in water source area, is hypothesized. Using the Rayleigh model, a new method for identifying ori-gin of summer monsoon rainfall is developed based on the hypothesis. In order to validate the method, the isotopic data at New Delhi, a typical station in the southwest monsoon region, and Hong Kong, a typical station in the southeast monsoon region, were collected and analyzed for case studies. The case studies indicate that the water source areas of the monsoon rainfall at the two stations identified by the method are accordant with the general atmosphere circulation pat-terns. The method developed in this paper is significantly important for tracing the origin of summer monsoon pre-cipitation.

关键词： monsoon stable isotopes origin of monsoon precipita-tion.

Variations of near-surface atmospheric CO_(2)and H_(2)O concentrations during summer on Muztagata

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Science China Earth Sciences 2006年第1期49卷 18-26页

作者： XU Baiqing1,2, YAO Tandong1,2, LU Anxin2, GUO Xuejun, LIU Xianqin2 & LI Zhen2 1. Laboratory of environment and Process on Tibetan Plateau, Institute of Tibetan Plateau research, Chinese Academy of Sciences, Beijing 100085, China 2. Key Laboratory of Cryosphere and environment, Jointly Established by cold and arid regions environmental and Engi-neering research Institute and Institute of Tibetan Plateau research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, Lanzhou 730000, China Laboratory of environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Key Laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China

Expeditions during the summers of 2002 and 2003 implemented continuous monitoring of near-surface (2 m height) atmospheric CO2 and H2O concentrations at the 4500 m elevation on Muztagata. The resultant data sets reveal a slight decrease of CO2 concentrations (of about 5 μmol·mol?1) and changes in the diurnal variations from the end of June to the middle August. The daily maximum CO2 concentrations occur between 02:30―05:30 AM (local time) and the minimum levels occur between 12:00―15:30 PM. The atmospheric CO2 concentrations in the summer of 2002 were around 5 μmol·mol?1 lower than those during the same period of 2003, whereas the diurnal amplitude was higher. In contrast, we found that the daily mean atmospheric H2O content in 2003 was much lower than that in 2002 and there exists a striking negative correlation between CO2 and H2O con-centrations. We therefore suggest that the near-surface atmospheric CO2 concentration is affected not only by photosynthesis and respiration, but also by the air H2O content in the glaciated region around Muztagata.

关键词： atmospheric CO2 and H2O concentration, continuous monitoring, glaciation region, Muztagata.

Variations of δ^(18)O in precipitation from the Muztagata Glacier, East Pamirs

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Science China Earth Sciences 2006年第1期49卷 36-42页

作者： LI Zhen1, YAO Tandong1,2, TIAN Lide1,2, XU Baiqing1,2 & Wu Guangjian2 1. Key Laboratory of Cryosphere and environment, Jointly Established by cold and arid regions environmental and Engi-neering research Institute and Institute of Tibetan Plateau research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, CAS, Lanzhou 730000, China 2. Laboratory of environment and Process on Tibetan Plateau, Institute of Tibetan Plateau research, Chinese Academy of Sciences, Beijing 100085, China Key Laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China Laboratory of environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China

Expeditions to Muztagata (in the eastern Pamirs) during the summer seasons of 2002 and 2003 collected precipitation samples and measured their oxygen isotopes. The δ 18O in precipita-tion displays a wide range, varying from ?17.40‰ to +1.33‰ in June-September 2002 and from ?22.31‰ to +4.59‰ in May-August 2003. The δ 18O in precipitation correlates with the initial tem-perature of precipitation during the observing periods. The positive correlation between δ 18O and tem- perature suggests that δ 18O can be used as an indicator of temperature in this region. The δ 18O values in fresh-snow samples collected from two snow events at different elevations on the Muztagata Gla-cier show a strong “altitude effect”, with a ratio of nearly ?0.40‰ per 100 m from 5500 m to 7450 m.

关键词： Muztagata, δ18O, temperature, altitude effect.

Relationships between δ ^(18)O in summer precipitation and temperature and moisture trajectories at Muztagata, western China

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Science China Earth Sciences 2006年第1期49卷 27-35页

作者： YU Wusheng1,2, YAO Tandong1,2, TIAN Lide1,2, LI Zhen2, SUN Weizhen2 & WANG Yu2 1. Laboratory of environment and Process on Tibetan Plateau, Institute of Tibetan Plateau research, Chinese Academy of Sciences, Beijing 100085, China 2. Key Laboratory of Cryosphere and environment, Jointly Established by cold and arid regions environmental and Engi-neering research Institute and Institute of Tibetan Plateau research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, CAS, Lanzhou 730000, China Laboratory of environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Key Laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China

Based on summer observations of stable isotope of precipitation at Muztagata, western China, during 2002―2003, this paper presents the relationship between δ 18O in precipitation and air temperature, and discusses the effect of moisture transport on δ 18O in precipitation. Results show that air temperature correlates positively with δ 18O in precipitation, and the temperature effect controls the δ 18O of precipitation in this area. The Muztagata region exhibits high δ 18O values in summer precipi-tation, similar to those shown at stations in adjacent regions. According to the results of our model set up to trace the moisture trajectories, the westerlies and local moisture circulation contribute to varia-tions of oxygen isotopes in precipitation. In addition, the impacts of the moisture transport distance, the moisture transport level, and the incursion of the polar air mass also influence the variations of δ 18O in precipitation. The moisture origins and transport mechanisms also contribute to the variation of δ 18O in precipitation at Muztagata.

关键词： Muztagata, δ18O, precipitation, temperature, moisture transport.

Characteristics of DDF at Baishui Glacier No.1 region in Yulong Snow Mountain

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Journal of Earth Science 2010年第2期21卷 148-156页

作者：和献中杜建括吉亚鹏张宁宁李宗省王世金 Wilfred H Theakstone State Key Laboratory of Cryospheric Sciences Yulong Snow Mountain Glacial and Environmental Observation StationCold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Graduate University of Chinese Academy of Sciences Institute of environment and Climate Change research in Western China Lanzhou University School of environment and Development University of Manchester

Based on observed mass balance and meteorological data since September 2008 and ablation data by the expedition team of Tibetan plateau from June to August 1982 at Baishui （白水） Glacier No. 1 region, we analyzed the spatial and temporal changes of degree-day factor （DDF） of the Baishui Glacier No. 1 following the changes of space, time, and temperature, which lays a theoretical foundation to establish DDF model. The results indicate that the melting DDF of ice showed a significant downward trend with rising temperatures, and larger value of DDF only appeared at low temperature conditions. A larger value of DDF appeared in the high altitude areas, and as altitude rises, the value of DDF increased. The snow DDF is lower than the DDF of ice, and the DDF is higher in temperate glaciers than those in other glaciers. The melting DDF of snow has a more obvious seasonal variation than the melting DDF of ice.

关键词： degree-day factor (DDF) Baishui Glacier No. 1 ablation monsoonal temperate glaciers.