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大型空间环模设备液氮喷射器的设计与研究(一) 被引量:1
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作者 徐烈 曹庆 +1 位作者 陈汉平 余品瑞 《低温工程》 CAS CSCD 1995年第3期1-6,共6页
比较了几种大型空间环境模拟设备的液氮系统,指出使用液氮喷射器是其发展方向,并从理论上论证了液氮喷射器在系统中的稳压补液作用。运用流体力学理论导出了喷射器的基本性能方程组,分析了液氮喷射器的汽蚀性能。利用数值解结果在给... 比较了几种大型空间环境模拟设备的液氮系统,指出使用液氮喷射器是其发展方向,并从理论上论证了液氮喷射器在系统中的稳压补液作用。运用流体力学理论导出了喷射器的基本性能方程组,分析了液氮喷射器的汽蚀性能。利用数值解结果在给定参数下计算并得出了液氮喷射器的基本尺寸和性能参数。在此基础上进行了稳压性能和补液性能的模拟实验,结果与分析相符。结果表明,液氮喷射器系统(本设计)的稳压性能优于高压杜瓦系统(如KM4),补液性能完全满足设计要求。 展开更多
关键词 空间环模 液氮 喷射器 飞行器
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空间环模设备超大尺寸冷屏的设计
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作者 景加荣 《低温工程》 CAS CSCD 北大核心 2008年第5期30-34,共5页
介绍了卫星环模试验中,用作红外辐射定标试验冷背景的低于18 K超大尺寸冷屏的设计方法,详细介绍了冷屏的结构设计、材料的选择、热设计、工艺制造等关键技术。试验应用结果表明,冷屏的实际技术性能指标达到并超过了设计要求。
关键词 卫星 空间环模 红外辐射定标 超大尺寸冷屏 设计
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KM3大型空间环模设备放气污染检测与污染控制
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作者 赵建萍 《航天器环境工程》 1998年第3期48-59,共12页
首次建立了对空间环模设备放气污染检测的6种测试方法,应用于KM3大型空间环模设备的多次试验中,并依据检测结果,对 KM3系统的污染特性从污染来源、成分及分布进行了详细论述,提出了一些相应的控制方法。
关键词 空间环模设备 空间模拟室 放气污染
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KFT空间环模设备热沉的设计与研制 被引量:2
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作者 龚吉君 《低温工程》 CAS CSCD 1989年第5期18-28,共11页
关键词 空间环模设备 热沉 航天器 KET
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浅析航天器的污染及其控制 被引量:6
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作者 程广河 《航天器环境工程》 2003年第1期35-39,共5页
在校准真空规时发现,即使采用无油真空抽气系统,来自航天器和空间环境模拟试验设备的污染依然严峻。文章分析了污染源和污染对航天器的影响,建议尽快制定污染控制标准和研制相应设备。
关键词 空间环模 污染控制
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DEM Production/Updating Based on Environmental Variables Modeling and Conflation of Data Sources 被引量:1
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作者 Tomaz Podobnikar 《Journal of Civil Engineering and Architecture》 2010年第11期33-44,共12页
Availability of digital elevation models (DEMs) of a high quality is becoming more and more important in spatial studies. Standard methods for DEM creation use only intentionally acquired data sources. Two approache... Availability of digital elevation models (DEMs) of a high quality is becoming more and more important in spatial studies. Standard methods for DEM creation use only intentionally acquired data sources. Two approaches which employ various types of data sets for DEM production are proposed: (1) Method of weighted sum of different data sources with morphological enhancement that conflates any additional data sources to principal DEM, and (2) DEM updating methods of modeling absolute and relative temporal changes, considering landslides, earthquakes, quarries, watererosion, building and highway constructions, etc. Spatial modeling of environmental variables concerning both approaches for (a) quality control of data sources, considering regions, (b) pre-processing of data sources, and (c) processing of the final DEM, have been applied. The variables are called rate of karst, morphologic roughness (modeled from slope, profile curvature and elevation), characteristic features, rate of forestation, hydrological network, and rate of urbanization. Only the variables evidenced as significant were used in spatial modeling to generate homogeneous regions in spatial modeling a-c. The production process uses different regions to define high quality conflation of data sources to the final DEM. The methodology had been confirmed by case studies. The result is an overall high quality DEM with various well-known parameters. 展开更多
关键词 Digital elevation/terrain model environmental variables data quality data conflation/integration spatial modeling.
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Implications of tree species–environment relationships for the responsiveness of Himalayan krummholz treelines to climate change 被引量:3
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作者 Niels SCHWAB Udo SCHICKHOFF +5 位作者 Birgit BURZLE Michael MULLER Jurgen BOHNER Ram Prasad CHAUDHARY Thomas SCHOLTEN Jens OLDELAND 《Journal of Mountain Science》 SCIE CSCD 2017年第3期453-473,共21页
Climate warming is expected to advance treelines to higher elevations. However, empirical studies in diverse mountain ranges give evidence of both advancing alpine treelines as well as rather insignificant responses. ... Climate warming is expected to advance treelines to higher elevations. However, empirical studies in diverse mountain ranges give evidence of both advancing alpine treelines as well as rather insignificant responses. In this context, we aim at investigating the sensitivity and responsiveness of the near-natural treeline ecotone in Rolwaling Himal, Nepal, to climate warming. We analysed population densities of tree species along the treeline ecotone from closed forest stands via the krummholz belt to alpine dwarf shrub heaths (3700-4200 m) at 50 plots in 2013 and 2014. We quantified species - environment relationships, i.e. the change of environmental conditions (e.g., nutrient and thermal deficits, plant interactions) across the ecotone by means of redundancy analyses, variation partitioning and distance-based Moran's eigenvector maps. In particular, we focus on explaining the high competitiveness of Rhododendron campanulatum forming a dense krummholz belt and on the implications for the responsiveness of Himalayan krummholz treelines to climate change. Results indicate that treeline trees in the ecotone show species-specific responses to the influence of environmental parameters, and that juvenile and adult tree responses are modulated by environmental constraints in differing intensity. Moreover, the species - environment relationships suggest that the investigated krummholz belt will largely prevent the upward migration of other tree constrain the future response species and thus of Himalayan krummholz treelines to climate warming. 展开更多
关键词 HIMALAYA Nepal Population structure Rhododendron campanulatum Spatial patterns Species-environment relationships Stand density Variation partitioning
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ANALYSIS OF HABITAT PATTERN CHANGE OF RED-CROWNED CRANES IN THE LIAO HE DELTA USING SPATIAL DIVERSITY INDEX 被引量:3
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作者 WANGLing LIXiu-zhen +1 位作者 HUYuan-man GUODu-fa 《Chinese Geographical Science》 SCIE CSCD 2003年第2期164-170,共7页
Habitat pattern change of red-crowned cranes (Grus japonensis) in t he Liaohe Delta between 1988 and 1998 was analyzed with the help of Spatial Dive rsity Index based on remote sensing data and field investigation. Th... Habitat pattern change of red-crowned cranes (Grus japonensis) in t he Liaohe Delta between 1988 and 1998 was analyzed with the help of Spatial Dive rsity Index based on remote sensing data and field investigation. The result sho wed that the influence from human activities on the wetland habitat of red-crow ned cranes was prominent with the development of oil and agricultural exploitati on, and the habitat pattern of red-crowned cranes had been obviously changed by the human disturbance during the ten years. The areas with high Spatial Diversi ty values (SD≥0.65) and that with mid-high values (0.5≤SD< 0.65), which const ituted the main part of suitable habitat of red-crowned cranes,had reduced to 9142ha and 5576ha respectively, with the shrinking of natural land cover, such a s reed and Suaeda community. The habitat pattern became more fragmented, which w as caused by roads and wells during oil exploration. It was indicated that the s uitability and quality of habitat for red-crowned cranes in the Liaohe Delta we re degraded in the last decade. The results also showed that diversity index cou ld reflect the habitat suitability of red-crowned cranes quantitatively and des cribe the spatial pattern of the habitat explicitly. This study will provide a s cientific basis for habitat protection of red-crowned cranes and other rare spe cies in wetlands. 展开更多
关键词 spatial diversity Index red-crowned crane ( GrUS japonensis) habitatpattern the liaohe delta
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Modeling and of Diatom Mud in Residential Space and the Application Scenario Research 被引量:1
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作者 Wei Xiaohui 《International Journal of Technology Management》 2017年第1期10-12,共3页
Our original ecological diatom mud qualities as a starting point for research, analyzes people’s consumption concept, aesthetics, environmental protection awareness. This article describes the basics and the origin o... Our original ecological diatom mud qualities as a starting point for research, analyzes people’s consumption concept, aesthetics, environmental protection awareness. This article describes the basics and the origin of diatom mud, diatom mud analyzes the features, functions and defects, the diatom mud paint and wallpaper were compared to explain the process and the market situation diatom mud, silicon Prospects algae mud were discussed. Through analysis of this environmentally friendly decorative paint diatom mud, summed diatom mud there are some problems in the conventional construction; through research and exploration of the diatom mud module series is proposed in the form of modules forming diatom mud can serialization assembly decorative product design concept. 展开更多
关键词 diatom mud living environment living space MODELING APPLICATION
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An Extended Closed-loop Subspace Identification Method for Error-in-variables Systems 被引量:1
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作者 刘涛 邵诚 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第6期1136-1141,共6页
A closed-loop subspace identification method is proposed for industrial systems subject to noisy input-output observations, known as the error-in-variables (EIV) problem. Using the orthogonal projection approach to el... A closed-loop subspace identification method is proposed for industrial systems subject to noisy input-output observations, known as the error-in-variables (EIV) problem. Using the orthogonal projection approach to eliminate the noise influence, consistent estimation is guaranteed for the deterministic part of such a system. A strict proof is given for analyzing the rank condition for such orthogonal projection, in order to use the principal component analysis (PCA) based singular value decomposition (SVD) to derive the extended observability matrix and lower triangular Toeliptz matrix of the plant state-space model. In the result, the plant state matrices can be retrieved in a transparent manner from the above matrices. An illustrative example is shown to demonstrate the effectiveness and merits of the proposed subspace identification method. 展开更多
关键词 closed-loop error-in-variables system subspace identification extended observability matrix orthogonal projection
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Physiological responses of people in working faces of deep underground mines 被引量:5
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作者 You Bo Wu Chao +1 位作者 Li Ji Liao Huimin 《International Journal of Mining Science and Technology》 SCIE EI 2014年第5期683-688,共6页
The research studied the influences of high temperature, high pressure, high humidity, noise and other harmful factors in mining conditions on the people health and safety, and investigated the impacts of confined env... The research studied the influences of high temperature, high pressure, high humidity, noise and other harmful factors in mining conditions on the people health and safety, and investigated the impacts of confined environmental on human physiology factors, including temperature, humidity, noise, pressure,toxic and harmful gases in terms of environmental characteristics in underground mines and an artificial intelligence system for simulation of the environment in a confined space of deep mines. Our results show that the systolic pressure, diastolic pressure, mean pressure, heart rate, respiratory rate, typing test speed and memory level percentage are negatively correlated with temperature value, and positively correlated with humidity value; the human temperature and weight are positively correlated with temperature value, and negatively correlated with humidity value. This research lays the foundation for the study of interaction between the deep confined space environment and safety behavior. 展开更多
关键词 Deep mine Confined space High temperature and high humidity Simulation experiment Human physiological index
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Urban-Design Process with Snow and Wind Simulations: A Study on the Kitami City Hall
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作者 Norihiro Watanabe Tsuyoshi Setoguchi +2 位作者 Shota Yokoyama Zhiming Guo Takuya Tsutsumi 《Journal of Civil Engineering and Architecture》 2017年第2期107-120,共14页
Regional climatic conditions should be considered while designing urban development plans, with special attention to the impact of snowfall on public spaces in cities with harsh winters. The Kitami-city-hall-renewal p... Regional climatic conditions should be considered while designing urban development plans, with special attention to the impact of snowfall on public spaces in cities with harsh winters. The Kitami-city-hall-renewal project in Hokkaido, Japan was studied as an environmental assessment of snow drifting. Assessments of the two site plans proposed during the architectural planning process (A-type and B-type) were conducted in terms of the following three items: (1) The two site plans indicate snow-drifting problems around the main entrance; (2) More number of local snowdrifts on the main-street sidewalks were suggested in the B-type design; (3) Less number of snowdrifts in the parking area beside the railroad were indicated in the A-type design. These results were reflected in the architectural planning process. On the basis of this study, a desirable design process incorporating environmental assessments has been identified for cities with harsh winters. 展开更多
关键词 Winter cities snow simulations wind tunnel urban design environmental assessments.
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Incorporating the Built Environment Interactions into Spatial Pattern Models to Understand Urban Metabolism in Tokyo's Residential Area
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作者 Akiko Kokubun Eiji Hato 《Journal of Civil Engineering and Architecture》 2013年第7期854-866,共13页
In Tokyo, as residential areas exist in the urban areas and are composed of areas owned by individual land owners, basically spatial changes are brought by redevelopments of each sites conducted by individual circumst... In Tokyo, as residential areas exist in the urban areas and are composed of areas owned by individual land owners, basically spatial changes are brought by redevelopments of each sites conducted by individual circumstances and motivations. Continuous redevelopments and spatial changes can be found dispersedly in areas. Once the spatial change in a certain site occurred in an area as a building, it will be contained in the built environment of the residential area which is defined by residents, planners and designers who will take part in the following spatial changes. In Tokyo, public transportation facilities are well developed, and residents' daily life involves activities such as a slow walking and bicycle, etc. around the place of residence near the public transportation hubs, each living territories are formed in this kind of manner. Considering the maintenance of spatial value in residential areas while understanding transformation of visual local environment in residential areas which focuses on appearance of each spatial change in an area of street will be of significant importance. In this paper, the authors try to describe interactions of spatial changes in existing urban residential areas focusing on utility of players who might take part in the following spatial changes and the method of discrete choice model. 展开更多
关键词 Existing urban residential areas in Tokyo redevelopment of housing site modification interaction discrete choicemodel.
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Impact of Different East Asian Summer Monsoon Circulations on Aerosol-Induced Climatic Effects
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作者 JU Li-Xia HAN Zhi-Wei 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第5期227-232,共6页
The different spatial distributions of aerosol-induced direct radiative forcing and climatic effects in a weak (2003) and a strong (2006) East Asian summer monsoon (EASM) circulation were simulated using a high-... The different spatial distributions of aerosol-induced direct radiative forcing and climatic effects in a weak (2003) and a strong (2006) East Asian summer monsoon (EASM) circulation were simulated using a high-resolution regional climate model (RegCM3).Results showed that the atmospheric circulations of summer monsoon have direct relations with transport of aerosols and their climatic effects.Both the top-of-the-atmosphere (TOA) and the surface-negative radiative forcing of aerosols were stronger in weak EASM circulations.The main difference in aerosol-induced negative forcing in two summers varied between 2 and 14 W m-2 from the Sichuan Basin to North China,where a maximum in aerosol-induced negative forcing was also noticed in the EASM-dominated areas.The spatial difference in the simulated aerosol optical depth (AOD) in two summers generally showed the similar pictures.Surface cooling effects induced by aerosols were spatially more uniform in weak EASM circulations and cooler by about 1-4.5℃.A preliminary analysis here indicated that a weaker low-level wind speed not conducive to the transport and diffusion of aerosols could make more contributions to the differences in the two circulations. 展开更多
关键词 AEROSOLS climatic effects East Asian summer monsoon regional climate model
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A high-level synthesis based dual-module redundancy with multi-residue detection(DMR-MRD)fault-tolerant method for on-board processing satellite communication systems
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作者 杨文慧 Chen Xiang +2 位作者 Wang Yu Zhao Ming Wang Jing 《High Technology Letters》 EI CAS 2014年第3期245-252,共8页
On board processing(OBP) satellite systems have obtained more and more attentions in recent years because of their high efficiency and performance.However,the OBP transponders are very sensitive to the high energy par... On board processing(OBP) satellite systems have obtained more and more attentions in recent years because of their high efficiency and performance.However,the OBP transponders are very sensitive to the high energy particles in the space radiation environments.Single event upset(SEU)is one of the major radiation effects,which influences the satellite reliability greatly.Triple modular redundancy(TMR) is a classic and efficient method to mask SEUs.However,TMR uses three identical modules and a comparison logic,the circuit size becomes unacceptable,especially in the resource limited environments such as OBP systems.Considering that,a new SEU-tolerant method based on residue code and high-level synthesis(HLS) is proposed,and the new method is applied to FIR filters,which are typical structures in the OBP systems.The simulation results show that,for an applicable HLS scheduling scheme,area reduction can be reduced by 48.26%compared to TMR,while fault missing rate is 0.15%. 展开更多
关键词 single event upset (SEU) residue code triple modular redundancy (TMR) high-level synthesis (HLS) fault missing rate
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Long-Term Evolution of the Black Sea Dynamics Derived from Modeling
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作者 Viktor Dorofeyev Larisa Sukhikh 《Journal of Shipping and Ocean Engineering》 2017年第1期35-42,共8页
Long-term evolution of the Black Sea dynamics (1980-2020) is reconstructed by means of numerical simulation. The model of the Black Sea circulation is z-coordinate model with 4.8 km horizontal space resolution and 4... Long-term evolution of the Black Sea dynamics (1980-2020) is reconstructed by means of numerical simulation. The model of the Black Sea circulation is z-coordinate model with 4.8 km horizontal space resolution and 40 levels in vertical direction. Mixing processes in the upper layer are parameterized with the Mellor-Yamada turbulent model. As for the boundary conditions on the sea surface, we used atmospheric forcing functions for the Black Sea region provided by CMCC using regional climate model COSMO-CLM. These data have a spatial resolution of 14km and a daily temporal resolution. To evaluate the quality of the Black Sea circulation dynamics, derived from simulation, the modeling results are compared with results of the Black Sea physical reanalysis. This reanalysis was performed by assimilating the temperature and salinity profiles from hydrographic surveys conducted during 1971-1993. 展开更多
关键词 Numerical modeling the Black Sea ocean currents seasonal variation.
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Spatial data modeling for coalfield geological environment
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作者 JIA Bei SU Qiao-mei LIU Chen LI Hui-juan 《Journal of Coal Science & Engineering(China)》 2010年第3期300-305,共6页
Presented a study on the design and implementation of spatial data modelingand application in the spatial data organization and management of a coalfield geologicalenvironment database.Based on analysis of a number of... Presented a study on the design and implementation of spatial data modelingand application in the spatial data organization and management of a coalfield geologicalenvironment database.Based on analysis of a number of existing data models and takinginto account the unique data structure and characteristic, methodology and key techniquesin the object-oriented spatial data modeling were proposed for the coalfield geological environment.The model building process was developed using object-oriented technologyand the Unified Modeling Language (UML) on the platform of ESRI geodatabase datamodels.A case study of spatial data modeling in UML was presented with successful implementationin the spatial database of the coalfield geological environment.The modelbuilding and implementation provided an effective way of representing the complexity andspecificity of coalfield geological environment spatial data and an integrated managementof spatial and property data. 展开更多
关键词 spatial data model OBJECT-ORIENTED Unified Modeling Language (UML) coal- field geological environment
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Modeling Long-term Forest Carbon Spatiotemporal Dynamics With Historical Climate and Recent Remote Sensing Data 被引量:1
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作者 Jing M.Chen 《Science Foundation in China》 CAS 2010年第1期30-56,共27页
Forests have long life cycles of up to several hundred years and longer.They also have very different growth rates at different stages of their life cycles.Therefore the carbon cycle in forest ecosystems has long time... Forests have long life cycles of up to several hundred years and longer.They also have very different growth rates at different stages of their life cycles.Therefore the carbon cycle in forest ecosystems has long time scales,making it necessary to consider forest age in estimating the spatiotemporal dynamics of carbon sinks in forests.The focus of this article is to review methods for combining recent remote sensing data with historical climate data for estimating the forest carbon source and sink distribution.Satellite remote sensing provides useful data for the land surface in recent decades. The information derived from remote sensing data can be used for short-term forest growth estimation and for mapping forest stand age for longterm simulations.For short-term forest growth estimation, remote sensing can provide forest structural parameters as inputs to process-based models,including big-leaf,two-leaf,and multi-layered models. These models use different strategies to upscale from leaf to canopy,and their reliability and suitability for remote sensing applications will be examined here.For long-term forest carbon cycle estimation, the spatial distribution of the forest growth rate(net primary productivity,NPP) modeled using remote sensing data in recent years is a critical input.This input can be combined with a forest age map to simulate the historical variation of NPP under the influence of climate and atmospheric changes. Another important component of the forest carbon cycle is heterotrophic respiration in the soil,which depends on the sizes of soil carbon pools as well as climate conditions.Methods for estimating the soil carbon spatial distribution and its separation into pools are described.The emphasis is placed on how to derive the soil carbon pools from NPP estimation in current years with consideration of forest carbon dynamics associated with stand age variation and climate and atmospheric changes.The role of disturbance in the forest carbon cycle and the effects of forest regrowth after disturbance are also considered in this review.An example of national forest carbon budget estimation in Canada is given at the end.It illustrates the importance of forest stand age structure in estimating the national forest carbon budgets and the effects of climate and atmospheric changes on the forest carbon cycle. 展开更多
关键词 forest carbon cycle forest age DISTURBANCE remote sensing NBP NPP NEP
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Spatial distribution of 10m firn temperature in the Antarctic Ice Sheet
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作者 WANG YeTang1,3 & HOU ShuGui2,3 1 Shandong Marine Fisheries Research Institute,Yantai 264006,China 2 MOE,Key Laboratory for Coast and Island Development,School of Geographic and Oceanographic Sciences,Nanjing University,Nanjing 210093,China 3State Key Laboratory of Cryospheric Science,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China 《Science China Earth Sciences》 SCIE EI CAS 2011年第5期655-666,共12页
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... 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. 展开更多
关键词 ANTARCTICA 10 m firn temperature spatial distribution
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