检索结果-南通市图书馆

Advances in Atmospheric Sciences 2010年第3期27卷 605-620页

作者：韩博吕世华奥银焕 cold and arid Regions environmental and engineering research institute Chinese Academy of Sciences

The kinetic energy variations of mean flow and turbulence at three levels in the surface layer were calculated by using eddy covariance data from observations at Jinta oasis in 2005 summer. It is found that when the mean horizontal flow was stronger, the turbulent kinetic energy was increased at all levels, as well as the downward mean wind at the middle level. Since the mean vertical flow on the top and bottom were both negligible at that time, there was a secondary circulation with convergence in the upper half and divergence in the lower half of the column. After consideration of energy conversion, it was found that the interaction between turbulence and the secondary circulation caused the intensification of each other. The interaction reflected positive feedback between turbulence and the vertical shear of the mean flow. Turbulent sensible and latent heat flux anomaly were also analyzed. The results show that in both daytime and at night, when the surface layer turbulence was intensified as a result of strengthened mean flow, the sensible heat flux was decreased while the latent heat flux was increased. Both anomalous fluxes contributed to the cold island effect and the moisture island effect of the oasis.

关键词： heterogeneous atmospheric boundary layer turbulent kinetic energy equations energy con-version secondary circulation oasis effect

Connection Between Atmospheric Latent Energy and Energy Fluxes Simulated by Nine CMIP5 Models

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological research 2015年第3期29卷 412-431页

作者：韩博吕世华李瑞青奥银焕陈昊高艳红马迪 Key Laboratory of Land Surface Process and Climate Change in cold and arid Regions Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

The atmospheric latent energy and incoming energy fluxes of the atmosphere are analyzed here based on the historical simulations of nine coupled models from the Coupled Model Intercomparison Project Phase 5 （CMIP5） and two reanalysis datasets. The globally averaged atmospheric latent energy is found to be highly correlated with several types of energy flux, particularly the surface latent heat flux, atmosphere absorbed solar radiation flux, and surface net radiation flux. On the basis of these connections, a hydrological cycle controlled feedback （HCCF） is hypothesized. Through this feedback, the atmosphere absorbed solar radiation is enhanced and causes intensification of the surface latent heat flux when the atmospheric latent energy is abnormally strong. The representativeness of the HCCF during different periods and over different latitudinal zones is also discussed. Although such a feedback cannot be confirmed by reanalysis, it proves to be a common mechanism for all the models studied.

关键词： atmospheric latent energy CMIP5 hydrological cycle climate feedback

The changes in the annual distribution of mountain runoff during the period of 1965-2018 in Hexi Corridor,Northwest China

在线全文

学校读者我要写书评

暂无评论

research in cold and arid Regions 2024年第2期16卷 73-83页

作者： Yan Luo ZhiXiang Lu Qi Feng Meng Zhu JinBo Zhang Key Laboratory of Ecological Safety and Sustainable Development in arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China University of Chinese Academy of Sciences Beijing 100049China cCollege of Resources and environmental Sciences Gansu Agricultural UniversityLanzhouGansu 730000China

The annual distribution characteristics of river runoff in arid regions have significant implications for water resource stability and *** on the mountain runoff data from 1965 to 2018,this study examines the annual change characteristics of monthly runoff of the Shiyang River Basin,Heihe River Basin,and Shule River Basin in the Hexi Corridor,Northwest *** indexes are used and analyzed,including the coefficient of variance,the complete regulation coefficient,the concentration degree and concentration period,the magnitude of change,the skewness coefficient,and the kurtosis coefficient of the annual distribution *** results reveal the following:(1)The inhomogeneity of annual runoff distribution in the Taolai River and the rivers to the west of it,except the Shiyou River,show an increasing ***,the inhomogeneity of the rivers to the east of the Taolai River generally show a downward trend,but the coefficient of variance value is still very high.(2)In the Shiyang River Basin,the annual distribution of the concentration period is characterized by a relatively discrete ***,the Heihe River Basin exhibits a relatively concentrated pattern,and the distribution pattern of the Shule River Basin is quite ***,all concentration periods in the three basins have shifted backward after the 2000s.(3)The Shiyang River Basin exhibits disordered annual distribution curves of runoff in different *** contrast,the Heihe River Basin presents a typical‘single-peak’pattern with a prominent *** Shule River Basin has regular distribution curves,with a gradually significant‘double-peak’pattern from east to ***,there has been a slight change in runoff in the Shiyang River Basin,while the Heihe River Basin and Shule River Basin have experienced significant increases in *** annual distribution curves of runoff in the Liyuan River and the rivers to the east of it exhibit a gentle peak pattern,and th

关键词： Hexi Corridor Inland rivers Mountain runoff Annual distribution characteristics of runoff

Response of Atmospheric Energy to Historical Climate Change in CMIP5

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological research 2015年第1期29卷 93-105页

作者：韩博吕世华高艳红奥银换李瑞青 Key Laboratory of Land Surface Process and Climate Change in cold and arid Regions Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Three forms of atmospheric energy, i.e., internal, potential, and latent, are analyzed based on the historical simulations of 32 Coupled Model Intercomparison Project Phase 5（CMIP5） models and two reanalysis datasets（NCEP/NCAR and ERA-40）. The spatial pattern of climatological mean atmospheric energy is well reproduced by all CMIP5 models. The variation of globally averaged atmospheric energy is similar to that of surface air temperature（SAT） for most models. The atmospheric energy from both simulation and reanalysis decreases following the volcanic eruption in low-latitude zones. Generally, the climatological mean of simulated atmospheric energy from most models is close to that obtained from NCEP/NCAR, while the simulated atmospheric energy trend is close to that obtained from ERA-40. Under a certain variation of SAT, the simulated global latent energy has the largest increase ratio, and the increase ratio of potential energy is the smallest.

关键词： atmospheric energy CMIP5 historical climate change

A Diagnostic Analysis on the Effect of the Residual Layer in Convective Boundary Layer Development near Mongolia Using 20th Century Reanalysis Data

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2015年第6期32卷 807-820页

作者： HAN Bo ZHAO Cailing L Shihua WANG Xin Key Laboratory of Land Surface Process and Climate Change in cold and arid Regions Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Although the residual layer has already been noted in the classical diurnal cycle of the atmospheric boundary layer, its effect on the development of the convective boundary layer has not been well studied. In this study, based on 3-hourly 20th century reanalysis data, the residual layer is considered as a common layer capping the convective boundary layer. It is identified dally by investigating the development of the convective boundary layer. The region of interest is bounded by （30^-60~N, 80^-120~E）, where a residual layer deeper than 2000 m has been reported using radiosondes. The lapse rate and wind shear within the residual layer are compared with the surface sensible heat flux by investigating their climatological means, interannual variations and daily variations. The lapse rate of the residual layer and the convective boundary layer depth correspond well in their seasonal variations and climatological mean patterns. On the interannual scale, the correlation coefficient between their regional averaged （40°-50°N, 90°-110°E） variations is higher than that between the surface sensible heat flux and convective boundary layer depth. On the daily scale, the correlation between the lapse rate and the convective boundary layer depth in most months is still statistically significant during 1970-2012. Therefore, we suggest that the existence of a deep neutral residual layer is crucial to the formation of a deep convective boundary layer near the Mongolian regions.

关键词： convective boundary layer residual layer lapse rate surface sensible heat flux wind shear

Effect of traffic restriction on atmospheric particle concentrations and their size distributions in urban Lanzhou, Northwestern China

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2014年第2期26卷 362-370页

作者： Suping Zhao Ye Yu Na Liu Jianjun He Jinbei Chen Key Laboratory of Land Surface Process and Climate Change in cold and arid Regions Cold & Arid Regions Environmental & Engineering Research Institute Chinese Academy of Sciences University of Chinese Academy of Sciences

During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect of these measures on urban air quality, especially particle concentrations and their size distributions, atmospheric particle size distributions （0.5-20μm） obtained using an aerodynamic particle sizer （model 3321, TSI, USA） in June 2012 were analyzed. It was found that the particle number, surface area and volume concentrations for size range 0.5-10 μm were （15.0±2.1） cm-3, （11.8±2.6） μm2/cm3 and （1.9±0.6） μm2/cm3, respectively, on the traffic-restricted day （Sunday）, which is 63.2%, 53.0% and 47.2% lower than those on a normal Sunday. For number and surface area concentrations, the most affected size range was 0.5-0.7 and 0.5-0.8 μm, respectively, while for volume concentration, the most affected size ranges were 0.5-0.8, 1.7-2.0 and 5.0-5.4 μm. Number and volume concentrations of particles in size range 0.5-1.0μm correlated well with the number of non-CNG （Compressed Natural Gas） powered vehicles, while their correlation with the number of CNG-powered vehicles was very low, suggesting that reasonable urban traffic controls along with vehicle technology improvements could play an important role in improving urban air quality.

关键词： traffic restriction particle concentration size distribution urban air quality

Ecohydrological change mechanism of a rainfed revegetation ecosystem at southeastern edge of Tengger desert,Northwest China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2004年第z1期47卷 71-77页

作者： XIAO Honglang CHENG Guodong LI Xinrong SONG Yaoxuan WANG Xinping Shapotou Desert Experimental research Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Shapotou Desert Experimental Research Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Shapotou Desert Experimental Research Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Shapotou Desert Experimental Research Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Shapotou Desert Experimental Research Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Study is made on a 45 km-long artificial ecosystem without irrigation in Tengger desert on the basis of long-term ecological monitoring and ecohydrological *** in water allocation, utilization, cycle and balance patterns in more than 40-year evolution of the soil-plant system are analyzed. The formation of a drought horizon in shrub rhizosphere and its effect, ecohydrological function of the crust and its effect on the soil-plant system change are discussed. Driven by water self-regulation and water stress, the soil-plant system is going to develop towards the steppe desert to ensure more effective use and optimum collocation of water resource.

关键词： ecohydrology, artificial ecosystem, soil-plant evolution, water balance, drought horizon, bio-crust, Chinese desert.

Effects of Initial and Boundary Conditions on Heavy Rainfall Simulation over the Yellow Sea and the Korean Peninsula:Comparison of ECMWF and NCEP Analysis Data Effects and Verification with Dropsonde Observation

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第9期41卷 1787-1803页

作者： Jiwon HWANG Dong-Hyun CHA Donghyuck YOON Tae-Young GOO Sueng-Pil JUNG Department of Civil Urban Earth and environmental engineering Ulsan National Institute of Science and TechnologyUlsan 44919South Korea Program in Atmospheric and Oceanic Sciences Princeton UniversityPrincetonNew Jersey 08544USA National institute of Meteorological Sciences NIMSJeju 63568South Korea

This study evaluated the simulation performance of mesoscale convective system(MCS)-induced precipitation,focusing on three selected cases that originated from the Yellow Sea and propagated toward the Korean *** evaluation was conducted for the European Centre for Medium-Range Weather Forecasts(ECMWF)and National Centers for environmental Prediction(NCEP)analysis data,as well as the simulation result using them as initial and lateral boundary conditions for the Weather research and Forecasting ***,temperature and humidity profiles from 3D dropsonde observations from the National Center for Meteorological Science of the Korea Meteorological Administration served as validation *** showed that the ECMWF analysis consistently had smaller errors compared to the NCEP analysis,which exhibited a cold and dry bias in the lower levels below 850 *** model,in terms of the precipitation simulations,particularly for high-intensity precipitation over the Yellow Sea,demonstrated higher accuracy when applying ECMWF analysis data as the initial *** advantage also positively influenced the simulation of rainfall events on the Korean Peninsula by reasonably inducing convective-favorable thermodynamic features(i.e.,warm and humid lower-level atmosphere)over the Yellow *** conclusion,this study provides specific information about two global analysis datasets and their impacts on MCS-induced heavy rainfall simulation by employing dropsonde observation ***,it suggests the need to enhance the initial field for MCS-induced heavy rainfall simulation and the applicability of assimilating dropsonde data for this purpose in the future.

关键词： initial conditions dropsonde heavy rainfall forecast global model analysis evaluation

Estimation of tree transpiration and response of tree conductance to meteorological variables in desert-oasis system of Northwest China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2004年第z1期47卷 9-20页

作者： CHEN Rensheng KANG Ersi ZHANG Zhihui ZHAO Wenzhi SONG Kechao ZHANG Jishi LAN Yongchao cold and arid Regions environmental and engineering research institute Chinese Academy of Sciences Lanzhou 730000 China

Transpirations of three dominated tree species, namely Mongol Scotch Pine (Pinus sylvestris var. mongolica Litvin), White elm (Ulmus pumila) and Gansu Poplar (Populus gansuensis Wang et Yang) in oasis shelter forest (Linze site) and of two dominated tree species,namely Euphrates Poplar (Populus euphratica Oliv.) and Russia olive (Elaeagnus angustifolia Linn.) in lowland desert (Erjinaqi site) have been estimated using measured sapflow in summer,autumn and winter, 2002 and in spring, 2003. An ENVIS System was used for each site to measure microclimate variables, soil moisture and sapflow every half an hour, and the study time scale is one day. In the 104 days of observation during the growing season at the Linze site, the average daily sapflow of Gansu Poplar is 9.93L·d-1,and the average transpiration per unit leaf area is 1.99mm·*** White elm tree,the daily average sapflow is 4.08L·d-1,while the daily average transpiration per unit leaf area is 0.49mm·*** values for Mongol Scotch Pine are 3.91L·d-1 and 0.25mm·d-1,*** the total 73 days of observation during the growing season at the Erjinaqi site, the daily average sapflows of Russia olive and Euphrates Poplar are 12.1 and 20.97L·d-1,respectively,and the average transpirations per unit leaf area are 0.22 amd 0.31mm·d-1,*** the observation period of the growing season,tree conductances of Mongol Scotch Pine, White elm, Gansu Poplar or Russia olive show an exponential relationship with the daily average air temperature or vapour pressure deficit, but the relationship is not so obvious between tree conductance and global radiation. The transpiration process of each tree species is affected by all the observed four environmental variables. The response of tree conductance to different climatic factors changes with tree species. The effect of the same factor to the same tree species is also variable in different growing stages. The sapflow of every tree species is relatively large in later

关键词： sapflow tree conductance leaf area transpiration soil water content climatic variable.

Integrated modeling environment and a preliminary application on the Heihe River Basin, China

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第8期54卷 2145-2156页

作者： NAN ZhuoTong SHU LeLe ZHAO YanBo LI Xin DING YongJian cold and arid Regions environmental and engineering research institute Chinese Academy of Sciences Lanzhou 730000 China

environmental and water issues are essentially complex interdisciplinary problems. Multiple models from different disciplines are usually integrated to solve those problems. Integrated modeling environment is an effective technical approach to model integration. Although a number of modeling environments worldwide are available, they cannot meet current challenges faced. Their old-fashion designs and original development purposes constrain their possible applications to the domain of hydrologic or land surface modeling. One of the challenges is that we intend to link knowledge database or ontology system to the modeling environment in order to make the modeling support more intelligent and powerful. In this paper, we designed and implemented an integrated modeling environment (HIME) for hydrological and land surface modeling purpose in a much extendable, efficient and easy use manner. With such design, a physical process was implemented as a module, or component. A new model can be generated in an intuitive way by linking module icons together and establishing their relationships. Following an introduction to the overall architecture, the designs for module linkage and data transfer between modules are described in details. Using XML based meta-information, modules in either source codes or binary form can be utilized by the environment. As a demonstration, with the help of HIME, we replaced the evaporation module of TOPMODEL with the evapotranspiration module from the Noah land surface model which explicitly accounts for vegetation transpiration. This example showed the effectiveness and efficiency of the modeling environment on model integration.

关键词： modeling environment the Heihe River Basin TOPMODEL Noah LSM