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  • Articles
    Jia Zhenzhen, Liu Shaomin, Mao Defa, Wang Zhiliang,Xu Ziwei, Zhang Ru
    Advances in Earth Science. 2010, 25(11): 1248-1260.

    A comprehensive validation method of remotely sensed Evapotranspiration (ET) based on observation data was proposed to ensure the accuracy of estimated ET. Thus, an observation system was equipped with a large aperture scintillometer, an eddy covariance system and an automatic weather station, and then an observation network was established at Miyun, Guantao, Daxing and Xiaotangshan sites in Hai river  basin, which were set up from 2002 for ET and correlative parameters measurements at different satellite pixel scales. On this basis, rigorous data process and quality control were executed to ensure the high quality of observations. Meanwhile, a validation procedure of remotely sensed ET based on ground measurements was presented, and the method of selecting validation pixels and evaluation index were investigated intensively. According to this method, validation of remote sensing ET was performed in Beijing. Based on the LAS measurements at Miyun and Daxing sites in 2008, regional ET in Beijing area estimated by MODIS data was validated. The results demonstrated  that  the proposed validation method based on LAS observation data was feasible. The RMSE and MRE of estimated monthly and daily ET were  13.75、0.91 mm and 22.79%、18.61% respectively.

  • Articles
    DONG Xiaofeng;SHI Yulong;ZHANG Zhiqiang;LI Xiaoying
    Advances in Earth Science. 2005, 20(10): 1067-1074.

    The Metropolitan region is an international model of the spatial organization for the modern Urban Agglomeration. The first part of this paper focuses on the national and international study about analysis conceptions, development tendencies and characteristics of metropolitan region. The development of research and practice about metropolitan region in the world was recognized. Based on the analysis, we made an analysis of the development of the research and the practice about metropolitan region in China. The author summed up the understanding about Metropolitan Region from Chinese scholars and packed up the practices in China in order to further understand the connotation of this conception. Then, we built up the development theory system of Metropolitan Region, including the conception and standards of Metropolitan Region which is seasoned with the situation of our country and the tendencies of development, the nature of metropolitan region which is a development pattern as well as a phenomenon, the spatial structure which circles from inside to outside, the effect, the phase of metropolitan region development and discussed how to manage this region. Lastly, we summed up the content of the metropolitan region development planning. The importance of incorporation and habitation conception for the development of Metropolitan Region was emphasized. As a kind of urban development model, Metropolitan Region is vital for the construction of urban area which has conditions to develop this model and the development of regional economy.

  • Articles
    Bai Jie, Liu Shaomin, Ding Xiaoping, Lu Li
    Advances in Earth Science. 2010, 25(11): 1148-1165.

    Sensible/latent heat fluxes can be obtained by Large Aperture Scintillometer (LAS) over several kilometers, which play an significant role in the analysis  of and application to agricultural and forestry, hydrology and meteorology research. Take LAS observations in Miyun and Guantao stations over Hai River Basin in 2008 as an example. The way of data screening and quality control under unstable conditions as well as the effect of different calculation method on sensible heat flux have been discussed. The results showed: the structure parameter of the refractive index (C2n) should be calculated with the variance of the voltage of structure parameter of the refractive index; Humidity correction can be done with daily Bowen ratio; The effective height of LAS can be calculated with spatial averaged function;  The Andreas(1988) function is  used to get reliable sensible heat flux. Meanwhile, the nonlinear regression method and dynamic linear  regression method have been used to fill the 30min and daily missing data  while the 30  min missing data under stable conditions can be set to zero. The correlation relationship between daily ET measured by LAS and EC has been constructed to estimate daily ET when daily Rn<50 W/m2. Based on the above analysis, a set of LAS data processing scheme has been set up, which ensures continuous and high quality sensible/latent data can be obtained over various surfaces and weather conditions.

  • Articles
    Zhang Jianyong,Liu Wenhui,Tenger,Wang Xiaofeng,Qing Ying, Ma Fengliang
    Advances in Earth Science. 2008, 23(4): 390-400.

    The thermochemical sulphate reduction (TSR) is believed to be the determinative factor for gas reservoirs to generate high content of H2S (the volume percent of H2S above 5%), but the main hydrocarbon compounds react with sulphate are still not distinctly made sure. In this paper, based on the contrast analysis of TSR reaction systems ( wet gas and magnesium sulfate, methane and calcium sulphate, heavy hydrocarbon and magnesium sulfate), through the analysis of TSR chemical equations and study of chemical kinetics and chemical thermodynamics, combined with geologic information, it is concluded that methane is believed to be the product of the TSR reaction between heavy hydrocarbon and sulphate, and not main reactant; there is synchroneity between the TSR reaction and the increasing of C2+  gaseous Alkane, the TSR reaction rate increase as C2+ Gaseous Alkane increase and the volume of H2S almost not increase till the wet gas cracked to be dry gas and then dry gas with H2S is generated. According to the analysis of oil and gas evolution stage, it is believed that TSR mainly at the stage of condensate gas generation by thermal cracking. When crude oil being cracked to be natural gas with H2S, the pressure system is changed and gas with H2S will be newly accumulated and the natural gas with H2S will be accumulated again in new traps if the structural environment changes. So, the volume of H2S in natural gas reservoirs is not only controlled by generation conditions but by other factors, such as migration pathway conditions, reservoirs conditions and preservation conditions.

  • Articles
    HAN Wei-guo, WANG Jin-feng, LIU Xu-hua
    Advances in Earth Science. 2004, 19(6): 925-930.

    This paper uses SIR model to back-analyze the parameters of SARS transmission based on the data released by the health authorities of Beijing and Hong Kong, we get the important parameters such as the peak period, the hospitalized cases and the removed parameter. It can be seen that these parameters of the model allow for better understanding of the SARS transmission because the result fits the actual data approximately. As a result, SIR model could be used to fit data, predict trend and simulate process of SARS transmission.

  • Articles
    HU Yi-chang, DONG Wen-jie, HE Yong
    Advances in Earth Science. 2007, 22(10): 1066-1075.

    More and more researches pay attention to extreme events because of their destructive impacts. Both observing and modeling studies found that extreme temperature and precipitation had significant changes. Further more, there may be more severe extreme events in the future with global warming. Of course, there are still many uncertainties contained in these results. Two main factors contribute to these uncertaintiesne. One is associated with models. There are usually great difference of outputs between different models; the other is the possible difference resulted from the period of different length analyzed. From the definition of extreme events, progresses about the study of extreme events in the last few years are described in detail first for both observing and modeling studies. Then the main progresses are listed, and some problems hanging in doubt are summarized.

  • Articles
    Zhong Lingzhi, Liu Liping, Ge Runsheng
    Advances in Earth Science. 2009, 24(4): 383-391.

           With the recent emphasis on understanding the role of clouds in the global radiation budget, cloud detection becomes more and more important. Although there are optical remote sensing techniques (e.g., satellite lidar, ceilometer, etc.) to measure cloud properties, optical signals cannot penetrate into thick cloud to observe the cloud′s horizontal and vertical dimensions and its internal structure. The scope of radar meteorology has expanded to include measurements of cloud properties and structure for radar′s wavelength is close to cloud′s diameter. Millimeter-wavelength radar is recognized as having the potential to provide a more sensitive probe of cloud particles ranging from a few micrometers in diameter to precipitation drops. Since the backscatter cross section of tiny drops (i.e., several tens of micrometers in diameter) increases in proportion to λ-4, where  λ is the radar wavelength, cloud drops are more easily detected by radars of millimeter rather than centimeter wavelengths. On the other hand, attenuation of millimeter waves is much stronger, and the λ-4 advantage gained using millimeter waves is offset by the strong attenuation these waves experience. The 10-cm-wavelength radar, used principally for storm warnings, cannot detect weak and no precipitation clouds well, compared with the mm radars. Compared to normal weather radar, millimeter wavelength radar has following superiorities in observing clouds: ①strong capability in detecting small particles like cloud, fog and dust; ②better resolution and precision of Doppler velocity; ③high special resolution result from its narrow beamwidth. In this paper, the status about cloud radar in and abroad about radars′ technology and application on clouds′ micro and macrophysics research, airports safe flight are introduced. Also present is a prospect on millimeter-wavelength radar.

  • Articles
    Advances in Earth Science. 2011, 26(1): 75-132.
  • Articles
    Zhang Yunguo, Zhou Chaoxian
    Advances in Earth Science. 2011, 26(11): 1173-1190.

    Porphyry copper deposit as the largest source of Cu is one of the most important deposits in the world. Porphyry Copper Deposit not only occured in Circum-Pacific ore-forming region, but also occured in Tethys ore-forming region and Middle-Asian(Paleo-Asian Oceanic) oreforming region. The mineralization materials derived from the deep. Porphyry forms through four stages: “Oceanic Crust-Mantle Lava Flow”,“Original Magma”,“Shallow Ore Magma”,“Crystallization of Magma-Minerali-zation”. In the stage of “Original Magma”, much metallogenic materials and energy gather through the process of “MASH”. Ore-forming fluids are high-grade fliuds of gas-liquid phase, which are of fluid-rich, high temperature, high pressure, high salinity, strong oxidizing, high oxygen fugacity. The characteristics of ore-forming fluids are favorable for metallogenic materials to gather from magmas to fluids in the process of magma-hydrothermal separation. The copper is transported and migrated in form of Cl-complexes. With the ascent of ore-forming fluids, lowering of temperature and pressure is the main factors resulting in copper precipitation. The crystallization of magnetite resulting from lowering temperature and pressure provides much of S2- and  plays an important role in the formation of porphyry copper ore. From the inner to the outside, the alteration zones,in general,are composed of quartz zone,potassic zone,SCC zone and  argillic zone.The proposed genesis models which are commonly accepted,up to now, include the classical model, the system model and the model of polyphasal overprinting events.

  • Articles
    Zhang Rui, Ma Jianwen
    Advances in Earth Science. 2009, 24(5): 555-562.

           Support Vector Machine (SVM) is a state-of-the-art machine learning algorithm based on statistical learning theory. It tries to find the optimal classification hyperplane in high dimensional feature space to handle complicated classification and regression problems by solving optimization problems. With the development of the theory and its applications, SVM has been used in remote sensing community successfully. SVM has been applied to land cover/land use classification for remotely sensed data, change detection for multi-temporal remote sensing data, and information fusion for multiple source data. Moreover, it has become a standard technique for hyperspectral data process. In this paper, the applications of SVM in remote sensing are reviewed. First, we introduced the basic theory of the SVM briefly. Then we reviewed the state of the art in different remote sensing applications. At last, we stated the development of several new SVM algorithms, which were derived from the SVM theory, and applications in remote sensing community.

  • Articles
    Sun He,Xiao Yilin
    Advances in Earth Science. 2009, 24(10): 1105-1121.

           Fluids are aubiquitous transport medium for heat and matter in most geological process. The presence of fluids in rocks may affect the chemical and physical properties, mineral reaction velocity and heat budget of geological systems, Direct sample of geological fluids could be preserved only in fluid inclusions that were trapped during the growth of their host mineral. Fluid inclusions can provide us unique information for the presence and composition of ancient fluids which can not be obtained by other geochemical methods (e.g. the component and evolution of diagenetic fluid; process of fluid-rock interaction; migration of trace elements in fluid). The study of fluid inclusions thus has become one of the “hottest” fields in earth sciences, and plays an important role in studies correlated with geological processes. Starting with a general introduction to the fluid inclusion properties and a summarization about the classification of primary- and secondary-fluid inclusions, this paper reveiws the most recent development in analytical methods in the fluid inclusion research field. We also review the current application of fluid inclusions to various fields in earth sciences (e.g. metamorphic fluid, ore-deposit, petroleum geology and biomarker) in the paper. Finally, we give a short outlook on potential future research topics about fluid inclusion studies.

  • Articles
    Advances in Earth Science. 1991, 6(5): 46-49.
  • Articles
    Wang Xiaojun, Ma Hao
    Advances in Earth Science. 2011, 26(11): 1191-1199.

    With the development of mesoscale atmospheric model, the next generation mesoscale Weather Research and Forecast Model is widely used at home and abroad, primarily because of its complete openness, easy portability, and fast update. The application of WRF model in China in recent decade is introduced from three aspects: the physical parameterization scheme, real-time simulation and comparison with MM5, which indicates the usefulness and advantage of WRF model in mesoscale simulation. Furthermore, two main prospects of WRF model in the near future are proposed: one is to develop Climate-Weather Research and Forecasting Model(CWRF), aiming to simulate and predict both weather and climate at mesoscale level, and the other is to couple WRF model with regional ocean model and construct a regional coupled model with high resolution. It is hoped that our summary can provide some necessary helps for the users of WRF model.

  • Articles
    Xia Jun, Liu Chunzhen, Ren Guoyu
    Advances in Earth Science. 2011, 26(1): 1-12.

    The impact of climate change on water resources security is a challenging issue with widespread concern globally. It is as well the great strategic issue in the national sustainable development of China. Based on a wide review of related research, it is concluded that the research of climate change impact on the water cycle is one of the most exiting research perspectives in the study of relationship of climate change and water science. Due to the serious water resource situation plus climate change influence, the challenge and opportunity of the basic research work in the climate change impact on water resource were given. The climate change and water cycle study is the international forefront in the area of climatology, meteorology and hydrology. The detection and attribution of water cycle components change have become the international challenging problems, as well as the quantitative analysis and prediction of the uncertainties in a hydrological system; the research of water cycle response to climate change is developing from offline hydrologic simulations to coupling climate change with hydrological dynamics; study of the water resources vulnerability has become a key problem to deal with climate change and secure the water resources security. In the circumstances of the climate change, it is necessary to reexamine the hypotheses in traditional hydrological theories, as well as the spatial variability, uncertainty and hydrological extremes in regional hydrological studies. Carrying out the research of climate change impact on water resource and adoption measures is one of the  biggest scientific problems of water sciences and water resource in the 21 century. 

  • Articles
    ZHOU Guang-sheng;XU Zhen-zhu;WANG Yu-hui1
    Advances in Earth Science. 2004, 19(4): 642-649.

    Adaptation of terrestrial ecosystems to global change has become a key issue of global change study and of countermeasures formulation for human being. The adaptation of terrestrial ecosystems to global change would be reviewed in this paper from four aspects, [WTBX]i.e.[WT], (1) changes of CO2 concentrations in the atmosphere, (2) climatic change, (3) combined changes of CO2 concentrations in the atmosphere and climatic change, and (4) human disturbance, in terms of the definition of global change. Based on the present research, some important tasks related to adaptation of terrestrial ecosystems to global change are suggested. Among them, the threshold assessment of adaptation practices should draw more and more attention in the future.

  • Articles
    ZHANG Xiao-ye
    Advances in Earth Science. 2007, 22(1): 12-16.

    This article provides a brief introduction of a new 973 project, entitled “Aerosol over China and their climate effect”.

  • Articles
    Zhao Tianbao,Fu Congbin,Ke Zongjian,Guo Weidong
    Advances in Earth Science. 2010, 25(3): 241-254.

    During the last decades, reanalysis of past meteorological observations using modern data assimilation technique and restructure the long-term and consistent gridded data products have been made great progress. Such datasets provide us the most primary research tools to identify the state and evolution of atmosphere, and understand the climate change and variability at different spatial-temporal scales. In this paper, the current research status and advances in the global reanalysis datasets including some of international global atmosphere reanalysis projects and the corresponding reanalyzed products, the important applications of reanalyzed products in some research fields of the atmospheric science, the validation and evaluation of the reanalysis datasets,and some quality problems represented by the reanalyzed products in climate change studies are systematically reviewed. Moreover,the prospects of the studies on atmospheric reanalysis in the future are also discussed in this paper.

  • Articles
    Sea-Floor Observation Group, Marine Science & Technology Center, Tongji Universi
    Advances in Earth Science. 2011, 26(6): 650-655.

    Abstract: This paper briefly introduces two marine observation systems in the United States: the Ocean Observatories Initiative (OOI) sponsored by NSF, and the Integrated Ocean Observing System (IOOS) organized by NOOA. The two programs are closely related, but differentiated from each other. As China is now developing its own marine observation systems, there is much to be learned from the US experience.

  • Articles
    Xu Ziwei,Liu Shaomin,Gong Lijuan,Wang Jiemin,Li Xiaowen
    Advances in Earth Science. 2008, 23(4): 357-370.

    The eddy covariance (EC) technique can measure turbulent exchanges between surface and atmosphere directly, and is now used widely in all of the flux stations. Since this method is based on certain assumptions, the obtained surface fluxes are not true values if there are no necessary corrections. Recent development and some focal points of the eddy-covariance method are reviewed, and used in the processing of the data collected in Miyun station, which is one of the flux stations near Beijing. The analysis of EC data at Miyun station shows: Despiking and the sonic temperature and coordinate rotation corrections have a rather little effects on the surface sensible and latent fluxes (about 1%), however, coordinate rotation has large effect on the momentum flux. The air density correction (WPL correction) is important for water vapor and CO2 fluxes, and should be applied. The turbulent spectral checks in the data quality evaluation are satisfactory. Turbulence stationarity and integral characteristics are used in the flux data quality analysis. After rigorously data screening, the final result shows that about 75% flux data is good, and 2% flux data need to be discarded. Footprint analysis shows for all day and daytime periods, over 70% source area of the fluxes is located in the interested area (non mountainous region) with over 90% of the biggest contribution points in the area.

  • Articles
    Duan Jing,Mao Jietai
    Advances in Earth Science. 2008, 23(3): 252-261.

    Aerosol and cloud play important roles in determining the earth's climate. Along with the further knowledge about these important roles, the researches on the interaction between aerosol and cloud became more and more important. A comprehensive review about the research methods and the development in recent twenty years on this field is discussed in this paper. The observation by airplane, satellite and the composite method of observation and model were the main research method in this research. Some data of observation and the model results have given evidences of the influence between aerosol and the other cloud physical characteristics including radiation, cloud drop and precipitation. Aerosol can transform to the cloud condensation nucleus (CCN) in some special situations. Through this process, aerosol influences the cloud characteristics. Therefore, the CCN is an important link in all interaction theory between aerosol and cloud. There were great progresses in the observation technology of CCN. The nonlinear relationship between saturated water vapor pressure and temperature was used to make the instrument to observe the CCN. The related theories about CCN and cloud also have made some progresses. In China, the research methods were changed from the analyzing single observation data to the way of using model and the methods combining observation and model. Finally, several pieces of proposal are brought forward in this research area.

  • Articles
    Zhu Hua
    Advances in Earth Science. 2008, 23(8): 830-839.

    A total of 31 regional floras that covered whole Yunnan province were used for making frequency maps of distribution types at generic level by Arcview software. The following results were given: 1. Tropical genera account for 29.6% to 94.1% of the total genera in regional floras with the highest proportion in the areas of southern Yunnan, while temperate genera account for 6% to 70.4% of the total genera with the highest proportion from the area of northwestern Yunnan. 2. Among tropical elements, the genera of Pantropical distribution contribute from 13.64% to 46% of the total genera in regional floras with the highest proportion in dry and hot valleys in western and southeastern Yunnan, and the genera of Tropical Asian distribution contribute from 3.33% to 42.26% with the highest proportion in southern Yunnan. 3. Among temperate elements, the genera of North temperate distribution contribute from 2% to 30.39% of the total genera in regional floras with the highest proportion in northwestern Yunnan, and the ones of East Asian distribution contribute from 2% to 14.57% with the highest proportion in Hengduan Mountains in northwestern Yunnan. 4. In relationship with vegetations of Yunnan, the genera of Tropical Asia, Old world tropics and Tropical Asia to Australia distributions occur mainly in the tropical forests in southern Yunnan; the genera of Pantropical and Tropical Asia to Tropical Africa distributions occur mainly in the vegetations on dry and hot valleys; the genera of North temperate distribution occur mainly in forests on mountains with a cold and wet climate, while the genera of East Asian, East Asian and North America disjunct, and Old world temperate distributions occur mainly in the vegetations of the area with a warm climate. 5. In biogeography, the frequent patterns of the genera of seed plants imply that the “Tanaka line” could also act as a demarcation line between the tropical Asia flora (Indo-Malaysia flora) and East Asia flora in Yunnan; the semi-savanna vegetation in the dry and hot valleys in Yunnan could have floristic affinity to savanna of Africa; the Yunnan geo-plate could have clock-wise movement by bumping of India plate during the uplift of Himalayas. It is supported that Yunnan should be a region with tropical areas as the horizontal base because almost all areas of lower elevation are tropical in nature regardless of their latitudinal location.

  • Articles
    LIANG Si-hai, CHEN Jiang, JIN Xiao-mei, WAN Li, GONG Bin
    Advances in Earth Science. 2007, 22(1): 33-40.

    Analysis of the vegetation coverage changing with the time in the last 21 years is the purpose of this paper to study the regularity of the regional eco-environment in the Tibetan plateau. Based on the remote sensing data GIMMS NDVI, statistical processing and analysis, also calculation, the paper gives quantitative analyses and evaluations of the variability of vegetated rate of the Tibetan plateau. In the last 21 years, the regional vegetation coverage has been on the slow increase at the rate of 3 961.9 km2/a as a whole, except for some place degradation, and also the human have not done damage to the eco-environment. From 1982 to 1991, the vegetation coverage of the whole region increased, except for degrading region at the middle and the west of the area. The value increased is decreasing from the south and the east to the north and the west. The induction, the climate benefiting the vegetation growing, changing with degree of longitude and latitude, can be worked out. It's the main period from 1992 to 2002 that the vegetation degrade, those deteriorated regions are located in the resource regions of the Yangtze river, the Yellow river, the Lancangjiang river and the Nujiang river, which indicates the changing climate would be adverse to the vegetation. The NDVI also has two significant periods of 7 years and 3.5 years, caused by the same significant periods of the temperature, and that indicates that the plateau plant is more senstive to the temperature than to the precipitation. Over 21 years, there are 7 from 8 types vegetation coverage which are raising unstably including clod-arid-region plant with vulnerability and difficult recovery.

  • Articles
    Advances in Earth Science. 2001, 16(6): 813-820.

    As a typical artificial landscape, the spatial structure of city is the type of high collective landscape and the function of city appears as the diversities of culture, high capability and high energy flow. Landscape ecology on city includes urban spatial structure and ecological process, urban landscape scene and urban ecological construction and urban landscape planning. The most direct application of landscape ecology on city is landscape planning. This paper, firstly, discusses on the valuations of urban landscape quality and value which include the valuation of landscape aesthetics and the capability of landscape vision. The topic of this paper is urban spatial structure and the principles on landscape planning, which involves urban spatial patterns, the corridor influence of urban spatial extension and the analysis on the spatial structure of urban greenbelt system. Based on the cases of greenbelt systems in Shanghai and Guangzhou, the authors analyze on the landscape change of the ecotone landscape between urban and rural. At the same time, the characteristics of the processes of urbanization are described by urban landscape patterns and its dynamics according to the typical researches in Shanghai and Shenyang.

  • Articles
    Wang Linghe,Yan Denghua,Long Aihua,Yang Shuyuan
    Advances in Earth Science. 2009, 24(8): 891-898.

    Ecohydrology combines the studies of hydrological and ecological processes and their interrelations in soil and water. It aims at a better understanding of hydrological factors determining the development of natural and human-driven terrestrial ecosystems, and of ecological factors influencing the hydrology. This paper analyzes the understanding of ecohydrological process by researchers from ecohydrology connotation view. Terrestrial landscape ecohydrology research is a hotspot. This paper summaries the ecohydrological process advances of mountainous region, wetland, dry land and basin integration modelling, analyzes the strategy of establishing ecohydrological model, gathers part of developed ecohydrological models, considers the three problems in model establishment, scales, data, definition. We should pay more attention to the following four aspects: ①the basic research on ecohydrological process;  ②the integration modeling research on ecohydrological process;  ③ecohydrological process on-line coupling research with database and GIS/RS technologies;  ④ecohydrological process research combining with prototype observation. To establish ecohydrological models that accord with local condition is the important task in today′s China ecohydrology research.

  • Articles
    YU Gui-rui, WANG Qiu-feng, YU Zhen-liang
    Advances in Earth Science. 2004, 19(5): 831-839.

    Water and carbon cycles are not only the cores of material cycle and energy exchange in terrestrial ecosystem, but also two basic coupling ecological processes. Managements of water and carbon of regional or global ecosystem are two key topics of global change science and sustainable development research, simultaneously, an important ecological approach for human to maintain the cycle and renewal of natural resource and the material and energy cycle in global ecosystem. In this paper we reviewed the development trend of modern applied ecology comprehensively, based on the relationship among water and carbon cycles in terrestrial ecosystem and ecosystem management, brought forward the content and framework about the processes management, and illuminated new design on the synthetic research of the mechanism and simulation of water-carbon coupling cycle in terrestrial ecosystem. 

  • Articles
    Gao Zhenmin,Luo Taiyi
    Advances in Earth Science. 1995, 10(2): 183-187.

    Researches of fixed-ammonium in mineralogy, lithology and ore-exploration and relative results of thermodynamic experiments in water fluid containing ammonia-ammonium have been commented, the action of ammonium (ammonia) in geological fluid media and some key problems in relative researches of ore deposits geochemistry have been discussed. At last, the prospects of using ammonium as an exploration tool in China has been investigated.

  • Articles
    Lin Yunping, Zhao Chunsheng
    Advances in Earth Science. 2009, 24(5): 488-496.

           The tropospheric oxidation is an important indicator of the cleansing capacity of the atmosphere. Most trace gases emitted into the atmosphere are removed by oxidizing chemical reactions involving ozone and the hydroxyl free radical. The  research history of tropospheric OH including the fundamental reactions, measurement techniques and the long-term trend is reviewed in this paper. Due to the increased emissions of CO, NOx(=NO+NO2) and hydrocarbons by human activities, global mean OH concentrations have decreased since pre-industrial times, and the future trend of tropospheric OH still depends on the emissions of CO, NOx(=NO+NO2) and hydrocarbons. Using a 3-D global chemistry and transport model (MOZART), the distributions and trend of tropospheric OH over China and its neighborhood are studied. The results show that, consistent with variations in sunlight and water vapor, the concentrations of tropospheric OH over China increase gradually from winter to summer. In addition, by reason of the various emissions strength of OH precursors or sinks, such as ozone, CO and NOx, the highest concentrations of OH in July arise in North China and Pearl River Delta, while the lowest concentrations occur in those plateau areas in West China. Analysis of the impacts of various emissions of air pollutants on tropospheric OH in East China reveals a significant increase of tropospheric OH as a result of the pronounced increase of NOx emissions in China. Looking to the future, there is urgent need for more observations of tropospheric OH to improve and ultimately validate models and further understand the oxidation processes in our atmosphere.


  • Articles
    Xiao Dengpan, Tao Fulu, Moiwo Juana P
    Advances in Earth Science. 2011, 26(11): 1217-1224.

    Surface albedo is a critical consideration for energy balance at the land-air interface. It determines the allocation of radiant energy between the earth′s surface and atmosphere. Changes in surface albedo affect the energy balance of land-air system, which could in turn lead to climate change. Land Use/Cover Change (LUCC) is an important element of global climate change. LUCC affects surface albedo, and thus climate change. Surface albedo is controlled by solar elevation angle, land surface nature, soil moisture, weather condition, etc. This paper presents an in-depth review of the driving factors of surface albedo. Conventional observations of surface albedo are point-based, and therefore have limited spatial representation. On the other hand, surface albedo retrieved by Remote Sensing (RS) could have a large spatial representation. However, RS-driven surface albedo needs validation by ground-truth observations. Hence this paper reviews and epitomizes observational and RS-based analyses surface albedo. It also summarizes research progress in surface albedo in relation to global climate. Moreover, this review highlights the strengths, weaknesses and future directions of surfacealbedo/climate-change research. The points documented herein could profoundly augment current understanding about global climate change and  related driving factors.

  • Articles
    FAN Lijun;FU Congbin;CHEN Deliang,
    Advances in Earth Science. 2005, 20(3): 320-329.

    Coupled General Circulation models (AOGCMs) are widely used as an important tool of projecting global climate change. However, their resolution is too coarse to provide the regional scale information required for regional impact assessments. Therefore, downscaling methods for extracting regional scale information from output of AOGCMs have been developed. Regional climate models nested in AOGCMs, statistical downscaling, and dynamicalstatistical downscaling are usually used for downscaling. In this review paper, focus is placed on statistical downscaling techniques. These methods can be used to predict regional scale climate from AOGCM output using statistical relationship between the large-scale climate and the regional-scale climate, which offers the advantages of being computationally inexpensive. The principle and assumptions of three categories of statistical downscaling are introduced. Important issues in using statistical downscaling to create future climate change scenario is also discussed. At the same time, dynamical downscaling is briefly compared with statistical downscaling in terms of their advantages and disadvantages. Finally, prospects of developing new downscaling techniques by combining statistical and dynamical downscaling techniques are pointed out.

  • Articles
    Liu Shaomin,Li Xiaowen,Shi Shengjin,Xu Ziwei,Bai Jie,Ding Xiaoping,Jia Zhenzhen
    Advances in Earth Science. 2010, 25(11): 1113-1127.

    The measurements of surface energy and water vapor fluxes at large scale are crucial for solving the area-averaging problem from local in situ measurements to area-integrated information, validating hydrological and meteorological models, and verifying remote sensing products etc. This paper reviews the worldwide progress in surface energy and water vapor fluxes at large scale using scintillometer, from these aspects of observation instruments and experiments, and processing, analysis and application of observational  data. A  brief  outlook  about scintillometer is given.

  • Articles
    Xiao Guoqiao, Zhan Tao, Ge Junyi
    Advances in Earth Science. 2010, 25(4): 365-373.

    For Middle Mesozoic to Quaternary times, the geomagnetic polarity record is central to the construction of geologic time scales. The precision of the standard geomagnetical polarity time scale (GPTS) strongly influences the development of related disciplines, such as stratigraphy,paleontology, paleoclimatology and so on. We review the history of the developments in GPTS, and mainly present the recent progress in calibration of the astronomical polarity time scale (APTS), as well the shortages of the present APTS. It can be divided into three stages according to the characteristics of the GPTS development: (1) early stage, during the 1960s, is characterized by K/Ar dating and measuring the magnetization of igneous rocks, constructed the recent 5 Ma GPTS| (2) middle stage, from late 1960s to early 1990s, is characterized by analysis of marine magnetic profiles from the world′s ocean basins, constructed the integrated GPTS since Middle Mesozoic| and (3) in the last three decades, with the developments of the Milankovitch theory (astronomical climate theory) and the astronomical calculation of the Earth′s orbit, the geological time scale can be constructed by orbital tuning, which have being successfully developed as a powerful geochronometer in calibration the APTS. The precise APTS is expected to replace the CK95 GPTS and will be widely used in related disciplines.

  • Articles
    Deng Zhenyong, Zhang Qiang,Xu Jinfang,Chen min,Qin Sanjie,Zhang Shuyu
    Advances in Earth Science. 2009, 24(8): 865-873.

    This paper summarized six aspects such as the harm characteristics, type and index, climatic characteristics, causes, responding to globe changes, protecting technology and answering tactics of hot-dry wind and high temperature heat wave. There is distinction and relationship between hotdry wind and high temperature heat wave. This includes that both of hot-dry wind and high temperature heat wave belong to serious shorter time scale weather disasters. Lower humidity and higher temperature are their main characteristics. The two causes of abnormal circulation characteristics and impacts of the disasters from climate change are basically the same. The disasters may occur in the same area during the same period. Arid season is helphul for their development and aggravation damage. There are differences on harm characteristics, type and index, climatic characteristics, protecting technology and answering tactics in this two weather disasters in that the high temperature heat wave is the comprehensiveness meteorological disasters and dry-hot wind is the agrometeorological disasters.

  • Articles
    Hu Ning, Zhang Chaolin, Zhong Jiqin, Li Yuhuan
    Advances in Earth Science. 2011, 26(4): 375-385.

    The Stratosphere-Troposphere Exchange (STE) refers to atmospheric mass exchange between stratosphere and troposphere in both directions, including Stratosphere-to-Troposphere Transport (STT) and Troposphere-to-Stratosphere Transport (TST). STE has important impacts on atmospheric chemical composition and radiative equilibrium. Therefore, it is very important to investigate STE activities for further advancement in atmospheric chemistry, climate change, and stratosphere troposphere coupling in atmospheric models. In this paper, we review major STE processes in observations, simulations, diagnoses, and mechanisms, and compare their difference either on methods or on models. Although many synoptic-scale STE studies have been conducted, STE events in meso and micro-scales remain to be further investigated, especially in physic mechanism, observations and simulations. It attracts more and more attention on stratospheric influences of troposphere pollutant transport, especially on the impacts resulting from the meso and micro-scales strong convection weather events. With the rapid global urbanization in the global, it is very essential to investigate the TST events under the background with strong convection activities over heavy air polluted metropolitan areas.

  • Articles
    WEI Chao-yang, CHEN Tong-bin
    Advances in Earth Science. 2002, 17(6): 833-839.

    Phytoremediation—a technique using plants to remove contaminants from soils has become a topic in current research. The basic concept and contents of phytoremediation has been summarized with examples illustrated in this paper. Phytoremdiation can be subdivided into phytoextraction, phytostabilization, rhizofitration and phytovolotization. The technique are based on a series number of special plants which are tolerant to some toxic heavy metals or metalloids, and/or can accumulate these metals or metalloids in their above ground parts. Some kinds of such tolerant or accumulating plants have been intensively investigated and even applied in the field, in most cases with addition of chemical chelator such as EDTA to enhance phytoextraction effect, or chemical amendments such as lime, phosphor minerals, beringite, fly ash, sewage sludge and biosolids to enhance phytostabilization of toxic and hazardous elements. The authors also give a brief introduction of some case studies of phytoremediation on its effectiveness and economical advantage. 
    The paper concluded that multi-channel approaches should be taken to make phytoremediation commercial and engineering available, including more deep studies on tolerance and accumulation mechanisms, field survey at more place to try to search for more tolerant and accumulating plants which may provide great values for the breakthrough of phytoremediation technique. Studies on phytoremdiation processes such as methods for enhancing biomass and accumulation capacity of plants as well as their ecological impact are also high desirable.

  • Articles
    Du Yan, Fang Guohong
    Advances in Earth Science. 2011, 26(11): 1131-1142.

     This paper reviews the relevant ocean dynamics study of the Indonesian Seas and Indonesian Throughflow in the last 30 years. Centred at the heart of Maritime Contininent, the Indonesian Seas connect the Western Pacific Warm Pool and Indian Ocean Warm Pool, having a direct impact on the large scale atmospheric circulations. The Indonesian Throughflow (ITF), weaving through the mutli-straits and passages in the Indonesian Seas, balances the thermal and saline distribution of the world ocean. In a long time scale, ITF has an influence on the structure of general circulation and climate change. Based on the advance of the in situ observation by international cooperation, the global scientific community has a significant advance in the regional oceanography of the Indonesian Seas and ITF. Those studies include two aspects. In the study of the regional oceanography of the Indonesian Seas, this paper reviews the major advance in ocean circulation, wave dynamics, tide and mixing, ocean vertical stratifications and air-sea interactions. In the study of the ITF, which is the only ocean connection of the global conveyer belt in the tropics, this paper review the advance in the ITF pathway, vertical structure, multiscale variations, water mass origin and their influence, heat and saline transport, ITF relationship with the Pacific circulations and Indian Ocean circulations, and its impact on the large scale ocean-atmosphere interactions, etc. This paper categorizes and discusses the relevant study and proposes prospects.

  • Articles
    Chen Dake,Xu Jianping,Ma Jirui,Chen Xianyao,Wang Guihua,Wang Wei,Han Guijun
    Advances in Earth Science. 2008, 23(1): 1-7.

    This paper is an introduction to a new project of the National Basic Research Program of China, “Studies of upper ocean structure, variability and predictability based on Argo observation network”. We first discuss the great opportunities and challenges for ocean and atmosphere sciences provided by the international Argo program. Then, we briefly review the scientific advances in the studies of northwest Pacific and tropic Indian-Pacific Oceans, the focus area of our proposed research. At last we outline the key scientific questions to address and the main research components of the present project.

  • Jia Kun, Yao Yunjun, Wei Xiangqin, Gao Shuai, Jiang Bo, Zhao Xiang
    Advances in Earth Science. 2013, 28(7): 774-782.

    Fractional vegetation cover is a key parameter for characterizing land surface vegetation coverage, and plays an important role in global change research, earth surface processes simulation and hydro-ecological models. Remote sensing can provide the vegetation coverage information and variation trend on different spatial scales, and become the important means in obtaining the information of regional or global fractional vegetation cover. In this paper, the commonly used remote sensing data sources including hyperspectral data, multispectral data, microwave data and LiDAR data for fractional vegetation cover estimation are analyzed, and multispectral data will be the long term main data source for fractional vegetation cover estimation because of  the advantage of  its easily acquisition, wide coverage and continuous observation advantages. Then, characteristics  and advantages of different estiation methods are analyzed, which include  the regression model, the pixel unmixing model, the machine learning method, the physical model, the spectral gradient difference and the forest canopy density mapping model. The dimidiate pixel model of the pixel unmixing model is extensively used for its simple form and certain physical significance, and the neural network method is widely used for generating products because of its extendibility and rapidity of calculation. Furthermore, the existing remote sensing data based fractional vegetation cover products are presented. However, the validation results indicate that almost all of the fractional vegetation cover products have underestimation problem and variational estimation accuracy in different regions. Finally, the fractional vegetation cover estimation research prospect is discussed and high spatial-temporal resolution global fractional vegetation cover dataset, multi-source remote sensing data fusion and assimilation method are the future development of fractional vegetation cover estimation using remote sensing data.

  • Articles
    Xiao Shengsheng, Dong Yunshe, Qi Yuchun,Peng Qin, He Yating, Yang Zhijie
    Advances in Earth Science. 2009, 24(10): 1138-1148.

          The stocks and its change mechanism of soil carbon pool in grassland are the core of grassland ecosystem carbon cycle research. Grassland are undergoing serious disturbance, such as land-use change, nitrogen input (nitrogen decomposition and fertilization), elevated CO2 and global warming. Strengthening the research in responses of grass soil organic carbon pool to the disturbance is of great importance. Here we reviewed the effects of grazing, grassland cultivation, and external nitrogen input on soil organic carbon pool including soil active carbon fraction and their responses to global change. The main research directions in this field in the future were also suggested.

  • Articles
    Zhang Zhiqiang,Zheng Junwei
    Advances in Earth Science. 2009, 24(8): 854-864.

    The classification, abundance, distribution, exploration and exploitation technologies of low-permeability oil and gas resources at home and abroad were systematically investigated. It has become an international hot research field for the technologies of low-permeability reservoir identification and adaptation, and the drilling technologies. The current and future focus of the low-permeability oil and gas resources will be concerned as follows: low permeability reservoir quality prediction, fracturing, horizontal well, multi-branch wells, slim hole, advanced injection, explosion layer production, microbial enhanced oil recovery, etc. It is necessary for China to further develop the ultradeep drilling technique, high-resolution seismic exploration and interpretation techniques on complex surface conditions (i.e. desert mountain), complex lithologic logging layer technique, low-permeability oil-bearing zone optimization technique, micro-pore structure technique for low-permeability reservoir, pre-fissure prediction technique for low-permeability reservoirs, development and fracturing optimized injection-production system technique, horizontal wells, fracturing technique for complex structure well, gas injection enhanced oil recovery technique for low-permeability reservoirs, and slim hole technique.

  • Articles
    Wu Bingfang, Meng Jihua, Li Qiangzi
    Advances in Earth Science. 2010, 25(10): 1003-1012.

    Dependable information on large-area agricultural production and production estimation are essential for agricultural markets and the formulation of national and international agricultural policies. It can provide information and technical support for regional or global food security. Factors like worldwide climate change, increasing population and fast changes in land use/cover make the need more urgent. Traditional collection of crop information depends on huge in-situ investigation, which is expensive, time consuming and vulnerable to subjective difference. Along with the development in remote sensing technology and its application to crop information acquirement, some operational crop monitoring systems were developed and put into operation by several countries and international organizations. The development of major crop monitoring systems worldwide (United States, Europe, FAO, Canada, Brazil, Argentina, Russia and India) was reviewed and  introduced in detail. The paper points out that the crop acreage estimation, crop yield prediction, crop condition monitoring and drought monitoring are the four  primary themes in remote sensing based crop monitoring. In crop acreage monitoring, along with the development of remote sensing technology, the dependence of these systems on field survey has not been reduced, or even increased for some reasons. This is against the primary intention of remote sensing application: to reduce or substitute field survey. The potential of remote sensing in large-area crop monitoring has not been fully exerted. Independent crop yield predicting method with remote sensing is also in great need. How to increase the role of remote sensing will be the major direction for the development of remote sensing based crop monitoring systems.