检索结果-南通市图书馆

Principle and application of three-band gradient difference vegetation index

Science china Earth Sciences 2005年第2期48卷 241-249页

作者： TANG Shihao, ZHU Qijiang, WANG Jindi, ZHOU Yuyu & ZHAO Feng Research center for Remote Sensing and GIS, Department of Geography, beijing Normal University, beijing 100875,{3. national Satellite meteorological center,{3. meteorological administration, beijing 100081,{3. Research center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing China national Satellite meteorological center China Meteorological Administration Beijing China

Vegetation index is a simple, effective and experiential measurement of terrestrial vegetation activity, and plays a very important role in qualitative and quantitative remote sensing. Aiming at shortages of current vegetation indices, and starting from the analysis of vegetation spectral characteristics, we put forward a new vegetation index, the three-band gradient difference vegetation index (TGDVI), and established algorithms to inverse crown cover fraction and leaf area index (LAI) from it. Theoretical analysis and model simulation show that TGDVI has high saturation point and the ability to remove the influence of background to some degree, and the explicit functional relation with crown cover fraction and LAI can be established. Moreover, study shows that TGDVI also has the ability to partly remove the influence of thin cloud. Experiment in the Shunyi District, beijing, china shows that reasonable result can be reached using the vegetation index to retrieve LAI. We also theoretically analyzed the reason why the normalized difference vegetation index (NDVI) owns the low saturation point, and show that it is determined by the definition of NDVI and the characteristic of vegetation spectra, and is unavoidable to some degree. Meanwhile, through model simulation, we also indicate that the relationship between simple ratio vegetation index (SR) and LAI closes to a piecewise linear one instead of a linear one, which is mainly caused by the influence of background and different change rates of reflectance in red and infrared bands with LAI increasing.

关键词： vegetation index, remote sensing, LAI, crown cover fraction, remote sensing inversion.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Water-vapor source shift of Xinjiang region during the recent twenty years

引用

Progress in Natural Science:Materials International 2007年第5期17卷 569-575页

作者： Dai Xingang , Li Weijing , Ma Zhuguo and Wang Ping (Key Laboratory of Regional climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, chinese Academy of Sciences, beijing 100029,{3. Laboratory for climate Change, chinese meteorological administration, beijing 100081,{3.) Key Laboratory of Regional climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Laboratory for climate Change Chinese Meteorological Administration Beijing 100081 China

The aim of this paper is to investigate the climate water-vapor sources of Xinjiang region and their shifts during the past 20 years. First, the principle and steps are roughly regulated to seek the water-vapor sources. Second, the climate stationary water-vapor transport in troposphere is calculated to distinguish where the water vapor comes from by ERA-40 reanalysis. In addition, the collocation between the transport and the atmospheric column water vapor content is analyzed. The results show that the major vapor comes from the west side of Xinjiang for mid-month of seasons, apart from July while the water vapor comes from the north or northwest direction. The water vapor sources are different for different seasons, for example, the Caspian Sea and Mediterranean are the sources in January and April, the North Atlantic and the Arctic sea in July, and the Black Sea and Caspian Sea in October, respectively. In recent ten years more water vapor above Xinjiang comes from the high latitudes and the Arctic sea with global warming, and less from Mediterranean in comparison with the case of 1973.1986. In fact, the air over subtropics becomes dry and the anomalous water vapor transport direction turns to west or southwest during 1987—2000. By contrast, the air over middle and high latitudes is warmer and wetter than 14 years ago.

关键词： global warming water-vapor source water-vapor transport precipitable water Xinjiang climate inter-decadal change.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Persistent anomalous flows over the subtropical western Pacific insummer

引用

chinese Science Bulletin 1998年第8期43卷 672-675页

作者： ZHUANG Shiyu\+1 and JI Liren\+2 1. national meteorological Centre, china meteorological administration, beijing 100081, china 2. LASG, Institute of Atmospheric Physics, chinese Academy of Sciences, beijing 100080, china national meteorological Ccntre China Meteomlcgical Administration Beijing China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The distribution of global persistent anomalies shows that the subtropical western Pacific is a key region with high_frequency occurrence of persistent anomalies. Analyses of streamfunction anomalies, OLR anomalies etc. suggest that the convective heating related to Indian monsoon might be responsible for the development of WPA. The results of numerical experiment by two linear barotropic models support the observation.

关键词： persistent anomalies subtropical high Indian monsoon anomalous forcing.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sea-salt aerosol transport patterns over the Northern Hemisphere inferred from two subarctic ice core records

引用

Science china Earth Sciences 2005年第4期48卷 576-584页

作者： YAN Yuping1,2, KANG Shichang2,3.5, SUN Junying4,5, Paul A. Mayewski2 & QIN Dahe5 1. national climate center,{3. meteorological administration, beijing 100081,{3. 2. climate Change Institute, University of Maine, Orono, ME 04469, USA 3. Institute of Tibetan Plateau Research, chinese Academy of Sciences, beijing 100085,{3. 4. chinese Academy of meteorological Sciences, beijing 100081,{3. 5. Key Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Environmental and Engineering Research Institute, chinese Academy of Sciences, Lanzhou 73.000,{3. national climate center China Meteorological Administration Beijing China climate Change Institute University of Maine Orono ME USA Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Key Laboratory of Ice Core and Cold Regions Environment Cold and Arid Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China chinese Academy of meteorological Sciences Beijing China

Atmospheric circulation reconstruction based on glaciochemical records requires knowledge of chemical concentration controls, such as source, transport pathway and strength. To gain insight into these processes, the relationships between glaciochemical records from two Northern Hemisphere sites (Mt. Logan in Yukon Territory and 20D in southern Greenland) and instrumental sea level pressure (SLP) series are investigated. Calibrations between Mt. Logan sea-salt sodium (ssNa+) concentration and SLP series show that ssNa+ concentrations are closely correlated with the autumntime (SON) Aleutian Low and the summertime (JJA) North Pacific Subtropical High. Both the deepened Aleutian Low and enhanced North Pacific Sub- tropical High strengthen the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. Calibrations between 20D ssNa+ concentrations and SLP series indicate that ssNa+ concentrations are closely related to the wintertime (Jan.) Icelandic Low. A deepening of the Icelandic Low strengthens winter storms and frequent cyclogenesis over the North Atlantic and pushes more sea-salt laden air masses to the Greenland ice sheet. Therefore, ice core ssNa+ records from the Mt. Logan region can be considered as a proxy for reconstructing the au- tumntime Aleutian Low and summertime North Pacific Subtropical High, and the ssNa+ records from Greenland ice core (20D) may provide a proxy for reconstructing the wintertime Icelandic Low.

关键词： sea-salt aerosol, ice core records, sea level pressure, subarctic regions.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Solar release time of solar energetic particles and associated acceleration source in corona

引用

chinese Science Bulletin 2008年第2期53卷 161-168页

作者： LE GuiMing1,2,3.4, TANG YuHua1 & HAN YanBen4 1 Department of Astronomy, Nanjing University, Nanjing 210093. china 2 Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, china meteorological {3., beijing 100081, china 3.national center for Space Weather, china meteorological {3., beijing 100081, china 4 national Astronomical Observatories, chinese Academy of Sciences, beijing 100012, china Department of Astronomy Narijing University Nanjing 210093 China Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites China Meteorological Administration Beijing 100081 China national center for Space Weather China Meteorological Administration Beijing 100081 China Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

Solar energetic particles (SEPs) are accelerated in corona at an early phase of solar energetic particle events (SEPE). The acceleration mechanism of SEPs in corona can only be inferred from an analysis of multi-band observational data, as the observation of SEPs is usually made around 1AU. In this context, people have investigated spectrums, charge state, solar release time (SRT), and multi-band data of SEPEs, in an attempt to judge the acceleration mechanism of SEPs. The SRT computation of SEPs is an important and commonly used approach to study the acceleration mechanism of SEPs in corona. This paper reviews some important findings concerning the SRT computation of SEPs, and analyzes different merits of each approach for such calculation, based on a range of SEPE case studies. This paper also analyzes and discusses both possible and actual acceleration mechanisms of a number of SEPEs, by calculating the SRT of the SEPEs. Finally, the paper summarizes the possible problems in studying an acceleration mechanism of SEPEs inferred from the SRT of SEP.

关键词：阳光释放时间加速度电晕太阳耀斑

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Inertial theory of the mean Hadley circulation under the condition of nonstatic equilibrium

引用

Science china Earth Sciences 2006年第5期49卷 546-553页

作者： CHAO Jiping1 & LIU Fei2,3.1. national Marine Environmental Forecasting center, beijing 100081,{3. 2. Key Laboratory Regional climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, chinese Academy of Sciences, beijing 100029,{3. 3. Graduate University of chinese Academy of Sciences, beijing 100049,{3. national Marine Environmental Forecasting center Key Laboratory Regional climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Graduate University of chinese Academy of Sciences

Tropical atmosphere is divided into two layers, the layer near the ground is the planet boundary layer, where the motion is linear, if the radiation equilibrium temperature is given at the top of the boundary layer, the vertical motion there can be obtained. It is the non-viscous ideal atmos- pheric layer above the boundary one, where the motion is nonlinear. After getting the conservation laws of angular momentum, potential temperature and potential vortex, the inertial theory of the Hadley circulation driven by the vertical motion of the boundary layer is established, followed by sev- eral examples of its application.

关键词： Hadley circulation, inertial theory, conservation laws of angular momentum, potential temperature and potential vortex.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Absolute radiometric calibration of CBERS-02 IRMSS thermal band

引用

Science china(Technological Sciences) 2005年第S2期48卷 72-90页

作者： ZHANG Yong1,2,3. GU Xingfa1,3.4, YU Tao1,3. ZHANG Yuxiang5, CHEN Liangfu1,3. LI Xiaoying1,2,3. LI Xiaowen1,3.& HE Liming6 1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of chinese Academy of Sciences and beijing Normal University, beijing 100101,{3. 2. Graduate University of chinese Academy of Sciences, beijing 10003.,{3. 3. The center for national Spaceborne Demonstration, beijing 100101,{3. 4. Institut national de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. national Satellite {13. center, beijing 100081,{3. 6. State Environmental Protection administration, beijing 100029,{3. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Graduate University of chinese Academy of Sciences The center for national Spa

Based on the laboratory calibration before launch of CBERS-02 IRMSS thermal infrared channel, the onboard blackbody calibration, the radiometric cross- calibration against TERRA MODIS corresponding channel and the in-flight field calibration at Lake Qinghai: water surface radiometric calibration test site of china on Aug. 17, 2004 are carried out in this research. When making onboard blackbody calibration of CBERS-02 IRMSS, it is necessary to understand inside structures and light path in IRMSS camera and receive and process calibration blackbody signals at normal and high temperatures. Onboard blackbody calibration results of each detector are very important to relative radiometric calibration of images processing and absolute radiometric calibration of each detector. In-flight field calibration mainly contains field experiments, obtaining synchronous images, spectrum marching and MODTRAN radiative transmi- ssion computation. Radiometric cross-calibration of CBERS-02 IRMSS thermal band against TERRA MODIS selected 6 times synchronous images of two sensors passing through Lake Qinghai and Lake Taihu from August to December, 2004 to compute the cross calibration data. Combining the in-flight field calibration and radiometric cross calibration data, the absolute radiometric calibration coefficients are calculated by the linear regression method. This new calibration model can obviously control the radiometric calibration uncertainties aroused by the single point method used in the in-flight calibration of CBERS-02 IRMSS, this kind of sensors cannot receive the cosmic background radiation. In this research, the radiometric calibration coefficients obtained through the linear regression model are 8.53.(gain, unit: DN/W m?2sr?1μm?1) and 44.92 (offset, unit: DN).

关键词： CBERS-02 IRMSS thermal band in-flight field calibration onboard blackbody calibration cross calibration.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

GLOBAL climate CHANGES AND THE TOURISM OF china

引用

Journal of Geographical Sciences 1996年第2期6卷 97-102页

作者： Ren Guoyu(national climate center,{3.People’s Republic of china) national climate center Beijing 100081 China

The future global climate changes induced by the increased atmospheric CO2 concentration is receiving much attention from the scientific community as well as the public. Model simulations and palaeoclimatic data studies show an evident change in temperature and precipitation over china will occur under conditions of the global warming. Possible scenarios of the future climates are given here for china on the basis of synthesizing model simulations and palaeoclimatic data. Most parts of china will experience an increase in temperature, but the warming may be more remarkable in winter in h1e northern half of the country. Increase in precipitation will be seen in nearly every parts of the eastern china, and it will be larger in North and Northeast china. Impacts of the climate changes on the national tourism are assessed. Regions suitable for tourisin development in terms of climate comfortable index will shift northward. Some scenic spots and toruism facilities will be damaged due to sea level rise and increased rainfall. Some regions will benefit from the dimate change, but the tourism industry as a whole will be negatively affected.

关键词： IPCC GLOBAL climate CHANGES AND THE TOURISM OF china

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Progress in china’s climate change study in the 20th century

引用

Journal of Geographical Sciences 2004年第S1期 5-13页

作者： ZHAI Panmao1,2, CHAO Qingchen1,2, ZOU Xukai1,2(1. Laboratory for climate Studies, china meteorological {3., beijing 100081, china 2. national climate center, china meteorological {3., beijing 100081, china)

Studies on the 20th century climate change in china have revealed that under the background of global warming over the past century, climate in china has also experienced significant change with mean annual temperature increased by about 0.5 oC. More reliable results for the latter part of the 20th century indicate that the largest warming occurred in Northwest china, North china and Northeast china, and the warming in winter is most significant. Although no obvious increase or decrease trends were detected for mean precipitation over china in the past half century, regional differences are very distinct. In the middle and lower reaches of the Yangtze River, precipitation increased, while that in the Yellow River Basin markedly decreased. Studies suggest that climate change in china seems to be related not only with the internal factors such as ENSO, PDO, and the others, but also with the anthropogenic effects such as greenhouse gas emissions, and land use. The future climate change studies in china seem to be important in narrowing understanding the nature of china's climate change and its main causes, since it is significant for projection and for impact assessment of climate change in the future.

关键词： th century climate change china

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Global analysis theory of climate system and its applications

引用

chinese Science Bulletin 2003年第10期48卷 1034-1039页

作者： LI Jianping1,2 & CHOU Jifan2,3.1. LASG, Institute of Atmospheric Physics, chinese Academy of Sciences, beijing 100029, china 2. Department of Atmospheric Sciences, Lanzhou University, Lanzhou 73.000, china 3. Training center for china meteorological administration, beijing 100081, china Department of Atmospheric Sciences Lanzhou University Lanzhou 730000 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The idea and main theoretical results of the global analysis theory of climate system are briefly summarized in this paper. A theorem on the global behavior of climate system is given, i.e. there exists a global attractor in the dynamical equations of climate, any state of climate system will be evolved into the global attractor as time increases, indicating the nonlinear adjustment process of climate system to external forcing. The different effects of external forcing, dissipation and nonlinearity on the long-term behavior of solutions are pointed out, and some main applications of the global analysis theory are also introduced. Especially, three applications, the adjustment and evolution processes of climate, the principle of numerical model design and the optimally numerical integration, are discussed.

关键词：整体分析理论气侯体系应用不定性计算法则气侯科学数字模型

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：