检索结果-南通市图书馆

Dynamic Variation of Vegetation NPP and Its Driving Forces in the Yellow River Basin, China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2025年第1期35卷 24-37页

作者： WANG Shimei MA Yutao GONG Jie JIN Tiantian Key Laboratory of Western China’s environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China center for remote sensing of Ecological Environments in Cold and Arid Regions Lanzhou UniversityLanzhou 730000China

The productivity of vegetation is influenced by both climate change and human *** the specific contributions of these influencing factors is crucial for ecological conservation and regional *** study utilized a combination of multi-source data to examine the spatiotemporal patterns of Net Primary Productivity(NPP)in the Yellow River Basin(YRB),China from 1982 to ***,a scenario-based approach was employed to compare Potential NPP(PNPP)with Actual NPP(ANPP)to determine the relative roles of climatic and human factors in NPP *** PNPP was estimated using the Lund-Potsdam-Jena General Ecosystem Simulator(LPJ-GUESS)model,while ANPP was evaluated by the Carnegie-Ames-Stanford Approach(CASA)model using different NDVI data *** model simulations revealed that significant greening occurring in the YRB,with a gradual decrease observed from southeast to *** to the LPJ_GUESS model simulations,areas experiencing an increasing trend in NPP accounted for 86.82% of the *** using GIMMS and MODIS NDVI data with CASA model simulations,areas showing an increasing trend in NPP accounted for 71.42% and 97.02%,***,both climatic conditions and human factors had positive effects on vegetation restoration;approximated 41.15% of restored vegetation areas were influenced by both climate variation and human activities,while around 31.93% were solely affected by climate ***,it was found that human activities served as the principal driving force of vegetation degradation within the YRB,impacting 26.35% of degraded areas solely due to human ***,effective management strategies encompassing both human activities and climate change adaptation are imperative for facilitating vegetation restoration within this *** findings will valuable for enhancing our understanding in NPP changes and its underlying factors,thereby contributing to improved ecological man

关键词： Net Primary Productivity(NPP) vegetation greening Carnegie-Ames-Stanford Approach(CASA) Lund-Potsdam-Jena General Ecosystem Simulator(LPJ_GUESS) Yellow River Basin(YRB),China

同方期刊数据库

Simulations of GaoFen-5 Directional Polarimetric Camera(DPC) Observations Using the Advanced Vector Discrete Ordinate Radiative Transfer Model

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2025年第3期42卷 486-500页

作者： Yuchen XIE Ziqiang ZHU Fuzhong WENG Zhengqiang LI Xiuzhen HAN School of remote sensing&Geomatics Engineering Nanjing University of Information Science&TechnologyNanjing 210044China Earth System Modeling and Prediction Centre China Meteorological AdministrationBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China environmental Protection Key Laboratory of Satellite remote sensing&Key Laboratory of remote sensing and Digital Earth Aerospace Information Research InstituteChinese Academy of Sciences.Beijing 100101China National Satellite Meteorological center China Meteorological AdministrationBeijing 100081China

In recent years,polarization remote sensing has garnered increasing attention,particularly within the realm of *** accurately simulate polarization information,the vector discrete-ordinate radiative transfer(VDISORT)model developed earlier by the community is further enhanced to an advanced version(referred to as A-VDISORT)through an improved ocean surface *** Fresnel reflection matrix,which includes wind-generated roughness and shading effects,is served by an ocean bidirectional reflection distribution function(BRDF).The simulation from AVDISORT is compared with SCIATRAN for a Rayleigh scattering atmosphere,and the influence of water-leaving radiance is analyzed by the PSTAR(Polarized System for Transfer of Atmospheric Radiation) *** GaoFen-5 Directional Polarimetric Camera(DPC) observations with polarization and multi-angle information,clear-sky pixel recognition over the ocean is first carried *** DPC reflectance of clear conditions is normalized and compared with the *** is shown that A-VDISORT has a high simulation accuracy with a bias of –*** difference between simulation and observation exhibits a standard normal probability distribution function.

关键词： vector radiative transfer equation A-VDISORT ocean BRDF GF-5 DPC

Assessment of ecological geological vulnerability in Mu Us Sandy Land based on GIS and suggestions of ecological protection and restoration

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Geology 2025年第1期8卷 117-140页

作者： Jian-yu Liu Hong-feng Nie Liang Xu Chun-lei Xiao Wei Li Guo-li Yuan Yan-peng Huang Xin-yang Ji Tian-qi Li China Aero Geophysical Survey&remote sensing center for Natural Resources China Geological SurveyMinistry of Natural ResourcesBeijing 100083China China University of Geosciences(Beijing) Beijing 100083China

Eco-geological vulnerability assessment is a significant research topic within the field of eco-geology,but it remains poorly *** Mu Us Sandy Land,located in the central part of the farming-pastoral ecotone in northern China,plays a critical role in maintaining the ecological security pattern in this ***,this sandy land also faces severe sandy desertification and ecological *** study conducted a regional eco-geological vulnerability assessment of the Mu Us Sandy Land using a comprehensive index evaluation method based on eco-geological theories and survey *** construct an appropriate index system for the eco-geological vulnerability assessment of the Mu Us Sandy Land,the study considered the sandy land’s unique characteristics and identified 15 factors of five categories,namely geology,meteorology,soil,topography,and *** paper calculated the comprehensive weights of all the indices using the analytic hierarchy process(AHP)and the entropy weight method(EWM).Furthermore,it established the eco-geological vulnerability index(EGVI)and obtained the assessment *** results showed that the eco-geological vulnerability of the Mu Us Sandy Land gradually intensifies from east to west,manifested as vulnerable eco-geological conditions ***,extremely vulnerable zones are found in the northwestern and southeastern parts of the study area,highly vulnerable zones in the western and southern parts,moderately vulnerable zones in the central part,and slightly and potentially vulnerable zones in the eastern and southern *** with high spatial autocorrelations include the northern Uxin Banner-Otog Banner-Angsu Town area,the surrounding areas of Hongdunjie Town in the southeastern part of the study area,the Hongshiqiao Township-Xiaohaotu Township area,Otog Front Banner,and Bainijing Town,which should be prioritized in the ecological conservation and ***,the paper proposed suggestions for

关键词： Eco-geological vulnerability Analytic hierarchy process Entropy weight method Evaluation and zonation Mu Us Sandy Land Geology-meteorology-soil-topography-vegetation Precipitation and groundwater environmental protection and restoration environmental restoration engineering Inner Mongolia Plateau

Climate Change in the Subtropical Jetstream during 1950–2009

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2015年第1期32卷 140-148页

作者： B.ABISH P.V.JOSEPH Ola.M.JOHANNESSEN nansen environmental Research Centre India Department of Atmospheric Sciences Cochin University of Science and Technology nansen environmental and remote sensing center nansen Scientific Society

A study of six decades（1950–2009） of reanalysis data reveals that the subtropical jetstream（STJ） of the Southern（Northern） Hemisphere between longitudes 0°E and 180°E has weakened（strengthened） during both the boreal winter（January,February） and summer（July, August） seasons. The temperature of the upper troposphere of the midlatitudes has a warming trend in the Southern Hemisphere and a cooling trend in the Northern Hemisphere. Correspondingly, the north–south temperature gradient in the upper troposphere has a decreasing trend in the Southern Hemisphere and an increasing trend in the Northern Hemisphere, which affects the strength of the STJ through the thermal wind relation. We devised a method of isotach analysis in intervals of 0.1 m s-1in vertical sections of hemispheric mean winds to study the climate change in the STJ core wind speed, and also core height and latitude. We found that the upper tropospheric cooling of the Asian mid-latitudes has a role in the strengthening of the STJ over Asia, while throughout the rest of the globe the upper troposphere has a warming trend that weakens the STJ. Available studies show that the mid-latitude cooling of the upper troposphere over Asia is caused by anthropogenic aerosols（particularly sulphate aerosols） and the warming over the rest of the global mid-latitude upper troposphere is due to increased greenhouse gases in the atmosphere.

关键词： subtropical jetstream upper troposphere greenhouse gases aerosols

Eurasian Winter Cooling: Intercomparison of Reanalyses and CMIP5 Data Sets

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2013年第5期6卷 324-331页

作者： Stephen OUTTEN Richard DAVY Igor ESAU nansen environmental and remote sensing Centre

A cooling trend in wintertime surface air temperature over continental Eurasia has been identified in reanalysis and the Coupled Model Inter-comparison Project phase 5(CMIP5)‘historical’simulations over the period 1989–*** the authors have shown that this cooling trend is related to changes in Arctic sea-ice around the Barents-Kara *** study illustrates a consistent spatial and temporal structure of the wintertime temperature variability centered over Asia using state-of-the-art reanalyses and global climate model *** findings indicate that there is a physical basis for seasonal predictions of near-surface temperatures over continental Asia based on changes to the ice-cover in the Barents-Kara seas.

关键词： climate change climate simulation atmospheric tele-connections

A “Dressed” Ensemble Kalman Filter Using the Hybrid Coordinate Ocean Model in the Pacific

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2009年第5期26卷 1042-1052页

作者：万莉颖朱江王辉闫长香 Laurent BERTINO National Marine environmental Forecasting center Institute of Atmospheric Physics Chinese Academy of Sciences Mohn-Sverdrup center/nansen environmental and remote sensing center

The computational cost required by the Ensemble Kalman Filter （EnKF） is much larger than that of some simpler assimilation schemes, such as Optimal Interpolation （OI） or three-dimension variational as- similation （3DVAR）. Ensemble optimal interpolation （EnOI）, a crudely simplified implementation of EnKF, is sometimes used as a substitute in some oceanic applications and requires much less computational time than EnKF. In this paper, to compromise between computational cost and dynamic covariance, we use the idea of ＂dressing＂ a small size dynamical ensemble with a larger number of static ensembles in order to form an approximate dynamic covariance. The term ＂dressing＂ means that a dynamical ensemble seed from model runs is perturbed by adding the anomalies of some static ensembles. This dressing EnKF （DrEnKF for short） scheme is tested in assimilation of real altimetry data in the Pacific using the HYbrid Coordinate Ocean Model （HYCOM） over a four-year period. Ten dynamical ensemble seeds are each dressed by 10 static ensemble members selected from a 100-member static ensemble. Results are compared to two EnKF assimilation runs that use 10 and 100 dynamical ensemble members. Both temperature and salinity fields from the DrEnKF and the EnKF are compared to observations from Argo floats and an OI SST dataset. The results show that the DrEnKF and the 100-member EnKF yield similar root mean square errors （RMSE） at every model level. Error covariance matrices from the DrEnKF and the 100-member EnKF are also compared and show good agreement.

关键词： Dressing Ensemble Kalman Filter (DrEnKF) HYbrid Coordinate Ocean Model root meansquare errors

The cold pool of the Bay of Bengal and its association with the break phase of the Indian summer monsoon

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2017年第3期10卷 214-220页

作者： Mary Swapna GEORGE Porathur Vareed JOSEPH Kochuparampil Ajith JOSEPH Laurent BERTINO Ola Mathias JOHANNESSEN nansen environmental Research Centre(India) KochiIndia nansen environmental and remote sensing center BergenNorway nansen Scientific Society BergenNorway

During the summer monsoon season, strong coastal upwelling occurs along the southwest coast of India and at the southern tip of India, which cools the surface temperature of the waters around these regions. The summer monsoon current carries the upwelled cold waters into the Bay of Bengal and forms the ‘cold pool of the Bay of Bengal', with its core south of Sri Lanka and over the southcentral Bay of Bengal. The present study focuses on the intrusion of these cold waters into the south of the Bay of Bengal, its interannual variability, and its association with the surface wind during the break phase of the summer monsoon, when strong westerly surface winds flow south of 10°*** authors hypothesize that the enhanced cooling in the cold pool region during monsoon spells is associated with the strong westerly wind stress there during the break spells of the *** cases of long break monsoon spells that occurred during the nine years from 2001 to 2009 are analyzed, and the results confirm our hypothesis.

关键词： Cold pool Indian Ocean Bay of Bengal Indian summer monsoon break monsoon

Contribution of the tropical sea surface temperature in the Arctic tropospheric warming during 1979-2013

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2023年第5期16卷 108-112页

作者： Lingling Suo nansen environmental and remote sensing center and Bjerknes center for Climate Research BergenNorway

本文通过CAM6-Nor大气环流模式模拟实验研究热带海表温度在1979-2013年北极对流层增温中的贡献.分析结果表明热带海表温度变化可以解释历史模拟实验中的秋季和1月增温的30%-40%.这意味着热带海表温度可能是1979年至2013年间北极冬季对... 详细信息

本文通过CAM6-Nor大气环流模式模拟实验研究热带海表温度在1979-2013年北极对流层增温中的贡献.分析结果表明热带海表温度变化可以解释历史模拟实验中的秋季和1月增温的30%-40%.这意味着热带海表温度可能是1979年至2013年间北极冬季对流层变暖的主要驱动因素之一.除了1月份850hPa以下的北极增温,热带海表温度的影响通常来自热带中东部太平洋,热带印度-西太平洋和热带大西洋的联合作用.对1月份850hPa以下的北极增温的影响主要来自热带印度-西太平洋.

关键词：热带海表温度北极气候变化北极对流层变暖遥相关

Impact of net-zero emissions on atmospheric CO2 concentration in China: Ideal simulations based on the GEOS-Chem model

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第3期68卷 867-881页

作者： Jingye TAN Jun WANG Huiqin MAO Hengmao WANG Zhiqiang LIU Meirong WANG Ran YAN Xunmei WANG Fei JIANG Frontiers Science center for Critical Earth Material Cycling International Institute for Earth System Science Nanjing University Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources School of Geography and Ocean Science Nanjing University Satellite environmental Application center Ministry of Environmental Protection CMA Key Open Laboratory of Transforming Climate Resources to Economy Chongqing Institute of Meteorological Sciences State Key Laboratory of Climate System Prediction and Risk Management Key Laboratory of Meteorological Disaster Ministry of EducationCollaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology Xizang Field Station for Scientific Observation and Research on Atmospheric Water Cycle in Mêdog Xigazê and Mêdog National Climate ObservatoryXizang Meteorological Service

Elevated atmospheric carbon dioxide（CO2） concentrations have caused global climate change such as global warming and more frequent climate extremes. Countries worldwide have proposed carbon neutrality strategies to curb the rising CO2concentrations. To investigate the impact of China's carbon neutrality goal on atmospheric CO2concentrations, we conducted a series of ideal simulations from 2015 to 2019 using a global 3D chemistry transport model, Goddard Earth Observing System Chemistry（GEOS-Chem）. Compared with the column-averaged dry-air mole fraction of atmospheric CO2（XCO2） from Orbiting Carbon Observatory-2（OCO-2） and surface CO2measurements in Obs Pack, we find that GEOS-Chem effectively reproduces the spatiotemporal variability of CO2. The model exhibits a root mean square error（RMSE） of 1.51 ppm（R2=0.89） for OCO-2 XCO2in China and 2.65 ppm（R2=0.75） for surface CO2concentrations at the WLG station. Further, compared to 2.83 ppm yr-1in the control experiment, we suggest that net-zero CO2emissions in China decelerate the increasing trends of XCO2to 1.81 ppm yr-1,making a decrease of approximately 35.89%. Meanwhile, the seasonal cycle amplitude（SCA） of XCO2is moderately reduced from 7.39±0.81 to 6.75±0.70 ppm, representing a relative reduction of 9.91%. Spatially, net-zero CO2emissions induce a more significant decrease in XCO2trends over northern and southern China, while their impact on SCA is more evident in northern and northeastern China. Moreover, ideal experiments demonstrate that zero fossil CO2emissions lead to a greater attenuation of the linear trends of XCO2by 40.81%, while the absence of terrestrial CO2sinks largely diminishes the SCA by 16.61%. Additionally,trends and SCA in surface CO2concentrations exhibit almost identical decreasing responses to net-zero CO2emissions but display greater sensitivities compared to XCO2. Overall, our study underscores the potential of China's carbon neutrality goal in mitigating global warming, underscoring the need

关键词： XCO2 GEOS-Chem Carbon neutrality Net-zero emissions Surface CO2 concentrations

同方期刊数据库