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Spatio-temporal dynamics of vegetation in Jungar Banner of China during 2000–2017

Journal of Arid Land 2019年第6期11卷 837-854页

作者： LI Xinhui LEI Shaogang CHENG Wei LIU Feng WANG Weizhong Engineering research center of Ministry of Education for Mine Ecological Restoration China University of Mining and TechnologyXuzhou 221116China School of Environment Science and spatial Informatics China University of Mining and TechnologyXuzhou 221116China Environmental Restoration and Management center of Jungar Banner Mining Area Erdos 017100China

It is known that the exploitation of opencast coal mines has seriously damaged the environments in the semi-arid *** status can reliably reflect the ecological degeneration and restoration in the opencast mining areas in the semi-arid ***-time series MODIS NDVI data are widely used to simulate the vegetation cover to reflect the disturbance and restoration of local *** this study, both qualitative(linear regression method and coefficient of variation(CoV)) and quantitative(spatial buffer analysis, and change amplitude and the rate of change in the average NDVI) analyses were conducted to analyze the spatio-temporal dynamics of vegetation during 2000–2017 in Jungar Banner of Inner Mongolia Autonomous Region, China, at the large(Jungar Banner and three mine groups) and small(three types of functional areas: opencast coal mining excavation areas, reclamation areas and natural areas) *** results show that the rates of change in the average NDVI in the reclamation areas(20%–60%) and opencast coal mining excavation areas(10%–20%) were considerably higher than that in the natural areas(spatial heterogeneity under the influences of mining and reclamation *** ratio of vegetation improvement area to vegetation degradation area in the west, southwest and east mine groups during 2000–2017 was 8:1, 20:1 and 33:1, *** regions with the high CoV of NDVI above 0.45 were mainly distributed around the opencast coal mining excavation areas, and the regions with the CoV of NDVI above 0.25 were mostly located in areas with low(28.8%) and medium-low(10.2%) vegetation *** average disturbance distances of mining activities on vegetation in the three mine groups(west, southwest and east) were 800, 800 and 1000 m, *** greater t

关键词： NDVI spatio-temporal dynamics linear regression method mining activities opencast coal mining areas reclamation areas Jungar Banner

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FGOALS-s2 Simulation of Upper-level Jet Streams over East Asia: Mean State Bias and Synoptic-scale Transient Eddy Activity

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Advances in Atmospheric Sciences 2013年第3期30卷 739-753页

作者：宋丰飞周天军 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Graduate University of the Chinese Academy of Sciences Climate Change research center Chinese Academy of Sciences

Upper-level jet streams over East Asia simulated by the LASG/IAP coupled climate system model FGOALS-s2 were assessed, and the mean state bias explained in terms of synoptic-scale transient eddy activ- ity （STEA）. The results showed that the spatial distribution of the seasonal mean jet stream was reproduced well by the model, except that following a weaker meridional temperature gradient （MTG）, the intensity of the jet stream was weaker than in National centers for Environment Prediction （NCEP）/Department of Energy Atmospheric Model Inter-comparison Project II reanalysis data （NCEP2）. Based on daily mean data, the jet core number was counted to identify the geographical border between the East Asian Sub- tropical Jet （EASJ） and the East Asian Polar-front Jet （EAPJ）. The border is located over the Tibetan Plateau according to NCEP2 data, but was not evident in FGOALS-s2 simulations. The seasonal cycles of the jet streams were found to be reasonably reproduced, except that they shifted northward relative to reanalysis data in boreal summer owing to the northward shift of negative MTGs. To identify the reasons for mean state bias, the dynamical and thermal forcings of STEA on mean flow were examined with a focus on boreal winter. The dynamical and thermal forcings were estimated by extended Eliassen-Palm flux （E） and transient heat flux, respectively. The results showed that the failure to reproduce the tripolar-pattern of the divergence of E over the jet regions led to an unsuccessful separation of the EASJ and EAPJ, while dynamical forcing contributed less to the weaker EASJ. In contrast, the weaker transient heat flux partly explained the weaker EASJ over the ocean.

关键词： FGOALS-s2 jet stream synoptic-scale transient eddy activity meridional temperature gradi-ent extended Eliaseen-Palm flux transient heat flux

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Iso-propagation vortices with OAM-independent size and divergence toward future faster optical communications

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Advanced Photonics 2024年第3期6卷 51-59页

作者： Wenxiang Yan Zhaozhong Chen Xian Long Yuan Gao Zheng Yuan Zhi-Cheng Ren Xi-Lin Wang Jianping Ding Hui-Tian Wang Nanjing University School of Physics National Laboratory of Solid State Microstructures Nanjing University Collaborative Innovation Center of Advanced Microstructures University of Glasgow James Watt School of Engineering Nanjing University Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics

Recognized in the 1990s, vortex beams' ability to carry orbital angular momentum(OAM) has significantly contributed to applications in optical manipulation and high-dimensional classical and quantum information communication. However, inherent diffraction in free space results in the inevitable expansion of beam size and divergence contingent upon the OAM, limiting vortex beams' applicability in areas such as spatial mode multiplexing communication, fiber-optic data transmission, and particle manipulation. These domains necessitate vortex beams with OAM-independent propagation *** introduce iso-propagation vortices(IPVs), vortex beams characterized by OAM-independent propagation behavior, achieved through precise radial index configuration of Laguerre–Gaussian beams. IPVs display notable transmission dynamics, including a reduced quality factor, resilience post-damage, and decreased and uniform modal scattering under atmospheric turbulence. Their distinctive attributes render IPVs valuable for potential applications in imaging, microscopy, optical communication, metrology, quantum information processing, and light–matter interactions. Notably, within optical communication, the case study suggests that the IPV basis, due to its OAM-independent propagation behavior, provides access to a more extensive spectrum of data channels compared with conventional spatial multiplexing techniques, consequently augmenting information capacity.

关键词： orbital angular momentum optical communication structured light optical vortices

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Changes in surface air temperature over China under the 1.5 and 2.0 ℃ global warming targets

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Advances in Climate Change research 2018年第2期9卷 112-119页

作者： FU Yuan-Hai LU Ri-Yu GUO Dong Climate Change research center Chinese Academy of Sciences Beijing 100029 China National Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

This study investigated the projected changes in the annual mean surface air temperature （SAT） over China under the 1.5 and 2.0 ℃ targets, by analyzing the outputs from 22 models of the Coupled Model Intercomparison Project Phase 5. Under the 1.5 ℃ target, the scope of changes in the average SAT over China is quite narrow and has the largest probability to increase by 1.7-2.0 ℃ under the various RCP pathways, although the time of occurrence of the 1.5 ℃ target has a large spread of 40-60 years. Similarly, the models consistently show that the average SAT over China would most likely increase by 2.4-2.7 ℃ under the 2.0 ℃ target. Furthermore, the warming shows a clear spatial distinction over China： being stronger in the northwest part and weaker in the southeast part. Under all RCP pathways, the SAT over the northwest part would increase by 1.9-2.1 ℃ for the 1.5℃ target, which is much stronger than the SAT increase over the southeast part （1.3-1.5 ℃）. A similar spatial pattern appears for the 2.0 ℃ target.

关键词： Temperature Warming 1.5 ℃ target 2.0 ℃ target China

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spatial and temporal patterns of the inter-annual oscillations of glacier mass over Central Asia inferred from Gravity Recovery and Climate Experiment(GRACE) data

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Journal of Arid Land 2017年第1期9卷 87-97页

作者： ZHU Chuandong LU Yang SHI Hongling ZHANG Zizhan State Key Laboratory of Geodesy and Earth's dynamics Chinese Academy of Sciences Wuhan 430077 China University of Chinese Academy of Sciences Beijing 100049 China center for Space research University of Texas at Austin Austin 78759 USA

Monitoring glacier mass balance is crucial to managing water resources and also to understanding climate change for the arid and semi-arid regions of Central Asia. This study extracted the inter-annual oscillations of glacier mass over Central Asia from the first ten principal components（S-PCs） of filtered variability via multichannel singular spectral analysis（MSSA）, based on gridded data of glacier mass inferred from Gravity Recovery and Climate Experiment（GRACE） data obtained from July 2002 to March 2015. Two significant cycles of glacier mass balance oscillations were identified. The first cycle with a period of 6.1-year accounted for 54.5% of the total variance and the second with a period of 2.3-year accounted for 4.3%. The 6.1-year oscillation exhibited a stronger variability compared with the 2.3-year oscillation. For the 6.1-year oscillation, the results from lagged cross-correlation function suggested that there were significant correlations between glacier mass balances and precipitation variations with the precipitation variations leading the response of glacier mass balances by 9–16 months.

关键词： Gravity Recovery and Climate Experiment glacier mass balance multichannel singular spectral analysis Central Asia

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Tip-induced directional charge separation on one-dimensional BiVO4 nanocones for asymmetric light absorption

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Journal of Energy Chemistry 2022年第9期31卷 326-332,I0009页

作者： Nengcong Yang Ruotian Chen Chenwei Ni Dongfeng Li Qi Sun Lifang Liu Yu Qi Shengye Jin Xiuli Wang Fengtao Fan Can Li Fuxiang Zhang State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsDalian National Laboratory for Clean EnergyChinese Academy of SciencesDalian 116023LiaoningChina State Key Laboratory of Molecular Reaction dynamics and dynamics research center for Energy and Environmental Materials Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

One dimensional(1D)semiconductor is a class of extensively attractive materials for many emerging solar energy conversion ***,it is still of shortage to assess the impact of 1D structural symmetry on spatial charge separation and understand its underlying *** we take controllably-synthesized 1D BiVO_(4)nanocones and nanorods as prototypes to study the influence of 1D symmetry on charge *** is found that the asymmetric BiVO_(4)nanocones enable more effective charge separation compared with the symmetric *** unexpected spatial charge separation on the nanocones is mainly ascribed to uneven light absorption induced diffusion-controllable charge separation due to symmetry breaking of 1D nanostructure,as evidenced by spatial and temporal resolved ***,the promotion effect of charge separation on the nanocones was quantitatively evaluated to be over 20 times higher than that in BiVO_(4)*** work gives the first demonstration of the influence of 1D structural symmetry on the charge separation behavior,providing new insights to design and fabricate semiconductor materials for efficient solar energy conversion.

关键词： Charge separation Tip-enhanced light absorption Surface photovoltage BiVO4 Photocatalysis

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Heat budget analysis in three typical warm periods simulated by FGOALS-s2

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Atmospheric and Oceanic Science Letters 2016年第2期9卷 83-89页

作者： LUAN Yi-Hua YU Yong-Qiang ZHENG Wei-Peng State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences Climate Change research center Chinese Academy of Sciences

This study compared basic warming patterns among three typical warm periods — the midHolocene（MH）, Medieval Warm Period（MWP）, and the twentieth century warming（20CW） — and carried out a comprehensive heat budget analysis using four experiments simulated by the Flexible Global Ocean–Atmosphere–Land System model, Spectral Version 2（FGOALS-s2）. The model simulates similar spatial warming patterns in all three warm periods, e.g. stronger warming appears in the high latitudes. However, changes in surface air temperature（SAT） over the tropical regions are different： a significant warming occurs in the 20 CW and MWP but a significant cooling in the MH. The heat budget analysis suggested that SAT changes are mainly induced by the heat flux. In the MH, the insolation and positive snow and ice feedback are responsible for the warming in the Southern Ocean but the wind anomalies and decreased downward longwave radiation（DLR） induce the cooling in the tropics. In the 20 CW, the decreased shortwave radiation and increased sea surface temperature dependency of evaporation dampen the warming in the tropics. In the MWP, the shortwave radiation induces the Southern Ocean warming, but the DLR and wind anomalies warm the SAT in the tropics. The simulated ocean temperature and ocean heat content anomalies are different in the upper ocean（above 1500 m）, which are mainly induced by the wind stress changes, but similar in the deep ocean in all three warm periods.

关键词： Surface air temperature heat flux mid-holocene Medieval warm period twentieth century warming

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Monthly gravity field solution from GRACE range measurements using modified short arc approach

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Geodesy and Geodynamics 2015年第4期6卷 261-266页

作者： Shen Yunzhong Chen Qiujie Xu Houze College of Surveying and Geo-Informatics Tongji University center for spatial Information Science and Sustainable Development Department of Land Surveying and Geo-Informatics Hong Kong Polytechnic University State Key Laboratory of Geodesy and Earth's dynamics Institute of Geodesy and GeophysicsChinese Academy of Sciences

In this paper we present a series of monthly gravity field solutions from Gravity Recovery and Climate Experiment（GRACE） range measurements using modified short arc approach,in which the ambiguity of range measurements is eliminated via differentiating two adjacent range *** data used for developing our monthly gravity field model are same as Tongji-GRACEOl model except that the range measurements are used to replace the range rate measurements,and our model is truncated to degree and order 60,spanning Jan.2004 to Dec.2010 also same as Tongji-GRACE01 *** on the comparison results of the C_（2,0）,C_（2,1）,S_（2,1）,and C_（15,15）,S_（15,15）,time series and the global mass change signals as well as the mass change time series in Amazon area of our model with those of Tongji-GRACE01 model,we can conclude that our monthly gravity field model is comparable with Tongji-GRACE01 monthly model.

关键词： Satellite geodesy Gravity field model Time-variable gravity field Gravity satellite Gravity Recovery and Climate Experiment (GRACE)Short arc approach Range data Mass change Tongji-GRACE01

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An Introduction to the Integrated Climate Model of the center for Monsoon System research and Its Simulated Influence of El Ni?no on East Asian–Western North Pacific Climate

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Advances in Atmospheric Sciences 2014年第5期31卷 1136-1146页

作者： HUANG Ping WANG Pengfei HU Kaiming HUANG Gang ZHANG Zhihua LIU Yong YAN Bangliang center for Monsoon System research Institute of Atmospheric Physics Chinese Academy of Science State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid dynamics Institute of Atmospheric Physics Chinese Academy of Science Key Laboratory of Regional Climate-Environment research for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Science National Marine Environmental Forecasting center

This study introduces a new global climate model--the Integrated Climate Model （ICM）--developed for the seasonal prediction of East Asian-western North Pacific （EA-WNP） climate by the center for Monsoon System research at the Institute of Atmospheric Physics （CMSR, IAP）, Chinese Academy of Sciences. ICM integrates ECHAM5 and NEMO2.3 as its atmospheric and oceanic components, respectively, using OASIS3 as the coupler. The simulation skill of ICM is evaluated here, including the simulated climatology, interannual variation, and the influence of E1 Nifio as one of the most important factors on EA-WNP climate. ICM successfully reproduces the distribution of sea surface temperature （SST） and precipitation without climate shift, the seasonal cycle of equatorial Pacific SST, and the precipitation and circulation of East Asian summer monsoon. The most prominent biases of ICM are the excessive cold tongue and unrealistic westward phase propagation of equatorial Pacific SST. The main interannual variation of the tropical Pacific SST and EA-WNP climate E1 Nifio and the East Asia-Pacific Pattern--are also well simulated in ICM, with realistic spatial pattern and period. The simulated E1 Nifio has significant impact on EA-WNP climate, as in other models. The assessment shows ICM should be a reliable model for the seasonal prediction of EA-WNP climate.

关键词： Integrated Climate Model (ICM) global climate model E1 Nifio East Asian climate

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Improved ENSO simulation in regional coupled GCM using regressive correction method

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Science China Earth Sciences 2007年第8期50卷 1258-1265页

作者： FU WeiWei1 & ZHOU GuangQing2 1 Nansen-Zhu International research center (NZC), Institute of Atmospheric Physics, Chinese Academy of Sciences (CAS), Beijing 100029, China 2 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid dynamics (LASG), Institute of At-mospheric Physics, CAS, Beijing 100029, China Nansen-Zhu International research center (NZC) Institute of Atmospheric Physics Chinese Academy of Sciences (CAS) Beijing China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid dynamics (LASG) Institute of Atmospheric Physics CAS Beijing China

A regressive correction method is presented with the primary goal of improving ENSO simulation in regional coupled GCM. It focuses on the correction of ocean-atmosphere exchanged fluxes. On the basis of numerical experiments and analysis, the method can be described as follows: first, driving the ocean model with heat and momentum flux computed from a long-term observation data set; the pro-duced SST is then applied to force the AGCM as its boundary condition; after that the AGCM’s simula-tion and the corresponding observation can be correlated by a linear regressive formula. Thus the re-gressive correction coefficients for the simulation with spatial and temporal variation could be obtained by linear fitting. Finally the coefficients are applied to redressing the variables used for the calculation of the exchanged air-sea flux in the coupled model when it starts integration. This method together with the anomaly coupling method is tested in a regional coupled model, which is composed of a global grid-point atmospheric general circulation model and a high-resolution tropical Pacific Ocean model. The comparison of the results shows that it is superior to the anomaly coupling both in reducing the coupled model ‘climate drift’ and in improving the ENSO simulation in the tropical Pacific Ocean.

关键词： anomaly coupling regressive correction method regional coupled model ENSO simulation

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