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Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

Science China Earth Sciences 2024年第3期67卷 811-825页

作者： Ge CHEN Xiaoyan CHEN Frontiers Science center for Deep Ocean Multispheres and Earth System School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) Geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. Specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies Eddy propagation Eddy meridional deflection Satellite observation Geostrophic adjustment

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全球地表覆盖制图有限样本稳定分类的理论与实验

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Science Bulletin 2024年第12期69卷 1862-1865页

作者：宫鹏王杰黄华兵 Department of Geography and Department of Earth SciencesThe University of Hong KongHong Kong 999077China Peng Cheng Laboratory Shenzhen 518000China School of Geospatial Engineering and Science Sun Yat-Sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China

Global land cover(GLC)maps are essential to understanding of Earth surface processes including physical and biogeochemical processes such as carbon and nitrogen cycling,climate and hydrological dynamics,as well as anthropogenic processes such as land use change and disease *** land cover maps at the global scale are produced by analyzing satellite images through image *** particular,the accessibility of Landsat and Sentinel images has significantly improved mapping resolution from kilometer level to 10–30 m[1,2].

关键词：有限样本 mapping 理论与实验

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Impacts of major volcanic eruptions over the past two millennia on both global and Chinese climates:A review

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Science China Earth Sciences 2024年第1期67卷 61-78页

作者： Weiyi SUN Deliang CHEN Guonian LÜ Liang NING Chaochao GAO Renhe ZHANG Bin WANG Jian LIU Key Laboratory for Virtual Geographic Environment Ministry of EducationState Key Laboratory Cultivation Base of Geographical Environment Evolution of Jiangsu ProvinceJiangsu Center for Collaborative Innovation in Geographical Information Resource Development and ApplicationSchool of Geography ScienceNanjing Normal UniversityNanjing 210023China Regional Climate Group Department of Earth SciencesUniversity of GothenburgGothenburg 40530Sweden College of Environmental and Resource Science Zhejiang UniversityHangzhou 310058China Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences Fudan UniversityShanghai 200437China Department of Atmospheric Sciences and Atmosphere-Ocean research center University of Hawaii at ManoaHonoluluHI 96825USA Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical ScienceNanjing Normal UniversityNanjing 210023China Open Studio for the Simulation of Ocean-Climate-Isotope Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China

Major volcanic eruptions(MVEs)have attracted increasing attention from the scientific *** studies have explored the climatic impact of MVEs over the past two ***,proxy-based reconstructions and climate model simulations indicate divergent responses of global and China’s regional climates to ***,we used multiple data from observations,reconstructions,simulations,and assimilations to summarize the historical facts of MVEs,the characteristics and mechanisms of their climatic impact,and directions for future *** reviewed volcanic datasets and determined intensive MVE periods;these periods corresponded to the years 530–700,1200‒1460,and 1600‒1840 *** tropical MVEs,a substantial cooling effect is observed throughout the globe and China on the interannual-interdecadal time scales but an inconsistent cooling magnitude is detected between reconstructions and *** the first summer after tropical MVEs,a decrease in global and monsoonal precipitation is *** reconstructions and simulations,an increased precipitation is seen for the Yangtze River Basin,while large uncertainties in precipitation changes are present for other regions of *** drought can be induced by frequent eruptions and volcanism superimposed on low solar irradiation and internal *** affect climate directly through the radiative effect and indirectly by modulating internal variability,such as the El Niño‒Southern Oscillation(ENSO)and Atlantic Multidecadal Oscillation(AMO).However,changes in the phase,amplitude,and periodicity of ENSO and AMO after MVEs and the associated mechanisms remain controversial,which could account for model-reconstruction ***,other internal variability,uncertainties in reconstruction methods and aerosol‒climate models,and climate background may also induce model-reconstruction *** gaps and directions for future research are also discussed.

关键词： Major volcanic eruption Climate variability Mechanism Past two millennia Internal variability

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地球大数据及其推动可持续发展的作用

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Science Bulletin 2024年第11期69卷 1623-1627页

作者：郭华东梁栋 international research center of big data for sustainable development goals Beijing 100094China Aerospace Information research Institute Chinese Academy of SciencesBeijing 100094China University of Chinese Academy of Sciences Beijing 100049China

The information age has been a product of, and has been fueled by, the process of decades-long digitization aided by digital technologies that progressed rapidly, consequently transforming human societies globally.

关键词：大数据 globally digit

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乌克兰卡霍夫卡大坝损毁的多维度影响评估

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Science Bulletin 2024年第11期69卷 1642-1646页

作者：陈斌安佳夫黄玉飞陈曦东吴胜标林晨宫鹏 Future Urbanity&sustainable Environment(FUSE)Lab Division of Landscape ArchitectureDepartment of ArchitectureFaculty of ArchitectureThe University of Hong KongHong Kong 999077China Department of Real Estate and Construction Faculty of ArchitectureThe University of Hong KongHong Kong 999077China Faculty of Business and Economics The University of Hong KongHong Kong 999077China Department of Geography and Department of Earth SciencesThe University of Hong KongHong Kong 999077China

Water plays a central role in sustaining a thriving human society. Given its immense importance, safeguarding the related water infrastructure such as dams and reservoirs, which ensures the proper functioning of water... 详细信息

关键词：影响评估 reservoirs immense

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Optimizing segmented trajectory data storage with HBase for improved spatio-temporal query efficiency

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international Journal of Digital Earth 2023年第1期16卷 1124-1143页

作者： Yi Bao Zhou Huang Xuri Gong Yuyang Zhang Ganmin Yin Han Wang Institute of Remote Sensing and Geographical Information Systems Peking UniversityBeiingPeople's Republic of China Beijing Key Lab of Spatial Information Integration&Its Applications Peking UniversityBejjingPeople's Republic of China

The surging accumulation of trajectory data has yielded invaluable insights into urban systems,but it has also presented challenges for data storage and management *** response,specialized storage systems based on non-relational databases have been developed to support large data quantities in distributed ***,these systems often utilize storage by point or storage by trajectory methods,both of which have *** this study,we evaluate the effectiveness of segmented trajectory data storage with HBase optimizations for spatio-temporal *** develop a prototype system that includes trajectory segmentation,serialization,and spatio-temporal indexing and apply it to taxi trajectory data in *** indicate that the segmented system provides enhanced query speed and reduced memory usage compared to the Geomesa system.

关键词： Trajectory storage HBase trajectory segmentation spatio-temporal query

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Assessing OSM building completeness for almost 13,000 cities globally

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international Journal of Digital Earth 2022年第1期15卷 2400-2421页

作者： Qi Zhou Yuheng Zhang Ke Chang Maria Antonia Brovelli School of Geography and Information Engineering China University of GeosciencesWuhanPeople’s Republic of China international research center of big data for sustainable development goals BeijingPeople’s Republic of China Department of Civil and Environmental Engineering Politecnico di MilanoMilanoItaly

OpenStreetMap(OSM)is an essential source for acquiring building data,although such data may suffer from quality *** studies have focused on assessing OSM building data quality but few have been carried out on a global *** study aims to assess OSM building completeness(a quality measure)for 12,975 cities across the *** was achieved by employing population grid data as a proxy for reference building *** only the completeness of each city but also that of the grids within that city was *** assessment results were evaluated based on calculating the overall accuracy and the r-square value between estimated and reference OSM building completeness *** showed that for 75%of cities,the completeness is lower than 20%;no more than 9%of cities have an estimated completeness higher than 80%.The overall accuracies of most countries were higher than 80%.The estimated completeness was also highly correlated with the reference completeness,which verifies the effectiveness of our *** results may be useful for acquiring and updating building data in OSM.A global and open dataset related to OSM building completeness has been made available for public use.

关键词： OpenStreetMap building data data quality population data WorldPop

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HyperRefiner:a refined hyperspectral pansharpening network based on the autoencoder and self-attention

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international Journal of Digital Earth 2023年第1期16卷 3268-3294页

作者： Bo Zhou Xianfeng Zhang Xiao Chen Miao Ren Ziyuan Feng Institute of Remote Sensing and Geographic Information System Peking UniversityBeiigPeople's Republic of China

Deep learning has been developed to generate promising super resolution hyperspectral imagery by fusing hyperspectral imagery with the panchromatic ***,it is still challenging to maintain edge spectral information in the necessary upsampling processes of these approaches,and diffcult to guarantee effective feature *** study proposes a pansharpening network denoted as HyperRefiner that consists of,(1)a well performing upsampling network SRNet,in which the dual attention block and refined attention block are cascaded to accomplish the extraction and fusion of features;(2)a spectral autoencoder that is embedded to perform dimensionality reduction under constrained feature extraction;and(3)the optimization module which performs self-attention at the pixel and feature levels.A comparisonwithseveral state-of-the-art models reveals that HyperRefiner can improve the quality of the fused ***,compared to the single-head HyperTransformer and with the Chikusei dataset,our network improved the Peak Signal-to-Noise Ratio,Erreur Relative Globale Adimensionnelle de Synthese and Spectral Angle Mapper by 0.86%,3.62%,and 2.09%,and reduce the total memory,floating point operations,model parameters and computation time by 41%,75%,86%and 46%,*** experimental results show that HyperRefiner outperforms several networks and demonstrates its usefulness in hyperspectral image *** code is publicly available athttps://***/zsspo/Fusion_HyperRefiner.

关键词： Image fusion hyperspectral self-attention autoencoder edge spectrum

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Improving GPP estimates by partitioning green APAR from total APAR in two deciduous forest sites

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Journal of Forestry research 2023年第4期34卷 915-927页

作者： Siyuan Chen Liangyun Liu Lichun Sui Xinjie Liu College of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054People’s Republic of China Aerospace Information research Institute Chinese Academy of SciencesBeijing 100094People’s Republic of China

Non-photosynthetic components within a forest ecosystem account for a large proportion of the canopy but are not involved in ***,the accuracy of gross primary production(GPP)estimates is expected to improve by removing these ***,their infl uence in GPP estimations has not been quantitatively evaluated for deciduous *** vegetation indices have been used recently to estimate the fraction of photosynthetically active radiation absorbed by photosynthetic components(FAPAR_(green))for partitioning APAR green(photosynthetically active radiation absorbed by photosynthetic components).In this study,the enhanced vegetation index(EVI)estimated FAPAR_(green)and to separate the photosynthetically active radiation absorbed by photosynthetic components(APAR green)from total APAR observations(APAR_(total))at two deciduous forest *** eddy covariance-light use effi ciency(EC-LUE)algorithm was employed to evaluate the infl uence of non-photosynthetic components and to test the performance of APAR green in GPP *** results show that the infl uence of non-photosynthetic components have a seasonal pattern at deciduous forest sites,large diff erences are observed with normalized root mean square error(RMSE*)values of APAR green-based GPP and APAR_(total)-based GPP between tower-based GPP during the early and end stages,while slight diff erences occurred during peak growth *** addition,daily GPP estimation was significantly improved using the APAR green-based method,giving a higher coeffi cient of determination and lower normalized root mean square error against the GPP estimated by the APAR_(total)-based *** results demonstrate the signifi cance of partitioning APAR green from APAR_(total)for accurate GPP estimation in deciduous forests.

关键词： Gross primary production Absorbed photosynthetically active radiation Photosynthetic component Vegetation index AmeriFlux European fl uxes database

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HASM quantum machine learning

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Science China Earth Sciences 2023年第9期66卷 1937-1945页

作者： Tianxiang YUE Chenchen WU Yi LIU Zhengping DU Na ZHAO Yimeng JIAO Zhe XU Wenjiao SHI State Key Laboratory of Resources and Environment Information System Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Yanqi Lake Beijing Institute of Mathematical Sciences and Applications Beijing 101408China College of Resources and Environment University of Chinese Academy of SciencesBeijing 101499China College of Land Resources and Environment Jiangxi Agricultural UniversityNanchang 330045China

The miniaturization of transistors led to advances in computers mainly to speed up their *** miniaturization has approached its fundamental ***,many practices require better computational resources than the capabilities of existing ***,the development of quantum computing brings light to solve this *** briefly review the history of quantum computing and highlight some of its advanced *** on current studies,the Quantum Computing Advantage(QCA)seems *** challenge is how to actualize the practical quantum advantage(PQA).It is clear that machine learning can help with this *** method used for high accuracy surface modelling(HASM)incorporates reinforced machine *** can be transformed into a large sparse linear system and combined with the Harrow-Hassidim-Lloyd(HHL)quantum algorithm to support quantum machine *** has been successfully used with classical computers to conduct spatial interpolation,upscaling,downscaling,data fusion and model-data assimilation of ecoenvironmental ***,a training experiment on a supercomputer indicates that our HASM-HHL quantum computing approach has a similar accuracy to classical HASM and can realize exponential acceleration over the classical algorithms.A universal platform for hybrid classical-quantum computing would be an obvious next step along with further work to improve the approach because of the many known limitations of the HHL *** addition,HASM quantum machine learning might be improved by:(1)considerably reducing the number of gates required for operating HASM-HHL;(2)evaluating cost and benchmark problems of quantum machine learning;(3)comparing the performance of the quantum and classical algorithms to clarify their advantages and disadvantages in terms of accuracy and computational speed;and(4)the algorithms would be added to a cloud platform to support applications and gather active feedback from users

关键词： Quantum computing Machine learning Eco-environmental surface High accuracy surface modelling Quantum computational advantage Practical quantum advantage

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