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Energy injection, transport, and dissipation in earth's magnetosphere

Science China earth sciences 2025年第2期68卷 363-388页

作者： Huishan FU Jinbin CAO school of Space and earth sciences Beihang UniversityBeijing 100191China Key Laboratory of Space environment Monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing 100191China

The earth's magnetosphere is a region occupied by many artificial satellites, and also is a region that spacecraft must cruise during the deep-space exploration. In this sense, the earth's magnetosphere is closely related to human activity and is a candidate for us to expand our living space. Generally, the earth's magnetosphere can preclude most energetic particles from the Sun and the interstellar space, effectively protecting human beings on the earth from being attacked and thus making the earth to be a habitable planet. However, in some conditions, the earth's magnetosphere becomes dynamic and energetic, and consequently may damage the artificial satellites, threaten the astronauts' health, and disrupt the ground infrastructure, which leads to a decline in the national economy. Therefore, investigating how energy is injected into the magnetosphere, how it is transported in the magnetosphere, and how it is ultimately dissipated in the magnetosphere are the key issues in space physics. Targeting these key issues, in this paper, we review the recent progress on them. Particularly, we introduce the relevant scientific questions,models, methods, and spacecraft missions, for better building a physical link among the energy injection, transport, and dissipation in the magnetosphere, present an energy chain of the magnetosphere, reveal the relationship between such energy chain and the space weather events, and discuss the forecasting and warning methods for energetic-particle events in the magnetosphere. The magnetospheric energy chain discussed in this paper will help us reveal the mechanisms of space weather events, establish the models of space environment, and forecast the disastrous space weather events.

关键词： earth's magnetosphere Energy injection Energy transport Energy dissipation

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Gradient maturation experiment on hairs implies taphonomic changes in fossil hairs

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Science China earth sciences 2025年第1期68卷 62-73页

作者： Xin LI Yibo ZHOU Tao ZHAO Xingjian HE Yanhong PAN State Key Laboratory for Mineral Deposits Research Center for Critical Earth Material CyclingCentre for Research and Education on Biological Evolution and Environment and Frontiers ScienceSchool of Earth Sciences and EngineeringNanjing UniversityNanjing210023China Institute of Palaeontology Yunnan Key Laboratory of Earth System ScienceYunnan Key Laboratory for PalaeobiologyYunnan UniversityKunming650500China

Mammalian hair,as a key feature related to endothermy,physical protection,and camouflage,has a long geohistorical record that dates back even to the ***,the limited information on the taphonomy of hair hinders the understanding of its evolutionary significance in deep *** address this,we conducted taphonomic experiments to simulate the transformation process of black *** changes in the morphological structure,microscopic characteristics,and chemical composition of hair during the simulated fossilization process were documented by scanning electron microscopy,Fourier transform infrared(FTIR)spectroscopy,and Raman *** results revealed that damage to the morphology of hair began at a mild temperature(150–175℃),and hair transformed into a fluid-like mass at a relatively high temperature(200℃).In addition,the morphological structure of melanosomes had relatively greater preservation potential than keratins did,and the microscopic features of melanosomes were persistently *** Raman and FTIR spectra indicated that the characteristic melanin and keratin peaks changed as the temperature *** the chemical signals were not lost completely,the variations in the characteristic amide bands in the FTIR spectra indicate that the keratins severely degraded at high temperatures(>200℃),whereas the characteristic melanin bands in the Raman spectra suggested that melanin signals were still recognizable,even at high temperatures(>200℃).These results were confirmed by principal component analysis(PCA)and principal component analysis linear discriminant analysis(PCA–LDA).In addition,the Raman signals of all the samples in the simulated experiments were distinguished from the signals of common geological carbonaceous materials(humic acid),which suggested that Raman spectroscopy can be used to detect melanin in fossils.

关键词： Mammalian hair Melanin Keratin Fossilization Experimental taphonomy

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Vegetation mapping of Yunnan Province by integrating remote sensing, field observations, and models

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Science China earth sciences 2025年第3期68卷 836-849页

作者： Mingjian XIAHOU Mingchun PENG Zehao SHEN Qingzhong WEN Chongyun WANG Yannan LIU Qiuyuan ZHANG Lei PENG Changyuan YU Xiaokun OU Jingyun FANG Key Laboratory of Ministry of Education for earth Surface Processes College of Urban & Environmental SciencesPeking University school of Ecology and environment Yunnan University Yunnan Institute of Forest Inventory and Planning

Vegetation maps are crucial for ecologists and decision-makers, providing essential information on the spatial distribution of various vegetation types to support ecosystem exploration and management. Despite advancements in earth observation and machine learning enabling large-scale vegetation mapping, creating detailed and accurate maps in biodiversity hotspots remains challenging due to significant environmental heterogeneity and frequent human disturbances. The lack of sufficient ground-based data and complex climate-vegetation interactions further limits mapping accuracy. In this study, we developed an integrated framework for multi-source data fusion to enhance vegetation mapping and validation in Yunnan Province, a global biodiversity hotspot region in Southwest China. The mapping process involved four key steps:(1) vegetation classification using random forest and Landsat imagery,(2) boundary calibration based on a locally calibrated static climatevegetation model,(3) patch correction with independent forest inventory data, and(4) validation using adequate field observations. This approach enabled the mapping of 17 vegetation types and 44 subtypes in Yunnan Province(1:50000), categorized based on the growth-form composition of dominant species of the community. The overall accuracies were 0.747 and0.710 for natural vegetation types and subtypes, and 0.905 and 0.891 for artificial types and subtypes. This high-resolution map enhances our understanding of vegetation distribution and ecological complexity in this region, offering valuable insights for policymakers to support conservation efforts and sustainable management strategies.

关键词： Vegetation mapping Biodiversity hotspot region Multi-source data Data-fusion framework Ecological diversity

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Seasonal variation of boron isotopic compositions in river water within the Qinghai Lake watershed and its controlling factors

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Science China earth sciences 2025年第3期68卷 811-823页

作者： Yitong QIN Zhangdong JIN Maoyong HE Longfei GOU Jun XIAO Institute of Global environmental Change School of Human Settlements and Civil Engineering Xi'an Jiaotong University State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Department of Geography Chang'an University

Riverine boron（B） and its isotopic compositions(δ11B) are commonly used to trace silicate weathering within watersheds, but its sources and isotopic fractionation mechanisms remain contentious. In this study, we collected the seasonal river waters of the Buha River, the largest inlet river of Qinghai Lake, which is sensitive to climate change, and analyzed its seasonal variations of the major ions, B concentrations, and δ11B, to explore its sources and controlling factors. The results indicate that B in the Buha River predominantly originates from weathering of silicate rocks, with significantly seasonal variations in the geochemical behaviour of B isotopes. In the rainy seasons, the riverine B isotopic fractionation is primarily controlled by weathering of silicate rocks under the influence of hydrological conditions, where clay minerals preferentially absorb10B, leading to the enrichment of heavier B isotopes in river waters. In contrast, in the dry seasons, the B of river waters may mainly come from the recharge of groundwater(whose δ11B with a notable p H dependence); owing to prolonged retention of fluids, the steady state of δ11B is reached by the isotopic equilibrium through adsorption of clay minerals. This study highlights that the seasonal variations in riverine δ11B in semi-arid regions are jointly governed by silicate weathering, hydrological conditions, and water-rock interactions, with water p H and rainfall as key regulators. Consequently, riverine δ11B in the rainy seasons under semi-arid climatic conditions can effectively trace hydrologically-controlled silicate weathering processes within the watershed.

关键词： Boron isotopes Silicate weathering Seasonal variation Water-rock interactions Qinghai Lake watershed

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Lightning-induced neutrons as a possible source of charged particles in the earth's inner radiation belt

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earth and Planetary Physics 2025年第02期9卷 444-451页

作者： QuanQi Shi ChenYao Han Qiu-Gang Zong Alexander Degeling Shuo Wang SuiYan Fu PengZhi He Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial environment School of Space Science and Technology Institute of Space Sciences Shandong University school of earth and Space sciences Peking University WeiHai Research Institute of Industrial Technology of Shandong University

The Van Allen radiation belts are doughnut-shaped zones surrounding earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cosmic ray albedo neutron decay(CRAND),radial diffusion, and local acceleration have been considered principal sources of electrons, whereas protons are predominantly from CRAND and solar protons. In this article, lightning-induced neutrons from earth's upper atmosphere are suggested as a possible source of protons and electrons in the inner radiation belt. These terrestrial neutrons can contribute to the inner belt population by undergoing nuclear decay. Several approaches are proposed and discussed to evaluate the potential contribution of lightning-induced neutrons to the inner belt, including magnitude estimation, Monte Carlo simulations, and in situ observations. This article discusses some avenues of further study to determine the contribution of lightning-induced neutrons to the inner radiation belt.

关键词： Van Allen radiation belts cosmic ray albedo neutron decay(CRAND) lightning neutrons

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A Newly Established Air Pollution Data Center in China

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Advances in Atmospheric sciences 2025年第4期42卷 597-604页

作者： Mei ZHENG Tianle ZHANG Yaxin XIANG Xiao TANG Yinan WANG Guannan GENG Yuying WANG Yingjun LIU Chunxiang YE Caiqing YAN Yingjun CHEN Jiang ZHU Qiang ZHANG Tong ZHU SKL-ESPC College of Environmental Sciences and Engineeringand Center for Environment and HealthPeking UniversityBeijing 100871China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China school of environment Tsinghua UniversityBeijing 100084China school of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044China environment Research Institute Shandong UniversityQingdao 266237China Department of environmental Science and Engineering Fudan UniversityShanghai 200092China Department of earth System Science Tsinghua UniversityBeijing 100084China

Air pollution in China covers a large area with complex sources and formation mechanisms,making it a unique place to conduct air pollution and atmospheric chemistry *** National Natural Science Foundation of China’s Major Research Plan entitled“Fundamental Researches on the Formation and Response Mechanism of the Air Pollution Complex in China”(or the Plan)has funded 76 research projects to explore the causes of air pollution in China,and the key processes of air pollution in atmospheric physics and atmospheric *** order to summarize the abundant data from the Plan and exhibit the long-term impacts domestically and internationally,an integration project is responsible for collecting the various types of data generated by the 76 projects of the *** project has classified and integrated these data,forming eight categories containing 258 datasets and 15 technical reports in *** integration project has led to the successful establishment of the China Air Pollution Data Center(CAPDC)platform,providing storage,retrieval,and download services for the eight *** platform has distinct features including data visualization,related project information querying,and bilingual services in both English and Chinese,which allows for rapid searching and downloading of data and provides a solid foundation of data and support for future related *** pollution control in China,especially in the past decade,is undeniably a global exemplar,and this data center is the first in China to focus on research into the country’s air pollution complex.

关键词： air pollution data center platform multi-source data China

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Comparative analysis of empirical and deep learning models for ionospheric sporadic E layer prediction

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earth and Planetary Physics 2025年第1期9卷 10-19页

作者： BingKun Yu PengHao Tian XiangHui Xue Christopher JScott HaiLun Ye JianFei Wu Wen Yi TingDi Chen XianKang Dou Institute of Deep Space sciences Deep Space Exploration LaboratoryHefei 230088China CAS Key Laboratory of Geospace environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China Department of Meteorology University of ReadingReading RG66BBUK

Sporadic E(Es)layers in the ionosphere are characterized by intense plasma irregularities in the E region at altitudes of 90-130 *** they can significantly influence radio communications and navigation systems,accurate forecasting of Es layers is crucial for ensuring the precision and dependability of navigation satellite *** this study,we present Es predictions made by an empirical model and by a deep learning model,and analyze their differences comprehensively by comparing the model predictions to satellite RO measurements and ground-based ionosonde *** deep learning model exhibited significantly better performance,as indicated by its high coefficient of correlation(r=0.87)with RO observations and predictions,than did the empirical model(r=0.53).This study highlights the importance of integrating artificial intelligence technology into ionosphere modelling generally,and into predicting Es layer occurrences and characteristics,in particular.

关键词： ionospheric sporadic E layer radio occultation ionosondes numerical model deep learning model artificial intelligence

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Mining Subsidence Based on Integrated SBAS-InSAR and Unmanned Aerial Vehicles Technology

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Journal of Ocean University of China 2025年第1期24卷 113-129页

作者： CHEN Xuewei CHEN Jianping WANG Genhou ZHANG Qian ZHENG Yanwei school of earth sciences and Resources China University of GeosciencesBeijing 100083China Beijing Key Laboratory of Development and Research for Land Resources Information Beijing 100083China

The Small Baseline Subset InSAR(SBAS-InSAR)and unmanned aerial vehicles(UAVs)as common ocean-land technologies,have been extensively applied in subsidence,glacial movement,surface deformation,and maritime positioning and navigation.A novel method integrating SBAS-InSAR and UAV photogrammetry is used to analyze ground subsidence deformation in the Gesar gold mine located in Maqu,Northwest *** approach uses SBAS-InSAR to calculate two-dimensional deformation data for capturing ascending and descending *** method can provide precise information on small-sized deformations within mining *** deformation data obtained from UAVs and the vertical deformation data derived from InSAR are integrated to generate comprehensive and accurate ground subsidence data from the mining *** demonstrate that using a combined InSAR(vertical)and UAV technique to analyze surface subsidence in mining districts resolves inconsistency between the line-of-sight and deformation ***,the incoherence issue of InSAR in regions with large deformation gradients is addressed,while the inherent errors of UAV monitoring of mining surface subsidence are *** genetic algorithm(GA)-backpropagation(BP)neural network algorithm is combined with InSAR data to predict subsidence in collapsed *** observed,the GA-BP algorithm has the smallest residual under the same training ***,the GA-BP neural network model can effectively predict surface subsidence in mining areas and can be used for subsequent subsidence prediction.

关键词： SBAS-InSAR two-dimensional deformation solution UAV photogrammetry data fusion subsidence prediction

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An embedded electron current layer observed at the edge of the plasma sheet in the earth’s magnetotail

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earth and Planetary Physics 2025年第1期9卷 148-158页

作者： ChenChen Zhan RongSheng Wang QuanMing Lu San Lu XinMin Li Deep Space Exploration Laboratory/school of earth and Space sciences University of Science and Technology of ChinaHefei 230026China Chinese Academy of sciences(CAS)Center for Excellence in Comparative Planetology/CAS Key Laboratory of Geospace environment/Anhui Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center of Astronautical Science and Technology Harbin 150001China

The formation of an embedded electron current sheet within the magnetotail plasma sheet has been poorly *** this article,we present an electron current layer detected at the edge of the magnetotail plasma *** ions were demagnetized inside the electron current layer,but the electrons were still frozen in with the magnetic field ***,this decoupling of ions and electrons gave rise to a strong Hall electric field,which could be the reason for the formation of the embedded thin current *** magnetized electrons,the absence of the nongyrotropic electron distribution,and negligible energy dissipation in the layer indicate that magnetic reconnection had not been triggered within the embedded thin current *** highly asymmetric plasma on the two sides of the current layer and low magnetic shear across it could suppress magnetic *** observations indicate that the embedded electric current layer,probably generated by the Hall electric field,even down to electron scale,is not a sufficient condition for magnetic reconnection.

关键词： magnetotail plasma sheet magnetic reconnection

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A review on global spatial distribution,sources and toxicity of perfluoroalkyl acid and prospect in the cryosphere

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Journal of Mountain Science 2025年第1期22卷 167-183页

作者： LI Bowen Du Wentao KANG Shichang CHEN Jizu JIANG Youyan YIN Lichen LU Changsheng LIU Hongyi State Key Laboratory of Cryospheric Science and frozen soil engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences(CAS)Lanzhou 730000China University of Chinese Academy of sciences Beijing 100049China Gansu Provincial Industry Technology Center of Intelligent Equipment and Big Data for Disaster Prevention Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences(CAS)Lanzhou 730000China Lanzhou Regional Climate Center Lanzhou 730000China school of earth sciences and Spatial Information Engineering Hunan University of Science and TechnologyXiangtan 411201China school of Energy and Power Engineering Lanzhou University of TechnologyLanzhou 730000China Zhangye Meteorological Service Zhangye 734000China

Perfluoroalkyl acid analogs(PFAAs)are a class of chemically stable environmentally persistent organic pollutants(POPs)that are difficult to degrade and have a strong capacity to accumulate in the human *** have been found to be biotoxic to humans and have been detected in various environmental media,especially in the cryosphere at trace *** cryosphere,sensitively responds to climate change,plays a crucial role in the global water,carbon and energy ***,researches on cryosphere PFAAs especially in Tibetan Plateau(TP)is ***,we summarize the physicochemical properties,physiological toxicity,spatiotemporal distribution,sources,diffusion and migration pathways,as well as analysis and removal methods of PFAAs in the cryosphere *** results show that PFAAs pollutants are mainly produced and distributed in the more economically developed countries in Europe and the United States,as well as in East Asia,and PFAAs can be transported by atmospheric circulation and water cycle to remote regions including cryosphere *** current detection methods for PFAAs in cryosphere need to be further refined for increased accuracy and *** is also a need to develop more effective removal methods that will reduce the environmental and human threats posed by these ***,we propose key scientific questions for future research in cryosphere including PFAAs redistribution influenced by cryosphere changes,human activities,and the interaction of other spheres.

关键词： Perfluoroalkyl acid Cryosphere Physiological toxicity Analytical method Removal method

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