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Impacts of Multi-Scale Disturbances on Tropical Cyclone Genesis over the Northern Part of the Western North Pacific 认领 引用
1
作者 Jingliang HUANGFU Yulian TANG +3 位作者 Wen CHEN Ronghui HUANG Pengfei WANG Qingtian SHI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2026年第7期1435-1447,共13页
Recent studies consistently highlight a northward shift in tropical cyclone(TC)activity in the western North Pacific(WNP);however,the impacts of the underlying drivers governing this shift remain insufficiently explor... Recent studies consistently highlight a northward shift in tropical cyclone(TC)activity in the western North Pacific(WNP);however,the impacts of the underlying drivers governing this shift remain insufficiently explored.This study focuses on TC genesis over the northern WNP(north of 20°N)and identifies a significant meridional seesaw relationship in TC genesis frequency between the northern and southern WNP(bounded by 20°N).Furthermore,we quantitatively diagnose the relative contributions of three key atmospheric disturbances—the Madden–Julian Oscillation(MJO),Quasi-Biweekly Oscillation(QBWO),and synoptic-scale disturbance(SSD)—to the interannual variability of northern WNP TC genesis.Results show that these multi-scale disturbances together explain 39.2%of the total variance in northern WNP TC genesis,with their individual contributions accounting for 40.9%(MJO),35.1%(QBWO),and 24.0%(SSD).The joint effect of these disturbances induces a Matsuno–Gill-like circulation pattern across the tropical Indo-Pacific,which drives downward vertical motion over the off-equatorial WNP.Additionally,tropical interactions triggered by these disturbances activate the meridional Pacific–Japan(PJ)or East Asia–Pacific(EAP)atmospheric teleconnection pattern.This teleconnection generates anomalous cyclonic winds and enhances the water vapor supply north of 20°N,creating favorable conditions for TC genesis in the northern WNP.This study clarifies the relative importance of multi-scale disturbances in regulating northern WNP TC genesis and highlights the necessity of incorporating SSDs into future analyses of interannual TC variability. 展开更多
关键词 synoptic-scale disturbance intraseasonal variability tropical cyclone genesis northern WNP
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Sedimentary Characteristics and Evolution of the High-resolution Sequence Stratigraphic Framework of the Taiyuan Formation in the Hangjinqi Area,Northern Ordos Basin 认领 引用
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作者 ZHAO Mingsheng TIAN Jingchun +1 位作者 SU Bingrui ZHANG Xiang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2026年第1期54-68,共15页
The Ordos Basin is a large superimposed hydrocarbon-bearing basin in China,and further research on the sedimentary characteristics and sedimentary evolution of the sequence framework of target layers is of great theor... The Ordos Basin is a large superimposed hydrocarbon-bearing basin in China,and further research on the sedimentary characteristics and sedimentary evolution of the sequence framework of target layers is of great theoretical and practical significance for guiding oil and gas exploration.The sedimentary facies and sedimentary evolution of the high-resolution sequence framework of the Carboniferous Taiyuan Formation in the Hangjinqi area have been systematically analyzed for the first time by drilling,logging and seismic data.The results show that four types of sequence interfaces can be identified in the Taiyuan Formation:regional unconformity surfaces,scour surfaces,lithologic-lithofacies transformation surfaces and flooding surfaces.According to the sedimentary response caused by the upward and downward movements of the base level at different levels,the Taiyuan Formation can be divided into 2 long-term cycles(LSC1-LSC2),4 mid-term cycles(MSC1-MSC4)and 7 short-term cycles(SSC1-SSC7).The long-and mid-term cycles correspond to members T1and T2and layers T1-1,T1-2,T2-1,and T2-2,respectively.Long-term cycles are dominated by C1;mid-term cycles are dominated by C1and C2,followed by A2;and short-term cycles are dominated by C1,C2,A1 and A2.Under the high-resolution sequence stratigraphic framework,the Hangjinqi area underwent a transformation of fan delta and tidal flat depositional systems during the Taiyuan Formation sedimentary period.In the MSC1-MSC2stage,owing to a large-scale paleocontinent,the fan delta sedimentary body,which was limited in scale and scope,developed only in the southeastern corner and gradually transitioned basinward to tidal flat facies.In the MSC3-MSC4 stage,as the paleocontinent continuously decreased and the sedimentary range expanded,fan-delta plain sedimentation began in the study area.Several braided distributary channels with poor connectivity developed on the fan-delta plain,and between them were floodplains and peat swamps. 展开更多
关键词 high-resolution sequence framework sedimentary characteristics sedimentary evolution Taiyuan Formation Hangjinqi area northern Ordos Basin
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Probabilistic seismic hazard analysis for the northern segment of the North-South Seismic Belt in China based on improved spatial smoothing and fault source model integration 认领 引用
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作者 Yaohu Zhang Hua Pan +1 位作者 Meng Zhang Ying Shi 《Earthquake Science》 CAS CSCD 2026年第1期1-31,共31页
The northern segment of the North-South Seismic Belt is characterized by intense crustal deformation,well-developed active tectonics,and frequent occurrences of strong earthquakes.Therefore,conducting a Probabilistic ... The northern segment of the North-South Seismic Belt is characterized by intense crustal deformation,well-developed active tectonics,and frequent occurrences of strong earthquakes.Therefore,conducting a Probabilistic Seismic Hazard Analysis(PSHA)for this region is of significant importance for supporting seismic fortification in major engineering projects and formulating disaster prevention and mitigation policies.In this study,a composite seismic source model was constructed by integrating data on historical earthquakes,active faults,and paleoseismicity.Furthermore,a logic tree framework was employed to quantify epistemic uncertainties,enabling a systematic seismic hazard assessment of the region.To more accurately characterize the spatial heterogeneity of seismic activity,improvements were made to both the Circular Spatial Smoothing Model(CSSM)with a fixed radius and the Adaptive Spatial Smoothing Model(ASSM),with full consideration given to the spatiotemporal completeness of historical earthquake magnitudes.Regarding the CSSM,for scenarios involving small sample sizes in earthquake catalogs,the cross-validation method proposed in this study demonstrated higher robustness than the maximum likelihood method in determining the optimal correlation distance.Performance evaluation results indicate that while both models effectively characterize seismic activity,the ASSM exhibits superior overall predictive performance compared to the CSSM,owing to its ability to adaptively adjust the smoothing radius according to seismic density.Significant discrepancies were observed in the Peak Ground Acceleration(PGA)results calculated with a 10%probability of exceedance in 50 years across different combinations of seismic source models.The single spatially smoothed point-source model yielded a maximum PGA of approximately 0.52 g,with high-value areas concentrated near historical epicenters,thereby significantly underestimating the hazard associated with major fault zones.When combined with the simple fault-source model,the maximum PGA increased to 0.8 g,with high-value zones exhibiting a zonal distribution along faults;however,the risk remained underestimated for faults with low slip rates that are nevertheless approaching their recurrence cycles.Following the introduction of the time-dependent characteristic fault-source model,local PGA values for faults in the middle-to-late stages of their recurrence cycles increased by a factor of 2 to 7 compared to the single model.These results demonstrate that the characteristic fault-source model reasonably delineates the time-dependence of large earthquake recurrence,thereby providing a more accurate assessment of imminent seismic risks.By comprehensively applying the improved spatially smoothed pointsource model,the simple fault-source model,and the characteristic fault-source model,the following faults within the region were identified as having high seismic hazard:the Huangxianggou,Zhangxian,and Tianshui segments of the Xiqinling northern edge fault;the Maqin-Maqu segment of the Dongkunlun fault;the Longriqu fault;the Maoergai fault;the Elashan fault;the Riyueshan fault;the eastern segment of the Lenglongling fault;the Maxianshan segment of the Maxianshan northern Margin fault;and the Maomaoshan-Jinqianghe segment of the Laohushan-Maomaoshan fault.As these faults are located within seismic gaps or are approaching the recurrence periods of large earthquakes,they should be prioritized for current and future seismic monitoring as well as disaster prevention and mitigation efforts. 展开更多
关键词 northern segment of the North-South Seismic Belt fault-source characteristic earthquake spatial smoothing model
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New material of Eospalax simplicidens(Spalacidae,Rodentia)from Jianyucha,Zichang,northern Shaanxi 认领 引用
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作者 CHANG Mei-Jing SHI Qin-Qin +1 位作者 NI Xi-Jun LI Qiang 《古脊椎动物学报（中英文）》 CSCD 北大核心 2026年第1期26-46,共21页
Eospalax,one of the only two extant genera within the Myospalacinae,has a high species richness.Each species is distinguished by unique cranial and dental morphologies,as well as variations in temporal and spatial dis... Eospalax,one of the only two extant genera within the Myospalacinae,has a high species richness.Each species is distinguished by unique cranial and dental morphologies,as well as variations in temporal and spatial distribution.Consequently,Eospalax serves as a reliable indicator for the biochronologic and paleoenvironmental studies of the Quaternary of East Asia.A recent discovery of a complete fossil skull in a conglomerate deposit,a part of the Lower Pleistocene Sanmen Formation,near Jianyucha Town,Zichang County,northern Shaanxi Province,has been subjected to a detailed analysis.The specimens were identified as Eospalax simplicidens,an extinct species of Eospalax,based on dental morphology.The recent discovery of E.simplicidens in Jianyucha offers significant insights into the species’cranial morphology and contributes to a more comprehensive understanding of its geographical distribution.The distinctive feature of the posterodorsal location of the external acoustic meatus indicates either a plesiomorphy or an evolutionary convergence among E.simplicidens,African root rats(Tachyoryctes),and bamboo rats(Rhizomyini).A skull(IVPP V5398.1)and four upper jaws(V5398.2)from Gongwangling in Lantian,Shaanxi,previously identified as Myospalax fontanieri,is transferred to the species E.lingtaiensis.A skull(IVPP RV35055)from Jingou,Xin’an,Henan,previously identified as E.simplicidens,is transferred to the species E.youngianus.In this study,body mass estimates are made for extinct Eospalax.Both E.lingtaiensis and E.simplicidens are small-sized zokors,with an estimated body mass of less than or approximately 300 g,respectively. 展开更多
关键词 northern Shaanxi Loess Plateau Early Pleistocene Myospalacinae cranial morphology
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Tectonic differentiation of basins in the northern South China Sea and its control on hydrocarbon accumulation 认领 引用
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作者 XIE Yuhong FAN Caiwei +2 位作者 TONG Chuanxin YOU Junjun ZHOU Gang 《Petroleum Exploration and Development》 SCIE 2026年第2期285-298,共14页
Based on seismic data,well log data,and analyses of hydrocarbon accumulation elements in typical oil and gas fields,this study systematically investigates the tectonic differentiation and its control on hydrocarbon ac... Based on seismic data,well log data,and analyses of hydrocarbon accumulation elements in typical oil and gas fields,this study systematically investigates the tectonic differentiation and its control on hydrocarbon accumulation in four major Cenozoic petroliferous basins(Beibuwan,Pearl River Mouth,Qiongdongnan and Yinggehai)of the northern South China Sea.The results show that the tectonic evolution in the study area exhibits a significant differentiation characterized by“east-west staging and north-south zonation”,with major subsidence events occurred progressively later from west to east and from north to south,allowing the basins to be classified into two types:passive continental margin basins and transform continental margin basins.This tectonic differentiation governs hydrocarbon accumulation through a“triple-control”mechanism:subsidence-thermal evolution divergence controls source rock type and maturation;tectonic-depositional cycle coupling controls reservoirrap type and reservoir-caprock assemblage;and structural configurations control hydrocarbon accumulation,preservation and enrichment patterns.Moderate heat flow on the northern shelf favors oil generation from the Paleogene lacustrine source rocks,while high geothermal gradients in the southern deep-water area promote late-stage rapid gas generation from coal measures,forming the resource distribution framework with“oil in the north and gas in the south”;Tectonic-depositional coupling regulates reservoir distribution and reservoir-caprock assemblage effectiveness,with the rift-stage faulting inducing isolated lacustrine delta reservoirs,the southward shift of subsidence during the rift-drift transition giving rise to extensive marine delta sandstones,the detachment faults in deep-water areas governing the development of canyon channels,and regional transgressive mudstones and overpressure mudstones serving as key caprocks;Structural styles dictate accumulation models,including primary oil reservoirs characterized by the association of weakly reworked traps and regional seals,deep-water gas reservoirs characterized by shelf-break controlled sand and high heat flow-driven gas migration,composite gas reservoirs characterized by transfer zone controlled reservoirs and overpressure mudstone sealing,and late-stage rapid hydrocarbon accumulation characterized by strike-slip stress transition and diapir conduit.Analysis of hydrocarbon accumulation in typical oil and gas fields validates these cognitions,revealing the comprehensive control of tectonic evolution on source rock maturation,reservoir distribution,trap types and preservation conditions.Based on these findings,it is recommended to differentiate exploration strategies by areas and layers,with focus on structural-lithological traps under high heat flow setting in deep-water areas and primary oil reservoirs with weak reworking in shallow-water areas. 展开更多
关键词 northern South China Sea basins tectonic differentiation oil in the north and gas in the south accumulation model Beibuwan Basin Pearl River Mouth Basin Qiongdongnan Basin Yinggehai Basin
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Seasonal variation of the surface cross-shelf exchange in the northern South China Sea:a Lagrangian perspective 认领 引用
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作者 Dongliang Hou Tingting Zu +6 位作者 Zhiqiang Liu Lixin Qu Zhongya Cai Yeqiang Shu Kristen M.Thyng Qiang Wang Robert D.Hetland 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2026年第2期39-59,共21页
Previous studies on cross-shelf exchange,predominantly adopted an Eulerian perspective,struggled to identify water sources and pathways.Using a high-resolution regional ocean modeling system(ROMS)and Lagrangian partic... Previous studies on cross-shelf exchange,predominantly adopted an Eulerian perspective,struggled to identify water sources and pathways.Using a high-resolution regional ocean modeling system(ROMS)and Lagrangian particle tracking,this study systematically investigates the seasonal variation and dynamics of surface cross-shelf exchange in the northern South China Sea(NSCS)from a Lagrangian perspective.Based on daily released 30-d drifter trajectories we identify the key pathways,source regions for surface cross-shelf exchange,revealing pronounced seasonal variability.Results show the surface cross-shelf exchange generally following monsoon-driven Ekman transport.However,local dynamics,especially topographic modulation,can outweigh the expected Ekman-driven transport,producing surface exchange patterns opposite to that predicted from the prevailing winds.Topographic effects vary across different scales.In the coastal waters of western Guangdong during winter,despite downwelling-favorable winds,the modulation of alongshore currents by island topography induces an eastward pressure gradient.This gradient,through geostrophic balance,drives offshore flows opposite to wind-driven Ekman onshore transport.Furthermore,the eastern widened shelf exhibits a distinct seasonal variation of cross-shelf exchange,with strong offshore transport(opposite to the direction of Ekman transport)in winter and exceedingly weak exchange in summer.Analysis of the underlying mechanisms reveals that this winter offshore transport is primarily attributed to geostrophic flows driven by surface pressure gradient that is jointly modulated by the Kuroshio intrusion and local widened shelf topography,and enhanced by cumulative submesoscale processes.In summer,a persistent and strong along-isobath jet acts as a dynamic barrier,effectively suppressing the exchange.These findings highlight the important role of topography in regulating surface material transport,and have important implications for predicting the advection and dispersion of plankton or oil spills over the continental shelf influenced by monsoon. 展开更多
关键词 northern South China Sea cross-shelf exchange connectivity Lagrangian particle tracking ROMS
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Measured Wave Analysis in the Northern Yellow Sea 认领 引用
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作者 LI Zikang SHI Hongyuan +3 位作者 SUN Liqin ZHU Ruiqi XUE Huaiyuan LI Yan 《Journal of Ocean University of China》 SCIE CAS CSCD 2026年第3期755-764,共10页
Measured wave data are important for offshore engineering design.Wave data measured using a Doppler wave and current profiler were utilized to statistically analyze wave parameters and examine the characteristics of t... Measured wave data are important for offshore engineering design.Wave data measured using a Doppler wave and current profiler were utilized to statistically analyze wave parameters and examine the characteristics of typhoon processes for evaluating the wave conditions in the surrounding waters of the northern Yellow Sea.Results indicate that the study area exhibits a mean wave period of 3.4 s and a significant wave height of 0.67 m,with the prevailing wave direction from the southeast(SE)and the dominant storm wave direction from the south(S).Characteristic wave heights follow a typical Rayleigh distribution.The overall average wave duration shortens with increasing wave height,with a more rapid decay rate detected during typhoons compared with nontyphoon periods.The overall wave energy resources in this area are relatively limited,which makes wave energy development currently unfeasible.These findings offer valuable references for marine engineering design and maritime transportation safety in this region. 展开更多
关键词 northern Yellow Sea measured waves wave characteristics wave duration wave energy assessment
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Rogue waves in the northern part of the South China Sea:chaotic dynamics and multiparameter synergy determination 认领 引用
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作者 Tao FENG Tianyu ZHANG +4 位作者 Danchen YAN Hailong WANG Jian YANG Xun LIN Junping ZHANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2026年第3期950-962,共13页
Based on wave data recorded in 2020 from 10 buoy stations in the northern part of the South China Sea,the synergistic effects of wave parameters such as wave steepness,spectral width,kurtosis,skewness and Benjamin-Fei... Based on wave data recorded in 2020 from 10 buoy stations in the northern part of the South China Sea,the synergistic effects of wave parameters such as wave steepness,spectral width,kurtosis,skewness and Benjamin-Feir index(BFI)on a rogue wave group in the northern waters of the South China Sea were investigated.The frequency and energy distributions of three types of rogue waves were recognized based on wavelet transform.Chaotic dynamics was introduced to study the chaotic phenomena in the wave series where rogue wave were located.Results show that wave steepening enhanced the nonlinear effect of waves,and a narrow spectrum could suppress the dispersion effect,which increased the BFI,triggered the modulation instability of waves,and promoted the generation of distorted waves.When kurtosis>3,the BFI increases as the degree of kurtosis deviation from the Gaussian distribution increases.In particular,when kurtosis>3 and H/Hs>2.2,the increase in kurtosis contributes significantly to the increase in the anomalous intensity of the rogue wave.Rogue waves induced by modulation instability and those induced by the superposition of wave clusters can be explained by phase and dispersion modulation as well as by energy distribution,whereas the generation mechanism of rogue waves that have not grown sufficiently is difficult to resolve from the time-domain waveform characteristics and the frequency-domain wavelet energy density.Qualitative analysis by the Poincarécross section and quantitative analysis by the Lyapunov exponent verified that the nonlinear wave system,in which a rogue wave is located in the wave train,has weakly chaotic dynamic behavior. 展开更多
关键词 northern South China Sea rogue wave wave parameter threshold energy distribution chaotic dynamic
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Evaluation of Global NWP Data on the Convection Environment over the Data-Sparse Northern South China Sea by Long-Term Observations 认领 引用
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作者 Ling HUANG Zhiyong MENG Murong ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2026年第5期965-980,共16页
The coastal regions of southern China experience the country's most frequent convective weather.Accurately representing the low-level upstream atmospheric state over the data-sparse South China Sea(SCS)is crucial ... The coastal regions of southern China experience the country's most frequent convective weather.Accurately representing the low-level upstream atmospheric state over the data-sparse South China Sea(SCS)is crucial for reliable convection predictions in numerical models.Utilizing 10 years of radiosonde observations launched over the SCS,this study presents the upstream offshore convective environments and evaluates the global model data performance including NCEP FNL,ERA5,CRA-40,JRA-3Q,and MERRA-2.Results show that thermodynamic state variables such as temperature and humidity exhibit greater biases than kinetic variables,particularly at low levels.Deeper-layer parameters exhibit smaller uncertainties,especially wind-related variables,while moisture-related parameters have the largest uncertainties,compared to shallower-layer parameters.All model data tend to underestimate the conditional instability and equilibrium level,while overestimating the condensation level,storm relative helicity(SRH),with minimal bias in lapse rate,convective inhibition,vertical wind shear(VWS),and mean winds.These biases primarily arise from the model data's underestimation of temperature and moisture below 700 hPa and lower wind speeds below 950 hPa.Among the global models,CRA-40 performs best in dynamic parameters,with highest correlation and lowest mean absolute error in low-level winds,SRH,VWS,and mean winds.ERA5 excels in thermodynamic parameters.Additional convective-permitting numerical experiments indicate that minor initial condition errors over the upstream ocean significantly affect coastal rainfall production.The rainfall production on windward coasts is most sensitive to the low-level air temperature errors during nocturnal hours,while the rainfall over the PRD is most sensitive to the low-level wind errors. 展开更多
关键词 Radiosonde convective environments rainfall northern South China Sea
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Driving Factors of Aboveground Biomass in Grasslands on Northern Slope of Tianshan Mountains,China 认领 引用
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作者 ZHANG Chenglong LI Gangyong +4 位作者 LUO Geping FRIDAY Uchenna Ochege WU Shuai GUO Kang WANG Yuangang 《Chinese Geographical Science》 SCIE CAS CSCD 2026年第6期1097-1110,共14页
Aboveground biomass(AGB)is a key indicator of grassland productivity and ecosystem functioning.Understanding the mechanisms through which environmental factors regulate AGB is essential for maintaining ecosystem funct... Aboveground biomass(AGB)is a key indicator of grassland productivity and ecosystem functioning.Understanding the mechanisms through which environmental factors regulate AGB is essential for maintaining ecosystem functioning and ecological security.Based on an extensive field survey across the northern slope of the Tianshan Mountains,China,this study integrated threshold regression and piecewise structural equation modeling(SEM)to quantify the direct and indirect effects of biotic and abiotic factors on grassland AGB and to identify threshold-dependent shifts in these mechanisms.Results showed significant differences in AGB among grassland types,with meadow grasslands showing the highest AGB(191.32 g/m2),followed by steppe grasslands(85.24 g/m2)and desert grasslands(68.20 g/m2).Among biotic factors,vegetation height and coverage were reliable indicators of AGB.Vegetation height was most strongly correlated with AGB in meadow grasslands(r=0.54),whereas vegetation coverage was dominant correlate in steppe and desert grasslands(r=0.44 and r=0.37,respectively).Climatic effects on AGB were nonlinear and threshold-dependent.In meadow grasslands,both precipitation and temperature promoted AGB growth below their thresholds of 263.7 mm and 6.5°C,respectively;however,precipitation exceeded 263.7 mm,its direct effect reversed to significant inhibition(path coefficient:−0.25),while temperature remained the main positive driver(path coefficient:0.45).In steppe grasslands,precipitation was the dominant driver and had a positive linear effect on AGB,whereas the positive effect of temperature was limited to values below 4.8°C.In desert grasslands,precipitation also dominanted AGB variation,while the effect of temperature shifted from positive to negative at 7.3°C.Across all grassland types,climatic factors additionally affected AGB indirectly through their influences on soil nutrients and organic matter,which further regulated biotic attributes.These results provide new insightss into threshold dependent biomass regulation and offer a scientific basis for adaptive grassland management in arid regions. 展开更多
关键词 aboveground biomass(AGB)of grassland abiotic factor threshold regression structural equation model(SEM) northern slope of Tianshan Mountains,China
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Carbon Sinks in Northern China During 1982-2023:Pattern,Evolution and Driving Forces 认领 引用
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作者 QU Wei DU Huishi HASI Eerdun 《Chinese Geographical Science》 SCIE CAS CSCD 2026年第6期1062-1076,共15页
The ecological environment in Northern China is fragile,its overall carbon sink capacity has long been underestimated,and its spatial differentiation is significant.Based on the Carnegie-Ames-Stanford Approach(CASA)mo... The ecological environment in Northern China is fragile,its overall carbon sink capacity has long been underestimated,and its spatial differentiation is significant.Based on the Carnegie-Ames-Stanford Approach(CASA)model and the Thornthwaite memorial model,this study analyzed the spatial-temporal characteristics and driving mechanisms of actual net ecosystem productivity(NEPA)in Northern China from 1982 to 2023.The results show that:1)NEPA fluctuated between 139.48 and 174.74 g C/(m2·yr),with the year 2000 serving as a pivotal transition point after which ecological restoration projects reversed the preceding declining trend.Approximately 52.07%of the study area exhibited carbon sink improvement,concentrated in the eastern plains such as the Songnen Plain,Liaohe Plain,and Haihe Plain,while 47.93%exhibited degradation,primarily in the western arid region.2)The relative contributions of climate change and human activities to carbon sink changes were quantitatively separated.In carbon sink-improved areas,human activities dominated,contributing 61.51%versus 38.49%from climate change.In carbon sink-degraded areas,climate change and human activities contributed nearly equally(51.94%and 48.06%,respectively).Among climatic factors,precipitation exerted the most extensive influence,with NEPA showing a significant positive correlation(P<0.05)in 31.93%of the study area,particularly in the Hulun Buir Sandy Land and the northern Haihe Plain.These findings elucidate the spatially differentiated driving mechanisms of vegetation carbon sinks under climate and human impacts,providing a scientific basis for region-specific ecosystem management and the achievement of carbon neutrality goals.Future research incorporating higher-resolution data and advanced attribution frameworks is needed to reduce uncertainties associated with mixed-pixel effects in heterogeneous landscapes. 展开更多
关键词 carbon sink satellite observation data net ecosystem productivity(NEP) Carnegie-Ames-Stanford approach model(CASA) driving factors Northern China
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Multi-Stage Magmatic and Hydrothermal Events Formed Giant Caosiyao Porphyry Mo Deposit in the Northern Margin of North China Craton 认领 引用
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作者 Peiwen Chen Tiancheng Zhou +1 位作者 Yong Fu Qingdong Zeng 《Journal of Earth Science》 SCIE CAS CSCD 2026年第1期92-113,共22页
The formation of Caosiyao giant porphyry Mo deposit is related to three granitic porphyries:coarse-grained granite porphyry(CG),fine-grained granite porphyry(FG),and giant plagioclase phenocryst bearing granite porphy... The formation of Caosiyao giant porphyry Mo deposit is related to three granitic porphyries:coarse-grained granite porphyry(CG),fine-grained granite porphyry(FG),and giant plagioclase phenocryst bearing granite porphyry(PG).To investigate the mineralization significance of three porphyries,Microthermometry,Laser micro-Raman Spectra,and H-O-He-Ar isotope analyses of fluid inclusions were conducted.Intermediate density with high temperatures(>550℃)and moderate-low salinities(~10 wt.%)characterizes CG-related initial exsolved fluids.Vapor-rich and brine phases separated from the initial fluid following a continuous decrease in pressure and temperature,inducing molybdenite precipitation.FG-related initial fluids are characterized by high temperatures(>550℃)and salinities(>65 wt.%).The mixing of low-salinity fluids led to a rapid decrease in the salinity of FG-related fluid,promoting the deposit of the Mo element.The lead-zinc mineralization is closely related to the FG-related fluid,and the addition of meteoric fluid induced the formation of galena and sphalerite.The ore-forming fluid related to the PG is CO2-rich and accompanied by the addition of mantle-derived He-Ar.The presence of CO2 did not contribute to the solubility of Mo,resulting in the absence of a considerable amount of molybdenite. 展开更多
关键词 fluid inclusion microthermometry H-O-He-Ar Caosiyao northern margin of NCC
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Tracing the agro-pastoral ecotone transition in northern China from the human-Earth system perspective 认领 引用 被引量：3
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作者 BAI Yu LIU Yansui YUAN Xuefeng 《Journal of Geographical Sciences》 SCIE CSCD 2025年第4期783-799,共17页
The agro-pastoral ecotone in northern China (APENC) is an ecologically fragile region with a variable climate and unbalanced socioeconomic development.Identifying the spatial range and transitional dynamics of the APE... The agro-pastoral ecotone in northern China (APENC) is an ecologically fragile region with a variable climate and unbalanced socioeconomic development.Identifying the spatial range and transitional dynamics of the APENC is crucial for understanding the delicate balance between regional ecology,the economy,and society.The human-Earth system provides a comprehensive research framework in which human activities and the natural environment are viewed as interdependent and dynamically interactive.Guided by the principles of human-Earth system science,in this study,the boundaries of the APENC are identified by integrating core parameters,including water,land,climate,ecology,and human factors.Raster-based spatial data analysis is employed to examine the spatial and temporal evolution of the APENC from 1990 to 2020.The APENC extends from northeast to southwest along the central axis of northern China,displaying trends of contraction and fragmentation over time,with its centre of gravity shifting closer to the Hu Huanyong Line.The peripheral areas exhibit heightened sensitivity to environmental and ecological changes,highlighting the region’s vulnerability to external pressures.In this study,management strategies grounded in sustainable development principles are proposed,a framework for integrating ecological changes with socioeconomic strategies is established,and actionable guidance for policymakers to promote sustainable development in this fragile and dynamic region is provided. 展开更多
关键词 agro-pastoral ecotone in northern China(APENC) human-Earth system spatiotemporal evolution sustainable development
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Provenance and Paleogeographic Evolution of the Upper Paleozoic-Lower Mesozoic Strata in Northern Laos 认领 引用 被引量：1
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作者 Jingjie Jin Xin Qian +2 位作者 Vongpaseuth Senebouttalath Yuzhi Zhang Yuejun Wang 《Journal of Earth Science》 SCIE CAS CSCD 2025年第3期861-879,共19页
The Late Paleozoic-Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance,paleogeographic patterns,and the tectonic ev... The Late Paleozoic-Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance,paleogeographic patterns,and the tectonic evolution of the eastern Paleotethyan Ocean.This study presents systematic stratigraphy,petrology,geochemistry,and detrital zircon U-Pb-Hf isotopic analyses for the Late Carboniferous-Jurassic sedimentary strata on both sides of the Luang Prabang Basin.Based on distinct stratigraphic ages and provenance characteristics,the clastic rock samples can be divided into four groups.The Group 1 Late Carboniferous-Early Permian samples from the western part of the basin yield detrital zircon age-peaks of~348 and~1425 Ma,with correspondingεHf(t)values ranging from-2.0 to+15.5 and+1.5 to+14,respectively.The age spectrum of Group 2 Late Carboniferous-Early Permian samples from the eastern part of the basin shows major age-peaks of~287 and~1860 Ma,withεHf(t)values of-5.9--0.9 and-3.6-+4.2,respectively.Group 3 Late Permian-Triassic samples exhibit age-peaks of~242 and~1853 Ma,along withεHf(t)values of-0.7-+14.4 and-5.4--1.8,respectively.Group 4 Middle-Late Jurassic samples yield agepeaks of~237,~431,~813,~1833,and~2460 Ma,lacking Late Devonian(413-345 Ma)detrital zircons.All these data collectively suggest that the Group 1 sample primarily originated from the Sukhothai arc in western Indochina,Group 2 was from the Kontum and Truong Son in eastern Indochina,and Group 3 has a combined provenance of the Sukhothai,Kontum,and Truong Son.Regional comparisons suggest that the Jurassic provenance was mainly derived from South China,which was imported through the northern river system.Our data,combined with the regional angular unconformities between the Jurassic continental strata and pre-Jurassic marine strata,suggest that the Luang Prabang Basin transformed into a superimposed collisional retroforeland basin during the Jurassic,and the closure of the Luang Prabang BAB occurred before the Late Triassic. 展开更多
关键词 Late Paleozoic-Early Mesozoic detrital zircon paleogeographic evolution Paleotethyan Ocean Luang Prabang BAB northern Laos sedimentary rocks tectonics
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Hydrographic control on subsurface chlorophyll maximum in the northern South China Sea in autumn 认领 引用 被引量：1
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作者 Xiang GONG Hui LIU +2 位作者 Xun GONG Jiyao LIU Huiwang GAO 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2025年第4期1213-1226,共14页
As a frequently-observed phenomenon in the northern South China Sea(nSCS),subsurface chlorophyll maximum(SCM)evolution from summer to winter remains unclear,neither the associated hydrographic control.In this study,on... As a frequently-observed phenomenon in the northern South China Sea(nSCS),subsurface chlorophyll maximum(SCM)evolution from summer to winter remains unclear,neither the associated hydrographic control.In this study,on the basis of in-situ data of fall-season cruises in 2004–2006,we characterized the depth,thickness and intensity of the SCM in the nSCS using a general Gaussian-function fitting approach,and investigated a linkage to the corresponding ocean vertical buoyance properties.Our results show that the SCM becomes deeper,thicker and less intense offshore-wards in the nSCS during fall seasons.In parallel,a correlation between the SCM variation and mixed layer depth exists in the nSCS,and it becomes pronounced in the shelf region compared to the slope and basin areas in autumn.Physically,once warmer surface ocean and thus stronger thermo-determined stratification,the SCM layer goes deeper and becomes thicker and less intense in the nSCS,especially in the shelf area of the nSCS.Moreover,the impact of water temperatures at deeper layers on the vertical stratification exerts more consequent roles on the spatial variability of SCM,compared to surface temperatures in the nSCS.Specifically,the isotherm line of 22℃ acts as crucial indicator for variations of the SCM in the nSCS during autumns. 展开更多
关键词 subsurface chlorophyll maximum(SCM) northern South China Sea(nSCS) autumn season hydrographic control
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Pollution and carbon reduction effects of the pilot policy on clean winter heating in Northern China:Evidence from the county level 认领 引用 被引量：1
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作者 Yan Chen Jiaqi Li +1 位作者 Yue Zhang Fan Yang 《Chinese Journal of Population,Resources and Environment》 CSCD 2025年第1期85-95,共11页
Coal dependence and inefficient decentralized heating have significantly increased China’s energy consumption for winter heating,increasing air pollution and exacerbating the greenhouse effect.In 2017,China implement... Coal dependence and inefficient decentralized heating have significantly increased China’s energy consumption for winter heating,increasing air pollution and exacerbating the greenhouse effect.In 2017,China implemented the Pilot Policy on Clean Winter Heating in Northern China,aiming to achieve high central heating coverage and cleaner energy consumption.Studying the effects of this policy can help promote its implementation and serve as a reference for effective adjustment of the contents in the future.However,few studies have investigated this policy and its carbon reduction effects,and most focus on the provincial or city levels.Therefore,this paper considers the policy’s influence on air pollution and carbon emissions at the county level to provide a precise and comprehensive assessment of the policy effects.We use panel data from 1290 counties in 15 provinces in Northern China from 2014 to 2021,applying a multiperiod difference-in-differences model to quantify the impact of the policy on carbon emissions and air quality in the pilot area.We then conduct a series of tests to demonstrate the robustness of the results and analyze the mechanisms of the policy effects from two perspectives,namely,central heating and natural gas use,through a mediating effect model.Finally,we examine the heterogeneity of policy effects between counties based on geographic location and per capita income levels of rural residents through a moderating effect model.The results reveal that the policy significantly reduces air pollution and carbon emissions in the pilot area by increasing the central heating area and natural gas use.Compared with the central and western regions in the north and areas with low-income rural residents,the policy effects in the eastern regions in the north and areas with high-income rural residents are more pronounced. 展开更多
关键词 Pilot policy on clean winter heating Pollution and carbon reduction Multiperiod difference-in-differences model County-level analysis Northern China
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Spatiotemporal distribution of seasonal snow density in the Northern Hemisphere based on in situ observation 认领 引用 被引量：1
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作者 Tao Che LiYun Dai Xin Li 《Research in Cold and Arid Regions》 CAS CSCD 2025年第3期137-144,共8页
The snow density is a fundamental variable of the snow physical evolution processes,which can reflect the snowpack condition due to the thermal and gravitational compaction.Snow density is a bridge to transfer snow de... The snow density is a fundamental variable of the snow physical evolution processes,which can reflect the snowpack condition due to the thermal and gravitational compaction.Snow density is a bridge to transfer snow depth to snow water equivalent(SWE)for the snow water resources research.Therefore,it is important to understand the spatiotemporal distribution of snow density for the appropriate estimation of SWE.In this study,in situ snow densities from more than 6,000 stations in the Northern Hemisphere were used to analyze the spatial and temporal variations in snow density.The results displayed that snow density varied spatially and temporally in the Northern Hemisphere,with range of below 0.1 to over 0.4 g/cm3.The average snow densities in the mountainous regions of western North America,southeastern Canada,and Europe range from approximately 0.24 to 0.26 g/cm3,which is significantly greater than the values of 0.16–0.17 g/cm3observed in Siberia,central Canada,the Great Plains of the United States,and China.The seasonal growth rates also present large spatial heterogeneity.The rates are over 0.024 g/cm3per month in Southeastern Canada,the west mountain of North America and Europe,approximately 0.017 g/cm3per month in Siberia,much larger than approximately 0.004 g/cm3per month in other regions.Snow cover duration is a critical factor to determine the snow density.This study endorses the small snow density in China based on meteorological station observations,which results from that the meteorological stations are dominantly distributed in plain areas with relative short snow cover duration and shallow snow. 展开更多
关键词 Snow density Snow depth Snow cover duration Northern Hemisphere
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Formation of late-stage passive-roof duplexes in fold-and-thrust belts:Thrusting sequence and thermochronologic constraints from the Northern Apennines(Italy) 认领 引用
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作者 Marco Bonini Daniele Maestrelli +2 位作者 Domenico Montanari Federico Sani Maria Laura Balestrieri 《Geoscience Frontiers》 SCIE CAS CSCD 2025年第4期1-23,共23页
Passive-roof duplexes accommodate shortening at the mountain front of many fold-and-thrust belts worldwide.These structures typically manifest at the surface by hinterland-verging backthrusts that decouple thin-skinne... Passive-roof duplexes accommodate shortening at the mountain front of many fold-and-thrust belts worldwide.These structures typically manifest at the surface by hinterland-verging backthrusts that decouple thin-skinned thrust sheets from underlying foreland-verging duplexes.Although the main fac-tors controlling the development of passive-roof duplexes have mostly been identified,some of their intrinsic characteristics are still poorly defined.These relate to their spatio-temporal relationships to thrust faults located further inland in orogens,and their ability to transport younger rocks over older ones.This study explores these issues in the Casentino-Romagna axial sector of the Northern Apennines,which expose regional forethrusts and backthrusts.Detailed field mapping and analysis of superposed tectonic structures were integrated with apatite fission-track dating for constraining the tim-ing of rock exhumation and correlated tectonic events.Collectively,the results have allowed us to inter-pret the evolution of the study area in terms of two main deformation stages.Specifically,a first,long phase(D1)progressed from NE-directed,in-sequence thrusting(∼18 to∼10-9 Ma)to late out-of-sequence thrusting(∼8-5 Ma).A successive deformation phase,that we refer to as D2(∼4-2 Ma),con-sisted of backthrusts and associated folds that were ubiquitous and systematically overprinted onto the foreland-verging D1structures.Such retrovergent structures identify a late deformation phase dom-inated by the development of passive-roof duplexes that propagated hinterlandward into the orogen up to beyond the primary watershed ridge.Orogen-scale processes controlled the evolution of forelandward D1-phase thrusts,although late erosion could have played a major role by bringing the Apennine thrust wedge toward an undercritical state.The latter conditions could have contributed to keeping the out-of-sequence thrusts active,and eventually promoted the development of the D2passive-roof duplexes. 展开更多
关键词 Passive-roof duplexes Structural analysis Apatite fission-track dating Northern Apennines Critical wedge stability
Prediction of Extreme Air Temperature and Wind Speed Along the Northern Sea Route(NSR)with Application for the Safety of Polar Vessels 认领 引用
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作者 CHAI Wei QI Jian-zhang +3 位作者 HE Lin Bernt J.LEIRA Chana SINSABVARODOM SHU Ya-qing 《China Ocean Engineering》 SCIE EI CSCD 2025年第4期744-754,共11页
Due to global warming and diminishing ice cover in Arctic regions,the northern sea route(NSR)has attracted increasing attention in recent years.Extreme cold temperatures and high wind speeds in Arctic regions present ... Due to global warming and diminishing ice cover in Arctic regions,the northern sea route(NSR)has attracted increasing attention in recent years.Extreme cold temperatures and high wind speeds in Arctic regions present substantial risks to vessels operating along the NSR.Consequently,analyzing extreme temperature and wind speed values along the NSR is essential for ensuring maritime operational safety in the region.This study analyzes wind and temperature data spanning 40 years,from 1981 to 2020,at four representative sites along the NSR for extreme value analysis.The average conditional exceedance rate(ACER)method and the Gumbel method are employed to estimate extreme wind speed and air temperature at these sites.Comparative analysis reveals that the ACER method provides higher accuracy and lower uncertainty in estimations.The predicted extreme wind speed for a 100-year return period is 30.36 m/s,with a minimum temperature of-56.66°C,varying across the four sites.Furthermore,the study presents extreme values corresponding to each return period,providing temperature extremes as a basis for guiding steel thickness specifications.These findings provide valuable reference for designing polar vessels and offshore structures,contributing to enhanced engineering standards for Arctic conditions. 展开更多
关键词 northern sea route(NSR) air temperature wind speed extreme value prediction ACER method
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PM10 dust emission in the Erenhot-Huailai zone of northern China based on model simulation 认领 引用
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作者 WANG Yong YAN Ping +3 位作者 WU Wei WANG Yijiao HU Chanjuan LI Shuangquan 《Journal of Arid Land》 SCIE CSCD 2025年第3期324-336,共13页
The Erenhot-Huailai zone, as an important dust emission source area in northern China, affects the air quality of Beijing City, Tianjin City, and Hebei Province and human activities in this zone have a profound impact... The Erenhot-Huailai zone, as an important dust emission source area in northern China, affects the air quality of Beijing City, Tianjin City, and Hebei Province and human activities in this zone have a profound impact on surface dust emission. In order to explore the main source areas of surface dust emission and quantify the impacts of human activities on surface dust emission, we investigated the surface dust emission of different land types on the Erenhot-Huailai zone by model simulation, field observation, and comparative analysis. The results showed that the average annual inhalable atmospheric particles(PM10) dust emission fluxes in arid grassland, Hunshandake Sandy Land, semi-arid grassland,semi-arid agro-pastoral area, dry sub-humid agro-pastoral area, and semi-humid agro-pastoral area were 4.41, 0.71, 3.64, 1.94, 0.24, and 0.14 t/hm2, respectively, and dust emission in these lands occurred mainly from April to May. Due to the influence of human activities on surface dust emission, dust emission fluxes from different land types were 1.66–4.41 times greater than those of their background areas, and dust emission fluxes from the main dust source areas were 1.66–3.89 times greater than those of their background areas. According to calculation, the amount of PM10 dust emission influenced by human disturbance accounted for up to 58.00% of the total dust emission in the study area. In addition, the comparative analysis of model simulation and field observation results showed that the simulated and observed dust emission fluxes were relatively close to each other, with differences ranging from 0.01 to 0.21 t/hm2 in different months, which indicated that the community land model version 4.5(CLM4.5) had a high accuracy. In conclusion, model simulation results have important reference significance for identifying dust source areas and quantifying the contribution of human activities to surface dust emission. 展开更多
关键词 northern China classification of land type model simulation dust emission human disturbance
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