Extreme traffic loads significantly challenge the safety and cost-effectiveness of highway bridges,especially under site-specific traffic conditions.Conventional assessments often rely on overly conservative load mode...Extreme traffic loads significantly challenge the safety and cost-effectiveness of highway bridges,especially under site-specific traffic conditions.Conventional assessments often rely on overly conservative load models,leading to excessive structural design.In this study,a framework for the prediction of maximum bending moments in simply supported bridges is developed by integrating weigh-in-motion(WIM)data,traffic microsimulation,and generalized extreme value(GEV)regression modeling to establish relationships between the GEV parameters(μ,σ,ξ)and traffic factors—heavy vehicle proportion,bridge span length,vehicle speed,headway,and traffic volume.Using one-year WIM data from 7.4 million vehicles,the developed models for μ and σ exhibit high predictive accuracy(R^(2)>0.95)and are validated through leave-one-out cross-validation.The prediction of ξ is less accurate(R^(2)≈0.6),requiring further improvement.Applying these models to a 1000-year return level yields a reliable,data-driven extrapolation,supporting optimized bridge design and safety assessment under varying traffic conditions.展开更多
The development of infrared engineering technologies for extreme environments remains a formidable challenge due to the inherent trade-offs among optical performance,thermal stability,and mechanical integrity in therm...The development of infrared engineering technologies for extreme environments remains a formidable challenge due to the inherent trade-offs among optical performance,thermal stability,and mechanical integrity in thermal photonic metamaterials(TPMs).This work introduces a novel multi-obj ective design framework and demonstrates the design,fabrication,and validation of a TPM operating under extreme temperatures up to 1873 K.We have established a holistic design framework integrating temperaturedependent neural network and Pareto multi-obj ective optimization to co-optimize spectral response,component light-weighting,and structural efficiency.The framework achieves 100 times faster computation than genetic algorithms.The performance of the designed TPM was evaluated under various atmospheric models and detection distances.The TPM achieved a peak radiance suppression efficiency of 82%and a maximum attenuation of-7.4 dB at 1200-1500 K.Experimentally,we fabricated an all-dielectric TPM using a refractory TiO_(2)/BeO multilayer stack with only 5 layers and 2um total thickness.The optimized structure shows high reflectivity(0.62 at 3-5 um;0.48 at 8-14μm)for radiative suppression and high emissivity(0.87 at 5-8μm)for radiative cooling.The TPM withstands 1873 K for 12 h in air with less than 3%spectral drift,retaining excellent mechanical properties.On high-temperature components,it achieves 40-50%radiative suppression and 40-60 K(~10.1 kW m^(-2))radiative cooling at 1100 K,endures over 20 times thermal shock cycles(>150 K s^(-1),700-1500 K),and maintains stable performance over 5 cycles,with 78%visible and 98%microwave transmittance.This work establishes a new paradigm in the design and application of photonic materials for extreme environments.展开更多
Hydrological extremes,such as floods,droughts,and compound events,are extremely dangerous to human societies,ecosystems,and infrastructures,whose frequency and severity are affected by climate change more and more.Eff...Hydrological extremes,such as floods,droughts,and compound events,are extremely dangerous to human societies,ecosystems,and infrastructures,whose frequency and severity are affected by climate change more and more.Effective disaster preparedness,water resource management,and climate adaptation have to do with accurate prediction and extensive risk assessment.This review sums up recent progress in predictive modeling and risk assessment systems in the framework of hydrological extremes in the changing climatic conditions.Statistical and empirical techniques,including extreme value theory and nonstationary frequency analysis,give probabilistic information using historic records,whereas process-based models give an understanding of physical hydrological processes at different climate and land-use conditions.New information-based and hybrid methods that use machine learning and high-resolution data take advantage of the complexity and nonlinearities and enhance the predictive power.Hazard,exposure,vulnerability,and adaptive capacity risk assessment models allow predictive output to be translated into actionable decision support,with socio-economic aspects and analysis of the scenario.Case studies of various regions across the globe show the use of these techniques to address floods,droughts,and compound events,with success and current problems.The review also addresses current trends such as compound hazard,multi-hazard integration,AI-enabled modelling,and cross-sectoral decision support,and outlines research priorities of improving predictive capability and resilience.This review will inform researchers,policymakers,and practitioners by offering a synthesis of all the effects of the hydrological extremes in climate change to formulate sound strategies for alleviating these effects.展开更多
This study investigated the characteristics and mechanisms of summer regional persistent extreme precipitation events(RPEPEs)over South China(SC)modulated by distinct intensity regimes of 10-30-day intraseasonal oscil...This study investigated the characteristics and mechanisms of summer regional persistent extreme precipitation events(RPEPEs)over South China(SC)modulated by distinct intensity regimes of 10-30-day intraseasonal oscillation(ISO).Diagnostic analyses revealed that the spatiotemporal evolution of RPEPEs exhibits robust phase-locking with the 10-30-day intraseasonal precipitation.By classifying RPEPEs into strong-ISO(SRPEPE)and weak-ISO(WRPEPE)composites based on the amplitude of 10-30-day filtered precipitation,we demonstrate a 14.6%enhancement in peak precipitation intensity during SRPEPEs compared to WRPEPEs.These distinct precipitation regimes are governed by fundamentally different Rossby wave teleconnection patterns over Eurasia.During SRPEPEs,a robust southeastward-propagating 10-30-day Rossby wave train originating from the Barents Sea traverses midlatitude Eurasia,effectively perturbing the northwestern Pacific upper-level circulation and establishing a favorable dynamic environment over SC.In contrast,WRPEPEs are associated with weaker eastward-propagating wave trains constrained along the subtropical jet stream.The horizontal convergence of background moisture driven by 10-30-day winds significantly amplifies lower-tropospheric humidity during SRPEPEs.The thermal advection of background temperature by 10-30-day geostrophic winds enhances baroclinic instability and vertical motion,intensifying precipitation under these moisture conditions.展开更多
Extreme rainfall events(EREs)frequently hit the middle and lower reaches of the Yellow River basin(YRB)during boreal summer.Recent observations have indicated that EREs exhibit teleconnection patterns across long spat...Extreme rainfall events(EREs)frequently hit the middle and lower reaches of the Yellow River basin(YRB)during boreal summer.Recent observations have indicated that EREs exhibit teleconnection patterns across long spatial distances.This study investigated ERE teleconnections in the YRB using the Event Synchronization(ES)method in combination with Complex Network(CN)theory.EREs in the YRB are significantly synchronized with other regions from regional to global scales.Additionally,high-resolution CMIP6 models in general show better skill in capturing these characteristics compared to low-resolution models.A further examination shows that the spatial synchronization patterns exhibit pronounced timescale dependence.Significant ERE synchronizations between the YRB and Europe were uncovered,where the YRB lags Eastern Europe by 3-5 days and Western Europe by 5-7 days,with Rossby wave propagation playing a key role.Wave trains from Europe propagate downstream along the Eurasian jet,inducing anomalous circulations over the YRB that enhance vertical upward motion and moisture transport,ultimately triggering EREs.Two distinct wave trains are observed:one is associated with Eastern Europe-YRB synchronization,occurring in the midlatitude region;the other is linked to Western Europe-YRB synchronization,positioned at higher latitudes.Notably,17.5%of Eastern Europe-YRB synchronization cases and 17.0%of Western Europe-YRB cases overlap.Quantitative analysis indicates that the synchronized events between Eastern(Western)Europe and the YRB account for roughly 28%(30%)of EREs in the YRB.These findings are critical for better understanding ERE mechanisms,offering guidance for forecasting and early warning capabilities for EREs in the YRB.展开更多
Objective:To analyze the clinical application value of autologous periosteum graft combined with platelet-rich plasma(PRP)in the treatment of long bone fractures in the extremities.Methods:A total of 40 patients with ...Objective:To analyze the clinical application value of autologous periosteum graft combined with platelet-rich plasma(PRP)in the treatment of long bone fractures in the extremities.Methods:A total of 40 patients with long bone fractures in the extremities admitted to Santai Hospital Affiliated to North Sichuan Medical College from January 2023 to January 2025 were included,including cases of upper extremity forearm fractures and lower extremity femoral and tibial fractures.The patients were evenly divided using a random number table,with the control group undergoing open reduction and internal fixation(ORIF)combined with autologous periosteum graft,and the observation group undergoing ORIF,autologous periosteum graft,and PRP injection.Surgical indicators,complication rates,excellent fracture healing rates,functional satisfaction,and joint range of motion were compared between the two groups.Results:The surgical indicators in the observation group were similar to those in the control group(p>0.05).The complication rate in the observation group was lower than that in the control group,while the excellent fracture healing rate and functional satisfaction were higher in the observation group(p<0.05).Conclusion:Autologous periosteum graft combined with PRP technology is safe and reliable for the treatment of long bone fractures in the extremities,with satisfactory clinical outcomes.展开更多
Nail changes following upper extremity transplantation(UET)cannot be overlooked as they possess diagnostic and prognostic relevance in allotransplantation of upper limbs.This comprehensive review explores nail and nai...Nail changes following upper extremity transplantation(UET)cannot be overlooked as they possess diagnostic and prognostic relevance in allotransplantation of upper limbs.This comprehensive review explores nail and nail bed related changes encountered in UET recipients in the literature.The differential diagnosis of nail abnormalities in UET includes a wide range of systemic,local and iatrogenic conditions other than immune responses to the allograft.It requires interdisciplinary evaluation by primary transplant surgeons,pathologists,dermatologists and immunologists.The possible underlying mechanisms of nail pathology in UET and the management are discussed.It also underscores the importance of onychodystrophy and need for timely intervention and to improve outcomes in UET recipients.展开更多
Recent studies have suggested that rapid warming over the Mongolian Plateau(MP)may intensify extreme heat events(EHEs).However,the characteristics and mechanisms driving summer EHEs over the MP(MP-EHEs)remain unclear....Recent studies have suggested that rapid warming over the Mongolian Plateau(MP)may intensify extreme heat events(EHEs).However,the characteristics and mechanisms driving summer EHEs over the MP(MP-EHEs)remain unclear.This study explores the interannual variations in summer MP-EHEs and their relationship with the summer soil moisture over the Inner Tibetan Plateau(TP-SM).The results reveal that changes in the MP-EHEs are linked to descending atmospheric motion induced by a local high-pressure system over the MP region.Descending motion further results in decreased mid-tolow-level cloud cover and increased shortwave radiation,thereby warming the surface and triggering summer MP-EHEs.Further analysis indicates that increased TP-SM results in a greater latent heat flux,triggering a local secondary circulation that reinforces the local high-pressure system over the MP region,thus serving to promote the occurrence of summer MPEHEs.Additionally,model results from the linear baroclinic model(LBM)and CMIP6 further confirm that variations in summer TP-SM contribute to the occurrence of the MP-EHEs.展开更多
This study takes"ocean heat waves"as a typical case to study the scientific definition,driving mechanisms,multi-dimensional impacts,and response strategies of extreme climate events.The definition of extreme...This study takes"ocean heat waves"as a typical case to study the scientific definition,driving mechanisms,multi-dimensional impacts,and response strategies of extreme climate events.The definition of extreme events requires a comprehensive consideration of statistical thresholds and social impacts.It is mainly driven by global warming caused by human emissions of greenhouse gases,and is also influenced by the interaction of natural variations such as ENSO.Extreme events cause systematic and cascading impacts on human health,infrastructure,agricultural economy,and ecosystems(especially marine ecosystems).Advanced technologies such as satellite remote sensing,climate models,and artificial intelligence have significantly enhanced their monitoring and prediction capabilities.However,effective responses still require a parallel strategy of mitigation and adaptation,and international cooperation is strengthened through the framework of the Paris Agreement.展开更多
Amphibious vehicles are more prone to attitude instability compared to ships,making it crucial to develop effective methods for monitoring instability risks.However,large inclination events,which can lead to instabili...Amphibious vehicles are more prone to attitude instability compared to ships,making it crucial to develop effective methods for monitoring instability risks.However,large inclination events,which can lead to instability,occur frequently in both experimental and operational data.This infrequency causes events to be overlooked by existing prediction models,which lack the precision to accurately predict inclination attitudes in amphibious vehicles.To address this gap in predicting attitudes near extreme inclination points,this study introduces a novel loss function,termed generalized extreme value loss.Subsequently,a deep learning model for improved waterborne attitude prediction,termed iInformer,was developed using a Transformer-based approach.During the embedding phase,a text prototype is created based on the vehicle’s operation log data is constructed to help the model better understand the vehicle’s operating environment.Data segmentation techniques are used to highlight local data variation features.Furthermore,to mitigate issues related to poor convergence and slow training speeds caused by the extreme value loss function,a teacher forcing mechanism is integrated into the model,enhancing its convergence capabilities.Experimental results validate the effectiveness of the proposed method,demonstrating its ability to handle data imbalance challenges.Specifically,the model achieves over a 60%improvement in root mean square error under extreme value conditions,with significant improvements observed across additional metrics.展开更多
Northern Xinjiang,an arid inland area in Northwest China,is highly vulnerable to air pollution under intensifying climate extremes,yet the relative roles of temperature and precipitation extremes remain insufficiently...Northern Xinjiang,an arid inland area in Northwest China,is highly vulnerable to air pollution under intensifying climate extremes,yet the relative roles of temperature and precipitation extremes remain insufficiently understood.Using multi-source datasets for 2000-2023,including China High Air Pollutants(CHAP)particulate matter 2.5(PM_(2.5)),particulate matter 10(PM_(10)),and ozone(O3)products and Expert Team on Climate Change Detection and Indices(ETCCDI)extreme climate indices derived from the European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis v5(ERA5)-Land,together with trend detection,change-point analysis,pixel-wise Pearson correlation,and random forest(RF)modeling,we investigated the spatiotemporal evolution of major air pollutants and their responses to meteorological extremes in northern Xinjiang.PM_(2.5) and PM_(10) generally declined from 2000 to 2023,whereas O3 increased,indicating a shift from particulate-dominated pollution toward stronger photochemical pollution.Interannually,PM_(2.5) showed a rise-decline pattern,PM_(10) exhibited a rise-decline-rebound pattern,and O3 increased markedly after 2015.Clear seasonal contrasts were observed,with PM_(2.5) peaking in winter,PM_(10) in spring,and O3 in summer.During the same period,northern Xinjiang exhibited a pronounced warming-drying tendency,characterized by increasing heat-related indices,decreasing cold-related indices,reduced precipitation totals and heavy-rainfall frequency,and increasing consecutive dry days.Pollutant-climate relationships showed strong spatial heterogeneity and pollutant-specific contrasts across the Urumqi-Changji-Shihezi corridor,the Ili River Valley,and the Junggar Basin.PM_(2.5) responses to precipitation shifted from predominantly positive to negative,PM_(10) showed mainly negative associations with precipitation extremes,and O3 responses varied by subregion.Temperature-related extremes generally explained more pollutant variability than precipitation-related extremes,with PM_(2.5) showing the highest sensitivity.These findings highlight the coupled influences of warming,drying,emissions,and terrain-controlled transport on air quality and support region-specific,multi-pollutant strategies for coordinated climate adaptation and air pollution control in northern Xinjiang.展开更多
Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the...Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the coordination with virtual power plants(VPPs).The proposed strategy improves systemflexibility and responsiveness by optimizing the power adjustment of flexible resources.In the proposed strategy,theGaussian Process Regression(GPR)is firstly employed to determine the adjustable range of aggregated power within the VPP,facilitating an assessment of its potential contribution to power supply support.Then,an optimal dispatch model based on a leader-follower game is developed to maximize the benefits of the VPP and flexible resources while guaranteeing the power balance at the same time.To solve the proposed optimal dispatch model efficiently,the constraints of the problem are reformulated and resolved using the Karush-Kuhn-Tucker(KKT)optimality conditions and linear programming duality theorem.The effectiveness of the strategy is illustrated through a detailed case study.展开更多
Summary What''s New?:This study introduces a novel,periosteum-preserving iliac crest transverse transport(ICTT)technique for high-level lower extremity arteriosclerosis obliterans(LEASO),targeting patients uns...Summary What''s New?:This study introduces a novel,periosteum-preserving iliac crest transverse transport(ICTT)technique for high-level lower extremity arteriosclerosis obliterans(LEASO),targeting patients unsuitable for conventional revascularization.Technical Innovation:By relocating the osteotomy from the weight-bearing tibia to the non-weight-bearing ilium,this minimally invasive technique eliminates the risk of stress fractures,allows for immediate full weight-bearing,and expands indications to patients with proximal arterial occlusions.展开更多
This past year, 2024, is on track to be the warmest year, joining 2023 as the two hottest years on record. With the exceptional heat, weather and climate extremes were common across the world. In particular, 2024 has ...This past year, 2024, is on track to be the warmest year, joining 2023 as the two hottest years on record. With the exceptional heat, weather and climate extremes were common across the world. In particular, 2024 has seen a remarkable run of extreme precipitation events and resulting impacts. Here, we provide an overview of the most notable extreme events of the year, including extreme precipitation and floods, tropical cyclones, and droughts. The characteristics and impacts of these extreme events are summarized, followed by discussion on the physical drivers and the role of global warming.Finally, we also discuss the future prospects in extreme event studies, including impact-based perspectives, challenges in attribution of precipitation extremes, and the existing gap to minimize impacts from climate extremes.展开更多
In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future...In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future extreme climate changes in the Asian arid region and Tibetan Plateau,this study applied the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP-CMIP6)to assess the changes in EHP(Rx5d and R95pTOT)and EHT(TX90p and TXx)under different emission scenarios in the 21st century.Findings suggest that both the frequency and the intensity of the extreme indices will increase,exhibiting accelerated growth under higher emission scenarios,particularly under the SSP5-8.5 emission scenario.It is suggested that the growth of EHT and EHP in the early subperiod of the 21st century(2026-2045)will be relatively moderate,with small differences between different emission scenarios.However,by the middle subperiod of the 21st century(2041-2060),the differences between different emission scenarios will become larger than the 2035s and the growth will become more intense.In western central Asia,TX90p,TXx,Rx5d,and R95pTOT increase by 9.7%-14.2%(13.3%-24.7%),1.3℃-1.7℃(1.6℃-2.7℃),6.5%-8.9%(8.2%-8.8%),and 18.1%-27.0%(25.6%-30.0%)by the early(middle)subperiod;in eastern central Asia,TX90p,TXx,Rx5d,and R95pTOT increase 8.1%-12.0%(11.3%-21.1%),1.4℃-1.8℃(1.9℃-2.9℃),7.4%-9.7%(10.4%-13.8%),and 20.2%-29.3%(32.0%-40.8%)by the early(middle)subperiod;and over the Tibetan Plateau,TX90p,TXx,Rx5d,and R95pTOT increase 12.5%-17.4%(17.0%-31.0%),1.2℃-1.5℃(1.6℃-2.5℃),7.2%-10.0%(9.9%-15.0%),and 26.6%-33.1%(36.1%-55.3%)by the early(middle)subperiod.展开更多
The escalation of compound extreme events has resulted in noteworthy economic and property losses.Recognizing the intricate interconnections among these events has become imperative.To tackle this challenge,we have fo...The escalation of compound extreme events has resulted in noteworthy economic and property losses.Recognizing the intricate interconnections among these events has become imperative.To tackle this challenge,we have formulated a comprehensive framework for the systematic analysis of their dependencies.This framework consists of three steps.(1)Define extreme events using Mahalanobis distance thresholds.(2)Represent dependencies among multiple extreme events through a point process-based method.(3)Verify dependencies with residual tail coefficients,determining thefinal dependency structure.Applying this framework to assess the extreme dependence of precipitation on wind speed and temperature in China,revealed four distinct dependency structures.In northern,Jianghuai,and southern China,precipitation heavily relies on wind speed,while tempera-tures maintain relative independence.In northeastern and northwestern China,precipitation exhibits relative independence,yet a notable dependence exists between temperatures and wind speed.In southwestern China,precipitation strongly depends on temperature,while wind speed remains relatively indepen-dent.The Qinghai–Tibet Plateau region displays a significant dependence relationship among precipitation,wind speed,and temperature,with weaker dependence between extreme wind speed and temperature.This framework is instrumental for analyzing dependencies among extreme values in compound events.展开更多
Deforestation has a significant influence on the hydrological cycle.Understanding the impact of deforestation on precipitation extremes is crucial for addressing global environmental challenges.This study investigates...Deforestation has a significant influence on the hydrological cycle.Understanding the impact of deforestation on precipitation extremes is crucial for addressing global environmental challenges.This study investigates the impact of deforestation on precipitation extremes(R95p index,which represents the total amount of precipitation exceeding the 95th percentile of the reference period)in China,using outputs from three earth system models(CanESM5,IPSL-CM6A-LR,and MIROC-ES2L).All models,along with their multimodel mean,indicate a general decrease in R95p in Northeast China and southern China,and changes in Northwest China and the Tibetan Plateau are minimal.In contrast,the responses are model-dependent in the Huanghuai and Jianghuai regions.The overall nationwide multimodel mean suggests an annual R95p decrease of 10.7 mm,with individual model variations ranging from-28.0 to 2.0 mm.Further analysis using precipitation extremes scaling reveals a high spatial correlation with direct precipitation extremes changes on both annual and seasonal scales,albeit with slightly smaller magnitudes.Decomposing the response into dynamic and thermodynamic scaling,the authors find that dynamic contributions predominantly drive the changes in precipitation extremes on both annual and seasonal scales.The authors findings highlight the substantial role of dynamic processes in modulating the response of precipitation extremes to deforestation in China.展开更多
The Tarim River Basin(TRB)is a vast area with plenty of light and heat and is an important base for grain and cotton production in Northwest China.In the context of climate change,however,the increased frequency of ex...The Tarim River Basin(TRB)is a vast area with plenty of light and heat and is an important base for grain and cotton production in Northwest China.In the context of climate change,however,the increased frequency of extreme weather and climate events is having numerous negative impacts on the region's agricultural production.To better understand how unfavorable climatic conditions affect crop production,we explored the relationship of extreme weather and climate events with crop yields and phenology.In this research,ten indicators of extreme weather and climate events(consecutive dry days(CDD),min Tmax(TXn),max Tmin(TNx),tropical nights(TR),warm days(Tx90p),warm nights(Tn90p),summer days(SU),frost days(FD),very wet days(R95p),and windy days(WD))were selected to analyze the impact of spatial and temporal variations on the yields of major crops(wheat,maize,and cotton)in the TRB from 1990 to 2020.The three key findings of this research were as follows:extreme temperatures in southwestern TRB showed an increasing trend,with higher extreme temperatures at night,while the occurrence of extreme weather and climate events in northeastern TRB was relatively low.The number of FD was on the rise,while WD also increased in recent years.Crop yields were higher in the northeast compared with the southwest,and wheat,maize,and cotton yields generally showed an increasing trend despite an earlier decline.The correlation of extreme weather and climate events on crop yields can be categorized as extreme nighttime temperature indices(TNx,Tn90p,TR,and FD),extreme daytime temperature indices(TXn,Tx90p,and SU),extreme precipitation indices(CDD and R95p),and extreme wind(WD).By using Random Forest(RF)approach to determine the effects of different extreme weather and climate events on the yields of different crops,we found that the importance of extreme precipitation indices(CDD and R95p)to crop yield decreased significantly over time.As well,we found that the importance of the extreme nighttime temperature(TR and TNx)for the yields of the three crops increased during 2005-2020 compared with 1990-2005.The impact of extreme temperature events on wheat,maize,and cotton yields in the TRB is becoming increasingly significant,and this finding can inform policy decisions and agronomic innovations to better cope with current and future climate warming.展开更多
Against the backdrop of global warming,China has been facing increasingly frequent and severe extreme weather and climate events,with a prominent risk of compound extreme events induced by interactions among multiple ...Against the backdrop of global warming,China has been facing increasingly frequent and severe extreme weather and climate events,with a prominent risk of compound extreme events induced by interactions among multiple climate drivers and/or hazards.The present study first reviews the definition and classification of compound extreme events in China.Then,it summarizes research progress on the evolutionary characteristics,formation mechanisms,and future projections of different types of compound extreme events.The potential risks and possible impact pathways of three specific event types—namely,continuous day–night hot extremes,temperature–humidity compound events,and high-temperature–ozone compound events—on the health of the Chinese population are then explored.Finally,a framework for assessing the hazard risk of compound extreme events is constructed,accompanied by response strategies based on carbon neutrality targets.Building on existing research achievements,five future research directions are proposed:(1)identifying the risk chains of compound events;(2)addressing the constraints of observational records and coupled model performances;(3)attributing and understanding the drivers of compound extreme events;(4)finding optimal pathways for carbon reduction and air quality improvement;and(5)promoting inter-disciplinary,multi-regional,and cross-sectoral collaboration.Strengthening research in these directions will deepen our understanding of compound extreme events and provide technological support for climate change adaptation and health risk responses in China.展开更多
Extreme waves may considerably impact crucial coastal and marine engineering structures. The First Scientific Assessment Report on Ocean and Climate Change of China and The Fourth Assessment Report on Climate Change o...Extreme waves may considerably impact crucial coastal and marine engineering structures. The First Scientific Assessment Report on Ocean and Climate Change of China and The Fourth Assessment Report on Climate Change of China were published in 2020 and 2022, respectively.However, no concrete results on the long-term trends in wave changes in China have been obtained. In this study, long-term trends in extreme wave elements over the past 55 years were investigated using wave data from five in situ observation sites(i.e., Lao Hu Tan, Cheng Shan Tou,Ri Zhao, Nan Ji, Wei Zhou) along the coast of China. The five stations showed different trends in wave height. Results show a general downward trend in wave heights at the LHT and CST stations, reaching-0.78 and-1.44 cm/a, respectively, in summer at middle and high latitudes. NJI stations at middle-to-low latitudes are influenced by the winter monsoon and summer tropical cyclones, showing a substantial increase in extreme wave heights(0.7 cm/a in winter and 2.68 cm/a in summer). The cumulative duration of H_(1/10) ≥ 3 m at NJI and RZH has grown since 1990.展开更多
基金The National Natural Science Foundation of China(No.52278149)the Natural Science Foundation of Jiangsu Province(No.BZ2024015)+1 种基金the Opening Project of State Key Laboratory for Track Technology of High-Speed Railway(No.2023YJ375)the Opening Project of Zhejiang Engineering Centre of Road and Bridge Intelligent Operation and Maintenance Technology(No.202402G).
文摘Extreme traffic loads significantly challenge the safety and cost-effectiveness of highway bridges,especially under site-specific traffic conditions.Conventional assessments often rely on overly conservative load models,leading to excessive structural design.In this study,a framework for the prediction of maximum bending moments in simply supported bridges is developed by integrating weigh-in-motion(WIM)data,traffic microsimulation,and generalized extreme value(GEV)regression modeling to establish relationships between the GEV parameters(μ,σ,ξ)and traffic factors—heavy vehicle proportion,bridge span length,vehicle speed,headway,and traffic volume.Using one-year WIM data from 7.4 million vehicles,the developed models for μ and σ exhibit high predictive accuracy(R^(2)>0.95)and are validated through leave-one-out cross-validation.The prediction of ξ is less accurate(R^(2)≈0.6),requiring further improvement.Applying these models to a 1000-year return level yields a reliable,data-driven extrapolation,supporting optimized bridge design and safety assessment under varying traffic conditions.
基金supported by National Key Research and Development Program of China(2024YFA1210500,2023YFB4606105)Fundamental Research Center Projects(52488301)of National Natural Science Foundation of China(NSFC)+1 种基金Key Research Program of Frontier Sciences(ZDBS-LYJSC030)of Chinese Academy of SciencesWestern Light Program(xbzg-zdsys-202402)of Chinese Academy of Sciences。
文摘The development of infrared engineering technologies for extreme environments remains a formidable challenge due to the inherent trade-offs among optical performance,thermal stability,and mechanical integrity in thermal photonic metamaterials(TPMs).This work introduces a novel multi-obj ective design framework and demonstrates the design,fabrication,and validation of a TPM operating under extreme temperatures up to 1873 K.We have established a holistic design framework integrating temperaturedependent neural network and Pareto multi-obj ective optimization to co-optimize spectral response,component light-weighting,and structural efficiency.The framework achieves 100 times faster computation than genetic algorithms.The performance of the designed TPM was evaluated under various atmospheric models and detection distances.The TPM achieved a peak radiance suppression efficiency of 82%and a maximum attenuation of-7.4 dB at 1200-1500 K.Experimentally,we fabricated an all-dielectric TPM using a refractory TiO_(2)/BeO multilayer stack with only 5 layers and 2um total thickness.The optimized structure shows high reflectivity(0.62 at 3-5 um;0.48 at 8-14μm)for radiative suppression and high emissivity(0.87 at 5-8μm)for radiative cooling.The TPM withstands 1873 K for 12 h in air with less than 3%spectral drift,retaining excellent mechanical properties.On high-temperature components,it achieves 40-50%radiative suppression and 40-60 K(~10.1 kW m^(-2))radiative cooling at 1100 K,endures over 20 times thermal shock cycles(>150 K s^(-1),700-1500 K),and maintains stable performance over 5 cycles,with 78%visible and 98%microwave transmittance.This work establishes a new paradigm in the design and application of photonic materials for extreme environments.
文摘Hydrological extremes,such as floods,droughts,and compound events,are extremely dangerous to human societies,ecosystems,and infrastructures,whose frequency and severity are affected by climate change more and more.Effective disaster preparedness,water resource management,and climate adaptation have to do with accurate prediction and extensive risk assessment.This review sums up recent progress in predictive modeling and risk assessment systems in the framework of hydrological extremes in the changing climatic conditions.Statistical and empirical techniques,including extreme value theory and nonstationary frequency analysis,give probabilistic information using historic records,whereas process-based models give an understanding of physical hydrological processes at different climate and land-use conditions.New information-based and hybrid methods that use machine learning and high-resolution data take advantage of the complexity and nonlinearities and enhance the predictive power.Hazard,exposure,vulnerability,and adaptive capacity risk assessment models allow predictive output to be translated into actionable decision support,with socio-economic aspects and analysis of the scenario.Case studies of various regions across the globe show the use of these techniques to address floods,droughts,and compound events,with success and current problems.The review also addresses current trends such as compound hazard,multi-hazard integration,AI-enabled modelling,and cross-sectoral decision support,and outlines research priorities of improving predictive capability and resilience.This review will inform researchers,policymakers,and practitioners by offering a synthesis of all the effects of the hydrological extremes in climate change to formulate sound strategies for alleviating these effects.
基金sponsored by the National Natural Science Foundation of China (grant 42575038)the National Key Research and Development Program of China (grant2022YFF0801702)the National Natural Science Foundation of China (grant 42206257 and 42205163)
文摘This study investigated the characteristics and mechanisms of summer regional persistent extreme precipitation events(RPEPEs)over South China(SC)modulated by distinct intensity regimes of 10-30-day intraseasonal oscillation(ISO).Diagnostic analyses revealed that the spatiotemporal evolution of RPEPEs exhibits robust phase-locking with the 10-30-day intraseasonal precipitation.By classifying RPEPEs into strong-ISO(SRPEPE)and weak-ISO(WRPEPE)composites based on the amplitude of 10-30-day filtered precipitation,we demonstrate a 14.6%enhancement in peak precipitation intensity during SRPEPEs compared to WRPEPEs.These distinct precipitation regimes are governed by fundamentally different Rossby wave teleconnection patterns over Eurasia.During SRPEPEs,a robust southeastward-propagating 10-30-day Rossby wave train originating from the Barents Sea traverses midlatitude Eurasia,effectively perturbing the northwestern Pacific upper-level circulation and establishing a favorable dynamic environment over SC.In contrast,WRPEPEs are associated with weaker eastward-propagating wave trains constrained along the subtropical jet stream.The horizontal convergence of background moisture driven by 10-30-day winds significantly amplifies lower-tropospheric humidity during SRPEPEs.The thermal advection of background temperature by 10-30-day geostrophic winds enhances baroclinic instability and vertical motion,intensifying precipitation under these moisture conditions.
基金the Guangdong Basic and Applied Basic Research Foundation (Grant No. 2023B1515020084)the National Natural Science Foundation of China (Grant Nos.42175068, 42475057, and 42261144687)
文摘Extreme rainfall events(EREs)frequently hit the middle and lower reaches of the Yellow River basin(YRB)during boreal summer.Recent observations have indicated that EREs exhibit teleconnection patterns across long spatial distances.This study investigated ERE teleconnections in the YRB using the Event Synchronization(ES)method in combination with Complex Network(CN)theory.EREs in the YRB are significantly synchronized with other regions from regional to global scales.Additionally,high-resolution CMIP6 models in general show better skill in capturing these characteristics compared to low-resolution models.A further examination shows that the spatial synchronization patterns exhibit pronounced timescale dependence.Significant ERE synchronizations between the YRB and Europe were uncovered,where the YRB lags Eastern Europe by 3-5 days and Western Europe by 5-7 days,with Rossby wave propagation playing a key role.Wave trains from Europe propagate downstream along the Eurasian jet,inducing anomalous circulations over the YRB that enhance vertical upward motion and moisture transport,ultimately triggering EREs.Two distinct wave trains are observed:one is associated with Eastern Europe-YRB synchronization,occurring in the midlatitude region;the other is linked to Western Europe-YRB synchronization,positioned at higher latitudes.Notably,17.5%of Eastern Europe-YRB synchronization cases and 17.0%of Western Europe-YRB cases overlap.Quantitative analysis indicates that the synchronized events between Eastern(Western)Europe and the YRB account for roughly 28%(30%)of EREs in the YRB.These findings are critical for better understanding ERE mechanisms,offering guidance for forecasting and early warning capabilities for EREs in the YRB.
文摘Objective:To analyze the clinical application value of autologous periosteum graft combined with platelet-rich plasma(PRP)in the treatment of long bone fractures in the extremities.Methods:A total of 40 patients with long bone fractures in the extremities admitted to Santai Hospital Affiliated to North Sichuan Medical College from January 2023 to January 2025 were included,including cases of upper extremity forearm fractures and lower extremity femoral and tibial fractures.The patients were evenly divided using a random number table,with the control group undergoing open reduction and internal fixation(ORIF)combined with autologous periosteum graft,and the observation group undergoing ORIF,autologous periosteum graft,and PRP injection.Surgical indicators,complication rates,excellent fracture healing rates,functional satisfaction,and joint range of motion were compared between the two groups.Results:The surgical indicators in the observation group were similar to those in the control group(p>0.05).The complication rate in the observation group was lower than that in the control group,while the excellent fracture healing rate and functional satisfaction were higher in the observation group(p<0.05).Conclusion:Autologous periosteum graft combined with PRP technology is safe and reliable for the treatment of long bone fractures in the extremities,with satisfactory clinical outcomes.
文摘Nail changes following upper extremity transplantation(UET)cannot be overlooked as they possess diagnostic and prognostic relevance in allotransplantation of upper limbs.This comprehensive review explores nail and nail bed related changes encountered in UET recipients in the literature.The differential diagnosis of nail abnormalities in UET includes a wide range of systemic,local and iatrogenic conditions other than immune responses to the allograft.It requires interdisciplinary evaluation by primary transplant surgeons,pathologists,dermatologists and immunologists.The possible underlying mechanisms of nail pathology in UET and the management are discussed.It also underscores the importance of onychodystrophy and need for timely intervention and to improve outcomes in UET recipients.
基金supported by the National Natural Science Foundation of China(Grant No.42288101)the Young Scientists Fund of the National Natural Science Foundation of China(Grand No.42505018)the Shanghai“Science and Technology Innovation Action Plan”Venus Project(Grant No.23YF1437300)。
文摘Recent studies have suggested that rapid warming over the Mongolian Plateau(MP)may intensify extreme heat events(EHEs).However,the characteristics and mechanisms driving summer EHEs over the MP(MP-EHEs)remain unclear.This study explores the interannual variations in summer MP-EHEs and their relationship with the summer soil moisture over the Inner Tibetan Plateau(TP-SM).The results reveal that changes in the MP-EHEs are linked to descending atmospheric motion induced by a local high-pressure system over the MP region.Descending motion further results in decreased mid-tolow-level cloud cover and increased shortwave radiation,thereby warming the surface and triggering summer MP-EHEs.Further analysis indicates that increased TP-SM results in a greater latent heat flux,triggering a local secondary circulation that reinforces the local high-pressure system over the MP region,thus serving to promote the occurrence of summer MPEHEs.Additionally,model results from the linear baroclinic model(LBM)and CMIP6 further confirm that variations in summer TP-SM contribute to the occurrence of the MP-EHEs.
基金Supported by the School-level Project of Sichuan Minzu College(XYZB2017ZB).
文摘This study takes"ocean heat waves"as a typical case to study the scientific definition,driving mechanisms,multi-dimensional impacts,and response strategies of extreme climate events.The definition of extreme events requires a comprehensive consideration of statistical thresholds and social impacts.It is mainly driven by global warming caused by human emissions of greenhouse gases,and is also influenced by the interaction of natural variations such as ENSO.Extreme events cause systematic and cascading impacts on human health,infrastructure,agricultural economy,and ecosystems(especially marine ecosystems).Advanced technologies such as satellite remote sensing,climate models,and artificial intelligence have significantly enhanced their monitoring and prediction capabilities.However,effective responses still require a parallel strategy of mitigation and adaptation,and international cooperation is strengthened through the framework of the Paris Agreement.
基金Supported by the National Defense Basic Scientific Research Program of China.
文摘Amphibious vehicles are more prone to attitude instability compared to ships,making it crucial to develop effective methods for monitoring instability risks.However,large inclination events,which can lead to instability,occur frequently in both experimental and operational data.This infrequency causes events to be overlooked by existing prediction models,which lack the precision to accurately predict inclination attitudes in amphibious vehicles.To address this gap in predicting attitudes near extreme inclination points,this study introduces a novel loss function,termed generalized extreme value loss.Subsequently,a deep learning model for improved waterborne attitude prediction,termed iInformer,was developed using a Transformer-based approach.During the embedding phase,a text prototype is created based on the vehicle’s operation log data is constructed to help the model better understand the vehicle’s operating environment.Data segmentation techniques are used to highlight local data variation features.Furthermore,to mitigate issues related to poor convergence and slow training speeds caused by the extreme value loss function,a teacher forcing mechanism is integrated into the model,enhancing its convergence capabilities.Experimental results validate the effectiveness of the proposed method,demonstrating its ability to handle data imbalance challenges.Specifically,the model achieves over a 60%improvement in root mean square error under extreme value conditions,with significant improvements observed across additional metrics.
基金supported by the Tianshan Talent Training Program of Xinjiang Uygur Autonomous Region(2022TSYCLJ0011)the Key Research and Development(R&D)Program of Xinjiang Uygur Autonomous Region(2022B03021)the National Key R&D Program of China(2024YFC3713504).
文摘Northern Xinjiang,an arid inland area in Northwest China,is highly vulnerable to air pollution under intensifying climate extremes,yet the relative roles of temperature and precipitation extremes remain insufficiently understood.Using multi-source datasets for 2000-2023,including China High Air Pollutants(CHAP)particulate matter 2.5(PM_(2.5)),particulate matter 10(PM_(10)),and ozone(O3)products and Expert Team on Climate Change Detection and Indices(ETCCDI)extreme climate indices derived from the European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis v5(ERA5)-Land,together with trend detection,change-point analysis,pixel-wise Pearson correlation,and random forest(RF)modeling,we investigated the spatiotemporal evolution of major air pollutants and their responses to meteorological extremes in northern Xinjiang.PM_(2.5) and PM_(10) generally declined from 2000 to 2023,whereas O3 increased,indicating a shift from particulate-dominated pollution toward stronger photochemical pollution.Interannually,PM_(2.5) showed a rise-decline pattern,PM_(10) exhibited a rise-decline-rebound pattern,and O3 increased markedly after 2015.Clear seasonal contrasts were observed,with PM_(2.5) peaking in winter,PM_(10) in spring,and O3 in summer.During the same period,northern Xinjiang exhibited a pronounced warming-drying tendency,characterized by increasing heat-related indices,decreasing cold-related indices,reduced precipitation totals and heavy-rainfall frequency,and increasing consecutive dry days.Pollutant-climate relationships showed strong spatial heterogeneity and pollutant-specific contrasts across the Urumqi-Changji-Shihezi corridor,the Ili River Valley,and the Junggar Basin.PM_(2.5) responses to precipitation shifted from predominantly positive to negative,PM_(10) showed mainly negative associations with precipitation extremes,and O3 responses varied by subregion.Temperature-related extremes generally explained more pollutant variability than precipitation-related extremes,with PM_(2.5) showing the highest sensitivity.These findings highlight the coupled influences of warming,drying,emissions,and terrain-controlled transport on air quality and support region-specific,multi-pollutant strategies for coordinated climate adaptation and air pollution control in northern Xinjiang.
基金supported by the Science and Technology Project of Sichuan Electric Power Company“Power Supply Guarantee Strategy for Urban Distribution Networks Considering Coordination with Virtual Power Plant during Extreme Weather Event”(No.521920230003).
文摘Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the coordination with virtual power plants(VPPs).The proposed strategy improves systemflexibility and responsiveness by optimizing the power adjustment of flexible resources.In the proposed strategy,theGaussian Process Regression(GPR)is firstly employed to determine the adjustable range of aggregated power within the VPP,facilitating an assessment of its potential contribution to power supply support.Then,an optimal dispatch model based on a leader-follower game is developed to maximize the benefits of the VPP and flexible resources while guaranteeing the power balance at the same time.To solve the proposed optimal dispatch model efficiently,the constraints of the problem are reformulated and resolved using the Karush-Kuhn-Tucker(KKT)optimality conditions and linear programming duality theorem.The effectiveness of the strategy is illustrated through a detailed case study.
基金Harbin Municipal Bureau of Science and Technology Science and Technology Plan Self-funded Project(Grant/Award Number:2023ZCZJNS076)。
文摘Summary What''s New?:This study introduces a novel,periosteum-preserving iliac crest transverse transport(ICTT)technique for high-level lower extremity arteriosclerosis obliterans(LEASO),targeting patients unsuitable for conventional revascularization.Technical Innovation:By relocating the osteotomy from the weight-bearing tibia to the non-weight-bearing ilium,this minimally invasive technique eliminates the risk of stress fractures,allows for immediate full weight-bearing,and expands indications to patients with proximal arterial occlusions.
基金jointly supported by the National Natural Science Foundation of China (Grant Nos.42422502 and 42275038)the China Meteorological Administration Climate Change Special Program (Grant No.QBZ202306)funded by the Met Office Climate Science for Service Partnership (CSSP) China project under the International Science Partnerships Fund (ISPF)。
文摘This past year, 2024, is on track to be the warmest year, joining 2023 as the two hottest years on record. With the exceptional heat, weather and climate extremes were common across the world. In particular, 2024 has seen a remarkable run of extreme precipitation events and resulting impacts. Here, we provide an overview of the most notable extreme events of the year, including extreme precipitation and floods, tropical cyclones, and droughts. The characteristics and impacts of these extreme events are summarized, followed by discussion on the physical drivers and the role of global warming.Finally, we also discuss the future prospects in extreme event studies, including impact-based perspectives, challenges in attribution of precipitation extremes, and the existing gap to minimize impacts from climate extremes.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program[grant number 2019QZKK0101]。
文摘In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future extreme climate changes in the Asian arid region and Tibetan Plateau,this study applied the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP-CMIP6)to assess the changes in EHP(Rx5d and R95pTOT)and EHT(TX90p and TXx)under different emission scenarios in the 21st century.Findings suggest that both the frequency and the intensity of the extreme indices will increase,exhibiting accelerated growth under higher emission scenarios,particularly under the SSP5-8.5 emission scenario.It is suggested that the growth of EHT and EHP in the early subperiod of the 21st century(2026-2045)will be relatively moderate,with small differences between different emission scenarios.However,by the middle subperiod of the 21st century(2041-2060),the differences between different emission scenarios will become larger than the 2035s and the growth will become more intense.In western central Asia,TX90p,TXx,Rx5d,and R95pTOT increase by 9.7%-14.2%(13.3%-24.7%),1.3℃-1.7℃(1.6℃-2.7℃),6.5%-8.9%(8.2%-8.8%),and 18.1%-27.0%(25.6%-30.0%)by the early(middle)subperiod;in eastern central Asia,TX90p,TXx,Rx5d,and R95pTOT increase 8.1%-12.0%(11.3%-21.1%),1.4℃-1.8℃(1.9℃-2.9℃),7.4%-9.7%(10.4%-13.8%),and 20.2%-29.3%(32.0%-40.8%)by the early(middle)subperiod;and over the Tibetan Plateau,TX90p,TXx,Rx5d,and R95pTOT increase 12.5%-17.4%(17.0%-31.0%),1.2℃-1.5℃(1.6℃-2.5℃),7.2%-10.0%(9.9%-15.0%),and 26.6%-33.1%(36.1%-55.3%)by the early(middle)subperiod.
基金National Key R&D Program of China,Grant/Award Number:2022YFC3002705National Natural Science Foundation of China,Grant/Award Number:5220904China Institute of Water Resources and Hydropower Research,Grant/Award Number:SKL2022TS11。
文摘The escalation of compound extreme events has resulted in noteworthy economic and property losses.Recognizing the intricate interconnections among these events has become imperative.To tackle this challenge,we have formulated a comprehensive framework for the systematic analysis of their dependencies.This framework consists of three steps.(1)Define extreme events using Mahalanobis distance thresholds.(2)Represent dependencies among multiple extreme events through a point process-based method.(3)Verify dependencies with residual tail coefficients,determining thefinal dependency structure.Applying this framework to assess the extreme dependence of precipitation on wind speed and temperature in China,revealed four distinct dependency structures.In northern,Jianghuai,and southern China,precipitation heavily relies on wind speed,while tempera-tures maintain relative independence.In northeastern and northwestern China,precipitation exhibits relative independence,yet a notable dependence exists between temperatures and wind speed.In southwestern China,precipitation strongly depends on temperature,while wind speed remains relatively indepen-dent.The Qinghai–Tibet Plateau region displays a significant dependence relationship among precipitation,wind speed,and temperature,with weaker dependence between extreme wind speed and temperature.This framework is instrumental for analyzing dependencies among extreme values in compound events.
基金supported by National Natural Science Foundation of China[grant number 42305041].
文摘Deforestation has a significant influence on the hydrological cycle.Understanding the impact of deforestation on precipitation extremes is crucial for addressing global environmental challenges.This study investigates the impact of deforestation on precipitation extremes(R95p index,which represents the total amount of precipitation exceeding the 95th percentile of the reference period)in China,using outputs from three earth system models(CanESM5,IPSL-CM6A-LR,and MIROC-ES2L).All models,along with their multimodel mean,indicate a general decrease in R95p in Northeast China and southern China,and changes in Northwest China and the Tibetan Plateau are minimal.In contrast,the responses are model-dependent in the Huanghuai and Jianghuai regions.The overall nationwide multimodel mean suggests an annual R95p decrease of 10.7 mm,with individual model variations ranging from-28.0 to 2.0 mm.Further analysis using precipitation extremes scaling reveals a high spatial correlation with direct precipitation extremes changes on both annual and seasonal scales,albeit with slightly smaller magnitudes.Decomposing the response into dynamic and thermodynamic scaling,the authors find that dynamic contributions predominantly drive the changes in precipitation extremes on both annual and seasonal scales.The authors findings highlight the substantial role of dynamic processes in modulating the response of precipitation extremes to deforestation in China.
基金funded by the Tianshan Yingcai Program of the Xinjiang Uygur Autonomous Region(2022TSYCCX0038)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2022108)the Postdoctoral Fellowship Program of Chinese Postdoctoral Science Foundation(CPSF)(GZC20232962).
文摘The Tarim River Basin(TRB)is a vast area with plenty of light and heat and is an important base for grain and cotton production in Northwest China.In the context of climate change,however,the increased frequency of extreme weather and climate events is having numerous negative impacts on the region's agricultural production.To better understand how unfavorable climatic conditions affect crop production,we explored the relationship of extreme weather and climate events with crop yields and phenology.In this research,ten indicators of extreme weather and climate events(consecutive dry days(CDD),min Tmax(TXn),max Tmin(TNx),tropical nights(TR),warm days(Tx90p),warm nights(Tn90p),summer days(SU),frost days(FD),very wet days(R95p),and windy days(WD))were selected to analyze the impact of spatial and temporal variations on the yields of major crops(wheat,maize,and cotton)in the TRB from 1990 to 2020.The three key findings of this research were as follows:extreme temperatures in southwestern TRB showed an increasing trend,with higher extreme temperatures at night,while the occurrence of extreme weather and climate events in northeastern TRB was relatively low.The number of FD was on the rise,while WD also increased in recent years.Crop yields were higher in the northeast compared with the southwest,and wheat,maize,and cotton yields generally showed an increasing trend despite an earlier decline.The correlation of extreme weather and climate events on crop yields can be categorized as extreme nighttime temperature indices(TNx,Tn90p,TR,and FD),extreme daytime temperature indices(TXn,Tx90p,and SU),extreme precipitation indices(CDD and R95p),and extreme wind(WD).By using Random Forest(RF)approach to determine the effects of different extreme weather and climate events on the yields of different crops,we found that the importance of extreme precipitation indices(CDD and R95p)to crop yield decreased significantly over time.As well,we found that the importance of the extreme nighttime temperature(TR and TNx)for the yields of the three crops increased during 2005-2020 compared with 1990-2005.The impact of extreme temperature events on wheat,maize,and cotton yields in the TRB is becoming increasingly significant,and this finding can inform policy decisions and agronomic innovations to better cope with current and future climate warming.
基金the National Natural Science Foundation of China[grant numbers 42141019 and 42261144687]An Investigation Research Program between Ecological Environment and Human Health in Wuyi Mountain[grant number 20242120035]Natural Science Foundation of Hubei Province,China[grant number 2024AF-B115]。
文摘Against the backdrop of global warming,China has been facing increasingly frequent and severe extreme weather and climate events,with a prominent risk of compound extreme events induced by interactions among multiple climate drivers and/or hazards.The present study first reviews the definition and classification of compound extreme events in China.Then,it summarizes research progress on the evolutionary characteristics,formation mechanisms,and future projections of different types of compound extreme events.The potential risks and possible impact pathways of three specific event types—namely,continuous day–night hot extremes,temperature–humidity compound events,and high-temperature–ozone compound events—on the health of the Chinese population are then explored.Finally,a framework for assessing the hazard risk of compound extreme events is constructed,accompanied by response strategies based on carbon neutrality targets.Building on existing research achievements,five future research directions are proposed:(1)identifying the risk chains of compound events;(2)addressing the constraints of observational records and coupled model performances;(3)attributing and understanding the drivers of compound extreme events;(4)finding optimal pathways for carbon reduction and air quality improvement;and(5)promoting inter-disciplinary,multi-regional,and cross-sectoral collaboration.Strengthening research in these directions will deepen our understanding of compound extreme events and provide technological support for climate change adaptation and health risk responses in China.
基金Supported by the National Natural Science Foundation of China (No. 52271271)National Key Research and Development Program of China (No. 2022YFE0104500)Major Science and Technology Projects of the Ministry of Water Resources (No. SKS-2022025)。
文摘Extreme waves may considerably impact crucial coastal and marine engineering structures. The First Scientific Assessment Report on Ocean and Climate Change of China and The Fourth Assessment Report on Climate Change of China were published in 2020 and 2022, respectively.However, no concrete results on the long-term trends in wave changes in China have been obtained. In this study, long-term trends in extreme wave elements over the past 55 years were investigated using wave data from five in situ observation sites(i.e., Lao Hu Tan, Cheng Shan Tou,Ri Zhao, Nan Ji, Wei Zhou) along the coast of China. The five stations showed different trends in wave height. Results show a general downward trend in wave heights at the LHT and CST stations, reaching-0.78 and-1.44 cm/a, respectively, in summer at middle and high latitudes. NJI stations at middle-to-low latitudes are influenced by the winter monsoon and summer tropical cyclones, showing a substantial increase in extreme wave heights(0.7 cm/a in winter and 2.68 cm/a in summer). The cumulative duration of H_(1/10) ≥ 3 m at NJI and RZH has grown since 1990.
