The accelerated pace of natural and human-driven climate change presents profound challenges for Earth's systems.Oceans and ice sheets are critical regulators of climate systems,functioning as carbon sinks and the...The accelerated pace of natural and human-driven climate change presents profound challenges for Earth's systems.Oceans and ice sheets are critical regulators of climate systems,functioning as carbon sinks and thermal reservoirs.However,they are increasingly vulnerable to warming and greenhouse gas emissions.展开更多
Arctic sea ice is an important component of the global climate system and has experienced rapid changes during in the past few decades,the prediction of which is a significant application for climate models.In this st...Arctic sea ice is an important component of the global climate system and has experienced rapid changes during in the past few decades,the prediction of which is a significant application for climate models.In this study,a Localized Error Subspace Transform Kalman Filter is employed in a coupled climate system model(the Flexible Global Ocean–Atmosphere–Land System Model,version f3-L(FGOALS-f3-L))to assimilate sea-ice concentration(SIC)and sea-ice thickness(SIT)data for melting-season ice predictions.The scheme is applied through the following steps:(1)initialization for generating initial ensembles;(2)analysis for assimilating observed data;(3)adoption for dividing ice states into five thickness categories;(4)forecast for evolving the model;(5)resampling for updating model uncertainties.Several experiments were conducted to examine its results and impacts.Compared with the control experiment,the continuous assimilation experiments(CTNs)indicate assimilations improve model SICs and SITs persistently and generate realistic initials.Assimilating SIC+SIT data better corrects overestimated model SITs spatially than when only assimilating SIC data.The continuous assimilation restart experiments indicate the initials from the CTNs correct the overestimated marginal SICs and overall SITs remarkably well,as well as the cold biases in the oceanic and atmospheric models.The initials with SIC+SIT assimilated show more reasonable spatial improvements.Nevertheless,the SICs in the central Arctic undergo abnormal summer reductions,which is probably because overestimated SITs are reduced in the initials but the strong seasonal cycle(summer melting)biases are unchanged.Therefore,since systematic biases are complicated in a coupled system,for FGOALS-f3-L to make better ice predictions,oceanic and atmospheric assimilations are expected required.展开更多
The Arctic plays a pivotal role in the Earth’s climate system,with its rapid transformation exerting profound impacts on global climate dynamics,ecosystems,and human societies.In recent decades,Arctic warming has sig...The Arctic plays a pivotal role in the Earth’s climate system,with its rapid transformation exerting profound impacts on global climate dynamics,ecosystems,and human societies.In recent decades,Arctic warming has significantly outpaced the global mean temperature increase,driving the enhanced sea ice decline,the accelerated mass loss of the Greenland Ice Sheet,permafrost degradation,and glacier retreat.These changes modulate atmospheric and oceanic circulation patterns,establishing teleconnections with mid-and low-latitude climate systems.Investigating the historical evolution,current state,and projected future trends of the Arctic climate system,as well as its global impacts,is crucial for elucidating the mechanisms underlying Arctic amplification,refining climate change projections,attributing extreme weather and climate events,and informing sustainable development strategies.展开更多
A reasonable past millennial climate simulation relies heavily on the specified external forcings, including both natural and anthropogenic forcing agents. In this paper, we examine the surface temperature responses t...A reasonable past millennial climate simulation relies heavily on the specified external forcings, including both natural and anthropogenic forcing agents. In this paper, we examine the surface temperature responses to specified external forcing agents in a millennium-scale transient climate simulation with the fast version of LASG IAP Flexible Global Ocean-Atmosphere-Land System model （FGOALS-gl） developed in the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics （LASG/IAP）. The model presents a reasonable performance in comparison with reconstructions of surface temperature. Differentiated from significant changes in the 20th century at the global scale, changes during the natural-forcing-dominant period are mainly manifested in the Northern Hemisphere. Seasonally, modeled significant changes are more pronounced during the wintertime at higher latitudes. This may be a manifestation of polar amplification associated with sea-ice-temperature positive feedback. The climate responses to total external forcings can explain about half of the climate variance during the whole millennium period, especially at decadal timescales. Surface temperature in the Antarctic shows heterogeneous and insignificant changes during the preindustrial period and the climate response to external forcings is undetectable due to the strong internal variability. The model response to specified external forcings is modulated by cloud radiative forcing （CRF）. The CRF acts against the fluctuations of external forcings. Effects of clouds are manifested in shortwave radiation by changes in cloud water during the natural-forcing-dominant period, but mainly in longwave radiation by a decrease in cloud amount in the ant hropogenic- forcing-dominant period.展开更多
On the basis of more than 200-year control run, the performance of the climate system model of Chinese Academy of Sciences （CAS-ESM-C） in simulating the E1 Nifio-Southern Oscillation （ENSO） cycle is evalu- ated, i...On the basis of more than 200-year control run, the performance of the climate system model of Chinese Academy of Sciences （CAS-ESM-C） in simulating the E1 Nifio-Southern Oscillation （ENSO） cycle is evalu- ated, including the onset, development and decay of the ENSO. It is shown that, the model can reasonably simulate the annual cycle and interannual variability of sea surface temperature （SST） in the tropical Pacif- ic, as well as the seasonal phase-locking of the ENSO. The model also captures two prerequisites for the E1 Nino onset, i.e., a westerly anomaly and a warm SST anomaly in the equatorial western Pacific. Owing to too strong forcing from an extratropical meridional wind, however, the westerly anomaly in this region is largely overestimated. Moreover, the simulated thermocline is much shallower with a weaker slope. As a result, the warm SST anomaly from the western Pacific propagates eastward more quickly, leading to a faster develop- ment of an E1 Nino. During the decay stage, owing to a stronger E1Nino in the model, the secondary Gill-type response of the tropical atmosphere to the eastern Pacific warming is much stronger, thereby resulting in a persistent easterly anomaly in the western Pacific. Meanwhile, a cold anomaly in the warm pool appears as a result of a lifted thermocline via Ekman pumping. Finally, an E1 Nino decays into a La Nina through their interactions. In addition, the shorter period and larger amplitude of the ENSO in the model can be attribut- ed to a shallower thermocline in the equatorial Pacific, which speeds up the zonal redistribution of a heat content in the upper ocean.展开更多
This paper describes the historical simulations produced by the Chinese Academy of Meteorological Sciences(CAMS)climate system model(CAMS-CSM),which are contributing to phase 6 of the Coupled Model Intercomparison Pro...This paper describes the historical simulations produced by the Chinese Academy of Meteorological Sciences(CAMS)climate system model(CAMS-CSM),which are contributing to phase 6 of the Coupled Model Intercomparison Project(CMIP6).The model description,experiment design and model outputs are presented.Three members’historical experiments are conducted by CAMS-CSM,with two members starting from different initial conditions,and one excluding the stratospheric aerosol to identify the effect of volcanic eruptions.The outputs of the historical experiments are also validated using observational data.It is found that the model can reproduce the climatological mean states and seasonal cycle of the major climate system quantities,including the surface air temperature,precipitation,and the equatorial thermocline.The long-term trend of air temperature and precipitation is also reasonably captured by CAMS-CSM.There are still some biases in the model that need further improvement.This paper can help the users to better understand the performance and the datasets of CAMS-CSM.展开更多
The climate system models from Beijing Climate Center, BCC_CSM1.1 and BCC_CSM1.1-M, are used to carry out most of the CMIP5 experiments. This study gives a general introduction of these two models, and provides main i...The climate system models from Beijing Climate Center, BCC_CSM1.1 and BCC_CSM1.1-M, are used to carry out most of the CMIP5 experiments. This study gives a general introduction of these two models, and provides main information on the experiments including the experiment purpose, design, and the external forcings. The transient climate responses to the CO2 concentration increase at 1% per year are presented in the simulation of the two models. The BCC_CSM1.1-M result is closer to the CMIP5 multiple models ensemble. The two models perform well in simulating the historical evolution of the surface air temperature, globally and averaged for China. Both models overestimate the global warming and underestimate the warming over China in the 20th century. With higher horizontal resolution, the BCC_CSM1.1-M has a better capability in reproducing the annual evolution of surface air temperature over China.展开更多
By analyzing the Fractal Dimension(FD) distribution of the Short-range Climate system(SCS) in China, it is found that the FD varies in different region and this just agrees with the regionally of the monsoon climate i...By analyzing the Fractal Dimension(FD) distribution of the Short-range Climate system(SCS) in China, it is found that the FD varies in different region and this just agrees with the regionally of the monsoon climate in China. The FD of the SCS Lays between 2.0 and 5.0. In the vast eastern area of China, the FD almost grows gradually with the latitude. Line 4.0 is along the mountain chains from the Nanlin Mountain to the Wuyi Mountain. North of the line the FD varies only slightly and all are above 4.0. Only in coastal islands the FD is smaller than 3.0.展开更多
Climate system models are useful tools for understanding the interactions among the components of the climate system and predicting/projecting future climate change. The development of climate models has been a centra...Climate system models are useful tools for understanding the interactions among the components of the climate system and predicting/projecting future climate change. The development of climate models has been a central focus of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences(LASG/IAP) since the establishment of the laboratory in 1985. In China, many pioneering component models and fully coupled models of the climate system have been developed by LASG/IAP. The fully coupled climate system developed in the recent decade is named FGOALS(Flexible Global Ocean-Atmosphere-Land System Model). In this paper, an application-oriented review of the LASG/IAP FGOALS model is presented. The improved model performances are demonstrated in the context of cloud-radiation processes, Asian monsoon, ENSO phenomena, Atlantic Meridional Overturning Circulation(AMOC) and sea ice. The FGOALS model has contributed to both CMIP5(Coupled Model Intercomparison Project-phase 5) and IPCC(Intergovernmental Panel on Climate Change) AR5(the Fifth Assessment Report). The release of FGOALS data has supported the publication of nearly 500 papers around the world. The results of FGOALS are cited ~106 times in the IPCC WG1(Working Group 1) AR5. In addition to the traditional long-term simulations and projections, near-term decadal climate prediction is a new set of CMIP experiment, progress of LAGS/IAP in the development of nearterm decadal prediction system is reviewed. The FGOALS model has supported many Chinese national-level research projects and contributed to the national climate change assessment report. The crucial role of FGOALS as a modeling tool for supporting climate sciences is highlighted by demonstrating the model's performances in the simulation of the evolution of Earth's climate from the past to the future.展开更多
To better understand the physical mechanism of the climate change on interdecadal-centennial timescale, this paper focuses on analysing and modelling the evolution characteristics of the climate change. The method of ...To better understand the physical mechanism of the climate change on interdecadal-centennial timescale, this paper focuses on analysing and modelling the evolution characteristics of the climate change. The method of wavelet transform is used to pick out the interdecadal timescale oscillations from long-term instrumental observations, natural proxy records, and modelling series. The modelling series derived from the most simplified nonlinear climatic model are used to identify whether modifications are concerned with some forcings such as the solar radiation on the climate system. The results show that two major oscillations exist in various observations and model series, namely the 20- 30a and the 60-70a timescale respectively, and these quasi-periodicities are modulated with time. Further, modelling results suggest that the originations of these oscillations are not directly linked with the periodic variation of solar radiations such as the 1-year cycle, the 11-year cycle, and others, but possibly induced by the internal nonlinear effects of the climate system. It seems that the future study on the genesis of the climate change with interdecadal-centennial timescale should focus on the internal nonlinear dynamics in the climate system.展开更多
One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of "common but differentiated responsibilities". Thi...One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of "common but differentiated responsibilities". This formulation depends primarily on the quantitative attribution of the responsibilities of developed and developing countries for historical climate change. Using the Commuity Earth System Model(CESM), we estimate the responsibilities of developed countries and developing countries for climatic change from 1850 to 2005 using their carbon dioxide, methane and nitrous oxide emissions. The results indicate that developed countries contribute approximately 53%–61%, and developing countries approximately 39%–47%, to the increase in global air temperature, upper oceanic warming, sea-ice reduction in the NH, and permafrost degradation. In addition, the spatial heterogeneity of these changes from 1850 to 2005 is primarily attributed to the emissions of greenhouse gases(GHGs)in developed countries. Although uncertainties remain in the climate model and the external forcings used, GHG emissions in developed countries are the major contributor to the observed climate system changes in the 20 th century.展开更多
During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where trad...During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where traditional observations are difficult to obtain.China has been actively engaging in polar expeditions.Many observations were conducted during this period,accompanied by improved Earth climate models,leading to a series of insightful understandings concerning Arctic and Antarctic climate changes.Here,we review the recent progress China has made concerning Arctic and Antarctic climate change research over the past decade.The Arctic temperature increase is much higher than the global-mean warming rate,associated with a rapid decline in sea ice,a phenomenon called the Arctic Amplification.The Antarctic climate changes showed a zonally asymmetric pattern over the past four decades,with most of the fastest changes occurring over West Antarctica and the Antarctic Peninsula.The Arctic and Antarctic climate changes were driven by anthropogenic greenhouse gas emissions and ozone loss,while tropical-polar teleconnections play important roles in driving the regional climate changes and extreme events over the polar regions.Polar climate changes may also feedback to the entire Earth climate system.The adjustment of the circulation in both the troposphere and the stratosphere contributed to the interactions between the polar climate changes and lower latitudes.Climate change has also driven rapid Arctic and Southern ocean acidification.Chinese researchers have made a series of advances in understanding these processes,as reviewed in this paper.展开更多
Climate change and energy security issues are prominent challenges in current energy system management,which should be governed synergistically due to the feedback relationships between them.The“Energy Systems Manage...Climate change and energy security issues are prominent challenges in current energy system management,which should be governed synergistically due to the feedback relationships between them.The“Energy Systems Management and Climate Change”Special Collection Issue in the journal of Energy Engineering provide insights into the field of energy systems management and climate change.From an extended perspective,this study discusses the key issues,research methods and models for energy system management and climate change research.Comprehensive and accurate prediction of energy supply and demand,the evaluation on the energy system resilience to climate change and the coupling methodology application of both nature and social science field maybe the frontier topics around achieving sustainable development goals of energy systems.展开更多
In the beginning of the 21st century, the Tenth Five-Year Priority Research Projects of the Earth Sci- ences of the National Natural Science Foundation of China (NSFC) were initiated. After nearly a two-year long pr...In the beginning of the 21st century, the Tenth Five-Year Priority Research Projects of the Earth Sci- ences of the National Natural Science Foundation of China (NSFC) were initiated. After nearly a two-year long process to prepare, the ?rst version of six Priority Research Projects of Earth Sciences was pub- lished in October 2001 by NSFC, viz., Local Response to Global Changes, Life Process and Environment, Dynamics and Physical Processes in the Weather and Climate System, Continental Dynamics, Regional Sustainable Development, Solar-Terrestrial Environment and Space Weather. The process involved more than 200 renowned Chinese scientists and many departments and agencies in China. The six Priority Research Projects guide the research e?ort of the earth sciences for the NSFC from year 2001 to 2005. This paper provides a brief introduction to the Third Priority Research Project of the Department of Earth Sciences of NSFC—-Dynamics and Physical Processes in the Weather and Climate System (DPWCS).展开更多
This study shows that the heretofore assumed condition for no temperature-profile (TP)/lapse-rate feedback, for all altitudes z, or , in fact yields a negative feedback. The correct condition for no TP feedback is for...This study shows that the heretofore assumed condition for no temperature-profile (TP)/lapse-rate feedback, for all altitudes z, or , in fact yields a negative feedback. The correct condition for no TP feedback is for all z, where Ts is the surface temperature. This condition translates into a uniform increase (decrease) in lapse rate with altitude for an increase (decrease) in Ts. The temperature changes caused by a change in solar irradiance and/or planetary albedo satisfy the condition for no TP feedback. The temperature changes caused by a change in greenhouse gas concentration do not satisfy the condition for no TP feedback and, instead, yield a positive feedback.展开更多
Error accumulation in long-term predictions of chaotic climate systems is caused primarily by the model's high sensitivity to initial conditions and the absence of dynamic adjustment mechanisms,leading to gradual ...Error accumulation in long-term predictions of chaotic climate systems is caused primarily by the model's high sensitivity to initial conditions and the absence of dynamic adjustment mechanisms,leading to gradual forecast divergence.This presents a critical challenge to achieving stable long-term predictions.While current data-driven approaches perform well in short-term forecasting,their accuracy deteriorates significantly over time.To overcome this limitation,we propose an autonomous echo state network with a snow ablation optimizer(AESN-SAO),which significantly improves the adaptability and robustness of data-driven methods under varying initial conditions.This approach not only eliminates the need for manual hyperparameter tuning in traditional AESNs but also effectively mitigates the common issue of initial conditions sensitivity in chaotic climate systems.Furthermore,we introduce a sparse observation insertion mechanism based on the Lyapunov time and valid prediction time(VPT),which enables AESNSAO to correct errors prior to system divergence,effectively extending the prediction horizon.Numerical experiments conducted on the Lorenz-63 and Climate Lorenz-63 systems demonstrate that integrating sparse observations with AESN-SAO approach extends the VPT to approximately 99 Lyapunov times,markedly reducing error accumulation in long-term forecasts.This study provides a reliable and efficient framework for long-term predictions in climate systems with nonlinear and chaotic dynamics,with promising applications in weather forecasting,climate modeling,and disaster risk assessment.展开更多
Food systems are deeply affected by climate change and air pollution,while being key contributors to these environmental challenges.Understanding the complex interactions among food systems,climate change,and air poll...Food systems are deeply affected by climate change and air pollution,while being key contributors to these environmental challenges.Understanding the complex interactions among food systems,climate change,and air pollution is crucial for mitigating climate change,improving air quality,and promoting the sustainable development of food systems.However,the literature lacks a comprehensive review of these interactions,particularly in the current phase of rapid development in the field.To address this gap,this study systematically reviews recent research on the impacts of climate change and air pollution on food systems,as well as the greenhouse gas and air pollutant emissions from agri-food systems and their contribution to global climate change and air pollution.In addition,this study summarizes various strategies for mitigation and adaptation,including adjustments in agricultural practices and food supply chains.Profound changes in food systems are urgently needed to enhance adaptability and reduce emissions.This review offers a critical overview of current research on the interactions among food systems,climate change,and air pollution and highlights future research directions to support the transition to sustainable food systems.展开更多
This study examines the potential impacts o climate change on Lake Biwa,Japan’s largest freshwate lake,with a focus on temperature,wind speed,and pre cipitation variations.Leveraging data from the IPCC Sixth Assessme...This study examines the potential impacts o climate change on Lake Biwa,Japan’s largest freshwate lake,with a focus on temperature,wind speed,and pre cipitation variations.Leveraging data from the IPCC Sixth Assessment Report,including CCP scenarios,projecting a significant temperature rise of 3.3–5.7℃in the case o very high GHG emission power,the research investigates how these shifts may influence dissolved oxygen levels in Lake Biwa.Through a one-dimensional model incorporat ing sediment redox reactions,various scenarios where ai temperature and wind speed are changed are simulated.I is revealed that a 5℃increase in air temperature leads to decreasing 1-2 mg/L of dissolved oxygen concentrations from the surface layer to the bottom layer,while a decrease in air temperature tends to elevate 1–3 mg/L of oxygen lev els.Moreover,doubling wind speed enhances surface laye oxygen but diminishes it in deeper layers due to increased mixing.Seasonal variations in wind effects are noted with significant surface layer oxygen increases from 0.4to 0.8 mg/L during summer to autumn,increases from 0.4 to 0.8 mg/L in autumn to winter due to intensified vertica mixing.This phenomenon impacts the lake’s oxygen cycle year-round.In contrast,precipitation changes show limited impact on oxygen levels,suggesting minor influence com pared to other meteorological factors.The study suggests the necessity of comprehensive three-dimensional models that account for lake-specific and geographical factors fo accurate predictions of future water conditions.A holistic approach integrating nutrient levels,water temperature,and river inflow is deemed essential for sustainable management of Lake Biwa’s water resources,particularly in addressing precipitation variations.展开更多
There is a need for more focus in understanding the economic benefits of Climate-Smart Agriculture(CSA)interventions,particularly in sub-Saharan Africa,where extreme climate events are significantly affecting agricult...There is a need for more focus in understanding the economic benefits of Climate-Smart Agriculture(CSA)interventions,particularly in sub-Saharan Africa,where extreme climate events are significantly affecting agriculture and rural livelihoods.This study used the Net Present Value(NPV),Internal Rate of Return(IRR),Benefit-Cost Ratio(BCR),and payback period to evaluate the economic viability of the adopted CSA interventions in the three villages(Doggoh,Jeffiri,and Wulling)of the dryland farming systems of northern Ghana,where CSA interventions were mostly practiced.Data were collected from 161 farm households by the questionnaire survey.The results showed that CSA interventions including livestock-crop integration,mixed cropping,crop rotation,nutrient integration,and tie ridging enhanced crop yield and the household income of smallholder farmers.The five CSA interventions selected by smallholders were in the following order of priority:livestock-crop integration(BCR=2.87),mixed cropping(BCR=2.54),crop rotation(BCR=2.24),nutrient integration(BCR=1.98),and tie ridging(BCR=1.42).Results further showed that livestock-crop integration was the most profitable CSA intervention even under a pessimistic assumption with a long payback period of 5.00 a.Moreover,this study indicated that the implementation of CSA interventions,on average,was relatively profitable and had a nominal financial risk for smallholder farmers.Understanding the economic viability of CSA interventions will help in decision-making process toward selecting the right CSA interventions for resilience development.展开更多
Agriculture extension and advisory services(AEAS)are integral to smart agricultural systems and play a pivotal role in supporting sustainable agricultural development.The study aimed to assess the role of AEAS in stre...Agriculture extension and advisory services(AEAS)are integral to smart agricultural systems and play a pivotal role in supporting sustainable agricultural development.The study aimed to assess the role of AEAS in strengthening climate-smart coastal farming system to enhance coastal agricultural sustainability.A mixed-methods study was conducted in the southwestern coastal region of Bangladesh in 2023,which involved administering a structured questionnaire and conducing face-to-face interviews with 390 farmers.Perceived role index(PRI)was employed to assess the potential role of AEAS.To forecast the perceived role outcomes,the machine learning model was undertaken by utilizing suitable algorithms.Additionally,feature importance was calculated to underpin the significant factors of perceived role outcomes.The findings showed that coastal farming communities held a comprehensive understanding of the role of AEAS.Key roles included diffusion of agricultural innovations,acting as a bridge between farmers and research organizations,using demonstration techniques to educate farmers,training farmers on food storage,processing,and utilization,and promoting awareness and adoption of best practices.The machine learning model exposed a significant relationship between farmers’socio-economic characteristics and their perception behavior.The results identified that factors like innovativeness,awareness,training exposure,access to AEAS,and access to information significantly influenced how farmers perceived the efficacy of AEAS in promoting a smart coastal farming system.However,farmers confronted multiple constraints in receiving demand-driven services and maintaining coastal farm sustainability.These insights can guide concerned authorities and policy-makers in providing AEAS for the purpose of strengthening climate-smart coastal farming system,particularly with a special focus on capacity building programs and machine learning application.Moreover,the outcomes of this study can assist the authorities of similar coastal systems throughout the world to initiate potential strategies for enhancing region-specific agricultural sustainability.展开更多
文摘The accelerated pace of natural and human-driven climate change presents profound challenges for Earth's systems.Oceans and ice sheets are critical regulators of climate systems,functioning as carbon sinks and thermal reservoirs.However,they are increasingly vulnerable to warming and greenhouse gas emissions.
基金jointly funded by the National Natural Science Foundation of China(NSFC)[grant number 42130608]the China Postdoctoral Science Foundation[grant number 2024M753169]。
文摘Arctic sea ice is an important component of the global climate system and has experienced rapid changes during in the past few decades,the prediction of which is a significant application for climate models.In this study,a Localized Error Subspace Transform Kalman Filter is employed in a coupled climate system model(the Flexible Global Ocean–Atmosphere–Land System Model,version f3-L(FGOALS-f3-L))to assimilate sea-ice concentration(SIC)and sea-ice thickness(SIT)data for melting-season ice predictions.The scheme is applied through the following steps:(1)initialization for generating initial ensembles;(2)analysis for assimilating observed data;(3)adoption for dividing ice states into five thickness categories;(4)forecast for evolving the model;(5)resampling for updating model uncertainties.Several experiments were conducted to examine its results and impacts.Compared with the control experiment,the continuous assimilation experiments(CTNs)indicate assimilations improve model SICs and SITs persistently and generate realistic initials.Assimilating SIC+SIT data better corrects overestimated model SITs spatially than when only assimilating SIC data.The continuous assimilation restart experiments indicate the initials from the CTNs correct the overestimated marginal SICs and overall SITs remarkably well,as well as the cold biases in the oceanic and atmospheric models.The initials with SIC+SIT assimilated show more reasonable spatial improvements.Nevertheless,the SICs in the central Arctic undergo abnormal summer reductions,which is probably because overestimated SITs are reduced in the initials but the strong seasonal cycle(summer melting)biases are unchanged.Therefore,since systematic biases are complicated in a coupled system,for FGOALS-f3-L to make better ice predictions,oceanic and atmospheric assimilations are expected required.
文摘The Arctic plays a pivotal role in the Earth’s climate system,with its rapid transformation exerting profound impacts on global climate dynamics,ecosystems,and human societies.In recent decades,Arctic warming has significantly outpaced the global mean temperature increase,driving the enhanced sea ice decline,the accelerated mass loss of the Greenland Ice Sheet,permafrost degradation,and glacier retreat.These changes modulate atmospheric and oceanic circulation patterns,establishing teleconnections with mid-and low-latitude climate systems.Investigating the historical evolution,current state,and projected future trends of the Arctic climate system,as well as its global impacts,is crucial for elucidating the mechanisms underlying Arctic amplification,refining climate change projections,attributing extreme weather and climate events,and informing sustainable development strategies.
基金supported by the Major State Basic Research Development Program of China(973 Program)under Grant No.2010CB951903the National Natural Science Foundation of China under Grant Nos.40890054,41205043,and 41105054
文摘A reasonable past millennial climate simulation relies heavily on the specified external forcings, including both natural and anthropogenic forcing agents. In this paper, we examine the surface temperature responses to specified external forcing agents in a millennium-scale transient climate simulation with the fast version of LASG IAP Flexible Global Ocean-Atmosphere-Land System model （FGOALS-gl） developed in the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics （LASG/IAP）. The model presents a reasonable performance in comparison with reconstructions of surface temperature. Differentiated from significant changes in the 20th century at the global scale, changes during the natural-forcing-dominant period are mainly manifested in the Northern Hemisphere. Seasonally, modeled significant changes are more pronounced during the wintertime at higher latitudes. This may be a manifestation of polar amplification associated with sea-ice-temperature positive feedback. The climate responses to total external forcings can explain about half of the climate variance during the whole millennium period, especially at decadal timescales. Surface temperature in the Antarctic shows heterogeneous and insignificant changes during the preindustrial period and the climate response to external forcings is undetectable due to the strong internal variability. The model response to specified external forcings is modulated by cloud radiative forcing （CRF）. The CRF acts against the fluctuations of external forcings. Effects of clouds are manifested in shortwave radiation by changes in cloud water during the natural-forcing-dominant period, but mainly in longwave radiation by a decrease in cloud amount in the ant hropogenic- forcing-dominant period.
基金The Strategic Priority Research Program of Chinese Academy of Sciences under contract No.XDA05110201the National Basic Research Program(973 Program) of China under contract No.2010CB951901
文摘On the basis of more than 200-year control run, the performance of the climate system model of Chinese Academy of Sciences （CAS-ESM-C） in simulating the E1 Nifio-Southern Oscillation （ENSO） cycle is evalu- ated, including the onset, development and decay of the ENSO. It is shown that, the model can reasonably simulate the annual cycle and interannual variability of sea surface temperature （SST） in the tropical Pacif- ic, as well as the seasonal phase-locking of the ENSO. The model also captures two prerequisites for the E1 Nino onset, i.e., a westerly anomaly and a warm SST anomaly in the equatorial western Pacific. Owing to too strong forcing from an extratropical meridional wind, however, the westerly anomaly in this region is largely overestimated. Moreover, the simulated thermocline is much shallower with a weaker slope. As a result, the warm SST anomaly from the western Pacific propagates eastward more quickly, leading to a faster develop- ment of an E1 Nino. During the decay stage, owing to a stronger E1Nino in the model, the secondary Gill-type response of the tropical atmosphere to the eastern Pacific warming is much stronger, thereby resulting in a persistent easterly anomaly in the western Pacific. Meanwhile, a cold anomaly in the warm pool appears as a result of a lifted thermocline via Ekman pumping. Finally, an E1 Nino decays into a La Nina through their interactions. In addition, the shorter period and larger amplitude of the ENSO in the model can be attribut- ed to a shallower thermocline in the equatorial Pacific, which speeds up the zonal redistribution of a heat content in the upper ocean.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFC1510001)the National Natural Science Foundation of China(Grant No.91637210)+1 种基金the Basic Research Fund of CAMS(Grant No.2018Z007)the Jiangsu Collaborative Innovation Center for Climate Change。
文摘This paper describes the historical simulations produced by the Chinese Academy of Meteorological Sciences(CAMS)climate system model(CAMS-CSM),which are contributing to phase 6 of the Coupled Model Intercomparison Project(CMIP6).The model description,experiment design and model outputs are presented.Three members’historical experiments are conducted by CAMS-CSM,with two members starting from different initial conditions,and one excluding the stratospheric aerosol to identify the effect of volcanic eruptions.The outputs of the historical experiments are also validated using observational data.It is found that the model can reproduce the climatological mean states and seasonal cycle of the major climate system quantities,including the surface air temperature,precipitation,and the equatorial thermocline.The long-term trend of air temperature and precipitation is also reasonably captured by CAMS-CSM.There are still some biases in the model that need further improvement.This paper can help the users to better understand the performance and the datasets of CAMS-CSM.
基金supported by the National Basic Research Program of China (973 Program) under No. 2010CB951903the National Science Foundation of China under Grant No. 41105054, 41205043the China Meteorological Administration under Grant No.GYHY201106022, GYHY201306048, CMAYBY2012-001
文摘The climate system models from Beijing Climate Center, BCC_CSM1.1 and BCC_CSM1.1-M, are used to carry out most of the CMIP5 experiments. This study gives a general introduction of these two models, and provides main information on the experiments including the experiment purpose, design, and the external forcings. The transient climate responses to the CO2 concentration increase at 1% per year are presented in the simulation of the two models. The BCC_CSM1.1-M result is closer to the CMIP5 multiple models ensemble. The two models perform well in simulating the historical evolution of the surface air temperature, globally and averaged for China. Both models overestimate the global warming and underestimate the warming over China in the 20th century. With higher horizontal resolution, the BCC_CSM1.1-M has a better capability in reproducing the annual evolution of surface air temperature over China.
基金This work is supported by both NKPFR and NNSF of China.
文摘By analyzing the Fractal Dimension(FD) distribution of the Short-range Climate system(SCS) in China, it is found that the FD varies in different region and this just agrees with the regionally of the monsoon climate in China. The FD of the SCS Lays between 2.0 and 5.0. In the vast eastern area of China, the FD almost grows gradually with the latitude. Line 4.0 is along the mountain chains from the Nanlin Mountain to the Wuyi Mountain. North of the line the FD varies only slightly and all are above 4.0. Only in coastal islands the FD is smaller than 3.0.
基金supported by the National Natural Science Foundation of China (Grant No. 41330423, 41420104006 & 41530426 )the International Partnership Program of Chinese Academy of Sciences under Grant No.134111KYSB20160031
文摘Climate system models are useful tools for understanding the interactions among the components of the climate system and predicting/projecting future climate change. The development of climate models has been a central focus of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences(LASG/IAP) since the establishment of the laboratory in 1985. In China, many pioneering component models and fully coupled models of the climate system have been developed by LASG/IAP. The fully coupled climate system developed in the recent decade is named FGOALS(Flexible Global Ocean-Atmosphere-Land System Model). In this paper, an application-oriented review of the LASG/IAP FGOALS model is presented. The improved model performances are demonstrated in the context of cloud-radiation processes, Asian monsoon, ENSO phenomena, Atlantic Meridional Overturning Circulation(AMOC) and sea ice. The FGOALS model has contributed to both CMIP5(Coupled Model Intercomparison Project-phase 5) and IPCC(Intergovernmental Panel on Climate Change) AR5(the Fifth Assessment Report). The release of FGOALS data has supported the publication of nearly 500 papers around the world. The results of FGOALS are cited ~106 times in the IPCC WG1(Working Group 1) AR5. In addition to the traditional long-term simulations and projections, near-term decadal climate prediction is a new set of CMIP experiment, progress of LAGS/IAP in the development of nearterm decadal prediction system is reviewed. The FGOALS model has supported many Chinese national-level research projects and contributed to the national climate change assessment report. The crucial role of FGOALS as a modeling tool for supporting climate sciences is highlighted by demonstrating the model's performances in the simulation of the evolution of Earth's climate from the past to the future.
文摘To better understand the physical mechanism of the climate change on interdecadal-centennial timescale, this paper focuses on analysing and modelling the evolution characteristics of the climate change. The method of wavelet transform is used to pick out the interdecadal timescale oscillations from long-term instrumental observations, natural proxy records, and modelling series. The modelling series derived from the most simplified nonlinear climatic model are used to identify whether modifications are concerned with some forcings such as the solar radiation on the climate system. The results show that two major oscillations exist in various observations and model series, namely the 20- 30a and the 60-70a timescale respectively, and these quasi-periodicities are modulated with time. Further, modelling results suggest that the originations of these oscillations are not directly linked with the periodic variation of solar radiations such as the 1-year cycle, the 11-year cycle, and others, but possibly induced by the internal nonlinear effects of the climate system. It seems that the future study on the genesis of the climate change with interdecadal-centennial timescale should focus on the internal nonlinear dynamics in the climate system.
基金funded by the National Natural Science Foundation of China(Grant Nos.41330527 and 41505068)National Key Program for Global Change Research of China(Grant No.2010CB950500)Fundamental Research Funds of CAMS(Grant No.2015Y004)
文摘One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of "common but differentiated responsibilities". This formulation depends primarily on the quantitative attribution of the responsibilities of developed and developing countries for historical climate change. Using the Commuity Earth System Model(CESM), we estimate the responsibilities of developed countries and developing countries for climatic change from 1850 to 2005 using their carbon dioxide, methane and nitrous oxide emissions. The results indicate that developed countries contribute approximately 53%–61%, and developing countries approximately 39%–47%, to the increase in global air temperature, upper oceanic warming, sea-ice reduction in the NH, and permafrost degradation. In addition, the spatial heterogeneity of these changes from 1850 to 2005 is primarily attributed to the emissions of greenhouse gases(GHGs)in developed countries. Although uncertainties remain in the climate model and the external forcings used, GHG emissions in developed countries are the major contributor to the observed climate system changes in the 20 th century.
基金supported by the National Key Research and Development Program of China(2018YFA 0605703)the National Natural Science Foundation of China(No.41976193 and No.42176243)+8 种基金X.CHEN was supported by the National Key Research and Development Program of China(2019YFC1509100)the National Science Foundation of China(No.41825012)B.WU was supported by the Major Program of the National Natural Science Foundation of China(41790472)the National Key Basic Research Project of China(2019YFA0607002)the National Natural Science Foundation of China(41730959)X.CHENG was funded by the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.311021008)M.DING was supported by the National Natural Science Foundation of China(42122047 and 42105036)the Basic Research Fund of the Chinese Academy of Meteorological Sciences(2021Y021 and 2021Z006)Q.SUN was supported by the National Key R&D Program of China(No.2022YFE0106300).
文摘During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where traditional observations are difficult to obtain.China has been actively engaging in polar expeditions.Many observations were conducted during this period,accompanied by improved Earth climate models,leading to a series of insightful understandings concerning Arctic and Antarctic climate changes.Here,we review the recent progress China has made concerning Arctic and Antarctic climate change research over the past decade.The Arctic temperature increase is much higher than the global-mean warming rate,associated with a rapid decline in sea ice,a phenomenon called the Arctic Amplification.The Antarctic climate changes showed a zonally asymmetric pattern over the past four decades,with most of the fastest changes occurring over West Antarctica and the Antarctic Peninsula.The Arctic and Antarctic climate changes were driven by anthropogenic greenhouse gas emissions and ozone loss,while tropical-polar teleconnections play important roles in driving the regional climate changes and extreme events over the polar regions.Polar climate changes may also feedback to the entire Earth climate system.The adjustment of the circulation in both the troposphere and the stratosphere contributed to the interactions between the polar climate changes and lower latitudes.Climate change has also driven rapid Arctic and Southern ocean acidification.Chinese researchers have made a series of advances in understanding these processes,as reviewed in this paper.
基金supported by the Fundamental Research Funds for the Central Universities(2022SKNY01,2022YJSNY04).
文摘Climate change and energy security issues are prominent challenges in current energy system management,which should be governed synergistically due to the feedback relationships between them.The“Energy Systems Management and Climate Change”Special Collection Issue in the journal of Energy Engineering provide insights into the field of energy systems management and climate change.From an extended perspective,this study discusses the key issues,research methods and models for energy system management and climate change research.Comprehensive and accurate prediction of energy supply and demand,the evaluation on the energy system resilience to climate change and the coupling methodology application of both nature and social science field maybe the frontier topics around achieving sustainable development goals of energy systems.
文摘In the beginning of the 21st century, the Tenth Five-Year Priority Research Projects of the Earth Sci- ences of the National Natural Science Foundation of China (NSFC) were initiated. After nearly a two-year long process to prepare, the ?rst version of six Priority Research Projects of Earth Sciences was pub- lished in October 2001 by NSFC, viz., Local Response to Global Changes, Life Process and Environment, Dynamics and Physical Processes in the Weather and Climate System, Continental Dynamics, Regional Sustainable Development, Solar-Terrestrial Environment and Space Weather. The process involved more than 200 renowned Chinese scientists and many departments and agencies in China. The six Priority Research Projects guide the research e?ort of the earth sciences for the NSFC from year 2001 to 2005. This paper provides a brief introduction to the Third Priority Research Project of the Department of Earth Sciences of NSFC—-Dynamics and Physical Processes in the Weather and Climate System (DPWCS).
文摘This study shows that the heretofore assumed condition for no temperature-profile (TP)/lapse-rate feedback, for all altitudes z, or , in fact yields a negative feedback. The correct condition for no TP feedback is for all z, where Ts is the surface temperature. This condition translates into a uniform increase (decrease) in lapse rate with altitude for an increase (decrease) in Ts. The temperature changes caused by a change in solar irradiance and/or planetary albedo satisfy the condition for no TP feedback. The temperature changes caused by a change in greenhouse gas concentration do not satisfy the condition for no TP feedback and, instead, yield a positive feedback.
基金supported by the National Natural Science Foundation of China(Grant Nos.42430112,42371377)。
文摘Error accumulation in long-term predictions of chaotic climate systems is caused primarily by the model's high sensitivity to initial conditions and the absence of dynamic adjustment mechanisms,leading to gradual forecast divergence.This presents a critical challenge to achieving stable long-term predictions.While current data-driven approaches perform well in short-term forecasting,their accuracy deteriorates significantly over time.To overcome this limitation,we propose an autonomous echo state network with a snow ablation optimizer(AESN-SAO),which significantly improves the adaptability and robustness of data-driven methods under varying initial conditions.This approach not only eliminates the need for manual hyperparameter tuning in traditional AESNs but also effectively mitigates the common issue of initial conditions sensitivity in chaotic climate systems.Furthermore,we introduce a sparse observation insertion mechanism based on the Lyapunov time and valid prediction time(VPT),which enables AESNSAO to correct errors prior to system divergence,effectively extending the prediction horizon.Numerical experiments conducted on the Lorenz-63 and Climate Lorenz-63 systems demonstrate that integrating sparse observations with AESN-SAO approach extends the VPT to approximately 99 Lyapunov times,markedly reducing error accumulation in long-term forecasts.This study provides a reliable and efficient framework for long-term predictions in climate systems with nonlinear and chaotic dynamics,with promising applications in weather forecasting,climate modeling,and disaster risk assessment.
基金supported by the National Natural Science Foundation of China(42277087,42130708,42471021,42277482,and 42361144876)the Natural Science Foundation of Guangdong Province(2024A1515012550)+3 种基金the Hainan Institute of National Park grant(KY-23ZK01)the Tsinghua Shenzhen International Graduate School Cross-disciplinary Research and Innovation Fund Research Plan(JC2022011)the Shenzhen Science and Technology Program(JCYJ20240813112106009 and ZDSYS20220606100806014)the Scientific Research Start-up Funds(QD2021030C)from Tsinghua Shenzhen International Graduate School。
文摘Food systems are deeply affected by climate change and air pollution,while being key contributors to these environmental challenges.Understanding the complex interactions among food systems,climate change,and air pollution is crucial for mitigating climate change,improving air quality,and promoting the sustainable development of food systems.However,the literature lacks a comprehensive review of these interactions,particularly in the current phase of rapid development in the field.To address this gap,this study systematically reviews recent research on the impacts of climate change and air pollution on food systems,as well as the greenhouse gas and air pollutant emissions from agri-food systems and their contribution to global climate change and air pollution.In addition,this study summarizes various strategies for mitigation and adaptation,including adjustments in agricultural practices and food supply chains.Profound changes in food systems are urgently needed to enhance adaptability and reduce emissions.This review offers a critical overview of current research on the interactions among food systems,climate change,and air pollution and highlights future research directions to support the transition to sustainable food systems.
基金Open Access funding provided by Kobe UniversityThis research was partially performed by the Environment Research and Technology Development Fund(2RL-2301)of the Environmental Restoration and Conservation Agency provided by Ministry of the Environment of Japan.
文摘This study examines the potential impacts o climate change on Lake Biwa,Japan’s largest freshwate lake,with a focus on temperature,wind speed,and pre cipitation variations.Leveraging data from the IPCC Sixth Assessment Report,including CCP scenarios,projecting a significant temperature rise of 3.3–5.7℃in the case o very high GHG emission power,the research investigates how these shifts may influence dissolved oxygen levels in Lake Biwa.Through a one-dimensional model incorporat ing sediment redox reactions,various scenarios where ai temperature and wind speed are changed are simulated.I is revealed that a 5℃increase in air temperature leads to decreasing 1-2 mg/L of dissolved oxygen concentrations from the surface layer to the bottom layer,while a decrease in air temperature tends to elevate 1–3 mg/L of oxygen lev els.Moreover,doubling wind speed enhances surface laye oxygen but diminishes it in deeper layers due to increased mixing.Seasonal variations in wind effects are noted with significant surface layer oxygen increases from 0.4to 0.8 mg/L during summer to autumn,increases from 0.4 to 0.8 mg/L in autumn to winter due to intensified vertica mixing.This phenomenon impacts the lake’s oxygen cycle year-round.In contrast,precipitation changes show limited impact on oxygen levels,suggesting minor influence com pared to other meteorological factors.The study suggests the necessity of comprehensive three-dimensional models that account for lake-specific and geographical factors fo accurate predictions of future water conditions.A holistic approach integrating nutrient levels,water temperature,and river inflow is deemed essential for sustainable management of Lake Biwa’s water resources,particularly in addressing precipitation variations.
文摘There is a need for more focus in understanding the economic benefits of Climate-Smart Agriculture(CSA)interventions,particularly in sub-Saharan Africa,where extreme climate events are significantly affecting agriculture and rural livelihoods.This study used the Net Present Value(NPV),Internal Rate of Return(IRR),Benefit-Cost Ratio(BCR),and payback period to evaluate the economic viability of the adopted CSA interventions in the three villages(Doggoh,Jeffiri,and Wulling)of the dryland farming systems of northern Ghana,where CSA interventions were mostly practiced.Data were collected from 161 farm households by the questionnaire survey.The results showed that CSA interventions including livestock-crop integration,mixed cropping,crop rotation,nutrient integration,and tie ridging enhanced crop yield and the household income of smallholder farmers.The five CSA interventions selected by smallholders were in the following order of priority:livestock-crop integration(BCR=2.87),mixed cropping(BCR=2.54),crop rotation(BCR=2.24),nutrient integration(BCR=1.98),and tie ridging(BCR=1.42).Results further showed that livestock-crop integration was the most profitable CSA intervention even under a pessimistic assumption with a long payback period of 5.00 a.Moreover,this study indicated that the implementation of CSA interventions,on average,was relatively profitable and had a nominal financial risk for smallholder farmers.Understanding the economic viability of CSA interventions will help in decision-making process toward selecting the right CSA interventions for resilience development.
基金the Science and Technology Fellowship Trust, Bangladesh
文摘Agriculture extension and advisory services(AEAS)are integral to smart agricultural systems and play a pivotal role in supporting sustainable agricultural development.The study aimed to assess the role of AEAS in strengthening climate-smart coastal farming system to enhance coastal agricultural sustainability.A mixed-methods study was conducted in the southwestern coastal region of Bangladesh in 2023,which involved administering a structured questionnaire and conducing face-to-face interviews with 390 farmers.Perceived role index(PRI)was employed to assess the potential role of AEAS.To forecast the perceived role outcomes,the machine learning model was undertaken by utilizing suitable algorithms.Additionally,feature importance was calculated to underpin the significant factors of perceived role outcomes.The findings showed that coastal farming communities held a comprehensive understanding of the role of AEAS.Key roles included diffusion of agricultural innovations,acting as a bridge between farmers and research organizations,using demonstration techniques to educate farmers,training farmers on food storage,processing,and utilization,and promoting awareness and adoption of best practices.The machine learning model exposed a significant relationship between farmers’socio-economic characteristics and their perception behavior.The results identified that factors like innovativeness,awareness,training exposure,access to AEAS,and access to information significantly influenced how farmers perceived the efficacy of AEAS in promoting a smart coastal farming system.However,farmers confronted multiple constraints in receiving demand-driven services and maintaining coastal farm sustainability.These insights can guide concerned authorities and policy-makers in providing AEAS for the purpose of strengthening climate-smart coastal farming system,particularly with a special focus on capacity building programs and machine learning application.Moreover,the outcomes of this study can assist the authorities of similar coastal systems throughout the world to initiate potential strategies for enhancing region-specific agricultural sustainability.
