The Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System atmospheric component model(FGOALS-f3-L)participated in Phase 6 of the Coupled Model Intercomparison Project,but its reproducibility of surf...The Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System atmospheric component model(FGOALS-f3-L)participated in Phase 6 of the Coupled Model Intercomparison Project,but its reproducibility of surface temperature(T_(s))over the Tibetan Plateau(TP)as a key climatically sensitive region remains unclear.This study evaluates the capability of FGOALS-f3-L in reproducing the climatological T_(s)over the TP relative to the Climate Forecast System Reanalysis.The results show that FGOALS-f3-L can reasonably capture the spatial pattern of T_(s)but underestimates the annual mean T_(s)for the whole TP.The simulated T_(s)for the whole TP shows a cold bias in winter and spring and a warm bias in summer and autumn.Further quantitative analysis based on the surface energy budget equation shows that the surface albedo feedback(SAF)term strongly contributes to the annual,winter,and spring mean cold bias in the western TP and to the warm bias in the eastern TP.Compared with the SAF term,the surface sensible and latent heat flux terms make nearly opposite contributions to the T_(s)bias and considerably offset the bias due to the SAF term.The cloud radiative forcing term strongly contributes to the annual and seasonal mean weak cold bias in the eastern TP.The longwave radiation term associated with the overestimated water vapor content accounts for a large portion of the warm bias over the whole TP in summer and autumn.Improving land surface and cloud processes in FGOALS-f3-L is critical to reduce the T_(s)bias over the TP.展开更多
The outputs of the Chinese Academy of Sciences(CAS) Flexible Global Ocean–Atmosphere–Land System(FGOALS-f3-L) model for the baseline experiment of the Atmospheric Model Intercomparison Project simulation in the Diag...The outputs of the Chinese Academy of Sciences(CAS) Flexible Global Ocean–Atmosphere–Land System(FGOALS-f3-L) model for the baseline experiment of the Atmospheric Model Intercomparison Project simulation in the Diagnostic,Evaluation and Characterization of Klima common experiments of phase 6 of the Coupled Model Intercomparison Project(CMIP6) are described in this paper. The CAS FGOALS-f3-L model, experiment settings, and outputs are all given. In total,there are three ensemble experiments over the period 1979–2014, which are performed with different initial states. The model outputs contain a total of 37 variables and include the required three-hourly mean, six-hourly transient, daily and monthly mean datasets. The baseline performances of the model are validated at different time scales. The preliminary evaluation suggests that the CAS FGOALS-f3-L model can capture the basic patterns of atmospheric circulation and precipitation well, including the propagation of the Madden–Julian Oscillation, activities of tropical cyclones, and the characterization of extreme precipitation. These datasets contribute to the benchmark of current model behaviors for the desired continuity of CMIP.展开更多
This study documents simulated oceanic circulations and sea ice by the coupled climate system model FGOALS-f3-L developed at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Flui...This study documents simulated oceanic circulations and sea ice by the coupled climate system model FGOALS-f3-L developed at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics,Chinese Academy of Sciences,under historical forcing from phase 6 of the Coupled Model Intercomparison Project(CMIP6).FGOALS-f3-L reproduces the fundamental features of global oceanic circulations,such as sea surface temperature(SST),sea surface salinity(SSS),mixed layer depth(MLD),vertical temperature and salinity,and meridional overturning circulations.There are notable improvements compared with the previous version,FGOALS-s2,such as a reduction in warm SST biases near the western and eastern boundaries of oceans and salty SSS biases in the tropical western Atlantic and eastern boundaries,and a mitigation of deep MLD biases at high latitudes.However,several obvious biases remain.The most significant biases include cold SST biases in the northwestern Pacific(over 4°C),freshwater SSS biases and deep MLD biases in the subtropics,and temperature and salinity biases in deep ocean at high latitudes.The simulated sea ice shows a reasonable distribution but stronger seasonal cycle than observed.The spatial patterns of sea ice are more realistic in FGOALS-f3-L than its previous version because the latitude–longitude grid is replaced with a tripolar grid in the ocean and sea ice model.The most significant biases are the overestimated sea ice and underestimated SSS in the Labrador Sea and Barents Sea,which are related to the shallower MLD and weaker vertical mixing.展开更多
Two versions of the Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System model(CASFGOALS),version f3-L and g3,are used to simulate the two interglacial epochs of the mid-Holocene and the Last Inter...Two versions of the Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System model(CASFGOALS),version f3-L and g3,are used to simulate the two interglacial epochs of the mid-Holocene and the Last Interglacial in phase 4 of the Paleoclimate Modelling Intercomparison Project(PMIP4),which aims to study the impact of changes in orbital parameters on the Earth’s climate.Following the PMIP4 experimental protocols,four simulations for the mid-Holocene and two simulations for the Last Interglacial have been completed,and all the data,including monthly and daily outputs for the atmospheric,oceanic,land and sea-ice components,have been released on the Earth System Grid Federation(ESGF)node.These datasets contribute to PMIP4 and CMIP6(phase 6 of the Coupled Model Intercomparison Project)by providing the variables necessary for the two interglacial periods.In this paper,the basic information of the CAS-FGOALS models and the protocols for the two interglacials are briefly described,and the datasets are validated using proxy records.Results suggest that the CAS-FGOALS models capture the large-scale changes in the climate system in response to changes in solar insolation during the interglacial epochs,including warming in mid-to-high latitudes,changes in the hydrological cycle,the seasonal variation in the extent of sea ice,and the damping of interannual variabilities in the tropical Pacific.Meanwhile,disagreements within and between the models and the proxy data are also presented.These datasets will help the modeling and the proxy data communities with a better understanding of model performance and biases in paleoclimate simulations.展开更多
The three-member historical simulations by the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System model,version f3-L(CAS FGOALS-f3-L),which is contributing to phase 6 of the Coupled Model Inter...The three-member historical simulations by the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System model,version f3-L(CAS FGOALS-f3-L),which is contributing to phase 6 of the Coupled Model Intercomparison Project(CMIP6),are described in this study.The details of the CAS FGOALS-f3-L model,experiment settings and output datasets are briefly introduced.The datasets include monthly and daily outputs from the atmospheric,oceanic,land and sea-ice component models of CAS FGOALS-f3-L,and all these data have been published online in the Earth System Grid Federation(ESGF,https://esgf-node.llnl.gov/projects/cmip6/).The three ensembles are initialized from the 600th,650th and 700th model year of the preindustrial experiment(piControl)and forced by the same historical forcing provided by CMIP6 from 1850 to 2014.The performance of the coupled model is validated in comparison with some recent observed atmospheric and oceanic datasets.It is shown that CAS FGOALS-f3-L is able to reproduce the main features of the modern climate,including the climatology of air surface temperature and precipitation,the long-term changes in global mean surface air temperature,ocean heat content and sea surface steric height,and the horizontal and vertical distribution of temperature in the ocean and atmosphere.Meanwhile,like other state-of-the-art coupled GCMs,there are still some obvious biases in the historical simulations,which are also illustrated.This paper can help users to better understand the advantages and biases of the model and the datasets。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 cherish the memory of the late Professor Duzheng YE on what would have been his 100 th birthday, and to celebrate his great accomplishment in opening a new era of Tibetan Plateau（TP） meteorology, this review pape...To cherish the memory of the late Professor Duzheng YE on what would have been his 100 th birthday, and to celebrate his great accomplishment in opening a new era of Tibetan Plateau（TP） meteorology, this review paper provides an assessment of the atmospheric heat source（AHS） over the TP from different data resources, including observations from local meteorological stations, satellite remote sensing data, and various reanalysis datasets. The uncertainty and applicability of these heat source data are evaluated. Analysis regarding the formation of the AHS over the TP demonstrates that it is not only the cause of the atmospheric circulation, but is also a result of that circulation. Based on numerical experiments, the review further demonstrates that land–sea thermal contrast is only one part of the monsoon story. The thermal forcing of the Tibetan–Iranian Plateau plays a significant role in generating the Asian summer monsoon（ASM）, i.e., in addition to pumping water vapor from sea to land and from the lower to the upper troposphere, it also generates a subtropical monsoon–type meridional circulation subject to the angular momentum conservation, providing an ascending-air large-scale background for the development of the ASM.展开更多
Following the High-Resolution Model Intercomparison Project(HighResMIP)Tier 2 protocol under the Coupled Model Intercomparison Project Phase 6(CMIP6),three numerical experiments are conducted with the Chinese Academy ...Following the High-Resolution Model Intercomparison Project(HighResMIP)Tier 2 protocol under the Coupled Model Intercomparison Project Phase 6(CMIP6),three numerical experiments are conducted with the Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System Model,version f3-H(CAS FGOALS-f3-H),and a 101-year(1950–2050)global high-resolution simulation dataset is presented in this study.The basic configuration of the FGOALSf3-H model and numerical experiments design are briefly described,and then the historical simulation is validated.Forced by observed radiative agents from 1950 to 2014,the coupled model essentially reproduces the observed long-term trends of temperature,precipitation,and sea ice extent,as well as the large-scale pattern of temperature and precipitation.With an approximate 0.25°horizontal resolution in the atmosphere and 0.1°in the ocean,the coupled models also simulate energetic western boundary currents and the Antarctic Circulation Current(ACC),reasonable characteristics of extreme precipitation,and realistic frontal scale air-sea interaction.The dataset and supporting detailed information have been published in the Earth System Grid Federation.展开更多
Large-ensemble simulations of the atmosphere-only time-slice experiments for the Polar Amplification Model Intercomparison Project(PAMIP)were carried out by the model group of the Chinese Academy of Sciences(CAS)Flexi...Large-ensemble simulations of the atmosphere-only time-slice experiments for the Polar Amplification Model Intercomparison Project(PAMIP)were carried out by the model group of the Chinese Academy of Sciences(CAS)Flexible Global Ocean-Atmosphere-Land System(FGOALS-f3-L).Eight groups of experiments forced by different combinations of the sea surface temperature(SST)and sea ice concentration(SIC)for pre-industrial,present-day,and future conditions were performed and published.The time-lag method was used to generate the 100 ensemble members,with each member integrating from 1 April 2000 to 30 June 2001 and the first two months as the spin-up period.The basic model responses of the surface air temperature(SAT)and precipitation were documented.The results indicate that Arctic amplification is mainly caused by Arctic SIC forcing changes.The SAT responses to the Arctic SIC decrease alone show an obvious increase over high latitudes,which is similar to the results from the combined forcing of SST and SIC.However,the change in global precipitation is dominated by the changes in the global SST rather than SIC,partly because tropical precipitation is mainly driven by local SST changes.The uncertainty of the model responses was also investigated through the analysis of the large-ensemble members.The relative roles of SST and SIC,together with their combined influence on Arctic amplification,are also discussed.All of these model datasets will contribute to PAMIP multi-model analysis and improve the understanding of polar amplification.展开更多
The influences of interannual surface potential vorticity forcing over the Tibetan Plateau(TP)on East Asian summer rainfall(EASR)and upper-level circulation are explored in this study.The results show that the interan...The influences of interannual surface potential vorticity forcing over the Tibetan Plateau(TP)on East Asian summer rainfall(EASR)and upper-level circulation are explored in this study.The results show that the interannual EASR and associated circulations are closely related to the surface potential vorticity negative uniform leading mode(PVNUM)over the TP.When the PVNUM is in the positive phase,more rainfall occurs in the Yangtze River valley,South Korea,Japan,and part of northern China,less rainfall occurs in southern China,and vice versa.A possible mechanism by which PVNUM affects EASR is proposed.Unstable air induced by the positive phase of PVNUM could stimulate significant upward motion and a lower-level anomalous cyclone over the TP.As a result,a dipole heating mode with anomalous cooling over the southwestern TP and anomalous heating over the southeastern TP is generated.Sensitivity experiment results regarding this dipole heating mode indicate that anomalous cooling over the southwestern TP leads to local and northeastern Asian negative height anomalies,while anomalous heating over the southeastern TP leads to local positive height anomalies.These results greatly resemble the realistic circulation pattern associated with EASR.Further analysis indicates that the anomalous water vapor transport associated with this anomalous circulation pattern is responsible for the anomalous EASR.Consequently,changes in surface potential vorticity forcing over the TP can induce changes in EASR.展开更多
This study presents the simulated aerosol spatiotemporal characteristics over the Tibetan Plateau(TP)with a newly developed coupled aerosol-climate model(FGOALS-f3-L).The aerosol properties are simulated over the TP f...This study presents the simulated aerosol spatiotemporal characteristics over the Tibetan Plateau(TP)with a newly developed coupled aerosol-climate model(FGOALS-f3-L).The aerosol properties are simulated over the TP for the period 2002-11.The results indicate that soil dust,sulfate,and carbonaceous aerosols(black carbon(BC),organic carbon(OC)and BC/OC)account for 53.6%,32.2%,and 14.2%of the total aerosol mass over the TP,respectively.The simulated aerosol surface mass concentrations and aerosol optical depths(AODs)are evaluated with ground-based and satellite observations,respectively.Underestimations of the aerosol surface mass concentration are found at the Lhasa site,especially for BC and OC.The spatial distribution and interannual variation of AOD are consistent with MODIS observations,with the RMSE of 0.081 and bias of 0.036.Due to the uncertainty of the parameterization of dust emissions,the model’s performance in summer and autumn is much better than that in spring.展开更多
Cloud dominates influence factors of atmospheric radiation, while aerosol–cloud interactions are of vital importance in its spatiotemporal distribution. In this study, a two-moment(mass and number) cloud microphysics...Cloud dominates influence factors of atmospheric radiation, while aerosol–cloud interactions are of vital importance in its spatiotemporal distribution. In this study, a two-moment(mass and number) cloud microphysics scheme, which significantly improved the treatment of the coupled processes of aerosols and clouds, was incorporated into version 1.1 of the IAP/LASG global Finite-volume Atmospheric Model(FAMIL1.1). For illustrative purposes, the characteristics of the energy balance and cloud radiative forcing(CRF) in an AMIP-type simulation with prescribed aerosols were compared with those in observational/reanalysis data. Even within the constraints of the prescribed aerosol mass, the model simulated global mean energy balance at the top of the atmosphere(TOA) and at the Earth’s surface, as well as their seasonal variation, are in good agreement with the observational data. The maximum deviation terms lie in the surface downwelling longwave radiation and surface latent heat flux, which are 3.5 W m-2(1%) and 3 W m-2(3.5%), individually. The spatial correlations of the annual TOA net radiation flux and the net CRF between simulation and observation were around 0.97 and 0.90, respectively. A major weakness is that FAMIL1.1 predicts more liquid water content and less ice water content over most oceans. Detailed comparisons are presented for a number of regions, with a focus on the Asian monsoon region(AMR). The results indicate that FAMIL1.1 well reproduces the summer–winter contrast for both the geographical distribution of the longwave CRF and shortwave CRF over the AMR. Finally, the model bias and possible solutions, as well as further works to develop FAMIL1.1 are discussed.展开更多
The datasets for the tier-1 Scenario Model Intercomparison Project(ScenarioMIP)experiments from the Chinese Academy of Sciences(CAS)Flexible Global Ocean-Atmosphere-Land System model,finite-volume version 3(CAS FGOALS...The datasets for the tier-1 Scenario Model Intercomparison Project(ScenarioMIP)experiments from the Chinese Academy of Sciences(CAS)Flexible Global Ocean-Atmosphere-Land System model,finite-volume version 3(CAS FGOALS-f3-L)are described in this study.ScenarioMIP is one of the core MIP experiments in phase 6 of the Coupled Model Intercomparison Project(CMIP6).Considering future CO2,CH4,N2O and other gases’concentrations,as well as land use,the design of ScenarioMIP involves eight pathways,including two tiers(tier-1 and tier-2)of priority.Tier-1 includes four combined Shared Socioeconomic Pathways(SSPs)with radiative forcing,i.e.,SSP1-2.6,SSP2-4.5,SSP3-7.0 and SSP5-8.5,in which the globally averaged radiative forcing at the top of the atmosphere around the year 2100 is approximately 2.6,4.5,7.0 and 8.5 W m−2,respectively.This study provides an introduction to the ScenarioMIP datasets of this model,such as their storage location,sizes,variables,etc.Preliminary analysis indicates that surface air temperatures will increase by about 1.89℃,3.07℃,4.06℃ and 5.17℃ by around 2100 under these four scenarios,respectively.Meanwhile,some other key climate variables,such as sea-ice extension,precipitation,heat content,and sea level rise,also show significant long-term trends associated with the radiative forcing increases.These datasets will help us understand how the climate will change under different anthropogenic and radiative forcings.展开更多
The outputs of the Chinese Academy of Sciences(CAS)Flexible Global Ocean-Atmosphere-Land System(FGOALSf3-L)model for the decadal climate prediction project(DCPP)of the Coupled Model Intercomparison Project Phase 6(CMI...The outputs of the Chinese Academy of Sciences(CAS)Flexible Global Ocean-Atmosphere-Land System(FGOALSf3-L)model for the decadal climate prediction project(DCPP)of the Coupled Model Intercomparison Project Phase 6(CMIP6)are described in this paper.The FGOALS-f3-L was initialized through the upgraded,weakly coupled data assimilation scheme,referred to as EnOI-IAU,which assimilates observational anomalies of sea surface temperature(SST)and upper-level(0–1000-m)ocean temperature and salinity profiles into the coupled model.Then,nine ensemble members of 10-year hindcast/forecast experiments were conducted for each initial year over the period of 1960–2021,based on initial conditions produced by three initialization experiments.The hindcast and forecast experiments follow the experiment designs of the Component-A and Component-B of the DCPP,respectively.The decadal prediction output datasets contain a total of 44 monthly mean atmospheric and oceanic variables.The preliminary evaluation indicates that the hindcast experiments show significant predictive skill for the interannual variations of SST in the north Pacific and multi-year variations of SST in the subtropical Pacific and the southern Indian Ocean.展开更多
泥沙连通性是表征泥沙在地貌单元间物理级联关系的重要参数,探讨其对土地利用变化的响应,对揭示流域内部水沙动态以及不同土地利用类型的水土保持效应具有重要意义。基于延河流域1990—2019年土地利用与径流输沙量等数据资料,结合连通...泥沙连通性是表征泥沙在地貌单元间物理级联关系的重要参数,探讨其对土地利用变化的响应,对揭示流域内部水沙动态以及不同土地利用类型的水土保持效应具有重要意义。基于延河流域1990—2019年土地利用与径流输沙量等数据资料,结合连通性指数(index of connectivity,IC)分析土地利用变化对泥沙连通性时空分布的影响及与径流输沙量的关系。结果表明:1)近30年来,延河流域土地利用变化以退耕还林还草为主,加之少量的建设用地扩张。2)1990—2019年,延河流域IC整体呈下降趋势,截至2019年降低17.85%。退耕还林还草和建设用地扩张可有效降低泥沙连通程度,且退耕还林还草具有长期生态效益。3)IC存在明显的空间分异规律,呈现由南向北、由东向西的增加趋势。流域中部是主要退耕还林还草区和建设用地扩张区,也是泥沙连通性明显下降区;流域西北部泥沙连通性较高,且随土地利用变化降幅较小;流域南部泥沙连通性低。4)IC与输沙量之间存在显著正相关关系(P<0.05),适用于流域输沙预测。研究成果可为深入理解流域泥沙输移过程提供科学依据,并为布局和优化土地利用提供参考。展开更多
随着气候变化和人类活动对景观格局及生态过程扰动的增强,关于景观连通性的研究越来越多,但缺乏系统的文献梳理,对其研究现状及前沿热点认识不足。基于Web of Science核心合集数据库检索的文献数据及文献计量学软件CiteSpace,对2000—2...随着气候变化和人类活动对景观格局及生态过程扰动的增强,关于景观连通性的研究越来越多,但缺乏系统的文献梳理,对其研究现状及前沿热点认识不足。基于Web of Science核心合集数据库检索的文献数据及文献计量学软件CiteSpace,对2000—2021年景观连通性研究的发文数量、发文学科、研究力量以及高被引文献等进行可视化分析。结果表明:(1)近20年来,该研究历经了缓慢发展、稳步增长和快速发展阶段,主要分布于生态学、环境科学和地理科学等学科。(2)中国科学院和北京师范大学发表了较多相关成果,大大提升了中国在此研究领域中的国际影响力。(3)景观连通性相关研究的基础内容主要包括探究生物物种扩散机制、自然保护区设计构建与生态网络规划、景观破碎化分析等。发展与应用景观连通性相关评估指标与模型是主要热点内容,从连通性角度开展泥沙输移过程的量化、生物多样性保护与生态系统服务功能评价、气候变化与人类活动双重影响下水文连通性多尺度效应评估是研究前沿。展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDB40000000]the National Natural Science Foundation of China[grant numbers 42175076 and 42288101].
基金funded by the National Key Research and Development Program of China[Grant No.2020YFA0608903]the National Natural Science Foundation of China[Grant Nos.42122035 and 91937302].
基金supported by the National Key Research and Development Program of China[grant number 2018YFC1505706]the National Natural Science Foundation of China[grant numbers 91937302,91737306,41975109]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA17010105]。
文摘The Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System atmospheric component model(FGOALS-f3-L)participated in Phase 6 of the Coupled Model Intercomparison Project,but its reproducibility of surface temperature(T_(s))over the Tibetan Plateau(TP)as a key climatically sensitive region remains unclear.This study evaluates the capability of FGOALS-f3-L in reproducing the climatological T_(s)over the TP relative to the Climate Forecast System Reanalysis.The results show that FGOALS-f3-L can reasonably capture the spatial pattern of T_(s)but underestimates the annual mean T_(s)for the whole TP.The simulated T_(s)for the whole TP shows a cold bias in winter and spring and a warm bias in summer and autumn.Further quantitative analysis based on the surface energy budget equation shows that the surface albedo feedback(SAF)term strongly contributes to the annual,winter,and spring mean cold bias in the western TP and to the warm bias in the eastern TP.Compared with the SAF term,the surface sensible and latent heat flux terms make nearly opposite contributions to the T_(s)bias and considerably offset the bias due to the SAF term.The cloud radiative forcing term strongly contributes to the annual and seasonal mean weak cold bias in the eastern TP.The longwave radiation term associated with the overestimated water vapor content accounts for a large portion of the warm bias over the whole TP in summer and autumn.Improving land surface and cloud processes in FGOALS-f3-L is critical to reduce the T_(s)bias over the TP.
基金funded by the National Key Research and development Program of China (Grant No. 2017YFA0604004)the National Natural Science Foundation of China (Grant Nos. 91737306, U1811464, 41530426, 91837101, 41730963, and 91637312)
文摘The outputs of the Chinese Academy of Sciences(CAS) Flexible Global Ocean–Atmosphere–Land System(FGOALS-f3-L) model for the baseline experiment of the Atmospheric Model Intercomparison Project simulation in the Diagnostic,Evaluation and Characterization of Klima common experiments of phase 6 of the Coupled Model Intercomparison Project(CMIP6) are described in this paper. The CAS FGOALS-f3-L model, experiment settings, and outputs are all given. In total,there are three ensemble experiments over the period 1979–2014, which are performed with different initial states. The model outputs contain a total of 37 variables and include the required three-hourly mean, six-hourly transient, daily and monthly mean datasets. The baseline performances of the model are validated at different time scales. The preliminary evaluation suggests that the CAS FGOALS-f3-L model can capture the basic patterns of atmospheric circulation and precipitation well, including the propagation of the Madden–Julian Oscillation, activities of tropical cyclones, and the characterization of extreme precipitation. These datasets contribute to the benchmark of current model behaviors for the desired continuity of CMIP.
基金This study was jointly supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA19060102 and XDB42000000)the National Natural Science Foundation of China(Grant Nos.41530426,91958201,and 41931183).
文摘This study documents simulated oceanic circulations and sea ice by the coupled climate system model FGOALS-f3-L developed at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics,Chinese Academy of Sciences,under historical forcing from phase 6 of the Coupled Model Intercomparison Project(CMIP6).FGOALS-f3-L reproduces the fundamental features of global oceanic circulations,such as sea surface temperature(SST),sea surface salinity(SSS),mixed layer depth(MLD),vertical temperature and salinity,and meridional overturning circulations.There are notable improvements compared with the previous version,FGOALS-s2,such as a reduction in warm SST biases near the western and eastern boundaries of oceans and salty SSS biases in the tropical western Atlantic and eastern boundaries,and a mitigation of deep MLD biases at high latitudes.However,several obvious biases remain.The most significant biases include cold SST biases in the northwestern Pacific(over 4°C),freshwater SSS biases and deep MLD biases in the subtropics,and temperature and salinity biases in deep ocean at high latitudes.The simulated sea ice shows a reasonable distribution but stronger seasonal cycle than observed.The spatial patterns of sea ice are more realistic in FGOALS-f3-L than its previous version because the latitude–longitude grid is replaced with a tripolar grid in the ocean and sea ice model.The most significant biases are the overestimated sea ice and underestimated SSS in the Labrador Sea and Barents Sea,which are related to the shallower MLD and weaker vertical mixing.
基金This study was supported by the National Key R&D Program for Developing Basic Sciences(Grant Nos.2016YFC1401401 and 2016YFC1401601)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDA19060102 and XDB42000000)the National Natural Science Foundation of China(Grants Nos.91958201,41530426,41576025,41576026,41776030,41931183,41976026 and 41376002).
文摘Two versions of the Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System model(CASFGOALS),version f3-L and g3,are used to simulate the two interglacial epochs of the mid-Holocene and the Last Interglacial in phase 4 of the Paleoclimate Modelling Intercomparison Project(PMIP4),which aims to study the impact of changes in orbital parameters on the Earth’s climate.Following the PMIP4 experimental protocols,four simulations for the mid-Holocene and two simulations for the Last Interglacial have been completed,and all the data,including monthly and daily outputs for the atmospheric,oceanic,land and sea-ice components,have been released on the Earth System Grid Federation(ESGF)node.These datasets contribute to PMIP4 and CMIP6(phase 6 of the Coupled Model Intercomparison Project)by providing the variables necessary for the two interglacial periods.In this paper,the basic information of the CAS-FGOALS models and the protocols for the two interglacials are briefly described,and the datasets are validated using proxy records.Results suggest that the CAS-FGOALS models capture the large-scale changes in the climate system in response to changes in solar insolation during the interglacial epochs,including warming in mid-to-high latitudes,changes in the hydrological cycle,the seasonal variation in the extent of sea ice,and the damping of interannual variabilities in the tropical Pacific.Meanwhile,disagreements within and between the models and the proxy data are also presented.These datasets will help the modeling and the proxy data communities with a better understanding of model performance and biases in paleoclimate simulations.
基金This study is jointly supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDA19060102 and XDB42010400)the Natural Science Foundation of China(Grant Nos.41530426,91958201 and 41931183).
文摘The three-member historical simulations by the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System model,version f3-L(CAS FGOALS-f3-L),which is contributing to phase 6 of the Coupled Model Intercomparison Project(CMIP6),are described in this study.The details of the CAS FGOALS-f3-L model,experiment settings and output datasets are briefly introduced.The datasets include monthly and daily outputs from the atmospheric,oceanic,land and sea-ice component models of CAS FGOALS-f3-L,and all these data have been published online in the Earth System Grid Federation(ESGF,https://esgf-node.llnl.gov/projects/cmip6/).The three ensembles are initialized from the 600th,650th and 700th model year of the preindustrial experiment(piControl)and forced by the same historical forcing provided by CMIP6 from 1850 to 2014.The performance of the coupled model is validated in comparison with some recent observed atmospheric and oceanic datasets.It is shown that CAS FGOALS-f3-L is able to reproduce the main features of the modern climate,including the climatology of air surface temperature and precipitation,the long-term changes in global mean surface air temperature,ocean heat content and sea surface steric height,and the horizontal and vertical distribution of temperature in the ocean and atmosphere.Meanwhile,like other state-of-the-art coupled GCMs,there are still some obvious biases in the historical simulations,which are also illustrated.This paper can help users to better understand the advantages and biases of the model and the datasets。
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.
基金supported by the Key Research Program of Frontier Sciences of the Chinese Academy of Sciencesthe Major Research Plan of the National Natural Science Foundation of China(Grant Nos.91637312,91437219,91637208,and 41530426)the Special Program for Applied Research on Super Computation of the NSFC–Guangdong Joint Fund(second phase)(Grant No.U1501501)
文摘To cherish the memory of the late Professor Duzheng YE on what would have been his 100 th birthday, and to celebrate his great accomplishment in opening a new era of Tibetan Plateau（TP） meteorology, this review paper provides an assessment of the atmospheric heat source（AHS） over the TP from different data resources, including observations from local meteorological stations, satellite remote sensing data, and various reanalysis datasets. The uncertainty and applicability of these heat source data are evaluated. Analysis regarding the formation of the AHS over the TP demonstrates that it is not only the cause of the atmospheric circulation, but is also a result of that circulation. Based on numerical experiments, the review further demonstrates that land–sea thermal contrast is only one part of the monsoon story. The thermal forcing of the Tibetan–Iranian Plateau plays a significant role in generating the Asian summer monsoon（ASM）, i.e., in addition to pumping water vapor from sea to land and from the lower to the upper troposphere, it also generates a subtropical monsoon–type meridional circulation subject to the angular momentum conservation, providing an ascending-air large-scale background for the development of the ASM.
基金jointly supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA19060102 and XDB42000000)National Natural Science Foundation of China(Grant Nos.91958201 and 42130608)+1 种基金the National Key Research and Development Program of China(Grant No.2020YFA0608800)supported by the National Key Scientific and Technological Infrastructure project“Earth System Numerical Simulation Facility”(EarthLab)。
文摘Following the High-Resolution Model Intercomparison Project(HighResMIP)Tier 2 protocol under the Coupled Model Intercomparison Project Phase 6(CMIP6),three numerical experiments are conducted with the Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System Model,version f3-H(CAS FGOALS-f3-H),and a 101-year(1950–2050)global high-resolution simulation dataset is presented in this study.The basic configuration of the FGOALSf3-H model and numerical experiments design are briefly described,and then the historical simulation is validated.Forced by observed radiative agents from 1950 to 2014,the coupled model essentially reproduces the observed long-term trends of temperature,precipitation,and sea ice extent,as well as the large-scale pattern of temperature and precipitation.With an approximate 0.25°horizontal resolution in the atmosphere and 0.1°in the ocean,the coupled models also simulate energetic western boundary currents and the Antarctic Circulation Current(ACC),reasonable characteristics of extreme precipitation,and realistic frontal scale air-sea interaction.The dataset and supporting detailed information have been published in the Earth System Grid Federation.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA19070404)the National Natural Science Foundation of China(Grant Nos.42030602,91837101 and 91937302).
文摘Large-ensemble simulations of the atmosphere-only time-slice experiments for the Polar Amplification Model Intercomparison Project(PAMIP)were carried out by the model group of the Chinese Academy of Sciences(CAS)Flexible Global Ocean-Atmosphere-Land System(FGOALS-f3-L).Eight groups of experiments forced by different combinations of the sea surface temperature(SST)and sea ice concentration(SIC)for pre-industrial,present-day,and future conditions were performed and published.The time-lag method was used to generate the 100 ensemble members,with each member integrating from 1 April 2000 to 30 June 2001 and the first two months as the spin-up period.The basic model responses of the surface air temperature(SAT)and precipitation were documented.The results indicate that Arctic amplification is mainly caused by Arctic SIC forcing changes.The SAT responses to the Arctic SIC decrease alone show an obvious increase over high latitudes,which is similar to the results from the combined forcing of SST and SIC.However,the change in global precipitation is dominated by the changes in the global SST rather than SIC,partly because tropical precipitation is mainly driven by local SST changes.The uncertainty of the model responses was also investigated through the analysis of the large-ensemble members.The relative roles of SST and SIC,together with their combined influence on Arctic amplification,are also discussed.All of these model datasets will contribute to PAMIP multi-model analysis and improve the understanding of polar amplification.
基金the National Natural Science Foundation of China(Grant Nos.91837101,42122035,and 91937302)the National Key Research and Development Program of China(Grant No.2018YFC1505706 and 2020YFA0608903).
文摘The influences of interannual surface potential vorticity forcing over the Tibetan Plateau(TP)on East Asian summer rainfall(EASR)and upper-level circulation are explored in this study.The results show that the interannual EASR and associated circulations are closely related to the surface potential vorticity negative uniform leading mode(PVNUM)over the TP.When the PVNUM is in the positive phase,more rainfall occurs in the Yangtze River valley,South Korea,Japan,and part of northern China,less rainfall occurs in southern China,and vice versa.A possible mechanism by which PVNUM affects EASR is proposed.Unstable air induced by the positive phase of PVNUM could stimulate significant upward motion and a lower-level anomalous cyclone over the TP.As a result,a dipole heating mode with anomalous cooling over the southwestern TP and anomalous heating over the southeastern TP is generated.Sensitivity experiment results regarding this dipole heating mode indicate that anomalous cooling over the southwestern TP leads to local and northeastern Asian negative height anomalies,while anomalous heating over the southeastern TP leads to local positive height anomalies.These results greatly resemble the realistic circulation pattern associated with EASR.Further analysis indicates that the anomalous water vapor transport associated with this anomalous circulation pattern is responsible for the anomalous EASR.Consequently,changes in surface potential vorticity forcing over the TP can induce changes in EASR.
基金financially supported by the National Natural Science Foundation of China grant Nos.4187513341590875+2 种基金41605083the Youth Innovation Promotion Association CAS grant No.2020078the Strategic Priority Research Program of the Chinese Academy of Sciences grant No.XDA2006010302。
文摘This study presents the simulated aerosol spatiotemporal characteristics over the Tibetan Plateau(TP)with a newly developed coupled aerosol-climate model(FGOALS-f3-L).The aerosol properties are simulated over the TP for the period 2002-11.The results indicate that soil dust,sulfate,and carbonaceous aerosols(black carbon(BC),organic carbon(OC)and BC/OC)account for 53.6%,32.2%,and 14.2%of the total aerosol mass over the TP,respectively.The simulated aerosol surface mass concentrations and aerosol optical depths(AODs)are evaluated with ground-based and satellite observations,respectively.Underestimations of the aerosol surface mass concentration are found at the Lhasa site,especially for BC and OC.The spatial distribution and interannual variation of AOD are consistent with MODIS observations,with the RMSE of 0.081 and bias of 0.036.Due to the uncertainty of the parameterization of dust emissions,the model’s performance in summer and autumn is much better than that in spring.
基金funded by the National Natural Science Foundation of China (Grants 41675100, 91737306, and U1811464)
文摘Cloud dominates influence factors of atmospheric radiation, while aerosol–cloud interactions are of vital importance in its spatiotemporal distribution. In this study, a two-moment(mass and number) cloud microphysics scheme, which significantly improved the treatment of the coupled processes of aerosols and clouds, was incorporated into version 1.1 of the IAP/LASG global Finite-volume Atmospheric Model(FAMIL1.1). For illustrative purposes, the characteristics of the energy balance and cloud radiative forcing(CRF) in an AMIP-type simulation with prescribed aerosols were compared with those in observational/reanalysis data. Even within the constraints of the prescribed aerosol mass, the model simulated global mean energy balance at the top of the atmosphere(TOA) and at the Earth’s surface, as well as their seasonal variation, are in good agreement with the observational data. The maximum deviation terms lie in the surface downwelling longwave radiation and surface latent heat flux, which are 3.5 W m-2(1%) and 3 W m-2(3.5%), individually. The spatial correlations of the annual TOA net radiation flux and the net CRF between simulation and observation were around 0.97 and 0.90, respectively. A major weakness is that FAMIL1.1 predicts more liquid water content and less ice water content over most oceans. Detailed comparisons are presented for a number of regions, with a focus on the Asian monsoon region(AMR). The results indicate that FAMIL1.1 well reproduces the summer–winter contrast for both the geographical distribution of the longwave CRF and shortwave CRF over the AMR. Finally, the model bias and possible solutions, as well as further works to develop FAMIL1.1 are discussed.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA19060102 and XDB42000000)the National Natural Science Foundation of China(Grants Nos.41530426 and 91958201)。
文摘The datasets for the tier-1 Scenario Model Intercomparison Project(ScenarioMIP)experiments from the Chinese Academy of Sciences(CAS)Flexible Global Ocean-Atmosphere-Land System model,finite-volume version 3(CAS FGOALS-f3-L)are described in this study.ScenarioMIP is one of the core MIP experiments in phase 6 of the Coupled Model Intercomparison Project(CMIP6).Considering future CO2,CH4,N2O and other gases’concentrations,as well as land use,the design of ScenarioMIP involves eight pathways,including two tiers(tier-1 and tier-2)of priority.Tier-1 includes four combined Shared Socioeconomic Pathways(SSPs)with radiative forcing,i.e.,SSP1-2.6,SSP2-4.5,SSP3-7.0 and SSP5-8.5,in which the globally averaged radiative forcing at the top of the atmosphere around the year 2100 is approximately 2.6,4.5,7.0 and 8.5 W m−2,respectively.This study provides an introduction to the ScenarioMIP datasets of this model,such as their storage location,sizes,variables,etc.Preliminary analysis indicates that surface air temperatures will increase by about 1.89℃,3.07℃,4.06℃ and 5.17℃ by around 2100 under these four scenarios,respectively.Meanwhile,some other key climate variables,such as sea-ice extension,precipitation,heat content,and sea level rise,also show significant long-term trends associated with the radiative forcing increases.These datasets will help us understand how the climate will change under different anthropogenic and radiative forcings.
基金supported by National Key Research and Development Program of China(Grant No.2018YFA0606300)the NSFC(Grant No.42075163),the NSFC BSCTPES project(Grant No.41988101)+1 种基金the NSFC(Grant No.42205039)supported by the Jiangsu Collaborative Innovation Center for Climate Change and the National Key Scientific and Technological Infrastructure project“Earth System Science Numerical Simulator Facility”(EarthLab).
文摘The outputs of the Chinese Academy of Sciences(CAS)Flexible Global Ocean-Atmosphere-Land System(FGOALSf3-L)model for the decadal climate prediction project(DCPP)of the Coupled Model Intercomparison Project Phase 6(CMIP6)are described in this paper.The FGOALS-f3-L was initialized through the upgraded,weakly coupled data assimilation scheme,referred to as EnOI-IAU,which assimilates observational anomalies of sea surface temperature(SST)and upper-level(0–1000-m)ocean temperature and salinity profiles into the coupled model.Then,nine ensemble members of 10-year hindcast/forecast experiments were conducted for each initial year over the period of 1960–2021,based on initial conditions produced by three initialization experiments.The hindcast and forecast experiments follow the experiment designs of the Component-A and Component-B of the DCPP,respectively.The decadal prediction output datasets contain a total of 44 monthly mean atmospheric and oceanic variables.The preliminary evaluation indicates that the hindcast experiments show significant predictive skill for the interannual variations of SST in the north Pacific and multi-year variations of SST in the subtropical Pacific and the southern Indian Ocean.
文摘泥沙连通性是表征泥沙在地貌单元间物理级联关系的重要参数,探讨其对土地利用变化的响应,对揭示流域内部水沙动态以及不同土地利用类型的水土保持效应具有重要意义。基于延河流域1990—2019年土地利用与径流输沙量等数据资料,结合连通性指数(index of connectivity,IC)分析土地利用变化对泥沙连通性时空分布的影响及与径流输沙量的关系。结果表明:1)近30年来,延河流域土地利用变化以退耕还林还草为主,加之少量的建设用地扩张。2)1990—2019年,延河流域IC整体呈下降趋势,截至2019年降低17.85%。退耕还林还草和建设用地扩张可有效降低泥沙连通程度,且退耕还林还草具有长期生态效益。3)IC存在明显的空间分异规律,呈现由南向北、由东向西的增加趋势。流域中部是主要退耕还林还草区和建设用地扩张区,也是泥沙连通性明显下降区;流域西北部泥沙连通性较高,且随土地利用变化降幅较小;流域南部泥沙连通性低。4)IC与输沙量之间存在显著正相关关系(P<0.05),适用于流域输沙预测。研究成果可为深入理解流域泥沙输移过程提供科学依据,并为布局和优化土地利用提供参考。
文摘随着气候变化和人类活动对景观格局及生态过程扰动的增强,关于景观连通性的研究越来越多,但缺乏系统的文献梳理,对其研究现状及前沿热点认识不足。基于Web of Science核心合集数据库检索的文献数据及文献计量学软件CiteSpace,对2000—2021年景观连通性研究的发文数量、发文学科、研究力量以及高被引文献等进行可视化分析。结果表明:(1)近20年来,该研究历经了缓慢发展、稳步增长和快速发展阶段,主要分布于生态学、环境科学和地理科学等学科。(2)中国科学院和北京师范大学发表了较多相关成果,大大提升了中国在此研究领域中的国际影响力。(3)景观连通性相关研究的基础内容主要包括探究生物物种扩散机制、自然保护区设计构建与生态网络规划、景观破碎化分析等。发展与应用景观连通性相关评估指标与模型是主要热点内容,从连通性角度开展泥沙输移过程的量化、生物多样性保护与生态系统服务功能评价、气候变化与人类活动双重影响下水文连通性多尺度效应评估是研究前沿。
