Using the simulations performed by 15 cli mate models under the latest protocol of the Paleoclimate Modeling Intercomparison Project(PMIP)Phase 3(PMIP3),the authors revisited the annual and seasona temperature changes...Using the simulations performed by 15 cli mate models under the latest protocol of the Paleoclimate Modeling Intercomparison Project(PMIP)Phase 3(PMIP3),the authors revisited the annual and seasona temperature changes over China during the mid-Holocene Similar to the previous results produced by PMIP Phase 1(PMIP1)and 2(PMIP2)models,14(15)of the 15 PMIP3models reproduced colder annual(boreal winter and spring)temperature in response to mid-Holocene insola tion changes,with an average cooling of 0.33 K(1.31 K and 1.58 K)over China.The mid-Holocene boreal sum mer(autumn)temperature increased in all(13)of the 15PMIP3 models,with an average warming of 1.02 K(0.61K)at the national scale.Those changes simulated by the PMIP3 models were similar to those from the PMIP2simulations but generally weaker than those from the PMIP1 models.A considerable mismatch still existed between the simulated cooling by the PMIP3 models and the reconstructed warming for annual and winter tem peratures over China during the mid-Holocene,as wa also the case between the previous PMIP1/2 simulation and proxy data.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
In this study, the climate changes over Arid Central Asia(ACA) during the mid-Holocene(approximately 6,000 calendar years ago, MH) and the Last Glacial Maximum(approximately 21,000 calendar years ago, LGM) were invest...In this study, the climate changes over Arid Central Asia(ACA) during the mid-Holocene(approximately 6,000 calendar years ago, MH) and the Last Glacial Maximum(approximately 21,000 calendar years ago, LGM) were investigated using multimodel simulations derived from the Paleoclimate Modelling Intercomparison Project Phase 3(PMIP3). During the MH, the multimodel median(MMM) shows that in the core region of ACA, the regionally averaged annual surface air temperature(SAT) decreases by 0.13°C and annual precipitation decreases by 3.45%, compared with the preindustrial(PI) climate. The MMM of the SAT increases by 1.67/0.13°C in summer/autumn, whereas it decreases by 1.23/1.11°C in spring/winter. The amplitude of the seasonal cycles of the SAT increases over ACA due to different MH orbital parameters. For precipitation, the regionally averaged MMM decreases by 5.77%/5.69%/0.39%/5.24% in spring/summer/autumn/winter, respectively. Based on the analysis of the aridity index(AI), compared with the PI, a drier climate appears in southern Central Asia and western Xinjiang due to decreasing precipitation. During the LGM, the MMM shows that the regionally averaged SAT decreases by 5.04/4.36/4.70/5.12/5.88°C and precipitation decreases by 27.78%/28.16%/31.56%/27.74%/23.29% annually and in the spring, summer, autumn, and winter, respectively. Robust drying occurs throughout almost the whole core area. Decreasing precipitation plays a dominant role in shaping the drier conditions, whereas strong cooling plays a secondary but opposite role. In response to the LGM external forcings, over Central Asia and Xinjiang, the seasonal cycle of precipitation has a smaller amplitude compared with that under the PI climate. In the model-data comparison, the simulated MH moisture changes over ACA are to some extent consistent with the reconstructions, further confirming that drier conditions occurred during that period than during the PI.展开更多
The increasing trend of the Southern Annular Mode （SAM） in recent decades has influenced climate change in the Southem Hemisphere （SH）.How the SAM will respond increased greenhouse gas concentrations in the future...The increasing trend of the Southern Annular Mode （SAM） in recent decades has influenced climate change in the Southem Hemisphere （SH）.How the SAM will respond increased greenhouse gas concentrations in the future remains uncertain.Understanding the variability of the SAM in the past under a colder climate such as during the Last Glacial Maximum （LGM） might provide some understanding of the response of the SAM under a future warmer climate.We analyzed the changes in the SAM during the LGM in comparison to pre-industrial （PI） simulations using five coupled ocean-atmosphere models （CCSM,FGOALS,IPSL,MIROC,HadCM） from the second phase of the Paleoclimate Modelling Intercomparison Project （PMIP2）.In CCSM,MIROC,IPSL,and FGOALS,the variability of the simulated SAM appears to be reduced in the LGM compared to the PI simulations,with a decrease in the standard deviation of the SAM index.Overall,four out of the five models suggest a weaker SAM amplitude in the LGM consistent with a weaker SH polar vortex and westerly winds found in some proxy records and model analyses.The weakening of the SAM in the LGM was associated with an increase in the vertical propagation of Rossby waves in southern high latitudes.展开更多
When considering potential global warming projections, it is useful to understand the impact of each climate condition at 6 kyr before present. Asian paleoclimate was simulated by performing an integration of the mult...When considering potential global warming projections, it is useful to understand the impact of each climate condition at 6 kyr before present. Asian paleoclimate was simulated by performing an integration of the multi-model ensemble with the paleoclimate modeling intercomparison project（PMIP） models. The reconstructed winter（summer） surface air temperature at 6 kyr before present was 0.85 oC（0.21 oC） lower（higher） than the present day over Asia, 60oE-150oE, 10oN-60oN. The seasonal variation and heating differences of land and ocean in summer at 6 kyr before present might be much larger than present day. The winter and summer precipitation of 6 kyr before present were 0.067 and 0.017 mm·day-1larger than present day, respectively. The Group B climate, which means the dry climates based on K？ppen climate classification, at 6 kyr before present decreased 17% compared to present day, but the Group D which means the continental and microthermal climates at 6 kyr before present increased over 7%. Comparison between the results from the model simulation and published paleo-proxy record agrees within the limited sparse paleo-proxy record data.展开更多
基金supported by the National Natural Science Foundation of China[grant numbers 41931181 and 42075048]the Youth Innovation Promotion Association of the Chinese Academy of Sciences[grant number 2022075]。
基金supported by the National Natural Science Foundation of China(Grant No.41222034)
文摘Using the simulations performed by 15 cli mate models under the latest protocol of the Paleoclimate Modeling Intercomparison Project(PMIP)Phase 3(PMIP3),the authors revisited the annual and seasona temperature changes over China during the mid-Holocene Similar to the previous results produced by PMIP Phase 1(PMIP1)and 2(PMIP2)models,14(15)of the 15 PMIP3models reproduced colder annual(boreal winter and spring)temperature in response to mid-Holocene insola tion changes,with an average cooling of 0.33 K(1.31 K and 1.58 K)over China.The mid-Holocene boreal sum mer(autumn)temperature increased in all(13)of the 15PMIP3 models,with an average warming of 1.02 K(0.61K)at the national scale.Those changes simulated by the PMIP3 models were similar to those from the PMIP2simulations but generally weaker than those from the PMIP1 models.A considerable mismatch still existed between the simulated cooling by the PMIP3 models and the reconstructed warming for annual and winter tem peratures over China during the mid-Holocene,as wa also the case between the previous PMIP1/2 simulation and proxy data.
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 research was supported by the National Key R&D Program of China (Grant No. 2018YFA0606403)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA20070103)+1 种基金the National Natural Science Foundation of China (Grants 41822502)the CAS–PKU Joint Research Program
文摘In this study, the climate changes over Arid Central Asia(ACA) during the mid-Holocene(approximately 6,000 calendar years ago, MH) and the Last Glacial Maximum(approximately 21,000 calendar years ago, LGM) were investigated using multimodel simulations derived from the Paleoclimate Modelling Intercomparison Project Phase 3(PMIP3). During the MH, the multimodel median(MMM) shows that in the core region of ACA, the regionally averaged annual surface air temperature(SAT) decreases by 0.13°C and annual precipitation decreases by 3.45%, compared with the preindustrial(PI) climate. The MMM of the SAT increases by 1.67/0.13°C in summer/autumn, whereas it decreases by 1.23/1.11°C in spring/winter. The amplitude of the seasonal cycles of the SAT increases over ACA due to different MH orbital parameters. For precipitation, the regionally averaged MMM decreases by 5.77%/5.69%/0.39%/5.24% in spring/summer/autumn/winter, respectively. Based on the analysis of the aridity index(AI), compared with the PI, a drier climate appears in southern Central Asia and western Xinjiang due to decreasing precipitation. During the LGM, the MMM shows that the regionally averaged SAT decreases by 5.04/4.36/4.70/5.12/5.88°C and precipitation decreases by 27.78%/28.16%/31.56%/27.74%/23.29% annually and in the spring, summer, autumn, and winter, respectively. Robust drying occurs throughout almost the whole core area. Decreasing precipitation plays a dominant role in shaping the drier conditions, whereas strong cooling plays a secondary but opposite role. In response to the LGM external forcings, over Central Asia and Xinjiang, the seasonal cycle of precipitation has a smaller amplitude compared with that under the PI climate. In the model-data comparison, the simulated MH moisture changes over ACA are to some extent consistent with the reconstructions, further confirming that drier conditions occurred during that period than during the PI.
基金supported by the "Investigation of Climate Change Mechanism by Observation and Simulation of Polar Climate Change for the Past and Present" project (PE14010) of the KOPRIthe Special Project of Basic Science and Technology (2011FY120300)+1 种基金the Korea Meteorological Administration Research and Development Program under Grant CATER 2012-3061 (PN13010)supported by the Jiangsu Collaborative Innovation Center for Climate Change
文摘The increasing trend of the Southern Annular Mode （SAM） in recent decades has influenced climate change in the Southem Hemisphere （SH）.How the SAM will respond increased greenhouse gas concentrations in the future remains uncertain.Understanding the variability of the SAM in the past under a colder climate such as during the Last Glacial Maximum （LGM） might provide some understanding of the response of the SAM under a future warmer climate.We analyzed the changes in the SAM during the LGM in comparison to pre-industrial （PI） simulations using five coupled ocean-atmosphere models （CCSM,FGOALS,IPSL,MIROC,HadCM） from the second phase of the Paleoclimate Modelling Intercomparison Project （PMIP2）.In CCSM,MIROC,IPSL,and FGOALS,the variability of the simulated SAM appears to be reduced in the LGM compared to the PI simulations,with a decrease in the standard deviation of the SAM index.Overall,four out of the five models suggest a weaker SAM amplitude in the LGM consistent with a weaker SH polar vortex and westerly winds found in some proxy records and model analyses.The weakening of the SAM in the LGM was associated with an increase in the vertical propagation of Rossby waves in southern high latitudes.
基金funded by the National Institute of Fisheries Science of Korea (No. RP-2016-ME-036)
文摘When considering potential global warming projections, it is useful to understand the impact of each climate condition at 6 kyr before present. Asian paleoclimate was simulated by performing an integration of the multi-model ensemble with the paleoclimate modeling intercomparison project（PMIP） models. The reconstructed winter（summer） surface air temperature at 6 kyr before present was 0.85 oC（0.21 oC） lower（higher） than the present day over Asia, 60oE-150oE, 10oN-60oN. The seasonal variation and heating differences of land and ocean in summer at 6 kyr before present might be much larger than present day. The winter and summer precipitation of 6 kyr before present were 0.067 and 0.017 mm·day-1larger than present day, respectively. The Group B climate, which means the dry climates based on K？ppen climate classification, at 6 kyr before present decreased 17% compared to present day, but the Group D which means the continental and microthermal climates at 6 kyr before present increased over 7%. Comparison between the results from the model simulation and published paleo-proxy record agrees within the limited sparse paleo-proxy record data.
