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
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
Paleoclimate simulations of the mid-Holocene (MH) and Last Glacial maximum (LGM) by the latest versions of the Flexible Global Ocean-Atmosphere-Land System model, Spectral Version 2 and Grid-point Version 2 (FGOA...Paleoclimate simulations of the mid-Holocene (MH) and Last Glacial maximum (LGM) by the latest versions of the Flexible Global Ocean-Atmosphere-Land System model, Spectral Version 2 and Grid-point Version 2 (FGOALS-s2 and g2) are evaluated in this study. The MH is characterized by changes of insolation induced by orbital parameters, and the LGM is a glacial period with large changes in greenhouse gases, sea level and ice sheets. For the MH, both versions of FGOALS simulate reasonable responses to the changes of insolation, such as the enhanced summer monsoon in African-Asian regions. Model differences can be identified at regional and seasonal scales. The global annual mean surface air temperature (TAS) shows no significant change in FGOALS-s2, while FGOALS-g2 shows a global cooling of about 0.7~C that is related with a strong cooling during boreal winter. The amplitude of ENSO is weaker in FGOALS-g2, which agrees with proxy data. For the LGM, FGOALS-g2 captures the features of the cold and dry glacial climate, including a global cooling of 4.6℃ and a decrease in precipitation by 10%. The ENSO is weaker at the LGM, with a tendency of stronger ENSO cold events. Sensitivity analysis shows that the Equilibrium Climate Sensitivity (ECS) estimated for FGOALS ranges between 4.23℃ and 4.59℃. The sensitivity of precipitation to the changes of TAS is -2.3%℃-1, which agrees with previous studies. FGOALS-g2 shows better simulations of the Atlantic Meridional Overturning Circulation (AMOC) and African summer monsoon precipitation in the MH when compared with FGOALS-gl.0; however, it is hard to conclude any improvements for the LGM.展开更多
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 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 Chinese National Basic Research Program(Grant Nos.2010CB950502 and 2012CB955202)the "Strategic Priority Research Program Climate Change:Carbon Budget and Relevant Issues" of the Chinese Academy of Sciences(Grant No.XDA05110301)+2 种基金the National Natural Science Foundation of China(Grant Nos.41006008 and 41023002)the public science and technology research funds projects of meteorology(Grant No.GYHY200906020)the National Key Technologies R&D Program project(Grant No.2010AA012302)
文摘Paleoclimate simulations of the mid-Holocene (MH) and Last Glacial maximum (LGM) by the latest versions of the Flexible Global Ocean-Atmosphere-Land System model, Spectral Version 2 and Grid-point Version 2 (FGOALS-s2 and g2) are evaluated in this study. The MH is characterized by changes of insolation induced by orbital parameters, and the LGM is a glacial period with large changes in greenhouse gases, sea level and ice sheets. For the MH, both versions of FGOALS simulate reasonable responses to the changes of insolation, such as the enhanced summer monsoon in African-Asian regions. Model differences can be identified at regional and seasonal scales. The global annual mean surface air temperature (TAS) shows no significant change in FGOALS-s2, while FGOALS-g2 shows a global cooling of about 0.7~C that is related with a strong cooling during boreal winter. The amplitude of ENSO is weaker in FGOALS-g2, which agrees with proxy data. For the LGM, FGOALS-g2 captures the features of the cold and dry glacial climate, including a global cooling of 4.6℃ and a decrease in precipitation by 10%. The ENSO is weaker at the LGM, with a tendency of stronger ENSO cold events. Sensitivity analysis shows that the Equilibrium Climate Sensitivity (ECS) estimated for FGOALS ranges between 4.23℃ and 4.59℃. The sensitivity of precipitation to the changes of TAS is -2.3%℃-1, which agrees with previous studies. FGOALS-g2 shows better simulations of the Atlantic Meridional Overturning Circulation (AMOC) and African summer monsoon precipitation in the MH when compared with FGOALS-gl.0; however, it is hard to conclude any improvements for the LGM.