末次间冰期127 ka时期植被反馈增强东亚夏季风降水的数值模拟研究  

Enhanced East Asian summer monsoon precipitation due to vegetation feedback during the last interglacial 127 ka

作　　者：张琼 陈婕 Zhang Qiong;Chen Jie(Department of Physical Geography and Bolin Centre for Climate Research,Stockholm University,Stockholm 10691,Sweden;Key Laboratory of Western China's Environmental Systems,Ministry of Education,College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,Gansu)

机构地区：[1]Department of Physical Geography and Bolin Centre for Climate Research,Stockholm University,Stockholm 10691,Sweden [2]兰州大学资源环境学院,西部环境教育部重点实验室,甘肃兰州730000

出　　处：《第四纪研究》2020年第6期1499-1512,共14页Quaternary Sciences

基　　金：瑞典国家自然科学基金项目VR(资助号:2013-06476和2017-04232);中国国家自然科学基金重大项目(批准号:41690115)共同资助。

摘　　要：黄土和石笋等古气候代用资料表明在末次间冰期间,东亚夏季风增强、降水增多。本研究利用地球系统模式EC-Earth模拟了末次间冰期127 ka时期的气候,通过和工业革命前的气候模拟控制试验做比对,分析了127 ka时期由于地球轨道参数变化导致的东亚夏季风的空间变化特征。我们利用了两种EC-Earth的模式配置,即"大气-陆面-海洋-海冰"耦合模式和"大气-陆面-海洋-海冰-动态植被"耦合模式,分别估算轨道强迫和植被反馈对东亚夏季风降水变化的贡献。数值模拟结果表明,地球轨道强迫导致的海陆热力差异使得东亚夏季风系统显著增强并北移西伸,中国中部及华北地区降水增多而东部沿海地区降水减少。耦合了动态植被模式的试验结果表明,127 ka时期温暖湿润的气候致使东亚地区植被增多,植被的蒸腾作用使得地表的感热和潜热通量显著增大,从而增强了局地水循环,使降水进一步增多。植被的反馈作用在原本温暖湿润的华南地区对降水的影响并不显著,但是对相对干旱的我国中部和华北地区降水有显著影响。数值试验结果表明轨道强迫和植被反馈的共同作用能使内陆的四川盆地到华北一带夏季降水增加约40%,其中30%的增加是由于轨道强迫作用,约10%是由于植被反馈。这个研究也提醒我们,要得到更加合理的对过去或未来气候变化的模拟结果,有必要使用耦合动态植被的气候系统模式。The paleo-proxy records,such as loess and speleothem,indicate that the east Asian summer monsoon(EASM)was stronger during the last interglacial period(LIG)127 ka than that in today.In this study we simulate the climate during the 127 ka using an earth climate system model EC-Earth.We use two different EC-Earth model configurations,Atmosphere-Land-Ocean-Sea-ice and Atmosphere-Land-Ocean-Sea-ice-dynamic-vegetation,to examine the contribution of orbital forcing and vegetation feedback to climate change during 127 ka by comparing with the control simulation for the pre-industrial(PI)climate.The simulation results show that the orbital forcing induced stronger land-sea contrast significantly enhances the intensity of EASM,leads to the westward and northward moving of the monsoon system,results in an increased precipitation in central and north China but a decreased precipitation in the east costal area.The simulation with coupled dynamic vegetation module produces the development of vegetation under warm and wet 127 ka climate.Increased vegetation coverage enhances the local surface sensible and latent heating through increased evapotranspiration,which leads to decrease in surface air temperature and increase in regional precipitation.Such vegetation feedback is more efficient in the dry climate region in north China,but less efficient in south China with dominant tropical climate.The estimated changes in EASM precipitation increase is about 40%,with contribution from both orbital forcing and vegetation feedback,in which the orbital forcing alone contributes nearly 30% and vegetation feedback contributes about 10%.This study also reminds us that it is necessary to use the coupled dynamic vegetation model to obtain the reasonable results in simulating the climate change in the past or future.

关 键 词：末次间冰期 127 KA 东亚夏季风降水 气候模拟 轨道强迫 植被反馈 

分 类 号：P532[天文地球—古生物学与地层学] P534.631[天文地球—地质学]