新生代南极冰盖演化的模拟研究——气候场不确定性的影响  

MODELING THE CENOZOIC EVOLUTION OF THE ANTARCTIC ICE SHEET—INFLUENCE OF THE UNCERTAINTY IN CLIMATE FORCING

作　　者：满凯 魏强 谭宁 张仲石 李熙晨[1] 刘永岗 MAN Kai;WEI Qiang;TAN Ning;ZHANG Zhongshi;LI Xichen;LIU Yonggang(Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;Department of Atmospheric and Oceanic Sciences,School of Physics,Peking University,Beijing 100871;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;Department of Atmospheric Science,School of Environment Studies,China University of Geosciences(Wuhan),Wuhan 430074,Hubei)

机构地区：[1]中国科学院大气物理研究所,北京100029 [2]北京大学物理学院大气与海洋科学系,北京100871 [3]中国科学院地质与地球物理研究所,北京100029 [4]中国地质大学(武汉)环境学院大气科学系,湖北武汉430074

出　　处：《第四纪研究》2023年第4期911-924,共14页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:41888101和42225606)资助。

摘　　要：观测显示,南极冰盖在始新世到渐新世交界时期(34 Ma)开始形成,之后随着全球气候的逐渐变冷而扩张并趋于稳定。以此为约束,可以检验气候模式和冰盖模式在模拟中晚新生代气候和冰盖演化的有效性。本研究采用冰盖模式ISSM4.18,分别使用两个气候模式CESM1.2.2和NorESM-L模拟得到的新生代气候场为强迫场,对南极冰盖的演化进行了模拟,对比了两种气候场得到的南极冰盖演化的差异。其中,CESM1.2.2模拟采用的CO_(2)浓度是以重建的全球平均温度为约束反推得到的,而NorESM-L模拟则是采用由地质记录中的CO_(2)代用资料重建得到的浓度。结果显示,CESM1.2.2模拟的气候场在30 Ma时可以在东南极形成冰盖,在20 Ma和10 Ma该冰盖持续存在,但始终都没有形成显著的西南极冰盖。而NorESM-L模拟的气候场在10 Ma之前都不能形成冰盖,但在10 Ma时可以形成包括西南极冰盖在内的大冰盖。总的来说,使用CESM1.2.2模拟的气候场给出的南极冰盖演化相对更为合理,也在一定程度上说明了新生代全球平均温度重建的合理性。Observations suggest that the Antarctic Ice Sheet began to develop during the Eocene⁃Oligocene transition(34 Ma)and grew as the global climate gradually cooled.Constrained by that,we evaluate the validity of climate and ice sheet models in simulating the climate and ice sheet during the Mesozoic and Late Cenozoic.Here,we use ISSM4.18 to simulate the evolution of the Antarctic Ice Sheet,forced by the temperature and precipitation simulated by two climate models,CESM1.2.2 and NorESM⁃L.Differences in the modeling results are also compared.The CESM1.2.2 simulation used the CO_(2) concentration constrained by the reconstructed global mean surface temperature,while the NorESM⁃L simulation directly used the CO_(2) concentration reconstructed from proxies.Results show that when forced with the CESM1.2.2 simulated climates,the East Antarctica Ice sheet developed at 30 Ma and persisted at 20 Ma and 10 Ma,but no significant ice sheet formed in West Antarctica.In contrast,no ice sheet developed before 10 Ma when forced with the NorESM⁃L simulated climates,but a much larger West Antarctic Ice Sheet formed at 10 Ma.In conclusion,the evolution of the Antarctic Ice Sheet given by the climate field simulated by CESM1.2.2 is relatively more reasonable.The results also indicate the validity of the reconstructed Cenozoic global mean temperature.

关 键 词：南极冰盖 古气候 新生代 CESM NorESM 

分 类 号：P467[天文地球—大气科学及气象学]