EMIC Intercomparison Project (EMIP–CO2): comparative analysis of EMIC simulations of climate, and of equilibrium and transient responses to atmospheric CO2 doubling
EMIC Intercomparison Project (EMIP–CO2): comparative analysis of EMIC simulations of climate, and of equilibrium and transient responses to atmospheric CO2 doubling
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EMIC 对比项目 (EMIP-CO2)：EMIC 气候模拟以及大气 CO2 倍增的平衡和瞬态响应的比较分析
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
A. Weaver
中科院分区：
文献类型：
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作者：
V. Petoukhov;M. Claussen;A. Berger;M. Crucifix;M. Crucifix;M. Eby;A. Eliseev;T. Fichefet;A. Ganopolski;H. Goosse;I. Kamenkovich;I. I. Mokhov;M. Montoya;L. Mysak;A. Sokolov;P. Stone;Zhaomin Wang;A. Weaver
对八个 EMIC（中等复杂性的地球系统模型）进行了相互比较，以研究模拟结果的变化和分散性：(1) 规定的 280 ppm 大气 CO2 浓度下的气候特征，以及 (2) 对大气中 CO2 倍增的平衡和瞬态响应。比对第一部分的结果表明 EMIC 与当前的观测数据相当一致。 EMIC结果的离散度总体上属于大气环流模型（GCM）结果的范围，该模型参与了大气模型比对项目（AMIP）和耦合模型比对项目第一阶段（CMIP1）。分析了 EMIC 气候特征模拟中观察到的差异的可能原因。本比对的第二部分选择了这样一种情景：在前 70 年中，大气中的二氧化碳浓度逐渐增加（每年复合 1%），随后在超过 1,500 年的时间内稳定在 560 ppm 的水平。看来，对 CO2 倍增的平衡和瞬态响应的 EMIC 结果在参与大气-板片海洋模型比对项目和耦合模型比对项目第二阶段（CMIP2）的 GCM 的相应结果范围内。特别是，EMIC 显示出类似的温度和降水变化，其幅度相当，并且分布在模型中，如 GCM 中发现的那样。降水对二氧化碳变化的模拟响应中最大的分散发生在亚热带地区。海冰覆盖减少的幅度也出现了显着差异。在二氧化碳加倍的情况下，参与比对的每个 EMIC 都表现出北大西洋温盐环流强度的降低，最大降低发生在瞬态实验开始后 100 到 300 年之间。在这种短暂的减少之后（其最小值因模型而异），温盐环流的强度在每个模型中再次增加，缓慢上升回到新的平衡。
An intercomparison of eight EMICs (Earth system Models of Intermediate Complexity) is carried out to investigate the variation and scatter in the results of simulating (1) the climate characteristics at the prescribed 280 ppm atmosphere CO2 concentration, and (2) the equilibrium and transient responses to CO2 doubling in the atmosphere. The results of the first part of this intercomparison suggest that EMICs are in reasonable agreement with the present-day observational data. The dispersion of the EMIC results by and large falls within the range of results of General Circulation Models (GCMs), which took part in the Atmospheric Model Intercomparison Project (AMIP) and Coupled Model Intercomparison Project, phase 1 (CMIP1). Probable reasons for the observed discrepancies among the EMIC simulations of climate characteristics are analysed. A scenario with gradual increase in CO2 concentration in the atmosphere (1% per year compounded) during the first 70 years followed by a stabilisation at the 560 ppm level during a period longer than 1,500 years is chosen for the second part of this intercomparison. It appears that the EMIC results for the equilibrium and transient responses to CO2 doubling are within the range of the corresponding results of GCMs, which participated in the atmosphere-slab ocean model intercomparison project and Coupled Model Intercomparison Project, phase 2 (CMIP2). In particular EMICs show similar temperature and precipitation changes with comparable magnitudes and scatter across the models as found in the GCMs. The largest scatter in the simulated response of precipitation to CO2 change occurs in the subtropics. Significant differences also appear in the magnitude of sea ice cover reduction. Each of the EMICs participating in the intercomparison exhibits a reduction of the strength of the thermohaline circulation in the North Atlantic under CO2 doubling, with the maximum decrease occurring between 100 and 300 years after the beginning of the transient experiment. After this transient reduction, whose minimum notably varies from model to model, the strength of the thermohaline circulation increases again in each model, slowly rising back to a new equilibrium.