Behaviour of the winter North Atlantic eddy-driven jet stream in the CMIP3 integrations
Behaviour of the winter North Atlantic eddy-driven jet stream in the CMIP3 integrations
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DOI：
10.1007/s00382-012-1560-4
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发表时间：
2013-08-01
期刊：
影响因子：
4.6
通讯作者：
Woollings, Tim
中科院分区：
文献类型：
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作者：
Hannachi, Abdel;Barnes, Elizabeth A.;Woollings, Tim
冬季北大西洋涡驱动的急流纬度和风速从52个模型集成，从耦合模型相互比较项目第3阶段，进行了系统的分析，并从ERA-40再分析获得的结果进行了比较。我们在这里考虑一个控制模拟，二十世纪的模拟，和两个时间段（2046-2065年和2081-2100年）从二十一世纪，高排放A2强制模拟。急流风速的季节性被发现是相似的二十世纪的模拟和ERA-40再分析之间的控制和强迫模拟，虽然近一半的模型高估了季节性周期的幅度。一个系统的赤道偏置的模型喷气纬度的季节性，由高达7A度，观察到，和模型另外高估的季节性周期的喷气纬度的平均值，与大多数的模型显示赤道和极地偏置在寒冷和温暖的季节分别。这项工作的一个主要发现是，没有GCM在任何强迫的情况下，这里考虑的是能够模拟所观察到的急流纬度分布的三峰行为。该模型遭受严重的问题，喷流变异的结构，而不仅仅是在统计矩的定量误差。
A systematic analysis of the winter North Atlantic eddy-driven jet stream latitude and wind speed from 52 model integrations, taken from the coupled model intercomparison project phase 3, is carried out and compared to results obtained from the ERA-40 reanalyses. We consider here a control simulation, twentieth century simulation, and two time periods (2046-2065 and 2081-2100) from a twenty-first century, high-emission A2 forced simulation. The jet wind speed seasonality is found to be similar between the twentieth century simulations and the ERA-40 reanalyses and also between the control and forced simulations although nearly half of the models overestimate the amplitude of the seasonal cycle. A systematic equatorward bias of the models jet latitude seasonality, by up to 7A degrees, is observed, and models additionally overestimate the seasonal cycle of jet latitude about the mean, with the majority of the models showing equatorward and poleward biases during the cold and warm seasons respectively. A main finding of this work is that no GCM under any forcing scenario considered here is able to simulate the trimodal behaviour of the observed jet latitude distribution. The models suffer from serious problems in the structure of jet variability, rather than just quantitiative errors in the statistical moments.