A regime view of the North Atlantic Oscillation and its response to anthropogenic forcing.
A regime view of the North Atlantic Oscillation and its response to anthropogenic forcing.
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DOI：
10.1175/2009jcli3087.1
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发表时间：
2010-03
影响因子：
4.9
通讯作者：
T. Woollings;A. Hannachi;B. Hoskins;A. Turner
中科院分区：
文献类型：
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作者：
T. Woollings;A. Hannachi;B. Hoskins;A. Turner
摘要 40 年 ECMWF 再分析 (ERA-40) 中每日冬季北大西洋涛动 (NAO) 指数的分布存在显着负偏态。动力学和统计分析都表明，这种偏度反映了两种不同状态的存在，即“格陵兰阻塞”和“副极地急流”。研究表明，相对发生率和制度结构的变化有助于 ERA-40 期间的长期 NAO 趋势。这与英国气象局统一模型 (HadCM3) 的第三种气候配置的 100 年控制模拟和双倍二氧化碳积分形成对比。该模型在控制运行中对 NAO 的模拟存在明显缺陷，因此必须谨慎对待其对未来行为的预测。然而，在人为强迫下，副极地急流状况确实变得更加占主导地位，虽然这种变化很小，但在统计上显然是显着的，并且确实代表了北半球性质的真正变化……
Abstract The distribution of the daily wintertime North Atlantic Oscillation (NAO) index in the 40-yr ECMWF Re-Analysis (ERA-40) is significantly negatively skewed. Dynamical and statistical analyses both suggest that this skewness reflects the presence of two distinct regimes—referred to as “Greenland blocking” and “subpolar jet.” Changes in both the relative occurrence and in the structure of the regimes are shown to contribute to the long-term NAO trend over the ERA-40 period. This is contrasted with the simulation of the NAO in 100-yr control and doubled CO2 integrations of the third climate configuration of the Met Office Unified Model (HadCM3). The model has clear deficiencies in its simulation of the NAO in the control run, so its predictions of future behavior must be treated with caution. However, the subpolar jet regime does become more dominant under anthropogenic forcing and, while this change is small it is clearly statistically significant and does represent a real change in the nature of NA...