Global Atmospheric Oscillation: An Integrity of ENSO and Extratropical Teleconnections
Global Atmospheric Oscillation: An Integrity of ENSO and Extratropical Teleconnections
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DOI：
10.1007/s00024-019-02182-8
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发表时间：
2019-04
影响因子：
2
通讯作者：
I. Serykh;Dmitry M. Sonechkin;V. Byshev;V. Neiman;Yu. A. Romanov
中科院分区：
文献类型：
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作者：
I. Serykh;Dmitry M. Sonechkin;V. Byshev;V. Neiman;Yu. A. Romanov
许多研究人员已经认识到厄尔尼诺-南方涛动（ENSO）事件与全球气候系统中的一些其他过程之间的远距离遥相关，这些过程通常发生在远离太平洋赤道带的地区。在本文中，我们研究了类似的联系之间的ENSO和outtratrophic过程采取在他们的整个集合。为此，我们计算了自十九世纪末至二十一世纪初观测到的与厄尔尼诺或拉尼娜事件相对应的海平面气压和近地面空气（海面）温度全球场之间的差异。结果表明，ENSO与北大西洋涛动（NAO）、北极涛动（AO）、北方半球环形（NHA）模态和太平洋-北美（PNA）模态等热带外遥相关以及它们在南半球的类似模态在年际尺度上存在着完整的联系。我们将这种完整性命名为全球大气振荡（GAO），定义了两个代表性的GAO指数，并研究了这些指数的时间动态。研究表明，不管ENSO如何，GAO的大气外成分可能是真实的，而ENSO在所有情况下都伴随着GAO。另外，由于高纬涛动的空间结构总体上是向东传播的，因此，在厄尔尼诺（La Niña）形成之前，高纬涛动的一些非热带分量就已经表现出了特征的变化。利用这些特征作为即将到来的ENSO演变的指纹，我们定义了另一个GAO指数的厄尔尼诺预测的提前时间约为1年。最后，我们建立了一些CMIP 5模型复制GAO合理。
Many researchers have recognized the long distance teleconnections between El Niño–Southern Oscillation (ENSO) events and some other processes in the global climate system happening in areas often very far from the equatorial zone of the Pacific Ocean. In this paper we investigate similar links between ENSO and extratropical processes taken in their whole set. For this goal we compute differences between the sea-level pressure and the near-surface air (sea surface) temperature global fields which correspond to either El Niño or La Niña events observed since the end of the XIX century and up to the beginning of the XXI century. As a result, we establish that an integrity exists of ENSO and the extratropical teleconnections such as North Atlantic Oscillation (NAO), Arctic Oscillation (AO), the Northern Hemisphere annular (NHA) mode as well as the Pacific–North American (PNA) pattern, and their analogs in the Southern Hemisphere in the interannual timescale. Named this integrity the Global Atmospheric Oscillation (GAO), we define two representative indices of GAO, and investigate the temporal dynamics of these indices. This investigation reveals that GAO’s extratropical components may be real irrespective of ENSO while the latter accompanies GAO in all cases. Moreover, in view of a general eastward propagation of the GAO as a spatial structure, some its extratropical components show changes of their features prior the El Niño (La Niña) begins to form. Using these features as fingerprints of the forthcoming evolution of ENSO, we define another GAO index for the El Niño prediction with the lead-time of about 1 year. At last, we establish that some of the CMIP5-models reproduce GAO reasonably well.