Sea Surface Temperature Anomalies off Baja California: A Possible Precursor of ENSO
Sea Surface Temperature Anomalies off Baja California: A Possible Precursor of ENSO
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DOI：
10.1175/jas-d-13-0397.1
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发表时间：
2014-04
影响因子：
3.1
通讯作者：
Jiaxin Feng;Zhaohua Wu;X. Zou
中科院分区：
文献类型：
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作者：
Jiaxin Feng;Zhaohua Wu;X. Zou
近年来的许多研究表明，观测到的厄尔尼诺-南方涛动（ENSO）事件具有空间和时间上的多样性，并经历了特征的变化。为了定量捕捉这些特征，采用多维系综经验模态分解（MEEMD）分离自然分离时间尺度上海温异常的时空演变。另外还定义了一个可选的尼诺-3.4指数，以更多地反映赤道太平洋海温的年际变化。利用这一替代指数，确定了27个ENSO暖事件，并分析了每个事件的时空演变。研究发现，加利福尼亚下海海温区在1年左右向西南方向扩展，到达赤道附近的国际日期变更线。这个温暖信号随后放大并向东延伸，发展成为ENSO温暖事件。近几十年来，这种类型的发展一直占主导地位。对于这类……
AbstractMany recent studies have shown that observed El Nino–Southern Oscillation (ENSO) events are spatially and temporally diverse and that they have undergone changes in characteristics. To quantitatively capture these features, multidimensional ensemble empirical mode decomposition (MEEMD) is employed to isolate the temporal–spatial evolution of the sea surface temperature anomalies (SSTAs) on naturally separated time scales. An alternative Nino-3.4 index is also defined to reflect more on the interannual variability of equatorial Pacific SSTAs. Using this alternative index, 27 ENSO warm events are identified and the spatial–temporal evolution of each event is examined. It is found that a patch of SSTAs off Baja California appears to extend southwestward and reach the equatorial region near the international date line in about 1 year. This warm signal then amplifies and extends eastward, developing into an ENSO warm event. This type of development has been dominant in recent decades. For this type of ...