Hong Chi-Cherng, Hsu Huang-Hsiung, Tseng Wan-Ling, Lee Ming-Ying, Chow Chun-Hoe, Jiang Li-Chiang
Department of Earth and Life, University of Taipei, Taipei, Taiwan.
Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan.
Sci Rep. 2017 Apr 24;7:46692. doi: 10.1038/srep46692.
In this paper, we report the triggering effect of extratropical perturbation on the onset of an atypical Madden-Julian Oscillation (MJO) and onset of the 2015-16 El Niño in March 2015. The MJO exhibited several unique characteristics: the effect of extratropical forcing, atypical genesis location and timing in the equatorial western Pacific, and the extremity of amplitudes in many aspects. The southward-penetrating northerly associated with the extratropical disturbances in the extratropical western North Pacific contributed to triggering the deep convection and westerly wind burst (WWB) and onset of the MJO over the anomalously warm tropical western Pacific in early March. The persisting strong WWB forced downwelling Kelvin wave-like oceanic perturbation that propagated eastward and led to the onset of the 2015-16 El Niño. The proposed novel extratropical forcing mechanism explaining the unique extratropics-MJO-El Niño association, based on both data diagnostics and numerical experiments, warrants further attention for a more detailed understanding of the onset of the MJO and its potential effect on El Niño.
在本文中，我们报告了温带扰动对2015年3月一次非典型马登-朱利安振荡（MJO）的爆发以及2015 - 16年厄尔尼诺现象爆发的触发作用。此次MJO表现出几个独特特征：温带强迫作用、在赤道西太平洋非典型的生成位置和时间，以及在许多方面的振幅极值。与北太平洋西部温带扰动相关的向南穿透的北风促成了3月初热带西太平洋异常温暖区域深厚对流、西风爆发（WWB）以及MJO的爆发。持续强烈的WWB迫使类似开尔文波的下沉海洋扰动向东传播，导致了2015 - 16年厄尔尼诺现象的爆发。基于数据诊断和数值实验提出的解释温带 - MJO - 厄尔尼诺独特关联的新型温带强迫机制，值得进一步关注，以便更详细地了解MJO的爆发及其对厄尔尼诺的潜在影响。
