La Niña Modoki impacts Australia autumn rainfall variability
La Niña Modoki impacts Australia autumn rainfall variability
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DOI：
10.1029/2009gl037885
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发表时间：
2009-06
影响因子：
5.2
通讯作者：
Wenju Cai;T. Cowan
中科院分区：
文献类型：
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作者：
Wenju Cai;T. Cowan
厄尔尼诺-南方涛动（ENSO）和ENSO Modoki都影响澳大利亚的降雨，但它们影响的共性和对比尚未得到充分探讨。我们发现，这两种类型都具有强烈的不对称性之间的影响，拉尼娜和厄尔尼诺在南方秋季（3月至5月）;拉尼娜澳大利亚降雨遥相关是统计上显着的，而厄尔尼诺澳大利亚降雨的关系是没有。日界线附近的拉尼娜·莫多基冷异常有效地将对流向西转移，导致澳大利亚西北部的秋季降雨量增加，并延伸到默里-达令盆地（Murray‐Darling Basin）的北方，而不是像传统的拉尼娜那样在东部。在厄尔尼诺莫多基期间，澳大利亚降雨量减少的趋势要弱得多。这种不对称性解释了ENSO之间降水异常的强烈变化，包括1983年，当时强烈的厄尔尼诺残留与潮湿的秋季有关。我们的研究结果强调了在预测ENSO的影响时考虑La Niña Modoki的影响的重要性。
Both El Niño‐Southern Oscillation (ENSO) and ENSO Modoki affect Australian rainfall but the commonalities and contrasts of their impacts have not been fully explored. We show that both types feature a strong asymmetry between impacts of La Niña and El Niño in austral autumn (March–May); the La Niña‐Australian rainfall teleconnection is statistically significant, whereas the El Niño‐Australian rainfall relationship is not. A La Niña Modoki cold anomaly near the Dateline is effective in shifting convection westward, causing an autumn rainfall increase over northwestern Australia extending to the northern Murray‐Darling Basin, rather than over the east as in a conventional La Niña. During an El Niño Modoki, the tendency for lower Australian rainfall is far weaker. The asymmetry explains the strong inter‐ENSO variations in rainfall anomalies, including 1983, when a strong El Niño residual was associated with a wet autumn. Our results highlight the importance of considering the influence from La Niña Modoki in predicting ENSO's impacts.