Intensification of Westerly Wind Bursts Caused by the Coupling of the Madden‐Julian Oscillation to SST During El Niño Onset and Development
Intensification of Westerly Wind Bursts Caused by the Coupling of the Madden‐Julian Oscillation to SST During El Niño Onset and Development
复制标题
厄尔尼诺现象发生和发展过程中马登-朱利安振荡与海温耦合引起的西风爆发加剧
DOI：
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发表时间：
2021
影响因子：
5.2
通讯作者：
P. Haertel
中科院分区：
文献类型：
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作者：
Y. Liang;A. Fedorov;P. Haertel
马登-朱利安振荡（MJO）在厄尔尼诺动力学中起着重要作用，与赤道太平洋发生的西风爆发（WWBs）有关;然而，我们对这些气候现象之间的关系的理解仍然不完整。在这里，我们使用拉格朗日大气模型（LAM）来研究MJO和由此产生的WWBs对海表温度（SST）异常的响应，这些异常与厄尔尼诺发生和发展期间观察到的异常相似。我们发现，当12月至4月在赤道太平洋中西部施加局部SST异常（≤1°C）时（模拟厄尔尼诺爆发），MJO对流包络线从南半球向赤道移动。当5月至11月赤道太平洋中东部出现海温异常（≤1.5°C）（模拟厄尔尼诺发展）时，MJO在西北太平洋减弱，但在赤道太平洋中部增强。在这两个实验中，随之而来的变化增强MJO活动沿着赤道，促进WWB。
The Madden‐Julian Oscillation (MJO) plays an important role in El Niño dynamics in connection with westerly wind bursts (WWBs) that occur in the equatorial Pacific; however, our understanding of the relationship between these climate phenomena remains incomplete. Here, we use a Lagrangian Atmospheric Model (LAM) to examine the response of the MJO and resulting WWBs to sea surface temperature (SST) anomalies similar to those observed during the onset and development of El Niño. We find that when a localized SST anomaly (≤1°C) is imposed in the western‐central equatorial Pacific between December and April (mimicking El Niño onset), the MJO convective envelope shifts from the southern hemisphere toward the equator. When an SST anomaly (≤1.5°C) is imposed in the central‐eastern equatorial Pacific between May and November (mimicking El Niño development), the MJO weakens in the northwestern Pacific, but strengthens in the central equatorial Pacific. In both experiments, the ensuing changes enhance MJO activity along the equator, facilitating WWBs.