Barrier for the Eastward Propagation of Madden‐Julian Oscillation Over the Maritime Continent: A Possible New Mechanism
Barrier for the Eastward Propagation of Madden‐Julian Oscillation Over the Maritime Continent: A Possible New Mechanism
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DOI：
10.1029/2020gl090211
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发表时间：
2020-10
影响因子：
5.2
通讯作者：
Lei Zhang;W. Han
中科院分区：
文献类型：
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作者：
Lei Zhang;W. Han
马登-朱利安振荡（MJO）是热带对流层季节内的主要变率。许多MJO起源于热带印度洋，并通过海洋大陆（MC）传播到太平洋。然而，30-50%的MJO在MC上失速，而其原因尚不清楚。在这里，我们发现，一个新的跨流域耦合现象被称为“暖池偶极子”（WPD），这是与在印度洋东南部和热带太平洋中西部的异相海表温度异常（SSTA），可能在控制MJO传播的重要作用。在正WPD期间，约67%的MJO在MC上停滞，而在其负相位期间没有停滞。正是世界和平与发展两极的SSTA共同产生了这些影响。结果是强大的跨数据集的差异和模型实验的支持，虽然小的观测样本量限制了他们的统计意义。
The Madden‐Julian Oscillation (MJO) is the dominant intraseasonal variability of the tropical troposphere. Many MJOs originate from the tropical Indian Ocean and propagate into the Pacific via the Maritime Continent (MC). However, 30–50% of the MJO stalls over the MC, while its cause remains unclear. Here, we find that a new interbasin coupled phenomenon dubbed “Warm Pool Dipole” (WPD), which is associated with out‐of‐phase sea surface temperature anomalies (SSTAs) in the southeast Indian Ocean and the western central tropical Pacific, may play an important role in controlling the MJO propagation. During the positive WPD, ~67% of the MJO is stalled over the MC, whereas none is stalled during its negative phase. It is the SSTAs at both poles of the WPD together that produce these effects. The results are robust to cross–data set differences and supported by model experiments, although the small observational sample size limits their level of statistical significance.