Mode of precipitation variability generated by coupling of ENSO with seasonal cycle in the tropical Pacific.
Mode of precipitation variability generated by coupling of ENSO with seasonal cycle in the tropical Pacific.
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ENSO 与热带太平洋季节周期耦合产生的降水变化模式。
DOI：
10.1029/2021gl095204
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发表时间：
2021
影响因子：
5.2
通讯作者：
and F.-F. Jin
中科院分区：
文献类型：
--
作者：
Fukuda;Y.;M. Watanabe;and F.-F. Jin
赤道太平洋中部和东部的热带降水异常在极端厄尔尼诺现象的发展阶段和衰退期表现出非常不同的模式，尽管海洋表面温度异常的模式相似。利用1979-2018年的观测资料和大气模拟资料，我们确定了热带降水变率的一种经向偶极子模，称为太平洋降水偶极子模(PPDM)，它对极端厄尔尼诺相关的季节变化的降水型是至关重要的。我们用一个数值模式研究了PPDM的产生机制，发现赤道东太平洋暖SST波段的季节变化与极端SST异常相结合，导致PPDM位相反转。Ppdm可以看作是厄尔尼诺/南方涛动组合模式的不同表现形式，这也解释了极端厄尔尼诺事件对东亚地区的明显影响。
Tropical precipitation anomalies show very different patterns over the central‐eastern equatorial Pacific between the developing and decay phases of extreme El Niño despite similar patterns of sea surface temperature (SST) anomalies. Using observational data and atmospheric simulations for 1979–2018, we identified a meridional dipole mode of tropical precipitation variability, called the Pacific precipitation dipole mode (PPDM), which is critical for seasonally varying rainfall patterns related to extreme El Niño. We examined the mechanism of PPDM using a numerical model and found that the seasonal shift of the warm SST band in the eastern equatorial Pacific, when coupled with extreme SST anomalies, causes phase reversal of the PPDM. The PPDM can be regarded as a different manifestation of the El Niño/Southern Oscillation combination mode, as revealed by the surface wind anomalies, which also explains the distinct impact of extreme El Niño events over East Asia.