Three evolution patterns of Central‐Pacific El Niño
Three evolution patterns of Central‐Pacific El Niño
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DOI：
10.1029/2010gl042810
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发表时间：
2010-04
影响因子：
5.2
通讯作者：
Jin‐Yi Yu;Seon Tae Kim
中科院分区：
文献类型：
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作者：
Jin‐Yi Yu;Seon Tae Kim
根据1958-2007年期间发生的事件，中太平洋（CP）型厄尔尼诺有三种演变模式：（1）对称衰减型，其海表温度异常相对于峰值相位对称增长和衰减;（2）长期衰减型，衰减缓慢，随后在东太平洋（EP）发生暖事件;以及（3）在峰值之后迅速终止并且随后是EP中的冷事件的突然衰减模式。赤道温跃层的深度被发现，以确定哪种演变模式发生。如果CP厄尔尼诺发生在一个重新充电的温跃层状态（即，在CP事件的衰减阶段可能会出现EP变暖，以减缓衰减，从而产生延长的衰减模式。如果温跃层处于排放状态（即，深度比正常深度浅），可能会发生EP冷却，突然终止CP厄尔尼诺。如果温跃层处于中性状态（即，正常深度），CP事件可能具有对称的增长和衰减模式。虽然存在少数例外情况，但这些结果表明，在CP厄尔尼诺事件的高峰阶段，赤道温跃层状态可能是该事件可能衰减方式的潜在预测因素。
Three evolution patterns are identified for the Central‐Pacific (CP) type of El Niño based on events that occurred during 1958–2007: (1) a symmetric‐decaying pattern whose sea surface temperature anomalies grow and decay symmetrically with respect to a peak phase; (2) a prolonged‐decaying pattern that decays slowly and is followed by a warm event in the eastern Pacific (EP); and (3) an abrupt‐decaying pattern that terminates rapidly after the peak and is followed by a cold event in the EP. The depth of the equatorial thermocline is found to determine which evolution pattern occurs. If the CP El Niño occurs in a recharged thermocline state (i.e., deeper‐than‐normal depth), an EP warming may appear in the decaying phase of the CP event to slow down the decay, giving rise to the prolonged‐decaying pattern. If the thermocline is in a discharged state (i.e., shallower‐than‐normal depth), an EP cooling may occur to abruptly terminate the CP El Niño. If the thermocline is in a neutral state (i.e., normal depth), the CP event may have a symmetric pattern of growth and decay. Although a few exceptions exist, these results indicate that the equatorial thermocline state at the peak phase of a CP El Niño event can be a potential predictor of the way the event may decay.