Seasonal predictability of ENSO teleconnections: the role of the remote ocean response
Seasonal predictability of ENSO teleconnections: the role of the remote ocean response
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DOI：
10.1007/s00382-004-0393-1
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发表时间：
2004-05-01
期刊：
影响因子：
4.6
通讯作者：
Davey, MK
中科院分区：
文献类型：
--
作者：
Spencer, H;Slingo, JM;Davey, MK
在这项模拟研究中，厄尔尼诺现象的遥相关研究使用大气环流模式（AGCM），HadAM 3。研究了远离热带太平洋但与ENSO遥相关的海表温度异常的影响。厄尔尼诺和拉尼娜SST的复合周期被创建并施加在HadAM 3上。这些SST被施加在不同的地区，气候SST在其他地方，以找到不同地区的SST的影响。结果表明，ENSO的大部分可重复响应是在ENSO事件高峰前直接来自热带太平洋的强迫。然而，在ENSO的峰值和衰减期间，远程SST在整个热带地区变得越来越有影响力（在98%的显著性水平上）。由于遥远海洋的记忆，这可能导致扩大与厄尔尼诺/南方涛动有关的可预测性。印度洋和海洋大陆的SST被认为是特别有影响力的。印度洋海温异常减弱了热带太平洋的遥相关，并迫使热带大西洋上空的大气。更一般地说，当热带海温异常被强加时，大气异常被强迫局部与西方相反的异常。热带大西洋对ENSO的一些可再现的响应不是直接来自热带太平洋，而是来自印度洋，而印度洋又受到热带太平洋的强迫。随后，热带大西洋的延迟海温异常抑制了当地的响应，并以相反的方式迫使热带太平洋上空的大气。
In this modelling study, the teleconnections of ENSO are studied using an atmospheric general circulation model (AGCM), HadAM3. The influence of sea surface temperature anomalies (SSTAs) remote from the tropical Pacific but teleconnected with ENSO is investigated. Composite cycles of El Nino and La Nina SSTs are created and imposed on HadAM3. These SSTs are imposed in different areas, with climatological SSTs elsewhere, in order to find the influences of SSTs in different regions. It is found that most of the reproducible response to ENSO is forced directly from the tropical Pacific before the peak of the event. However, during the peak and decay of ENSO, remote SSTs become increasingly influential throughout the tropics (at the 98% significance level). This could lead to extended ENSO-related predictability due to the memory of the remote oceans. The Indian Ocean and Maritime Continent SSTs are found to be particularly influential. Indian Ocean SSTAs dampen the teleconnections from the tropical Pacific and force the atmosphere above the tropical Atlantic. More generally, when a tropical SSTA is imposed, atmospheric anomalies are forced locally with anomalies of the opposite sign to the west. Some of the reproducible response to ENSO in the tropical Atlantic is forced, not directly from the tropical Pacific but from the Indian ocean, which in turn is forced by the tropical Pacific. Subsequently, delayed SSTAs in the tropical Atlantic damp the local response and force the atmosphere above the tropical Pacific in the opposite manner.