Relative Contributions of the Indian Ocean and Local SST Anomalies to the Maintenance of the Western North Pacific Anomalous Anticyclone during the El Niño Decaying Summer
Relative Contributions of the Indian Ocean and Local SST Anomalies to the Maintenance of the Western North Pacific Anomalous Anticyclone during the El Niño Decaying Summer
复制标题
DOI：
10.1175/2010jcli3300.1
复制
发表时间：
2010-05
影响因子：
4.9
通讯作者：
Bo Wu;Tim Li;Tianjun Zhou
中科院分区：
文献类型：
--
作者：
Bo Wu;Tim Li;Tianjun Zhou
摘要为了研究在El Nino衰减的夏季，西北太平洋（WNP）或印度洋海盆模态（IOBM）的冷海温异常（SSTA）在维持西北太平洋（WNPAC）异常反气旋中的相对作用，利用大气环流模式ECHAM4进行了一系列数值试验。在敏感的实验中，厄尔尼诺综合海温在WNP或热带印度洋中指定，而气候海温在其他地方指定。结果表明，西北太平洋是由西北太平洋负海温的局地强迫和印度洋边界层的远程强迫共同作用维持的。前（后）贡献从6月到8月逐渐减弱（增强）。西北太平洋海温的负异常是西北太平洋在初夏维持的关键。然而，由于负的海气反馈，负的SSTA逐渐衰减，局地强迫效应。增强的局部对流伴随着……
Abstract To investigate the relative role of the cold SST anomaly (SSTA) in the western North Pacific (WNP) or Indian Ocean basin mode (IOBM) in maintaining an anomalous anticyclone over the western North Pacific (WNPAC) during the El Nino decaying summer, a suite of numerical experiments is performed using an atmospheric general circulation model, ECHAM4. In sensitive experiments, the El Nino composite SSTA is specified in either the WNP or the tropical Indian Ocean, while the climatological SST is specified elsewhere. The results indicate that the WNPAC is maintained by the combined effects of the local forcing of the negative SSTA in the WNP and the remote forcing from the IOBM. The former (latter) contribution gradually weakens (enhances) from June to August. The negative SSTA in the WNP is crucial for the maintenance of the WNPAC in early summer. However, because of a negative air–sea feedback, the negative SSTA gradually decays, as does the local forcing effect. Enhanced local convection associated ...