A New Type of the Indian Ocean Dipole since the Mid-1970s
A New Type of the Indian Ocean Dipole since the Mid-1970s
复制标题
20世纪70年代中期以来的新型印度洋偶极子
DOI：
10.1175/jcli-d-12-00047.1
复制
发表时间：
2013-02-01
影响因子：
4.9
通讯作者：
Wu, Yanling
中科院分区：
文献类型：
--
作者：
Du, Yan;Cai, Wenju;Wu, Yanling
热带印度洋偶极子/纬向模(IOD)与南半球的冬春季节是位相锁定的。这项研究描述了三种类型的IOD，它们的峰值时间和持续时间。特别是，作者重点研究了一种新的IOD类型，它在5-6月发育，在7-8月成熟，与典型的IOD截然不同，典型的IOD可能发展较晚，在9-11月达到峰值，或持续到6-11月。这种不合时宜的IOD事件只在1970年代中期才被观察到，在那之后热带印度洋与太平洋的关系更密切。不合时宜的IOD是印度洋的一种固有模式，不会出现随之而来的厄尔尼诺现象。赤道风的变化被认为是一种主要的强迫。风的变化反过来又与南半球冬季印度洋区域的沃克环流减弱有关，这在一定程度上是由于印度洋迅速变暖所致。因此，尽管不合时宜的IOD的发生可能会...
AbstractThe tropical Indian Ocean dipole/zonal mode (IOD) is phase locked with the austral winter and spring seasons. This study describes three types of the IOD in terms of their peak time and duration. In particular, the authors focus on a new type that develops in May–June and matures in July–August, which is distinctively different from the canonical IOD, which may develop later and peak in September–November or persist from June to November. Such “unseasonable” IOD events are only observed since the mid-1970s, a period after which the tropical Indian Ocean has a closer relationship with the Pacific Ocean. The unseasonable IOD is an intrinsic mode of the Indian Ocean and occurs without an ensuing El Nino. A change in winds along the equator is identified as a major forcing. The wind change is in turn related to a weakening Walker circulation in the Indian Ocean sector in austral winter, which is in part forced by the rapid Indian Ocean warming. Thus, although the occurrence of the unseasonable IOD may...