Decadal Variation of the Indian Ocean Dipole

印度洋偶极子的年代际变化

基本信息

批准号：
17204040
负责人：
YAMAGATA Toshio
金额：
$ 26.79万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17204040/
关键词：
Indian Ocean Dipole Decadal Variation E1 Nino Southern Oscillation Indonesian Throughflow Mascarene High Agulhas Current Coupled GCM Tropical Indian Ocean

项目摘要

The processes that affect the decadal variation of the Indian Ocean Dipole (IOD) are investigated.1) Using outputs from a high-resolution coupled general circulation model (CGCM), decadal modulations of El Nino/Southern Oscillation (ENSO) is examined. Changes in the phase-locking nature of the ENSO to the seasonal cycle are shown to play an important role in the decadal modulation of the ENSO. This, in turn, modulates the heat transport by the Indonesian Throughflow, and thus the occurrence of the IOD.2) Heat budget analysis using the above model outputs has revealed that the occurrence of IOD events is governed by variations in the southward Ekman heat transport across 15°S, which is strongly linked with the Mascarene high activities.3) To understand the variability of the Agulhas Current, which influences the heat budget of the Indian Ocean, the interannual variation in the west coast of Africa is studied. It is found that the Angola Dome located in the above region undergoes significant interannual variations associated with the Atlantic Nino, which is a major climate mode in the tropical Atlantic.4) Since understanding of the past IOD is useful in understanding the current and future variability of the IOD, atmospheric general circulation model (AGCM) experiments with the permanent IOD and E1 Nino condition seen in Pliocene are conducted. The heat absorption from the atmosphere to the ocean in the tropics and the heat release from the ocean to the atmosphere in the mid-latitude are significantly reduced under this condition.

研究了影响印度洋偶极子（IOD）（IOD）的过程。1）使用高分辨率耦合一般循环模型（CGCM），El Nino/Southern振荡（ENSO）的衰老调制的输出。显示ENSO对季节周期的相锁定性质的变化在ENSO的十年调制中起着重要作用。反过来，这又可以调节印尼遍布的热量传输，从而调节了IOD的发生。2）使用上述模型输出的热预算分析表明，IOD事件的发生在跨越Ekman热量中的变化跨越15°s的变化来控制，这与MAGEANS高度的预算紧密相关。非洲西海岸的年际变化是研究的。发现位于上述区域的安哥拉圆顶经历了与大西洋尼诺（Nino）相关的显着年度变化，这是热带大西洋中的主要气候模式。在这种情况下，从大气到海洋的热量吸收到来自海洋到大气的热量释放。