The Indian Ocean Dipole/Zonal mode (IOD) is an interannual phenomenon over the tropical Indian Ocean, causing a pronounced impact worldwide. Here, we investigate the mechanism of the change in IOD characteristics in a CO₂ removal simulation for an earth system model (ESM). As the CO₂ concentration increases, the intensity of IOD tends to increase, but at high CO₂ concentrations, further increases decrease the IOD intensity. The minimum IOD amplitude was recorded during the early decrease in CO₂. First, we developed a conceptual model for IOD that is composed of local air-sea coupled feedback, delayed ocean dynamics, El Niño impact, and noise forcing. Then, by adopting ESM results into this simple IOD model, we revealed that the local air–sea coupled feedback is a major factor for changing IOD amplitude, while El Niño does not exert a change in IOD amplitude. The local air–sea coupled feedback including thermocline feedback, wind-evaporation feedback, and Ekman feedback is strongly modified by the air–sea coupling strength during progression of a global warming. Consequently, under the higher CO₂ concentrations, IOD amplitude is reduced due to the weakening of air-sea coupling over tropical Indian Ocean.

印度洋偶极子/纬向模式 (IOD) 是热带印度洋上空的一种年际现象，在全球范围内造成了显着影响。_{在这里，我们研究了地球系统模型 (ESM) 的 CO 2}去除模拟中 IOD 特性变化的机制。随着CO ₂浓度的增加，IOD 的强度趋于增加，但在高CO ₂浓度下，进一步增加会降低IOD 强度。_{在 CO 2}的早期下降过程中记录了最小 IOD 幅度. 首先，我们开发了一个 IOD 概念模型，该模型由局部海气耦合反馈、延迟海洋动力学、厄尔尼诺影响和噪声强迫组成。然后，通过将 ESM 结果应用到这个简单的 IOD 模型中，我们揭示了局部海气耦合反馈是 IOD 幅度变化的主要因素，而厄尔尼诺现象并没有影响 IOD 幅度的变化。包括温跃层反馈、风蒸发反馈和埃克曼反馈在内的局部海气耦合反馈在全球变暖进程中受到海气耦合强度的强烈影响。因此，在较高的CO ₂浓度下，由于热带印度洋上空海气耦合减弱，IOD 幅度降低。