Understanding the impacts of the Indonesian Throughflow (ITF) on the eastward propagation of the Madden-Julian Oscillation (MJO) is crucial for accurately simulating the MJO and achieving high-skill sub-seasonal predictions. Our analyses demonstrate a significant enhancement of MJO eastward propagation due to the strong ITF. Blocking the ITF decreases the eastward sea surface temperature (SST) gradient over the tropical Indian Ocean, hindering MJO propagation across the Maritime Continent (MC). Removing the MJO circulation-induced intraseasonal variability of the ITF transport also weakens the eastward propagation of the MJO, as the MJO easterly winds enhance the ITF transport and warm the eastern tropical Indian Ocean. These experiments reveal that mean and intraseasonal variability of the ITF transport contribute to 73% and 42% of the eastward propagation of the MJO over the MC, respectively. The findings presented in this study highlight the significant role of the ITF in shaping the propagation of the MJO.

了解印度尼西亚通流 （ITF） 对 Madden-Julian 振荡 （MJO） 向东传播的影响对于准确模拟 MJO 和实现高技能的子季节预测至关重要。我们的分析表明，由于强大的 ITF，MJO 向东传播显着增强。阻塞 ITF 会降低热带印度洋向东的海面温度 （SST） 梯度，阻碍 MJO 在海洋大陆 （MC） 的传播。消除 MJO 环流诱导的 ITF 运输的季节内变化也削弱了 MJO 的东向传播，因为 MJO 东风增强了 ITF 运输并温暖了东部热带印度洋。这些实验表明，ITF 传输的均值和季节内变率分别贡献了 MJO 在 MC 上向东传播的 73% 和 42%。本研究中提出的研究结果强调了 ITF 在塑造 MJO 传播中的重要作用。