The weather and climate over the Indian Ocean are influenced strongly by the ocean circulation in the Indian Ocean. The seasonal reversal of monsoon winds and concurrent ocean currents, presence of strong barrier layers, the relatively deep thermocline along the equator and many other ocean-atmosphere features make the Indian Ocean unique. The strong oceanic variability in the region shapes the Indian Ocean’s very dynamic role in the intraseasonal, seasonal, and interannual variability of the monsoons, as well as its air-sea interactions. Recent field experiments in the Bay of Bengal, Arabian Sea, Tropical Indian Ocean and over the Maritime Continent as well as related modeling efforts, have advanced our understanding of the Indian Ocean circulation and its role in Monsoon Intraseasonal Oscillations (MISO). Nonetheless, significant gaps remain in understanding, observing, modeling, and predicting Indian Ocean variability and change across a range of timescales. Understanding and reliable prediction of the initiation, propagation, strength, and variability of Monsoon Intraseasonal Oscillations (MISO) in tropical and sub-tropical Indian Ocean-atmosphere constitute building blocks of monsoon forecasting, which is crucial for ensuring water-supply reliability, socioeconomic wellbeing, and safety of nearly one billion inhabitants of the Indian subcontinent. This session invites contributions based on observations, modeling, and theory in the Indian Ocean that focus on understanding and predicting the links between Indian Ocean variability and monsoon systems on (intra)seasonal to interannual timescales, interactions and exchanges between the Indian Ocean and other ocean basins, decadal variability and its prediction, response to climate change and extreme events.