In the tropical Pacific and Indian Oceans, unique and obvious atmosphere-ocean coupled phenomena with various timescale are observed. In particular, the El Nino, the Indian Ocean dipole mode phenomenon, the monsoons, and the Madden-Julian Oscillation - the major tropical ocean/atmosphere variations - are all mutually interrelated, and have great impact on global weather and short term climate change, hence affect human life and economic activities. This Program studies these phenomena and their interactions and contributes to the improvement of their predictability. Specifically, the Program aims to reveal the mechanisms of fluctuation in El Nino and the dipole mode phenomenon based on an observation network of moored buoys. In the Western Pacific and Indian Ocean, including the Indonesian and Indochina regions, the Program aims to construct high-precision observation networks of the ocean, atmosphere and land, and to reveal the water cycling mechanism related to the monsoons, from diurnal to annual variability, as well as the mechanism of the Madden-Julian Oscillation and its effects.