Contribution of tropical cyclone for the preconditioning of the Madden-Julian Oscillation during CINDY2011

During the international field experiment "Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011 (CINDY2011)", three Madden-Julian Oscillation (MJO) were generated over the Indian Ocean. In this study, the preconditioning process of the third MJO is investigated. After the second active phase of MJO reached maritime continent in early December 2011, its eastward propagation became unclear. Different convections were activated over the maritime continent in mid-December and third MJO was generated in late December over the Indian Ocean. During the preconditioning stage of the third MJO, westward propagating disturbances were observed from Sumatera Island to the central Indian Ocean and moistened the atmosphere. Convections over the Sumatera Island were activated from December 15th when the moist air mass reached from South China Sea. The origin of the moist air mass was tropical cyclone which was formed in South China Sea in December 10th. The high moisture associated with tropical cyclone activated the convection over Sumatera Island, promoted westward propagating disturbances, and acted a favorable environment for the preconditioning of the MJO.