Abstract

During the Asian winter Monsoon (November-March), most of the time the Indonesia Maritime Continent area has been covered by mostly deep convection cloud. During this t period, there would be a synoptic scale disturbance over Northwest of Borneo Island of the so called Borneo vortex.

The othe phenomenon of the so called Madden-Julian Oscillation (MJO) might be the same impact to the on deep convection over Indonesia Maritime Continent during Boreal Australian Summer. This study aims to study impact of interaction Borneo vortex and MJO (during MJO active period in phase 3, 4 and 5) and rainfall condition over the western part of Indonesia Maritime Continent using compositing technique in the period of November-March 2015/2016. The parameters used to identify the incidence of Borneo vortex, MJO, and its interaction is vertical velocity. When MJO is active, Borneo vortex occurs most often in phase 5 and at least in phase 3. However, Borneo vortex occurs most often when the MJO is inactive. The interaction between Borneo vortex and MJO seems may affect not so much rainfall occurrence in western part of IMC.