Dynamical downscaling of diurnal convection around the Maritime Continent associated with MJO activity

The diurnal convection and precipitation around the Maritime Continent associated with MJO activity was simulated using the NCEP global ensemble forecast products. The maritime continent is one of the most active regions for the development of deep convection. Using satellite images, many studies have indicated that this convective activity has a notable diurnal cycle in most parts of the maritime continent. Diurnal migration of clouds toward the Indian Ocean is frequently observed, in particular around the island of Sumatra, and the amplitude of diurnal cycle was associated with MJO activity. Recently, many operational centers are attending the MJO forecasts activity using the dynamical global models with rough horizontal resolution over one degree. It should be suitable resolution for the prediction of synoptic phenomena such MJO, however, for the diurnal convection in regional scale, it is necessary to downscale these data to capture the interaction between the environmental field by MJO and the diurnal convection. The downscaled convection and precipitation tend to have large amplitude of diurnal cycle when the MJO activity was classified as strong by the MJO index. In the presentation, we will discuss the statistical intensity of the simulated diurnal precipitation, and will show the comparison with the field campaign data of Pre-YMC 2015.