Active and weakening MJO events in the Maritime Continent

Abstract To better understand the Madden–Julian Oscillation (MJO) in Maritime Continent (MC), events from 1980 to 2019 were classified as active or weakening according propagation characteristics and amplitude changes two leading indices, Real-time Multivariate MJO (RMM) index Outgoing Longwave Radiation (OLR) Index (OMI). Active had larger amplitudes than events, those differences appeared at day − 3 RMM 8 OMI remained through + 15 both indices (day 0 marked an event entered MC). Thus, stronger they approached crossed MC. environments between these composites of OLR specific humidity compared for each. consistently more negative anomalies greater boundary layer free troposphere events. Those persisted during easterly westerly phases Quasi-biennial (QBO) La Niña El Niño. QBO winds did winds. Finally, featured a diurnal cycle lower-tropospheric over land areas MC, amount atmospheric moisture available was ones. These results indicate that amplitude, OLR, tropospheric can all be important tools identifying including different Niño-Southern (ENSO).