The MJO Impact on Daily Precipitation in Indonesia During 1981-2012

Abstract:

The Madden-Julian Oscillation (MJO) is the dominant mode of intraseasonal variability of rainfall in Indonesia, particularly during the rainy season, but its signal is often obscured in individual station data, where effects are most directly felt at the local level. The characteristic of the MJO during its propagation through the Maritime Continent has always been a challenge to comprehend despite decades of research attempts in that region. The impact of MJO on daily precipitation during the rainy season (October to April) extremes in Indonesia has been evaluated using 86 daily station rain gauge data from 1981 - 2012.

The results suggest a strong impact of MJO on rainfall in Indonesia were observed on phase 3 – 5, which confirm the previous studies. The highest positive precipitation anomalies were observed at phase 4 and 5 with >8 mm/day. While, the lowest negative precipitation anomalies were observed at phase 1 and 8 reaching 5 - 6 mm/day. Spatial analysis based on inland, coastline and high elevation stations were also conducted in this study.