Abstract/Summary

This chapter describes the characteristics and sub-seasonal prediction of the Madden-Julian Oscillation (MJO), the dominant mode of intraseasonal variability in the tropical climate system and as such, a major source of predictability on sub-seasonal timescales. It describes the observed convective signal and circulation of the MJO and its global impacts on the weather; summarizes theories for its maintenance and propagation and the ability of weather and climate models to simulate the MJO; and reviews current operational skill for MJO prediction. The chapter concludes by identifying some outstanding questions in MJO research of relevance to sub-seasonal prediction.