Abstract/Summary

Since its discovery in the early 1970s, the crucial role of the Madden-Julian Oscillation (MJO) in the global hydrological cycle and its tremendous influence of high-impact climate and weather extremes have been well recognised. The MJO also serves as a primary source of predictability for global Earth system variability on subseasonal time scales. The MJO remains poorly represeted in our state-of-the-art climate and weather forecasting models, however. Moreover, despite the advances made in recent decades, theories for the MJO still disagree at a fundamental level. The problems of understanding and modeling the MJO have attracted significant interest from the research community. As part of the AGU's Centennial collection, this article provides a review of recent progress, particularly over the last decade, in observational, modeling and theoretical study of the MJO. A brief outlook for near-future MJO research directions is also provided.