Towards a climatology of fast and slow Madden-Julian Oscillation events

Satellite observations show that convective events located in the Madden-Julian Oscillation (MJO) region of the wavenumber-frequency domain have a range of eastward phase speeds. Some events have eastward phase speeds lower than 4 m/s. This presentation will show where and during what seasons fast and slow MJO events tend to occur. Then, a composite analysis of a few remotely-sensed and reanalysis atmospheric and oceanic variables will show what background conditions are associated with fast and slow MJO events and how several dynamical fields evolve during fast and slow MJO events. Similarities and differences will be highlighted to begin an understanding of what environmental processes influence MJO phase speed.