MJO events can be subdivided into “small” and “big” events, as defined by the details of their OLR signatures. Big MJO events exhibit precursor signals and circulations that promote MJO initiation over a variety of Indian Ocean background states. Small MJO and ED events lack one or more of these precursor signals, but are frequently distinguished by their background upper ocean state: small MJO events are associated with downwelling oceanic Kelvin and equatorial Rossby waves (which promote SST warming), while ED events are associated with upwelling Rossby waves (which limit SST warming).
In this study I will explore the relative contributions of atmospheric circulations and ocean feedbacks to each type of event. I will also demonstrate how this kind of analysis can shed light on MJO events simulated by models.