Diversity of the MJO since 1974 compared with events during TOGA COARE and CINDY/DYNAMO

As reported by several recent studies, the convective envelopes that made up the MJO and “MJO-like” events during the CINDY/DYNAMO field campaign were characterized by a wide variety of disturbances. This diversity is not only evident between events, but also within an individual event as it evolves. Three independent techniques to assess the scale and type of disturbances within the MJO are applied to the DYNAMO period and compared with results from TOGA COARE and the historical record of OLR and higher resolution brightness temperature satellite metrics. One approach uses a tracking algorithm that is particularly well-suited to providing a “census” of mesoscale convective complexes. This can also be adapted to track convectively-coupled equatorial waves (CCEWs) using suitably filtered data. The other technique utilizes a spatio-temporal wavelet transform that can quantify the contribution of CCEWs across an individual MJO envelope. A third technique measures the variance of various CCEWs within a given MJO event. Initial results reveal that, while there is a tendency for some systematic organization of CCEWs and mesoscale systems across the MJO, the enormous range of scales involved from one event to another during DYNAMO is quite typical of the historical record.