Multiscale structure of the MJO events during the CINDY/DYNAMO field campaign

The multiscale structure of the MJO events during the CINDY/DYNAMO field campaign is explored taking advantage of a relatively novel analysis tool, called the spatio-temporal wavelet transform (STWT). The STWT is a two-dimensional version of the wavelet transform and is designed to document the instantaneous space-time power spectral characteristics of cloudiness, enabling us to effectively reveal the synoptic-scale building blocks of the MJO in terms of convectively coupled equatorial waves. The two MJO events that occurred in October and November exhibited some commonalities and differences in the multiscale structure. For example, westward inertia-gravity waves were pronounced in both MJOs, while a variety of CCEWs including Kelvin, mixed-Rossby gravity, and TD-type waves were also pronounced in the November MJO. The difference in the multiscale structure may account for the different impact of the MJO: tropical cyclone genesis was clearly seen in association with the November MJO. We hypothesize that better understanding of the multiscale structure and its diversity of the MJO lead to better understanding of not only the physics of the MJO but also the MJO's role in weather and climate. The case study results are quantitatively compared with other case study (TOGA COARE) and with statistical analysis.