Vertical Structure and Physical Processes of the MJO: A Global Model Evaluation Project

Given the central role of the diabatic heating for prevailing MJO theories and demands for reducing the model deficiencies in simulating the MJO, it is of great interest and urgent need to explore how the MJO vertical heating and moistening structures are represented in current GCMs. Through a collaborative effort between the Year of Tropical Convection (YOTC) / MJO Task Force and the GEWEX Global Atmospheric System Study (GASS), we have completed the initial stage of a model and observation intercomparison project on physical processes and vertical structure associated with the MJO. Based on this project, the diabatic heating and associated physical processes (i.e. all physical tendency terms for u, v, q, t) over the life cycle of the MJO have been explored in three experimental components: i) climatological simulations; ii) short-term / detailed-“physics” hindcasts, and iii) less-detailed but longer-lead hindcasts extending from ii); and with the hindcasts focusing on MJO events during the period of YOTC. This presentation will provide an overview of the initial results coming from the three different components of this study.