Progress and status of MJO simulation in climate models and process-oriented diagnostics

Abstract

Despite its tremendous influence on extreme weather worldwide, realistic simulations of the Madden-Julian oscillation (MJO) have been a grand challenge for global climate models. In the first part of this chapter, a brief overview of recent advances in modeling the MJO is provided by particularly highlighting improved MJO simulations achieved through implementations of stochastic cumulus approaches. In the second part, the most recent community efforts in the development of process-oriented diagnostics and metrics for MJO simulations are briefly reviewed. These diagnostics and metrics have been built upon the process understanding of key MJO physics, providing important guidance to expose critical model deficiencies in simulating the MJO. These processes include convective sensitivity to environment moisture, convection-circulation interactions, cloud-radiation feedbacks, and large-scale control (e.g., the lower-tropospheric mean moisture pattern).