Zonal Asymmetry of Moist Static Energy Tendency and Madden-Julian Oscillation (MJO) Eastward Propagation in Climate Models

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Through improved model physics and initial conditions in past 50 years, weather can now be predicted reasonably well for up to 5 days. On the other hand, due to improved monitoring and understanding of El Nino dynamics in past 20-30 years, monthly or seasonal outlook skill is also in good progress. The extended-range (5-30-day) prediction is currently most difficult. The major predictability source in extended range is an atmospheric low-frequency mode named "Madden-Julian Oscillation (MJO)". However, current operational models have difficulty to predict this oscillation. This project will investigate the representations and couplings of fundamental dynamic and physical processes in 26 current state-of-the-art climate models to gain a understanding of why only about a quarter of these models are able to capture the observed spatiotemporal evolution characteristics of MJO while others cannot. This study combines observational data analysis, diagnosis of the 26 climate model outputs, and idealized numerical model experiments in which key dynamic/physical processes are isolated.The successful completion of this project would not only advance the knowledge of dynamics of the Madden-Julian Oscillation but also help identify problems in the current state-of-the-art operational weather prediction models and help improve the model representations of the atmospheric low-frequency oscillation and its associated teleconnection patterns. The improved capability of extended-range predictions would offer an avenue for bridging the gap between the short-range weather and long-term climate predictions and benefit economy and society for prevention of natural disasters and for government planning. This project supports a graduate student in the area of tropical large-scale dynamics and climate modeling.