Effects of Air–Sea Coupling on the Simulation of DYNAMO MJO Events

The effect of air-sea coupling on the simulation of DYNAMO MJO events is tested in this study using the Unified Wave Interface Coupled Model (UWIN-CM). In UWIN-CM, the Weather Research and Forecasting model atmosphere is coupled to the Hybrid Coordinate Ocean Model. The domain is set over the Indian Ocean with a 4km spatial resolution in the inner-most domain of the atmosphere and ocean resolution of 0.08°. The freely-coupled simulation of the MJO events is compared to an uncoupled simulation of the MJO events where the atmospheric model is forced with the sea surface temperature (SST) from the coupled simulation. The relationships between SST, latent heat flux, and rainfall will be discussed, emphasizing lag-lead relationships and their influence on MJO propagation, amplitude, and coupled feedbacks. Observational estimates from DYNAMO, reanalysis products and satellite based data will be used to validate model diagnosed relationships.