Wave/wave and atmosphere/ocean interaction in MJO initiation

The interactions between convectively coupled equatorial waves (Kelvin waves, mixed Rossby gravity waves and Rossby waves) and their influence on rapid development of CINDY/DYNAMO MJOs are examined using the TRMM precipitation wavelet analysis and COAMPS simulations. Precipitation analysis indicates the presence of eastward and westward propagating high frequency, short disturbances associated with the initiation of each MJO. The role of these perturbations is examined using the coupled COAMPS forecasts. Model simulations show the interaction between the Kelvin wave and mixed Rossby-gravity wave that leads to the rapid development of November MJO. It was found that the phase relationship between the waves is critical for this process. The Rossby modes that develop few days later trigger high winds, large equatorial surface fluxes and subsequent development of another Kelvin wave, while the MRG waves influence the signal propagation The effects on air –sea coupling on theses convectively coupled waves and their interaction, and subsequent development of MJO is examined.