The Madden-Julian Oscillation

A tropical channel model was constructed to study thelong-standing problem of the initiation of theMadden-Julian Oscillation (MJO). Two MJO cases werestudied through numerous sensitivity tests. Thesetests demonstrated that the simulated MJO initiationwas critically dependent on the time dependentlateral boundary conditions from the reanalysis. Themechanisms of extratropical influences were furtherexplored which showed the importance of momentumtransport at the lower troposphere and waveactivities at the upper troposphere. The dynamics ofthe MJO and its dependence on the mean state werealso studied using multi-year simulation of a nestedregional climate model. In short this study hasshown that the extratropical influences can be anefficient mechanism for the MJO initiation and callsfor further research attention to this mechanism thathas been somewhat neglected by mainstream MJOresearch. This work should be useful to researchersin tropical dynamics and thermodynamics and numericalmodeling. It would also be helpful to students whoare studying Meteorology Atmospheric Sciences orPhysical Oceanography.