Moist thermodynamics of Madden Julian Oscillation in a high resolution regional model

The moist thermodynamic processes that sustain the Madden Julian Oscillation and provide it with its characteristic timescale are investigated using moisture and eddy available potential energy budget analyses on a cloud resolving WRF simulation. The model realistically simulates the two MJO episodes observed during the winter of 2007-2008. The various moistening and drying processes involved in determining the timescale of the low-frequency variability in the model are evaluated. The roles of various types of clouds in creating instability and damping during the lifecycle of the MJO are identified. The implications of these results for improving the representation of the interactions between convective systems and their environment in low-resolution models are discussed.