A New Model of the Madden–Julian Oscillation

David J. Raymond
2001 Journal of the Atmospheric Sciences  
A new model of the Madden-Julian oscillation (MJO) is presented. Cloudradiation interactions in this model make the tropical atmosphere susceptible to large-scale radiative-convective overturning. The modeled MJO takes the form of such an instability, though its behavior is substantially modified by the effects of surface heat flux variability. The dynamics of the disturbance in the model are quasi-balanced, in the sense that the low-level flow in the disturbance is more associated with the
more » ... ciated with the vorticity than with the divergence. The cumulus parameterization used in the model allows a lag of several days to exist between the strongest surface heat flux into a column and the development of heavy precipitation in that column. This lag plays a key role in model dynamics. 6 References Betts, A. K., 1986: A new convective adjustment scheme. Part I: Observational and theoretical basis. Quart. J. Roy. Meteor. Soc., 112, 677-691. Betts, A. K., and M. J. Miller, 1986: A new convective adjustment scheme. Part II: Single column tests using GATE wave, BOMEX, ATEX and arctic air-mass data sets. Quart. J. Roy. Meteor. Soc., 112, 693-709.
doi:10.1175/1520-0469(2001)058<2807:anmotm>2.0.co;2 fatcat:774jp7zmxvgsdb2j3lemtzbtzi