Madden-Julian Oscillation described as a Nonlinear Burgers Kink in the Meridional Vorticity Equation

Abstract: A dynamic equation for a large scale convective event in the tropical atmosphere similar to the Madden--Julian Oscillation (MJO) is suggested based on the meridional vorticity equation with buoyancy parametrized by Convective Available Potential Energy (CAPE). The propagation is determined by the nonlinear Burgers equation with a stationary solution describing a kink moving towards the moisture source. In this conceptual model, the propagation speed depends on the asymmetry in the zonal surface winds which is observed in the boundary layer in the vicinity of an MJO event and attributed to Rossby and Kelvin waves. Furthermore, the model predicts convection at the equator in the east of the MJO which is not correlated with Kelvin and Rossby waves.