Some Hindcast Simulations of the MJO: Surprising Sensitivities to the Treatement of Surface Fluxes Under Light Winds

A series of hindcast simulations of the MJO were performed using a superparameterized version of the global WRF model. Results show strong sensitivity to the treatment of surface heat fluxes under light wind conditions. In particular, the simulated MJO is seen to become more pronounced as the amplitude of the parameterized "gustiness" effect is increased, so that convection can more easily be sustained near the equator, where 10-m wind speeds are typically weakest.