Impact of a modified convective scheme on the Madden-Julian Oscillation and El Nino-Southern Oscillation in a coupled climate model

The connection between the intraseasonal Madden-Julian Oscillation (MJO) and interannual El Nino-Southern Oscillation (ENSO) has been proposed and investigated for the last two decades. However, many fully coupled atmosphere-ocean general circulation models (GCMs) are still unable to simulate many important characteristics of these two phenomena partly due to the great uncertainty in the representation of subgrid-scale cloud systems. We report herein the simulation of an El Nino in a fully coupled GCM with a modified convection scheme, which captures many of the observed features of the 1997/1998 El Nino event. The representation of convection in the coupled model plays a major role in modeling both interannual ENSO and intraseasonal MJO variability in closer accord with observations, and in reproducing the evolution of 1997/1998 El Nino-type events.