Title: Why are GCMs bad at simulating the MJO?

Abstract: Most General Circulation Models still have difficulties to simulate realistic Madden-Julian Oscillation events. Two leading hypotheses have been proposed to explain this widespread deficiency. The first one posits that the GCMs do not simulate a realistic vertical profile of diabatic heating associated with clouds and cloud envelopes. The second hypothesis considers that the GCMs are unable to simulate the large-scale, spatial organisation of convection necessary to initiate an MJO event because their parametrisations of convection lack the sub-grid and inter-grid processes that are essential to its development. The presentation will present studies that address questions inspired by these hypotheses: how do diabatic-heating profiles simulated by GCMs compare to observations? On what scales should we expect convection to organise?

Speaker Information


Gilles Bellon


Senior Lecturer




University of Auckland


Yannick Peings

Date and Time: 

Wednesday, January 23, 2019 - 3:00pm


The Jenkins Room | Croul Hall 3101