Model output of: Excitation of an MJO event in response to a transient sea surface warming in Super-Parameterized CAM

Recent studies have suggested that the Madden-Julian Oscillation (MJO)
could be generated in the atmospheric adjustment to equatorial heating
anomalies in models properly resolving moist convection. Here we use
Super-Parameterized CAM to simulate atmospheric response to transient sea
surface warming in the equatorial Indian Ocean, which leads to the
excitation of an MJO event, robust across different ensemble members, in
addition to the much-expected equatorial Rossby and Kelvin waves. A moist
static energy (MSE) budget analysis suggests that longwave and surface
turbulent latent heat flux anomalies are predominantly responsible for the
MJO excitation; however, these terms oppose its eastward propagation. In
contrast, advection of MSE generally weakens the MJO amplitude, but
contributes to its eastward propagation. These results highlight the role
of the MJO in the moist atmospheric adjustment to equatorial heating, with
implications for the MJO mechanisms and prediction.