Moist Static Energy budget for Madden-Julian Oscillation like disturbances in Super-Parameterized CAM on an aquaplanet

The equatorial atmospheric variability shows a spectrum of significant peaks in the wave number-frequency domain. While most of these peaks have been identified with the equatorially trapped wave modes of rotating shallow water wave theory, The Madden-Julian Oscillation (MJO) appears as a very strong signal at zonal wave numbers 1--7 and periods of 30--100 days.

There have been attempts to understand the mechanisms of the MJO using convectively coupled-shallow water wave models where buoyancy drives the dynamics. These models have generally been inconclusive. This is consistent with the observation that the MJO power does not lie on any of the Matsuno dispersion curves. Recently, it has been suggested that the MJO is instead a "moisture mode" where the humidity is the driving field of the dynamics.

In order to investigate this hypothesis, we will present a Moist Static Energy budget and for the MJO-like signal in Super Parameterized CAM (SP-CAM) on an aquaplanet.