Analytical model of equatorial waves with CAPE and moisture closure

Abstract

The convective available potential energy (CAPE) closure and the moisture closure is implemented on an analytical linearized model for large-scale motions. The model includes cloud-radiation interaction (CRI), gross moist stability and wind-induced surface heat exchange (WISHE). The model is done in an equatorial non-rotating atmosphere and is vertically resolved.

As the gravity waves in non-rotating atmosphere map to Kelvin waves in rotating atmosphere, the modeled modes are fast Kelvin waves that resemble adiabatic modes, convectively coupled Kelvin modes that are damped and move with the observed phase speed of 17 ms–1 and the unstable slow moisture mode. The slow moisture mode owes its propagation speed to WISHE and instability to CRI and gross moist instability. It is thought that it can be related to the easterly waves and perhaps even the Madden-Julian oscillation (MJO).