Vorticity budget of convectively coupled equatorial Rossby waves: propagation and growth mechanisms

Convectively coupled equatorial Rossby waves (CCERWs) are an intrinsic part of the spectrum of tropical weather systems, and can bring extreme precipitation to tropical locations. They are usually interpreted as modified versions of the theoretical dry equatorial Rossby wave solutions of the shallow water equations. However, the structure and dynamics of CCERWs are rather different to their theoretical cousins. Here, a vorticity budget is presented for both theoretical equatorial Rossby waves and for CCERWs (based on reanalysis data). The different strengths of the vorticity budget terms between the theoretical waves and CCERWs gives insights into CCERW propagation and growth mechanisms, and provides a focus and testbed for future model and forecast improvements.