Convectively Coupled Equatorial Waves
George N. Kiladis, Matthew C. Wheeler, Patrick T. Haertel, Katherine H. Straub, Paul E. Roundy
2008: Rev. Geophys., Revised (accepted) version.
Abstract
Convectively coupled equatorial waves (CCEWs) control a substantial fraction of tropical
rainfall variability. Their horizontal structures and dispersion characteristics correspond to
Matsuno's solutions of the shallow water equations on an equatorial beta plane, namely Kelvin,
equatorial Rossby, mixed-Rossby-gravity, and inertio-gravity waves. Due to moist processes, the
tilted vertical structures of CCEWs are complex, and their scales do not correspond to that
expected from the linear theory of dry waves. The dynamical structures and cloud morphology of
CCEWs display a large degree of self-similarity over a surprisingly wide range of scales, with
shallow convection at their leading edge, followed by deep convection then stratiform
precipitation, mirroring that of individual mesoscale convective complexes. CCEWs have broad
impacts within the tropics, and their simulation in general circulation models is still problematic,
although progress has been made using simpler models. A complete understanding of CCEWs
remains as a challenge in tropical meteorology.