Effects of clouds and phase changes on fast-wave averaging: a numerical assessment

A remarkable property of geophysical fluids is that, even for nonlinear flows, a slow component can sometimes evolve independently of the fast-wave components. The dry Boussinesq equations, for instance, are known to exhibit this property for small Froude (. As an explanation and physical interpretation, it is shown that, while linear waves have a time average of zero, the piecewise-linear waves that arise due to phase changes actually have a non-zero time-averaged component.