Mesoscale model simulations of gravity waves in a convecting atmosphere

A mesoscale model, with periodic channel boundary conditions, is used to perform simulations in which gravity waves are imposed on an atmosphere which is otherwise in approximate radiative-convective equilibrium. SST is uniform, domain size is 4500 km by 1200 km, and horizontal resolution 30 km in most of the simulations. Overall, the waves are damped, consistent with the concept of "moist convective damping" as in quasi-equilibrium theory. However, the damping rate is relatively small in some cases, and in most of the simulations the waves experience episodes of transient growth superimposed on the decaying trend. Feedbacks between the wave dynamics and the atmospheric humidity field appear to be important to certain aspects of the waves' behavior.