Abstract
Assuming that instantaneous wind can be separated into synoptic scale, mesoscale, and turbulent scale within a grid element of a GCM, the mesoscale kinetic energy per unit mass is defined as half the variance of mesoscale perturbations from the synoptic‐scale wind. A simulation of the atmospheric boundary layer that develops above a locally deforested region is used to illustrate the relation that exists between mesoscale kinetic energy and mesoscale latent and sensible heat fluxes. A prognostic equation for mesoscale kinetic energy is suggested to relate subgrid‐scale landscape heterogeneity to subgrid‐scale convective clouds, which could be used to improve the parameterization of clouds and precipitation in GCMs.