  A simplified model for stellar and planetary convection is derived for the
magnitude of the rms velocity, degree of superadiabaticity, and characteristic
length scale with Rossby number as well as with thermal and viscous
diffusivities. Integrating the convection model into a linearization of the
dynamics in the transition region between convectively unstable and
stably-stratified region yields a Rossby number, diffusivity, and pressure
scale height dependent convective penetration depth into the stable region.
This may have important consequences for mixing along the evolution of rotating
stars.
