Two Scaling Regimes for Rotating Rayleigh-Bénard Convection

Using a turbulence model, we derive two scaling regimes for rapidly rotating Rayleigh-B\'enard turbulent convection. For Ra*<Ra<Ra**, where Ra* and Ra** are functions of Ω, the Nusselt number Nu is a function only of the scaling variable Ra/Ra*; this corresponds to the first regime. For Ra>Ra**, Nu is almost unaffected by rotation and satisfies the nonrotating scaling law Nu~Ra^γ, γ~1/3. The two scaling laws are confirmed by existing data.