Left: Profiles of turbulent viscosity, ν(r), and turbulent thermal diffusivity, κ(r), as functions of radius. They are expressed by Eqs. (8) and (9). Right: Profile of super-adiabaticity, δ(r), as a function of radius (Eq. 10). The super-adiabaticity profile from the standard Model S is represented by the dashed red curve (Christensen-Dalsgaard et al. 1996). The y-axis is linear for |δ|< 10⁻⁷ and logarithmic beyond that. In both panels, the green-shaded area denotes the CZ, the grey-shaded region the OS, and the orange-shaded region the RZ.