Gas surface density and α_visc radial profiles. Top: Red dotted and blue solid lines show the actual and fitted α_visc values in the layered disk model with a dead zone, while the orange dashed line corresponds to an MRI-active disk with a constant α_visc. Bottom: Corresponding radial profiles of the gas surface density obtained from the actual hydro-dynamic simulation (red dotted line), from solution of the steady-state Eq. (A.1) with radially varying α_visc (blue solid line), and from Eq. (A.1) with a spatially constant α_visc (orange dashed line).