Physical ingredients: meridional profiles of (a) α-effect, (b) BL-effect, as well as (c) the stream function ψ (MC) and (d) normalized radial profiles of the latter quantities, taken at θ = π/4, along with the magnetic diffusivity η. These profiles result from Eqs. (7)–(10), respectively. The α-term is here confined between (r₁, r₂) = (0.67, 0.73), as in the reference cases. The BL source term S is shown for the case of B_ϕ(r_BCZ, θ, t) = 1. The sign of the meridional circulation, u_p, is represented with arrows on a black iso-contour of ψ.