Butterfly diagram for the solution with diamagnetic pumping, Babcock-Leighton-type source term for the poloidal magnetic field, and a turbulent magnetic diffusivity η_T = 10¹² cm²/ s. Left: classical solar case with a poloidal-field generation by active regions at low latitudes. Right: observationally driven case with a poloidal-field generation around 70° latitudes. In both cases the toroidal magnetic field at the bottom of the convection zone is plotted because this is the field relevant for spots in the Babcock-Leighton scenario.