Latitudinal contours of the toroidal magnetic field obtained with a forked dynamo including α quenching. Top panel: toroidal field in the overshoot layer. Bottom panel: Azimuthal potential vector at the base of the convection zone. Solid lines represent the times when the positive toroidal field reaches its maximum and dashed lines show where the negative poloidal field is maximum. Contours correspond to the same values of Β as in Fig. 3.