Normalised rotation rate in the quasi-steady state. Top panel (5a): this is the third panel of Fig. 3 presented on a smaller rotation rate scale. As a result, the DZ is saturated in colour. Bottom panel (5b): enlargement of the black-delimited zone displayed in the top panel. In each panels, the poloidal field lines are also represented (black lines). For the sake of clarity, every other field line is plotted in red in the bottom panel. The parameters are the same as in Figs. 3 and 4.