Structure of the flow and of the magnetic field during the non-linear evolution. Left panel: meridional cut of the normalised differential rotation δΩ/Ω₀ (colour) with the streamlines associated with the meridional circulation U = U_re_r + U_θe_θ (black contours). The dashed (solid) lines correspond to an anticlockwise (clockwise) circulation. Right panel: meridional cut of the normalised norm of the poloidal magnetic field ∥B_p∥/B₀ (colour) and its associated field lines (in black). The fixed point, located at r = 0.47r₀ and θ ≈ 2π/5, corresponds to the location where the norm of the poloidal field is plotted in Fig. 18 for a stable and an unstable case. These snapshots have been taken at t = 3τ_c. The parameters are Re_c = 1, L_u = 10⁴, E = 10⁻⁴, P_r(N₀/Ω₀)² = 10⁴, and P_m = 10² (run Q10 of Table 1).