Differential rotation normalised to the rotation rate of the outer sphere δΩ(r, θ)/Ω₀ in the viscous regime (first and third panels) and norm of the total meridional velocity field (second and fourth panels) with the streamlines of the associated total meridional circulation (in black). In the two left panels the parameters of the simulation are P_r(N₀/Ω₀)² = 10⁴, Re_c = 10⁻², and E = 10⁻⁵ (run 3.4 in Table 3), and in the two right panels the parameters are P_r(N₀/Ω₀)² = 10⁴, Re_c = 10, and E = 10⁻⁴ (run 4.3 in Table 3). In the second and fourth panels the black solid lines represent the streamlines of an ascending and inwardly directed circulation, while the black dashed lines correspond to a descending and inwardly directed one.