Role of the Ω-effect in the production of the toroidal field for two selected simulations in thick shells (upper panels) and in thin shells (lower panel). For each simulation, the Ω-effect (colour levels) and the axisymmetric azimuthal field (solid and dashed lines) are displayed on the left part, while the axisymmetric zonal flow is given on the right part. Red (blue) corresponds to positive (negative) values.