Evolution of the volume-integrated magnetic energy and the root mean square of the vorticity, ω_rms, for some dynamo runs (as in the legend). The dynamo and vorticity growth rates increases with the shearing amplitude. The baroclinicity slightly enhances the dynamo growth rate even though it takes longer for the instability to start. The vorticity keeps growing after its exponential growth, during the magnetic dynamo phase. It then decays to lower values. The straight lines indicate the fits we obtained for the growth rates of the dynamo, r, of the vorticity dynamo, r_ω, and of the growth of the vorticity during the first part of its saturation phase, r_ω,sat. Their values are reported in Table 7.