Vertical magnetic field at the surface (grey-scale maps) and slices through y = 0 Mm showing the unsigned magnetic field strength and vertical flows at three different times of the Ω = 0Ω_⊙ non-rotational MHD simulation. The red and yellow symbols show the centres of the positive and negative magnetic poles, respectively. The crosses indicate the flux-weighted centres of the polarities over a threshold of |B_z| = 800 G, and the dots indicate the centres without a threshold. See the movies of the simulation online and here.