Snapshot of the simulation after 3850 s, showing: the vertical velocity at the photosphere (panel a) the normalised intensity at 500 nm (panel b), the vertical magnetic field at the photosphere (panel c), and the vertical magnetic field at a height of 2 Mm in the chromosphere (panel d). The dashed green lines show the slices taken in Fig. 2. Panels c and d have been saturated in order to show the fine structure of the magnetic field. Slices at the photosphere are taken at the contour where τ₅₀₀ = 1.