Initial magnetic field. Vertical field B_z + B_opp (top left), radial field B_r (top right), total field |B| (bottom left), and inclination to the surface normal γ. The legend in the top left panel shows the simulations plotted in the first three panels. The legend in the bottom right panel gives a selection of the simulations shown there, the rest is given in Table A.1; for each line in that table (colour), the further right the column is (the higher B₀ or B_opp, the changing numbers in the run names), the higher the inclination.