Projected magnetic field lines in the period A (left column) and B (right column) simulations, on days 0, 60, 120, and 180. Greyscale shading on r = r₀ shows B_r (white positive, black negative, saturated at ± 10 G), and projected coronal magnetic field lines traced from height r = r₀ are coloured (red/blue) according to , saturated at ± 0.5 Mx. Animated versions of this figure for periods A and B are available online.