Modelled Dst using simulation data (black line, left axis), the B_z component of the magnetic field (red line, right axis), and the dynamic pressure (blue line, right axis) in the case of the slow wind – double eruption (left side) and faster wind – stealth speed (right side). The curves have not been overlapped, and so they indicate the actual simulated arrival time. The grey dashed line shows the polarity reversal of B_z.