Left: parameters along the line with maximum blueshifts. We show Doppler velocities from the polynomial fit (solid blue lines), Doppler velocities from the Fourier method (dashed blue), the magnetic inclination (green), the total magnetic field strength (violet), and the horizontal magnetic field strength (orange). Horizontal lines mark the zero reference for velocities (blue) and 90° for the magnetic inclination (green). Right: parameters for the maximum redshift. Here, the velocities are displayed in red. An animation of this figure is available online.