The observed Stokes profile analyzed in this paper (solid black curves; left vertical scale; same reference direction as Fig. 2). The horizontal dashed line in the top panel corresponds to the adopted continuum level. Also plotted (red solid lines) are best fit profiles for a height of 6.3 Mm, obtained for a magnetic field of 320 G, with an inclination of 95° with respect to the local solar vertical, and an azimuth of  − 86° (see Sect. 3.3).