Magnetic field maps at the layer corresponding to log τ = −0.5 and log τ = −2. The color maps correspond to the vertical component and the arrows to the horizontal component of the magnetic field vector. The lower two panels show a zoom-in of the area denoted by the red rectangle in the upper two panels. The black line corresponds to the vertical slice shown in Fig. 4. The color-bar scale for B_z is asymmetric.