Example of the model atmosphere for the Gaussian inversion. Top row, left to right: temperature in Kelvin, electron pressure in dyn cm^-2, field strength in Gauss. Bottom row: line-of-sight velocity in m s^-1, field inclination to the LOS in degree, field azimuth in degree. Dashed: initial values of the background field atmosphere, solid: final best-fit background field with perturbation added. The values are given versus logarithmic optical depth, the final background field values can be simply read off from the values at log τ = −4 since they are constant with depth.