Zooms on the HARPS final altitude profile from method 1 (Fig. 12) with a Noxon correction for the Ring effect, except in the deep telluric lines (Sioris & Evans 2000). Oxygen and water vapour absorption spectra at arbitrary scale are shown. Oxygen shows up very clearly. Water vapour is barely visible around 6500 Å above 25 km and weak lines are visible in the higher Na I D1 D2 region. Note that our Noxon correction does not completely remove the wings of the Na I solar lines. The wings disappear with a stronger correction, but the two Na I peaks then reach an altitude well above 100 km which is not realistic.