Left: map of the H₂O/CO₂ mixing ratio (in ppmv) retrieved from the TEXES data recorded on March 1, 2014 (Ls = 96°), converted from the HDO/CO₂ mixing ratio map (Fig. 8), assuming a Martian mean D/H ratio of 5 times the terrestrial value. The black circle corresponds to region A where the TEXES spectra were modeled (see text). Right: GCM synthetic map of the H₂O₂/CO₂ column-averaged mixing ratio (in ppmv) calculated for the same observing conditions.