Left and middle: HDO /CO₂ maps recorded on January 10 and 12, 2012, using the HDO transition at at 1350.25 cm^-1 and the CO₂ transition at 1350.35 cm^-1. The orientation of the north-south axis has been corrected. Right: HDO/CO₂ map obtained on October 5, using the HDO line at 1344.90 cm^-1 and the CO₂ transition at 1345.22 cm^-1. The three maps show a rather uniform spatial distribution, with variations less than about +/−50%.