Data availability.
ACS data are available from ESA Planetary Science Archive (PSA) Level 2
https://archives.esac.esa.int/psa/#!Table%20View/ACS=instrument. The H2O, temperature and saturation coefficient vertical profiles generated from ACS measurements and analyzed in this study are available on ftp://193.232.13.174/ACS_NIR_Results/S_climatology/ for review purposes. Data will be stored after review in the Mendeley repository.