Figure 1. Example occultation spectra of CO2 and H2O bands measured by ACS NIR and the retrieved profiles for occultation 4154 in MY34 (Ls=278°, latitude:55°S, longitude 317°E, local time 3:06). A) synthetic spectra of CO2 and H2O absorptions (target altitude of 20 km); the ranges corresponding to measured diffraction orders are marked by vertical bars. B) observed (black) and best fit model (magenta) transmittances in order 49 at 35 km with residual. C) observed (black) and best fit model (blue) transmittances in order 54 at 35 km with residual. D) observed (black) and best fit model (red) transmittances in order 56 at 35 km with residual. Lower panels show profiles retrieved from this occultation: (E) temperature in Kelvin from order 49 (magenta) and 54 (blue), (F) CO2 density in cm-3 from the same orders and (G) water vapor mixing ratio in ppmv from order 56 with saturation ratio (black) calculated as explained in Section 2.3.