Pluto’s kinetic temperature profile from New Horizons (T_kin, solid black line) and inferred vibrational temperature profiles for CH₄, CH₃D, and C₂H₂, color-coded by band. For CH₄, T_vib for the fundamental (ν₄) and first two overtone (2ν₄ and 3ν₄) levels, are shown. The dashed green curve is an alternative T_vib profile for the ν₄ level which does not satisfy observations (see Fig. A.2, top panel). The solid green curve (nominal T_vib) for the ν₄ CH₄ band was also used for calculating the CH₃D ν₆ emission. The dashed-dotted light blue curve is the retrieved T_vib for the ν₅ band of C₂H₂, assuming the C₂H₂ Lavvas et al. (2021) vertical profile. The black dashed-dotted and dotted lines are the equatorial and north polar kinetic temperature profiles retrieved by Lellouch et al. (2022) from ALMA 2017 observations.