Title: Mean molecular weight and hydrogen abundance of Titan's atmosphere
Abstract: The 200–600 cm−1 continuum opacity in the troposphere and lower stratosphere of Titan is inferred from thermal emission spectra from the Voyager 1 IR spectrometer (IRIS). The surface temperature and mean molecular weight are 94 K < TG < 97K and 28.3<M<29.2 AMU, respectively. The mole fraction of molecular hydrogen is 0.002±0.001, which is equivalent to an abundance of ∼0.2±0.1 km amagat.