Stratospheric HF and HCl observations (15 June 1981)

We have measured seven far‐infrared rotational lines of HF and HCl from a balloon platform at 28.5 km. Other lines, including H2O and O3, were observed simultaneously. At an effective altitude of about 33 km, we find an abundance ratio HF/HCl= 0.18±0.02, and a water vapor mixing ratio of about 4 ppmv. Modelled values of HF/HCl for an atmosphere containing this much H2O are slightly higher, but in reasonable agreement.