Measurements of stratospheric HBr using high resolution far infrared spectroscopy

Far infrared spectral features of HBr have been observed in the stratospheric emission spectrum using a balloon borne high resolution Fourier transform spectrometer equipped with a high sensitivity detector specially designed for this purpose. The value of 1.6±0.6 parts per trillion in volume for the HBr mixing ratio has been retrieved, from the global-fit analysis of 121 spectra, in the 25-36.5 km altitude range. The result is briefly compared with models and previous assessments.