Measurements of H₂O-broadening coefficients of O₂ A-band lines

We report laboratory measurements of H₂O-broadening coefficients of O₂ absorption lines in the A-band near 13,000 cm⁻¹. For this, four spectra of oxygen gas mixed with water vapor were recorded with a high resolution Fourier transform spectrometer for total pressures ranging from 125 to 175 Torr at 323 K, and a fifth at 175 Torr and 365 K. Broadening coefficients of 39 transitions (up to J^″=21) were retrieved from the measured spectra through fits using Galatry line profiles. Values at room temperature (296 K) were then extrapolated and compared with previous determinations in the A-band and millimeter waves region. This enables to resolve some controversial issues related to the inconsistencies between these studies. Finally, comparing our results with the line broadening coefficients by dry air confirms that H₂O-broadenings of oxygen lines are, on average, 10% larger than those by dry air.