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

- Five spectra of O2 in H2O were recorded with a high resolution FTS.
- H2O-broadening of 39 infrared O2 lines in the A-band were measured.
- H2O-broadenings of O2 lines are, on average, 10% larger than those for dry air.

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.