COLLISIONAL BROADENING OF WATER-VAPOR LINES .1. A SURVEY OF EXPERIMENTAL RESULTS

The present work is a critical survey of experimental results on the pressure broadening of (H2O)-O-16 absorption lines. A systematic collection of the published water vapor collisional broadening measurements by various perturbers has been made. This database includes about 4000 H2O line-width measurements, 500 for which the temperature dependence has been studied. Although many experiments are available, much remains to be done in regards of the data required for practical applications. The collected half-widths sets have been used for intercomparison between different works and for study of the influence of the vibrational states, collision partner, and temperature on broadening. The results show that measurements by different authors are often inconsistent, probably on account of an underestimation of experimental errors. Furthermore, since the influence of vibration remains generally within measurement uncertainties, no clear conclusion concerning vibrational dependence of half-widths can be drawn. Finally, filtering of the data sets has enabled determination of reliable values for some widely studied lines. The latter should be useful for tests of experimental procedures, remote sensing, and validation of theoretical models. Recommendations for future measurements in order to complete these data sets are also made.