Pressure-broadening and pressure-shifting of spectral lines of ozone

Abstract

This work is a critical review of experimental and theoretical results of pressure-broadened halfwidths and pressure-induced line shifts of 16O 3 absorption lines. The perturbing gases considered are air, N 2, O 2, and O 3. A search of the literature produced a database of 4619 measured halfwidths, 969 transitions for which the temperature dependence of the halfwidth is reported. The database of calculated ozone halfwidths contains ∼5000 values, mostly from a single reference, with the temperature dependence of the halfwidth studied for ∼140 transitions. Although many data are available, there remains much to be done with regards the data and accuracy required for practical applications. The experimental database is used for intercomparison and to study the influence of the vibrational states, collision partner, and temperature on the halfwidth. Finally, averaging of the data sets has allowed the determination of a number of `reliable' values for a number of lines. The latter should be useful for tests of experimental procedures, remote sensing, and validation of theoretical models. Recommendations for future measurements and calculations to complete these data sets are also made. Due to the lack of experimental data on pressure-induced line shifts, no systematic comparison is made. The data are discussed and suggestions for future measurements to aid in the validation of theoretical calculations made.