MEASUREMENTS AND CALCULATIONS OF ROOM-TEMPERATURE OZONE LINE-BROADENING BY N2 AND O2 IN THE NU-1+NU-3 BAND

A high-resolution Fourier transform spectrometer has been used to record a large number of spectra, with ozone and foreign gas pressures ranging from 5 to 50 Torr and 80 to 700 Torr, respectively. The 2100-cm-1 region corresponding to the ν1 + ν3 band of O3 has been analyzed and the broadening coefficients by N2 and O2 at room temperature have been derived for 112 lines with an accuracy better than 3 × 10-3 cm-1 atm-1. This study covers a wide range of rotational quantum numbers (J″ = 0-40, K″a = 0-11) in an A-type band (ν1 + ν3). Calculations of these broadening coefficients have been performed with a theoretical model successfully tested on H2O linewidths. This model provides a correct modeling of close collisions since the contributions of an atom-atom potential and trajectory modifications at short distance are accounted for. It has been previously applied to O3 line broadening by N2 and O2 but only a dozen of B-type lines were then investigated. In the present study, the atom-atom parameters for the O3-N2 and O3-O2 interactions have been adjusted to match experiment since no intermolecular anisotropic potential is. to our knowledge, available for O3. The standard deviations between experimental and theoretical results are about 6%, with absolute maximum deviations of about 14% for O3-N2 and O3-O2. Furthermore, use of simple empirical polynomial corrections of calculated results versus rotational quantum numbers leads to agreement between observations and calculations better than 2% for the O2 and N2 broadenings of most lines. © 1993 Academic Press, Inc.