Fourier-Transform Spectroscopy of Ozone Broadening

Abstract

Until recently, very few measurements of broadening of O3 absorption lines have been made (see Table IV of Ref. 1), covering only about 230 different vibration-rotation lines. However, investigators desiring to accurately model infrared radiative transfer in the terrestrial atmosphere require spectroscopic parameters (including air-broadened halfwidths) for thousands of vibration-rotation lines (2). Self-broadened halfwidths are needed for accurate quantitative analysis of laboratory spectra of gas mixtures containing high concentrations of ozone. In the studies reported here, the broad spectral coverage possible with Fourier transform spectroscopy has enabled us to measure air- and nitrogen-broadened halfwidths and shifts for about 70 ozone lines in the 9 μm region, and self-broadened halfwidths for over 160 ozone lines in the 4-14 μm region. The results are compared with previous measurements and calculations.