Overview of High-Resolution Infrared Measurement and Analysis for Atmospheric Monitoring of Halocarbons

The current state of the art in recording and analyzing rotationally resolved vibration-rotation bands of atmospheric pollutant halocarbon species is reviewed. It is shown that in order to obtain molecular constants of sufficient accuracy to simulate the vibration-rotation structure over the range of atmospheric temperatures, it is necessary to obtain spectra at a range of temperatures using static cooling cells, supersonic jet expansions, and collisional cooling devices; employ sophisticated pattern recognition and analysis software; assign and fit spectral perturbations; and use spectral simulation and digital spectral subtraction (SASSI) to further simplify spectral bands for analysis. To demonstrate the techniques, an analysis of the v(5) band of CH(37)ClF(2) in natural abundance is presented.