Articles | Volume 8, issue 8
https://doi.org/10.5194/amt-8-3197-2015
https://doi.org/10.5194/amt-8-3197-2015
Research article
 | 
12 Aug 2015
Research article |  | 12 Aug 2015

New and improved infrared absorption cross sections for dichlorodifluoromethane (CFC-12)

J. J. Harrison

Abstract. Despite its widespread commercial use throughout the twentieth century, primarily in the refrigeration industry, dichlorodifluoromethane (CFC-12) is now known to have the undesirable effect of depleting stratospheric ozone. As this long-lived molecule slowly degrades in the atmosphere, monitoring its vertical concentration profile using infrared sounders on satellite platforms crucially requires accurate laboratory spectroscopic data. This work describes new high-resolution infrared absorption cross sections of dichlorodifluoromethane over the spectral range 800–1270 cm−1, determined from spectra recorded using a high-resolution Fourier transform spectrometer (Bruker IFS 125HR) and a 26 cm pathlength cell. Spectra of dichlorodifluoromethane/dry synthetic air mixtures were recorded at resolutions between 0.01 and 0.03 cm−1 (calculated as 0.9/MOPD; MOPD = maximum optical path difference) over a range of temperatures and pressures (7.5–761 Torr and 190–294 K) appropriate for atmospheric conditions. This new cross-section dataset improves upon the one currently available in the HITRAN and GEISA databases.

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Short summary
Using infrared sounders on satellite platforms to monitor concentrations of atmospheric CFC-12, a stratospheric-ozone-depleting molecule with a long lifetime, crucially requires accurate laboratory spectroscopic data. This work describes a new high-resolution infrared absorption cross-section data set for remote-sensing purposes; this dataset improves upon the one currently available in the HITRAN and GEISA databases.