Abstract. Trichlorofluoromethane (CFC-11), a widely used refrigerant throughout
much of the twentieth century and a very potent (stratospheric)
ozone-depleting substance (ODS), is now banned under the Montreal Protocol.
With a long atmospheric lifetime, it will only slowly degrade in the
atmosphere, so monitoring its vertical concentration profile using
infrared-sounding instruments, and thereby validating stratospheric loss
rates in atmospheric models, is of great importance; this in turn requires
high-quality laboratory spectroscopic data. This work describes new high-resolution infrared absorption cross sections of
trichlorofluoromethane/dry synthetic air over the spectral range
710–1290 cm−1, determined from spectra recorded using a
high-resolution Fourier transform spectrometer (Bruker IFS 125HR) and a
26 cm pathlength cell. Spectra 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 (7.5–760 Torr and
192–293 K) appropriate for atmospheric conditions. This new cross-section
dataset improves upon the one currently available in the HITRAN (HIgh-resolution TRANsmission) and
GEISA (Gestion et Étude des Informations Spectroscopiques Atmosphériques) databases through an extension to the range of pressures and
temperatures, improved signal-to-noise
and wavenumber calibrations, the lack of channel fringing, the better
consistency in integrated band intensities, and additionally the coverage of
the weak combination band ν2+ν5.