S. Fally et al., Fourier transform spectroscopy of the O-2 Herzberg bands. III. Absorption cross sections of the collision-induced bands and of the Herzberg continuum, J MOL SPECT, 204(1), 2000, pp. 10-20
Absorption spectra of molecular oxygen were measured in the laboratory unde
r temperature and pressure conditions prevailing in the Earth's atmosphere.
Spectra of pure O-2, O-2 + N-2, and O-2 + Ar were recorded in the 41 700 t
o 33 000 cm(-1) region (240-300 nm) at a maximal optical path difference of
0.45 cm using a Fourier transform spectrometer and a multiple reflection g
as cell. The different components of the spectra, namely the discrete bands
of the three Herzberg systems, the Herzberg continuum, and the collision-i
nduced diffuse Wulf bands, were separated. The contribution of the Herzberg
bands was first subtracted using the line parameters determined previously
LA. Jenouvrier, M.-F. Merienne, B. Coquart, M. Carleer, S. Fally, A. C. Va
ndaele, C. Hermans, and R. Colin, J. Mel. Spectrosc. 198, 136-162 (1999)] f
rom high-resolution data. Spectra recorded at various pressures then made i
t possible to determine by linear regression the intensity of the Wulf band
s and the Herzberg continuum. The characteristics of the Wulf bands have be
en investigated in details: vibrational analysis, pressure effect, foreign
gas effect, and a simulated spectrum are reported. The Herzberg continuum c
ross section is determined below the dissociation limit. A comparison with
literature data is given. The new O-2 absorption cross sections and O-2-O-3
collision-induced absorption cross sections are useful in connection with
atmospheric measurements of ozone and other trace gases in the UV spectral
region. (C) 2000 Academic Press.