The СО2 absorption near band heads in the 8000 см–1 region
T.E. Klimeshina, T.M. Petrova, O.B. Rodimova, A.A. Solodov, A.M. Solodov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch, 1, Academician Zuev square, Tomsk, 634021, Russia
Keywords: continuum absorption, carbon dioxide, self-broadening, spectral line wings
Abstract
The CO2 absorption is measured in the 8000 cm–1 region, calculation of the absorption coefficient is performed using the asymptotic line wing shape theory with fitting to the experimental data. Calculated coefficient values agree well with the measured data. According to the line wing theory the absorption in the band wings is conditioned by the wings of the strong lines of the near band. Within the framework of the theory, experimental and calculated data on the CO2 absorption coefficient in the wings of two bands in the 8000 cm–1 region can provide the information about the line shape at frequency detunings corresponding to several tens of half-widths. The results obtained support the hypothesis that line shape parameters in the line wings related to the transitions with the same initial state appear to be close to each other. The expression of the spectral line shape at large frequency detunings may be useful for modeling the radiative transfer in the atmospheric windows of the planets with significant CO2 content.
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