SELF- AND CO2-BROADENED LINE SHAPE PARAMETERS FOR THE _2 AND _3 BANDS OF HDO

Devi, V. Malathy

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Description

Title

SELF- AND CO2-BROADENED LINE SHAPE PARAMETERS FOR THE _2 AND _3 BANDS OF HDO

Author(s)

Devi, V. Malathy

Contributor(s)

• Villanueva, Geronimo L.
• Gamache, Robert R.
• Smith, Mary Ann H.
• Mantz, Arlan
• Brown, Linda
• Sung, Keeyoon
• Benner, D. Chris

Issue Date

22-Jun-15

Keyword(s)

Small molecules

Abstract

Knowledge of CO$_2$-broadened HDO widths and their temperature dependence exponents are required to interpret atmospheric spectra of Mars and Venus. We therefore used nine high-resolution, high signal-to-noise spectra of HDO and HDO+CO$_2$ mixtures to obtain broadening coefficients for selected transitions of the $nu_2$ and $nu_3$ vibrational bands located at 7.13 and 2.70 $mu m$, respectively. The gas samples were prepared by mixing equal amounts of high-purity distilled H$_2$O and a 99% enriched D$_2$O sample. Spectra at different temperatures (255-296 K) were obtained using a 20.38 cm long coolable cellfootnote{K. Sung, A.W. Mantz, M.A.H. Smith, L.R. Brown, T.J. Crawford, V.M. Devi, D.C. Benner. J. Mol. Spectrosc. 162 (2010) 124-134.} installed in the sample compartment of the Bruker 125HR Fourier transform spectrometer at the Jet Propulsion Laboratory, in Pasadena, CA. The retrieved parameters included accurate line positions, intensities, self- and CO$_2$-broadened half-width and pressure-shift coefficients and the temperature dependences of CO$_2$ broadened HDO. The spectroscopic parameters for many transitions were obtained simultaneously by multispectrum fittingfootnote{D.C. Benner, C.P. Rinsland, V. Malathy Devi, M.A.H. Smith, and D. Atkins. JQSRT 53 (1995) 705-721.} of all nine spectra in each band. A non-Voigt line shape with speed dependence was applied. Line mixing was also observed for several transition pairs. Preliminary results will be compared to other recent measurements reported in the literature.footnote{Research described in this paper are performed at the College of William and Mary, Jet Propulsion Laboratory, California Institute of Technology, Connecticut College and NASA Langley Research Center under contracts and cooperative agreements with the National Aeronautics and Space Administration.}

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

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