University of Illinois Urbana-Champaign

SELF- AND AIR-BROADENED LINE SHAPE PARAMETERS OF 12CH4 : 4500-4620 CM−1

Devi, V. Malathy

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TI16_Abstract.pdf
TI16_Abstract.txt
TI16_Presentation.pptx

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https://hdl.handle.net/2142/50833

Description

Title
SELF- AND AIR-BROADENED LINE SHAPE PARAMETERS OF 12CH4 : 4500-4620 CM−1
Author(s)
Devi, V. Malathy
Contributor(s)
  • Predoi-Cross, Adriana
  • Mantz, Arlan
  • Smith, Mary Ann H.
  • Crawford, Timothy J.
  • Brown, Linda
  • Sung, Keeyoon
  • Benner, D. Chris
Issue Date
2014-06-17
Keyword(s)
Atmospheric science
Date of Ingest
  • 2014-09-17T16:55:06Z
  • 2015-04-14T18:40:35Z
Abstract
Accurate knowledge of spectral line shape parameters is important for infrared transmission and radiance calculations in the terrestrial atmosphere. We report the self- and air-broadened Lorentz widths, shifts and line mixing coefficients along with their temperature dependences for methane absorption lines in the 2.2 $\mu$m spectral region. For this, we obtained a series of high-resolution, high S/N spectra of 99.99$\%$ $^{12}$C-enriched samples of pure methane and its dilute mixtures in dry air at cold temperatures down to 150 K using the Bruker IFS 125HR Fourier transform spectrometer at JPL. The coolable absorption cell had an optical path of 20.38 cm and was specially built to reside inside the sample compartment of the Bruker FTS\footnote{K.~Sung, A.~W.~Mantz, L.~R.~Brown, \textit{et al.}, \textit{J. Mol. Spectrosc.} \underline{\textbf{162}} (2010) 124-134.}. The 13 spectra used in the analysis consisted of seven pure $^{12}$CH$_4$ spectra at pressures from 4.5 to 169 Torr and six air-broadened spectra with total sample pressures of 113-300 Torr and methane volume mixing ratios between 4 and 9.7$\%$. These 13 spectra were fit simultaneously using the multispectrum least-squares fitting technique\footnote{D.~C.~Benner, C.~P.~Rinsland, V.~Malathy Devi, M.~A.~H.~Smith and D.~Atkins, \textit{JQSRT} \underline{\textbf{53}} (1995) 705-721.}. The results will be compared to existing values reported in the literature.\footnote{Research described in this paper was performed at Connecticut College, the College of William and Mary, NASA Langley Research Center and the Jet Propulsion Laboratory, California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration.}
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
text
Genre of Resource
Conference Paper / Presentation
Language
English
Permalink
http://hdl.handle.net/2142/50833
DOI
https://doi.org/10.15278/isms.2014.TI16
Copyright and License Information
Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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Abstracts & Presentations - 2014 International Symposium on Molecular Spectroscopy PRIMARY