LINE SHAPE PARAMETERS FOR NEAR INFRARED CO2 BANDS IN THE 1.61 AND 2.06 MICRON SPECTRAL REGIONS

Devi, V. Malathy

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Description

Title

LINE SHAPE PARAMETERS FOR NEAR INFRARED CO2 BANDS IN THE 1.61 AND 2.06 MICRON SPECTRAL REGIONS

Author(s)

Devi, V. Malathy

Contributor(s)

• Mantz, Arlan
• Smith, Mary Ann H.
• Crawford, Timothy J.
• Brown, Linda
• Sung, Keeyoon
• Benner, D. Chris

Issue Date

22-Jun-15

Keyword(s)

Linelists

Abstract

Accurate spectroscopic measurements of self- and air-broadened Lorentz half-width and pressure-shift coefficients and their temperature dependence exponents are crucial for the Orbiting Carbon Observatory (OCO-2) mission.footnote {D. Crisp, B.M. Fisher, C. O�Dell, et.al., Atmos. Meas. Tech. Discuss 4 (2011) 1-59.} We therefore analyzed 73 high-resolution high signal-to-noise spectra of CO$_2$ and CO$_2$+air for OCO-2 channels at 1.61 and 2.06 $mu m$. These spectra were recorded at various spectral resolutions (0.004-0.013 cm$^{-1}$) using two spectrometers (the Kitt Peak FTS in Arizona and the Bruker 125HR FTS at the Jet Propulsion Laboratory in Pasadena, California). Six different absorption cells with path lengths between 0.2 and 121 m were used with gas samples at a range of temperatures (170-297 K). The gas pressures ranged from (0.3-898 Torr for pure sample and 26-924 Torr for mixtures of CO$_2$ and air with CO$_2$ volume mixing ratios between 0.01 and 0.4. The cold sample spectra were acquired using a short 0.2038 m straight pass celland a multipass Herriott cell having a 20.941 m total path A multispectrum fitting technique was employed to fit all the spectra simultaneously with a non-Voigt line shape profile including speed dependence and full line mixing. Examples of fitted spectra and retrieved parameters in both CO$_2$ band regions will be shown. Comparisons of some of the results with other published values will be provided.footnote {Research described in this paper are performed at the College of William and Mary, Jet Propulsion Laboratory, California Institute of Technology, NASA Langley Research Center and Connecticut College 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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