View in EDS

Using high-resolution laboratory and ground-based solar spectra to assess CH4 absorption coefficient calculations.

Saved in:
Bibliographic Details
Title: Using high-resolution laboratory and ground-based solar spectra to assess CH4 absorption coefficient calculations.
Authors: Mendonca, J.1 joseph.mendonca@utoronto.ca, Strong, K.1, Sung, K.2, Devi, V.M.3, Toon, G.C.2, Wunch, D.4, Franklin, J.E.5
Source: Journal of Quantitative Spectroscopy & Radiative Transfer. Mar2017, Vol. 190, p48-59. 12p.
Subjects: Solar radiation, Absorption spectra, Absorption coefficients, Algorithms, Monotonic functions, Computer software
Abstract: A quadratic-speed-dependent Voigt line shape (qSDV) with line mixing (qSDV+LM), together with spectroscopic line parameters from Devi et al. [ 1,2 ] for the 2v 3 band of CH 4 , was used to retrieve total columns of CH 4 from atmospheric solar absorption spectra. The qSDV line shape (Tran et al., 2013) [ 3 ] with line mixing (Lévy et al., 1992) [ 4 ] was implemented into the forward model of GFIT (the retrieval algorithm that is at the heart of the GGG software (Wunch et al., 2015) [ 5 ]) to calculate CH 4 absorption coefficients. High-resolution laboratory spectra of CH 4 were used to assess absorption coefficients calculated using a Voigt line shape and spectroscopic parameters from the atm line list (Toon, 2014) [ 6 ]. The same laboratory spectra were used to test absorption coefficients calculated using the qSDV+LM line shape with spectroscopic line parameters from Devi et al. [ 1,2 ] for the 2v 3 band of CH 4 and a Voigt line shape for lines that don’t belong to the 2v 3 band. The spectral line list for lines that don’t belong to the 2v 3 band is an amalgamation of multiple spectral line lists. We found that for the P, Q, and R branches of the 2v 3 band, the qSDV+LM simulated the laboratory spectra better than the Voigt line shape. The qSDV+LM was also used in the spectral fitting of high-resolution solar absorption spectra from four ground-based remote sensing sites and compared to spectra fitted with a Voigt line shape. The average root mean square (RMS) residual for 131,124 solar absorption spectra fitted with absorption coefficients calculated using the qSDV+LM for the 2v 3 band of CH 4 and the new spectral line list for lines for lines that don’t belong to the 2v 3 band, was reduced in the P, Q, and R branches by 5%, 13%, and 3%, respectively when compared with spectra fitted using a Voigt line shape and the atm line list. We found that the average total column of CH 4 retrieved from these 131,124 spectra, with the qSDV+LM was 1.1±0.3% higher than the retrievals performed using a Voigt and the atm line list. The airmass dependence of the retrieved total columns was found to change depending on the choice of spectral line shape. With the Voigt line shape, we found a minimum in CH 4 total columns at a solar zenith angle (SZA) of about 70°. With the qSDV+LM, the retrieved total column of CH 4 decreased monotonically as a function of SZA. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Quantitative Spectroscopy & Radiative Transfer is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
FullText Text:
  Availability: 0
Header DbId: egs
DbLabel: Engineering Source
An: 121244489
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Using high-resolution laboratory and ground-based solar spectra to assess CH4 absorption coefficient calculations.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Mendonca%2C+J%2E%22">Mendonca, J.</searchLink><relatesTo>1</relatesTo><i> joseph.mendonca@utoronto.ca</i><br /><searchLink fieldCode="AR" term="%22Strong%2C+K%2E%22">Strong, K.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Sung%2C+K%2E%22">Sung, K.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Devi%2C+V%2EM%2E%22">Devi, V.M.</searchLink><relatesTo>3</relatesTo><br /><searchLink fieldCode="AR" term="%22Toon%2C+G%2EC%2E%22">Toon, G.C.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Wunch%2C+D%2E%22">Wunch, D.</searchLink><relatesTo>4</relatesTo><br /><searchLink fieldCode="AR" term="%22Franklin%2C+J%2EE%2E%22">Franklin, J.E.</searchLink><relatesTo>5</relatesTo>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Quantitative+Spectroscopy+%26+Radiative+Transfer%22">Journal of Quantitative Spectroscopy & Radiative Transfer</searchLink>. Mar2017, Vol. 190, p48-59. 12p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Solar+radiation%22">Solar radiation</searchLink><br /><searchLink fieldCode="DE" term="%22Absorption+spectra%22">Absorption spectra</searchLink><br /><searchLink fieldCode="DE" term="%22Absorption+coefficients%22">Absorption coefficients</searchLink><br /><searchLink fieldCode="DE" term="%22Algorithms%22">Algorithms</searchLink><br /><searchLink fieldCode="DE" term="%22Monotonic+functions%22">Monotonic functions</searchLink><br /><searchLink fieldCode="DE" term="%22Computer+software%22">Computer software</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: A quadratic-speed-dependent Voigt line shape (qSDV) with line mixing (qSDV+LM), together with spectroscopic line parameters from Devi et al. [ 1,2 ] for the 2v 3 band of CH 4 , was used to retrieve total columns of CH 4 from atmospheric solar absorption spectra. The qSDV line shape (Tran et al., 2013) [ 3 ] with line mixing (Lévy et al., 1992) [ 4 ] was implemented into the forward model of GFIT (the retrieval algorithm that is at the heart of the GGG software (Wunch et al., 2015) [ 5 ]) to calculate CH 4 absorption coefficients. High-resolution laboratory spectra of CH 4 were used to assess absorption coefficients calculated using a Voigt line shape and spectroscopic parameters from the atm line list (Toon, 2014) [ 6 ]. The same laboratory spectra were used to test absorption coefficients calculated using the qSDV+LM line shape with spectroscopic line parameters from Devi et al. [ 1,2 ] for the 2v 3 band of CH 4 and a Voigt line shape for lines that don’t belong to the 2v 3 band. The spectral line list for lines that don’t belong to the 2v 3 band is an amalgamation of multiple spectral line lists. We found that for the P, Q, and R branches of the 2v 3 band, the qSDV+LM simulated the laboratory spectra better than the Voigt line shape. The qSDV+LM was also used in the spectral fitting of high-resolution solar absorption spectra from four ground-based remote sensing sites and compared to spectra fitted with a Voigt line shape. The average root mean square (RMS) residual for 131,124 solar absorption spectra fitted with absorption coefficients calculated using the qSDV+LM for the 2v 3 band of CH 4 and the new spectral line list for lines for lines that don’t belong to the 2v 3 band, was reduced in the P, Q, and R branches by 5%, 13%, and 3%, respectively when compared with spectra fitted using a Voigt line shape and the atm line list. We found that the average total column of CH 4 retrieved from these 131,124 spectra, with the qSDV+LM was 1.1±0.3% higher than the retrievals performed using a Voigt and the atm line list. The airmass dependence of the retrieved total columns was found to change depending on the choice of spectral line shape. With the Voigt line shape, we found a minimum in CH 4 total columns at a solar zenith angle (SZA) of about 70°. With the qSDV+LM, the retrieved total column of CH 4 decreased monotonically as a function of SZA. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Quantitative Spectroscopy & Radiative Transfer is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=121244489
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1016/j.jqsrt.2016.12.013
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 12
        StartPage: 48
    Subjects:
      – SubjectFull: Solar radiation
        Type: general
      – SubjectFull: Absorption spectra
        Type: general
      – SubjectFull: Absorption coefficients
        Type: general
      – SubjectFull: Algorithms
        Type: general
      – SubjectFull: Monotonic functions
        Type: general
      – SubjectFull: Computer software
        Type: general
    Titles:
      – TitleFull: Using high-resolution laboratory and ground-based solar spectra to assess CH4 absorption coefficient calculations.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Mendonca, J.
      – PersonEntity:
          Name:
            NameFull: Strong, K.
      – PersonEntity:
          Name:
            NameFull: Sung, K.
      – PersonEntity:
          Name:
            NameFull: Devi, V.M.
      – PersonEntity:
          Name:
            NameFull: Toon, G.C.
      – PersonEntity:
          Name:
            NameFull: Wunch, D.
      – PersonEntity:
          Name:
            NameFull: Franklin, J.E.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 15
              M: 03
              Text: Mar2017
              Type: published
              Y: 2017
          Identifiers:
            – Type: issn-print
              Value: 00224073
          Numbering:
            – Type: volume
              Value: 190
          Titles:
            – TitleFull: Journal of Quantitative Spectroscopy & Radiative Transfer
              Type: main
ResultId 1