Abstract

Room temperature argon broadened halfwidth and pressure-induced line shift coefficients have been determined for 118 transitions in the ν4 band of 12CH4 from analysis of high resolution laboratory absorption spectra recorded with the McMath Fourier transform spectrometer operated on Kitt Peak by the National Solar Observatory. Transitions up to J″ = 12 have been measured using a nonlinear least-squares spectral fitting procedure. The variation of the measured halfwidth coefficients with symmetry type and rotational quantum number is very similar to that measured previously for N2 and air broadening, but the absolute values of the argon broadening coefficients are all smaller. On average, the ratio of the argon broadened halfwidth coefficient to the corresponding N2 broadened halfwidth coefficient is 0.877 ± 0.017 (2σ). More than 95% of the pressure-induced shifts are negative with values ranging from −0.0081 to +0.0055 cm−1 atm−1. The pressure shifts in argon are nearly equal to corresponding values measured previously in N2 and air.

© 1989 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. V. Malathy Devi, C. P. Rinsland, M. A. H. Smith, D. C. Benner, “Measurements of 12CH4ν4 Band Halfwidths Using a Tunable Diode Laser System and a Fourier Transform Spectrometer,” Appl. Opt. 24, 2788–2791 (1985).
    [CrossRef] [PubMed]
  2. V. Malathy Devi, C. P. Rinsland, M. A. H. Smith, D. C. Benner, “Tunable Diode Laser Measurements of Widths of Air-and Nitrogen-Broadened Lines in the ν4 Band of 13CH4,” Appl. Opt. 24, 3321–3322 (1985).
    [CrossRef] [PubMed]
  3. C. P. Rinsland, V. Malathy Devi, M. A. H. Smith, D. C. Benner, “Measurements of Air-Broadened and Nitrogen-Broadened Lorentz Width Coefficients and Pressure Shift Coefficients in the ν4 and ν2 Bands of 12CH4,” Appl. Opt. 27, 631–651 (1988).
    [CrossRef] [PubMed]
  4. V. Malathy Devi, C. P. Rinsland, M. A. H. Smith, D. C. Benner, “Air-Broadened Lorentz Halfwidths and Pressure-Induced Line Shifts in the ν4 Band of 13CH4,” Appl. Opt. 27, 2296–2308 (1988).
    [CrossRef]
  5. D. M. Hunten, M. G. Tomasko, F. M. Flasar, R. E. Samuelson, D. F. Strobel, D. J. Stevenson, “Titan,” in Saturn, T. Gehrels, M. S. Matthews, Eds. (U. Arizona Press, Tucson, 1984), pp. 671–759.
  6. C. R. Webster, S. Sander, R. Beer, J. Ballard, “Titan Probe Diode Laser Spectrometer,” in Proceedings, Atmospheric Spectroscopy Applications Workshop, Rutherford Appleton Laboratory, 1–3 Sept. 1987, J. Ballard, Ed., Rutherford Appleton Laboratory Publ. RAL-88-009 (1987), paper 12.5.
  7. C. R. Webster, “Stratospheric Composition Measurements of Earth and Titan Using High-Resolution Tunable Diode Laser Spectroscopy,” J. Quant. Spectrosc. Radiat. Transfer, in press.
  8. C. P. Rinsland, D. C. Benner, D. J. Richardson, R. A. Toth, “Absolute Intensity Measurements of the (1110)II ← 0000 Band of 12C16O2 at 5.2 μm,” Appl. Opt. 22, 3805–3809 (1983).
    [CrossRef] [PubMed]
  9. L. R. Brown, R. A. Toth, “Comparison of the Frequencies of NH3, CO2, H2O, N2O, CO, and CH4 as Infrared Calibration Standards,” J. Opt. Soc. Am. B 2, 842–856 (1985).
    [CrossRef]
  10. P. Varanasi, L. A. Pugh, B. R. P. Bangaru, “Measurement of Multiplet Intensities and Noble Gas-Broadened Line Widths in the ν4-Fundamental of Methane,” J. Quant. Spectrosc. Radiat. Transfer 14, 829–838 (1974).
    [CrossRef]
  11. P. Varanasi, S. Chudamani, “Measurements of Collision-Broadened Line Widths in the ν4-Fundamental Band of 12CH4 at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer, in press.
  12. L. S. Rothman et al., “The HITRAN Database: 1986 Edition,” Appl. Opt. 26, 4058–4097 (1987).
    [CrossRef] [PubMed]
  13. P. Varanasi, S. Chudamani, “Intensity and Line Width Measurements in the ν4-Fundamental Band of 13CH4,” J. Geophys. Res., in press.
  14. K. Fox, D. E. Jennings, E. A. Stern, R. Hubbard, “Measurements of Argon-, Helium-, Hydrogen-, and Nitrogen-Broadened Widths of Methane Lines near 9000 cm−1,” J. Quant. Spectrosc. Radiat. Transfer 39, 473–476 (1988).
    [CrossRef]
  15. H. J. Gerritsen, M. E. Heller, “High-Resolution Tuned-Laser Spectroscope,” Appl. Opt. Suppl. 2, 73–77 (1965).
  16. M. A. H. Smith, C. P. Rinsland, B. Fridovich, K. Narahari Rao, “Intensities and Collision Broadening Parameters from Infrared Spectra,” in Molecular Spectroscopy: Modern Research, Vol. 3, K. Narahari Rao, Ed. (Academic, Orlando, FL, 1985), Chap. 3.
  17. G. D. T. Tejwani, P. Varanasi, K. Fox, “Collision-Broadened Linewidths of Tetrahedral Molecules-II. Computations for CH4 Lines Broadened by N2, O2, He, Ne and Ar,” J. Quant. Spectrosc. Radiat. Transfer 15, 243–254 (1975).
    [CrossRef]
  18. P. Varanasi, “Collision-Broadened Line Widths of Tetrahedral Molecules—I. Theoretical Formulation,” J. Quant. Spectrosc. Radiat. Transfer 14, 995–1008 (1974).
    [CrossRef]
  19. P. Varanasi, “Infrared Line Widths at Planetary Atmospheric Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 39, 13–25 (1988).
    [CrossRef]

1988 (4)

C. P. Rinsland, V. Malathy Devi, M. A. H. Smith, D. C. Benner, “Measurements of Air-Broadened and Nitrogen-Broadened Lorentz Width Coefficients and Pressure Shift Coefficients in the ν4 and ν2 Bands of 12CH4,” Appl. Opt. 27, 631–651 (1988).
[CrossRef] [PubMed]

V. Malathy Devi, C. P. Rinsland, M. A. H. Smith, D. C. Benner, “Air-Broadened Lorentz Halfwidths and Pressure-Induced Line Shifts in the ν4 Band of 13CH4,” Appl. Opt. 27, 2296–2308 (1988).
[CrossRef]

K. Fox, D. E. Jennings, E. A. Stern, R. Hubbard, “Measurements of Argon-, Helium-, Hydrogen-, and Nitrogen-Broadened Widths of Methane Lines near 9000 cm−1,” J. Quant. Spectrosc. Radiat. Transfer 39, 473–476 (1988).
[CrossRef]

P. Varanasi, “Infrared Line Widths at Planetary Atmospheric Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 39, 13–25 (1988).
[CrossRef]

1987 (1)

1985 (3)

1983 (1)

1975 (1)

G. D. T. Tejwani, P. Varanasi, K. Fox, “Collision-Broadened Linewidths of Tetrahedral Molecules-II. Computations for CH4 Lines Broadened by N2, O2, He, Ne and Ar,” J. Quant. Spectrosc. Radiat. Transfer 15, 243–254 (1975).
[CrossRef]

1974 (2)

P. Varanasi, “Collision-Broadened Line Widths of Tetrahedral Molecules—I. Theoretical Formulation,” J. Quant. Spectrosc. Radiat. Transfer 14, 995–1008 (1974).
[CrossRef]

P. Varanasi, L. A. Pugh, B. R. P. Bangaru, “Measurement of Multiplet Intensities and Noble Gas-Broadened Line Widths in the ν4-Fundamental of Methane,” J. Quant. Spectrosc. Radiat. Transfer 14, 829–838 (1974).
[CrossRef]

1965 (1)

H. J. Gerritsen, M. E. Heller, “High-Resolution Tuned-Laser Spectroscope,” Appl. Opt. Suppl. 2, 73–77 (1965).

Ballard, J.

C. R. Webster, S. Sander, R. Beer, J. Ballard, “Titan Probe Diode Laser Spectrometer,” in Proceedings, Atmospheric Spectroscopy Applications Workshop, Rutherford Appleton Laboratory, 1–3 Sept. 1987, J. Ballard, Ed., Rutherford Appleton Laboratory Publ. RAL-88-009 (1987), paper 12.5.

Bangaru, B. R. P.

P. Varanasi, L. A. Pugh, B. R. P. Bangaru, “Measurement of Multiplet Intensities and Noble Gas-Broadened Line Widths in the ν4-Fundamental of Methane,” J. Quant. Spectrosc. Radiat. Transfer 14, 829–838 (1974).
[CrossRef]

Beer, R.

C. R. Webster, S. Sander, R. Beer, J. Ballard, “Titan Probe Diode Laser Spectrometer,” in Proceedings, Atmospheric Spectroscopy Applications Workshop, Rutherford Appleton Laboratory, 1–3 Sept. 1987, J. Ballard, Ed., Rutherford Appleton Laboratory Publ. RAL-88-009 (1987), paper 12.5.

Benner, D. C.

Brown, L. R.

Chudamani, S.

P. Varanasi, S. Chudamani, “Intensity and Line Width Measurements in the ν4-Fundamental Band of 13CH4,” J. Geophys. Res., in press.

P. Varanasi, S. Chudamani, “Measurements of Collision-Broadened Line Widths in the ν4-Fundamental Band of 12CH4 at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer, in press.

Flasar, F. M.

D. M. Hunten, M. G. Tomasko, F. M. Flasar, R. E. Samuelson, D. F. Strobel, D. J. Stevenson, “Titan,” in Saturn, T. Gehrels, M. S. Matthews, Eds. (U. Arizona Press, Tucson, 1984), pp. 671–759.

Fox, K.

K. Fox, D. E. Jennings, E. A. Stern, R. Hubbard, “Measurements of Argon-, Helium-, Hydrogen-, and Nitrogen-Broadened Widths of Methane Lines near 9000 cm−1,” J. Quant. Spectrosc. Radiat. Transfer 39, 473–476 (1988).
[CrossRef]

G. D. T. Tejwani, P. Varanasi, K. Fox, “Collision-Broadened Linewidths of Tetrahedral Molecules-II. Computations for CH4 Lines Broadened by N2, O2, He, Ne and Ar,” J. Quant. Spectrosc. Radiat. Transfer 15, 243–254 (1975).
[CrossRef]

Fridovich, B.

M. A. H. Smith, C. P. Rinsland, B. Fridovich, K. Narahari Rao, “Intensities and Collision Broadening Parameters from Infrared Spectra,” in Molecular Spectroscopy: Modern Research, Vol. 3, K. Narahari Rao, Ed. (Academic, Orlando, FL, 1985), Chap. 3.

Gerritsen, H. J.

H. J. Gerritsen, M. E. Heller, “High-Resolution Tuned-Laser Spectroscope,” Appl. Opt. Suppl. 2, 73–77 (1965).

Heller, M. E.

H. J. Gerritsen, M. E. Heller, “High-Resolution Tuned-Laser Spectroscope,” Appl. Opt. Suppl. 2, 73–77 (1965).

Hubbard, R.

K. Fox, D. E. Jennings, E. A. Stern, R. Hubbard, “Measurements of Argon-, Helium-, Hydrogen-, and Nitrogen-Broadened Widths of Methane Lines near 9000 cm−1,” J. Quant. Spectrosc. Radiat. Transfer 39, 473–476 (1988).
[CrossRef]

Hunten, D. M.

D. M. Hunten, M. G. Tomasko, F. M. Flasar, R. E. Samuelson, D. F. Strobel, D. J. Stevenson, “Titan,” in Saturn, T. Gehrels, M. S. Matthews, Eds. (U. Arizona Press, Tucson, 1984), pp. 671–759.

Jennings, D. E.

K. Fox, D. E. Jennings, E. A. Stern, R. Hubbard, “Measurements of Argon-, Helium-, Hydrogen-, and Nitrogen-Broadened Widths of Methane Lines near 9000 cm−1,” J. Quant. Spectrosc. Radiat. Transfer 39, 473–476 (1988).
[CrossRef]

Malathy Devi, V.

Narahari Rao, K.

M. A. H. Smith, C. P. Rinsland, B. Fridovich, K. Narahari Rao, “Intensities and Collision Broadening Parameters from Infrared Spectra,” in Molecular Spectroscopy: Modern Research, Vol. 3, K. Narahari Rao, Ed. (Academic, Orlando, FL, 1985), Chap. 3.

Pugh, L. A.

P. Varanasi, L. A. Pugh, B. R. P. Bangaru, “Measurement of Multiplet Intensities and Noble Gas-Broadened Line Widths in the ν4-Fundamental of Methane,” J. Quant. Spectrosc. Radiat. Transfer 14, 829–838 (1974).
[CrossRef]

Richardson, D. J.

Rinsland, C. P.

Rothman, L. S.

Samuelson, R. E.

D. M. Hunten, M. G. Tomasko, F. M. Flasar, R. E. Samuelson, D. F. Strobel, D. J. Stevenson, “Titan,” in Saturn, T. Gehrels, M. S. Matthews, Eds. (U. Arizona Press, Tucson, 1984), pp. 671–759.

Sander, S.

C. R. Webster, S. Sander, R. Beer, J. Ballard, “Titan Probe Diode Laser Spectrometer,” in Proceedings, Atmospheric Spectroscopy Applications Workshop, Rutherford Appleton Laboratory, 1–3 Sept. 1987, J. Ballard, Ed., Rutherford Appleton Laboratory Publ. RAL-88-009 (1987), paper 12.5.

Smith, M. A. H.

Stern, E. A.

K. Fox, D. E. Jennings, E. A. Stern, R. Hubbard, “Measurements of Argon-, Helium-, Hydrogen-, and Nitrogen-Broadened Widths of Methane Lines near 9000 cm−1,” J. Quant. Spectrosc. Radiat. Transfer 39, 473–476 (1988).
[CrossRef]

Stevenson, D. J.

D. M. Hunten, M. G. Tomasko, F. M. Flasar, R. E. Samuelson, D. F. Strobel, D. J. Stevenson, “Titan,” in Saturn, T. Gehrels, M. S. Matthews, Eds. (U. Arizona Press, Tucson, 1984), pp. 671–759.

Strobel, D. F.

D. M. Hunten, M. G. Tomasko, F. M. Flasar, R. E. Samuelson, D. F. Strobel, D. J. Stevenson, “Titan,” in Saturn, T. Gehrels, M. S. Matthews, Eds. (U. Arizona Press, Tucson, 1984), pp. 671–759.

Tejwani, G. D. T.

G. D. T. Tejwani, P. Varanasi, K. Fox, “Collision-Broadened Linewidths of Tetrahedral Molecules-II. Computations for CH4 Lines Broadened by N2, O2, He, Ne and Ar,” J. Quant. Spectrosc. Radiat. Transfer 15, 243–254 (1975).
[CrossRef]

Tomasko, M. G.

D. M. Hunten, M. G. Tomasko, F. M. Flasar, R. E. Samuelson, D. F. Strobel, D. J. Stevenson, “Titan,” in Saturn, T. Gehrels, M. S. Matthews, Eds. (U. Arizona Press, Tucson, 1984), pp. 671–759.

Toth, R. A.

Varanasi, P.

P. Varanasi, “Infrared Line Widths at Planetary Atmospheric Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 39, 13–25 (1988).
[CrossRef]

G. D. T. Tejwani, P. Varanasi, K. Fox, “Collision-Broadened Linewidths of Tetrahedral Molecules-II. Computations for CH4 Lines Broadened by N2, O2, He, Ne and Ar,” J. Quant. Spectrosc. Radiat. Transfer 15, 243–254 (1975).
[CrossRef]

P. Varanasi, “Collision-Broadened Line Widths of Tetrahedral Molecules—I. Theoretical Formulation,” J. Quant. Spectrosc. Radiat. Transfer 14, 995–1008 (1974).
[CrossRef]

P. Varanasi, L. A. Pugh, B. R. P. Bangaru, “Measurement of Multiplet Intensities and Noble Gas-Broadened Line Widths in the ν4-Fundamental of Methane,” J. Quant. Spectrosc. Radiat. Transfer 14, 829–838 (1974).
[CrossRef]

P. Varanasi, S. Chudamani, “Measurements of Collision-Broadened Line Widths in the ν4-Fundamental Band of 12CH4 at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer, in press.

P. Varanasi, S. Chudamani, “Intensity and Line Width Measurements in the ν4-Fundamental Band of 13CH4,” J. Geophys. Res., in press.

Webster, C. R.

C. R. Webster, “Stratospheric Composition Measurements of Earth and Titan Using High-Resolution Tunable Diode Laser Spectroscopy,” J. Quant. Spectrosc. Radiat. Transfer, in press.

C. R. Webster, S. Sander, R. Beer, J. Ballard, “Titan Probe Diode Laser Spectrometer,” in Proceedings, Atmospheric Spectroscopy Applications Workshop, Rutherford Appleton Laboratory, 1–3 Sept. 1987, J. Ballard, Ed., Rutherford Appleton Laboratory Publ. RAL-88-009 (1987), paper 12.5.

Appl. Opt. (6)

Appl. Opt. Suppl. (1)

H. J. Gerritsen, M. E. Heller, “High-Resolution Tuned-Laser Spectroscope,” Appl. Opt. Suppl. 2, 73–77 (1965).

J. Opt. Soc. Am. B (1)

J. Quant. Spectrosc. Radiat. Transfer (5)

P. Varanasi, L. A. Pugh, B. R. P. Bangaru, “Measurement of Multiplet Intensities and Noble Gas-Broadened Line Widths in the ν4-Fundamental of Methane,” J. Quant. Spectrosc. Radiat. Transfer 14, 829–838 (1974).
[CrossRef]

G. D. T. Tejwani, P. Varanasi, K. Fox, “Collision-Broadened Linewidths of Tetrahedral Molecules-II. Computations for CH4 Lines Broadened by N2, O2, He, Ne and Ar,” J. Quant. Spectrosc. Radiat. Transfer 15, 243–254 (1975).
[CrossRef]

P. Varanasi, “Collision-Broadened Line Widths of Tetrahedral Molecules—I. Theoretical Formulation,” J. Quant. Spectrosc. Radiat. Transfer 14, 995–1008 (1974).
[CrossRef]

P. Varanasi, “Infrared Line Widths at Planetary Atmospheric Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 39, 13–25 (1988).
[CrossRef]

K. Fox, D. E. Jennings, E. A. Stern, R. Hubbard, “Measurements of Argon-, Helium-, Hydrogen-, and Nitrogen-Broadened Widths of Methane Lines near 9000 cm−1,” J. Quant. Spectrosc. Radiat. Transfer 39, 473–476 (1988).
[CrossRef]

Other (6)

M. A. H. Smith, C. P. Rinsland, B. Fridovich, K. Narahari Rao, “Intensities and Collision Broadening Parameters from Infrared Spectra,” in Molecular Spectroscopy: Modern Research, Vol. 3, K. Narahari Rao, Ed. (Academic, Orlando, FL, 1985), Chap. 3.

P. Varanasi, S. Chudamani, “Intensity and Line Width Measurements in the ν4-Fundamental Band of 13CH4,” J. Geophys. Res., in press.

P. Varanasi, S. Chudamani, “Measurements of Collision-Broadened Line Widths in the ν4-Fundamental Band of 12CH4 at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer, in press.

D. M. Hunten, M. G. Tomasko, F. M. Flasar, R. E. Samuelson, D. F. Strobel, D. J. Stevenson, “Titan,” in Saturn, T. Gehrels, M. S. Matthews, Eds. (U. Arizona Press, Tucson, 1984), pp. 671–759.

C. R. Webster, S. Sander, R. Beer, J. Ballard, “Titan Probe Diode Laser Spectrometer,” in Proceedings, Atmospheric Spectroscopy Applications Workshop, Rutherford Appleton Laboratory, 1–3 Sept. 1987, J. Ballard, Ed., Rutherford Appleton Laboratory Publ. RAL-88-009 (1987), paper 12.5.

C. R. Webster, “Stratospheric Composition Measurements of Earth and Titan Using High-Resolution Tunable Diode Laser Spectroscopy,” J. Quant. Spectrosc. Radiat. Transfer, in press.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)

Fig. 1
Fig. 1

Example of a least-squares fit to one of the laboratory spectra. The fitted region contains the strong R(1) F21←F11 line of 12CH4 at 1316.8272 cm−1. The spectrum was recorded at 0.010-cm−1 resolution and 22.4°C with a sample of 0.407% natural CH4 by volume in argon, a total pressure of 499.9 Torr, and a 25-cm absorption path. The lower panel shows a plot of the laboratory spectrum (solid line) and the least-squares best fit to the data (plus symbols). Residuals in the upper panel (observed minus calculated values) are shown on an expanded vertical scale and are expressed as a percentage of the peak measured intensity in the fitted region. The residual water vapor line marked beneath the spectrum by a solid circle is the ( J = 7 , K a = 4 , K c = 3 ) ( J = 8 , K a = 5 , K c = 4 ) ν 2 band line of H216O at 1316.973 cm−1. (Primes and double primes indicate upper and lower state rotational quantum numbers, respectively.)

Fig. 2
Fig. 2

Upper plot shows measured Lorentz halfwidth at 296 K vs total sample pressure for the R(1) F21←F11 line of 12CH4 at 1316.8272 cm−1. The fitted broadening coefficient corresponds to the slope of the least-squares fit (solid line passing close to the measurements and through the origin). The lower plot presents calibrated line position vs total sample pressure for the same transition. The unshifted line position and pressure-induced line shift coefficient correspond, respectively, to the ordinate intercept and slope of the least-squares fit (solid line passing close to the measurements).

Fig. 3
Fig. 3

Plot of b L 0 ( Ar ) vs b L 0 ( N 2 ). Error bars are 2-σ statistical error limits. The dashed line shows the relation b L 0 ( Ar ) = 0 . 879 b L 0 ( N 2 ) obtained from fitting the data.

Fig. 4
Fig. 4

Comparison of line shift coefficients measured for argon broadening and nitrogen broadening. Error bars show 2-σ statistical error limits. The dashed line indicates the relation obtained for equal line shifts in argon and N2.

Tables (2)

Tables Icon

Table I Halfwidth and Pressure-induced Lineshift Coefficientsa Measured in the ν4 Band of 12CH4

Tables Icon

Table II Comparison of Argon-Broadened Halfwidth Coefficients Measured at Room Temperature in the ν4 Band of 12CH4

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

b L = b L 0 p , ν L = ν 0 + δ 0 p ,

Metrics