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9th HITRAN Database & Atmospheric Spectroscopy Applications conferences

Formaldehyde broadening coefficients. David Jacquemart, Fridolin Kwabia-Tchana, and Nelly Lacome La boratoire de D ynamique, I nteractions et R éactivité ( LADIR ), CNRS, Université Pierre et Marie Curie-Paris 6, France HR FT spectra and line broadening measurements.

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9th HITRAN Database & Atmospheric Spectroscopy Applications conferences

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  1. Formaldehydebroadening coefficients David Jacquemart, Fridolin Kwabia-Tchana, and Nelly Lacome Laboratoire de Dynamique, Interactions et Réactivité (LADIR), CNRS, Université Pierre et Marie Curie-Paris 6, France HR FT spectra and line broadening measurements Anne Laraia and Bob Gamache Department of Environmental, Earth & Atmospheric Sciences University of Mass. Lowell, USA Calculation of broadening parameters Agnès Perrin Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), CNRS, Université Paris XII, Créteil, France Hamiltonian constants 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  2. - Two spectral regions of atmospheric interest: around 3.5 µm (2600-3200 cm-1) complete update in HITRAN 2008 around 5.7 µm (1700-1800 cm-1) new line list available in HITRAN 2008 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  3. n2 band n1, n5 + 6 other bands Bruker HR120-FTS spectrum recorded at LADIR 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  4. Summary of the presentation 1/ Experimental measurements of both self- and N2-broadening coefficients 2/ Empirical model for the rotational dependence of broadening coefficients 3/ Theoretical calculation of N2-broadening coefficients and their temperature exponents 4/ Comparison with literature 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  5. Multispectrum fitting procedure → 284 transitions at 5.7 µm region → 456 transitions at 3.5 µm region Self-and N2-broadening coefficients 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  6. In HITRAN: Self-widths fixed to 0.00 cm-1/atm Air-widths fixed to 0.107/0.108 cm-1/atm 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  7. Ka dependence of the N2-broadening coefficients obtained at 3.5 and 5.7 µm Transitions having same value of Jlow = 8 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  8. Summary of the presentation 1/ Experimental measurements of both self- and N2-broadening coefficients 2/ Empirical model for the rotational dependence of broadening coefficients 3/ Theoretical calculation of N2-broadening coefficients and their temperature exponents 4/ Comparison with literature 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  9. No evidence of a vibrational dependence (5.7µm  3.6 µm) Evidence of a J- and Ka-rotational dependence of the linewidths

  10. For each set of γ having same J’’ value: J’’ = 8 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  11. Empirical parameters describing the J-and Ka-rotational dependence of the N2-broadening coefficients 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  12. Empirical parameters describing the J-and Ka-rotational dependence of the self-broadening coefficients 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  13. Line broadening (self and by N2) can easily be calculated using these constants JQSRT111 (2010), 1209-1222. 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  14. Summary of the presentation 1/ Experimental measurements of both self- and N2-broadening coefficients 2/ Empirical model for the rotational dependence of broadening coefficients 3/ Theoretical calculation of N2-broadening coefficients and their temperature exponents 4/ Comparison with literature 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  15. Complex Robert-Bonamy formalism for N2-broadening coefficients Calculation done for the 2 band → Constants for dipole moment of H2CO, for quadrupole of H2CO and N2 taken from literature → Parameters for Lennard-Jones atom-atom potential have been manually fitted to match a reduced set of N2-broadening measurements 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  16. Comparison between measurements, empirical model and theoretical calculation (CRB) T = 296 K 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  17. Comparison between measurements, empirical model and theoretical calculation (CRB) T = 296 K 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  18. CRB calculation of N2-broadening coefficients at 296 K 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  19. Temperature exponent based on CRB formalism calculations at various temperatures Set of 7 temperatures: 200, 225, 275, 296, 350, 500, 700 K 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  20. Temperature exponent from CRB calculations (200-350 K) In HITRAN 2008: nair fixed to 0.7 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  21. Summary of the presentation 1/ Experimental measurements of both self- and N2-broadening coefficients 2/ Empirical model for the rotational dependence of broadening coefficients 3/ Theoretical calculation of N2-broadening coefficients and their temperature exponents 4/ Comparison with literature 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  22. Comparison for low Ka values 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  23. Conclusion → Measurements of self- and N2-line widths at 296K (for more than 700 transitions) → Empirical model to reproduce the rotational dependence of the measurements → CRB calculation of N2 widths for temperatures ranging from 200 to 700K → Temperature exponents for the N2-widths derived from CRB calculations Generation of self-, air-widths, and nair for HITRAN 2008 line list (available as supplementary materials of JQSRT 111(2010), 1209-1222.) 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  24. In the special issue dedicated to Larry 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  25. Thanks for your attention… 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  26. 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  27. 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  28. Sample of the 5.7-µm spectral region 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  29. 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  30. 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

  31. For each set of γ having same Jlow value: Jlow = 8 9th HITRAN Database& Atmospheric Spectroscopy Applications conferences

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