1. 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences Formaldehyde broadening coefficients Agnès Perrin Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), CNRS, Université Paris XII, Créteil, France Hamiltonian constants 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

2. 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences - 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

3. Bruker HR120-FTS spectrum recorded at LADIR 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences 2 band 1, 5 + 6 other bands

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

5. 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences Multispectrum fitting procedure → 284 transitions at 5.7 µm region → 456 transitions at 3.5 µm region Self-and N 2 -broadening coefficients

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

7. 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences K a dependence of the N 2 -broadening coefficients obtained at 3.5 and 5.7 µm Transitions having same value of J low = 8

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

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

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

11. 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences Empirical parameters describing the J-and K a -rotational dependence of the N 2 -broadening coefficients

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

13. 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences Line broadening (self and by N 2 ) can easily be calculated using these constants JQSRT 111 (2010), 1209-1222.

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

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

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

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

18. 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences CRB calculation of N 2 -broadening coefficients at 296 K

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

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

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

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

23. 9th HITRAN Database & Atmospheric Spectroscopy Applications conferences Conclusion → Measurements of self- and N 2 -line widths at 296K (for more than 700 transitions) → Empirical model to reproduce the rotational dependence of the measurements → CRB calculation of N 2 widths for temperatures ranging from 200 to 700K → Temperature exponents for the N 2 -widths derived from CRB calculations Generation of self-, air-widths, and n air for HITRAN 2008 line list (available as supplementary materials of JQSRT 111(2010), 1209-1222.)

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

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

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

31. For each set of γ having same J low value: J low = 8