1. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 HIGH RESOLUTION SPECTROSCOPY AND GLOBAL ANALYSIS OF THE TETRADECAD REGION OF METHANE 12 CH 4 A.NIKITIN, Institute of Atmospheric Optics, 634055 Tomsk, Russia and Laboratoire GSMA, UMR 6089 CNRS-Universit´e de Reims Champagne Ardenne, Moulin de la Housse BP 1039, Cases 16-17, F-51687 Reims Cedex 2, France; V. BOUDON, C. WENGER, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 5209 CNRS-Universit´e de Bourgogne, 9. Av. A. Savary, BP 47870, F- 21078 Dijon Cedex, France; L. R. BROWN, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, USA; S. BAUERECKER, Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland and Institut für Physikalische und Theoretische Chemie, Technische Universität Braunschweig, D-38106, Germany; S. ALBERT, M. QUACK, Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland.

2. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Contents I.The polyads of CH 4 II.Analysis of line positions III.Analysis of line intensities IV.Conclusions and perspectives

3. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 I. The polyads of methane

4. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 The polyads of methane  Global fit 

5. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 The Tetradecad vibrational sublevels

6. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Tensorial formalism Systematic expansion of effective Hamiltonian and transition moment up to any order and for any polyad scheme, thanks to group theory and tensorial methods  All interactions are automatically included  Vibrational extrapolation  Global analyses ParametersRotationVibration

7. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 II. Analysis of line positions

8. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Tetradecad analysis Starting point: 0–4800 cm -1 global analysis up to Octad: Albert et al., Chem. Phys. 356, 131–146 (2009) and HITRAN 2008 Improved analysis (although still preliminary) by Andrei Nikitin with MIRS Parameter translation to STDS STDS improvements (fit procedure, higher order vibrational terms included) Global fit: 0 – 6200 cm -1 with STDS Paper to be submitted

9. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Fit details

10. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Residuals for line positions The octad is slightly worse than in Albert et al. (but still OK)

11. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Residuals for line positions

12. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Calculated levels and mixings

13. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Observed levels and mixings

14. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 III. Analysis of line intensities

15. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Octad test

16. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Residuals for line intensities

17. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Global comparison at 296 K

18. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Global comparison at 80 K

19. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Comparison for 4ν 4 at 296 K

20. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Comparison for 4ν 4 at 78 K

21. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 IV. Conclusions and perspectives

22. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 CH 4 Spectroscopy: what next? Continue the « global fit » approach Tetradecad much better but still to improve Add new data (positions, intensities, hot bands) Icosad, … CH 4 “windows” (high J, far wings) Hot methane (combustions, brown dwarfs, hot jupiters, …) Titan / Cassini-Huygens Huygens DISR spectraBrown dwarf Gliese 229 B / HST

23. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Virtual Atomic and Molecular Data Center http://vamdc.icb.cnrs.fr/PHP/methane.php