SOIR Spectroscopy

1. SOIRSpectroscopy A.C. Vandaele, R. Drummond, A. Mahieux, S. Robert, V. Wilquet SOIR Team @ Belgian Institute for Space Aeronomy (IASB-BIRA)

2. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

3. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

4. Introduction (1) « Study of the electromagnetic radiation emitted or absorbed by a chemical specie » The molecules disassociate The molecules vibrate The molecules rotate Detection of molecular species Physical properties (geometry) quantity conditions (temperature, pressure) Intensity wavelength (l)

5. Introduction (2) 1 orbit  4 diffraction orders CO2 & HCl H2O CO2 CO Wavenumber (cm-1)

6. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

7. HITRAN Database • high-resolution transmission molecular absorption database • The HITRAN'2008 Database contains 2 713 968 spectral lines for 39 different molecules. http://www.cfa.harvard.edu/hitran http://hitran.iao.ru/ Need to be adapted for the CO2-rich atmosphere of Venus Literature: Toth and Darnton, JMS 49, 100-105 (1974) ; Sung & Varanasi, JQSRT 91, 319-322 (2005) ; L.R. Brown, C.M.Humphrey, R.R. Gamache et al., JMS 246 (2007) ; R.R. Gamache, A.L. Laraia, J. Lamouroux, Icarus 213, 720-730 (2011)

8. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

9. ! Spectral characteristics SOIR characteristics to keep in mind: • Spectral resolution : from 0.12 up to 0.21 cm-1 • Spectral range : 2200 - 4400 cm-1 (4.4 – 2.2 µm) • Main IR absorbing species : H2O, CO2, CO, HCl, … • Temperature range: 100 - 350K • Pressure range: 10-2 - 10-8 bar • Order addition

10. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

11. 626 636 628 627 CO2: isotopologues (1) Transmittance Wavenumber (cm-1)

12. CO2 isotopologues (3) : Diffraction order 149 3355 3330 Wavenumber (cm-1)

13. CO2 isotopologues (4) : Diffraction order 119 2660 2682 Wavenumber (cm-1)

14. HCl Transmittance X SPECIES Wavenumber (cm-1) New vibrational band 0 1 1 11- 0 0 0 01 band of 16O12C18O was not present in HITRAN or CDSD 2950 2975 Wilquet et al., JQSRT, 109, 895-905, 2008

15. New hot band CO2(628) 2 0 0 01 – 0 0 0 01 & 2 1 1 01 – 0 1 1 01 bands Orders 122 - 125 Never recorded in a laboratory

16. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

17. Orders 188…191 Orders 183…185 CO isotopologues (1) 2-0 Line intensity (HITRAN) Wavenumber (cm-1)

18. CO isotopologues (2) : Diffraction order 191 4298 4276 Wavenumber (cm-1)

19. CO isotopologues (3) : Diffraction order 185 4140 4165 Wavenumber (cm-1)

20. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

21. Orders 130…133 HCl isotopologues (1) 1-0 Wavenumber (cm-1)

22. HCl isotopologues (2) 2930 2919 Wavenumber (cm-1)

23. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

24. HF: Isotopologues

25. Overview • Introduction • HITRAN Database • Spectral characteristics • CO2 • CO • HCl • HF • H2O

26. H2O: isotopologues

28. New hot band CO2(628) 2 1 1 01 – 0 1 1 01 band & non-fitted HCl lines Order 125 – Orbit 1038.1 (bin 1) T= 186.7K ; p=0.074 mbar HCl

29. Exotic isotopologue CO2(638) 2 0 0 01 – 0 0 0 01 band & HDO lines T= 201.8K ; p=1.376 mbar Order 121 – Orbit 1374.1 (bin 1)

30. Spectral analysis Calibration usingHDO lines

31. Spectral analysis Calibration usingHDO lines