Water monomer linelists

Matt BarberJonathan TennysonDepartment of Physics and AstronomyUniversity College London

December 2009

Monomer line list

Extended to cover 800-20000 cm-1

Now uses HITRAN 2008 The HITRAN 2008 molecular spectroscopic database

Rothman, LS; Gordon, IE; Barbe, A, et al. JQSRT 110, 533-572 (2009) with correction to 8000 – 9000 cm-1 region

Includes calculated line profile data

IUPAC group: Recommends not using Voigt profiles – introduce speed-dependent widths

Monomer linelists: general strategy

Augment Hitran with1. Other experimental data2. Our calculated data (BT2 linelist)Aim: to model CRDS experiments at 100 C

12800 12850 12900 12950 13000 13050 13100 13150 13200

0.00E+000

1.00E-026

2.00E-026

3.00E-026

4.00E-026

5.00E-026

6.00E-026

7.00E-026

8.00E-026

HITRAN (296K)

UCL (296K)

Frequency / cm-1

Inte

nst

ity /

cm m

ol-

1UCL and HITRAN spectra compared at 296K

12800 12850 12900 12950 13000 13050 13100 13150 13200

0.00E+000

1.00E-026

2.00E-026

3.00E-026

4.00E-026

5.00E-026

6.00E-026

7.00E-026

8.00E-026

HITRAN (368K)

UCL (368K)

Frequency /cm-1

Inte

nsi

ty/ c

m m

ol-

1UCL and HITRAN spectra compared at 368K

Monomer linelists: general strategy

Augment Hitran with1. Other experimental data2. Our calculated data (BT2 linelist)Aim: to model CRDS experiments at 100 C

Extensions to this strategy:1. Calculated pressure broadening parameters

(Voronin et al) added where none present.2. Special analysis of 7000 – 10000 cm-1 region.

5000 5100 5200 5300 5400 5500 56000.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

Comparison of line lists

Frequency / cm-1

Ratio

of H

ITR

AN

08/U

CL09

6000 6500 7000 7500 8000 8500 9000 9500 10000 10500 11000

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

Frequency / cm-1

Ra

tio o

f UC

L0

9/H

ITR

AN

08

Comparison of calculated vs HITRAN intensites: near IR

Expect theory to ~2% too strong.Conclusion: HITRAN intensities 8000 - 9500 cm-1 are too weak

Monomer linelists: general strategy

Augment Hitran with1. Other experimental data2. Our calculated data (BT2 linelist)Aim: to model CRDS experiments at 100 C

Extensions to this strategy:1. Calculated pressure broadening parameters

(Voronin et al) added where none present.2. Special analysis of 7000 – 10000 cm-1 region. Calculated intensities used in place of HITRAN 8000 - 9500 cm -1.

Conclusion

Our linelists appear to make a significant difference (improvement)

Work on this now complete (?)