Poster-HITEMP - Harvard-Smithsonian Center for Astrophysics

Report
HITEMP, the high-temperature molecular spectroscopic database
Laurence S. Rothman,a Iouli E. Gordona
R.J. Barber,b J. Tennyson,b V.I. Perevalov,c S.A. Tashkun,c
A. Goldman,d R.R. Gamache,e H. Dothef
aHarvard-Smithsonian
Center for Astrophysics,
Atomic & Molecular Physics Division, Cambridge MA, USA
bUniversity College London, London, UK
cInstitute of Atmospheric Optics, Tomsk, RUSSIA
dUniversity
of Denver, Denver CO, USA
eUniversity of Massachusetts, Lowell MA, USA
fSpectral Sciences Inc., Burlington MA, USA
Files contained in new HITEMP database
A new molecular spectroscopic database for high-temperature
modeling of the spectra of molecules in the gas phase is described.
This database, called HITEMP, is analogous to the HITRAN database
but encompasses many more bands and transitions than HITRAN for
the absorbers H2O, CO2, CO, NO, and OH. HITEMP provides users
with a powerful tool for a great many applications: astrophysics,
planetary and stellar atmospheres, industrial processes, surveillance,
non-local thermodynamic equilibrium problems, and investigating
molecular interactions, to name a few. The structure and content of
the HITEMP database are described. Some examples of the
simulations that are enabled by HITEMP are presented.
The compilation is available on a public ftp-site at the HarvardSmithsonian Center for Astrophysics <cfa-ftp.harvard.edu>.
Contact author for access instructions.
Mol_v1-v2_HITEMP2010.zip
Comparison of line lists
Spectral
coverage
(cm-1)
Molecule
Number of
isotopologues
(HITEMP2010)
Number of
transitions
(HITEMP2010)
Number of
transitions
(HITEMP1995)
Number of
transitions
(HITRAN)*
Dissociation
Energy
(cm-1)
H2O
0 – 30 000
6
114 241 164
1 283 486
69 201
41 146
CO2
5 – 12 785
7
11 193 608
1 032 269
312 479
44 360
CO
0 – 8 465
6
113 631
113 022
4 477
90 674
NO
0 – 9 274
3
115 610
---
105 079
52 265
OH
0 – 19 268
3
41 557
40 055
31 976
35 593
* The number of transitions listed in this column are for the equivalent
number of isotopologues and spectral range consistent with HITEMP2010
HITEMP Line-by-line Spectroscopic Parameters
Parameter
Field
size
Definition
Mol
I2
Molecule number
Iso
I1
Isotopologue no.(1 = most abundant, 2 = second most abundant, …)
νif
F12.6
Transition wavenumber in vacuum [cm-1]
Sif
E10.3 Intensity [cm-1/(molecule∙cm-2) @ 296K]
Aif
E10.3 Einstein A-coefficient [s-1]
γair
F5.4
Air-broadened half-width (HWHM) [cm-1/atm @ 296K]
γself
F5.3
Self-broadened half-width (HWHM) [cm-1/atm @ 296K]
E″
F10.4
Lower-state energy [cm-1]
nair
F4.2
Temperature-dependence coefficient of γair
δair
F8.6
Air pressure-induced shift [cm-1/atm @ 296K]
v′, v″
2A15
Upper and Lower “global” quanta
q′, q″
2A15
Upper and Lower “local” quanta
ierr
6I1
Uncertainty indices for νif , Sif , γair , γself , nair , δair
iref
6I2
Reference pointers for νif , Sif , γair , γself , nair , δair
*
A1
Flag for line-coupling algorithm
2F7.1
Upper and Lower statistical weights
g′, g″
Data Sources
• H2O: See flow diagram below.
• CO2: CDSD (carbon dioxide spectroscopic databank) 296, Venus,
and 1000K versions.
• CO: Solar atlas, D. Goorvitch, “Infrared CO line list for the X1Σ+
state,” Astrophys J Suppl Ser 95, 535–52 (1994) plus HITRAN
updates.
• NO: Extension of HITRAN parameters (Goldman et al)
• OH: Goldman et al line list, updated with re-analysis of solar
spectrum by R. Colin and P.F. Bernath
Flow diagram of water-vapor line list assembly
160-character total
Note: field descriptor adjusted for intensities with exponents lower than 10-99, for example carbon monoxide.
A whole new internet-based software system for HITRAN
is under development at the Institute of Atmospheric Optics
in Tomsk, Russia. You can access this program by going to
HITRAN on the Web <http://hitran.iao.ru/>.
New paradigms for the structure and retrieval of HITRAN
and HITEMP data are also under development through the
programs of the IUPAC water-vapor task group1 and the
Virtual Atomic and Molecular Data Centre (VAMDC)2.
BT2: R.J. Barber, J. Tennyson, G.J. Harris, R.N. Tolchenov, “A high-accuracy computed water line list,”
Mon Not R Astron Soc 368, 1087-94 (2006).
__________________________________________________________________________________
1. J. Tennyson et al, JQSRT 110, 573-96 (2009); 111, 2160-84 (2010).
2. M.L. Dubernet et al, JQSRT 111, 2151-59 (2010).
Some Recent Successes and the Future of HITEMP
Comparison of new high-temperature laboratory data (1200K H2O) from Stanford University
with HITRAN2008, HITEMP1995, and HITEMP2010
HITEMP2010 revisions improve simulation at 7471.61 and 7472.05 cm-1 1200K.
Only minor differences between simulations and SU data remain.
There are many topics planned for extending the
HITEMP compilation. These areas include:
CO2 simulations
► Adding molecular species:
CH4, NH3, NO+, hydrogen halides, N2O, C2H2, ...
Obs
HITEMP
HITEMP95
► Increasing the bands and lines to include
weaker features
► Extending to higher temperature regime
► Improving line-shape parameters as well as
adding broadeners
► Completing partition sums
Wavenumber (cm-1)
Conditions: T = 1200 K, 25 Torr Neat H2O, 152.4 cm path length
private communication: C. Goldenstein, J.B. Jeffries, and R.K. Hanson (2010)
Wavenumber (cm-1)
Conditions: T = 1200 K, 25 Torr Neat H2O, 152.4 cm path length
private communication: C. Goldenstein, J.B. Jeffries, and R.K. Hanson (2010)
Obs: D. Scutaru, L. Rosenmann, J. Taine, “Approximate intensities of
CO2 hot bands at 2.7, 4.3, and 12 μm for high temperature and medium
resolution applications,” JQSRT 52, 765–781 (1994) . (Pressure 1 atm,
Pathlength 7.75 cm, CO2 concentration 100%, ILS full width at half
maximum: 3 cm-1)
► Improving the accuracy of parameters
► Developing related database structures
Bootstrapping with recent highresolution, high-temperature experiments
permits improvement in judging the best
line list. It is hoped that the work of the
IUPAC water-vapor task group on the
main isotopologue of water will also
provide greater improvements.
HITEMP setting the pace for HITRAN?
Normally, the higher accuracy of transitions
in HITRAN has warranted the substitution
of identical transitions from HITRAN into
HITEMP. The generation of lines necessary
for HITEMP has led to a more complete
listing for future HITRAN editions, with no
“unidentified” transitions.
Obs
HITEMP
HITEMP95
Obs: S.P. Bharadwaj, M.F. Modest, “Medium resolution transmission
measurements of CO2 at high temperature - an update,” JQSRT 103,
146-55 (2007). (Pressure 1 atm, Pathlength 50 cm, CO2 concentration
100%, ILS full width at half maximum: 4 cm-1)
This effort has been supported by the
NASA Earth Observing System (EOS)
program, under grant NAG5-13534, the
NASA Planetary Atmospheres program
under grant NNX10AB94G, and a grant
from the US Civilian Research and
Development Foundation.

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