1. * The number of transitions listed in this column are for the equivalent number of isotopologues and spectral range consistent with HITEMP2010 Comparison of line lists HITEMP, the high-temperature molecular spectroscopic database Laurence S. Rothman, a Iouli E. Gordon a R.J. Barber, b J. Tennyson, b V.I. Perevalov, c S.A. Tashkun, c A. Goldman, d R.R. Gamache, e H. Dothe f 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 H 2 O, CO 2, 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 Harvard- Smithsonian Center for Astrophysics. Contact author for access instructions. There are many topics planned for extending the HITEMP compilation. These areas include: ► Adding molecular species: CH 4, NH 3, NO +, hydrogen halides, N 2 O, C 2 H 2,... ► 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 ► Improving the accuracy of parameters ► Developing related database structures HITEMP Line-by-line Spectroscopic Parameters 160-character total Parameter Field size Definition Mol I2 Molecule number Iso I1 Isotopologue no.(1 = most abundant, 2 = second most abundant, …) ν if F12.6 Transition wavenumber in vacuum [cm -1 ] S if E10.3 Intensity [cm -1 /(molecule∙cm -2 ) @ 296K] A if E10.3 Einstein A-coefficient [s -1 ] γ air F5.4 Air-broadened half-width (HWHM) [cm -1 /atm @ 296K] γ self F5.3 Self-broadened half-width (HWHM) [cm -1 /atm @ 296K] E″ F10.4 Lower-state energy [cm -1 ] n air F4.2 Temperature-dependence coefficient of γ air δ air 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 ν if, S if, γ air, γ self, n air, δ air iref 6I2 Reference pointers for ν if, S if, γ air, γ self, n air, δ air * A1 Flag for line-coupling algorithm g′, g″ 2F7.1 Upper and Lower statistical weights 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. 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. Some Recent Successes and the Future of HITEMP 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. 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 group 1 and the Virtual Atomic and Molecular Data Centre (VAMDC) 2. __________________________________________________________________________________ 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). d University of Denver, Denver CO, USA e University of Massachusetts, Lowell MA, USA f Spectral Sciences Inc., Burlington MA, USA CO 2 simulations Obs HITEMP HITEMP95 Obs: S.P. Bharadwaj, M.F. Modest, “Medium resolution transmission measurements of CO 2 at high temperature - an update,” JQSRT 103, 146-55 (2007). ( Pressure 1 atm, Pathlength 50 cm, CO 2 concentration 100%, ILS full width at half maximum: 4 cm -1 ) Obs HITEMP HITEMP95 Obs: D. Scutaru, L. Rosenmann, J. Taine, “Approximate intensities of CO 2 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, CO 2 concentration 100%, ILS full width at half maximum: 3 cm -1 ) Files contained in new HITEMP database Mol_v1-v2_HITEMP2010.zip Molecule Spectral coverage (cm -1 ) Number of isotopologues (HITEMP2010) Number of transitions (HITEMP2010) Number of transitions (HITEMP1995) Number of transitions (HITRAN)* Dissociation Energy (cm -1 ) H2OH2O 0 – 30 0006114 241 1641 283 48669 20141 146 CO 2 5 – 12 785711 193 6081 032 269312 47944 360 CO 0 – 8 4656113 631113 0224 47790 674 NO 0 – 9 2743115 610- - -105 07952 265 OH 0 – 19 268341 55740 05531 97635 593 Flow diagram of water-vapor line list assembly 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). a Harvard-Smithsonian Center for Astrophysics, Atomic & Molecular Physics Division, Cambridge MA, USA b University College London, London, UK c Institute of Atmospheric Optics, Tomsk, RUSSIA Data Sources H 2 O: See flow diagram below. CO 2 : CDSD (carbon dioxide spectroscopic databank) 296, Venus, and 1000K versions. CO: Solar atlas, D. Goorvitch, “Infrared CO line list for the X 1 Σ + 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 Note: field descriptor adjusted for intensities with exponents lower than 10 -99, for example carbon monoxide. Comparison of new high-temperature laboratory data (1200K H 2 O) from Stanford University with HITRAN2008, HITEMP1995, and HITEMP2010 Wavenumber (cm -1 ) Conditions: T = 1200 K, 25 Torr Neat H 2 O, 152.4 cm path length private communication: C. Goldenstein, J.B. Jeffries, and R.K. Hanson (2010) HITEMP2010 revisions improve simulation at 7471.61 and 7472.05 cm -1 1200K. Only minor differences between simulations and SU data remain. Wavenumber (cm -1 ) Conditions: T = 1200 K, 25 Torr Neat H 2 O, 152.4 cm path length private communication: C. Goldenstein, J.B. Jeffries, and R.K. Hanson (2010) Bootstrapping with recent high- resolution, 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.