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.