The Quest for Consistency and Accuracy of Spectroscopic Parameters in HITRAN:

Transcription

1 The Quest for Consistency and Accuracy of Spectroscopic Parameters in HITRAN: Bridge between Archive and Application Laurence S. Rothman Harvard-Smithsonian Center for Astrophysics Cambridge MA HITRAN Conference Cambridge MA June 2006

2 Bands Global Consistency Isotopologues Intensities, Positions Lines Different Parameters S vs γ, n, line-coupling γ Why?

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5 Consistency of Retrievals using three Different Bands SS2843: Arctic Occultation measured by ACE, late February 2004 (C. Boone and P. Bernath, U. Waterloo, private communication 2004) SS2843, HNO3 Retrieved from three different bands, HITRAN altitude (km) cm cm cm volume mixing ratio (ppb by volume)

6 Improvement of Consistency using HITRAN 2004 altitude (km) SS2843, HNO3 Retrieved from three different bands, HITRAN cm cm cm volume mixing ratio (ppb by volume)

7 Consistency of Retrievals using two Different Bands Consistency of Retrievals using two Different Bands (C. Boone and P. Bernath, U. Waterloo, private communication 2004) Occultations ~63 North measured by ACE March 22, 2004 altitude (km) altitude (km) Retrieved H2O (limited altitude range), ss3275 HITRAN 2000 ( cm-1) HITRAN 2004 ( cm-1) cm volume mixing ratio (ppm by volume) Retrieved H2O (limited altitude range), ss3277 HITRAN 2000 ( cm-1) HITRAN 2004 ( cm-1) cm volume mixing ratio (ppm by volume)

8 One step forward, two steps back Corroborated by Masiello et al., 2005

9 Validation (AER) N 2 O CO 2

10 Validation (ACE) tra n s m itta n c e residuals sr10063 H 2 O retrieval, 12.5 km obs HITRAN wavenumber (cm -1 ) transm ittance residuals sr10063 H 2 O retrieval, 12.5 km obs HITRAN wavenumber (cm -1 )

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12 Ethane spectrum near and cm -1 measured at cm -1 resolution with LIRHS (black) compared with spectra modeled using line positions and intensities from HITRAN (red) and from the U. Tennessee/GSFC atlas (blue). Note that the line at 1000 MHz does not appear in either atlas and the line intensities, number of lines and the frequency values are different from the line atlases. Measurements were made with a 30 cm long cell and 0.5 Torr ethane pressure.

13 File Structure of HITRAN Compilation Level 1 JavaHAWKS Software Installers and Documentation HITRAN (line-transition parameters) IR Crosssections UV Aerosol Refractive Indices Line Coupling CO 2 data Level 2 Lineby-line Crosssections Global Data Files, Tables, and References Supplemental Supplemental Alternate Moleculeby-molecule Level 3

14 HITRAN Line-by by-line Parameters Parameter Field size Definition Mol Iso I2 I1 Molecule number 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 K] A if E10.3 Einstein A-coefficient [s -1 ] γ air F5.4 Air-broadened half-width (HWHM) [cm K] γ self F5.4 Self-broadened half-width (HWHM) [cm K] Lower-state energy [cm -1 ] E F10.4 n air F4.2 Temperature-dependence coefficient of γ air Air pressure-induced shift [cm K] δ air v, v q, q ierr iref * g, g F8.6 2A15 2A15 6I1 6I2 A1 2F7.1 Upper and Lower global quanta Upper and Lower local quanta Uncertainty indices for ν if, S if, γ air, γ self, n air, δ air Reference pointers for ν if, S if, γ air, γ self, n air, δ air Flag for line-coupling algorithm Upper and Lower statistical weights 160-character total

15 Table summarizing species # Molecule No. of lines # Molecule No. of lines # Molecule No. of lines 1 H 2 O HF C 2 H CO HCl PH O HBr COF N 2 O HI SF CO ClO H 2 S CH OCS HCOOH O H 2 CO HO NO HOCl O 2 9 SO N ClONO NO HCN NO NH CH 3 Cl HOBr HNO H 2 O C 2 H OH C 2 H CH 3 OH Total = 1,778,549!

16 Future Requirements of Database Extended Spectral Coverage (more bands) Emphasis on near-ir and Visible Weak transitions of combination bands (CH 4, etc) Additional Molecular Species Additional Parameters Other foreign-gas broadeners (H, He, etc) Higher Line-shape Temperature parameters Capability Temperature-dependence parameters Collision-Induced Absorption T p T p T p T p 0 0 = T nair α (, ) Hγ 2 -H 2 (, O 2 -O, 2, etc )(1 χ) γ (, ) χ n0 self L air 0 0 T + self 0 0 T αl( p, T) γair ( p, T )(1 χ) γself ( p, T ) χ p T T n air

17 More Issues Improved database managing Improved documentation Validation, Comparisons, Recommendations, Acquisition Continuity, Funding

18 HITRAN International Advisory Committee

19 Et al

20 David Marie Iouli

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