HITRAN is an acronym for high-resolution transmission molecular absorption database. HITRAN is a compilation of spectroscopic parameters that a variety of computer codes use to predict and simulate the transmission and emission of light in the atmosphere.

News

Articles describing HITRANOnline, HAPI and new line shape representations

Video tutorial for using HITRANonline. Recording from 10.26.2015 webinar

This is a video tutorial for using HITRANonline. Users are given an overview of the capabilities of the system, including creating their own output formats, access to the sources of data, and the parameters that are new with respect to the traditional 160-character .par files. The link for the tutorial is

http://www.youtube.com/watch?v=jO08ly_odMM

All inquiries can now be made to HITRAN's support team at info@hitran.org!

The HITRAN support e-mail has now been established and our team is ready for questions!

Database Updates

Update of ν9 and ν8 band regions and addition of data for ν68 band region of diacetylene (C4H2)

  The ν9 band region (around 220 cm-1) of diacetylene (C4H2) has been completely replaced with a new line list from Antoine Jolly (LISA, Paris). The updated line list provides new intensity for the lines already existing in the database but also includes numerous hot bands. The ν8 band region (around 650 cm-1) was updated by scaling the intensities of all the lines in that region by a factor of 0.8 based on the recommendation given in Jolly et al, Planet. Space Sci. 97 (2014) 60–64. Finally, the ν68 region (around 1200 cm-1) was introduced into HITRAN for the first time. This line list was also supplied by A. Jolly.

Global update of the CO linelist, including addition of new bands up to the sixth overtone. Broadening and shift by CO2, H2 and He is also included for the first time.

  A new line list of CO (for all six stable isotopologues) was used to update and extend the HITRAN2012 data. The intensities in this list are based on a piece-wise dipole moment function from Li et al, Astrophys. J. Suppl. Ser. 216 (2015) 15. An intensity cutoff of 10-31cm-1/(cm-2 molecule) (in natural abundance of the isotopologues) was used for all IR lines, while a less stringent cutoff was introduced for the MW lines. This extended the amount of lines for the existing bands and allowed introducing new bands up to the sixth overtone. Line positions are based on the semi-empirical potential of Coxon and Hajigeorgiou, J. Chem. Phys. 121 (2004) 2992–3008. For some of the transitions, very high precision measurements (such as with frequency combs) of line positions were used if available. The broadening algorithm was very similar to that of HITRAN2012. Note however that the speed-dependent Voigt data for the first overtone is now completely disentangled from the Voigt data. We also add CO2 and H2 broadening (and its temperature dependence) and shift data from Li et al. Finally, the He broadening and shift of CO lines were also introduced based on extrapolation of the available experimental data.

Update of the line list for the principal isotopologue of ozone (16O3)

   A considerable amount of existing (in HITRAN2012) bands of the principal isotopologue of ozone were updated, while several new bands were added in different wavelength regions. The update is based on the S&MPO database (Babikov et al, J. Quant. Spectrosc. Radiat. Transf. 145 (2014) 169–196). The data correspond to the October 2016 version of S&MPO. The main feature of this update is the substantially improved intensities of lines in the 2-micron region.

Update of the HCFC-22, CFC-12 and CCl4 cross-sections and addition of the NIR cross-sections of C2H6

  Infrared cross-sections of air-broadened HCFC-22, CFC-12 and CCl4 were updated based on the data from the following papers:
1. HCFC-22: Harrison, Atmos. Meas. Tech. 9 (2016) 2593–2601.
2. CFC-12: Harrison, Atmos. Meas. Tech. 8 (2015) 3197–3207.
3. CCl4: Harrison et al, J. Quant. Spectrosc. Radiat. Transf. (2016), in press.
Finally, the NIR cross-section of pure and air-broadened ethane at 1.68 µm were added based on Reed and Hodges, J. Quant. Spectrosc. Radiat. Transf. 159 (2015) 87–93.
  Note that some data for HCFC-22, CFC-12 and CCl4 were available in previous editions of HITRAN originating from different sources. We temporarily retain all of these data, but due to redundancy with the more complete dataset from Harrison et al, a large portion of them will be relegated to the "Alternate" folder on the ftp site upon official release of the HITRAN2016 database

Update of broadening parameters for SO2

  Recent experimental measurements and calculations were employed to update the self- and air- broadening coefficients of line transitions of SO2. A semi-empirical method based on the fit to the available experimental data was used to compute the air-broadening coefficients of SO2. The self-broadening coefficients were updated using scaled semi-classical calculations from Tasinato et al, J. Quant. Spectrosc. Radiat. Transf. 130 (2013) 233–248.

More details about this update can be found in the report by Tan et al.

Removal of the HF and HCl (all isotopologues) lines corresponding to high-overtone transitions

  Transitions of HF with Δv (change in vibrational quantum number) larger than 10 were removed from the database as well as transitions with Δv>8 for DF; likewise for the high overtones of all isotopologues of HCl. This removal was because there were numerical issues in calculating the intensities of these transitions. Medvedev et al, J. Chem. Phys. 143, 154301 (2015) explain how the use of double precision in calculating overtone intensities may lead to numerical errors and that quadruple precision is needed. Additional numerical errors occur depending on the interpolation techniques used for the dipole moment functions as explained in Medvedev et al, J. Mol. Spectrosc. (2016). doi:10.1016/j.jms.2016.06.013.

  Transitions of HBr and HI do not appear to be affected by this issue (mainly because they did not have very high overtones) and the linelists for these molecules remain unchanged.

New lines and bands for the 14N218O isotopologue

  New lines for the 14N218O isotopologue have now been added to the database based on the work of Tashkun et al, J. Quant. Spectrosc. Radiat. Transf. 176 (2016) 62–69. Note that all lines that existed in the HITRAN2012 database were retained, and only new lines were added extending both wavenumber and dynamic range. The linelist for this isotopologue has a new intensity cutoff (under natural abundance) of 10-29 cm/molecule. This makes it temporarily the most complete linelist of all of the isotopologues of N2O, as previously the cutoff of 10-25 cm/molecule was used for all N2O isotopologues.

Correction of quantum identification of 50 HOCl lines in the 1200-1300 cm-1 region

  It was found by Prof. Stephen Ross (UNB, Canada) that 49 lines of the principal isotopologue of HOCl had an incorrect vibrational assignment being attributed to the ν2 band, while in reality they are 2ν3 lines. Also the quantum rotational assignment of the line at 1237.629280 cm-1 was incorrect. All of the assignments were fixed now based on the correct information provided in the original publication: Vander Auwera et al, Journal of Molecular Spectroscopy 204, 36-47 (2000).

Inclusion of HFC-23 and addition of new HFC-134a cross-sections

Cross-sections of Fluoroform (HFC-23) in the 950-1500 cm-1 spectral region were added to the database for the first time based on J.J. Harrison, J. Quant. Spectrosc. Radiat. Transf. 130 (2013) 359–364. Also 27 new cross-section sets were added for 1,1,1,2-tetrafluoroethane (HFC-134a) in the 750-1600 cm-1 region based on J.J. Harrison, J. Quant. Spectrosc. Radiat. Transf. 151 (2015) 210–216.

Addition of HT profile parameters in the ν3 band of N2O

  The air-induced line shape parameters within the Hartmann-Tran profile formalism were added to the lines in the ν3 band of the principal isotopologue of N2O. These data are based on the recent measurements by Loos et al, JQSRT 151 (2015) 300–309. Also the shifts of the corresponding lines within the traditional Voigt formalism were updated.

Update of SO3 lines in the pure rotational band

In HITRAN2012, there were 25 lines in the pure rotation band of SO3. They have now been replaced by 3439 lines based on the work of Underwood et al, J. Chem. Phys. 140 (2014) 244316.

Addition of HCN lines above 3500 cm-1

  The lines of the principal isotopologue of HCN from 3500 to 17586 cm-1 were added to HITRAN for the first time. These data are based on the linelist of Barber et al MNRAS 437 (2014) 1828-1835 which is a mixture of the ab initio intensities and line positions from Harris et al, MNRAS 367 (2006) 400-406, supplemented with empirically-derived line positions wherever possible

Update of the CH3Cl line list

  Recent experimental measurements and calculations were used to update the self- and air- broadening coefficients (with their temperature dependencies) of all CH3Cl lines. In addition, the 1900-2600 cm-1  spectral region was completely revised, with line positions and intensities calculated based on the recently analyzed Fourier transform spectra in the range of 1900-2600 cm-1 (Nikitin et al, JQSRT (2016) 177, 49–58).

  The details of the entire update are given in this linked report

Implementation of the Hartmann-Tran profile: H2 case study

  The IUPAC-recommended Hartmann-Tran profile (Tran et al, J. Quant. Spectrosc. Radiat. Transfer 129, 199-203 (2013); J. Quant. Spectrosc. Radiat. Transfer 134, 104 (2014)) is now implemented in the database. At this time it is implemented for self-broadening and shifting in four temperature regimes. Overall, 27 new parameters are added. The hydrogen molecule was chosen as a test case and every line of H2 now has these parameters. The description of how these parameters were derived and details of parametrization are given in the article Wcislo et al. “The implementation of non-Voigt line profiles in the HITRAN database: H2 case study” that is JQSRT, 177, 75-91 (2016).
  Note that no such parameters have been added to the HD isotopologue yet. Also we removed 527 transitions of H2 that correspond to high vibrational overtones. This was because there were numerical issues in calculating the intensities of these transitions. Medvedev et al, J. Chem. Phys. 143, 154301 (2015) explain how the use of double precision in calculating overtone intensities may lead to numerical errors and that quadruple precision is needed.

Update of broadening parameters for HO2 and H2O2

  The air-broadening coefficients of HO2 have been updated using an algorithm described in the report by Tan et al, "The air-broadening coefficients of HO2". This algorithm was derived based on recent experimental measurements. For the self-broadening, a default estimate value of 0.3 cm-1/atm was assigned to all transitions.
  For H2O2, the measurements of the air-broadening halfwidths from Malathy Devi et al, Appl.Opt. 25, 1844-1847 (1986); Goyette et al, JQSRT 40, 129–134 (1988); and Sato et al, JQSRT 111, 821–825 (2010) were included for the corresponding transitions. The majority of the air-broadened coefficients in the database still have same value of 0.1 cm-1/atm estimated from the measurements of Malathy Devi et al.

Addition of broadening and shift by H2, He and CO2

Broadening and shift parameters due to the foreign broadeners H2, He, and CO2 have been added to HITRAN for the first time. Currently, the corresponding half-widths, their temperature dependences and pressure-induced shifts by these perturbers for every HITRAN line of SO2, NH3, HF, HCl, OCS and C2H2 can be retrieved from HITRANonline. For HCl-H2 one can also obtain the temperature dependence of the shift. The data are described in the article Wilzewski et al. “H2, He, and CO2 line-broadening coefficients, pressure shifts and temperature-dependence exponents for the HITRAN database. Part 1: SO2, NH3, HF, HCl, OCS and C2H2” that was just published in JQSRT. JQSRT 168, 193–206 (2016).

Update to line positions of atomic oxygen

The values of line positions and lower-state energies for the O atom have been reverted to those given in the HITRAN1996-2000 editions. They originate from L.R. Zink, K.M. Evenson, F. Matsushima, T. Nelis, R.L. Robinson, "Atomic oxygen fine-structure splittings with tunable far-infrared spectroscopy", Astrophysical Journal, Part 2 - Letters 371, L85-L86 (1991). The HITRAN2004-2012 editions used now outdated values from the JPL catalogue, although the reference code still erroneously pointed to the work of Zink et al. The older JPL values have since been fixed in the JPL catalogue, and consequently we reverted back to the more accurate values of Zink et al.

Update for 14N15N

Similar to the error found for the HD molecule mentioned previously, the abundance of the 14N15N isotopologue was incorrectly calculated in the original release of HITRAN2012; this issue has now been fixed in the latest data available from this website.

Update for singly-deuterated molecular hydrogen (HD)

It was discovered by J. Mendrok (Lulea University of Technology, Kiruna, Sweden) that the abundance of the HD molecule was incorrectly calculated in the original release of HITRAN2012; this issue has now been fixed. The implication was that the intensities of the electric dipole transitions originally reported needed to be multiplied by two, although it did not affect the Einstein-A coefficients.

In addition, a total number of 7195 electric quadrupole transitions of the HD molecule have been calculated and added to the HITRAN line list. The calculation was carried out using the energy levels from the work by K. Pachucki and J. Komasa, “Rovibrational levels of HD”, Phys. Chem. Chem. Phys. 12, 9188-9196 (2010) and the quadrupole moment function of L. Wolniewicz, I. Simbotin, and A. Dalgarno, “Quadrupole Transition Probabilities for the Excited Rovibrational States of H2”, Astrophys. J. Suppl. Ser. 115, 293-313 (1998).

For the purpose of validation, comparisons between the HITRAN database, Kurucz database, and the most recent experimental results have been performed for the H2 and HD transitions. The corresponding report, Comparison of Hydrogen Databases, provides more details on this effort.