HITRANonline

There are now over 30000 users registered on www.hitran.org

Mark your calendars.

The 17^th Biennial HITRAN Conference united with 16^th ASA meeting will be held at the Center for Astrophysics | Harvard & Smithsonian in Cambridge, MA, USA from 24 – 26 June 2024. Click here for more details

50 years ago today (26 January 1973), the HITRAN project was born with the release of the original Air Force report. Today, we celebrate its continued success as an indispensable resource for molecular spectroscopy.

Thanks to multiple requests, the water vapor continuum is making its debut in HITRAN. The MT_CKD (Mlawer-Tobin-Clough-Kneizys-Davies) Water Vapor Continuum Model provides absorption coefficients due to water vapor that should be added to the contributions calculated from the line-by-line water vapor transitions to obtain the total absorption due to water vapor. Description of the parametrization and other details can be found in Mlawer et al., JQSRT (2023)

https://hitran.org/mtckd/

Dear Colleagues,

The data on this website corresponds to the HITRAN2020 edition of the database. The HITRAN2020paper describing the new edition is available in Open Access

Gordon, I.E., Rothman, L.S., Hargreaves, R.J., Hashemi, R., Karlovets, E.V., Skinner, F.M., Conway, E.K., Hill, C., Kochanov, R.V., Tan, Y., Wcisło, P., Finenko, A.A., Nelson, K., Bernath, P.F., Birk, M., Boudon, V., Campargue, A., Chance, K.V., Coustenis, A., Drouin, B.J., Flaud, J. –M., Gamache, R.R., Hodges, J.T., Jacquemart, D., Mlawer, E.J., Nikitin, A.V., Perevalov, V.I., Rotger, M., Tennyson, J., Toon, G.C., Tran, H., Tyuterev, V.G., Adkins, E.M., Baker, A., Barbe, A., Canè, E., Császár, A.G., Dudaryonok, A., Egorov, O., Fleisher, A.J., Fleurbaey, H., Foltynowicz, A., Furtenbacher, T., Harrison, J.J., Hartmann, J. –M., Horneman, V. –M., Huang, X., Karman, T., Karns, J., Kassi, S., Kleiner, I., Kofman, V., Kwabia–Tchana, F., Lavrentieva, N.N., Lee, T.J., Long, D.A., Lukashevskaya, A.A., Lyulin, O.M., Makhnev, V.Y., Matt, W., Massie, S.T., Melosso, M., Mikhailenko, S.N., Mondelain, D., Müller, H.S.P., Naumenko, O.V., Perrin, A., Polyansky, O.L., Raddaoui, E., Raston, P.L., Reed, Z.D., Rey, M., Richard, C., Tóbiás, R., Sadiek, I., Schwenke, D.W., Starikova, E., Sung, K., Tamassia, F., Tashkun, S.A., Auwera, J. Vander, Vasilenko, I.A., Vigasin, A.A., Villanueva, G.L., Vispoel, B., Wagner, G., Yachmenev, A., Yurchenko, S.N. The HITRAN2020 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transf. 277, 107949 (2022).
doi:10.1016/j.jqsrt.2021.107949.]

==> Note that we are constantly making ongoing improvements and additions to many molecular bands. Updates, improvements, and corrections to the edition are posted in the "Database Updates" panel located on the home page of the HITRAN website. When citing the database, it is recommended to indicate if an updated version of the HITRAN2020 edition was used.

Please e-mail us (info@hitran.org) a summary of any serious problems you encounter (or successes or suggestions).

A review article describing the history of the HITRAN database by Larry Rothman was just published in Nature Reviews Physics. https://doi.org/10.1038/s42254-021-00309-2

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

The air- and self-broadening parameters for C₂H₆ have been corrected for the torsional bands in the FIR. It was noticed that the broadening functions from Devi et al. (2010) were not applied correctly in the database for these bands. We thank Elizabeth Guest (UCL) for identifying this issue.

The line list for the CH₃CN molecule has been substantially extended and updated. Pure rotational, ν₈, 2ν₈, and corresponding hot bands were added to the database for the first time. The ν₄ band has been substantially updated.

The new line list is calculated based on Müller et al. (2021) and references therein.

MT_CKD water vapor continuum model was updated to version 4.1.1, where the foreign continuum changed in far-IR.

As a reminder, the details about MT_CKD water vapor continuum model in HITRAN can be found at:

https://hitran.org/mtckd/

The temperature dependences of the half-widths of CO₂ lines broadened by helium (He) have been updated using data from Deng et al. (2009) and Brimacombe & Reid (1983) .

The self-broadening parameters of the H₂ lines under the traditional .par format (Voigt profile parametrization) were updated using the corresponding parameters from the Hartmann-Tran profile parametrization reported in Wcisło et al. (2016). Specifically, γ_self, n_self and δ_self were updated using values corresponding to γ_{HT_0_self}(296), n_{HT_0_self}(296), δ_{HT_0_self}(296). Typically, it is not recommended to use Lorentzian widths determined with different profiles, however, it is still better than using the coarse approximation employed previously. The same parameters were also cloned for γ_H2, n_H2 and δ_H2.

The line list for water vapor above 4340 cm^-1 has been revised based on the evaluations carried out by Eli Mlawer and Mike Iacono (AER) using TCCON spectra from the Lamont site. The changes could be summarized into these categories:

1. Line shift parameters in HITRAN2020 that originated from Ref. ( https://doi.org/10.1016/j.jqsrt.2020.107030) were found to have errors for certain bands, resulting for instance in a large amount of positive values. While these models are being improved, the issue was fixed in the following way: The shifts that affected the quality of the residuals have been reverted back to the HITRAN2016 values or replaced with those from the AER list, which contains manual modifications of the HITRAN2016 parameters to better match the TCCON spectra.

2. The air-broadened half-widths that affected the quality of the residuals have been reverted back to the HITRAN2016 values or replaced with those from the AER list "aer3.8.1" ( https://doi.org/10.5281/zenodo.5120012), which contains manual modifications of the HITRAN2016 parameters to better match the TCCON spectra.

3. The intensities in the 4ν₂+ν₃ band were scaled down by 22%, while individual intensities (of ab initio origin) in different bands had to be scaled to match the TCCON spectra.

4. As pointed out by Alain Campargue (Grenoble), a large percentage of the lines in HITRAN2020 that were referencing W2020 MARVEL line list for the line positions were deviating slightly from the line positions in the original W2020 work. This has now been fixed.

It should be noted that the aforementioned changes affect primarily the principal isotopologue. Also, the line position changes proposed in ( https://doi.org/10.1080/00268976.2022.2051762) have not been implemented yet, but they are unlikely to impact the strong lines.

It was found that in the process of combining different line lists of ozone for HITRAN2020, the lines of the principal isotopologues of ozone in the 850-980 cm^-1 spectral region were accidentally omitted. These lines are now restored. Although most of these transitions are relatively weak, they are still important in remote sensing applications. We thank Norbert Glatthor (KIT) for pointing out this issue.

The data on this website corresponds to the HITRAN2020 edition. The updates to this edition will be announced in this section as they appear