HITRANonline

Dear Colleagues:

As you may have noticed, the number of updates has dramatically increased in recent weeks as we are transitioning to HITRAN2020. Within the next few weeks, the database will switch to the new edition. Upon the official release of the HITRAN2020 edition, we will encourage you to start using that as it will supersede in quality and extent all the previous editions, including intermittent updates.

There are now over 20000 users registered on www.hitran.org

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 HITEMP database has been expanded to include methane. The data is available through the HITEMP section of the website (https://hitran.org/hitemp/), with a python tool for extracting the compressed file. Further details are described by Hargreaves et al. (2020) (doi:10.3847/1538-4365/ab7a1a).

Dear Colleagues,

The data on this website corresponds to the HITRAN2016 edition of the database. The HITRAN2016 paper describing the new edition is available in Open Access

I.E. Gordon, L.S. Rothman, C. Hill, R.V. Kochanov, Y. Tan, P.F. Bernath, M. Birk, V. Boudon, A. Campargue, K.V. Chance, B.J. Drouin, J.-M. Flaud, R.R. Gamache, J.T. Hodges, D. Jacquemart, V.I. Perevalov, A. Perrin, K.P. Shine, M.-A.H. Smith, J. Tennyson, G.C. Toon, H. Tran, V.G. Tyuterev, A. Barbe, A.G. Császár, V.M. Devi, T. Furtenbacher, J.J. Harrison, J.-M. Hartmann, A. Jolly, T.J. Johnson, T. Karman, I. Kleiner, A.A. Kyuberis, J. Loos, O.M. Lyulin, S.T. Massie, S.N. Mikhailenko, N. Moazzen-Ahmadi, H.S.P. Müller, O.V. Naumenko, A.V. Nikitin, O.L. Polyansky, M. Rey, M. Rotger, S.W. Sharpe, K. Sung, E. Starikova, S.A. Tashkun, J. Vander Auwera, G. Wagner, J. Wilzewski, P. Wcisło, S. Yu, E.J. Zak, The HITRAN2016 Molecular Spectroscopic Database, J. Quant. Spectrosc. Radiat. Transf. (2017) 203, 3-69.
doi:10.1016/j.jqsrt.2017.06.038.]

==> 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 web-site. When citing the database it is recommended to indicate if an updated version of the HITRAN2016 edition was used.

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

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

The line list for water vapor has been revised and extended to 42000 cm^-1 (previously it was 25000 cm^-1). The line list is largely based on the ab initio line list from Conway et al. (2020). The line positions have been replaced with values derived from experimental works, and intensities of selected bands and lines have been adjusted based on high-quality measurements available in the literature. Apart from improving line positions and intensities, this update effectively solves some of the quantum assignment issues encountered in the previous edition.

The broadening and shift algorithm have been revised throughout the entire line list of water vapor. Note that Hartmann-Tran parameters are available for some of the stronger water vapor lines from 1800 to 4400 cm^-1 based on the measurements at DLR.

The line list of the principle isotopologue of ethane in the 3.3 μm region (which previously had only some of the stronger Q-branches) is completely revised. The ν₇ and some combination bands come from Lattanzi et al. (2011), with some lines from Villanueva et al. (2011) added. The ν₅ band is added from Radeva et al. (2011), with intensities scaled down by 20% and some of the line positions corrected, based on comparisons with experimental data.

In addition self-broadening parameters and temperature dependence of air broadening in the torsional ν₄ band were revised.

Rototranslational band of CO₂-Ar collision pair was added to HITRAN for the first time based on Odintsova et al. (2021).

Rototranslational band of N₂-N₂ was updated based on Chistikov et al. (2020).

O₂-N₂ and O₂-air band near 6.4 μm added to the database based on Thibault et al. (1997) and Orlando et al. (1991).

Global update of the line positions was carried out using the CDSD2019 database .

Intensities of dozens of individual bands were reevaluated based on validations against laboratory and atmospheric spectra

A number of new bands were added, above 8000 cm^-1 based on recent experimental and theoretical works. In addition magnetic dipole lines were included in HITRAN for the first time.

Line shape parameters were revised largely based on algorithms described in Hashemi et al. (2020) However, note that some of the parameters, especially those associated with self broadening slightly differ from that paper. It is important to emphasize that apart from the Voigt parameters, speed-dependent Voigt parameters are also provided for every line of CO₂. Also first order line mixing parameters are provided.

The Tables for the full line mixing, provided in the supplementary folder , have also been updated.

Numerous absorption cross sections have been added for multiple molecular species. These include: 1) additions or updates of absorption cross sections for trace gas molecules (including some that cover the UV region); 2) expansion of the scope to include absorption cross sections at high-temperature (up to 700 K) and low temperatures; 3) addition of absorption cross sections with broadening applicable to planetary atmospheres (e.g., H₂, He, N₂). A brief summary of the molecules included in this update is given below:

● High-temperatures (ethane, propene, propane)
● Trace species (SF₆, CFC-11, CF₄, HCFC-141b, N₂O₅)
● UV additions (O₃, SO₂)
● Broadened by H₂ and/or He (propane, isobutane, benzene)
● Broadened by N₂, including those at low temperatures (propane, benzene, butane, isobutane)

In addition to the updates introduced in July 2020, further additions and improvements have been made to the line list of C₂H₂.

Numerous bands have been added to HITRAN for ¹²C₂H₂ in the 13.6 μm region (ΔP=1) from Jacquemart et al. (2020). In addition, eight hot bands have been added for the ΔP=6 region (near 3900 cm^-1) using the global model developed by Lyulin & Perevalov (2016).

As many more C₂H₂ bands have been added to HITRAN, it has become necessary to update the vibrational quantum number format to avoid degeneracy and allow unique identifications. The C₂H₂ format has been updated for all lines to include both bending angular momentum quantum numbers (i.e, l₄ and l₅). Each state is now identified by the following: V₁, V₂, V₃, V₄, V₅, l₄, l₅, +/-, u/g (where V_i are the vibrational normal mode quantum numbers).

Finally, the air- and self-broadening parameters have been made consistent using the function provided by Jacquemart et al. (2003), and the H₂, He and CO₂ broadening parameters (described by Wilzewski et al., 2016) have been extended to all new transitions.

A global re-haul of the SO₂ line list was carried out. For the principal isotopologue (³²S¹⁶O₂) the majority of lines from HITRAN2016 were updated, while a plethora of additional bands were introduced based on the semi-empirical line list from the group of Olga Naumenko (IAO, Tomsk), partially described in Vasilenko et al. (2020) .

For the second isotopologue ³⁴S¹⁶O₂ multiple new bands were added based on the line list from NASA Ames, see Huang et al. (2019). The same line list was used to introduce two new (to HITRAN) isotopologues: ³³S¹⁶O₂ and ¹⁶O³²S¹⁸O.

The spectroscopic parameters of the O₂ A-band (0.76-μm region) have been updated based on the measured parameters by Payne et al. (2020).

The following parameters were updated for the O₂ A-band based on the Payne et al. measurements: line intensities, Einstein-A coefficients, air- and self-broadened half-widths and their temperature-dependence parameters (both Voigt and speed-dependent Voigt), air- and self-induced pressure shifts and their temperature dependences (both Voigt and speed-dependent Voigt), the air speed-dependence of the half-widths, and the first-order Rosenkranz line-mixing parameters for the air-broadened lines.

The ¹⁴NH₃ line list has been expanded and updated in a number of ways:

● Below 5500 cm^-1, several new bands have been included from an updated version of the CoYuTe line list (Coles, et al., 2019), which includes adjustments based on MARVEL energy levels (Furtenbacher, et al., 2020). In addition, a small number of empirically observed transitions have been added near 4400 cm-1, based on evaluations by Toon et al.
● Transitions in the 5500-6350 cm^-1 spectral region have been added from Cacciani et al., 2021
● Transitions in the 7400-8600 cm^-1 spectral region have been added and updated using the work of Vander Auwera & Vanfleteren, 2018

In addition to the updates described above, a small number of Einstein-A coefficients have been corrected and three lines of ¹⁵NH₃ have been reassigned to ¹⁴NH₃. Furthermore, The air-broadening parameters for both isotopologues have been updated for lines with J≥9.

In addition to the CO and N₂O updates announced in December, further additions to the line shape parameters were added including temperature dependences of some of the parameters as well as speed-dependent Voigt parameters for self-broadening.

Finally broadening parameters for the CO lines broadened by "planetary" gases He, H₂ and CO₂ have been revised based on recent experimental and semi-empirical data.

Spectroscopic line parameters of the most abundant isotopologue of nitrogen trifluoride (NF₃) have been included in HITRAN for the first time. The details of the line list are provided in Egorov et al. (2020)
https://doi.org/10.1016/j.jqsrt.2019.106668

An intensity cutoff of 10^-25 cm/molecule was applied when adapting this list for HITRAN. This line list includes 2 717 795 lines and covers the spectral range up to 2200 cm^-1.

Due to the considerable number of lines, this line list has been placed into the static supplemental folder
https://hitran.org/suppl/LBLstatic/55/.

The SF₆ line list has been updated and extended based on work of Ke et al.
https://doi.org/10.1016/j.jms.2020.111251.

SF₆ has low-lying vibrational modes and, as most applications will require hot bands (most of which are not present in this list), it continues to reside in the supplemental folder
https://hitran.org/suppl/LBLstatic/30/.

Intensities of carbon monoxide lines in the fundamental and corresponding hot bands were scaled down by 2% based on recommendation from Devi et al. (2018). Intensities of the second overtone and corresponding hot bands were increased by about 2.6% based on recent results of Borkov et al. (2020) and Cygan et al. (2019) .

Broadening and shifting parameters for many lines have been revised. In addition every line of CO in HITRAN has Speed-dependent Voigt (SDV) parameters for both air and self broadening.

It was found by Toon et al. that a few bands of OCS observable in the atmospheric spectra were missing from the HITRAN database. An empirical line list from Toon et al. (2018) was fit together with previously available spectroscopic information to obtain full spectroscopic parametrization of these missing bands. This also resulted in including ¹⁶O¹³C³⁴S isotopologue for the first time. Majority of the new bands lie in the spectral region of strong ν₃ fundamental.

The HITRAN line list for ¹⁵NH₃ has been updated based on the works of Canè et al. (2019, 2020) and covers the 0-3100 cm^-1 spectral region. These additions include numerous bands of ¹⁵NH₃, all with upper vibrational states of ν₂, 2ν₂, 3ν₂, ν₂+ν₄ and ν₄.

Broadening parameters due to ambient pressure of H₂, He, H₂O and CO₂ (presented in Wilzewski et al. 2016 and Tan et al. 2019) have also been applied to these ¹⁵NH₃ additions.

4ν₁+2ν₂ and 5ν₁ bands: The line intensities for these bands have been replaced by the recent NIST CRDS measurements Adkins et al. (2020) [private communication]. Also additional transitions up to J''= 91 were added for these bands.

ν₃ band : The measurements from [Loos et al. JQSRT, 150, 300-309, 2015] were used for updating the speed-dependent Voigt (SDV) parameter group such as air-broadening, air- speed dependence of width, air-shift, and the first-order line-mixing parameter for the measured transitions in this band. Note that these parameters were already present under Hartmann-Tran profile parametrization in HITRAN2016.

The line-shape parameters for lines of N₂O in other bands:The line shape parameters have been revised (or added) for Voigt (VP) and SDV profiles, which have been treated separately. The air-broadening parameters from NIST were fit with Pade approximates and the results have been applied for the air half widths (for both the VP and SDV), and the speed dependence of air widths (except for the ν₃ band). The temperature exponents of the air broadening were extrapolated as well using the Pade approximation fit to the data from [Nemtchinov et al. [JQSRT 83 (2004) 267–284]. The Voigt self broadened half widths were fitted using the data from Werwein et al. [JQSRT, 323, 28-42,2016], and the air- and self -shifts were calculated based on the method proposed by Hartmann [JQSRT, 110, 2019-2026,2009]. The first-order line-mixing coefficients were calculated based on the exponential power gap law (EPG) formalism and are now provided for every transition in HITRAN.

The hydroxyl radical (¹⁶OH) line list in HITRAN and HITEMP has received a major update based on the calculated line lists of Brooke et al. (2016) for the X²Π ground state and Yousefi et al. (2018) for the A²Σ⁺-X²Π electronic transitions. Except for pure rotational transitions with hyperfine splitting, all ¹⁶OH line positions and intensities have been replaced.

For this update, line positions of the X²Π ground state from of Brooke et al. have been refit using OH airglow spectral measurements from Noll et al. (2020).

The HITEMP2010 line list has also been replaced by this update and can be downloaded via:
https://hitran.org/hitemp/

The phosphine (PH₃) line list has received a significant update, which encompasses all spectral regions in HITRAN.

● Dyad: Line positions and intensities of the ν₂ and ν₃ bands of the dyad remain unchanged but have been supplemented with a number of hot/combination bands from an updated empirically-corrected ab initio line list provided by the TheoReTS team (M. Rey, 2020, private communication).
● Pentad: The same TheoReTS line list has also been used to replace the previous pentad data, after detailed comparisons to high resolution spectra.
● Octad: This spectral region has largely been replaced by the work of Nikitin et al. (2017), which used an effective Hamiltonian approach.

As part of these updates, the air and self-broadening parameters have been revised for all transitions (rotational/dyad/pentad/octad regions) and the Einstein-A coefficients and statistical weights for all E states have been corrected.

Furthermore, H₂ and He-broadening coefficients and their temperature dependencies have been added to every transition of phosphine in HITRAN to aid planetary research.

Far-IR ν₇ and ν₉ bands of formic acid have been added to HITRAN for the first time. The line list is based on the analyses of the spectra described in Hull et al. (2019) and the use of spectroscopic constants from Baskakov et al. (2006)

Spectroscopic line parameters of four most abundant isotopologues of carbon disulfide (CS₂) have been included in HITRAN for the first time. The details of the line list are provided in Karlovets et al. (2020)
https://doi.org/10.1016/j.jqsrt.2020.107275

An intensity cutoff of 10^-30 cm/molecule was applied when adapting this list for HITRAN. This comprehensive line list covers 19-6467 cm^-1 spectral range.

As a final update to the NO₂ line list prior to the HITRAN2020 release, additional bands (to the July update) of ¹⁴N¹⁶O₂ have been added between 6500 and 8000 cm^-1. This update includes the 4ν₁+ν₃ band (from Perrin et al. 2010) which is moderately strong in this spectral region.

This update also includes vibrational bands from Lukashevskaya et al. (2016), Mondelain et al. (2012) and Lukashevskaya et al. (2013)

Numerous bands for ¹²C₂H₂ and ¹²C¹³CH₂ have been added to HITRAN between 5690-10740 cm^-1 from a series of empirical studies (Lyulin et al., 2017, 2018, 2019, Lyulin & Campargue., 2018).

In addition, H₂, He and CO₂ broadening parameters (described by Wilzewski et al., 2016) have also been extended to all transitions of C₂H₂. Finally, a small number of Einstein-A coefficients and statistical weights have also been corrected for some of the bands of C₂H₂.

The spectral range for NO₂ has been extended to include transitions between 5720-7560 cm^-1, with the addition of six combination and overtone bands:

● 3ν₁+ν₂+ν₃ and ν₁+3ν₃ (Lukashevskaya, et al., 2017a)
● 4ν₃ (Lukashevskaya, et al., 2017b)
● 2ν₁+3ν₂+ν₃ (Lukashevskaya, et al., 2017c)
● ν₁+4ν₃ (Lukashevskaya, et al., 2018)
● ν₁+3ν₃ (Naumenko, et al., 2019)

Users should also be aware that the 4ν₁+ν₃ band is moderately strong in this spectral region (relative to the additions), but it is not included as part of this update.

The model that was used to predict line broadening parameters for all bands of NO₂ has been slightly revised to provide more realistic values for the high-J transitions.

The ¹⁵NO₂ isotopologue of NO₂ has been added to the HITRAN database for the first time. The ν₃ band of this isotopologue has been included based on the line list from Perrin et al. (2015).

In addition, Einstein A coefficients and statistical weights for non-hyperfine transitions of the principal isotopologue (¹⁴NO₂) have been corrected in both HITRAN and HITEMP. We would like to thank Drs. Valery Perevalov and Anastasiya Lukashevskayab (IAO, Tomsk) for bringing this issue to our attention.

The HITEMP database has now been expanded to include CH₄. This line list covers 0-13,400 cm^-1 and has been based on the TheoReTS line list from Rey at al. (2017) (doi:10.3847/1538-4357/aa8909). "Effective lines" have also been introduced to represent continuum-like features over the temperature range of study (296-2000 K).

The CH₄ HITEMP line list has been validated against experimental measurements making it the most accurate and easy-to-use line list for methane spectroscopy at high temperatures. Further details are described by Hargreaves et al. (2020) (doi:10.3847/1538-4365/ab7a1a).

Half-widths (and their temperature dependencies) associated with broadening of spectral lines of CO, N₂O and NH₃ by the pressure of ambient water vapor have been updated, based on revision of our paper that just appeared in JGR: atmospheres.

It was found that for spectral lines of ammonia (NH₃), broadening parameters due to H₂, He and CO₂ pressure were accidentally removed from the database. They have now been restored. We thank Dr. Clara Sousa-Silva (MIT) for pointing this out.

Finally, some of the Hartmann-Tran profile parameters for the self-broadening for the B-band of O₂ had to be divided by the factor of two, due to the differences in formalism used in original publication ( Domysławska et al, JQSRT. 155 (2015) 22–31.) and HITRAN. We thank Dr. Keeyoon Sung (JPL) for pointing this out.

Parameters associated with broadening of spectral lines by the pressure of ambient water vapor have been added to the database for the first time. In August we added broadening parameter gamma_H2O and its temperature dependence to all lines of carbon dioxide (CO₂). Now we add these parameters to the lines of N₂O, CO, CH₄, O₂, NH₃ and H₂S.

We remind the users that they have to create a custom output format to retrieve parameters associated with broadening by gases other than air or self. One can follow video tutorial number three for some instructions on this matter:

HITRAN YouTube Tutorials

The HITEMP database is currently undergoing a major expansion. This latest update refers to N₂O, CO, NO and NO₂ with the new data available for download via:
https://hitran.org/hitemp/

The CO line list for HITEMP has been updated and expanded. The update is largely based on Li et al.
https://doi.org/10.1088/0067-0049/216/1/15 but with improved line positions.

The NO line list for HITEMP has also been updated, along with N₂O and NO₂. These are the newest additions to the HITEMP database since 2010. Further details are described by Hargreaves et al.
https://doi.org/10.1016/j.jqsrt.2019.04.040

The NO₂ line list has been updated to include new bands within the 1900 - 2400 cm^-1 and 4000 - 4800 cm^-1 spectral regions by using the corrected NDSD-1000 databank (Lukashevskaya et al. (2017), JQSRT 202, 37).

In addition, the pressure shifts have been updated for many transitions using a semi-empirical approach based on the measurements from Benner et al. (2004), J. Mol. Spec. 228, 593.

Details of these updates are described by Hargreaves et al.
https://doi.org/10.1016/j.jqsrt.2019.04.040

We have substantially updated and extended the HITRAN collision-induced absorption section. The details are given in the Karman et al., paper which just appeared in Icarus.
https://doi.org/10.1016/j.icarus.2019.02.034

The collision-induced absorption (CIA) data in HITRAN is available at
https://hitran.org/cia/

As advertised in the HITRAN2016 paper, we now provide spectra for radioactive isotopologues in the supplemental section:
https://hitran.org/suppl/radioactive/

The first linelist that has being added is that of radioactive isotopologues of carbon monoxide, namely ¹⁴C¹⁶O (iso 7), ¹⁴C¹⁸O (iso 8) and ¹⁴C¹⁷O (iso 9).

Users should be aware that the line intensities of these radioactive isotopologues do not follow the standard HITRAN convention of being scaled by natural terrestrial isotopic abundance. Instead, they are provided at an abundance of 100% because of the large variation of radioactive isotopes in different environments. It is the responsibility of the user to account for this difference when comparing with the stable isotopologue intensities.

The NO line list has undergone a substantial update for all three isotopologues (¹⁴N¹⁶O, ¹⁵N¹⁶O, ¹⁴N¹⁸O). For ¹⁴N¹⁶O, the new wavenumber range covers 0-23,730 cm^-1 and includes bands with a maximum Δv=14 for the X ²Π electronic ground state. For ¹⁵N¹⁶O and ¹⁴N¹⁸O, the coverage is now up to 15,650 cm^-1. The primary source of the update has been the semi-empirical work of Wong et al. (2017), MNRAS 470, 882, however new hyperfine split line parameters have also been updated from Müller et al. (2015), JMS 310, 92. Also, ab initio intensities of some of the bands have been scaled to match experimental values.

In addition, the available data for air- and self-broadening parameters have been refit to a function that performs better for high J. The pressure shifts have also been updated to extend the measurements of Spencer et al. (1994), JMS 165, 506 to higher Δv.

The format for the wavenumber parameter has been adapted to enable an increased precision for the MW transitions, as has been previously done for HNO₃, PH₃, O₂ and NO⁺.

Details of these updates are described by Hargreaves et al.
https://doi.org/10.1016/j.jqsrt.2019.04.040

The line-mixing package for CO₂ had been updated, to make input line-widths consistent with the actual widths provided to the database, with an exception to when these line-widths were obtained with speed-dependent Voigt profile rather than Voigt. In that case alternative approach was used. In some regions the change results in appreciable differences corresponding to decrease of the residuals when applied to real laboratory data. The line-mixing package is available at http://hitran.org/suppl/LM/

It was discovered that the Einstein-A coefficients for all transitions of both isotopologue of phosgene were calculated erroneously in HITRAN2016. These parameters have been corrected in this update.

It was discovered that about 1500 lines with intensities of the order of 10^-28 cm/molecule in the 8340-10240 cm^-1 region were accidentally omitted from the database. These lines have been restored from the HITRAN 2012 edition. Also a small number of lines were removed or reassigned, fixing errors associated with different assignments of lines in the linelists that were combined together to form the HITRAN2016 edition.

Note that a very substantial update is underway to correct a number of errors associated with erroneous calculations of the statistical weights for some of the isotopologues of water vapor, especially D₂. The upcoming update however will not largely affect line positions nor intensities for most of the water vapor lines in HITRAN.

The broadening parameters of CO lines due to the pressure of CO₂, and especially their temperature dependencies, were updated using data from Hashemi et al, J of Molec Spectrosc (2016) 326, 60-72.

It was found that due to a programming error 19 lines (with P1_e assignment) of some bands of asymmetric isotopologues of carbon dioxide had air-broadened half-width values of zero in the official release of HITRAN2016. This has been fixed now and all of these lines have appropriate values for this parameter.

In addition the pure rotational transitions of the ¹⁶O¹²C¹⁷O isotopologue were missing upper-state quantum numbers associated with the hyperfine splitting. This in turn caused erroneous calculation of the upper-state statistical weight and the Einstein-A coefficients. All of these weak lines have been fixed now.

Once again we would like to remind users that the 11^th and 12^th isotopologues of carbon dioxide are labeled as A and B respectively if one asks for the output in the ".par" format. This should be taken into account in radiative transfer codes.