HITRAN2020: Practicality, Accuracy, Completeness, Traceability (PACT)
by Dr. Iouli Gordon, Dr. Laurence Rothman, Dr. Robert Hargreaves, Mrs./Ms. Frances Skinner, Dr. Robab Hashemi, Dr. Roman Kochanov, Mr. Artem Finenko, Dr. Christian Hill

Abstract

The HITRAN molecular spectroscopic database has been serving the atmospheric community for half a century. The 2020 edition of the database [1] builds on the success of the previous releases but encompasses substantial improvements and expansions. It consists of line-by-line lists, experimental absorption cross-sections, collision-induced absorption data, and aerosol indices of refraction. The line-by-line lists for the majority of the HITRAN molecules were updated (and molecules SO, CH3F, GeH4, CS2, CH3I and NF3 added) in comparison with the previous compilation HITRAN2016 [2] that has been in use, along with some intermediate updates, since 2016. The extent of the updates ranges from improvements of spectral parameters of a few lines of certain molecules to complete replacements of the lists and the introduction of additional isotopologues. The database now provides numerous parameters beyond the traditional “.par” format (the default output option) , including non-Voigt line profiles for many gases [3,4]; broadening by water vapor [5]; update of collision-induced absorption sets [6], to name a few. We continue to take advantage of the modern structure and interface available at www.hitran.org [7] and the HITRAN Application Programming Interface [8]. Both tools have been improved to work with the new edition. This presentation will demonstrate the significance of the updates and the importance of using the most recent edition of the database in the radiative transfer codes. The first steps towards the HITRAN2024 edition will be discussed. In the last four years, this work was supported through NASA grants NNX17AI78G, NNX16AG51G, 80NSSC20K0962, and 80NSSC20K1059. References [1] I.E. Gordon et al, JQSRT 277: 107949 (2022) [2] I.E. Gordon, et al. JQSRT, 203:3–69 (2017). [3] R. Hashemi et al. JQSRT, 256:107283 (2020). [4] R. Hashemi et al. JQSRT, 271:107735 (2021) [5] Y. Tan, et al., JGR-Atmos. 124, 11580 (2019). [6] T. Karman et al., Icarus, 328, 160 (2019)