Survey of the updated Oxygen line list in the HITRAN2024 spectroscopic database

Abstract

Light–matter interactions involving molecular oxygen (O₂) span numerous decades in the frequency of electromagnetic radiation and are important to many thermophysical and thermochemical mechanisms, ranging from atmospheric remote sensing of greenhouse gases, aerosols, pollutants, temperature and pressure, visible and infrared radiative exchange in the upper atmosphere, ozone formation and decomposition, and the search for life beyond Earth, among many other examples. Here, we highlight advances in the quantitative spectroscopy of O₂, for which updated band-specific, line-by-line parameters have been provided in the HITRAN2024 spectroscopic database. Theoretical results are presented for electric quadrupole transition intensities in the ground state of ¹⁶O₂, and the Noxon band in the near-infrared region has been included in HITRAN for the first time. Particular focus is placed on the 1.27 $\mu$m, A- and B-bands of O₂, in which intensities, line-shape (including beyond-Voigt parameterizations), and position parameters with improved accuracy and/or extended spectral coverage are presented. Corrections to the Schumann–Runge bands are also reported. The paper closes with recommendations and an outlook on key challenges in advancing our understanding of the spectroscopy of O₂.