Home – Home – Jornals – Atmospheric and Oceanic Optics 2026 number 5

Modern databases such as HITRAN and GEISA provide spectral line parameters only for Voigt profile (VP) calculations. Spectral modeling for describing various processes in many areas of chemistry, physics, earth sciences, and engineering uses this line profile for collisional isolated transitions. However, the use of VP leads to high errors as compared to high-precision experimental spectra. More sophisticated models have been developed for spectral modeling that take into account “non-Voigt" effects, such as changes in molecular velocity due to collisions and the velocity dependence of the broadening and shift coefficients during collisions. In this paper, we present the results of high-precision measurements and analysis of the absorption spectra in ¹²C¹⁶O in the pressure range from 0.001 to 0.3 atm using “non-Voigt” profiles. We analyze the pressure dependences of parameters of VP, RP, qSDVP-Δ₂, qSDVP, and qSDRP profiles of the P3-P8 lines of ¹²C¹⁶O. We show that the intensity S and the profile parameters Γ₀ and Δ₀ linearly depend on pressure, regardless of the profile type. The intensities S and the broadening Г₀/ P _CO and shift Δ₀/ P _CO coefficients for the profiles qSDVP-Δ₂ and qSDVP coincide with the experimental accuracy. Calculations using the VP demonstrate deviations of S , Г₀/ P _CO, and Δ₀/ P _CO values from the results for qSDVP-Δ₂ and qSDVP within 1-2%. A nonlinear dependence of Г₂ and Δ₂ on pressure is observed when using qSDVP-Δ₂, qSDVP, and qSDRP. The applicability limits of the profile models for describing high-precision experimental spectra of ¹²C¹⁶O molecule are estimated.