Impact of updates to the HITRAN spectroscopic database on the modeling of clear-sky infrared radiances

Abstract

Recent versions of the HITRAN spectroscopic database are evaluated to assess the impact of the latest revisions to line parameters on the ability to model clear-sky radiances. Observations made using the Met Office C-130 aircraft with an infrared interferometer are compared with line-by-line radiative transfer simulations incorporating the HITRAN 96 and HITRAN 2000 databases. Substantial reductions in the differences between observed and calculated spectra are found when including the latest database in the model, largely due to refinements in water vapor parameters. Although the use of HITRAN 2000 is broadly successful in reproducing the observed spectra, a number of discrepancies remain in some spectral regions which may indicate further room for improvement in the database.