FT spectroscopy of water vapor in the 0.9 µm transparency window

Abstract

Weak absorption spectrum of water vapor is recorded in the 0.9 µm transparency window using a Fourier transform spectrometer coupled with a 30-m base-length multipass cell. 780 vibration – rotation transitions of the H2O molecule were assigned on the base of accurate variational calculations, 410 of them are new. New experimental information is compared with the literature data and spectroscopic data base HITRAN2020. Significant distortions of the intensities of the (041)-(000) and (140)-(000) vibrational bands accepted in HITRAN2020 are discovered from the comparison with the experimental data. An accurate and detailed recommended list of the H216O absorption lines is reported in 9340–9790 cm−1 spectral region based on the experimental energy levels and variational calculation which reproduced the new intensity measurements in the best way.