CRDS of 17O enriched water between 5850 and 6671 cm−1: More than 1000 energy levels of H217O and HD17O newly determined.

The room temperature absorption spectrum of water vapor highly enriched in 17 O has been recorded by Cavity Ring Down Spectroscopy (CRDS) between 5850 and 6671 cm −1 . Two series of recordings were performed with pressure values of 1.0 and 12.0 Torr. The investigated spectral region corresponds to the important 1.55 μm transparency window of the atmosphere where water absorption is very weak. The high sensitivity of the recordings ( α min ~ 5×10 −11 cm −1 ) allows detecting lines with intensity spanning six orders of magnitude (1.4×10 −30 –3.6×10 −24 cm/molecule at room temperature). The experimental list includes more than 10,300 lines. The assignments of water lines were performed using known experimental energy levels as well as calculated line lists based on the results of Partridge and Schwenke. More than 8500 lines were assigned to 9619 transitions of six water isotopologues (H 2 16 O, H 2 17 O, H 2 18 O, HD 16 O, HD 17 O and HD 18 O). All but four transitions of the 1 6 O and 18 O isotopologues were assigned using known experimental energy levels. More than half of the assigned H 2 17 O and HD 17 O transitions correspond to new (or corrected) upper energy levels. About 1000 new H 2 17 O transitions associated with upper states of the second triad and of the first hexad were identified. Most of the newly assigned HD 17 O transitions belong to the ν 1 +ν 3 and 2ν 2 +ν 3 bands. The assigned transitions allowed to newly determine or correct 20 highly excited rotational levels of the vibrational ground state of this isotopologue. Overall 791 and 266 energy levels are newly determined for H 2 17 O and HD 17 O, respectively. A few additional levels were corrected compared to literature values. The obtained experimental results are compared to the spectroscopic parameters provided by the HITRAN database and to the empirical energy levels recommended by an IUPAC task group. [ABSTRACT FROM AUTHOR]