Accurate frequency measurements for H_2O and ^16O_3 in the 119-cm^−1OH atmospheric window

We report frequency measurements for relatively weak H2O and 16O3 rotational transitions in the ground state and in the ν2 = 1 vibrationally excited state. We obtained the frequency measurements by using the laboratory technique of tunable far-infrared spectroscopy with the objective of improving H2O and O3 line parameters required for modeling the important atmospheric spectral window near 119 cm−1. New sets of molecular constants are calculated from the 16O3 data, and improved values are reported for the frequencies of the H2O lines. The improvement in atmospheric simulations obtained with the new results is illustrated by comparison with recent high-resolution balloon-based atmospheric measurements. These new data significantly improve simulations of high-resolution atmospheric emission spectra.