Knowledge Bank

Survey measurements of absolute strengths and widths have been made on $H2O$ absorption bands near 10 700 $cm-1$. Bands in this region are known to show significant intensity enhancement due to Fermi resonance and coriolis interactions between upper state vibration-rotation levels. More than 25 lines arising from the overtone band $3\nu 1$ and the combination bands $2\nu 1+\nu 3,\nu 1+2\nu 3$ and $\nu 1+2\nu 2+\nu 3$ were measured. The intensities of the observed $3\nu 1$ lines are enhanced by Coriolis interactions with the $2\nu 1+\nu 3$ lines. The observed $\nu 1+2\nu 2+\nu 3$ and $\nu 1+2\nu 3$ lines are enhanced by Fermi resonances with $2\nu 1+\nu 3$ lines. A number of lines in the dominant $2\nu 1+\nu 3$ band were also measured. The quantitative measurements of intensities agree quite well with the qualitative intensities obtained from the solar $spectrum.1$