Absorption spectra of solar radiation in a narrow region about 3800 cm-1, including several intense lines of the rotational structure of the ν3 band of water vapor, have been measured at altitudes up to 25.3 km with small angular heights of the sun. The apparatus was calibrated with respect to an artificial atmosphere, using a multipass cell. The distribution of water vapor in altitudes 11-25.3 km was determined from the absorption in the 3816.07 cm line. The mixing ratio decreases from 12 × 10-6 g/g at 11 km to 2.5 × 10-6 g/g at 17 km, and then remains constant. At heights > 25.3 km the average mixing ratio is 4 × 10-6 g/g. These results correspond to the dry stratosphere model. Analysis of the experimental conditions indicates that a small influence by water vapor carried along upon the results of the measurements was achieved. The water mass function of the atmosphere was determined for small solar angles and large instrment heights, and a variation in the moisture of the stratosphere horizontally at great distances from the point of measurement was established.
B. S. Neporent, M. S. Kiseleva, A. G. Makogonenko, and V. I. Shlyakhov, "Determination of Moisture in the Atmosphere from Absorption of Solar Radiation," Appl. Opt. 6, 1845-1850 (1967)