Occurrence of Ozone in the Atmosphere

Abstract

WITH reference to the lecture of Lord Rayleigh published in NATURE of July 8 on “The Blue Sky and the Optical Properties of Air,” the conflicting results obtained by chemical methods in the estimation of atmospheric ozone are recalled. I beg to direct attention to my paper on “The Occurrence of Ozone in the Upper Atmosphere” (Proc. Roy. Soc., 1914, A, vol. xc., p. 204), in which it is shown that a reagent of potassium iodide solution can be made to provide a basis for the distinction of ozone and oxides of nitrogen at high dilutions and enable the approximate estimation of the former. By this method it is shown that, in accordance with the conclusions of Lord Rayleigh, ozone is present in the upper atmosphere, the amount present at an altitude of 10,000 ft. being of the order of 5 × 10^-6 parts per unit volume. Measurements made with sounding-balloons up to altitudes of 20 km. also showed the presence of definite amounts of ozone, but no detectable increase between 4 km and 20 km. The view was put forward that this amount of ozone must be taken into account in considering the optical properties of the sky.