Variation of natural radioactivity in the atmosphere with altitude

Abstract

The vertical distribution of radon decay products in the lower atmosphere has been measured during airplane flights, using both negative‐wire and precipitator methods of sample collection. Data taken by the wire method show a very gradual decrease in activity with height, with considerable activity found to exist at 16,000 ft (msl). The precipitator results indicate an approximately linear decrease with altitude, with no appreciable activity found in samples collected by this method above about 11,000 ft. Measurements made at four ground stations in the altitude interval 4620 to 10,297 ft gave similar results. The mean value for the coefficient of eddy diffusion in the atmosphere calculated from the precipitator data was 7 ± 4 m 2 /sec for the plane flights and 11 ± 7 m 2 /sec for the ground stations.