Atmospheric Circulation from Fission-Product Radioactivity in Surface Air

The beta-activity of fission products in surface air are analyzed in a diagram, with latitude and time as coordinates. Spring-season maxima and spread of new debris are readily discerned. Debris from 1961 Soviet testing, traveling by way of the upper troposphere or the stratosphere, arrived at 16 degrees to 35 degrees S more than a month before debris transported through the troposphere. A maximum lateral-diffusion coefficient of about 4 x 10(5) m(2) sec(-1) is implied for the tropical troposphere, and a much larger value in middle and high latitudes. Debris in the troposphere from United States testing at 2 degrees N spread mostly into the southern hemisphere.