Meteorological Fractionation of Nuclear Bomb Debris

Radioactive particles are produced by nuclear bomb explosions which are widely different in size and nature. Systematic differences in properties are expected for particles formed under different conditions. Differences in particle properties may cause sorting during deposition because of systematic differences in weather trends at different geographical locations and thus bring to light information about the particles.

Deposits at a mountain station in Norway appear to have contained more short-lived fission products than those at lowland stations, especially during periods when considerable fresh fission products have been present in the atmosphere. This could be due to a substantial chemical fractionation on particle sizes taking place during formation, or to the general formation of particles somewhat larger than 0.5 micron diameter during high-yield explosions.