Use of Radioactive Tracers in Studying Mass Transfer in the Atmospheric Boundary Layer

Certain natural surfaces such as snow act as almost perfect sinks for some radioactive gases. Experiments in which tracers of differing molecular diffusivities are released simultaneously, therefore, permit inferences to be drawn about the importance of the lowest few millimeters of the atmosphere in regulating vertical fluxes. The results of some tracer field experiments at Chalk River, Canada, are described, and the implications are discussed.