Some considerations on the study of radioactive debris at high altitude

Some critical examinations on the studies reported in the three previous articles are made. (1) The collecting efficiency of the airborne sampler used for sampling radioactive debris at high altitude is considered to be 100%. (2) The indication of the anemometer used for measuring air volume is purely volumetric and does not depend on the state of air. (3) Explosion dates of nuclear weapons are calculated from the collected samples by the formula A(t)=A₁t^-1.2 This formula holds well when 't' is small, but samples taken more than 50 days after explosion do not yield good results. (4) Time-dependent variations of the concentrations of radioactive debris sampled above the isles of Hokkaido, Chubu and Kyushu districts are studied. The study reveals that a turbulent diffusion mixing process must prevail in the meridional air flow mechanism in the lower stratosphere. (author)