Jahreszeitliche Schwankungen der 7Be-, 54Mn- und Spaltprodukt-Konzentrationen der bodennahen Luft

Manganese-54, Antimony-125 and Caesium-137 have been measured in ground level air in Brunswick (52°18’ N, 10°28’ E) since the end of 1963. Until 1967 the activity concentrations decrease with a stratospheric half-life of 11 months superimposed by seasonal variations, the ratio between maximum in may and minimum in late fall being 10. Against this the corresponding ratio for ⁷Be, produced by cosmic rays, is only 2.6. The reason for this difference is due to the fact, that the nuclear bomb debris during that time are of stratospheric origin exclusively whereas averaged over one year about 50% of Beryllium-7 stem from tropospheric production. From 1964 through 1968 the mean activity concentration of ⁷Be in ground level air was between 65 and 69 fCi/m³.