Atmospheric Radiocarbon Activity in 1959

Abstract

ATTENTION has already been directed to the appreciable rise in the atmospheric radiocarbon activity following the testing of nuclear weapons^1–4. On the basis of data obtained up till 1958, Broecker and Walton¹ estimated a rise in the atmospheric radiocarbon concentration in the northern hemisphere of 5 per cent per annum, though Münnich and Vogel² had arrived at a rate of rise of 3.2 per cent per annum. Measurements made in the summer of 1959, however, indicate a general level of activity greatly in excess of what might have been expected from either of these estimations.