Medium-Term Atmospheric 14C Variations

Abstract

High-precision 14C measurements are presented, carried out on single tree rings from a section of the floating South German Neolithic tree-ring chronology. They confirm the existence of pronounced medium-term variations in the order of 2 percent during the 33rd to 38th centuries BC. These variations turn out to be very regular while the precision of 1.5 per mil allows a comparison with a geochemical model calculation. Good agreement is acquired for an input function with a periodicity of about 150 years and an amplitude of approximately 30 percent in the 14C production rate.