Regional ~14CO_2 offsets in the Troposphere: Magnitude, Mechanism, and consequences

摘要

Radiocarbon dating methods typically assume that there are to significant tropospheric ~14CO_2 gradients within the low- to mid-latitude zone of the Northern hemisphere. Comparison of tree ring ~14C data form southern Ger- Many and Anatioal supports this assumption in general but also documents Episodes of significant short-erm regional ~14CO_2 offsets. We suggest that the Offset is caused by an enhanced seasonal ~14CO_2 cycle, with seasonally peaked Flux of stratospheric ~14C into the troposphere during periods of low solar Magnetic activity, coinciding with substantial atmospheric cooling. Sort-term Episodes of regional ~14CO_2 offsets are important to palaeoclimate studies and To high-resolution archaeological dating.