A Note on Single-Year Calibration of the Radiocarbon Time Scale, AD 1510–1954

Most data in this Calibration Issue are based on radiocarbon age determinations of tree-ring samples with dendrochronologically determined calibrated (cal) ages. For high-precision measurements, substantial sample amounts are needed, and the processed wood usually spans 10 or 20 tree rings. Thus, the calibration curve data points usually have decadal, or bidecadal, spacing. These curves, to be used for the calibration of samples formed over 1 or 2 decades, may not be fully applicable to samples (leaves, twigs, etc. ) formed in a single growing season.