Millennial-band climate spectrum resolved and linked to centennial-scale solar cycles

Spectral comparison of the Hulu Cave, GRIP, and GISP2 δ18O records suggests that the single dominant period centered on 1470 yr in the GISP2 spectrum, the so-called '1500-yr cycle', is an artifact of the age model. The 230Th-dated Hulu Cave record indicates a millennial-band spectrum with a weak spectral peak near this period flanked by two stronger peaks centered on 1667 and 1190 -yr, similar to the GRIP δ18O record. All three millennial-band cycles may derive from heterodynes of centennial-band solar cycles as observed in the Holocene record of atmospheric 14C production. This suggests a link between centennial-scale solar variability and abrupt climate change at the millennial time scale.