Zonally symmetric changes in the strength and position of the Southern Westerlies drove atmospheric CO2 variations over the past 14 k.y.

Abstract

Terrestrial records from 41 to 52°S across the Southern Hemisphere reveal nearly synchronous multimillennial trends in moisture derived from the Southern Westerly Winds (SWW) since 14 ka, pointing to a marked zonal symmetry in SWW changes across a broad swath of the southern middle latitudes. The data suggest a southward shift of the SWW that coincided with a rapid atmospheric CO2 rise starting ca. 12.5 ka, a widespread decline in SWW strength between ca. 10 and 7 ka contemporaneous with an ~8 ppm reversal in the deglacial atmospheric CO2 rise, followed by stronger SWW and a steady multimillennial increase in CO2 until the preindustrial maximum. We conclude that zonally symmetric changes in ..