NOAA/WDS Paleoclimatology - Holocene Chilean Margin Geochemistry and Benthic Isotope Data

Despite small direct changes to radiative forcing, solar sunspot cycles are observed in many climate records because of climate system amplification that primarily affects wind and precipitation belts. We present the first proxy record resolving the dominant sub-millennial periodicities across the entire Holocene in the South Westerly Winds, whose migrations are linked to ocean-atmosphere heat and carbon exchange. Here we use X-ray fluorescence core scanning to examine a rapidly accumulating sediment record (6 meters/kiloyear) recovered from the Chilean margin during Expedition 379T, yielding unprecedented <2-year resolution for the Holocene. Variations in terrigenous inputs to the site are linked to precipitation, and thus the SWW latitudinal migrations. Superimposed on a long-term decreasing trend throughout the Holocene, we detect significant centennial cycles in the terrestrial input consistent with solar periodicities. We then propose a mechanism by which southward South Westerly Wind shift during increasing total solar irradiance leads to cooling Antarctic temperatures.