Solar forcing of centennial-scale East Asian winter monsoon variability in the mid- to late Holocene

Centennial-scale variability of the East Asian winter monsoon during the Holocene is poorly understood because suitable archives and proxies are lacking. Here we present a high-resolution (similar to 30-yr spacing) planktonic foraminiferal delta O-18 record of Neogloboquadrina incompta (dextral form), which reflects sea surface temperature during the winter season, for the last 6000 yrs from marine sediments in the western North Pacific. Stronger winter monsoons indicated by cooler winter SSTs correspond to weaker summer monsoons indicated by the cave oxygen isotopes in centennial-scale variability. The variability also shows good correlation with delta O-18 records in lake sediments and ice cores from the Yukon Territory, Canada, spanning the last 4500 yrs, suggesting east-west climate coupling across the North Pacific. Furthermore, the climate changes across the North Pacific co-vary over widespread regions, such as the eastern tropical Pacific and the northern Red Sea, and the reconstructed solar activity. The cross-spectral and wavelet analyses show that the East Asian winter monsoon shares some cyclicity with the solar variability. Our results suggest that the solar activity is a fundamental forcing producing the centennial-scale EAWM variability mediated by the large-scale climate linkages. (C) 2014 Elsevier B.V. All rights reserved.