Asynchronous Holocene Optimum in East Asia monsoon region recorded by stalagmites and its underlying climate dynamics by Ming-Qiang Liang


May 16, 2023


BST 01

Reconstructions of Holocene Optimum (HO) in East Asian summer monsoon (EASM) regime from speleothem versus other proxy records have
yielded divergent phase relationships with the EASM and local precipitation. This apparent discrepancy has been partly attributed to
the uncertainties in the climatic representation of Chinese speleothem oxygen isotope (δ18O) records. Here we report first Holocene speleothem
records from the southeastern China in conjunction with a state-of-the-art isotope-enabled climate model to deconstruct the
asynchronous HO signal found in EASM speleothem records and underlying mechanisms. Our analysis suggests that 1)An incoherent orbital-scale
speleothem δ18O variability in EASM regime indicate that speleothem δ18 is largely controlled by the large-scale circulation and concomitant
latitude shifts of monsoon rain belt. 2) a marked southward shift of the HO period from early-Holocene in North China (NC) to late-Holocene in
South China (SC). During the Holocene, the variation of the convective precipitation is dominated by precession in summer, and Meltwater in Spring