Understanding the response of East Asian monsoon (EAM) rainfall patterns to different climate forcings is cardinal for constraining future climate change over East Asia. The magnitude and rate of EAM rainfall changes during the late Pleistocene-Holocene is reconstructed using the first well-dated Northeastern China lake-area record from a closed-lake basin, which enables reconstructing quantitative absolute paleo-rainfall amounts. In addition, compound specific hydrogen isotopes from long-chain alkanes (Dleafwax) in the lake-sediments were used to reconstruct the isotopic composition of rainwater and lake water. Lake-levels were 60m higher than present during the early and middle Holocene. This requires an absolute increase in mean annual rainfall to at least two times higher than today. The EAM intensity and northern extent alternated abruptly between wet and dry periods on time scales of a few centuries. Both the onset (~60 m rise at 11.5 ka BP) and termination (~35 m drop at 5.5 ka BP) of the Holocene humid period occurred abruptly, within centuries. The co-variation of lake-area and Dleafwax show, for the first time, that the “amount effect” is the cardinal driver of the isotopic composition of paleo tropical rainfall. Thus, resolving a current debate regarding the ability to use the isotopic composition of rainwater as a proxy for rainfall amount and validating the “intensity-based” interpretations of the Chinese cave deposit records.
