Intensified episodes of East Asian Winter Monsoon during the middle through late Holocene driven by North Atlantic cooling events: High-resolution lignin records from the South Yellow Sea, China

摘要

The varying intensity of the East Asian Winter Monsoon (EAWM) governs the strength of the counter-clockwise surface circulation of the South Yellow Sea and the redistribution of sediment and terrestrial organic material that had accumulated on the shallow shelf during the summer season into the central part of that basin. We compiled a time series spanning about 6.3 ka of terrestrial lignin proxies from sediment core N02 from Central Yellow Sea Mud that has well-preserved high-resolution sedimentary records (24 yr/cm average spacing). The "hydrodynamic sorting effect" driven by century-scale climate variation in the strength of the EAWM exerts the main underlying control on the variation of lignin proxies in marginal sea sediments, rather than paleovegetation variability in provenance region driven by the East Asian Summer Monsoon (EASM). Our lignin proxies data imply that North Atlantic climate forcing recorded by ice-rafted debris ("Bond cycles") played a critical role in generating EAWM variability on these centennial timescales during the Holocene. These variations of lignin records are superimposed on general multi-thousand-year trends that appear to mirror the relative frequency and intensity of the El Hino Southern Oscillation (ENSO). Our results indicate that lignin can be adopted as an additional reliable proxy for paleoclimate evolution, at least in South Yellow Sea area. (C) 2017 Elsevier B.V. All rights reserved.