Time-transgressive onset of the Holocene Optimum in the East Asian monsoon region

Abstract

The East Asian summer monsoon affects precipitation and hence vegetation in the densely populated Northwest Pacific region, yet a long-standing controversy exists concerning the spatial and temporal dynamics of the Holocene Optimum (HO) in the East Asian Monsoon Region. Here we use a detailed 14,000-year record reconstructing vegetation variations from a strategically selected crater lake from Northeast China, as well as a compilation of previous paleoclimatic studies, to show that the HO began around 6,000 Cal a BP in Northeast China, significantly later than generally recognized. By comparing our paleoenvironmental data with Holocene vegetation records from other regions of East Asia, we identified a marked northward shift for the onset of the HO from ~10,260 Cal a BP in South China to ~6,000 Cal a BP in Northeast China. The gradual northward transgression of the vegetation change could be caused by both the temperature and precipitation changes in different regions. Finally, we fitted a regression model of the start of the HO period versus latitude, which allowed us to make predictions for the beginning of the HO based at different geographical locations. This study reveals a strong relationship between latitude and the initiation of the HO, and provides a window towards better understanding the forcing of vegetation changes in the East Asian monsoon region.

Shrinkage of East Asia Winter Monsoon Associated With Increased ENSO Events Since the Mid‐Holocene

“…500-year cycle exists in the intensity change of the EAWM. A similar periodicity has been noted previously in other Holocene (Tarasov et al, 2009); (d and e) records of Quercus and Pinus from Tianchi Lake (Zhou et al, 2016); (f) Pinus record from Sihailongwan Maar Lake (Stebich et al, 2015); (g) δ 18 O record (‰, VPDB (Vienna Pee Dee Belemnite); 5-point running average) from Fukugaguchi Cave (Sone et al, 2013); (h) EAWM indicator from Huguang Maar lake (Wang et al, 2012). EAWM = East Asian winter monsoon.…”

“…On these views, it is believed that the variation of solar output makes the weakening of the Walker circulation, the increasing of El Niño events, and the shrinkage of the EAWM since the mid‐Holocene. This transition is synchronous with the onset of the “modern” ENSO (Moy et al, ; Sandweiss et al, ) and also is widely acknowledged globally in the mid‐Holocene (Mayewski et al, ; Steig, ) as the termination of the Holocene thermal maximum, the hemispheric even global cooling, drier conditions in central to eastern Asia and Africa under the abrupt weakening of the monsoonal system, wetter conditions in northern Europe and southern South America (Magny et al, ; Roland et al, ; Zhou et al, ). The synchronicity of all these transitions implies that a reorganization in the Earth's ocean‐atmosphere circulation system occurred in the mid‐Holocene.…”

Synchronous Strengthening of the Indian and East Asian Monsoons in Response to Global Warming Since the Last Deglaciation

“…The yellow star indicates Lake Tianchi, and the red star indicates Lake Bayanchagan. Solid circles with numbers indicate the locations of lakes for which previously published palaeomonsoon records (Table S1; Chen et al, 2014Chen et al, , 2015Cheng et al, 2013;Demske et al, 2009;Enzel et al, 1999;Herzschuh et al, 2006Herzschuh et al, , 2009Herzschuh et al, , 2014Jarvis, 1993;Kramer et al, 2010;Lee et al, 2010;Leipe et al, 2014;Li et al, 2011;Ma et al, 2014;Maxwell, 2001;Prasad et al, 2014;Quamar & Chauhan, 2012;Shen et al, 2005Shen et al, , 2006Singh et al, 1990;Stebich et al, 2015;Sun et al, 1993Sun et al, , 2016Tang et al, 2000;VanCampo et al, 1996;VanCampo & Gasse, 1993;Wang et al, 2007;Wen et al, 2010Wen et al, , 2017Wischnewski et al, 2011;Wunnemann et al, 2010;Xiao et al, 2004Xiao et al, , 2014Xiao et al, , 2015Zhang et al, 2016;Zhou et al, 2016) for the Indian summer monsoon area (yellow) or the East Asian summer monsoon area (red) were used in our combined analysis. The yellow dashed line indicates the northern limit of the modern Asian summer monsoon (Jiang, 2013).…”

“…However, the spatiotemporal patterns of the ISM and the EASM are debated. Some have argued for the asynchronous evolution of the ISM and the EASM, in terms of the onset of the Holocene Climate Optimum and the timing of peak Holocene warmth Herzschuh et al, 2006;Hong et al, 2005;Wang et al, 2010;Zhou et al, 2016), emphasizing the dominance of processes internal to the climate system. By contrast, others have documented roughly synchronous changes in the ISM and the EASM (Cheng et al, 2012;Dong et al, 2010;Zhang et al, 2013), pointing to primacy of insolation forcing of the Asian monsoon system.…”

Late Quaternary East Asian Summer Monsoon Variability Deduced From Lacustrine Mineral Magnetic Records of Dahu Swamp, Southern China

“…In recent decades, the EASM evolution has been studied in detail by many researchers via various natural archives (An et al, 2015), which has provided critical insight into its possible spatial‐temporal forcing and future prediction under global warming. However, the spatial‐temporal history of the EASM, especially monsoonal precipitation, is still not fully understood among different geological records (An et al, ; Zhang et al, ; Zhou et al, ) and model experiments (Jin et al, ; Shi et al, ) at different timescales, which may be partly because of the uncertainties in proxy interpretation and dating, but also by real spatial differences in the Asian monsoon system. In addition, the relative influence and importance of high and low latitudes as drivers of glacial/interglacial monsoon climate changes is still critical to understanding past climate processes (Beck et al, ).…”