Strengthening of the East Asian winter monsoon during the mid-Holocene

Abstract

The change in the East Asian winter (December–January–February) monsoon (EAWM) during the mid-Holocene, approximately 6000 years ago, was investigated using all available experiments within the Paleoclimate Modelling Intercomparison Project (PMIP). As defined by regional-averaged meridional wind speed at 850 hPa, the mid-Holocene EAWM intensity was consistently stronger than that of the reference period in 38 out of the 42 models chosen for analysis, with an average strengthening of 14% across all models. In response to changes in the Earth’s orbital parameters and atmospheric greenhouse gas concentrations, zonal and meridional land–sea thermal contrasts and sea-level pressure gradients were enhanced between the continent and the adjacent oceans of East Asia, leading to the strengthening of the mid-Holocene EAWM. In addition, there were uncertainties regarding the EAWM reconstructions and the effect of dynamic ocean and vegetation on the EAWM change during the mid-Holocene.

Responses of East Asian Winter Monsoon‐Australian Summer Monsoon to Local and Remote Orbital Forcing During Holocene

“…The mid‐Holocene shows a similar response with a surface cooling over the Eurasian continent, accompanied by an enhanced Siberian high and the EAWM, but with a weaker magnitude than early Holocene (Figures 3a and 3f). This overall reduction of the enhancement of EAWM from early to mid‐ Holocene is consistent with other model simulations (Tian & Jiang, 2018; X. Wen et al., 2016), which follows the boreal winter insolation anomaly showing a weaker insolation reduction at 6K than at 11K (Figure 1). However, the overall reduction of the enhancement of EAWM from early to mid‐ Holocene contradicts the grain size records (Yang & Ding, 2008) and high‐resolution records of titanium concentration from the Huguang Maar Lake (HML) (Yancheva et al., 2007) those show strengthening EAWM from early Holocene to late Holocene.…”

“…The mid-Holocene shows a similar response with a surface cooling over the Eurasian continent, accompanied by an enhanced Siberian high and the EAWM, but with a weaker magnitude than early Holocene (Figures 3a and 3f). This overall reduction of the enhancement of EAWM from early to mid-Holocene is consistent with other model simulations (Tian & Jiang, 2018;X. Wen et al, 2016), which follows the boreal winter insolation anomaly showing a weaker insolation reduction at 6K than at 11K (Figure 1).…”

Spatial variation of East Asian winter monsoon evolution between northern and southern China since the last glacial maximum

“…The stronger- than-present EAWM intensity during the mid-Holocene (Fig. 6g and h) is supported by the results of Tian and Jiang (2018) in southern China, whereas the EAWM intensity change, slight or similar to the present (Fig. 6g and h), during the LGM was not exactly identical to the PMIP model results of Jiang and Lang (2010).…”

“…Note that there is a deviation between the reconstruction and the simulation during the late Holocene. The former indicates a strengthening EAWM, while the latter from TraCE simulation and multiple PMIP models (Tian and Jiang, 2018) shows a weakening EAWM. The significance of human activity of northern China in the late Holocene (Jing, 1991; Dong et al, 1993; Rhode et al, 2007; Li et al, 2009; Schlütz and Lehmkuhl, 2009; Zhou et al, 2011; Yu et al, 2012, 2016) can account for the observed deviation.…”

A Synthesized Study of the Spatiotemporal Evolution of Central Yellow Sea Mud Depositional Processes During the Holocene

“…Due to the strong trapping ability of the central weak tidal zone, SRs would be most likely controlled by the sediment source input, which in turn would be closely affected by the EAWM. Recent studies of Holocene EAWM variations have suggested a strengthened EAWM during the mid-Holocene, and a generally less intense EAWM after 5 ka (Hu et al, 2012;Li and Morrill, 2014;Wang L. et al, 2012;Tian and Jiang, 2018; Figure 5E). Over the last 7 ka, high SRs in the CYSM zone appear to correspond well with a strong EAWM during the 7-5 ka period; low CYSM SRs seem consistent with a weakened EAWM since 5 ka (Figures 5F,G).…”