Quantification of Asian monsoon variability from 68 ka BP through pollen-based climate reconstruction

Northern Hemisphere Summer Insolation and Ice Volume Driven Variations in Hydrological Environment in Southwest China

“…Although, the NHSI and SITIG are nearly identical in phase, the decreasing NHSI is contrasting the elevated precipitation during MIS3, which is synchronous to SITIG (Figure 1). This finding supports the fact that inter‐hemispheric heat contrasts also cause ASM precipitation variation (Beck et al., 2018; Zhang et al., 2023). To validate this forcing, we compared our X/Ca PC1 record with marine proxies from ASM moisture source region (Figures 1b and 1g).…”

“…This process, while increasing East Asian monsoon precipitation, also produces more depleted δ 18 O values in the speleothem records due to significant upstream moisture convergence and rainout (Figures 1a, 1b, and 1g) (Liu et al., 2014; Ruan et al., 2019). The above phenomena and processes have been confirmed in quantitatively reconstructed precipitation records on orbital scales based on pollen in southern China and loess in the north China (Beck et al., 2018; Zhang et al., 2023). For the first time, we observe similar features in stalagmite trace element records from southern China.…”

“… Comparison of the YZ1 X/Ca records with paleoclimate records from different regions of China. (a) Gulang loess δ 13 C (Sun et al., 2015); (b) Zhenzhu Cave stalagmite δ 13 C (Y. X. Li et al., 2020); (c) Mangshan loess brGDGT‐derived soil pH (Peterse et al., 2014); (d) Weinan loess δ 2 H (Thomas et al., 2016); (e) Tai Lake pollen ratio of Woody/Herbaceous (Miao et al., 2015); (f) IODP U1429 planktonic foraminifer δ 18 O (gray) (Clemens et al., 2018); Haozhu cave stalagmite trace elements PC1 (bule) (Zhang et al., 2018); Dajiuhu pollen‐based mean annual precipitation (purple) (Zhang et al., 2023); Yongxing cave stalagmite Sr/Ca (orange) (Wang, Chen, et al., 2022); (g) YZ1 X/Ca PC1 (this study); (h) Pollen‐based MAP records of Caohai (green) and Tengchong‐Qinghai (pink), respectively (Zhang et al., 2023); (i) Maar lake sediments Magnetic susceptibility (Wang, Lu, et al., 2022). The red/blue bars indicate paleoclimatic records where increased/decreased insolation corresponds to decreased/increased precipitation.…”

“…For example, summer precipitation in northern China is controlled by precession, showing significant 23 ka cycles, while in southern China 100 ka cycles are well present, indicating the dominant influence of the background climate state as for example, represented by the global ice volume (Dai et al., 2021; Lyu et al., 2021; Zhao, Lu, et al., 2023). In addition to NHSI and ice volume, it has also been hypothesized that the ASM is primarily driven by the Summer Inter‐Tropical Insolation Gradient (SITIG) (Cheng et al., 2022; Zhang et al., 2023). During the precessional minima ( P min ), the increase in SITIG leads to a more pronounced northward shift of the Intertropical convergence zone (ITCZ) and enhanced western Pacific subtropical high and winter hemisphere trans‐equatorial Hadley circulation (Beck et al., 2018).…”

Holocene Variability of the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation Inferred From Chinese Speleothem δ18O Records

“…Compared with the several centennial to multicentennial weakening AM events identified in single‐cave δ 18 O s records (R. Duan et al., 2023; Tan et al., 2020, 2021; Z. Wang et al., 2022; X. Zhang, Zheng, et al., 2023), our synthesized AM series exhibits a prominent weakening in AM at ∼8.2 ka BP over the Holocene. Regional characteristics and trigger mechanisms of the 8.2 ka event have been extensively investigated and interpreted as a release of meltwater into the Labrador Sea, subsequently weakening the poleward heat transport in the North Atlantic (Y. Liu et al., 2013; Parker & Harrison, 2022; Tan et al., 2020).…”