Indian summer monsoon variations during the Younger Dryas as revealed by a laminated stalagmite record from the Tibetan Plateau

High-resolution and precisely dated hydroclimate records in the southeastern Tibetan Plateau (TP) remain sparse beyond the Holocene, which hampers our ability to understand the hydroclimate variability in this important Indian summer monsoon (ISM) fringe area and its global teleconnection. Here we present 3-y resolution δ¹⁸O and δ¹³C records from a laminated stalagmite (RG-3) from Rige Cave in the southeastern TP, spanning the Younger Dryas (YD). The records allow us to precisely characterize the timing, structure, and particularly centennial-scale events within the YD, and probe the control factors of precipitation δ¹⁸O (δ¹⁸O_p) in the ISM fringe area. On centennial–millennial timescales, the Rige δ¹⁸O record shows coherent pattern with the East Asian summer monsoon (EASM) counterpart, combined with modeled δ¹⁸O_p results and spatial analysis, suggesting that δ¹⁸O_p in this part of the TP is largely controlled by the large-scale atmosphere circulation (or the ISM strength), and the altitude increase in the TP may not potentially result in an opposite δ¹⁸O_p pattern at least in the monsoonal TP regime. We also found significant δ¹³C-δ¹⁸O covariation on the centennial timescale, suggesting a coincided ISM rainfall and biomass change during the YD. In the Rige records, one weak centennial-scale ISM event (namely the intra-Allerød cold period, IACP) and three strong centennial-scale ISM events within the YD (namely A1′-A2′-A3′) were prominent and occurred between ∼12,470 and 12,310 ± 14, ∼12,210–12,090 ± 12 and ∼12,010–11,920 ± 12 y BP (before present, where present = 1950 CE), respectively. Spectral analyses of Rige records also revealed a significant ∼200-y periodicity, which is nearly in-phase with observed centennial-scale variations of the North Atlantic temperature and mid-latitude westerly-jet during that time. These observations support the hypothesis that the solar de Vries cycle (207-y) triggered the centennial-scale climate variations in high northern latitude, leading to the ISM variations via fast atmospheric processes.