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The 8.2 ka abrupt cooling event has been extensively studied, whereas the 7.2 ka event and their comparations rarely mentioned. Here, we present a high resolution (∼4 years) and precisely dated (±25 years) speleothem multi-proxy record from Zhangjia Cave (northern margin of Sichuan basin, China) spanning the 7.2 and 8.2 ka events within the transition of early to middle Holocene. The speleothem δ18O mainly reflects the dynamic facets of the East Asian summer monsoon (EASM) system, while its δ13C and trace elements ratios serve as an indicator of local hydrological conditions. Our results reveal intense dry conditions in southwest China during the 7.2 ka event, despite the 7.2 event was characterized by a relatively stronger monsoon compared to the 8.2 ka event. Furthermore, the hydrological conditions during the 7.2 ka event and the middle Holocene appear to exhibit "north flood and south drought" pattern when compared to different paleoclimate records in EASM domains, while it can be summarized as "spatially consistent drought" in the 8.2 ka event. These different hydrological conditions are a response to the weakening of the EASM, a phenomenon also observed in modern climatic observations and empirical simulations, which underpins our understanding that the speleothem δ18O variations are mainly dynamical manifestations of the EASM system, likely different with its thermodynamical appearances. • In the 7.2 ka event, we observed more intense dryness in southwest China compared to the 8.2 ka event, despite the 7.2 event having a relatively stronger monsoon. • The precipitation patterns differed between the 7.2 ka event, 8.2 ka event, as well as the Early and Middle Holocene. During the 7.2 ka event, hydrological conditions exhibited a "north flood and south drought" pattern, while the 8.2 ka event was characterized by "spatially consistent drought." • The varying precipitation patterns under similar East Asian Summer Monsoon (EASM) intensities enhance our understanding of speleothem δ18O. This suggests that speleothem δ18O primarily reflects the dynamics of the EASM system rather than the thermodynamics. [ABSTRACT FROM AUTHOR]

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. • Precipitation δ18O and its millennial-centennial patterns in SE Tibet Plateau are controlled by large monsoon circulations • Centennial δ13C-δ18O covariations in Younger Dryas suggest a link of the local biomass to Indian summer monsoon rainfall • Centennial Indian summer monsoon events in Younger Dryas correlate precisely to the North Atlantic climate variations • Solar de Vries cycle (207-y) triggered centennial Indian summer monsoon variations via North Atlantic climate changes [ABSTRACT FROM AUTHOR]

Speleothem oxygen isotope (δ18O s) record as a climatic proxy in southeastern China is still in debate due to multifaceted influencing factors, a modern δ18O s record, which can be calibrated or compared with observational data, is critical to explore the interpretation of δ18O s proxy. Here we present a seasonally resolved δ18O s record spanning the interval of 1898–2018 CE from Niubi Cave, Guangdong Province, southeastern China. A comparison between the Niubi δ18O s and instrumental data reveals that the Niubi δ18O s variability is primarily controlled by changes in precipitation seasonality modulated by El Niño-Southern Oscillation on interannual to interdecadal timescales. Higher (lower) δ18O s values correspond to lower (higher) ratios of the East Asian summer monsoon/non-summer monsoon precipitation during the El Niño (La Niña) events associated with concomitant changes in the outgoing longwave radiation, wind field and Western Pacific Subtropical High. While ∼73% historical drought events correlate to positive anomalies in Niubi δ18O s values over the last 120 years, the rest of drought events associate with the negative δ18O s anomalies. This observation suggests two different mechanisms for the drought events with more and less diminution of rainfall amount in the East Asian summer monsoon relative to the non-summer monsoon precipitation, respectively. Additionally, our Niubi δ18O s record from southeastern China, together with other high-resolution speleothem and tree ring records, demonstrate a "tripole pattern" of summer precipitation during the last ∼100 years in eastern China. • δ18O s records from SEC is controlled by the precipitation seasonality modulated by the ENSO on interannual timescales. • Not all drought events correspond to the higher δ18O s in NB cave because of the effect of precipitation seasonality. • A "tripole pattern" of summer rainfall in eastern China can be observed in palaeoclimatic records over the past ∼100 years. [ABSTRACT FROM AUTHOR]