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We reconstructed high-resolution paleoclimate records with 24 230Th/U dates, 706 sets of stable isotope values (δ18O and δ13C) from a stalagmite from Shima Cave, Hunan Province, central China. The stalagmite grew during the last deglaciation from 19.7 to 13.3 ka, with a 1500-year hiatus during Heinrich Stadial 1. We interpret stalagmite δ18O as the East Asian summer monsoon (EASM) intensity, while δ13C as terrestrial CO 2 related with biomass production and local hydrogeochemical processes. Long-term trend and millennial-scale changes in δ18O record are absent in the δ13C record, possibly due to the low biomass production and small vegetation changes in central China across the studied period, which is contrast to an obvious recovery of the biomass in northern China during the Bølling-Allerød period. Besides, high frequency of δ13C record displays quasi periods of 30–50 years, which are consistent with typical periodicities of the Pacific Decadal Oscillation (PDO). Furthermore, comparison of our δ18O record with measures of solar variability shows clear evidence for solar forcing on the EASM on the centennial timescale, which could possibly be mediated by the Atlantic Meridional Overturning Circulation and El Niño/Southern Oscillation/PDO. Therefore, we suggest that monsoonal climate and ecological changes during the last deglaciation could have been modulated by solar activity and sea surface temperature variability in both the Atlantic and the Pacific Ocean. [ABSTRACT FROM AUTHOR]

The Last Glacial Maximum (LGM) is the period when global ice volume reached its maximum, the radioactive forcing well-defined and the climate in the quasi-equilibrium state. However, few proxy records have a temporal resolution high enough to capture detailed climate variabilities at this timescale. Here we reconstruct absolutely-dated and high-resolution δ18O and δ13C records from Shima Cave, central China, covering from 22.4 to 20.2 ka BP, with a temporal resolution of ∼14 years. Both δ18O and δ13C records show clear multicentennial-scale variations. Comparison with highly-resolved geological archives from the mid-to-low latitudes shows that multicentennial-scale changes are evident in the East Asian summer monsoon (EASM) and South American summer monsoon regions, but in antiphased relationship. Altogether six multicentennial-scale strong EASM periods are consistent with warmings in Greenland and northward movement of the jet stream over the Euro-Asia continent, and monsoon weakenings are linked with the ice-rafted debris peaks and Greenland cooling, indicating persistent influence of the North Atlantic climates on the EASM through shifts of the atmospheric circulations during the LGM. • A high-resolution and well-dated East Asian summer monsoon history during the Last Glacial Maximum. • Multicentennial precipitation variability occurs in the low-latitude regions, with antiphased relationship in two hemispheres. • Multicentennial monsoon variabilities strongly coupled with North Atlantic climates through atmospheric circulations. [ABSTRACT FROM AUTHOR]

The Heinrich Stadial 2 (HS2) event is poorly defined in the Greenland δ18O ice core record; however, it can be identified in stalagmite records from China. In this paper, we reconstruct an absolutely-dated and high-resolution calcite δ18O record from Shima Cave, central China, covering the interval from 26.0 to 23.9 ka BP, with a temporal resolution of ~16 years. By integrating our newly reported record with all available δ18O records of Marine Isotope Stage 2 from China, which are securely 230Th/U-dated, we calculate the timing of the onset, termination and duration of HS2. The statistical results show that the prominent HS2a phase started at ~24.4 ± 0.1 ka BP and ended at ~23.6 ± 0.1 ka BP, lasting approximately 0.8 ± 0.3 ka. If the onset of the Dansgaard-Oeschger 2 event in the Greenland δ18O record is synchronous with the termination of HS2a, then the GICC05 chronology should be adjusted by +230 years to align it with stalagmite results. Further investigation of HS2 shows that Chinese cave records exhibit a distinct two-fold structure, corresponding to HS2a and HS2b, as observed in marine sediment cores, particularly those recovered around the Atlantic Ocean. These records show comparable changes in relative amplitudes during the HS2a and HS2b phases, which could possibly be related to different weakening episodes in the Atlantic Meridional Overturning Circulation. • An ~16-year-resolution East Asian summer monsoon (EASM) history covering the onset of Heinrich Stadial 2 event. • Statistical analyses of timing for Heinrich Stadial 2. • Globally pervasive twofold structure during Heinrich Stadial 2. [ABSTRACT FROM AUTHOR]

Spatial differences of rainfall in monsoonal China during the last glacial period remain contentious. Here, we present new 230Th-dated stalagmite records (δ13C and δ18O) from central China (the Yangtze River valley), spanning approximately 75–10 ka BP, to address this issue. We interpret the stalagmite δ13C variations primarily as indicators of regional rainfall changes, which show significantly decreased rainfall during MIS 4 and late MIS 3 to MIS 2. On the millennial timescale, the δ13C record indicates decreased rainfall during Heinrich (H) events and increased rainfall during Dansgaard-Oeschger interstadials. The strong correlations between our δ13C record and the westerly proxies suggest that the westerly jet played a crucial role in influencing rainfall patterns in monsoonal China throughout the last glacial period. We propose that rainfall changes in central China were consistent with northern China on both orbital and millennial timescales during the last glacial period. This observation contrasts with the modern rainfall differences between northern and central China. Our results imply that with a colder climate in high northern latitudes, the rain belt over monsoonal China influenced by the westerly jet shifted further south beyond the Yangtze River Valley during MIS 4, late MIS 3 to MIS 2 and H events, leading to a consistent decrease in rainfall over central and northern China. In contrast to the rainfall records, the stalagmite δ18O values were more negative during late MIS 3. The δ18O variations on the orbital timescale are likely related to the changes in the tropical ocean conditions controlled by insolation, which determines the δ18O values in evaporated moisture before its transport into the Asian continent. On the millennial timescale, our δ13C and δ18O records exhibit coupled variations, implying that the stalagmite δ18O variations are consistent with the rainfall changes in central and northern China. • New stalagmite δ13C and δ18O records spanning the last glacial period (75–10 ka BP) from central China. • Consistent rainfall changes in central and northern China on both orbital and millennial timescales. • Coupled variations between δ13C and δ18O records on the millennial timescale. [ABSTRACT FROM AUTHOR]

Both external forcing and internal climate variability are playing significant roles in driving the East Asian summer monsoon (EASM) changes. However, dynamic linkages between these natural forcings and EASM on decadal timescales remain uncertain, partly due to the limited instrumental climate data. Here, we present a high-resolution EASM record over the past 200 years based on 2315 δ18O measurements from two annually laminated stalagmites (YX92 and YX120) in Yongxing Cave over the middle Yangtze River Valley (mid-YRV). Our records match well with the δ18O records from the nearby Heshang Cave, showing that EASM intensity in the mid-YRV varies at a dominant periodicity of ∼80 years. The multidecadal-scale oscillations in the EASM intensity are closely related to the ENSO-like states, supporting a notion that the ENSO dominantly modulates the EASM variability. Furthermore, the decadal oscillations in EASM and ENSO are synchronous with tropical volcanic eruptions during the solar minima, probably leading to the enhanced El Niño-like response, intensified EASM and strengthened ENSO-EASM coupling. Our findings imply that external forcings potentially contribute to the anomalies in ENSO and EASM during the ongoing global warming. • EASM changes at a dominant periodicity of ∼80 years over the past 200 years. • Multidecadal-scale oscillations in EASM intensity closely related to ENSO-like states. • Decadal oscillations in EASM and ENSO evolution synchronous with tropical volcanic eruptions during the solar minima. • Tropical volcanic eruptions likely enhanced the ENSO-EASM coupling. [ABSTRACT FROM AUTHOR]

Meteorological observations indicate that both natural and anthropogenic forcing contribute to regional drought/flood in the East Asian summer monsoon (EASM) domain. However, spatiotemporal rainfall pattern and its dynamics during natural climatic variability remains unclear. Here we reconstruct a ∼3 year-resolution EASM precipitation record over the past two millennia, based on 13 230Th dates and 600 δ18O in a stalagmite from Songya Cave, southeastern China. The δ18O sequence shows a long-term decreasing trend, indicating an increasing monsoon precipitation over the past two millennia. A series of centennial-scale fluctuations are superimposed on the long-term trend, with a wetter Little Ice Age than the Medieval Warm Period. The long-term trend and centennial-scale oscillations in EASM rainfall are broadly related to El Niño-Southern Oscillation (ENSO) and Pacific decadal oscillation (PDO) variations, with an increased (decreased) EASM rainfall corresponding to El Niño-like (La Niña-like) conditions and positive (negative) phase of PDO. Comparison of δ18O records from Songya and Wanxiang Cave shows an anti-phased spatial rainfall pattern between southeastern and northwestern China. This spatiotemporal rainfall pattern, consistent with the modern observations, is possibly regulated by the ENSO, through changes in the location and strength of the Western Pacific Subtropical High (WPSH). • A long-term increasing monsoon precipitation in southeastern China over the past two millennia. • An anti-phased "southeastern-northwestern" rainfall pattern in the monsoonal China. • The spatiotemporal pattern of EASM precipitation modulated by ENSO and PDO. [ABSTRACT FROM AUTHOR]

• A composite high-resolution monsoon precipitation record over the mid-YRV. • Centennial-scale oscillations in EASM rainfall related to solar activity and ENSO. • An anti-phase relationship of monsoon rainfall between the mid-YRV and tropical WNP. • A new EAP index calculated as the difference between monsoon rainfall in the mid-YRV and WNP. • A strong correlation between the EAP and SOI index. Meteorological observations reveal an inverse relationship of summer monsoon rainfall between the tropical western North Pacific (WNP) and middle Yangtze River Valley (mid-YRV) on interannual and intraseasonal timescales. This seesaw-like pattern, named the East Asian-Pacific (EAP) pattern, is one of the major teleconnections that affect summer precipitation in the mid-YRV. However, due to the scarcity of long and continuous instrumental data, the behavior and mechanism of the EAP pattern on a long timescale are poorly understood. Here, we present a composite high-resolution summer monsoon rainfall record from 230 BC to 1810 AD, based on 1221 δ 18 O measurements and 22 230Th dates from two stalagmites (EB1 and EB5) in Shenqi Cave over the mid-YRV. Our new record shows that monsoon rainfall in the mid-YRV varies at a dominant periodicity of ∼100 years, probably linked to solar activity and ENSO variability. The multi-centennial fluctuations in the EB record, broadly consistent with the North Hemisphere temperature reconstruction, display strong similarities to two stalagmite δ 18 O records from nearby Heshang and Luoshui caves. To represent the integrated hydroclimate variations over the mid-YRV, we extracted the first principal component (PC1) of these three cave δ 18 O records by using the principal component analysis. We reveal a striking inverse relationship of wet/dry conditions between the mid-YRV and tropical WNP, suggesting that changes in the EAP pattern have an important impact on centennial-scale monsoon precipitation changes. Furthermore, we compile monsoon rainfall records from the mid-YRV and WNP to reconstruct a new EAP index. This EAP index exhibits a strong correlation with the ENSO proxy, confirming that the ENSO variability may play a key role in modulating the monsoon rainfall in the mid-YRV through the EAP teleconnection. [ABSTRACT FROM AUTHOR]