Oxygen isotope records of five stalagmites from Hulu Cave near Nanjing bear a remarkable resemblance to oxygen isotope records from Greenland ice cores, suggesting that East Asian Monsoon intensity changed in concert with Greenland temperature between 11,000 and 75,000 years before the present (yr. B.P.). Between 11,000 and 30,000 yr. B.P., the timing of changes in the monsoon, as established with 230Th dates, generally agrees with the timing of temperature changes from the Greenland Ice Sheet Project Two (GISP2) core, which supports GISP2's chronology in this interval. Our record links North Atlantic climate with the meridional transport of heat and moisture from the warmest part of the ocean where the summer East Asian Monsoon originates.
High-resolution speleothem records from China have provided insights into the factors that control the strength of the East Asian monsoon [1][2][3][4] . Our understanding of these factors remains incomplete, however, owing to gaps in the record of monsoon history over the past two interglacial-glacial cycles. In particular, missing sections have hampered our ability to test ideas about orbital-scale controls on the monsoon [5][6][7] , the causes of millennial-scale events 8,9 and relationships between changes in the monsoon and climate in other regions. Here we present an absolute-dated oxygen isotope record from Sanbao cave, central China, that completes a Chinesecave-based record of the strength of the East Asian monsoon that covers the past 224,000 years. The record is dominated by 23,000-year-long cycles that are synchronous within dating errors with summer insolation at 656 N (ref. 10), supporting the idea that tropical/subtropical monsoons respond dominantly and directly to changes in Northern Hemisphere summer insolation on orbital timescales 5 . The cycles are punctuated by millennial-scale strongsummer-monsoon events (Chinese interstadials 1 ), and the new record allows us to identify the complete series of these events over the past two interglacial-glacial cycles. Their duration decreases and their frequency increases during glacial build-up in both the last and penultimate glacial periods, indicating that ice sheet size affects their character and pacing. The ages of the events are exceptionally well constrained and may thus serve as benchmarks for correlating and calibrating climate records.The last glacial period is characterized by millennial-scale events, first identified in Greenland, including 25 Greenland interstadials (GIS) during the last interglacial-glacial period [11][12][13] . We previously identified a number of Chinese interstadial (CIS) events 2,4 (relatively strong summer millennial-scale East Asian monsoon, EAM, events) and correlated them with analogous GIS events. We also identified CIS events from portions of the penultimate glacial period, and established a nomenclature with last glacial period CIS denoted CIS A1, A2, and so on, from youngest to oldest, and those of the penultimate glacial period denoted CIS B1, B2, and so on 1 . Here we present an EAM record from Sanbao cave, together with our previous Hulu records 1,2 , and characterize the complete CIS series for the last and penultimate interglacial-glacial cycles, including events not previously identified.Sanbao cave is in Hubei province, central China, on the northern slope of Mt Shennongjia, near the southern edge of the Chinese loess plateau (110u 269 E, 31u 409 N, 1,900 m above sea level). Regional climate is dominated by the EAM, a sub-system of the Asian monsoon (AM) (Supplementary Fig. 1), with a mean annual rainfall of 1,900-2,000 mm and a mean temperature of 8-9 uC. During boreal summer (June to September), warm/humid air from the equatorial Pacific penetrates to the northern slope of Mt Shennongjia, delivering mo...
Thorium-230 ages and oxygen isotope ratios of stalagmites from Dongge Cave, China, characterize the Asian Monsoon and low-latitude precipitation over the past 160,000 years. Numerous abrupt changes in 18O/16O values result from changes in tropical and subtropical precipitation driven by insolation and millennial-scale circulation shifts. The Last Interglacial Monsoon lasted 9.7 +/- 1.1 thousand years, beginning with an abrupt (less than 200 years) drop in 18O/16O values 129.3 +/- 0.9 thousand years ago and ending with an abrupt (less than 300 years) rise in 18O/16O values 119.6 +/- 0.6 thousand years ago. The start coincides with insolation rise and measures of full interglacial conditions, indicating that insolation triggered the final rise to full interglacial conditions.
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