.95 ~ 56 Kabp, Periods Of East Asian Monsoon Stalagmite ¦Ä ~ (18) O Record And Its Significance Discussed

During the last glacial period, climate was dominated by abrupt climate events (Dansgaard/Oeschger events, Heinrich events). Exploring the forcing mechanisms of the abrupt climate events plays an important role in predicting future abrupt climate changes developed within a few decades. Hulu Cave record from mid-latitude of central China revealed a series of Dansgaard/Oeschger events during the mid to late last glacial, among them several latest events synchronous with abrupt climate events recorded in Greenland ice cores. However, the early D/O events in East Asian Monsoon area are still uncovered from documentaries mainly due to the limitation of materials. Based on 23 U/Th analyses and 532 oxygen isotopic data, we establish an averaged 80-yr stalagmite oxygen isotopic composition series through 95 to 56 thousand years before present (ka BP) from two speleothems in Shanbao Cave, Shennongjia, Central China. Our Shanbao Cave record (referred as SB record), well replicates with Hulu Cave record, extending the characteristics of millennial oscillations in East-Asian-Summer-Monsoon (EASM) to the past 95 ka. The trend of SB record generally follows 65°N mid-July solar insolation, suggesting that mid-high northern latitude insolation, in the first order, controls changes of EASM intensity. Millennial oscillations of EASM recorded in stalagmites are well related to the Greenland interstadials referred as Dansgaard/Oeschger (D/O) events from 1 to 22, indicating that rapid ocean-atmosphere reorganization in North Atlantic has a remote effect in EASM.At present, the differences of chronologies of D/O events in different ice cores usually exceed the duration of one single D/O event. A few researches suggested that the well-dated D/O events by stalagmites probably provide an absolute calibration for chronologies of the Greenland ice cores. In our research, the timings of D/O events in the SB record are variously different from those in Greenland ice cores. Especially for D/O 19 and 20, the age offsets between the stalagmites' and the Greenland ice cores' are significant, far exceeding the uncertainties of uranium-series dating. The two events in the SB record are younger than those in North GRIP (ss09sea time scale) by 1～2ka, and older than GISP2 by approximate 3～4ka.Climate correlation between hemispheres shows apparent confusions in both model and paleoclimate data. Nevertheless, the most fundamental premise for understanding mechanisms behind abrupt climate events is to put correlation of climate events in the same relative (or absolute) temporal framework. Under the same dating method and the precise dated D/O events in both records, a comparison between the Brazil stalagmite record and ours shows an anti-phase correlation in millennial-scale monsoon precipitation D/O events between the two localities. This supports a mode for the coupled ocean-atmosphere "See-saw".