Multidecadally resolved Asian summer monsoon dynamics during MIS 5a-5d

A strong correlation between the Asian summer monsoon (ASM) and the North Atlantic climate on millennial and sub-millennial timescales during the last glacial period (MIS 4-2) and deglacial sequence has been demonstrated. However, our knowledge of this millennial- and sub-millennial-scale climatic link before MIS 4 is limited. Here, we present a new U-Th-dated absolute chronology of ASM variability from 113.5 to 86.6 kyr BP, covering marine isotope stages (MIS) 5a-5d. This integrated multidecadally resolved record, based on 1435 oxygen isotope data and 46 U-Th dates with 2-sigma errors as low as ±0.3 kyr from three stalagmites collected in Sanxing Cave, southwestern China, can be a reference for calibrating paleoclimate proxy sequences. The Sanxing oxygen isotope record follows the 23 kyr precessional cycle of insolation and is punctuated by prominent millennial-scale oscillations of the Chinese Interstadials (CIS) 25 to 22, corresponding to Greenland Interstadials (GIS) 25 to 22. A centennial-scale precursor event at 104.1 ± 0.3 kyr BP preceding CIS 23 is clearly registered. These events in the Sanxing record are synchronous with those identified in stalagmites from the European Alps (NALPS), except for the onset of GIS 25 and the end of GIS 22, and are up to 2.3 kyr older than the corresponding ones in Greenland ice core records. The high degree of similarity of the oxygen isotope records between Sanxing Cave and Greenland supports the northern hemisphere forcing of the ASM. The anti-phase relationship of oxygen isotope records between Sanxing stalagmites and Antarctic ice cores suggests an additional ASM linkage to the Southern Hemisphere.