A high‐resolution monsoon record of millennial‐scale oscillations during Late MIS 3 from Wulu Cave, south‐west China

Abstract

ABSTRACTA speleothem record from south‐western China characterizes in detail the millennial‐scale changes in Asian Monsoon (AM) intensity from 39.3 to 28.7 ka. The calcite δ18O profile, with an average resolution of ∼8 years, shows several strong monsoon events concurrent with Greenland Interstadials (GIS) 8–4. To gain a systematic perspective of AM millennial‐scale variability, the new and previously reported data from the same cave are combined, showing that AM variation exhibits a broad similarity with Greenland ice δ18O records and with Antarctica but in an opposite sense. For the interval that encompasses GIS 5 and GIS 4.1, however, our stalagmite δ18O record depicts a sustained strong monsoon with no distinctive oscillation between these interstadials. Another prominent characteristic in our record is a gradual transition into Chinese Interstadial (CIS) 8, which is well constrained by an annually laminated sequence. We find that an initial rise in monsoon intensity, lasting a few centuries, significantly precedes the abrupt onset of CIS 8 in the AM realm. This suggests that atmospheric moisture and heat transport are probably capable of inducing abrupt climate change when a rapid reorganization of ocean/atmosphere circulations passes a tipping point.