重庆金佛洞石笋记录的410 ka弱季风事件OA北大核心CSTPCD

The freshwater discharge from melting ice sheets in the deglaciation or glaciation is prone to anomalies in ocean-atmosphere transport between different latitudes,which can lead to a series of abrupt millennial-scale climate events,either obvious or not,such as the Younger Dryas(YD)events and YD-like events.Marine Isotope Stage 11c(MIS 11c)serves as one of the best references for the current Holocene,and the studies of possible YD-like events and their triggering mechanisms during Holocene are conducive to the understanding of the occurrence pattern of extreme climate events.In this paper,the results of the study on the J33 δ18O sequence records of stalagmites in Jinfo Cave,Chongqing,are shown:(1)Stalagmites in the Asian monsoon climate zone reveal a millennial-scale weak monsoon event that occurred around 410 ka BP prior to the Glacial Maximum of MIS 11 interglacial period.(2)Both the 410 ka weak monsoon event and the YD event occurred during the gradual strengthening of the monsoon and ascending branch of summer insolation in the Northern Hemisphere prior to the Glacial Maximum of interglacial period.This was also a time when Atlantic Meridional Overturning Circulation(AMOC)disturbance occurred.The duration,internal structure,and pattern of the events were similar,with differences in the change magnitude and ice volume conditions.(3)The weak monsoon event that occurred in 410 ka BP was primarily influenced by the combined effects of insolation and AMOC.This event was characterized by a sustained warming process that accelerated the melting of the Greenland ice sheet,leading to the destabilization of this ice sheet.The continuous flowing of freshwater into the North Atlantic resulted in a short-lived AMOC oscillation.The weakening of the AMOC resulted in a cold anomaly over the North Atlantic.As a result of atmospheric telecorrelation,the weaker AMOC led to a weaker Asian Summer Monsoon(ASM)