Centennial-scale monsoon collapses during Marine Isotope Stage (MIS)7e detected in a northern Chinese stalagmite record

Occurrence or absence of centennial-scale climatic variability during Marine Isotope Stage (MIS)7e, the first peak interval of the Penultimate Interglacial, remains ambiguous due to the limited available high-resolved records. Here, we present a decadal-resolved stalagmite δ18O record from northern China spanning from 242.3 to 236.8 ka BP, covering MIS7e. The composite KLS δ18O record, integrating this study with the previous record in the same cave, shows a descending trend from Termination III to MIS7e, which follows the increasing Northern Hemisphere summer insolation (NHSI). This observation further emphasizes the important influence of NHSI on the glacial/interglacial transition. There are more large-amplitude, millennial- to centennial-scale variability occurring during Termination III compared with MIS7e, implying that ice-sheet decay potentially plays an important role in climatic excursions. Four centennial-scale summer monsoon collapses, peaking at ∼242.1, ∼240.8, ∼239.3 and ∼238.2 ka BP, are detected in our new record, indicating the pervasiveness of the intra-interglacial climatic instability. Given the lack of solar activity and freshwater outbursts data during MIS7e, it is not possible to conclude about the drivers of the identified abrupt climatic anomalous. Following the dynamic mechanisms of sub-millennial climatic anomalous during early Holocene, we tentatively propose that slowdown of the meridional overturning circulation caused by freshwater fluxes into North Atlantic and/or attenuated solar irradiance is the potential forcing for the abrupt climate events within MIS7e. Additionally, attenuated solar irradiance could also result in climatic anomalies through low-latitude processes.