Centennial- to multidecadal-scale monsoon precipitation variability during the mid-Holocene

Multidecadal to centennial climate variability and the dynamics of the Asian summer monsoon (ASM) in the mid-Holocene are important for understanding the contribution of natural variability to global warming. In this study, we present a 1.7-year resolution and precisely dated record of stalagmite XSY-G from Xiaoshanyan Cave, Southwest China. Our δ¹⁸O record depicts the ASM intensity and multidecadal to centennial precipitation variability from 6.37 to 4.64 thousand years before present (ka BP). The results reveal nine weak monsoon intervals (WMIs) at decadal to centennial scales, defined as excursions exceeding 1 standard deviation. These WMIs are centered at approximately 6.20, 6.03, 5.78, 5.66, 5.54, 5.38, 5.15, 4.98, and 4.74 ka BP, coinciding with notable droughts in the nearby high-resolution stalagmite record. Furthermore, centennial- to decadal-scale periodicities of 330-, 210-, 128-, 96- and 79-year are observed. The verification of existing stalagmite records reveals that the centennial-scale 5.3 ka BP event has an asymmetric double-plunging structure and a duration of ∼340 years, corresponding to the strongest period of Bond 4 event in North Atlantic. These WMIs are probably linked to solar activity and tropical sea surface temperature minima, resulting in decreased precipitation over Southwest China. Our study suggests that high-latitude cooling and tropical ocean-atmosphere interaction may have exerted superimposed effects on the ASM variability during the mid-Holocene.