High-resolution stalagmite records from Southwest China reveal a North Atlantic link to the 8.2 ka event

The 8.2 ka event represents a critical benchmark for understanding abrupt climate variability, yet prominent stalagmite records (DA and D4) from southwestern China display notable discrepancies, underscoring the need for new, precisely dated reconstructions to clarify regional monsoon responses. Here we present a high-resolution speleothem δ 18 O and δ 13 C record (SH) from Shuanghe Cave, southwestern China, with ∼2-year sampling resolution and a chronological uncertainty of ≤40 years, which captures detailed variability in the East Asian summer monsoon (EASM) during the 8.2 ka event. The SH δ 18 O record reveals a pronounced weak-monsoon signal with a characteristic double-plunging structure, terminating at 8070 ± 40 yr BP, consistent within dating uncertainties with Greenland ice cores and other high resolution monsoon stalagmite δ 18 O records. Simulated June–August wind anomalies from the TraCE model further corroborate a substantial reduction in EASM intensity during this interval. Moreover, the SH δ 18 O and δ 13 C records, together with other multi-proxy stalagmite data, indicate a largely synchronous hydroclimatic response from the northern to southern Chinese monsoon domain, characterized by a coherent shift toward drier conditions during the 8.2 ka event. When considered alongside Greenland ice-core evidence, these results highlight a strong North Atlantic–East Asian teleconnection, supporting the interpretation that abrupt North Atlantic cooling—caused by a slowdown of the Atlantic Meridional Overturning Circulation (AMOC)—shifted the Intertropical Convergence Zone (ITCZ) southward, thereby weakening the East Asian summer monsoon (EASM) and resulting in diminished rainfall across the Chinese monsoon domain. • Precisely-dated, high resolution speleothem record from SW China during the 8.2 ka event. • δ 18 O and δ 13 C records show a dry climate in southwestern China with weakened EASM. • The 8.2 ka summer monsoon weakening triggered a coherent north–south shift toward drier conditions across the Chinese monsoon domain.