Enhanced tropical cyclone precipitation variability is linked to Pacific Decadal Oscillation since the 1940s

Southeastern China is pivotal for understanding tropical cyclone (TC) behavior in the Northwest Pacific, the most active TC basin on Earth. However, short instrumental records limit our knowledge of past tropical cyclone precipitation (TCP) and its response to human-driven warming. Here we combine multi-year monitoring of xylem cell formation with a process-based tree growth model to demonstrate that latewood width in coastal conifers is an effective proxy for TCP. We build a latewood chronology from the western Taiwan Strait and reconstruct July-September TCP from 1846 to 2020, explaining 62.6% of observed variance. The reconstruction reveals a marked increase in interannual TCP variability since the 1940s, closely associated with enhanced variability of the Pacific Decadal Oscillation. This work provides physiological evidence linking TCP to intra-annual tree-ring dynamics and establishes tree rings as a proxy for high-resolution TC reconstructions and climate risk assessment across the Pacific Rim. Latewood width records from southeast China show that increased tropical cyclone precipitation variability is linked to stronger Pacific Decadal Oscillation variability since the 1940s, indicating tree-ring dynamics as a new proxy for Pacific Rim climate risk.