Amplified summer extreme precipitation over the Tibetan Plateau in the early 21st century
Xiaojing Jia, Fangchi Liu, Wei Dong, Xinhai Chen, Qifeng Qian
Abstract
The Tibetan Plateau (TP) has experienced significant intensification of extreme precipitation events in recent decades, with cascading risks to water security and fragile ecosystems. This study reveals a distinct post-2000 surge in summer extreme precipitation over the TP, characterized primarily by a sharp increase in event frequency, with the northwestern TP emerging as the predominant hotspot. We attribute this amplification to enhanced moisture convergence, dynamically modulated by an anomalous anticyclone to the east of the northwestern TP. Mechanistically, this key anticyclonic anomaly constitutes a pivotal node in an atmospheric wave train anchored by concurrent North Atlantic sea surface warming and Arctic sea ice loss. Our findings underscore a post-2000 increased Arctic control over Third Pole hydroclimate variability, providing new insights into how Arctic climate impacts vulnerable mountain systems.