Tibetan-Plateau heating subseasonally bursts marine heatwaves in Kuroshio Extension

Marine heatwaves (MHWs) are occurring frequently under global warming and causing enormous disasters. MHWs in the Kuroshio Extension (KE) region exhibit the highest mean intensity of extreme warm-water events in the North Pacific and rank among the most intense worldwide, severely affecting marine ecosystems and bringing substantial socioeconomic consequences. However, current numerical models show relatively low skill in predicting the KE-MHWs, owing to limited understanding of their triggers and inadequate representation of their mechanisms. Given the importance of elucidating the precursors of KE-MHWs for reliable predictions, this study presents a new perspective on the atmospheric drivers of KE-MHW onset on the subseasonal timescale. We find that the strong latent heating released from precipitation over the southeastern Tibetan Plateau can burst a teleconnection wave train propagating eastward, inducing an anomalous anticyclonic circulation in the KE region. Through the combined effects of local atmospheric dynamics and air-sea interactions, this circulation ultimately triggers the KE MHWs. Our findings offer a new insight into the physical drivers of KE-MHWs and highlight a previously overlooked yet robust source of subseasonal predictability, with important implications for improving early warning systems and supporting marine ecosystem management in climate-sensitive areas.