Datensatz

Zusammenfassung

This study aimed at the large scale factors contributing to the extreme Mei-Yu rainfall in the East Asia in recent decades by the observation and CMIP 6 simulation. The potential effect of SST warming trends was assessed by comparing the 2020 event with a 1998 extreme event. The results revealed that a record North Indian Ocean (NIO) SST induced anomalous overturning and horizontal circulations in the Indo–western Pacific region, which played a crucial role in maintaining the extreme Mei-Yu rainfall. A major upward SST trend in the NIO was identified, and it accounted for approximately 40% of the total SST variance in 2020; this phenomenon was not identified in the 1998 event. Furthermore, a significant upward precipitation trend was observed in the Mei-Yu region that contributed approximately 15% of the total rainfall. The role of warming trends in amplifying the extreme Mei-Yu rainfall was further verified through Atmospheric Model Intercomparison Project–type experiments and the air–sea fully coupled simulations of Climate Model Intercomparison Project 6. The observations and simulations yielded consistent results, indicating that a warming trend contributed substantially to the record event in 2020. The 2020 event reflects the presence of a warming trend, which was not observed in the 1998 extreme event.