[A-AS02] 台風研究の新展開～過去・現在・未来

[AAS02-P07] Modulation of Landfalling Tropical Cyclone Activity in the Western North Pacific by North Atlantic Tripolar SST

*Shibin Xu¹、Tingting Fan² (1.Ocean University of China、2.Qingdao University of Technology and Science)

キーワード：North Atlantic tripole SSTA, WNP landfalling TCs

Previous research on the effects of Atlantic sea surface temperature (SST) on tropical cyclones (TCs) in the western North Pacific (WNP) has primarily focused on the tropical Atlantic region. This study investigates the relationship between the extra-equatorial North Atlantic tripole (NAT) sea surface temperature anomaly (SSTA) pattern and landfalling TCs in the WNP. The findings reveal a significant positive correlation between the negative–positive–negative NAT SSTA pattern and the occurrence of landfalling TCs in the WNP. Furthermore, the NAT SSTA influences the tracks of these landfalling TCs. In high NAT years, the NAT tropical cold SSTA transmit signals to the WNP via two ways: the eastward pathway through the North Indian Ocean (NIO) and the westward pathway through the eastern North Pacific (ENP). This enhances cyclonic vorticity in the WNP monsoon trough region and promotes a higher frequency of TC genesis in the WNP. The NAT SSTA pattern persists into summer, triggering a mid-high latitude teleconnection wave train that propagates downstream. This induces an anomalous anticyclone over Northeast Asia and an accompanying cyclonic circulation to its west. This leads to the recurving of TC tracks rather than a northwestward or westward direction. The results suggest that the NAT SSTA is a potential predictor of TC formations and track patterns in the WNP.