Poleward Shift in Tropical Cyclone Tracks in the Northwest Pacific During Warm Periods: Past and Future.

We used the top age of storm‐relocated coral blocks (SRCBs) from Xisha Islands and Huangyan Island, South China Sea (SCS), in combination with existing paleotempestology records and instrumental climatic data, to reconstruct the spatio‐temporal changes in tropical cyclone (TC) activity over the past millennium, and to project its future trends in the Northwestern Pacific region. We found a positive correlation between the frequencies of TCs, typhoons, and super‐typhoons and the NINO3.4 on the interannual timescale during 1945–2019. TCs latitude has a significant positive correlation with sea surface temperature, with a northward migration rate of 80 ± 11 km per decade during 1951–2019. Coral δ18O can well indicate the month of paleo‐TCs occurrence. The frequency of SRCBs (and by inference, TCs) is relatively low during relatively warm periods (RWP) but high during relatively cold periods (RCP) in the SCS. The spatio‐temporal pattern inferred from paleotempestology records further supports the notion of North‐South migration in TC activity as revealed by the instrumental record in this study. TC activity mainly affected relatively low latitudes (e.g., Philippines, Vietnam, and Hainan, Guangdong, Taiwan) during the RCP (AD 1450–1900), but it migrated from low latitudes towards higher latitudes during the RWP (AD 1000–1450), affecting locations such as Zhejiang, Jiangsu, and Shandong, southwestern Japan, the Korean Peninsula, and even Northeast China. Fujian and northern Guangdong may be in a transition zone of paleo‐TC activity between the North and the South in the past millennium. As global warming continues, the mean tracks and landfall locations of TCs will continue to migrate northward in this region. Key Points: Tropical cyclones (TC) latitude and sea surface temperature are positively correlated; TCs had a northward migration rate of 80 ± 11 km per decade during AD 1951–2019The coral δ18O can indicate the month when the paleo‐TC event happened; SRCBs appeared more frequently during relatively cold periods in the South China SeaPaleo‐TCs mainly affected relatively high latitudes during climatically warm periods, but lower latitudes during cold periods in the Northwestern Pacific region [ABSTRACT FROM AUTHOR]