In recent years, the East Asian (EA) region experienced escalated cost of damages associated with tropical cyclones (TC) during the mature boreal autumn (i.e., September−October). Questions arise whether such increased TC-associated cost of damages are indicative of increasing activity of TCs in EA, particularly during the mature boreal autumn. Here we show evidence of significantly increasing activity of TCs in EA from 1981 to 2019 that is mainly accompanied by an abrupt regime shift in TC passage frequency since 1998. Such trend and shift are robustly linked to the shift of the Pacific Decadal Oscillation (PDO) to its negative phase in the mid-1990s. Characterized by warm sea surface temperature anomalies in the subtropical North Pacific, a negative PDO phase is related to the weakening of the East Asian subtropical jetstream and the westward displacement of the WNP subtropical high, which initiates a favorable steering environment for increased TC passages into the EA region. Contrasting environmental patterns are associated in a positive PDO phase. Considering the prominence of EA in the global economy, our paper contributes additional insights on long-term tropical cyclone risk reduction and management in the region.

近年来，东亚 (EA) 地区在成熟的北方秋季（即 9 月至 10 月）期间经历了与热带气旋 (TC) 相关的损害成本不断上升的情况。问题出现了，这种增加的 TC 相关损害成本是否表明 EA 中 TC 活动的增加，特别是在成熟的北方秋季期间。在这里，我们展示了 1981 年至 2019 年 EA 中 TC 活动显着增加的证据，这主要伴随着自 1998 年以来 TC 通过频率的突然政权转变。这种趋势和转变与太平洋年代际涛动 (PDO) 的转变密切相关到 1990 年代中期的消极阶段。以副热带北太平洋温暖的海面温度异常为特征，负PDO阶段与东亚副热带急流减弱和WNP副热带高压向西位移有关，这为增加进入东亚地区的TC通道提供了有利的转向环境。对比的环境模式与积极的 PDO 阶段相关联。考虑到 EA 在全球经济中的突出地位，我们的论文为该地区的长期热带气旋风险降低和管理提供了更多见解。