Taiwan Island, adjacent to the main stream of the Kuroshio, represents a key region where the intense western boundary current interacts with local dynamics, making it a typical hotspot of spatial variability in sea level change, whose patterns are strongly modulated by complex local dynamics. Using tide-gauge (TG) records from 16 stations around Taiwan Island (2004-2024) and satellite altimetry gridded product (1993-2024), we identify a decadal shift of coastal sea level changes around Taiwan Island, which is dynamically tied to large‑scale ocean circulation. Observations reveal a decadal shift in coastal sea level around Taiwan Island around 2014, with the overall average rise rate accelerating from approximately 2.8 mm/yr before 2014 to about 4.7 mm/yr afterward. Specially, most of TG stations (12/16) show accelerated rise after 2014, some show a decline after 2014, and others (3/16) exhibit an initial rapid rise after 2004 followed by a subsequent slowdown. Further analysis indicates that the spatial pattern of this coastal response is primarily governed by a marked intensification of offshore sea‑level anomalies east of Taiwan, where the maximum anomaly reaches about 40 mm, concentrated in the eastern waters and tightly coupled with coastal changes. Meanwhile, the decadal oscillation of the Kuroshio axis, which migrated slowly in the first decade and then accelerated sharply coastward after 2014, plays a supplementary modulating role. Together, these two factors shape the typical “south‑up, north‑down, offshore‑high, coastal‑low” response pattern. In terms of driving mechanisms, a climate regime shift in the central‑eastern Pacific generates anomalous wind stress, which excites westward‑propagating Rossby waves that transmit the signal remotely across the basin to the coastal sea around Taiwan Island, triggering offshore anomalies. The Pacific Decadal Oscillation and interdecadal ENSO variability likely provide the background for this remote influence. We show that Rossby‑wave‑mediated Pacific forcing, rather than the Kuroshio alone, drives the decadal coastal sea level shift around Taiwan Island, with implications for regional forecasting.

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