[A-OS18] Kuroshio Large Meander

[AOS18-P02] The relationship between Kuroshio meander and observed tidal-regime shift along southern coast of Japan

*Takumi Kamura¹, Hiromi Matsuura¹, Katsuto Uehara² (1.Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 2.Research Institute for Applied Mechanics, Kyushu University)

Keywords:Kuroshio meandering, tides, sea level

Relationships between the Kuroshio meander and tidal changes over decadal time scales along Japanese coasts, which has not been well verified compared to the relationship between the meandering phase and the sea-level difference, were studied by conducting harmonic analyses of sea levels at five tide-gauge stations north of the major Kuroshio meandering region, Osaka, Komatsushima, Shirahama, Kushimoto, and Uragami, for duration from 1950 to 2019. It was found that at Kushimoto located on the western side of the southern end of the Kii Peninsula, M2 tidal amplitudes increased intermittently by about 4%, which have taken place at irregular intervals ranging from years to decades, and that the timing of such events coincided with the occurrence of the Kuroshio meander. This result indicates a relation between changes in coastal tides and the Kuroshio path.