[A-CG40] 海洋と大気の波動・渦・循環の力学

[ACG40-08] Relationship between incoherence of semidiurnal internal tides and Kuroshio Current near the Luzon Strait

*Anzhou Cao¹、Zheng Guo²、Shuya Wang³、Jinbao Song¹、Xinyu Guo³ (1.Zhejiang Univ.、2.Zhejiang Ocean Univ.、3.Ehime Univ.)

キーワード：Semidiurnal internal tide, Incoherence, Kuroshio Current, Luzon Strait

Internal tides (ITs) are internal waves with tidal frequencies. Under the influence of varying background currents and stratification, ITs often exhibit incoherent features. Based on 9-month-long numerical simulation results, we show the relation between incoherence of semidiurnal ITs and Kuroshio Current near the Luzon Strait (LS) in this study. Results show that the relative variation (standard deviation/mean value) of mode-1 phase speed is an effective indicator for the incoherence of semidiurnal ITs near the LS and it is dominated by the advection term (Doppler shifting). The monthly incoherence of semidiurnal ITs is found to be highly related to the variation of surface kinetic energy of Kuroshio Current near the LS. These results deepen our understanding about the incoherent nature of ITs.