Incoherence of the M2 and K1 internal tides radiated from the Luzon Strait under the influence of looping and leaping Kuroshio

Abstract

The Kuroshio in different paths is considered to have different impacts on the generation, propagation and energetics of internal tides (ITs) originated from the Luzon Strait (LS). However, its influence on the incoherence of ITs remains unknown. Based on a regional model simultaneously simulating ITs and background circulations, this study examines the incoherence of the M2 and K1 ITs radiated from the LS under the influence of looping and leaping Kuroshio. The looping Kuroshio causes stronger incoherence of the M2 and K1 ITs than the leaping Kuroshio. The reason is that the looping Kuroshio causes a larger variation of eigenspeed, which results in stronger incoherence of ITs than the leaping Kuroshio does. For both the looping and leaping Kuroshio, the low-frequency background currents play a more important role than the stratification in changing the eigenspeed. We believe that the results of this study can deepen our understanding of the incoherent nature of ITs near the LS.