Reflection of K₁ Internal Tides at the Continental Slope in the Northern South China Sea

Abstract Reflection of the K 1 internal tides (ITs) in the northern South China Sea (SCS) is investigated using a high‐resolution three‐dimensional numerical model. The simulated results indicate that the westward K 1 ITs generated at the Luzon Strait (LS) first impact the continental slope in the northern SCS, and thereafter are reflected. There is a total of 0.31 GW of K 1 energy that are reflected, suggesting a weak reflection considering 3.54 GW of westward K 1 energy from the LS. Two reflected K 1 beams are revealed. The southeast one is the more energetic and can propagate across the deep basin, agreeing with that extracted from satellite altimeter data. The eastward one propagates toward the LS, but it is absent in altimeter results because of its lower intensity. Both the two reflected beams are radiated from the supercritical region in shallow water. Different from the incident waves that are dominated by mode‐1, the reflected waves exhibit a multimodal structure. Contribution of high modes to reflected waves is comparable to that of mode‐1. Moreover, modal content is different for the two reflected beams, with higher proportion of high‐mode energy flux for eastward reflected beam. In contrast to the K 1 ITs, no remarkable reflected O 1 ITs are detected from either simulated or altimeter results. This is due to the weak generation of O 1 ITs at the LS, which leads to less O 1 energy reaching the continental slope. The results of this work can provide essential insight on IT dynamics in the SCS.