[A-OS14] 海洋物理学一般

[AOS14-P07] Experimental study on internal lee waves over a ridge

*Bingning Meng¹、Jing Meng¹、Xu Chen¹ (1.Ocean University of China)

キーワード：Lee waves, Froude number, Experiments

In the stratified ocean, the interaction between steady flow and rough topographies generates internal lee waves. The breaking of lee waves causes strong turbulent mixing near the topography, which significantly affects vertical nutrient transport. In this study, we carry out laboratory experiments to investigate the generation of internal lee waves in two-layer fluid. The experimental results indicate that the waveform is strongly determined by the Froude number which is defined as the ratio of linear wave speed to background flow speed. The wave pattern is strongly dependent on the Froude number. Sinusoidal waves are generated for subcritical cases (Fr<1); while internal hydraulic jump occurs for supercritical cases (Fr>1). Both the amplitude and wavelength of lee waves first increase and then decrease with the increase of Froude number, reaching their maximum when Fr=1. The results of this study provide insights on internal lee wave dynamics. Future experiments will be conducted with high-resolution measurement on velocity and density fields to qualify the mixing induced by lee waves.