Effect of stratification profile on internal wave energy generated by flow over realistic topographies*

Previous research has shown that evanescent waves, which are formed in weakly stratified regions and decay rapidly, can pass into regions of stronger stratification and become propagating internal waves. To better understand the potential impact of these uniquely formed internal waves on the ocean energy budget, experiments were performed with four different topographies and with four types of realistic stratifications profiles. Specifically, two Gaussian topographies, a sinusoidal topography with two peaks, and a complex topography were used to represent a local seamount, multiple hills, and a complex variation of topography. Experiments indicate that the kinetic energy content of the internal waves is highly dependent upon the topography shape and the stratification profile in both the evanescent and propagating regions. The experimental analysis of kinetic energy is compared to both an analytical model and numerical simulations with good agreement.