Internal tides are internal waves of tidal period generated by tidal currents flowing over submarine topography. Tall ridges that are nominally two-dimensional (2-D) are sites of particularly strong generation. The subsequent dissipation of internal tides contributes to ocean mixing, thereby playing an important role in the circulation of the ocean. Strong internal tides can also evolve into internal wave solitons, which affect acoustic communication, offshore structures and submarine navigation. This thesis addresses the generation of internal tides by tall submarine ridges using a combined analytical and experimental approach.The first part of the thesis is an experimental investigation of a pre-existing Green function formulation for internal tide generation by a tall symmetric ridge in a uniform density stratification. A modal decomposition technique was developed to characterize the structure of the experimental wave fields generated by 2D model topographies in a specially configured wave tank. The theory accurately predicts the low mode structure of internal tides, and reasonably predicts the conversion rate of internal tides in finite tidal excursion regimes, for which the emergence of non-linearities was notable in the laboratory.In the second part of the thesis, the Green function method is advanced for asymmetric and multiple ridges in weakly non-uniform stratifications akin to realistic ocean situations. A preliminary investigation in uniform stratification with canonical asymmetric and double ridges reveals asymmetry in the internal tide that can be very sensitive to the geometric configuration. This approach is then used with realistic topography and stratification data to predict the internal tide generated by the ridges at Hawaii and at the Luzon Strait. Despite the assumption of two-dimensionality, there is remarkably good agreement between field data, simulations and the new theory for the magnitude, asymmetry and modal content of the internal tide at these sites.The final part of the thesis investigates the possibility of internal wave attractors in the valley of double-ridge configurations. A one-dimensional map is developed to identify the existence and stability of attractors as a function of the ridge geometry. The Green function method is further advanced to include a viscous correction to balance energy focusing and dissipation along an attracting orbit of internal wave rays, and very good agreement is obtained between experiment and theory, even in the presence of an attractor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.