Refraction and Reflection of Nonlinear Internal Waves from Steep Topography
Abstract
Internal waves are an important mechanism of energy transfer from tides and winds driving mixing which shapes the stratification a,nd circulation of the ocean with important implications for climate. Large amplitude, nonlinear internal waves (NLIWs) can induce st,rong currents, upwell dense water high in nutrients, and also affect marine operations and acoustic communications.The processes tha,t determine generation and propagation of NLIWs have been the focus of extensive research. The bulk of work addressing NLIW transfor,mation as they interact with topography, including shoaling and breaking, has largely focused on 2D topography. A number of remote s,ensing studies have noted significant redirection of NLIW energy associated with steep 3D topography, however. The dynamics of NLIW,refraction around steep features is not yet well-understood.Here, we propose to explore processes that determine NLIW transformation, over steep, 3D topography - including refraction, shoaling and reflection along with the implications of these processes on the i,nternal wave environment at larger scales. The broad objective for the project is to improve forecasting and predictability for nonl,inear internal waves in the ocean. The proposed work will make use of high resolution numerical simulations combined with analysis o,f existing observational data to examine the effects of wave characteristics, flow history, local internal tides and changes in rota,tion on NLIW transformation and on subsequent generation of residual circulation and trapped baroclinic energy.Results from the nume,rical experiments will be used to guide a set of focused field observations to be carried out at Dongsha Atoll, a steep, nearly circ,ular feature in the South China Sea. Extensive work has previously been carried out on NLIWs in this region, where some of the large,st internal waves on the planet have been observed. The modeling work and field observations build on long-standing collaborative ef,forts between the project PIs, Taiwanese colleagues and other ONR supported researchers. The proposed field observations, in particu,lar, are expected to be carried out in collaboration with researchers in Taiwan.Approved for Public Release.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- N000142212023
Entities
People
- Eugene Pawlak
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego