Non linear internal waves modeling of their influence on acoustic mode energy fluctuations and characterization using SAR systems
Colosi, John A.
Durkee, Philip A.
MetadataShow full item record
Non Linear Internal Waves (NLIW) are ubiquitous and appear wherever a proper combination of stratified water, current and bathymetry occur. In recent years, they have also been proven of primary interest for acoustic oceanography, since they are known to play an important role in sound speed fluctuations in shallow waters. The predictability of acoustic variability caused by these waves has been somewhat limited, and largely based on direct numerical simulation. Through this project, we present a simple and computationally efficient analytic model based on coupled mode theory. For this purpose, narrow and broadband acoustic normal mode fluctuations in the 2001 South China Sea ASIAEX experiment are first examined. Then ASIAEX environmental data are used to characterize the space/time scales of NLIW sound speed structure. Finally, a comparison is conducted between the observed normal mode variability and the predictions from an analytic model utilizing the observed NLIW structure, such as its width, amplitude and speed. As the model proves to be very sensitive to these characteristics, an overview of the Synthetic Aperture Radar capabilities to retrieve them is also conducted. In this latter part of the project, particular attention is given to wind effects on SAR data.
Showing items related by title, author, creator and subject.
Computer simulation of acoustic fluctuations due to finescale temperature perturbations measured by thermistor chain. Crabtree, Gregory D. (Monterey, California. Naval Postgraduate School, 1992-03);Finescale temperature features in the oceanic mixed layer (OML) modify acoustic propagation by perturbing the index of refraction. A thermistor chain measures temperature from the surface to 250 m with 2 m vertical ...
Korbet, Michael Thomas (Monterey, California. Naval Postgraduate School, 1974-03);An underwater acoustics experiment conducted in shallow water (70 feet ) off the New Zealand east coast in 1972-1973 is described. Short acoustic pulses of 35 and 65 KHz sound were projected along near-orthogonal paths ...
Horizontal anisotropy and seasonal variation of acoustic fluctuations observed during the 2010–2011 Philippine Sea experiment Marwoto, Bambang (Monterey, California: Naval Postgraduate School, 2015-12);The anisotropic ocean environment will lead to variability of ocean acoustic travel time. The variability of travel times comes from several ocean dynamical processes, including eddies, internal tides, and stochastic ...