Modeling the effects of transbasin nonlinear internal waves through the South China Sea basin

Download
Author
Ceschini, Joseph J.
Date
2013-06Advisor
Chiu, Ching-Sang
Second Reader
Joseph, John
Metadata
Show full item recordAbstract
The objective of this research is to model and study the effects of transbasin internal waves on low-frequency signal transmission through the South China Sea (SCS) basin. Specifically, the fluctuations in the multipath arrival structure of a 400-Hz acoustic pulse transmitted through a distance of 167-km in the SCS basin in the presence of an internal ocean soliton was modeled and examined. The modeling entailed the integration of a raytracing program with an eigenray search and arrival-structure calculation program, and the use of measured bathymetry and inferred bottom-loss characteristics from previous research. A range-dependent perturbation was added to a range-independent background sound-speed profile to model the varying sound-speed field as the nonlinear ocean internal soliton propagates along the transmission path. All cases studied, each simulating a soliton at a different location, had six distinct acoustic arrivals that suffered from large-amplitude fluctuations (~ 10 dB). The factors that affect the amplitude of the arrivals are changes: in the number of bottom interaction, in ray tube spreading, phase interference and in the number of eigenrays making up an arrival. The results also show that the closer the soliton to the receiver, the less impact the soliton has on the arrival structure.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.Collections
Related items
Showing items related by title, author, creator and subject.
-
Observed acoustic arrival structure and intensity variability induced by transbasin nonlinear internal waves in the South China Sea basin
Chiu, Chingsang; Reeder, Benjamin D.; Miller, Christopher; Reeves, Justin; Ramp, Steve; Yang, Yiing-Jang; Wei, Ruey-Chang; Chen, Chifang (Acoustical Society of America, 2008);During the 2005-2006 Windy Island Nonlinear Soliton Experiment (WISE), large-amplitude internal waves were observed by in situ oceanographic sensors to propagate eastward from the Luzon Strait, through the deep basin, ... -
Statistical analysis of acoustic signal propagating through the South China Sea basin
Chen, Meihuei (Monterey, California. Naval Postgraduate School, 2016-03);During the Windy Islands Soliton Experiment, two deep water moorings were deployed 167 km apart in the northeastern South China Sea (SCS) basin to study the effects of nonlinear internal waves on 400- Hz acoustic signal ... -
Two dimensional acoustic propagation through oceanic internal solitary waves weak scattering theory and numerical simulation
Young, Aaron C. (Monterey, California. Naval Postgraduate School, 2006-06);Internal solitary waves, or solitons, are often generated in coastal or continental shelf regions when tidal currents advect stratified water over bathymetric relief, creating an internal tide which non-linearly evolves ...