Observation of NLIW in the South China Sea using PIES
Abstract
The long-term goal of this project is to study the mechanisms of generation, evolution, and propagation of high-frequency nonlinear internal waves (NLIW) in the vicinity and west of Luzon Strait in the South China Sea, making use of pressure equipped inverted echo sounders. The specific objectives of this study are as follows: (1) to observe the internal tide propagating west of Luzon Strait and its progressive evolution in shape and speed as it traverses the South China Sea under the influence of nonlinearity, nonhydrostatic effects, rotation, topography, currents, and stratification; and (2) to interpret the results with the help of models that incorporate these effects. Our approach involved the deployment of three modified pressure equipped inverted echo-sounders (PIES) set up to transmit every 6s. These instruments measure the return acoustic travel time from sea floor to surface, which is modified by variations in the local stratification resulting from the passage of internal waves. Knowledge of background stratification is provided by CTD casts. Time series measurements of the acoustic travel time then provide a basis for inferring the first mode internal response. Nonlinear, nonhydrostatic models can be used to interpret the evolution of the waves as they pass successive measurement sites. Additional modeling is used to simulate the generation of the internal tide measured within Luzon Strait.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2009
- Accession Number
- ADA527066
Entities
People
- David M. Farmer
Organizations
- University of Rhode Island