Estimation of sea surface wave spectra using acoustic tomography
Miller, James H.
MetadataShow full item record
This thesis develops a new technique for estimating quasi-homogeneous and quasi-stationary sea surface wave frequency-direction spectra using acoustic tomography. The analysis of acoustic (mode and ray) phase and travel time perturbations due to a rough sea surface is presented. Two canonical waveguides (ideal shallow water and linear squared index of refraction) are used as examples for the mode perturbation. The analysis is used to explain high mode coherence measured in the FRAM N experiment. The forward problem of computing the acoustic phase and travel time perturbation spectra given the surface wave spectrum is solved to first order. An application of the technique to ray phase data taken during the MIZEX '84 experiment is shown. The inverse problems for the homogeneous and quasi-homogel1eous frequency-direction spectrum are introduced. The theory is applied to synthetic data which simulate a fetch-dependent sea. The estimates made agree well with the "actual" (synthetic data) spectrum. The effect of noise in the travel time estimates is studied. The sensitivity of the technique. to the number of rays used in the inversion is investigated and the resolution and variance of the inverse method are addressed.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 1987
Showing items related by title, author, creator and subject.
Silverthorne, Katherine E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-06)Observational and modeling techniques are employed to investigate the thermal and inertial upper ocean response to wind and buoyancy forcing in the North Atlantic Ocean. First, the seasonal kinetic energy variability of ...
Workman, Rhea K. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005-06)This thesis uses trace elements and radiogenic isotope tracers to define elemental abundances in reservoirs of the Earth's mantle, including EM2 (the Enriched Mantle 2), as seen in the Samoan hotspot track, and DMM (the ...
Geochemical tools and paleoclimate clues : multi-molecular and isotopic investigations of tropical marine sediments and alpine ice Makou, Matthew C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2006-02)South American climate has undergone dramatic changes since the last glacial period, as evidenced from Cariaco Basin (Venezuelan coast) and Peru Margin marine sediment biomarker records. Compounds derived from vascular ...