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dc.contributor.authorRapo, Mark A.  Concept link
dc.date.accessioned2007-06-22T20:21:16Z
dc.date.available2007-06-22T20:21:16Z
dc.date.issued2006-02
dc.identifier.urihttps://hdl.handle.net/1912/1716
dc.descriptionSubmitted in partial fulfillment of the requirements for the degree of Master of Science in Oceanographic Engineering at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2005en
dc.description.abstractThe challenge of estimating the Reynolds stress in an energetic ocean environment derives from the turbulence process overlapping in frequency, or in wavenumber, with the wave process. It was surmised that they would not overlap in the combined wavenumber-frequency spectrum, due to each process having a different dispersion relationship. The turbulence process is thought to obey a linear dispersion relationship, as the turbulent flow is advected with the mean current (Taylor's frozen turbulence approximation). However, the Acoustic Doppler Current Profiler (ADCP) looks at radial wavenumbers and frequencies, and finds overlap. Another approach is to exploit the physical differences of each process, namely that the wave induced velocities are correlated over much larger distances than the turbulence induced velocities. This method was explored for current meters by Shaw and Trowbridge. Upon adapting the method for the ADCP, it is found that the resulting Reynolds stress estimates are of the correct order of magnitude, but somewhat noisy. The work of this thesis is to uncover the source of that noise, and to quantify the performance limits of estimating the Reynolds Stress when using ADCP measurements that are contaminated with strong wave-induced velocities. To that end, the space-time correlations of the error, turbulence, and wave processes are developed and then utilized to find the extent to which the environmental and internal processing parameters contribute to this error. It is found that the wave-induced velocities, even when filtered, introduce error variances which are of similar magnitude to that of the Reynolds stresses.en
dc.description.sponsorshipThis thesis has been funded by the NDSEG Fellowship Program (National Defense Science and Engineering Graduate Fellowship), in association with ASEE (American Society for Engineering Education).en
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen
dc.relation.ispartofseriesWHOI Thesesen
dc.subjectReynolds stressen_US
dc.subjectSignal processingen_US
dc.subjectDigital techniquesen_US
dc.titleError and uncertainty in estimates of Reynolds stress using ADCP in an energetic ocean stateen
dc.typeThesisen
dc.identifier.doi10.1575/1912/1716


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