Influence of swimming marine organisms on turbulence in the ocean from in-situ measurements

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dc.contributor.author Rousseau, Shani
dc.date.accessioned 2009-07-23T17:49:50Z
dc.date.available 2009-07-23T17:49:50Z
dc.date.copyright 2009 en
dc.date.issued 2009-07-23T17:49:50Z
dc.identifier.uri http://hdl.handle.net/1828/1475
dc.description.abstract Microstructure and acoustic data were collected in Saanich Inlet, British Columbia, and at Ocean Station P in the eastern subarctic North Pacific Ocean with the objective of observing krill-generated turbulence. At Ocean Station P, although a number of species composing the zooplankton community are large enough to generate turbulent flow (Re > 10e3), no turbulence events could be correlated with presence of swimming marine organisms and measurements indicated turbulence generated by shear. Zooplankton densities were likely too low to produce turbulence at the scale of an aggregation and the O(10e-2 m) scattered turbulent signals generated by individuals are difficult to detect in the natural environment. In Saanich Inlet, higher dissipation rates were observed in regions of high acoustic backscattering, suggesting that zooplankton-generated turbulence was occurring. Although presence of zooplankton was often correlated with high dissipation rates, high dissipation rates were frequently observed in the absence of zooplankton, suggesting multiple sources of turbulence. High dissipation rates were observed in the presence of non-migrating zooplankton as much as in the migrating layer. These turbulence events occurred at a scale of more than 1 m as they were positively detected by our dissipation rate estimation technique. This suggests that marine organisms can act together to generate turbulence at scales that can produce diapycnal mixing. Over all time-series collected, dissipation rates in the presence of zooplankton averaged 1.4 x 10e-8 W/kg whereas the average in the absence of zooplankton was 0.7 x 10e-8 W/kg. en
dc.language English eng
dc.language.iso en en
dc.rights Available to the World Wide Web en
dc.subject Turbulence en
dc.subject Zooplankton en
dc.subject Euphausia pacifica en
dc.subject Vertical migration en
dc.subject Mixing en
dc.subject.lcsh UVic Subject Index::Sciences and Engineering::Earth and Ocean Sciences::Oceanography en
dc.title Influence of swimming marine organisms on turbulence in the ocean from in-situ measurements en
dc.type Thesis en
dc.contributor.supervisor Kunze, Eric
dc.contributor.supervisor Dower, John F.
dc.degree.department School of Earth and Ocean Sciences en
dc.degree.level Master of Science M.Sc. en

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