Show simple item record

dc.contributor.authorGerbi, Gregory P.  Concept link
dc.coverage.spatialMartha's Vineyard, MA
dc.date.accessioned2008-08-08T20:39:43Z
dc.date.available2008-08-08T20:39:43Z
dc.date.issued2008-06
dc.identifier.urihttps://hdl.handle.net/1912/2321
dc.descriptionSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2008en
dc.description.abstractThis study presents observations of turbulence dynamics made during the low winds portion of the Coupled Boundary Layers and Air-Sea Transfer experiment (CBLAST-Low). Observations were made of turbulent fluxes, turbulent kinetic energy, and the length scales of flux-carrying and energy-containing eddies in the ocean surface boundary layer. A new technique was developed to separate wave and turbulent motions spectrally, using ideas for turbulence spectra that were developed in the study of the bottom boundary layer of the atmosphere. The observations of turbulent fluxes allowed the closing of heat and momentum budgets across the air-sea interface. The observations also show that flux-carrying eddies are similar in size to those expected in rigid-boundary turbulence, but that energy-containing eddies are smaller than those in rigid-boundary turbulence. This suggests that the relationship between turbulent kinetic energy, depth, and turbulent diffusivity are different in the ocean surface boundary layer than in rigid-boundary turbulence. The observations confirm previous speculation that surface wave breaking provides a surface source of turbulent kinetic energy that is transported to depth where it dissipates. A model that includes the effects of shear production, wave breaking and dissipation is able to reproduce the enhancement of turbulent kinetic energy near the wavy ocean surface. However, because of the different length scale relations in the ocean surface boundary layer, the empirical constants in the energy model are different from the values that are used to model rigid-boundary turbulence. The ocean surface boundary layer is observed to have small but finite temperature gradients that are related to the boundary fluxes of heat and momentum, as assumed by closure models. However, the turbulent diffusivity of heat in the surface boundary layer is larger than predicted by rigid-boundary closure models. Including the combined effects of wave breaking, stress, and buoyancy forcing allows a closure model to predict the turbulent diffusivity for heat in the ocean surface boundary layer.en
dc.description.sponsorshipThis work was supported by Office of Naval Research grants N00014-00-1-0409, N00014-01-1-0029, and N00014-03-1-0681, the Woods Hole Oceanographic Institution Academic Programs Office, and National Aeronautics and Space Administration grant NAG5-11933.en
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen
dc.relation.ispartofseriesWHOI Thesesen
dc.subjectOcean-atmosphere interactionen_US
dc.subjectOceanic mixingen_US
dc.titleObservations of turbulent fluxes and turbulence dynamics in the ocean surface boundary layeren
dc.typeThesisen
dc.identifier.doi10.1575/1912/2321


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record