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dc.contributor.authorDusenberry, Jeffrey A.  Concept link
dc.coverage.spatialSargasso Sea
dc.date.accessioned2012-12-13T18:47:58Z
dc.date.available2012-12-13T18:47:58Z
dc.date.issued1995-02
dc.identifier.urihttps://hdl.handle.net/1912/5615
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 February 1995en_US
dc.description.abstractFluctuations in light intensity due to vertical mixing in the open ocean surface layer will affect phytoplankton physiology. Conversely, indicators of phytoplankton photoacclimation will be diagnostic of mixing processes if the appropriate kinetics are known. A combination of laboratory and field experimental work, field observations, and theoretical models were used to quantify the relationship between vertical mixing and photoacclimation in determining the time and space evolution of single cell optical properties for the photosynthetic picoplankton, Prochlorococcus spp. Diel time-series observations from the Sargasso Sea reveal patterns in single-cell fluorescence distributions within Prochlorococcus spp. populations which appear to correspond to decreasing mixing rates and photoacclimation during the day, and increased mixing at night. Reciprocal light shift experiments were used to quantify the photoacclimation kinetics for Prochlorococcus spp. fluorescence. A laboratory continuous culture system was developed which could simulate the effects of mixing across a light gradient at the level of the individual cell. This system was operated at four different simulated diffusivities. Prochlorococcus marinus strain Med4 fluorescence distributions show distinct patterns in the mean and higher moments which are consistent with a simple quasi-steady turbulent diffusionphotoacclimation model. In both, daytime photoacclimation drove the development of a gradient in mean fluorescence, a decrease in variance overall, and skewing of distributions away from the boundaries. These results suggest that picophytoplankton single-cell fluorescence distributions could prove to be a useful diagnostic indicator of the mixing environment.en_US
dc.description.sponsorshipThis project received primary financial support from the Office of Naval Research, with additional support from the National Science Foundation, the Environmental Protection Agency, Sea Grant, M.I.T. Sloan funds and M.I.T. Department of Civil and Environmental Engineering funds. I also wish to acknowledge support from a Rockwell Fellowship and a National Science Foundation Graduate Fellowship.
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen_US
dc.relation.ispartofseriesWHOI Thesesen_US
dc.subjectPhytoplanktonen_US
dc.subjectPhotosynthesisen_US
dc.subjectPrimary productivityen_US
dc.subjectAcclimatizationen_US
dc.subjectOceanic mixingen_US
dc.subjectOceanus (Ship : 1975-) Cruise OC214en_US
dc.subjectEndeavor (Ship: 1976-) Cruise EN232en_US
dc.titlePicophytoplankton photoacclimation and mixing in the surface oceansen_US
dc.typeThesisen_US
dc.identifier.doi10.1575/1912/5615


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