Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 5 of 5 for “"Seward Johnson (Ship) Cruise"”.
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Scale closure in upper ocean optical properties : from single particles to ocean color
… cycle. Current models describing the relationship between optical properties and chlorophyll do not account for much of the optical variability observed in natural waters, because of the presence of seawater constituents that do not covary with phytoplankton pigment concentration. In an …
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Diversity of the marine cyanobacterium Trichodesmium : characterization of the Woods Hole culture collection and quantification of field populations
Trichodesmium is a colonial, N2-fixing cyanobacterium found in tropical oceans. Species of Trichodesmium are genetically similar but several species exist together in the same waters. In order to coexist, Trichodesmium spp. may occupy different niche spaces through differential utilization of …
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The marine geochemistry of iron and iron isotopes
This thesis addressed questions about the Fe cycle by measuring detailed profiles and transects of Fe species in the ocean and also by exploring the use of a new tracer of Fe, Fe isotopic fractionation. In the subtropical and tropical Atlantic Ocean, transects and profiles are presented for …
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The relationship between iron and nitrogen fixation in Trichodesmium spp.
Trichodesmium spp. are considered the dominant nitrogen (N) fixing cyanobacteria in tropical and subtropical oceans, regimes frequently characterized by low iron (Fe). Limited information exists about what levels of Fe limit Trichodesmium N fixation. I developed a diagnostic for Fe limitation using …
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The marine biogeochemistry of molybdenum
Prevailing wisdom holds that the vertical distribution of molybdenum (Mo) in the open ocean is conservative, despite Mo's important biological role and association with Mn oxides and anoxic sediments. Mo is used in both nitrogenase, the enzyme responsible for Nz fixation, and nitrate reductase, …