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 14 of 14 for “"North Pacific Subtropical Gyre"”.
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Siderophore cycling in the North Pacific Subtropical Gyre
… in the upper 1000 m of the US GEOTRACES GP15 Pacific Meridional Transect. Siderophore concentration ranges from 0-70 pM, and there is no correlation between the concentration of siderophores and dissolved Fe (dFe, <0.2 μm). In contrast, most siderophore hotspots, defined by concentration that …
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Dimensions of microbial biodiversity in the North Pacific subtropical Gyre
… a long-term study site representative of the North Pacific Subtropical Gyre (NPSG). We observed changes in diversity and community composition at Station ALOHA across time, ocean depth and on plastic debris, a new anthropogenically derived niche in the NPSG. Despite surface waters only …
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Determining the effects of ocean perturbations on marine phytoplankton assemblages
… consistent with ocean acidification and North Pacific Subtropical Gyre (NPSG) upwelling patterns. These experiments demonstrated the feasibility and value of such perturbations in studying phytoplankton responses to environmental forcing.
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Iron and the ecology of marine microbes
… experiments in different regions of the Pacific Ocean. Using metagenomics, I characterized the impact of iron availability on the microbial community structure of the Central Equatorial Pacific Ocean. This study showed that addition of iron to an iron-limited ecosystem triggers a …
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Resolving the molecular ecology of marine microbial eukaryotes with metatranscriptomes
The surface waters of the North Pacific ocean host diverse populations of microbial eukaryotes, who collectively mediate the flux of energy and matter in their environment with a significant impact on global biogeochemical cycles. The evolutionary history of these organisms spans billions of years …
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Mechanistic models of oceanic nitrogen fixation
… of nitrogen fixers (or diazotrophs) in the northern subtropical gyres suggest variability in nitrogen fixation on interannual and longer timescales. I use a highly idealized, two-layer model of the nitrogen and phosphorus biogeochemistry and ecology of a subtropical gyre to explore the …
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The Effects of Food Quality and Temperature on Mesozooplankton Physiology
… variations in seston N:P ratio was found in the North Sea and in the North Pacific Subtropical Gyre. Field measurements revealed latitudinal and temporal changes in food quality at the chlorophyll maximum along an Atlantic Meridional Transect (AMT). Better quality food was found in the Temperate …
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Marine microbial intact polar diacylglycerolipids and their application in the study of nutrient stress and bacterial production
… stress. In the surface waters of the western North Atlantic I used three experimental approaches to identify the microbial sources of the nine most abundant classes of IP-DAGs. Phytoplankton are the primary source of one class of sulfolipid, sulfoquinovosyldiacylglycerol, and one class of …
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Chemical controls on the cycling and reactivity of marine dissolved organic matter
… C-P lyase activity (CLA) profiles from the North Pacific Subtropical Gyre (NPSG) showed a sharp activity maximum near the deep-chlorophyll maximum (DCM). High-resolution nutrient measurements suggest that this subsurface CLA maximum is the result of a high nitrate flux at the top of the …
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A Lagrangian perspective of mesoscale biophysical interactions in the subtropical ocean
… advective properties of eddies across the North Pacific Subtropical Gyre, finding that only half of the remotely sensed eddies identified from the traditional, Eulerian sea level anomaly method trap waters for these timescales. We then statistically compare satellite-observed chlorophyll-a …
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Marine microbial intact polar diacylglycerolipids and their application in the study of nutrient stress and bacterial production
… stress. In the surface waters of the western North Atlantic I used three experimental approaches to identify the microbial sources of the nine most abundant classes of IP-DAGs. Phytoplankton are the primary source of one class of sulfolipid, sulfoquinovosyldiacylglycerol, and one class of …
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Chemical Controls on the Cycling and Reactivity of Marine Dissolved Organic Matter
… C-P lyase activity (CLA) profiles from the North Pacific Subtropical Gyre (NPSG) showed a sharp activity maximum near the deep-chlorophyll maximum (DCM). High-resolution nutrient measurements suggest that this subsurface CLA maximum is the result of a high nitrate flux at the top of the …
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A Lagrangian perspective of mesoscale biophysical interactions in the subtropical ocean
… advective properties of eddies across the North Pacific Subtropical Gyre, finding that only half of the remotely sensed eddies identified from the traditional, Eulerian sea level anomaly method trap waters for these timescales. We then statistically compare satellite-observed chlorophyll-a …
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Microbial responses to environmental forcing and implications for trophic transfer through the lens of lipidomics
… phytoplankton responses to nutrients in the North Pacific Subtropical Gyre (NPSG), and to light in the western Antarctic Peninsula (WAP). In the NPSG, I utilized lipid biomarkers to differentiate between cyanobacterial and eukaryotic signs of stress, in response to the passage of mesoscale …