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Full-Text Articles in Other Oceanography and Atmospheric Sciences and Meteorology
Isotopic Fingerprints Of The Coastal Margins: Tracing Dissolved Iron Sources From Land To Sea, Hannah R. Hunt
Isotopic Fingerprints Of The Coastal Margins: Tracing Dissolved Iron Sources From Land To Sea, Hannah R. Hunt
USF Tampa Graduate Theses and Dissertations
Dissolved iron (dFe) is an essential micronutrient for sustaining life in the surface ocean. Nearly four decades of research dedicated to understanding sources, cycling and biogeochemical modifications of Fe sources in the global oceans has generated a significant body of research supporting the idea that the concentration of Fe in the surface ocean exerts significant controls on primary production and carbon uptake in the surface ocean. Creation of the GEOTRACES program greatly increased the spatial and temporal resolution of high-quality trace element and trace element isotope data revealing new insights into the global Fe cycle, especially through the use of …
Dissolved Nickel Speciation At The Bermuda Atlantic Time-Series Study (Bats) Site, Caitlyn E. Parente
Dissolved Nickel Speciation At The Bermuda Atlantic Time-Series Study (Bats) Site, Caitlyn E. Parente
USF Tampa Graduate Theses and Dissertations
Here I present the first depth profiles of dissolved nickel (DNi) speciation over an annual cycle at the Bermuda Atlantic Time-series Study (BATS) site in the North Atlantic. Seawater samples were collected in March, May, August, and November 2019 and analyzed for labile DNi using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV). Labile DNi was measured by CLE-AdCSV as the fraction of DNi that exchanges with an added competitive ligand in an overnight equilibration. Results revealed two distinct fractions of DNi present throughout the water column: a labile fraction, and a strongly organically complexed (i.e., non-labile) fraction. More than 50% …
Labile Dissolved Nickel (Ni) Concentrations In The North Pacific, Calyn M. Crawford
Labile Dissolved Nickel (Ni) Concentrations In The North Pacific, Calyn M. Crawford
USF Tampa Graduate Theses and Dissertations
Nickel (Ni) is an important micronutrient for phytoplankton and bacteria that serves as a required co-factor in several metalloenzymes. Despite these known biological uses, total dissolved Ni concentrations remain elevated in global surface waters, in contrast to the surface depletion commonly observed for macronutrients and other nutrient-type trace elements. A prevailing hypothesis for the muted depletion of dissolved Ni concentrations in surface waters is that dissolved Ni in seawater is not in a bioavailable form. The chemical lability of Ni in seawater provides insight into Ni speciation and bioavailability, but few measurements have been made in the open ocean to …
A Process-Based Approach To Evaluating The Role Of Organic Ligands In Trace Metal Cycling In The Marine Environment, Travis Mellett
A Process-Based Approach To Evaluating The Role Of Organic Ligands In Trace Metal Cycling In The Marine Environment, Travis Mellett
USF Tampa Graduate Theses and Dissertations
In addition to control by major nutrient elements (nitrogen, phosphorous, and silicon) growth and community composition of marine phytoplankton is also regulated by trace element nutrients (iron, copper, manganese, zinc, cobalt, nickel, and cadmium). Of these, iron is the most influential in the modern ocean, regulating phytoplankton growth and carbon export in high-nutrient low-chlorophyll regimes and exerting an important control on the marine nitrogen cycle through its role in di-nitrogen fixation. The distributions of these metals has the capacity to control primary production and phytoplankton community composition through differences in cellular quotas or metal sensitivities amongst species. The relationship between …
Investigating The Isotope Signatures Of Dissolved Iron In The Southern Atlantic Ocean, Brent A. Summers
Investigating The Isotope Signatures Of Dissolved Iron In The Southern Atlantic Ocean, Brent A. Summers
USF Tampa Graduate Theses and Dissertations
Iron (Fe), used as a cofactor in nitrogen fixation and photosynthesis by oceanic microorganisms, has extremely low dissolved concentrations in the surface ocean, leading to widespread limitation of phytoplankton growth. Dissolved Fe isotope ratios (δ56Fe) have been shown to be useful in helping to quantify the sources and cycling of Fe in the oceans if Fe source signatures and fractionation processes are well understood. Here, this thesis presents data from GEOTRACES section GA10W, and investigate the isotopic signature of sediment-derived dissolved Fe from the South Atlantic margins. My results show that there are both shallow (δ56Fe of -0.2‰) and deep …
Open Ocean Dms Air/Sea Fluxes Over The Eastern South Pacific Ocean, C. A. Marandino, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman
Open Ocean Dms Air/Sea Fluxes Over The Eastern South Pacific Ocean, C. A. Marandino, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Air/sea fluxes of dimethylsulfide (DMS) were measured by eddy correlation over the Eastern South Pacific Ocean during January 2006. The cruise track extended from Manzanillo, Mexico, along 110 degrees W, to Punta Arenas, Chile. Bulk air and surface ocean DMS levels were also measured and gas transfer coefficients (k(DMS)) were computed. Air and seawater DMS measurements were made using chemical ionization mass spectrometry (API-CIMS) and a gas/liquid membrane equilibrator. Mean surface seawater DMS concentrations were 3.8 +/- 2.2 nM and atmospheric mixing ratios were 340 +/- 370 ppt. The air/sea flux of DMS was uniformly out of the ocean, with …