Index Catalog // ScholarsArchive@OSU

A study on the effects of enhanced pCO2 on open ocean diazotrophic assemblages

Creator:: Gradoville, Mary Rose
Abstract:: Biological di-nitrogen (N₂) fixation is a key process in open-ocean ecosystems, where the new nitrogen (N) provided by marine diazotrophs can support a large fraction of primary productivity and carbon (C) drawdown. Recent laboratory studies have shown that elevated pCO₂ enhances the rate of N₂ fixation by select laboratory isolates...
Resource Type:: Masters Thesis
Full Text:: : _____________________________________________________________________ Ricardo M. Letelier Biological di-nitrogen (N2) fixation is a key process in open-ocean

New Insights on the Southern Ocean Carbon Cycle from Biogeochemical Argo Floats

Creator:: Williams, Nancy L.
Abstract:: The Southern Ocean plays an important role in the ocean’s uptake of heat and carbon yet the processes controlling this uptake are not well understood. To date, more than 100 biogeochemical profiling floats that measure water column pH, oxygen, nitrate, fluorescence, and backscattering at 10-day intervals have been deployed throughout...
Resource Type:: Dissertation
Full Text:: other members of my committee: Richard Feely, Burke Hales, and Ricardo Letelier. You have challenged

Ecology and Environmental Controls of Two Keystone Groups of Oceanic Microorganisms : Diazotrophs and Pathogenic Vibrio

Creator:: Gradoville, Mary Rose
Abstract:: Marine bacteria play vital roles in every niche of the ocean, from small-scale symbioses to large-scale productivity and the regulation of Earth’s climate. Recent advances in molecular tools now allow us to probe the genetic potential of entire microbial communities. The next step is linking these diverse communities to the...
Resource Type:: Dissertation

Kinematics and Dynamics of a Model Eastern-boundary Poleward Undercurrent

Creator:: Duran, Rodrigo
Abstract:: A carefully calibrated primitive-equation model from 41°N to 48°N is used to study the poleward undercurrent off the US west coast. Chapter 2 describes poleward flow over the slope from Eulerian and Lagrangian perspectives. The model is robust, in the sense of several characteristics being qualitatively consistent with observational and...
Resource Type:: Dissertation
Full Text:: approved: Roger M. Samelson A carefully calibrated primitive-equation model from 41ıN to 48ıN is used to

Transport and Mixing of Buoyant Water from Small Mountainous Rivers : An Investigation of Estuarine Residence Timescales and Coastal Current Propagation

Creator:: Lemagie, Emily P.
Abstract:: Small rivers, such as those that line the Oregon coast, have been shown to deliver significant concentrations of suspended sediments and nutrients to estuaries and the coastal ocean during wet seasons during which winds are predominantly downwelling-favorable. The fate of the buoyant source water and of any suspended or dissolved...
Resource Type:: Dissertation
Full Text:: members Ricardo Matano, Alexander Kurapov, and Ed Dever, for their limitless enthusiasm for this project

Coastal ocean variability inferred from high resolution models : two case studies

Creator:: Mauch, Matthew L.
Abstract:: In this thesis, high resolution ocean models are used to evaluate and forecast coastal ocean variability in two different applications. In the first study, the 2-km resolution ocean circulation model for the Eastern Bering Sea is utilized to understand whether slope-interior exchange along the path of the Aleutian North Slope...
Resource Type:: Masters Thesis
Full Text:: temperature maximum on the isopycnal surface 26.8 kg m-3, approximately 300-400 m deep. The simulation

Intra-seasonal sea level variability along the west coast of India

Creator:: Dhage, Laxmikant
Abstract:: The importance of local versus distant forcing is studied for the wind driven intra- seasonal (30-120 day) sea level anomaly (SLA) variations along the west coast of India. Three locations on the continental slope are chosen to represent the west coast. Two more locations, one east of Sri-Lanka and another...
Resource Type:: Masters Thesis
Full Text:: generation is of order 1-2 days, with phase propagation speeds of 2 m/s, resulting in maximum correlations

Evolution of Turbulence, Heat Content, and Freshwater Lenses in the Diurnal Warm Layer

Creator:: Moulin, Aurélie J.
Abstract:: Thorough understanding of the mechanisms controlling the temperature structure in the surface mixed layer of the ocean and, in particular, accurate values of sea surface temperature are critical for properly parameterizing air-sea heat exchange and quantifying the amount of heat redistributed below the surface. It is however difficult to obtain...
Resource Type:: Dissertation
Full Text:: abilities. My committee members Ricardo Matano, Bill Smyth, and Eric Skyllingstad all provided valuable

Novel Copper and Iron Complexes along the Oregon Coastal Upwelling Margin

Creator:: Bright, Peter, W.
Abstract:: Copper and iron are essential micronutrients that are required by marine primary producers for a variety of metabolic processes. Over 99% of both copper and iron are bound within organic complexes in the marine environment, however the molecular identity of many of these complexes remains unknown. The speciation of these...
Resource Type:: Masters Thesis
Full Text:: Abstract approved: ______________________________________________________ Rene M. Boiteau

Ensemble-variational data assimilation for dynamically challenging coastal ocean circulation

Creator:: Pasmans, Ivo
Abstract:: Currently, forecasts produced by the Oregon-Washington (OR-WA) Coastal Ocean Forecast System are constrained by assimilation of only surface observations. The 4-dimensional variational (4DVAR) data assimilation (DA) algorithm is utilized to combine the model and the data, with the time-independent forecast ("background'') error covariance B. In this study, two possible improvements...
Resource Type:: Dissertation
Full Text:: 5. The NH10 buoy observations used in these two chapters were obtained from M. Levine and C. Risien

The Influence of Model Resolution on Dispersal and Retention in Oregon Coastal Waters

Creator:: Wong-Ala, Jennifer A. T. K.
Abstract:: Lagrangian particle tracking (LPT) models are used to explore how physical processes influence the transport of particles (e.g., eggs, larvae, or propagules) in the ocean. On the Oregon continental shelf and slope, the Northern California Current System (CCS) is influenced by spatially and temporally variable coastal currents driven by weather,...
Resource Type:: Masters Thesis
Full Text:: km2 (e.g., Otter Rock) to 37 km2 (e.g., Cape Perpetua) and average maximum depths of 18 m (e.g

Spatiotemporal Variability in Benthic-Pelagic Coupling on the Oregon-Washington Shelf: An Investigation of Bottom Water and Benthic Flux Data

Creator:: Hughes, Anna R.
Abstract:: Continental shelf sediments are sinks for dissolved oxygen and sources of many major and minor nutrients required for oceanic surface primary production, resulting in a strong coupling between benthic and pelagic biogeochemical cycling. However, the influence and spatiotemporal variability of benthic remineralization on bottom-water chemistry and the supply of nutrients...
Resource Type:: Masters Thesis
Full Text:: balance of nitrogen, were between 0.21 to 1.82 mmol N m-2 day-1 and in the range of past estimates

Decoding DOM Degradation with Metatranscriptomics : How Do Sunlight and Microbial Communities Interact to Degrade Dissolved Organic Matter in Arctic Freshwaters?

Creator:: Nalven, Sarah G.
Abstract:: Arctic soils are warming, making vast stores of organic carbon available for conversion to CO₂. This could create a positive feedback loop and accelerate global warming, but the processes that convert this carbon into CO₂ are not well understood. We investigated how the combined activities of sunlight and microbes degrade...
Resource Type:: Masters Thesis
Full Text:: . Rick Colwell, Ricardo Letelier, Ryan Mueller, Yuan Jiang and Yanming Di. Our Geomicro seminar group

Ocean Acidification Impacts on Bivalves at Multiple Organizational Levels: From Individual Larvae to Bivalve Aggregations Habitats

Creator:: Gimenez Calvo, Iria
Abstract:: Many marine bivalves are sensitive to ocean acidification (OA) stress and often show heightened sensitivity during brief early larval and post-larval life stages, potentially leading to population bottlenecks. Most of the evidence to date has been collected in laboratory experiments that focused on physiological responses at the organismal level under...
Resource Type:: Dissertation
Full Text:: Ozkan-Haller, Ricardo Letelier, Clare Reimers, Joe Jennings, Dale Hubbard, Marnie Jo Zirbel, Jesse

Understanding Signals of the South Pole Ice Core: Chronology, Climate, and Firn Processes

Creator:: Epifanio, Jenna A.
Abstract:: The South Pole ice core (SPC14), drilled in the field seasons of 2014/2015 and 2015/2016, is an intermediate length, 1,751-m ice core which preserves a 54,000-year record of past climate and atmospheric composition. The SPC14 ice core adds to the spatial grid of ice cores in Antarctica extending into the...
Resource Type:: Dissertation
Full Text:: the field seasons of 2014/2015 and 2015/2016, is an intermediate length, 1,751-m ice core which

Detection of Physical and Biological Fronts in the Northern California Current System and the Drivers Behind Their Seasonal to Interannual Variability

Creator:: Jamil, Aliya L.
Abstract:: Oceanic fronts mark the boundary between two water masses and are often sites of complex bio-physical processes and multi-trophic level interactions, making them particularly important features in marine ecosystems. As global climate change induces multi-scale shifts in the driving physical mechanisms of fronts, spatiotemporal tracking of frontal variability can aid...
Resource Type:: Masters Thesis
Full Text:: Current System. Bathymetry/elevation values are in meters. Shelf break is represented by the -200 m

Effects of Dissolved Oxygen, Temperature, and Dietary Carbon Sources on the Condition of Juvenile English Sole (Parophrys vetulus) from the Oregon Coast

Creator:: Stowell, Michelle A.
Abstract:: Observations of the Oregon coast’s physical oceanography over the last few decades have revealed falling dissolved oxygen levels associated with seasonal upwelling, as well as rising water temperatures. In extreme cases, these changes have been associated with die-offs, redistribution, and decreased abundance and diversity of benthic fish and invertebrates. Many...
Resource Type:: Masters Thesis
Full Text:: continental shelf in the water column at 200 m to 1,000 m depth, and are caused by a combination of

Intraseasonal Oscillations of ~20 days Revisited: The Jet Stream and its Ecological Implications along the Oregon Coast

Creator:: Herweck, Kendra
Abstract:: Intraseasonal oscillations in the atmosphere-ocean system can affect weather patterns and regional ecosystems. In turn, these oscillations can be affected by climate variability, resulting in additive and/or non-linear responses of regional ecosystems to climate forcing. In the Northern California Current, a strong correlation was identified between the location of the...
Resource Type:: Masters Thesis
Full Text:: 200 m isobath. b 11 In order to further isolate the periodicity and lag in the

Optics, structure and variability of the offshore Columbia River plume

Creator:: Saldías, Gonzalo
Abstract:: The Columbia River delivers the greatest amount of freshwater to the coastal ocean along the U.S. Pacific coast. This freshwater forms the Columbia River plume, a mesoscale plume with significant implications on coastal ocean physical, biological, chemical, and geological processes. The plume is transported south and offshore during the upwelling...
Resource Type:: Dissertation
Full Text:: stress of -0.05 N m−2, which is turned on at t = 8 days. (e-h) Corresponding cross-shore sections of

Incorporating the Impacts of Climate Variability on Growth in Fish Population Dynamics Models

Creator:: Moron Correa, Giancarlo Helar
Abstract:: Variations in ocean conditions influenced by climate fluctuations may impact fish populations by changing their spatial distribution, physiology, survival, and other ecological features. Somatic growth is a crucial aspect of the biology of fishes and an important contributor to biomass fluctuations. Climate variability also affects somatic growth rates along the...
Resource Type:: Dissertation
Full Text:: my first year in CEOAS: George, Lauren, and Ricardo, for showing and making me understand the

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