Browsing Oceanography by Subject "Oceanography"
Now showing items 1-20 of 61
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A New Instrument and Method for Nitrogen-loss Studies in Oxygen Deficient Zones
The ocean’s biogeochemical cycles are coming under increasing stress due to global climate change and anthropogenic emissions of carbon dioxide. Three different factors are stressing the oceans: rising temperatures, ... -
Acquisition, degradation, and cycling of organic matter within sea-ice brines by bacteria and their viruses
Marine dissolved organic carbon (DOC) is a major component of the global carbon pool, and thus can have significant effects on global carbon cycling. Within the oceans, DOC is largely regulated by microbial communities, ... -
Biosphere Impacts of Ocean Hypoxia in a Warming Climate
Earth’s climate and biology mediate the availability of dissolved oxygen (O2) in seawater, a key environmental constraint on energy acquisition for diverse marine life. Energy available for organismal growth, activity, and ... -
Characterization of organic iron and cobalt ligands in the subtropical North Pacific
Trace metals are essential to the growth of marine organisms, but they exist in very low concentrations in the ocean, and are mostly complexed to diverse suites of organic ligands. While these metal-binding ligands directly ... -
Chemical and Biological Controls on Coral Nucleation
Coral reefs are vibrant and important ecosystems in the oceans, but reefs today are under threat from multiple sources. One such threat is ocean acidification due to anthropogenic climate change, which is reducing both ... -
Circulation-Informed Seafloor Geodetic Techniques for Understanding Plate Boundary Processes
Tectonic plate boundaries host a range of solid-Earth physical processes of scientific and societal interest, including the majority of the world’s volcanism and earthquakes. However, these marginal systems are primarily ... -
Climate-driven shifts in abundance, distribution, and composition of the pelagic fish community in a rapidly changing Pacific Arctic
The Chukchi Sea is experiencing rapid environmental change due to warming temperatures, reductions in sea ice, and increases in transport of warm southern-origin waters into the region. Continued changes in the physical ... -
Coastal sources of estuarine inflow
This dissertation considers the source of water that enters estuaries from the coastal ocean using a series of realistic and idealized ocean models. The first project examines the source of planktonic larvae of the marine ... -
Computational and experimental models of diatom-bacteria interaction
Microbial interactions structure ecosystems and fuel biogeochemical cycling. The metabolic activities operating in the ocean are critical to the entire planet. In this work, I focused on interactions between diatoms and ... -
Connecting sediment dynamics to coastal morphology over linked spatial and temporal scales in Myanmar and New Zealand
Low-lying coastal environments are threatened by sea-level rise (SLR), which is often locally exacerbated by anthropogenic alterations that accelerate subsidence. Managing and protecting these valuable regions requires ... -
Consequences of ocean change for ecological function:Observational and modeling case studies of larval echinoderms
(2013-02-25)Planktonic larvae of many marine invertebrates play important roles in connecting and sustaining disjunct adult populations. Most larvae are denser than seawater and rely on swimming to regulate their vertical positions. ... -
Constructing a Toolbox of Geochemical Indicators of Community Composition Shifts in Coral Reef Ecosystems Under Stress
Modern coral reef ecosystems house 25% of the planet’s entire marine biodiversity in ~ 0.1% of the surface area cover of the ocean and provide numerous ecosystem services for human populations. Unfortunately, these marine ... -
Eddy Vertical Structure and Variability: vortex evolution and the geography of geostrophic turbulence
Glider observations of submesoscale and mesoscale eddy structure, behavior, and evolution are analyzed revealing both processes of eddy decay and statistical properties of geostrophic turbulence (i.e. mesoscale eddy-eddy ... -
Elucidating Temporal Variability in Organic Matter Sources and Cycling in Tropical Rivers
(2012-09-13)Tropical rivers are large sources of carbon to the atmosphere and the ocean. The composition of riverine organic matter (OM) affects the size of these fluxes by governing how much carbon will be returned to the atmosphere ... -
Environmentally induced changes to the diatom cell wall and the implications of these changes on biogeochemical cycles
(2013-02-25)Diatoms are responsible for 20% of global primary production, control the marine silicon cycle, and are a major constituent of the organic matter that sinks into the deep ocean. Diatom cell walls, or frustules, are composed ... -
Estimates of Drag Coefficients and Surface Waves under Tropical Cyclones using Subsurface EM-APEX floats
Nineteen autonomous EM-APEX floats were air-launched from aircraft to measure the profiles of ocean current velocity, temperature, salinity, and high-frequency velocity variance (σ_u ) ̃^2 under five different tropical ... -
Evaluating Physical and Biogeochemical Controls on Ocean Oxygen, Nitrate, and Carbon in Coupled Biogeochemical Ocean Circulation Models
The balance of ocean physics and the photosynthetic production and respiratory consumption of O2 dynamically links oxygen, organic carbon, and nitrate in the ocean. This thesis uses coupled biogeochemical ocean circulation ... -
Evolutionary response of marine bacteria to the co-occurring pnictogens phosphorus and arsenic
Phosphorus is an essential component of biomolecules, and is believed to be the limiting nutrient in the marine environment on geologic timescales. In marine waters, phosphorus co-occurs with arsenic, an element with many ... -
Evolving Ice-Ocean Dynamics of the Western Arctic
This dissertation examines the western Arctic Ocean and how its freshwater content and dynamics have evolved, particularly in the Beaufort Gyre circulation system north of Alaska. The recent growth of the Beaufort Sea ... -
Fine-Grained Sediment Dynamics and Morphodynamics in Tide-Dominated Channels
Rivers supply the bulk of sediment to the world ocean and are, therefore, crucial in building the foundation of coastal ecosystems and communities. As rivers approach the ocean, sediment dispersal can become dominated by ...