Tide-topography coupling is important for understanding surface-tide energy loss, the intermittency of internal tides, and the cascade of internal-tide energy from large to small scales. Although tide-topography coupling has been observed and modeled for 50 years, the identification of surface and internal tides over arbitrary topography has not been standardized....
ROSS (Robotic Oceanographic Surface Sampler) is an autonomous boat, equipped with oceanographic sensors, used for studying the ocean’s surface. One of its advantages over traditional research vessels is its ability to sample near glaciers, an area too dangerous for manned ships. In order to properly ascertain deep ocean heat’s effect...
This dissertation investigates the dynamics of the tidally modulated outflow from the Columbia River mouth using high resolution measurements of velocity, density and turbulent microstructure. At high tide, flow through the river mouth reverses from flood (onshore) to ebb (offshore). During ebb, buoyant fluid issues from the river mouth and...
It is becoming increasingly important to understand fundamental hillslope-scale hydrological processes. Most hillslope-sale transport experiments have generally focused on conceptual findings or other aspect of flow behavior, rather than the quantification of the mass transport mechanisms of advection and dispersion. When the velocities have been quantified, dispersion has been mentioned...
Recent observations of tidewater glaciers find that the currently accepted model for predicting ice melt vastly underestimates observed melt rates. The release of pressurized air bubbles into the ocean from pores in the ice is one process that can amplify glacier melt. To incorporate this process into models, we need...
This work investigates a methodology for estimating the ocean stratification gradient based on high-resolution, in space and time, remote sensing observations of internal wave propagation speeds. The internal wave speed observations were collected using a shore-based, X-band marine radar and the ocean vertical density profiles were collected simultaneously from an...
A new set of data from a large-scale sand bar migration experiment is presented. During this experiment, two sandbars were generated. One of the bar was generated by the action of undertow, and sediment moved offshore. The other bar was generated by the shoreward movement of sediment coming from the...
Time‐dependent buoyant plumes form at the outflow of tidally dominated estuaries. When estuary discharge velocity exceeds plume internal wave speed c, a sharp front forms at the plume’s leading edge that expands from the time‐dependent source. Using observations of the Columbia River tidal plume from multiple tidal cycles we characterize...
Observations of currents, hydrography, and turbulence provide unambiguous evidence for hydraulic control of flow over an isolated three-dimensional topographic feature on Oregon’s continental shelf. The flow becomes critical at the crest of the bank, forming a strong supercritical downslope flow in the lower layer. Farther downstream, internal hydraulic jumps form...
Direct determination of the irreversible turbulent flux of salinity in the ocean has not been possible because of the complexity of measuring salinity on the smallest scales over which it mixes. Presented is an analysis of turbulent salinity microstructure from measurements using a combined fast-conductivity/temperature probe on a slowly falling...
At the smallest length scales, conductivity measurements include a contribution from salinity fluctuations in
the inertial–convective and viscous–diffusive ranges of the turbulent scalar variance spectrum. Interpreting these
measurements is complicated because conductivity is a compound quantity of both temperature and salinity.
Accurate estimates of the dissipation rate of salinity variance...
The decisions in Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers, 531 U.S. 159 (2001) (SWANCC) and Rapanos v. United States, 547 U.S. ___(2006), deviated from the more broad interpretations of congressional intent granted by the court in past assessments of the constitutionality of environmental...
Despite unprecedented access to information, the American public has been shown to have difficulty distinguishing factually correct information from misinformation. Misinformation can, and does, alter voting patterns and policy preferences which impact the range of policy solutions available to policymakers. In recent years, media organizations have begun specialized ‘fact-‐checking’ operations...
Analogous to ocean surface waves, waves in the ocean interior also experience steepening, breaking, and dissipation as they approach the coastline. Much less is known about this internal beach. In this work, extensive moored Acoustic Doppler Current Profiler and temperature/salinity data together with optical remote sensing are combined to describe...
Basin-scale superinertial oceanic tides have been observed globally to resonate with the continental shelf (e.g., the Patagonian Shelf) with a clear theoretical framework. However, the response of the shelf to atmospheric tides – another basin-scale forcing – has not been discussed. This study explores this response using a prominent S2...
The southwest monsoon, which may be idealized as the northward movement of the intertropical convergence zone in the Indian Ocean associated with differential heating of land and ocean, brings a seasonal reversal of currents and winds in the Bay of Bengal and the Arabian Sea. Atmospheric convection from monsoon activity...
Inner-shelf circulation and mechanisms of across-shelf transport of water masses were examined using seven years of observations collected by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) program, a long-term monitoring effort along the central Oregon coast. Since 1998, moored velocity and hydrographic measurements have been obtained during the...
Several topics are presented in this dissertation, each of which has applications to solar cells and photodetectors. First, we discuss the growth of Cu10Te4S13, copper tellurium tetrahedrite. This material has interesting optical properties; it has a large joint density of states at the conduction band maximum and valence band minimum,...
The ability to engineer stiffness and strength in any desired direction make composites an ideal material candidate for various applications when compared to their traditional isotropic counterparts. In spite of this, the ability to model the material response in composites has yet to be fully explored. Composite research largely focuses...