In the northwestern Gulf of Mexico there is a need for reliable water level forecasts to facilitate safe commercial navigation, marine construction, and emergency management. Though the low amplitude tides of the region can be predicted with conventional harmonic techniques, frequent strong storms make accurate forecasts of water levels difficult....
This thesis presents the details of a large-scale laboratory experiment to study the
turbulence generated by waves breaking on a fixed barred beach. The data set includes
comprehensive measurements of free surface displacement and fluid velocity for one
random and one regular wave case.
Observations of the time-averaged turbulent kinetic...
Field deployments, flume experiments, and a 2D wave model have been used to identify the characteristics of Clark-type oxygen microelectrodes and measurement parameters that could possibly bias eddy correlation (EC) flux measurements made under waves. Eddy correlation is a technique adapted from atmospheric sciences that couples concurrent and co-located velocity...
Hazards threaten coastal communities and ecosystems over a wide range of spatiotemporal scales. One of the most pressing concerns for coastal property owners, decision makers, and researchers is the uncertain role that a changing climate will have on the intensity and frequency of these hazards. The significant uncertainties associated with...
Rates of benthic O₂ exchange are important measurements for determining organic matter remineralization, and can shed light on factors driving biogeochemical processes in coastal environments. Measurement of in situ O₂ consumption and production within permeable sediments, such as those found over ~43% of the Oregon-Washington shelf, has traditionally been done...
Wave-induced circulation is the defining characteristic of the nearshore. Within this region, the constant feedback cycle between incoming waves, wave-generated currents, and the mobile sediment bed is responsible for the evolution of complex patterns in nearshore and beach morphology. Central to our understanding of this system is knowledge of the...
The Large Wave Flume at the O.H. Hinsdale Wave Research Laboratory houses a piston wavemaker with a built-in active absorption system designed by MTS Systems Corporation. The performance of the active absorption system has not been properly assessed yet. This thesis evaluates the performance of the MTS active absorption system...
A wave-by-wave forecasting system is desired for optimization of wave energy conversion devices and for improving safety of vessel-based marine operations. This study outlines the first validation attempts of a recently developed forecasting system called Wavecast. The forecasting approach uses X-Band marine radar images for data assimilation, then reconstructs and...
Radiation stresses, defined as the excess flow of momentum due to the presence of waves (Longuet-Higgins, 1964), are the main drivers behind the cross-shore and longshore forcing that results in wave setup, set-down, and longshore currents (e.g. Svendsen, 2006). Longshore currents entrain and transport sediment and therefore play an important...
Estuaries represent the confluence of land and ocean environments and encompass a number of complex interactions amongst tides, winds, offshore waves and the riverine contributions, all of which contribute to total water levels (TWLs). The study of TWLs and the relative weight of its components can assist local communities in...
Oregon State University conducted a series of laboratory experiments to measure and quantify the near-field wave effects caused within arrays of Wave Energy Converters (WEC). As the waves and WECs interact, the WECs generate radiated waves; these effects vary with the location within the array. Analyzing the near-field waves will...
Coastal vegetation dampens waves which can provide benefits to the local area, but existing literature shows large variations in the degree of wave height attenuation depending on plant properties and wave conditions. Better knowledge of how to predict the wave height decay accurately in different types of vegetation may help...
Understanding the past, present, and future behavior of our nation's shorelines is vital for sensible coastal management. Localized areas of erosion, termed "erosional hot spots", can shift the shoreline landward threatening coastal infrastructure (Kraus and Galgano, 2001; Stauble and Gravens, 2004; McNinch, 2004). One specific type of erosional hot spot...
A variety of stakeholders require information about marine systems. In the open ocean, pilots of marine vessels require knowledge about environmental conditions for safe passage and route planning. On the coastline, communities rely on information about nearshore dynamics to increase safety from coastal hazards such as nearshore pollutants, coastal erosion,...
Coastal flooding and erosion are major concerns for low lying coastal communities -- particularly in light of accelerated sea level rise and climate change. To improve quantitative understanding of the physical drivers of both flooding and coastal landscape change, this dissertation explores coastal morphodynamics bridging the land-sea interface on modally...
In this dissertation the interactions between hydrodynamics, sediment suspension and transport, and morphological evolution in the surf zone was investigated with a large-scale laboratory experiment data, CROss-Shore Sediment Transport Experiment (CROSSTEX). The data set included comprehensive measurements of water surface elevation, fluid velocity, sediment concentration, and morphology for irregular waves...
The subaerial beach, composed of sand dunes and the foreshore, provides a natural buffer zone between vulnerable land and the dissipation of storm wave energy due to wave breaking. The natural beauty of this region is attractive to people, and as a result, significant investment has been placed in this...
Waves are the primary input of energy in the nearshore region, and together with the currents forced through the transfer of momentum that occurs during the wave breaking process they are the principal mechanism for sediment transport in the nearshore. The basic physics of waves and currents are thought to...
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...
Coastal communities in the U.S. Pacific Northwest (PNW) are rapidly engaging with the idea that hazards and environmental pressures are changing and may be characteristically different in the near future. This has led to a need for scientific knowledge and tools that can help coastal communities prepare and build resilience...