Time‐dependent, three‐dimensional, upwelling circulation on the continental shelf off the Oregon coast is studied using a primitive equation numerical model. A limited area domain with a high‐resolution curvilinear grid is utilized. The response of the coastal ocean to forcing by observed wind stress and heat flux during the summer 2001...
High‐resolution three‐dimensional (3‐D) seismic reflection data acquired on the R/V Thomas G. Thompson in 2000 reveal a pair of bottom simulating reflections (BSRs) across a broad region of southern Hydrate Ridge, offshore Oregon. The primary BSR (BSRp) is a regionally extensive reflection that lies 120–150 m below seafloor and exhibits...
The Oregon State University Mars MM5 was used in a comprehensive high-resolution study of northern polar summertime circulations. Three simulations (Ls = 120, Ls = 135, and Ls = 150) characterize the changing circulation. The atmosphere is dry, and model dynamics are hydrostatic. A modified TES thermal inertia map provides...
Most climate models predict a weakening of the North Atlantic thermohaline circulation for the 21st century when forced by increasing levels of greenhouse gas concentrations. The model spread, however, is rather large, even when the forcing scenario is identical, indicating a large uncertainty in the response to forcing. In order...
This report documents the observations of velocity, temperature and conductivity made from moorings deployed in the Kauai Channel on the ridge extending NW from Oahu, Hawaii. Two moorings (Al, Bl) were deployed in August 2002 for three months and one mooring
(A2) was redeployed in November 2002 for seven months...
As part of the U. S. GLOBEC NorthEast Pacific Program we made repeated seasonal hydrographic surveys in the northern California Current system (Figure 1) between July 1997 and September 2003. These surveys included early spring sampling along a pair of hydrographic sections, one north (at 44.6ºN) and one south (at...
A remote sensing method to measure directional oceanic surface waves by three laser altimeters on the NOAA LongEZ aircraft is investigated. To examine feasibility and sensitivity of the wavelet analysis method to various waves, aircraft motions, and aircraft flight directions relative to wave propagation directions, idealized surface waves are simulated...
Energy flux is a fundamental quantity for understanding internal wave generation, propagation, and dissipation. In this paper, the estimation of internal wave energy fluxes <u′p′> from ocean observations that may be sparse in either time or depth are considered. Sampling must be sufficient in depth to allow for the estimation...
Direct numerical simulations are used to compare turbulent diffusivities of heat and salt during the growth and collapse of Kelvin–Helmholtz billows. The ratio of diffusivities is obtained as a function of buoyancy Reynolds number Re[subscript]b and of the density ratio R[subscript]ρ (the ratio of the contributions of heat and salt...
This article presents a semianalytic method to investigate the properties of energy transmission across bottom topography by barotropic Rossby waves. The method is first used to revisit the analytical estimates derived from wave-matching techniques and Wentzel–Kramers–Brillouin (WKB) approximations. The comparison between the semianalytic method and WKB indicates that the results...
An analytical model of subtropical mode water is presented, based on ventilated thermocline theory and on numerical solutions of a planetary geostrophic basin model. In ventilated thermocline theory, the western pool is a region bounded on the east by subsurface streamlines that outcrop at the western edge of the interior,...
The sublimation of snow and evaporation of melted snow is contrasted between brush, grass and bare ground sites using eddy-correlation data. Averaged over the entire winter season, the evaporation/sublimation is about 20% greater over the brush site than the bare ground site, apparently due to greater supply of snow. Blowing...
Underground temperatures contain a record of past changes in the energy balance at the Earth's surface, such that borehole temperature data can be used to reconstruct long‐term trends of ground surface temperature (GST) changes. In addition to surface air temperature, however, GST is the response of the ground to other...
We discuss connections between inner‐shelf and mid‐shelf circulation near Point Conception, California, as well as the wind forcing of inner‐shelf circulation. Point Conception marks the southern edge of a major upwelling zone that extends from Oregon to central California. The coastline makes a sharp eastward turn at Point Conception, and...
We measured iron concentrations off the Oregon coast in spring (May–June) and summer (August) of 2001 as part of the Coastal Ocean Advances in Shelf Transport (COAST) program. Dissolvable and total dissolvable iron levels in surface waters were generally higher in spring (mean of 2.1 and 33.9 nmol L¯¹, respectively)...
We examined variability in the natural fluorescence yield of a neritic diatom, Thalassiosira weissflogii, in continuous cultures. In this species, kinetics in natural fluorescence yield over time scales less than a photoperiod were characterized by sharp decreases, occurring at irradiance intensities that presumably coincide with the onset of nonphotochemical fluorescence...
In the past, sharks, skates and ray species have mainly occurred in incidental fisheries. Now they are increasingly being directly targeted due to the depleted status of traditionally targeted species. The life history characteristics of many elasmobranch species make them more sensitive to high rates of fishing mortality. The combination...
Numerical model and assimilation experiments were conducted in the tropical Pacific Ocean to obtain a better understanding of the processes that control the cold tongue surface mixed layer temperature balance during August 1999 to July 2004. The numerical model was first applied to test two hypotheses (asymmetric background currents and...
In the early 1980's the first evidence of biological alteration of basalt glass (sideromelane) was published. Since that time additional evidence, including DNA staining, isotopic abundance and chemical mapping, has come to light suggesting that this unique alteration of glass can be attributed to microbial activity. Microbial alteration textures have...
Westward transport of water vapor across the Panama Isthmus helps to
maintain the salinity contrast between the Atlantic and Pacific Oceans, important in
thermohaline circulation and global climate. Relatively low sea-surface salinities and a
strong, shallow pycnocline in the eastern Pacific warm pool (EPWP) region near
Central America reflect high...
Atmospheric boundary layers become stably stratified at night over land when the surface becomes colder than the air layer above. In stable nocturnal boundary layers (SNBL), turbulence becomes weak and intermittent, terrain-induced phenomena such as drainage currents or gravity-waves emerge and the surface heterogeneity is enhanced. Because of their complexity...
Advanced Very-High Resolution Radiometer 4-km data were collected over the northeast Atlantic for May-August, 1995-1999. Aerosol optical depth was retrieved in cloud-free pixels. In pixels containing clouds from only single-layered, low-level systems, a retrieval scheme that accounts for partly-cloudy pixels was used to retrieve: cloud optical depth, droplet effective radius,...
Lingcod (Ophiodon elongatus) are known to utilize certain estuaries along the Pacific coast of the United States, but the importance of these habitats to the coast-wide population is not well understood. In this study, general patterns of estuarine habitat use were assessed by tracking the movement of sub-adult and adult...
Advanced Very High Resolution Radiometer (AVHRR) 4-km data collected over the northeastern Atlantic off the coast of the Iberian Peninsula for May to August 1995 were used to investigate the feasibility of empirically deriving estimates of the aerosol indirect radiative forcing. A retrieval scheme was used to derive cloud visible...
Female calanoid copepods of the family Calanidae can mature with either the juvenile and most typical female pattern of setation, termed trithek (T), or with the male pattern, termed quadrithek (Q). It was suggested by Fleminger (1985), but not proved, that females with the Q pattern have switched from development...
In this study we present new information on seasonal variation in absolute growth rate in length of coho salmon (Oncorhynchus kisutch) in the ocean off Oregon and Washington, and relate these changes in growth rate to concurrent changes in the spacing of scale circuli. Average spacing of scale circuli and...
A pair of hydrographic sections, one north and one south of Cape Blanco at 42.9N, was sampled in five summers (1998–2000 and 2002–2003). The NH line at 44.6N lies about 130 km south of the Columbia River, and spans a relatively wide shelf off Newport, Oregon. The CR line at...
This Master's Degree project is intended to document historical ecological conditions and land use histories during the past 150 years for selected Oregon watersheds and tidal wetland sites. The sites are the subject of current research into the ability of tidal wetlands to provide rearing habitat and prey for juvenile...
Coastal-based high-frequency (HF) radar systems are an increasingly used tool for measuring surface currents in the coastal ocean. These systems provide a spatial and temporal resolution not achievable with other methods. Standard-range sites typically generate hourly maps of surface currents on a 2km grid extending approximately 50km from shore while...
This project, to propose an implementation strategy for standard monitoring
protocols, builds on my Pacific Northwest National Laboratory Fellowship to support a
study entitled Evaluating Cumulative Ecosystem Response to Restoration Projects in the
Columbia River Estuary (Diefenderfer et al. 2005). The major objective of the study was
to develop a...
Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification of such marine, biological hotspots would be of great importance to resource managers, conservationists, and research planners, and is consequently a growing area...
The data set presented here includes the discrete depth profile data and time series data
from the vertical profiling cruises carried out as a portion of the “Coastal Ocean Advances in Shelf Transport” (COAST) project. The primary purpose for collection of this data set was to calibrate the optical parameters...
In 2000, the US Congress responded to the industry-wide constriction of the West Coast groundfish industry by allocating $5 million in disaster relief for Oregon, Washington, and California. Each state, with minimal federal oversight, designed and executed its own disaster response program to help impacted members of the fishing industry...
The fishing industry in the Pacific Northwest is a dynamic and highly competitive industry that must constantly respond to rapidly changing resource, regulatory and market forces. These forces have already had a significant impact on our fisheries and will continue to do so as we learn more about the biology...
Nonpoint source pollution is currently the major source of water pollution in Oregon as
well as the United States as a whole. The Environmental Protection Agency designated
marinas as one of the sources of nonpoint pollution to coastal waters. In an effort to
reduce nonpoint pollution from marinas and to...
An empirical statistical model is developed that relates the non-tidal motion of the ocean surface currents off the Oregon coast to forecasts of the coastal winds. The empirical statistical model is then used to produce predictions of the surface currents that are evaluated for their agreement with measured currents. Measurements...