The slow β relaxation is understood to be a universal feature of glassy dynamics. Its presence in bulk metallic
glasses (BMGs) is evidence of a broad relaxation time spectrum that extends to deep within the glassy state.
Despite the breadth of research devoted to this phenomenon, its microscopic origin is...
The influence of localized regions of intensified vertical mixing on the stratification and circulation in a large-scale ocean model is investigated with idealized numerical experiments. Numerical solutions are obtained of a closed-basin, single-hemisphere ocean model based on the planetary geostrophic equations. Mesoscale eddy effects are minimized, and vertical mixing at...
The development of new technologies in science is a balance between existence and use. There are three versions of this duality – something is built and users come, something is built and users don’t come, and, finally, potential users show up but the ballpark has not yet been built. In...
The diffusivity dependence of internal boundary layers in solutions of the continuously stratified, diffusive
thermocline equations is revisited. If a solution exists that approaches a two-layer solution of the ideal thermocline
equations in the limit of small vertical diffusivity kᵥ, it must contain an internal boundary layer that collapses
to...
Thermal structure in the seasonal thermocline at Lake Tahoe was
investigated through the analysis of vertical temperature profiles
taken in the upper 70 m during late summer stratification. Different
ranges of horizontal and temporal scales were sampled in each of
three subsets of finestructure profiles: (1) a three-week sequence
at...
A reduced-gravity model is presented of the warm-water branch of the middepth meridional overturning circulation in a rectangular basin with a circumpolar connection. The model describes the balance between production of warm water by Ekman advection across the circumpolar current, dissipation of warm water by eddy fluxes southward across the...
Two idealized, three-dimensional, analytical models of middepth meridional overturning in a basin with a Southern Hemisphere circumpolar connection are described. In the first, the overturning circulation can be understood as a “pump and valve” system, in which the wind forcing at the latitudes of the circumpolar connection is the pump...
A simple theory is presented for steady geostrophic circulation of a stratified fluid in a rectangular basin with a circumpolar connection. The interior flow obeys the β-plane Sverdrup vorticity balance, and the circulation is closed by geostrophic boundary currents. The circulation is forced by surface thermal gradients and wind-driven Ekman...
A recently proposed reduced-gravity model of the warm-water branch of the middepth meridional overturning circulation in a rectangular basin with a circumpolar connection is extended to include time dependence. The model describes the balance between gain of warm water through northward Ekman advection across the circumpolar current, loss of warm...
Polycyclic aromatic hydrocarbons (PAHs) are among the most widely known and studied environmental contaminants, originating from a range of natural and anthropogenic sources. PAHs are known to occur in the environment as complex mixtures, containing both unsubstituted PAHs, as well as a range of PAH derivatives. Among the less-studied of...
Magnetic materials can be used in modern soft robotics as a method for external stimulus actuation and motion control. By combining aspects of biology and mechanics, devices are fabricated to create a structure capable of complex movement. Applications that these devices are subject to can be broken down into four...
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....
Dissolved oxygen profiles made with an in situ polarographic
device reveal structure in the form of inversions and gradient
changes in the 100-600 meter depth zone off Oregon. Inversions
10-70 meters thick are traced over distances of 40 miles in some
cases and are bracketed by a distance of 8...
The overriding goal of this study was to provide first order estimates of dilution and tidal flushing of waste discharges released hypothetically into various Oregon estuaries during critical low flows and tides. Causal relationships between discharged wastes and subsequent estuarine response were studied. Various approaches to determine the assimilative capacity...
Remote areas are frequently homes to regional subpopulations of endangered green sea turtles (Chelonia mydas) and their essential habitat. Local communities are often the users and primary stewards of this valuable and charismatic resource. Recognizing this, a Hatohobeian community group in Palau has engaged in longterm monitoring and conservation management...
Objective: To describe associations between self-reported general health status, chronic conditions, and use of supplements containing botanicals (SCB) and describe reasons for use among U.S. adult supplement users.
Design: Cross-sectional analysis using data from the 2009-2014 National Health and Nutrition Examination Survey (NHANES). Information on self-reported dietary supplement use and...
Sardines and anchovies are small pelagic fishes that support important commercial fisheries around the world. This project reviews the inverse cyclic behavior in the abundance of these two stocks, which is a striking feature in many regions. In addition, the project used qualitative loop analysis techniques to analyze the feasible...
Satellite observations and idealized numerical studies reveal intensification of long-period (on the order of one cycle per year) waves in the western part of ocean basins. The authors explore the idea that the intensification is associated with the spatial growth of purely time periodic, but baroclinically unstable, motions. The framework...
A layered model of the study circulation in the South Pacific Ocean is constructed along the lines of Luyten, Pedlosky and Stommel, and driven by the mean annual wind stress distributions computed by Hellerman and Rosenatein. The results of the model agree quite well with published maps of topography of...
Moored observations are used to investigate the seasonal change in vertical structure of the cross-shelf
circulation at a midshelf location in the northern California Current System. A streamwise–normal coordinate
system is employed to eliminate meander- and eddy-induced biases in the cross-shelf flow that are unaccounted
for with an alternative, commonly...
The focus of this dissertation is the analysis of submesoscale and finescale features measured at oceanic fronts and the role they play in the transport of heat and salt. Two different geographical areas were used to analyze this transport: one, an area on the western side of the North Atlantic...
A simulation method using a hybrid computer is developed in
this dissertation to enhance the study of wind-driven ocean circulation.
The simulation is based on the mathematical model developed by
Ekman. Pure digital simulation is not economical due to excessive
computer time required for the solution of the partial differential...
OBJECTIVES: To improve understanding of factors that may influence disclosure of complementary and alternative medicine (CAM) use in the U.S.
DESIGN: Cross-sectional survey.
METHODS: Data are from the 2001 Health Care Quality Survey (HCQS), a nationally representative study of adults aged 18 and older living in the continental United States....
The method used to separate surface and internal tides ultimately defines properties such as internal‐tide generation and the depth structure of internal‐tide energy flux. Here, we provide a detailed analysis of several surface‐/internal‐tide decompositions over arbitrary topography. In all decompositions, surface‐tide velocity is expressed as the depth average of total...
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,...
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. DEWAR
The Florida State University, Tallahassee, Florida
R. M. SAMELSON
College of Oceanic and
Observations of turbulence, internal waves, and subinertial flow were made over a steep, corrugated continental slope off Virginia during May–June 1998. At semidiurnal frequencies, a convergence of low-mode, onshore energy flux is approximately balanced by a divergence of high-wavenumber offshore energy flux. This conversion occurs in a region where the...
Abstract: Tide-topography interactions dominate the transfer of tidal energy from large to small scales. At present, it is poorly understood how low-mode internal tides reflect and scatter along the continental margins. Here, the coupling equations for linear tides model (CELT) are derived to determine the independent modal solutions to Laplace's...
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,...
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. Dewar1, R. M. Samelson2, and G. K. Vallis3
1Florida State University, Tallahassee, FL
dewar
To investigate the dynamics of the Atlantic meridional overturning circulation (AMOC) on
timescales longer than the observational records, model-data comparisons of past AMOC variability
are imperative. However, this remains challenging because of dissimilarities between different proxy-based
AMOC tracers and the difficulty of comparing these to model output. We present an...
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: Toward a more direct
model-data comparison
Bakker, P., Govin, A., Thornalley, D. J. R., Roche, D. M
Lateral stirring is a basic oceanographic phenomenon affecting the distribution of physical, chemical, and biological fields. Eddy stirring at scales on the order of 100 km (the mesoscale) is fairly well understood and explicitly represented in modern eddy-resolving numerical models of global ocean circulation. The same cannot be said for...
The accuracy of state-of-the-art global barotropic tide models is assessed using bottom
pressure data, coastal tide gauges, satellite altimetry, various geodetic data on Antarctic ice shelves, and
independent tracked satellite orbit perturbations. Tide models under review include empirical, purely
hydrodynamic (“forward”), and assimilative dynamical, i.e., constrained by observations. Ten dominant...
Present GEK (Geomagnetic Electrokinetograph) theory is extended
to include internal waves of the lowest mode. The predicted
towed electrode GEK signal is determined to second-order for long-crested
internal waves in a finite but deep ocean. The analysis includes
the determination of GEK signatures for small amplitude and
finite amplitude interfacial...
Air-sea interaction at ocean fronts and eddies exhibits positive correlation between sea surface temperature (SST), wind speed, and heat fluxes out of the ocean, indicating that the ocean is forcing the atmosphere. This contrasts with larger scale climate modes where the negative correlations suggest that the atmosphere is driving the...
The authors present inferences of diapycnal diffusivity from a compilation of over 5200 microstructure
profiles. As microstructure observations are sparse, these are supplemented with indirect measurements of
mixing obtained from (i) Thorpe-scale overturns from moored profilers, a finescale parameterization applied to
(ii) shipboard observations of upper-ocean shear, (iii) strain as...
In 1976, John D. Isaacs proposed to use wave energy to invert the density structure of the ocean and pump deep, nutrient-rich water into the sunlit surface layers. The basic principle is simple: a length of tubing attached to a surface buoy at the top, and a one-way valve at...
Although oceanographers such as Roger Revelle are typically associated with key indicators
of anthropogenic change, he and other scientists at midcentury had very different
scientific priorities and ways of seeing the oceans. How can we join the narrative of the
triumph of mathematical, dynamic oceanography with the environmental narrative? Dynamic...
Ecosystem services (ES) represent a way to represent and quantify multiple uses, values as well as connectivity between ecosystem processes and human well-being. Ecosystem-based fisheries management approaches may seek to quantify expected trade-offs in ecosystem services due to actions such as restoration and gear restrictions, or due to changes such...
The subtidal salt balance and the mechanisms driving the downgradient salt flux in the Hudson River estuary are investigated using measurements from a cross-channel mooring array of current meters, temperature and conductivity sensors, and cross-channel and along-estuary shipboard surveys obtained during the spring of 2002. Steady (subtidal) vertical shear dispersion,...
Toxoplasma gondii, the most common parasitic infection of human brain and eye, persists across lifetimes, can progressively damage sight, and is currently incurable. New, curative medicines are needed urgently. Herein, we develop novel models to facilitate drug development: EGS strain T. gondii forms cysts in vitro that induce oocysts in...
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substituted
5,6,7,8-tetrahydroquinolin-4-one inhibits active infection (IC50, 30 nM) and cysts (IC50, 4 μM
The OSU global coupled atmosphere/ocean general circulation
model (A/O GCM) has been used to simulate the present (lxCO₂)
climate and to investigate a CO₂-induced (2xCO₂) climate change.
Previous analysis of the lxCO₂ simulation showed distinct errors in
the simulated sea surface temperature (SST) and sea ice which were
attributed primarily...
The effects of solar radiation diurnal cycle on intraseasonal mixed layer variability in the tropical Indian Ocean during boreal wintertime Madden-Julian Oscillation (MJO) events are examined using the HYbrid Coordinate Ocean Model. Two parallel experiments, the main run and the experimental run, are performed for the period of 2005–2011 with...
Heat and salt balances over the New England shelf are examined using 10 month time
series of currents, temperature, and salinity from a four element moored array and surface
heat and freshwater fluxes from a meteorological buoy. A principal result is closure of
the heat budget to 10 W m−2....
Sequences of coastal zone color scanner (CZCS) images from the offshore region adjacent to Vancouver Island, Canada, have been analyzed to estimate the time rate of decorrelation of surface phytoplankton chlorophyll pigment patterns. In these high-latitude, high-pigment areas, CZCS-derived pigment estimates were lower than those obtained from ship samples by...
No hydrologic study has previously been made of the South Slough Estuary drainage basin. Yet, since freshwater runoff is paramount to an estuary, it would seem that such a study is vital to the proper understanding -- and hence management -- of the estuary. Therefore, a brief hydrologic analysis of...
The probable pollution distribution and flushing times have been
calculated for the Columbia River Estuary, a coastal plain estuary.
The pollution distribution was determined by the fresh water fraction
and by the diffusion equation. The flushing times were calculated by
the modified tidal prism method and by the fraction of...
Isohaline coordinate analysis is used to compare the exchange flow in two contrasting estuaries, the long (with respect to tidal excursion) Hudson River and the short Merrimack River, using validated numerical models. The isohaline analysis averages fluxes in salinity space rather than in physical space, yielding the isohaline exchange flow...
The sea as a dynamic conducting medium interacts continually
with the earth' s magnetic field. The physical principles underlying
this interaction are reviewed. These results are applied to the
particular problem of towed electrodes at the sea surface. Data
using this method are then shown to be sensitive to stability...
We designed an experiment to see if turbulence induced by shear instability
could be a mechanism. Using equipment readily available we completed
an experiment from the Ice Island T-3. A sensor array of current meters
and thermistors (described later on) was suspended beneath the sea ice of
Colby Bay, T-3,...
The diffusion process in a variable density, turbulent
flow is a factor which greatly influences the waste
disposal characteristics of tidal estuaries. Waste disposal
from cities and industries, is posing an increasing
threat to the estuarine environment. Accurate prediction
of the effects of proposed waste outfalls in well-mixed
estuaries (which...
Observations of wind, currents, sea level and hydrography
obtained during the 1972 Coastal Upwelling Experiment (CUE-I) are
described. Only phenomena with periods longer than a day are considered.
One section describes the changes observed during a period
of variable winds in early July 1972. Another describes a ribbon of
relatively...
The evolution of the covariance of two tracers involves a quantity called codissipation, proportional to the covariance of the gradients of the two tracers, and analogous to the dissipation of tracer variance. The evolution of the variance of a composite tracer—a linear combination of two simple, primary tracers—depends on the“composite...
Current and hydrographic observations from the Coastal Mixing and Optics experiment moored array, deployed from August 1996 through June 1997, are used to describe the velocity variability and evaluate the dynamics of circulation over the New England shelf on timescales ranging from a few days to several months. Subtidal (days...
Reporter gene transactivation by human p53 is inhibited in budding yeast lacking the TRR1 gene encoding thioredoxin reductase. Thioredoxin reductase specifically catalyzes the NADPH-dependent reduction of thioredoxin. Thioredoxin provides a source of electrons for disulfide reduction in various cellular processes. Reduction of disulfides within the cell can be accomplished by...
An experimental investigation of the thermohaline, diffusive interface between convecting layers, with heat fluxes more similar to natural fluxes than in previous studies, shows that the formula suggested by Huppert (1971) for the dependence of heat flux on interface stability cannot be extrapolated to stability numbers higher than seven and...
An analytical two-layer model consisting of a time-dependent stratified
boundary layer topped by stratified free flow is developed in order
to study atmospheric boundary layer production of vertical motion. To
avoid use of a constant eddy viscosity, the boundary layer equations are
layer-integrated over a fixed depth, and surface stress...
Within composition studies, rhetorical genre studies (RGS) and labor-based grading (LBG) are engaged in similar projects that consider students not only as individuals but also as always part of a community; as such, both have worked to understand how students learn, how students value themselves and their work, and how...
Altimetric data from the TOPEX/POSEIDON mission will be used for studies of global ocean circulation and marine geophysics. However, it is first necessary to remove the ocean tides, which are aliased in the raw data. The tides are constrained by two distinct types of information: the hydrodynamic equations which the...
The Geochemical Ocean Sections Study (GEOSECS) program has carried
out an intensive study of physical and chemical parameters in the
Pacific and Atlantic Ocean. As a result, an enormous collection of high
quality data has been amassed for these two oceans. To analyze the
Pacific data, fourteen stations extending from...
This article investigates the origins of the variability of the Malvinas Current (MC)
transport using the results of an eddy-permitting ocean general circulation model. First, the
dynamical links between the variabilities of the MC and the Antarctic Circumpolar
Current (ACC) transports at the Drake Passage are established. Time series analyses...
A method is described for determining the absolute dynamic topography of the sea surface. Using hydrographic and wind data obtained in 1963, the surface topography and the horizontal and vertical mass transports off the southeast Arabian coast during the summer monsoon are calculated. As indicated by the calculations, upwelling occurs...
The connectivity among straits of the northwest Pacific marginal seas is investigated with a primitive-equation ocean circulation model simulated for 10 years from 1994 to 2003. Over the simulation interval the temporal and spatial means and variations of the model sea surface temperature are comparable to those of the satellite...
The tidally varying circulation, stratification, and salt flux mechanisms are
investigated in a shallow salt wedge estuary where fluvial and tidal velocities are large and
the steady baroclinic circulation is comparatively weak. The study integrates field
observations and numerical simulations of the Merrimack River estuary. At moderate to
high discharge...
This report vas prepared at this time at the suggestion or the Director of Research of the Oregon Fish Commission. Most of the data upon which it is based were collected by Mr. L. D. Marriage and his assistants of the Oregon Fish Commission. These data are scheduled to be...
This investigation is an exploration of the use of inherent optical properties towards further elucidation of coastal circulation processes occurring on the continental shelf and slope in the Middle Atlantic Bight, south of Cape Cod Massachusetts, during 14-Aug to 1-Sep 1996 and 25-Apr to 15-May 1997. Assessing the possibility of...
A summary of the first. year's results in a program of current measuring techniques employing the electromagnetic method is presented. The data was taken on hydrographic survey cruises ranging to 165 miles offshore from Oregon. The measurements in this first phase consist solely of those taken by the method of...
A tidally and cross-sectionally averaged model based on the temporal evolution of the quasi-steady Hansen and Rattray equations is applied to simulate the salinity distribution and vertical exchange flow along the Hudson River estuary. The model achieves high skill at hindcasting salinity and residual velocity variation during a 110-day period...
Vertical transports of plankton, momentum, heat, and turbulence are modeled. A novel integration of high resolution turbulence and biophysical modeling is used to show the influence of a Kelvin-Helmholtz instability on the vertical migration of simple gyrotactic organisms. A viscous limit on mixing driven by shear turbulence is proposed. Large...
This research presents an analysis of thermal stratification in the reactor cold leg of the Advanced Plant Experiment-Combustion Engineering (APEX-CE). This phenomenon may be a precursor leading to a Pressurized Thermal Shock (PTS) event in a nuclear power plant. This work was performed in support of the U.S. Nuclear Regulatory...
Small, aloricate ciliates with equivalent spherical cell diameters <20 µm (biovolume <4,000 µm3) compose, on average, 4–57% of the total biomass of heterotrophic (apochlorotic) nanoplankton in diverse marine systems. Biomass production of nanoplanktonic ciliates in a southeastern U.S. estuary was also a significant part of the total production of heterotrophic...
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...
The oceanic phenomenon of upwelling along the Oregon coast is
examined. Upwelling in both the open ocean and coastal regions is
discussed. An idealized model is used, envisaging the ocean off
Oregon to consist of homogeneous surface and deep layers separated
by a pycnocline. The equations of motion are solved...
The local and remote sources of variability of the South Atlantic Ocean are investigated using a set of numerical experiments and satellite data. A global, eddy-permitting, numerical simulation is analyzed to investigate the dynamical links between the Antarctic Circumpolar Current (ACC) and the Malvinas Current (MC). The model results indicate...
The reason for the initial rise in atmospheric
CO₂ during the last deglaciation remains unknown. Most recent
hypotheses invoke Southern Hemisphere processes such
as shifts in midlatitude westerly winds. Coeval changes in
the Atlantic meridional overturning circulation (AMOC) are
poorly quantified, and their relation to the CO₂ increase is
not...
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possibility of rapid transitions between them
(Stommel, 1961). Moreover, AMOC variations are consistent
with
The intensification of cyclonic winds in the Gulf of Alaska
during winter belies the relatively constant geostrophic circulation
as being indicative of actual flow. In the absence of direct current
measurements, effects of various meteorological phenomena have
been eliminated from monthly mean sea level measurements over the
decade 1950 to...
Walking is the most popular type of physical activity among the adult population in the United States including individuals with disabilities. Considering the popularity of the activity, walking-related physical activity should be a focus of health promotion campaigns among the adult population. Rhodes and Nigg (2011) suggested that employing theory-based...
Turbulent flow with suspended, non-spherical particles can be found in nature and several industrial applications. Although turbulence with dispersed spherical particles has been studied extensively, modeling the dynamics of non-spherical particles in a turbulent flow has not been studied extensively. Motion of spherical particles in complex flows is typically captured...
The ability to determine a bulk estuarine turnover timescale that is well defined under realistic conditions is in high demand for estuarine research and management. We compare how turnover timescales vary with tidal and river forcing from idealized forcing scenarios using a three-dimensional circulation model of the Yaquina Bay estuary...
The principal salinity extrema and extremum surfaces of the
world ocean are described by the analysis and plotting of data from
885 hydrographic stations in the three major oceans, the Southern
Ocean, and the American Mediterranean Sea. The distributions of
salinity, temperature, depth, and density along the extremum surfaces,
plotted...
We consider long planetary waves of annual period linearized about a steady, wind-driven subtropical (ST) gyre circulation. The circulation divides the gyre into an eastern zone (EZ) where only the surface layer is in steady motion and a western zone (WZ) where both the surface and the middle layer are...
This thesis presents the steps that were taken to develop thematic findings using data from a qualitative study. Using a grounded approach, the study focused on qualitatively exploring Mexican origin caregivers' conceptualizations of elder caregiving in terms of role functioning, social norms, cultural beliefs, and familial obligations. Data collected from...
Tensor mathematics provides a powerful language to visualize and analyze physical phenomena. In the last three decades, tensors have been used in various application areas. The visualization and analysis of tensors fields have seen much advance, both in 2D and 3D. However, the physical interpretations of the topological analysis are...
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5.3 Temperature distribution at 300 m depth from the NODC dataset showing
the occurrence of the
Two Autonomous Underwater Vehicle Gliders have alternated continuous sampling of a 45-nautical mile transect line (the Newport Hydrographic Line) across the Oregon continental shelf since April, 2006. Strong currents (>25cm/s) push the gliders off their trajectories as they survey this transect line, preventing them from sampling the historically occupied stations...
Direct measurements of vertical water motions were made in
the Oregon coastal region during the 1972 summer upwelling season.
The instruments used were the Webb-Voorhis vertical current meters
which are freely drifting neutrally buoyant floats capable of sensing
vertical motion. It was found that in the region studied, water tended...
Thermohaline interleaving is an important mechanism for laterally fluxing salt, heat, and nutrients between oceanic water masses. Interleaving is driven by a release of potential energy resulting from the vastly differing diffusivities of heat and salt in seawater. The flows are composed of stacked intrusions that flux more buoyant and...
INTRODUCTION: Between 2004 and 2010, the number of home births in the United States rose by 41%, increasing the need for accurate assessment of the safety of planned home birth. This study examines outcomes of planned home births in the United States between 2004 and 2009.
METHODS: We calculated descriptive...
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sensitization 41 (0.2)
Multiple gestation, n (%) 60 (0.4)
Breech presentation,m n (%) 222 (1.3)
Abbreviations