We have measured ³He/⁴He ratios and He and Ne concentrations on a suite of 24 basalt glasses from the neovolcanic zone of the Juan de Fuca Ridge (JdFR) from 44.6°N near the Blanco Transform up to 48.0°N on the Endeavour Segment. The helium isotope ratios exhibit a clear geographic variation,...
The Vizcaino block is an anomalously shallow region of the western U.S continental margin located southwest of the Mendocino triple junction. It originated as part of the accretionary prism of the North America plate and was transferred to the Pacific plate in the Miocene as the Pacific-North America plate boundary...
Models of magnetic and gravity anomalies along two E-W transects offshore central Oregon, one of which is coincident with a detailed velocity model, provide quantitative limits on the structure of the subducting oceanic crust and the crystalline backstop. The models indicate that the backstop-forming western edge of the Siletz terrane,...
Analytical and numerical models are used to study the effects of a meridional ridge on the propagation of barotropic Rossby waves produced by distant wind stress forcing. The analytical model illustrates the qualitative aspects of the problem by solving a simplified form of the potential vorticity equation. The analytical results...
The sensitivity of the tropics to climate change, particularly the amplitude of glacial‐to‐interglacial changes in sea surface temperature (SST), is one of the great controversies in paleoclimatology. Here we reassess faunal estimates of ice age SSTs, focusing on the problem of no‐analog planktonic foraminiferal assemblages in the equatorial oceans that...
Benthic foraminiferal δ¹³C data from site 502 in the Caribbean Sea (sill depth 1800 m) indicate that throughout the past 2.6 m.y., glacial δ¹³C values in the middepth Atlantic were higher during glaciations than interglaciations. This is interpreted as indicating a greater proportion of Upper North Atlantic Deep Water (UNADW)...
We evaluate the reliability of statistical estimates of sea surface temperature (SST) derived from planktonic foraminiferal faunas using the modern analog method and the Imbrie‐Kipp method. Global core top faunas provide a calibration data set, while modern sediment trap faunas are used for validation. Linear regression of core top predicted...
Relative humidity (RH) measurements acquired in orographic wave cloud and cirrus environments are used to investigate the temperature‐dependent RH required to nucleate ice crystals in the upper troposphere, RHnuc(T). High ice‐supersaturations in clear air—conducive to the maintenance of aircraft contrails yet below RHnuc and therefore insufficient for cirrus formation—are not...
A temperature spectrum if heterogeneous freezing nuclei concentrations in continental air in the upper troposphere was determined based on airborne measurements. Numerical model simulations incorporating ice formation by heterogeneous and homogeneous freezing of deliquesced soluble aerosol particles were performed to investigate the effect of the heterogeneous freezing nuclei were predicted...
Meanders of the shelf break front in the Mid-Atlantic Bight (MAB) during April and May of 1997 were associated with chlorophyll enhancement along a hydrographic and a topographic feature. The hydrographic feature was the surface outcrop of the front, which ranged from ~10 to >100 km seaward of the shelf...
The majority of bacteria suspended in seawater do not appear to be metabolically active or in good physiological condition as assessed by various methods. We tested the idea that a large fraction of ‘inactive’ bacterial cells can become ‘active’ with respect to detectable cell-specific electron transport system (ETS) activity, determined...
The location of the Antarctic Polar Front (PF) was mapped over a 7-year period (1987-1993) within images of satellite-deprived sea surface temperature. The mean path of the PF is strongly steered by the topographic features of the Southern Ocean. The topography places vorticity constraints on the dynamics of the PF...
Degradation and release to solution of intracellular dimethylsulfoniopropionate (DMSP) from Emiliania huxleyi 370 was observed during grazing by the heterotrophic dinoflagellate Oxyrrhis marina in 24 h bottle incubations. Between 30 and 70 % of the lost algal DMSP was metabolized by the grazers without production of dimethylsulfide (DMS) when grazer...
A Lagrangian drifter was deployed in a cold filament off northern California as part of the Coastal Transition Zone program. The drifter was equipped with an optical package (consisting of a spectroradiometer, a fluorometer, and a beam transmissometer) suspended at 8.5-m depth and a water sampler suspended at 16.3-m depth....
The sorbed gases at all four Ocean Drilling Program Leg 139 sites (855, 856, 857, and 858) showed the unmistakable presence of thermogenic hydrocarbons. No indication of abiogenic gas was found. The evidence for the thermogenic hydrocarbons includes elevated contents of higher hydrocarbons (i.e., C₁/[C₂ + C₃] ca. 2-20), δ¹³CCH₄...
The shallow sections of most holes drilled during Ocean Drilling Program Leg 139 contain alkenones derived from prymnesiophyte algae. The alkenones indicate a paleotemperature of the photic zone in the upper ocean during primary carbon fixation of 7°-15°C, with an average of 10.7°C. Based on laboratory hydrous pyrolyses these alkenones...
Carbonate nodules and associated sediments from Ocean Drilling Program Leg 139 sites of the Middle Valley, Juan de Fuca Ridge, were studied using a combination of inorganic and organic geochemical techniques. The mineralogy and stable isotopic compositions defined three types of nodules, reflecting the conditions of carbonate precipitation. Nodule ingrowth...
The subduction of the oceanic spreading center at the Chile Triple Junction is marked by a substantial thermal perturbation
and marked changes in the hydrogeologic and aqueous geochemical regimes in the overthrust plate. Ridge subduction substantially
changes the fluid chemistry in the wedge through variably hydrating the oceanic basement, accretionary...
Oxygen and strontium isotopic composition of sedimentary pore fluids obtained by drilling at the Chile Triple Junction have been used to obtain information on the diagenesis and transport mechanisms of fluids. Samples were collected from three sites located on an east-west transect of the pre-collision zone (Sites 859, 860, and...
Ocean Drilling Program (ODP) Leg 138 was designed to study the late Neogene paleoceanography of the equatorial Pacific Ocean at time scales of thousands to millions of years. Crucial to this objective was the acquisition of continuous, high-resolution sedimentary records. It is well known that between successive advanced piston corer...
Sediment spectral reflectance measurements were generated aboard the JOIDES Resolution during Ocean Drilling Program Leg 162 shipboard operations. The large size of the raw data set (over 1.3 gigabytes) and limited computer hard disk storage space precluded detailed analysis of the data at sea, although broad band averages were used...
Benthic foraminifer and δ¹³C data from Site 849, on the west flank of the East Pacific Rise (0°11'N, 110°3l'W; 3851 m), give relatively continuous records of deep Pacific Ocean stable isotope variations between 0 and 5 Ma. The mean sample spacing is 4 k.y. Most analyses are from Cibicides wuellerstorfi>...
A series of automated tests is developed for tower and aircraft time series to identify instrumentation problems, flux sampling problems, and physically plausible but unusual situations. The automated procedures serve as a safety net for quality controlling data. A number of special flags are developed representing a variety of potential...
Accurate ship velocity is important for determining absolute currents from acoustic Doppler current profiler (ADCP) measurements. In this paper, the authors describe the application of two methods to improve the quality of ship velocity estimates. The first uses wide-area differential global positioning system (WADGPS) navigation to improve ship positioning. During...
Several simple laboratory experiments have been conducted to study the dynamic behavior of the vector-averaging current meter (VACM) compass and vane follower. They demonstrate that the behavior of the compass and vane follower can be modeled as a damped linear harmonic oscillator for small-amplitude forcing. The combined eddy-current and bearing-friction...
We examine and compare near-forward light scattering that is caused by turbulence and typical particulate assemblages in the ocean. The near-forward scattering by particles was calculated using Mie theory for homogeneous spheres and particle size distributions representative of natural assemblages in the ocean. Direct numerical simulations of a passive scalar...
Calculation of vector winds from spaceborne fan-beam scatterometers requires that backscatter measurements from different antennas be relatively calibrated to high accuracy. A method is developed to perform postlaunch antenna calibration using global mean ocean backscatter measurements in conjunction with estimates of the statistical distribution of near-surface wind velocity and the...
Wind-generated inertial currents can radiate from the mixed layer as horizontally and vertically propagating new-inertial internal gravity waves. To study the timescale of the decay of mixed layer energy and the magnitude of the energy transfer to the ocean below, the authors developed a numerical, linear model on a β...
Motivated by satellite altimeter observations of enhanced sea level variability near steep topographic slopes in the Southern Ocean, effects of topography on the spatial distribution of mesoscale eddies and on eddy–mean flow interaction are investigated using a two-layer, wind-forced, quasigeostrophic channel model. The principal topography, a zonal ridge with a...
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...
Appearing in this issue of the Journal of Physical Oceanography are three papers that present new observations of a distinct, narrow band, and diurnally varying signal in temperature records obtained in the low Richardson number shear flow above the core of the equatorial undercurrent. Moored data suggest that the intrinsic...
We undertook an interlaboratory comparison of techniques used to extract and analyze trapped gases in ice cores. The intercomparison included analyses of standard reference gases and samples of ice from the Greenland Ice Sheet Project 2 (GISP2) site. Concentrations of CO₂, CH₄, the δ¹⁸O of O₂, the δ¹⁵N of N₂,...
The oceanic circulation near the eastern margin of the African continent is dominated by the poleward flow of the Agulhas Current. The Agulhas Current separates from the African coast near the southern tip of the continent, makes an abrupt turn to the east (known as the Agulhas Retroflection), and flows...
Datasets taken near the coasts of Peru and California have been analyzed to explore the evidence of a correlation between the high frequency (period < 10.8 hour) and low frequency (period > 4 day) motions. A large part of the high frequency current is consistent with internal wave dynamics. They...
The European Centre for Medium-Range Weather Forecasts (ECMWF) and Institut Francais Pour la Recherche et l’Exploitation de la Mer European Remote-Sensing Satellite, named IFR2, surface wind velocity data products are compared during July 1995 over the Arabian Sea. Substantial differences were found. The central positions of the maximum isotach were...
Two-dimensional, primitive equation model studies of wind-forced flow over a continental shelf Show that, under upwelling conditions, high levels of near-inertial wave energy are found in the interior over the shelf. The regions of elevated wave energy, with maximum wave amplitudes of around ±0.2 m s⁻¹, persist for up to...
An improved bound is obtained for the radius of the semicircle in the complex plane containing the complex phase speed of baroclinically unstable plane wave disturbances. In the limit of long waves, this bound contains a term increasing with β and decreasing with the mean stratification (i.e., decreasing with the...
The generalized inverse is constructed for a nonlinear, single-layer quasigeostrophic model, together with initial conditions and a finite number of interior data. With the exception of doubly Periodic boundary condition all constraints are weak. The inverse minimizes a penalty functional that is quadratic in the errors in prior estimates of...
Analysis of simulations performed with the NASA/Ames Mars GCM shows that under dusty conditions the Northern Hemisphere winter solstice circulation becomes characterized by a zonally averaged state in which the potential vorticity at upper levels is very small outside of high latitudes. The available observational data-in particular the 15-µm observations...
As part of a program to improve understanding of the dynamics of the complicated, vigorous eddy and jet flow fields recently observed over the continental shelf and slope, we investigate the potential of intermediate models for use in both process and data assimilation studies of these flows. Intermediate models incorporate...
Motivated by the general objective of pursuing oceanographic process and data assimilation studies of the complex, nonlinear eddy and jet current fields observed over the continental shelf and slope off the west coast of the United States, we investigate the use of intermediate models for that purpose. Intermediate models contain...
The authors reconsider the problem of estimating the sensible heat transfer at the earth's surface from direct measurements of turbulent fluxes in the atmospheric boundary layer. For simplicity, only horizontally homogeneous conditions are considered for a thin atmospheric layer containing no liquid water, adjacent to the earth's ground surface. Applying...
The vertical structure of coastal-trapped disturbances in several idealized models of a stably stratified lower atmosphere is examined. The vertical structure and phase speeds of the trapped modes depend on the resting stratification and the height of the orographic step. The presence of a stable layer above the boundary layer...
Global 1° × 1° climatologies of the first baroclinic gravity-wave phase speed c¹ and the Rossby radius of deformation λ1 are computed from climatological average temperature and salinity profiles. These new atlases are compared with previously published 5° × 5° coarse resolution maps of λ₁ for the Northern Hemisphere and...
Bulk aerodynamic formulas are applied to meteorological data from low-altitude aircraft flights to observational estimates of the subgrid enhancement of momentum, sensible heat, and latent heat the atmospheric–oceanic boundary in light wind, fair weather conditions during TOGA COARE Global Atmosphere Coupled Ocean–Atmosphere Response Experiment). Here, subgrid enhancement the contributions of...
A strong, isolated October storm generated 0.35–0.7 m s⁻¹ inertial frequency currents in the 40-m deep mixed layer of a 300 km×300 km region of the northeast Pacific Ocean. The authors describe the evolution of these currents and the background flow in which they evolve for nearly a month following...
Although the process of restratification of the ocean surface layer at the equator following nighttime convection is similar in many ways to the process at midlatitudes, there are important differences. A composite day calculated from 15 days of consistent conditions at 140°W on the equator was compared with midlatitude observations...
This study examines the bulk aerodynamic method for estimating surface fluxes of heat and moisture using the surface radiative temperature. The surface radiative temperature is often the only available surface temperature from field measurements. Models typically predict heat fluxes from the surface radiative temperature computed from the surface energy balance....
Conductivity‐temperature‐depth surveys during 1988 encountered strong baroclinic jets that were evident in acoustic Doppler current profiler and hydrographic data. During June and July 1988 a filament with high surface nitrate, high chlorophyll, abundant populations of neritic centric diatoms, and higher rates of primary production was evident perpendicular to the coast...
Three upward looking acoustic Doppler current profilers (ADCP) were deployed beneath meteorological buoys in the Gulf of Tehuantepec, Mexico, during winter 1988-1989. Hourly averaged wind speed data from the buoys and from ship when in the vicinity were compared with surface acoustic backscatter intensity recorded at the ADCPs. The backscatter...
Since the early surveys carried out by the Eastern Tropical Pacific (EASTROPIC) and Scripps Tuna Oceanographic Research (STOR) projects in the tropical Pacific off Mexico, the northerly winds which blow over the Gulf of Tehuantepec were described as an Important factor controlling the dynamics of this coastal ocean. In January-February...
The aerodynamic temperature is required for prediction of the surface heat flux using Monin-Obukhov similarity. This "fictitious" temperature is not systematically equal to the actual air temperature near the surface and is not directly available from observations or in numerical models. The aerodynamic temperature is normally replaced with either the...
This study examines the dependence of the computed drag coefficient on wind speed, stability, fetch, flux sampling problems, and method of calculation of the drag coefficient. The analysis is applied to data collected at a tower 2 km off the coast of Denmark during the Risø Air Sea Experiment (RASEX)....
We describe observations of tropical stratospheric water vapor q that show clear evidence of large‐scale upward advection of the signal from annual fluctuations in the effective “entry mixing ratio” qE of air entering the tropical stratosphere. In other words, air is “marked,” on emergence above the highest cloud tops, like...
Measurements of stratospheric water vapor by the Microwave Limb Sounder aboard the Upper Atmosphere Research Satellite show that in the tropical lower stratosphere, low‐frequency variations are closely related to the annual cycle in tropical tropopause temperatures. Tropical stratospheric air appears to retain information about the tropopause conditions it encountered for...
Air and trace gases are exchanged between the stratosphere and the troposphere on a variety of scales; but general circulation models (GCMs) are unable to represent the smaller scales. It would be useful to see how a GCM represents stratosphere-troposphere exchange (STE), both to identify possible model deficiencies which would...
Broadband body waves recorded at 15 digital seismic stations worldwide are used to study the rupture process of the May 23, 1989 Macquarie Ridge earthquake. The centroidal solution (strike 211°, dip 86°, rake 180°, and depth of 10 km below the seafloor) indicates shallow rupture with pure right-lateral strike-slip motion...
Sea surface temperature (SST) estimates were made using data for C37‐39 alkenones analyzed in modern and glacial‐age intervals of sediment cores collected along an east‐west (∼42°N from 125° to 132°W) and a north‐south (41°–33°N) transect of the California Current system (CCS). The prymnesiophyte biomarker results suggest that surface waters warmed...
Previous work has demonstrated selective feeding by bacterivorous protists on the of prey size. Other prey characteristics may also affect protist grazing rates. In this relative uptake rates of fluorescently labeled bacterial (FLB) cells made from starving bacteria (S-FLB), and of live-stained motile vs non-motile bacteria by marine We also...
On Oregon coastal rocky shores, filter‐feeders were relatively abundant and macrophytes were relatively scarce at Strawberry Hill, whereas opposite abundance patterns occurred at Boiler Bay. To determine whether nearshore oceanographic differences were associated with these patterns, we made shore‐based measurements of nutrient and Chl a concentrations. We used a three‐level...
The axial component of the oceanic tidal angular momentum (OTAM) has been demonstrated to be responsible for most of the diurnal and semidiurnal variations in Earth's rotational rate. In this paper we study the equatorial components of OTAM and their corresponding effects on the orientation of Earth's rotational axis, or...
From measurements of the energy‐containing scales of turbulence in the ocean thermocline, two new formulations are examined: (1) an inviscid estimate for the viscous dissipation rate of turbulent kinetic energy and (2) a mixing length estimate for the turbulent heat flux. These formulations are tested using coincident measurements of the...
This paper presents a series of observing system simulation experiments (OSSEs) which are intended as a design study for a proposed array of instrumented moorings in the tropical Atlantic Ocean. Fields of TOPEX/Poseidon sea surface height anomalies are subsampled with the goal being reconstruction of the original fields through the...
Ecological effects of populations of the salp Cyclosalpa bakeri were studied in late summer of 1984, 1987 and 1988 dunng the Subarctic Pacific Ecosystem Research Station P in the northeast Pacific. Salps occurred largely in the top 60 m, with from 76 to 3621 mg C m⁻². Three approaches were...
The spectral composition of internal gravity waves under the Arctic pack ice during the Arctic Internal Wave Experiment (AIWEX) was found to be strikingly different from observations at lower latitudes. Time series of vertical displacement were inferred from horizontal and vertical arrays of temperature and conductivity sensors. Frequency spectra indicate...
At the submerged margins of the North Atlantic, andesitic to dacitic and basaltic volcanic rocks occur together. The silicic rocks were derived by processes requiring the presence of continental crust (crustal anatexis and/or contamination of mafic magmas) while the majority of the basaltic lavas had little or no contact with...
In this study, we use a time domain numerical model based on the fully nonlinear extended Boussinesq equations [Wei et al., 1995] to investigate surface wave transformation and breaking-induced nearshore circulation. The energy dissipation due to wave breaking is modeled by introducing an eddy viscosity term into the momentum equations,...
Optical oceanography models of attenuation and scattering properties often contain simple spectral relationships. Electromagnetic theory, however, predicts fluctuations in the spectra of the attenuation coefficients and scattering properties of substances at wavelengths near an absorption peak. We have modeled these effects for phytoplankton using homogeneous, two‐layered, and three‐layered sphere models...
Monte Carlo simulations are carried out to determine the error in the inversion of backscattering from remotely sensed reflectance when geometrical shape factors of the light field are assumed to be unity. The results show that error in backscattering inversion can vary from a 40% overestimation to a 20% underestimation...
The relationships between beam attenuation, absorption, suspended particle concentration, size distribution and pigment content are examined for a region where the particle concentration and pigment maxima are widely separated. Mie scattering analyses are performed on this data to predict the profiles of backscattering. It was found that absorption and scattering...
The Moderate Resolution Imaging Spectroradiometer (MODIS) will add a significant new capability for investigating the 70% of the Earth's surface that is covered by oceans, in addition to contributing to the continuation of a decadal scale time series necessary for climate change assessment in the oceans. Sensor capabilities of particular...
Analysis of multichannel seismic reflection profiles reveals that listric normal faulting is widespread on the northern Oregon and Washington continental shelf and upper slope, suggesting E-W extension in this region. Fault activity began in the late Miocene and, in some cases, has continued into the Holocene. Most listric faults sole...
The wave-induced velocity field in the nearshore is composed of contributions from incident wind waves (f > 0.05 Hz), surface infragravity waves (f < 0.05 Hz, lkl < (σ²/gβ) and shear waves (f < 0.05 Hz, lkl > σ²/gβ), where ƒ is the frequency, σ = 2πf, k is the...
A form of the linear, inviscid shallow water wave equation which includes alongshore uniform, but cross-shore variable, longshore currents and bathymetry is presented. This formulation provides a continuum between gravity waves (either leaky or edge waves) on a longshore current, and the recently discovered shear waves. In this paper we...
Hydrothermal vents appear to be the tip of the subsurface biosphere in the ocean crust. The primary prducers in this biosphere are prokaryotes that tolerate a wide variety of physical and chemical conditions and are versatile in their use of inorganic compounds to drive metabolism. A synthesis of chemical and...
Temperature‐depth data from six boreholes in western Utah and nine boreholes in southeastern Utah are reanalyzed for evidence of ground surface temperature (GST) histories. We invert the temperature‐depth data using the functional space inverse algorithm of Shen and Beck [1991, 1992] which we prefer over previous inversions of these data...
Based on a long-term set of observations and measurements at a station in the subtropical North Pacific Ocean, it now appears that contemporaneous rates of primary production in low-nutrient open ocean regions and perhaps in the ocean as a whole may be greater than had been considered in field studies...
A system of quasilinear degenerate parabolic equations arising in the modeling of diffusion in a fissured medium is studied. There is one such equation in the local cell coordinates at each point of the medium, and these are coupled through a similar equation in the global coordinates. It is shown...
A general porous-medium equation is uniquely solved subject to a pair of boundary conditions for the trace of the solution and a second function on the boundary. The use of maximal monotone graphs for the three nonlinearities permits not only the inclusion of the usual boundary conditions of Dirichlet, Neumann,...
The distributed-microstructure model for the flow of single phase
fluid in a partially fissured composite medium due to Douglas-Peszyńska-Showalter [12] is extended to a quasi-linear version. This model contains the
geometry of the local cells distributed throughout the medium, the flux exchange
across their intricate interface with the imbedded fissure...
We have measured voltage-current characteristics for YBa₂Cu₃O₇ thin films in magnetic fields from 5
T to ambient, including some in the millitesla range. In all cases, the resistivity —current density isotherms
can be separated into two classes: those which exhibit upward curvature, and have constant
resistivity at low currents, and...
We have measured sweep-rate-dependent magnetization hysteresis curves of thin-film Bi₂Sr₂CaCu₂O[subscript 8+δ] using a Hall probe magnetometer in an unconventional geometry. We find a structure in the response well below the three-dimensional to two-dimensional crossover field. The observed strong enhancement of the perpendicular field component’s creep rate in the presence of...
We have investigated the depinning process of magnetic flux vortices in twinned crystals of YBa₂Cu₃O₇₋δ in intermediate applied magnetic fields parallel to the crystallographic c axis through precise resistivity measurements before and after fast-neutron irradiation. Of particular interest for each field is the power-law dependence of the electric field on...
Metal-plate-connected wood trusses with semi-rigid joints were investigated by the matrix method of structural analysis. The element-stiffness matrix and fixed-end forces of an individual member with one or both ends semi-rigid were derived as modifications of the idealized cases. The case of unequal elastic connections at two ends of a...
A commercially available, three-dimensional finite-element analysis software was used to model the load-displacement
behavior of metal-plate-connected (MPC) joints in wooden trusses. Model features included consideration
of material properties, teeth-to-grain-to-direction-of-force orientation, wood-to-wood interaction, and gaps between wood
members. To simulate wood-to-plate interaction, the main feature of the model, each tooth of...
A previously developed, three-dimensional (3-D) finite-element (FE) joint model and several two-dimensional
(2-D), beam-element based FE models with different joint-stiffness assumptions (pinned, rigid, and semi-rigid) were used
to analyze the full-scale behavior of a metal-plate-connected (MPC) wood scissors truss. The truss displacement and
force results were investigated for sensitivity with...
We contrast the two approaches to ‘‘classical’’ signature change used by Hayward with the one used by us (Hellaby and Dray). There is (as yet) no rigorous derivation of appropriate distributional field equations. Hayward’s distributional approach is based on a postulated modified form of the field equations. We make an...
We consider the (massless) scalar field on a two-dimensional manifold with metric that changes signature from Lorentzian to Euclidean. Requiring a conserved momentum in the spatially homogeneous case leads to a particular choice of propagation rule. The resulting mix of positive and negative frequencies depends only on the total (conformal)...
The divergence theorem as usually stated cannot be applied across a change of signature unless it is reexpressed to allow for a finite source term on the signature change surface. Consequently all conservation laws must also be ‘‘modified,’’ and therefore insistence on conservation of matter across such a surface cannot...
We derive conditions for rotating particle detectors to respond in a variety of bounded spacetimes and
compare the results with the folklore that particle detectors do not respond in the vacuum state appropriate to
their motion. Applications involving possible violations of the second law of thermodynamics are briefly
addressed.
The divergence theorem in its usual form applies only to suitably smooth vector fields. For vector fields which are merely piecewise smooth, as is natural at a boundary between regions with different physical properties, one must patch together the divergence theorem applied separately in each region. We give an elegant...
A parametric manifold is a manifold on which all tensor fields depend on an additional parameter, such as time, together with a parametric structure, namely a given (parametric) one‐form field. Such a manifold admits natural generalizations of Lie differentiation, exterior differentiation, and covariant differentiation, all based on a nonstandard action...
A parametric manifold can be viewed as the manifold of orbits of a (regular) foliation of a manifold by means of a family of curves. If the foliation is hypersurface orthogonal, the parametric manifold is equivalent to the one‐parameter family of hypersurfaces orthogonal to the curves, each of which inherits...
We examine some of the subtleties inherent in formulating a theory of spinors on a manifold with a smooth degenerate metric. We concentrate on the case where the metric is singular on a hypersurface that partitions the manifold into Lorentzian and Euclidean domains. We introduce the notion of a complex...
We discuss Einstein’s field equations in the presence of signature change using variational methods, obtaining a generalization of the Lanczos equation relating the distributional term in the stress tensor to the discontinuity of the extrinsic curvature. In particular, there is no distributional term in the stress tensor, and hence no...
A maternally transmitted, noninfectious disease known as the Cayuga syndrome caused 100% mortality in larval offspring of wild-caught landlocked Atlantic salmon Salmo salar from several of New York's Finger Lakes. Survival of lake trout Salvelinus namaycush from Lakes Erie and Ontario was also impaired, but not until yolk absorption was...
We describe a disease syndrome that afflicts larval, landlocked Atlantic salmon Salmo salar from Cayuga Lake, one of central New York's Finger Lakes. Mortality associated with the “Cayuga syndrome” is 98–100%. Death usually occurs between 650 and 850 centigrade degree-days after fertilization, approximately 2–4 weeks before yolk resorption is complete....
The “Cayuga syndrome” is a maternally transmitted, naturally occurring thiamine deficiency that causes 100% mortality of larval landlocked Atlantic salmon Salmo salar in several of New York's Finger Lakes, Results of multiyear studies to qualify and quantify the neurobehavioral and gross pathological signs of this condition are described, Affected sac...
Eight spontaneous orocutaneous papillomas of adult, wild-caught brown bullheads Ictalurus
nebulosus and 4 anatomically matching control tissue samples were examined by electron
microscopy. Ultrastructural characteristics of normal and neoplastic Malpighian epithelial cells were
compared and neoplastic cells were described. Normal Malpighian epithelial cells of brown bullheads
were similar to those...