Thoreau's experiment at Walden Pond reveals two potentially contradictory desires, one of which can be linked to agrarian reform, and the other to ecological knowledge. Thoreau conceived his Walden project in a cultural milieu in which agrarian reform was receiving incrasing attention, and the Walden experiments was, in important ways,...
The results of a new multispectral infrared retrieval scheme for obtaining fractional cloud cover and 11-μm emissivity are compared with those of the spatial coherence method which obtains fractional cloud cover assuming that the clouds are opaque at infrared wavelengths. Both methods are applied to 4-km NOAA advanced very high...
From 25 April through 30 October 1992, I conducted 14 waterbird and raptor censuses at Cabell Marsh. I observed 33 waterbird taxa and seven raptor species, including hatch-year individuals of five waterbird species. The records for each census are given.
I conducted 14-22 waterbird and raptor censuses each year from 1992-1995 during late April or early May through October. I observed 44 waterbird and 13 raptor species, including hatch year individuals of seven waterbird species. The records for each census are given.
⁴⁰Ar-³⁹Ar incremental heating experiments were performed on volcanic rocks recovered by drilling during Ocean Drilling Program Leg 152, southeast Greenland Margin (63°N), and Deep Sea Drilling Project Leg 81, southwest Rockall Plateau (56°N). Both of these legs drilled into thick sections of submerged lava flows, known as seaward-dipping reflector sequences,...
Results of ⁴⁰Ar–³⁹Ar Ar dating constrain the age of the submerged volcanic succession, part of the seaward-dip ping reflector sequence of the Southeast Greenland volcanic rifted margin, recovered during Leg 163. At the 3°Ne 6 drilling transect, the fully normally magnetized volcanic units at Holes 989B (Unit 1) and 990A...
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...
The southern portion of the Kodiak-Bowie seamonnt chain in the southeastern
Gulf of Alaska presents a unique opportunity to investigate loading on young oceanic
lithosphere. Oceanic lithosphere younger than 25 Ma is loaded both by sediments in a deep
offshore trough and by seamount 100-200 km offshore. Free-air gravity anomaly...
In the spring of 1992 an optical closure experiment was conducted at Lake
Pend Oreille, Idaho. A primary objective of the experiment was to compare techniques
for the measurement of the spectral absorption coefficient and other inherent optical
properties of natural waters. Daily averages of absorption coefficients measured using
six...
Recent measurements (21 September - 15 October 1992) of methane and water vapor by the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) are compared with model results for the same season from a troposphere-middle atmosphere version of the National Center for Atmospheric Research (NCAR )Community Climate...
An indirect fluorescent antibody test (IFAT) was developed for detection of the rickettsia that was causing epizootics among salmonids cultured in seawater net-pens in southern Chile. Antiserum against the rickettsial agent was produced in New Zealand white rabbits with a preparation grown in antibiotic-free chinook salmon embryo (CHSE-214) cell cultures...
A Geosat altimeter wind speed algorithm is derived by cross-calibrating Geosat and Seasat
altimeter estimates of the normalized radar cross section σ₀ and modifying an existing Seasat
altimeter wind speed model function to obtain a model function appropriate for Geosat observations.
It is argued that the σ₀ distribution measured by...
We have mapped a recently active left-lateral strike-slip fault (the Wecoma fault) on the floor of Cascadia Basin west of the Oregon convergent margin, using SeaMARC I sidescan sonar, Seabeam bathymetry and multichannel seismic and magnetic data. The fault intersects the base of the continental slope at 45°10’N and extends...
A layered model of steady geostrophic ocean circulation driven by wind stress and buoyancy flux at the surface is derived. Potential vorticity, or thickness, of the two near-surface layers is driven by Ekman pumping and buoyancy pumping. The latter is represented as a flow of mass proportional to the modified...
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...
A parallel algorithm is described for variational assimilation of observations into oceanic and atmospheric models. The algorithm may be coded first for execution on a serial computer and then trivially modified for execution on a parallel computer such as the Intel iPSC/860. The speedup factor for parallel execution is roughly...
In 1989, we conducted an onshore/offshore seismic experiment to image the crustal structure of the Cascadia forearc. In this paper, we discuss the processing and interpretation of a multichannel seismic reflection profile across the continental margin that was collected as part of this effort. This profile reveals several features of...
Time and length scales of beach variability have been quantified using 16 years
of beach surveys sampled at the Army Corps of Engineers' Field Research Facility,
located on the U.S. Atlantic coast. Between 50% and 90% of the bathymetric variability at
this site was explained by alongshore-uniform response over the...
We described a simplified physics approach to generating time-varying global wind and temperature fields suitable for conducting transport studies on Mars. The goal is to develop a computationally fast algorithm that will enable long-term simulations of the planet’s climate system. Thus we use a three-dimensional log-pressure global spectral model forced...
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...
An expression for the ratio of the upwelling nadir radiance L(π, z) and the downwelling scalar irradiance Eod(Z) is derived from the following equation of radiative transfer. This expression is given by RSR(z)=[L(π, z)]/Eod(Z) = [fb(z)bb(z)]/2π[k(π, z) + c(z) – fL(z)bf(z)], where bb(z) is the backscattering coefficient, k(π, z) is...
A fast-response chromel–constantan thermocouple sensor was constructed for use on the microstructure profiler Chameleon and used for 60 ocean profiles off the coast of Oregon. The stability of the thermocouple was compared to that of an FP07 microbead thermistor, and its frequency response was compared to a high-resolution microconductivity probe....
There were 21 days with observations during 30 January-21 May 1974. Herons were already displaying on January 30, so nesting activity can occur much earlier than has been supposed. A yearling was often seen at the nests, but most nesting activity was by adults. Although eggs were laid in at...
Theoretical scattering computations are performed on a phytoplankton model consisting of three
concentric spheres. The outer sphere represents the wall, membrane, or frustule and is assigned a
relatively high index of refraction with no absorption. The middle layer represents the chloroplasts
and is assigned a relatively low index of refraction...
The ability of 15 bacterial and fungal isolates to inhibit fungal stain of ponderosa pine sapwood was studied on small wood samples exposed in a moist environment. Several isolates including Bacillus subtilis were capable of inhibiting fungal stain although the protective effect was lost upon prolonged exposure. More detailed evaluations...
We have measured the absorption coefficient of pure and salt water at 15 wavelengths in the visible and near-infrared regions of the spectrum using WETLabs nine-wavelength absorption and attenuation meters and a three-wavelength absorption meter. The water temperature was varied between 15 and 30 °C, and the salinity was varied...
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...
Over 20 global ocean tide models have been developed since 1994, primarily as a
consequence of analysis of the precise altimetric measurements from TOPEX/POSEIDON and as a result of parallel developments numerical tidal modeling and data assimilation. This paper
provides an accuracy assessment of 10 such tide models and discusses...
Acetylene is a slow-binding inhibitor of the Ni- and Fe-containing dimeric hydrogenase isolated
from Azotobacter vinelandii. Acetylene was released from hydrogenase during the recovery from inhibition.
This indicates that no transformation of acetylene to another compound occurred as a result of the interaction
with hydrogenase. However, the release of C2H2...
We evaluated the extent to which the average metabolic activity of open ocean bacterioplankton
changed during 2 to 3 d incubations of 1 μm filtered seawater at in situ temperature. Indices
of bacterial activity during incubation experiments were compared to those of in situ bacterioplankton,
which were repeatedly sampled at...
Basalts from the four southernmost segments of the subducting Chile Ridge (numbered 1-4 stepping away from the trench) display large variations in Sr, Nd, Pb, and He isotope and trace element compositions. Klein and Karsten [1995] showed that segments 1 and 3 display clear trace element evidence for recycled material...
Due to distortion of airflow streamlines, flow velocities and droplet size distributions measured around a moving aircraft can differ from freestream conditions. This can complicate measurements made from aircraft platforms. Potential flow calculations were used to predict airflow characteristics and the spatial distribution of different-sized droplets around the Lockheed Electra...
Alias periods and wavelengths for the M2, S2, N2, K1, O1, and P1 tidal constituents are calculated for TOPEX/POSEIDON. Alias wavelengths calculated in previous studies are shown to be in error, and a correct method is presented. With the exception of the K1 constituent, all of these tidal aliases for...
A unique approach for obtaining bright and efficient saturated green phosphors for alternating-current thin-film electroluminescent (ACTFEL) device applications is presented. The approach involves color-shifting blue SrS:Cu,F ACTFEL phosphors into the green region of the spectrum via the incorporation of alkali metal ions into the SrS lattice. Alkali metals are incorporated...
We analyzed the unsaturation ratio (U k/37 ) of long-chain ketones—a molecular sea-surface temperature (SST) indicator—concentrations of carbonate and organic carbon in sediments from Site 846 in the eastern equatorial Pacific Ocean. Based on an isotopic age model for the composite depth section of 0-46 m below seafloor and on...
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...
Prior studies have demonstrated that juvenile walleye pollock Theragra chalcogramma forage socially in schools for spatially and temporally clumped food, but forage more independently for spatially and temporally dispersed food. One advantage of social foraging is that fish in schools may be able to locate more food clumps than fish...
Data from Geosat and TOPEX altimeters are used to infer the structure of the Peru-Chile Countercurrent, a jet that flows from at least as far north as 10ºS (historical data suggests 7ºS) to 35º–40ºS, maintaining its position between approximately 100–300 km offshore. Although the annual mean current cannot be determined...
In this paper, we evaluate the temporal and horizontal resolution of geostrophic
surface velocities calculated from TOPEX satellite altimeter heights. Moored velocities
(from vector-averaging current meters and an acoustic Doppler current profiler) at depths
below the Ekman layer are used to estimate the temporal evolution and accuracy of
altimeter geostrophic...
Seasonal and diel changes in nutrient concentrations and nitrogen assimilation rates were used to assess the effects of NH4+ on NO3- assimilation. Surface-water NO3- concentrations ranged from 6 to 17 μM while NH4+ concentrations ranged from 0 to 0.4 μM. Total N assimilation ranged from 84 to 732 nM d–1...
Ammonium uptake and regeneration rates were measured in time course experiments with 15N as a tracer. Both ammonium uptake and regeneration rates measured over 12 to 18 h remained essentially constant. However, as the length of the incubations increased the amount of usable data decreased dramatically due to substrate depletion...
To remove small-scale variance and noise, time series of data are generally filtered using a moving window with a specified distribution of weights. Such filters unfortunately smooth sharp changes associated with larger scale structures. In this study, an adaptive low-pass filter is developed that not only effectively removes random small-scale...
The sea-state bias in Geosat altimeter range measurements expressed as a percentage of significant
wave height (SWH) is examined as a function of SWH. The bias is shown to be approximately
a fixed -3.5% of SWH for SWH smaller than about 4 m. For larger SWH, the bias decreases in...
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...
We have developed and successfully collected data with a unique, bottom-transecting vehicle (ROVER) that permits the first long time-series measurements of sediment community oxygen consumption (SCOC). This instrument has the, following capabilities: (1) it operates as an autonomous, free vehicle on the sea floor to 6,000-m depth for periods up...
Empirical algorithms for the total absorption coefficient and absorption
coefficient by pigments for surface waters at 440 nm were developed by applying a quadratic formula that combines two spectral ratios of remote-sensing reflectance. For
total absorption coefficients ranging from 0.02 to 2.0 m⁻¹, a goodness of fit was achieved
between...