One goal of the Oregon Library Association's Vision 2010 is to promote a strong and diverse workforce throughout all of the state's libraries. The forecasted shortage of librarians in the next decade prompted the OLA Board to request a demographic study of Oregon's libraries. A simple survey was adminstered at...
Search sessions consist of a person presenting a query to a search engine, followed by that person examining the search
results, selecting some of those search results for further review, possibly following some series of hyperlinks, and perhaps
backtracking to previously viewed pages in the session. The series of pages...
Objective ‐ The authors describe a simple and effective tool for selecting digitization
projects from competing alternatives, providing decision makers with objective,
quantitative data.
Methods ‐ The paper adopts the value engineering methodology for the selection,
evaluation and ranking of digitization project proposals. Project selection steps are described. Selection criteria...
Expectations for technology proficiency in counseling and counselor education have increased; nevertheless, very little information is available in the counseling literature which describes how to effectively evaluate online resources from a design and utility standpoint. This study provides a model for such assessments, employing an affordable small scale usability study...
The results of 703 observations are given; most of these were made in the 1930's by James Macnab, Jane Claire Dirks-Edmunds, Dorothy McKey-Fender, and others. These results are the most comprehensive throughout the year for any site above 1,000 ft in Lincoln County and hint that bird communities at sites...
The impetus for this Project began in 1968-1973 with birders at the Marine Science Center (MSC). But in the past 10 or so years the focus has shifted to a county group, Yaquina Birders & Naturalists. 120 individuals or couples have each contributed 100 or more records with 51% of...
This paper supersedes and significantly revises my compilation of 1992. The focus remains on live birds seen on or from land, but special codes are now given for records of species only reported beached or at sea.
Additionally, confirmation codes are now listed for records of some rare species and...
Acoustic backscattering strength is often used as an index of biomass; however, the relationship between these variables has not been directly validated. Relationships were investigated between acoustic cross section at 200 kHz, measured as part of a previous study, and measured values of length, biovolume, dry weight, ash-free dry weight,...
It has been suggested that production in offshore waters of the subarctic Pacific is limited by availability of dissolved Fe. Although that is not yet adequately established, the functional consequences of the limitation (if it exists) can be characterized from the results of the Subarctic Pacific Ecosystem Research (SUPER) program....
Few studies have examined the partitioning of organic matter in upwelling systems, despite the fact that these systems play a key role in carbon and nitrogen budgets in the ocean. We examined the production and partitioning of phytoplankton-derived organic matter in deck incubations off Oregon during the upwelling season. During...
Using 15N-labeled NH4+, we assessed the time-course of NH4+ uptake, the parameters of saturation kinetics, and the rates of incorporation of NH4+ into trichloroacetic acid-insoluble material by Chesapeake Bay phytoplankton. The amount of NH4+ taken up by the phytoplankton increased linearly with time for 2 h for all samples growing...
Flux estimates show that upward mixing of the deep-water nitrate pool accounts for more than 85% of the total new nitrogen input to the euphotic zone of Crater Lake. Because measured primary productivity (360 mg C m-2 d-1) is 10–30 times higher than a level supported solely by the input...
The objective of this study was to compare two techniques for estimating benthic fluxes of nutrients (nitrate, phosphate, and silicic acid) and Ge/Si flux ratios. In situ flux chambers were deployed, and cores were collected and incubated at 9 sites along the California margin in July 2001. Both techniques were...
Small temporal and spatial variations in the distribution of dissolved oxygen in Crater Lake, Oregon, are used to estimate the mean age of the lake’s deep water, the flux of labile organic carbon to the deep lake, and the influence of hydrothermal activity on the concentration of dissolved oxygen within...
Active inputs of thermally and chemically enriched fluids at the bottom of Crater Lake create small vertical and horizontal heterogeneities in the deep-lake temperature and salt distribution. Using an internally recording CTD and a precise definition for salinity as a function of in situ conductivity and temperature, we assess the...
On average, the water column of Lake Superior is undersaturated with respect to dissolved oxygen and supersaturated with respect to carbon dioxide during the summer-stratified period. On the basis of temporal changes in water column dissolved oxygen, we calculate rates of oxygen consumption that range from 0.19 to 0.75 mmol...
We measured oxygen consumption rates, the activities of citrate synthase (CS) and lactate dehydrogenase (LDH) and protein contents for over 30 species of deep-sea pelagic Copepoda. The lowest oxygen consumption rates were measured in Euaugaptilus magnus and the highest rates were measured in Paraeuchaeta tonsa. Weight-specific oxygen consumption rates declined...
We made stable and rapid-responding pH and pCO2 microelectrodes. The pH microelectrode has a ~100-μm-diameter half-sphere bulb tip of pH glass, and the pCO2 sensor has a 200–300-μm-diameter silicone-membrane covered tip. Because the pH microelectrodes have electrical resistances that arc > 1O[to the tenth] ohms, all electrical connections are kept...
Infrared radiometers, photographs, and a multispectral
scanner were used in a remote sensing study of the ocean off
Oregon during the summer of 1969. Upwelling appeared on
infrared temperature maps as a zone of cold water along the
coast and Columbia River water appeared as a warm water
"plume". Sharp...
The levels of copper, chromium, and arsenic in soil surrounding CCA-treated posts and beneath CCA-treated stakes were investigated at a plot near Gainesville, Florida. Metal levels were elevated in soil immediately adjacent to the treated wood, but decreased with distance away or depth. Mean extractable arsenic levels ranged from 1.74...
This report describes the state of the California Current System (CCS)—meteorological, physical, chemical, and biological—from January 2003 to the spring of 2004. The area covered in this report ranges from Oregon coastal waters to southern Baja California. Over the past year, most physical, chemical, and biological parameters were close to...
Isolation, detection with diagnostic polymerase chain reaction (PCR), and microscopy demonstrated the presence of Phytophthora ramorum in the sapwood of mature, naturally infected tanoak (Lithocarpus densiflorus) trees. The pathogen was strongly associated with discolored sapwood (P < 0.001), and was recovered or detected from 83% of discolored sapwood tissue samples....
Twenty-two steelhead trout (Salmo gairdneri) containing coded wire tags (CWT's) were captured in gillnets fished by the Oshoro-Maru in the Gulf of Alaska and along 180 during 1982-85. These fish originated from North American streams and hatcheries in British Columbia, Idaho, and Washington. One fish was age 0.1, 16 were...
The cohesion-tension theory of water transport states that hydrogen bonds hold water molecules together and that they are pulled through the xylem under tension. This tension could cause transport failure in at least two ways: collapse of the conduit walls (implosion), or rupture of the water column through air-seeding. The...
The cultural and ecological values of Pacific lamprey (Lampetra tridentata) have not been understood by Euro-Americans and thus their great decline has almost gone unnoticed except by Native Americans, who elevated the issue and initiated research to restore its populations, at least in the Columbia Basin. They regard Pacific lamprey...
Twenty-two steelhead trout (Salmo gairdneri) containing coded wire tags (CWT's) were captured in gillnets fished by the Oshoro-Maru in the Gulf of Alaska and along 180 during 1982-85. These fish originated from North American streams and hatcheries in British Columbia, Idaho, and Washington. One fish was age 0.1, 16 were...
Juvenile chinook salmon Oncorhynchus tshawytscha were subjected to handling and tagging protocols typical of normal hatchery operations and monitored for their physiological response to stress. Treatments included coded-wire-tagging, counting, ventral fin clipping, adipose fin clipping, and a procedure simulating a pond split. Treatment fish were also subjected to a standardized...
The accelerated diagenesis, maturation, and catagenesis of organic matter to hydrothermal petroleum was studied in sediments from Ocean Drilling Program Leg 139 in Middle Valley, northern Juan de Fuca Ridge. Sediments at Sites 855 and 856 have experienced high heat flow resulting in accelerated diagenesis of the immature organic matter...
To study whether pruning young Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) hastens the transition from juvenile to mature wood, we investigated the effects on wood properties in an intensively managed young plantation in the Coast Range of Oregon. Ten years after trees were pruned to a fixed height (3.4...
We demonstrate a technique for terahertz pulse shaping via optical rectification in the pre-engineered domain structure of poled lithium niobate crystals. The terahertz wave forms coincide with the crystal domain structures. The one-dimensional nonlinear wave equation simulates the experimental results with a good qualitative agreement.
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...
The data presented in this report demonstrate significant improvements
in the ability to constrain trace element and Sr isotopic
concentrations in sediments overlying ridge-flank hydrothermal
systems. Improved sampling methods orchestrated by the Integrated
Ocean Drilling Program (i.e., advanced piston coring and
anoxic sample processing) enabled the collection of reactive pore...
We carried out a detailed rock magnetic and paleomagnetic study of deep-sea sediments from selected intervals of Site 1233 in order to assess whether they contain reproducible evidence for submillennial-scale environmental, climatic, and geomagnetic field variability. Three 1.5-m sediment intervals from oxygen isotope Stages 1, 2, and 3 were sampled...
Many species of Populus, particularly cottonwoods of sections Aigeiros and Tacamahaca, remain recalcitrant to genetic transformation. We demonstrate that transgenic trees can be readily produced in several poplar genotypes using wild-type Agrobacterium rhizogenes. Hairy roots were produced in a variety of clones that included Populus trichocarpa Torr. & A. Gray,...
Nitrogen incorporation from red alder (Alnus rubra Bong.) into an Oregon upland mesic forest soil was studied by tracing the fate of 15N added as 15N-labeled alder leaf litter. The recovery of 15N in vegetation, litter, light- and heavy-fractions of the soil, the chloroform-labile (microbial biomass) pool, and the whole...
During Ocean Drilling Program Leg 204, 80 in situ measurements of
subseafloor temperature were made; 68 of these showed good frictional
pulses on insertion and extraction from the seafloor and were used to
constrain the subsurface temperature. Considering uncertainties from
various sources, uncertainties in the in situ temperatures are estimated...
We present benthic isotope stratigraphies for Sites 1236, 1237, 1239, and 1241 that span the late Miocene–Pliocene time interval from 6 to 2.4 Ma. Orbitally tuned timescales were generated for Sites 1237 and 1241 by correlating the high-frequency variations in gamma ray attenuation density, percent sand of the carbonate fraction,...
Mapped cpDNA restriction site characters were analyzed cladistically and the resulting phylogenetic hypotheses were used to test monophyly and relationships of the infrageneric classification of Lathyrus (Fabaceae) proposed by Kupicha (1983, Notes from the Royal Botanic Garden Edinburgh 41: 209–244). The validity of previously proposed classification systems and questions presented...
The amount and type of carbon (C) in a forest soil reflects the past balance between C accumulation and loss. In an old-growth forest soil, C is thought to be in dynamic equilibrium between accumulations and losses. Disturbance upsets this equilibrium by altering the microclimate, the amount and type of...
The nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) region has been characterized in the sister genera Larix and Pseudotsuga (Pinaceae). Complete sequences were obtained for seven species of Larix from North America and Eurasia and five species of Pseudotsuga from western North America and eastern Asia. ITS region lengths...
Organellar DNA sequences are widely used in evolutionary and population genetic studies, however, the conservative nature of chloroplast gene and genome evolution often limits phylogenetic resolution and statistical power. To gain maximal access to the historical record contained within chloroplast genomes, we have adapted multiplex sequencing-by-synthesis (MSBS) to simultaneously sequence...
In a multilevel study to determine limits to underplanted conifer seedling growth, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex D. Don), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were planted beneath second-growth Douglas-fir stands that had...
An integrated model, combining spatial wildlife population and timber harvest and growth models, was developed to explore tradeoffs between the likelihood of persistence of a wildlife species, the northern flying squirrel (Glaucomys sabrinus), and timber production on a landscape on the west side of the Oregon Cascade Range. A simplified...
We tested two genes together in hybrid poplars (genus Populus), CP4 and GOX, for imparting tolerance to glyphosate (the active ingredient in Roundup® herbicide). Using Agrobacterium-based transformation, 80 independent transgenic lines (i.e., products of asexual gene transfer) were produced in a variety of hybrid poplar clones (40 lines in Populus...
The quality of lumber and veneer recovered from logs of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is directly influenced by the maximum limb size attained on the crop tree. Because limb sizes are influenced by standdensity regimes, a need has arisen for quantitative tools that link a wide array of silvicultural...
Benthic chamber measurements of the reactants and products involved with biogenic matter diagenesis (oxygen, ammonium, nitrate, silicate, phosphate, TCO₂, alkalinity) were used to define fluxes of these solutes into and out of the sediments off southern and central California. Onshore to offshore transects indicate many similarities in benthic fluxes between...
Many ocean regions important to the global carbon budget, including the equatorial Pacific Ocean, have low chlorophyll concentrations despite high levels of conventional nutrients. Iron may instead by the limiting nutrient, and elevated input of terrigenous Fe during windy glacial episodes has been hypothesized to stimulate oceanic productivity through time...
Carbon isotopically based estimates of CO₂ levels have been generated from a record of the photosynthetic fractionation of ¹³C (≡εp) in a central equatorial Pacific sediment core that spans the last ~255 ka. Contents of ¹³C in phytoplanktonic biomass were determined by analysis of C37 alkadienones. These compounds are exclusive...
Pacific winter waters, a major source of nutrients and buoyancy to the Arctic Ocean, are thought to ventilate the Arctic's lower halocline either by injection (isopycnal or penetrative) of cold saline shelf waters, or by cooling and freshening Atlantic waters upwelled onto the shelf. Although ventilation at salinity (S) >...
Variation in bacterial abundance and activity was assessed by sampling the upper 35 to 80 m of the water column during 2 to 5 d periods at 3 sites: eutrophic-mesotrophic midshelf, mesotrophic-oligotrophic slope, and oligotrophic gyre edge, off the Oregon coast in late summer 1997 and 1998. Bacterial abundances varied...
We evaluated whether bacteria with higher cell-specific nucleic acid content (HNA) or an active electron transport system, i.e., positive for reduction of 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), were responsible for the bulk of bacterioplankton metabolic activity. We also examined whether the phylogenetic diversity of HNA and CTC-positive cells differed from the...
We have selected square subareas (110 km on a side) from coastal zone color scanner (CZCS) and advanced very high resolution radiometer (AVHRR) images for 1981 in the California Current region off northern California for which we could identify sequences of cloud-free data over periods of days to weeks. We...
THE ROLE OF THE OCEANS in Earth systems ecology, and the effects of climate variability on the ocean and its ecosystems, can be understood only by observing, describing, and ultimately predicting the state of the ocean as a physically forced ecological and biogeochemical system. This is a daunting but exciting...
A formalism is presented for quantifying the sampling error of an arbitrary linear estimate of a time-averaged quantity constructed from a time series of irregularly spaced observations at a fixed location. The method is applicable to any irregularly sampled time series; it is applied here to satellite observations of chlorophyll...
Every year, from December to April, anthropogenic haze spreads over most of the North Indian Ocean, and South and Southeast Asia. The Indian Ocean Experiment (INDOEX) documented this Indo-Asian haze at scales ranging from individual particles to its contribution to the regional climate forcing. This study integrates the multiplatform observations...
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...
Empirical estimates of the aerosol indirect radiative forcing often rely on threshold cloud retrievals applied to multispectral satellite imagery data. In such retrievals, pixels having radiances that surpass prescribed thresholds are assumed to be overcast even if they are only partially cloud covered. This assumption leads to cloud visible optical...
Visible and near infrared reflectances from NOAA-14 Advanced Very High Resolution Radiometer (AVHRR) daytime passes are used to derive optical depths at 0.55 μm, an index of aerosol type, continental or marine, and the direct effect of the aerosol on the top of the atmosphere and surface solar radiative fluxes...
The Earth Radiation Budget Experiment (ERBE) used angular direction models (ADMs) to convert satellite scanning radiometer measurements to radiative fluxes at the top of the atmosphere. The ADMs were assumed to depend only on the physical characteristics of the scene being observed, and they were taken to be independent of...
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...
The effective radius of water cloud droplets is retrieved using remotely sensed passive microwave and visible data collected by aircraft during the Indian Ocean Experiment. The purpose of this study is to assess the aerosols’ effect on cloud microphysical and radiative properties. To study this effect, we investigate the relationships...
A new model of global climate, ocean circulation, ecosystems, and biogeochemical cycling, including a fully coupled carbon cycle, is presented and evaluated. The model is consistent with multiple observational data sets from the past 50 years as well as with the observed warming of global surface air and sea temperatures...
The primary impacts of anthropogenic CO2 emissions on marine biogeochemical cycles predicted so far include ocean acidification, global warming induced shifts in biogeographical provinces, and a possible negative feedback on atmospheric CO2 levels by CO2-fertilized biological production. Here we report a new potentially significant impact on the oxygen-minimum zones of...
This special section discusses a rare phenomenon: strong enhancement of Subarctic influence in the California Current system in the summer of 2002. This cold, fresh anomaly in the upper halocline was more extreme than any prior observation, though historical records extend back for several decades. The Subarctic anomaly extended more...
Subsurface upper ocean waters off Oregon and Vancouver Island were about 1° cooler in July 2002 than in July 2001. The anomalously cool layer coincides with the permanent halocline which has salinities of 32.2 to 33.8, suggesting an invasion of nutrient-rich Subarctic waters. The anomalously cool layer lies at 30–150...
The first three years of SeaWiFS data (1997-2000) provide the most complete quantification to date of chlorophyll seasonal variability along the full latitudinal extent of the four major eastern boundary currents (EBCs). Comparisons to previously published chlorophyll seasonal climatologies deduced from the relatively sparse coverage provided by the Coastal Zone...
Surface transports into the California Current are calculated from TOPEX/POSEIDON altimeter surface height slopes during the 9.5 year period from October 1992–May 2002. These quantify the anomalous onshore and southward displacements of the water column during the 2000–2002 period, which had been hypothesized by others based on anomalous water properties...
Five years (1997–2002) of northern California Current SeaWiFS ocean color data put cold, low salinity hydrographic anomalies observed in summer 2002 into a spatial/temporal context and present their biological ramifications. Monthly mean chlorophyll concentrations were >1.0 mg m–3 larger than the previous 3 year average over the entire shelf from...
Bioturbating infauna significantly modify reaction and transport processes in permeable sediments, though most studies to date are limited in the scope of species examined. We conducted a comparative field study measuring density-dependent effects of six common bioturbating species on porewater advection and biogeochemistry, across three intertidal permeable sediment habitats. The...
Dynamical assimilation of surface elevation from tide gauges is investigated to estimate the bottom drag coefficient and surface stress as a first step in improving modeled tidal and wind-driven circulation in the Chesapeake Bay. A two-dimensional shallow water model and an adjoint variational method with a limited memory quasi-Newton optimization...
The isotopic composition of the dissolved inorganic carbon (DIC) collected at sites of active methane discharge on Hydrate Ridge, Oregon, reveals anaerobic methane oxidation mediated by bacteria, with δ13CDIC reaching values as low as –48‰ in the upper 4 cm of the sediment. In spite of the high sulfide levels...
Throughout South Asia biomass is commonly used as a fuel source for cooking and heating homes. The smoke from domestic use of these fuels is expected to be a major source of atmospheric particulate matter in the region and needs to be characterized for input in regional source apportionment models...
The NASA Ames Mars General Circulation Model is used to interpret selected results from the Mars Pathfinder atmospheric structure instrument/meteorology (ASI/MET) experiment. The present version of the model has an improved soil thermal model, a new boundary layer scheme, and a correction for non-local thermodynamic equilibrium effects at solar wavelengths....
In late May of 2008, the NASA/JPL Phoenix spacecraft will touch down near its targeted landing site on Mars (68.2°N, 126.6°W). Entry, descent, and landing (EDL) occurs in the late afternoon (~1630 hours local solar time (LST)) during late northern spring (Ls ~ 78°). Using a mesoscale and a large-eddy...
Analysis of satellite ocean color, sea surface temperature, and sea ice cover data reveals consistent patterns between biological production, iron availability, and physical forcings in the Southern Ocean. The consistency of these patterns, in conjunction with information on physical conditions during the last glacial maximum (LGM), enables estimates of export...
The Coastal Ocean Advances in Shelf Transport (COAST) program conducted an
interdisciplinary study of coastal upwelling off central Oregon during summer 2001.
Two intensive field efforts during May–June and August 2001 were coordinated with
ocean circulation, ecosystem, and atmospheric modeling of the region. A primary
goal was to contrast the...
We use Ar-40-Ar-39 incremental heating to fingerprint bulk fluvial sediment entering the northeast Pacific Ocean, with the long-term intent of tracking sediment source and transport changes from the terrestrial system to the marine environment through time. We show reproducible age spectra from individual rivers accounting for the majority of sediment...
The pre-Tertiary oceanic crust exposed on the west coast of Costa Pica has been broadly referred to as the Nicoya Complex. This study was designed to determine the age of the Nicoya Complex in the Nicoya Peninsula, Playa Jaco, and the Quepos Peninsula using Ar-40-Ar-39 radiometric dating and to assess...
Within the Australian-Antarctic Discordance (AAD), a boundary exists between isotopically defined “Pacific-type” and “Indian-type” mid-ocean ridge basalt (MORB) erupted along the Southeast Indian Ridge (SEIR). This boundary has migrated westward beneath the easternmost AAD spreading segment at a minimum rate of 25 mm/yr since 4 Ma; however, its long-term history...
The island of Tahiti, the largest in French Polynesia, comprises two major volcanoes aligned NW-SE, parallel with the general trend of the Society Islands hotspot track. Rocks form this volcanic system are basalts transitional to tholeiites, alkali basalts, basanites, picrites, and evolved lavas. Through K-Ar radiometric dating we have established...
Data from the Coastal Transition Zone (CTZ) experiment are used to describe the velocity fields and water properties associate with cold filaments in the California Current. Combined with previous field surveys and satellite imagery, these show seasonal variability with maximum dynamic height ranges and velocities in summer and minimum values...
Observations of CO2 were made in the upper troposphere and lower stratosphere in the deep tropics in order to determine the patterns of large-scale vertical transport and age of air in the Tropical Tropopause Layer (TTL). Flights aboard the NASA WB-57F aircraft over Central America and adjacent ocean areas took...
Sea surface temperature (SST) fronts are determined for the 2001–2004 time period
from Geostationary Operational Environmental Satellites (GOES) data in the California
Current System (CCS). The probability of detecting a SST front at an individual pixel
location in the CCS is presented as a bi-monthly climatology. Fronts clearly indicate the...
Data from Geostationary Operational Environmental
Satellites are used to study the seasonal evolution of
temperature fronts in the northern California Current
System (CCS), focusing on the interactions with
topographic features. Fronts first appear close to the coast
in response to upwelling winds, moving offshore with the
continuous input of energy...
During summer 2001, high-resolution hydrographic, velocity, and bio-optical surveys
were conducted over Heceta Bank off central Oregon. North of the bank, upwelling
over simple bottom topography exhibited a classic response with a midshelf, baroclinic
coastal jet and upwelled isopycnals. The coastal upwelling jet follows the bank
topography as it widens...
Planktonic foraminiferal faunas of the southeast Pacific indicate that sea surface temperatures (SST) have
varied by as much as 8–10°C in the Peru Current, and by ~5–7°C along the equator, over the past 150,000 years.
Changes in SST at times such as the Last Glacial Maximum reflect incursion of high-latitude...
The summit crater of Vailulu’u Seamount, the youngest volcano in the Samoan chain, hosts an active
hydrothermal system with profound impact on the ocean water column inside and around its crater (2 km
wide and 407 m deep at a 593 m summit depth). The turbidity of the ocean water...
Application of the ²³⁰Th normalization method to estimate sediment burial fluxes in six cores from the
eastern equatorial Pacific (EEP) reveals that bulk sediment and organic carbon fluxes display a coherent regional
pattern during the Holocene that is consistent with modern oceanographic conditions, in contrast with estimates
of bulk mass...
Data from nine stratocumulus clouds in the northeastern Pacific Ocean were analyzed
to determine the effect of aerosol particles on cloud microphysical and radiative properties.
Seven nighttime and two daytime cases were included. The number concentration of
below-cloud aerosol particles (> 0.10 μm diameter) was highly correlated with cloud
droplet...
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...
Present methods used to retrieve altimeter data do not provide reliable estimates of
sea surface height (SSH) in the nearshore region, resulting in a measurement gap of
25–50 km next to the coast. In the present work, gridded SSH fields produced by
Archiving, Validation, and Interpretation of Satellite Oceanographic data...
We used wavelet analyses of sea surface height (SSH) from >13 years of satellite
altimeter data to characterize the variability in mesoscale circulation in the northern
California Current (35°N–49°N) and explore the mechanisms of variability. We defined
‘‘mesoscale’’ circulation as features, such as eddies and filaments, which have 50- to...
In this article we analyze the momentum and vorticity balances of a numerical
simulation of the upwelling circulation off central Chile (34° –40°S) and its response to
interannual local wind changes. Our analysis indicates that the path of the upwelling jet is
strongly controlled by the bottom topography. This topographic...
Mean fields, seasonal cycles, and interannual variability are examined for fields of
satellite-derived chlorophyll pigment concentrations (CHL), sea surface height (SSH), and
sea surface temperature (SST) during 1997–2002. The analyses help to identify three
dynamic regions: an upwelling zone next to the coast, the Ensenada Front in the north,
and...
Monthly composite images from the global coastal zone color scanner
(CZCS) data set are used to provide an initial illustration and comparison of seasonal
and interannual variability of phytoplankton pigment concentration along the western
coasts of South and North America in the Peru Current system (PCS) and California
Current system...
Satellite-derived data provide the temporal means and seasonal and nonseasonal
variability of four physical and biological parameters off Oregon and Washington
(41°–48.5°N). Eight years of data (1998–2005) are available for surface chlorophyll
concentrations, sea surface temperature (SST), and sea surface height, while six years of
data (2000–2005) are available for...
The Gorda Escarpment is a north facing scarp immediately south of the Mendocino transform fault (the Gorda/Juan de Fuca-Pacific plate boundary) between 126°W and the Mendocino triple junction. It elevates the seafloor at the northern edge of the Vizcaino block, part of the Pacific plate, ~1.5 km above the seafloor...
As the Mendocino Triple Junction migrates northward along the California margin it is widely presumed to leave a "slab-free" or "asthenospheric" window in its wake. A 250-km-long south-north seismic refraction-reflection profile crossing the transition from transform to subduction regimes allows us to compare and contrast crust and upper mantle of...