Index Catalog // ScholarsArchive@OSU

Phosphorus physiology and environmental forcing of oceanic cyanobacteria, primarily Trichodesmium spp.

Creator:: White, Angelicque E.
Abstract:: The biological transformation of dinitrogen gas (N2) into combined forms(termed N2 fixation) by certain genera of oceanic cyanobacteria represents the largest incoming flux of nitrogen to the global ocean. As such, biological nitrogen fixation plays a significant role in the regulation of oceanic productivity and the export of carbon and...
Resource Type:: Dissertation
Full Text:: : _____________________________________________________________________ Ricardo M. Letelier Yvette H. Spitz The biological

Primary production dynamics in the North Pacific subtropical gyre

Creator:: Corno, Guido
Abstract:: The North Pacific subtropical gyre (NPSG), once considered to be a biological desert due to low primary production (PP) and its associated variability, has been found more productive and variable than previously thought. The environmental conditions controlling this relatively high PP variability are yet to be elucidated, despite important implications...
Resource Type:: Dissertation
Full Text:: : _____________________________________________________________________ Mark R. Abbott, Ricardo M. Letelier The North Pacific subtropical gyre (NPSG), once

Seconds to hour scale photosynthetic responses in marine microalgae

Creator:: Laney, Samuel R.
Abstract:: Our view of phytoplankton has historically revolved around their inability to control their location in space. The term phytoplankton itself underscores this particular difference between phytoplankton and their sessile terrestrial counterparts. Yet there are other differences between land plants and the phytoplankton that are perhaps equally important, beyond this sessile-planktonic...
Resource Type:: Dissertation
Full Text:: . CONTRIBUTION OF AUTHORS Contributions and advice by Ricardo M. Letelier and Mark R. Abbott were central

Phosphorus control of nitrogen fixation

Creator:: Watkins-Brandt, Katie S.
Abstract:: Under conditions of fixed N-limitation, as with most oligotrophic systems, the process of biological N₂ fixation (diazotrophy) is favored, provided the necessary trace elements and vitamins are sufficient. Despite the well understood contributions of N₂ fixation in oligotrophic regions, the nutritional and ecological controls of marine diazotrophs have not been...
Resource Type:: Masters Thesis
Full Text:: : Angelicque E. White Ricardo M. Letelier Yvette H. Spitz Under conditions of fixed N

Nitrogen isotopes in a global ocean biogeochemical model : constraints on the coupling between denitrification and nitrogen fixation

Creator:: Somes, Christopher J.
Abstract:: We present a new nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth System Climate Model designed for millennial timescale simulations. The model includes prognostic tracers for the stable nitrogen isotopes, ¹⁴N and ¹⁵N, in the nitrate (NO₃ˉ), phytoplankton, zooplankton, and detritus variables of the marine...
Resource Type:: Masters Thesis
Full Text:: invaluable to my growth as a scientist. I would like to thank my committee members Alan Mix and Ricardo

Phytoplankton fluorescence and survival below the euphotic zone in the California current system

Creator:: Murphy, Alice M.
Resource Type:: Masters Thesis
Full Text:: , Tim Cowles. Thanks also to my committee members, Ricardo Letelier, Dan Shafer, and Jeriy Heidel

Light driven seasonal patterns of chlorophyll and nitrate in the lower euphotic zone of the North Pacific Subtropical Gyre

Creator:: Letelier, Ricardo M., Karl, David M., Abbott, Mark R., and Bidigare, Robert R.
Abstract:: The euphotic zone below the deep chlorophyll maximum layer (DCML) at Station ALOHA (a long-term oligotrophic habitat assessment; 22º45′N, 158º00′W) transects the nearly permanently stratified upper thermocline. Hence, seasonal changes in solar radiation control the balance between photosynthesis and respiration in this lightlimited region. Combining profiles of radiance reflectance, algal...
Resource Type:: Article
Full Text:: Letelier, Ricardo M., David M. Karl, Mark R. Abbott, and Robert R

The role of dissolved organic matter release in the productivity of the oligotrophic North Pacific Ocean

Creator:: Karl, David M., Hebel, Dale V., Björkman, K., and Letelier, Ricardo M.
Abstract:: 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...
Resource Type:: Article
Full Text:: KARL, DAVID M., DALE V. HEBEL, K. BJÖRKMAN, AND R. M. LETELIER

Jet stream intraseasonal oscillations drive dominant ecosystem variations in Oregon’s summertime coastal upwelling system

Creator:: Bane, John M., Spitz, Yvette H., Letelier, Ricardo M., and Peterson, William T.
Abstract:: Summertime wind stress along the coast of the northwestern United States typically exhibits intraseasonal oscillations (ISOs) with periods from ≈15 to 40 days, as well as fluctuations on the 2- to 6-day “weather-band” and 1-day diurnal time scales. Coastal upwelling of cool, nutrient-rich water is driven by extended periods of...
Resource Type:: Article
Full Text:: ‡, Ricardo M. Letelier‡, and William T. Peterson§ *Department of Marine Sciences, University of North

Chlorophyll natural fluorescence response to upwelling events in the Southern Ocean

Creator:: Letelier, Ricardo M., Abbott, Mark R., and Karl, David M.
Abstract:: Variability of solar-induced (natural) fluorescence and chlorophyll were measured on scales of hours to weeks in the upper layer of a cyclonic eddy located south of the Antarctic Polar Front using a free-floating drifter. The fluorescence signal was analyzed both in terms of chlorophyll concentration and as an indicator of...
Resource Type:: Article

Production and partitioning of organic matter during simulated phytoplankton blooms

Creator:: Wetz, Michael S.
Abstract:: 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...
Resource Type:: Masters Thesis
Full Text:: also thank my committee members, Ricardo Letelier, Evelyn Sherr, and Fred Prahl, for their willingness

Parameterizing the natural fluorescence kinetics of Thalassiosira weissflogii

Creator:: Laney, Samuel R., Letelier, Ricardo M., and Abbott, Mark R.
Abstract:: We examined variability in the natural fluorescence yield of a neritic diatom, Thalassiosira weissflogii, in continuous cultures. In this species, kinetics in natural fluorescence yield over time scales less than a photoperiod were characterized by sharp decreases, occurring at irradiance intensities that presumably coincide with the onset of nonphotochemical fluorescence...
Resource Type:: Article
Full Text:: Laney, S. R., R. M. Letelier, and M. R. Abbott. Parameterizing the

Prokaryotes associated with marine crust

Creator:: Mason, Olivia Underwood
Abstract:: Oceanic crust covers nearly 70% of the Earth's surface, of which, the upper, sediment layer is estimated to harbor substantial microbial biomass. Marine crust; however, extends several kilometers beyond this surficial layer, and includes the basalt and gabbro layers. In particular, the basalt layer has high permeabilities which allows for...
Resource Type:: Dissertation
Full Text:: also like to thank my committee members, Drs. Michael S. Rappé, Ricardo M. Letelier, Mario E. Magana

Relationships of in situ spectral absorption, pigment ratios and environmental parameters for phytoplankton assemblages in coastal waters

Creator:: Eisner, Lisa B.
Abstract:: In situ optical measurements of spectral absorption and beam attenuation provide information on the fine scale horizontal and vertical variations in phytoplankton pigments and other measures of phytoplankton photophysiology and ecology in coastal waters. Phytoplankton pigment ratios from discrete sample analyses with High Performance Liquid Chromatography were compared to in...
Resource Type:: Dissertation
Full Text:: examples to follow. I thank Pat Wheeler, Ricardo Letelier, Ron Zaneveld, Scott Pegau and Steve Giovannoni

Late Quaternary paleoceanography of the Northeast Pacific and Atlantic Oceans based on diatom transfer functions

Creator:: Lopes, Cristina Isabel Coelho Dias
Abstract:: Modern upwelling conditions and corresponding oceanographic properties are investigated and reconstructed for the Late Quaternary. The oceanographic conditions considered influence diatom ecology and the record of fossil diatom frustules in the sediments. Diatoms from modern sediments are evaluated as paleoceanographic proxies and transfer functions (TFs) are calibrated using the Imbrie...
Resource Type:: Dissertation
Full Text:: committee members Nicklas Pisias, Ricardo Letelier, Peter Clark and Stephen Giovannoni and to Jim McManus

Bacterioplankton in the Oregon upwelling system: distribution, cell-specific leucine incorporation, and diversity

Creator:: Longnecker, Krista
Abstract:: Marine bacterioplankton play an important role in global elemental cycles because they return carbon dioxide and nutrients to the biosphere as they reduce organic matter. Furthermore, marine bacterioplankton are not uniformly active, and subpopulations of the in situ community may be more or less active at any given time. Defining...
Resource Type:: Dissertation
Full Text:: members (Kate Field, Steve Giovannoni, Wayne Huber, and Ricardo Letelier) have also asked intriguing and

Dynamics of organic matter production and degradation during coastal diatom blooms

Creator:: Wetz, Michael S.
Abstract:: Experiments were designed to answer key questions about diatom-derived organic matter cycling (i.e., production and degradation) in coastal systems. Dissolved organic matter (DOM) production was examined in axenic batch cultures of five diatom species. Dissolved organic carbon (DOC) release rates varied between species, but were significantly higher for all species...
Resource Type:: Dissertation
Full Text:: ) Ricardo Letelier, who was one of the first faculty here other than Pat who I had significant

Role of late winter mesoscale events in the biogeochemical variability of the upper water column of the North Pacific Subtropical Gyre

Creator:: Letelier, Ricardo M., Karl, David M., Abbott, Mark R., Flament, P., Freilich, Michael H., Lukas, Roger, and Strub, P. Ted
Abstract:: Continuous records of upper water column (0–150 m) temperature profiles, spectral distribution of downwelling irradiance, and phytoplankton solar-induced fluorescence at 25 m depth were obtained during the inaugural deployment of the Hawaii Air-sea Logging Experiment, A Long-term Oligotrophic Habitat Assessment (HALE ALOHA) mooring, near the Hawaii Ocean Time-series (HOT) Station...
Resource Type:: Article

The South Atlantic Ocean response to local and remote forcings

Creator:: Fetter Filho, Antonio F. H.
Abstract:: 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...
Resource Type:: Dissertation
Full Text:: South Atlantic Ocean Response to Local and Remote Forcings Abstract approved: Ricardo P. Matano The

Does eddy-eddy interaction control surface phytoplankton distribution and carbon export in the North Pacific Subtropical Gyre?

Creator:: Guidi, Lionel, Calil, Paulo H. R., Duhamel, Solange, Bjoerkman, Karin M., Doney, Scott C., Jackson, George A., Li, Binglin, Church, Matthew J., Tozzi, Sasha, Kolber, Zbigniew S., Richards, Kelvin J., Fong, Allison A., Letelier, Ricardo M., Gorsky, Gabriel, Stemmann, Lars, and Karl, David M.
Abstract:: In the North Pacific Subtropical Gyre (NPSG), the regular occurrence of summer phytoplankton blooms contributes to marine ecosystem productivity and the annual carbon export. The mechanisms underlying the formation, maintenance, and decay of these blooms remain largely unknown; nitrogen fixation, episodic vertical mixing of nutrients, and meso- (<100 km) and...
Resource Type:: Article
Full Text:: . Richards,1,2 Allison A. Fong,1,2 Ricardo M. Letelier,2,9 Gabriel Gorsky,10 Lars Stemmann,10 and David M

Formation and pathways of the intermediate water in the Parallel Ocean Circulation Model's Southern Ocean

Creator:: Schouten, Mathijs W. and Matano, Ricardo P.
Abstract:: The formation mechanisms and pathways of intermediate water in the Southern Ocean are analyzed from output of a high-resolution ocean general circulation model. Deep winter mixed layer formation in the Southern Ocean is diagnosed from the model results and is found to be mostly consistent with observations. Diapycnal water mass...
Resource Type:: Article
Full Text:: in the Parallel Ocean Circulation Model’s Southern Ocean Mathijs W. Schouten1,2 and Ricardo P

A numerical study of the upwelling circulation off central Chile

Creator:: Mesias, Jorge M., Matano, Ricardo P., and Strub, P. Ted
Abstract:: We present a modeling study of the upwelling ocean circulation off central Chile (34°–40°S). Using a primitive equation model, we make a numerical simulation of the ocean circulation for summer of 1993, a year characterized by moderate but persistent equatorward winds. The results indicate the formation of an eastern boundary...
Resource Type:: Article

A numerical study of the upwelling circulation off central Chile

Creator:: Mesias, Jorge M.
Resource Type:: Dissertation

Development, performance evaluation and application of a physical model of the Kenyan-Tanzanian coastal region

Creator:: Mayorga Adame, Claudia Gabriela
Abstract:: A Regional Ocean Modeling System (ROMS) application for the coastal region of Kenya and Tanzania (0-10° S, 38.7-46.98° E) was developed with the aim of better resolving the circulation patterns in the coastal region that is poorly represented in global models. The model has a horizontal resolution of 4 km,...
Resource Type:: Masters Thesis
Full Text:: . I also thank the members of my committee Yvette Spitz, Ricardo Matano and Staci Simonich for their

Shelfbreak upwelling induced by alongshore currents: analytical and numerical results

Creator:: Miller, Robert N., Matano, Ricardo P., and Palma, Elbio D.
Abstract:: Alongshore flow in the direction of propagation of coastal trapped waves can result in upwelling at the shelfbreak. The intensity of this upwelling can be comparable in magnitude to wind-driven coastal upwelling, with its associated ecological features. Recent numerical experiments by Matano & Palma indicate that this upwelling results from...
Resource Type:: Article
Full Text:: : analytical and numerical results Robert N. Miller1,2†, Ricardo P. Matano1 and Elbio D. Palma3 1 College of

Atomspheric driving forces for the Agulhas Current in the subtropics

Creator:: Fetter, A., Lutjeharms, J. R. E., and Matano, Ricardo P.
Abstract:: The Agulhas Current is the western boundary current of the South Indian Ocean and is thought to play an important role in the global overturning circulation. In this study, we investigate the contribution from the wind stress field over each ocean basin of the southern hemisphere to the variability of...
Resource Type:: Article
Full Text:: depth of the Agulhas Current may decrease from 3000 to 2300 m over a period of less than 3 months

Modeling studies of mesoscale circulation in the Gulf of California

Creator:: Martínez Alcalá, José Antonio
Abstract:: The mesoscale circulation in the Gulf of California is investigated using a numerical model (Princeton Ocean Model). Forced by satellite-derived winds, the circulation in the gulf shows a complex pattern dominated in the southern gulf by multiple eddies. Near the coast and in most of the north gulf, the circulation...
Resource Type:: Dissertation

Turbulence in sheared, salt-fingering favorable environment

Creator:: Kimura, Satoshi
Abstract:: Instability and turbulence in sheared, salt-fingering favorable stratification are studied using three-dimensional direct numerical simulations (DNS). Salt-fingering favorable stratification is gravitationally stable, because the unstable vertical gradient of salinity is stabilized by temperature (warm, salty over cool, fresh water-masses). Salt-fingering instability can occur at the interface of these different water-masses....
Resource Type:: Dissertation
Full Text:: Jim Moum, Eric Skyllingstad, Ricardo Matano, and Bill Bogley. I appreciate all the energy and time

An investigation into nitrogen uptake by Emilania huxleyi during continuous darkness

Creator:: Royer, Ida M.
Abstract:: Experiments were conducted with two strains of the coccolithophorid Emiliania huxleyi. Previous experiments with CCMP1742 and 372 at a light intensity of 60 µEin/m²-s showed that during five-day periods of continuous darkness, strain 1742 was taking up nitrate from the media while strain 372 was not. The nitrate uptake in...
Resource Type:: Masters Thesis
Full Text:: AN ABSTRACT OF THE THESIS OF Ida M. Royer for the degree of Master of Science in Oceanography

A Numerical Modeling Study of the Upwelling Source Waters along the Oregon Coast during 2005

Creator:: Rivas, David and Samelson, R. M.
Abstract:: Regional ocean circulation along the Oregon coast is studied numerically for forcing fields derived from year 2005 and climatological-mean conditions. The primary object is to study directly the Lagrangian pathways by which fluid arrives in the Oregon upwelling zone. Roughly half of the upwelling fluid is found to arrive in...
Resource Type:: Article
Full Text:: Source Waters along the Oregon Coast during 2005 DAVID RIVAS* AND R. M. SAMELSON College of Oceanic and

Riverine input of macronutrients, iron, and organic matter to the coastal ocean off Oregon, U.S.A., during the winter

Creator:: Wetz, Michael S., Hales, Burke, Chase, Zanna, Wheeler, Patricia A., and Whitney, Michael M.
Abstract:: Three cross‐shelf transects were conducted off northern Oregon in February, 2003, coincident with flooding of Coast Range rivers, to assess the riverine impact on coastal ocean biogeochemistry. During downwelling conditions, low salinity river‐influenced water was located in a narrow band near the coast and contained elevated macronutrient, iron, and organic...
Resource Type:: Article
Full Text:: through early March of nearly every year from 1998–2003 (R. M. Letelier unpubl. data), while shipboard

Minor and trace element chemistry of Lake Baikal, its tributaries, and surrounding hot springs

Creator:: Falkner, Kelly, Church, M., Measures, Chris I., LeBaron, G., Thouron, D., Jeandel, C., Stordal, M. C., Gill, G. A., Mortlock, R., Froelich, P., and Chan, L.-H.
Abstract:: A Russian–American fieldwork effort on Lake Baikal, its tributaries, and surrounding hot springs was undertaken in June–July 1991. Here we report on aspects of major ion (Ca2+, Mg2+, Na+, K+, Alk, Cl–, SO42–) and several minor and trace element (Li isotopes, Sr isotopes, Ba, Al, V, Cr, Ni, Cu, Ge,...
Resource Type:: Article
Full Text:: FALKNER, K. KENNISON, M. CHURCH, C. I. MEASURES, G. LEBARON, D

Studies on the spatial variability of phytoplankton physiology and biomass in the Oregon upwelling system

Creator:: Sanders, Rachel B.
Abstract:: The Oregon upwelling system is a region of high biomass and primary productivity as well as strong mesoscale variability. In order to examine the interaction of physical forcing and ecosystem dynamics, four 3-week sampling cruises were conducted in the Oregon upwelling system as part of the Northeast Pacific Global Ocean...
Resource Type:: Masters Thesis
Full Text:: my major and minor advisors, Mark Abbott and Ricardo Letelier for their support and guidance

Nitrogen isotope simulations show the importance of atmospheric iron deposition for nitrogen fixation across the Pacific Ocean

Creator:: Somes, Christopher J., Schmittner, Andreas, and Altabet, Mark A.
Abstract:: Nitrogen (N) fixation by specialized microorganisms (diazotrophs) influences global plankton productivity because it provides the ocean with most of its bio-available N. However, its global rate and large-scale spatial distribution is still regarded with considerable uncertainty. Here we use a global ocean nitrogen isotope model, in comparison with δ15NO3 observations,...
Resource Type:: Article
Full Text:: , 285 JosephMontoya, Ricardo Letelier, and AlanMix for helpful comments. This 286 work is funded by the

Laboratory investigations of the natural fluorescence of marine phytoplankton

Creator:: Laney, Samuel R.
Abstract:: The influence of nitrate availability and irradiance on phytoplankton natural fluorescence was investigated in laboratory cultures of the marine diatom Thalassiosira weissflogii (Bacillariophyceae). Two cultures of phytoplankton, differing only in the nitrate-limited growth rate, were compared to learn how increases in irradiance influences natural fluorescence. Instrumentation was developed for these...
Resource Type:: Masters Thesis
Full Text:: substantially poorer had not Ricardo Letelier been such an encouraging and active mentor. The substantial

The inherent optical properties of the oceans: from closure to prediction

Creator:: Barnard, Andrew Heath
Abstract:: Precise in situ measurement of the spectral absorption and scattering coefficients in several regions has revealed patterns in the distribution of the inherent optical properties on spatial scales that were previously unobtainable. The precision of the measurements was found to be consistent and unbiased across a variety of oceanic regimes...
Resource Type:: Dissertation
Full Text:: thesis. Ricardo Letelier and Jasmine Bartlett were always willing to lend me a hand. I thank the

Hyperspectral Imager for the Coastal Ocean: instrument description and first images

Creator:: Lucke, Robert L., Corson, Michael, McGlothlin, Norman R., Butcher, Steve D., Wood, Daniel L., Korwan, Daniel R., Li, Rong R., Snyder, William A., Davis, Curt O., and Chen, Davidson T.
Abstract:: The Hyperspectral Imager for the Coastal Ocean (HICO) is the first spaceborne hyperspectral sensor designed specifically for the coastal ocean and estuarial, riverine, or other shallow-water areas. The HICO generates hyperspectral images, primarily over the 400–900 nm spectral range, with a ground sample distance of ≈90 m (at nadir) and a high...
Resource Type:: Article
Full Text:: , includes Earth rotation HICO Hardware Lens FL 67:16mm Gives 83m nadir IFOV for 16 μm pixels and 350km

Energy Transmission by Barotropic Rossby Waves Revisited

Creator:: Matano, R. P. and Palma, E. D.
Abstract:: This article presents a semianalytic method to investigate the properties of energy transmission across bottom topography by barotropic Rossby waves. The method is first used to revisit the analytical estimates derived from wave-matching techniques and Wentzel–Kramers–Brillouin (WKB) approximations. The comparison between the semianalytic method and WKB indicates that the results...
Resource Type:: Article
Full Text:: taller than �1000 m and wider than �500 km. For these parameter values both methods predict the passage

Development of satellite bloom detection products for coastal Oregon

Creator:: McKibben, S. Morgaine
Abstract:: Two bloom-detection products were developed for the Oregon coast that describe the relative percent change observed between successive pairs of 8-day chlorophyll-a (CHL) and fluorescence line-height (FLH) products obtained from the MODerate Resolution Imaging Spectroradiometer aboard the Aqua spacecraft (MODIS-Aqua). The CHL[subscript dev] and FLH[subscript dev] products, respectively, were optimized...
Resource Type:: Masters Thesis
Full Text:: Pipeline Fellowship (2009-2010 academic year). The wonderful people of the Letelier/White/Davis lab

A Correction to the Baroclinic Pressure Gradient Term in the Princeton Ocean Model

Creator:: Robertson, Robin, Padman, Laurie, and Levine, Murray D.
Abstract:: An error in the calculation of the baroclinic pressure gradient term in the Princeton Ocean Model (POM) was identified while modeling the M₂ tidal current near its critical latitude in the southern Weddell Sea. The error arises from the present calculation of density, which involves the subtraction of a background...
Resource Type:: Article
Full Text:: atot_18_614.1068_1075.tp 1068 VOLUME 18J O U R N A L O F A T M O S P H

Physical and chemical factors controlling the distribution of the major phytoplankton classes at the Antarctic Polar Front, 170 °W

Creator:: Mengelt, Claudia
Abstract:: This study was part of the Antarctic Environment and Southern Ocean Study (AESOPS) program, whose main goal was to investigate the role of the biota in the carbon flux from the atmosphere to the interior of the ocean. We quantified the abundance of the major phytoplankton classes and examined the...
Resource Type:: Masters Thesis
Full Text:: to thank Ricardo Letelier for taking so much time in advising me with science questions and

Variability in mesoscale circulation and its effects on zooplankton distribution in the Northern California Current

Creator:: Keister, Julie Eileen
Abstract:: In eastern boundary current upwelling ecosystems, mesoscale circulation features such as eddies and upwelling filaments play a prominent role in the transfer of water and the associated plankton from the productive nearshore to the oligotrophic deep sea. The relationship between mesoscale circulation, zooplankton distributions, and the across-shelf transport of coastal...
Resource Type:: Dissertation
Full Text:: to estimate seaward transport of 0.5 Sv in the upper 100 m of the filament, in which zooplankton

Production and partitioning of organic matter during simulated phytoplankton blooms

Creator:: Wetz, Michael S. and Wheeler, Patricia A.
Abstract:: 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...
Resource Type:: Article
Full Text:: thank Evelyn Sherr, Ricardo Letelier, Ron Benner, Lee Karp- Boss, Jennifer Jarrell-Wetz, and three

Horizontal and vertical distribution of juvenile pollock (Theragra chalcogramma) in the southeastern Bering Sea

Creator:: McIntosh, Neal E.
Abstract:: Juvenile walleye pollock (Theragra chalcogramma) are one of the primary prey items for bird and mammal predators in the Bering Sea and support a large commercial fishery. An understanding of the environmental factors that determine the horizontal and vertical distribution of juvenile pollock is needed to estimate the effects that...
Resource Type:: Masters Thesis
Full Text:: Cowles, Bob Emmett, Marta Torres, Charlie Miller, Marnie Jo Zirbel, Ricardo Letelier, and Margaret

Investigating the ecological role of cell signaling in free-living marine heterotrophic protists

Creator:: Hartz, Aaron J.
Abstract:: Phagotrophic protists are major consumers of microbial biomass in aquatic ecosystems. However, biochemical mechanisms underlying prey recognition and phagocytosis by protists are not well understood. We investigated the potential roles of cell signaling mechanisms in chemosensory response to prey, and in capture of prey cells, by a marine ciliate (Uronema...
Resource Type:: Masters Thesis
Full Text::  Ricardo Letellier for the  assistance he provided.  My office mates Wiley Evans, Brandon Briggs, Maria

Two coastal upwelling domains in the northern California Current system

Creator:: Huyer, Adriana, 1945-, Fleischbein, Jane, Keister, Julie Eileen, Kosro, P. Michael, 1951-, Perlin, Natalie, Smith, Robert L. (Robert Lloyd), 1935-, and Wheeler, Patricia A.
Abstract:: A pair of hydrographic sections, one north and one south of Cape Blanco at 42.9N, was sampled in five summers (1998–2000 and 2002–2003). The NH line at 44.6N lies about 130 km south of the Columbia River, and spans a relatively wide shelf off Newport, Oregon. The CR line at...
Resource Type:: Article
Full Text:: high (15 mg C m�3) inshore of the mid-shelf on both NH and CR lines, and is also high in the core of

A terrestrial organic matter depocenter on a high-energy margin adjacent to a low-sediment-yield river : the Umpqua River margin, Oregon

Creator:: Hastings, Roxanne H.
Abstract:: Small, mountainous river systems have been increasingly studied due to their importance as sources of fluvial sediment and organic matter to the coastal ocean. Thus far, studies of small, mountainous river systems have focused on rivers with very high sediment loads. The well-studied Eel River dispersal system in northern California...
Resource Type:: Masters Thesis
Full Text:: mid-shelf depocenter located from 85 to 115 m water depth stretching more than 40 km along-shelf on

Annual cycles of organic matter and phytoplankton attributes in the Columbia and Willamette Rivers, with reference to the Columbia River Estuary

Creator:: Sullivan, Barbara Elaine
Resource Type:: Masters Thesis
Full Text:: Margaret Sparrow, Sandy Moore, Ricardo Letelier and Bruce Eversmeyer for all the laboratory assistance and

Surface wind modification near mid-latitude ocean fronts : observational and dynamical analysis

Creator:: O'Neill, Larry W.
Abstract:: Interactions between surface winds and meanders in mid-latitude sea surface temperature (SST) fronts with horizontal length scales of 100-1000 km are investigated from satellite observations and numerical simulations. Observations from the Sea- Winds scatterometer on the QuikSCAT satellite show that the magnitude, direction, curl, and divergence of the surface wind...
Resource Type:: Dissertation
Full Text:: 10-m winds are well correlated with small-scale SST structures associated with large-scale ocean

Physical-biological interactions in the Southern Ocean

Creator:: Moore, Jefferson Keith
Abstract:: Physical-biological interactions in the Southern Ocean were investigated using remote sensing data from several different satellite sensors. Satellite sea surface temperature data were used to study the dynamics of the Antarctic Polar Front (PF). Satellite ocean color data were used to estimate surface chlorophyll concentrations and their relation to various...
Resource Type:: Dissertation
Full Text:: sinks below 200 m depth [Deacon 1933, 1937, Orsi et al., 1995], South of Africa, the sub-surface and

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