Open Access. Powered by Scholars. Published by Universities.®

Oceanography and Atmospheric Sciences and Meteorology Commons™

Open Access. Powered by Scholars. Published by Universities.®

2006

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 151 - 180 of 215

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Evaluating The Biogeochemical Cycle Of Selenium In San Francisco Bay Through Modeling, Shannon L. Meseck, Gregory A. Cutter Jan 2006

Evaluating The Biogeochemical Cycle Of Selenium In San Francisco Bay Through Modeling, Shannon L. Meseck, Gregory A. Cutter

OES Faculty Publications

A biogeochemical model was developed to simulate salinity, total suspended material, phytoplankton biomass, dissolved selenium concentrations (selenite, selenate, and organic selenide), and particulate selenium concentrations (selenite + selenate, elemental selenium, and organic selenide) in the San Francisco Bay estuary. Model-generated estuarine profiles of total dissolved selenium reproduced observed estuarine profiles at a confidence interval of 91- 99% for 8 different years under various environmental conditions. The model accurately reproduced the observed dissolved speciation at confidence intervals of 81-98% for selenite, 72-91% for selenate, and 60-96% for organic selenide. For particulate selenium, model-simulated estuarine profiles duplicated the observed behavior of total …

Go to article

Dynamics Of Carbon Allocation In A Deep-Water Population Of The Deciduous Kelp Pleurophycus Gardeneri (Laminariales), Clare M. Dominik, Richard C. Zimmerman Jan 2006

Dynamics Of Carbon Allocation In A Deep-Water Population Of The Deciduous Kelp Pleurophycus Gardeneri (Laminariales), Clare M. Dominik, Richard C. Zimmerman

OES Faculty Publications

Pleurophycus gardneri (Laminariales) is common in the low intertidal of the Northeast Pacific, but dominates many deep (30 to 40 m) rocky reefs in central California. Seasonal dynamics of productivity and resource allocation of a deep-water population of this deciduous, stipitate kelp were studied to understand how blade abscission affects the annual carbon budget. Patterns of growth, metabolism, and carbon storage and mobilization were measured monthly for 1 yr relative to in situ light and temperature, and used to model the annual carbon budget. The resulting carbon budget was used to determine if blade abscission effectively reduced respiratory demand during …

Go to article

Iron In Ice Cores From Law Dome: A Record Of Atmospheric Iron Deposition For Maritime East Antarctica During The Holocene And Last Glacial Maximum, Ross Edwards, Peter N. Sedwick, Vin Morgan, Claude Boutron Jan 2006

Iron In Ice Cores From Law Dome: A Record Of Atmospheric Iron Deposition For Maritime East Antarctica During The Holocene And Last Glacial Maximum, Ross Edwards, Peter N. Sedwick, Vin Morgan, Claude Boutron

OES Faculty Publications

Total dissolvable iron (TDFe) was measured in sections of ice cores recovered from Law Dome on the coast of Wilkes Land, East Antarctica. These samples include ice dating from the Last Glacial Maximum (LGM), the Last Deglaciation, and the early and mid Holocene as well as samples from the Anthropocene that have been dated with seasonal to annual resolution. Combining our TDFe concentration data with estimates of the ice accumulation rate, we estimate the atmospheric iron deposition for Law Dome and the adjacent Southern Ocean during these periods. Our results indicate that the atmospheric iron deposition flux to this region …

Go to article

Red And Black Tides: Quantitative Analysis Of Water-Leaving Radiance And Perceived Color For Phytoplankton, Colored Dissolved Organic Matter, And Suspended Sediments, Heidi M. Dierssen, Raphael M. Kudela, John P. Ryan, Richard C. Zimmerman Jan 2006

Red And Black Tides: Quantitative Analysis Of Water-Leaving Radiance And Perceived Color For Phytoplankton, Colored Dissolved Organic Matter, And Suspended Sediments, Heidi M. Dierssen, Raphael M. Kudela, John P. Ryan, Richard C. Zimmerman

OES Faculty Publications

Using field measurements and quantitative modeling, we demonstrate that red coloration of the sea surface is not associated with any particular group of phytoplankton and is strongly dependent on the physiology of the human visual system. Red or brown surface waters can be produced by high concentrations of most types of algae, colored dissolved organic matter, or suspended sediment. Even though light reflected by red tides commonly peaks in the yellow spectral region (570–580 nm), human color perception requires consideration of the entire spectrum of light relative to receptors within the human eye. The color shift from green to red …

Go to article

The Role Of Lipids During Embryonic Development Of The Euphausiids Euphausia Pacifica And Thysanoessa Spinifera, Se-Jong Ju, H. Rodger Harvey, Jaime Gómez-Gutiérrez, William T. Peterson Jan 2006

The Role Of Lipids During Embryonic Development Of The Euphausiids Euphausia Pacifica And Thysanoessa Spinifera, Se-Jong Ju, H. Rodger Harvey, Jaime Gómez-Gutiérrez, William T. Peterson

OES Faculty Publications

To understand the role of lipids during early embryogenesis, major lipid classes together with individual fatty acid and sterol composition were determined in embryos from multiple developmental stages of the euphausiids Euphausia pacifica and Thysanoessa spinifera. Average lipid content in embryos of E. pacifica and T. spiniferafrom the earliest stage (multicell) were 4.45 and 3.69 µg embryo-1,respectively. During development, the lipid content decreased at similar rates in the embryos of both species. In contrast to many crustacean eggs, phospholipids were the dominant lipid class in all embryonic stages, with decreasing concentrations seen during development. Individual …

Go to article

Nitrogen Fixation And Release Of Fixed Nitrogen By Trichodesmium Spp. In The Gulf Of Mexico, Margaret R. Mulholland, Peter W. Bernhardt, Cynthia A. Heil, Deborah A. Bronk, Judith M. O'Neil Jan 2006

Nitrogen Fixation And Release Of Fixed Nitrogen By Trichodesmium Spp. In The Gulf Of Mexico, Margaret R. Mulholland, Peter W. Bernhardt, Cynthia A. Heil, Deborah A. Bronk, Judith M. O'Neil

OES Faculty Publications

During a 3-yr study in the Gulf of Mexico, we measured dinitrogen (N2) fixation and nitrogen (N) release by Trichodesmium and compared these rates with water column N demand and the estimated N necessary to support blooms of Karenia brevis, a toxic dinoflagellate that severely affects the West Florida shelf. Net and gross N2 fixation rates were compared in simultaneous incubations using 15N2 uptake and acetylene reduction, respectively. The difference between net and gross N2 fixation is assumed to be an approximation of the rate of N release. Results demonstrate that Trichodesmium in …

Go to article

Western Caribbean Sea Surface Temperatures During The Late Quaternary, Matthew W. Schmidt, Maryline J. Vautravers, Howard J. Spero Jan 2006

Western Caribbean Sea Surface Temperatures During The Late Quaternary, Matthew W. Schmidt, Maryline J. Vautravers, Howard J. Spero

OES Faculty Publications

[1] Mg/Ca ratios in the planktonic foraminifera Globigerinoides ruber from Colombian Basin core ODP 999A suggest that Caribbean sea surface temperatures ( SSTs) were from 2.1 to 2.7°C colder than the present during the last three glacial maximums. In comparison, faunal derived SSTs ( SIMMAX method) show that August SSTs in the Caribbean varied < 2° over the past 360 kyr, whereas February SSTs varied between 21.0°C and 26.5°C. Changes in the Mg/Ca-SST record contain a strong 23 kyr periodicity, suggesting the Mg/Ca-SST record reflects a warm season weighted SST average rather than an annual mean SST. Combining several dissolution indices, we identify brief periods of decreased carbonate preservation in our record and show that MIS 11 stands out as the most intensive dissolution cycle in the Caribbean over the last 460 kyr. Comparison of Caribbean SST change with a similar estimate of tropical SST variability in the western Pacific over the past 360 kyr reveals shifts in the east-west tropical SST gradient that are coeval with glacial-interglacial climate change and consistent both with a southward migration of the glacial ITCZ and with a glacial El Niño-like mode of tropical circulation.

Go to article

Past Glacial And Interglacial Conditions In The Arctic Ocean And Marginal Seas - A Review, Dennis A. Darby, Leonid Polyak, Henning A. Bauch Jan 2006

Past Glacial And Interglacial Conditions In The Arctic Ocean And Marginal Seas - A Review, Dennis A. Darby, Leonid Polyak, Henning A. Bauch

OES Faculty Publications

Past changes in the Arctic Ocean and its marginal seas have been profound, even during the last 10,000 years. Understanding these changes, such as those occurring during the transition from glacial to interglacial climates, are important for research on modern processes, because this knowledge provides a framework and unique perspective in which to view the modern physical and biological processes. This paper discusses our current understanding of past environmental change and processes relative to those currently in progress. Special emphasis is placed on the most recent transition from a glacial state to the modern interglacial conditions.

Go to article

Correlation Between Energetic Ion Enhancements And Heliospheric Current Sheet Crossings In The Outer Heliosphere, John D. Richardson, Edward C. Stone, Ace C. Cummings, Justin C. Kasper, Ming Zhang, Leonard F. Burlaga, Nudel F. Ness, Ying Liu Jan 2006

Correlation Between Energetic Ion Enhancements And Heliospheric Current Sheet Crossings In The Outer Heliosphere, John D. Richardson, Edward C. Stone, Ace C. Cummings, Justin C. Kasper, Ming Zhang, Leonard F. Burlaga, Nudel F. Ness, Ying Liu

Aerospace, Physics, and Space Science Faculty Publications

Voyagers 1 and 2 observed highly-variable beams of energetic ions in the foreshock region upstream of the termination shock (TS). At Voyager 2 (V2), the ion intensities are generally not related to the plasma properties. At Voyager 1 (V1), the beams are often coincident with crossings of the heliospheric current sheet (HCS). The V1 intensity peaks occur when the HCS is crossed from negative to positive magnetic polarities and V1 is within a few AU of the TS. Two mechanisms are considered: current sheet drift and streaming of ions from the TS along magnetic field lines which are parallel to …

Go to article

Ocean Warming And Freshening In The Northern Gulf Of Alaska, Thomas C. Royer, Chester E. Grosch Jan 2006

Ocean Warming And Freshening In The Northern Gulf Of Alaska, Thomas C. Royer, Chester E. Grosch

CCPO Publications

Water column temperatures on the shelf in the northern Gulf of Alaska have increased more than 0.8 degrees C and vertical density stratification has increased since 1970 near Seward, Alaska throughout the 250 m depth. This high latitude marine system has low water temperatures, high rates of precipitation, glacial melting, high wind speeds and high rates of biological productivity. A more than 300 km alongshore shift ( locally westward) of isotherms is suggested. The observations are consistent with a conceptual ocean-atmosphere circulation model that employs coastal freshwater discharge, glacial ablation and wind forcing. Positive regional feedback mechanisms accelerate the discharge …

Go to article

Inter-Annual Sea Level Variability In The Southern Gulf Of Mexico (1966-1976), David Alberto Salas-De-León, Maria Adela Monreal-Gómez, David Salas-Monreal, Mayra Lorena Riveron-Enzastiga, Norma Leticia Sánchez-Santillan Jan 2006

Inter-Annual Sea Level Variability In The Southern Gulf Of Mexico (1966-1976), David Alberto Salas-De-León, Maria Adela Monreal-Gómez, David Salas-Monreal, Mayra Lorena Riveron-Enzastiga, Norma Leticia Sánchez-Santillan

CCPO Publications

Hourly time series at seven locations throughout the southern Gulf of Mexico were used to calculate the trend and the inter-annual sea level. The sea level series from January 1966 to December 1976 were filtered using a Lanczos low pass filter to remove oscillations with periods smaller than one year. The results revealed a sea level increment of about 1.4 mm yr(-1) from 1966 to 1976 in the southern Gulf of Mexico. The monthly sea level variability obtained after the trends were removed, presented a sea level setup during winter and a sea level depression in summer attributed to seasonal …

Go to article

The Influence Of Supplemental Feeding On The Movement Patterns Of The Southern Stingray, Dasyatis Americana, At Grand Cayman, Cayman Islands, Mark John Corcoran Jan 2006

The Influence Of Supplemental Feeding On The Movement Patterns Of The Southern Stingray, Dasyatis Americana, At Grand Cayman, Cayman Islands, Mark John Corcoran

HCNSO Student Theses and Dissertations

There are currently over 300 sites in nearly 40 countries where a variety of marine animals are provided supplemental food by humans. The influence of this supplemental feeding on the behavior, physiology, growth, reproduction and movements of the animals involved is seldom known. Intentional supplemental feeding of the southern stingray, Dasyatis americana, has occurred at Stingray City (SC) and Stingray City Sandbar (SCS) at Grand Cayman since 1986. There are no specific regulations governing the feeding of D. americana at Grand Cayman, and neither the species nor the feeding sites are afforded any official protective status. This study investigated …

Go to article

Evaluating The Deep-Sea Coral Acanella From Hawaii As A Paleoceanographic Archive, Geraldine Hourigan Lantier Jan 2006

Evaluating The Deep-Sea Coral Acanella From Hawaii As A Paleoceanographic Archive, Geraldine Hourigan Lantier

Geology Theses and Dissertations

Deep-sea corals have emerged as potential proxies of changing paleoceanographic properties. The utility of deep-sea corals for the purpose of interpreting paleoclimatic reconstructions is still in the discovery phase. However, long life spans, a relatively stable habitat, and unique growth geometry provide support to the growing body of research that has identified deep-sea corals as indicators of past climate and ocean properties. Two colonies of Acanella were collected from the permanent thermocline at depths between 414 and 437 m in the Makapuu Coral Bed, Oahu, HI in 1997 by submersible. Here I present results from a pilot study of the …

Go to article

Assessing The Paleoceanographic Potential Of The Coral Montipora Venosa At Fanning Atoll, Central Equatorial Pacific, Alexa Stolorow Jan 2006

Assessing The Paleoceanographic Potential Of The Coral Montipora Venosa At Fanning Atoll, Central Equatorial Pacific, Alexa Stolorow

Geology Theses and Dissertations

As interest in global climate change increases, so does the need for better and more extensive climate proxies. The central equatorial Pacific has been established as the region with the largest ENSO-related sea surface temperature (SST) and precipitation (PPT) anomalies, which are known to impact global interannual climate variability. To date, the coral genus Porites has been most commonly utilized for coral-based paleo-reconstructions of ENSO and lower frequency phenomena. However, due to questions of biological artifacts in coral, to more fully understand coral-based reconstruction, different coral genera need to be analyzed.
In this study, oxygen (δ18O) and carbon (δ13C) isotopic …

Go to article

Optimal Image Blending For Underwater Mosaics, Fan Gu, Yuri Rzhanov Jan 2006

Optimal Image Blending For Underwater Mosaics, Fan Gu, Yuri Rzhanov

Center for Coastal and Ocean Mapping

No abstract provided.

Go to article

Evaluation Of Water-Retention Ability Of Eastern Arkansas Prairie And Agricultural Soil, Maria L. Barrenechea, Kristofor R. Brye Jan 2006

Evaluation Of Water-Retention Ability Of Eastern Arkansas Prairie And Agricultural Soil, Maria L. Barrenechea, Kristofor R. Brye

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Agricultural land use affects soil physical properties, such as bulk density, water content, organic matter content, and soil structure; all of which in turn affect ecosystem productivity. The objective of this study was to evaluate the effects of: 1) time since aboveground biomass has been removed by haying (i.e., 0 vs. 23 years), and 2) land use (i.e., undisturbed tallgrass prairie vs. cultivated agriculture) on water-retention characteristics in a silt-loam soil of the Grand Prairie region of eastern Arkansas. Soil samples were collected from the 0- to 10-cm depth and were wetted with varying amounts of distillated water to create …

Go to article

Water Quality Issues In The Illinois River Watershed: A Proposal For New Voluntary Incentives, Tory B. Hodges, Jennie S. Popp Jan 2006

Water Quality Issues In The Illinois River Watershed: A Proposal For New Voluntary Incentives, Tory B. Hodges, Jennie S. Popp

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Concerns about water quality degradation exist in Northwest Arkansas. The purpose of this study was to analyze the potential usefulness of U.S. conservation programs in addressing water quality concerns on farms in the Illinois River watershed as well as greater Washington County, Arkansas. It was hypothesized that neither the Environmental Quality Incentives Program (EQIP) nor the Conservation Security Program (CSP) in their current forms effectively assists farmers in meeting water-quality management goals. That hypothesis was tested by 1) examining agricultural characteristics of the watershed, 2) actual adoption of EQIP and CSP in Washington County and Arkansas, and, 3) identifying factors …

Go to article

Estimating Surface Runoff In The Illinois River Basin For The Management Of Nonpoint-Source Phosphorus Loads, Adam T. Mcclymont, Mary C. Savin, Brian E. Haggard Jan 2006

Estimating Surface Runoff In The Illinois River Basin For The Management Of Nonpoint-Source Phosphorus Loads, Adam T. Mcclymont, Mary C. Savin, Brian E. Haggard

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

With the growing concern about elevated phosphorus (P) concentrations in regional lakes, rivers, and streams, it is essential to investigate factors contributing to P transport from the landscape. Phosphorus fluxes from nonpoint sources, particularly land applications of poultry litter and other animal manures, are closely related to the amount and production of surface runoff. Daily stream discharge and the software program, Base Flow Index (BFI), were used to estimate the amount and temporal patterns of surface runoff at different locations within the Illinois River Basin, including selected tributaries in northwest Arkansas and northeast Oklahoma. Daily streamflow data from nine U.S. …

Go to article

A Tool For Estimating Best Management Practice Effectiveness In Arkansas, Katherine R. Merriman, Margaret Gitau, Indrajeet Chaubey Jan 2006

A Tool For Estimating Best Management Practice Effectiveness In Arkansas, Katherine R. Merriman, Margaret Gitau, Indrajeet Chaubey

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Increased nutrient and sediment losses from expanding agricultural practices and urban development in Arkansas are important environmental concerns. Best Management Practices (BMPs) are being implemented to lessen the effects of these developments on existing water bodies. There is, however, insufficient scientific base as to the effectiveness of these practices. A number of studies have been conducted in recent years to determine BMP effectiveness. Data from these studies can only be reliably used for the individual site from which they were obtained. When considered collectively, these data comprise quantitative effectiveness over a wide range of conditions and can thus be used …

Go to article

Quantifying Changes In Fish Habitat Use In Coastal Waters Of Louisiana, Usa: A Hydroacoustic Approach, Kevin Mershon Boswell Jan 2006

Quantifying Changes In Fish Habitat Use In Coastal Waters Of Louisiana, Usa: A Hydroacoustic Approach, Kevin Mershon Boswell

LSU Doctoral Dissertations

The development of reliable tools for identifying essential fish habitat (EFH) has proven problematic. Knowledge of the distribution and biomass of fishes over discrete habitat types is a prerequisite for effective use of EFH in the management of important commercial and recreational fish species. Resolution of the influence of habitat type and environmental factors on the distribution of fishes is confounded by limitations of traditional sampling gears. To date, hydroacoustic technology has been widely accepted as a tool for surveying fishery resources; however few studies have implemented acoustics in ultra shallow (<2 m) coastal waters. Efforts should be made to utilize hydroacoustics for quantifying changes in fish distributions within estuarine environments given the benefits provided through acoustic technology (e.g. ease of deployment, reduced sampling effort, and non-invasive sampling attributes). A technique was developed for acoustically sensing fishes in the shallow, turbid waters of Barataria Bay, Louisiana. A robust and lightweight remotely-controlled transducer platform was designed for deploying acoustic gear. Sources of scattering within the bay were identified through a series of exclosure net experiments designed to quantify potential effects of plankton and suspended solids on acoustic scattering. Analysis filters were developed to reduce the effects of bubble-induced noise, often observed during periods when wind speeds were greater than 4.5 m s-1. Side-aspect acoustic target strength-length and target …

Go to article

Belowground Biomass Of Spartina Alterniflora: Seasonal Variability And Response To Nutrients, Faith Armand Darby Jan 2006

Belowground Biomass Of Spartina Alterniflora: Seasonal Variability And Response To Nutrients, Faith Armand Darby

LSU Doctoral Dissertations

Spartina alterniflora is a salt marsh macrophyte found from Canada to the Gulf of Mexico which often provides the dominant plant cover. Although S. alterniflora is well known for its high aboveground productivity, fifty to ninety percent of the total plant production occurs belowground. No previous studies address the seasonal variation of belowground biomass or the response of above-and belowground biomass to nutrients at the southern limits of its U. S. range. The objectives of this study were to: 1) document the seasonal variability of its above- and belowground biomass and test for responses to various combinations of N, P, …

Go to article

Effects Of Diesel-Fuel And Copper Contaminants On Benthic Microalgae, Soraya Silva Jan 2006

Effects Of Diesel-Fuel And Copper Contaminants On Benthic Microalgae, Soraya Silva

LSU Doctoral Dissertations

Salt marshes are dynamic, highly productive habitats and serve as nursery grounds for many commercially and economically important species. Benthic microalgae (BMA) are considered an important food source for benthos and provide the principal source of nutrition that fuels secondary production. Estuarine sediments around the world are a repository for many contaminants from anthropogenic sources. In particular, hydrocarbons and metals are ubiquitous contaminants in coastal systems. The primary goal of this study was to study the effects of diesel fuel and copper, alone and in combination, on the BMA assemblage from a coastal salt marsh. To achieve this objective, salt …

Go to article

Topographic Influence On Overflow Dynamics: Idealized Numerical Simulations And The Faroe Bank Channel Overflow, Tal Ezer Jan 2006

Topographic Influence On Overflow Dynamics: Idealized Numerical Simulations And The Faroe Bank Channel Overflow, Tal Ezer

CCPO Publications

Properties of the North Atlantic Deep Water (NADW) depend on mixing that occurs in the Denmark Strait (DS) and the Faroe Bank Channel (FBC) overflow regions. How the sill's topography in those regions may affect mixing processes and downstream variability is thus investigated using a high-resolution terrain-following ocean model. Model results agree with observations that show enhanced mixing and entrainment downstream from the sill; however, mixing seems to occur over a longer distance downstream from the FBC sill and more abruptly downstream from the DS sill. Sensitivity experiments with various FBC sill widths demonstrate that the narrow sill is responsible …

Go to article

Loop Current Warming By Hurricane Wilma, Lie-Yauw Oey, Tal Ezer, Dong-Ping Wang, S. J. Fan, Xun-Qiang Yin Jan 2006

Loop Current Warming By Hurricane Wilma, Lie-Yauw Oey, Tal Ezer, Dong-Ping Wang, S. J. Fan, Xun-Qiang Yin

CCPO Publications

Hurricanes mix and cool the upper ocean, as shown here in observations and modeling of the Caribbean Sea and the Gulf of Mexico during the passage of hurricane Wilma. Curiously, the upper ocean around the Loop Current warmed prior to Wilma's entrance into the Gulf. The major cause was increased volume and heat transports through the Yucatan Channel produced by storm-induced convergences in the northwestern Caribbean Sea. Such oceanic variability may have important impacts on hurricane predictions.

Go to article

A Comparison Of Global Estimates Of Marine Primary Production From Ocean Color, Mary-Elena Carr, Marjorie A. M. Friedrichs, Marjorie Schmeltz, Maki Noguchi Aita, David Antoine, Kevin R. Arrigo, Ichio Asanuma, Oliver Aumont, Richard Barber, Michael Behrenfeld Jan 2006

A Comparison Of Global Estimates Of Marine Primary Production From Ocean Color, Mary-Elena Carr, Marjorie A. M. Friedrichs, Marjorie Schmeltz, Maki Noguchi Aita, David Antoine, Kevin R. Arrigo, Ichio Asanuma, Oliver Aumont, Richard Barber, Michael Behrenfeld

CCPO Publications

The third primary production algorithm round robin (PPARR3) compares output from 24 models that estimate depth-integrated primary production from satellite measurements of ocean color, as well as seven general circulation models (GCMs) coupled with ecosystem or biogeochemical models. Here we compare the global primary production fields corresponding to eight months of 1998 and 1999 as estimated from common input fields of photosynthetically-available radiation (PAR), sea-surface temperature (SST), mixed-layer depth, and chlorophyll concentration. We also quantify the sensitivity of the ocean-color-based models to perturbations in their input variables. The pair-wise correlation between ocean-color models was used to cluster them into groups …

Go to article

Pelagic Functional Group Modeling: Progress, Challenges And Prospects, Raleigh R. Hood, Edward A. Laws, Robert A. Armstrong, Nicholas R. Bates, Christopher W. Brown, Craig A. Carlson, Fei Chai, Scott C. Doney, Paul G. Falkowski, Richard A. Feely, Marjorie A. M. Friedrichs Jan 2006

Pelagic Functional Group Modeling: Progress, Challenges And Prospects, Raleigh R. Hood, Edward A. Laws, Robert A. Armstrong, Nicholas R. Bates, Christopher W. Brown, Craig A. Carlson, Fei Chai, Scott C. Doney, Paul G. Falkowski, Richard A. Feely, Marjorie A. M. Friedrichs

CCPO Publications

In this paper, we review the state of the art and major challenges in current efforts to incorporate biogeochemical functional groups into models that can be applied on basin-wide and global scales, with an emphasis on models that might ultimately be used to predict how biogeochemical cycles in the ocean will respond to global warming. We define the term "biogeochemical functional group" to refer to groups of organisms that mediate specific chemical reactions in the ocean. Thus, according to this definition, "functional groups" have no phylogenetic meaning-these are composed of many different species with common biogeochemical functions.

Substantial progress has …

Go to article

Transport Of Antarctic Krill (Euphausia Superba) Across The Scotia Sea. Part Ii: Krill Growth And Survival, Bettina A. Fach, Eileen E. Hofmann, Eugene J. Murphy Jan 2006

Transport Of Antarctic Krill (Euphausia Superba) Across The Scotia Sea. Part Ii: Krill Growth And Survival, Bettina A. Fach, Eileen E. Hofmann, Eugene J. Murphy

CCPO Publications

A time-dependent, size-structured, physiologically based krill growth model was used in conjunction with a circulation model to test the hypothesis that Antarctic krill (Euphausia superba) populations at South Georgia are sustained by import of individuals from upstream regions. Surface phytoplankton concentrations along the simulated drifter trajectories were extracted from historical Coastal Zone Color Scanner (CZCS) measurements and sea ice biota concentrations were calculated from sea ice concentration and extent extracted along drifter trajectories from Special Sensor Microwave/ Imager measurements. As additional food sources, a time series of heterotrophic food was constructed from historical data, and time series of …

Go to article

Habitat Use By Nekton In A Saltmarsh Estuary Along A Stream-Order Gradient In Northeastern Barataria Bay, Louisiana, Pablo Granados-Dieseldorff Jan 2006

Habitat Use By Nekton In A Saltmarsh Estuary Along A Stream-Order Gradient In Northeastern Barataria Bay, Louisiana, Pablo Granados-Dieseldorff

LSU Master's Theses

Mesohaline estuarine regions in Louisiana play an important role in coastal ecosystems. To begin to understand how nektonic species and communities respond to environmental variables before habitat modification, I examined patterns of habitat use by fishes and decapod crustaceans in a seemingly pristine mesohaline system that drains into Bay Batiste, southeastern Louisiana. The study area was focused on a relatively unaltered core saltmarsh complex drained by intertidal and subtidal streams and it was representative of a larger surrounding system in terms of nekton community structure and associated environmental variables. Stratified monthly sampling (February – November 2004) along a stream-order gradient …

Go to article

Petrological And Geochemical Investigations Of Deep Sea Turbidite Sands In The Pandora And Moresby Troughs: Source To Sink Papua New Guinea Focus Area, Luke Jeremiah Patterson Jan 2006

Petrological And Geochemical Investigations Of Deep Sea Turbidite Sands In The Pandora And Moresby Troughs: Source To Sink Papua New Guinea Focus Area, Luke Jeremiah Patterson

LSU Master's Theses

The Moresby and Pandora Troughs of the northern Coral Sea are components of the deep-sea depositional system that is the ultimate sink for the Source to Sink Papua New Guinea (PNG) Focus Area. Cores collected from the R/V Melville during March-April 2004 reveal marine volcaniclastic and terrigenous turbidites deposited in these troughs during the Quaternary. Constraining the spatial, temporal, and provenance characteristics for these terrigenous sands through mineralogical, chemical, and textural analysis is the primary focus of this study. All cores contain thinly-bedded sandy turbidite packages interlayered with hemipelagic marls and typical centimeter-to-meter-thick turbidite sequences. The Moresby Trough core JPC22 …

Go to article

Laboratory And Field Measurements Of Bioturbation By Macrofauna In A Coastal Setting, Skyler Neylon Jan 2006

Laboratory And Field Measurements Of Bioturbation By Macrofauna In A Coastal Setting, Skyler Neylon

LSU Master's Theses

Two ophiuroid species, Hemipholis elongata and Ophiophragmus spp. were studied in laboratory microcosms to elucidate patterns of sediment mixing for key bioturbators in the Mississippi Sound, Mississippi. The effects of bioturbation on artificially stratified sediments in microcosms were traced via time-series digital x-radiography. Preliminary results indicate that for three population densities of the brittle stars (comparable to field densities), a steady state volumetric bioturbation rate of 1-2 cm3/d is reached within two months of introduction to a fresh system. The preservation quotient, q, a fractional measure of preserved primary fabric, reached a minimum of 0.5 during the 16-week experiment. Maximum …

Go to article

First Prev Next Last