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Articles 5881 - 5910 of 13997

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Determining The Viability Of Recent Storms As Modern Analogues For North-Central Gulf Of Mexico Paleotempestology Through Sedimentary Analysis And Storm Surge Reconstruction, Joshua Caleb Bregy Aug 2016

Determining The Viability Of Recent Storms As Modern Analogues For North-Central Gulf Of Mexico Paleotempestology Through Sedimentary Analysis And Storm Surge Reconstruction, Joshua Caleb Bregy

Master's Theses

The northern Gulf of Mexico has been devastated by recent intense storms. Camille (1969) and Katrina (2005) are two notable hurricanes that made landfall in virtually the same location in Mississippi. However, fully understanding the risks and processes associated with hurricane impacts is impeded by a short and fragmented instrumental record. Paleotempestology could potentially use modern analogues from intense storms in this region to extend the hurricane record back to pre-observational time. Existing empirically based models can back-calculate surge heights over coastal systems as a function of transport distance, particle settling velocity, and gravitational acceleration. We collected cores in a …


Chlorine Demand Shows Thresholds And Hierarchy With Source Water Quality At Beaver Lake, Arkansas, Jaime M. Gile Aug 2016

Chlorine Demand Shows Thresholds And Hierarchy With Source Water Quality At Beaver Lake, Arkansas, Jaime M. Gile

Graduate Theses and Dissertations

This study investigated the effects of source water quality in Beaver Lake on the amount of chlorine (Cl) needed to develop decision support system to help guide chlorination practices in pre-treatment of source water. Chlorine demand assays were performed on water samples from Beaver Lake collected from the intake structure at Beaver Water District from March 2014 through August 2015, and using data from these assays, the two points of interest in this study were the Cl dose at which Cl residuals began to accumulate and the mean Cl demand occurring after that dose. Three methods of analysis were used …


Is The Detection Of Accelerated Sea Level Rise Imminent?, J. T. Fasullo, R. S. Nerem, B. Hamlington Aug 2016

Is The Detection Of Accelerated Sea Level Rise Imminent?, J. T. Fasullo, R. S. Nerem, B. Hamlington

CCPO Publications

Global mean sea level rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of sea level rise to have decreased from the first to second decades of the altimeter era. Here, a combined analysis of altimeter data and specially designed climate model simulations shows the 1991 eruption of Mt Pinatubo to likely have masked the acceleration that would have otherwise occurred. This masking …


Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson Aug 2016

Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson

Graduate Theses and Dissertations

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …


Tornado Density And Return Periods In The Southeastern United States: Communicating Risk And Vulnerability At The Regional And State Levels, Michelle Bradburn Aug 2016

Tornado Density And Return Periods In The Southeastern United States: Communicating Risk And Vulnerability At The Regional And State Levels, Michelle Bradburn

Electronic Theses and Dissertations

Tornado intensity and impacts vary drastically across space, thus spatial and statistical analyses were used to identify patterns of tornado severity in the Southeastern United States and to assess the vulnerability and estimated recurrence of tornadic activity. Records from the Storm Prediction Center's tornado database (1950-2014) were used to estimate kernel density to identify areas of high and low tornado frequency at both the regional- and state-scales. Return periods (2-year, 5-year, 10-year, 25-year, 50-year, and 100-year) were calculated at both scales as well using a composite score that included EF-scale magnitude, injury counts, and fatality counts. Results showed that the …


Wind Climatology: A Study Of Trends On Rodgers' Dry Lakebed, Dana Coppernoll-Houston Aug 2016

Wind Climatology: A Study Of Trends On Rodgers' Dry Lakebed, Dana Coppernoll-Houston

STAR Program Research Presentations

A number of smaller projects at the Armstrong Flight Research Center fly on or close to the ground and are subject to ground-level winds. Many of these are new prototype models, such as PRANDTL-D (Preliminary Research Aerodynamic Design to Lower Drag). Waiting for the right conditions on a day of variable winds can sometimes mean that teams fail to complete testing. A strategic analysis of wind behavior at a locations where winds can vary greatly due to terrain could lend insight into the best times to test for near-ground aircraft. The purpose of this project was to data mine historical …


Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise Aug 2016

Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise

Graduate Theses and Dissertations

A steady-state mass diffusion model used with simple measurable and calculable inputs for determining sediment oxygen demand (SOD) is compared to an intact core incubation (ICI) SOD method using samples from three lakes. The mass diffusion model coupled with inputs is known as the measure-calculate method (M-C) and is a potential alternative to existing methods for measuring SOD which are more complex, time-consuming, and costly. The M-C method requires inputs for volumetric sediment oxygen uptake (Ṅsed), sediment density and porosity, and water properties. Ṅsed was determined by suspending sediment in oxygen-saturated water with a DO probe and determining the steady …


Electrodeionization Versus Electrodialysis: A Clean-Up Of Produced Water In Hydraulic Fracturing, Brigitte Marie Rodgers Aug 2016

Electrodeionization Versus Electrodialysis: A Clean-Up Of Produced Water In Hydraulic Fracturing, Brigitte Marie Rodgers

Graduate Theses and Dissertations

Electrodeionization (EDI) is a widely studied process ranging from applications in wastewater clean-up in the food and beverage industry to purifying organic compounds. To date, there are no apparent studies on applying this technology to produced wastewater recovered from hydraulic fracking sites. Water consumption within hydraulic fracturing sites can reach in the upwards of millions of gallons per site, so a need for a water recycling process becomes necessary within areas where water requirements are scarce. Implementation of an EDI module that is capable of handling high salt solutions from produced wastewater in subsequent fracturing practices will decrease overall water …


The Impact Of Climate Change In Bangladesh On The Rice Market And Farm Households, Mst Ashrafun Nahar Aug 2016

The Impact Of Climate Change In Bangladesh On The Rice Market And Farm Households, Mst Ashrafun Nahar

Graduate Theses and Dissertations

Bangladesh is trying to achieve self-sufficiency in domestic rice production but climate change effects on agricultural production makes it challenging to attain the goal. The country is highly vulnerable to the effects of climate change since it is the major cause to rise in sea level, more warm summer, and happening food and cyclone in the country.

This study develops an Aggregate Farm Household Model to analyze the impact of potential land loss and yield reduction from climate change on production, consumption, prices, welfare, and the ability of government to achieve self-sufficiency in rice production. The model is calibrated to …


Biogeochemistry Of A Saline, Alkaline, Terminal Lake Ecosystem In Transition; Walker Lake, Nevada, Katherine Lynn Willever Aug 2016

Biogeochemistry Of A Saline, Alkaline, Terminal Lake Ecosystem In Transition; Walker Lake, Nevada, Katherine Lynn Willever

UNLV Theses, Dissertations, Professional Papers, and Capstones

Walker Lake is a saline, alkaline, terminal lake ecosystem located in west-central Nevada. For over one hundred years, anthropogenic streamflow diversions within the Walker River Basin have ultimately led to little or no water reaching Walker Lake, the basin’s terminus for water flow. These diversions have resulted in a >46 meter decrease in the lake surface altitude and increases in salinity and dissolved salt constituents that have caused the elimination of native fish species. This study examines how the lack of freshwater inflow has altered the physical, chemical, and microbiological structure of Walker Lake during the lake’s ongoing desiccation.

Between …


Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson Aug 2016

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Graduate Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment zones’ (PICZ) and …


Elevation Data And Mapping Updates, Doug Marcy Jul 2016

Elevation Data And Mapping Updates, Doug Marcy

July 29, 2016: The Latest in Sea Level Rise Science

No abstract provided.


Street Level Predictive Modeling Of Nuisance Flooding In Norfolk, Va, Jon Derek Loftis, Harry V. Wang, David R. Forrest, William 'Skip' A. Stiles Jul 2016

Street Level Predictive Modeling Of Nuisance Flooding In Norfolk, Va, Jon Derek Loftis, Harry V. Wang, David R. Forrest, William 'Skip' A. Stiles

July 29, 2016: The Latest in Sea Level Rise Science

No abstract provided.


Noaa Inundation Dashboard, Audra Luscher, Paul Fanelli Jul 2016

Noaa Inundation Dashboard, Audra Luscher, Paul Fanelli

July 29, 2016: The Latest in Sea Level Rise Science

No abstract provided.


The Science Of Sea Level Rise And The Impact Of The Gulf Stream, Tal Ezer Jul 2016

The Science Of Sea Level Rise And The Impact Of The Gulf Stream, Tal Ezer

July 29, 2016: The Latest in Sea Level Rise Science

No abstract provided.


Risk Of Extreme Events, Don Resio Jul 2016

Risk Of Extreme Events, Don Resio

July 29, 2016: The Latest in Sea Level Rise Science

No abstract provided.


Subsidence Monitoring In Hampton Roads Using Satellites, Ben Hamlington Jul 2016

Subsidence Monitoring In Hampton Roads Using Satellites, Ben Hamlington

July 29, 2016: The Latest in Sea Level Rise Science

No abstract provided.


Agenda, Hr Adaptation Forum Jul 2016

Agenda, Hr Adaptation Forum

July 29, 2016: The Latest in Sea Level Rise Science

No abstract provided.


Total Water Level And Wave Run Up Forecast, Eric Seymour Jul 2016

Total Water Level And Wave Run Up Forecast, Eric Seymour

July 29, 2016: The Latest in Sea Level Rise Science

No abstract provided.


Coral Persistence To Ocean Warming Via Developmental Acclimation, Heather L. Schaneen Jul 2016

Coral Persistence To Ocean Warming Via Developmental Acclimation, Heather L. Schaneen

HCNSO Student Theses and Dissertations

Scleractinian corals are the ‘engineers’ of tropical coral reef ecosystems. Their three-dimensional structure provides habitat for thousands of fish and invertebrate species. The persistence of corals is threatened by climate change. In this study I investigated if corals may be able to increase tolerance to ocean warming through developmental acclimation, i.e. if corals that experience warmer temperatures during embryonic and larval development are better able to cope with higher temperatures later in life. Larvae of the broadcast spawning coral Montastraea cavernosa were raised at ambient (29°C) and future projected ocean warming temperatures (+2°C, 31°C). After larval settlement, coral juveniles from …


Temporal And Spatial Distribution Of Cetacean Strandings Focusing On The Bottlenose Dolphin (Tursiops Truncatus) With A Synthesis Of Potential Causes, April D. Clark Jul 2016

Temporal And Spatial Distribution Of Cetacean Strandings Focusing On The Bottlenose Dolphin (Tursiops Truncatus) With A Synthesis Of Potential Causes, April D. Clark

HCNSO Student Capstones

A comprehensive review of the literature and a quantitative statistical analysis of that information are presented. A total of 6,015 cetaceans stranded at 36 locations from 24 peer reviewed articles published between 1999 and 2014 are documented, with the two most common stranding locations being the Canary Islands - accounting for 49 of the total cetacean stranding events - and Cape Cod - accounting for 31 of total cetacean stranding events. The documented cetacean stranding events included 805 for bottlenose dolphins (Tursiops truncatus) at a total of ten locations from 11 peer reviewed articles. When all single stranding …


Multiple New-Particle Growth Pathways Observed At The Us Doe Southern Great Plains Field Site, Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. Mcmurry, James N. Smith, Jeffery R. Pierce Jul 2016

Multiple New-Particle Growth Pathways Observed At The Us Doe Southern Great Plains Field Site, Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. Mcmurry, James N. Smith, Jeffery R. Pierce

Civil and Environmental Engineering Faculty Publications and Presentations

New-particle formation (NPF) is a significant source of aerosol particles into the atmosphere. However, these particles are initially too small to have climatic importance and must grow, primarily through net uptake of low volatility species, from diameters ∼ 1 to 30–100 nm in order to potentially impact climate. There are currently uncertainties in the physical and chemical processes associated with the growth of these freshly formed particles that lead to uncertainties in aerosol-climate modeling. Four main pathways for new-particle growth have been identified: condensation of sulfuric-acid vapor (and associated bases when available), condensation of organic vapors, uptake of organic acids …


Transgenerational Effects Of Thermal Stress: Impacts On And Beyond Coral Reproduction, Alyson Kuba Jul 2016

Transgenerational Effects Of Thermal Stress: Impacts On And Beyond Coral Reproduction, Alyson Kuba

HCNSO Student Theses and Dissertations

Ocean warming causes stress to corals and records reveal that periods of thermal stress are increasing in frequency and severity. Previous studies show that thermal stress negatively impacts the reproductive output of corals. However, the transgenerational impacts of coral bleaching have never been quantified. As a consequence, it is unclear how ocean warming may alter population dynamics due to effects on reproduction and recruitment. This study quantified the transgenerational impacts of thermal stress in Montastraea cavernosa. To assess transgenerational effects of temperature stress during gametogenesis, colonies were exposed to elevated temperature for two weeks four months prior to spawning, …


Can Skeletal Morphology Support New Molecular Phylogenies Of Antedonidae (Crinoidea: Comatulida)?, Brenna Hays Jul 2016

Can Skeletal Morphology Support New Molecular Phylogenies Of Antedonidae (Crinoidea: Comatulida)?, Brenna Hays

HCNSO Student Theses and Dissertations

Antedonidae (Crinoidea: Comatulida) is the largest of extant crinoid families; it currently includes ~155 accepted species in 50 genera and accounts for ~23% of extant crinoid species (~29% of feather stars) and 27% of genera. Molecular phylogenies have returned the family as polyphyletic, with several clades scattered among non-antedonid sister groups (Hemery 2011, Hemery et al. 2013, Rouse et al. in prep.). Traditional morphological characteristics are thus inadequate for reconstructing relationships among taxa. SEM imaging was used in an effort to discover new diagnostic features that will support the molecular data, focusing on skeletal ossicles within the calyx, specifically the …


Artificial Reefs As Juvenile Fish Habitats In Marinas, Allison Patranella Jul 2016

Artificial Reefs As Juvenile Fish Habitats In Marinas, Allison Patranella

HCNSO Student Theses and Dissertations

Coastal infrastructure has replaced many vital fish nursery habitats with structures designed without fully mitigating for the loss of the natural ecosystems. This thesis details research focused on the use of small, inexpensive, artificial reef modules as replacement juvenile fish habitat within marinas. My research hypothesis was that the placement of small, structurally complex artificial reef modules would increase fish abundance and species richness relative to unmodified marina seawalls. Non-destructive visual surveys of fishes were completed monthly for 14 months for 12 artificial reef sites and 12 control (unmodified) sites within the Nova Southeastern University Guy Harvey Oceanographic Center (NSU-GHOC) …


Reproductive Ecology Of Dragonfishes (Family: Stomiidae) In The Gulf Of Mexico, Alex D. Marks Jul 2016

Reproductive Ecology Of Dragonfishes (Family: Stomiidae) In The Gulf Of Mexico, Alex D. Marks

HCNSO Student Theses and Dissertations

The most speciose group of fishes in the Gulf of Mexico is the dragonfishes (Family: Stomiidae). These fishes are dominant mesopelagic predators occurring throughout the world’s oceans, including the Antarctic seas. Little is known regarding their reproductive ecology, a consequence attributed to insufficient sample sizes of mature adults due to inadequacies of sampling gear; larger, sexually mature stomiid adults are more adept at net avoidance, thereby obfuscating synoptic reproductive biology studies. Between 2010-2011, the Offshore Nekton Sampling and Analysis Program was initiated in the northern Gulf of Mexico over all four seasons using a discrete-depth sampling system (MOCNESS) and a …


Sunlight Induced Chlorophyll Fluorescence In The Near-Infrared Spectral Region In Natural Waters: Interpretations Of The Narrow Reflectance Peak Around 761nm, Yingcheng Lu, Linhai Li, Minwei Zhang, Shaojie Sun, Chunguang Lv Jul 2016

Sunlight Induced Chlorophyll Fluorescence In The Near-Infrared Spectral Region In Natural Waters: Interpretations Of The Narrow Reflectance Peak Around 761nm, Yingcheng Lu, Linhai Li, Minwei Zhang, Shaojie Sun, Chunguang Lv

Marine Science Faculty Publications

Sunlight induced chlorophyll a fluorescence (SICF) can be used as a probe to estimate chlorophyll a concentrations (Chl) and infer phytoplankton physiology. SICF at ∼685 nm has been widely applied to studies of natural waters. SICF around 740 nm has been demonstrated to cause a narrow reflectance peak at ∼761 nm in the reflectance spectra of terrestrial vegetation. This narrow peak has also been observed in the reflectance spectra of natural waters, but its mechanism and applications have not yet been investigated and it has often been treated as measurement artifacts. In this study, we aimed to interpret …


Modeling The Global Atmospheric Transport And Deposition Of Mercury To The Great Lakes, Mark D. Cohen, Roland R. Draxler, Richard S. Artz, Pierrette Blanchard, Mae Sexauer Gustin, Young-Ji Han, Thomas M. Holsen, Daniel A. Jaffe, Paul Kelley, Hang Lei, Christopher P. Loughner, Winston T. Luke, Seth N. Lyman, David Niemi, Jozef M. Pacyna, Martin Pilote, Laurier Poissant, Dominique Ratte, Xinrong Ren, Frits Steenhuisen, Alexandra Steffen, Rob Tordon, Simon J. Wilson Jul 2016

Modeling The Global Atmospheric Transport And Deposition Of Mercury To The Great Lakes, Mark D. Cohen, Roland R. Draxler, Richard S. Artz, Pierrette Blanchard, Mae Sexauer Gustin, Young-Ji Han, Thomas M. Holsen, Daniel A. Jaffe, Paul Kelley, Hang Lei, Christopher P. Loughner, Winston T. Luke, Seth N. Lyman, David Niemi, Jozef M. Pacyna, Martin Pilote, Laurier Poissant, Dominique Ratte, Xinrong Ren, Frits Steenhuisen, Alexandra Steffen, Rob Tordon, Simon J. Wilson

USU Uintah Basin Faculty Publications

Mercury contamination in the Great Lakes continues to have important public health and wildlife ecotoxicology impacts, and atmospheric deposition is a significant ongoing loading pathway. The objective of this study was to estimate the amount and source-attribution for atmospheric mercury deposition to each lake, information needed to prioritize amelioration efforts. A new global, Eulerian version of the HYSPLIT-Hg model was used to simulate the 2005 global atmospheric transport and deposition of mercury to the Great Lakes. In addition to the base case, 10 alternative model configurations were used to examine sensitivity to uncertainties in atmospheric mercury chemistry and surface exchange. …


Can Twilight Reefs Usher In A New Dawn For Depauperate Shallow Coral Reefs?, Hunter Kg Noren Jul 2016

Can Twilight Reefs Usher In A New Dawn For Depauperate Shallow Coral Reefs?, Hunter Kg Noren

HCNSO Student Theses and Dissertations

As shallow reefs continue to decline, scientists are searching for the key to their persistence; as it turns out, they may just need to look deeper. Below many shallow tropical reefs, there exist healthy and more stable mesophotic coral reef communities. The ability of these reefs to act as a refuge for declining shallow populations has garnered significant interest among the scientific community; however, the reproductive and larval aspects necessary for this to occur are unknown. This study assesses the ability of deep reefs to act as a reproductive refuge for shallow counterparts by examining gametic compatibility, viability and larval …


Effects Of Emf Emissions From Undersea Electric Cables On Coral Reef Fishes, Robert F. Jermain Jul 2016

Effects Of Emf Emissions From Undersea Electric Cables On Coral Reef Fishes, Robert F. Jermain

HCNSO Student Theses and Dissertations

The objective of this project was to determine if the electromagnetic field (EMF) emissions from undersea power cables impacted the local and transient marine life, with an emphasis on reef fishes. The work was done at South Florida Ocean Measurement Facility of Naval Surface Warfare Center, Carderock Division, Broward County, Florida. This facility functions as the hub for a range of active undersea detection and data transmission cables. It has multiple active submarine power cables that extend several miles offshore and which can deliver power and enable data transmission to and from a range of acoustic and EMF sensors. The …