Physical Sciences and Mathematics Commons^™

Wave Transformation At A Saltmarsh Edge And Resulting Marsh Edge Erosion: Observations And Modeling, Kevin J. Trosclair

University of New Orleans Theses and Dissertations

This study examines wind generated waves during winter storms, their transformation/attenuation near the marsh edge, and the resulting saltmarsh edge erosion. A simple numerical model for wave generation, transmission and marsh edge erosion was developed and validated against observations from Lake Borgne, Louisiana. Results suggest that meteorological conditions modify the local water depth via wind or wave setup and atmospheric pressure, thus exerting a first order control on the location of wave attack, which in turn determines the type of wave forces (shear vs. impact) that dominate the erosion process. Scarp failure follows, at a location determined by water level, …

Shark Community Structure In Winyah Bay, Sc, Keenen Fryman

Honors Theses

Assessments of local shark stocks are vital to understand population trends and their causes. Local data are incomplete despite many studies over many years. The first published study listed all of the shark species found off the coast of SC (Bearden 1965). Following Bearden's work, Schwartz (2003) used a 30 year data set to describe the elasmobranchs found in NC and SC. In 2004, a survey of coastal habitats in southeast NC helped to identify the nursery habitat for C. acronotus, C. brevipinna, C. limbatus, C. obscurus, C. plumbeus, M. canis, R. terraenovae, S. tiburo, and S. lewini (Thorpe et …

How Does Climate Change Affect Coral Reefs?, Rachel Goff

Honors Theses

Climate change is a very real phenomenon that currently affects many of the ecosystems on Earth. Climate change occurs on a global scale and can be very detrimental to different environments. This occurrence can cause ocean warming, sea level rise, ocean acidification, and increased storm intensity. According to the EPA, the ocean's temperature has increased 1.4°F over the past century, and sea levels have risen 3.2 millimeters through the past 20 years. These changes to the oceans can greatly affect many of the ecosystems that reside in them. One of the main ecosystems that are being affected by climate change …

Identification And Characterization Of Fine Particulate Matter Hot Spots On An Urban Arterial Corridor Integrating Probe Vehicle, Traffic And Land Use Data, Katherine Eleanor Bell

Dissertations and Theses

The purpose of this study is to explore the use of integrated probe vehicle, traffic and land use data to identify and characterize fine particulate matter (PM[subscript 2.5]) hot spot locations on urban arterial corridors. In addition, a preliminary analysis is conducted to consider volatile organic compound (VOC) hot spot locations. A pollutant hot spot is defined as a location on a corridor in which the mean pollutant concentrations are consistently above the 85th percentile of pollutant concentrations when compared to all locations along the corridor. In order to collect data for this study, an electric vehicle was equipped with …

Scenario Development And Analysis Of Freshwater Ecosystem Services Under Land Cover And Climate Change In The Tualatin And Yamhill River Basins, Oregon, Robert Wesley Hoyer

Dissertations and Theses

Humans make decisions within ecosystems to enhance their well-being, but choices can lead to unintended consequences. The ecosystem services (ES) approach supports decision-making that considers all environmental goods and services. Many challenges remain in the implementation of the ES approach like how specific ES vary through space and time. We address this research problem using the Tualatin and Yamhill river basins in northwestern Oregon as a study area. Freshwater ES are quantified and mapped with the spatially-explicit ES modeling tool, Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST). In chapter II, we develop a simple urban land cover change modeling …

Robinson Point, Belize: An Important Foraging Ground For Endangered Sea Turtles In The Western Caribbean Sea, Linda Searle

HCNSO Student Theses and Dissertations

Anecdotal reports, flipper tag returns, satellite migration paths, and above-water and net surveys have identified an important foraging area for sea turtles in the Robinson Point area, 12 kilometers southwest of Belize City. Visual observations confirmed that sea turtles were actively foraging at Robinson Point. Sixteen 30 minute visual observations from stationary and drifting boats made 132 sea turtle sightings from October 2007 through January 2008, with a maximum of 40 sightings made in one survey. In-water capture methodology tested the traditional turtle net, which captured 14 turtles in 63 sets for a success rate of only 22%. There were …

Species Composition And Reproductive Strategies Of Commensal Synalpheus Shrimp (Decapoda:Alpheidae) Occupying The Sponges Spheciospongia Vesparium And Spongia Sp. Of The Florida Reef Tract, Brittnee Nicole Barris

HCNSO Student Theses and Dissertations

Synalpheus shrimp species of the gambarelloides group are the only marine organisms displaying the highest level of social functioning, eusociality. Their social hierarchies are equally complex compared to the reproductive abnormalities that have been recently discovered. For instance, snapping shrimp of the genus Synalpheus were thought to be gonochoric, i.e. developing as independent sexes, until scanning electron microscopy studies revealed intersexed gonopores in several species. This project analyzed both the species composition, and accompanying reproductive structures, of Synalpheus spp. (Caridea: Alpheidae) comprised of densely aggregating communal and pair-living colonies in the Florida Keys, Florida.

Colonies of pair-living and communal Synalpheus …

Educating The Masses: Human Attitudes Affecting Reef Health, Ashley Wiehl

HCNSO Student Theses and Dissertations

About two thirds of the world’s population lives within 60 km of a coastline, however many members of the public do not recognize the importance of the nearby coral reef ecosystems. Although reef degradation is currently occurring at alarming rates, there is hope for the future of coral reef health. It is proven that humans have a large effect on the current health of coral reefs. This thesis aims to determine how marine scientists and educators can best influence the general public to affect behaviors to improve reef health. To do this involves taking analyzing the many effects of human …

Developing An Acoustic Method For Reducing North Atlantic Right Whale (Eubalaena Glacialis) Ship Strike Mortality Along The United States Eastern Seaboard, Kaitlyn Allen Mullen

Electronic Theses and Dissertations

North Atlantic right whales (Eubalaena glacialis) are among the world’s most endangered cetaceans. Although protected from commercial whaling since 1949, North Atlantic right whales exhibit little to no population growth. Ship strike mortality is the leading known cause of North Atlantic right whale mortality. North Atlantic right whales exhibit developed auditory systems, and vocalize in the frequency range that dominates ship acoustic signatures. With no behavioral audiogram published, current literature assumes these whales should be able to acoustically detect signals in the same frequencies they vocalize. Recorded ship acoustic signatures occur at intensities that are similar or higher to those …

A Crowdsourced Hail Dataset: Potential, Biases, And Inaccuracies, Joseph Robert Pehoski

Theses and Dissertations

Hail is a substantial severe weather hazard in the USA, with significant damage to property and

crops occurring annually. Traditional methods of forecasting hail size have limited accuracy, and despite

improvements in remote sensing of precipitation, the fall characteristics of hail make quantification of

hail imprecise. Research into hail is ongoing, but traditional hail datasets have known biases and low

spatiotemporal resolution. The increased usage of smartphones creates the opportunity to use a

crowdsourced dataset provided by the Precipitation Identification Near the Ground (PING) program, a

program developed by the National Severe Storms Laboratory. PING data is compared to approximate …

Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca

UNLV Theses, Dissertations, Professional Papers, and Capstones

An assessment of the growth response of key vegetative species to climatic variability is vital to identifying possible local impacts on ecosystems faced with imminent climate change. With current climate projections in Nevada predicting a shift to an even more arid climate with greater year-to-year variability, the imperative exists to identify the effects of specific climatic controls on plant growth and to research methods to assess large-scale vegetative changes, especially in more remote areas where readily available data sets may be lacking. This study utilized annual growth ring indices constructed from big sagebrush (Artemisia tridentatassp.tridentata) stems collected in Spring Valley, …

Temperature Trends And Urban Heat Island Intensity Mapping Of The Las Vegas Valley, Adam Leland Black

UNLV Theses, Dissertations, Professional Papers, and Capstones

Modified urban climate regions that are warmer than rural areas at night are referred to as Urban Heat Islands or UHI. Islands of warmer air over a city can be 12 degrees Celsius greater than the surrounding cooler air. The exponential growth in Las Vegas for the last two decades provides an opportunity to detect gradual temperature changes influenced by an increasing presence of urban materials. This thesis compares ground based thermometric observations and satellite based remote sensing temperature observations to identify temperature trends and UHI areas caused by urban development.

Analysis of temperature trends between 2000 and 2010 at …

Impacts Of Climate Changes On The Spatiotemporal Distribution Of Precipitation In The Western United States, Peng Jiang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Precipitation in the Intermountain West is characterized by its great variability in both spatial and temporal distributions. Moreover, the spatiotemporal distribution of the precipitation is changing due to the climate changes. In this dissertation, three studies are conducted to investigate the multi-scale temporal variability of precipitation, the performance of current climate models on this variability, the influence of large-scale ocean oscillations on heavy precipitation, and the impact of human induced global warming on storm properties.

The first study is to examine the performance of current climate models on the simulation of the multi-scale temporal variability determined from the observed station …

Examining Spring And Autumn Phenology In A Temperate Deciduous Urban Woodlot, Rong Yu

Theses and Dissertations

This dissertation is an intensive phenological study in a temperate deciduous urban woodlot over six consecutive years (2007-2012). It explores three important topics related to spring and autumn phenology, as well as ground and remote sensing phenology. First, it examines key climatic factors influencing spring and autumn phenology by conducting phenological observations four days a week and recording daily microclimate measurements. Second, it investigates the differences in phenological responses between an urban woodlot and a rural forest by employing comparative basswood phenological data. Finally, it bridges ground visual phenology and remote sensing derived phenological changes by using the Normalized Difference …

A Model Study Of The Copper River Plume And Its Effects On The Northern Gulf Of Alaska, Yuan Wang

Electronic Theses and Dissertations

Using a three-level nested Regional Ocean Modeling System coupled with the Carbon, Silicate, Nitrogen Ecosystem model, this study examined the seasonal evolution of the Copper River (CR) plume and how it influences the along- and across-shore transport in the northern Gulf of Alaska (NGoA). A passive tracer was introduced in the model to delineate the growth and decay of the plume and to diagnose the spread of the CR discharge in the shelf, into Prince William Sound (PWS) and offshore. Furthermore, a model experiment with doubled discharge was conducted to investigate potential impacts of accelerated glacier melt in future climate …

Assessing Trichloromethane Formation And Control In Algal-Stimulated Waters Amended With Nitrogen And Phosphorus, Clinton Mash

Graduate Theses and Dissertations

Nitrogen (N) and phosphorus (P) enrichments can stimulate algal growth in drinking water sources, which can cause increased production of disinfection byproduct (DBP) precursors. However, the effect of systematic N and P enrichments on DBP formation and control has not been adequately studied. In this work, we enriched samples from a drinking water source - sampled on April 5, May 30, and August 19, 2013 - with N and P to stimulate algal growth at N:P ratios covering almost five orders of magnitude (0.2-4,429). To simulate DBP-precursor removal processes at drinking water treatment plants (DWTPs), the samples were treated with …

Reservoir Management Techniques To Enhance Biological Productivity And Protect Water Quality, Ben Alan Thompson

Graduate Theses and Dissertations

Three reservoirs of similar size, watershed land use, and qualitative characteristics in northwest Arkansas, USA were selected to compare the effects of chemical fertilization and pulsed artificial-upwelling on whole-lake productivity, specifically primary production and phytoplankton biomass. Numerous water quality parameters were quantified over a two year period (2011-13) with the goal of understanding how each management technique would stimulate productivity. This experiment was the first step towards a larger goal to ultimately enhance sport fish production. The first year of monitoring occurred in 2011 and served as a control year for the three lakes. Treatments were initiated in two of …

Mapping Of The Quasi-Periodic Oscillations At The Flank Magnetopause Into The Ionosphere, Emily R. Dougal

Doctoral Dissertations and Master's Theses

We have estimated the ionospheric location, area, and travel time of quasi-periodic oscillations originating from the magnetospheric flanks. This was accomplished by utilizing global and local MHD models and Tsyganenko semi-empirical magnetic field model on multiple published and four new cases believed to be caused by the Kelvin-Helmholtz Instability. Finally, we used auroral, magnetometer, and radar instruments to observe the ionospheric signatures. The ionospheric magnetic latitude determined using global MHD and Tsyganenko models ranged from 58.3-80.2 degrees in the northern hemisphere and -59.6 degrees to -83.4 degrees in the southern hemisphere. The ionospheric magnetic local time ranged between 5.0-13.8 hours …

Auroral Ion Upflows: Sources, High Altitude Dynamics, And Neutral Wind Effects, Meghan R. Burleigh

Doctoral Dissertations and Master's Theses

Large upwellings of thermal plasma are commonly observed in the high-latitude, topside ionosphere. These auroral ion upflows have a range of potential sources including frictional heating, electron precipitation, neutral winds, and higher-altitude density cavities. The unique signatures and detailed evolution of these upflows are examined through the use of Incoherent Scatter Radar data and a sophisticated ionospheric fluid model.

A survey of solar cycle 23 shows that at Sondrestrom upflows occur most often in the cusp region and midnight auroral zone. Simplified force balance analysis and steady state velocity calculations are applied to a few select events to elucidate the …

Methyl Halide Production By Calcareous Periphyton Mats From The Florida Everglades, Ann Eileen Raffel

Dissertations and Theses

Methyl halides are trace gases with both natural and anthropogenic origins. Once generated, these gases transport chlorine and bromine into the stratosphere, where they play an important role in ozone depleting catalytic cycles. The Florida Everglades is one location where methyl halide emissions have been proposed to be elevated due to high primary production and ionic halogens. This region also provides a unique study environment due to salt water intrusions, which occur during storm or low marsh water level-high tide events. The purpose of this research was twofold. First, quantification of methyl chloride (CH₃Cl) and methyl bromide (CH …

Quantifying Crop Yield, Bioenergy Production And Greenhouse Gas Emissions From Cropland And Marginal Land Using A Model-Data Fusion Approach, Zhangcai Qin

Open Access Dissertations

Bioenergy is becoming increasingly attractive to many countries, but has sparked an intensive debate regarding energy, economy, society and environment. Biofuels provide alternative energy to conventional fossil fuels. However, the environmental impact of producing and using biofuel is a major concern to our society. This study is dedicated to quantifying and evaluating biofuel production and potential climate change mitigation due to potential large-scale bioenergy expansion in the conterminous United States, using model-data fusion approaches.

Biofuel made from conventional (e.g., maize (Zea mays L.)) and cellulosic crops (e.g., switchgrass (Panicum virgatum L.) and Miscanthus (Miscanthus × giganteus)) …

Phosphorus Cycling In Tropical Carbonate Sediment-Seagrass Systems, Zachary Howerton

OES Theses and Dissertations

This thesis presents two studies focusing on phosphorus cycling in calcium carbonate sediments inhabited by seagrasses. Phosphorus is a major limiting nutrient for primary productivity in these sediments as well as in the overlying waters. In large part this is due to removal of phosphate from solution by adsorption and precipitation reactions.

In chapter II, the relationship between the size of the sedimentary phosphorus pool and the abundance of seagrass on the Great Bahama Bank, as well as the relationship between phosphorus content and grain size in the sediments, were examined to better understand the biogeochemistry of carbonate sediments and …

Migratory Patterns And Habitat Use Of The Sand Tiger Shark (Carcharias Taurus) In The Western North Atlantic Ocean, Shara Marie Teter

HCNSO Student Theses and Dissertations

Large population declines for sand tiger sharks (Carcharias taurus) in parts of its global range are well documented, resulting in a strong need for biologically informed conservation and management measures. Although sand tigers in the western North Atlantic have been listed as a Species of Concern by the US government since 1997, details of their seasonal migratory movements and especially vertical habitat use patterns along the US East Coast are limited. Understanding these movement patterns is vital to reducing fishery-related mortality of these sharks and informing other management efforts aimed at recovery of their stocks in the US Atlantic. …

Characterization Of Secondary Organic Aerosol Precursors Using Two-Dimensional Gas Chromatography With Time Of Flight Mass Spectrometry (Gc×Gc/Tofms), Melissa Jordan Roskamp

Dissertations and Theses

The oxidation of volatile organic compounds (VOCs) plays a role in both regional and global air quality through the formation of secondary organic aerosols (SOA). More than 1000TgC/yr of non-methane VOCs are emitted from biogenic sources (significantly greater than from anthropogenic sources). Despite this magnitude and potential importance for air quality, the body of knowledge around the identities, quantities and oxidation processes of these compounds is still incomplete (e.g., Goldstein & Galbally, 2007; Robinson et al., 2009). Two-dimensional gas chromatography paired with time-of-flight mass spectrometry (GC×GC/TOFMS) is a powerful analytical technique which is explored here for its role in better …

Safety Analysis Of Ice Navigation In Huanghua Waters, Hongtu Qiu

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Incorporating Chemical Activity And Relative Humidity Effects In Regional Air Quality Modeling Of Organic Aerosol Formation, Marguerite Colasurdo Marks

Dissertations and Theses

Atmospheric particulate matter is known to have significant effects on human health, visibility, and global climate. The magnitudes of these effects, however, depend in complex ways on chemical composition, relative humidity, temperature, phase state, and other parameters. Current regional air quality models such as CMAQ (Community Multiscale Air Quality model) ignore many of these considerations, and consider that the formation of secondary organic aerosol (SOA) can be calculated by assuming thermodynamic ideality in the organic particulate matter (OPM) phase as well as negligible uptake of water into the OPM phase. Theoretical predictions and model simulations considering non-ideality and water uptake …

Ccaat/Enhancer-Binding Protein Delta (C/Ebp-Delta) Expression In Antarctic Fishes: Implications For Cell Cycle And Apoptosis, Isaac Martin Sleadd

Dissertations and Theses

Chapter 1: Antarctic fishes are extremely cold adapted. Despite their inability to upregulate heat shock proteins, recent studies have demonstrated a capacity for heat response in these animals. A cDNA microarray study looked at the Notothenioid fish Trematomus bernacchii and revealed heat sensitivities for hundreds of genes, two of which code for members of the CCAAT/Enhancer-binding protein (C/EBP) family of transcription factors. These molecular switches are best known for their roles in apoptosis, inflammation and cell cycle arrest. This dissertation further elucidates the role of C/EBP-delta in the Antarctic fishes T. bernacchii and Pagothenia borchgrevinki.

Chapter 2: C/EBP-delta is constitutively …

Geochemical Tracers Linking Submarine Groundwater Discharge To Hypoxia Formation In Long Bay, South Carolina, Usa, Sarah Lynn Chappell

Electronic Theses and Dissertations

Long Bay, South Carolina has experienced hypoxic conditions (<2mg/L dissolved oxygen) in the nearshore environment, not fully attributed to traditional formation mechanisms. Past research suggested physical, biological, and/or anthropogenic influences on low dissolved oxygen levels. This project aimed to determine the contribution of submarine groundwater discharge (SGD) to hypoxia formation. We measured activities of 222Rnxs, 224Raxs, 223Ra, 228Ra, and 226Ra (3.8d, 3.6d, 11.5d, 5.8yr, 1600yr half-lives, respectively) in nearshore bottom waters from April 2012 through April 2013. Radium activities observed during a hypoxic event on 16-Aug-2012 were up to an order of magnitude higher than those seen during oxic conditions and the highest ever observed in the open ocean, to our knowledge. We determined that a hypoxic water mass, comprised heavily of offshore anoxic SGD, migrated inshore due to physical conditions constraining mixing over a two week time period. High groundwater content suggests that observed hypoxic conditions in nearshore Long Bay may be independent of biological influence once offshore SGD occurs.

Evaluating Predictability In The Community Earth System Model In Response To The Eruption Of Mount Pinatubo, Abigail Laurel Gaddis

Doctoral Dissertations

A central goal of climate research is to determine the perceptible effects of climate change on humans; in other words, the regional and decadal scale effects of carbon dioxide forcing. Identifying the most pronounced and long-lasting responses of climate variables to forcing is important for decadal prediction since forcing terms are a source of predictability on those time scales. Powerful volcanic eruptions provide a transient forcing on the climate system, creating a test bed for climate models. In this study, the Mount Pinatubo eruption is simulated in the Community Earth System Model, CESM1.0, for three model configurations: fully coupled T85 …

Evaluating The Summer Thermal Structure Of Southern Green Bay, Lake Michigan, Brice Grunert

Theses and Dissertations

The summer thermal structure of southern Green Bay, Lake Michigan was evaluated using cable moorings equipped with thermistors and a near real-time coastal monitoring buoy. The net heat flux for the southern bay was calculated over the study period. Cold water intrusions from Lake Michigan were tracked using water temperature, with the path of these water masses tracking along the western shore of Green Bay. Water clarity was measured across the study region as kd. Surface diel warming was evaluated and compared with meteorological forcing variables and sensible and latent heat flux to determine the effect of water clarity on …