Physical Sciences and Mathematics Commons^™

Histological Evidence Of Annual And Lunar Reproductive Rhythms Of Atlantic Sea Urchin, Arbacia Punctulata In The Gulf Of Mexico: Changes In Nutritive Phagocytes In Relation To Gametogenesis, Eleazar Hernandez Ii

Theses and Dissertations

Environmental phenomena such as temperature, photoperiod, tidal cycle, and lunar rhythm act as external cues that stimulate the reproductive activity of marine organisms. In this study, I report the annual and lunar reproductive cycles, and changes in nutritive phagocytes (NPs) in relation to gonadal maturation of Atlantic sea urchin (Arbacia punctulata, a primeval species). Monthly and weekly changes in gonadal development/maturation were observed histologically. In male, the testicular lobules were densely packed with sperm from June to August. In female, on the other hand, mature eggs first appeared in some ovaries in May, numerically increased from June to …

A Sinking Feeling: The Fate Of Concrete Pyramids Deployed In Artificial Reefs In The Texas Gulf Of Mexico, Cameron J. Moody

Theses and Dissertations

The deployment of 2,611 concrete pyramids in Texas gulf waters represents a significant undertaking. In collaboration with Texas Parks and Wildlife, bathymetric sidescan data was collected at three reefs hit by Hurricane Harvey from 2017 to 2019. All reefs lost significant pyramid height between 2017 and 2019. The pyramids demonstrated greater subsidence in the year when Harvey occurred and minimal subsidence the following year. Pyramids that moved outside the reefs were due to hurricane forces and shrimp trawl activity. Pyramids that remained inside the reef remained at their deployment location for two reefs. The pyramids remaining in the third reef …

Measurements And Synthetic Imaging Of Water Surface Gravity Waves Using Optical Techniques, Jennifer Closson

Theses and Dissertations

Remote sensing technologies are useful tools when gathering spatial and temporal information about dynamic coastal regions. A method is proposed using an in-situ space-time imaging technique for evaluating wave periods and wavelengths of surface water waves in shallow urban coastal water environments. Video imagery of shallow water waves was acquired using high definition video cameras. Video imagery records of surface water waves using staff gauges and simultaneously deployed targets were used to determine wave periods, wavelengths and wave amplitudes. Time series analyses is applied to the video derived time series. Wave energy spectrums are extracted and used to simulated synthetic …

Enabling High Quality Oxygen Measurements During Robotic Based Studies Of Ocean Ecological And Biogeochemical Processes, Brianna A. Alanis

Theses and Dissertations

Dissolved oxygen is an essential parameter necessary for understanding marine ecological and biogeochemical processes. New robotic vehicles and autonomous platforms are being applied to an even wider range of ecological and biogeochemical studies. Thus, arises the opportunity for matching the best possible oxygen sensing techniques and methods to these new platforms. In so doing, we can enable both more targeted and higher resolution oxygen measurements than previously possible and potentially use oxygen measurements for a wider range of applications, including in situ incubation experiments and primary productivity measurements. This thesis tested three different oxygen sensors in a trade study for …

Identifying The N Sources For Black Mangrove (Avicennia Germinans) In A South Texas Mangrove Forest, Ashley Elizabeth Murphy

Theses and Dissertations

Black mangrove (Avicennia germinans) in south Texas provide ecosystem services and benefits to humans including: habitat for wildlife, prevention of coastline erosion, and mitigation of natural disasters. One step to preserve their ecological functions is to identify and protect the source of their nitrogen (N). Nitrogen stable isotopes were sampled for one year beginning August 2018 and used as tracers to identify how mangroves obtain N. Total N in (A. germinans) and associated (Batis maritima) (plants) (2.1%) was more abundant than in cyanobacteria (0.6%) and sediment (0.1%). Plant d15N signatures (5.52‰) were more similar to sediment (5.21‰) than cyanobacteria (1.98‰), …

Dna Barcoding Reveals Unexpected Diversity In Octocorallia In The Northwestern Gulf Of Mexico, Chelsea L. Pavliska

Theses and Dissertations

Coral reefs are an integral tier of marine ecosystems. They provide habitat and foraging opportunities for many ecologically and economically important fishes. Protection of coral reef biodiversity and connectivity is imperative to the continued health and sustainability of marine fisheries. Mesophotic reefs, such as those found in the northwest Gulf of Mexico, have unique coral communities because of the limited light penetration at mesophotic depths (30 – 150m). Because there is limited knowledge in regards to the biodiversity of coral reefs of the northwestern Gulf of Mexico (GOM), particularly the South Texas Banks (STBs), thesis work presented here aims to …

The Role Of Sediment Resuspension In Estuarine Inorganic Nutrient Cycling, Kirsten Jo Ayres

Theses and Dissertations

Time-scaling of estuarine inorganic nitrogen cycling contains many assumptions due to biogeochemical interactions. Nitrogen, often a limiting factor for primary production, is transformed and utilized by many estuarine organisms. Inorganic nitrogen is especially high in porewater. High nutrient pore water, contained within the interstitial spaces of sediment, has been assumed to influx high concentrations of inorganic nutrients into surface waters during resuspension events. These short-term resuspension events rapidly introducing high concentration of nutrients into the water column. In order to determine the internal time scale of inorganic nitrogen cycling, a box-model nutrient budget, horizontal in situ transects, and vertical nutrient …

Gut Content Analysis Of Benthic Foraging Fish Compared To Invertebrate Infauna Distributions In Dredged Vs. Undredged Habitats, Danielle Louise Juzwick

Theses and Dissertations

The Indian River Lagoon (IRL) has experienced a loss in seagrasses due to organic sediment accumulation and harmful algal blooms. Seagrasses are an essential nursery habitat for many fishes and benthic invertebrates. IRL fish known to utilize benthic habitat and feed on invertebrates include Atlantic croaker (Micropogonias undulates), juvenile Red Drum (Sciaenops ocellatus), and Mojarra (Eucinostomus spp.). The most abundant major infaunal taxa of the IRL are crustaceans, polychaetes, and mollusks. Environmental dredging in the IRL’s Turkey Creek is intended to improve water quality, remove harmful sediments and restore benthic habitat. Such dredging may impact benthic invertebrate populations and, indirectly, …

Sedimentological And Geochemical Analysis Of Deep-Water Deposits In The Mojón De Hierro Formation At Arroyo Garrido, Tepuel-Genoa Basin, Patagonia, Argentina, Natalie Beatrice Mcnall

Theses and Dissertations

The Earth has had multiple Phanerozoic glacial intervals but the Late Paleozoic Ice Age (LPIA) was its longest and most extensive, lasting from the Late Devonian (~372 Ma) until the Late Permian (~254 Ma). The LPIA is the last complete climate shift from a greenhouse to icehouse and back to a greenhouse state and the only one to occur on a biologically complex Earth. Therefore, it provides perspectives on deep-time climatic transitions, the parameters controlling them, and the Earth’s physical, chemical and biological responses to such climate changes. Research on mid to high-latitude deposits in Gondwana provides evidence that the …

Developing Multispectral Imaging Techniques To Determine Canopy Coverage And Carbon Storage Of Seagrasses In The Gulf Of Mexico, Ivy Michelle Hinson

Theses and Dissertations

Although seagrass beds provide global ecosystem services, coverage is in rapid decline, with the capacity of seagrasses to sequester carbon of special concern. Current seagrass monitoring methods are labor intensive and may not offer a complete picture of coverage. Remote sensing offers the ability to oversee landscapes but water in coastal environments presents challenges, as the commonly used near-infrared wavelength dissipates in water.

This project aimed to provide reliable methodology to assess seagrass coverage using multispectral imagery taken from an unmanned aerial vehicle and to provide evidence for the link between seagrass coverage and stored belowground carbon for common seagrasses …

Evaluating Responses Of Benthic Macrofauna To Artificial Reef Presence In The Gulf Of Mexico, Douglas Faircloth

Theses and Dissertations

Artificial reef research has long concerned itself with the interactions of fishes and has tended to favor commercially valuable species. Because of this, a larger yet less known group that heavily benefits fishes have been overlooked; benthic macrofauna. Benthic macrofauna are marine invertebrates that live below the sediment-water interface and play many roles in the ecosystem. Macrofauna are important prey items, ecosystem engineers, and bioindicators, as well as being ubiquitous in the marine environment. Since macrofauna have been largely ignored in this field, not much is known regarding their interaction with the placement of artificial reefs. To try and fill …

The Role Of The Southern Ocean On Global Ocean Circulation And Climate, Brady Scott Ferster

Theses and Dissertations

The Southern Ocean (SO) is a unique and highly dynamic region with strong temperature and salinity gradients. A comparison between satellite-derived salinity and observations indicates strong differences along coastal boundaries, areas of low temperature, and regions of strong currents. Although differences throughout much of the SO are shown to be negligible, resolution and smoothing in the products create large biases in horizontal gradients and errors in estimating the water cycle. The three-dimensional movement of water within the SO plays an important role in the global Meridional Overturning Circulation (MOC), where the Southern Hemisphere westerlies drive both zonal and meridional transports …

An Analysis Of Momentum Flux Budgets And Profiles In A Large-Eddy Model, Steffen Domke

Theses and Dissertations

Momentum fluxes and variances play an important role in the characterization and forecast of weather phenomena, but cannot be measured easily.

A subdivision of the flux changes into budget terms by the underlying physical processes, such as buoyancy transport, can assist in understanding their sources and influences.

Momentum flux and variance budgets for SAM, the System for Atmospheric Modeling, have been implemented and are compared to existing budgets from other simulations.

A tool for the visualization of these quantities from three-dimensional grid data has been developed to show and explain their distribution in conjunction with shallow cumulus and stratocumulus clouds. …

Effects Of Global Warming On Gonadal Functions, Cellular Apoptosis, And Oxidative Stress In The American Oyster, Sarah B. Nash

Theses and Dissertations

Global warming due to climate change is predicted to intensify the heat stress in marine and coastal organisms, affecting their development, growth and reproductive functions. In this study. I analyzed gonadal development, heat shock protein 70 (HSP70), nitrotyrosine protein (NTP), dinitrophenyl (DNP) expressions, cellular apoptosis, and coelomic fluid (CF) conditions in American oyster. Oysters were placed in six aquariums and exposed to control (24°C), medium (28°C), and high (32°C) temperatures for one week. Higher temperature significantly decreased the number of eggs and sperm. CF protein concentrations also declined compared to control. In contrast, CF pH and HSP70 expression in gonad …

A Probabilistic Approach To Generating Representative Wind Forcing And Wave Heights Within An Estuarine Environment, Vanessa Maria Haley

Theses and Dissertations

While wind driven waves affect erosion, sediment resuspension, and flow in shallow estuaries like the Indian River Lagoon (IRL), neither winds nor waves are well observed in this environment. In order to calculate accurate significant wave heights, the winds used for the calculation must be consistent with the observed winds over the lagoon. Given the complex land/water geometry and subsequent limited fetch, a probabilistic approach is used to produce a representative wind field over the IRL. Observed winds, near the IRL, are used to sample wind distributions obtained from 180 high resolution atmospheric model simulations in order to generate a …

Green Energy At Any Cost: How Ethanol Producer Magazine Uses Science To Frame Ethanol Production, Ashley Kappers

Theses and Dissertations

This thesis investigates the use of science by media to shape discussions about policy in society. Specifically, it investigates how one influential trade publication, Ethanol Producer Magazine, used science in its construction of pro-ethanol production stories. This study is a multi-method analysis of Ethanol Producer Magazine’s feature articles. To determine how sources and writers use science to frame ethanol production during policy changes in the industry, 36 feature stories from four issues in 2009 and 2010 of Ethanol Producer Magazine were analyzed. The results of this study found that Ethanol Producer Magazine is a publication that presents one side of …

An Analysis Of Momentum Flux Budgets And Profiles In A Large-Eddy Model, Steffen Domke

Theses and Dissertations

Momentum fluxes and variances play an important role in the characterization and forecast of weather phenomena, but cannot be measured easily.

A subdivision of the flux changes into budget terms by the underlying physical processes, such as buoyancy transport, can assist in understanding their sources and influences.

Momentum flux and variance budgets for SAM, the System for Atmospheric Modeling, have been implemented and are compared to existing budgets from other simulations.

A tool for the visualization of these quantities from three-dimensional grid data has been developed to show and explain their distribution in conjunction with shallow cumulus and stratocumulus clouds. …

Ecological Responses To Eutrophication And Restoration In A Shallow Subtropical Estuary, Xiao Ma

Theses and Dissertations

Like many other estuaries in the world, the Indian River Lagoon (IRL) is experiencing serious environmental health challenges in recent years. Ecosystem challenges include the connected phenomena of Harmful Algal Blooms (HABs) due to eutrophication and accumulation of fine-grained organic-rich sediments on the benthos. Fine-grained organic-rich sediments, referred to as “muck”, is a source of nutrients and fuels algal blooms in the water column, and excess particles associated with algal blooms sink to bottom and contribute to muck. This dissertation aims to better understand these problems by addressing two main objectives: first, to determine whether key herbivorous mesozooplankton have the …

The Effect Of Environmental Muck Dredging On Abundance And Community Richness Of Benthic Amphipods In The Indian River Lagoon, Nayan Mallick

Theses and Dissertations

Anthropogenic eutrophication has polluted and degraded estuarine ecosystems throughout the world. The Indian River Lagoon (IRL), a diverse North American estuary, has accumulated an abundance of Fine-Grained Organic-Rich Sediments (FGORS or “muck”) due to eutrophication. Muck creates stressful, sometimes uninhabitable conditions for benthic flora and fauna, with far-reaching ancillary ecosystem impacts. In an attempt to ameliorate negative ecosystem impacts, muck deposits in Turkey Creek were dredged by Brevard County Natural Resources (Florida). One month after the dredging, mean abundance of amphipods rose to 110±90 individuals m-2 from 0±0 individuals m-2 in the dredged muck sites. Four amphipod species colonized muck …

Using Evolutionary Programming To Generate A Tropical Cyclone Intensity Model, Jesse Schaffer

Theses and Dissertations

An innovative statistical-dynamical tropical cyclone (TC) intensity model is developed from a large ensemble of algorithms through evolutionary programming (EP). EP mimics the evolutionary principles of genetic information, reproduction, and mutation to develop through selective pressure a population of algorithms with skillful predictor combinations. From this process the 100 most skillful algorithms as determined by root-mean square error on cross-validation data is kept and bias corrected. Bayesian model combination is then used to assign individual weights to a subset of ten algorithms from the 100 best algorithms list, which are chosen to minimize mean-absolute error (MAE) and maximize mean-absolute difference …

Using Evolutionary Programming To Generate A Tropical Cyclone Intensity Model, Jesse Schaffer

Theses and Dissertations

An innovative statistical-dynamical tropical cyclone (TC) intensity model is developed from a large ensemble of algorithms through evolutionary programming (EP). EP mimics the evolutionary principles of genetic information, reproduction, and mutation to develop through selective pressure a population of algorithms with skillful predictor combinations. From this process the 100 most skillful algorithms as determined by root-mean square error on cross-validation data is kept and bias corrected. Bayesian model combination is then used to assign individual weights to a subset of ten algorithms from the 100 best algorithms list, which are chosen to minimize mean-absolute error (MAE) and maximize mean-absolute difference …

Source Term Estimation Of Atmospheric Pollutants Using An Ensemble Of Hysplit Concentration Simulations, Casey L. Zoellick

Theses and Dissertations

In support of Comprehensive Nuclear-Test-Ban Treaty (CTBT) monitoring and nuclear event detection, this study works toward source term estimation (STE) of dispersive pollutants using a novel method|an ensemble of forward trajectory concentration simulations using a meteorology-coupled dispersion model. Traditionally a mathematically and physically rigorous problem, STE of a plume of atmospheric pollutants can be solved in a variety of ways depending on what is known regarding the emission, but little has been studied on the sensitivity between the horizontal resolution of the meteorology data in relation to the dispersion model and the results derived from known concentrations at multiple locations. …

Quantifying Uncertainty Of Ensemble Transport And Dispersion Simulations Using Hysplit, Daniel W. Bazemore

Theses and Dissertations

Uncertainty associated with determining the source location of nuclear pollutants in the atmosphere after a nuclear fallout using a numerical model is difficult to determine. Uncertainty can originate from input data (meteorological and emissions), internal model error, physics parameterizations, and stochastic processes. This study uses the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model with data from the 1983 Cross Appalachian Tracer Experiment (CAPTEX) (Ferber et al. 1986) and simulating six nuclear detonations (Rolph et al. 2014) to quantify and communicate uncertainty in ensemble dispersion simulations. This is accomplished by utilizing an ensemble of forward trajectory simulations varying initial conditions …

Analysis Of The Gálvez-Davison Index For Convective Forecasting Over Africa Using The Galwem, William A. Hanson

Theses and Dissertations

From the hot, arid Sahara Desert to the humid, West African monsoon, Africa is a continent with vastly different weather and climate patterns from one region to the next. For this reason, thunderstorm forecasting over Africa has presented significant difficulty. The Gálvez-Davison Index (GDI) was developed for the Americas and provides a more accurate convective forecasting index than the conventional indices for thunderstorm forecasting, including the K, Total Totals, Showalter, and Lifted indices. Previous research using the GDI via the Global Forecasting System (GFS) model data over Africa showed promising results for areal coverage (Donndelinger 2018), especially during the spring …

Coupled Atmospheric Surface Observations With Surface Aerosol Particle Counts For Daytime Sky Radiance Quantification, Scott S. Wolfmeyer

Theses and Dissertations

This study investigates the radiative transfer code, Laser Environmental Effects Definition and Reference (LEEDR), developed by the Center for Directed Energy at the Air Force Institute of Technology. Many multi- and hyperspectral applications are limited to the nighttime due in large part to daytime solar background noise and it is advantageous to be able to quantify this background noise using LEEDR. Real-time meteorological surface observations, numerical weather prediction, and aerosol particle concentrations were used to investigate the accuracy of LEEDR radiances simulations. Comparisons between simulations and measured values show that aerosol concentrations, weather predictions, and meteorological observations provide enough information …

Global Ionosonde And Gps Radio Occultation Sporadic-E Intensity And Height Comparison, Joshua Y. Gooch

Theses and Dissertations

A global, multi-year comparison of low and mid-latitude COSMIC GPS radio occultation (RO) sporadic-E (E_s) plasma frequency and altitude and Digisonde blanketing frequency (fbEs) and altitude within 150 km and 30 minutes of each other. RO methods used to estimate the intensity of the E_s layer include the scintillation index S4, total electron content (TEC) with both a constant and variable E_s cloud thickness, and an Abel transform. The S4 and TEC with varying thickness techniques both under-represent the fbEs values while the TEC with constant thickness and Abel transform better estimate Digisonde fbEs values. …

Comparing Dual-Polarization Radar Lightning Forecast Methods Across Southwest Utah, Daniel O. Katuzienski

Theses and Dissertations

Lightning poses a significant hazard to space launch operations to include ground processing, launch window forecasts, and rocket-triggered lightning events. Two lightning initiation forecast methods using weather radar developed in Gremillion and Orville (1999) and Travis (2015) for Cape Canaveral Air Force Station (CCAFS) and Kennedy Space Center (KSC), Florida are tested in a new geographical region. This is accomplished by applying the highest-performing radar parameters from Gremillion and Orville (1999): reectivity (Z) ≥ 40 dBZ for two consecutive volume scans at the -10°C thermal height and Travis (2015): Z ≥ 36.5 dBZ with differential reflectivity (ZDR) ≥ 0.31 dB …

Variations Of Heavy Ion Abundances Relative To Proton Abundances In Large Solar Energetic Particle Events, Joseph F. Round

Theses and Dissertations

Past studies of heavy ions (Z>2) in large (E>10 MeV/nuc) gradual solar energetic particle (SEP) events have focused on elemental abundances relative to those of a single element, such as Fe or O, and have often neglected ionized H (the primary element used for space weather purposes). This work analyzes SEP abundances in a group of 15 large gradual SEP events from 2000 to 2015 across the energy range of 13.5-50.7 MeV. Hourly flux averages of He, C, O, Mg and Fe from the Advanced Composition Explorer/Solar Isotope Spectrometer (ACE/SIS) are compared to two-hour averages of H flux …

Lightning Prediction Using Recurrent Neural Networks, Dominick V. Speranza

Theses and Dissertations

Cape Canaveral Air Force Station (CCAFS), Kennedy Space Center (KSC), and Patrick Air Force Base (PAFB) all reside in the thunderstorm capital of the United States. According to the Florida Climate Center, these installations experience more thunderstorms per year than any other place in the United States. It is the mission of the 45th Weather Squadron to provide timely and accurate warnings of weather conditions such as lightning that pose a risk to assets and personnel CCAFS, KSC and PAFB. To aid 45th Weather Squadron forecasters, a network of 30 Electric Field Mills (EFM) was installed in the area in …

Characterization Of Tropical Cyclone Intensity Using Microwave Imagery, Amanda M. Nelson

Theses and Dissertations

In the absence of wind speed data from aircraft reconnaissance of tropical cyclones (TCs), analysts rely on remote sensing tools to estimate TC intensity. For over 40 years, the Dvorak technique has been applied to estimate intensity using visible and infrared (IR) satellite imagery, but its accuracy is sometimes limited when the radiative effects of high clouds obscure the TC convective structure below. Microwave imagery highlights areas of precipitation and deep convection revealing different patterns than visible and IR imagery. This study explores application of machine learning algorithms to identify patterns in microwave imagery to infer storm intensity, particularly focusing …