Digital Commons Network^™

Understanding Variations And Trends In Convection Over The Congo Basin From A Diurnal Perspective, Kathrin Alber

Legacy Theses & Dissertations (2009 - 2024)

Tropical rainforests regulate global and regional climate systems and play a vital role in the world’s water and carbon cycles. The Congo Basin, situated in central equatorial Africa, is home to the second largest rainforest on the planet and is one of the most convective regions in the world. Recent studies indicate that a large-scale and long-term drying trend, characterized by an increase in dry season length, a decrease in forest greenness, and a decrease in precipitation, has been stressing the region since the 1980’s. Despite the alarming drying trend and the Congo’s important role in the planetary circulation and …

The Impact Of Wildfire Activities On Air Quality And Solar Energy In New York And California, Chin-An Lin

Legacy Theses & Dissertations (2009 - 2024)

An increasing trend of wildfire activity over North America over the past decades has been observed. Elevated surface fine mode particulate matter (PM2.5) concentration and reduction of solar radiation during the smoke episodes have been widely reported. Given that the intensity and frequency of wildfires are expected to increase under changing climate, the impact of smoke aerosols on air quality and solar energy could become more significant. This study aims to characterize the transport of smoke aerosols and quantify their impact on local air quality and solar energy over New York (NY) and California (CA) States. A multi-year analysis of …

The Role Of Climate Feedbacks, Poleward Energy Transport, And Clouds In Causing Arctic Amplification And Their Link To Sea-Ice Loss, Matthew Todd Jenkins

Legacy Theses & Dissertations (2009 - 2024)

Arctic amplification (AA) refers to larger warming in the Northern high latitudes than the rest of the world under increased greenhouse gas (GHG) concentrations. Many processes have been suggested to influence AA such as sea-ice loss, positive climate feedbacks, enhanced downwelling longwave (LW) radiation from increased water vapor and cloud cover, or enhanced poleward energy transport. However, many of these processes are coupled with each other and with Arctic warming, making it difficult to separate and quantify their individual contributions to Arctic warming and AA. This dissertation focuses on the roles of sea-ice loss, climate feedbacks, cloud property changes, and …

Cultural And Environmental Change In A Period Of Westernized Tourism: Bali, Indonesia, Barbara Buck

ALL - Honors Theses

Dutch colonizers opened Bali for tourism at the beginning of the 20th century, and since that time tourism has led to changes in Bali’s culture, environment, and local resources. In the late 1900s, tourism grew to a new level, which resulted in a shift of industry control away from Balinese people. This project examines the problem of tourism from a social and environmental science lens. By compiling literature and science from various fields of study, this project aims to illustrate the complexity of Bali’s tourism problem in an interdisciplinary way. The lack of local control over tourism perpetuated and exacerbated …

Evaluating And Enhancing The New York State Mesonet (Nysm) Snow Accumulation Estimation, Christopher Gilberti

ALL - Honors Theses

This research project aims to examine and enhance the performance of the New York State Mesonet (NYSM) Snow Accumulation Estimation. The NYSM is a state-of-the-art network of 126 standard weather stations located across the state of New York, collecting high-quality meteorological data to improve forecast accuracy, reduce uncertainty, and mitigate harm. All NYSM standard stations measure snow depth with Campbell Scientific’s SR50A ultrasonic distance sensor. This acoustic sensor measures the distance from the sensor to a rigid snowboard if there is no snow on the ground or the top of snow layer. A reference distance and a temperature correction are …

Categorizing The Societal Impacts From Extreme Rainfall In The New York City Metropolitan Area, Evan Belkin

ALL - Honors Theses

Numerous studies have shown that the frequency and intensity of extreme rainfall events have increased significantly across the contiguous United States (CONUS) over the past several decades associated with warming global temperatures. This surge in extreme rainfall has resulted in the loss of life and property within vulnerable communities due to widespread river and flash flooding. For example, 11 of the 14 fatalities in New York City associated with Tropical Cyclone Ida’s remnants in September 2021 occurred in flooded basement apartments. The creation of a scale to differentiate extreme rainfall events with higher societal impacts from those with lower impacts …

Diurnal To Seasonal Hurricane Variability And Predictability, Jeremiah Otero Piersante

Legacy Theses & Dissertations (2009 - 2024)

Prediction of tropical cyclone (TC) impact extends across a range of forecast lead times. At shorter timescales, radially outward-propagating, diurnal pulses in TCs are associated with TC intensity and structure changes. At weekly periods, synoptic-scale Rossby waves influence the direction of TC tracks. At seasonal timescales, climate modes affect the overall (in)favorability of TC activity. The research shown in this dissertation seeks to improve the understanding and predictability of TC variability across these scales using numerical weather prediction, reanalysis fields, and storm track observations.Diurnal pulses associated with cloud-top cooling, so-called cooling pulses (CPs), pose a risk for hazardous weather because …

Examining The Performance Of The High-Resolution Rapid Refresh Model During Clear, Isolated, And Widespread Convective Days In The New York State Capital Region, Rachel A. Eldridge

Legacy Theses & Dissertations (2009 - 2024)

Forecasting can be more challenging in areas of complex terrain, such as in and around the valleys and mountains of Upstate New York. Biases in numerical weather prediction models, related to the lack of resolution of the terrain and errors in physical parameterizations, can affect forecasts. The main goal of this research is to assess biases in the High-Resolution Rapid Refresh (HRRR) model that could contribute to deficiencies in forecasts for days with and without convection. We investigate how the HRRR model performed in the New York Capital Region for 4 clear days, 4 isolated convective days, and 4 widespread …

Coastal-Ocean And Estuarine Acidification In Long Bay, South Carolina: A Comparison Of In-Situ Water Quality Monitoring With Measured Carbonate System Parameters, Mary Olsen

Electronic Theses and Dissertations

One of the major water-quality issues impacting our coast and estuaries is coastal-ocean and estuarine acidification. Due to a relative dearth of data in the southeastern United States it is increasingly difficult to determine the full extent and intensity of this problem. This study provides the first characterization of coastal-ocean and estuarine acidification in Long Bay, SC by attempting to leverage long-term water quality data sets at two coastal-ocean pier sites using in-situ YSI EXO sondes deployed at both the surface and bottom waters along with two estuarine sites sampled by volunteer monitors using Orion star multi-meters. Discrete samples (120) …

Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation, Emmanuel Ogwuche Audu

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The uncertainty in model projections of future precipitation across the Sahel has persisted across many generations of Earth System Models (ESMs), with some models predicting drying and others moistening across this region. These discrepancies in future projections pose a challenge for stakeholders and decision makers. Many projections of Sahel precipitation found in the ESMs participating in the sixth phase of Coupled Model Intercomparison Project (CMIP6) show a zonal dipole in precipitation trend, with moistening across the Central and Eastern Sahel and drying projected for the Western Sahel. Previous studies have connected precipitation variability across the Sahel to changes in various …

Polarimetric Radar Signatures In Significant Severe Left-Moving Supercells, Raychel Nelson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Left-moving (LM) supercells, though rarer than right-moving (RM) supercells, may produce significant severe weather. However, there are very few existing studies on LM supercells, particularly polarimetric radar analyses. The upgrade of the nationwide Weather Surveillance Radar-1988 Doppler (WSR-88D) network to polarimetric capability and subsequent studies vastly improved understanding of RM supercells, but similar efforts have largely not been made for LM supercells. This study employs an automated polarimetric radar signature detection algorithm to examine a dataset of significant severe (hail ≥ 2.00”, wind ≥ 65 kts) LM supercells to quantify their polarimetric signatures. Comparisons are made with RM supercells to …

A Dual-Polarimetric Analysis Of A Large Sample Of Left-Moving Supercells, Ben Schweigert

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Supercells have been researched extensively since they were first described over 50 years ago. They are prolific severe weather producers, responsible for the most severe hail, severe wind gusts, and tornadoes. These rotating thunderstorms require attention from forecasters to protect life and property from their threats, most effectively done with Doppler radars. While extensive amounts of radar-based investigations have been completed, they focused almost exclusively on right-moving (RM) supercells, resulting in a knowledge gap surrounding their counter-rotating (left-moving, LM) partners. This study works to fill the void by developing a dataset of LM supercells and analyzing the dual-polarimetric features observed …

A Compilation, Analysis, And Categorization Of 403 Atmospheric And Climate Science Misconceptions, Haeli Leighty

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The National Association of Geoscience Teachers (NAGT) has listed the inaccessibility of research related to misconceptions in atmospheric and climate science as a Geoscience Education Research Grand Challenge (Cervato et al. 2018). This project was a direct response to this call for research and consisted of three distinct steps: 1) data gathering, which included reviewing the literature for relevant misconception data, 2) a qualitative analysis, which included compiling, organizing, and categorizing the data collected, and 3) a quantitative analysis, which included determining the prevalence of each misconception across topic categories, demographic categories, and over time. A total of 403 misconceptions …

Lake Mead: A Living Museum, Marley Salveter

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lake Mead, the largest man-made water project in the nation and a prolific source of electricity, irrigation, and recreation for much of the western population, is currently experiencing a drastic transformation. Amid the ongoing water crisis parching the west, the once overflowing reservoir is consistently shrinking, descending into depths historically uncharted.

While serving as a bleak demonstration of climate change’s effects, the body of water is simultaneously assuming an alternative role that may be less apparent to the public. As water levels decline, Lake Mead is actively metamorphosing into a “Living Museum”, by gradually unveiling previously submerged artifacts. As a …

Evaluating Novel Approaches For Improving Anadromous Fish Passage In Coastal Rivers, Aaron Bunch

All Dissertations

Few of the world's rivers remain free-flowing for over 1000 km, significantly impacting anadromous fish populations due to dam-induced habitat fragmentation. Three partial migration barriers (low-head dams) on North Carolina's Cape Fear River (USA)—lock and dam 1 (LD1), lock and dam 2 (LD2), and lock and dam 3 (LD3)—impact American shad Alosa sapidissima, Atlantic sturgeon Acipenser oxyrinchus oxyrinchus, and striped bass Morone saxatilis populations. Mitigation strategies to pass fish upstream have included conservation locking, nature-like fishway construction, and environmental flows (e-flows). This study introduced a novel e-flow (dam submergence flow), tested acoustic double-tagging techniques for tracking American …

Patterns In Macrofaunal Abundance And Biodiversity At Sites In The Florida Keys, Cydney Wolff

Theses, Dissertations and Culminating Projects

Coral reef health in the Florida Keys, USA has been declining in recent years. To gain an understanding of the current state of macrofaunal abundance and biodiversity on these reefs, research was conducted to identify and count the macrofauna colonizing standardized settlement plates at two coral reef sites, one in the middle (Delta Shoal) and one in the lower (Pelican Shoal) Florida Keys. Plates were deployed for a one-month period in June 2023. At each site, the plates were placed at two heights: ocean bottom and 2 m above ocean bottom (two plates per height per site for a total …

The Impacts Of Wind On Coastal Trees, Julian Halil

All Theses

Trees in hurricane-prone areas are exposed to severe winds and flooding. We studied the physiological and structural responses of forested wetland trees in relation to wind stress. We evaluated the windfirmness of two forested wetland tree species. Baldcypress was chosen because of high survival in post-hurricane studies. In contrast, laurel oak co-occurs with baldcypress yet resists hurricane-force winds poorly. In a static winching study, we quantified the critical turning moment (Mcrit) required to topple both species. Mcrit increased with trunk diameter at breast height (DBH) and crown size. Baldcypress and laurel oak demonstrated similar Mcrit, but regression models indicate baldcypress …

Bay Water Level Influences On Inundation And Morphological Changes Of A Semi-Connected Barrier Island During A Hurricane, Sydney D. Goodman

Graduate Theses and Dissertations (2019 - present)

This research aims to identify flooding and erosion changes along a semi-connected barrier island system due to varying bay water levels during storm conditions. The numerical model XBeach is used to simulate Hurricane Michael conditions and the resulting inundation and morphological change near Tyndall Air Force Base (Tyndall AFB). The installation is located 12 miles southeast of Panama City Beach along the panhandle of Florida and is vulnerable to flooding due to its proximity to the Gulf of Mexico (GoM), Saint Andrew Sound and Saint Andrew Bay. A land bridge connects the barrier island to the mainland of Tyndall AFB …

Consequences Of The Megafauna Extinction: Changes In Food Web Networks On The Edwards Plateau Across The Pleistocene–Holocene Transition, Quentin A. Smith Jr.

School of Biological Sciences: Dissertations, Theses, and Student Research

We are experiencing biodiversity loss due to climate change and human impacts, which is not only harmful to the environment but can also alter the composition of communities and interactions among species. The late Pleistocene experienced a loss of large-bodied mammals which resulted in significant changes in community structure due to changes in body size, diet, and species associations. The impact of these changes on species interactions and community structure across the Pleistocene-Holocene transition remains poorly understood. Using a robust data set of species composition, stable isotopes, body size, and climate variables, we constructed and compared ecological networks of mammal …

Geomagnetic Substorms Prediction Model Using Combined Physics-Based And Deep Learning Modeling Techniques, Ruthba Yasmin

Graduate Theses and Dissertations (2019 - present)

This thesis aims to develop a hybrid physics-incorporated neural network model (PINN) for classifying geomangnetic substorms in Earth's Magnetosphere. The model is trained using a comprehensive list of substorm onsets, ground magentometer data from a global network, and solar wind parameters from the Advanced Composition Explorer (ACE) satellite. Two different neural network architectures are used, and the physics model used for training is called WINDMI. The magnetic field components on the ground, which are a function of the ionospheric currents, are captured by the SML index. The methodology involves using 60-minute data segments preceding an event to train the hybrid …

Developing A Suitability Model And Feasibility Report For The Tennessee Mesonet, Tristan Holmes

Electronic Theses and Dissertations

Mesoscale networks, also known as Mesonets, are advanced environmental monitoring systems that consist of multiple high-quality weather stations that collect meteorological data at frequent intervals (5 minutes or less). Tennessee currently lacks a Mesonet system, and this study identifies suitable and feasible locations for stations in all 95 counties. Layers needed to develop the suitability model included land cover, road centerlines, elevation, flood zones, building footprints, and hydrologic soil types. Geospatial analysis techniques were used to process and combine these layers to identify suitable areas. Once suitable areas were determined, a feasibility assessment that examined land ownership, accessibility, and cell …

2024 May - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

Resource Scarcity Caused By Environmental Changes: Driving Factor In Terrorism Attacks In Afghanistan, Pakistan, Syria, Amaris Bustamante

Open Access Theses & Dissertations

Climate change, resource scarcity, and terrorist attacks are ever-growing crises that disproportionately impact different states. They are crises that can impact the stability and resilience of humanity in the following decades if they are not addressed and mitigated. This study addresses the impact of resource scarcity caused by climate change that can then serve as a driving force in terrorist attacks in climate-sensitive and conflict-prone states. The objective of this mixed-methods study is to identify the correlation between climate changes that lead to resource scarcity such as rainfall and surface temperatures with terrorist attacks when taking into consideration other demographic, …

Blade Design And Validation Of Hydrokinetic Turbine To Harvest Water Current Energy, Setare Sadeqi

LSU New Orleans Theses and Dissertations

The innovative aspect of this research lies in the careful integration of cutting-edge technologies throughout the entire process of designing, fabricating, and testing the carbon fiber propeller for the 3-bladed horizontal axis ocean current turbine (OCT). SolidWorks software played a pivotal role in the initial design phase, enabling a meticulous and precise modeling of the propeller's geometry. The utilization of SolidWorks allowed for a detailed exploration of various design parameters, ensuring that the propeller's structure and form were optimized for performance in ocean current conditions. Moving beyond the realm of virtual design, the choice of carbon fiber as the fabrication …

Catchment-Scale Thawing And Greening Decreases Long-Term Nitrogen Export In Ne Greenland, Shannon L. Speir, Jennifer L. Tank, Ada Pastor, Marc F. Muller, Mikhail Mastepanov, Tenna Riis

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Climate change is expected to alter nitrogen (N) export from Arctic rivers, with potential implications for fragile coastal ecosystems and fisheries. Yet, the directionality of change is poorly understood, as increased mobilization of N in a 'thawing' Arctic is countered by higher rates of vegetative uptake in a 'greening' Arctic, particularly in the understudied region of Greenland. We use an unprecedented dataset of long-term (n = 18 years) river chemistry, streamflow, and catchment-scale changes in snow and vegetation to document changing riverine N loss in Greenland. We documented decreasing inorganic and organic N loads, linked to decreasing snow stores, …

A Statistical Fetch Model For Water Wave Glint Correction Using Worldview-3 Imagery, Amanda Jade Quintanilla

Theses and Dissertations

Sun glint in satellite imagery of the water surface contaminates the upwelling signal received by a detector. Many models exist that attempt to correct for this wave facet effect and phenomena. In this work a model for sun glint correction is created using the comparison of image transects between two nearly simultaneously collected images of the same area, although with differing sensor geometry. One image utilized in this research is almost entirely glint free while the other is contaminated by water wave facet glint. Although many models for removing sun glint exist based on various techniques, none are completely accurate, …

El Nino Prediction At 1- And 3- Year Lead Times Driven By The Western North Pacific Precursor And Their Impacts, Krishna Borhara

All Graduate Theses and Dissertations, Fall 2023 to Present

The El Niño–Southern Oscillation (ENSO) is a climate variability characterized by fluctuations in the atmospheric and upper ocean conditions of the tropical Pacific Ocean that result in either warmer- or colder-than-average sea surface temperatures (SST) in the tropical eastern Pacific. These changes cause variations in weather and climate in distant locations through large-scale atmospheric circulation patterns. These variations often manifest in form of adverse effects or extremes such as heat waves, droughts, or floods, making efforts towards improving ENSO prediction critical in mitigating its impact on various sectors. This dissertation focuses on how interactions between the atmosphere and ocean in …

Deterministic Global 3d Fractal Cloud Model For Synthetic Scene Generation, Aaron M. Schinder, Shannon R. Young, Bryan J. Steward, Michael L. Dexter, Andrew Kondrath, Stephen Hinton, Ricardo Davila

Faculty Publications

This paper describes the creation of a fast, deterministic, 3D fractal cloud renderer for the AFIT Sensor and Scene Emulation Tool (ASSET). The renderer generates 3D clouds by ray marching through a volume and sampling the level-set of a fractal function. The fractal function is distorted by a displacement map, which is generated using horizontal wind data from a Global Forecast System (GFS) weather file. The vertical windspeed and relative humidity are used to mask the creation of clouds to match realistic large-scale weather patterns over the Earth. Small-scale detail is provided by the fractal functions which are tuned to …

Angular Distribution Of Bremsstrahlung Spectral Temperature Measured In A Full Dimension Of Ecr Ion Source Using Nai(Ti) Detector, Mwingereza J. Kumwenda

Tanzania Journal of Science

Measurement of angular distribution (AD) of the bremsstrahlung spectral temperature from a full dimension of the Electron Cyclotron Resonance Ion Source (ECRIS) along the beam axis is challenging. To overcome some challenges, this paper presents the AD of the bremsstrahlung spectral temperature measured in a full dimension of the ECRIS along the beam axis using data obtained from the Busan Center of Korea Basic Science Institute (KBSI). The bremsstrahlung spectral temperature from 28-GHz ECR Ion source at the KBSI was measured in six, three, and nine azimuthal angles at the injection, centre, and extraction sides of the ECRIS using three …

Investigating Turbulence Distribution In The Lower Atmosphere Using Time-Lapse Imagery From A Camera Bank, Benjamin C. Wilson, Santasri R. Bose-Pillai, Jack E. Mccrae, Steven T. Fiorino, Robert P. Freeman, Laura R. Slabaugh

Faculty Publications

The atmosphere’s surface layer (first 50–100 m above the ground) is extremely dynamic and is influenced by surface radiative properties, roughness, and atmospheric stability. Understanding the distribution of turbulence in the surface layer is critical to many applications, such as directed energy and free space optical communications. Several measurement campaigns in the past have relied on weather balloons or sonic detection and ranging (SODAR) to measure turbulence up to the atmospheric boundary layer. However, these campaigns had limited measurements near the surface. We have developed a time-lapse imaging technique to profile atmospheric turbulence from turbulence-induced differential motion or tilts between …