Physical Sciences and Mathematics Commons^™

Radio Propagation Through Density Irregularities In The Auroral Ionosphere, Pralay Raj Vaggu

Doctoral Dissertations and Master's Theses

A radio wave propagating through a structured or turbulent ionosphere undergoes multiple effects, such as refraction, diffraction, etc., that distort the incident radio wave by inducing phase and amplitude fluctuations. These fluctuations are called ionospheric scintillation. Scintillation effects can be detrimental to Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS), but the observed effects can be used as a tool to study the underlying plasma process that causes scintillation. Scintillation is commonly seen in equatorial and high-latitude regions. This study centers around the scintillation and its causative plasma processes that dominantly happen in the high-latitude ionosphere …

Balloon Borne Gps-Enabled Radiosondes That Enable Simultaneous Multi-Point Atmospheric Sensing With A Single Ground Station, Peter A. Ribbens

Doctoral Dissertations and Master's Theses

Radiosondes are balloon borne atmospheric instruments that are a critical tool for understanding dynamics in the lower layers of the atmosphere. The low-cost radiosondes developed in the Space and Atmospheric Instrumentation Lab have been further developed to improve the system's use as a science-quality atmospheric instrument that is unique in its ability to simultaneously track multiple sondes with a single ground station. Sensors to measure temperature and pressure were added to improve measurements of the atmospheric state. A printed circuit board shield and 3D-printed shell were designed to make mass manufacturing possible. A thermistor-based temperature sensor was developed and tested …

Spatio-Temporal Analysis Of The Roadside Transportation-Related Air Quality (Startraq 2022): Data-Driven Exposure Analysis By Transportation Modes, Jaymin Kwon, Yushin Ahn, Steve Chung

Mineta Transportation Institute

Particulate matter (PM) pollution poses significant health risks, influenced by various meteorological factors and seasonal variations. This study investigates the impact of temperature and other meteorological variables on PM10 and PM2.5 levels in Fresno County, known for high air pollution. Multiple linear regression (MLR) and generalized additive models (GAMs) assess the significance of these relationships. Analyzing data from Fresno County, we examine PM10 and PM2.5 levels across "hot" (June to August) and "cool" (September to May) seasons. Findings indicate PM10, both MLR and GAM models identify statistically significant variables, excluding temperature and wind direction in each season. However, during the …

The Application Of Carbonate And Sediment Budgets To Assess The Stability Of Marginal Reef Systems, Shannon Dee, Adi Zweifler, Michael Cuttler, Jake Nilsen, Joshua Bonesso, Michael O'Leary, Nicola K. Browne

Research outputs 2022 to 2026

Coral reefs and their associated landforms (carbonate islands and shorelines) are under increasing threat from the effects of anthropogenic climate change, including sea level rise (SLR). The ability of a reef to keep up with SLR depends on the rate of calcium carbonate accretion. Census-based carbonate budgets quantify rates of net calcium carbonate production on a reef and facilitate estimations of vertical reef accretion potential (RAP). To date, most carbonate budget studies have been undertaken in clear-water settings resulting in a limited understanding of how inshore reefs situated in more marginal environmental settings are functioning now and under future climate …

Strong Marine Heatwaves Trigger Flowering In Seagrass, Catalina A. García-Escudero, Victoria Litsi-Mizan, Pavlos T. Efthymiadis, Vasilis Gerakaris, Oscar Serrano, Eugenia T. Apostolaki

Research outputs 2022 to 2026

In recent decades, the global intensification of marine heatwaves has impacted several ecosystems and species, including the endemic Mediterranean seagrass Posidonia oceanica. However, the scarcity of research in Eastern Mediterranean meadows, where historical and present thermal conditions differ from those of the Western Mediterranean, hampers our ability to draw comprehensive conclusions regarding the species' response to elevated sea temperatures. Here, we studied flowering patterns of P. oceanica meadows (3–15 m depth) of the Greek seas and assessed their potential association with marine heatwaves, while also examining the effects on plant growth associated with the transition from vegetative to sexual reproduction. …

2024 June 27 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Assessment And Prediction Of Meteorological Drought Using Machine Learning Algorithms And Climate Data, Khalid En-Nagre, Mourad Aqnouy, Ayoub Ouarka, Syed Ali Asad Naqvi, Ismail Bouizrou, Jamal Eddine Stitou El Messari, Aqil Tariq, Walid Soufan, Wenzhao Li, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Monitoring drought in semi-arid regions due to climate change is of paramount importance. This study, conducted in Morocco’s Upper Drâa Basin (UDB), analyzed data spanning from 1980 to 2019, focusing on the calculation of drought indices, specifically the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) at multiple timescales (1, 3, 9, 12 months). Trends were assessed using statistical methods such as the Mann-Kendall test and the Sen’s Slope estimator. Four significant machine learning (ML) algorithms, including Random Forest, Voting Regressor, AdaBoost Regressor, and K-Nearest Neighbors Regressor, were evaluated to predict the SPEI values for both three …

2024 June 20 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Risk Of Climate Damage In The Mountain West, 2024, Taylor Volk, Isabelle G. Graham, Ivan Sun, Zachary Billot, Caitlin J. Saladino, William E. Brown Jr.

Environment

This fact sheet examines 2024 data on the estimated annual cost per person of damage to infrastructure, agriculture, and population from climate related disasters for the five Mountain West states of Arizona, Colorado, Nevada, New Mexico, and Utah. The original report, “States at Greatest Risk of Climate Damage - 2024 Study,” by Jaclyn DeJohn and published by SmartAsset, includes data on climate disaster risk for all 50 states.

Near-Surface Thermodynamic Influences On Evaporation Duct Shape, Sarah E. Wessinger, Daniel P. Greenway, Tracy Haack, Erin E. Hackett

Marine Science

This study utilizes in situ measurements and numerical weather prediction forecasts curated during the Coupled Air–Sea Processes Electromagnetic Ducting Research (CASPER) east field campaign to assess how thermodynamic properties in the marine atmospheric surface layer influence evaporation duct shape independent of duct height. More specifically, we investigate evaporation duct shape through a duct shape parameter, a parameter known to affect the propagation of X-band radar signals and is directly related to the curvature of the duct. Relationships between this duct shape parameter and air sea temperature difference (ASTD) reveal that during unstable periods (ASTD < 0), the duct shape parameter is generally larger than in near-neutral or stable atmospheric conditions, indicating tighter curvature of the M-profile. Furthermore, for any specific duct height, a strong linear relationship between the near-surface-specific humidity gradient and the duct shape parameter is found, suggesting that it is primarily driven by near-surface humidity gradients. The results demonstrate that an a priori estimate of duct shape, for a given duct height, is possible if the near-surface humidity gradient is known.

This article was published Open Access …

Establishment Of A Research Site At The Kennedy Mountain Campus For The Observation Of Airborne Particulate Matter, Alyssa Knaus

Undergraduate Theses, Capstones, and Recitals

This thesis explored particulate matter (PM) concentrations at two sites within the Colorado Front Range. The study utilized two models of PurpleAir PM sensors, Flex and SD-II, to provide real-time, accessible data on PM1, PM2.5, and PM10 mass concentrations with the goal of establishing the first research site at the Kennedy Mountain Campus (KMC). The first of the two sites used during this study was at a suburban location outside of Denver, CO. This period was used as an instrument intercomparison period in order to conduct instrument analysis. The initial findings from this period found significant correlations between PM concentration …

Scale-Dependent Effects Of Urban Canopy Cover, Canopy Volume, And Impervious Surfaces On Near Surface Air Temperature In Portland, Or, Carson Ralls

Geography Masters Research Papers

Cities are significantly warmer than their surrounding rural environments. Known as the ‘urban heat island effect’, it can affect the health of urban residents and lead to increased energy use. Although this effect is extensively researched, less is known about how landscape characteristics within cities affect local temperature variation. With a warming climate and the need for heat mitigation strategies becoming more urgent, having a finer detailed understanding of the effects on temperature is critical to guide proper management policies. This study examined how tree canopy cover, canopy volume, and impervious surface cover affect daytime near surface air temperature, and …

2024 June 13 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Monitoring Air Fluxes In Caves Using Digital Flow Metres, Claudio Pastore, Amir Sedaghatkish, Eric Weber, Nicolas Schmid, Pierre-Yves Jeannin, Marc Luetscher

International Journal of Speleology

Precise measurements of airflow within caves are increasingly demanded to assess heat and mass transfers and their impacts on the karst environment, including subsurface ecosystems, hydrochemistry of karst water and secondary mineral precipitates. In this study, we introduce a new, low-cost and lightweight device adapted to monitoring air fluxes in caves which addresses the need for reliable measurements, low power consumption, durability and affordability. The device was calibrated in a wind tunnel, showing the high accuracy and precision of the device. Field-related uncertainties were further investigated in a ventilated cave to determine the effect of local airflow conditions on the …

2024 June 6 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

The Core Of It All: From The Forest To The Concrete Jungle, Ayo Andra J. Deas

Dissertations, Theses, and Capstone Projects

The Core of It All is a component of principle within Fasaha. The mission of Fasaha is to implement programming directed toward development of one’s Core through self-actualization. Self-Actualization is defined as bringing forth the total essential qualities of one’s own consciousness, character, and identity through positive behavior. Throughout this manuscript, principle is defined as the standard of natural essential qualities determining intrinsic consciousness, character and identity. Programming is defined as providing with intrinsic instructions for the automatic performance of a task.

Fasaha is a support service that enhances the existing organization’s service. Throughout this dissertation, it will be apparent …

An Index Of Biotic Integrity For Macroinvertebrate Stream Bioassessment Conducted By Community Scientists, Patrick M. Edwards, Daniel Bedell, Shannon Hubler, Chad A. Larson, Kate H. Macneale, Elisa Mickelson, Chris Prescott, Elinore Webb, Jo Wilhelm

Environmental Science and Management Faculty Publications and Presentations

Community science bioassessment has great potential to inform comprehensive stream management plans, but regional analytical tools are needed to evaluate macroinvertebrate data collected through community science programs. To this end, we modified a pre-existing professional index of biotic integrity (IBI) to create a community science IBI (CS-IBI), designed for stream macroinvertebrate data collected by community scientists with minimal training. We used data collected by both professional and community scientists to develop, calibrate, and validate the CS-IBI at 76 streamsites in the Puget Lowland andWillamette Valley ecoregions of the PacificNorthwest in theUnited States. Community science data were taxonomically coarser andmore variable …

College Of Saint Benedict And Saint John's University Fy2023 Greenhouse Gas Emissions Inventory, Csb+Sju Office Of Sustainability

Sustainability Office Publications

The College of Saint Benedict (CSB) and Saint John’s University (SJU) Office of Sustainability conducted a comprehensive Greenhouse Gas (GHG) Inventory that includes emissions from both CSB and SJU campuses. This report details GHG emissions for Fiscal Year (FY) 2023 (July 1, 2022-June 30, 2023) in Metric Tons of Carbon Dioxide Equivalents (MTCO2e), the standard unit of measurement used to track and report GHG emissions based on their global warming potential. Data was collected, organized, and analyzed by staff in the CSB and SJU Sustainability Office.

Phase Error Scaling Law In Two-Wavelength Adaptive Optics, Milo W. Hyde Iv, Matthew Kalensky, Michael J. Spencer

Faculty Publications

We derive a simple, physical, closed-form expression for the optical-path difference (OPD) of a two-wavelength adaptive-optics (AO) system. Starting from Hogge and Butts’ classic OPD variance integral expression, we apply Mellin transform techniques to obtain series and asymptotic solutions to the integral. For realistic two-wavelength AO systems, the former converges slowly and has limited utility. The latter, on the other hand, is a simple formula in terms of the separation between the AO sensing (i.e., the beacon) and compensation (or observation) wavelengths. We validate this formula by comparing it to the OPD variances obtained from the aforementioned series and direct …

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

Tennessee Climate Office Monthly Report

No abstract provided.

Investigation Of Volatility, Composition, And Gas-Particle Phase Partitioning Of Atmospheric Organic Compounds Through Novel Instrumentation And Techniques, Karolina Cysneiros De Carvalho

McKelvey School of Engineering Theses & Dissertations

Atmospheric aerosols are ubiquitous indoors and outdoors and their impact on human life on Earth is extensive. Aerosol particles scatter and absorb solar radiation, are key in the formation of clouds and precipitation, and can affect the abundance and distribution of greenhouse and atmospheric trace gases by physicochemical multiphase processes, thus they play an important role in regulating regional and global climate. On the other hand, poor indoor and outdoor air quality associated with high particulate matter (PM) levels is among the leading health risks worldwide, affecting life quality and expectancy by increasing the risk of cancer, cardiovascular and respiratory …

2024 May 23 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Atmospheric Circulation, Climate Change, And Related Impacts Over The Western United States, Graham Patrick Taylor

Dissertations and Theses

This dissertation characterizes the range of atmospheric circulation patterns and select associated meteorology impacting the northwest United States, the onset timing of rain and wind relevant to wildfire across the western United States, and how these may respond to global warming. The ability of a suite of models contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) to simulate observed large-scale atmospheric circulation patterns over the Pacific Northwest of North America is evaluated. Climate model projections of atmospheric circulation patterns, their frequency, and associated temperature and precipitation anomalies under a high-end global warming scenario are assessed over …

Operation Shark: Addressing The Negative Portrayal Of Sharks In Media, Michael R. O'Shea

Masters Theses

Sharks are some of the most well adapted and effective animals in the animal kingdom. Unfortunately, they are also some of the most feared. For many people the word shark evokes images of vicious attacks like those seen in movies such as Jaws. Sharks have also been negatively portrayed in the media. This negative portrayal of sharks has led to misconceptions about sharks that have damaged their populations. Efforts have been made to raise awareness and fight common misconceptions of sharks. However, many people still hold on to the incorrect ideas they have about sharks. This thesis will examine the …

Elevating Urban Landscapes: How Green Roofs Enhance Biodiversity And Address Climate Change In California, Jeffrey R. Beaudoin

Master's Projects and Capstones

Green roofs are increasingly valued for mitigating the Urban Heat Island effect, providing thermal comfort amidst rising temperatures of climate change, enhancing hydrological properties, and improving urban biodiversity. In this report, I explore the environmental benefits and practical challenges of green roofs, with a specific focus on California. My study evaluates the effectiveness of green roofs in enhancing environmental sustainability using a weighted rating system. I categorize the benefits of green roofs into key areas: thermal performance, stormwater management, ecological support, mental health benefits, noise reduction, air quality improvement, and water quality enhancement. Green roofs have shown the potential for …

2024 May 16 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Conceptualising And Enacting Pathways To Transformative Climate Justice: Examples From The Philippines, Justin See, Anne Shangrila Fuentes, Emma Porio, Brooke Wilmsen

Sociology & Anthropology Department Faculty Publications

Scholarship on climate change adaptation is increasingly moving from incremental responses to climate injustice towards transformative approaches that deliberately change systems to achieve just and equitable outcomes. A transformative understanding of climate justice is relatively new and evidence of how this could be achieved is in its infancy. In this paper, we conceptualise transformative climate justice as comprised of three subcomponents: (1) inclusive justice (seeking to ensure that no one, especially the most vulnerable, is left behind), (2) epistemological justice (drawing upon diverse knowledges and worldviews), and (3) restorative justice (healing and restoration of communities and the environment). We then …

The State Of Knowledge Of Cca Diversity In The Caribbean Coral Reefs, Danielle Macias, Alain Duran, Fabio Nauer

FIU Undergraduate Research Journal

Crustose coralline algae (CCA) are a diverse and ecologically important species found in most of the world’s oceans. The current lack of taxonomic knowledge and relative abundance compromises our ability to predict species diversity numbers and, thus, their ecological roles and impacts on coral reefs. To gather a better understanding of the state of knowledge of crustose coralline algae taxonomy in the Caribbean, 107 different research papers, and other primary and secondary literature were studied; any source with taxonomical information, species identification, or genetic markers for identification was recorded. All Genebank codes were collected and sorted by supposed species marker …

2024 May 9 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Relative Influence Of Sea State And Mean, Turbulent, And Heterogenous Refractivity On X-Band Propagation, Douglas M. Pastore, Erin E. Hackett

Marine Science

In predicting electromagnetic wave propagation within the marine atmospheric surface layer, it is common to assume steady homogenous conditions. However, discrepancies between predicted and measured propagation remain, which could be due in-part to turbulent fluctuations of the refractive index, spatially heterogenous evaporative ducting environments, and mischaracterization of the rough ocean bottom boundary. To better understand the relative importance of these contributors, this study explores the sensitivity of X-band propagation to parameters describing sea-state conditions and refractive environments, including turbulent fluctuations and spatially heterogenous conditions. This study employs the extended Fourier Amplitude Sensitivity Test to compute sensitivity indices that evaluate the …