Physical Sciences and Mathematics Commons^™

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 …

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 …

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 …

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 …

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 …

Comparison Of Multidecadal Variability In Climate Reanalyses And Global Models, Andrew A. Westgate

Theses and Dissertations

Superimposed on the linear upward trend of observed global surface air temperature anomalies since the late nineteenth century is, what appears to be, a multidecadal undulation. However, this undulation is either muted or virtually absent in both the previous and current generations of the state-of-the-art climate models used to not only simulate past climates but also predict future climates. One possibility is that this signal is due to a series of complex responses to the global climate forcing; an alternative is that this signal is contained within the internal variability and teleconnected via atmospheric channels. Either way, the existential threat …

Analytic Approximations Of Higher Order Moments In Terms Of Lower Order Moments, Sven Detlef Bergmann

Theses and Dissertations

The Cloud Layers Unified By Binormals (CLUBB) model uses the sum of two normal probability density function (pdf) components to represent subgrid variability within a single grid layer of an atmospheric model. This binormal approach, while computationally efficient, restricts the model’s ability to capture the full spectrum of potential shapes encountered inreal-world atmospheric data.

This thesis proposes to introduce a third normal pdf component strategically positioned between the existing two, significantly enhancing the model’s representational flexibility. This trinormal representation allows for a wider range of grid-layer shapes while permitting analytic solutions for certain higher order moments.

The core of this …

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 …

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 …

An Assessment Of The High-Resolution Rapid Refresh Model’S Ability To Resolve The Great Lakes Marine Atmospheric Boundary Layer And Lake-Breeze Front, Collin Paul Deyoung

Theses and Dissertations

We determined the ability of the High-Resolution Rapid Refresh (HRRR) mesoscale model to predict the lake-breeze front’s structure and faithfully represent the marine atmospheric boundary layer (MABL) behind it. First, two field missions were completed during the 2023 warm season over Lake Michigan to characterize the spatiotemporal evolution of the MABL and validate HRRR forecasts. We found the Lake Michigan MABL was characterized by minimal thermodynamic and kinematic variability on diurnal time scales, regardless of the stability or flow regime. Additionally, the HRRR was able to resolve MABL thermodynamic structures effectively but underestimated the vertical temperature distribution, leading to a …

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 …

Predictability Of The Overland Reintensification Of North Atlantic Tropical Cyclone Erin (2007), Ariel Tickner-Ernst

Theses and Dissertations

Tropical cyclones (TC) typically decrease in intensity upon interacting with land because of increased surface roughness and decreased surface evaporation. However, several studies have documented cases in which TCs maintain their intensity or even intensify over land within non- or weakly baroclinic environments. Yet, our understanding of the precise physical processes that support maintenance or intensification over land in non- or weakly baroclinic environments remains limited, and the predictive skill for these outcomes has yet to be quantified.

We begin this process by quantifying the predictive skill and forecast uncertainty of the overland intensification of North Atlantic Tropical Storm Erin …

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

<strong> Theses and Dissertations </strong>

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 …

Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform, Joshua W. Milford

Doctoral Dissertations and Master's Theses

Low-cost and low-size-weight-and-power (SWaP) magnetometers can provide greater accessibility for distributed simultaneous measurements in the ionosphere, either onboard sounding rockets or on CubeSats. The Space and Atmospheric Instrumentation Laboratory (SAIL) at Embry-Riddle Aeronautical University has launched a multitude of sounding rockets in recent history: one night-time mid-latitude rocket from Wallops Flight Facility in August 2022 and three mid-latitude rockets from White Sands Missile Range during the October 2023 annular solar eclipse. All rockets had a comprehensive suite of instruments for electrodynamics and neutral dynamics measurements. Among this suite was one science-grade three-axis fluxgate magnetometer (Billingsley TFM65VQS / TFM100G2) and up …

Spectroscopy Of Atmospheres, Randika Dodangodage

Physics Theses & Dissertations

Spectroscopic methods are used to study planetary and stellar atmospheres. The information obtained from spectroscopic studies provides insight into atmospheric compositions and dynamics, which can be used to model and characterize atmospheres and climates. Laboratory-recorded absorption cross-sections are needed to interpret the recorded spectra of planets and stars. High resolution ethane, neopentane, propene, and n-butane spectra have been recorded, and absorption cross-sections have been provided for different temperatures and total pressures with different broadening gases, including hydrogen, helium, and nitrogen. The Atmospheric Chemistry Experiment (ACE) satellite orbits Earth and records spectra through solar occultation limb observations. HOCl is a chlorine …

Understanding Local And Large-Scale Drivers Of Rainfall Variability And Change Over The Hawaiian Islands Region, Katrina Fandrich

Electronic Theses & Dissertations (2024 - present)

Hawaiian rainfall variability is strongly influenced by anthropogenic climate change and natural variability (e.g., Pacific Decadal Oscillation (PDO), Pacific North American (PNA) pattern, El Niño–Southern Oscillation (ENSO)). For local decision-makers and resource managers, understanding the drivers of rainfall variability and change in Hawai‘i is crucial for climate adaptation and mitigation planning. Previous studies have applied statistical and dynamical downscaling to produce high-resolution rainfall projections for the Hawaiian Islands region. However, to date, downscaling has only been used to investigate the influence of anthropogenic forcing on late-century rainfall projections for the Hawaiian Islands. For regions like Hawai’i, that are highly vulnerable …

The Effects Of Temperature, Flooding, And Goose Feces Addition On Greenhouse Gas Emissions And Ammonification In Four High-Latitude Soils From Western Alaska, Jenna M. Ross

Electronic Theses and Dissertations

The large carbon (C) stock of wetlands is vulnerable to climate change, especially in high latitudes that are warming at a disproportional rate. Likewise, low-elevation Arctic coastal areas will flood more frequently under climate change and sea-level rise, which may alter goose herbivory and fecal deposition patterns if geese move inland. While temperature, flooding, and feces impact soil C emissions, their interactive effects have been rarely studied. Here, I explore the impact of these interactions on CO2 and CH4 emissions and nitrogen (N) mineralization (ammonification) in soils collected from four plant communities in the Yukon-Kuskokwim (Y-K) Delta, a high latitude …

Effects Of El Nino And Sunspot Cycles On Global And Reginal Climate, August Nathan Tolzman

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Sunspots and El Nino affect the interannual variability of temperature on earth. Separately there is a positive relationship between higher sunspots and warmer temperatures or more intense El Nino and warmer temperatures globally and in Missoula. This is with the bias of climate change removed. Putting these two processes together it is expected that when intense El Ninos and high sunspots happen in the same year there will be warmer temperatures. This was not the case, there was no data to support that putting these to processes together makes them more or less intense.

A Comparison Of Arctic And Atlantic Basin Cyclone Predictability From A Climatology And Case Study Perspective, Peyton Capute

Electronic Theses & Dissertations (2024 - present)

Arctic cyclones (ACs) can transport warm, moist air into the Arctic region, which combined with strong winds may lead to rapid declines in sea ice during the summer. As a consequence, accurate sea ice predictions during the summer may rely on being able to predict cyclone-related wind speed and direction, which critically depends on the cyclone track and intensity. Despite this, there are relatively few studies that have documented the predictability of ACs during the summer, beyond a few case studies. In addition, there has been no extensive comparison of whether these cyclones are more or less predictable relative to …

Role Of Relative Humidity In New Particle Formation From Ozonlysis Of Atmospheric Volatile Organic Compounds, Christopher Snyder

Graduate College Dissertations and Theses

The impact of relative humidity (RH) on organic new particle formation (NPF) from ozonolysis of biogenic volatile organic compounds (BVOCs) remains an area of active debate. Previous reports provide contradictory results indicating both depression and enhancement of NPF under conditions of moderate RH, while others ignore the potential impact. Only several reports have suggested that the effect may depend on absolute mixing ratio of the precursor volatile organic compound (VOC, ppbv). However, before any experiments could be completed, development of new methods was necessary to overcome the limitation of sampling ultrafine nanoparticles (<50 nm aerodynamic diameter) with aerosol mass spectrometry. This dissertation includes a report on a new Particle Growth Apparatus (PaGA) that artificially grows particles from as small as 17 nm to over 110nm. Considerable effort was made to identify the most suitable growth matrix (squalane) and optimize particle growth for reproducibility and sensitivity.

The PaGA was then utilized in the …

Hysplit In Simulating The Atmospheric Dispersion Of Hazardous Aerosols: A Case Study In St. Louis, Missouri, Ahmet Tolga Odabasi

Masters Theses

"Atmospheric dispersion and transmission play an important role in the behavior and effects of air pollution. Human health can be adversely affected by air pollution in a variety of ways, both immediately and over time. The Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) modeling program, a computer model and software package, tracks the transport trajectories and distributions of air pollution and various pollutants, including radioactive pollutants, in the atmosphere. It also facilitates research on pollution sources. This study simulated the transport of hazardous aerosols in St. Louis region for the years 2020, 2021, and 2022 using the HYSPLIT modeling …

Predictability Of Downslope Windstorms And Mechanisms Controlling Their Onset, Matthew James Brewer

Electronic Theses & Dissertations (2024 - present)

Downslope windstorms in the western United States often contribute to the ignition and ex- acerbation of existing wildfires due to their hot, dry, and gusty nature. Accurate forecasts of these windstorms are imperative for mitigating wildfire risk. However, forecasting downslope windstorms remains challenging due to their sensitivity to environmental conditions.

The Sundowner Windstorms of the Santa Barbara, California region have been asso- ciated with many large wildfires in the area. This study analyzes special observations from the Sundowner Wind Experiment field campaign to better understand the diurnal cycle of these windstorms. Analysis of the strongest windstorm during the campaign indicates …

Using Airborne Measurements To Evaluate Forecasts Of Freezing Drizzle Aloft Results From The Wintre-Mix Field Campaign, Megan Schiede

Electronic Theses & Dissertations (2024 - present)

Icing associated with the accretion of supercooled large droplets (SLD) serves as a significant hazard to aviation activities. Forecasting SLD events is complex due in part to the limitations of numerical weather prediction models. The Winter Precipitation Type Research Multiscale Experiment (WINTRE-MIX) aimed to comprehend such limitations within numerical forecasts of precipitation type (p-type) through the use of extensive observations during events with multiple p-types. To investigate precipitation processes aloft in winter storms with near-freezing surface conditions, research flights were orchestrated with the National Research Council of Canada Convair-580 aircraft. This study examines a WINTRE-MIX intensive observing period that took …

Initiation Criteria For The Onset Of Geomagnetic Substorms Based On Auroral Observations And Electrojet Current Signatures, Mayowa Michael Kayode-Adeoye

<strong> Theses and Dissertations </strong>

In recent years, several substorm onset criteria have been developed, either from auroral observations (many authors) or from auroral electrojet properties such as those described by (Forsyth et al., 2015; Maimaiti et al., 2019; Newell & Gjerloev, 2011; Partamies et al., 2011) The different criteria are being investigated using a low order physics model of the magnetosphere called WINDMI (Spencer et al., 2009) and inferences are being made in line with the WINDMI model. The model variables will be compared with the criteria for substorm onset proposed by examining the SML index.

The WINDMI model uses solar wind and IMF …

Translation Speed Influence On Tropical Cyclone Storm Tide And Surge Generation Along The Gulf Of Mexico Coast, Samantha L. Camarda

LSU Master's Theses

This research examines tropical cyclone translation speed as a factor in storm tide and surge height upon landfall on the United States Gulf Coast. Understanding the effect of translation speed on peak storm tide/surge height is needed to better prepare for and predict future damage from tropical cyclone events. Tropical cyclone data are taken from hourly interpolated best-track HURDAT2 data from 1970–2021. This study uses the HURDAT2 hourly interpolated observation data points (24-hours) pre-landfall to landfall. Translation speed is calculated based on the distance traversed between hourly points. Peak storm tide and storm surge data are taken from SURGEDAT from …

Characteristics Of Refractivity And Sea State In The Marine Atmospheric Surface Layer And Their Influence On X-Band Propagation, Douglas Matthew Pastore

Electronic Theses and Dissertations

Predictions of environmental conditions within the marine atmospheric surface layer (MASL) are important to X-band radar system performance. Anomalous propagation occurs in conditions of non-standard atmospheric refractivity, driven by the virtually permanent presence of evaporation ducts (ED) in marine environments. Evaporation ducts are commonly characterized by the evaporation duct height (EDH), evaporation duct strength, and the gradients below the EDH, known as the evaporation duct curvature. Refractivity, and subsequent features, are estimated in the MASL primarily using four methods: in-situ measurements, numerical weather and surface layer modeling, boundary layer theory, and inversion methods.

The existing refractivity estimation techniques often assume …

Precipitation Variability And Predictability Over The Arabian Peninsula, Central Southwest Asia, And Southern Africa, Matthew Francis Horan

Doctoral Dissertations

The Northern Hemisphere winter is the main rainy season for the Arabian Peninsula (AP), Central Southwest Asia (CSWA), and Southern Africa (SF), where precipitation predictability is limited or understudied. This dissertation research focuses on improving our understanding of these regions' wet-season precipitation characteristics and predictability.

First, I have identified the AP's key moisture sources through a Lagrangian back-trajectory algorithm. Mid-latitude land and water bodies, such as the Mediterranean and Caspian Seas, are the primary moisture sources in the northern region. Areas further south rely on moisture transport from the Western Indian Ocean and the African continent. A significant drying trend …

Decadal Climate Variability In Mesoscale-Resolving Coupled Models, Ilijana Mastilovic

Theses and Dissertations

Most of our knowledge about the causes of 20th-century climate change comes from simulation using numerical models. However, the observed climate variability and the one simulated by the state-of-the-art climate models exhibit substantial discrepancies at the decadal-to-multidecadal time scale and thus it hinders our fundamental understanding of the observed climate change. Evidence is mounting that vigorous intrinsic variability associated with mesoscale oceanic features contributes significantly to large-scale low-frequency climate variability, with fundamental implications for decadal climate low-frequency climate prediction. As of yet, extensive simulation of these decadal effects using high-resolution state-of-the-art coupled climate models has been computationally prohibitive, as it …

A Framework For Statistical Modeling Of Wind Speed And Wind Direction, Eva Murphy

All Dissertations

Atmospheric near surface wind speed and wind direction play an important role in many applications, ranging from air quality modeling, building design, wind turbine placement to climate change research. It is therefore crucial to accurately estimate the joint probability distribution of wind speed and direction. This dissertation aims to provide a modeling framework for studying the variation of wind speed and wind direction. To this end, three projects are conducted to address some of the key issues for modeling wind vectors.\\

First, a conditional decomposition approach is developed to model the joint distribution of wind speed and direction. Specifically, the …

Investigation Of The Flow Field In The Jack Rabbit Ii Mock Urban Environment Field Tests Using A 1:50 Scale Wind Tunnel Model, Paulo Victor De Freitas Lopes

Graduate Theses and Dissertations

Accidental release of toxic chemicals can put workers and nearby populations at significant risk. Consequence assessment of accidents in urban environments is of particular interest. Urban geometries create wind channels between buildings, along with particularly dangerous areas downwind of buildings, where near-stagnant flow is present. Furthermore, recirculation zones can be formed between buildings, trapping high concentrations of toxic gases at ground level, particularly for denser-than-air gases. In 2015, the Department of Homeland Security conducted the Jack Rabbit II Field Test (JR-II) at Dugway Proving Ground, UT. During JR-II, chlorine was released at the center of a Mock Urban Environment (MUE) …