Establishment Of A Research Site At The Kennedy Mountain Campus For The Observation Of Airborne Particulate Matter,
2024
University of Denver
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 …
Monitoring Air Fluxes In Caves Using Digital Flow Metres,
2024
Swiss Institute for Speleology and Karst Studies (SISKA), La Chaux-de-Fonds, Switzerland
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 …
Phase Error Scaling Law In Two-Wavelength Adaptive Optics,
2024
Air Force Institute of Technology
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 …
Remote Profiling Of Atmospheric Turbulence: Enhanced Resolution With Stacked Rayleigh Beacons In Tardis,
2024
Air Force Institute of Technology
Remote Profiling Of Atmospheric Turbulence: Enhanced Resolution With Stacked Rayleigh Beacons In Tardis, Benjamin C. Wilson
Theses and Dissertations
A stacked beacon turbulence profiling methodology has been introduced and applied to have increased profiling on the Turbulence and Aerosol Research and Investigation System (TARDIS). The model was derived and demonstrated the applicability through discussion on data processing and inversion processes. The methodology was applied for two different nighttime experiments, one in Summer and one in Fall. C 2 n profiles were derived into the 1300 m altitude ranges for both nights and the summer experiment was compared to a co-located DELTA Sky measurements and LEEDR generated Climatological profiles. The comparison implied promise in the methodology with additional work needed …
Development Of The Nebraska Department Of Transportation Winter Severity Index – Phase Ii,
2024
University of Nebraska - Lincoln
Development Of The Nebraska Department Of Transportation Winter Severity Index – Phase Ii, Mark Anderson, Curtis L. Walker, Thomas Kauzlarich
Nebraska Department of Transportation: Research Reports
For the Nebraska Department of Transportation (NDOT), the Nebraska Winter Severity Index (NEWINS) provided an independent framework to calculate a winter season’s severity by categorizing individual winter storms. However, one of the greatest limitations of NEWINS is that it is not predictive. Thus, this study builds on the previously developed NEWINS by creating a predictive winter storm severity index known as NEWINS-Predictive (NEWINS-P). The quantitative precipitation forecast, snow accumulation, ice accumulation, and surface wind speed parameters from the National Digital Forecast Database (NDFD) are used to develop the five components composing the NEWINS-P framework. These components consist of snow severity …
Investigation Of Volatility, Composition, And Gas-Particle Phase Partitioning Of Atmospheric Organic Compounds Through Novel Instrumentation And Techniques,
2024
Washington University in St. Louis
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 Graduate Student 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,
2024
Portland State University
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 …
Quantification Of Surface Layer Turbulence Using Sensible Heat Values From Energy Balance Versus Aerodynamic Methods,
2024
Air Force Institute of Technology
Quantification Of Surface Layer Turbulence Using Sensible Heat Values From Energy Balance Versus Aerodynamic Methods, Steven T. Fiorino, Yogendra Raut, Jaclyn Schmidt, Laura Slabaugh, Blaine Fourman, Jack E. Mccrae, Benjamin C. Wilson, Santasri R. Bose-Pillai
Faculty Publications
Surface layer optical turbulence values in the form of the refractive index structure function C_n^2 are often calculated from surface layer temperature, moisture, and wind characteristics and compared to measurements from sonic anemometers, differential temperature sensors, and imaging systems. A key derived component needed in the surface layer turbulence calculations is the sensible heat value. Typically, the sensible heat is calculated using the bulk aerodynamic method that assumes a certain surface roughness and a friction velocity that approximates the turbulence drag on temperature and moisture mixing from the change in the average surface layer vertical wind velocity. These assumptions/approximations generally …
A Multi-Century Reconstruction Of Sea Surface Temperature, Salinity, And Density From A Northern Red Sea Coral.,
2024
University at Albany, State University of New York
A Multi-Century Reconstruction Of Sea Surface Temperature, Salinity, And Density From A Northern Red Sea Coral., Daliza Nanette Rivera-Matos
Legacy Theses & Dissertations (2009 - 2024)
The Red Sea Outflow Water (RSOW), an intermediate water mass formed in the northern Red Sea, is a primary Red Sea water circulation process. Understanding these water circulation processes gives us an insight into this region's climate dynamics. The intermediate water formation is one of the main processes of the water circulation in the northern Red Sea and feeds the Indian Ocean with saltier and colder water. Despite understanding the RSWO's association with the North Atlantic Oscillation (NAO), its historical response to this climate mode remains unclear. There has not been a long-term record to analyze the relationship between the …
Understanding Variations And Trends In Convection Over The Congo Basin From A Diurnal Perspective,
2024
University at Albany, State University of New York
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,
2024
University at Albany, State University of New York
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 …
Cultural And Environmental Change In A Period Of Westernized Tourism: Bali, Indonesia,
2024
University at Albany, State University of New York
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 …
Categorizing The Societal Impacts From Extreme Rainfall In The New York City Metropolitan Area,
2024
University at Albany, State University of New York
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,
2024
University at Albany, State University of New York
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,
2024
University at Albany, State University of New York
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 …
Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation,
2024
University of Nebraska-Lincoln
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,
2024
University of Nebraska-Lincoln
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,
2024
University of Nebraska-Lincoln
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 …
The Impacts Of Wind On Coastal Trees,
2024
Clemson University
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 …
Geomagnetic Substorms Prediction Model Using Combined Physics-Based And Deep Learning Modeling Techniques,
2024
University of South Alabama
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 …
