Atmospheric Sciences Commons^™

Understanding And Predicting Precipitation Characteristics In The United States Through Machine Learning, Numerical Modeling And Measurements, Cody Luther Ratterman

All Graduate Theses and Dissertations, Fall 2023 to Present

Precipitation is one of the most important yet uncertain variables in the climate system. It varies dramatically in terms of timing, accumulation, rate, and phase, depending on location, season, circulation patterns, and atmospheric conditions. Precipitation forecasts, especially snowfall, are essential to supporting drought mitigation and water management in the Intermountain West. Because rainfall and snowfall lead to opposite effects on snowpack, accurately partitioning rain and snow is important to estimate snowpack levels, winter recreation, mountain ecosystems and runoff. The research findings in this dissertation have advanced the understanding and prediction of precipitation and snowpack in the U.S. by addressing the …

A Statistical Analysis Of Current And Future Hurricane Activity In The North Indian Ocean, Basil Lund

2026 Symposium

A hurricane is defined as a tropical storm with winds sustained at 74 mph or greater. I examined major (category 3 and above) hurricane activity over the North Indian Ocean from the years 1972-2019 as reported by Colorado State University Hurricane Forecast Archive. Using RStudio, I conducted a binomial analysis of the CSU dataset to calculate probabilities of zero to ten years with one or more major North Indian Ocean hurricanes in the next decade. I conducted a geometric analysis to determine probabilities associated with waiting periods for the next year with a major hurricane, as well as a Poisson …

Recent Climatology And Changes In Precipitating Storm Characteristics Over Conus, Tyler Landsparger

Electronic Theses & Dissertations (2024 - present)

As anthropogenic greenhouse gas emissions continue to warm the global climate system, improving our understanding of how precipitating storms are responding in the real world has become increasingly important.  This study leverages 22 years of high-resolution hourly precipitation data from the NCEP Stage IV dataset to produce a seasonal climatology and long-term trend analysis of precipitating storm frequency, duration, area, and intensity across the Contiguous United States (CONUS) from March 2002 through February 2024.  Storms were identified and tracked using an object-tracking algorithm and their characteristics were computed for each season, from which 22-year climatology and trends were derived.  The …

Stream Temperature Responses To Summer Urban Rain Events Along The Savannah River, Joseph E. Wermter, Vivian L. Turner, Max K. Appelbaum, James M. Shepherd, Jacob Z. Lott

Journal of South Carolina Water Resources

The hydrological urban heat island (HUHI) is a recent facet of the urban heat island (UHI), describing thermal enhancement of bodies of water in response to urbanization. Although the forefront of this work has been studied for large Metropolitan areas, this effect on developing cities is currently unknown. To locally measure and quantify HUHI effects in a developing city, we utilized Multi-Radar Multi Sensor (MRMS) radar-derived rainfall data to estimate rainfall in the Augusta Metropolitan Area (AMA) and the Savannah Metropolitan Area (SMA), two developing communities adjacent to the Savannah River. We analyzed mean temperature trends of two stream gauges …

Seeking Structure In Complex Systems: From Feature Analysis To Space-Time Causal Discovery With Earth Science Applications, Jeffrey J. Nichol

Computer Science ETDs

Complex systems are difficult to study because of their many interacting parts, emergent phenomena, and feedback loops. These systems underpin all life on Earth. We need improved tools for seeking an understanding of them. This body of research presents my investigations into data-driven methods for understanding complex systems, including my invention of a novel causal discovery meta-algorithm for space-time gridded data. I demonstrated machine learning feature importance and causal discovery capabilities for comparing simulated and observed climate data. I developed a new benchmark for modeling space-time dynamics of locally driven phenomena and examined a prominent causal discovery algorithm. Finding that …

Rain-On-Snow Event Climatology And Hydrological Impacts In The Connecticut River Watershed, Samuel Davidson

Masters Theses & Specialist Projects

Rain-on-snow events, characterized by rain falling on existing snowpack, have the potential to bring about significant hydrological and environmental impacts including snowmelt, flooding, landslides, and other natural hazards. Despite prior evidence suggesting the Connecticut River Watershed has endured socioeconomic and environmental setbacks due to rain-on-snow events in the past, limited prior research has been performed on the role of rain-onsnow events within the region’s hydroclimatology. Gaining a deeper understanding of the occurrence and impacts of such events would provide valuable insights for risk and water resource managers. The purpose of this research was to create a climatology of rain-on-snow events …

Statistical Analysis Of Climate Trends And Variability In Tarrant County Using Annual, Decade, And Three-Decade Time Periods, Quinnton Debolt

Earth & Environmental Sciences Theses - Archive

This study is a statistical analysis of climate trends within the Dallas-Fort Worth metroplex according to several time-scale models to understand how the climate for the locality has changed and to provide a basis for projections of what future climate might look like. Trends in mean temperature and precipitation for North Central Texas generally correlate with corresponding global trends linked to natural variability and anthropogenic-induced climate change. Temperature rises in this region annually by 0.08°C and by 0.22°C for a three-decade average. Seasonal increases in three-decadal averages of temperature for North Central Texas relative to the average of the reference …

A Wall Of Smoke: Understanding The Drivers Of The June 2023 Canadian Wildfire Smoke Event For New York City, Gregory S. Randazzo

Dissertations and Theses

The 2023 Canadian wildfire season was notable for its extent and the dense smoke it produced. Motivated by the resulting air quality impacts in the New York City region, we explore how the total particulate matter output from the Quebec fires influenced PM2.5 concentrations downstream in New York City. Using injection height data from the Regional Advanced Baseline Imager + VIIRS Emissions dataset, we relate the tropospheric injection heights of the fires with the broader synoptic context and surface PM2.5 concentrations. Using data from the NYS Mesonet Profiler Network, radiosondes, and ERA5 reanalysis, we document the connection between an anomalous …

An Evaluation Of High-Resolution Model Simulations Of Orographic Precipitation, Snowpack, Atmospheric Rivers, And Their Climate Sensitivities In The Southern Andes, Erin Potter

Legacy Theses & Dissertations (2009 - 2024)

Orographic precipitation and snowpack are important for water resources and hydrometeorological hazards in the Andes Mountain range. As the climate warms, South American atmospheric rivers (ARs) are expected to increase in frequency and intensity, leading to increased orographic precipitation. Improved understanding of orographic precipitation and snowpack, and their association with ARs, in a warming climate is needed to provide a foundation for understanding future hydroclimate change over the Andes. The goal of this research is to evaluate how well variations in high-resolution regional climate simulations over the southern Andes (30-55°S), agree with observations of (1) orographic precipitation and (2) snowpack …

Communicating About Extreme Heat: Results From Card Sorting And Think Aloud Interviews With Experts From Differing Domains, Jeannette Sutton, Nicholas Waugh, Savannah Olivas

Emergency Preparedness, Homeland Security, and Cybersecurity Faculty Scholarship

Climate trends indicate that extreme heat events are becoming more common and more severe over time, requiring improved strategies to communicate heat risk and protective actions. However, there exists a disconnect in heat-related communication from experts, who commonly include heat related jargon (i.e., technical language), to decision makers and the general public. The use of jargon has been shown to reduce meaningful engagement with and understanding of messages written by experts. Translating technical language into comprehensible messages that encourage decision makers to take action has been identified as a priority to enable impact-based decision support. Knowing what concepts and terms …

Changes Of Winter Severity In Arkansas During 1901-2100, Christian Garcia

Graduate Theses and Dissertations

The objective of this study was to quantify the winter severity in a way that was reproduceable and easy to understand. The Accumulated Winter Severity Seasonal Index (AWSSI) was chosen for this reason and was used to quantify winter severity by season across the state of Arkansas. The variables that go into the AWSSI calculation are maximum daily temperature, minimum daily temperature, daily snowfall, and daily snow depth. When the snowfall and snow depth were missing, they can be estimated using daily temperature and precipitation. Then the estimated snowfall and snow depth can be subsequently used to quantify the winter …

An Investigation Of Water Obstructions And Related Weather Conditions For Nebraska Roadways, Logan Bundy

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

Roadway resilience across the 10,000 miles of road and 3,500 bridges in Nebraska is critical to the economic success of production and logistics. In a state where historical flooding scenarios, such as the one in March 2019 that caused $150 million in damage, could potentially be increasing, it has become essential to understand the spatial and temporal distribution of high-frequency water obstruction areas on roadways. Using Nebraska Department of Transportation (NDOT) historical water obstruction data from June 2016 through August 2021, statistical and spatial analyses were conducted to quantify the relationship between water obstructions and their associated meteorological conditions, and …

Dynamic Impacts Of Hadley Circulation On Saharan Desert Warming Amplification, Alejandro Manuel Ayala

Legacy Theses & Dissertations (2009 - 2024)

Changes in temperature due to climate change are not spatially uniform, and deserts and other drylands, which are greatly underrepresented in climate studies, are warming at a much faster rate than much of the globe with increasing concentrations of greenhouse gases. This strong warming amplification over deserts, termed Desert Amplification (DA), is most pronounced over the world’s largest and driest Sahara Desert and the Arabian Peninsula. The Sahara and Arabian deserts are formed in the subtropical subsiding branch of the Hadley Circulation (HC) and so the changes in large-scale subsidence associated with adiabatic heating could impact the DA dynamically. While …

Optical And Physicochemical Properties Of Atmospherically Processed Brown Carbon Using Novel First-Principle Instrumentation, Benjamin Sumlin

McKelvey School of Engineering Graduate Student Theses & Dissertations

Atmospheric processing of brown carbon (BrC) – a class of spherical, internally-mixed, light-absorbing organic aerosol – emitted from smoldering biomass combustion is an understudied phenomenon with implications for climate science, air quality models, and satellite retrieval algorithms. BrC aerosols have received significant attention as a strong contributor to atmospheric light absorption in the shorter visible wavelengths and a driver of UV photochemistry. Their complex refractive indices (m=n+ik), size distributions, and carbon oxidation states dictate their optical properties, atmospheric residence times, and chemical interactions, respectively. There is currently a gap in our understanding of these fundamental particle properties and their evolution …

Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman

Chemistry Faculty Publications

This Special Issue provides the first literature collection focused on the development and implementation of unmanned aircraft systems (UAS) and their integration with sensors for atmospheric measurements on Earth. The research covered in the Special Issue combines chemical, physical, and meteorological measurements performed in field campaigns as well as conceptual and laboratory work. Useful examples for the development of platforms and autonomous systems for environmental studies are provided, which demonstrate how careful the operation of sensors aboard UAS must be to gather information for remote sensing in the atmosphere. The work serves as a key collection of articles to introduce …

Lightning Activity In The Continental United States On An Enso Time Scale, 2002-2015, Tyler M. Gingrich

Senior Honors Projects, 2020-current

This investigation examined the frequency and spatial pattern of lightning in the continental United States from 2002 to 2015. Before analysis, flashes were grouped based on their El Niño Southern Oscillation (ENSO) phase and Spatial Synoptic Classification (SSC) type for the winter season (December, January, and February). The purpose of this study is to better understand the relationship between planetary teleconnections, synoptic scale air masses, and micro scale phenomena, specifically lightning, in the continental United States. Evidence suggests ENSO cold phase flashes tend to have a lower frequency in number of flashes and flash days, as well as a northward …

An Analysis Of Temperature Trends In The Northeast United States : 1950-2019, Christopher Selca

Legacy Theses & Dissertations (2009 - 2024)

The warming signal associated with anthropogenic climate change shows a significant positive trend globally over the last century. Trends in the magnitude and frequency of annual mean and extreme events do not display a globally uniform signal, as some regions have shown negative trends. This study examines the trends in daily mean and extreme temperatures in the Northeast region of the United States. Station data was selected from the GHCN-D Version 3 data set, using a blend of stations from the weather forecast offices and the cooperative observing network. Station criteria included using a threshold of less than 5% of …

Application Of A Hybrid Statistical–Dynamical System To Seasonal Prediction Of North American Temperature And Precipitation, Sarah Strazzo, Dan C. Collins, Andrew Schepen, Q. J. Wang, Emily Becker, Liweli Jia

Publications

Recent research demonstrates that dynamical models sometimes fail to represent observed teleconnection patterns associated with predictable modes of climate variability. As a result, model forecast skill may be reduced. We address this gap in skill through the application of a Bayesian postprocessing technique—the calibration, bridging, and merging (CBaM) method—which previously has been shown to improve probabilistic seasonal forecast skill over Australia. Calibration models developed from dynamical model reforecasts and observations are employed to statistically correct dynamical model forecasts. Bridging models use dynamical model forecasts of relevant climate modes (e.g., ENSO) as predictors of remote temperature and precipitation. Bridging and calibration …

An Overview Of Dynamic Heterogeneous Oxidations In The Troposphere, Elizabeth A. Pillar-Little, Marcelo I. Guzman

Chemistry Faculty Publications

Due to the adverse effect of atmospheric aerosols on public health and their ability to affect climate, extensive research has been undertaken in recent decades to understand their sources and sinks, as well as to study their physical and chemical properties. Atmospheric aerosols are important players in the Earth’s radiative budget, affecting incoming and outgoing solar radiation through absorption and scattering by direct and indirect means. While the cooling properties of pure inorganic aerosols are relatively well understood, the impact of organic aerosols on the radiative budget is unclear. Additionally, organic aerosols are transformed through chemical reactions during atmospheric transport. …

Introduction To Weather And Climate (Vsu), Jason Allard, Weimin Feng

Geological Sciences and Geography Grants Collections

This Grants Collection for Introduction to Weather and Climate was created under a Round Seven ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

• Linked Syllabus
• Initial Proposal
• Final Report

Climate Modeling, Outgoing Longwave Radiation, And Tropical Cyclone Forecasting, Thomas Rechtman

Honors Undergraduate Theses

Climate modeling and tropical cyclone forecasting are two significant is- sues that are continuously being improved upon for more accurate weather forecasting and preparedness. In this thesis, we have studied three climate models and formulated a new model with a view to determine the outgoing longwave radiation (OLR) budget at the top of the atmosphere (TOA) as ob- served by the National Oceanic and Atmospheric Administration’s (NOAA) satellite based Advanced Very High Resolution Radiometer (AVHRR). In 2006, Karnauskas proposed the African meridional OLR as an Atlantic hur- ricane predictor, the relation was further proven in 2016 by Karnauskas and Li …

Investigation Of Microphysical Properties Of Laboratory And Atmospheric Clouds Using Digital In-Line Holography, Neel Desai

Dissertations, Master's Theses and Master's Reports

In this study, we attempt to perform in-cloud measurements, both in the laboratory using the Michigan Tech $\Pi$-chamber and in the atmosphere via the CSET field campaign. Atmospheric turbulence is believed to play a critical role in the growth, development and dissipation of clouds and it is important to study its effect in order to better understand and predict cloud properties such as albedo and lifetime. We use digital in-line holography to measure the effect of turbulence on cloud microphysical properties such as variations in droplet number concentration and droplet or ice particle size. In the first half, we study …

Land Use Land Cover Change Effects On Southern Great Plains Precipitation, Alexandra Caruthers

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

Great Plains land use has changed substantially over the last 160 years, altering the properties of the land through increased settlement and advances in irrigation. Changing the interface between the land and atmosphere has implications for the atmospheric boundary layer, the regional circulation, the local surface energy budget and resulting precipitation patterns. Land use land cover (LULC) changes are an important topic for this region due to its heavy dependence on agriculture. This study investigates differences in Southern Great Plains precipitation patterns between four LULC scenarios: the pre-settlement, 1920’s, Dust Bowl and present day eras. Using the Weather Research and …

Influence Of Volcanic Eruptions On Tropical Hydroclimate During The Last Millennium, Christopher Colose

Legacy Theses & Dissertations (2009 - 2024)

Volcanic eruptions exert the most important radiative forcing on Earth’s climate during the pre-industrial interval of the last millennium. In this thesis, I investigate the role of volcanic eruptions in altering tropical climate, including temperature and rainfall. I primarily use forced transient simulations of the last millennium as a tool to explore how explosive volcanic events project onto the hydrologic cycle, as well as the imprint of water isotopologues (H216O, H218O) associated with rainfall. Attention is given to the South American continent specifically (in chapter 2), and to the entire tropics (in chapter 3).

Impacts Of Internal Variability On Climate Trends In Large Ensemble Simulations By Two Climate Models, Christine Bloecker

Legacy Theses & Dissertations (2009 - 2024)

Internal climate variability (ICV) can influence trends in observations and model simulations over periods spanning decades, making it difficult to quantify the response of the climate system to external forcing. We analyze two large ensembles of climate simulations from 1950-2100 by two fully coupled climate models, namely the CanESM2 and CESM1, to quantify the effects of ICV on apparent trends in annual surface air temperature (T) and precipitation (P) over different time periods and regions. In comparison with observations, the CanESM2 overestimates the global T and P trends during 1979-2014 while they fall within the ICV-induced range of the CESM1. …

The Cloud-Radiative Forcing Of The U.S. Landfalling Atmospheric Rivers, Qianwen Luo

Open Access Dissertations

Atmospheric rivers (ARs) are narrow channels in the atmosphere that transport an enormous amount of moisture from the tropics to the higher latitudes. Streaks of highly reflective clouds are observed along with the ARs in satellite imagery. These clouds both influence the moisture transport of ARs, as well as modify the Earth-Atmospheric energy budget through pathways such as cloud-radiative forcing (CRF). This dissertation studies the CRF of the U.S. Landfalling ARs in weather and climate scales. Three crucial questions are addressed. First, how do clouds produced by the ARs modulate the moisture and heat balance of the Earth-Atmospheric system? Even …

Wind Climatology: A Study Of Trends On Rodgers' Dry Lakebed, Dana Coppernoll-Houston

STAR Program Research Presentations

A number of smaller projects at the Armstrong Flight Research Center fly on or close to the ground and are subject to ground-level winds. Many of these are new prototype models, such as PRANDTL-D (Preliminary Research Aerodynamic Design to Lower Drag). Waiting for the right conditions on a day of variable winds can sometimes mean that teams fail to complete testing. A strategic analysis of wind behavior at a locations where winds can vary greatly due to terrain could lend insight into the best times to test for near-ground aircraft. The purpose of this project was to data mine historical …

Nres/Metr/Bsen 479/879: Hydroclimatology—A Peer Review Of Teaching Project Benchmark Portfolio, Francisco Munoz-Arriola

UNL Faculty Course Portfolios

Rising temperatures and extreme hydrometeorological and climate events are evidences of a changing climate. An increasing population together with their demands for food, energy and water make changes in climate evidence the need to train a new generation of multidisciplinary professionals with a clear understanding of the effects of a changing climate in their activities. Historically, climate sciences were used for scientific and weather operational contexts and engineers applied stationary assumptions for multi-term planning. My goal is to identify elements built from classroom experiences about (a) the suitability of a hydroclimatology course for engineers and scientists; (b) the multidisciplinary skills; …

Springtime Melt Onset On Arctic Sea Ice From Satellite Observations And Related Atmospheric Conditions, Angela C. Bliss

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

The timing of snowmelt onset (MO) on Arctic sea ice derived from passive microwave satellite data is examined by determining the melting area (in km²) on a daily basis for the spring and summer melt season months over the 1979 – 2012 data record. The date of MO on Arctic sea ice has important implications for the amount of total solar energy absorbed by the ice-ocean system in a given year. Increasingly early mean MO dates have been recorded over the 34-year data record as evidenced by statistically significant trends of 6.6 days decade^-1 over the extent …

Remote Sensing And Modeling Of Atmospheric Dust And Studying Its Impact On Environment, Weather, And Climate, Hesham El-Askary, Seon K. Park, Slobodan Nickovic, Mian Chin

Mathematics, Physics, and Computer Science Faculty Articles and Research

An overview of the 2015 volume of Advances in Meteorology, which was co-edited by Chapman faculty member Dr. Hesham El-Askary.