Oceanography and Atmospheric Sciences and Meteorology Commons^™

Historical And Potential Future Climate Of Extreme Daily Precipitation Over The Contiguous United States Using Convection-Permitting Simulations, Sylvia Stinnett

Graduate Research Theses & Dissertations

The impacts of anthropogenic climate change will be felt most strongly through changes in hazards such as extreme precipitation. The potential for extreme precipitation changes—both increases and decreases—may have significant societal impacts (e.g., agriculture production, loss of life and property). However, limited research has quantified future projected changes in extreme precipitation due to computational limitations and considerable time expenditure for convection-permitting simulations of substantial duration.This project sought to analyze changes in extreme daily precipitation—defined as the 99th percentile daily accumulated value—due to climate change in the contiguous United States (CONUS) using a dynamically downscaled and convection-permitting regional climate modeling framework. …

Cirrus Microphysical Properties And The Controlling Factors Using A Machine Learning Approach, Derek D. Ngo

Master's Theses

Cirrus clouds are located at high altitudes and are composed of ice crystals. The unique location of cirrus clouds and their large variability in-cloud microphysical properties allow them to have either warming or cooling effects on Earth’s surface and affect the Earth’s energy budget on a global scale. The examination of cirrus radiative effects is further complicated by multiple factors affecting their formation and evolution, including the effects of thermodynamic, dynamic, aerosol, and chemical tracer variables. In this work, we developed a composite aircraft-based in-situ observation dataset based on seven National Science Foundation (NSF) and five NASA flight campaigns that …

Enhancing The Impact Of Infrared Satellite Observations On Data Assimilation Through Aerosol-Aware Framework, Shih-Wei Wei

Legacy Theses & Dissertations (2009 - 2024)

Aerosol radiative effects, both direct and indirect, have been extensively studied in climate projection and numerical weather prediction. However, the aerosol impacts on radiance in the context of data assimilation (DA) have received less research attention. In modern DA systems, thermal infrared (IR) radiance observations have been extensively assimilated since the mid-1990s. Prior studies have shown pronounced reduction of brightness temperature (BT) at the IR window region due to the presence of aerosols. Despite its effects on IR radiance, aerosol information is not considered in most DA systems.Without considering the aerosol impacts on radiance, the representation errors arise from the …

Precision Meteorological Prediction Employing A Data-Driven, Adaptive, Real-Time (Dart) Approach, Sujit Sinha

Theses and Dissertations--Mechanical and Aerospace Engineering

The objective of this research is to improve precision meteorological prediction, benefiting both uncrewed aerial vehicle (UAV) operations by avoiding hazardous flight conditions and tracking contaminant or toxic clouds caused by incidents, accidents, or fires. The operational concept is to collect meteorological observations from instruments mounted on a swarm of UAVs, telemeter the data to a weather simulation model, revise the predicted solution by adapting the flow field to the observations, and then transmit the updated forecast to appropriate personnel as well as to the guidance system of UAVs for repositioning to the next set of most beneficial measurements. While …

Unmanned Aircraft Systems For Precision Meteorology: An Analysis Of Gnss Position Measurement Error And Embedded Sensor Development, Karla S. Ladino

Theses and Dissertations--Biosystems and Agricultural Engineering

The overarching objective of this research was to enhance our comprehension of the three-dimensional precision of meteorological measurements obtained using small unmanned aircraft systems (UAS). Two complimentary experiments were conducted to achieve this objective.

The first experiment entailed the development and implementation of a system to determine the global navigation satellite system (GNSS) position accuracy on a UAS platform. This system was utilized to assess the static and dynamic accuracy of L1 and L1/L2 GNSS receivers in real-time kinematic (RTK) and non-RTK fix modes. Adjusted two-sample t-tests revealed significant differences in horizontal and vertical error between RTK and non-RTK receivers …

Precipitation Recorded In The Turkana Basin From 2005 To 2022., Acacia Leakey, Greg Henkes, Mae Saslaw, Dino Martins

Geosciences Research Data

This is a dataset of precipitation recorded at three sites in northern Kenya near Lake Turkana using standard rain gauges. The data was recorded at the Koobi Fora Research Station (3.947736, 36.186166) from March 2003 until 2006, at the Turkana Basin Institute’s Ileret facility (4.28510, 36.262158) from 2006 to 2022 and at the Turkana Basin Institute’s Turkwel facility (3.140825, 35.864599) from 2012 to 2022. The data was collected manually by TBI staff observing gradation lines on the collectors following rainfall events and recorded as a single total for each 24 hour period.

An Exploration Of Cloud Droplet Growth By Condensation And Collision-Coalescence In A Convection-Cloud Chamber, Jacob T. Kuntzleman

Dissertations, Master's Theses and Master's Reports

Atmospheric clouds are crucial to weather and climate, and the rate at which droplets collide and coalesce to form precipitation is one of the fundamental controlling processes. The convection-cloud chamber allows the interactions between aerosols and cloud droplets produced by condensation to be investigated within a turbulent environment. Studying the full range of microphysical conditions in atmospheric clouds is not possible, however, unless conditions for droplet growth by collision and coalescence are also achieved. In this study, we explore the conditions favorable to collision-coalescence growth in convection-cloud chambers, extending previous work on steady-state droplet size distributions due to condensation alone. …

Shallow Water Coral Distribution And Its Response To Climate Change, Amaury De Jesus

Dissertations and Theses

Shallow water corals are one of the main reef-building organisms that secrete carbonates as their skeletons, and therefore, are one of the major sinks of CO2 in the ocean. These reef builders are also very crucial to marine environments and human society. As the global energy demand continues rising, fossil fuel burning increases at a faster pace despite the increase in energy supply using clean and renewable energy. The increase of CO2 in the atmosphere has been shown to exacerbate global warming and may cause ocean acidification, threatening the habitat of shallow-water corals. Many recent observations show alarming signs of …

Climatology Of The Elevated Mixed Layer Over The Contiguous United States And Northern Mexico: 1979–2021, Margo Siciliano Andrews

Graduate Research Theses & Dissertations

Elevated mixed layers (EMLs) are an important influence on the severe convective storm climatology in the contiguous United States (CONUS), playing a role in storm generation, sustenance, and suppression. A function of the topography in the western CONUS and northern Mexico, EMLs are elevated layers of nearly dry adiabatic lapse rates and high potential temperature, typically with a capping inversion at their base. Although it is well-established that EMLs are primarily a warm-season phenomenon most frequent in the Great Plains, no research to date has examined their variability in-depth, or whether they have changed through time. This study creates an …

2023 January - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

Impacts Of Synoptic-Scale Dynamics On Cloud Properties And Radiation In High Southern Latitudes, Tyler R. Barone

Master's Theses

Predicting future climate change relies on accurate representations of the earth’s surface radiation budget. Complex interactions between large-scale dynamical conditions (e.g., low-pressure systems) and microscale processes (e.g., cloud properties) are key contributors to energy budget biases within global climate models. Proper estimation of cloud microscale processes and their responses to synoptic-scale dynamics will greatly improve the accuracy of the simulated energy balance within global climate models. High-latitudinal clouds have significant influences on the Earth’s radiative balance. We examined observations from two field campaigns at Macquarie Island in the Southern Ocean and McMurdo Station in Antarctica. Two global climate models are …

Daily Synoptic-Scale Influences On Weather-Dependent Renewable Energy Supply And Demand In Hypothetical Fully Electrified North American Interconnections, Howard Tang

Master's Theses

Energy grids around the world are becoming increasingly penetrated by renewable energy sources, resulting in progressively variable energy generation. This study aims to provide a fundamental basis for observing atmospheric conditions in relation to weather-dependent renewable energy supply, where daily synoptic-scale influences are considered in hypothetical fully electrified North American interconnections. Three renewable energy types – 100% wind energy, 100% solar energy, and a 50-50 split of wind and solar energy – are scaled to meet weather-driven energy demand on average in three interconnections, namely the Western Interconnection, the Eastern Interconnection, and a hypothetical combined interconnection composed of the Western, …

Cloud Phase Distribution At A Global-Scale And The Governing Factors Using Satellite And In-Situ Airborne Observations, Dao Wang

Master's Theses

Cloud thermodynamic phase distributions play a crucial role in accurately representing cloud radiative effects and feedback in a changing climate. The partitioning of cloud thermodynamic phases (ice, liquid, and mixed phase) significantly influences Earth's surface temperature and its ability to mitigate the impact of global warming. Satellite-based cloud phase data are frequently used for the evaluation of global climate models, yet validation of them against in-situ observations is still lacking. This study examines global cloud phase distributions and their determinant factors by validating three satellite-based cloud phase products against an extensive in-situ airborne dataset. CALIPSO exhibits the most similar ice …

Spatial And Temporal Characteristics Of Historical Surface Climate Over The Northwest Territories, Canada, Bhaleka D. Persaud

Theses and Dissertations (Comprehensive)

Climate change is putting many of the Northwest Territories (NWT) ecosystems, its people and animal populations at risk due to accelerated warming, permafrost thaw, and changing precipitation regimes. As the NWT continues to warm, at disproportionately higher rates when compared to the rest of Canada, threats to the stability of NWT’s ecosystems are expected to increase. Consequently, understanding how climate warming has changed historically and its implications on natural ecosystems requires point-to-region-specific, long-term climatic data to elucidate important drivers of observed changes relevant to decision makers at community, Indigenous, Territorial and Federal government levels. However, in situ climate data are …

Atmospheric Meteorological Effects On Forecasting Daily Lightning Occurrence At Cape Canaveral Space Force Station, Jon Saul, Torrey J. Wagner, Eric G. Mbonimpa, Brent T. Langhals

Faculty Publications

As the Cape Canaveral Space Force Station and Kennedy Space Center increase their launch rate, any process that could assist in the automation of the currently-manual lightning forecast would be valuable. This work examines the possibility of machine-learning assistance with the daily lighting forecast which is produced by the 45th Weather Squadron. A dataset consisting of 34 lightning, pressure, temperature and windspeed measurements taken from 334 daily weather balloon (rawinsonde) launches in the timeframe 2012-2021 was examined. Models were created using recursive feature elimination on logistic regression and XGClassifier algorithms, as well as Bayesian and bandit optimization of neural network …

2022 - Tennessee Annual Climate Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

2022 December 29 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

2022 December 22 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Relative Importance Of Radar Variables For Nowcasting Heavy Rainfall: A Machine Learning Approach, Yi Victor Wang, Seung Hee Kim, Geunsu Lyu, Choeng-Lyong Lee, Gyuwon Lee, Ki-Hong Min, Menas C. Kafatos

Institute for ECHO Articles and Research

Highly short-term forecasting, or nowcasting, of heavy rainfall due to rapidly evolving mesoscale convective systems (MCSs) is particularly challenging for traditional numerical weather prediction models. To overcome such a challenge, a growing number of studies have shown significant advantages of using machine learning (ML) modeling techniques with remote sensing data, especially weather radar data, for high-resolution rainfall nowcasting. To improve ML model performance, it is essential first and foremost to quantify the importance of radar variables and identify pertinent predictors of rainfall that can also be associated with domain knowledge. In this study, a set of MCS types consisting of …

2022 December 15 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

From The Sky To The Smartphone: Communicating Weather Information In A Digital Age, Cole M. Vaughn

Theses and Dissertations

As new technology has emerged in the digital era, the public can now choose from a variety of new media from which to get weather information. Weather applications (apps) and social media have emerged as some of the popular new media. This study sought to understand the extent to which these new media are used, how weather apps are perceived, how the news media used Twitter during Hurricane Irma, and how the public engaged with the news media’s tweets. A survey and dataset of tweets were used to evaluate the research questions and hypotheses of this research. The study found …

2022 December 8 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

The Contribution Of Non-Tropical Cyclone Vortices To The Rainfall Of The Philippines, Lyndon Mark P. Olaguera, Jun Matsumoto, John A. Manalo

Physics Faculty Publications

Weaker disturbances than tropical cyclones (TCs) such as tropical depressions and cold surges can significantly induce heavy rainfall and flooding events over the Philippines. However, the analysis of these disturbances including their rainfall contributions are often neglected in previous studies. As the first attempt to address this research gap, this study investigates the rainfall contribution of non-TC vortices over the Philippines from 1979 to 2020. Only those rainfall-producing non-TC vortices that formed and appeared within a 500-km radius from the Philippine coastline were examined in this study. A total of 7,686 non-TC vortex days (50% of the total days during …

2022 December - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

Comparison Of 2018-2021 Tropical Cyclone Track Forecasts Before And After Noaa G-Iv Missions, Melissa Piper

Legacy Theses & Dissertations (2009 - 2024)

Tropical cyclone (TC) hazards are primarily dictated by the TC position; thus, it is important to produce accurate TC track forecasts. Many different features can influence a TC’s motion, yet these features are not always well sampled by in-situ observations over the open ocean, creating a need for supplemental observation collected via aircraft, including the deployment of dropsondes. In 1997, the National Hurricane Center (NHC) began operational synoptic surveillance missions in the near-storm environments of TCs using the Gulfstream IV-SP jet aircraft (G-IV), with the goal of reducing track forecast errors. In the first 10 years of operational missions, the …

¿Aviso O Alerta? Developing Effective, Inclusive, And Consistent Watch And Warning Translations For U.S. Spanish Speakers, Joseph E. Trujillo-Falcón, América R. Gaviria Pabón, Joseph T. Ripberger, Abby Bitterman, Jonathan B. Thornton, Mackenzie J. Krocak, Sean R. Ernst, Estilita Cassiani Obeso, John Lipski

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

Spanish-speaking populations in the United States are more vulnerable in disaster contexts due to inequities, such as language barriers, that prevent them from receiving life-saving information. For the past couple of decades, governmental organizations have addressed these issues by translating weather watches, warnings, and advisories into Spanish. Previous studies suggest that these Spanish translations do not communicate the same level of urgency as their English counterparts. To identify whether these translated products result in inequities between English and Spanish speaker reception and comprehension of forecast information, we asked a representative sample of U.S. English (n = 1,550) and Spanish (n …

Cloud Image Classification Using Machine Learning, Marcus Peter Cote

Theses and Dissertations

Machine learning is a rapidly expanding technology that has proven to be highly useful for image classification. Ground-based camera networks are an emerging resource for aviation weather information with near real-time imagery available online for public viewing and download. While raw web camera imagery can be analyzed by aviators, high pilot workload motivates the use of machine learning to autonomously interpret cloud type information from images that is relevant to aviation weather hazards. In particular, transfer learning is a machine learning approach by which elements of a pre-trained machine learning model are refitted for new tasks. By employing transfer learning …

2022 December 1 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Assessing Changes In Tornado Vulnerablitiy In North Alabama, Mckenna Danielle Brahler

Honors Capstone Projects and Theses

No abstract provided.

Comparing Past And Future Drought And Surplus Periods In The Colorado River Basin, Rama Bedri

Student Scholar Symposium Abstracts and Posters

The Colorado River Basin is crucial to the Western United States, providing water for seven states and Mexico. Historical and future periods of drought and surplus are analyzed in 17 Colorado River stations. Unimpaired streamflow data are evaluated from the U.S. Geological Survey, Bureau of Reclamation, and Coupled Modeled Intercomparison Projection 5 from 1950-2099. Future projections are based on eight climate scenarios. Four climate models (HadGEM2-ES, CNRM-CM5, CanESM2, MI-ROC5) are observed at Representative Concentration Pathways (RCP) 4.5 and 8.5 emission scenarios. Furthermore, the ensemble water year means of the four models are analyzed. The durations of drought or surplus, magnitudes, …