Meteorology Commons^™

Using Asos Ceilings And Mesonet Relative Humidity To Improve General Aviation Flight Planning And Decision Making In Complex Terrain, Connor Hayden Welch

Theses and Dissertations

Despite the increasing availability of weather products and access to data, the issue of weather representativeness, especially in relation to terrain, persists in the aviation industry. Data-sparse regions pose a particular challenge, requiring focused research efforts to address this issue and reduce accident and fatality rates within the general aviation (GA) community. This thesis aims to tackle the specific problem of representing visibility conditions, with a focus on obscuration conditions in elevated terrain.

To achieve this goal, data from Automated Surface Observing System (ASOS) ceilometers and nearby mesonet relative humidity (RH) were analyzed to establish a relationship between the lowest …

Obscuration Analysis Of Camera Imagery For Aviation Applications, Patrick James Roelant

Theses and Dissertations

Image feature detection is a potent tool with many applications, such as fog identification, roadway conditions, etc. As part of the recent surge in machine learning applications, cloud detection has also become an increasingly engaged area of research. Identifying low clouds is especially useful with respect to aviation, particularly in regions of complex topography prone to visibility-related hazards such as haze or fog. To address this issue, a threshold-based semi-automated algorithm was developed and tested to determine whether or not an image is obscured by fog or haze. Images were obtained from a ground-based camera network in Southern California, the …

Verification Of The Localized Aviation Mos Program (Lamp) At Major Us Airports For Ifr Conditions, Mackenzie O'Rourke

Theses and Dissertations

The objective of this research is to quantify the LAMP’s performance when forecasting for IFR conditions at specific major airports for forecast hours one, three, six, and twelve, and further determine how the LAMP performs seasonally at those specific airports and forecast hours. Two by two contingency tables were used to calculate the Probability of Detection (POD), False Alarm Ratio (FAR), Critical Success Index (CSI), Heidke Skill Score (HSS), and Bias score. The results show that the LAMP performs relatively better in the cool season compared to the warm season consistently at each chosen airport, and that the LAMP performs …

Tornado Outbreak False Alarm Probabilistic Forecasts With Machine Learning, Kirsten Reed Snodgrass

Theses and Dissertations

Tornadic outbreaks occur annually, causing fatalities and millions of dollars in damage. By improving forecasts, the public can be better equipped to act prior to an event. False alarms (FAs) can hinder the public’s ability (or willingness) to act. As such, a probabilistic FA forecasting scheme would be beneficial to improving public response to outbreaks.

Here, a machine learning approach is employed to predict FA likelihood from Storm Prediction Center (SPC) tornado outbreak forecasts. A database of hit and FA outbreak forecasts spanning 2010 – 2020 was developed using historical SPC convective outlooks and the SPC Storm Reports database. Weather …

Protecting The Vulnerable: Tornado Sheltering And Communication Of Public Shelters With A Case Study From The Covid-19 Pandemic, Craig Douglas Croskery

Theses and Dissertations

One of the greatest natural hazards that is faced with in much of the United States are tornadoes. Despite improvements in the warning processes, the risk of significant loss of life remains high. That is particularly true with vulnerable communities which have higher proportions of mobile homes; however, violent tornadoes are very difficult to manage in permanent homes or buildings as well. As a result, tornado shelters have been built in some communities and have become available to the public. However, their presence is intermittent, and there are many tornado-prone areas that lack such shelters.

After a public survey, it …

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 …

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 …

The Effects Of Incorporating 0-500 M Srh Into The Violent Tornado Parameter, Jay Palmer Roberts

Theses and Dissertations

Between 2011-2021, violent tornadoes accounted for an average of 65% of all tornado-related fatalities. The Violent Tornado Parameter (VTP), created in 2018, attempts to address this forecast problem but has issues with false alarms. Storm Relative Helicity has historically been used in tornado forecasting. Recent studies have shown the 0-500 m effective layer SRH (ESRH) has skill in discerning significantly tornadic events from those that are not.

This study explored the effects of incorporating 0-500 m ESRH into the VTP and issues relating to the parameter’s false alarm rate by examining RUC/RAP forecast soundings for 302 U.S. tornadic events (83 …

Defining Viable Solar Resource Locations In The Southeast United States Using The Satellite-Based Glass Product, Jolie Kavanagh

Theses and Dissertations

This research uses satellite data and the moment statistics to determine if solar farms can be placed in the Southeast US. From 2001-2019, the data are analyzed in reference to the Southwest US, where solar farms are located. The clean energy need is becoming more common; therefore, more locations than arid environments must be observed. The Southeast US is the main location of interest due to the warm, moist environment throughout the year. This research uses the Global Land Surface Satellite (GLASS) photosynthetically active radiation product (PAR) to determine viable locations for solar panels. A probability density function (PDF) along …

An Investigation Of Geostationary Satellite Imagery To Compare Developing And Non-Developing African Easterly Waves, Jenna Bartlett

Theses and Dissertations

African easterly waves (AEWs) are known precursors to tropical cyclone (TC) formation, although it is not always clear which AEWs will develop and which AEWs will not. To investigate AEW evolution, this study examines novel observations from the geostationary Advanced Baseline Imager (ABI) during July-September 2019. Case studies are conducted for two AEWs: one that became Hurricane Dorian, the strongest and most devastating hurricane of the 2019 Atlantic hurricane season, and a long-lived September AEW that did not become a TC. Lower-level moisture and flow, and the strength and spatial distribution of convective activity, differed between these two waves. By …

Impact Of Climate Oscillations/Indices On Hydrological Variables In The Mississippi River Valley Alluvial Aquifer., Meena Raju

Theses and Dissertations

The Mississippi River Valley Alluvial Aquifer (MRVAA) is one of the most productive agricultural regions in the United States. The main objectives of this research are to identify long term trends and change points in hydrological variables (streamflow and rainfall), to assess the relationship between hydrological variables, and to evaluate the influence of global climate indices on hydrological variables. Non-parametric tests, MMK and Pettitt’s tests were used to analyze trend and change points. PCC and Streamflow elasticity analysis were used to analyze the relationship between streamflow and rainfall and the sensitivity of streamflow to rainfall changes. PCC and MLR analysis …

Deep Learning For Weather Clustering And Forecasting, Nathaniel R. Beveridge

Theses and Dissertations

Clustering weather data is a valuable endeavor in multiple respects. The results can be used in various ways within a larger weather prediction framework or could simply serve as an analytical tool for characterizing climatic differences of a particular region of interest. This research proposes a methodology for clustering geographic locations based on the similarity in shape of their temperature time series over a long time horizon of approximately 11 months. To this end an emerging and powerful class of clustering techniques that leverages deep learning, called deep representation clustering (DRC), are utilized. Moreover, a time series specific DRC algorithm …

Ccsfs/Ksc Total Lightning Warning Radii Optimization For Merlin Using Preexisting Lightning Areas, Kimberly G. Holland

Theses and Dissertations

The purpose of this research is to optimize lightning warning radii specifications for the 45th Space Wing (45 SW), thus reducing the number of unnecessary warnings that delay ground processing needed for space launch execution at Kennedy Space Center and Cape Canaveral Space Force Station. This thesis sought to answer two key research questions addressing: 1) What radius reduction effectively balances both safety and operations and do reduction recommendations from previous research align with results from the new detection system? 2) What insights can be gained from comparing measurement results for seasonal lightning events as well as lightning types? This …

Correction Of Back Trajectories Utilizing Machine Learning, Britta F. Gjermo Morrison

Theses and Dissertations

The goal of this work was to analyze 24-hour back trajectory performance from a global, low-resolution weather model compared to a high-resolution limited area weather model in particular meteorological regimes, or flow patterns using K-means clustering, an unsupervised machine learning technique. The duration of this study was from 2015-2019 for the contiguous United States (CONUS). Three different machine learning algorithms were tested to study the utility of these methods improving the performance of the CFS relative to the performance of the RAP. The aforementioned machine learning techniques are linear regression, Bayesian ridge regression, and random forest regression. These results mean …

Behavior Of Lightning In Developing Storms, Erick A. Tello

Theses and Dissertations

Air Force weather squadrons issue a warning when lightning activity is observed within 5 nautical miles (NM) of protected areas. Upon receiving this warning, personnel outdoors are expected to pause work and move inside. Studies sponsored by the 45th Weather Squadron (45 WS) have concluded that the 5 NM warning radius can be safely reduced for well-developed storms. This thesis investigates whether radii for storms in early development can also be reduced. Our research develops algorithms to partition lightning sensor data into storms. Next, storms are filtered to their earliest lightning events, and the study calculates distances between successive early …

An Analysis Of A Lighting Prediction Threshold For 45th Weather Squadron Electric Field Mill Data, Charles A. Skrovan

Theses and Dissertations

The mission of the 45th Weather Squadron (45 WS) is to “exploit the weather to assure safe access to air and space” for Patrick Air Force Base, Cape Canaveral Air Force Station (CCAFS), and Kennedy Space Center (KSC) in support of various operations (United States Air Force, n.d.). To support that mission the 45 WS hosts a suite of weather detection instruments that include a lightning warning system that consists of an array of 31 electric field mills (EFM) and a lightning detection and ranging system (Department of the Air Force, 1976). Electric field mills at Cape Canaveral continuously record …

A Probabilistic Approach To Generating Representative Wind Forcing And Wave Heights Within An Estuarine Environment, Vanessa Maria Haley

Theses and Dissertations

While wind driven waves affect erosion, sediment resuspension, and flow in shallow estuaries like the Indian River Lagoon (IRL), neither winds nor waves are well observed in this environment. In order to calculate accurate significant wave heights, the winds used for the calculation must be consistent with the observed winds over the lagoon. Given the complex land/water geometry and subsequent limited fetch, a probabilistic approach is used to produce a representative wind field over the IRL. Observed winds, near the IRL, are used to sample wind distributions obtained from 180 high resolution atmospheric model simulations in order to generate a …

Coupled Atmospheric Surface Observations With Surface Aerosol Particle Counts For Daytime Sky Radiance Quantification, Scott S. Wolfmeyer

Theses and Dissertations

This study investigates the radiative transfer code, Laser Environmental Effects Definition and Reference (LEEDR), developed by the Center for Directed Energy at the Air Force Institute of Technology. Many multi- and hyperspectral applications are limited to the nighttime due in large part to daytime solar background noise and it is advantageous to be able to quantify this background noise using LEEDR. Real-time meteorological surface observations, numerical weather prediction, and aerosol particle concentrations were used to investigate the accuracy of LEEDR radiances simulations. Comparisons between simulations and measured values show that aerosol concentrations, weather predictions, and meteorological observations provide enough information …

Comparing Dual-Polarization Radar Lightning Forecast Methods Across Southwest Utah, Daniel O. Katuzienski

Theses and Dissertations

Lightning poses a significant hazard to space launch operations to include ground processing, launch window forecasts, and rocket-triggered lightning events. Two lightning initiation forecast methods using weather radar developed in Gremillion and Orville (1999) and Travis (2015) for Cape Canaveral Air Force Station (CCAFS) and Kennedy Space Center (KSC), Florida are tested in a new geographical region. This is accomplished by applying the highest-performing radar parameters from Gremillion and Orville (1999): reectivity (Z) ≥ 40 dBZ for two consecutive volume scans at the -10°C thermal height and Travis (2015): Z ≥ 36.5 dBZ with differential reflectivity (ZDR) ≥ 0.31 dB …

Lightning Prediction Using Recurrent Neural Networks, Dominick V. Speranza

Theses and Dissertations

Cape Canaveral Air Force Station (CCAFS), Kennedy Space Center (KSC), and Patrick Air Force Base (PAFB) all reside in the thunderstorm capital of the United States. According to the Florida Climate Center, these installations experience more thunderstorms per year than any other place in the United States. It is the mission of the 45th Weather Squadron to provide timely and accurate warnings of weather conditions such as lightning that pose a risk to assets and personnel CCAFS, KSC and PAFB. To aid 45th Weather Squadron forecasters, a network of 30 Electric Field Mills (EFM) was installed in the area in …

Effect Of Using Probabilistic Contingency Tables To Modify Forecast Predictions, Sarah A. Gold

Theses and Dissertations

The 45th Weather Squadron (45 WS) records daily rain and lightning probabilistic forecasts and the associated binary event outcomes. Subsequently, they evaluate forecast performance and determine necessary adjustments with an implemented verification process. For deterministic outcomes, weather forecast analysis typically utilizes a Tradition Contingency Table (TCT) for verification, however the 45 WS uses an alternative tool, the Probabilistic Contingency Table (PCT). Using the TCT for verification requires a threshold, typically at 50%, to dichotomize probabilistic forecasts. The PCT maintains the valuable information in probabilities and verifies the true forecasts being reported. Simulated forecasts and outcomes as well as 2015-2018 45 …

Wind-Driven Setup, Roughness, And Drag Over A Depth- And Fetch-Limited Coastal Estuary, Jeffrey Allen Colvin

Theses and Dissertations

The understanding of the momentum exchange across the air-sea interface is critical to accurately model and forecast wind speed, wave properties, setup, and circulation. This is particularly true for a restricted estuary, such as the Indian River Lagoon (IRL), where wind is the driving force behind water movement due to the limited number of direct ocean connections. Current atmospheric and hydrodynamic models use formulations of the drag coefficient and/or roughness length based on open ocean studies in which wave properties are not considered. This dissertation develops two parameterizations – one for wind setup and one for the drag coefficient – …

The Geographic Distribution Of Downburst Frequency Across Spaceport Florida, Tania M. Garza

Theses and Dissertations

Strong winds from downbursts pose a significant hazard to personnel and launch operations at Cape Canaveral Air Force Station (CCAFS) and NASA Kennedy Space Center (KSC). The CCAFS/KSC complex has a robust mesonet from which an 18 year (1995-2012) warm-season convective wind climatology (WSCWC) was developed (Koermer 2017). While the frequency of downbursts in the area has been determined, the frequency at the individual tower locations has not. The 5-minute peak wind data from the WSCWC was analyzed to determine the geographic distribution of downburst frequency across Spaceport Florida. For this project a downburst was determined by the threshold of …

A New Analysis Of The Gálvez-Davison Index For Convective Forecasts In Northern Africa, Gabriel D. Donndelinger

Theses and Dissertations

Severe wind gusts and thunderstorms have been difficult to forecast in Africa. Traditional convective forecast tools (e.g. Total Totals Index, Lifted Index, K Index (KI) and Convective Available Potential Energy) do not accurately portray potential for thunderstorms in Africa. This research effort used the Gálvez-Davison Index (GDI), a convective index created for the tropics, and assess its applicability to northern Africa. GDI was produced for the Caribbean and Central America, and utilized temperature, moisture, mid-level stability, dry air entrainment and an elevation factor to calculate convective potential. In this research, GDI and KI were calculated using Global Forecast System (GFS) …

Methodology To Analyze Tropical Cyclone Intensity From Microwave Imagery, Matthew W. Perkins

Theses and Dissertations

Satellites with microwave remote sensing capabilities can be utilized to study atmospheric phenomena through high-level cloud cover (particularly cirrus), an advantage over visible and infrared bands, which only sense cloud tops. This unique capability makes microwave imagery ideal for studying the cloud structures of tropical cyclones (TCs) in detail, and relating these features to TC intensity. Techniques to estimate the intensity of TCs using infrared imagery, such as the Dvorak technique, have been used in TC forecasting for 40 years. However, due to the inherent temporal limitations of microwave imagery, no such similar technique exists for the microwave spectrum. This …

Forecasting Lightning Cessation Using Dual-Polarization Radar And Lightning Mapping Array Near Washington, D.C., Nancy M. Holden

Theses and Dissertations

Accurate forecasts of thunderstorms are important to space launch, aviation, and public safety. While prior studies have primarily focused on atmospheric conditions leading to lightning onset, less research has been dedicated to the challenging problem of predicting lightning cessation. This study verifies the probabilistic lightning cessation model developed by Joseph Patton (2017) at Florida State University for use by the U.S. Air Force's 45th Weather Squadron at Cape Canaveral Air Force Station (CCAFS) and the National Aeronautics and Space Administration (NASA) Kennedy Space Center (KSC). The Washington, D.C. greater metropolitan area, which presents a climate different to that of central …

Adaptive Monte Carlo Sampling For Cloud And Microphysics Calculations, Thomas Franz-Peter Roessler

Theses and Dissertations

An important problem in large-scale modeling of the atmosphere is the parametrization of clouds and microphysics on subgrid scales. The framework Cloud Layers Unified By Binormals (CLUBB) was developed to improve the parametrization of subgrid variability. Monte Carlo sampling is used to couple the different physical processes, which improves the grid average of subgrid tendencies.

In this Thesis we develop an adaptive Monte Carlo sampling algorithm that re-uses sample points of the previous time step by re-weighting them according to the change of the underlying distribution. This process is called 'what-if sampling' and is an application of importance sampling. An …

Influence Of Ndbc Buoy Design On Sea Surface Temperature Trends In The Coastal United States, Alexander Keith Nickerson

Theses and Dissertations

The sea surface temperature (SST) record is the one of the oldest climate records, stretching back to 1662. Since that time, voluntary observing ships (VOSs) have been including these data in their ship‘s log. Due to the sparseness of VOS data, moored buoys were created to provide data at regular intervals in order to provide a more continuous record with data collection unaffected by human error. The SST sensor in National Data Buoy Center (NDBC) buoys is inside a hull and not in direct contact with the ocean. Thus, the design of the buoy may subject them to additional biases …

An Analysis Of The Moisture And Moist Static Energy Budgets In Amip Simulations, Kristine Adelaide Boykin

Theses and Dissertations

An analysis of the second phase of the Atmospheric Model Intercomparison Project (AMIP) simulations has been conducted to understand the physical processes that control precipitation in the tropics. This is achieved primarily through the analysis of the moisture and moist static energy budgets. Overall, there is broad agreement between the simulated and observed precipitation, although specific tropical regions such as the Maritime Continent poses challenges to these simulations. The models in general capture the latitudinal distribution of precipitation and key precipitating regions including the Inter-Tropical Convergence Zone (ITCZ) and the Asian Monsoon. The simulations portrayed the global patterns of evaporation …

Surface Cooling Due To Precipitation In The Tropics, Camila Gomes Martins Ramos

Theses and Dissertations

Precipitation is an important component of the global hydrological cycle. It affects the upper ocean salinity by adding freshwater to the ocean. In addition, precipitation plays a role in cooling the ocean and land surfaces, when the temperature of the raindrops is lower than the temperature of the surface. However, the surface cooling due to precipitation (QP) remains an overlooked feature and is not included in the Intergovernmental Panel on Climate Change (IPCC) models. One might expect that heavy precipitation events may lead to large QP, which can impact the surface temperature, surface energy balance, and local- to regional-scale circulations. …