Meteorology Commons^™

Impacts Of Physical Parameterization Schemes And Soil Moisture Initialization On Boundary Layer Evolution In The Weather Research And Forecasting (Wrf) Model, Grace Cutting

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

Numerical weather prediction (NWP) models have become a necessary addition to the atmospheric research community over the last several decades, and atmospheric modeling has been used internationally for numerous operational and research purposes. NWP models contain a vast number of combinations of physical and dynamical parameterization schemes; however, they are not always accurate in forecasting weather phenomena at a particular location, as different combinations of parameterization schemes represent differing conditions. Weather Research and Forecasting (WRF) model simulations were run to explore which of the commonly used planetary boundary layer (PBL) schemes best represented upper-air data (as well as PBL evolution) …

Examining The Impact Of Stratospheric Vortex Variability On Us Surface Temperature, Elena M. Fernandez

Legacy Theses & Dissertations (2009 - 2024)

Variability in high-latitude stratospheric flow, including major sudden stratospheric warming (SSW) or strong polar vortex events, can modulate tropospheric circulation and have meteorological implications on surface temperature and weather. The largest tropospheric impacts from Northern Hemisphere stratospheric variability – and the regions of focus in the literature – are observed in the North Atlantic, Europe and Asia. Impacts on North America occur but have received less research attention. The goal of this thesis research is to identify and quantify the relationship between high-latitude stratospheric variability and North American wintertime temperature.Using the ERA-Interim and ERA-5 reanalysis for the period of 1999/2000–2018/19, …

Using Remote And In Situ Observations From Torus To Investigate A Preexisting Airmass Boundary And Its Influence On A Tornadic Supercell On 28 May 2019, Kristen Axon

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

During the 2019 field phase of Targeted Observation by Radars and UAS of Supercells (TORUS), a preexisting airmass boundary was sampled on 28 May 2019 in north-central Kansas in close proximity to a tornadic supercell. This work hypothesized that the preexisting airmass boundary was associated with a mesoscale air mass with high theta-E (MAHTE) that favorably interacted with the tornadic supercell to increase the likelihood of tornadogenesis. Observations from TORUS including mobile mesonets, unoccupied aerial vehicles, soundings, and ground-based mobile radar were used along with GOES-16 visible satellite imagery, Kansas mesonet surface stations, and KUEX WSR-88D data to investigate this …

Nashville-Basin Tornadoes: Using Storm Types To Elucidate The Local Climatology And Forecasting Challenges, Morgan Steckler, Kelsey Ellis

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Early 3 March 2020 was a devastating night for many middle Tennessee residents. A strong EF-3 tornado tore through Nashville at 65 mph, and another EF-4 killed 18 in Baxter and Cookeville alone. Residents of the Southeastern United States are particularly vulnerable to tornadoes. This study aims to better understand local forecasting challenges by looking at the types of storms that produce tornadoes. Storm types, also known as convective modes, divide tornado-producing storms into categories by length, shape, multiplicity, and intensity. Distinguishing storms by these modes allows for a broader understanding of their occurrences and impacts. This study specifically evaluates …

Inland Tropical Cyclone Intensity Decay In The Continental United States, Yijie Zhu

USF Tampa Graduate Theses and Dissertations

Tropical cyclone (TC) hazard preparation is mostly focused on coastal cities with less attention typically paid to inland regions. The impact of TCs that propagate far inland is often underestimated and can cause unexpected loss of life and economic loss. This dissertation aims to understand the decay process of TCs during the post-landfall stage by answering three main research questions: (1) What are the general patterns of inland tropical cyclones, including spatial variations, decay rates, and translation speeds? (2) Are there temporal changes in the intensity decay from inland moving hurricanes? (3) How is the hurricane post-landfall dissipation related to …

A Numerical Investigation Of Tornado Production And Intensification In Tropical Cyclones, Marco Paredes

FIU Electronic Theses and Dissertations

The environmental conditions required for tornado formation and development in tropical cyclones (TCs) and the mechanisms underlying the intensification of TC tornadoes remain poorly understood. Previous research has suggested that low and mid-level dry air intrusion in TCs may enhance convective instability and influence the production of tornadoes. However, observations have their limitations in answering some of the key questions regarding the relationship among thermodynamic instability, dry air, and TC tornado genesis, development, and dissipation. In this study, a multiple nested Weather Research and Forecasting (WRF) model in a hindcasting mode is used to simulate Hurricane Ivan (2004) by resolving …

Climatology Of Rainfall Distribution And Asymmetries Of Tropical Cyclones: A Global Perspective, Oscar Guzman Rey

FIU Electronic Theses and Dissertations

Estimating the magnitude of tropical cyclone (TC) rainfall at different landfalling states is an important aspect of the TC forecast that directly affects the level of response from emergency managers in coastal areas. This research analyses the spatial distribution of the rainfall magnitude in tropical cyclones (TCs) at different stages over global oceans. The research’s central hypothesis is that TC rainfall exhibits distinct features in the long-term satellite dataset due to the evolution of the spatial distribution, radial variation, and asymmetries at the stages before, during, and after landfall. The resulting patterns are analyzed through a statistical approach that takes …

Understanding Coastal And Inland Hydrometeorological Hazards Produced By Extratropical And Tropical Cyclones Along The East Coast Of The United States, Katherine Towey

Dissertations, Theses, and Capstone Projects

As global temperatures continue to rise, the effects of anthropogenic climate change will impact the magnitude and frequency of pluvial, fluvial, and coastal flooding events. If we want to accurately predict changes in these flooding events, we need to fully understand them in the current climate. As such, this research examines the relationship between hydrometeorological hazards and the characteristics of the storm types, such as extratropical cyclones (ETCs) and tropical cyclones (TCs), that produce such hazards. Through the use of observational and reanalysis data, the work herein utilizes a cyclone-hazard association algorithm and extreme value analysis to assess the extent, …

Feasibility Of Obtaining Surface Layer Moisture Flux Using An Ir Thermometer, Steven T. Fiorino, Lance Todorowski, Jaclyn Schmidt, Yogendra Raut, Jacob Margraf

Faculty Publications

This paper evaluates the feasibility of a method using a single hand-held infrared (IR) thermometer and a mini tower of wet and dry paper towels to psychometrically obtain surface layer temperature and moisture gradients and fluxes. Sling Psychrometers have long been standard measuring devices for quantifying the thermodynamics of near-surface atmospheric gas–vapor mixtures, specifically moisture parameters. However, these devices are generally only used to measure temperature and humidity at one near-surface level. Multiple self-aspirating psychrometers can be used in a vertical configuration to measure temperature and moisture gradients and fluxes in the first 1–2 m of the surface layer. This …

Changes In Heat Metrics Following A Major Hurricane And Implications On Heat Stress, Cade Reesman

LSU Master's Theses

Tropical cyclones modify surface-atmosphere interactions in several ways, including the destruction of patches of tree canopy, increasing the direct and diffuse (shortwave) radiation reaching the surface. This addition of radiation at the surface impacts the sensible, latent, and substrate heat (energy) fluxes, generating heat anomalies along the hurricane’s track, which, among other effects, contributes to the higher post-hurricane surface air temperatures. This study consists of a case study on Hurricane Laura (2020) to examine hurricane defoliation impacts on heat stress metrics. Normalized difference vegetation index (NDVI) data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) identified the spatial extent of defoliation …

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 …

X-Band Phased-Array Weather-Radar Polarimetry Testbed, William Heberling Iv

Doctoral Dissertations

Phased-array weather radar have potential to replace reflector dish radar in major weather radar networks such as NEXRAD, providing faster update times and greater scan flexibility. However, the use of electronic scanning introduces polarization errors on weather radar measurables, requiring polarimetric bias calibration. The sources of polarimetric bias have been described theoretically, but experimental verification is still limited. Additionally, no standard method of calibration for polarimetric bias exists for phased-arrays. Therefore, the University of Massachusetts Amherst (UMass) presents a fully operational X-Band phased-array weather radar polarimetric testbed. The testbed evaluates the calibration of a planar dual-polarization X-band phased-array radar through …

Comparing Composite Severe Weather Indices Of Thunderstorm Activity On Sea-Breeze And Non-Sea-Breeze Days In The Mobile, Alabama Area, Elizabeth Seiler

Poster Presentations

Poster for the Honors Thesis project.

Sea breezes (SB) occur frequently from May through October along the U.S. Gulf of Mexico Coast. One reason why SBs interest forecasters is their ability to spawn summertime thunderstorms, which can cause flash flooding, lightning, and hail. However, forecasting the exact timing and location of SB-driven convection can be challenging. This thesis will focus on Mobile and Baldwin Counties in southwest Alabama, which experience two types of phenomena – SBs along the Gulf of Mexico Coast and bay breezes on either side of Mobile Bay. Over the past years, multiple undergraduate students have analyzed …

Comparing Composite Severe Weather Indices Of Thunderstorm Activity On Sea-Breeze And Non-Sea-Breeze Days In The Mobile, Alabama Area, Elizabeth Seiler

Undergraduate Honors Theses

Sea breezes (SB) occur frequently from May through October along the U.S. Gulf of Mexico Coast. One reason why SBs interest forecasters is their ability to spawn summertime thunderstorms, which can cause flash flooding, lightning, and hail. However, forecasting the exact timing and location of SB-driven convection can be challenging. This thesis will focus on Mobile and Baldwin Counties in southwest Alabama, which experience two types of phenomena – SBs along the Gulf of Mexico Coast and bay breezes on either side of Mobile Bay. Over the past years, multiple undergraduate students have analyzed Mobile, Alabama radar imagery of past …

The Impact Of Sea-Level Rise In Numerically Modeled Landfalling Hurricanes: Katrina And The Gulf Coast., Serenity Nadirah Mercuri

Electronic Theses and Dissertations

With climate change, landfalling hurricanes become an increasing threat to coastal regions. However, the interactions between the coastal landscape and landfalling hurricanes are often overlooked when addressing sea-level rise outside of inundation and independent of sea surface temperature. This study analyzed the potential impacts regarding structure and intensity as a result of sea-level rise in the Gulf of Mexico using the WRF-ARW numerical model coupled with a 1D ocean model. Analysis showed that 10 m windspeed from landfall forward was higher in modified coastlines, and minimum sea-level pressure post-landfall was consistently lower for modified runs where storms maintain a higher …

A Mesonet-Based Analysis Of Severe Convective Winds In West Texas., Quint Long

Electronic Theses and Dissertations

Multiple studies have investigated the occurrence of severe convective-related winds and have increased our understanding of the forces driving severe winds and their spatial and temporal patterns. Data for these studies have come from airport stations maintained by the National Weather Service. Their standardization across the United States makes them ideal for research, but they are limited in their distribution. This study aims to create a similar climatology of severe surface level winds using a mesoscale network (“mesonet”). Like their ASOS (Automated Surface Observing System) and AWOS (Automated Weather Observing System) counterparts, these stations are standardized and well maintained. This …

Small-Scale Variability In Warm Season, Precipitation Around An Urban Area: A Case Study Of Louisville-Jefferson County, Ky., Isaiah I. Kingsberry

Electronic Theses and Dissertations

Numerous studies have detected anomalous precipitation patterns occurring up to 50 km downwind of major cities, providing major evidence that cities inadvertently modify precipitation and atmospheric circulations. Louisville is one such major city with a growing body of evidence of inadvertent precipitation modification. Despite these efforts, the physical mechanisms driving small-scale and unintentional changes in urban precipitation are little understood, being rooted largely in theory rather than in physical observations. This study seeks to build upon previous research by analyzing ground-based precipitation observations recorded by a high-density gauge network located within approximately 40 km of Louisville’s urban center. The results …

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 …

Effects Of Meteorologic Events On Wave Climate And Current Regime In A Shallow, Microtidal Bay, Jay S. Merrill

LSU Master's Theses

Along coastal Louisiana and within the shallow microtidal Barataria Bay estuary, meteorological events can play a primary role in influencing wave climate and circulation patterns. Understanding the effects of hurricanes and smaller tropical storms on hydrodynamic processes is important for constraining and predicting hydrodynamic variation in Barataria Bay, which, largely due to impacts from wave energy, is currently experiencing rapid wetland loss and is a major focus of coastal restoration efforts. Two bottom-mounted upward-facing Acoustic Current Doppler Profilers and wave, temperature, and depth recorders were installed in the lower portions of Barataria Bay to measure the wave climate and three-dimensional …

Water: The Gift And The Curse: A Climate Change Preparedness Study On An Increased Rainfall Scenarios In The Yunguilla Cloud Forest, Ecuador, Emilia Dick Fiora Del Fabro

Independent Study Project (ISP) Collection

The purpose of this project was to try and better understand the risks posed to the Yunguilla community in an increased rainfall climate change scenario. While climate modeling is not exact, many models do predict increased rain and storm intensity in this area (“Explainer…”, 2018). This project studies erosion risk, and the potential damage to crops through a series of experiments and mapping.

The first experiment used three hydration percentages 50, 75 and 100, to water two crop types, Fragaria and Caspium, and monitored plant health to see the water's effect. The hydraulic stress testing did not model an increased …