Atmospheric Sciences Commons^™

Spatio-Temporal Analysis Of The Roadside Transportation-Related Air Quality (Startraq 2022): Data-Driven Exposure Analysis By Transportation Modes, Jaymin Kwon, Yushin Ahn, Steve Chung

Mineta Transportation Institute

Particulate matter (PM) pollution poses significant health risks, influenced by various meteorological factors and seasonal variations. This study investigates the impact of temperature and other meteorological variables on PM10 and PM2.5 levels in Fresno County, known for high air pollution. Multiple linear regression (MLR) and generalized additive models (GAMs) assess the significance of these relationships. Analyzing data from Fresno County, we examine PM10 and PM2.5 levels across "hot" (June to August) and "cool" (September to May) seasons. Findings indicate PM10, both MLR and GAM models identify statistically significant variables, excluding temperature and wind direction in each season. However, during the …

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 …

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 …

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, 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 …

Characterizing Differential Reflectivity Calibration Dependence On Environmental Temperature Using The X-Band Teaching And Research Radar (Xtrra): Looking For A Relationship Between Temperature And Differential Reflectivity Bias, Emma Miller

The Journal of Purdue Undergraduate Research

Calibration scans are important for the maintenance of data and the quality of the information that radars output. In this study we looked for a temperature dependency in a full year’s worth of differential reflectivity (ZDR) calibration scan data collected by the X-band Teaching and Research Radar (XTRRA) located near the Purdue University campus. In a vertically pointing calibration scan, the radar scans the drops from below while rotating. From this angle, the overall shape will be circular, which corresponds to a ZDR value of approximately 0 dB. To process the data for the year 2021, a Python script was …

On The Understanding Of The Coastal-Urban Nexus Of Weather, Air Quality And Energy, Harold Gamarro

Dissertations and Theses

Urban environments exhibit complex interactions between atmospheric processes, building energy consumption, and air quality, particularly during periods of seasonal extremes such as summer ozone peaks and winter heating. Accurate representation of these interactions in urban modeling is crucial for understanding and addressing air pollution and energy management challenges in cities. This research presents a comprehensive study that advances urban atmosphere simulations by integrating building energy dynamics, air quality, and robust multi-source observational evaluation. Leveraging the Weather Research and Forecasting (WRF) model, coupled with a multilayer building environment parameterization (BEP) and a building energy model (BEM), with an improved boundary layer …

The Impact Of Thunderstorms On Take-Off Data In South Africa, Quinton Jacobs Mr.

International Journal of Aviation, Aeronautics, and Aerospace

Aviation and meteorology are entwined disciplines, as aviation occurs in the atmosphere. Prevailing weather conditions at take-off are of utmost importance to aviation. This determines the payload of the aircraft and runway in use. Forecast verification is essential to aviation as it determines the quality of the forecasting products. The tolerances for take-off data are stringent and slightly relaxed tolerances are used in South Africa by mutual agreement.

There are six aerodromes in South Africa where Take-off Data are produced, in varying climatic conditions as South Africa is in both the tropics and midlatitudes. Thunderstorms are a common occurrence over …

Sources And Significance Of Symmetric Instability In The Outflow Layer Of Tropical Cyclones, Minghao Zhou

Electronic Theses & Dissertations (2024 - present)

The tropical cyclone (TC) outflow layer is an integral part of the TC transverse circulation: warm and moist air converges in the boundary layer of the TC; rising motion and condensational heating occur in the TC eyewall and rainbands; the TC warm core and divergent anticyclone establish in the mid-upper troposphere, with the mass imported into the TC center exported away through outflow near the tropopause.

A series of state-of-the-art numerical simulations were utilized to investigate different scenarios of TC outflow evolution, from an idealized axisymmetric setup to a semi-idealized asymmetric setup, to a real-case setup of TC–trough interaction. Large …

A Comparison Of Arctic And Atlantic Basin Cyclone Predictability From A Climatology And Case Study Perspective, Peyton Capute

Electronic Theses & Dissertations (2024 - present)

Arctic cyclones (ACs) can transport warm, moist air into the Arctic region, which combined with strong winds may lead to rapid declines in sea ice during the summer. As a consequence, accurate sea ice predictions during the summer may rely on being able to predict cyclone-related wind speed and direction, which critically depends on the cyclone track and intensity. Despite this, there are relatively few studies that have documented the predictability of ACs during the summer, beyond a few case studies. In addition, there has been no extensive comparison of whether these cyclones are more or less predictable relative to …

A Climatology Of Mesoscale Airmasses With High Theta-E, Charles J. Kropiewnicki

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

A Mesoscale Airmass with High Theta-E (MAHTE) is a narrow region of larger theta-e located on the cool side of an airmass boundary. MAHTEs typically possesses higher CAPE than the warm side of the boundary, creating a more favorable environment for severe convection. MAHTEs can also be characterized by larger low-level shear and lower LCLs and may also have a propensity for supporting tornadogenesis. The majority of MAHTE research to date has been comprised of case studies, and the prevalence of MAHTEs is not well understood. This project fills that knowledge gap by creating a climatology of MAHTE occurrence. This …

An Empirical Examination Of The Environmental Variability That Impacted Supercell Evolution, Longevity, And Severe Weather Production On 22 May 2019 In Oklahoma, Kyle D. Pittman

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

Mesoscale environmental heterogeneity can have significant impacts on thunderstorm organization, evolution, longevity, and severe weather production. This study examines the 22 May 2019 thunderstorm event in Oklahoma, where a relatively broad area of strong instability and vertical wind shear existed along a synoptic boundary and in the open warm sector that would seem to support long-lived supercells and tornadoes. There were two particularly dangerous situation (PDS) tornado watches issued during the event, but few severe reports and no tornadoes formed in the watch that covered the southwestern portion of the state. Several tornadic supercells and many more severe reports occurred …

An Analysis Of Moisture Environments Associated With Mature North Atlantic Tropial Cyclones, Katherine Berislavich

Theses and Dissertations

Tropical cyclone (TC) intensity and structure are affected by their environments, including sea surface temperature, vertical wind shear, and atmospheric moisture. Analyses of TC environments often rely on area-averaged quantities, yet the spatial variability of these fields can affect TC behavior, such as moisture distribution impacting where and how much rain falls. This study identifies spatial patterns of environmental moisture surrounding mature North Atlantic TCs during 2000-2021 in shear of less than 20 knots. Empirical orthogonal function analysis of total column water vapor reveals six dominant patterns. These patterns account for nearly 67% of the variance in the dataset and …

Droughtscape, Summer 2023, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Summer 2023

Hyper-Local Weather Predictions With The Enhanced General Urban Area Microclimate Predictions Tool, Kevin A. Adkins, William Becker, Sricharan Ayyalasomayajula, Steven Lavenstein, Kleoniki Vlachou, David Miller, Marc Compere, Avinash Muthu Krishnan, Nickolas Macchiarella

Publications

This paper presents enhancements to, and the demonstration of, the General Urban area Microclimate Predictions tool (GUMP), which is designed to provide hyper-local weather predictions by combining machine-learning (ML) models and computational fluid dynamic (CFD) simulations. For the further development and demonstration of GUMP, the Embry–Riddle Aeronautical University (ERAU) campus was used as a test environment. Local weather sensors provided data to train ML models, and CFD models of urban- and suburban-like areas of ERAU’s campus were created and iterated through with a wide assortment of inlet wind speed and direction combinations. ML weather sensor predictions were combined with best-fit …

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 …

Atmospheric Impacts From The 2010 Deepwater Horizon Oil Spill, Charles Philip Johnson

LSU Master's Theses

Although the ecological devastations induced by an oil spill are well studied, the hydrometeorological impacts from a long-term slick have gone unnoticed. The ocean-surface alterations stemming from the lasting oil footprint increase solar radiation absorption which in turn alters the surface pressure and moisture gradients and wind speeds thereby influencing precipitation surrounding the oil spill. Revealing the potential impacts from these could better aid in the safety of crews cleaning spills and provide a better understanding of how humans alter the landscape. This thesis examines the changes in local hydrometeorology brought on by the 2010 summer Deepwater Horizon (DWH) oil …

Radar Signatures In Tropical Cyclone Tornadic And Nontornadic Supercells, Michaela Wood

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

Tropical cyclones (TCs) contain highly-sheared environments that are conducive for supercell thunderstorms. These TC supercells sometimes produce tornadoes, often with little warning. Given the often-close proximity of tornadic and nontornadic TC supercells, environments may not be well-distinguished, pointing to the potential value of radar observations. In this study, dual-polarimetric radar signatures of a sample of TC supercells are examined in the context of known supercell structure and microphysics. Tornadic and nontornadic TC supercells are compared with their midlatitude counterparts, and the environments and characteristic structure of these storms are shown to be notably different. An attempt is made to distinguish …

An Analysis Of Hurricane Laura's Storm Surge In Cameron Parish Using Synthetic Storm Tracks, Climatology, And Statistics, Cameron Goff

LSU Master's Theses

Cameron Parish is a large coastal parish in southwest Louisiana that has been impacted by several powerful tropical cyclones. In 2020, the strongest hurricane in recorded history to ever hit this region, Hurricane Laura, set a state record for the highest storm surge measurement at 6.34 meters. I examine the climatology of tropical cyclone landfalls in this parish, looking for trends in intensity and frequency with time. I then compare the extreme surge of Hurricane Laura with a dataset of 645 synthetic tropical cyclones generated and used by the Coastal Hazards System for Louisiana. Plots comparing various meteorological statistics to …

Droughtscape, Spring 2023, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Spring 2023

Droughtscape, Winter 2023, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Winter 2023

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. …

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 …

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 …

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 …

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 …

Estimation Of Economic Risk From Coastal Natural Hazards In Louisiana, Rubayet Bin Mostafiz

LSU Doctoral Dissertations

Louisiana, U.S.A., is among the most vulnerable areas globally to coastal natural hazards, with risk vulnerability likely increasing. The risks associated with non-tropical-cyclone hazards in Louisiana’s coastal zone have been understudied. This research enhances present and future (i.e., 2050) Louisiana risk assessment using locally-weighted, model-based hazard frequency/intensity and population projections.

Results suggest that property risks associated with extreme cold temperature and tornado are and will remain costlier than those for hail and lightning. Property risks of extreme cold temperature and hail are projected to decrease with the expected warming temperatures, with those of all four of these hazards peaking in …

Polarimetric Radar And Vhf Lightning Observations In A Significantly Tornadic Supercell, Jacob Bruss

The Journal of Purdue Undergraduate Research

No abstract provided.