Physical Sciences and Mathematics Commons^™

Validating And Highlighting The Advantages Of The Optimal Estimation Method For Rayleigh Lidar Middle Atmospheric Temperature Retrievals, Ali Jalali

Electronic Thesis and Dissertation Repository

An improved understanding of temperature variations in Earth’s middle atmosphere is important for the improvement of our understanding of climate and weather on the surface. The optimal estimation method (OEM) is an inversion modeling approach, which uses regularized nonlinear regression to retrieve, in this case, the temperature of Earth’s middle atmosphere using Rayleigh-scatter lidar measurements. The OEM regularization term is the a priori knowledge of the atmospheric temperature profile. In this thesis I use lidar temperatures in the altitude range 30–110km to construct a temperature climatology using over 500 nights of measurements obtained by the Purple Crow Lidar in London, …

The Advanced Mesospheric Temperature Mapper: Remote Sensing Of The Nighttime Oh Layer During The Deepwave Campaign, Pattilyn Mclaughlin

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The Advanced Mesospheric Temperature Mapper [AMTM] is a remote sensing instrument developed at Utah State University to map temperature structures in the hydroxyl airglow emission at ~87 km. These maps can then be used to quantify wave field characteristics and to observe general climatology trends. Two recent campaigns that it has been involved with are the DEEPWAVE campaign in Lauder, New Zealand and the Super Soaker campaign in Fairbanks, Alaska.

The Deep Propagating Gravity Wave Experiment, “DEEPWAVE” was an international measurement and modeling program intended to characterize the generation and propagation of a broad range of atmospheric gravity waves with …

Methanogens, Plausible Extraterrestrial Life Forms On Mars, And Their Tolerance To Increasing Concentrations Of Illite Clay, Chandler Kern

Biological Sciences Undergraduate Honors Theses

Methanogens, some of Earth’s most primitive prokaryotic organisms, are candidates for possible life forms capable of inhabiting Mars. Specifically, four different species (Methanobacterium formicicum, Methanococcus maripaludis, Methanosarcina barkeri, Methanothermobacter wolfeii) were analyzed for their tolerance to the presence of illite clay. Illite is a crystalline mineral that has been identified from regions of Mars’s surface. Results indicated that all four species grew with some success in the illite at different concentrations. This experimentation with methanogens’ abilities to survive and reproduce in the presence of illite allows for a more accurate understanding of the potential capability of microbial …

A Remote Observatory For Geocoronal Hydrogen Emissions, Margaret A. Gallant

Doctoral Dissertations and Master's Theses

The Investigating Near Space Interaction Regions (INSpIRe) observatory is an adaptable research facility that is designed to use Fabry-Perot interferometer (FPI) to study the faint Balmer series emissions of the terrestrial upper thermosphere and exosphere, collectively known as the geocorona. This instrumentation is designed to be deployable to a clear-air site, necessitating remote operations of the entire observatory, including control and monitoring. The facility currently employs a siderostat to allow for pointing at sky targets, a pressure-tuned dual-etalon FPI to allow for high spectral resolution (R_80,000) measurements, and several charge-coupled device (CCD) imagers for guiding and collecting data. The environment …

Multidecadal Variability In Climate Models And Observations, Alex Carl Oser

Theses and Dissertations

Climate change attribution and prediction using state-of-the-art models continue to garner an ever-growing focus amongst both the scientific community and public alike. Recent analyses showing discrepancies in the structure of modeled and observed decadal climate variability (DCV), therefore, have engendered efforts to not only diagnose the dynamics underpinning observed DCV, but also to characterize the behavior of DCV within climate models. In this thesis, we employ Multichannel Singular Spectrum Analysis (M-SSA) to show that while the DCV signal in observations is best described as a coherent oscillation with complex propagation across the globe, modeled DCV lacks this structure altogether. Specifically, …

Quantifying The Effects Of Wind Regimes And Temperature On Surface Melt Over The Antarctic Peninsula (1982–2017) Through Modeling, Remote Sensing And In-Situ Data, Rajashree Datta

Dissertations, Theses, and Capstone Projects

Surface melting over the Antarctic Peninsula (AP) plays a crucial role for the stability of ice shelves and dynamics of grounded ice, hence modulating the mass balance in a region of the world which is particularly sensitive to increasing surface temperatures. Understanding the processes that drive melting using surface energy and mass balance models is fundamental to improving estimates of current and future surface melting and associated sea level rise through ice-shelf collapse. This is even more important in view of the specific challenges presented by how circulation patterns over the topographically-complex Antarctic Peninsula, especially foehn winds, impact surface melt. …

Using Self-Organizing Maps As A Forecasting Tool, Andrea Honor

Theses and Dissertations

Some extreme weather events, such as the early season heavy snow and cold weather outbreak of early November 2014, can be traced back to the influence of tropical or extratropical cyclones on the planetary scale flow. Such planetary scale reorganization also occurs in conjunction with serial extratropical cyclogenesis. Potential temperature on the dynamic tropopause (defined by the 2 PVU surface) allows for a dynamically compact characterization of the flow. NCEP Climate Forecast Systems Reanalysis data spanning 32 years are used to provide this measure, and Self-Organizing Maps (SOM) are then constructed to identify our atmospheric regimes. Key elements of this …

Impacts Of Climate Extremes On Terrestrial Productivity, Suhua Wei

Dissertations, Theses, and Capstone Projects

Terrestrial biosphere absorbs approximately 28% of anthropogenic CO₂ emissions. This terrestrial carbon sink might become saturated in a future climate regime. To explore the issues associated with this topic, an accurate estimate of gross primary production (GPP) of global terrestrial ecosystems is needed. A major uncertainty in modeling global terrestrial GPP is the parameter of light use efficiency (LUE). Most LUE estimates in global models are satellite-based and coarsely measured with emphasis on environmental variables. Others are from eddy covariance towers with much greater spatial and temporal data quality and emphasis on mechanistic processes, but in a limited number …

Developing A Probabilistic Heavy-Rainfall Guidance Forecast Model For Great Lakes Cities, Cory Kevin Rothstein

Theses and Dissertations

A method for predicting the probability of exceeding specific warm-season (April-October) 0-24 hour precipitation thresholds is developed based upon daily maximums of meteorological parameters. North American Regional Reanalysis and Daily Unified Precipitation data from 2002-2017 were used to gather meteorological data for the Milwaukee and Chicago County Warning Areas. Individual artificial neural networks and multiple logistic regressions were conducted for daily rainfall thresholds above 0.5'', 1'', 1.5'' and 2'' to determine the probability of threshold exceedances for each County Warning Area. The most important parameters were 1000-500 hPa specific humidity, vertical velocities at various levels, high cloud cover, precipitable water …

Nonlinear Acoustic Waves Generated By Surface Disturbances And Their Effect On Lower Thermospheric Composition, Benedict Piñeyro

Doctoral Dissertations and Master's Theses

Recent nonlinear atmospheric models have provided important insight into acoustic waves generated by seismic events, which may steepen into shocks or saw-tooth trains while also dissipating strongly in the thermosphere. Although they have yielded results that agree with observations of ionospheric perturbations, dynamical models for the diffusive and stratified lower thermosphere often use single gas approximations with height-dependent physical properties (e.g. mean molecular weight, specific heats) that do not vary with time (fixed composition). This approximation is simpler and less computationally expensive than a true multi-fluid model, yet captures the important physical transition between molecular and atomic gases in the …

An Investigation Of The Conditional Practical Predictability Of The 31 May 2013 Heavy-Rain-Producing Mesoscale Convective System, Aidan Kuroski

Theses and Dissertations

On 31 May 2013, strong thunderstorms initiated in west-central Oklahoma with one of the storms eventually creating a very strong tornado near El Reno, OK. The storms then grew upscale into a quasi-stationary mesoscale convective system that produced prolonged heavy rainfall that led to severe flooding across parts of Oklahoma, including the Oklahoma City metropolitan area. A 50-member ensemble of short range (0-24 h) forecasts was conducting using a set of initial conditions generated via cycled data assimilation to quantify event predictability and identify forecast sensitivities, primarily with CI and initial upscale growth. Both a composite and ensemble sensitivity analysis …

Using Advanced Post-Processing Methods With The Hrrr-Tle To Improve The Prediction Of Cold Season Precipitation Type, Timothy Thielke

Theses and Dissertations

In this study we explore advanced statistical methods with the operational High-Resolution Rapid Refresh Model (HRRR) Time-Lagged Ensemble (TLE) to improve the prediction of cold season precipitation type. TLEs are a computationally efficient method to provide a slightly improved probabilistic forecast as the differences between model runs are an approximation of initial condition uncertainty. We apply evolutionary programming, weight-decay bias correction, and Bayesian Model Combination with fifteen HRRR forecast variables that potentially relate to precipitation type for station locations in the contiguous United States that are along and to the east of 100 W longitude to obtain probabilistic precipitation type …

Impacts Of Anisotropy, Wave Heating, And Neutral Winds On High-Latitude Ionospheric Dynamics, Meghan R. Burleigh

Doctoral Dissertations and Master's Theses

Significant amounts of ionospheric plasma can be transported to high altitudes (ion upflow) in response to a variety of plasma heating and uplifting processes such as DC electric fields and precipitation. Once ions have been lifted to high altitudes, transverse ion acceleration by broadband ELF waves can give the upflowing ions sufficient energy for the mirror force to propel these ions to escape into the magnetosphere (ion outflow). In order to accurately examine the connection between upflow and outflow processes, a new two dimensional, anisotropic fluid model is developed.

The new model, named GEMINI-TIA, is based on a Bi-Maxwellian distribution …

Impact Of Data Selection On The Accuracy Of Atmospheric Refractivity Inversions Performed Over Marine Surfaces, Ian Joseph Matsko

Electronic Theses and Dissertations

Within the Earth’s atmosphere there is a planetary boundary layer that extends from the surface to roughly 1 km above the surface. Within this planetary boundary layer exists the marine atmospheric boundary layer, which is a complex turbulent surface layer that extends from the sea surface to roughly 100 m in altitude. The turbulent nature of this layer combined with the interactions across the air-sea interface cause ever changing environmental conditions within it, including atmospheric properties that affect the index of refraction, or atmospheric refractivity. Variations in atmospheric refractivity lead to many types of anomalous propagation phenomena of electromagnetic (EM) …

Madden-Julian Oscillation Relationships With Cool Season Cyclogenesis, Daily Precipitation, And Cool Season Severe Weather Frequencies In The Gulf Of Mexico Region, Stephen Paul Caparotta

LSU Doctoral Dissertations

Tropical cyclone variability in the Gulf of Mexico (GoM) has been the focus of a considerable amount of research. Variability on both interannual scales, related to the El Niño-Southern Oscillation (ENSO), and on subseasonal scales, related to the Madden-Julian Oscillation (MJO), is well documented. By contrast, very little research exists on the relationships between the MJO and cool season, non-tropical cyclones in the GoM.

The MJO influence on cool season (October-March) cyclogenesis in the GoM variability is explored here. Additionally, daily precipitation variability and cool season severe weather variability is examined for areas near and just inland of the GoM. …

Assessment Of Observational Uncertainty In Extreme Precipitation Over The Continental United States, Emily Anne Slinskey

Dissertations and Theses

An extreme precipitation categorization scheme, developed to temporally and spatially visualize and track the multi-scale variability of extreme precipitation climatology, is introduced over the continental United States and used as the basis for an observational dataset intercomparison. The categorization scheme groups three-day precipitation totals exceeding 100 mm into five precipitation categories, or "P-Cats". To assess observational uncertainty across a range of precipitation measurement approaches, we compare in situ station data from the Global Historical Climatology Network-Daily (GHCN-D), satellite derived data from the Tropical Rainfall Measuring Mission (TRMM), gridded station data from the Parameter-elevation Regression on Independent Slopes Model (PRISM), global …

Differences Between High Shear / Low Cape Environments In The Northeast Us Favoring Straight-Line Damaging Winds Versus Tornadoes, Michael E. Main, Ross A. Lazear, Lance F. Bosart

Atmospheric & Environmental Sciences

High shear / low CAPE (HSLC) environments are common in the Northeast US and can occur at any time of year. Severe weather in HSLC environments is notoriously hard to predict, often catching both forecasters and the general public off-guard. The goal of this project is to help forecasters to identify HSLC environments favorable for severe weather in the Northeast US, and to discriminate between HSLC environments that are supportive of tornadoes versus those that favor straight-line damaging winds (SDW). A 10-year HSLC severe weather environmental climatology was created for the Northeast US (New England, New York, New Jersey, Pennsylvania). …

Understanding Microphysical Processes Occurring In Lake-Effect Snowbands Using Quasi-Vertical Profiles Of Wsr-88d Parameters, Marquette Rocque

Atmospheric & Environmental Sciences

Knowing the composition and microphysical processes that occur in lake-effect precipitation systems is important in making sure models capture these processes accurately, and could aid forecasters in predicting snow totals and snow water equivalents. Many studies have shown that processes such as riming and dendritic growth can be seen in dual-polarization radar data through parameters such as equivalent radar reflectivity factor, differential reflectivity (ZDR), correlation coefficient, and differential phase. This research examines WSR-88D data from the KTYX (Montague, NY) radar located on the Tug Hill Plateau for several long-lake-axis-parallel lake-effect systems from the Ontario Winter Lake-effect Systems (OWLeS) field campaign …

Assessing Effective Rhetoric On Twitter In Relation To Forecast Uncertainty In Hurricane Tracks, Erin K. Lynch

Atmospheric & Environmental Sciences

A forecast is only as good as the way it is communicated. As the National Weather Service (NWS) transitions to an Impact-Based Communication style, the new public forecasts discuss how to effectively prepare and protect oneself from harm in the face of severe and significant weather. After severe events, meteorologists need to take the time to analyze the language and style of the rhetoric to assess how effective it was at getting people in harm’s way to take protective actions. It is even more important to understand how information was communicated when there is large uncertainty in the forecast. Uncertainty …

Isolating Secular Signals In Observations And Climate Model Simulations Using M-Ssa Based Wiener Filtering, Christian Grimm

Theses and Dissertations

In this thesis, Wiener filtering of gridded surface-temperature time series from observations and climate model simulations is performed by using multi-channel singular spectrum analysis (M-SSA) in order to isolate non-stationary climate signals. The contributions to the singular spectrum from shorter-term internal climate variability, treated in this context as noise, are estimated by fitting to the data spatially extended stochastic models, which are subsequently used to produce synthetic ensembles of surface temperature time series and the corresponding synthetic M-SSA spectra. The full spectra are weighted by the signal-to-noise ratios and transformed back to physical space to obtain reconstructions of the non-stationary …

A Climatology Of Extreme South American Andean Cold Surges, Kevin Prince

Theses and Dissertations

Interactions between the tropics and midlatitudes have been an ongoing area of research since the inception of meteorology. Cold surges represent one of several phenomena by which midlatitude features can modulate the atmosphere, both dynamically and thermodynamically, deep into the tropics. This study performs a climatology of particularly strong South American cold surges that follow along the Andes mountains to quantify the maximum extent to which these surges can modulate the atmosphere from the midlatitudes to the tropics. Data was collected for Austral winter (JJAS) from 1980-2010 (31 years). To identify events, standardized anomalies for 925 hPa meridional wind and …

Statistical Analysis And Comparison Of Optical Classification Of Atmospheric Aerosol Lidar Data, Kwasi Gyening Afrifa

Electrical & Computer Engineering Projects for D. Eng. Degree

This dissertation presents a new study for the analysis and classification of atmospheric aerosols in remote sensing LIDAR data. Information on particle size and associated properties are extracted from these remote sensing atmospheric data which are collected by a ground-based LIDAR system. This study first considers optical LIDAR parameter-based classification methods for clustering and classification of different types of harmful aerosol particles in the atmosphere. Since accurate methods for aerosol prediction behaviors are based upon observed data, computational approaches must overcome design limitations, and also consider appropriate calibration and estimation accuracy. Consequently, two statistical methods based on generalized linear models …

The Influence Of Vertical Advection Discretization In Wrf-Arw Model On Capping Inversion Representation In Warm-Season, Thunderstorm Supporting Environments, David Nevius

Theses and Dissertations

This study evaluates forecasts of capping inversions and thermodynamic variables for believed areas of possible deep, moist convection initiation during the warm-season using the Weather Research and Forecasting Model (WRF) with the Advanced Research core (WRF-ARW). WRF-ARW was configured nearly identical to the National Severe Storms Laboratory (NSSL) version of WRF (NSSL-WRF). WRF-ARW's default third-order-accurate vertical advection scheme, which is an odd-order-accurate scheme, is known to introduce implicit damping which acts to dampen short wavelength features (Skamarock et al. 2008), such as capping inversions. It is hypothesized that by increasing WRF-ARW's vertical advection to the next higher, even-order-accurate vertical advection …

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) …

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 …

Impacts Of Sub-Auroral Polarization Streams On High Frequency Operations As A Function Of Modeled Particle Energy Flux, Nathan D. Smith

Theses and Dissertations

Space weather events can cause irregularities within the ionosphere; in particular, this research examines sub-auroral polarization streams (SAPS), as their accompanying irregularities and effects can degrade high-frequency (HF) signal propagation. It is known that the strongest westerly current drifts delineating SAPS are associated with a deep ionospheric trough, which in turn contaminates HF data with clutter from the non-standard ionosphere. Having a methodology to track and identify these occurrences on current computational architecture would provide operators enhanced situational awareness in knowing to expect degradation in HF processes. This study has discovered a weak, yet significant, exponentially decaying correlation between maximum …

Evaluation Of A Cloud Detection Technique Using Spatial And Radiometric Thresholds For Near Infrared Satellite Imagery, William J. Graff

Theses and Dissertations

Knowledge of cloud location in near infrared (NIR) imagery is of interest to the meteorological community given the wavelengths greater spatial resolution compared to longwave infrared and its potential nighttime applications. This method consists of an algorithm that can be employed by multiple instrument platforms. It analyzes changes between satellite image radiances and a seasonal synthetic background radiance image. The NIR sensor bands of the Sentinel-2 Multispectral Instrument (MSI) and Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) satellite instruments are used to evaluate the performance of a monochromatic change detection technique designed to locate areas …

Forecasting Lightning Initiation Utilizing Dual-Polarization Radar Parameters Over Washington, D.C., Sarah A. Olsen

Theses and Dissertations

Accurate forecasts of thunderstorms are vital to space launch, aviation, and public safety. Prior studies by Woodard (2011), Thurmond (2014), and Travis (2015) show that dual-polarization radar can be utilized to identify the presence of hydrometeors necessary for cloud charging. These studies emphasized that a combination of radar reflectivity (Z) and differential reflectivity (Z_DR) predictors have the potential to improve forecast skill of lightning initiation over methods that rely on Z alone (Roeder and Pinder, 1998; Yang and King, 2010). Travis (2015) discovered two parameters, when used together, produced the best results: Z ≥ 36.5 dBZ and ZDR …

Evolution Of The Maximum Upper Level Divergence Field In Gulf-Atlantic Tropical Cyclogenesis, Sara A. Ates

LSU Master's Theses

Upper-level (horizontal) divergence (ULD) is an important variable in tropical weather systems. As part of the circulation within a tropical cyclone (TC), it carries air in the upper troposphere away from the center of circulation (COC). To date, most research assumes the 200 hPa pressure level (approximately 12 km, varying with latitude and time of year) as the height for maximum ULD in a TC, possibly because weather observation at the 200 hPa level by radiosonde have remained mandatory for aviation purposes. The more recent availability of gridded, high-spatial-resolution, global “reanalysis” data at multiple levels, along with improvements in spatial …

A Comparative Study Characterizing Traffic Related Air Pollutant Concentrations At Near-Road Communities In El Paso, Texas, Adan Rangel

Open Access Theses & Dissertations

Numerous scientific studies have demonstrated the influence of traffic related air pollution at near-road communities and the associated health risks for these populations. This study uses on-site air quality monitors to characterize air pollutants at near-road schools in El Paso, TX to understand children's exposure to traffic-related air pollutants. Ambient air monitoring stations were installed at Coldwell Elementary, Bliss Elementary, and a residential house located in close proximity to major inter-state roadways. In this study, air quality data for PM2.5, PM10, NO2, and O3 was collected over a period of nine weeks in Fall 2018. The spatial and temporal variability …